os_linux.cpp revision 10145:c5480d4abfe4
11541Srgrimes/* 21541Srgrimes * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved. 31541Srgrimes * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 41541Srgrimes * 51541Srgrimes * This code is free software; you can redistribute it and/or modify it 61541Srgrimes * under the terms of the GNU General Public License version 2 only, as 71541Srgrimes * published by the Free Software Foundation. 81541Srgrimes * 91541Srgrimes * This code is distributed in the hope that it will be useful, but WITHOUT 101541Srgrimes * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 111541Srgrimes * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 121541Srgrimes * version 2 for more details (a copy is included in the LICENSE file that 131541Srgrimes * accompanied this code). 141541Srgrimes * 151541Srgrimes * You should have received a copy of the GNU General Public License version 161541Srgrimes * 2 along with this work; if not, write to the Free Software Foundation, 171541Srgrimes * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 181541Srgrimes * 191541Srgrimes * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 201541Srgrimes * or visit www.oracle.com if you need additional information or have any 211541Srgrimes * questions. 221541Srgrimes * 231541Srgrimes */ 241541Srgrimes 251541Srgrimes// no precompiled headers 261541Srgrimes#include "classfile/classLoader.hpp" 271541Srgrimes#include "classfile/systemDictionary.hpp" 281541Srgrimes#include "classfile/vmSymbols.hpp" 291541Srgrimes#include "code/icBuffer.hpp" 301541Srgrimes#include "code/vtableStubs.hpp" 311541Srgrimes#include "compiler/compileBroker.hpp" 321541Srgrimes#include "compiler/disassembler.hpp" 331541Srgrimes#include "interpreter/interpreter.hpp" 3444510Swollman#include "jvm_linux.h" 351541Srgrimes#include "logging/log.hpp" 361541Srgrimes#include "memory/allocation.inline.hpp" 37116182Sobrien#include "memory/filemap.hpp" 38116182Sobrien#include "mutex_linux.inline.hpp" 39116182Sobrien#include "oops/oop.inline.hpp" 40247777Sdavide#include "os_linux.inline.hpp" 41187664Srwatson#include "os_share_linux.hpp" 42247777Sdavide#include "prims/jniFastGetField.hpp" 43247777Sdavide#include "prims/jvm.h" 44247777Sdavide#include "prims/jvm_misc.hpp" 45187664Srwatson#include "runtime/arguments.hpp" 461541Srgrimes#include "runtime/atomic.inline.hpp" 471541Srgrimes#include "runtime/extendedPC.hpp" 48177859Sjeff#include "runtime/globals.hpp" 4933392Sphk#include "runtime/interfaceSupport.hpp" 50248031Sandre#include "runtime/init.hpp" 51177859Sjeff#include "runtime/java.hpp" 521541Srgrimes#include "runtime/javaCalls.hpp" 53133229Srwatson#include "runtime/mutexLocker.hpp" 5474914Sjhb#include "runtime/objectMonitor.hpp" 55177859Sjeff#include "runtime/orderAccess.inline.hpp" 5668840Sjhb#include "runtime/osThread.hpp" 57150188Sjhb#include "runtime/perfMemory.hpp" 58187664Srwatson#include "runtime/sharedRuntime.hpp" 59171053Sattilio#include "runtime/statSampler.hpp" 60115810Sphk#include "runtime/stubRoutines.hpp" 61177859Sjeff#include "runtime/thread.inline.hpp" 621541Srgrimes#include "runtime/threadCritical.hpp" 63220456Sattilio#include "runtime/timer.hpp" 64220456Sattilio#include "semaphore_posix.hpp" 65220456Sattilio#include "services/attachListener.hpp" 66220456Sattilio#include "services/memTracker.hpp" 67247777Sdavide#include "services/runtimeService.hpp" 68247777Sdavide#include "utilities/decoder.hpp" 69247777Sdavide#include "utilities/defaultStream.hpp" 70247777Sdavide#include "utilities/events.hpp" 71187664Srwatson#include "utilities/elfFile.hpp" 72260817Savg#include "utilities/growableArray.hpp" 73187664Srwatson#include "utilities/macros.hpp" 74260817Savg#include "utilities/vmError.hpp" 75187664Srwatson 76187664Srwatson// put OS-includes here 77247777Sdavide# include <sys/types.h> 78115810Sphk# include <sys/mman.h> 79115810Sphk# include <sys/stat.h> 80115810Sphk# include <sys/select.h> 81115810Sphk# include <pthread.h> 82115810Sphk# include <signal.h> 83115810Sphk# include <errno.h> 84173760Sattilio# include <dlfcn.h> 85173760Sattilio# include <stdio.h> 86173760Sattilio# include <unistd.h> 87115810Sphk# include <sys/resource.h> 88115810Sphk# include <pthread.h> 89115810Sphk# include <sys/stat.h> 90247777Sdavide# include <sys/time.h> 91247777Sdavide# include <sys/times.h> 92247777Sdavide# include <sys/utsname.h> 93247777Sdavide# include <sys/socket.h> 94247777Sdavide# include <sys/wait.h> 95247777Sdavide# include <pwd.h> 96247777Sdavide# include <poll.h> 97247777Sdavide# include <semaphore.h> 98247777Sdavide# include <fcntl.h> 99247777Sdavide# include <string.h> 100247777Sdavide# include <syscall.h> 101247777Sdavide# include <sys/sysinfo.h> 102247777Sdavide# include <gnu/libc-version.h> 103248031Sandre# include <sys/ipc.h> 104248031Sandre# include <sys/shm.h> 105248031Sandre# include <link.h> 106248031Sandre# include <stdint.h> 107248031Sandre# include <inttypes.h> 10833392Sphk# include <sys/ioctl.h> 10933392Sphk 11033392Sphk#ifndef _GNU_SOURCE 11133392Sphk #define _GNU_SOURCE 112247715Sdavide #include <sched.h> 1132112Swollman #undef _GNU_SOURCE 114200510Sluigi#else 115247777Sdavide #include <sched.h> 116247777Sdavide#endif 117247777Sdavide 118247777Sdavide// if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling 119247777Sdavide// getrusage() is prepared to handle the associated failure. 120247777Sdavide#ifndef RUSAGE_THREAD 121220456Sattilio #define RUSAGE_THREAD (1) /* only the calling thread */ 122220456Sattilio#endif 123220456Sattilio 124247777Sdavide#define MAX_PATH (2 * K) 125247777Sdavide 126220456Sattilio#define MAX_SECS 100000000 127247777Sdavide 128247777Sdavide// for timer info max values which include all bits 129247777Sdavide#define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 130247777Sdavide 131248699Sdavide#define LARGEPAGES_BIT (1 << 6) 132220456Sattilio//////////////////////////////////////////////////////////////////////////////// 133247813Sdavide// global variables 134247813Sdavidejulong os::Linux::_physical_memory = 0; 135220456Sattilio 136247467Sdavideaddress os::Linux::_initial_thread_stack_bottom = NULL; 137220456Sattiliouintptr_t os::Linux::_initial_thread_stack_size = 0; 138200510Sluigi 139200510Sluigiint (*os::Linux::_clock_gettime)(clockid_t, struct timespec *) = NULL; 140200510Sluigiint (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL; 141177859Sjeffint (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL; 142242402SattilioMutex* os::Linux::_createThread_lock = NULL; 143247777Sdavidepthread_t os::Linux::_main_thread; 144278800Srrsint os::Linux::_page_size = -1; 145177859Sjeffconst int os::Linux::_vm_default_page_size = (8 * K); 146247777Sdavidebool os::Linux::_supports_fast_thread_cpu_time = false; 147247777Sdavideconst char * os::Linux::_glibc_version = NULL; 148247777Sdavideconst char * os::Linux::_libpthread_version = NULL; 149247777Sdavidepthread_condattr_t os::Linux::_condattr[1]; 150247777Sdavide 151177859Sjeffstatic jlong initial_time_count=0; 152247777Sdavide 153278694Ssbrunostatic int clock_tics_per_sec = 100; 154177859Sjeff 155128024Scperciva// For diagnostics to print a message once. see run_periodic_checks 156278800Srrsstatic sigset_t check_signal_done; 157278800Srrsstatic bool check_signals = true; 158278800Srrs 159278800Srrs// Signal number used to suspend/resume a thread 160177859Sjeff 161278800Srrs// do not use any signal number less than SIGSEGV, see 4355769 162278800Srrsstatic int SR_signum = SIGUSR2; 163278800Srrssigset_t SR_sigset; 164278800Srrs 165278800Srrs// Declarations 166220456Sattiliostatic void unpackTime(timespec* absTime, bool isAbsolute, jlong time); 167177859Sjeff 168220456Sattilio// utility functions 169177859Sjeff 170177859Sjeffstatic int SR_initialize(); 171177859Sjeff 172177859Sjeffjulong os::available_memory() { 173177859Sjeff return Linux::available_memory(); 174177859Sjeff} 175177859Sjeff 176177859Sjeffjulong os::Linux::available_memory() { 177177859Sjeff // values in struct sysinfo are "unsigned long" 178220456Sattilio struct sysinfo si; 179177859Sjeff sysinfo(&si); 180177859Sjeff 181177859Sjeff return (julong)si.freeram * si.mem_unit; 182278694Ssbruno} 183247777Sdavide 184247777Sdavidejulong os::physical_memory() { 185247777Sdavide return Linux::physical_memory(); 186247777Sdavide} 187247777Sdavide 188247777Sdavide// Return true if user is running as root. 189227293Sed 190177859Sjeffbool os::have_special_privileges() { 191139831Scperciva static bool init = false; 192177859Sjeff static bool privileges = false; 193247777Sdavide if (!init) { 194247777Sdavide privileges = (getuid() != geteuid()) || (getgid() != getegid()); 195177859Sjeff init = true; 196127969Scperciva } 197247777Sdavide return privileges; 198141428Siedowse} 199141428Siedowse 200173760Sattilio 201155957Sjhb#ifndef SYS_gettid 202247777Sdavide// i386: 224, ia64: 1105, amd64: 186, sparc 143 203177859Sjeff #ifdef __ia64__ 204155957Sjhb #define SYS_gettid 1105 205247777Sdavide #else 206127969Scperciva #ifdef __i386__ 207128024Scperciva #define SYS_gettid 224 2081541Srgrimes #else 209247777Sdavide #ifdef __amd64__ 210220456Sattilio #define SYS_gettid 186 211220456Sattilio #else 212247777Sdavide #ifdef __sparc__ 213220456Sattilio #define SYS_gettid 143 214220456Sattilio #else 215278800Srrs #error define gettid for the arch 216278800Srrs #endif 217278800Srrs #endif 218220456Sattilio #endif 219278800Srrs #endif 220278800Srrs#endif 221278800Srrs 222278800Srrs// Cpu architecture string 223278800Srrsstatic char cpu_arch[] = HOTSPOT_LIB_ARCH; 224220456Sattilio 225220456Sattilio 226220456Sattilio// pid_t gettid() 227220456Sattilio// 228220456Sattilio// Returns the kernel thread id of the currently running thread. Kernel 229220456Sattilio// thread id is used to access /proc. 230220456Sattiliopid_t os::Linux::gettid() { 231247777Sdavide int rslt = syscall(SYS_gettid); 232220456Sattilio assert(rslt != -1, "must be."); // old linuxthreads implementation? 233220456Sattilio return (pid_t)rslt; 234220456Sattilio} 235278800Srrs 236220456Sattilio// Most versions of linux have a bug where the number of processors are 237220456Sattilio// determined by looking at the /proc file system. In a chroot environment, 238220456Sattilio// the system call returns 1. This causes the VM to act as if it is 239220456Sattilio// a single processor and elide locking (see is_MP() call). 240220456Sattiliostatic bool unsafe_chroot_detected = false; 241220456Sattiliostatic const char *unstable_chroot_error = "/proc file system not found.\n" 242248032Sandre "Java may be unstable running multithreaded in a chroot " 243248032Sandre "environment on Linux when /proc filesystem is not mounted."; 24482127Sdillon 245248032Sandrevoid os::Linux::initialize_system_info() { 246248032Sandre set_processor_count(sysconf(_SC_NPROCESSORS_CONF)); 24782127Sdillon if (processor_count() == 1) { 248177859Sjeff pid_t pid = os::Linux::gettid(); 249177859Sjeff char fname[32]; 25082127Sdillon jio_snprintf(fname, sizeof(fname), "/proc/%d", pid); 251248031Sandre FILE *fp = fopen(fname, "r"); 252248031Sandre if (fp == NULL) { 253248141Sandre unsafe_chroot_detected = true; 254248141Sandre } else { 255248031Sandre fclose(fp); 256248031Sandre } 257248031Sandre } 258248031Sandre _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE); 259248031Sandre assert(processor_count() > 0, "linux error"); 260243853Salfred} 261243853Salfred 26282127Sdillonvoid os::init_system_properties_values() { 263243853Salfred // The next steps are taken in the product version: 26482127Sdillon // 26582127Sdillon // Obtain the JAVA_HOME value from the location of libjvm.so. 266248032Sandre // This library should be located at: 267248032Sandre // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so. 268248032Sandre // 269248032Sandre // If "/jre/lib/" appears at the right place in the path, then we 270248032Sandre // assume libjvm.so is installed in a JDK and we use this path. 271248032Sandre // 272248032Sandre // Otherwise exit with message: "Could not create the Java virtual machine." 273248032Sandre // 274248032Sandre // The following extra steps are taken in the debugging version: 275248032Sandre // 276278694Ssbruno // If "/jre/lib/" does NOT appear at the right place in the path 27782127Sdillon // instead of exit check for $JAVA_HOME environment variable. 278248032Sandre // 27982127Sdillon // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 280248032Sandre // then we append a fake suffix "hotspot/libjvm.so" to this path so 281248032Sandre // it looks like libjvm.so is installed there 282248032Sandre // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 283177859Sjeff // 284278694Ssbruno // Otherwise exit. 285177859Sjeff // 286177859Sjeff // Important note: if the location of libjvm.so changes this 287177859Sjeff // code needs to be changed accordingly. 288177859Sjeff 289177859Sjeff // See ld(1): 290177859Sjeff // The linker uses the following search paths to locate required 291248113Sdavide // shared libraries: 292248032Sandre // 1: ... 293247777Sdavide // ... 294247777Sdavide // 7: The default directories, normally /lib and /usr/lib. 295247777Sdavide#if defined(AMD64) || defined(_LP64) && (defined(SPARC) || defined(PPC) || defined(S390)) 296247777Sdavide #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib" 297247777Sdavide#else 298247777Sdavide #define DEFAULT_LIBPATH "/lib:/usr/lib" 299278694Ssbruno#endif 300278694Ssbruno 301248032Sandre// Base path of extensions installed on the system. 302177859Sjeff#define SYS_EXT_DIR "/usr/java/packages" 303177859Sjeff#define EXTENSIONS_DIR "/lib/ext" 304177859Sjeff 305177859Sjeff // Buffer that fits several sprintfs. 306177859Sjeff // Note that the space for the colon and the trailing null are provided 307177859Sjeff // by the nulls included by the sizeof operator. 308177859Sjeff const size_t bufsize = 309177859Sjeff MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. 310177859Sjeff (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir 311220456Sattilio char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 31282127Sdillon 313220456Sattilio // sysclasspath, java_home, dll_dir 314220456Sattilio { 315220456Sattilio char *pslash; 316220456Sattilio os::jvm_path(buf, bufsize); 317220456Sattilio 318220456Sattilio // Found the full path to libjvm.so. 319220456Sattilio // Now cut the path to <java_home>/jre if we can. 320220456Sattilio pslash = strrchr(buf, '/'); 321220456Sattilio if (pslash != NULL) { 322220456Sattilio *pslash = '\0'; // Get rid of /libjvm.so. 323220456Sattilio } 324220456Sattilio pslash = strrchr(buf, '/'); 325225057Sattilio if (pslash != NULL) { 326225057Sattilio *pslash = '\0'; // Get rid of /{client|server|hotspot}. 327225057Sattilio } 328225057Sattilio Arguments::set_dll_dir(buf); 329225057Sattilio 330220456Sattilio if (pslash != NULL) { 331225057Sattilio pslash = strrchr(buf, '/'); 332220456Sattilio if (pslash != NULL) { 333220456Sattilio *pslash = '\0'; // Get rid of /<arch>. 334220456Sattilio pslash = strrchr(buf, '/'); 335225057Sattilio if (pslash != NULL) { 336220456Sattilio *pslash = '\0'; // Get rid of /lib. 337220456Sattilio } 338220456Sattilio } 339220456Sattilio } 340220456Sattilio Arguments::set_java_home(buf); 341220456Sattilio set_boot_path('/', ':'); 342177859Sjeff } 343177859Sjeff 344177859Sjeff // Where to look for native libraries. 345177859Sjeff // 346177859Sjeff // Note: Due to a legacy implementation, most of the library path 347177859Sjeff // is set in the launcher. This was to accomodate linking restrictions 348177859Sjeff // on legacy Linux implementations (which are no longer supported). 349177859Sjeff // Eventually, all the library path setting will be done here. 350177859Sjeff // 351177859Sjeff // However, to prevent the proliferation of improperly built native 352177859Sjeff // libraries, the new path component /usr/java/packages is added here. 353177859Sjeff // Eventually, all the library path setting will be done here. 354214746Sjhb { 355177859Sjeff // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 356177859Sjeff // should always exist (until the legacy problem cited above is 357209059Sjhb // addressed). 358177859Sjeff const char *v = ::getenv("LD_LIBRARY_PATH"); 359177859Sjeff const char *v_colon = ":"; 360177859Sjeff if (v == NULL) { v = ""; v_colon = ""; } 361248032Sandre // That's +1 for the colon and +1 for the trailing '\0'. 362278694Ssbruno char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 363177859Sjeff strlen(v) + 1 + 364177859Sjeff sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1, 365177859Sjeff mtInternal); 36682127Sdillon sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch); 367177859Sjeff Arguments::set_library_path(ld_library_path); 368177859Sjeff FREE_C_HEAP_ARRAY(char, ld_library_path); 369177859Sjeff } 370177859Sjeff 371247777Sdavide // Extensions directories. 372247777Sdavide sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 373247777Sdavide Arguments::set_ext_dirs(buf); 374247777Sdavide 375247777Sdavide FREE_C_HEAP_ARRAY(char, buf); 376247777Sdavide 377247777Sdavide#undef DEFAULT_LIBPATH 378247777Sdavide#undef SYS_EXT_DIR 379247777Sdavide#undef EXTENSIONS_DIR 380247777Sdavide} 381247777Sdavide 382247777Sdavide//////////////////////////////////////////////////////////////////////////////// 383247777Sdavide// breakpoint support 384247777Sdavide 385247777Sdavidevoid os::breakpoint() { 386247777Sdavide BREAKPOINT; 387177859Sjeff} 388247777Sdavide 389177859Sjeffextern "C" void breakpoint() { 390247777Sdavide // use debugger to set breakpoint here 391177859Sjeff} 392247777Sdavide 393247777Sdavide//////////////////////////////////////////////////////////////////////////////// 394247777Sdavide// signal support 395247777Sdavide 396247777Sdavidedebug_only(static bool signal_sets_initialized = false); 397247777Sdavidestatic sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 398247777Sdavide 399177859Sjeffbool os::Linux::is_sig_ignored(int sig) { 400247777Sdavide struct sigaction oact; 401247777Sdavide sigaction(sig, (struct sigaction*)NULL, &oact); 402247777Sdavide void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 403247777Sdavide : CAST_FROM_FN_PTR(void*, oact.sa_handler); 404247777Sdavide if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) { 405247777Sdavide return true; 406247777Sdavide } else { 407247777Sdavide return false; 408247777Sdavide } 409247777Sdavide} 410247777Sdavide 411247777Sdavidevoid os::Linux::signal_sets_init() { 412247777Sdavide // Should also have an assertion stating we are still single-threaded. 413247777Sdavide assert(!signal_sets_initialized, "Already initialized"); 414247777Sdavide // Fill in signals that are necessarily unblocked for all threads in 415247777Sdavide // the VM. Currently, we unblock the following signals: 416247777Sdavide // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 417247777Sdavide // by -Xrs (=ReduceSignalUsage)); 418247777Sdavide // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 419247777Sdavide // other threads. The "ReduceSignalUsage" boolean tells us not to alter 420247777Sdavide // the dispositions or masks wrt these signals. 421247777Sdavide // Programs embedding the VM that want to use the above signals for their 422177859Sjeff // own purposes must, at this time, use the "-Xrs" option to prevent 423247777Sdavide // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 424247777Sdavide // (See bug 4345157, and other related bugs). 425177859Sjeff // In reality, though, unblocking these signals is really a nop, since 426247777Sdavide // these signals are not blocked by default. 427247777Sdavide sigemptyset(&unblocked_sigs); 428247777Sdavide sigemptyset(&allowdebug_blocked_sigs); 429247777Sdavide sigaddset(&unblocked_sigs, SIGILL); 430247777Sdavide sigaddset(&unblocked_sigs, SIGSEGV); 431247777Sdavide sigaddset(&unblocked_sigs, SIGBUS); 432247777Sdavide sigaddset(&unblocked_sigs, SIGFPE); 433247777Sdavide#if defined(PPC64) 434247777Sdavide sigaddset(&unblocked_sigs, SIGTRAP); 435247777Sdavide#endif 436247777Sdavide sigaddset(&unblocked_sigs, SR_signum); 437247777Sdavide 438247777Sdavide if (!ReduceSignalUsage) { 439247777Sdavide if (!os::Linux::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 440247777Sdavide sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 441247777Sdavide sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); 442247777Sdavide } 443247777Sdavide if (!os::Linux::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 444247777Sdavide sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 445247777Sdavide sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); 446247777Sdavide } 447278800Srrs if (!os::Linux::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 448247777Sdavide sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 449247777Sdavide sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); 450247777Sdavide } 451247777Sdavide } 452247777Sdavide // Fill in signals that are blocked by all but the VM thread. 453247777Sdavide sigemptyset(&vm_sigs); 454247777Sdavide if (!ReduceSignalUsage) { 455247777Sdavide sigaddset(&vm_sigs, BREAK_SIGNAL); 456278800Srrs } 457278800Srrs debug_only(signal_sets_initialized = true); 458247777Sdavide 459247777Sdavide} 460247777Sdavide 461247777Sdavide// These are signals that are unblocked while a thread is running Java. 462247777Sdavide// (For some reason, they get blocked by default.) 463247777Sdavidesigset_t* os::Linux::unblocked_signals() { 464247777Sdavide assert(signal_sets_initialized, "Not initialized"); 465247777Sdavide return &unblocked_sigs; 466247777Sdavide} 467247777Sdavide 468247777Sdavide// These are the signals that are blocked while a (non-VM) thread is 469247777Sdavide// running Java. Only the VM thread handles these signals. 470247777Sdavidesigset_t* os::Linux::vm_signals() { 471247777Sdavide assert(signal_sets_initialized, "Not initialized"); 472247777Sdavide return &vm_sigs; 473247777Sdavide} 474247777Sdavide 475247777Sdavide// These are signals that are blocked during cond_wait to allow debugger in 476247777Sdavidesigset_t* os::Linux::allowdebug_blocked_signals() { 477247777Sdavide assert(signal_sets_initialized, "Not initialized"); 478247777Sdavide return &allowdebug_blocked_sigs; 479247777Sdavide} 480247777Sdavide 481247777Sdavidevoid os::Linux::hotspot_sigmask(Thread* thread) { 482247777Sdavide 483247777Sdavide //Save caller's signal mask before setting VM signal mask 484247777Sdavide sigset_t caller_sigmask; 485247777Sdavide pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 486247777Sdavide 487180608Sjeff OSThread* osthread = thread->osthread(); 488247777Sdavide osthread->set_caller_sigmask(caller_sigmask); 489247777Sdavide 490247777Sdavide pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL); 491247777Sdavide 492247777Sdavide if (!ReduceSignalUsage) { 493247777Sdavide if (thread->is_VM_thread()) { 494247777Sdavide // Only the VM thread handles BREAK_SIGNAL ... 495247777Sdavide pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 496247777Sdavide } else { 497247777Sdavide // ... all other threads block BREAK_SIGNAL 498247777Sdavide pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 499247777Sdavide } 500247777Sdavide } 501247777Sdavide} 502247777Sdavide 503247777Sdavide////////////////////////////////////////////////////////////////////////////// 504247777Sdavide// detecting pthread library 505177859Sjeff 506177859Sjeffvoid os::Linux::libpthread_init() { 507177859Sjeff // Save glibc and pthread version strings. 508177859Sjeff#if !defined(_CS_GNU_LIBC_VERSION) || \ 509177859Sjeff !defined(_CS_GNU_LIBPTHREAD_VERSION) 510247777Sdavide #error "glibc too old (< 2.3.2)" 511177859Sjeff#endif 512177859Sjeff 513177859Sjeff size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); 514177859Sjeff assert(n > 0, "cannot retrieve glibc version"); 515177859Sjeff char *str = (char *)malloc(n, mtInternal); 516177859Sjeff confstr(_CS_GNU_LIBC_VERSION, str, n); 517177859Sjeff os::Linux::set_glibc_version(str); 518177859Sjeff 519177859Sjeff n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); 520177859Sjeff assert(n > 0, "cannot retrieve pthread version"); 521177859Sjeff str = (char *)malloc(n, mtInternal); 522220456Sattilio confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); 523220456Sattilio os::Linux::set_libpthread_version(str); 524220456Sattilio} 525220456Sattilio 526220456Sattilio///////////////////////////////////////////////////////////////////////////// 527220456Sattilio// thread stack expansion 528220456Sattilio 529177859Sjeff// os::Linux::manually_expand_stack() takes care of expanding the thread 530177859Sjeff// stack. Note that this is normally not needed: pthread stacks allocate 531177859Sjeff// thread stack using mmap() without MAP_NORESERVE, so the stack is already 532177859Sjeff// committed. Therefore it is not necessary to expand the stack manually. 533177859Sjeff// 53482127Sdillon// Manually expanding the stack was historically needed on LinuxThreads 535177859Sjeff// thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays 53682127Sdillon// it is kept to deal with very rare corner cases: 53782127Sdillon// 538220456Sattilio// For one, user may run the VM on an own implementation of threads 539247777Sdavide// whose stacks are - like the old LinuxThreads - implemented using 540247777Sdavide// mmap(MAP_GROWSDOWN). 541247777Sdavide// 542220456Sattilio// Also, this coding may be needed if the VM is running on the primordial 543247777Sdavide// thread. Normally we avoid running on the primordial thread; however, 544220456Sattilio// user may still invoke the VM on the primordial thread. 545220456Sattilio// 546247777Sdavide// The following historical comment describes the details about running 547247777Sdavide// on a thread stack allocated with mmap(MAP_GROWSDOWN): 548220456Sattilio 549220456Sattilio 550247777Sdavide// Force Linux kernel to expand current thread stack. If "bottom" is close 551220456Sattilio// to the stack guard, caller should block all signals. 552247777Sdavide// 553247777Sdavide// MAP_GROWSDOWN: 554247777Sdavide// A special mmap() flag that is used to implement thread stacks. It tells 555247777Sdavide// kernel that the memory region should extend downwards when needed. This 556247777Sdavide// allows early versions of LinuxThreads to only mmap the first few pages 557247777Sdavide// when creating a new thread. Linux kernel will automatically expand thread 558247777Sdavide// stack as needed (on page faults). 559247777Sdavide// 560278800Srrs// However, because the memory region of a MAP_GROWSDOWN stack can grow on 561247777Sdavide// demand, if a page fault happens outside an already mapped MAP_GROWSDOWN 562247777Sdavide// region, it's hard to tell if the fault is due to a legitimate stack 563247777Sdavide// access or because of reading/writing non-exist memory (e.g. buffer 564247777Sdavide// overrun). As a rule, if the fault happens below current stack pointer, 565247777Sdavide// Linux kernel does not expand stack, instead a SIGSEGV is sent to the 566255877Sdavide// application (see Linux kernel fault.c). 567255877Sdavide// 568247777Sdavide// This Linux feature can cause SIGSEGV when VM bangs thread stack for 569247777Sdavide// stack overflow detection. 570247777Sdavide// 571247777Sdavide// Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do 572220456Sattilio// not use MAP_GROWSDOWN. 573247777Sdavide// 574220456Sattilio// To get around the problem and allow stack banging on Linux, we need to 575220456Sattilio// manually expand thread stack after receiving the SIGSEGV. 576234981Skib// 577234981Skib// There are two ways to expand thread stack to address "bottom", we used 578234981Skib// both of them in JVM before 1.5: 579234981Skib// 1. adjust stack pointer first so that it is below "bottom", and then 580243901Skib// touch "bottom" 581243901Skib// 2. mmap() the page in question 582243901Skib// 583243901Skib// Now alternate signal stack is gone, it's harder to use 2. For instance, 584234981Skib// if current sp is already near the lower end of page 101, and we need to 585234981Skib// call mmap() to map page 100, it is possible that part of the mmap() frame 586243901Skib// will be placed in page 100. When page 100 is mapped, it is zero-filled. 587247777Sdavide// That will destroy the mmap() frame and cause VM to crash. 588247777Sdavide// 589247777Sdavide// The following code works by adjusting sp first, then accessing the "bottom" 590247777Sdavide// page to force a page fault. Linux kernel will then automatically expand the 591247777Sdavide// stack mapping. 592234981Skib// 593255747Sdavide// _expand_stack_to() assumes its frame size is less than page size, which 594234981Skib// should always be true if the function is not inlined. 595234981Skib 596234981Skib#if __GNUC__ < 3 // gcc 2.x does not support noinline attribute 597234981Skib #define NOINLINE 598255747Sdavide#else 599255747Sdavide #define NOINLINE __attribute__ ((noinline)) 600234981Skib#endif 601234981Skib 602234981Skibstatic void _expand_stack_to(address bottom) NOINLINE; 603234981Skib 604247777Sdavidestatic void _expand_stack_to(address bottom) { 605248699Sdavide address sp; 606234981Skib size_t size; 607247777Sdavide volatile char *p; 608247793Sdavide 609234981Skib // Adjust bottom to point to the largest address within the same page, it 610247777Sdavide // gives us a one-page buffer if alloca() allocates slightly more memory. 611234981Skib bottom = (address)align_size_down((uintptr_t)bottom, os::Linux::page_size()); 612234981Skib bottom += os::Linux::page_size() - 1; 613234981Skib 614243901Skib // sp might be slightly above current stack pointer; if that's the case, we 615243901Skib // will alloca() a little more space than necessary, which is OK. Don't use 616243901Skib // os::current_stack_pointer(), as its result can be slightly below current 617234981Skib // stack pointer, causing us to not alloca enough to reach "bottom". 618255747Sdavide sp = (address)&sp; 619255747Sdavide 620255747Sdavide if (sp > bottom) { 621255747Sdavide size = sp - bottom; 622255747Sdavide p = (volatile char *)alloca(size); 623255747Sdavide assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?"); 624255747Sdavide p[0] = '\0'; 625234981Skib } 626234981Skib} 627234981Skib 628234981Skibbool os::Linux::manually_expand_stack(JavaThread * t, address addr) { 629234981Skib assert(t!=NULL, "just checking"); 630234981Skib assert(t->osthread()->expanding_stack(), "expand should be set"); 631234981Skib assert(t->stack_base() != NULL, "stack_base was not initialized"); 632234981Skib 633278800Srrs if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) { 634278800Srrs sigset_t mask_all, old_sigset; 635278800Srrs sigfillset(&mask_all); 636234981Skib pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset); 637234981Skib _expand_stack_to(addr); 638255747Sdavide pthread_sigmask(SIG_SETMASK, &old_sigset, NULL); 639234981Skib return true; 640234981Skib } 641234981Skib return false; 642234981Skib} 643278800Srrs 644234981Skib////////////////////////////////////////////////////////////////////////////// 645234981Skib// create new thread 646234981Skib 647234981Skib// Thread start routine for all newly created threads 648278800Srrsstatic void *java_start(Thread *thread) { 649234981Skib // Try to randomize the cache line index of hot stack frames. 650247777Sdavide // This helps when threads of the same stack traces evict each other's 651234981Skib // cache lines. The threads can be either from the same JVM instance, or 652247777Sdavide // from different JVM instances. The benefit is especially true for 653247777Sdavide // processors with hyperthreading technology. 654234981Skib static int counter = 0; 655234981Skib int pid = os::current_process_id(); 656247777Sdavide alloca(((pid ^ counter++) & 7) * 128); 657234981Skib 658247777Sdavide thread->initialize_thread_current(); 659234981Skib 660234981Skib OSThread* osthread = thread->osthread(); 661234981Skib Monitor* sync = osthread->startThread_lock(); 662234981Skib 663247777Sdavide osthread->set_thread_id(os::current_thread_id()); 664234981Skib 665247777Sdavide if (UseNUMA) { 666247777Sdavide int lgrp_id = os::numa_get_group_id(); 667234981Skib if (lgrp_id != -1) { 668234981Skib thread->set_lgrp_id(lgrp_id); 669278694Ssbruno } 670278694Ssbruno } 671247793Sdavide // initialize signal mask for this thread 672247777Sdavide os::Linux::hotspot_sigmask(thread); 673234981Skib 674234981Skib // initialize floating point control register 675260817Savg os::Linux::init_thread_fpu_state(); 676234981Skib 677260817Savg // handshaking with parent thread 678234981Skib { 679247793Sdavide MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 680247793Sdavide 681247793Sdavide // notify parent thread 682247793Sdavide osthread->set_state(INITIALIZED); 683247793Sdavide sync->notify_all(); 684247793Sdavide 685234981Skib // wait until os::start_thread() 686234981Skib while (osthread->get_state() == INITIALIZED) { 687234981Skib sync->wait(Mutex::_no_safepoint_check_flag); 688234981Skib } 689247793Sdavide } 690234981Skib 691234981Skib // call one more level start routine 692234981Skib thread->run(); 693278694Ssbruno 694234981Skib return 0; 695234981Skib} 696234981Skib 697234981Skibbool os::create_thread(Thread* thread, ThreadType thr_type, 698234981Skib size_t stack_size) { 699278800Srrs assert(thread->osthread() == NULL, "caller responsible"); 700278800Srrs 701278800Srrs // Allocate the OSThread object 702234981Skib OSThread* osthread = new OSThread(NULL, NULL); 703234981Skib if (osthread == NULL) { 704234981Skib return false; 705234981Skib } 706234981Skib 707234981Skib // set the correct thread state 708247777Sdavide osthread->set_thread_type(thr_type); 709247777Sdavide 710243912Sattilio // Initial state is ALLOCATED but not INITIALIZED 711243912Sattilio osthread->set_state(ALLOCATED); 712243912Sattilio 713243912Sattilio thread->set_osthread(osthread); 714243912Sattilio 715243901Skib // init thread attributes 716243901Skib pthread_attr_t attr; 717278800Srrs pthread_attr_init(&attr); 718234981Skib pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 719278800Srrs 720234981Skib // stack size 721247777Sdavide // calculate stack size if it's not specified by caller 722243912Sattilio if (stack_size == 0) { 723243901Skib stack_size = os::Linux::default_stack_size(thr_type); 724234981Skib 725234981Skib switch (thr_type) { 726234981Skib case os::java_thread: 727234981Skib // Java threads use ThreadStackSize which default value can be 728234981Skib // changed with the flag -Xss 729278800Srrs assert(JavaThread::stack_size_at_create() > 0, "this should be set"); 730278800Srrs stack_size = JavaThread::stack_size_at_create(); 731278800Srrs break; 732278800Srrs case os::compiler_thread: 733278800Srrs if (CompilerThreadStackSize > 0) { 734247777Sdavide stack_size = (size_t)(CompilerThreadStackSize * K); 735234981Skib break; 736234981Skib } // else fall through: 737243912Sattilio // use VMThreadStackSize if CompilerThreadStackSize is not defined 738243912Sattilio case os::vm_thread: 739243912Sattilio case os::pgc_thread: 740243912Sattilio case os::cgc_thread: 741234981Skib case os::watcher_thread: 742278800Srrs if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 743234981Skib break; 744234981Skib } 745234981Skib } 746234981Skib 747243901Skib stack_size = MAX2(stack_size, os::Linux::min_stack_allowed); 748234981Skib pthread_attr_setstacksize(&attr, stack_size); 749234981Skib 750234981Skib // glibc guard page 751234981Skib pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type)); 752247777Sdavide 753248699Sdavide ThreadState state; 754247777Sdavide 755234981Skib { 756234981Skib pthread_t tid; 757234981Skib int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 758234981Skib 759234981Skib pthread_attr_destroy(&attr); 760234981Skib 761243901Skib if (ret != 0) { 762243901Skib if (PrintMiscellaneous && (Verbose || WizardMode)) { 763243901Skib perror("pthread_create()"); 764243901Skib } 765243901Skib // Need to clean up stuff we've allocated so far 766243901Skib thread->set_osthread(NULL); 767243901Skib delete osthread; 768243901Skib return false; 769243901Skib } 770243901Skib 771243901Skib // Store pthread info into the OSThread 772243912Sattilio osthread->set_pthread_id(tid); 773243912Sattilio 774234981Skib // Wait until child thread is either initialized or aborted 775234981Skib { 77682127Sdillon Monitor* sync_with_child = osthread->startThread_lock(); 777247467Sdavide MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 77829680Sgibbs while ((state = osthread->get_state()) == ALLOCATED) { 77929680Sgibbs sync_with_child->wait(Mutex::_no_safepoint_check_flag); 78029680Sgibbs } 781128630Shmp } 78229680Sgibbs } 78329680Sgibbs 78429680Sgibbs // Aborted due to thread limit being reached 78529680Sgibbs if (state == ZOMBIE) { 78629680Sgibbs thread->set_osthread(NULL); 78732388Sphk delete osthread; 78829680Sgibbs return false; 7891541Srgrimes } 7901541Srgrimes 7911541Srgrimes // The thread is returned suspended (in state INITIALIZED), 7921541Srgrimes // and is started higher up in the call chain 793177859Sjeff assert(state == INITIALIZED, "race condition"); 7941541Srgrimes return true; 795177859Sjeff} 796102936Sphk 797247777Sdavide///////////////////////////////////////////////////////////////////////////// 798247777Sdavide// attach existing thread 799247777Sdavide 8001541Srgrimes// bootstrap the main thread 801177859Sjeffbool os::create_main_thread(JavaThread* thread) { 802177859Sjeff assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread"); 803247777Sdavide return create_attached_thread(thread); 804247777Sdavide} 805247777Sdavide 806247777Sdavidebool os::create_attached_thread(JavaThread* thread) { 807247777Sdavide#ifdef ASSERT 808247777Sdavide thread->verify_not_published(); 809247777Sdavide#endif 810247777Sdavide 811247777Sdavide // Allocate the OSThread object 812247777Sdavide OSThread* osthread = new OSThread(NULL, NULL); 8131541Srgrimes 814247777Sdavide if (osthread == NULL) { 815115810Sphk return false; 816115810Sphk } 817173760Sattilio 818115810Sphk // Store pthread info into the OSThread 819247777Sdavide osthread->set_thread_id(os::Linux::gettid()); 820177859Sjeff osthread->set_pthread_id(::pthread_self()); 8211541Srgrimes 8221541Srgrimes // initialize floating point control register 8231541Srgrimes os::Linux::init_thread_fpu_state(); 8241541Srgrimes 8251541Srgrimes // Initial thread state is RUNNABLE 8261541Srgrimes osthread->set_state(RUNNABLE); 8271541Srgrimes 8281541Srgrimes thread->set_osthread(osthread); 8291541Srgrimes 83029680Sgibbs if (UseNUMA) { 83129680Sgibbs int lgrp_id = os::numa_get_group_id(); 83229680Sgibbs if (lgrp_id != -1) { 8331541Srgrimes thread->set_lgrp_id(lgrp_id); 834247698Smav } 83529680Sgibbs } 83629680Sgibbs 83729680Sgibbs if (os::Linux::is_initial_thread()) { 8381541Srgrimes // If current thread is initial thread, its stack is mapped on demand, 83929680Sgibbs // see notes about MAP_GROWSDOWN. Here we try to force kernel to map 84029680Sgibbs // the entire stack region to avoid SEGV in stack banging. 84133824Sbde // It is also useful to get around the heap-stack-gap problem on SuSE 8421541Srgrimes // kernel (see 4821821 for details). We first expand stack to the top 84369147Sjlemon // of yellow zone, then enable stack yellow zone (order is significant, 8441541Srgrimes // enabling yellow zone first will crash JVM on SuSE Linux), so there 845177859Sjeff // is no gap between the last two virtual memory regions. 84629680Sgibbs 84729680Sgibbs JavaThread *jt = (JavaThread *)thread; 8481541Srgrimes address addr = jt->stack_reserved_zone_base(); 849177859Sjeff assert(addr != NULL, "initialization problem?"); 850177859Sjeff assert(jt->stack_available(addr) > 0, "stack guard should not be enabled"); 8511541Srgrimes 852177859Sjeff osthread->set_expanding_stack(); 85329680Sgibbs os::Linux::manually_expand_stack(jt, addr); 85429680Sgibbs osthread->clear_expanding_stack(); 8551541Srgrimes } 856177859Sjeff 85744510Swollman // initialize signal mask for this thread 858177859Sjeff // and save the caller's signal mask 859177859Sjeff os::Linux::hotspot_sigmask(thread); 8601541Srgrimes 86129680Sgibbs return true; 8621541Srgrimes} 8631541Srgrimes 8641541Srgrimesvoid os::pd_start_thread(Thread* thread) { 86529680Sgibbs OSThread * osthread = thread->osthread(); 86633824Sbde assert(osthread->get_state() != INITIALIZED, "just checking"); 8671541Srgrimes Monitor* sync_with_child = osthread->startThread_lock(); 86829680Sgibbs MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 8691541Srgrimes sync_with_child->notify(); 870177859Sjeff} 8711541Srgrimes 87229680Sgibbs// Free Linux resources related to the OSThread 87329680Sgibbsvoid os::free_thread(OSThread* osthread) { 87429680Sgibbs assert(osthread != NULL, "osthread not set"); 87529680Sgibbs 87629680Sgibbs if (Thread::current()->osthread() == osthread) { 87729680Sgibbs // Restore caller's signal mask 87829680Sgibbs sigset_t sigmask = osthread->caller_sigmask(); 87929680Sgibbs pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 880177859Sjeff } 88144510Swollman 88244510Swollman delete osthread; 883177859Sjeff} 8841541Srgrimes 8851541Srgrimes////////////////////////////////////////////////////////////////////////////// 88624101Sbde// initial thread 88729680Sgibbs 88829680Sgibbs// Check if current thread is the initial thread, similar to Solaris thr_main. 88929680Sgibbsbool os::Linux::is_initial_thread(void) { 89029680Sgibbs char dummy; 89129680Sgibbs // If called before init complete, thread stack bottom will be null. 89244510Swollman // Can be called if fatal error occurs before initialization. 89344510Swollman if (initial_thread_stack_bottom() == NULL) return false; 89444510Swollman assert(initial_thread_stack_bottom() != NULL && 89544510Swollman initial_thread_stack_size() != 0, 89644510Swollman "os::init did not locate initial thread's stack region"); 89744510Swollman if ((address)&dummy >= initial_thread_stack_bottom() && 89844510Swollman (address)&dummy < initial_thread_stack_bottom() + initial_thread_stack_size()) { 89944510Swollman return true; 90050673Sjlemon } else { 90144510Swollman return false; 902140487Scperciva } 903140487Scperciva} 904140487Scperciva 90550673Sjlemon// Find the virtual memory area that contains addr 90650673Sjlemonstatic bool find_vma(address addr, address* vma_low, address* vma_high) { 90744510Swollman FILE *fp = fopen("/proc/self/maps", "r"); 908149879Sglebius if (fp) { 909247777Sdavide address low, high; 910247777Sdavide while (!feof(fp)) { 91144510Swollman if (fscanf(fp, "%p-%p", &low, &high) == 2) { 912247777Sdavide if (low <= addr && addr < high) { 913177859Sjeff if (vma_low) *vma_low = low; 914247777Sdavide if (vma_high) *vma_high = high; 91544510Swollman fclose(fp); 916247777Sdavide return true; 917247777Sdavide } 918247777Sdavide } 919247777Sdavide for (;;) { 920247777Sdavide int ch = fgetc(fp); 921247777Sdavide if (ch == EOF || ch == (int)'\n') break; 922247777Sdavide } 923247777Sdavide } 924247777Sdavide fclose(fp); 925247777Sdavide } 926247777Sdavide return false; 927247777Sdavide} 928247777Sdavide 929247777Sdavide// Locate initial thread stack. This special handling of initial thread stack 930247777Sdavide// is needed because pthread_getattr_np() on most (all?) Linux distros returns 931247777Sdavide// bogus value for initial thread. 932247777Sdavidevoid os::Linux::capture_initial_stack(size_t max_size) { 933247777Sdavide // stack size is the easy part, get it from RLIMIT_STACK 934247777Sdavide size_t stack_size; 935247777Sdavide struct rlimit rlim; 936247777Sdavide getrlimit(RLIMIT_STACK, &rlim); 937247777Sdavide stack_size = rlim.rlim_cur; 938247777Sdavide 939247777Sdavide // 6308388: a bug in ld.so will relocate its own .data section to the 940247777Sdavide // lower end of primordial stack; reduce ulimit -s value a little bit 941247777Sdavide // so we won't install guard page on ld.so's data section. 942247777Sdavide stack_size -= 2 * page_size(); 943247777Sdavide 944247777Sdavide // 4441425: avoid crash with "unlimited" stack size on SuSE 7.1 or Redhat 945247777Sdavide // 7.1, in both cases we will get 2G in return value. 946247777Sdavide // 4466587: glibc 2.2.x compiled w/o "--enable-kernel=2.4.0" (RH 7.0, 947247777Sdavide // SuSE 7.2, Debian) can not handle alternate signal stack correctly 948247777Sdavide // for initial thread if its stack size exceeds 6M. Cap it at 2M, 949255877Sdavide // in case other parts in glibc still assumes 2M max stack size. 950255877Sdavide // FIXME: alt signal stack is gone, maybe we can relax this constraint? 951255877Sdavide // Problem still exists RH7.2 (IA64 anyway) but 2MB is a little small 952255877Sdavide if (stack_size > 2 * K * K IA64_ONLY(*2)) { 953247777Sdavide stack_size = 2 * K * K IA64_ONLY(*2); 954247777Sdavide } 955247777Sdavide // Try to figure out where the stack base (top) is. This is harder. 956247777Sdavide // 957247777Sdavide // When an application is started, glibc saves the initial stack pointer in 958177859Sjeff // a global variable "__libc_stack_end", which is then used by system 959177859Sjeff // libraries. __libc_stack_end should be pretty close to stack top. The 960177859Sjeff // variable is available since the very early days. However, because it is 961177859Sjeff // a private interface, it could disappear in the future. 962177859Sjeff // 963177859Sjeff // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar 964278800Srrs // to __libc_stack_end, it is very close to stack top, but isn't the real 965278800Srrs // stack top. Note that /proc may not exist if VM is running as a chroot 966278800Srrs // program, so reading /proc/<pid>/stat could fail. Also the contents of 967278800Srrs // /proc/<pid>/stat could change in the future (though unlikely). 968278800Srrs // 969278800Srrs // We try __libc_stack_end first. If that doesn't work, look for 970278800Srrs // /proc/<pid>/stat. If neither of them works, we use current stack pointer 971278800Srrs // as a hint, which should work well in most cases. 972247777Sdavide 973247777Sdavide uintptr_t stack_start; 974247777Sdavide 975177859Sjeff // try __libc_stack_end first 976278800Srrs uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end"); 977127969Scperciva if (p && *p) { 978127969Scperciva stack_start = *p; 979173760Sattilio } else { 980141428Siedowse // see if we can get the start_stack field from /proc/self/stat 981127969Scperciva FILE *fp; 982278800Srrs int pid; 983278800Srrs char state; 984278800Srrs int ppid; 985141428Siedowse int pgrp; 986141428Siedowse int session; 987141428Siedowse int nr; 988141428Siedowse int tpgrp; 989163246Sglebius unsigned long flags; 990163246Sglebius unsigned long minflt; 991163246Sglebius unsigned long cminflt; 992177859Sjeff unsigned long majflt; 993149879Sglebius unsigned long cmajflt; 994141428Siedowse unsigned long utime; 995278800Srrs unsigned long stime; 996278800Srrs long cutime; 997278800Srrs long cstime; 998278800Srrs long prio; 999278800Srrs long nice; 1000278800Srrs long junk; 1001278800Srrs long it_real; 1002278800Srrs uintptr_t start; 1003278800Srrs uintptr_t vsize; 1004278800Srrs intptr_t rss; 1005278800Srrs uintptr_t rsslim; 1006278800Srrs uintptr_t scodes; 1007278800Srrs uintptr_t ecode; 1008278800Srrs int i; 1009278800Srrs 1010278800Srrs // Figure what the primordial thread stack base is. Code is inspired 1011278800Srrs // by email from Hans Boehm. /proc/self/stat begins with current pid, 1012278800Srrs // followed by command name surrounded by parentheses, state, etc. 1013278800Srrs char stat[2048]; 1014128024Scperciva int statlen; 1015133190Scperciva 1016247777Sdavide fp = fopen("/proc/self/stat", "r"); 1017278800Srrs if (fp) { 1018278800Srrs statlen = fread(stat, 1, 2047, fp); 1019247777Sdavide stat[statlen] = '\0'; 1020247777Sdavide fclose(fp); 1021247777Sdavide 1022149879Sglebius // Skip pid and the command string. Note that we could be dealing with 1023177859Sjeff // weird command names, e.g. user could decide to rename java launcher 1024133190Scperciva // to "java 1.4.2 :)", then the stat file would look like 1025220456Sattilio // 1234 (java 1.4.2 :)) R ... ... 1026220456Sattilio // We don't really need to know the command string, just find the last 102744510Swollman // occurrence of ")" and then start parsing from there. See bug 4726580. 1028220456Sattilio char * s = strrchr(stat, ')'); 1029220456Sattilio 1030220456Sattilio i = 0; 103144510Swollman if (s) { 1032177859Sjeff // Skip blank chars 1033278800Srrs do { s++; } while (s && isspace(*s)); 1034278800Srrs 1035278800Srrs#define _UFM UINTX_FORMAT 1036278800Srrs#define _DFM INTX_FORMAT 1037278800Srrs 1038278800Srrs // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 1039278800Srrs // 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 1040278800Srrs i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM, 1041278800Srrs &state, // 3 %c 1042278800Srrs &ppid, // 4 %d 1043278800Srrs &pgrp, // 5 %d 1044278800Srrs &session, // 6 %d 1045278800Srrs &nr, // 7 %d 1046278800Srrs &tpgrp, // 8 %d 1047278800Srrs &flags, // 9 %lu 1048278800Srrs &minflt, // 10 %lu 1049278800Srrs &cminflt, // 11 %lu 1050278800Srrs &majflt, // 12 %lu 1051278800Srrs &cmajflt, // 13 %lu 1052278800Srrs &utime, // 14 %lu 1053278800Srrs &stime, // 15 %lu 1054278800Srrs &cutime, // 16 %ld 1055278800Srrs &cstime, // 17 %ld 1056247777Sdavide &prio, // 18 %ld 1057247777Sdavide &nice, // 19 %ld 1058247777Sdavide &junk, // 20 %ld 1059247777Sdavide &it_real, // 21 %ld 1060220456Sattilio &start, // 22 UINTX_FORMAT 1061220456Sattilio &vsize, // 23 UINTX_FORMAT 1062220456Sattilio &rss, // 24 INTX_FORMAT 1063220456Sattilio &rsslim, // 25 UINTX_FORMAT 1064177859Sjeff &scodes, // 26 UINTX_FORMAT 1065220456Sattilio &ecode, // 27 UINTX_FORMAT 1066177859Sjeff &stack_start); // 28 UINTX_FORMAT 1067247777Sdavide } 1068247777Sdavide 1069247777Sdavide#undef _UFM 1070247777Sdavide#undef _DFM 1071177859Sjeff 1072149879Sglebius if (i != 28 - 2) { 1073149879Sglebius assert(false, "Bad conversion from /proc/self/stat"); 107444510Swollman // product mode - assume we are the initial thread, good luck in the 107544510Swollman // embedded case. 1076181191Ssam warning("Can't detect initial thread stack location - bad conversion"); 1077181191Ssam stack_start = (uintptr_t) &rlim; 1078181191Ssam } 107981481Sjhb } else { 1080181191Ssam // For some reason we can't open /proc/self/stat (for example, running on 1081181191Ssam // FreeBSD with a Linux emulator, or inside chroot), this should work for 1082181191Ssam // most cases, so don't abort: 1083181191Ssam warning("Can't detect initial thread stack location - no /proc/self/stat"); 1084181191Ssam stack_start = (uintptr_t) &rlim; 1085181191Ssam } 1086181191Ssam } 1087181191Ssam 1088181191Ssam // Now we have a pointer (stack_start) very close to the stack top, the 1089181191Ssam // next thing to do is to figure out the exact location of stack top. We 1090181191Ssam // can find out the virtual memory area that contains stack_start by 1091181191Ssam // reading /proc/self/maps, it should be the last vma in /proc/self/maps, 1092127969Scperciva // and its upper limit is the real stack top. (again, this would fail if 1093127969Scperciva // running inside chroot, because /proc may not exist.) 1094127969Scperciva 1095127969Scperciva uintptr_t stack_top; 1096220456Sattilio address low, high; 1097173760Sattilio if (find_vma((address)stack_start, &low, &high)) { 1098247777Sdavide // success, "high" is the true stack top. (ignore "low", because initial 1099278800Srrs // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.) 1100127969Scperciva stack_top = (uintptr_t)high; 1101173760Sattilio } else { 1102173760Sattilio // failed, likely because /proc/self/maps does not exist 1103173760Sattilio warning("Can't detect initial thread stack location - find_vma failed"); 1104173760Sattilio // best effort: stack_start is normally within a few pages below the real 1105173760Sattilio // stack top, use it as stack top, and reduce stack size so we won't put 1106173760Sattilio // guard page outside stack. 1107173760Sattilio stack_top = stack_start; 1108173760Sattilio stack_size -= 16 * page_size(); 1109173760Sattilio } 1110173760Sattilio 1111173760Sattilio // stack_top could be partially down the page so align it 1112173760Sattilio stack_top = align_size_up(stack_top, page_size()); 1113173760Sattilio 1114173760Sattilio if (max_size && stack_size > max_size) { 1115247777Sdavide _initial_thread_stack_size = max_size; 1116172025Sjhb } else { 1117220456Sattilio _initial_thread_stack_size = stack_size; 1118172025Sjhb } 1119177859Sjeff 1120220456Sattilio _initial_thread_stack_size = align_size_down(_initial_thread_stack_size, page_size()); 1121278800Srrs _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size; 1122278800Srrs} 1123278800Srrs 1124278800Srrs//////////////////////////////////////////////////////////////////////////////// 1125278800Srrs// time support 1126278800Srrs 1127278800Srrs// Time since start-up in seconds to a fine granularity. 1128278800Srrs// Used by VMSelfDestructTimer and the MemProfiler. 1129278800Srrsdouble os::elapsedTime() { 1130278800Srrs 1131278800Srrs return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution 1132278800Srrs} 1133278800Srrs 1134278800Srrsjlong os::elapsed_counter() { 1135278800Srrs return javaTimeNanos() - initial_time_count; 1136278800Srrs} 1137278800Srrs 1138278800Srrsjlong os::elapsed_frequency() { 1139278800Srrs return NANOSECS_PER_SEC; // nanosecond resolution 1140278800Srrs} 114144510Swollman 1142220456Sattiliobool os::supports_vtime() { return true; } 1143220456Sattiliobool os::enable_vtime() { return false; } 1144220456Sattiliobool os::vtime_enabled() { return false; } 1145220456Sattilio 1146220456Sattiliodouble os::elapsedVTime() { 1147220456Sattilio struct rusage usage; 1148220456Sattilio int retval = getrusage(RUSAGE_THREAD, &usage); 1149278800Srrs if (retval == 0) { 1150220456Sattilio return (double) (usage.ru_utime.tv_sec + usage.ru_stime.tv_sec) + (double) (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000 * 1000); 1151220456Sattilio } else { 1152220456Sattilio // better than nothing, but not much 1153220456Sattilio return elapsedTime(); 1154220456Sattilio } 1155220456Sattilio} 1156220456Sattilio 1157220456Sattiliojlong os::javaTimeMillis() { 1158220456Sattilio timeval time; 1159155957Sjhb int status = gettimeofday(&time, NULL); 1160155957Sjhb assert(status != -1, "linux error"); 1161155957Sjhb return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 116244510Swollman} 116344510Swollman 116450673Sjlemonvoid os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) { 1165155957Sjhb timeval time; 1166155957Sjhb int status = gettimeofday(&time, NULL); 1167155957Sjhb assert(status != -1, "linux error"); 1168155957Sjhb seconds = jlong(time.tv_sec); 1169155957Sjhb nanos = jlong(time.tv_usec) * 1000; 1170278800Srrs} 1171163246Sglebius 1172163246Sglebius 1173177859Sjeff#ifndef CLOCK_MONOTONIC 1174172025Sjhb #define CLOCK_MONOTONIC (1) 1175278800Srrs#endif 1176141428Siedowse 1177141428Siedowsevoid os::Linux::clock_init() { 1178155957Sjhb // we do dlopen's in this particular order due to bug in linux 1179141428Siedowse // dynamical loader (see 6348968) leading to crash on exit 1180127969Scperciva void* handle = dlopen("librt.so.1", RTLD_LAZY); 1181155957Sjhb if (handle == NULL) { 1182155957Sjhb handle = dlopen("librt.so", RTLD_LAZY); 1183155957Sjhb } 1184155957Sjhb 1185127969Scperciva if (handle) { 1186278800Srrs int (*clock_getres_func)(clockid_t, struct timespec*) = 1187171053Sattilio (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres"); 1188171053Sattilio int (*clock_gettime_func)(clockid_t, struct timespec*) = 1189171053Sattilio (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime"); 1190177859Sjeff if (clock_getres_func && clock_gettime_func) { 1191171053Sattilio // See if monotonic clock is supported by the kernel. Note that some 1192171053Sattilio // early implementations simply return kernel jiffies (updated every 1193172025Sjhb // 1/100 or 1/1000 second). It would be bad to use such a low res clock 1194172025Sjhb // for nano time (though the monotonic property is still nice to have). 1195172025Sjhb // It's fixed in newer kernels, however clock_getres() still returns 1196172025Sjhb // 1/HZ. We check if clock_getres() works, but will ignore its reported 1197177859Sjeff // resolution for now. Hopefully as people move to new kernels, this 1198172025Sjhb // won't be a problem. 1199172025Sjhb struct timespec res; 1200172025Sjhb struct timespec tp; 1201172025Sjhb if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 && 1202172025Sjhb clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) { 1203171053Sattilio // yes, monotonic clock is supported 1204172025Sjhb _clock_gettime = clock_gettime_func; 1205177859Sjeff return; 1206247777Sdavide } else { 1207278800Srrs // close librt if there is no monotonic clock 1208172025Sjhb dlclose(handle); 1209220456Sattilio } 1210172025Sjhb } 1211172025Sjhb } 1212220456Sattilio warning("No monotonic clock was available - timed services may " \ 1213220456Sattilio "be adversely affected if the time-of-day clock changes"); 1214220456Sattilio} 1215220456Sattilio 1216220456Sattilio#ifndef SYS_clock_getres 1217220456Sattilio #if defined(IA32) || defined(AMD64) 1218220456Sattilio #define SYS_clock_getres IA32_ONLY(266) AMD64_ONLY(229) 1219278800Srrs #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) 1220171053Sattilio #else 1221177859Sjeff #warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time" 1222247777Sdavide #define sys_clock_getres(x,y) -1 1223278800Srrs #endif 1224177859Sjeff#else 1225171053Sattilio #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) 1226247777Sdavide#endif 1227278800Srrs 1228247777Sdavidevoid os::Linux::fast_thread_clock_init() { 1229172025Sjhb if (!UseLinuxPosixThreadCPUClocks) { 1230220456Sattilio return; 1231171053Sattilio } 1232171053Sattilio clockid_t clockid; 1233171053Sattilio struct timespec tp; 1234177859Sjeff int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) = 1235155957Sjhb (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid"); 1236247777Sdavide 1237278800Srrs // Switch to using fast clocks for thread cpu time if 1238278800Srrs // the sys_clock_getres() returns 0 error code. 1239155957Sjhb // Note, that some kernels may support the current thread 1240173760Sattilio // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks 1241173760Sattilio // returned by the pthread_getcpuclockid(). 1242155957Sjhb // If the fast Posix clocks are supported then the sys_clock_getres() 1243173760Sattilio // must return at least tp.tv_sec == 0 which means a resolution 1244155957Sjhb // better than 1 sec. This is extra check for reliability. 1245155957Sjhb 1246278800Srrs if (pthread_getcpuclockid_func && 1247163246Sglebius pthread_getcpuclockid_func(_main_thread, &clockid) == 0 && 1248163246Sglebius sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) { 1249247777Sdavide _supports_fast_thread_cpu_time = true; 1250220456Sattilio _pthread_getcpuclockid = pthread_getcpuclockid_func; 1251177859Sjeff } 1252172025Sjhb} 1253141428Siedowse 1254278800Srrsjlong os::javaTimeNanos() { 1255278800Srrs if (os::supports_monotonic_clock()) { 1256278800Srrs struct timespec tp; 1257278800Srrs int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp); 1258278800Srrs assert(status == 0, "gettime error"); 1259278800Srrs jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1260278800Srrs return result; 1261278800Srrs } else { 1262278800Srrs timeval time; 1263234952Skib int status = gettimeofday(&time, NULL); 1264278800Srrs assert(status != -1, "linux error"); 1265278800Srrs jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1266278800Srrs return 1000 * usecs; 1267278800Srrs } 1268278800Srrs} 1269278800Srrs 1270278800Srrsvoid os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1271278800Srrs if (os::supports_monotonic_clock()) { 1272278800Srrs info_ptr->max_value = ALL_64_BITS; 1273278800Srrs 1274278800Srrs // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1275278800Srrs info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1276278800Srrs info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1277278800Srrs } else { 1278234952Skib // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1279234952Skib info_ptr->max_value = ALL_64_BITS; 1280234952Skib 1281278800Srrs // gettimeofday is a real time clock so it skips 1282155957Sjhb info_ptr->may_skip_backward = true; 1283163246Sglebius info_ptr->may_skip_forward = true; 1284163246Sglebius } 1285177859Sjeff 1286172025Sjhb info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 128781481Sjhb} 128844510Swollman 1289172025Sjhb// Return the real, user, and system times in seconds from an 1290278800Srrs// arbitrary fixed point in the past. 1291172025Sjhbbool os::getTimesSecs(double* process_real_time, 129250673Sjlemon double* process_user_time, 129344510Swollman double* process_system_time) { 1294234981Skib struct tms ticks; 1295234981Skib clock_t real_ticks = times(&ticks); 1296278800Srrs 1297278800Srrs if (real_ticks == (clock_t) (-1)) { 1298278800Srrs return false; 1299278800Srrs } else { 1300278800Srrs double ticks_per_second = (double) clock_tics_per_sec; 1301278800Srrs *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1302278800Srrs *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1303278800Srrs *process_real_time = ((double) real_ticks) / ticks_per_second; 1304234981Skib 1305177859Sjeff return true; 130681481Sjhb } 130744510Swollman} 130844510Swollman 130944510Swollman 131069147Sjlemonchar * os::local_time_string(char *buf, size_t buflen) { 131144510Swollman struct tm t; 131269147Sjlemon time_t long_time; 131344510Swollman time(&long_time); 131444527Swollman localtime_r(&long_time, &t); 1315141428Siedowse jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1316173760Sattilio t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1317141428Siedowse t.tm_hour, t.tm_min, t.tm_sec); 1318141428Siedowse return buf; 1319173760Sattilio} 1320141428Siedowse 1321141428Siedowsestruct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1322177859Sjeff return localtime_r(clock, res); 132344510Swollman} 132444510Swollman 1325141428Siedowse//////////////////////////////////////////////////////////////////////////////// 1326173760Sattilio// runtime exit support 1327141428Siedowse 1328173760Sattilio// Note: os::shutdown() might be called very early during initialization, or 1329141428Siedowse// called from signal handler. Before adding something to os::shutdown(), make 1330141428Siedowse// sure it is async-safe and can handle partially initialized VM. 1331141428Siedowsevoid os::shutdown() { 1332173760Sattilio 1333173760Sattilio // allow PerfMemory to attempt cleanup of any persistent resources 1334173760Sattilio perfMemory_exit(); 1335173760Sattilio 1336173760Sattilio // needs to remove object in file system 1337176013Sattilio AttachListener::abort(); 1338176013Sattilio 1339173760Sattilio // flush buffered output, finish log files 1340173760Sattilio ostream_abort(); 1341177859Sjeff 1342141428Siedowse // Check for abort hook 1343141428Siedowse abort_hook_t abort_hook = Arguments::abort_hook(); 134431950Snate if (abort_hook != NULL) { 134531950Snate abort_hook(); 134631950Snate } 134731950Snate 134831950Snate} 134931950Snate 135031950Snate// Note: os::abort() might be called very early during initialization, or 135131950Snate// called from signal handler. Before adding something to os::abort(), make 135231950Snate// sure it is async-safe and can handle partially initialized VM. 135331950Snatevoid os::abort(bool dump_core, void* siginfo, const void* context) { 135431950Snate os::shutdown(); 135531950Snate if (dump_core) { 135631950Snate#ifndef PRODUCT 135731950Snate fdStream out(defaultStream::output_fd()); 135831950Snate out.print_raw("Current thread is "); 135931950Snate char buf[16]; 136031950Snate jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 136131950Snate out.print_raw_cr(buf); 136231950Snate out.print_raw_cr("Dumping core ..."); 136331950Snate#endif 136431950Snate ::abort(); // dump core 136531950Snate } 136631950Snate 136731950Snate ::exit(1); 136831950Snate} 136936127Sbde 137031950Snate// Die immediately, no exit hook, no abort hook, no cleanup. 137131950Snatevoid os::die() { 137231950Snate ::abort(); 137331950Snate} 137431950Snate 137531950Snate 137631950Snate// This method is a copy of JDK's sysGetLastErrorString 137731950Snate// from src/solaris/hpi/src/system_md.c 137831950Snate 137931950Snatesize_t os::lasterror(char *buf, size_t len) { 138031950Snate if (errno == 0) return 0; 138131950Snate 138231950Snate const char *s = ::strerror(errno); 138331950Snate size_t n = ::strlen(s); 138431950Snate if (n >= len) { 138531950Snate n = len - 1; 138631950Snate } 138731950Snate ::strncpy(buf, s, n); 138831950Snate buf[n] = '\0'; 138931950Snate return n; 139031950Snate} 139131950Snate 139231950Snate// thread_id is kernel thread id (similar to Solaris LWP id) 1393177859Sjeffintx os::current_thread_id() { return os::Linux::gettid(); } 139431950Snateint os::current_process_id() { 139531950Snate return ::getpid(); 139631950Snate} 139731950Snate 139831950Snate// DLL functions 139931950Snate 140031950Snateconst char* os::dll_file_extension() { return ".so"; } 140131950Snate 140231950Snate// This must be hard coded because it's the system's temporary 140331950Snate// directory not the java application's temp directory, ala java.io.tmpdir. 1404177859Sjeffconst char* os::get_temp_directory() { return "/tmp"; } 140531950Snate 140631950Snatestatic bool file_exists(const char* filename) { 140731950Snate struct stat statbuf; 140831950Snate if (filename == NULL || strlen(filename) == 0) { 1409247777Sdavide return false; 1410247777Sdavide } 1411247777Sdavide return os::stat(filename, &statbuf) == 0; 1412247777Sdavide} 1413247777Sdavide 1414247777Sdavidebool os::dll_build_name(char* buffer, size_t buflen, 1415247777Sdavide const char* pname, const char* fname) { 1416247777Sdavide bool retval = false; 1417247777Sdavide // Copied from libhpi 1418247777Sdavide const size_t pnamelen = pname ? strlen(pname) : 0; 1419247777Sdavide 1420247777Sdavide // Return error on buffer overflow. 1421247777Sdavide if (pnamelen + strlen(fname) + 10 > (size_t) buflen) { 1422247777Sdavide return retval; 1423247777Sdavide } 1424247777Sdavide 1425247777Sdavide if (pnamelen == 0) { 1426247777Sdavide snprintf(buffer, buflen, "lib%s.so", fname); 1427247777Sdavide retval = true; 1428247777Sdavide } else if (strchr(pname, *os::path_separator()) != NULL) { 1429247777Sdavide int n; 1430247777Sdavide char** pelements = split_path(pname, &n); 1431247777Sdavide if (pelements == NULL) { 1432247777Sdavide return false; 1433247777Sdavide } 1434247777Sdavide for (int i = 0; i < n; i++) { 1435247777Sdavide // Really shouldn't be NULL, but check can't hurt 1436247777Sdavide if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1437247777Sdavide continue; // skip the empty path values 1438247777Sdavide } 1439247777Sdavide snprintf(buffer, buflen, "%s/lib%s.so", pelements[i], fname); 1440247777Sdavide if (file_exists(buffer)) { 1441247777Sdavide retval = true; 1442247777Sdavide break; 1443247777Sdavide } 1444247777Sdavide } 1445247777Sdavide // release the storage 1446247777Sdavide for (int i = 0; i < n; i++) { 1447247777Sdavide if (pelements[i] != NULL) { 1448247777Sdavide FREE_C_HEAP_ARRAY(char, pelements[i]); 1449247777Sdavide } 1450247777Sdavide } 1451247777Sdavide if (pelements != NULL) { 1452247777Sdavide FREE_C_HEAP_ARRAY(char*, pelements); 1453247777Sdavide } 1454247777Sdavide } else { 1455247777Sdavide snprintf(buffer, buflen, "%s/lib%s.so", pname, fname); 1456247777Sdavide retval = true; 1457247777Sdavide } 1458247777Sdavide return retval; 1459247777Sdavide} 1460247777Sdavide 1461247777Sdavide// check if addr is inside libjvm.so 1462247777Sdavidebool os::address_is_in_vm(address addr) { 1463247777Sdavide static address libjvm_base_addr; 1464247777Sdavide Dl_info dlinfo; 1465247777Sdavide 1466247777Sdavide if (libjvm_base_addr == NULL) { 1467247777Sdavide if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1468247777Sdavide libjvm_base_addr = (address)dlinfo.dli_fbase; 1469247777Sdavide } 1470247777Sdavide assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1471247777Sdavide } 1472247777Sdavide 1473247777Sdavide if (dladdr((void *)addr, &dlinfo) != 0) { 1474247777Sdavide if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1475247777Sdavide } 1476247777Sdavide 1477247777Sdavide return false; 1478247777Sdavide} 1479247777Sdavide 1480247777Sdavidebool os::dll_address_to_function_name(address addr, char *buf, 1481247777Sdavide int buflen, int *offset, 1482247777Sdavide bool demangle) { 1483247777Sdavide // buf is not optional, but offset is optional 1484247777Sdavide assert(buf != NULL, "sanity check"); 1485247777Sdavide 1486247777Sdavide Dl_info dlinfo; 1487247777Sdavide 1488247777Sdavide if (dladdr((void*)addr, &dlinfo) != 0) { 1489247777Sdavide // see if we have a matching symbol 1490247777Sdavide if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1491247777Sdavide if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) { 1492247777Sdavide jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1493247777Sdavide } 1494247777Sdavide if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1495247777Sdavide return true; 1496247777Sdavide } 1497247777Sdavide // no matching symbol so try for just file info 1498247777Sdavide if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1499247777Sdavide if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1500247777Sdavide buf, buflen, offset, dlinfo.dli_fname, demangle)) { 1501247777Sdavide return true; 1502247777Sdavide } 1503247777Sdavide } 1504247777Sdavide } 1505247777Sdavide 1506247777Sdavide buf[0] = '\0'; 1507247777Sdavide if (offset != NULL) *offset = -1; 1508247777Sdavide return false; 1509247777Sdavide} 1510247777Sdavide 1511247777Sdavidestruct _address_to_library_name { 1512247777Sdavide address addr; // input : memory address 1513247777Sdavide size_t buflen; // size of fname 1514247777Sdavide char* fname; // output: library name 1515247777Sdavide address base; // library base addr 1516247777Sdavide}; 1517247777Sdavide 1518247777Sdavidestatic int address_to_library_name_callback(struct dl_phdr_info *info, 1519247777Sdavide size_t size, void *data) { 1520247777Sdavide int i; 1521247777Sdavide bool found = false; 1522247777Sdavide address libbase = NULL; 1523247777Sdavide struct _address_to_library_name * d = (struct _address_to_library_name *)data; 1524247777Sdavide 1525247777Sdavide // iterate through all loadable segments 1526247777Sdavide for (i = 0; i < info->dlpi_phnum; i++) { 1527 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); 1528 if (info->dlpi_phdr[i].p_type == PT_LOAD) { 1529 // base address of a library is the lowest address of its loaded 1530 // segments. 1531 if (libbase == NULL || libbase > segbase) { 1532 libbase = segbase; 1533 } 1534 // see if 'addr' is within current segment 1535 if (segbase <= d->addr && 1536 d->addr < segbase + info->dlpi_phdr[i].p_memsz) { 1537 found = true; 1538 } 1539 } 1540 } 1541 1542 // dlpi_name is NULL or empty if the ELF file is executable, return 0 1543 // so dll_address_to_library_name() can fall through to use dladdr() which 1544 // can figure out executable name from argv[0]. 1545 if (found && info->dlpi_name && info->dlpi_name[0]) { 1546 d->base = libbase; 1547 if (d->fname) { 1548 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name); 1549 } 1550 return 1; 1551 } 1552 return 0; 1553} 1554 1555bool os::dll_address_to_library_name(address addr, char* buf, 1556 int buflen, int* offset) { 1557 // buf is not optional, but offset is optional 1558 assert(buf != NULL, "sanity check"); 1559 1560 Dl_info dlinfo; 1561 struct _address_to_library_name data; 1562 1563 // There is a bug in old glibc dladdr() implementation that it could resolve 1564 // to wrong library name if the .so file has a base address != NULL. Here 1565 // we iterate through the program headers of all loaded libraries to find 1566 // out which library 'addr' really belongs to. This workaround can be 1567 // removed once the minimum requirement for glibc is moved to 2.3.x. 1568 data.addr = addr; 1569 data.fname = buf; 1570 data.buflen = buflen; 1571 data.base = NULL; 1572 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data); 1573 1574 if (rslt) { 1575 // buf already contains library name 1576 if (offset) *offset = addr - data.base; 1577 return true; 1578 } 1579 if (dladdr((void*)addr, &dlinfo) != 0) { 1580 if (dlinfo.dli_fname != NULL) { 1581 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1582 } 1583 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1584 *offset = addr - (address)dlinfo.dli_fbase; 1585 } 1586 return true; 1587 } 1588 1589 buf[0] = '\0'; 1590 if (offset) *offset = -1; 1591 return false; 1592} 1593 1594// Loads .dll/.so and 1595// in case of error it checks if .dll/.so was built for the 1596// same architecture as Hotspot is running on 1597 1598 1599// Remember the stack's state. The Linux dynamic linker will change 1600// the stack to 'executable' at most once, so we must safepoint only once. 1601bool os::Linux::_stack_is_executable = false; 1602 1603// VM operation that loads a library. This is necessary if stack protection 1604// of the Java stacks can be lost during loading the library. If we 1605// do not stop the Java threads, they can stack overflow before the stacks 1606// are protected again. 1607class VM_LinuxDllLoad: public VM_Operation { 1608 private: 1609 const char *_filename; 1610 char *_ebuf; 1611 int _ebuflen; 1612 void *_lib; 1613 public: 1614 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) : 1615 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {} 1616 VMOp_Type type() const { return VMOp_LinuxDllLoad; } 1617 void doit() { 1618 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen); 1619 os::Linux::_stack_is_executable = true; 1620 } 1621 void* loaded_library() { return _lib; } 1622}; 1623 1624void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1625 void * result = NULL; 1626 bool load_attempted = false; 1627 1628 // Check whether the library to load might change execution rights 1629 // of the stack. If they are changed, the protection of the stack 1630 // guard pages will be lost. We need a safepoint to fix this. 1631 // 1632 // See Linux man page execstack(8) for more info. 1633 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) { 1634 ElfFile ef(filename); 1635 if (!ef.specifies_noexecstack()) { 1636 if (!is_init_completed()) { 1637 os::Linux::_stack_is_executable = true; 1638 // This is OK - No Java threads have been created yet, and hence no 1639 // stack guard pages to fix. 1640 // 1641 // This should happen only when you are building JDK7 using a very 1642 // old version of JDK6 (e.g., with JPRT) and running test_gamma. 1643 // 1644 // Dynamic loader will make all stacks executable after 1645 // this function returns, and will not do that again. 1646 assert(Threads::first() == NULL, "no Java threads should exist yet."); 1647 } else { 1648 warning("You have loaded library %s which might have disabled stack guard. " 1649 "The VM will try to fix the stack guard now.\n" 1650 "It's highly recommended that you fix the library with " 1651 "'execstack -c <libfile>', or link it with '-z noexecstack'.", 1652 filename); 1653 1654 assert(Thread::current()->is_Java_thread(), "must be Java thread"); 1655 JavaThread *jt = JavaThread::current(); 1656 if (jt->thread_state() != _thread_in_native) { 1657 // This happens when a compiler thread tries to load a hsdis-<arch>.so file 1658 // that requires ExecStack. Cannot enter safe point. Let's give up. 1659 warning("Unable to fix stack guard. Giving up."); 1660 } else { 1661 if (!LoadExecStackDllInVMThread) { 1662 // This is for the case where the DLL has an static 1663 // constructor function that executes JNI code. We cannot 1664 // load such DLLs in the VMThread. 1665 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1666 } 1667 1668 ThreadInVMfromNative tiv(jt); 1669 debug_only(VMNativeEntryWrapper vew;) 1670 1671 VM_LinuxDllLoad op(filename, ebuf, ebuflen); 1672 VMThread::execute(&op); 1673 if (LoadExecStackDllInVMThread) { 1674 result = op.loaded_library(); 1675 } 1676 load_attempted = true; 1677 } 1678 } 1679 } 1680 } 1681 1682 if (!load_attempted) { 1683 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1684 } 1685 1686 if (result != NULL) { 1687 // Successful loading 1688 return result; 1689 } 1690 1691 Elf32_Ehdr elf_head; 1692 int diag_msg_max_length=ebuflen-strlen(ebuf); 1693 char* diag_msg_buf=ebuf+strlen(ebuf); 1694 1695 if (diag_msg_max_length==0) { 1696 // No more space in ebuf for additional diagnostics message 1697 return NULL; 1698 } 1699 1700 1701 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1702 1703 if (file_descriptor < 0) { 1704 // Can't open library, report dlerror() message 1705 return NULL; 1706 } 1707 1708 bool failed_to_read_elf_head= 1709 (sizeof(elf_head)!= 1710 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1711 1712 ::close(file_descriptor); 1713 if (failed_to_read_elf_head) { 1714 // file i/o error - report dlerror() msg 1715 return NULL; 1716 } 1717 1718 typedef struct { 1719 Elf32_Half code; // Actual value as defined in elf.h 1720 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1721 char elf_class; // 32 or 64 bit 1722 char endianess; // MSB or LSB 1723 char* name; // String representation 1724 } arch_t; 1725 1726#ifndef EM_486 1727 #define EM_486 6 /* Intel 80486 */ 1728#endif 1729#ifndef EM_AARCH64 1730 #define EM_AARCH64 183 /* ARM AARCH64 */ 1731#endif 1732 1733 static const arch_t arch_array[]={ 1734 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1735 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1736 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1737 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1738 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1739 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1740 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1741 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1742#if defined(VM_LITTLE_ENDIAN) 1743 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64"}, 1744#else 1745 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64 LE"}, 1746#endif 1747 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1748 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1749 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1750 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1751 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1752 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1753 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}, 1754 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"}, 1755 }; 1756 1757#if (defined IA32) 1758 static Elf32_Half running_arch_code=EM_386; 1759#elif (defined AMD64) 1760 static Elf32_Half running_arch_code=EM_X86_64; 1761#elif (defined IA64) 1762 static Elf32_Half running_arch_code=EM_IA_64; 1763#elif (defined __sparc) && (defined _LP64) 1764 static Elf32_Half running_arch_code=EM_SPARCV9; 1765#elif (defined __sparc) && (!defined _LP64) 1766 static Elf32_Half running_arch_code=EM_SPARC; 1767#elif (defined __powerpc64__) 1768 static Elf32_Half running_arch_code=EM_PPC64; 1769#elif (defined __powerpc__) 1770 static Elf32_Half running_arch_code=EM_PPC; 1771#elif (defined ARM) 1772 static Elf32_Half running_arch_code=EM_ARM; 1773#elif (defined S390) 1774 static Elf32_Half running_arch_code=EM_S390; 1775#elif (defined ALPHA) 1776 static Elf32_Half running_arch_code=EM_ALPHA; 1777#elif (defined MIPSEL) 1778 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1779#elif (defined PARISC) 1780 static Elf32_Half running_arch_code=EM_PARISC; 1781#elif (defined MIPS) 1782 static Elf32_Half running_arch_code=EM_MIPS; 1783#elif (defined M68K) 1784 static Elf32_Half running_arch_code=EM_68K; 1785#elif (defined AARCH64) 1786 static Elf32_Half running_arch_code=EM_AARCH64; 1787#else 1788 #error Method os::dll_load requires that one of following is defined:\ 1789 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K, AARCH64 1790#endif 1791 1792 // Identify compatability class for VM's architecture and library's architecture 1793 // Obtain string descriptions for architectures 1794 1795 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1796 int running_arch_index=-1; 1797 1798 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1799 if (running_arch_code == arch_array[i].code) { 1800 running_arch_index = i; 1801 } 1802 if (lib_arch.code == arch_array[i].code) { 1803 lib_arch.compat_class = arch_array[i].compat_class; 1804 lib_arch.name = arch_array[i].name; 1805 } 1806 } 1807 1808 assert(running_arch_index != -1, 1809 "Didn't find running architecture code (running_arch_code) in arch_array"); 1810 if (running_arch_index == -1) { 1811 // Even though running architecture detection failed 1812 // we may still continue with reporting dlerror() message 1813 return NULL; 1814 } 1815 1816 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1817 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1818 return NULL; 1819 } 1820 1821#ifndef S390 1822 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1823 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1824 return NULL; 1825 } 1826#endif // !S390 1827 1828 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1829 if (lib_arch.name!=NULL) { 1830 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1831 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1832 lib_arch.name, arch_array[running_arch_index].name); 1833 } else { 1834 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1835 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1836 lib_arch.code, 1837 arch_array[running_arch_index].name); 1838 } 1839 } 1840 1841 return NULL; 1842} 1843 1844void * os::Linux::dlopen_helper(const char *filename, char *ebuf, 1845 int ebuflen) { 1846 void * result = ::dlopen(filename, RTLD_LAZY); 1847 if (result == NULL) { 1848 ::strncpy(ebuf, ::dlerror(), ebuflen - 1); 1849 ebuf[ebuflen-1] = '\0'; 1850 } 1851 return result; 1852} 1853 1854void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf, 1855 int ebuflen) { 1856 void * result = NULL; 1857 if (LoadExecStackDllInVMThread) { 1858 result = dlopen_helper(filename, ebuf, ebuflen); 1859 } 1860 1861 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a 1862 // library that requires an executable stack, or which does not have this 1863 // stack attribute set, dlopen changes the stack attribute to executable. The 1864 // read protection of the guard pages gets lost. 1865 // 1866 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad 1867 // may have been queued at the same time. 1868 1869 if (!_stack_is_executable) { 1870 JavaThread *jt = Threads::first(); 1871 1872 while (jt) { 1873 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized 1874 jt->stack_guards_enabled()) { // No pending stack overflow exceptions 1875 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) { 1876 warning("Attempt to reguard stack yellow zone failed."); 1877 } 1878 } 1879 jt = jt->next(); 1880 } 1881 } 1882 1883 return result; 1884} 1885 1886void* os::dll_lookup(void* handle, const char* name) { 1887 void* res = dlsym(handle, name); 1888 return res; 1889} 1890 1891void* os::get_default_process_handle() { 1892 return (void*)::dlopen(NULL, RTLD_LAZY); 1893} 1894 1895static bool _print_ascii_file(const char* filename, outputStream* st) { 1896 int fd = ::open(filename, O_RDONLY); 1897 if (fd == -1) { 1898 return false; 1899 } 1900 1901 char buf[32]; 1902 int bytes; 1903 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { 1904 st->print_raw(buf, bytes); 1905 } 1906 1907 ::close(fd); 1908 1909 return true; 1910} 1911 1912void os::print_dll_info(outputStream *st) { 1913 st->print_cr("Dynamic libraries:"); 1914 1915 char fname[32]; 1916 pid_t pid = os::Linux::gettid(); 1917 1918 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid); 1919 1920 if (!_print_ascii_file(fname, st)) { 1921 st->print("Can not get library information for pid = %d\n", pid); 1922 } 1923} 1924 1925int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1926 FILE *procmapsFile = NULL; 1927 1928 // Open the procfs maps file for the current process 1929 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) { 1930 // Allocate PATH_MAX for file name plus a reasonable size for other fields. 1931 char line[PATH_MAX + 100]; 1932 1933 // Read line by line from 'file' 1934 while (fgets(line, sizeof(line), procmapsFile) != NULL) { 1935 u8 base, top, offset, inode; 1936 char permissions[5]; 1937 char device[6]; 1938 char name[PATH_MAX + 1]; 1939 1940 // Parse fields from line 1941 sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s", 1942 &base, &top, permissions, &offset, device, &inode, name); 1943 1944 // Filter by device id '00:00' so that we only get file system mapped files. 1945 if (strcmp(device, "00:00") != 0) { 1946 1947 // Call callback with the fields of interest 1948 if(callback(name, (address)base, (address)top, param)) { 1949 // Oops abort, callback aborted 1950 fclose(procmapsFile); 1951 return 1; 1952 } 1953 } 1954 } 1955 fclose(procmapsFile); 1956 } 1957 return 0; 1958} 1959 1960void os::print_os_info_brief(outputStream* st) { 1961 os::Linux::print_distro_info(st); 1962 1963 os::Posix::print_uname_info(st); 1964 1965 os::Linux::print_libversion_info(st); 1966 1967} 1968 1969void os::print_os_info(outputStream* st) { 1970 st->print("OS:"); 1971 1972 os::Linux::print_distro_info(st); 1973 1974 os::Posix::print_uname_info(st); 1975 1976 // Print warning if unsafe chroot environment detected 1977 if (unsafe_chroot_detected) { 1978 st->print("WARNING!! "); 1979 st->print_cr("%s", unstable_chroot_error); 1980 } 1981 1982 os::Linux::print_libversion_info(st); 1983 1984 os::Posix::print_rlimit_info(st); 1985 1986 os::Posix::print_load_average(st); 1987 1988 os::Linux::print_full_memory_info(st); 1989} 1990 1991// Try to identify popular distros. 1992// Most Linux distributions have a /etc/XXX-release file, which contains 1993// the OS version string. Newer Linux distributions have a /etc/lsb-release 1994// file that also contains the OS version string. Some have more than one 1995// /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and 1996// /etc/redhat-release.), so the order is important. 1997// Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have 1998// their own specific XXX-release file as well as a redhat-release file. 1999// Because of this the XXX-release file needs to be searched for before the 2000// redhat-release file. 2001// Since Red Hat has a lsb-release file that is not very descriptive the 2002// search for redhat-release needs to be before lsb-release. 2003// Since the lsb-release file is the new standard it needs to be searched 2004// before the older style release files. 2005// Searching system-release (Red Hat) and os-release (other Linuxes) are a 2006// next to last resort. The os-release file is a new standard that contains 2007// distribution information and the system-release file seems to be an old 2008// standard that has been replaced by the lsb-release and os-release files. 2009// Searching for the debian_version file is the last resort. It contains 2010// an informative string like "6.0.6" or "wheezy/sid". Because of this 2011// "Debian " is printed before the contents of the debian_version file. 2012 2013const char* distro_files[] = { 2014 "/etc/oracle-release", 2015 "/etc/mandriva-release", 2016 "/etc/mandrake-release", 2017 "/etc/sun-release", 2018 "/etc/redhat-release", 2019 "/etc/lsb-release", 2020 "/etc/SuSE-release", 2021 "/etc/turbolinux-release", 2022 "/etc/gentoo-release", 2023 "/etc/ltib-release", 2024 "/etc/angstrom-version", 2025 "/etc/system-release", 2026 "/etc/os-release", 2027 NULL }; 2028 2029void os::Linux::print_distro_info(outputStream* st) { 2030 for (int i = 0;; i++) { 2031 const char* file = distro_files[i]; 2032 if (file == NULL) { 2033 break; // done 2034 } 2035 // If file prints, we found it. 2036 if (_print_ascii_file(file, st)) { 2037 return; 2038 } 2039 } 2040 2041 if (file_exists("/etc/debian_version")) { 2042 st->print("Debian "); 2043 _print_ascii_file("/etc/debian_version", st); 2044 } else { 2045 st->print("Linux"); 2046 } 2047 st->cr(); 2048} 2049 2050static void parse_os_info(char* distro, size_t length, const char* file) { 2051 FILE* fp = fopen(file, "r"); 2052 if (fp != NULL) { 2053 char buf[256]; 2054 // get last line of the file. 2055 while (fgets(buf, sizeof(buf), fp)) { } 2056 // Edit out extra stuff in expected ubuntu format 2057 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL) { 2058 char* ptr = strstr(buf, "\""); // the name is in quotes 2059 if (ptr != NULL) { 2060 ptr++; // go beyond first quote 2061 char* nl = strchr(ptr, '\"'); 2062 if (nl != NULL) *nl = '\0'; 2063 strncpy(distro, ptr, length); 2064 } else { 2065 ptr = strstr(buf, "="); 2066 ptr++; // go beyond equals then 2067 char* nl = strchr(ptr, '\n'); 2068 if (nl != NULL) *nl = '\0'; 2069 strncpy(distro, ptr, length); 2070 } 2071 } else { 2072 // if not in expected Ubuntu format, print out whole line minus \n 2073 char* nl = strchr(buf, '\n'); 2074 if (nl != NULL) *nl = '\0'; 2075 strncpy(distro, buf, length); 2076 } 2077 // close distro file 2078 fclose(fp); 2079 } 2080} 2081 2082void os::get_summary_os_info(char* buf, size_t buflen) { 2083 for (int i = 0;; i++) { 2084 const char* file = distro_files[i]; 2085 if (file == NULL) { 2086 break; // ran out of distro_files 2087 } 2088 if (file_exists(file)) { 2089 parse_os_info(buf, buflen, file); 2090 return; 2091 } 2092 } 2093 // special case for debian 2094 if (file_exists("/etc/debian_version")) { 2095 strncpy(buf, "Debian ", buflen); 2096 parse_os_info(&buf[7], buflen-7, "/etc/debian_version"); 2097 } else { 2098 strncpy(buf, "Linux", buflen); 2099 } 2100} 2101 2102void os::Linux::print_libversion_info(outputStream* st) { 2103 // libc, pthread 2104 st->print("libc:"); 2105 st->print("%s ", os::Linux::glibc_version()); 2106 st->print("%s ", os::Linux::libpthread_version()); 2107 st->cr(); 2108} 2109 2110void os::Linux::print_full_memory_info(outputStream* st) { 2111 st->print("\n/proc/meminfo:\n"); 2112 _print_ascii_file("/proc/meminfo", st); 2113 st->cr(); 2114} 2115 2116void os::print_memory_info(outputStream* st) { 2117 2118 st->print("Memory:"); 2119 st->print(" %dk page", os::vm_page_size()>>10); 2120 2121 // values in struct sysinfo are "unsigned long" 2122 struct sysinfo si; 2123 sysinfo(&si); 2124 2125 st->print(", physical " UINT64_FORMAT "k", 2126 os::physical_memory() >> 10); 2127 st->print("(" UINT64_FORMAT "k free)", 2128 os::available_memory() >> 10); 2129 st->print(", swap " UINT64_FORMAT "k", 2130 ((jlong)si.totalswap * si.mem_unit) >> 10); 2131 st->print("(" UINT64_FORMAT "k free)", 2132 ((jlong)si.freeswap * si.mem_unit) >> 10); 2133 st->cr(); 2134} 2135 2136// Print the first "model name" line and the first "flags" line 2137// that we find and nothing more. We assume "model name" comes 2138// before "flags" so if we find a second "model name", then the 2139// "flags" field is considered missing. 2140static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) { 2141#if defined(IA32) || defined(AMD64) 2142 // Other platforms have less repetitive cpuinfo files 2143 FILE *fp = fopen("/proc/cpuinfo", "r"); 2144 if (fp) { 2145 while (!feof(fp)) { 2146 if (fgets(buf, buflen, fp)) { 2147 // Assume model name comes before flags 2148 bool model_name_printed = false; 2149 if (strstr(buf, "model name") != NULL) { 2150 if (!model_name_printed) { 2151 st->print_raw("\nCPU Model and flags from /proc/cpuinfo:\n"); 2152 st->print_raw(buf); 2153 model_name_printed = true; 2154 } else { 2155 // model name printed but not flags? Odd, just return 2156 fclose(fp); 2157 return true; 2158 } 2159 } 2160 // print the flags line too 2161 if (strstr(buf, "flags") != NULL) { 2162 st->print_raw(buf); 2163 fclose(fp); 2164 return true; 2165 } 2166 } 2167 } 2168 fclose(fp); 2169 } 2170#endif // x86 platforms 2171 return false; 2172} 2173 2174void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) { 2175 // Only print the model name if the platform provides this as a summary 2176 if (!print_model_name_and_flags(st, buf, buflen)) { 2177 st->print("\n/proc/cpuinfo:\n"); 2178 if (!_print_ascii_file("/proc/cpuinfo", st)) { 2179 st->print_cr(" <Not Available>"); 2180 } 2181 } 2182} 2183 2184#if defined(AMD64) || defined(IA32) || defined(X32) 2185const char* search_string = "model name"; 2186#elif defined(SPARC) 2187const char* search_string = "cpu"; 2188#elif defined(PPC64) 2189const char* search_string = "cpu"; 2190#else 2191const char* search_string = "Processor"; 2192#endif 2193 2194// Parses the cpuinfo file for string representing the model name. 2195void os::get_summary_cpu_info(char* cpuinfo, size_t length) { 2196 FILE* fp = fopen("/proc/cpuinfo", "r"); 2197 if (fp != NULL) { 2198 while (!feof(fp)) { 2199 char buf[256]; 2200 if (fgets(buf, sizeof(buf), fp)) { 2201 char* start = strstr(buf, search_string); 2202 if (start != NULL) { 2203 char *ptr = start + strlen(search_string); 2204 char *end = buf + strlen(buf); 2205 while (ptr != end) { 2206 // skip whitespace and colon for the rest of the name. 2207 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') { 2208 break; 2209 } 2210 ptr++; 2211 } 2212 if (ptr != end) { 2213 // reasonable string, get rid of newline and keep the rest 2214 char* nl = strchr(buf, '\n'); 2215 if (nl != NULL) *nl = '\0'; 2216 strncpy(cpuinfo, ptr, length); 2217 fclose(fp); 2218 return; 2219 } 2220 } 2221 } 2222 } 2223 fclose(fp); 2224 } 2225 // cpuinfo not found or parsing failed, just print generic string. The entire 2226 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86) 2227#if defined(AMD64) 2228 strncpy(cpuinfo, "x86_64", length); 2229#elif defined(IA32) 2230 strncpy(cpuinfo, "x86_32", length); 2231#elif defined(IA64) 2232 strncpy(cpuinfo, "IA64", length); 2233#elif defined(SPARC) 2234 strncpy(cpuinfo, "sparcv9", length); 2235#elif defined(AARCH64) 2236 strncpy(cpuinfo, "AArch64", length); 2237#elif defined(ARM) 2238 strncpy(cpuinfo, "ARM", length); 2239#elif defined(PPC) 2240 strncpy(cpuinfo, "PPC64", length); 2241#elif defined(ZERO_LIBARCH) 2242 strncpy(cpuinfo, ZERO_LIBARCH, length); 2243#else 2244 strncpy(cpuinfo, "unknown", length); 2245#endif 2246} 2247 2248static void print_signal_handler(outputStream* st, int sig, 2249 char* buf, size_t buflen); 2250 2251void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 2252 st->print_cr("Signal Handlers:"); 2253 print_signal_handler(st, SIGSEGV, buf, buflen); 2254 print_signal_handler(st, SIGBUS , buf, buflen); 2255 print_signal_handler(st, SIGFPE , buf, buflen); 2256 print_signal_handler(st, SIGPIPE, buf, buflen); 2257 print_signal_handler(st, SIGXFSZ, buf, buflen); 2258 print_signal_handler(st, SIGILL , buf, buflen); 2259 print_signal_handler(st, SR_signum, buf, buflen); 2260 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 2261 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 2262 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 2263 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 2264#if defined(PPC64) 2265 print_signal_handler(st, SIGTRAP, buf, buflen); 2266#endif 2267} 2268 2269static char saved_jvm_path[MAXPATHLEN] = {0}; 2270 2271// Find the full path to the current module, libjvm.so 2272void os::jvm_path(char *buf, jint buflen) { 2273 // Error checking. 2274 if (buflen < MAXPATHLEN) { 2275 assert(false, "must use a large-enough buffer"); 2276 buf[0] = '\0'; 2277 return; 2278 } 2279 // Lazy resolve the path to current module. 2280 if (saved_jvm_path[0] != 0) { 2281 strcpy(buf, saved_jvm_path); 2282 return; 2283 } 2284 2285 char dli_fname[MAXPATHLEN]; 2286 bool ret = dll_address_to_library_name( 2287 CAST_FROM_FN_PTR(address, os::jvm_path), 2288 dli_fname, sizeof(dli_fname), NULL); 2289 assert(ret, "cannot locate libjvm"); 2290 char *rp = NULL; 2291 if (ret && dli_fname[0] != '\0') { 2292 rp = realpath(dli_fname, buf); 2293 } 2294 if (rp == NULL) { 2295 return; 2296 } 2297 2298 if (Arguments::sun_java_launcher_is_altjvm()) { 2299 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 2300 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so". 2301 // If "/jre/lib/" appears at the right place in the string, then 2302 // assume we are installed in a JDK and we're done. Otherwise, check 2303 // for a JAVA_HOME environment variable and fix up the path so it 2304 // looks like libjvm.so is installed there (append a fake suffix 2305 // hotspot/libjvm.so). 2306 const char *p = buf + strlen(buf) - 1; 2307 for (int count = 0; p > buf && count < 5; ++count) { 2308 for (--p; p > buf && *p != '/'; --p) 2309 /* empty */ ; 2310 } 2311 2312 if (strncmp(p, "/jre/lib/", 9) != 0) { 2313 // Look for JAVA_HOME in the environment. 2314 char* java_home_var = ::getenv("JAVA_HOME"); 2315 if (java_home_var != NULL && java_home_var[0] != 0) { 2316 char* jrelib_p; 2317 int len; 2318 2319 // Check the current module name "libjvm.so". 2320 p = strrchr(buf, '/'); 2321 if (p == NULL) { 2322 return; 2323 } 2324 assert(strstr(p, "/libjvm") == p, "invalid library name"); 2325 2326 rp = realpath(java_home_var, buf); 2327 if (rp == NULL) { 2328 return; 2329 } 2330 2331 // determine if this is a legacy image or modules image 2332 // modules image doesn't have "jre" subdirectory 2333 len = strlen(buf); 2334 assert(len < buflen, "Ran out of buffer room"); 2335 jrelib_p = buf + len; 2336 snprintf(jrelib_p, buflen-len, "/jre/lib/%s", cpu_arch); 2337 if (0 != access(buf, F_OK)) { 2338 snprintf(jrelib_p, buflen-len, "/lib/%s", cpu_arch); 2339 } 2340 2341 if (0 == access(buf, F_OK)) { 2342 // Use current module name "libjvm.so" 2343 len = strlen(buf); 2344 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so"); 2345 } else { 2346 // Go back to path of .so 2347 rp = realpath(dli_fname, buf); 2348 if (rp == NULL) { 2349 return; 2350 } 2351 } 2352 } 2353 } 2354 } 2355 2356 strncpy(saved_jvm_path, buf, MAXPATHLEN); 2357 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 2358} 2359 2360void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 2361 // no prefix required, not even "_" 2362} 2363 2364void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 2365 // no suffix required 2366} 2367 2368//////////////////////////////////////////////////////////////////////////////// 2369// sun.misc.Signal support 2370 2371static volatile jint sigint_count = 0; 2372 2373static void UserHandler(int sig, void *siginfo, void *context) { 2374 // 4511530 - sem_post is serialized and handled by the manager thread. When 2375 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 2376 // don't want to flood the manager thread with sem_post requests. 2377 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 2378 return; 2379 } 2380 2381 // Ctrl-C is pressed during error reporting, likely because the error 2382 // handler fails to abort. Let VM die immediately. 2383 if (sig == SIGINT && is_error_reported()) { 2384 os::die(); 2385 } 2386 2387 os::signal_notify(sig); 2388} 2389 2390void* os::user_handler() { 2391 return CAST_FROM_FN_PTR(void*, UserHandler); 2392} 2393 2394struct timespec PosixSemaphore::create_timespec(unsigned int sec, int nsec) { 2395 struct timespec ts; 2396 // Semaphore's are always associated with CLOCK_REALTIME 2397 os::Linux::clock_gettime(CLOCK_REALTIME, &ts); 2398 // see unpackTime for discussion on overflow checking 2399 if (sec >= MAX_SECS) { 2400 ts.tv_sec += MAX_SECS; 2401 ts.tv_nsec = 0; 2402 } else { 2403 ts.tv_sec += sec; 2404 ts.tv_nsec += nsec; 2405 if (ts.tv_nsec >= NANOSECS_PER_SEC) { 2406 ts.tv_nsec -= NANOSECS_PER_SEC; 2407 ++ts.tv_sec; // note: this must be <= max_secs 2408 } 2409 } 2410 2411 return ts; 2412} 2413 2414extern "C" { 2415 typedef void (*sa_handler_t)(int); 2416 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 2417} 2418 2419void* os::signal(int signal_number, void* handler) { 2420 struct sigaction sigAct, oldSigAct; 2421 2422 sigfillset(&(sigAct.sa_mask)); 2423 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 2424 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 2425 2426 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 2427 // -1 means registration failed 2428 return (void *)-1; 2429 } 2430 2431 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 2432} 2433 2434void os::signal_raise(int signal_number) { 2435 ::raise(signal_number); 2436} 2437 2438// The following code is moved from os.cpp for making this 2439// code platform specific, which it is by its very nature. 2440 2441// Will be modified when max signal is changed to be dynamic 2442int os::sigexitnum_pd() { 2443 return NSIG; 2444} 2445 2446// a counter for each possible signal value 2447static volatile jint pending_signals[NSIG+1] = { 0 }; 2448 2449// Linux(POSIX) specific hand shaking semaphore. 2450static sem_t sig_sem; 2451static PosixSemaphore sr_semaphore; 2452 2453void os::signal_init_pd() { 2454 // Initialize signal structures 2455 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2456 2457 // Initialize signal semaphore 2458 ::sem_init(&sig_sem, 0, 0); 2459} 2460 2461void os::signal_notify(int sig) { 2462 Atomic::inc(&pending_signals[sig]); 2463 ::sem_post(&sig_sem); 2464} 2465 2466static int check_pending_signals(bool wait) { 2467 Atomic::store(0, &sigint_count); 2468 for (;;) { 2469 for (int i = 0; i < NSIG + 1; i++) { 2470 jint n = pending_signals[i]; 2471 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2472 return i; 2473 } 2474 } 2475 if (!wait) { 2476 return -1; 2477 } 2478 JavaThread *thread = JavaThread::current(); 2479 ThreadBlockInVM tbivm(thread); 2480 2481 bool threadIsSuspended; 2482 do { 2483 thread->set_suspend_equivalent(); 2484 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2485 ::sem_wait(&sig_sem); 2486 2487 // were we externally suspended while we were waiting? 2488 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2489 if (threadIsSuspended) { 2490 // The semaphore has been incremented, but while we were waiting 2491 // another thread suspended us. We don't want to continue running 2492 // while suspended because that would surprise the thread that 2493 // suspended us. 2494 ::sem_post(&sig_sem); 2495 2496 thread->java_suspend_self(); 2497 } 2498 } while (threadIsSuspended); 2499 } 2500} 2501 2502int os::signal_lookup() { 2503 return check_pending_signals(false); 2504} 2505 2506int os::signal_wait() { 2507 return check_pending_signals(true); 2508} 2509 2510//////////////////////////////////////////////////////////////////////////////// 2511// Virtual Memory 2512 2513int os::vm_page_size() { 2514 // Seems redundant as all get out 2515 assert(os::Linux::page_size() != -1, "must call os::init"); 2516 return os::Linux::page_size(); 2517} 2518 2519// Solaris allocates memory by pages. 2520int os::vm_allocation_granularity() { 2521 assert(os::Linux::page_size() != -1, "must call os::init"); 2522 return os::Linux::page_size(); 2523} 2524 2525// Rationale behind this function: 2526// current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2527// mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2528// samples for JITted code. Here we create private executable mapping over the code cache 2529// and then we can use standard (well, almost, as mapping can change) way to provide 2530// info for the reporting script by storing timestamp and location of symbol 2531void linux_wrap_code(char* base, size_t size) { 2532 static volatile jint cnt = 0; 2533 2534 if (!UseOprofile) { 2535 return; 2536 } 2537 2538 char buf[PATH_MAX+1]; 2539 int num = Atomic::add(1, &cnt); 2540 2541 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d", 2542 os::get_temp_directory(), os::current_process_id(), num); 2543 unlink(buf); 2544 2545 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2546 2547 if (fd != -1) { 2548 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2549 if (rv != (off_t)-1) { 2550 if (::write(fd, "", 1) == 1) { 2551 mmap(base, size, 2552 PROT_READ|PROT_WRITE|PROT_EXEC, 2553 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2554 } 2555 } 2556 ::close(fd); 2557 unlink(buf); 2558 } 2559} 2560 2561static bool recoverable_mmap_error(int err) { 2562 // See if the error is one we can let the caller handle. This 2563 // list of errno values comes from JBS-6843484. I can't find a 2564 // Linux man page that documents this specific set of errno 2565 // values so while this list currently matches Solaris, it may 2566 // change as we gain experience with this failure mode. 2567 switch (err) { 2568 case EBADF: 2569 case EINVAL: 2570 case ENOTSUP: 2571 // let the caller deal with these errors 2572 return true; 2573 2574 default: 2575 // Any remaining errors on this OS can cause our reserved mapping 2576 // to be lost. That can cause confusion where different data 2577 // structures think they have the same memory mapped. The worst 2578 // scenario is if both the VM and a library think they have the 2579 // same memory mapped. 2580 return false; 2581 } 2582} 2583 2584static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2585 int err) { 2586 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2587 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec, 2588 strerror(err), err); 2589} 2590 2591static void warn_fail_commit_memory(char* addr, size_t size, 2592 size_t alignment_hint, bool exec, 2593 int err) { 2594 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2595 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, 2596 alignment_hint, exec, strerror(err), err); 2597} 2598 2599// NOTE: Linux kernel does not really reserve the pages for us. 2600// All it does is to check if there are enough free pages 2601// left at the time of mmap(). This could be a potential 2602// problem. 2603int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) { 2604 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2605 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2606 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2607 if (res != (uintptr_t) MAP_FAILED) { 2608 if (UseNUMAInterleaving) { 2609 numa_make_global(addr, size); 2610 } 2611 return 0; 2612 } 2613 2614 int err = errno; // save errno from mmap() call above 2615 2616 if (!recoverable_mmap_error(err)) { 2617 warn_fail_commit_memory(addr, size, exec, err); 2618 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory."); 2619 } 2620 2621 return err; 2622} 2623 2624bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2625 return os::Linux::commit_memory_impl(addr, size, exec) == 0; 2626} 2627 2628void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2629 const char* mesg) { 2630 assert(mesg != NULL, "mesg must be specified"); 2631 int err = os::Linux::commit_memory_impl(addr, size, exec); 2632 if (err != 0) { 2633 // the caller wants all commit errors to exit with the specified mesg: 2634 warn_fail_commit_memory(addr, size, exec, err); 2635 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2636 } 2637} 2638 2639// Define MAP_HUGETLB here so we can build HotSpot on old systems. 2640#ifndef MAP_HUGETLB 2641 #define MAP_HUGETLB 0x40000 2642#endif 2643 2644// Define MADV_HUGEPAGE here so we can build HotSpot on old systems. 2645#ifndef MADV_HUGEPAGE 2646 #define MADV_HUGEPAGE 14 2647#endif 2648 2649int os::Linux::commit_memory_impl(char* addr, size_t size, 2650 size_t alignment_hint, bool exec) { 2651 int err = os::Linux::commit_memory_impl(addr, size, exec); 2652 if (err == 0) { 2653 realign_memory(addr, size, alignment_hint); 2654 } 2655 return err; 2656} 2657 2658bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2659 bool exec) { 2660 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0; 2661} 2662 2663void os::pd_commit_memory_or_exit(char* addr, size_t size, 2664 size_t alignment_hint, bool exec, 2665 const char* mesg) { 2666 assert(mesg != NULL, "mesg must be specified"); 2667 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec); 2668 if (err != 0) { 2669 // the caller wants all commit errors to exit with the specified mesg: 2670 warn_fail_commit_memory(addr, size, alignment_hint, exec, err); 2671 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2672 } 2673} 2674 2675void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2676 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) { 2677 // We don't check the return value: madvise(MADV_HUGEPAGE) may not 2678 // be supported or the memory may already be backed by huge pages. 2679 ::madvise(addr, bytes, MADV_HUGEPAGE); 2680 } 2681} 2682 2683void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2684 // This method works by doing an mmap over an existing mmaping and effectively discarding 2685 // the existing pages. However it won't work for SHM-based large pages that cannot be 2686 // uncommitted at all. We don't do anything in this case to avoid creating a segment with 2687 // small pages on top of the SHM segment. This method always works for small pages, so we 2688 // allow that in any case. 2689 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) { 2690 commit_memory(addr, bytes, alignment_hint, !ExecMem); 2691 } 2692} 2693 2694void os::numa_make_global(char *addr, size_t bytes) { 2695 Linux::numa_interleave_memory(addr, bytes); 2696} 2697 2698// Define for numa_set_bind_policy(int). Setting the argument to 0 will set the 2699// bind policy to MPOL_PREFERRED for the current thread. 2700#define USE_MPOL_PREFERRED 0 2701 2702void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2703 // To make NUMA and large pages more robust when both enabled, we need to ease 2704 // the requirements on where the memory should be allocated. MPOL_BIND is the 2705 // default policy and it will force memory to be allocated on the specified 2706 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on 2707 // the specified node, but will not force it. Using this policy will prevent 2708 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no 2709 // free large pages. 2710 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED); 2711 Linux::numa_tonode_memory(addr, bytes, lgrp_hint); 2712} 2713 2714bool os::numa_topology_changed() { return false; } 2715 2716size_t os::numa_get_groups_num() { 2717 int max_node = Linux::numa_max_node(); 2718 return max_node > 0 ? max_node + 1 : 1; 2719} 2720 2721int os::numa_get_group_id() { 2722 int cpu_id = Linux::sched_getcpu(); 2723 if (cpu_id != -1) { 2724 int lgrp_id = Linux::get_node_by_cpu(cpu_id); 2725 if (lgrp_id != -1) { 2726 return lgrp_id; 2727 } 2728 } 2729 return 0; 2730} 2731 2732size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2733 for (size_t i = 0; i < size; i++) { 2734 ids[i] = i; 2735 } 2736 return size; 2737} 2738 2739bool os::get_page_info(char *start, page_info* info) { 2740 return false; 2741} 2742 2743char *os::scan_pages(char *start, char* end, page_info* page_expected, 2744 page_info* page_found) { 2745 return end; 2746} 2747 2748 2749int os::Linux::sched_getcpu_syscall(void) { 2750 unsigned int cpu = 0; 2751 int retval = -1; 2752 2753#if defined(IA32) 2754 #ifndef SYS_getcpu 2755 #define SYS_getcpu 318 2756 #endif 2757 retval = syscall(SYS_getcpu, &cpu, NULL, NULL); 2758#elif defined(AMD64) 2759// Unfortunately we have to bring all these macros here from vsyscall.h 2760// to be able to compile on old linuxes. 2761 #define __NR_vgetcpu 2 2762 #define VSYSCALL_START (-10UL << 20) 2763 #define VSYSCALL_SIZE 1024 2764 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr)) 2765 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache); 2766 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu); 2767 retval = vgetcpu(&cpu, NULL, NULL); 2768#endif 2769 2770 return (retval == -1) ? retval : cpu; 2771} 2772 2773// Something to do with the numa-aware allocator needs these symbols 2774extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { } 2775extern "C" JNIEXPORT void numa_error(char *where) { } 2776 2777 2778// If we are running with libnuma version > 2, then we should 2779// be trying to use symbols with versions 1.1 2780// If we are running with earlier version, which did not have symbol versions, 2781// we should use the base version. 2782void* os::Linux::libnuma_dlsym(void* handle, const char *name) { 2783 void *f = dlvsym(handle, name, "libnuma_1.1"); 2784 if (f == NULL) { 2785 f = dlsym(handle, name); 2786 } 2787 return f; 2788} 2789 2790bool os::Linux::libnuma_init() { 2791 // sched_getcpu() should be in libc. 2792 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2793 dlsym(RTLD_DEFAULT, "sched_getcpu"))); 2794 2795 // If it's not, try a direct syscall. 2796 if (sched_getcpu() == -1) { 2797 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2798 (void*)&sched_getcpu_syscall)); 2799 } 2800 2801 if (sched_getcpu() != -1) { // Does it work? 2802 void *handle = dlopen("libnuma.so.1", RTLD_LAZY); 2803 if (handle != NULL) { 2804 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t, 2805 libnuma_dlsym(handle, "numa_node_to_cpus"))); 2806 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t, 2807 libnuma_dlsym(handle, "numa_max_node"))); 2808 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t, 2809 libnuma_dlsym(handle, "numa_available"))); 2810 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t, 2811 libnuma_dlsym(handle, "numa_tonode_memory"))); 2812 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t, 2813 libnuma_dlsym(handle, "numa_interleave_memory"))); 2814 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t, 2815 libnuma_dlsym(handle, "numa_set_bind_policy"))); 2816 2817 2818 if (numa_available() != -1) { 2819 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes")); 2820 // Create a cpu -> node mapping 2821 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2822 rebuild_cpu_to_node_map(); 2823 return true; 2824 } 2825 } 2826 } 2827 return false; 2828} 2829 2830// rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id. 2831// The table is later used in get_node_by_cpu(). 2832void os::Linux::rebuild_cpu_to_node_map() { 2833 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure 2834 // in libnuma (possible values are starting from 16, 2835 // and continuing up with every other power of 2, but less 2836 // than the maximum number of CPUs supported by kernel), and 2837 // is a subject to change (in libnuma version 2 the requirements 2838 // are more reasonable) we'll just hardcode the number they use 2839 // in the library. 2840 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT; 2841 2842 size_t cpu_num = os::active_processor_count(); 2843 size_t cpu_map_size = NCPUS / BitsPerCLong; 2844 size_t cpu_map_valid_size = 2845 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size); 2846 2847 cpu_to_node()->clear(); 2848 cpu_to_node()->at_grow(cpu_num - 1); 2849 size_t node_num = numa_get_groups_num(); 2850 2851 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal); 2852 for (size_t i = 0; i < node_num; i++) { 2853 if (numa_node_to_cpus(i, cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) { 2854 for (size_t j = 0; j < cpu_map_valid_size; j++) { 2855 if (cpu_map[j] != 0) { 2856 for (size_t k = 0; k < BitsPerCLong; k++) { 2857 if (cpu_map[j] & (1UL << k)) { 2858 cpu_to_node()->at_put(j * BitsPerCLong + k, i); 2859 } 2860 } 2861 } 2862 } 2863 } 2864 } 2865 FREE_C_HEAP_ARRAY(unsigned long, cpu_map); 2866} 2867 2868int os::Linux::get_node_by_cpu(int cpu_id) { 2869 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) { 2870 return cpu_to_node()->at(cpu_id); 2871 } 2872 return -1; 2873} 2874 2875GrowableArray<int>* os::Linux::_cpu_to_node; 2876os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu; 2877os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus; 2878os::Linux::numa_max_node_func_t os::Linux::_numa_max_node; 2879os::Linux::numa_available_func_t os::Linux::_numa_available; 2880os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory; 2881os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory; 2882os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy; 2883unsigned long* os::Linux::_numa_all_nodes; 2884 2885bool os::pd_uncommit_memory(char* addr, size_t size) { 2886 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2887 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2888 return res != (uintptr_t) MAP_FAILED; 2889} 2890 2891static address get_stack_commited_bottom(address bottom, size_t size) { 2892 address nbot = bottom; 2893 address ntop = bottom + size; 2894 2895 size_t page_sz = os::vm_page_size(); 2896 unsigned pages = size / page_sz; 2897 2898 unsigned char vec[1]; 2899 unsigned imin = 1, imax = pages + 1, imid; 2900 int mincore_return_value = 0; 2901 2902 assert(imin <= imax, "Unexpected page size"); 2903 2904 while (imin < imax) { 2905 imid = (imax + imin) / 2; 2906 nbot = ntop - (imid * page_sz); 2907 2908 // Use a trick with mincore to check whether the page is mapped or not. 2909 // mincore sets vec to 1 if page resides in memory and to 0 if page 2910 // is swapped output but if page we are asking for is unmapped 2911 // it returns -1,ENOMEM 2912 mincore_return_value = mincore(nbot, page_sz, vec); 2913 2914 if (mincore_return_value == -1) { 2915 // Page is not mapped go up 2916 // to find first mapped page 2917 if (errno != EAGAIN) { 2918 assert(errno == ENOMEM, "Unexpected mincore errno"); 2919 imax = imid; 2920 } 2921 } else { 2922 // Page is mapped go down 2923 // to find first not mapped page 2924 imin = imid + 1; 2925 } 2926 } 2927 2928 nbot = nbot + page_sz; 2929 2930 // Adjust stack bottom one page up if last checked page is not mapped 2931 if (mincore_return_value == -1) { 2932 nbot = nbot + page_sz; 2933 } 2934 2935 return nbot; 2936} 2937 2938 2939// Linux uses a growable mapping for the stack, and if the mapping for 2940// the stack guard pages is not removed when we detach a thread the 2941// stack cannot grow beyond the pages where the stack guard was 2942// mapped. If at some point later in the process the stack expands to 2943// that point, the Linux kernel cannot expand the stack any further 2944// because the guard pages are in the way, and a segfault occurs. 2945// 2946// However, it's essential not to split the stack region by unmapping 2947// a region (leaving a hole) that's already part of the stack mapping, 2948// so if the stack mapping has already grown beyond the guard pages at 2949// the time we create them, we have to truncate the stack mapping. 2950// So, we need to know the extent of the stack mapping when 2951// create_stack_guard_pages() is called. 2952 2953// We only need this for stacks that are growable: at the time of 2954// writing thread stacks don't use growable mappings (i.e. those 2955// creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this 2956// only applies to the main thread. 2957 2958// If the (growable) stack mapping already extends beyond the point 2959// where we're going to put our guard pages, truncate the mapping at 2960// that point by munmap()ping it. This ensures that when we later 2961// munmap() the guard pages we don't leave a hole in the stack 2962// mapping. This only affects the main/initial thread 2963 2964bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2965 if (os::Linux::is_initial_thread()) { 2966 // As we manually grow stack up to bottom inside create_attached_thread(), 2967 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and 2968 // we don't need to do anything special. 2969 // Check it first, before calling heavy function. 2970 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom(); 2971 unsigned char vec[1]; 2972 2973 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) { 2974 // Fallback to slow path on all errors, including EAGAIN 2975 stack_extent = (uintptr_t) get_stack_commited_bottom( 2976 os::Linux::initial_thread_stack_bottom(), 2977 (size_t)addr - stack_extent); 2978 } 2979 2980 if (stack_extent < (uintptr_t)addr) { 2981 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent)); 2982 } 2983 } 2984 2985 return os::commit_memory(addr, size, !ExecMem); 2986} 2987 2988// If this is a growable mapping, remove the guard pages entirely by 2989// munmap()ping them. If not, just call uncommit_memory(). This only 2990// affects the main/initial thread, but guard against future OS changes 2991// It's safe to always unmap guard pages for initial thread because we 2992// always place it right after end of the mapped region 2993 2994bool os::remove_stack_guard_pages(char* addr, size_t size) { 2995 uintptr_t stack_extent, stack_base; 2996 2997 if (os::Linux::is_initial_thread()) { 2998 return ::munmap(addr, size) == 0; 2999 } 3000 3001 return os::uncommit_memory(addr, size); 3002} 3003 3004// If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 3005// at 'requested_addr'. If there are existing memory mappings at the same 3006// location, however, they will be overwritten. If 'fixed' is false, 3007// 'requested_addr' is only treated as a hint, the return value may or 3008// may not start from the requested address. Unlike Linux mmap(), this 3009// function returns NULL to indicate failure. 3010static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 3011 char * addr; 3012 int flags; 3013 3014 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 3015 if (fixed) { 3016 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address"); 3017 flags |= MAP_FIXED; 3018 } 3019 3020 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 3021 // touch an uncommitted page. Otherwise, the read/write might 3022 // succeed if we have enough swap space to back the physical page. 3023 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 3024 flags, -1, 0); 3025 3026 return addr == MAP_FAILED ? NULL : addr; 3027} 3028 3029static int anon_munmap(char * addr, size_t size) { 3030 return ::munmap(addr, size) == 0; 3031} 3032 3033char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 3034 size_t alignment_hint) { 3035 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 3036} 3037 3038bool os::pd_release_memory(char* addr, size_t size) { 3039 return anon_munmap(addr, size); 3040} 3041 3042static bool linux_mprotect(char* addr, size_t size, int prot) { 3043 // Linux wants the mprotect address argument to be page aligned. 3044 char* bottom = (char*)align_size_down((intptr_t)addr, os::Linux::page_size()); 3045 3046 // According to SUSv3, mprotect() should only be used with mappings 3047 // established by mmap(), and mmap() always maps whole pages. Unaligned 3048 // 'addr' likely indicates problem in the VM (e.g. trying to change 3049 // protection of malloc'ed or statically allocated memory). Check the 3050 // caller if you hit this assert. 3051 assert(addr == bottom, "sanity check"); 3052 3053 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size()); 3054 return ::mprotect(bottom, size, prot) == 0; 3055} 3056 3057// Set protections specified 3058bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 3059 bool is_committed) { 3060 unsigned int p = 0; 3061 switch (prot) { 3062 case MEM_PROT_NONE: p = PROT_NONE; break; 3063 case MEM_PROT_READ: p = PROT_READ; break; 3064 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 3065 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 3066 default: 3067 ShouldNotReachHere(); 3068 } 3069 // is_committed is unused. 3070 return linux_mprotect(addr, bytes, p); 3071} 3072 3073bool os::guard_memory(char* addr, size_t size) { 3074 return linux_mprotect(addr, size, PROT_NONE); 3075} 3076 3077bool os::unguard_memory(char* addr, size_t size) { 3078 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE); 3079} 3080 3081bool os::Linux::transparent_huge_pages_sanity_check(bool warn, 3082 size_t page_size) { 3083 bool result = false; 3084 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE, 3085 MAP_ANONYMOUS|MAP_PRIVATE, 3086 -1, 0); 3087 if (p != MAP_FAILED) { 3088 void *aligned_p = align_ptr_up(p, page_size); 3089 3090 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0; 3091 3092 munmap(p, page_size * 2); 3093 } 3094 3095 if (warn && !result) { 3096 warning("TransparentHugePages is not supported by the operating system."); 3097 } 3098 3099 return result; 3100} 3101 3102bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) { 3103 bool result = false; 3104 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE, 3105 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB, 3106 -1, 0); 3107 3108 if (p != MAP_FAILED) { 3109 // We don't know if this really is a huge page or not. 3110 FILE *fp = fopen("/proc/self/maps", "r"); 3111 if (fp) { 3112 while (!feof(fp)) { 3113 char chars[257]; 3114 long x = 0; 3115 if (fgets(chars, sizeof(chars), fp)) { 3116 if (sscanf(chars, "%lx-%*x", &x) == 1 3117 && x == (long)p) { 3118 if (strstr (chars, "hugepage")) { 3119 result = true; 3120 break; 3121 } 3122 } 3123 } 3124 } 3125 fclose(fp); 3126 } 3127 munmap(p, page_size); 3128 } 3129 3130 if (warn && !result) { 3131 warning("HugeTLBFS is not supported by the operating system."); 3132 } 3133 3134 return result; 3135} 3136 3137// Set the coredump_filter bits to include largepages in core dump (bit 6) 3138// 3139// From the coredump_filter documentation: 3140// 3141// - (bit 0) anonymous private memory 3142// - (bit 1) anonymous shared memory 3143// - (bit 2) file-backed private memory 3144// - (bit 3) file-backed shared memory 3145// - (bit 4) ELF header pages in file-backed private memory areas (it is 3146// effective only if the bit 2 is cleared) 3147// - (bit 5) hugetlb private memory 3148// - (bit 6) hugetlb shared memory 3149// 3150static void set_coredump_filter(void) { 3151 FILE *f; 3152 long cdm; 3153 3154 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { 3155 return; 3156 } 3157 3158 if (fscanf(f, "%lx", &cdm) != 1) { 3159 fclose(f); 3160 return; 3161 } 3162 3163 rewind(f); 3164 3165 if ((cdm & LARGEPAGES_BIT) == 0) { 3166 cdm |= LARGEPAGES_BIT; 3167 fprintf(f, "%#lx", cdm); 3168 } 3169 3170 fclose(f); 3171} 3172 3173// Large page support 3174 3175static size_t _large_page_size = 0; 3176 3177size_t os::Linux::find_large_page_size() { 3178 size_t large_page_size = 0; 3179 3180 // large_page_size on Linux is used to round up heap size. x86 uses either 3181 // 2M or 4M page, depending on whether PAE (Physical Address Extensions) 3182 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use 3183 // page as large as 256M. 3184 // 3185 // Here we try to figure out page size by parsing /proc/meminfo and looking 3186 // for a line with the following format: 3187 // Hugepagesize: 2048 kB 3188 // 3189 // If we can't determine the value (e.g. /proc is not mounted, or the text 3190 // format has been changed), we'll use the largest page size supported by 3191 // the processor. 3192 3193#ifndef ZERO 3194 large_page_size = IA32_ONLY(4 * M) AMD64_ONLY(2 * M) IA64_ONLY(256 * M) SPARC_ONLY(4 * M) 3195 ARM32_ONLY(2 * M) PPC_ONLY(4 * M) AARCH64_ONLY(2 * M); 3196#endif // ZERO 3197 3198 FILE *fp = fopen("/proc/meminfo", "r"); 3199 if (fp) { 3200 while (!feof(fp)) { 3201 int x = 0; 3202 char buf[16]; 3203 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) { 3204 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) { 3205 large_page_size = x * K; 3206 break; 3207 } 3208 } else { 3209 // skip to next line 3210 for (;;) { 3211 int ch = fgetc(fp); 3212 if (ch == EOF || ch == (int)'\n') break; 3213 } 3214 } 3215 } 3216 fclose(fp); 3217 } 3218 3219 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) { 3220 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is " 3221 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size), 3222 proper_unit_for_byte_size(large_page_size)); 3223 } 3224 3225 return large_page_size; 3226} 3227 3228size_t os::Linux::setup_large_page_size() { 3229 _large_page_size = Linux::find_large_page_size(); 3230 const size_t default_page_size = (size_t)Linux::page_size(); 3231 if (_large_page_size > default_page_size) { 3232 _page_sizes[0] = _large_page_size; 3233 _page_sizes[1] = default_page_size; 3234 _page_sizes[2] = 0; 3235 } 3236 3237 return _large_page_size; 3238} 3239 3240bool os::Linux::setup_large_page_type(size_t page_size) { 3241 if (FLAG_IS_DEFAULT(UseHugeTLBFS) && 3242 FLAG_IS_DEFAULT(UseSHM) && 3243 FLAG_IS_DEFAULT(UseTransparentHugePages)) { 3244 3245 // The type of large pages has not been specified by the user. 3246 3247 // Try UseHugeTLBFS and then UseSHM. 3248 UseHugeTLBFS = UseSHM = true; 3249 3250 // Don't try UseTransparentHugePages since there are known 3251 // performance issues with it turned on. This might change in the future. 3252 UseTransparentHugePages = false; 3253 } 3254 3255 if (UseTransparentHugePages) { 3256 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages); 3257 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) { 3258 UseHugeTLBFS = false; 3259 UseSHM = false; 3260 return true; 3261 } 3262 UseTransparentHugePages = false; 3263 } 3264 3265 if (UseHugeTLBFS) { 3266 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS); 3267 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) { 3268 UseSHM = false; 3269 return true; 3270 } 3271 UseHugeTLBFS = false; 3272 } 3273 3274 return UseSHM; 3275} 3276 3277void os::large_page_init() { 3278 if (!UseLargePages && 3279 !UseTransparentHugePages && 3280 !UseHugeTLBFS && 3281 !UseSHM) { 3282 // Not using large pages. 3283 return; 3284 } 3285 3286 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) { 3287 // The user explicitly turned off large pages. 3288 // Ignore the rest of the large pages flags. 3289 UseTransparentHugePages = false; 3290 UseHugeTLBFS = false; 3291 UseSHM = false; 3292 return; 3293 } 3294 3295 size_t large_page_size = Linux::setup_large_page_size(); 3296 UseLargePages = Linux::setup_large_page_type(large_page_size); 3297 3298 set_coredump_filter(); 3299} 3300 3301#ifndef SHM_HUGETLB 3302 #define SHM_HUGETLB 04000 3303#endif 3304 3305char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment, 3306 char* req_addr, bool exec) { 3307 // "exec" is passed in but not used. Creating the shared image for 3308 // the code cache doesn't have an SHM_X executable permission to check. 3309 assert(UseLargePages && UseSHM, "only for SHM large pages"); 3310 assert(is_ptr_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3311 3312 if (!is_size_aligned(bytes, os::large_page_size()) || alignment > os::large_page_size()) { 3313 return NULL; // Fallback to small pages. 3314 } 3315 3316 key_t key = IPC_PRIVATE; 3317 char *addr; 3318 3319 bool warn_on_failure = UseLargePages && 3320 (!FLAG_IS_DEFAULT(UseLargePages) || 3321 !FLAG_IS_DEFAULT(UseSHM) || 3322 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 3323 char msg[128]; 3324 3325 // Create a large shared memory region to attach to based on size. 3326 // Currently, size is the total size of the heap 3327 int shmid = shmget(key, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W); 3328 if (shmid == -1) { 3329 // Possible reasons for shmget failure: 3330 // 1. shmmax is too small for Java heap. 3331 // > check shmmax value: cat /proc/sys/kernel/shmmax 3332 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 3333 // 2. not enough large page memory. 3334 // > check available large pages: cat /proc/meminfo 3335 // > increase amount of large pages: 3336 // echo new_value > /proc/sys/vm/nr_hugepages 3337 // Note 1: different Linux may use different name for this property, 3338 // e.g. on Redhat AS-3 it is "hugetlb_pool". 3339 // Note 2: it's possible there's enough physical memory available but 3340 // they are so fragmented after a long run that they can't 3341 // coalesce into large pages. Try to reserve large pages when 3342 // the system is still "fresh". 3343 if (warn_on_failure) { 3344 jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno); 3345 warning("%s", msg); 3346 } 3347 return NULL; 3348 } 3349 3350 // attach to the region 3351 addr = (char*)shmat(shmid, req_addr, 0); 3352 int err = errno; 3353 3354 // Remove shmid. If shmat() is successful, the actual shared memory segment 3355 // will be deleted when it's detached by shmdt() or when the process 3356 // terminates. If shmat() is not successful this will remove the shared 3357 // segment immediately. 3358 shmctl(shmid, IPC_RMID, NULL); 3359 3360 if ((intptr_t)addr == -1) { 3361 if (warn_on_failure) { 3362 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err); 3363 warning("%s", msg); 3364 } 3365 return NULL; 3366 } 3367 3368 return addr; 3369} 3370 3371static void warn_on_large_pages_failure(char* req_addr, size_t bytes, 3372 int error) { 3373 assert(error == ENOMEM, "Only expect to fail if no memory is available"); 3374 3375 bool warn_on_failure = UseLargePages && 3376 (!FLAG_IS_DEFAULT(UseLargePages) || 3377 !FLAG_IS_DEFAULT(UseHugeTLBFS) || 3378 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 3379 3380 if (warn_on_failure) { 3381 char msg[128]; 3382 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: " 3383 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error); 3384 warning("%s", msg); 3385 } 3386} 3387 3388char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes, 3389 char* req_addr, 3390 bool exec) { 3391 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3392 assert(is_size_aligned(bytes, os::large_page_size()), "Unaligned size"); 3393 assert(is_ptr_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3394 3395 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3396 char* addr = (char*)::mmap(req_addr, bytes, prot, 3397 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, 3398 -1, 0); 3399 3400 if (addr == MAP_FAILED) { 3401 warn_on_large_pages_failure(req_addr, bytes, errno); 3402 return NULL; 3403 } 3404 3405 assert(is_ptr_aligned(addr, os::large_page_size()), "Must be"); 3406 3407 return addr; 3408} 3409 3410// Helper for os::Linux::reserve_memory_special_huge_tlbfs_mixed(). 3411// Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address 3412// (req_addr != NULL) or with a given alignment. 3413// - bytes shall be a multiple of alignment. 3414// - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3415// - alignment sets the alignment at which memory shall be allocated. 3416// It must be a multiple of allocation granularity. 3417// Returns address of memory or NULL. If req_addr was not NULL, will only return 3418// req_addr or NULL. 3419static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) { 3420 3421 size_t extra_size = bytes; 3422 if (req_addr == NULL && alignment > 0) { 3423 extra_size += alignment; 3424 } 3425 3426 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE, 3427 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 3428 -1, 0); 3429 if (start == MAP_FAILED) { 3430 start = NULL; 3431 } else { 3432 if (req_addr != NULL) { 3433 if (start != req_addr) { 3434 ::munmap(start, extra_size); 3435 start = NULL; 3436 } 3437 } else { 3438 char* const start_aligned = (char*) align_ptr_up(start, alignment); 3439 char* const end_aligned = start_aligned + bytes; 3440 char* const end = start + extra_size; 3441 if (start_aligned > start) { 3442 ::munmap(start, start_aligned - start); 3443 } 3444 if (end_aligned < end) { 3445 ::munmap(end_aligned, end - end_aligned); 3446 } 3447 start = start_aligned; 3448 } 3449 } 3450 return start; 3451 3452} 3453 3454// Reserve memory using mmap(MAP_HUGETLB). 3455// - bytes shall be a multiple of alignment. 3456// - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3457// - alignment sets the alignment at which memory shall be allocated. 3458// It must be a multiple of allocation granularity. 3459// Returns address of memory or NULL. If req_addr was not NULL, will only return 3460// req_addr or NULL. 3461char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes, 3462 size_t alignment, 3463 char* req_addr, 3464 bool exec) { 3465 size_t large_page_size = os::large_page_size(); 3466 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes"); 3467 3468 assert(is_ptr_aligned(req_addr, alignment), "Must be"); 3469 assert(is_size_aligned(bytes, alignment), "Must be"); 3470 3471 // First reserve - but not commit - the address range in small pages. 3472 char* const start = anon_mmap_aligned(bytes, alignment, req_addr); 3473 3474 if (start == NULL) { 3475 return NULL; 3476 } 3477 3478 assert(is_ptr_aligned(start, alignment), "Must be"); 3479 3480 char* end = start + bytes; 3481 3482 // Find the regions of the allocated chunk that can be promoted to large pages. 3483 char* lp_start = (char*)align_ptr_up(start, large_page_size); 3484 char* lp_end = (char*)align_ptr_down(end, large_page_size); 3485 3486 size_t lp_bytes = lp_end - lp_start; 3487 3488 assert(is_size_aligned(lp_bytes, large_page_size), "Must be"); 3489 3490 if (lp_bytes == 0) { 3491 // The mapped region doesn't even span the start and the end of a large page. 3492 // Fall back to allocate a non-special area. 3493 ::munmap(start, end - start); 3494 return NULL; 3495 } 3496 3497 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3498 3499 void* result; 3500 3501 // Commit small-paged leading area. 3502 if (start != lp_start) { 3503 result = ::mmap(start, lp_start - start, prot, 3504 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3505 -1, 0); 3506 if (result == MAP_FAILED) { 3507 ::munmap(lp_start, end - lp_start); 3508 return NULL; 3509 } 3510 } 3511 3512 // Commit large-paged area. 3513 result = ::mmap(lp_start, lp_bytes, prot, 3514 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB, 3515 -1, 0); 3516 if (result == MAP_FAILED) { 3517 warn_on_large_pages_failure(lp_start, lp_bytes, errno); 3518 // If the mmap above fails, the large pages region will be unmapped and we 3519 // have regions before and after with small pages. Release these regions. 3520 // 3521 // | mapped | unmapped | mapped | 3522 // ^ ^ ^ ^ 3523 // start lp_start lp_end end 3524 // 3525 ::munmap(start, lp_start - start); 3526 ::munmap(lp_end, end - lp_end); 3527 return NULL; 3528 } 3529 3530 // Commit small-paged trailing area. 3531 if (lp_end != end) { 3532 result = ::mmap(lp_end, end - lp_end, prot, 3533 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3534 -1, 0); 3535 if (result == MAP_FAILED) { 3536 ::munmap(start, lp_end - start); 3537 return NULL; 3538 } 3539 } 3540 3541 return start; 3542} 3543 3544char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes, 3545 size_t alignment, 3546 char* req_addr, 3547 bool exec) { 3548 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3549 assert(is_ptr_aligned(req_addr, alignment), "Must be"); 3550 assert(is_size_aligned(alignment, os::vm_allocation_granularity()), "Must be"); 3551 assert(is_power_of_2(os::large_page_size()), "Must be"); 3552 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes"); 3553 3554 if (is_size_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) { 3555 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec); 3556 } else { 3557 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec); 3558 } 3559} 3560 3561char* os::reserve_memory_special(size_t bytes, size_t alignment, 3562 char* req_addr, bool exec) { 3563 assert(UseLargePages, "only for large pages"); 3564 3565 char* addr; 3566 if (UseSHM) { 3567 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec); 3568 } else { 3569 assert(UseHugeTLBFS, "must be"); 3570 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec); 3571 } 3572 3573 if (addr != NULL) { 3574 if (UseNUMAInterleaving) { 3575 numa_make_global(addr, bytes); 3576 } 3577 3578 // The memory is committed 3579 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 3580 } 3581 3582 return addr; 3583} 3584 3585bool os::Linux::release_memory_special_shm(char* base, size_t bytes) { 3586 // detaching the SHM segment will also delete it, see reserve_memory_special_shm() 3587 return shmdt(base) == 0; 3588} 3589 3590bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) { 3591 return pd_release_memory(base, bytes); 3592} 3593 3594bool os::release_memory_special(char* base, size_t bytes) { 3595 bool res; 3596 if (MemTracker::tracking_level() > NMT_minimal) { 3597 Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 3598 res = os::Linux::release_memory_special_impl(base, bytes); 3599 if (res) { 3600 tkr.record((address)base, bytes); 3601 } 3602 3603 } else { 3604 res = os::Linux::release_memory_special_impl(base, bytes); 3605 } 3606 return res; 3607} 3608 3609bool os::Linux::release_memory_special_impl(char* base, size_t bytes) { 3610 assert(UseLargePages, "only for large pages"); 3611 bool res; 3612 3613 if (UseSHM) { 3614 res = os::Linux::release_memory_special_shm(base, bytes); 3615 } else { 3616 assert(UseHugeTLBFS, "must be"); 3617 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes); 3618 } 3619 return res; 3620} 3621 3622size_t os::large_page_size() { 3623 return _large_page_size; 3624} 3625 3626// With SysV SHM the entire memory region must be allocated as shared 3627// memory. 3628// HugeTLBFS allows application to commit large page memory on demand. 3629// However, when committing memory with HugeTLBFS fails, the region 3630// that was supposed to be committed will lose the old reservation 3631// and allow other threads to steal that memory region. Because of this 3632// behavior we can't commit HugeTLBFS memory. 3633bool os::can_commit_large_page_memory() { 3634 return UseTransparentHugePages; 3635} 3636 3637bool os::can_execute_large_page_memory() { 3638 return UseTransparentHugePages || UseHugeTLBFS; 3639} 3640 3641// Reserve memory at an arbitrary address, only if that area is 3642// available (and not reserved for something else). 3643 3644char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 3645 const int max_tries = 10; 3646 char* base[max_tries]; 3647 size_t size[max_tries]; 3648 const size_t gap = 0x000000; 3649 3650 // Assert only that the size is a multiple of the page size, since 3651 // that's all that mmap requires, and since that's all we really know 3652 // about at this low abstraction level. If we need higher alignment, 3653 // we can either pass an alignment to this method or verify alignment 3654 // in one of the methods further up the call chain. See bug 5044738. 3655 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 3656 3657 // Repeatedly allocate blocks until the block is allocated at the 3658 // right spot. 3659 3660 // Linux mmap allows caller to pass an address as hint; give it a try first, 3661 // if kernel honors the hint then we can return immediately. 3662 char * addr = anon_mmap(requested_addr, bytes, false); 3663 if (addr == requested_addr) { 3664 return requested_addr; 3665 } 3666 3667 if (addr != NULL) { 3668 // mmap() is successful but it fails to reserve at the requested address 3669 anon_munmap(addr, bytes); 3670 } 3671 3672 int i; 3673 for (i = 0; i < max_tries; ++i) { 3674 base[i] = reserve_memory(bytes); 3675 3676 if (base[i] != NULL) { 3677 // Is this the block we wanted? 3678 if (base[i] == requested_addr) { 3679 size[i] = bytes; 3680 break; 3681 } 3682 3683 // Does this overlap the block we wanted? Give back the overlapped 3684 // parts and try again. 3685 3686 ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i]; 3687 if (top_overlap >= 0 && (size_t)top_overlap < bytes) { 3688 unmap_memory(base[i], top_overlap); 3689 base[i] += top_overlap; 3690 size[i] = bytes - top_overlap; 3691 } else { 3692 ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr; 3693 if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) { 3694 unmap_memory(requested_addr, bottom_overlap); 3695 size[i] = bytes - bottom_overlap; 3696 } else { 3697 size[i] = bytes; 3698 } 3699 } 3700 } 3701 } 3702 3703 // Give back the unused reserved pieces. 3704 3705 for (int j = 0; j < i; ++j) { 3706 if (base[j] != NULL) { 3707 unmap_memory(base[j], size[j]); 3708 } 3709 } 3710 3711 if (i < max_tries) { 3712 return requested_addr; 3713 } else { 3714 return NULL; 3715 } 3716} 3717 3718size_t os::read(int fd, void *buf, unsigned int nBytes) { 3719 return ::read(fd, buf, nBytes); 3720} 3721 3722size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 3723 return ::pread(fd, buf, nBytes, offset); 3724} 3725 3726// Short sleep, direct OS call. 3727// 3728// Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee 3729// sched_yield(2) will actually give up the CPU: 3730// 3731// * Alone on this pariticular CPU, keeps running. 3732// * Before the introduction of "skip_buddy" with "compat_yield" disabled 3733// (pre 2.6.39). 3734// 3735// So calling this with 0 is an alternative. 3736// 3737void os::naked_short_sleep(jlong ms) { 3738 struct timespec req; 3739 3740 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 3741 req.tv_sec = 0; 3742 if (ms > 0) { 3743 req.tv_nsec = (ms % 1000) * 1000000; 3744 } else { 3745 req.tv_nsec = 1; 3746 } 3747 3748 nanosleep(&req, NULL); 3749 3750 return; 3751} 3752 3753// Sleep forever; naked call to OS-specific sleep; use with CAUTION 3754void os::infinite_sleep() { 3755 while (true) { // sleep forever ... 3756 ::sleep(100); // ... 100 seconds at a time 3757 } 3758} 3759 3760// Used to convert frequent JVM_Yield() to nops 3761bool os::dont_yield() { 3762 return DontYieldALot; 3763} 3764 3765void os::naked_yield() { 3766 sched_yield(); 3767} 3768 3769//////////////////////////////////////////////////////////////////////////////// 3770// thread priority support 3771 3772// Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER 3773// only supports dynamic priority, static priority must be zero. For real-time 3774// applications, Linux supports SCHED_RR which allows static priority (1-99). 3775// However, for large multi-threaded applications, SCHED_RR is not only slower 3776// than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 3777// of 5 runs - Sep 2005). 3778// 3779// The following code actually changes the niceness of kernel-thread/LWP. It 3780// has an assumption that setpriority() only modifies one kernel-thread/LWP, 3781// not the entire user process, and user level threads are 1:1 mapped to kernel 3782// threads. It has always been the case, but could change in the future. For 3783// this reason, the code should not be used as default (ThreadPriorityPolicy=0). 3784// It is only used when ThreadPriorityPolicy=1 and requires root privilege. 3785 3786int os::java_to_os_priority[CriticalPriority + 1] = { 3787 19, // 0 Entry should never be used 3788 3789 4, // 1 MinPriority 3790 3, // 2 3791 2, // 3 3792 3793 1, // 4 3794 0, // 5 NormPriority 3795 -1, // 6 3796 3797 -2, // 7 3798 -3, // 8 3799 -4, // 9 NearMaxPriority 3800 3801 -5, // 10 MaxPriority 3802 3803 -5 // 11 CriticalPriority 3804}; 3805 3806static int prio_init() { 3807 if (ThreadPriorityPolicy == 1) { 3808 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 3809 // if effective uid is not root. Perhaps, a more elegant way of doing 3810 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 3811 if (geteuid() != 0) { 3812 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 3813 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux"); 3814 } 3815 ThreadPriorityPolicy = 0; 3816 } 3817 } 3818 if (UseCriticalJavaThreadPriority) { 3819 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 3820 } 3821 return 0; 3822} 3823 3824OSReturn os::set_native_priority(Thread* thread, int newpri) { 3825 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 3826 3827 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 3828 return (ret == 0) ? OS_OK : OS_ERR; 3829} 3830 3831OSReturn os::get_native_priority(const Thread* const thread, 3832 int *priority_ptr) { 3833 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 3834 *priority_ptr = java_to_os_priority[NormPriority]; 3835 return OS_OK; 3836 } 3837 3838 errno = 0; 3839 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 3840 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 3841} 3842 3843// Hint to the underlying OS that a task switch would not be good. 3844// Void return because it's a hint and can fail. 3845void os::hint_no_preempt() {} 3846 3847//////////////////////////////////////////////////////////////////////////////// 3848// suspend/resume support 3849 3850// the low-level signal-based suspend/resume support is a remnant from the 3851// old VM-suspension that used to be for java-suspension, safepoints etc, 3852// within hotspot. Now there is a single use-case for this: 3853// - calling get_thread_pc() on the VMThread by the flat-profiler task 3854// that runs in the watcher thread. 3855// The remaining code is greatly simplified from the more general suspension 3856// code that used to be used. 3857// 3858// The protocol is quite simple: 3859// - suspend: 3860// - sends a signal to the target thread 3861// - polls the suspend state of the osthread using a yield loop 3862// - target thread signal handler (SR_handler) sets suspend state 3863// and blocks in sigsuspend until continued 3864// - resume: 3865// - sets target osthread state to continue 3866// - sends signal to end the sigsuspend loop in the SR_handler 3867// 3868// Note that the SR_lock plays no role in this suspend/resume protocol. 3869 3870static void resume_clear_context(OSThread *osthread) { 3871 osthread->set_ucontext(NULL); 3872 osthread->set_siginfo(NULL); 3873} 3874 3875static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, 3876 ucontext_t* context) { 3877 osthread->set_ucontext(context); 3878 osthread->set_siginfo(siginfo); 3879} 3880 3881// Handler function invoked when a thread's execution is suspended or 3882// resumed. We have to be careful that only async-safe functions are 3883// called here (Note: most pthread functions are not async safe and 3884// should be avoided.) 3885// 3886// Note: sigwait() is a more natural fit than sigsuspend() from an 3887// interface point of view, but sigwait() prevents the signal hander 3888// from being run. libpthread would get very confused by not having 3889// its signal handlers run and prevents sigwait()'s use with the 3890// mutex granting granting signal. 3891// 3892// Currently only ever called on the VMThread and JavaThreads (PC sampling) 3893// 3894static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 3895 // Save and restore errno to avoid confusing native code with EINTR 3896 // after sigsuspend. 3897 int old_errno = errno; 3898 3899 Thread* thread = Thread::current(); 3900 OSThread* osthread = thread->osthread(); 3901 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 3902 3903 os::SuspendResume::State current = osthread->sr.state(); 3904 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 3905 suspend_save_context(osthread, siginfo, context); 3906 3907 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 3908 os::SuspendResume::State state = osthread->sr.suspended(); 3909 if (state == os::SuspendResume::SR_SUSPENDED) { 3910 sigset_t suspend_set; // signals for sigsuspend() 3911 3912 // get current set of blocked signals and unblock resume signal 3913 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 3914 sigdelset(&suspend_set, SR_signum); 3915 3916 sr_semaphore.signal(); 3917 // wait here until we are resumed 3918 while (1) { 3919 sigsuspend(&suspend_set); 3920 3921 os::SuspendResume::State result = osthread->sr.running(); 3922 if (result == os::SuspendResume::SR_RUNNING) { 3923 sr_semaphore.signal(); 3924 break; 3925 } 3926 } 3927 3928 } else if (state == os::SuspendResume::SR_RUNNING) { 3929 // request was cancelled, continue 3930 } else { 3931 ShouldNotReachHere(); 3932 } 3933 3934 resume_clear_context(osthread); 3935 } else if (current == os::SuspendResume::SR_RUNNING) { 3936 // request was cancelled, continue 3937 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 3938 // ignore 3939 } else { 3940 // ignore 3941 } 3942 3943 errno = old_errno; 3944} 3945 3946static int SR_initialize() { 3947 struct sigaction act; 3948 char *s; 3949 3950 // Get signal number to use for suspend/resume 3951 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 3952 int sig = ::strtol(s, 0, 10); 3953 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769. 3954 sig < NSIG) { // Must be legal signal and fit into sigflags[]. 3955 SR_signum = sig; 3956 } else { 3957 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.", 3958 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum); 3959 } 3960 } 3961 3962 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 3963 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 3964 3965 sigemptyset(&SR_sigset); 3966 sigaddset(&SR_sigset, SR_signum); 3967 3968 // Set up signal handler for suspend/resume 3969 act.sa_flags = SA_RESTART|SA_SIGINFO; 3970 act.sa_handler = (void (*)(int)) SR_handler; 3971 3972 // SR_signum is blocked by default. 3973 // 4528190 - We also need to block pthread restart signal (32 on all 3974 // supported Linux platforms). Note that LinuxThreads need to block 3975 // this signal for all threads to work properly. So we don't have 3976 // to use hard-coded signal number when setting up the mask. 3977 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 3978 3979 if (sigaction(SR_signum, &act, 0) == -1) { 3980 return -1; 3981 } 3982 3983 // Save signal flag 3984 os::Linux::set_our_sigflags(SR_signum, act.sa_flags); 3985 return 0; 3986} 3987 3988static int sr_notify(OSThread* osthread) { 3989 int status = pthread_kill(osthread->pthread_id(), SR_signum); 3990 assert_status(status == 0, status, "pthread_kill"); 3991 return status; 3992} 3993 3994// "Randomly" selected value for how long we want to spin 3995// before bailing out on suspending a thread, also how often 3996// we send a signal to a thread we want to resume 3997static const int RANDOMLY_LARGE_INTEGER = 1000000; 3998static const int RANDOMLY_LARGE_INTEGER2 = 100; 3999 4000// returns true on success and false on error - really an error is fatal 4001// but this seems the normal response to library errors 4002static bool do_suspend(OSThread* osthread) { 4003 assert(osthread->sr.is_running(), "thread should be running"); 4004 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 4005 4006 // mark as suspended and send signal 4007 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 4008 // failed to switch, state wasn't running? 4009 ShouldNotReachHere(); 4010 return false; 4011 } 4012 4013 if (sr_notify(osthread) != 0) { 4014 ShouldNotReachHere(); 4015 } 4016 4017 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 4018 while (true) { 4019 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 4020 break; 4021 } else { 4022 // timeout 4023 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 4024 if (cancelled == os::SuspendResume::SR_RUNNING) { 4025 return false; 4026 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 4027 // make sure that we consume the signal on the semaphore as well 4028 sr_semaphore.wait(); 4029 break; 4030 } else { 4031 ShouldNotReachHere(); 4032 return false; 4033 } 4034 } 4035 } 4036 4037 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 4038 return true; 4039} 4040 4041static void do_resume(OSThread* osthread) { 4042 assert(osthread->sr.is_suspended(), "thread should be suspended"); 4043 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 4044 4045 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 4046 // failed to switch to WAKEUP_REQUEST 4047 ShouldNotReachHere(); 4048 return; 4049 } 4050 4051 while (true) { 4052 if (sr_notify(osthread) == 0) { 4053 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 4054 if (osthread->sr.is_running()) { 4055 return; 4056 } 4057 } 4058 } else { 4059 ShouldNotReachHere(); 4060 } 4061 } 4062 4063 guarantee(osthread->sr.is_running(), "Must be running!"); 4064} 4065 4066/////////////////////////////////////////////////////////////////////////////////// 4067// signal handling (except suspend/resume) 4068 4069// This routine may be used by user applications as a "hook" to catch signals. 4070// The user-defined signal handler must pass unrecognized signals to this 4071// routine, and if it returns true (non-zero), then the signal handler must 4072// return immediately. If the flag "abort_if_unrecognized" is true, then this 4073// routine will never retun false (zero), but instead will execute a VM panic 4074// routine kill the process. 4075// 4076// If this routine returns false, it is OK to call it again. This allows 4077// the user-defined signal handler to perform checks either before or after 4078// the VM performs its own checks. Naturally, the user code would be making 4079// a serious error if it tried to handle an exception (such as a null check 4080// or breakpoint) that the VM was generating for its own correct operation. 4081// 4082// This routine may recognize any of the following kinds of signals: 4083// SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 4084// It should be consulted by handlers for any of those signals. 4085// 4086// The caller of this routine must pass in the three arguments supplied 4087// to the function referred to in the "sa_sigaction" (not the "sa_handler") 4088// field of the structure passed to sigaction(). This routine assumes that 4089// the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 4090// 4091// Note that the VM will print warnings if it detects conflicting signal 4092// handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 4093// 4094extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo, 4095 siginfo_t* siginfo, 4096 void* ucontext, 4097 int abort_if_unrecognized); 4098 4099void signalHandler(int sig, siginfo_t* info, void* uc) { 4100 assert(info != NULL && uc != NULL, "it must be old kernel"); 4101 int orig_errno = errno; // Preserve errno value over signal handler. 4102 JVM_handle_linux_signal(sig, info, uc, true); 4103 errno = orig_errno; 4104} 4105 4106 4107// This boolean allows users to forward their own non-matching signals 4108// to JVM_handle_linux_signal, harmlessly. 4109bool os::Linux::signal_handlers_are_installed = false; 4110 4111// For signal-chaining 4112struct sigaction sigact[NSIG]; 4113uint64_t sigs = 0; 4114#if (64 < NSIG-1) 4115#error "Not all signals can be encoded in sigs. Adapt its type!" 4116#endif 4117bool os::Linux::libjsig_is_loaded = false; 4118typedef struct sigaction *(*get_signal_t)(int); 4119get_signal_t os::Linux::get_signal_action = NULL; 4120 4121struct sigaction* os::Linux::get_chained_signal_action(int sig) { 4122 struct sigaction *actp = NULL; 4123 4124 if (libjsig_is_loaded) { 4125 // Retrieve the old signal handler from libjsig 4126 actp = (*get_signal_action)(sig); 4127 } 4128 if (actp == NULL) { 4129 // Retrieve the preinstalled signal handler from jvm 4130 actp = get_preinstalled_handler(sig); 4131 } 4132 4133 return actp; 4134} 4135 4136static bool call_chained_handler(struct sigaction *actp, int sig, 4137 siginfo_t *siginfo, void *context) { 4138 // Call the old signal handler 4139 if (actp->sa_handler == SIG_DFL) { 4140 // It's more reasonable to let jvm treat it as an unexpected exception 4141 // instead of taking the default action. 4142 return false; 4143 } else if (actp->sa_handler != SIG_IGN) { 4144 if ((actp->sa_flags & SA_NODEFER) == 0) { 4145 // automaticlly block the signal 4146 sigaddset(&(actp->sa_mask), sig); 4147 } 4148 4149 sa_handler_t hand = NULL; 4150 sa_sigaction_t sa = NULL; 4151 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 4152 // retrieve the chained handler 4153 if (siginfo_flag_set) { 4154 sa = actp->sa_sigaction; 4155 } else { 4156 hand = actp->sa_handler; 4157 } 4158 4159 if ((actp->sa_flags & SA_RESETHAND) != 0) { 4160 actp->sa_handler = SIG_DFL; 4161 } 4162 4163 // try to honor the signal mask 4164 sigset_t oset; 4165 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 4166 4167 // call into the chained handler 4168 if (siginfo_flag_set) { 4169 (*sa)(sig, siginfo, context); 4170 } else { 4171 (*hand)(sig); 4172 } 4173 4174 // restore the signal mask 4175 pthread_sigmask(SIG_SETMASK, &oset, 0); 4176 } 4177 // Tell jvm's signal handler the signal is taken care of. 4178 return true; 4179} 4180 4181bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) { 4182 bool chained = false; 4183 // signal-chaining 4184 if (UseSignalChaining) { 4185 struct sigaction *actp = get_chained_signal_action(sig); 4186 if (actp != NULL) { 4187 chained = call_chained_handler(actp, sig, siginfo, context); 4188 } 4189 } 4190 return chained; 4191} 4192 4193struct sigaction* os::Linux::get_preinstalled_handler(int sig) { 4194 if ((((uint64_t)1 << (sig-1)) & sigs) != 0) { 4195 return &sigact[sig]; 4196 } 4197 return NULL; 4198} 4199 4200void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 4201 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4202 sigact[sig] = oldAct; 4203 sigs |= (uint64_t)1 << (sig-1); 4204} 4205 4206// for diagnostic 4207int sigflags[NSIG]; 4208 4209int os::Linux::get_our_sigflags(int sig) { 4210 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4211 return sigflags[sig]; 4212} 4213 4214void os::Linux::set_our_sigflags(int sig, int flags) { 4215 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4216 if (sig > 0 && sig < NSIG) { 4217 sigflags[sig] = flags; 4218 } 4219} 4220 4221void os::Linux::set_signal_handler(int sig, bool set_installed) { 4222 // Check for overwrite. 4223 struct sigaction oldAct; 4224 sigaction(sig, (struct sigaction*)NULL, &oldAct); 4225 4226 void* oldhand = oldAct.sa_sigaction 4227 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4228 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4229 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 4230 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 4231 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 4232 if (AllowUserSignalHandlers || !set_installed) { 4233 // Do not overwrite; user takes responsibility to forward to us. 4234 return; 4235 } else if (UseSignalChaining) { 4236 // save the old handler in jvm 4237 save_preinstalled_handler(sig, oldAct); 4238 // libjsig also interposes the sigaction() call below and saves the 4239 // old sigaction on it own. 4240 } else { 4241 fatal("Encountered unexpected pre-existing sigaction handler " 4242 "%#lx for signal %d.", (long)oldhand, sig); 4243 } 4244 } 4245 4246 struct sigaction sigAct; 4247 sigfillset(&(sigAct.sa_mask)); 4248 sigAct.sa_handler = SIG_DFL; 4249 if (!set_installed) { 4250 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4251 } else { 4252 sigAct.sa_sigaction = signalHandler; 4253 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4254 } 4255 // Save flags, which are set by ours 4256 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4257 sigflags[sig] = sigAct.sa_flags; 4258 4259 int ret = sigaction(sig, &sigAct, &oldAct); 4260 assert(ret == 0, "check"); 4261 4262 void* oldhand2 = oldAct.sa_sigaction 4263 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4264 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4265 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 4266} 4267 4268// install signal handlers for signals that HotSpot needs to 4269// handle in order to support Java-level exception handling. 4270 4271void os::Linux::install_signal_handlers() { 4272 if (!signal_handlers_are_installed) { 4273 signal_handlers_are_installed = true; 4274 4275 // signal-chaining 4276 typedef void (*signal_setting_t)(); 4277 signal_setting_t begin_signal_setting = NULL; 4278 signal_setting_t end_signal_setting = NULL; 4279 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4280 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 4281 if (begin_signal_setting != NULL) { 4282 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4283 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 4284 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 4285 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 4286 libjsig_is_loaded = true; 4287 assert(UseSignalChaining, "should enable signal-chaining"); 4288 } 4289 if (libjsig_is_loaded) { 4290 // Tell libjsig jvm is setting signal handlers 4291 (*begin_signal_setting)(); 4292 } 4293 4294 set_signal_handler(SIGSEGV, true); 4295 set_signal_handler(SIGPIPE, true); 4296 set_signal_handler(SIGBUS, true); 4297 set_signal_handler(SIGILL, true); 4298 set_signal_handler(SIGFPE, true); 4299#if defined(PPC64) 4300 set_signal_handler(SIGTRAP, true); 4301#endif 4302 set_signal_handler(SIGXFSZ, true); 4303 4304 if (libjsig_is_loaded) { 4305 // Tell libjsig jvm finishes setting signal handlers 4306 (*end_signal_setting)(); 4307 } 4308 4309 // We don't activate signal checker if libjsig is in place, we trust ourselves 4310 // and if UserSignalHandler is installed all bets are off. 4311 // Log that signal checking is off only if -verbose:jni is specified. 4312 if (CheckJNICalls) { 4313 if (libjsig_is_loaded) { 4314 if (PrintJNIResolving) { 4315 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 4316 } 4317 check_signals = false; 4318 } 4319 if (AllowUserSignalHandlers) { 4320 if (PrintJNIResolving) { 4321 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 4322 } 4323 check_signals = false; 4324 } 4325 } 4326 } 4327} 4328 4329// This is the fastest way to get thread cpu time on Linux. 4330// Returns cpu time (user+sys) for any thread, not only for current. 4331// POSIX compliant clocks are implemented in the kernels 2.6.16+. 4332// It might work on 2.6.10+ with a special kernel/glibc patch. 4333// For reference, please, see IEEE Std 1003.1-2004: 4334// http://www.unix.org/single_unix_specification 4335 4336jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) { 4337 struct timespec tp; 4338 int rc = os::Linux::clock_gettime(clockid, &tp); 4339 assert(rc == 0, "clock_gettime is expected to return 0 code"); 4340 4341 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec; 4342} 4343 4344///// 4345// glibc on Linux platform uses non-documented flag 4346// to indicate, that some special sort of signal 4347// trampoline is used. 4348// We will never set this flag, and we should 4349// ignore this flag in our diagnostic 4350#ifdef SIGNIFICANT_SIGNAL_MASK 4351 #undef SIGNIFICANT_SIGNAL_MASK 4352#endif 4353#define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 4354 4355static const char* get_signal_handler_name(address handler, 4356 char* buf, int buflen) { 4357 int offset = 0; 4358 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 4359 if (found) { 4360 // skip directory names 4361 const char *p1, *p2; 4362 p1 = buf; 4363 size_t len = strlen(os::file_separator()); 4364 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 4365 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 4366 } else { 4367 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 4368 } 4369 return buf; 4370} 4371 4372static void print_signal_handler(outputStream* st, int sig, 4373 char* buf, size_t buflen) { 4374 struct sigaction sa; 4375 4376 sigaction(sig, NULL, &sa); 4377 4378 // See comment for SIGNIFICANT_SIGNAL_MASK define 4379 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4380 4381 st->print("%s: ", os::exception_name(sig, buf, buflen)); 4382 4383 address handler = (sa.sa_flags & SA_SIGINFO) 4384 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 4385 : CAST_FROM_FN_PTR(address, sa.sa_handler); 4386 4387 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 4388 st->print("SIG_DFL"); 4389 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 4390 st->print("SIG_IGN"); 4391 } else { 4392 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 4393 } 4394 4395 st->print(", sa_mask[0]="); 4396 os::Posix::print_signal_set_short(st, &sa.sa_mask); 4397 4398 address rh = VMError::get_resetted_sighandler(sig); 4399 // May be, handler was resetted by VMError? 4400 if (rh != NULL) { 4401 handler = rh; 4402 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 4403 } 4404 4405 st->print(", sa_flags="); 4406 os::Posix::print_sa_flags(st, sa.sa_flags); 4407 4408 // Check: is it our handler? 4409 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 4410 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 4411 // It is our signal handler 4412 // check for flags, reset system-used one! 4413 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) { 4414 st->print( 4415 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 4416 os::Linux::get_our_sigflags(sig)); 4417 } 4418 } 4419 st->cr(); 4420} 4421 4422 4423#define DO_SIGNAL_CHECK(sig) \ 4424 do { \ 4425 if (!sigismember(&check_signal_done, sig)) { \ 4426 os::Linux::check_signal_handler(sig); \ 4427 } \ 4428 } while (0) 4429 4430// This method is a periodic task to check for misbehaving JNI applications 4431// under CheckJNI, we can add any periodic checks here 4432 4433void os::run_periodic_checks() { 4434 if (check_signals == false) return; 4435 4436 // SEGV and BUS if overridden could potentially prevent 4437 // generation of hs*.log in the event of a crash, debugging 4438 // such a case can be very challenging, so we absolutely 4439 // check the following for a good measure: 4440 DO_SIGNAL_CHECK(SIGSEGV); 4441 DO_SIGNAL_CHECK(SIGILL); 4442 DO_SIGNAL_CHECK(SIGFPE); 4443 DO_SIGNAL_CHECK(SIGBUS); 4444 DO_SIGNAL_CHECK(SIGPIPE); 4445 DO_SIGNAL_CHECK(SIGXFSZ); 4446#if defined(PPC64) 4447 DO_SIGNAL_CHECK(SIGTRAP); 4448#endif 4449 4450 // ReduceSignalUsage allows the user to override these handlers 4451 // see comments at the very top and jvm_solaris.h 4452 if (!ReduceSignalUsage) { 4453 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 4454 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 4455 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 4456 DO_SIGNAL_CHECK(BREAK_SIGNAL); 4457 } 4458 4459 DO_SIGNAL_CHECK(SR_signum); 4460} 4461 4462typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 4463 4464static os_sigaction_t os_sigaction = NULL; 4465 4466void os::Linux::check_signal_handler(int sig) { 4467 char buf[O_BUFLEN]; 4468 address jvmHandler = NULL; 4469 4470 4471 struct sigaction act; 4472 if (os_sigaction == NULL) { 4473 // only trust the default sigaction, in case it has been interposed 4474 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 4475 if (os_sigaction == NULL) return; 4476 } 4477 4478 os_sigaction(sig, (struct sigaction*)NULL, &act); 4479 4480 4481 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4482 4483 address thisHandler = (act.sa_flags & SA_SIGINFO) 4484 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 4485 : CAST_FROM_FN_PTR(address, act.sa_handler); 4486 4487 4488 switch (sig) { 4489 case SIGSEGV: 4490 case SIGBUS: 4491 case SIGFPE: 4492 case SIGPIPE: 4493 case SIGILL: 4494 case SIGXFSZ: 4495 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 4496 break; 4497 4498 case SHUTDOWN1_SIGNAL: 4499 case SHUTDOWN2_SIGNAL: 4500 case SHUTDOWN3_SIGNAL: 4501 case BREAK_SIGNAL: 4502 jvmHandler = (address)user_handler(); 4503 break; 4504 4505 default: 4506 if (sig == SR_signum) { 4507 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 4508 } else { 4509 return; 4510 } 4511 break; 4512 } 4513 4514 if (thisHandler != jvmHandler) { 4515 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 4516 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 4517 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 4518 // No need to check this sig any longer 4519 sigaddset(&check_signal_done, sig); 4520 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 4521 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 4522 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 4523 exception_name(sig, buf, O_BUFLEN)); 4524 } 4525 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) { 4526 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 4527 tty->print("expected:"); 4528 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig)); 4529 tty->cr(); 4530 tty->print(" found:"); 4531 os::Posix::print_sa_flags(tty, act.sa_flags); 4532 tty->cr(); 4533 // No need to check this sig any longer 4534 sigaddset(&check_signal_done, sig); 4535 } 4536 4537 // Dump all the signal 4538 if (sigismember(&check_signal_done, sig)) { 4539 print_signal_handlers(tty, buf, O_BUFLEN); 4540 } 4541} 4542 4543extern void report_error(char* file_name, int line_no, char* title, 4544 char* format, ...); 4545 4546// this is called _before_ the most of global arguments have been parsed 4547void os::init(void) { 4548 char dummy; // used to get a guess on initial stack address 4549// first_hrtime = gethrtime(); 4550 4551 clock_tics_per_sec = sysconf(_SC_CLK_TCK); 4552 4553 init_random(1234567); 4554 4555 ThreadCritical::initialize(); 4556 4557 Linux::set_page_size(sysconf(_SC_PAGESIZE)); 4558 if (Linux::page_size() == -1) { 4559 fatal("os_linux.cpp: os::init: sysconf failed (%s)", 4560 strerror(errno)); 4561 } 4562 init_page_sizes((size_t) Linux::page_size()); 4563 4564 Linux::initialize_system_info(); 4565 4566 // main_thread points to the aboriginal thread 4567 Linux::_main_thread = pthread_self(); 4568 4569 Linux::clock_init(); 4570 initial_time_count = javaTimeNanos(); 4571 4572 // pthread_condattr initialization for monotonic clock 4573 int status; 4574 pthread_condattr_t* _condattr = os::Linux::condAttr(); 4575 if ((status = pthread_condattr_init(_condattr)) != 0) { 4576 fatal("pthread_condattr_init: %s", strerror(status)); 4577 } 4578 // Only set the clock if CLOCK_MONOTONIC is available 4579 if (os::supports_monotonic_clock()) { 4580 if ((status = pthread_condattr_setclock(_condattr, CLOCK_MONOTONIC)) != 0) { 4581 if (status == EINVAL) { 4582 warning("Unable to use monotonic clock with relative timed-waits" \ 4583 " - changes to the time-of-day clock may have adverse affects"); 4584 } else { 4585 fatal("pthread_condattr_setclock: %s", strerror(status)); 4586 } 4587 } 4588 } 4589 // else it defaults to CLOCK_REALTIME 4590 4591 // retrieve entry point for pthread_setname_np 4592 Linux::_pthread_setname_np = 4593 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np"); 4594 4595} 4596 4597// To install functions for atexit system call 4598extern "C" { 4599 static void perfMemory_exit_helper() { 4600 perfMemory_exit(); 4601 } 4602} 4603 4604// this is called _after_ the global arguments have been parsed 4605jint os::init_2(void) { 4606 Linux::fast_thread_clock_init(); 4607 4608 // Allocate a single page and mark it as readable for safepoint polling 4609 address polling_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 4610 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page"); 4611 4612 os::set_polling_page(polling_page); 4613 4614#ifndef PRODUCT 4615 if (Verbose && PrintMiscellaneous) { 4616 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", 4617 (intptr_t)polling_page); 4618 } 4619#endif 4620 4621 if (!UseMembar) { 4622 address mem_serialize_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 4623 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 4624 os::set_memory_serialize_page(mem_serialize_page); 4625 4626#ifndef PRODUCT 4627 if (Verbose && PrintMiscellaneous) { 4628 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", 4629 (intptr_t)mem_serialize_page); 4630 } 4631#endif 4632 } 4633 4634 // initialize suspend/resume support - must do this before signal_sets_init() 4635 if (SR_initialize() != 0) { 4636 perror("SR_initialize failed"); 4637 return JNI_ERR; 4638 } 4639 4640 Linux::signal_sets_init(); 4641 Linux::install_signal_handlers(); 4642 4643 // Check minimum allowable stack size for thread creation and to initialize 4644 // the java system classes, including StackOverflowError - depends on page 4645 // size. Add a page for compiler2 recursion in main thread. 4646 // Add in 2*BytesPerWord times page size to account for VM stack during 4647 // class initialization depending on 32 or 64 bit VM. 4648 os::Linux::min_stack_allowed = MAX2(os::Linux::min_stack_allowed, 4649 JavaThread::stack_guard_zone_size() + 4650 JavaThread::stack_shadow_zone_size() + 4651 (2*BytesPerWord COMPILER2_PRESENT(+1)) * Linux::vm_default_page_size()); 4652 4653 size_t threadStackSizeInBytes = ThreadStackSize * K; 4654 if (threadStackSizeInBytes != 0 && 4655 threadStackSizeInBytes < os::Linux::min_stack_allowed) { 4656 tty->print_cr("\nThe stack size specified is too small, " 4657 "Specify at least " SIZE_FORMAT "k", 4658 os::Linux::min_stack_allowed/ K); 4659 return JNI_ERR; 4660 } 4661 4662 // Make the stack size a multiple of the page size so that 4663 // the yellow/red zones can be guarded. 4664 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 4665 vm_page_size())); 4666 4667 Linux::capture_initial_stack(JavaThread::stack_size_at_create()); 4668 4669#if defined(IA32) 4670 workaround_expand_exec_shield_cs_limit(); 4671#endif 4672 4673 Linux::libpthread_init(); 4674 if (PrintMiscellaneous && (Verbose || WizardMode)) { 4675 tty->print_cr("[HotSpot is running with %s, %s]\n", 4676 Linux::glibc_version(), Linux::libpthread_version()); 4677 } 4678 4679 if (UseNUMA) { 4680 if (!Linux::libnuma_init()) { 4681 UseNUMA = false; 4682 } else { 4683 if ((Linux::numa_max_node() < 1)) { 4684 // There's only one node(they start from 0), disable NUMA. 4685 UseNUMA = false; 4686 } 4687 } 4688 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way 4689 // we can make the adaptive lgrp chunk resizing work. If the user specified 4690 // both UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn and 4691 // disable adaptive resizing. 4692 if (UseNUMA && UseLargePages && !can_commit_large_page_memory()) { 4693 if (FLAG_IS_DEFAULT(UseNUMA)) { 4694 UseNUMA = false; 4695 } else { 4696 if (FLAG_IS_DEFAULT(UseLargePages) && 4697 FLAG_IS_DEFAULT(UseSHM) && 4698 FLAG_IS_DEFAULT(UseHugeTLBFS)) { 4699 UseLargePages = false; 4700 } else if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) { 4701 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)"); 4702 UseAdaptiveSizePolicy = false; 4703 UseAdaptiveNUMAChunkSizing = false; 4704 } 4705 } 4706 } 4707 if (!UseNUMA && ForceNUMA) { 4708 UseNUMA = true; 4709 } 4710 } 4711 4712 if (MaxFDLimit) { 4713 // set the number of file descriptors to max. print out error 4714 // if getrlimit/setrlimit fails but continue regardless. 4715 struct rlimit nbr_files; 4716 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 4717 if (status != 0) { 4718 if (PrintMiscellaneous && (Verbose || WizardMode)) { 4719 perror("os::init_2 getrlimit failed"); 4720 } 4721 } else { 4722 nbr_files.rlim_cur = nbr_files.rlim_max; 4723 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 4724 if (status != 0) { 4725 if (PrintMiscellaneous && (Verbose || WizardMode)) { 4726 perror("os::init_2 setrlimit failed"); 4727 } 4728 } 4729 } 4730 } 4731 4732 // Initialize lock used to serialize thread creation (see os::create_thread) 4733 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false)); 4734 4735 // at-exit methods are called in the reverse order of their registration. 4736 // atexit functions are called on return from main or as a result of a 4737 // call to exit(3C). There can be only 32 of these functions registered 4738 // and atexit() does not set errno. 4739 4740 if (PerfAllowAtExitRegistration) { 4741 // only register atexit functions if PerfAllowAtExitRegistration is set. 4742 // atexit functions can be delayed until process exit time, which 4743 // can be problematic for embedded VM situations. Embedded VMs should 4744 // call DestroyJavaVM() to assure that VM resources are released. 4745 4746 // note: perfMemory_exit_helper atexit function may be removed in 4747 // the future if the appropriate cleanup code can be added to the 4748 // VM_Exit VMOperation's doit method. 4749 if (atexit(perfMemory_exit_helper) != 0) { 4750 warning("os::init_2 atexit(perfMemory_exit_helper) failed"); 4751 } 4752 } 4753 4754 // initialize thread priority policy 4755 prio_init(); 4756 4757 return JNI_OK; 4758} 4759 4760// Mark the polling page as unreadable 4761void os::make_polling_page_unreadable(void) { 4762 if (!guard_memory((char*)_polling_page, Linux::page_size())) { 4763 fatal("Could not disable polling page"); 4764 } 4765} 4766 4767// Mark the polling page as readable 4768void os::make_polling_page_readable(void) { 4769 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) { 4770 fatal("Could not enable polling page"); 4771 } 4772} 4773 4774// Get the current number of available processors for this process. 4775// This value can change at any time during a process's lifetime. 4776// sched_getaffinity gives an accurate answer as it accounts for cpusets. 4777// If it appears there may be more than 1024 processors then we do a 4778// dynamic check - see 6515172 for details. 4779// If anything goes wrong we fallback to returning the number of online 4780// processors - which can be greater than the number available to the process. 4781int os::active_processor_count() { 4782 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors 4783 cpu_set_t* cpus_p = &cpus; 4784 int cpus_size = sizeof(cpu_set_t); 4785 4786 int configured_cpus = processor_count(); // upper bound on available cpus 4787 int cpu_count = 0; 4788 4789 // To enable easy testing of the dynamic path on different platforms we 4790 // introduce a diagnostic flag: UseCpuAllocPath 4791 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) { 4792 // kernel may use a mask bigger than cpu_set_t 4793 log_trace(os)("active_processor_count: using dynamic path %s" 4794 "- configured processors: %d", 4795 UseCpuAllocPath ? "(forced) " : "", 4796 configured_cpus); 4797 cpus_p = CPU_ALLOC(configured_cpus); 4798 if (cpus_p != NULL) { 4799 cpus_size = CPU_ALLOC_SIZE(configured_cpus); 4800 // zero it just to be safe 4801 CPU_ZERO_S(cpus_size, cpus_p); 4802 } 4803 else { 4804 // failed to allocate so fallback to online cpus 4805 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); 4806 log_trace(os)("active_processor_count: " 4807 "CPU_ALLOC failed (%s) - using " 4808 "online processor count: %d", 4809 strerror(errno), online_cpus); 4810 return online_cpus; 4811 } 4812 } 4813 else { 4814 log_trace(os)("active_processor_count: using static path - configured processors: %d", 4815 configured_cpus); 4816 } 4817 4818 // pid 0 means the current thread - which we have to assume represents the process 4819 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) { 4820 if (cpus_p != &cpus) { 4821 cpu_count = CPU_COUNT_S(cpus_size, cpus_p); 4822 } 4823 else { 4824 cpu_count = CPU_COUNT(cpus_p); 4825 } 4826 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count); 4827 } 4828 else { 4829 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN); 4830 warning("sched_getaffinity failed (%s)- using online processor count (%d) " 4831 "which may exceed available processors", strerror(errno), cpu_count); 4832 } 4833 4834 if (cpus_p != &cpus) { 4835 CPU_FREE(cpus_p); 4836 } 4837 4838 assert(cpu_count > 0 && cpu_count <= processor_count(), "sanity check"); 4839 return cpu_count; 4840} 4841 4842void os::set_native_thread_name(const char *name) { 4843 if (Linux::_pthread_setname_np) { 4844 char buf [16]; // according to glibc manpage, 16 chars incl. '/0' 4845 snprintf(buf, sizeof(buf), "%s", name); 4846 buf[sizeof(buf) - 1] = '\0'; 4847 const int rc = Linux::_pthread_setname_np(pthread_self(), buf); 4848 // ERANGE should not happen; all other errors should just be ignored. 4849 assert(rc != ERANGE, "pthread_setname_np failed"); 4850 } 4851} 4852 4853bool os::distribute_processes(uint length, uint* distribution) { 4854 // Not yet implemented. 4855 return false; 4856} 4857 4858bool os::bind_to_processor(uint processor_id) { 4859 // Not yet implemented. 4860 return false; 4861} 4862 4863/// 4864 4865void os::SuspendedThreadTask::internal_do_task() { 4866 if (do_suspend(_thread->osthread())) { 4867 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 4868 do_task(context); 4869 do_resume(_thread->osthread()); 4870 } 4871} 4872 4873class PcFetcher : public os::SuspendedThreadTask { 4874 public: 4875 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 4876 ExtendedPC result(); 4877 protected: 4878 void do_task(const os::SuspendedThreadTaskContext& context); 4879 private: 4880 ExtendedPC _epc; 4881}; 4882 4883ExtendedPC PcFetcher::result() { 4884 guarantee(is_done(), "task is not done yet."); 4885 return _epc; 4886} 4887 4888void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 4889 Thread* thread = context.thread(); 4890 OSThread* osthread = thread->osthread(); 4891 if (osthread->ucontext() != NULL) { 4892 _epc = os::Linux::ucontext_get_pc((const ucontext_t *) context.ucontext()); 4893 } else { 4894 // NULL context is unexpected, double-check this is the VMThread 4895 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 4896 } 4897} 4898 4899// Suspends the target using the signal mechanism and then grabs the PC before 4900// resuming the target. Used by the flat-profiler only 4901ExtendedPC os::get_thread_pc(Thread* thread) { 4902 // Make sure that it is called by the watcher for the VMThread 4903 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 4904 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 4905 4906 PcFetcher fetcher(thread); 4907 fetcher.run(); 4908 return fetcher.result(); 4909} 4910 4911//////////////////////////////////////////////////////////////////////////////// 4912// debug support 4913 4914bool os::find(address addr, outputStream* st) { 4915 Dl_info dlinfo; 4916 memset(&dlinfo, 0, sizeof(dlinfo)); 4917 if (dladdr(addr, &dlinfo) != 0) { 4918 st->print(PTR_FORMAT ": ", p2i(addr)); 4919 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 4920 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname, 4921 p2i(addr) - p2i(dlinfo.dli_saddr)); 4922 } else if (dlinfo.dli_fbase != NULL) { 4923 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase)); 4924 } else { 4925 st->print("<absolute address>"); 4926 } 4927 if (dlinfo.dli_fname != NULL) { 4928 st->print(" in %s", dlinfo.dli_fname); 4929 } 4930 if (dlinfo.dli_fbase != NULL) { 4931 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase)); 4932 } 4933 st->cr(); 4934 4935 if (Verbose) { 4936 // decode some bytes around the PC 4937 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 4938 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 4939 address lowest = (address) dlinfo.dli_sname; 4940 if (!lowest) lowest = (address) dlinfo.dli_fbase; 4941 if (begin < lowest) begin = lowest; 4942 Dl_info dlinfo2; 4943 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 4944 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 4945 end = (address) dlinfo2.dli_saddr; 4946 } 4947 Disassembler::decode(begin, end, st); 4948 } 4949 return true; 4950 } 4951 return false; 4952} 4953 4954//////////////////////////////////////////////////////////////////////////////// 4955// misc 4956 4957// This does not do anything on Linux. This is basically a hook for being 4958// able to use structured exception handling (thread-local exception filters) 4959// on, e.g., Win32. 4960void 4961os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, 4962 JavaCallArguments* args, Thread* thread) { 4963 f(value, method, args, thread); 4964} 4965 4966void os::print_statistics() { 4967} 4968 4969bool os::message_box(const char* title, const char* message) { 4970 int i; 4971 fdStream err(defaultStream::error_fd()); 4972 for (i = 0; i < 78; i++) err.print_raw("="); 4973 err.cr(); 4974 err.print_raw_cr(title); 4975 for (i = 0; i < 78; i++) err.print_raw("-"); 4976 err.cr(); 4977 err.print_raw_cr(message); 4978 for (i = 0; i < 78; i++) err.print_raw("="); 4979 err.cr(); 4980 4981 char buf[16]; 4982 // Prevent process from exiting upon "read error" without consuming all CPU 4983 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 4984 4985 return buf[0] == 'y' || buf[0] == 'Y'; 4986} 4987 4988int os::stat(const char *path, struct stat *sbuf) { 4989 char pathbuf[MAX_PATH]; 4990 if (strlen(path) > MAX_PATH - 1) { 4991 errno = ENAMETOOLONG; 4992 return -1; 4993 } 4994 os::native_path(strcpy(pathbuf, path)); 4995 return ::stat(pathbuf, sbuf); 4996} 4997 4998bool os::check_heap(bool force) { 4999 return true; 5000} 5001 5002// Is a (classpath) directory empty? 5003bool os::dir_is_empty(const char* path) { 5004 DIR *dir = NULL; 5005 struct dirent *ptr; 5006 5007 dir = opendir(path); 5008 if (dir == NULL) return true; 5009 5010 // Scan the directory 5011 bool result = true; 5012 char buf[sizeof(struct dirent) + MAX_PATH]; 5013 while (result && (ptr = ::readdir(dir)) != NULL) { 5014 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 5015 result = false; 5016 } 5017 } 5018 closedir(dir); 5019 return result; 5020} 5021 5022// This code originates from JDK's sysOpen and open64_w 5023// from src/solaris/hpi/src/system_md.c 5024 5025int os::open(const char *path, int oflag, int mode) { 5026 if (strlen(path) > MAX_PATH - 1) { 5027 errno = ENAMETOOLONG; 5028 return -1; 5029 } 5030 5031 // All file descriptors that are opened in the Java process and not 5032 // specifically destined for a subprocess should have the close-on-exec 5033 // flag set. If we don't set it, then careless 3rd party native code 5034 // might fork and exec without closing all appropriate file descriptors 5035 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in 5036 // turn might: 5037 // 5038 // - cause end-of-file to fail to be detected on some file 5039 // descriptors, resulting in mysterious hangs, or 5040 // 5041 // - might cause an fopen in the subprocess to fail on a system 5042 // suffering from bug 1085341. 5043 // 5044 // (Yes, the default setting of the close-on-exec flag is a Unix 5045 // design flaw) 5046 // 5047 // See: 5048 // 1085341: 32-bit stdio routines should support file descriptors >255 5049 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 5050 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 5051 // 5052 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open(). 5053 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor 5054 // because it saves a system call and removes a small window where the flag 5055 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored 5056 // and we fall back to using FD_CLOEXEC (see below). 5057#ifdef O_CLOEXEC 5058 oflag |= O_CLOEXEC; 5059#endif 5060 5061 int fd = ::open64(path, oflag, mode); 5062 if (fd == -1) return -1; 5063 5064 //If the open succeeded, the file might still be a directory 5065 { 5066 struct stat64 buf64; 5067 int ret = ::fstat64(fd, &buf64); 5068 int st_mode = buf64.st_mode; 5069 5070 if (ret != -1) { 5071 if ((st_mode & S_IFMT) == S_IFDIR) { 5072 errno = EISDIR; 5073 ::close(fd); 5074 return -1; 5075 } 5076 } else { 5077 ::close(fd); 5078 return -1; 5079 } 5080 } 5081 5082#ifdef FD_CLOEXEC 5083 // Validate that the use of the O_CLOEXEC flag on open above worked. 5084 // With recent kernels, we will perform this check exactly once. 5085 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0; 5086 if (!O_CLOEXEC_is_known_to_work) { 5087 int flags = ::fcntl(fd, F_GETFD); 5088 if (flags != -1) { 5089 if ((flags & FD_CLOEXEC) != 0) 5090 O_CLOEXEC_is_known_to_work = 1; 5091 else 5092 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 5093 } 5094 } 5095#endif 5096 5097 return fd; 5098} 5099 5100 5101// create binary file, rewriting existing file if required 5102int os::create_binary_file(const char* path, bool rewrite_existing) { 5103 int oflags = O_WRONLY | O_CREAT; 5104 if (!rewrite_existing) { 5105 oflags |= O_EXCL; 5106 } 5107 return ::open64(path, oflags, S_IREAD | S_IWRITE); 5108} 5109 5110// return current position of file pointer 5111jlong os::current_file_offset(int fd) { 5112 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR); 5113} 5114 5115// move file pointer to the specified offset 5116jlong os::seek_to_file_offset(int fd, jlong offset) { 5117 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET); 5118} 5119 5120// This code originates from JDK's sysAvailable 5121// from src/solaris/hpi/src/native_threads/src/sys_api_td.c 5122 5123int os::available(int fd, jlong *bytes) { 5124 jlong cur, end; 5125 int mode; 5126 struct stat64 buf64; 5127 5128 if (::fstat64(fd, &buf64) >= 0) { 5129 mode = buf64.st_mode; 5130 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 5131 int n; 5132 if (::ioctl(fd, FIONREAD, &n) >= 0) { 5133 *bytes = n; 5134 return 1; 5135 } 5136 } 5137 } 5138 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) { 5139 return 0; 5140 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) { 5141 return 0; 5142 } else if (::lseek64(fd, cur, SEEK_SET) == -1) { 5143 return 0; 5144 } 5145 *bytes = end - cur; 5146 return 1; 5147} 5148 5149// Map a block of memory. 5150char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 5151 char *addr, size_t bytes, bool read_only, 5152 bool allow_exec) { 5153 int prot; 5154 int flags = MAP_PRIVATE; 5155 5156 if (read_only) { 5157 prot = PROT_READ; 5158 } else { 5159 prot = PROT_READ | PROT_WRITE; 5160 } 5161 5162 if (allow_exec) { 5163 prot |= PROT_EXEC; 5164 } 5165 5166 if (addr != NULL) { 5167 flags |= MAP_FIXED; 5168 } 5169 5170 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 5171 fd, file_offset); 5172 if (mapped_address == MAP_FAILED) { 5173 return NULL; 5174 } 5175 return mapped_address; 5176} 5177 5178 5179// Remap a block of memory. 5180char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 5181 char *addr, size_t bytes, bool read_only, 5182 bool allow_exec) { 5183 // same as map_memory() on this OS 5184 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 5185 allow_exec); 5186} 5187 5188 5189// Unmap a block of memory. 5190bool os::pd_unmap_memory(char* addr, size_t bytes) { 5191 return munmap(addr, bytes) == 0; 5192} 5193 5194static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time); 5195 5196static clockid_t thread_cpu_clockid(Thread* thread) { 5197 pthread_t tid = thread->osthread()->pthread_id(); 5198 clockid_t clockid; 5199 5200 // Get thread clockid 5201 int rc = os::Linux::pthread_getcpuclockid(tid, &clockid); 5202 assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code"); 5203 return clockid; 5204} 5205 5206// current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 5207// are used by JVM M&M and JVMTI to get user+sys or user CPU time 5208// of a thread. 5209// 5210// current_thread_cpu_time() and thread_cpu_time(Thread*) returns 5211// the fast estimate available on the platform. 5212 5213jlong os::current_thread_cpu_time() { 5214 if (os::Linux::supports_fast_thread_cpu_time()) { 5215 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5216 } else { 5217 // return user + sys since the cost is the same 5218 return slow_thread_cpu_time(Thread::current(), true /* user + sys */); 5219 } 5220} 5221 5222jlong os::thread_cpu_time(Thread* thread) { 5223 // consistent with what current_thread_cpu_time() returns 5224 if (os::Linux::supports_fast_thread_cpu_time()) { 5225 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); 5226 } else { 5227 return slow_thread_cpu_time(thread, true /* user + sys */); 5228 } 5229} 5230 5231jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 5232 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5233 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5234 } else { 5235 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time); 5236 } 5237} 5238 5239jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5240 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5241 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); 5242 } else { 5243 return slow_thread_cpu_time(thread, user_sys_cpu_time); 5244 } 5245} 5246 5247// -1 on error. 5248static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5249 pid_t tid = thread->osthread()->thread_id(); 5250 char *s; 5251 char stat[2048]; 5252 int statlen; 5253 char proc_name[64]; 5254 int count; 5255 long sys_time, user_time; 5256 char cdummy; 5257 int idummy; 5258 long ldummy; 5259 FILE *fp; 5260 5261 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid); 5262 fp = fopen(proc_name, "r"); 5263 if (fp == NULL) return -1; 5264 statlen = fread(stat, 1, 2047, fp); 5265 stat[statlen] = '\0'; 5266 fclose(fp); 5267 5268 // Skip pid and the command string. Note that we could be dealing with 5269 // weird command names, e.g. user could decide to rename java launcher 5270 // to "java 1.4.2 :)", then the stat file would look like 5271 // 1234 (java 1.4.2 :)) R ... ... 5272 // We don't really need to know the command string, just find the last 5273 // occurrence of ")" and then start parsing from there. See bug 4726580. 5274 s = strrchr(stat, ')'); 5275 if (s == NULL) return -1; 5276 5277 // Skip blank chars 5278 do { s++; } while (s && isspace(*s)); 5279 5280 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu", 5281 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy, 5282 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy, 5283 &user_time, &sys_time); 5284 if (count != 13) return -1; 5285 if (user_sys_cpu_time) { 5286 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); 5287 } else { 5288 return (jlong)user_time * (1000000000 / clock_tics_per_sec); 5289 } 5290} 5291 5292void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5293 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5294 info_ptr->may_skip_backward = false; // elapsed time not wall time 5295 info_ptr->may_skip_forward = false; // elapsed time not wall time 5296 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5297} 5298 5299void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5300 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5301 info_ptr->may_skip_backward = false; // elapsed time not wall time 5302 info_ptr->may_skip_forward = false; // elapsed time not wall time 5303 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5304} 5305 5306bool os::is_thread_cpu_time_supported() { 5307 return true; 5308} 5309 5310// System loadavg support. Returns -1 if load average cannot be obtained. 5311// Linux doesn't yet have a (official) notion of processor sets, 5312// so just return the system wide load average. 5313int os::loadavg(double loadavg[], int nelem) { 5314 return ::getloadavg(loadavg, nelem); 5315} 5316 5317void os::pause() { 5318 char filename[MAX_PATH]; 5319 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 5320 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile); 5321 } else { 5322 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 5323 } 5324 5325 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 5326 if (fd != -1) { 5327 struct stat buf; 5328 ::close(fd); 5329 while (::stat(filename, &buf) == 0) { 5330 (void)::poll(NULL, 0, 100); 5331 } 5332 } else { 5333 jio_fprintf(stderr, 5334 "Could not open pause file '%s', continuing immediately.\n", filename); 5335 } 5336} 5337 5338 5339// Refer to the comments in os_solaris.cpp park-unpark. The next two 5340// comment paragraphs are worth repeating here: 5341// 5342// Assumption: 5343// Only one parker can exist on an event, which is why we allocate 5344// them per-thread. Multiple unparkers can coexist. 5345// 5346// _Event serves as a restricted-range semaphore. 5347// -1 : thread is blocked, i.e. there is a waiter 5348// 0 : neutral: thread is running or ready, 5349// could have been signaled after a wait started 5350// 1 : signaled - thread is running or ready 5351// 5352// Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 5353// hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 5354// For specifics regarding the bug see GLIBC BUGID 261237 : 5355// http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 5356// Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 5357// will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 5358// is used. (The simple C test-case provided in the GLIBC bug report manifests the 5359// hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 5360// and monitorenter when we're using 1-0 locking. All those operations may result in 5361// calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 5362// of libpthread avoids the problem, but isn't practical. 5363// 5364// Possible remedies: 5365// 5366// 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 5367// This is palliative and probabilistic, however. If the thread is preempted 5368// between the call to compute_abstime() and pthread_cond_timedwait(), more 5369// than the minimum period may have passed, and the abstime may be stale (in the 5370// past) resultin in a hang. Using this technique reduces the odds of a hang 5371// but the JVM is still vulnerable, particularly on heavily loaded systems. 5372// 5373// 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 5374// of the usual flag-condvar-mutex idiom. The write side of the pipe is set 5375// NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 5376// reduces to poll()+read(). This works well, but consumes 2 FDs per extant 5377// thread. 5378// 5379// 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 5380// that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 5381// a timeout request to the chron thread and then blocking via pthread_cond_wait(). 5382// This also works well. In fact it avoids kernel-level scalability impediments 5383// on certain platforms that don't handle lots of active pthread_cond_timedwait() 5384// timers in a graceful fashion. 5385// 5386// 4. When the abstime value is in the past it appears that control returns 5387// correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 5388// Subsequent timedwait/wait calls may hang indefinitely. Given that, we 5389// can avoid the problem by reinitializing the condvar -- by cond_destroy() 5390// followed by cond_init() -- after all calls to pthread_cond_timedwait(). 5391// It may be possible to avoid reinitialization by checking the return 5392// value from pthread_cond_timedwait(). In addition to reinitializing the 5393// condvar we must establish the invariant that cond_signal() is only called 5394// within critical sections protected by the adjunct mutex. This prevents 5395// cond_signal() from "seeing" a condvar that's in the midst of being 5396// reinitialized or that is corrupt. Sadly, this invariant obviates the 5397// desirable signal-after-unlock optimization that avoids futile context switching. 5398// 5399// I'm also concerned that some versions of NTPL might allocate an auxilliary 5400// structure when a condvar is used or initialized. cond_destroy() would 5401// release the helper structure. Our reinitialize-after-timedwait fix 5402// put excessive stress on malloc/free and locks protecting the c-heap. 5403// 5404// We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 5405// It may be possible to refine (4) by checking the kernel and NTPL verisons 5406// and only enabling the work-around for vulnerable environments. 5407 5408// utility to compute the abstime argument to timedwait: 5409// millis is the relative timeout time 5410// abstime will be the absolute timeout time 5411// TODO: replace compute_abstime() with unpackTime() 5412 5413static struct timespec* compute_abstime(timespec* abstime, jlong millis) { 5414 if (millis < 0) millis = 0; 5415 5416 jlong seconds = millis / 1000; 5417 millis %= 1000; 5418 if (seconds > 50000000) { // see man cond_timedwait(3T) 5419 seconds = 50000000; 5420 } 5421 5422 if (os::supports_monotonic_clock()) { 5423 struct timespec now; 5424 int status = os::Linux::clock_gettime(CLOCK_MONOTONIC, &now); 5425 assert_status(status == 0, status, "clock_gettime"); 5426 abstime->tv_sec = now.tv_sec + seconds; 5427 long nanos = now.tv_nsec + millis * NANOSECS_PER_MILLISEC; 5428 if (nanos >= NANOSECS_PER_SEC) { 5429 abstime->tv_sec += 1; 5430 nanos -= NANOSECS_PER_SEC; 5431 } 5432 abstime->tv_nsec = nanos; 5433 } else { 5434 struct timeval now; 5435 int status = gettimeofday(&now, NULL); 5436 assert(status == 0, "gettimeofday"); 5437 abstime->tv_sec = now.tv_sec + seconds; 5438 long usec = now.tv_usec + millis * 1000; 5439 if (usec >= 1000000) { 5440 abstime->tv_sec += 1; 5441 usec -= 1000000; 5442 } 5443 abstime->tv_nsec = usec * 1000; 5444 } 5445 return abstime; 5446} 5447 5448void os::PlatformEvent::park() { // AKA "down()" 5449 // Transitions for _Event: 5450 // -1 => -1 : illegal 5451 // 1 => 0 : pass - return immediately 5452 // 0 => -1 : block; then set _Event to 0 before returning 5453 5454 // Invariant: Only the thread associated with the Event/PlatformEvent 5455 // may call park(). 5456 // TODO: assert that _Assoc != NULL or _Assoc == Self 5457 assert(_nParked == 0, "invariant"); 5458 5459 int v; 5460 for (;;) { 5461 v = _Event; 5462 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 5463 } 5464 guarantee(v >= 0, "invariant"); 5465 if (v == 0) { 5466 // Do this the hard way by blocking ... 5467 int status = pthread_mutex_lock(_mutex); 5468 assert_status(status == 0, status, "mutex_lock"); 5469 guarantee(_nParked == 0, "invariant"); 5470 ++_nParked; 5471 while (_Event < 0) { 5472 status = pthread_cond_wait(_cond, _mutex); 5473 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 5474 // Treat this the same as if the wait was interrupted 5475 if (status == ETIME) { status = EINTR; } 5476 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 5477 } 5478 --_nParked; 5479 5480 _Event = 0; 5481 status = pthread_mutex_unlock(_mutex); 5482 assert_status(status == 0, status, "mutex_unlock"); 5483 // Paranoia to ensure our locked and lock-free paths interact 5484 // correctly with each other. 5485 OrderAccess::fence(); 5486 } 5487 guarantee(_Event >= 0, "invariant"); 5488} 5489 5490int os::PlatformEvent::park(jlong millis) { 5491 // Transitions for _Event: 5492 // -1 => -1 : illegal 5493 // 1 => 0 : pass - return immediately 5494 // 0 => -1 : block; then set _Event to 0 before returning 5495 5496 guarantee(_nParked == 0, "invariant"); 5497 5498 int v; 5499 for (;;) { 5500 v = _Event; 5501 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 5502 } 5503 guarantee(v >= 0, "invariant"); 5504 if (v != 0) return OS_OK; 5505 5506 // We do this the hard way, by blocking the thread. 5507 // Consider enforcing a minimum timeout value. 5508 struct timespec abst; 5509 compute_abstime(&abst, millis); 5510 5511 int ret = OS_TIMEOUT; 5512 int status = pthread_mutex_lock(_mutex); 5513 assert_status(status == 0, status, "mutex_lock"); 5514 guarantee(_nParked == 0, "invariant"); 5515 ++_nParked; 5516 5517 // Object.wait(timo) will return because of 5518 // (a) notification 5519 // (b) timeout 5520 // (c) thread.interrupt 5521 // 5522 // Thread.interrupt and object.notify{All} both call Event::set. 5523 // That is, we treat thread.interrupt as a special case of notification. 5524 // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false. 5525 // We assume all ETIME returns are valid. 5526 // 5527 // TODO: properly differentiate simultaneous notify+interrupt. 5528 // In that case, we should propagate the notify to another waiter. 5529 5530 while (_Event < 0) { 5531 status = pthread_cond_timedwait(_cond, _mutex, &abst); 5532 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 5533 pthread_cond_destroy(_cond); 5534 pthread_cond_init(_cond, os::Linux::condAttr()); 5535 } 5536 assert_status(status == 0 || status == EINTR || 5537 status == ETIME || status == ETIMEDOUT, 5538 status, "cond_timedwait"); 5539 if (!FilterSpuriousWakeups) break; // previous semantics 5540 if (status == ETIME || status == ETIMEDOUT) break; 5541 // We consume and ignore EINTR and spurious wakeups. 5542 } 5543 --_nParked; 5544 if (_Event >= 0) { 5545 ret = OS_OK; 5546 } 5547 _Event = 0; 5548 status = pthread_mutex_unlock(_mutex); 5549 assert_status(status == 0, status, "mutex_unlock"); 5550 assert(_nParked == 0, "invariant"); 5551 // Paranoia to ensure our locked and lock-free paths interact 5552 // correctly with each other. 5553 OrderAccess::fence(); 5554 return ret; 5555} 5556 5557void os::PlatformEvent::unpark() { 5558 // Transitions for _Event: 5559 // 0 => 1 : just return 5560 // 1 => 1 : just return 5561 // -1 => either 0 or 1; must signal target thread 5562 // That is, we can safely transition _Event from -1 to either 5563 // 0 or 1. 5564 // See also: "Semaphores in Plan 9" by Mullender & Cox 5565 // 5566 // Note: Forcing a transition from "-1" to "1" on an unpark() means 5567 // that it will take two back-to-back park() calls for the owning 5568 // thread to block. This has the benefit of forcing a spurious return 5569 // from the first park() call after an unpark() call which will help 5570 // shake out uses of park() and unpark() without condition variables. 5571 5572 if (Atomic::xchg(1, &_Event) >= 0) return; 5573 5574 // Wait for the thread associated with the event to vacate 5575 int status = pthread_mutex_lock(_mutex); 5576 assert_status(status == 0, status, "mutex_lock"); 5577 int AnyWaiters = _nParked; 5578 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 5579 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 5580 AnyWaiters = 0; 5581 pthread_cond_signal(_cond); 5582 } 5583 status = pthread_mutex_unlock(_mutex); 5584 assert_status(status == 0, status, "mutex_unlock"); 5585 if (AnyWaiters != 0) { 5586 // Note that we signal() *after* dropping the lock for "immortal" Events. 5587 // This is safe and avoids a common class of futile wakeups. In rare 5588 // circumstances this can cause a thread to return prematurely from 5589 // cond_{timed}wait() but the spurious wakeup is benign and the victim 5590 // will simply re-test the condition and re-park itself. 5591 // This provides particular benefit if the underlying platform does not 5592 // provide wait morphing. 5593 status = pthread_cond_signal(_cond); 5594 assert_status(status == 0, status, "cond_signal"); 5595 } 5596} 5597 5598 5599// JSR166 5600// ------------------------------------------------------- 5601 5602// The solaris and linux implementations of park/unpark are fairly 5603// conservative for now, but can be improved. They currently use a 5604// mutex/condvar pair, plus a a count. 5605// Park decrements count if > 0, else does a condvar wait. Unpark 5606// sets count to 1 and signals condvar. Only one thread ever waits 5607// on the condvar. Contention seen when trying to park implies that someone 5608// is unparking you, so don't wait. And spurious returns are fine, so there 5609// is no need to track notifications. 5610 5611// This code is common to linux and solaris and will be moved to a 5612// common place in dolphin. 5613// 5614// The passed in time value is either a relative time in nanoseconds 5615// or an absolute time in milliseconds. Either way it has to be unpacked 5616// into suitable seconds and nanoseconds components and stored in the 5617// given timespec structure. 5618// Given time is a 64-bit value and the time_t used in the timespec is only 5619// a signed-32-bit value (except on 64-bit Linux) we have to watch for 5620// overflow if times way in the future are given. Further on Solaris versions 5621// prior to 10 there is a restriction (see cond_timedwait) that the specified 5622// number of seconds, in abstime, is less than current_time + 100,000,000. 5623// As it will be 28 years before "now + 100000000" will overflow we can 5624// ignore overflow and just impose a hard-limit on seconds using the value 5625// of "now + 100,000,000". This places a limit on the timeout of about 3.17 5626// years from "now". 5627 5628static void unpackTime(timespec* absTime, bool isAbsolute, jlong time) { 5629 assert(time > 0, "convertTime"); 5630 time_t max_secs = 0; 5631 5632 if (!os::supports_monotonic_clock() || isAbsolute) { 5633 struct timeval now; 5634 int status = gettimeofday(&now, NULL); 5635 assert(status == 0, "gettimeofday"); 5636 5637 max_secs = now.tv_sec + MAX_SECS; 5638 5639 if (isAbsolute) { 5640 jlong secs = time / 1000; 5641 if (secs > max_secs) { 5642 absTime->tv_sec = max_secs; 5643 } else { 5644 absTime->tv_sec = secs; 5645 } 5646 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 5647 } else { 5648 jlong secs = time / NANOSECS_PER_SEC; 5649 if (secs >= MAX_SECS) { 5650 absTime->tv_sec = max_secs; 5651 absTime->tv_nsec = 0; 5652 } else { 5653 absTime->tv_sec = now.tv_sec + secs; 5654 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 5655 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 5656 absTime->tv_nsec -= NANOSECS_PER_SEC; 5657 ++absTime->tv_sec; // note: this must be <= max_secs 5658 } 5659 } 5660 } 5661 } else { 5662 // must be relative using monotonic clock 5663 struct timespec now; 5664 int status = os::Linux::clock_gettime(CLOCK_MONOTONIC, &now); 5665 assert_status(status == 0, status, "clock_gettime"); 5666 max_secs = now.tv_sec + MAX_SECS; 5667 jlong secs = time / NANOSECS_PER_SEC; 5668 if (secs >= MAX_SECS) { 5669 absTime->tv_sec = max_secs; 5670 absTime->tv_nsec = 0; 5671 } else { 5672 absTime->tv_sec = now.tv_sec + secs; 5673 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_nsec; 5674 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 5675 absTime->tv_nsec -= NANOSECS_PER_SEC; 5676 ++absTime->tv_sec; // note: this must be <= max_secs 5677 } 5678 } 5679 } 5680 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 5681 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 5682 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 5683 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 5684} 5685 5686void Parker::park(bool isAbsolute, jlong time) { 5687 // Ideally we'd do something useful while spinning, such 5688 // as calling unpackTime(). 5689 5690 // Optional fast-path check: 5691 // Return immediately if a permit is available. 5692 // We depend on Atomic::xchg() having full barrier semantics 5693 // since we are doing a lock-free update to _counter. 5694 if (Atomic::xchg(0, &_counter) > 0) return; 5695 5696 Thread* thread = Thread::current(); 5697 assert(thread->is_Java_thread(), "Must be JavaThread"); 5698 JavaThread *jt = (JavaThread *)thread; 5699 5700 // Optional optimization -- avoid state transitions if there's an interrupt pending. 5701 // Check interrupt before trying to wait 5702 if (Thread::is_interrupted(thread, false)) { 5703 return; 5704 } 5705 5706 // Next, demultiplex/decode time arguments 5707 timespec absTime; 5708 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all 5709 return; 5710 } 5711 if (time > 0) { 5712 unpackTime(&absTime, isAbsolute, time); 5713 } 5714 5715 5716 // Enter safepoint region 5717 // Beware of deadlocks such as 6317397. 5718 // The per-thread Parker:: mutex is a classic leaf-lock. 5719 // In particular a thread must never block on the Threads_lock while 5720 // holding the Parker:: mutex. If safepoints are pending both the 5721 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 5722 ThreadBlockInVM tbivm(jt); 5723 5724 // Don't wait if cannot get lock since interference arises from 5725 // unblocking. Also. check interrupt before trying wait 5726 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 5727 return; 5728 } 5729 5730 int status; 5731 if (_counter > 0) { // no wait needed 5732 _counter = 0; 5733 status = pthread_mutex_unlock(_mutex); 5734 assert(status == 0, "invariant"); 5735 // Paranoia to ensure our locked and lock-free paths interact 5736 // correctly with each other and Java-level accesses. 5737 OrderAccess::fence(); 5738 return; 5739 } 5740 5741#ifdef ASSERT 5742 // Don't catch signals while blocked; let the running threads have the signals. 5743 // (This allows a debugger to break into the running thread.) 5744 sigset_t oldsigs; 5745 sigset_t* allowdebug_blocked = os::Linux::allowdebug_blocked_signals(); 5746 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 5747#endif 5748 5749 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 5750 jt->set_suspend_equivalent(); 5751 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 5752 5753 assert(_cur_index == -1, "invariant"); 5754 if (time == 0) { 5755 _cur_index = REL_INDEX; // arbitrary choice when not timed 5756 status = pthread_cond_wait(&_cond[_cur_index], _mutex); 5757 } else { 5758 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX; 5759 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime); 5760 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 5761 pthread_cond_destroy(&_cond[_cur_index]); 5762 pthread_cond_init(&_cond[_cur_index], isAbsolute ? NULL : os::Linux::condAttr()); 5763 } 5764 } 5765 _cur_index = -1; 5766 assert_status(status == 0 || status == EINTR || 5767 status == ETIME || status == ETIMEDOUT, 5768 status, "cond_timedwait"); 5769 5770#ifdef ASSERT 5771 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 5772#endif 5773 5774 _counter = 0; 5775 status = pthread_mutex_unlock(_mutex); 5776 assert_status(status == 0, status, "invariant"); 5777 // Paranoia to ensure our locked and lock-free paths interact 5778 // correctly with each other and Java-level accesses. 5779 OrderAccess::fence(); 5780 5781 // If externally suspended while waiting, re-suspend 5782 if (jt->handle_special_suspend_equivalent_condition()) { 5783 jt->java_suspend_self(); 5784 } 5785} 5786 5787void Parker::unpark() { 5788 int status = pthread_mutex_lock(_mutex); 5789 assert(status == 0, "invariant"); 5790 const int s = _counter; 5791 _counter = 1; 5792 if (s < 1) { 5793 // thread might be parked 5794 if (_cur_index != -1) { 5795 // thread is definitely parked 5796 if (WorkAroundNPTLTimedWaitHang) { 5797 status = pthread_cond_signal(&_cond[_cur_index]); 5798 assert(status == 0, "invariant"); 5799 status = pthread_mutex_unlock(_mutex); 5800 assert(status == 0, "invariant"); 5801 } else { 5802 // must capture correct index before unlocking 5803 int index = _cur_index; 5804 status = pthread_mutex_unlock(_mutex); 5805 assert(status == 0, "invariant"); 5806 status = pthread_cond_signal(&_cond[index]); 5807 assert(status == 0, "invariant"); 5808 } 5809 } else { 5810 pthread_mutex_unlock(_mutex); 5811 assert(status == 0, "invariant"); 5812 } 5813 } else { 5814 pthread_mutex_unlock(_mutex); 5815 assert(status == 0, "invariant"); 5816 } 5817} 5818 5819 5820extern char** environ; 5821 5822// Run the specified command in a separate process. Return its exit value, 5823// or -1 on failure (e.g. can't fork a new process). 5824// Unlike system(), this function can be called from signal handler. It 5825// doesn't block SIGINT et al. 5826int os::fork_and_exec(char* cmd) { 5827 const char * argv[4] = {"sh", "-c", cmd, NULL}; 5828 5829 pid_t pid = fork(); 5830 5831 if (pid < 0) { 5832 // fork failed 5833 return -1; 5834 5835 } else if (pid == 0) { 5836 // child process 5837 5838 execve("/bin/sh", (char* const*)argv, environ); 5839 5840 // execve failed 5841 _exit(-1); 5842 5843 } else { 5844 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 5845 // care about the actual exit code, for now. 5846 5847 int status; 5848 5849 // Wait for the child process to exit. This returns immediately if 5850 // the child has already exited. */ 5851 while (waitpid(pid, &status, 0) < 0) { 5852 switch (errno) { 5853 case ECHILD: return 0; 5854 case EINTR: break; 5855 default: return -1; 5856 } 5857 } 5858 5859 if (WIFEXITED(status)) { 5860 // The child exited normally; get its exit code. 5861 return WEXITSTATUS(status); 5862 } else if (WIFSIGNALED(status)) { 5863 // The child exited because of a signal 5864 // The best value to return is 0x80 + signal number, 5865 // because that is what all Unix shells do, and because 5866 // it allows callers to distinguish between process exit and 5867 // process death by signal. 5868 return 0x80 + WTERMSIG(status); 5869 } else { 5870 // Unknown exit code; pass it through 5871 return status; 5872 } 5873 } 5874} 5875 5876// is_headless_jre() 5877// 5878// Test for the existence of xawt/libmawt.so or libawt_xawt.so 5879// in order to report if we are running in a headless jre 5880// 5881// Since JDK8 xawt/libmawt.so was moved into the same directory 5882// as libawt.so, and renamed libawt_xawt.so 5883// 5884bool os::is_headless_jre() { 5885 struct stat statbuf; 5886 char buf[MAXPATHLEN]; 5887 char libmawtpath[MAXPATHLEN]; 5888 const char *xawtstr = "/xawt/libmawt.so"; 5889 const char *new_xawtstr = "/libawt_xawt.so"; 5890 char *p; 5891 5892 // Get path to libjvm.so 5893 os::jvm_path(buf, sizeof(buf)); 5894 5895 // Get rid of libjvm.so 5896 p = strrchr(buf, '/'); 5897 if (p == NULL) { 5898 return false; 5899 } else { 5900 *p = '\0'; 5901 } 5902 5903 // Get rid of client or server 5904 p = strrchr(buf, '/'); 5905 if (p == NULL) { 5906 return false; 5907 } else { 5908 *p = '\0'; 5909 } 5910 5911 // check xawt/libmawt.so 5912 strcpy(libmawtpath, buf); 5913 strcat(libmawtpath, xawtstr); 5914 if (::stat(libmawtpath, &statbuf) == 0) return false; 5915 5916 // check libawt_xawt.so 5917 strcpy(libmawtpath, buf); 5918 strcat(libmawtpath, new_xawtstr); 5919 if (::stat(libmawtpath, &statbuf) == 0) return false; 5920 5921 return true; 5922} 5923 5924// Get the default path to the core file 5925// Returns the length of the string 5926int os::get_core_path(char* buffer, size_t bufferSize) { 5927 /* 5928 * Max length of /proc/sys/kernel/core_pattern is 128 characters. 5929 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt 5930 */ 5931 const int core_pattern_len = 129; 5932 char core_pattern[core_pattern_len] = {0}; 5933 5934 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY); 5935 if (core_pattern_file == -1) { 5936 return -1; 5937 } 5938 5939 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len); 5940 ::close(core_pattern_file); 5941 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') { 5942 return -1; 5943 } 5944 if (core_pattern[ret-1] == '\n') { 5945 core_pattern[ret-1] = '\0'; 5946 } else { 5947 core_pattern[ret] = '\0'; 5948 } 5949 5950 char *pid_pos = strstr(core_pattern, "%p"); 5951 int written; 5952 5953 if (core_pattern[0] == '/') { 5954 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern); 5955 } else { 5956 char cwd[PATH_MAX]; 5957 5958 const char* p = get_current_directory(cwd, PATH_MAX); 5959 if (p == NULL) { 5960 return -1; 5961 } 5962 5963 if (core_pattern[0] == '|') { 5964 written = jio_snprintf(buffer, bufferSize, 5965 "\"%s\" (or dumping to %s/core.%d)", 5966 &core_pattern[1], p, current_process_id()); 5967 } else { 5968 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern); 5969 } 5970 } 5971 5972 if (written < 0) { 5973 return -1; 5974 } 5975 5976 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) { 5977 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY); 5978 5979 if (core_uses_pid_file != -1) { 5980 char core_uses_pid = 0; 5981 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1); 5982 ::close(core_uses_pid_file); 5983 5984 if (core_uses_pid == '1') { 5985 jio_snprintf(buffer + written, bufferSize - written, 5986 ".%d", current_process_id()); 5987 } 5988 } 5989 } 5990 5991 return strlen(buffer); 5992} 5993 5994bool os::start_debugging(char *buf, int buflen) { 5995 int len = (int)strlen(buf); 5996 char *p = &buf[len]; 5997 5998 jio_snprintf(p, buflen-len, 5999 "\n\n" 6000 "Do you want to debug the problem?\n\n" 6001 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n" 6002 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n" 6003 "Otherwise, press RETURN to abort...", 6004 os::current_process_id(), os::current_process_id(), 6005 os::current_thread_id(), os::current_thread_id()); 6006 6007 bool yes = os::message_box("Unexpected Error", buf); 6008 6009 if (yes) { 6010 // yes, user asked VM to launch debugger 6011 jio_snprintf(buf, sizeof(buf), "gdb /proc/%d/exe %d", 6012 os::current_process_id(), os::current_process_id()); 6013 6014 os::fork_and_exec(buf); 6015 yes = false; 6016 } 6017 return yes; 6018} 6019 6020 6021 6022/////////////// Unit tests /////////////// 6023 6024#ifndef PRODUCT 6025 6026#define test_log(...) \ 6027 do { \ 6028 if (VerboseInternalVMTests) { \ 6029 tty->print_cr(__VA_ARGS__); \ 6030 tty->flush(); \ 6031 } \ 6032 } while (false) 6033 6034class TestReserveMemorySpecial : AllStatic { 6035 public: 6036 static void small_page_write(void* addr, size_t size) { 6037 size_t page_size = os::vm_page_size(); 6038 6039 char* end = (char*)addr + size; 6040 for (char* p = (char*)addr; p < end; p += page_size) { 6041 *p = 1; 6042 } 6043 } 6044 6045 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) { 6046 if (!UseHugeTLBFS) { 6047 return; 6048 } 6049 6050 test_log("test_reserve_memory_special_huge_tlbfs_only(" SIZE_FORMAT ")", size); 6051 6052 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false); 6053 6054 if (addr != NULL) { 6055 small_page_write(addr, size); 6056 6057 os::Linux::release_memory_special_huge_tlbfs(addr, size); 6058 } 6059 } 6060 6061 static void test_reserve_memory_special_huge_tlbfs_only() { 6062 if (!UseHugeTLBFS) { 6063 return; 6064 } 6065 6066 size_t lp = os::large_page_size(); 6067 6068 for (size_t size = lp; size <= lp * 10; size += lp) { 6069 test_reserve_memory_special_huge_tlbfs_only(size); 6070 } 6071 } 6072 6073 static void test_reserve_memory_special_huge_tlbfs_mixed() { 6074 size_t lp = os::large_page_size(); 6075 size_t ag = os::vm_allocation_granularity(); 6076 6077 // sizes to test 6078 const size_t sizes[] = { 6079 lp, lp + ag, lp + lp / 2, lp * 2, 6080 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2, 6081 lp * 10, lp * 10 + lp / 2 6082 }; 6083 const int num_sizes = sizeof(sizes) / sizeof(size_t); 6084 6085 // For each size/alignment combination, we test three scenarios: 6086 // 1) with req_addr == NULL 6087 // 2) with a non-null req_addr at which we expect to successfully allocate 6088 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we 6089 // expect the allocation to either fail or to ignore req_addr 6090 6091 // Pre-allocate two areas; they shall be as large as the largest allocation 6092 // and aligned to the largest alignment we will be testing. 6093 const size_t mapping_size = sizes[num_sizes - 1] * 2; 6094 char* const mapping1 = (char*) ::mmap(NULL, mapping_size, 6095 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 6096 -1, 0); 6097 assert(mapping1 != MAP_FAILED, "should work"); 6098 6099 char* const mapping2 = (char*) ::mmap(NULL, mapping_size, 6100 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 6101 -1, 0); 6102 assert(mapping2 != MAP_FAILED, "should work"); 6103 6104 // Unmap the first mapping, but leave the second mapping intact: the first 6105 // mapping will serve as a value for a "good" req_addr (case 2). The second 6106 // mapping, still intact, as "bad" req_addr (case 3). 6107 ::munmap(mapping1, mapping_size); 6108 6109 // Case 1 6110 test_log("%s, req_addr NULL:", __FUNCTION__); 6111 test_log("size align result"); 6112 6113 for (int i = 0; i < num_sizes; i++) { 6114 const size_t size = sizes[i]; 6115 for (size_t alignment = ag; is_size_aligned(size, alignment); alignment *= 2) { 6116 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false); 6117 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " -> " PTR_FORMAT " %s", 6118 size, alignment, p2i(p), (p != NULL ? "" : "(failed)")); 6119 if (p != NULL) { 6120 assert(is_ptr_aligned(p, alignment), "must be"); 6121 small_page_write(p, size); 6122 os::Linux::release_memory_special_huge_tlbfs(p, size); 6123 } 6124 } 6125 } 6126 6127 // Case 2 6128 test_log("%s, req_addr non-NULL:", __FUNCTION__); 6129 test_log("size align req_addr result"); 6130 6131 for (int i = 0; i < num_sizes; i++) { 6132 const size_t size = sizes[i]; 6133 for (size_t alignment = ag; is_size_aligned(size, alignment); alignment *= 2) { 6134 char* const req_addr = (char*) align_ptr_up(mapping1, alignment); 6135 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); 6136 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", 6137 size, alignment, p2i(req_addr), p2i(p), 6138 ((p != NULL ? (p == req_addr ? "(exact match)" : "") : "(failed)"))); 6139 if (p != NULL) { 6140 assert(p == req_addr, "must be"); 6141 small_page_write(p, size); 6142 os::Linux::release_memory_special_huge_tlbfs(p, size); 6143 } 6144 } 6145 } 6146 6147 // Case 3 6148 test_log("%s, req_addr non-NULL with preexisting mapping:", __FUNCTION__); 6149 test_log("size align req_addr result"); 6150 6151 for (int i = 0; i < num_sizes; i++) { 6152 const size_t size = sizes[i]; 6153 for (size_t alignment = ag; is_size_aligned(size, alignment); alignment *= 2) { 6154 char* const req_addr = (char*) align_ptr_up(mapping2, alignment); 6155 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); 6156 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", 6157 size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? "" : "(failed)"))); 6158 // as the area around req_addr contains already existing mappings, the API should always 6159 // return NULL (as per contract, it cannot return another address) 6160 assert(p == NULL, "must be"); 6161 } 6162 } 6163 6164 ::munmap(mapping2, mapping_size); 6165 6166 } 6167 6168 static void test_reserve_memory_special_huge_tlbfs() { 6169 if (!UseHugeTLBFS) { 6170 return; 6171 } 6172 6173 test_reserve_memory_special_huge_tlbfs_only(); 6174 test_reserve_memory_special_huge_tlbfs_mixed(); 6175 } 6176 6177 static void test_reserve_memory_special_shm(size_t size, size_t alignment) { 6178 if (!UseSHM) { 6179 return; 6180 } 6181 6182 test_log("test_reserve_memory_special_shm(" SIZE_FORMAT ", " SIZE_FORMAT ")", size, alignment); 6183 6184 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false); 6185 6186 if (addr != NULL) { 6187 assert(is_ptr_aligned(addr, alignment), "Check"); 6188 assert(is_ptr_aligned(addr, os::large_page_size()), "Check"); 6189 6190 small_page_write(addr, size); 6191 6192 os::Linux::release_memory_special_shm(addr, size); 6193 } 6194 } 6195 6196 static void test_reserve_memory_special_shm() { 6197 size_t lp = os::large_page_size(); 6198 size_t ag = os::vm_allocation_granularity(); 6199 6200 for (size_t size = ag; size < lp * 3; size += ag) { 6201 for (size_t alignment = ag; is_size_aligned(size, alignment); alignment *= 2) { 6202 test_reserve_memory_special_shm(size, alignment); 6203 } 6204 } 6205 } 6206 6207 static void test() { 6208 test_reserve_memory_special_huge_tlbfs(); 6209 test_reserve_memory_special_shm(); 6210 } 6211}; 6212 6213void TestReserveMemorySpecial_test() { 6214 TestReserveMemorySpecial::test(); 6215} 6216 6217#endif 6218