os.cpp revision 3758:716c64bda5ba
1/* 2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25#include "precompiled.hpp" 26#include "classfile/classLoader.hpp" 27#include "classfile/javaClasses.hpp" 28#include "classfile/systemDictionary.hpp" 29#include "classfile/vmSymbols.hpp" 30#include "code/icBuffer.hpp" 31#include "code/vtableStubs.hpp" 32#include "gc_implementation/shared/vmGCOperations.hpp" 33#include "interpreter/interpreter.hpp" 34#include "memory/allocation.inline.hpp" 35#include "oops/oop.inline.hpp" 36#include "prims/jvm.h" 37#include "prims/jvm_misc.hpp" 38#include "prims/privilegedStack.hpp" 39#include "runtime/arguments.hpp" 40#include "runtime/frame.inline.hpp" 41#include "runtime/interfaceSupport.hpp" 42#include "runtime/java.hpp" 43#include "runtime/javaCalls.hpp" 44#include "runtime/mutexLocker.hpp" 45#include "runtime/os.hpp" 46#include "runtime/stubRoutines.hpp" 47#include "services/attachListener.hpp" 48#include "services/memTracker.hpp" 49#include "services/threadService.hpp" 50#include "utilities/defaultStream.hpp" 51#include "utilities/events.hpp" 52#ifdef TARGET_OS_FAMILY_linux 53# include "os_linux.inline.hpp" 54# include "thread_linux.inline.hpp" 55#endif 56#ifdef TARGET_OS_FAMILY_solaris 57# include "os_solaris.inline.hpp" 58# include "thread_solaris.inline.hpp" 59#endif 60#ifdef TARGET_OS_FAMILY_windows 61# include "os_windows.inline.hpp" 62# include "thread_windows.inline.hpp" 63#endif 64#ifdef TARGET_OS_FAMILY_bsd 65# include "os_bsd.inline.hpp" 66# include "thread_bsd.inline.hpp" 67#endif 68 69# include <signal.h> 70 71OSThread* os::_starting_thread = NULL; 72address os::_polling_page = NULL; 73volatile int32_t* os::_mem_serialize_page = NULL; 74uintptr_t os::_serialize_page_mask = 0; 75long os::_rand_seed = 1; 76int os::_processor_count = 0; 77size_t os::_page_sizes[os::page_sizes_max]; 78 79#ifndef PRODUCT 80julong os::num_mallocs = 0; // # of calls to malloc/realloc 81julong os::alloc_bytes = 0; // # of bytes allocated 82julong os::num_frees = 0; // # of calls to free 83julong os::free_bytes = 0; // # of bytes freed 84#endif 85 86void os_init_globals() { 87 // Called from init_globals(). 88 // See Threads::create_vm() in thread.cpp, and init.cpp. 89 os::init_globals(); 90} 91 92// Fill in buffer with current local time as an ISO-8601 string. 93// E.g., yyyy-mm-ddThh:mm:ss-zzzz. 94// Returns buffer, or NULL if it failed. 95// This would mostly be a call to 96// strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....) 97// except that on Windows the %z behaves badly, so we do it ourselves. 98// Also, people wanted milliseconds on there, 99// and strftime doesn't do milliseconds. 100char* os::iso8601_time(char* buffer, size_t buffer_length) { 101 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0" 102 // 1 2 103 // 12345678901234567890123456789 104 static const char* iso8601_format = 105 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"; 106 static const size_t needed_buffer = 29; 107 108 // Sanity check the arguments 109 if (buffer == NULL) { 110 assert(false, "NULL buffer"); 111 return NULL; 112 } 113 if (buffer_length < needed_buffer) { 114 assert(false, "buffer_length too small"); 115 return NULL; 116 } 117 // Get the current time 118 jlong milliseconds_since_19700101 = javaTimeMillis(); 119 const int milliseconds_per_microsecond = 1000; 120 const time_t seconds_since_19700101 = 121 milliseconds_since_19700101 / milliseconds_per_microsecond; 122 const int milliseconds_after_second = 123 milliseconds_since_19700101 % milliseconds_per_microsecond; 124 // Convert the time value to a tm and timezone variable 125 struct tm time_struct; 126 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) { 127 assert(false, "Failed localtime_pd"); 128 return NULL; 129 } 130#if defined(_ALLBSD_SOURCE) 131 const time_t zone = (time_t) time_struct.tm_gmtoff; 132#else 133 const time_t zone = timezone; 134#endif 135 136 // If daylight savings time is in effect, 137 // we are 1 hour East of our time zone 138 const time_t seconds_per_minute = 60; 139 const time_t minutes_per_hour = 60; 140 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour; 141 time_t UTC_to_local = zone; 142 if (time_struct.tm_isdst > 0) { 143 UTC_to_local = UTC_to_local - seconds_per_hour; 144 } 145 // Compute the time zone offset. 146 // localtime_pd() sets timezone to the difference (in seconds) 147 // between UTC and and local time. 148 // ISO 8601 says we need the difference between local time and UTC, 149 // we change the sign of the localtime_pd() result. 150 const time_t local_to_UTC = -(UTC_to_local); 151 // Then we have to figure out if if we are ahead (+) or behind (-) UTC. 152 char sign_local_to_UTC = '+'; 153 time_t abs_local_to_UTC = local_to_UTC; 154 if (local_to_UTC < 0) { 155 sign_local_to_UTC = '-'; 156 abs_local_to_UTC = -(abs_local_to_UTC); 157 } 158 // Convert time zone offset seconds to hours and minutes. 159 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour); 160 const time_t zone_min = 161 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute); 162 163 // Print an ISO 8601 date and time stamp into the buffer 164 const int year = 1900 + time_struct.tm_year; 165 const int month = 1 + time_struct.tm_mon; 166 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format, 167 year, 168 month, 169 time_struct.tm_mday, 170 time_struct.tm_hour, 171 time_struct.tm_min, 172 time_struct.tm_sec, 173 milliseconds_after_second, 174 sign_local_to_UTC, 175 zone_hours, 176 zone_min); 177 if (printed == 0) { 178 assert(false, "Failed jio_printf"); 179 return NULL; 180 } 181 return buffer; 182} 183 184OSReturn os::set_priority(Thread* thread, ThreadPriority p) { 185#ifdef ASSERT 186 if (!(!thread->is_Java_thread() || 187 Thread::current() == thread || 188 Threads_lock->owned_by_self() 189 || thread->is_Compiler_thread() 190 )) { 191 assert(false, "possibility of dangling Thread pointer"); 192 } 193#endif 194 195 if (p >= MinPriority && p <= MaxPriority) { 196 int priority = java_to_os_priority[p]; 197 return set_native_priority(thread, priority); 198 } else { 199 assert(false, "Should not happen"); 200 return OS_ERR; 201 } 202} 203 204// The mapping from OS priority back to Java priority may be inexact because 205// Java priorities can map M:1 with native priorities. If you want the definite 206// Java priority then use JavaThread::java_priority() 207OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) { 208 int p; 209 int os_prio; 210 OSReturn ret = get_native_priority(thread, &os_prio); 211 if (ret != OS_OK) return ret; 212 213 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) { 214 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ; 215 } else { 216 // niceness values are in reverse order 217 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ; 218 } 219 priority = (ThreadPriority)p; 220 return OS_OK; 221} 222 223 224// --------------------- sun.misc.Signal (optional) --------------------- 225 226 227// SIGBREAK is sent by the keyboard to query the VM state 228#ifndef SIGBREAK 229#define SIGBREAK SIGQUIT 230#endif 231 232// sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread. 233 234 235static void signal_thread_entry(JavaThread* thread, TRAPS) { 236 os::set_priority(thread, NearMaxPriority); 237 while (true) { 238 int sig; 239 { 240 // FIXME : Currently we have not decieded what should be the status 241 // for this java thread blocked here. Once we decide about 242 // that we should fix this. 243 sig = os::signal_wait(); 244 } 245 if (sig == os::sigexitnum_pd()) { 246 // Terminate the signal thread 247 return; 248 } 249 250 switch (sig) { 251 case SIGBREAK: { 252 // Check if the signal is a trigger to start the Attach Listener - in that 253 // case don't print stack traces. 254 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) { 255 continue; 256 } 257 // Print stack traces 258 // Any SIGBREAK operations added here should make sure to flush 259 // the output stream (e.g. tty->flush()) after output. See 4803766. 260 // Each module also prints an extra carriage return after its output. 261 VM_PrintThreads op; 262 VMThread::execute(&op); 263 VM_PrintJNI jni_op; 264 VMThread::execute(&jni_op); 265 VM_FindDeadlocks op1(tty); 266 VMThread::execute(&op1); 267 Universe::print_heap_at_SIGBREAK(); 268 if (PrintClassHistogram) { 269 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */, 270 true /* need_prologue */); 271 VMThread::execute(&op1); 272 } 273 if (JvmtiExport::should_post_data_dump()) { 274 JvmtiExport::post_data_dump(); 275 } 276 break; 277 } 278 default: { 279 // Dispatch the signal to java 280 HandleMark hm(THREAD); 281 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD); 282 KlassHandle klass (THREAD, k); 283 if (klass.not_null()) { 284 JavaValue result(T_VOID); 285 JavaCallArguments args; 286 args.push_int(sig); 287 JavaCalls::call_static( 288 &result, 289 klass, 290 vmSymbols::dispatch_name(), 291 vmSymbols::int_void_signature(), 292 &args, 293 THREAD 294 ); 295 } 296 if (HAS_PENDING_EXCEPTION) { 297 // tty is initialized early so we don't expect it to be null, but 298 // if it is we can't risk doing an initialization that might 299 // trigger additional out-of-memory conditions 300 if (tty != NULL) { 301 char klass_name[256]; 302 char tmp_sig_name[16]; 303 const char* sig_name = "UNKNOWN"; 304 InstanceKlass::cast(PENDING_EXCEPTION->klass())-> 305 name()->as_klass_external_name(klass_name, 256); 306 if (os::exception_name(sig, tmp_sig_name, 16) != NULL) 307 sig_name = tmp_sig_name; 308 warning("Exception %s occurred dispatching signal %s to handler" 309 "- the VM may need to be forcibly terminated", 310 klass_name, sig_name ); 311 } 312 CLEAR_PENDING_EXCEPTION; 313 } 314 } 315 } 316 } 317} 318 319 320void os::signal_init() { 321 if (!ReduceSignalUsage) { 322 // Setup JavaThread for processing signals 323 EXCEPTION_MARK; 324 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK); 325 instanceKlassHandle klass (THREAD, k); 326 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); 327 328 const char thread_name[] = "Signal Dispatcher"; 329 Handle string = java_lang_String::create_from_str(thread_name, CHECK); 330 331 // Initialize thread_oop to put it into the system threadGroup 332 Handle thread_group (THREAD, Universe::system_thread_group()); 333 JavaValue result(T_VOID); 334 JavaCalls::call_special(&result, thread_oop, 335 klass, 336 vmSymbols::object_initializer_name(), 337 vmSymbols::threadgroup_string_void_signature(), 338 thread_group, 339 string, 340 CHECK); 341 342 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass()); 343 JavaCalls::call_special(&result, 344 thread_group, 345 group, 346 vmSymbols::add_method_name(), 347 vmSymbols::thread_void_signature(), 348 thread_oop, // ARG 1 349 CHECK); 350 351 os::signal_init_pd(); 352 353 { MutexLocker mu(Threads_lock); 354 JavaThread* signal_thread = new JavaThread(&signal_thread_entry); 355 356 // At this point it may be possible that no osthread was created for the 357 // JavaThread due to lack of memory. We would have to throw an exception 358 // in that case. However, since this must work and we do not allow 359 // exceptions anyway, check and abort if this fails. 360 if (signal_thread == NULL || signal_thread->osthread() == NULL) { 361 vm_exit_during_initialization("java.lang.OutOfMemoryError", 362 "unable to create new native thread"); 363 } 364 365 java_lang_Thread::set_thread(thread_oop(), signal_thread); 366 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority); 367 java_lang_Thread::set_daemon(thread_oop()); 368 369 signal_thread->set_threadObj(thread_oop()); 370 Threads::add(signal_thread); 371 Thread::start(signal_thread); 372 } 373 // Handle ^BREAK 374 os::signal(SIGBREAK, os::user_handler()); 375 } 376} 377 378 379void os::terminate_signal_thread() { 380 if (!ReduceSignalUsage) 381 signal_notify(sigexitnum_pd()); 382} 383 384 385// --------------------- loading libraries --------------------- 386 387typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *); 388extern struct JavaVM_ main_vm; 389 390static void* _native_java_library = NULL; 391 392void* os::native_java_library() { 393 if (_native_java_library == NULL) { 394 char buffer[JVM_MAXPATHLEN]; 395 char ebuf[1024]; 396 397 // Try to load verify dll first. In 1.3 java dll depends on it and is not 398 // always able to find it when the loading executable is outside the JDK. 399 // In order to keep working with 1.2 we ignore any loading errors. 400 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify"); 401 dll_load(buffer, ebuf, sizeof(ebuf)); 402 403 // Load java dll 404 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "java"); 405 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf)); 406 if (_native_java_library == NULL) { 407 vm_exit_during_initialization("Unable to load native library", ebuf); 408 } 409 410#if defined(__OpenBSD__) 411 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so 412 // ignore errors 413 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "net"); 414 dll_load(buffer, ebuf, sizeof(ebuf)); 415#endif 416 } 417 static jboolean onLoaded = JNI_FALSE; 418 if (onLoaded) { 419 // We may have to wait to fire OnLoad until TLS is initialized. 420 if (ThreadLocalStorage::is_initialized()) { 421 // The JNI_OnLoad handling is normally done by method load in 422 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library 423 // explicitly so we have to check for JNI_OnLoad as well 424 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS; 425 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR( 426 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0])); 427 if (JNI_OnLoad != NULL) { 428 JavaThread* thread = JavaThread::current(); 429 ThreadToNativeFromVM ttn(thread); 430 HandleMark hm(thread); 431 jint ver = (*JNI_OnLoad)(&main_vm, NULL); 432 onLoaded = JNI_TRUE; 433 if (!Threads::is_supported_jni_version_including_1_1(ver)) { 434 vm_exit_during_initialization("Unsupported JNI version"); 435 } 436 } 437 } 438 } 439 return _native_java_library; 440} 441 442// --------------------- heap allocation utilities --------------------- 443 444char *os::strdup(const char *str, MEMFLAGS flags) { 445 size_t size = strlen(str); 446 char *dup_str = (char *)malloc(size + 1, flags); 447 if (dup_str == NULL) return NULL; 448 strcpy(dup_str, str); 449 return dup_str; 450} 451 452 453 454#ifdef ASSERT 455#define space_before (MallocCushion + sizeof(double)) 456#define space_after MallocCushion 457#define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t)) 458#define size_addr_from_obj(p) ((size_t*)p - 1) 459// MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly 460// NB: cannot be debug variable, because these aren't set from the command line until 461// *after* the first few allocs already happened 462#define MallocCushion 16 463#else 464#define space_before 0 465#define space_after 0 466#define size_addr_from_base(p) should not use w/o ASSERT 467#define size_addr_from_obj(p) should not use w/o ASSERT 468#define MallocCushion 0 469#endif 470#define paranoid 0 /* only set to 1 if you suspect checking code has bug */ 471 472#ifdef ASSERT 473inline size_t get_size(void* obj) { 474 size_t size = *size_addr_from_obj(obj); 475 if (size < 0) { 476 fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten (" 477 SIZE_FORMAT ")", obj, size)); 478 } 479 return size; 480} 481 482u_char* find_cushion_backwards(u_char* start) { 483 u_char* p = start; 484 while (p[ 0] != badResourceValue || p[-1] != badResourceValue || 485 p[-2] != badResourceValue || p[-3] != badResourceValue) p--; 486 // ok, we have four consecutive marker bytes; find start 487 u_char* q = p - 4; 488 while (*q == badResourceValue) q--; 489 return q + 1; 490} 491 492u_char* find_cushion_forwards(u_char* start) { 493 u_char* p = start; 494 while (p[0] != badResourceValue || p[1] != badResourceValue || 495 p[2] != badResourceValue || p[3] != badResourceValue) p++; 496 // ok, we have four consecutive marker bytes; find end of cushion 497 u_char* q = p + 4; 498 while (*q == badResourceValue) q++; 499 return q - MallocCushion; 500} 501 502void print_neighbor_blocks(void* ptr) { 503 // find block allocated before ptr (not entirely crash-proof) 504 if (MallocCushion < 4) { 505 tty->print_cr("### cannot find previous block (MallocCushion < 4)"); 506 return; 507 } 508 u_char* start_of_this_block = (u_char*)ptr - space_before; 509 u_char* end_of_prev_block_data = start_of_this_block - space_after -1; 510 // look for cushion in front of prev. block 511 u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data); 512 ptrdiff_t size = *size_addr_from_base(start_of_prev_block); 513 u_char* obj = start_of_prev_block + space_before; 514 if (size <= 0 ) { 515 // start is bad; mayhave been confused by OS data inbetween objects 516 // search one more backwards 517 start_of_prev_block = find_cushion_backwards(start_of_prev_block); 518 size = *size_addr_from_base(start_of_prev_block); 519 obj = start_of_prev_block + space_before; 520 } 521 522 if (start_of_prev_block + space_before + size + space_after == start_of_this_block) { 523 tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size); 524 } else { 525 tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size); 526 } 527 528 // now find successor block 529 u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after; 530 start_of_next_block = find_cushion_forwards(start_of_next_block); 531 u_char* next_obj = start_of_next_block + space_before; 532 ptrdiff_t next_size = *size_addr_from_base(start_of_next_block); 533 if (start_of_next_block[0] == badResourceValue && 534 start_of_next_block[1] == badResourceValue && 535 start_of_next_block[2] == badResourceValue && 536 start_of_next_block[3] == badResourceValue) { 537 tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size); 538 } else { 539 tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size); 540 } 541} 542 543 544void report_heap_error(void* memblock, void* bad, const char* where) { 545 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees); 546 tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock); 547 print_neighbor_blocks(memblock); 548 fatal("memory stomping error"); 549} 550 551void verify_block(void* memblock) { 552 size_t size = get_size(memblock); 553 if (MallocCushion) { 554 u_char* ptr = (u_char*)memblock - space_before; 555 for (int i = 0; i < MallocCushion; i++) { 556 if (ptr[i] != badResourceValue) { 557 report_heap_error(memblock, ptr+i, "in front of"); 558 } 559 } 560 u_char* end = (u_char*)memblock + size + space_after; 561 for (int j = -MallocCushion; j < 0; j++) { 562 if (end[j] != badResourceValue) { 563 report_heap_error(memblock, end+j, "after"); 564 } 565 } 566 } 567} 568#endif 569 570void* os::malloc(size_t size, MEMFLAGS memflags, address caller) { 571 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 572 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 573 574 if (size == 0) { 575 // return a valid pointer if size is zero 576 // if NULL is returned the calling functions assume out of memory. 577 size = 1; 578 } 579 580 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); 581 u_char* ptr = (u_char*)::malloc(size + space_before + space_after); 582 583#ifdef ASSERT 584 if (ptr == NULL) return NULL; 585 if (MallocCushion) { 586 for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue; 587 u_char* end = ptr + space_before + size; 588 for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad; 589 for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue; 590 } 591 // put size just before data 592 *size_addr_from_base(ptr) = size; 593#endif 594 u_char* memblock = ptr + space_before; 595 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 596 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock); 597 breakpoint(); 598 } 599 debug_only(if (paranoid) verify_block(memblock)); 600 if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock); 601 602 // we do not track MallocCushion memory 603 MemTracker::record_malloc((address)memblock, size, memflags, caller == 0 ? CALLER_PC : caller); 604 605 return memblock; 606} 607 608 609void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) { 610#ifndef ASSERT 611 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); 612 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); 613 void* ptr = ::realloc(memblock, size); 614 if (ptr != NULL) { 615 MemTracker::record_realloc((address)memblock, (address)ptr, size, memflags, 616 caller == 0 ? CALLER_PC : caller); 617 } 618 return ptr; 619#else 620 if (memblock == NULL) { 621 return malloc(size, memflags, (caller == 0 ? CALLER_PC : caller)); 622 } 623 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 624 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock); 625 breakpoint(); 626 } 627 verify_block(memblock); 628 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); 629 if (size == 0) return NULL; 630 // always move the block 631 void* ptr = malloc(size, memflags, caller == 0 ? CALLER_PC : caller); 632 if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr); 633 // Copy to new memory if malloc didn't fail 634 if ( ptr != NULL ) { 635 memcpy(ptr, memblock, MIN2(size, get_size(memblock))); 636 if (paranoid) verify_block(ptr); 637 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { 638 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr); 639 breakpoint(); 640 } 641 free(memblock); 642 } 643 return ptr; 644#endif 645} 646 647 648void os::free(void *memblock, MEMFLAGS memflags) { 649 NOT_PRODUCT(inc_stat_counter(&num_frees, 1)); 650#ifdef ASSERT 651 if (memblock == NULL) return; 652 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { 653 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock); 654 breakpoint(); 655 } 656 verify_block(memblock); 657 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); 658 // Added by detlefs. 659 if (MallocCushion) { 660 u_char* ptr = (u_char*)memblock - space_before; 661 for (u_char* p = ptr; p < ptr + MallocCushion; p++) { 662 guarantee(*p == badResourceValue, 663 "Thing freed should be malloc result."); 664 *p = (u_char)freeBlockPad; 665 } 666 size_t size = get_size(memblock); 667 inc_stat_counter(&free_bytes, size); 668 u_char* end = ptr + space_before + size; 669 for (u_char* q = end; q < end + MallocCushion; q++) { 670 guarantee(*q == badResourceValue, 671 "Thing freed should be malloc result."); 672 *q = (u_char)freeBlockPad; 673 } 674 if (PrintMalloc && tty != NULL) 675 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock); 676 } else if (PrintMalloc && tty != NULL) { 677 // tty->print_cr("os::free %p", memblock); 678 fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock); 679 } 680#endif 681 MemTracker::record_free((address)memblock, memflags); 682 683 ::free((char*)memblock - space_before); 684} 685 686void os::init_random(long initval) { 687 _rand_seed = initval; 688} 689 690 691long os::random() { 692 /* standard, well-known linear congruential random generator with 693 * next_rand = (16807*seed) mod (2**31-1) 694 * see 695 * (1) "Random Number Generators: Good Ones Are Hard to Find", 696 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988), 697 * (2) "Two Fast Implementations of the 'Minimal Standard' Random 698 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88. 699 */ 700 const long a = 16807; 701 const unsigned long m = 2147483647; 702 const long q = m / a; assert(q == 127773, "weird math"); 703 const long r = m % a; assert(r == 2836, "weird math"); 704 705 // compute az=2^31p+q 706 unsigned long lo = a * (long)(_rand_seed & 0xFFFF); 707 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16); 708 lo += (hi & 0x7FFF) << 16; 709 710 // if q overflowed, ignore the overflow and increment q 711 if (lo > m) { 712 lo &= m; 713 ++lo; 714 } 715 lo += hi >> 15; 716 717 // if (p+q) overflowed, ignore the overflow and increment (p+q) 718 if (lo > m) { 719 lo &= m; 720 ++lo; 721 } 722 return (_rand_seed = lo); 723} 724 725// The INITIALIZED state is distinguished from the SUSPENDED state because the 726// conditions in which a thread is first started are different from those in which 727// a suspension is resumed. These differences make it hard for us to apply the 728// tougher checks when starting threads that we want to do when resuming them. 729// However, when start_thread is called as a result of Thread.start, on a Java 730// thread, the operation is synchronized on the Java Thread object. So there 731// cannot be a race to start the thread and hence for the thread to exit while 732// we are working on it. Non-Java threads that start Java threads either have 733// to do so in a context in which races are impossible, or should do appropriate 734// locking. 735 736void os::start_thread(Thread* thread) { 737 // guard suspend/resume 738 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag); 739 OSThread* osthread = thread->osthread(); 740 osthread->set_state(RUNNABLE); 741 pd_start_thread(thread); 742} 743 744//--------------------------------------------------------------------------- 745// Helper functions for fatal error handler 746 747void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) { 748 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking"); 749 750 int cols = 0; 751 int cols_per_line = 0; 752 switch (unitsize) { 753 case 1: cols_per_line = 16; break; 754 case 2: cols_per_line = 8; break; 755 case 4: cols_per_line = 4; break; 756 case 8: cols_per_line = 2; break; 757 default: return; 758 } 759 760 address p = start; 761 st->print(PTR_FORMAT ": ", start); 762 while (p < end) { 763 switch (unitsize) { 764 case 1: st->print("%02x", *(u1*)p); break; 765 case 2: st->print("%04x", *(u2*)p); break; 766 case 4: st->print("%08x", *(u4*)p); break; 767 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break; 768 } 769 p += unitsize; 770 cols++; 771 if (cols >= cols_per_line && p < end) { 772 cols = 0; 773 st->cr(); 774 st->print(PTR_FORMAT ": ", p); 775 } else { 776 st->print(" "); 777 } 778 } 779 st->cr(); 780} 781 782void os::print_environment_variables(outputStream* st, const char** env_list, 783 char* buffer, int len) { 784 if (env_list) { 785 st->print_cr("Environment Variables:"); 786 787 for (int i = 0; env_list[i] != NULL; i++) { 788 if (getenv(env_list[i], buffer, len)) { 789 st->print(env_list[i]); 790 st->print("="); 791 st->print_cr(buffer); 792 } 793 } 794 } 795} 796 797void os::print_cpu_info(outputStream* st) { 798 // cpu 799 st->print("CPU:"); 800 st->print("total %d", os::processor_count()); 801 // It's not safe to query number of active processors after crash 802 // st->print("(active %d)", os::active_processor_count()); 803 st->print(" %s", VM_Version::cpu_features()); 804 st->cr(); 805 pd_print_cpu_info(st); 806} 807 808void os::print_date_and_time(outputStream *st) { 809 time_t tloc; 810 (void)time(&tloc); 811 st->print("time: %s", ctime(&tloc)); // ctime adds newline. 812 813 double t = os::elapsedTime(); 814 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in 815 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int 816 // before printf. We lost some precision, but who cares? 817 st->print_cr("elapsed time: %d seconds", (int)t); 818} 819 820// moved from debug.cpp (used to be find()) but still called from there 821// The verbose parameter is only set by the debug code in one case 822void os::print_location(outputStream* st, intptr_t x, bool verbose) { 823 address addr = (address)x; 824 CodeBlob* b = CodeCache::find_blob_unsafe(addr); 825 if (b != NULL) { 826 if (b->is_buffer_blob()) { 827 // the interpreter is generated into a buffer blob 828 InterpreterCodelet* i = Interpreter::codelet_containing(addr); 829 if (i != NULL) { 830 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin())); 831 i->print_on(st); 832 return; 833 } 834 if (Interpreter::contains(addr)) { 835 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code" 836 " (not bytecode specific)", addr); 837 return; 838 } 839 // 840 if (AdapterHandlerLibrary::contains(b)) { 841 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin())); 842 AdapterHandlerLibrary::print_handler_on(st, b); 843 } 844 // the stubroutines are generated into a buffer blob 845 StubCodeDesc* d = StubCodeDesc::desc_for(addr); 846 if (d != NULL) { 847 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin())); 848 d->print_on(st); 849 st->cr(); 850 return; 851 } 852 if (StubRoutines::contains(addr)) { 853 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) " 854 "stub routine", addr); 855 return; 856 } 857 // the InlineCacheBuffer is using stubs generated into a buffer blob 858 if (InlineCacheBuffer::contains(addr)) { 859 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr); 860 return; 861 } 862 VtableStub* v = VtableStubs::stub_containing(addr); 863 if (v != NULL) { 864 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point())); 865 v->print_on(st); 866 st->cr(); 867 return; 868 } 869 } 870 nmethod* nm = b->as_nmethod_or_null(); 871 if (nm != NULL) { 872 ResourceMark rm; 873 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT, 874 addr, (int)(addr - nm->entry_point()), nm); 875 if (verbose) { 876 st->print(" for "); 877 nm->method()->print_value_on(st); 878 } 879 st->cr(); 880 nm->print_nmethod(verbose); 881 return; 882 } 883 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin())); 884 b->print_on(st); 885 return; 886 } 887 888 if (Universe::heap()->is_in(addr)) { 889 HeapWord* p = Universe::heap()->block_start(addr); 890 bool print = false; 891 // If we couldn't find it it just may mean that heap wasn't parseable 892 // See if we were just given an oop directly 893 if (p != NULL && Universe::heap()->block_is_obj(p)) { 894 print = true; 895 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) { 896 p = (HeapWord*) addr; 897 print = true; 898 } 899 if (print) { 900 if (p == (HeapWord*) addr) { 901 st->print_cr(INTPTR_FORMAT " is an oop", addr); 902 } else { 903 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p); 904 } 905 oop(p)->print_on(st); 906 return; 907 } 908 } else { 909 if (Universe::heap()->is_in_reserved(addr)) { 910 st->print_cr(INTPTR_FORMAT " is an unallocated location " 911 "in the heap", addr); 912 return; 913 } 914 } 915 if (JNIHandles::is_global_handle((jobject) addr)) { 916 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr); 917 return; 918 } 919 if (JNIHandles::is_weak_global_handle((jobject) addr)) { 920 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr); 921 return; 922 } 923#ifndef PRODUCT 924 // we don't keep the block list in product mode 925 if (JNIHandleBlock::any_contains((jobject) addr)) { 926 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr); 927 return; 928 } 929#endif 930 931 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) { 932 // Check for privilege stack 933 if (thread->privileged_stack_top() != NULL && 934 thread->privileged_stack_top()->contains(addr)) { 935 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack " 936 "for thread: " INTPTR_FORMAT, addr, thread); 937 if (verbose) thread->print_on(st); 938 return; 939 } 940 // If the addr is a java thread print information about that. 941 if (addr == (address)thread) { 942 if (verbose) { 943 thread->print_on(st); 944 } else { 945 st->print_cr(INTPTR_FORMAT " is a thread", addr); 946 } 947 return; 948 } 949 // If the addr is in the stack region for this thread then report that 950 // and print thread info 951 if (thread->stack_base() >= addr && 952 addr > (thread->stack_base() - thread->stack_size())) { 953 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: " 954 INTPTR_FORMAT, addr, thread); 955 if (verbose) thread->print_on(st); 956 return; 957 } 958 959 } 960 961#ifndef PRODUCT 962 // Check if in metaspace. 963 if (ClassLoaderDataGraph::contains((address)addr)) { 964 // Use addr->print() from the debugger instead (not here) 965 st->print_cr(INTPTR_FORMAT 966 " is pointing into metadata", addr); 967 return; 968 } 969#endif 970 971 // Try an OS specific find 972 if (os::find(addr, st)) { 973 return; 974 } 975 976 st->print_cr(INTPTR_FORMAT " is an unknown value", addr); 977} 978 979// Looks like all platforms except IA64 can use the same function to check 980// if C stack is walkable beyond current frame. The check for fp() is not 981// necessary on Sparc, but it's harmless. 982bool os::is_first_C_frame(frame* fr) { 983#ifdef IA64 984 // In order to walk native frames on Itanium, we need to access the unwind 985 // table, which is inside ELF. We don't want to parse ELF after fatal error, 986 // so return true for IA64. If we need to support C stack walking on IA64, 987 // this function needs to be moved to CPU specific files, as fp() on IA64 988 // is register stack, which grows towards higher memory address. 989 return true; 990#endif 991 992 // Load up sp, fp, sender sp and sender fp, check for reasonable values. 993 // Check usp first, because if that's bad the other accessors may fault 994 // on some architectures. Ditto ufp second, etc. 995 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1); 996 // sp on amd can be 32 bit aligned. 997 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1); 998 999 uintptr_t usp = (uintptr_t)fr->sp(); 1000 if ((usp & sp_align_mask) != 0) return true; 1001 1002 uintptr_t ufp = (uintptr_t)fr->fp(); 1003 if ((ufp & fp_align_mask) != 0) return true; 1004 1005 uintptr_t old_sp = (uintptr_t)fr->sender_sp(); 1006 if ((old_sp & sp_align_mask) != 0) return true; 1007 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true; 1008 1009 uintptr_t old_fp = (uintptr_t)fr->link(); 1010 if ((old_fp & fp_align_mask) != 0) return true; 1011 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true; 1012 1013 // stack grows downwards; if old_fp is below current fp or if the stack 1014 // frame is too large, either the stack is corrupted or fp is not saved 1015 // on stack (i.e. on x86, ebp may be used as general register). The stack 1016 // is not walkable beyond current frame. 1017 if (old_fp < ufp) return true; 1018 if (old_fp - ufp > 64 * K) return true; 1019 1020 return false; 1021} 1022 1023#ifdef ASSERT 1024extern "C" void test_random() { 1025 const double m = 2147483647; 1026 double mean = 0.0, variance = 0.0, t; 1027 long reps = 10000; 1028 unsigned long seed = 1; 1029 1030 tty->print_cr("seed %ld for %ld repeats...", seed, reps); 1031 os::init_random(seed); 1032 long num; 1033 for (int k = 0; k < reps; k++) { 1034 num = os::random(); 1035 double u = (double)num / m; 1036 assert(u >= 0.0 && u <= 1.0, "bad random number!"); 1037 1038 // calculate mean and variance of the random sequence 1039 mean += u; 1040 variance += (u*u); 1041 } 1042 mean /= reps; 1043 variance /= (reps - 1); 1044 1045 assert(num == 1043618065, "bad seed"); 1046 tty->print_cr("mean of the 1st 10000 numbers: %f", mean); 1047 tty->print_cr("variance of the 1st 10000 numbers: %f", variance); 1048 const double eps = 0.0001; 1049 t = fabsd(mean - 0.5018); 1050 assert(t < eps, "bad mean"); 1051 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355; 1052 assert(t < eps, "bad variance"); 1053} 1054#endif 1055 1056 1057// Set up the boot classpath. 1058 1059char* os::format_boot_path(const char* format_string, 1060 const char* home, 1061 int home_len, 1062 char fileSep, 1063 char pathSep) { 1064 assert((fileSep == '/' && pathSep == ':') || 1065 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars"); 1066 1067 // Scan the format string to determine the length of the actual 1068 // boot classpath, and handle platform dependencies as well. 1069 int formatted_path_len = 0; 1070 const char* p; 1071 for (p = format_string; *p != 0; ++p) { 1072 if (*p == '%') formatted_path_len += home_len - 1; 1073 ++formatted_path_len; 1074 } 1075 1076 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal); 1077 if (formatted_path == NULL) { 1078 return NULL; 1079 } 1080 1081 // Create boot classpath from format, substituting separator chars and 1082 // java home directory. 1083 char* q = formatted_path; 1084 for (p = format_string; *p != 0; ++p) { 1085 switch (*p) { 1086 case '%': 1087 strcpy(q, home); 1088 q += home_len; 1089 break; 1090 case '/': 1091 *q++ = fileSep; 1092 break; 1093 case ':': 1094 *q++ = pathSep; 1095 break; 1096 default: 1097 *q++ = *p; 1098 } 1099 } 1100 *q = '\0'; 1101 1102 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched"); 1103 return formatted_path; 1104} 1105 1106 1107bool os::set_boot_path(char fileSep, char pathSep) { 1108 const char* home = Arguments::get_java_home(); 1109 int home_len = (int)strlen(home); 1110 1111 static const char* meta_index_dir_format = "%/lib/"; 1112 static const char* meta_index_format = "%/lib/meta-index"; 1113 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep); 1114 if (meta_index == NULL) return false; 1115 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep); 1116 if (meta_index_dir == NULL) return false; 1117 Arguments::set_meta_index_path(meta_index, meta_index_dir); 1118 1119 // Any modification to the JAR-file list, for the boot classpath must be 1120 // aligned with install/install/make/common/Pack.gmk. Note: boot class 1121 // path class JARs, are stripped for StackMapTable to reduce download size. 1122 static const char classpath_format[] = 1123 "%/lib/resources.jar:" 1124 "%/lib/rt.jar:" 1125 "%/lib/sunrsasign.jar:" 1126 "%/lib/jsse.jar:" 1127 "%/lib/jce.jar:" 1128 "%/lib/charsets.jar:" 1129 "%/lib/jfr.jar:" 1130#ifdef __APPLE__ 1131 "%/lib/JObjC.jar:" 1132#endif 1133 "%/classes"; 1134 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep); 1135 if (sysclasspath == NULL) return false; 1136 Arguments::set_sysclasspath(sysclasspath); 1137 1138 return true; 1139} 1140 1141/* 1142 * Splits a path, based on its separator, the number of 1143 * elements is returned back in n. 1144 * It is the callers responsibility to: 1145 * a> check the value of n, and n may be 0. 1146 * b> ignore any empty path elements 1147 * c> free up the data. 1148 */ 1149char** os::split_path(const char* path, int* n) { 1150 *n = 0; 1151 if (path == NULL || strlen(path) == 0) { 1152 return NULL; 1153 } 1154 const char psepchar = *os::path_separator(); 1155 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal); 1156 if (inpath == NULL) { 1157 return NULL; 1158 } 1159 strncpy(inpath, path, strlen(path)); 1160 int count = 1; 1161 char* p = strchr(inpath, psepchar); 1162 // Get a count of elements to allocate memory 1163 while (p != NULL) { 1164 count++; 1165 p++; 1166 p = strchr(p, psepchar); 1167 } 1168 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal); 1169 if (opath == NULL) { 1170 return NULL; 1171 } 1172 1173 // do the actual splitting 1174 p = inpath; 1175 for (int i = 0 ; i < count ; i++) { 1176 size_t len = strcspn(p, os::path_separator()); 1177 if (len > JVM_MAXPATHLEN) { 1178 return NULL; 1179 } 1180 // allocate the string and add terminator storage 1181 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal); 1182 if (s == NULL) { 1183 return NULL; 1184 } 1185 strncpy(s, p, len); 1186 s[len] = '\0'; 1187 opath[i] = s; 1188 p += len + 1; 1189 } 1190 FREE_C_HEAP_ARRAY(char, inpath, mtInternal); 1191 *n = count; 1192 return opath; 1193} 1194 1195void os::set_memory_serialize_page(address page) { 1196 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64); 1197 _mem_serialize_page = (volatile int32_t *)page; 1198 // We initialize the serialization page shift count here 1199 // We assume a cache line size of 64 bytes 1200 assert(SerializePageShiftCount == count, 1201 "thread size changed, fix SerializePageShiftCount constant"); 1202 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t))); 1203} 1204 1205static volatile intptr_t SerializePageLock = 0; 1206 1207// This method is called from signal handler when SIGSEGV occurs while the current 1208// thread tries to store to the "read-only" memory serialize page during state 1209// transition. 1210void os::block_on_serialize_page_trap() { 1211 if (TraceSafepoint) { 1212 tty->print_cr("Block until the serialize page permission restored"); 1213 } 1214 // When VMThread is holding the SerializePageLock during modifying the 1215 // access permission of the memory serialize page, the following call 1216 // will block until the permission of that page is restored to rw. 1217 // Generally, it is unsafe to manipulate locks in signal handlers, but in 1218 // this case, it's OK as the signal is synchronous and we know precisely when 1219 // it can occur. 1220 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page"); 1221 Thread::muxRelease(&SerializePageLock); 1222} 1223 1224// Serialize all thread state variables 1225void os::serialize_thread_states() { 1226 // On some platforms such as Solaris & Linux, the time duration of the page 1227 // permission restoration is observed to be much longer than expected due to 1228 // scheduler starvation problem etc. To avoid the long synchronization 1229 // time and expensive page trap spinning, 'SerializePageLock' is used to block 1230 // the mutator thread if such case is encountered. See bug 6546278 for details. 1231 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states"); 1232 os::protect_memory((char *)os::get_memory_serialize_page(), 1233 os::vm_page_size(), MEM_PROT_READ); 1234 os::protect_memory((char *)os::get_memory_serialize_page(), 1235 os::vm_page_size(), MEM_PROT_RW); 1236 Thread::muxRelease(&SerializePageLock); 1237} 1238 1239// Returns true if the current stack pointer is above the stack shadow 1240// pages, false otherwise. 1241 1242bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) { 1243 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check"); 1244 address sp = current_stack_pointer(); 1245 // Check if we have StackShadowPages above the yellow zone. This parameter 1246 // is dependent on the depth of the maximum VM call stack possible from 1247 // the handler for stack overflow. 'instanceof' in the stack overflow 1248 // handler or a println uses at least 8k stack of VM and native code 1249 // respectively. 1250 const int framesize_in_bytes = 1251 Interpreter::size_top_interpreter_activation(method()) * wordSize; 1252 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages) 1253 * vm_page_size()) + framesize_in_bytes; 1254 // The very lower end of the stack 1255 address stack_limit = thread->stack_base() - thread->stack_size(); 1256 return (sp > (stack_limit + reserved_area)); 1257} 1258 1259size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size, 1260 uint min_pages) 1261{ 1262 assert(min_pages > 0, "sanity"); 1263 if (UseLargePages) { 1264 const size_t max_page_size = region_max_size / min_pages; 1265 1266 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) { 1267 const size_t sz = _page_sizes[i]; 1268 const size_t mask = sz - 1; 1269 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) { 1270 // The largest page size with no fragmentation. 1271 return sz; 1272 } 1273 1274 if (sz <= max_page_size) { 1275 // The largest page size that satisfies the min_pages requirement. 1276 return sz; 1277 } 1278 } 1279 } 1280 1281 return vm_page_size(); 1282} 1283 1284#ifndef PRODUCT 1285void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) 1286{ 1287 if (TracePageSizes) { 1288 tty->print("%s: ", str); 1289 for (int i = 0; i < count; ++i) { 1290 tty->print(" " SIZE_FORMAT, page_sizes[i]); 1291 } 1292 tty->cr(); 1293 } 1294} 1295 1296void os::trace_page_sizes(const char* str, const size_t region_min_size, 1297 const size_t region_max_size, const size_t page_size, 1298 const char* base, const size_t size) 1299{ 1300 if (TracePageSizes) { 1301 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT 1302 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT 1303 " size=" SIZE_FORMAT, 1304 str, region_min_size, region_max_size, 1305 page_size, base, size); 1306 } 1307} 1308#endif // #ifndef PRODUCT 1309 1310// This is the working definition of a server class machine: 1311// >= 2 physical CPU's and >=2GB of memory, with some fuzz 1312// because the graphics memory (?) sometimes masks physical memory. 1313// If you want to change the definition of a server class machine 1314// on some OS or platform, e.g., >=4GB on Windohs platforms, 1315// then you'll have to parameterize this method based on that state, 1316// as was done for logical processors here, or replicate and 1317// specialize this method for each platform. (Or fix os to have 1318// some inheritance structure and use subclassing. Sigh.) 1319// If you want some platform to always or never behave as a server 1320// class machine, change the setting of AlwaysActAsServerClassMachine 1321// and NeverActAsServerClassMachine in globals*.hpp. 1322bool os::is_server_class_machine() { 1323 // First check for the early returns 1324 if (NeverActAsServerClassMachine) { 1325 return false; 1326 } 1327 if (AlwaysActAsServerClassMachine) { 1328 return true; 1329 } 1330 // Then actually look at the machine 1331 bool result = false; 1332 const unsigned int server_processors = 2; 1333 const julong server_memory = 2UL * G; 1334 // We seem not to get our full complement of memory. 1335 // We allow some part (1/8?) of the memory to be "missing", 1336 // based on the sizes of DIMMs, and maybe graphics cards. 1337 const julong missing_memory = 256UL * M; 1338 1339 /* Is this a server class machine? */ 1340 if ((os::active_processor_count() >= (int)server_processors) && 1341 (os::physical_memory() >= (server_memory - missing_memory))) { 1342 const unsigned int logical_processors = 1343 VM_Version::logical_processors_per_package(); 1344 if (logical_processors > 1) { 1345 const unsigned int physical_packages = 1346 os::active_processor_count() / logical_processors; 1347 if (physical_packages > server_processors) { 1348 result = true; 1349 } 1350 } else { 1351 result = true; 1352 } 1353 } 1354 return result; 1355} 1356 1357// Read file line by line, if line is longer than bsize, 1358// skip rest of line. 1359int os::get_line_chars(int fd, char* buf, const size_t bsize){ 1360 size_t sz, i = 0; 1361 1362 // read until EOF, EOL or buf is full 1363 while ((sz = (int) read(fd, &buf[i], 1)) == 1 && i < (bsize-2) && buf[i] != '\n') { 1364 ++i; 1365 } 1366 1367 if (buf[i] == '\n') { 1368 // EOL reached so ignore EOL character and return 1369 1370 buf[i] = 0; 1371 return (int) i; 1372 } 1373 1374 buf[i+1] = 0; 1375 1376 if (sz != 1) { 1377 // EOF reached. if we read chars before EOF return them and 1378 // return EOF on next call otherwise return EOF 1379 1380 return (i == 0) ? -1 : (int) i; 1381 } 1382 1383 // line is longer than size of buf, skip to EOL 1384 char ch; 1385 while (read(fd, &ch, 1) == 1 && ch != '\n') { 1386 // Do nothing 1387 } 1388 1389 // return initial part of line that fits in buf. 1390 // If we reached EOF, it will be returned on next call. 1391 1392 return (int) i; 1393} 1394 1395bool os::create_stack_guard_pages(char* addr, size_t bytes) { 1396 return os::pd_create_stack_guard_pages(addr, bytes); 1397} 1398 1399 1400char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) { 1401 char* result = pd_reserve_memory(bytes, addr, alignment_hint); 1402 if (result != NULL) { 1403 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1404 } 1405 1406 return result; 1407} 1408char* os::attempt_reserve_memory_at(size_t bytes, char* addr) { 1409 char* result = pd_attempt_reserve_memory_at(bytes, addr); 1410 if (result != NULL) { 1411 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1412 } 1413 return result; 1414} 1415 1416void os::split_reserved_memory(char *base, size_t size, 1417 size_t split, bool realloc) { 1418 pd_split_reserved_memory(base, size, split, realloc); 1419} 1420 1421bool os::commit_memory(char* addr, size_t bytes, bool executable) { 1422 bool res = pd_commit_memory(addr, bytes, executable); 1423 if (res) { 1424 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); 1425 } 1426 return res; 1427} 1428 1429bool os::commit_memory(char* addr, size_t size, size_t alignment_hint, 1430 bool executable) { 1431 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable); 1432 if (res) { 1433 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); 1434 } 1435 return res; 1436} 1437 1438bool os::uncommit_memory(char* addr, size_t bytes) { 1439 bool res = pd_uncommit_memory(addr, bytes); 1440 if (res) { 1441 MemTracker::record_virtual_memory_uncommit((address)addr, bytes); 1442 } 1443 return res; 1444} 1445 1446bool os::release_memory(char* addr, size_t bytes) { 1447 bool res = pd_release_memory(addr, bytes); 1448 if (res) { 1449 MemTracker::record_virtual_memory_release((address)addr, bytes); 1450 } 1451 return res; 1452} 1453 1454 1455char* os::map_memory(int fd, const char* file_name, size_t file_offset, 1456 char *addr, size_t bytes, bool read_only, 1457 bool allow_exec) { 1458 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec); 1459 if (result != NULL) { 1460 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); 1461 MemTracker::record_virtual_memory_commit((address)result, bytes, CALLER_PC); 1462 } 1463 return result; 1464} 1465 1466char* os::remap_memory(int fd, const char* file_name, size_t file_offset, 1467 char *addr, size_t bytes, bool read_only, 1468 bool allow_exec) { 1469 return pd_remap_memory(fd, file_name, file_offset, addr, bytes, 1470 read_only, allow_exec); 1471} 1472 1473bool os::unmap_memory(char *addr, size_t bytes) { 1474 bool result = pd_unmap_memory(addr, bytes); 1475 if (result) { 1476 MemTracker::record_virtual_memory_uncommit((address)addr, bytes); 1477 MemTracker::record_virtual_memory_release((address)addr, bytes); 1478 } 1479 return result; 1480} 1481 1482void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) { 1483 pd_free_memory(addr, bytes, alignment_hint); 1484} 1485 1486void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 1487 pd_realign_memory(addr, bytes, alignment_hint); 1488} 1489 1490