os_posix.cpp revision 11209:c84a6ce067ad 
1235274Sgabor/*
2 * Copyright (c) 1999, 2016, 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 "utilities/globalDefinitions.hpp"
26#include "prims/jvm.h"
27#include "semaphore_posix.hpp"
28#include "runtime/frame.inline.hpp"
29#include "runtime/interfaceSupport.hpp"
30#include "runtime/os.hpp"
31#include "utilities/vmError.hpp"
32
33#include <signal.h>
34#include <unistd.h>
35#include <sys/resource.h>
36#include <sys/utsname.h>
37#include <pthread.h>
38#include <semaphore.h>
39#include <signal.h>
40
41// Todo: provide a os::get_max_process_id() or similar. Number of processes
42// may have been configured, can be read more accurately from proc fs etc.
43#ifndef MAX_PID
44#define MAX_PID INT_MAX
45#endif
46#define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
47
48// Check core dump limit and report possible place where core can be found
49void os::check_dump_limit(char* buffer, size_t bufferSize) {
50  if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
51    jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
52    VMError::record_coredump_status(buffer, false);
53    return;
54  }
55
56  int n;
57  struct rlimit rlim;
58  bool success;
59
60  char core_path[PATH_MAX];
61  n = get_core_path(core_path, PATH_MAX);
62
63  if (n <= 0) {
64    jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
65    success = true;
66#ifdef LINUX
67  } else if (core_path[0] == '"') { // redirect to user process
68    jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
69    success = true;
70#endif
71  } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
72    jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
73    success = true;
74  } else {
75    switch(rlim.rlim_cur) {
76      case RLIM_INFINITY:
77        jio_snprintf(buffer, bufferSize, "%s", core_path);
78        success = true;
79        break;
80      case 0:
81        jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
82        success = false;
83        break;
84      default:
85        jio_snprintf(buffer, bufferSize, "%s (max size %lu kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", core_path, (unsigned long)(rlim.rlim_cur >> 10));
86        success = true;
87        break;
88    }
89  }
90
91  VMError::record_coredump_status(buffer, success);
92}
93
94int os::get_native_stack(address* stack, int frames, int toSkip) {
95#ifdef _NMT_NOINLINE_
96  toSkip++;
97#endif
98
99  int frame_idx = 0;
100  int num_of_frames;  // number of frames captured
101  frame fr = os::current_frame();
102  while (fr.pc() && frame_idx < frames) {
103    if (toSkip > 0) {
104      toSkip --;
105    } else {
106      stack[frame_idx ++] = fr.pc();
107    }
108    if (fr.fp() == NULL || fr.cb() != NULL ||
109        fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
110
111    if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
112      fr = os::get_sender_for_C_frame(&fr);
113    } else {
114      break;
115    }
116  }
117  num_of_frames = frame_idx;
118  for (; frame_idx < frames; frame_idx ++) {
119    stack[frame_idx] = NULL;
120  }
121
122  return num_of_frames;
123}
124
125
126bool os::unsetenv(const char* name) {
127  assert(name != NULL, "Null pointer");
128  return (::unsetenv(name) == 0);
129}
130
131int os::get_last_error() {
132  return errno;
133}
134
135bool os::is_debugger_attached() {
136  // not implemented
137  return false;
138}
139
140void os::wait_for_keypress_at_exit(void) {
141  // don't do anything on posix platforms
142  return;
143}
144
145// Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
146// so on posix, unmap the section at the start and at the end of the chunk that we mapped
147// rather than unmapping and remapping the whole chunk to get requested alignment.
148char* os::reserve_memory_aligned(size_t size, size_t alignment) {
149  assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
150      "Alignment must be a multiple of allocation granularity (page size)");
151  assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
152
153  size_t extra_size = size + alignment;
154  assert(extra_size >= size, "overflow, size is too large to allow alignment");
155
156  char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
157
158  if (extra_base == NULL) {
159    return NULL;
160  }
161
162  // Do manual alignment
163  char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
164
165  // [  |                                       |  ]
166  // ^ extra_base
167  //    ^ extra_base + begin_offset == aligned_base
168  //     extra_base + begin_offset + size       ^
169  //                       extra_base + extra_size ^
170  // |<>| == begin_offset
171  //                              end_offset == |<>|
172  size_t begin_offset = aligned_base - extra_base;
173  size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
174
175  if (begin_offset > 0) {
176      os::release_memory(extra_base, begin_offset);
177  }
178
179  if (end_offset > 0) {
180      os::release_memory(extra_base + begin_offset + size, end_offset);
181  }
182
183  return aligned_base;
184}
185
186int os::log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
187    return vsnprintf(buf, len, fmt, args);
188}
189
190int os::get_fileno(FILE* fp) {
191  return NOT_AIX(::)fileno(fp);
192}
193
194void os::Posix::print_load_average(outputStream* st) {
195  st->print("load average:");
196  double loadavg[3];
197  os::loadavg(loadavg, 3);
198  st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
199  st->cr();
200}
201
202void os::Posix::print_rlimit_info(outputStream* st) {
203  st->print("rlimit:");
204  struct rlimit rlim;
205
206  st->print(" STACK ");
207  getrlimit(RLIMIT_STACK, &rlim);
208  if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
209  else st->print("%luk", rlim.rlim_cur >> 10);
210
211  st->print(", CORE ");
212  getrlimit(RLIMIT_CORE, &rlim);
213  if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
214  else st->print("%luk", rlim.rlim_cur >> 10);
215
216  // Isn't there on solaris
217#if !defined(TARGET_OS_FAMILY_solaris) && !defined(TARGET_OS_FAMILY_aix)
218  st->print(", NPROC ");
219  getrlimit(RLIMIT_NPROC, &rlim);
220  if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
221  else st->print("%lu", rlim.rlim_cur);
222#endif
223
224  st->print(", NOFILE ");
225  getrlimit(RLIMIT_NOFILE, &rlim);
226  if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
227  else st->print("%lu", rlim.rlim_cur);
228
229  st->print(", AS ");
230  getrlimit(RLIMIT_AS, &rlim);
231  if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
232  else st->print("%luk", rlim.rlim_cur >> 10);
233  st->cr();
234}
235
236void os::Posix::print_uname_info(outputStream* st) {
237  // kernel
238  st->print("uname:");
239  struct utsname name;
240  uname(&name);
241  st->print("%s ", name.sysname);
242#ifdef ASSERT
243  st->print("%s ", name.nodename);
244#endif
245  st->print("%s ", name.release);
246  st->print("%s ", name.version);
247  st->print("%s", name.machine);
248  st->cr();
249}
250
251bool os::get_host_name(char* buf, size_t buflen) {
252  struct utsname name;
253  uname(&name);
254  jio_snprintf(buf, buflen, "%s", name.nodename);
255  return true;
256}
257
258bool os::has_allocatable_memory_limit(julong* limit) {
259  struct rlimit rlim;
260  int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
261  // if there was an error when calling getrlimit, assume that there is no limitation
262  // on virtual memory.
263  bool result;
264  if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
265    result = false;
266  } else {
267    *limit = (julong)rlim.rlim_cur;
268    result = true;
269  }
270#ifdef _LP64
271  return result;
272#else
273  // arbitrary virtual space limit for 32 bit Unices found by testing. If
274  // getrlimit above returned a limit, bound it with this limit. Otherwise
275  // directly use it.
276  const julong max_virtual_limit = (julong)3800*M;
277  if (result) {
278    *limit = MIN2(*limit, max_virtual_limit);
279  } else {
280    *limit = max_virtual_limit;
281  }
282
283  // bound by actually allocatable memory. The algorithm uses two bounds, an
284  // upper and a lower limit. The upper limit is the current highest amount of
285  // memory that could not be allocated, the lower limit is the current highest
286  // amount of memory that could be allocated.
287  // The algorithm iteratively refines the result by halving the difference
288  // between these limits, updating either the upper limit (if that value could
289  // not be allocated) or the lower limit (if the that value could be allocated)
290  // until the difference between these limits is "small".
291
292  // the minimum amount of memory we care about allocating.
293  const julong min_allocation_size = M;
294
295  julong upper_limit = *limit;
296
297  // first check a few trivial cases
298  if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
299    *limit = upper_limit;
300  } else if (!is_allocatable(min_allocation_size)) {
301    // we found that not even min_allocation_size is allocatable. Return it
302    // anyway. There is no point to search for a better value any more.
303    *limit = min_allocation_size;
304  } else {
305    // perform the binary search.
306    julong lower_limit = min_allocation_size;
307    while ((upper_limit - lower_limit) > min_allocation_size) {
308      julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
309      temp_limit = align_size_down_(temp_limit, min_allocation_size);
310      if (is_allocatable(temp_limit)) {
311        lower_limit = temp_limit;
312      } else {
313        upper_limit = temp_limit;
314      }
315    }
316    *limit = lower_limit;
317  }
318  return true;
319#endif
320}
321
322const char* os::get_current_directory(char *buf, size_t buflen) {
323  return getcwd(buf, buflen);
324}
325
326FILE* os::open(int fd, const char* mode) {
327  return ::fdopen(fd, mode);
328}
329
330void os::flockfile(FILE* fp) {
331  ::flockfile(fp);
332}
333
334void os::funlockfile(FILE* fp) {
335  ::funlockfile(fp);
336}
337
338// Builds a platform dependent Agent_OnLoad_<lib_name> function name
339// which is used to find statically linked in agents.
340// Parameters:
341//            sym_name: Symbol in library we are looking for
342//            lib_name: Name of library to look in, NULL for shared libs.
343//            is_absolute_path == true if lib_name is absolute path to agent
344//                                     such as "/a/b/libL.so"
345//            == false if only the base name of the library is passed in
346//               such as "L"
347char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
348                                    bool is_absolute_path) {
349  char *agent_entry_name;
350  size_t len;
351  size_t name_len;
352  size_t prefix_len = strlen(JNI_LIB_PREFIX);
353  size_t suffix_len = strlen(JNI_LIB_SUFFIX);
354  const char *start;
355
356  if (lib_name != NULL) {
357    name_len = strlen(lib_name);
358    if (is_absolute_path) {
359      // Need to strip path, prefix and suffix
360      if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
361        lib_name = ++start;
362      }
363      if (strlen(lib_name) <= (prefix_len + suffix_len)) {
364        return NULL;
365      }
366      lib_name += prefix_len;
367      name_len = strlen(lib_name) - suffix_len;
368    }
369  }
370  len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
371  agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
372  if (agent_entry_name == NULL) {
373    return NULL;
374  }
375  strcpy(agent_entry_name, sym_name);
376  if (lib_name != NULL) {
377    strcat(agent_entry_name, "_");
378    strncat(agent_entry_name, lib_name, name_len);
379  }
380  return agent_entry_name;
381}
382
383int os::sleep(Thread* thread, jlong millis, bool interruptible) {
384  assert(thread == Thread::current(),  "thread consistency check");
385
386  ParkEvent * const slp = thread->_SleepEvent ;
387  slp->reset() ;
388  OrderAccess::fence() ;
389
390  if (interruptible) {
391    jlong prevtime = javaTimeNanos();
392
393    for (;;) {
394      if (os::is_interrupted(thread, true)) {
395        return OS_INTRPT;
396      }
397
398      jlong newtime = javaTimeNanos();
399
400      if (newtime - prevtime < 0) {
401        // time moving backwards, should only happen if no monotonic clock
402        // not a guarantee() because JVM should not abort on kernel/glibc bugs
403        assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
404      } else {
405        millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
406      }
407
408      if (millis <= 0) {
409        return OS_OK;
410      }
411
412      prevtime = newtime;
413
414      {
415        assert(thread->is_Java_thread(), "sanity check");
416        JavaThread *jt = (JavaThread *) thread;
417        ThreadBlockInVM tbivm(jt);
418        OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
419
420        jt->set_suspend_equivalent();
421        // cleared by handle_special_suspend_equivalent_condition() or
422        // java_suspend_self() via check_and_wait_while_suspended()
423
424        slp->park(millis);
425
426        // were we externally suspended while we were waiting?
427        jt->check_and_wait_while_suspended();
428      }
429    }
430  } else {
431    OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
432    jlong prevtime = javaTimeNanos();
433
434    for (;;) {
435      // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
436      // the 1st iteration ...
437      jlong newtime = javaTimeNanos();
438
439      if (newtime - prevtime < 0) {
440        // time moving backwards, should only happen if no monotonic clock
441        // not a guarantee() because JVM should not abort on kernel/glibc bugs
442        assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
443      } else {
444        millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
445      }
446
447      if (millis <= 0) break ;
448
449      prevtime = newtime;
450      slp->park(millis);
451    }
452    return OS_OK ;
453  }
454}
455
456////////////////////////////////////////////////////////////////////////////////
457// interrupt support
458
459void os::interrupt(Thread* thread) {
460  assert(Thread::current() == thread || Threads_lock->owned_by_self(),
461    "possibility of dangling Thread pointer");
462
463  OSThread* osthread = thread->osthread();
464
465  if (!osthread->interrupted()) {
466    osthread->set_interrupted(true);
467    // More than one thread can get here with the same value of osthread,
468    // resulting in multiple notifications.  We do, however, want the store
469    // to interrupted() to be visible to other threads before we execute unpark().
470    OrderAccess::fence();
471    ParkEvent * const slp = thread->_SleepEvent ;
472    if (slp != NULL) slp->unpark() ;
473  }
474
475  // For JSR166. Unpark even if interrupt status already was set
476  if (thread->is_Java_thread())
477    ((JavaThread*)thread)->parker()->unpark();
478
479  ParkEvent * ev = thread->_ParkEvent ;
480  if (ev != NULL) ev->unpark() ;
481
482}
483
484bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
485  assert(Thread::current() == thread || Threads_lock->owned_by_self(),
486    "possibility of dangling Thread pointer");
487
488  OSThread* osthread = thread->osthread();
489
490  bool interrupted = osthread->interrupted();
491
492  // NOTE that since there is no "lock" around the interrupt and
493  // is_interrupted operations, there is the possibility that the
494  // interrupted flag (in osThread) will be "false" but that the
495  // low-level events will be in the signaled state. This is
496  // intentional. The effect of this is that Object.wait() and
497  // LockSupport.park() will appear to have a spurious wakeup, which
498  // is allowed and not harmful, and the possibility is so rare that
499  // it is not worth the added complexity to add yet another lock.
500  // For the sleep event an explicit reset is performed on entry
501  // to os::sleep, so there is no early return. It has also been
502  // recommended not to put the interrupted flag into the "event"
503  // structure because it hides the issue.
504  if (interrupted && clear_interrupted) {
505    osthread->set_interrupted(false);
506    // consider thread->_SleepEvent->reset() ... optional optimization
507  }
508
509  return interrupted;
510}
511
512
513
514static const struct {
515  int sig; const char* name;
516}
517 g_signal_info[] =
518  {
519  {  SIGABRT,     "SIGABRT" },
520#ifdef SIGAIO
521  {  SIGAIO,      "SIGAIO" },
522#endif
523  {  SIGALRM,     "SIGALRM" },
524#ifdef SIGALRM1
525  {  SIGALRM1,    "SIGALRM1" },
526#endif
527  {  SIGBUS,      "SIGBUS" },
528#ifdef SIGCANCEL
529  {  SIGCANCEL,   "SIGCANCEL" },
530#endif
531  {  SIGCHLD,     "SIGCHLD" },
532#ifdef SIGCLD
533  {  SIGCLD,      "SIGCLD" },
534#endif
535  {  SIGCONT,     "SIGCONT" },
536#ifdef SIGCPUFAIL
537  {  SIGCPUFAIL,  "SIGCPUFAIL" },
538#endif
539#ifdef SIGDANGER
540  {  SIGDANGER,   "SIGDANGER" },
541#endif
542#ifdef SIGDIL
543  {  SIGDIL,      "SIGDIL" },
544#endif
545#ifdef SIGEMT
546  {  SIGEMT,      "SIGEMT" },
547#endif
548  {  SIGFPE,      "SIGFPE" },
549#ifdef SIGFREEZE
550  {  SIGFREEZE,   "SIGFREEZE" },
551#endif
552#ifdef SIGGFAULT
553  {  SIGGFAULT,   "SIGGFAULT" },
554#endif
555#ifdef SIGGRANT
556  {  SIGGRANT,    "SIGGRANT" },
557#endif
558  {  SIGHUP,      "SIGHUP" },
559  {  SIGILL,      "SIGILL" },
560  {  SIGINT,      "SIGINT" },
561#ifdef SIGIO
562  {  SIGIO,       "SIGIO" },
563#endif
564#ifdef SIGIOINT
565  {  SIGIOINT,    "SIGIOINT" },
566#endif
567#ifdef SIGIOT
568// SIGIOT is there for BSD compatibility, but on most Unices just a
569// synonym for SIGABRT. The result should be "SIGABRT", not
570// "SIGIOT".
571#if (SIGIOT != SIGABRT )
572  {  SIGIOT,      "SIGIOT" },
573#endif
574#endif
575#ifdef SIGKAP
576  {  SIGKAP,      "SIGKAP" },
577#endif
578  {  SIGKILL,     "SIGKILL" },
579#ifdef SIGLOST
580  {  SIGLOST,     "SIGLOST" },
581#endif
582#ifdef SIGLWP
583  {  SIGLWP,      "SIGLWP" },
584#endif
585#ifdef SIGLWPTIMER
586  {  SIGLWPTIMER, "SIGLWPTIMER" },
587#endif
588#ifdef SIGMIGRATE
589  {  SIGMIGRATE,  "SIGMIGRATE" },
590#endif
591#ifdef SIGMSG
592  {  SIGMSG,      "SIGMSG" },
593#endif
594  {  SIGPIPE,     "SIGPIPE" },
595#ifdef SIGPOLL
596  {  SIGPOLL,     "SIGPOLL" },
597#endif
598#ifdef SIGPRE
599  {  SIGPRE,      "SIGPRE" },
600#endif
601  {  SIGPROF,     "SIGPROF" },
602#ifdef SIGPTY
603  {  SIGPTY,      "SIGPTY" },
604#endif
605#ifdef SIGPWR
606  {  SIGPWR,      "SIGPWR" },
607#endif
608  {  SIGQUIT,     "SIGQUIT" },
609#ifdef SIGRECONFIG
610  {  SIGRECONFIG, "SIGRECONFIG" },
611#endif
612#ifdef SIGRECOVERY
613  {  SIGRECOVERY, "SIGRECOVERY" },
614#endif
615#ifdef SIGRESERVE
616  {  SIGRESERVE,  "SIGRESERVE" },
617#endif
618#ifdef SIGRETRACT
619  {  SIGRETRACT,  "SIGRETRACT" },
620#endif
621#ifdef SIGSAK
622  {  SIGSAK,      "SIGSAK" },
623#endif
624  {  SIGSEGV,     "SIGSEGV" },
625#ifdef SIGSOUND
626  {  SIGSOUND,    "SIGSOUND" },
627#endif
628#ifdef SIGSTKFLT
629  {  SIGSTKFLT,    "SIGSTKFLT" },
630#endif
631  {  SIGSTOP,     "SIGSTOP" },
632  {  SIGSYS,      "SIGSYS" },
633#ifdef SIGSYSERROR
634  {  SIGSYSERROR, "SIGSYSERROR" },
635#endif
636#ifdef SIGTALRM
637  {  SIGTALRM,    "SIGTALRM" },
638#endif
639  {  SIGTERM,     "SIGTERM" },
640#ifdef SIGTHAW
641  {  SIGTHAW,     "SIGTHAW" },
642#endif
643  {  SIGTRAP,     "SIGTRAP" },
644#ifdef SIGTSTP
645  {  SIGTSTP,     "SIGTSTP" },
646#endif
647  {  SIGTTIN,     "SIGTTIN" },
648  {  SIGTTOU,     "SIGTTOU" },
649#ifdef SIGURG
650  {  SIGURG,      "SIGURG" },
651#endif
652  {  SIGUSR1,     "SIGUSR1" },
653  {  SIGUSR2,     "SIGUSR2" },
654#ifdef SIGVIRT
655  {  SIGVIRT,     "SIGVIRT" },
656#endif
657  {  SIGVTALRM,   "SIGVTALRM" },
658#ifdef SIGWAITING
659  {  SIGWAITING,  "SIGWAITING" },
660#endif
661#ifdef SIGWINCH
662  {  SIGWINCH,    "SIGWINCH" },
663#endif
664#ifdef SIGWINDOW
665  {  SIGWINDOW,   "SIGWINDOW" },
666#endif
667  {  SIGXCPU,     "SIGXCPU" },
668  {  SIGXFSZ,     "SIGXFSZ" },
669#ifdef SIGXRES
670  {  SIGXRES,     "SIGXRES" },
671#endif
672  { -1, NULL }
673};
674
675// Returned string is a constant. For unknown signals "UNKNOWN" is returned.
676const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
677
678  const char* ret = NULL;
679
680#ifdef SIGRTMIN
681  if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
682    if (sig == SIGRTMIN) {
683      ret = "SIGRTMIN";
684    } else if (sig == SIGRTMAX) {
685      ret = "SIGRTMAX";
686    } else {
687      jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
688      return out;
689    }
690  }
691#endif
692
693  if (sig > 0) {
694    for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
695      if (g_signal_info[idx].sig == sig) {
696        ret = g_signal_info[idx].name;
697        break;
698      }
699    }
700  }
701
702  if (!ret) {
703    if (!is_valid_signal(sig)) {
704      ret = "INVALID";
705    } else {
706      ret = "UNKNOWN";
707    }
708  }
709
710  if (out && outlen > 0) {
711    strncpy(out, ret, outlen);
712    out[outlen - 1] = '\0';
713  }
714  return out;
715}
716
717int os::Posix::get_signal_number(const char* signal_name) {
718  char tmp[30];
719  const char* s = signal_name;
720  if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
721    jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
722    s = tmp;
723  }
724  for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
725    if (strcmp(g_signal_info[idx].name, s) == 0) {
726      return g_signal_info[idx].sig;
727    }
728  }
729  return -1;
730}
731
732int os::get_signal_number(const char* signal_name) {
733  return os::Posix::get_signal_number(signal_name);
734}
735
736// Returns true if signal number is valid.
737bool os::Posix::is_valid_signal(int sig) {
738  // MacOS not really POSIX compliant: sigaddset does not return
739  // an error for invalid signal numbers. However, MacOS does not
740  // support real time signals and simply seems to have just 33
741  // signals with no holes in the signal range.
742#ifdef __APPLE__
743  return sig >= 1 && sig < NSIG;
744#else
745  // Use sigaddset to check for signal validity.
746  sigset_t set;
747  if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
748    return false;
749  }
750  return true;
751#endif
752}
753
754// Returns:
755// NULL for an invalid signal number
756// "SIG<num>" for a valid but unknown signal number
757// signal name otherwise.
758const char* os::exception_name(int sig, char* buf, size_t size) {
759  if (!os::Posix::is_valid_signal(sig)) {
760    return NULL;
761  }
762  const char* const name = os::Posix::get_signal_name(sig, buf, size);
763  if (strcmp(name, "UNKNOWN") == 0) {
764    jio_snprintf(buf, size, "SIG%d", sig);
765  }
766  return buf;
767}
768
769#define NUM_IMPORTANT_SIGS 32
770// Returns one-line short description of a signal set in a user provided buffer.
771const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
772  assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
773  // Note: for shortness, just print out the first 32. That should
774  // cover most of the useful ones, apart from realtime signals.
775  for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
776    const int rc = sigismember(set, sig);
777    if (rc == -1 && errno == EINVAL) {
778      buffer[sig-1] = '?';
779    } else {
780      buffer[sig-1] = rc == 0 ? '0' : '1';
781    }
782  }
783  buffer[NUM_IMPORTANT_SIGS] = 0;
784  return buffer;
785}
786
787// Prints one-line description of a signal set.
788void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
789  char buf[NUM_IMPORTANT_SIGS + 1];
790  os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
791  st->print("%s", buf);
792}
793
794// Writes one-line description of a combination of sigaction.sa_flags into a user
795// provided buffer. Returns that buffer.
796const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
797  char* p = buffer;
798  size_t remaining = size;
799  bool first = true;
800  int idx = 0;
801
802  assert(buffer, "invalid argument");
803
804  if (size == 0) {
805    return buffer;
806  }
807
808  strncpy(buffer, "none", size);
809
810  const struct {
811    // NB: i is an unsigned int here because SA_RESETHAND is on some
812    // systems 0x80000000, which is implicitly unsigned.  Assignining
813    // it to an int field would be an overflow in unsigned-to-signed
814    // conversion.
815    unsigned int i;
816    const char* s;
817  } flaginfo [] = {
818    { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
819    { SA_ONSTACK,   "SA_ONSTACK"   },
820    { SA_RESETHAND, "SA_RESETHAND" },
821    { SA_RESTART,   "SA_RESTART"   },
822    { SA_SIGINFO,   "SA_SIGINFO"   },
823    { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
824    { SA_NODEFER,   "SA_NODEFER"   },
825#ifdef AIX
826    { SA_ONSTACK,   "SA_ONSTACK"   },
827    { SA_OLDSTYLE,  "SA_OLDSTYLE"  },
828#endif
829    { 0, NULL }
830  };
831
832  for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
833    if (flags & flaginfo[idx].i) {
834      if (first) {
835        jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
836        first = false;
837      } else {
838        jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
839      }
840      const size_t len = strlen(p);
841      p += len;
842      remaining -= len;
843    }
844  }
845
846  buffer[size - 1] = '\0';
847
848  return buffer;
849}
850
851// Prints one-line description of a combination of sigaction.sa_flags.
852void os::Posix::print_sa_flags(outputStream* st, int flags) {
853  char buffer[0x100];
854  os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
855  st->print("%s", buffer);
856}
857
858// Helper function for os::Posix::print_siginfo_...():
859// return a textual description for signal code.
860struct enum_sigcode_desc_t {
861  const char* s_name;
862  const char* s_desc;
863};
864
865static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
866
867  const struct {
868    int sig; int code; const char* s_code; const char* s_desc;
869  } t1 [] = {
870    { SIGILL,  ILL_ILLOPC,   "ILL_ILLOPC",   "Illegal opcode." },
871    { SIGILL,  ILL_ILLOPN,   "ILL_ILLOPN",   "Illegal operand." },
872    { SIGILL,  ILL_ILLADR,   "ILL_ILLADR",   "Illegal addressing mode." },
873    { SIGILL,  ILL_ILLTRP,   "ILL_ILLTRP",   "Illegal trap." },
874    { SIGILL,  ILL_PRVOPC,   "ILL_PRVOPC",   "Privileged opcode." },
875    { SIGILL,  ILL_PRVREG,   "ILL_PRVREG",   "Privileged register." },
876    { SIGILL,  ILL_COPROC,   "ILL_COPROC",   "Coprocessor error." },
877    { SIGILL,  ILL_BADSTK,   "ILL_BADSTK",   "Internal stack error." },
878#if defined(IA64) && defined(LINUX)
879    { SIGILL,  ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
880    { SIGILL,  ILL_BREAK,    "ILL_BREAK",    "Application Break instruction" },
881#endif
882    { SIGFPE,  FPE_INTDIV,   "FPE_INTDIV",   "Integer divide by zero." },
883    { SIGFPE,  FPE_INTOVF,   "FPE_INTOVF",   "Integer overflow." },
884    { SIGFPE,  FPE_FLTDIV,   "FPE_FLTDIV",   "Floating-point divide by zero." },
885    { SIGFPE,  FPE_FLTOVF,   "FPE_FLTOVF",   "Floating-point overflow." },
886    { SIGFPE,  FPE_FLTUND,   "FPE_FLTUND",   "Floating-point underflow." },
887    { SIGFPE,  FPE_FLTRES,   "FPE_FLTRES",   "Floating-point inexact result." },
888    { SIGFPE,  FPE_FLTINV,   "FPE_FLTINV",   "Invalid floating-point operation." },
889    { SIGFPE,  FPE_FLTSUB,   "FPE_FLTSUB",   "Subscript out of range." },
890    { SIGSEGV, SEGV_MAPERR,  "SEGV_MAPERR",  "Address not mapped to object." },
891    { SIGSEGV, SEGV_ACCERR,  "SEGV_ACCERR",  "Invalid permissions for mapped object." },
892#ifdef AIX
893    // no explanation found what keyerr would be
894    { SIGSEGV, SEGV_KEYERR,  "SEGV_KEYERR",  "key error" },
895#endif
896#if defined(IA64) && !defined(AIX)
897    { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
898#endif
899#if defined(__sparc) && defined(SOLARIS)
900// define Solaris Sparc M7 ADI SEGV signals
901#if !defined(SEGV_ACCADI)
902#define SEGV_ACCADI 3
903#endif
904    { SIGSEGV, SEGV_ACCADI,  "SEGV_ACCADI",  "ADI not enabled for mapped object." },
905#if !defined(SEGV_ACCDERR)
906#define SEGV_ACCDERR 4
907#endif
908    { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
909#if !defined(SEGV_ACCPERR)
910#define SEGV_ACCPERR 5
911#endif
912    { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
913#endif // defined(__sparc) && defined(SOLARIS)
914    { SIGBUS,  BUS_ADRALN,   "BUS_ADRALN",   "Invalid address alignment." },
915    { SIGBUS,  BUS_ADRERR,   "BUS_ADRERR",   "Nonexistent physical address." },
916    { SIGBUS,  BUS_OBJERR,   "BUS_OBJERR",   "Object-specific hardware error." },
917    { SIGTRAP, TRAP_BRKPT,   "TRAP_BRKPT",   "Process breakpoint." },
918    { SIGTRAP, TRAP_TRACE,   "TRAP_TRACE",   "Process trace trap." },
919    { SIGCHLD, CLD_EXITED,   "CLD_EXITED",   "Child has exited." },
920    { SIGCHLD, CLD_KILLED,   "CLD_KILLED",   "Child has terminated abnormally and did not create a core file." },
921    { SIGCHLD, CLD_DUMPED,   "CLD_DUMPED",   "Child has terminated abnormally and created a core file." },
922    { SIGCHLD, CLD_TRAPPED,  "CLD_TRAPPED",  "Traced child has trapped." },
923    { SIGCHLD, CLD_STOPPED,  "CLD_STOPPED",  "Child has stopped." },
924    { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
925#ifdef SIGPOLL
926    { SIGPOLL, POLL_OUT,     "POLL_OUT",     "Output buffers available." },
927    { SIGPOLL, POLL_MSG,     "POLL_MSG",     "Input message available." },
928    { SIGPOLL, POLL_ERR,     "POLL_ERR",     "I/O error." },
929    { SIGPOLL, POLL_PRI,     "POLL_PRI",     "High priority input available." },
930    { SIGPOLL, POLL_HUP,     "POLL_HUP",     "Device disconnected. [Option End]" },
931#endif
932    { -1, -1, NULL, NULL }
933  };
934
935  // Codes valid in any signal context.
936  const struct {
937    int code; const char* s_code; const char* s_desc;
938  } t2 [] = {
939    { SI_USER,      "SI_USER",     "Signal sent by kill()." },
940    { SI_QUEUE,     "SI_QUEUE",    "Signal sent by the sigqueue()." },
941    { SI_TIMER,     "SI_TIMER",    "Signal generated by expiration of a timer set by timer_settime()." },
942    { SI_ASYNCIO,   "SI_ASYNCIO",  "Signal generated by completion of an asynchronous I/O request." },
943    { SI_MESGQ,     "SI_MESGQ",    "Signal generated by arrival of a message on an empty message queue." },
944    // Linux specific
945#ifdef SI_TKILL
946    { SI_TKILL,     "SI_TKILL",    "Signal sent by tkill (pthread_kill)" },
947#endif
948#ifdef SI_DETHREAD
949    { SI_DETHREAD,  "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
950#endif
951#ifdef SI_KERNEL
952    { SI_KERNEL,    "SI_KERNEL",   "Signal sent by kernel." },
953#endif
954#ifdef SI_SIGIO
955    { SI_SIGIO,     "SI_SIGIO",    "Signal sent by queued SIGIO" },
956#endif
957
958#ifdef AIX
959    { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
960    { SI_EMPTY,     "SI_EMPTY",    "siginfo contains no useful information" },
961#endif
962
963#ifdef __sun
964    { SI_NOINFO,    "SI_NOINFO",   "No signal information" },
965    { SI_RCTL,      "SI_RCTL",     "kernel generated signal via rctl action" },
966    { SI_LWP,       "SI_LWP",      "Signal sent via lwp_kill" },
967#endif
968
969    { -1, NULL, NULL }
970  };
971
972  const char* s_code = NULL;
973  const char* s_desc = NULL;
974
975  for (int i = 0; t1[i].sig != -1; i ++) {
976    if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
977      s_code = t1[i].s_code;
978      s_desc = t1[i].s_desc;
979      break;
980    }
981  }
982
983  if (s_code == NULL) {
984    for (int i = 0; t2[i].s_code != NULL; i ++) {
985      if (t2[i].code == si->si_code) {
986        s_code = t2[i].s_code;
987        s_desc = t2[i].s_desc;
988      }
989    }
990  }
991
992  if (s_code == NULL) {
993    out->s_name = "unknown";
994    out->s_desc = "unknown";
995    return false;
996  }
997
998  out->s_name = s_code;
999  out->s_desc = s_desc;
1000
1001  return true;
1002}
1003
1004void os::print_siginfo(outputStream* os, const void* si0) {
1005
1006  const siginfo_t* const si = (const siginfo_t*) si0;
1007
1008  char buf[20];
1009  os->print("siginfo:");
1010
1011  if (!si) {
1012    os->print(" <null>");
1013    return;
1014  }
1015
1016  const int sig = si->si_signo;
1017
1018  os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1019
1020  enum_sigcode_desc_t ed;
1021  get_signal_code_description(si, &ed);
1022  os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1023
1024  if (si->si_errno) {
1025    os->print(", si_errno: %d", si->si_errno);
1026  }
1027
1028  // Output additional information depending on the signal code.
1029
1030  // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1031  // so it depends on the context which member to use. For synchronous error signals,
1032  // we print si_addr, unless the signal was sent by another process or thread, in
1033  // which case we print out pid or tid of the sender.
1034  if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
1035    const pid_t pid = si->si_pid;
1036    os->print(", si_pid: %ld", (long) pid);
1037    if (IS_VALID_PID(pid)) {
1038      const pid_t me = getpid();
1039      if (me == pid) {
1040        os->print(" (current process)");
1041      }
1042    } else {
1043      os->print(" (invalid)");
1044    }
1045    os->print(", si_uid: %ld", (long) si->si_uid);
1046    if (sig == SIGCHLD) {
1047      os->print(", si_status: %d", si->si_status);
1048    }
1049  } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1050             sig == SIGTRAP || sig == SIGFPE) {
1051    os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1052#ifdef SIGPOLL
1053  } else if (sig == SIGPOLL) {
1054    os->print(", si_band: %ld", si->si_band);
1055#endif
1056  }
1057
1058}
1059
1060int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1061  return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1062}
1063
1064address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1065#ifdef TARGET_OS_FAMILY_linux
1066   return Linux::ucontext_get_pc(ctx);
1067#elif defined(TARGET_OS_FAMILY_solaris)
1068   return Solaris::ucontext_get_pc(ctx);
1069#elif defined(TARGET_OS_FAMILY_aix)
1070   return Aix::ucontext_get_pc(ctx);
1071#elif defined(TARGET_OS_FAMILY_bsd)
1072   return Bsd::ucontext_get_pc(ctx);
1073#else
1074   VMError::report_and_die("unimplemented ucontext_get_pc");
1075#endif
1076}
1077
1078void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1079#ifdef TARGET_OS_FAMILY_linux
1080   Linux::ucontext_set_pc(ctx, pc);
1081#elif defined(TARGET_OS_FAMILY_solaris)
1082   Solaris::ucontext_set_pc(ctx, pc);
1083#elif defined(TARGET_OS_FAMILY_aix)
1084   Aix::ucontext_set_pc(ctx, pc);
1085#elif defined(TARGET_OS_FAMILY_bsd)
1086   Bsd::ucontext_set_pc(ctx, pc);
1087#else
1088   VMError::report_and_die("unimplemented ucontext_get_pc");
1089#endif
1090}
1091
1092char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1093  size_t stack_size = 0;
1094  size_t guard_size = 0;
1095  int detachstate = 0;
1096  pthread_attr_getstacksize(attr, &stack_size);
1097  pthread_attr_getguardsize(attr, &guard_size);
1098  pthread_attr_getdetachstate(attr, &detachstate);
1099  jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1100    stack_size / 1024, guard_size / 1024,
1101    (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1102  return buf;
1103}
1104
1105
1106os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
1107  assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
1108}
1109
1110/*
1111 * See the caveats for this class in os_posix.hpp
1112 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1113 * method and returns false. If none of the signals are raised, returns true.
1114 * The callback is supposed to provide the method that should be protected.
1115 */
1116bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1117  sigset_t saved_sig_mask;
1118
1119  assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
1120  assert(!WatcherThread::watcher_thread()->has_crash_protection(),
1121      "crash_protection already set?");
1122
1123  // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1124  // since on at least some systems (OS X) siglongjmp will restore the mask
1125  // for the process, not the thread
1126  pthread_sigmask(0, NULL, &saved_sig_mask);
1127  if (sigsetjmp(_jmpbuf, 0) == 0) {
1128    // make sure we can see in the signal handler that we have crash protection
1129    // installed
1130    WatcherThread::watcher_thread()->set_crash_protection(this);
1131    cb.call();
1132    // and clear the crash protection
1133    WatcherThread::watcher_thread()->set_crash_protection(NULL);
1134    return true;
1135  }
1136  // this happens when we siglongjmp() back
1137  pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1138  WatcherThread::watcher_thread()->set_crash_protection(NULL);
1139  return false;
1140}
1141
1142void os::WatcherThreadCrashProtection::restore() {
1143  assert(WatcherThread::watcher_thread()->has_crash_protection(),
1144      "must have crash protection");
1145
1146  siglongjmp(_jmpbuf, 1);
1147}
1148
1149void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
1150    Thread* thread) {
1151
1152  if (thread != NULL &&
1153      thread->is_Watcher_thread() &&
1154      WatcherThread::watcher_thread()->has_crash_protection()) {
1155
1156    if (sig == SIGSEGV || sig == SIGBUS) {
1157      WatcherThread::watcher_thread()->crash_protection()->restore();
1158    }
1159  }
1160}
1161
1162#define check_with_errno(check_type, cond, msg)                             \
1163  do {                                                                      \
1164    int err = errno;                                                        \
1165    check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err),   \
1166               os::errno_name(err));                                        \
1167} while (false)
1168
1169#define assert_with_errno(cond, msg)    check_with_errno(assert, cond, msg)
1170#define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
1171
1172// POSIX unamed semaphores are not supported on OS X.
1173#ifndef __APPLE__
1174
1175PosixSemaphore::PosixSemaphore(uint value) {
1176  int ret = sem_init(&_semaphore, 0, value);
1177
1178  guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
1179}
1180
1181PosixSemaphore::~PosixSemaphore() {
1182  sem_destroy(&_semaphore);
1183}
1184
1185void PosixSemaphore::signal(uint count) {
1186  for (uint i = 0; i < count; i++) {
1187    int ret = sem_post(&_semaphore);
1188
1189    assert_with_errno(ret == 0, "sem_post failed");
1190  }
1191}
1192
1193void PosixSemaphore::wait() {
1194  int ret;
1195
1196  do {
1197    ret = sem_wait(&_semaphore);
1198  } while (ret != 0 && errno == EINTR);
1199
1200  assert_with_errno(ret == 0, "sem_wait failed");
1201}
1202
1203bool PosixSemaphore::trywait() {
1204  int ret;
1205
1206  do {
1207    ret = sem_trywait(&_semaphore);
1208  } while (ret != 0 && errno == EINTR);
1209
1210  assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
1211
1212  return ret == 0;
1213}
1214
1215bool PosixSemaphore::timedwait(struct timespec ts) {
1216  while (true) {
1217    int result = sem_timedwait(&_semaphore, &ts);
1218    if (result == 0) {
1219      return true;
1220    } else if (errno == EINTR) {
1221      continue;
1222    } else if (errno == ETIMEDOUT) {
1223      return false;
1224    } else {
1225      assert_with_errno(false, "timedwait failed");
1226      return false;
1227    }
1228  }
1229}
1230
1231#endif // __APPLE__
1232