1 /*
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/macros.hpp"
32 #include "utilities/vmError.hpp"
33
34 #include <signal.h>
35 #include <unistd.h>
36 #include <sys/resource.h>
37 #include <sys/utsname.h>
38 #include <pthread.h>
39 #include <semaphore.h>
40 #include <signal.h>
41
42 // Todo: provide a os::get_max_process_id() or similar. Number of processes
43 // may have been configured, can be read more accurately from proc fs etc.
44 #ifndef MAX_PID
45 #define MAX_PID INT_MAX
46 #endif
47 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
48
49 // Check core dump limit and report possible place where core can be found
50 void os::check_dump_limit(char* buffer, size_t bufferSize) {
51 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
52 jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
53 VMError::record_coredump_status(buffer, false);
54 return;
55 }
56
57 int n;
58 struct rlimit rlim;
59 bool success;
60
61 char core_path[PATH_MAX];
62 n = get_core_path(core_path, PATH_MAX);
63
64 if (n <= 0) {
65 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
66 success = true;
67 #ifdef LINUX
68 } else if (core_path[0] == '"') { // redirect to user process
69 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
70 success = true;
71 #endif
72 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
73 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
74 success = true;
75 } else {
76 switch(rlim.rlim_cur) {
77 case RLIM_INFINITY:
78 jio_snprintf(buffer, bufferSize, "%s", core_path);
79 success = true;
80 break;
81 case 0:
82 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
83 success = false;
84 break;
85 default:
86 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));
87 success = true;
88 break;
89 }
90 }
91
92 VMError::record_coredump_status(buffer, success);
93 }
94
95 int os::get_native_stack(address* stack, int frames, int toSkip) {
96 int frame_idx = 0;
97 int num_of_frames; // number of frames captured
98 frame fr = os::current_frame();
99 while (fr.pc() && frame_idx < frames) {
100 if (toSkip > 0) {
101 toSkip --;
102 } else {
103 stack[frame_idx ++] = fr.pc();
104 }
105 if (fr.fp() == NULL || fr.cb() != NULL ||
106 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
107
108 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
109 fr = os::get_sender_for_C_frame(&fr);
110 } else {
111 break;
112 }
113 }
114 num_of_frames = frame_idx;
115 for (; frame_idx < frames; frame_idx ++) {
116 stack[frame_idx] = NULL;
117 }
118
119 return num_of_frames;
120 }
121
122
123 bool os::unsetenv(const char* name) {
124 assert(name != NULL, "Null pointer");
125 return (::unsetenv(name) == 0);
126 }
127
128 int os::get_last_error() {
129 return errno;
130 }
131
132 bool os::is_debugger_attached() {
133 // not implemented
134 return false;
135 }
136
137 void os::wait_for_keypress_at_exit(void) {
138 // don't do anything on posix platforms
139 return;
140 }
141
142 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
143 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
144 // rather than unmapping and remapping the whole chunk to get requested alignment.
145 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
146 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
147 "Alignment must be a multiple of allocation granularity (page size)");
148 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
149
150 size_t extra_size = size + alignment;
151 assert(extra_size >= size, "overflow, size is too large to allow alignment");
152
153 char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
154
155 if (extra_base == NULL) {
156 return NULL;
157 }
158
159 // Do manual alignment
160 char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
161
162 // [ | | ]
163 // ^ extra_base
164 // ^ extra_base + begin_offset == aligned_base
165 // extra_base + begin_offset + size ^
166 // extra_base + extra_size ^
167 // |<>| == begin_offset
168 // end_offset == |<>|
169 size_t begin_offset = aligned_base - extra_base;
170 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
171
172 if (begin_offset > 0) {
173 os::release_memory(extra_base, begin_offset);
174 }
175
176 if (end_offset > 0) {
177 os::release_memory(extra_base + begin_offset + size, end_offset);
178 }
179
180 if (file_desc != -1) {
181 if (os::map_memory_to_file(aligned_base, size, file_desc) == NULL) {
182 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
183 }
184 }
185 return aligned_base;
186 }
187
188 int os::log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
189 return vsnprintf(buf, len, fmt, args);
190 }
191
192 int os::get_fileno(FILE* fp) {
193 return NOT_AIX(::)fileno(fp);
194 }
195
196 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
197 return gmtime_r(clock, res);
198 }
199
200 void os::Posix::print_load_average(outputStream* st) {
201 st->print("load average:");
202 double loadavg[3];
203 os::loadavg(loadavg, 3);
204 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
205 st->cr();
206 }
207
208 void os::Posix::print_rlimit_info(outputStream* st) {
209 st->print("rlimit:");
210 struct rlimit rlim;
211
212 st->print(" STACK ");
213 getrlimit(RLIMIT_STACK, &rlim);
214 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
215 else st->print("%luk", rlim.rlim_cur >> 10);
216
217 st->print(", CORE ");
218 getrlimit(RLIMIT_CORE, &rlim);
219 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
220 else st->print("%luk", rlim.rlim_cur >> 10);
221
222 // Isn't there on solaris
223 #if !defined(SOLARIS) && !defined(AIX)
224 st->print(", NPROC ");
225 getrlimit(RLIMIT_NPROC, &rlim);
226 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
227 else st->print("%lu", rlim.rlim_cur);
228 #endif
229
230 st->print(", NOFILE ");
231 getrlimit(RLIMIT_NOFILE, &rlim);
232 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
233 else st->print("%lu", rlim.rlim_cur);
234
235 st->print(", AS ");
236 getrlimit(RLIMIT_AS, &rlim);
237 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
238 else st->print("%luk", rlim.rlim_cur >> 10);
239 st->cr();
240 }
241
242 void os::Posix::print_uname_info(outputStream* st) {
243 // kernel
244 st->print("uname:");
245 struct utsname name;
246 uname(&name);
247 st->print("%s ", name.sysname);
248 #ifdef ASSERT
249 st->print("%s ", name.nodename);
250 #endif
251 st->print("%s ", name.release);
252 st->print("%s ", name.version);
253 st->print("%s", name.machine);
254 st->cr();
255 }
256
257 bool os::get_host_name(char* buf, size_t buflen) {
258 struct utsname name;
259 uname(&name);
260 jio_snprintf(buf, buflen, "%s", name.nodename);
261 return true;
262 }
263
264 bool os::has_allocatable_memory_limit(julong* limit) {
265 struct rlimit rlim;
266 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
267 // if there was an error when calling getrlimit, assume that there is no limitation
268 // on virtual memory.
269 bool result;
270 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
271 result = false;
272 } else {
273 *limit = (julong)rlim.rlim_cur;
274 result = true;
275 }
276 #ifdef _LP64
277 return result;
278 #else
279 // arbitrary virtual space limit for 32 bit Unices found by testing. If
280 // getrlimit above returned a limit, bound it with this limit. Otherwise
281 // directly use it.
282 const julong max_virtual_limit = (julong)3800*M;
283 if (result) {
284 *limit = MIN2(*limit, max_virtual_limit);
285 } else {
286 *limit = max_virtual_limit;
287 }
288
289 // bound by actually allocatable memory. The algorithm uses two bounds, an
290 // upper and a lower limit. The upper limit is the current highest amount of
291 // memory that could not be allocated, the lower limit is the current highest
292 // amount of memory that could be allocated.
293 // The algorithm iteratively refines the result by halving the difference
294 // between these limits, updating either the upper limit (if that value could
295 // not be allocated) or the lower limit (if the that value could be allocated)
296 // until the difference between these limits is "small".
297
298 // the minimum amount of memory we care about allocating.
299 const julong min_allocation_size = M;
300
301 julong upper_limit = *limit;
302
303 // first check a few trivial cases
304 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
305 *limit = upper_limit;
306 } else if (!is_allocatable(min_allocation_size)) {
307 // we found that not even min_allocation_size is allocatable. Return it
308 // anyway. There is no point to search for a better value any more.
309 *limit = min_allocation_size;
310 } else {
311 // perform the binary search.
312 julong lower_limit = min_allocation_size;
313 while ((upper_limit - lower_limit) > min_allocation_size) {
314 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
315 temp_limit = align_size_down_(temp_limit, min_allocation_size);
316 if (is_allocatable(temp_limit)) {
317 lower_limit = temp_limit;
318 } else {
319 upper_limit = temp_limit;
320 }
321 }
322 *limit = lower_limit;
323 }
324 return true;
325 #endif
326 }
327
328 const char* os::get_current_directory(char *buf, size_t buflen) {
329 return getcwd(buf, buflen);
330 }
331
332 FILE* os::open(int fd, const char* mode) {
333 return ::fdopen(fd, mode);
334 }
335
336 void os::flockfile(FILE* fp) {
337 ::flockfile(fp);
338 }
339
340 void os::funlockfile(FILE* fp) {
341 ::funlockfile(fp);
342 }
343
344 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
345 // which is used to find statically linked in agents.
346 // Parameters:
347 // sym_name: Symbol in library we are looking for
348 // lib_name: Name of library to look in, NULL for shared libs.
349 // is_absolute_path == true if lib_name is absolute path to agent
350 // such as "/a/b/libL.so"
351 // == false if only the base name of the library is passed in
352 // such as "L"
353 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
354 bool is_absolute_path) {
355 char *agent_entry_name;
356 size_t len;
357 size_t name_len;
358 size_t prefix_len = strlen(JNI_LIB_PREFIX);
359 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
360 const char *start;
361
362 if (lib_name != NULL) {
363 name_len = strlen(lib_name);
364 if (is_absolute_path) {
365 // Need to strip path, prefix and suffix
366 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
367 lib_name = ++start;
368 }
369 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
370 return NULL;
371 }
372 lib_name += prefix_len;
373 name_len = strlen(lib_name) - suffix_len;
374 }
375 }
376 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
377 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
378 if (agent_entry_name == NULL) {
379 return NULL;
380 }
381 strcpy(agent_entry_name, sym_name);
382 if (lib_name != NULL) {
383 strcat(agent_entry_name, "_");
384 strncat(agent_entry_name, lib_name, name_len);
385 }
386 return agent_entry_name;
387 }
388
389 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
390 assert(thread == Thread::current(), "thread consistency check");
391
392 ParkEvent * const slp = thread->_SleepEvent ;
393 slp->reset() ;
394 OrderAccess::fence() ;
395
396 if (interruptible) {
397 jlong prevtime = javaTimeNanos();
398
399 for (;;) {
400 if (os::is_interrupted(thread, true)) {
401 return OS_INTRPT;
402 }
403
404 jlong newtime = javaTimeNanos();
405
406 if (newtime - prevtime < 0) {
407 // time moving backwards, should only happen if no monotonic clock
408 // not a guarantee() because JVM should not abort on kernel/glibc bugs
409 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
410 } else {
411 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
412 }
413
414 if (millis <= 0) {
415 return OS_OK;
416 }
417
418 prevtime = newtime;
419
420 {
421 assert(thread->is_Java_thread(), "sanity check");
422 JavaThread *jt = (JavaThread *) thread;
423 ThreadBlockInVM tbivm(jt);
424 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
425
426 jt->set_suspend_equivalent();
427 // cleared by handle_special_suspend_equivalent_condition() or
428 // java_suspend_self() via check_and_wait_while_suspended()
429
430 slp->park(millis);
431
432 // were we externally suspended while we were waiting?
433 jt->check_and_wait_while_suspended();
434 }
435 }
436 } else {
437 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
438 jlong prevtime = javaTimeNanos();
439
440 for (;;) {
441 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
442 // the 1st iteration ...
443 jlong newtime = javaTimeNanos();
444
445 if (newtime - prevtime < 0) {
446 // time moving backwards, should only happen if no monotonic clock
447 // not a guarantee() because JVM should not abort on kernel/glibc bugs
448 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
449 } else {
450 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
451 }
452
453 if (millis <= 0) break ;
454
455 prevtime = newtime;
456 slp->park(millis);
457 }
458 return OS_OK ;
459 }
460 }
461
462 ////////////////////////////////////////////////////////////////////////////////
463 // interrupt support
464
465 void os::interrupt(Thread* thread) {
466 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
467 "possibility of dangling Thread pointer");
468
469 OSThread* osthread = thread->osthread();
470
471 if (!osthread->interrupted()) {
472 osthread->set_interrupted(true);
473 // More than one thread can get here with the same value of osthread,
474 // resulting in multiple notifications. We do, however, want the store
475 // to interrupted() to be visible to other threads before we execute unpark().
476 OrderAccess::fence();
477 ParkEvent * const slp = thread->_SleepEvent ;
478 if (slp != NULL) slp->unpark() ;
479 }
480
481 // For JSR166. Unpark even if interrupt status already was set
482 if (thread->is_Java_thread())
483 ((JavaThread*)thread)->parker()->unpark();
484
485 ParkEvent * ev = thread->_ParkEvent ;
486 if (ev != NULL) ev->unpark() ;
487
488 }
489
490 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
491 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
492 "possibility of dangling Thread pointer");
493
494 OSThread* osthread = thread->osthread();
495
496 bool interrupted = osthread->interrupted();
497
498 // NOTE that since there is no "lock" around the interrupt and
499 // is_interrupted operations, there is the possibility that the
500 // interrupted flag (in osThread) will be "false" but that the
501 // low-level events will be in the signaled state. This is
502 // intentional. The effect of this is that Object.wait() and
503 // LockSupport.park() will appear to have a spurious wakeup, which
504 // is allowed and not harmful, and the possibility is so rare that
505 // it is not worth the added complexity to add yet another lock.
506 // For the sleep event an explicit reset is performed on entry
507 // to os::sleep, so there is no early return. It has also been
508 // recommended not to put the interrupted flag into the "event"
509 // structure because it hides the issue.
510 if (interrupted && clear_interrupted) {
511 osthread->set_interrupted(false);
512 // consider thread->_SleepEvent->reset() ... optional optimization
513 }
514
515 return interrupted;
516 }
517
518
519
520 static const struct {
521 int sig; const char* name;
522 }
523 g_signal_info[] =
524 {
525 { SIGABRT, "SIGABRT" },
526 #ifdef SIGAIO
527 { SIGAIO, "SIGAIO" },
528 #endif
529 { SIGALRM, "SIGALRM" },
530 #ifdef SIGALRM1
531 { SIGALRM1, "SIGALRM1" },
532 #endif
533 { SIGBUS, "SIGBUS" },
534 #ifdef SIGCANCEL
535 { SIGCANCEL, "SIGCANCEL" },
536 #endif
537 { SIGCHLD, "SIGCHLD" },
538 #ifdef SIGCLD
539 { SIGCLD, "SIGCLD" },
540 #endif
541 { SIGCONT, "SIGCONT" },
542 #ifdef SIGCPUFAIL
543 { SIGCPUFAIL, "SIGCPUFAIL" },
544 #endif
545 #ifdef SIGDANGER
546 { SIGDANGER, "SIGDANGER" },
547 #endif
548 #ifdef SIGDIL
549 { SIGDIL, "SIGDIL" },
550 #endif
551 #ifdef SIGEMT
552 { SIGEMT, "SIGEMT" },
553 #endif
554 { SIGFPE, "SIGFPE" },
555 #ifdef SIGFREEZE
556 { SIGFREEZE, "SIGFREEZE" },
557 #endif
558 #ifdef SIGGFAULT
559 { SIGGFAULT, "SIGGFAULT" },
560 #endif
561 #ifdef SIGGRANT
562 { SIGGRANT, "SIGGRANT" },
563 #endif
564 { SIGHUP, "SIGHUP" },
565 { SIGILL, "SIGILL" },
566 { SIGINT, "SIGINT" },
567 #ifdef SIGIO
568 { SIGIO, "SIGIO" },
569 #endif
570 #ifdef SIGIOINT
571 { SIGIOINT, "SIGIOINT" },
572 #endif
573 #ifdef SIGIOT
574 // SIGIOT is there for BSD compatibility, but on most Unices just a
575 // synonym for SIGABRT. The result should be "SIGABRT", not
576 // "SIGIOT".
577 #if (SIGIOT != SIGABRT )
578 { SIGIOT, "SIGIOT" },
579 #endif
580 #endif
581 #ifdef SIGKAP
582 { SIGKAP, "SIGKAP" },
583 #endif
584 { SIGKILL, "SIGKILL" },
585 #ifdef SIGLOST
586 { SIGLOST, "SIGLOST" },
587 #endif
588 #ifdef SIGLWP
589 { SIGLWP, "SIGLWP" },
590 #endif
591 #ifdef SIGLWPTIMER
592 { SIGLWPTIMER, "SIGLWPTIMER" },
593 #endif
594 #ifdef SIGMIGRATE
595 { SIGMIGRATE, "SIGMIGRATE" },
596 #endif
597 #ifdef SIGMSG
598 { SIGMSG, "SIGMSG" },
599 #endif
600 { SIGPIPE, "SIGPIPE" },
601 #ifdef SIGPOLL
602 { SIGPOLL, "SIGPOLL" },
603 #endif
604 #ifdef SIGPRE
605 { SIGPRE, "SIGPRE" },
606 #endif
607 { SIGPROF, "SIGPROF" },
608 #ifdef SIGPTY
609 { SIGPTY, "SIGPTY" },
610 #endif
611 #ifdef SIGPWR
612 { SIGPWR, "SIGPWR" },
613 #endif
614 { SIGQUIT, "SIGQUIT" },
615 #ifdef SIGRECONFIG
616 { SIGRECONFIG, "SIGRECONFIG" },
617 #endif
618 #ifdef SIGRECOVERY
619 { SIGRECOVERY, "SIGRECOVERY" },
620 #endif
621 #ifdef SIGRESERVE
622 { SIGRESERVE, "SIGRESERVE" },
623 #endif
624 #ifdef SIGRETRACT
625 { SIGRETRACT, "SIGRETRACT" },
626 #endif
627 #ifdef SIGSAK
628 { SIGSAK, "SIGSAK" },
629 #endif
630 { SIGSEGV, "SIGSEGV" },
631 #ifdef SIGSOUND
632 { SIGSOUND, "SIGSOUND" },
633 #endif
634 #ifdef SIGSTKFLT
635 { SIGSTKFLT, "SIGSTKFLT" },
636 #endif
637 { SIGSTOP, "SIGSTOP" },
638 { SIGSYS, "SIGSYS" },
639 #ifdef SIGSYSERROR
640 { SIGSYSERROR, "SIGSYSERROR" },
641 #endif
642 #ifdef SIGTALRM
643 { SIGTALRM, "SIGTALRM" },
644 #endif
645 { SIGTERM, "SIGTERM" },
646 #ifdef SIGTHAW
647 { SIGTHAW, "SIGTHAW" },
648 #endif
649 { SIGTRAP, "SIGTRAP" },
650 #ifdef SIGTSTP
651 { SIGTSTP, "SIGTSTP" },
652 #endif
653 { SIGTTIN, "SIGTTIN" },
654 { SIGTTOU, "SIGTTOU" },
655 #ifdef SIGURG
656 { SIGURG, "SIGURG" },
657 #endif
658 { SIGUSR1, "SIGUSR1" },
659 { SIGUSR2, "SIGUSR2" },
660 #ifdef SIGVIRT
661 { SIGVIRT, "SIGVIRT" },
662 #endif
663 { SIGVTALRM, "SIGVTALRM" },
664 #ifdef SIGWAITING
665 { SIGWAITING, "SIGWAITING" },
666 #endif
667 #ifdef SIGWINCH
668 { SIGWINCH, "SIGWINCH" },
669 #endif
670 #ifdef SIGWINDOW
671 { SIGWINDOW, "SIGWINDOW" },
672 #endif
673 { SIGXCPU, "SIGXCPU" },
674 { SIGXFSZ, "SIGXFSZ" },
675 #ifdef SIGXRES
676 { SIGXRES, "SIGXRES" },
677 #endif
678 { -1, NULL }
679 };
680
681 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
682 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
683
684 const char* ret = NULL;
685
686 #ifdef SIGRTMIN
687 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
688 if (sig == SIGRTMIN) {
689 ret = "SIGRTMIN";
690 } else if (sig == SIGRTMAX) {
691 ret = "SIGRTMAX";
692 } else {
693 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
694 return out;
695 }
696 }
697 #endif
698
699 if (sig > 0) {
700 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
701 if (g_signal_info[idx].sig == sig) {
702 ret = g_signal_info[idx].name;
703 break;
704 }
705 }
706 }
707
708 if (!ret) {
709 if (!is_valid_signal(sig)) {
710 ret = "INVALID";
711 } else {
712 ret = "UNKNOWN";
713 }
714 }
715
716 if (out && outlen > 0) {
717 strncpy(out, ret, outlen);
718 out[outlen - 1] = '\0';
719 }
720 return out;
721 }
722
723 int os::Posix::get_signal_number(const char* signal_name) {
724 char tmp[30];
725 const char* s = signal_name;
726 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
727 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
728 s = tmp;
729 }
730 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
731 if (strcmp(g_signal_info[idx].name, s) == 0) {
732 return g_signal_info[idx].sig;
733 }
734 }
735 return -1;
736 }
737
738 int os::get_signal_number(const char* signal_name) {
739 return os::Posix::get_signal_number(signal_name);
740 }
741
742 // Returns true if signal number is valid.
743 bool os::Posix::is_valid_signal(int sig) {
744 // MacOS not really POSIX compliant: sigaddset does not return
745 // an error for invalid signal numbers. However, MacOS does not
746 // support real time signals and simply seems to have just 33
747 // signals with no holes in the signal range.
748 #ifdef __APPLE__
749 return sig >= 1 && sig < NSIG;
750 #else
751 // Use sigaddset to check for signal validity.
752 sigset_t set;
753 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
754 return false;
755 }
756 return true;
757 #endif
758 }
759
760 // Returns:
761 // NULL for an invalid signal number
762 // "SIG<num>" for a valid but unknown signal number
763 // signal name otherwise.
764 const char* os::exception_name(int sig, char* buf, size_t size) {
765 if (!os::Posix::is_valid_signal(sig)) {
766 return NULL;
767 }
768 const char* const name = os::Posix::get_signal_name(sig, buf, size);
769 if (strcmp(name, "UNKNOWN") == 0) {
770 jio_snprintf(buf, size, "SIG%d", sig);
771 }
772 return buf;
773 }
774
775 #define NUM_IMPORTANT_SIGS 32
776 // Returns one-line short description of a signal set in a user provided buffer.
777 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
778 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
779 // Note: for shortness, just print out the first 32. That should
780 // cover most of the useful ones, apart from realtime signals.
781 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
782 const int rc = sigismember(set, sig);
783 if (rc == -1 && errno == EINVAL) {
784 buffer[sig-1] = '?';
785 } else {
786 buffer[sig-1] = rc == 0 ? '0' : '1';
787 }
788 }
789 buffer[NUM_IMPORTANT_SIGS] = 0;
790 return buffer;
791 }
792
793 // Prints one-line description of a signal set.
794 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
795 char buf[NUM_IMPORTANT_SIGS + 1];
796 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
797 st->print("%s", buf);
798 }
799
800 // Writes one-line description of a combination of sigaction.sa_flags into a user
801 // provided buffer. Returns that buffer.
802 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
803 char* p = buffer;
804 size_t remaining = size;
805 bool first = true;
806 int idx = 0;
807
808 assert(buffer, "invalid argument");
809
810 if (size == 0) {
811 return buffer;
812 }
813
814 strncpy(buffer, "none", size);
815
816 const struct {
817 // NB: i is an unsigned int here because SA_RESETHAND is on some
818 // systems 0x80000000, which is implicitly unsigned. Assignining
819 // it to an int field would be an overflow in unsigned-to-signed
820 // conversion.
821 unsigned int i;
822 const char* s;
823 } flaginfo [] = {
824 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
825 { SA_ONSTACK, "SA_ONSTACK" },
826 { SA_RESETHAND, "SA_RESETHAND" },
827 { SA_RESTART, "SA_RESTART" },
828 { SA_SIGINFO, "SA_SIGINFO" },
829 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
830 { SA_NODEFER, "SA_NODEFER" },
831 #ifdef AIX
832 { SA_ONSTACK, "SA_ONSTACK" },
833 { SA_OLDSTYLE, "SA_OLDSTYLE" },
834 #endif
835 { 0, NULL }
836 };
837
838 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
839 if (flags & flaginfo[idx].i) {
840 if (first) {
841 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
842 first = false;
843 } else {
844 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
845 }
846 const size_t len = strlen(p);
847 p += len;
848 remaining -= len;
849 }
850 }
851
852 buffer[size - 1] = '\0';
853
854 return buffer;
855 }
856
857 // Prints one-line description of a combination of sigaction.sa_flags.
858 void os::Posix::print_sa_flags(outputStream* st, int flags) {
859 char buffer[0x100];
860 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
861 st->print("%s", buffer);
862 }
863
864 // Helper function for os::Posix::print_siginfo_...():
865 // return a textual description for signal code.
866 struct enum_sigcode_desc_t {
867 const char* s_name;
868 const char* s_desc;
869 };
870
871 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
872
873 const struct {
874 int sig; int code; const char* s_code; const char* s_desc;
875 } t1 [] = {
876 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
877 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
878 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
879 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
880 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
881 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
882 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
883 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
884 #if defined(IA64) && defined(LINUX)
885 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
886 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
887 #endif
888 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
889 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
890 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
891 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
892 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
893 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
894 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
895 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
896 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
897 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
898 #ifdef AIX
899 // no explanation found what keyerr would be
900 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
901 #endif
902 #if defined(IA64) && !defined(AIX)
903 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
904 #endif
905 #if defined(__sparc) && defined(SOLARIS)
906 // define Solaris Sparc M7 ADI SEGV signals
907 #if !defined(SEGV_ACCADI)
908 #define SEGV_ACCADI 3
909 #endif
910 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
911 #if !defined(SEGV_ACCDERR)
912 #define SEGV_ACCDERR 4
913 #endif
914 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
915 #if !defined(SEGV_ACCPERR)
916 #define SEGV_ACCPERR 5
917 #endif
918 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
919 #endif // defined(__sparc) && defined(SOLARIS)
920 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
921 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
922 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
923 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
924 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
925 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
926 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
927 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
928 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
929 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
930 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
931 #ifdef SIGPOLL
932 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
933 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
934 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
935 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
936 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
937 #endif
938 { -1, -1, NULL, NULL }
939 };
940
941 // Codes valid in any signal context.
942 const struct {
943 int code; const char* s_code; const char* s_desc;
944 } t2 [] = {
945 { SI_USER, "SI_USER", "Signal sent by kill()." },
946 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
947 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
948 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
949 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
950 // Linux specific
951 #ifdef SI_TKILL
952 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
953 #endif
954 #ifdef SI_DETHREAD
955 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
956 #endif
957 #ifdef SI_KERNEL
958 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
959 #endif
960 #ifdef SI_SIGIO
961 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
962 #endif
963
964 #ifdef AIX
965 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
966 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
967 #endif
968
969 #ifdef __sun
970 { SI_NOINFO, "SI_NOINFO", "No signal information" },
971 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
972 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
973 #endif
974
975 { -1, NULL, NULL }
976 };
977
978 const char* s_code = NULL;
979 const char* s_desc = NULL;
980
981 for (int i = 0; t1[i].sig != -1; i ++) {
982 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
983 s_code = t1[i].s_code;
984 s_desc = t1[i].s_desc;
985 break;
986 }
987 }
988
989 if (s_code == NULL) {
990 for (int i = 0; t2[i].s_code != NULL; i ++) {
991 if (t2[i].code == si->si_code) {
992 s_code = t2[i].s_code;
993 s_desc = t2[i].s_desc;
994 }
995 }
996 }
997
998 if (s_code == NULL) {
999 out->s_name = "unknown";
1000 out->s_desc = "unknown";
1001 return false;
1002 }
1003
1004 out->s_name = s_code;
1005 out->s_desc = s_desc;
1006
1007 return true;
1008 }
1009
1010 void os::print_siginfo(outputStream* os, const void* si0) {
1011
1012 const siginfo_t* const si = (const siginfo_t*) si0;
1013
1014 char buf[20];
1015 os->print("siginfo:");
1016
1017 if (!si) {
1018 os->print(" <null>");
1019 return;
1020 }
1021
1022 const int sig = si->si_signo;
1023
1024 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1025
1026 enum_sigcode_desc_t ed;
1027 get_signal_code_description(si, &ed);
1028 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1029
1030 if (si->si_errno) {
1031 os->print(", si_errno: %d", si->si_errno);
1032 }
1033
1034 // Output additional information depending on the signal code.
1035
1036 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1037 // so it depends on the context which member to use. For synchronous error signals,
1038 // we print si_addr, unless the signal was sent by another process or thread, in
1039 // which case we print out pid or tid of the sender.
1040 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
1041 const pid_t pid = si->si_pid;
1042 os->print(", si_pid: %ld", (long) pid);
1043 if (IS_VALID_PID(pid)) {
1044 const pid_t me = getpid();
1045 if (me == pid) {
1046 os->print(" (current process)");
1047 }
1048 } else {
1049 os->print(" (invalid)");
1050 }
1051 os->print(", si_uid: %ld", (long) si->si_uid);
1052 if (sig == SIGCHLD) {
1053 os->print(", si_status: %d", si->si_status);
1054 }
1055 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1056 sig == SIGTRAP || sig == SIGFPE) {
1057 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1058 #ifdef SIGPOLL
1059 } else if (sig == SIGPOLL) {
1060 os->print(", si_band: %ld", si->si_band);
1061 #endif
1062 }
1063
1064 }
1065
1066 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1067 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1068 }
1069
1070 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1071 #if defined(AIX)
1072 return Aix::ucontext_get_pc(ctx);
1073 #elif defined(BSD)
1074 return Bsd::ucontext_get_pc(ctx);
1075 #elif defined(LINUX)
1076 return Linux::ucontext_get_pc(ctx);
1077 #elif defined(SOLARIS)
1078 return Solaris::ucontext_get_pc(ctx);
1079 #else
1080 VMError::report_and_die("unimplemented ucontext_get_pc");
1081 #endif
1082 }
1083
1084 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1085 #if defined(AIX)
1086 Aix::ucontext_set_pc(ctx, pc);
1087 #elif defined(BSD)
1088 Bsd::ucontext_set_pc(ctx, pc);
1089 #elif defined(LINUX)
1090 Linux::ucontext_set_pc(ctx, pc);
1091 #elif defined(SOLARIS)
1092 Solaris::ucontext_set_pc(ctx, pc);
1093 #else
1094 VMError::report_and_die("unimplemented ucontext_get_pc");
1095 #endif
1096 }
1097
1098 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1099 size_t stack_size = 0;
1100 size_t guard_size = 0;
1101 int detachstate = 0;
1102 pthread_attr_getstacksize(attr, &stack_size);
1103 pthread_attr_getguardsize(attr, &guard_size);
1104 pthread_attr_getdetachstate(attr, &detachstate);
1105 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1106 stack_size / 1024, guard_size / 1024,
1107 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1108 return buf;
1109 }
1110
1111 // Check minimum allowable stack sizes for thread creation and to initialize
1112 // the java system classes, including StackOverflowError - depends on page
1113 // size. Add two 4K pages for compiler2 recursion in main thread.
1114 // Add in 4*BytesPerWord 4K pages to account for VM stack during
1115 // class initialization depending on 32 or 64 bit VM.
1116 jint os::Posix::set_minimum_stack_sizes() {
1117 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed,
1118 JavaThread::stack_guard_zone_size() +
1119 JavaThread::stack_shadow_zone_size() +
1120 (4 * BytesPerWord COMPILER2_PRESENT(+ 2)) * 4 * K);
1121
1122 _java_thread_min_stack_allowed = align_size_up(_java_thread_min_stack_allowed, vm_page_size());
1123
1124 size_t stack_size_in_bytes = ThreadStackSize * K;
1125 if (stack_size_in_bytes != 0 &&
1126 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1127 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1128 // ThreadStackSize so we go with "Java thread stack size" instead
1129 // of "ThreadStackSize" to be more friendly.
1130 tty->print_cr("\nThe Java thread stack size specified is too small. "
1131 "Specify at least " SIZE_FORMAT "k",
1132 _java_thread_min_stack_allowed / K);
1133 return JNI_ERR;
1134 }
1135
1136 #ifdef SOLARIS
1137 // For 64kbps there will be a 64kb page size, which makes
1138 // the usable default stack size quite a bit less. Increase the
1139 // stack for 64kb (or any > than 8kb) pages, this increases
1140 // virtual memory fragmentation (since we're not creating the
1141 // stack on a power of 2 boundary. The real fix for this
1142 // should be to fix the guard page mechanism.
1143
1144 if (vm_page_size() > 8*K) {
1145 stack_size_in_bytes = (stack_size_in_bytes != 0)
1146 ? stack_size_in_bytes +
1147 JavaThread::stack_red_zone_size() +
1148 JavaThread::stack_yellow_zone_size()
1149 : 0;
1150 ThreadStackSize = stack_size_in_bytes/K;
1151 }
1152 #endif // SOLARIS
1153
1154 // Make the stack size a multiple of the page size so that
1155 // the yellow/red zones can be guarded.
1156 JavaThread::set_stack_size_at_create(round_to(stack_size_in_bytes,
1157 vm_page_size()));
1158
1159 _compiler_thread_min_stack_allowed = align_size_up(_compiler_thread_min_stack_allowed, vm_page_size());
1160
1161 stack_size_in_bytes = CompilerThreadStackSize * K;
1162 if (stack_size_in_bytes != 0 &&
1163 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1164 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1165 "Specify at least " SIZE_FORMAT "k",
1166 _compiler_thread_min_stack_allowed / K);
1167 return JNI_ERR;
1168 }
1169
1170 _vm_internal_thread_min_stack_allowed = align_size_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1171
1172 stack_size_in_bytes = VMThreadStackSize * K;
1173 if (stack_size_in_bytes != 0 &&
1174 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1175 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1176 "Specify at least " SIZE_FORMAT "k",
1177 _vm_internal_thread_min_stack_allowed / K);
1178 return JNI_ERR;
1179 }
1180 return JNI_OK;
1181 }
1182
1183 // Called when creating the thread. The minimum stack sizes have already been calculated
1184 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1185 size_t stack_size;
1186 if (req_stack_size == 0) {
1187 stack_size = default_stack_size(thr_type);
1188 } else {
1189 stack_size = req_stack_size;
1190 }
1191
1192 switch (thr_type) {
1193 case os::java_thread:
1194 // Java threads use ThreadStackSize which default value can be
1195 // changed with the flag -Xss
1196 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1197 // no requested size and we have a more specific default value
1198 stack_size = JavaThread::stack_size_at_create();
1199 }
1200 stack_size = MAX2(stack_size,
1201 _java_thread_min_stack_allowed);
1202 break;
1203 case os::compiler_thread:
1204 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1205 // no requested size and we have a more specific default value
1206 stack_size = (size_t)(CompilerThreadStackSize * K);
1207 }
1208 stack_size = MAX2(stack_size,
1209 _compiler_thread_min_stack_allowed);
1210 break;
1211 case os::vm_thread:
1212 case os::pgc_thread:
1213 case os::cgc_thread:
1214 case os::watcher_thread:
1215 default: // presume the unknown thr_type is a VM internal
1216 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1217 // no requested size and we have a more specific default value
1218 stack_size = (size_t)(VMThreadStackSize * K);
1219 }
1220
1221 stack_size = MAX2(stack_size,
1222 _vm_internal_thread_min_stack_allowed);
1223 break;
1224 }
1225
1226 return stack_size;
1227 }
1228
1229 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
1230 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
1231 }
1232
1233 /*
1234 * See the caveats for this class in os_posix.hpp
1235 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1236 * method and returns false. If none of the signals are raised, returns true.
1237 * The callback is supposed to provide the method that should be protected.
1238 */
1239 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1240 sigset_t saved_sig_mask;
1241
1242 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
1243 assert(!WatcherThread::watcher_thread()->has_crash_protection(),
1244 "crash_protection already set?");
1245
1246 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1247 // since on at least some systems (OS X) siglongjmp will restore the mask
1248 // for the process, not the thread
1249 pthread_sigmask(0, NULL, &saved_sig_mask);
1250 if (sigsetjmp(_jmpbuf, 0) == 0) {
1251 // make sure we can see in the signal handler that we have crash protection
1252 // installed
1253 WatcherThread::watcher_thread()->set_crash_protection(this);
1254 cb.call();
1255 // and clear the crash protection
1256 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1257 return true;
1258 }
1259 // this happens when we siglongjmp() back
1260 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1261 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1262 return false;
1263 }
1264
1265 void os::WatcherThreadCrashProtection::restore() {
1266 assert(WatcherThread::watcher_thread()->has_crash_protection(),
1267 "must have crash protection");
1268
1269 siglongjmp(_jmpbuf, 1);
1270 }
1271
1272 void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
1273 Thread* thread) {
1274
1275 if (thread != NULL &&
1276 thread->is_Watcher_thread() &&
1277 WatcherThread::watcher_thread()->has_crash_protection()) {
1278
1279 if (sig == SIGSEGV || sig == SIGBUS) {
1280 WatcherThread::watcher_thread()->crash_protection()->restore();
1281 }
1282 }
1283 }
1284
1285 #define check_with_errno(check_type, cond, msg) \
1286 do { \
1287 int err = errno; \
1288 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
1289 os::errno_name(err)); \
1290 } while (false)
1291
1292 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
1293 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
1294
1295 // POSIX unamed semaphores are not supported on OS X.
1296 #ifndef __APPLE__
1297
1298 PosixSemaphore::PosixSemaphore(uint value) {
1299 int ret = sem_init(&_semaphore, 0, value);
1300
1301 guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
1302 }
1303
1304 PosixSemaphore::~PosixSemaphore() {
1305 sem_destroy(&_semaphore);
1306 }
1307
1308 void PosixSemaphore::signal(uint count) {
1309 for (uint i = 0; i < count; i++) {
1310 int ret = sem_post(&_semaphore);
1311
1312 assert_with_errno(ret == 0, "sem_post failed");
1313 }
1314 }
1315
1316 void PosixSemaphore::wait() {
1317 int ret;
1318
1319 do {
1320 ret = sem_wait(&_semaphore);
1321 } while (ret != 0 && errno == EINTR);
1322
1323 assert_with_errno(ret == 0, "sem_wait failed");
1324 }
1325
1326 bool PosixSemaphore::trywait() {
1327 int ret;
1328
1329 do {
1330 ret = sem_trywait(&_semaphore);
1331 } while (ret != 0 && errno == EINTR);
1332
1333 assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
1334
1335 return ret == 0;
1336 }
1337
1338 bool PosixSemaphore::timedwait(struct timespec ts) {
1339 while (true) {
1340 int result = sem_timedwait(&_semaphore, &ts);
1341 if (result == 0) {
1342 return true;
1343 } else if (errno == EINTR) {
1344 continue;
1345 } else if (errno == ETIMEDOUT) {
1346 return false;
1347 } else {
1348 assert_with_errno(false, "timedwait failed");
1349 return false;
1350 }
1351 }
1352 }
1353
1354 #endif // __APPLE__