1 /*
2 * Copyright (c) 1999, 2017, 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 "jvm.h"
26 #include "utilities/globalDefinitions.hpp"
27 #include "runtime/frame.inline.hpp"
28 #include "runtime/interfaceSupport.hpp"
29 #include "runtime/os.hpp"
30 #include "utilities/align.hpp"
31 #include "utilities/macros.hpp"
32 #include "utilities/vmError.hpp"
33
34 #ifndef __APPLE__
35 // POSIX unamed semaphores are not supported on OS X.
36 #include "semaphore_posix.hpp"
37 #endif
38
39 #include <dlfcn.h>
40 #include <pthread.h>
41 #include <semaphore.h>
42 #include <signal.h>
43 #include <sys/mman.h>
44 #include <sys/resource.h>
45 #include <sys/utsname.h>
46 #include <time.h>
47 #include <unistd.h>
48
49 // Todo: provide a os::get_max_process_id() or similar. Number of processes
50 // may have been configured, can be read more accurately from proc fs etc.
51 #ifndef MAX_PID
52 #define MAX_PID INT_MAX
53 #endif
54 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
55
56 #ifndef MAP_ANONYMOUS
57 #define MAP_ANONYMOUS MAP_ANON
58 #endif
59
60 #define check_with_errno(check_type, cond, msg) \
61 do { \
62 int err = errno; \
63 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
64 os::errno_name(err)); \
65 } while (false)
66
67 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
68 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
69
70 // Check core dump limit and report possible place where core can be found
71 void os::check_dump_limit(char* buffer, size_t bufferSize) {
72 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
73 jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
74 VMError::record_coredump_status(buffer, false);
75 return;
76 }
77
78 int n;
79 struct rlimit rlim;
80 bool success;
81
82 char core_path[PATH_MAX];
83 n = get_core_path(core_path, PATH_MAX);
84
85 if (n <= 0) {
86 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
87 success = true;
88 #ifdef LINUX
89 } else if (core_path[0] == '"') { // redirect to user process
90 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
91 success = true;
92 #endif
93 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
94 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
95 success = true;
96 } else {
97 switch(rlim.rlim_cur) {
98 case RLIM_INFINITY:
99 jio_snprintf(buffer, bufferSize, "%s", core_path);
100 success = true;
101 break;
102 case 0:
103 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
104 success = false;
105 break;
106 default:
107 jio_snprintf(buffer, bufferSize, "%s (max size " UINT64_FORMAT " kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", core_path, uint64_t(rlim.rlim_cur) / 1024);
108 success = true;
109 break;
110 }
111 }
112
113 VMError::record_coredump_status(buffer, success);
114 }
115
116 int os::get_native_stack(address* stack, int frames, int toSkip) {
117 int frame_idx = 0;
118 int num_of_frames; // number of frames captured
119 frame fr = os::current_frame();
120 while (fr.pc() && frame_idx < frames) {
121 if (toSkip > 0) {
122 toSkip --;
123 } else {
124 stack[frame_idx ++] = fr.pc();
125 }
126 if (fr.fp() == NULL || fr.cb() != NULL ||
127 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
128
129 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
130 fr = os::get_sender_for_C_frame(&fr);
131 } else {
132 break;
133 }
134 }
135 num_of_frames = frame_idx;
136 for (; frame_idx < frames; frame_idx ++) {
137 stack[frame_idx] = NULL;
138 }
139
140 return num_of_frames;
141 }
142
143
144 bool os::unsetenv(const char* name) {
145 assert(name != NULL, "Null pointer");
146 return (::unsetenv(name) == 0);
147 }
148
149 int os::get_last_error() {
150 return errno;
151 }
152
153 bool os::is_debugger_attached() {
154 // not implemented
155 return false;
156 }
157
158 void os::wait_for_keypress_at_exit(void) {
159 // don't do anything on posix platforms
160 return;
161 }
162
163 int os::create_file_for_heap(const char* dir) {
164
165 const char name_template[] = "/jvmheap.XXXXXX";
166
167 char *fullname = (char*)os::malloc((strlen(dir) + strlen(name_template) + 1), mtInternal);
168 if (fullname == NULL) {
169 vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
170 return -1;
171 }
172 (void)strncpy(fullname, dir, strlen(dir)+1);
173 (void)strncat(fullname, name_template, strlen(name_template));
174
175 os::native_path(fullname);
176
177 sigset_t set, oldset;
178 int ret = sigfillset(&set);
179 assert_with_errno(ret == 0, "sigfillset returned error");
180
181 // set the file creation mask.
182 mode_t file_mode = S_IRUSR | S_IWUSR;
183
184 // create a new file.
185 int fd = mkstemp(fullname);
186
187 if (fd < 0) {
188 warning("Could not create file for heap with template %s", fullname);
189 os::free(fullname);
190 return -1;
191 }
192
193 // delete the name from the filesystem. When 'fd' is closed, the file (and space) will be deleted.
194 ret = unlink(fullname);
195 assert_with_errno(ret == 0, "unlink returned error");
196
197 os::free(fullname);
198 return fd;
199 }
200
201 static char* reserve_mmapped_memory(size_t bytes, char* requested_addr) {
202 char * addr;
203 int flags = MAP_PRIVATE NOT_AIX( | MAP_NORESERVE ) | MAP_ANONYMOUS;
204 if (requested_addr != NULL) {
205 assert((uintptr_t)requested_addr % os::vm_page_size() == 0, "Requested address should be aligned to OS page size");
206 flags |= MAP_FIXED;
207 }
208
209 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
210 // touch an uncommitted page. Otherwise, the read/write might
211 // succeed if we have enough swap space to back the physical page.
212 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
213 flags, -1, 0);
214
215 if (addr != MAP_FAILED) {
216 MemTracker::record_virtual_memory_reserve((address)addr, bytes, CALLER_PC);
217 return addr;
218 }
219 return NULL;
220 }
221
222 static int util_posix_fallocate(int fd, off_t offset, off_t len) {
223 #ifdef __APPLE__
224 fstore_t store = { F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, len };
225 // First we try to get a continuous chunk of disk space
226 int ret = fcntl(fd, F_PREALLOCATE, &store);
227 if (ret == -1) {
228 // Maybe we are too fragmented, try to allocate non-continuous range
229 store.fst_flags = F_ALLOCATEALL;
230 ret = fcntl(fd, F_PREALLOCATE, &store);
231 }
232 if(ret != -1) {
233 return ftruncate(fd, len);
234 }
235 return -1;
236 #else
237 return posix_fallocate(fd, offset, len);
238 #endif
239 }
240
241 // Map the given address range to the provided file descriptor.
242 char* os::map_memory_to_file(char* base, size_t size, int fd) {
243 assert(fd != -1, "File descriptor is not valid");
244
245 // allocate space for the file
246 if (util_posix_fallocate(fd, 0, (off_t)size) != 0) {
247 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory."));
248 return NULL;
249 }
250
251 int prot = PROT_READ | PROT_WRITE;
252 int flags = MAP_SHARED;
253 if (base != NULL) {
254 flags |= MAP_FIXED;
255 }
256 char* addr = (char*)mmap(base, size, prot, flags, fd, 0);
257
258 if (addr == MAP_FAILED) {
259 return NULL;
260 }
261 if (base != NULL && addr != base) {
262 if (!os::release_memory(addr, size)) {
263 warning("Could not release memory on unsuccessful file mapping");
264 }
265 return NULL;
266 }
267 return addr;
268 }
269
270 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
271 assert(fd != -1, "File descriptor is not valid");
272 assert(base != NULL, "Base cannot be NULL");
273
274 return map_memory_to_file(base, size, fd);
275 }
276
277 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
278 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
279 // rather than unmapping and remapping the whole chunk to get requested alignment.
280 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
281 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
282 "Alignment must be a multiple of allocation granularity (page size)");
283 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
284
285 size_t extra_size = size + alignment;
286 assert(extra_size >= size, "overflow, size is too large to allow alignment");
287
288 char* extra_base;
289 if (file_desc != -1) {
290 // For file mapping, we do not call os:reserve_memory(extra_size, NULL, alignment, file_desc) because
291 // we need to deal with shrinking of the file space later when we release extra memory after alignment.
292 // We also cannot called os:reserve_memory() with file_desc set to -1 because on aix we might get SHM memory.
293 // So here to call a helper function while reserve memory for us. After we have a aligned base,
294 // we will replace anonymous mapping with file mapping.
295 extra_base = reserve_mmapped_memory(extra_size, NULL);
296 if (extra_base != NULL) {
297 MemTracker::record_virtual_memory_reserve((address)extra_base, extra_size, CALLER_PC);
298 }
299 } else {
300 extra_base = os::reserve_memory(extra_size, NULL, alignment);
301 }
302
303 if (extra_base == NULL) {
304 return NULL;
305 }
306
307 // Do manual alignment
308 char* aligned_base = align_up(extra_base, alignment);
309
310 // [ | | ]
311 // ^ extra_base
312 // ^ extra_base + begin_offset == aligned_base
313 // extra_base + begin_offset + size ^
314 // extra_base + extra_size ^
315 // |<>| == begin_offset
316 // end_offset == |<>|
317 size_t begin_offset = aligned_base - extra_base;
318 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
319
320 if (begin_offset > 0) {
321 os::release_memory(extra_base, begin_offset);
322 }
323
324 if (end_offset > 0) {
325 os::release_memory(extra_base + begin_offset + size, end_offset);
326 }
327
328 if (file_desc != -1) {
329 // After we have an aligned address, we can replace anonymous mapping with file mapping
330 if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
331 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
332 }
333 MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
334 }
335 return aligned_base;
336 }
337
338 int os::log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
339 return vsnprintf(buf, len, fmt, args);
340 }
341
342 int os::get_fileno(FILE* fp) {
343 return NOT_AIX(::)fileno(fp);
344 }
345
346 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
347 return gmtime_r(clock, res);
348 }
349
350 void os::Posix::print_load_average(outputStream* st) {
351 st->print("load average:");
352 double loadavg[3];
353 os::loadavg(loadavg, 3);
354 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
355 st->cr();
356 }
357
358 void os::Posix::print_rlimit_info(outputStream* st) {
359 st->print("rlimit:");
360 struct rlimit rlim;
361
362 st->print(" STACK ");
363 getrlimit(RLIMIT_STACK, &rlim);
364 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
365 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
366
367 st->print(", CORE ");
368 getrlimit(RLIMIT_CORE, &rlim);
369 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
370 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
371
372 // Isn't there on solaris
373 #if defined(AIX)
374 st->print(", NPROC ");
375 st->print("%d", sysconf(_SC_CHILD_MAX));
376 #elif !defined(SOLARIS)
377 st->print(", NPROC ");
378 getrlimit(RLIMIT_NPROC, &rlim);
379 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
380 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
381 #endif
382
383 st->print(", NOFILE ");
384 getrlimit(RLIMIT_NOFILE, &rlim);
385 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
386 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
387
388 st->print(", AS ");
389 getrlimit(RLIMIT_AS, &rlim);
390 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
391 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
392
393 st->print(", DATA ");
394 getrlimit(RLIMIT_DATA, &rlim);
395 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
396 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
397
398 st->print(", FSIZE ");
399 getrlimit(RLIMIT_FSIZE, &rlim);
400 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
401 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
402
403 st->cr();
404 }
405
406 void os::Posix::print_uname_info(outputStream* st) {
407 // kernel
408 st->print("uname:");
409 struct utsname name;
410 uname(&name);
411 st->print("%s ", name.sysname);
412 #ifdef ASSERT
413 st->print("%s ", name.nodename);
414 #endif
415 st->print("%s ", name.release);
416 st->print("%s ", name.version);
417 st->print("%s", name.machine);
418 st->cr();
419 }
420
421 bool os::get_host_name(char* buf, size_t buflen) {
422 struct utsname name;
423 uname(&name);
424 jio_snprintf(buf, buflen, "%s", name.nodename);
425 return true;
426 }
427
428 bool os::has_allocatable_memory_limit(julong* limit) {
429 struct rlimit rlim;
430 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
431 // if there was an error when calling getrlimit, assume that there is no limitation
432 // on virtual memory.
433 bool result;
434 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
435 result = false;
436 } else {
437 *limit = (julong)rlim.rlim_cur;
438 result = true;
439 }
440 #ifdef _LP64
441 return result;
442 #else
443 // arbitrary virtual space limit for 32 bit Unices found by testing. If
444 // getrlimit above returned a limit, bound it with this limit. Otherwise
445 // directly use it.
446 const julong max_virtual_limit = (julong)3800*M;
447 if (result) {
448 *limit = MIN2(*limit, max_virtual_limit);
449 } else {
450 *limit = max_virtual_limit;
451 }
452
453 // bound by actually allocatable memory. The algorithm uses two bounds, an
454 // upper and a lower limit. The upper limit is the current highest amount of
455 // memory that could not be allocated, the lower limit is the current highest
456 // amount of memory that could be allocated.
457 // The algorithm iteratively refines the result by halving the difference
458 // between these limits, updating either the upper limit (if that value could
459 // not be allocated) or the lower limit (if the that value could be allocated)
460 // until the difference between these limits is "small".
461
462 // the minimum amount of memory we care about allocating.
463 const julong min_allocation_size = M;
464
465 julong upper_limit = *limit;
466
467 // first check a few trivial cases
468 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
469 *limit = upper_limit;
470 } else if (!is_allocatable(min_allocation_size)) {
471 // we found that not even min_allocation_size is allocatable. Return it
472 // anyway. There is no point to search for a better value any more.
473 *limit = min_allocation_size;
474 } else {
475 // perform the binary search.
476 julong lower_limit = min_allocation_size;
477 while ((upper_limit - lower_limit) > min_allocation_size) {
478 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
479 temp_limit = align_down(temp_limit, min_allocation_size);
480 if (is_allocatable(temp_limit)) {
481 lower_limit = temp_limit;
482 } else {
483 upper_limit = temp_limit;
484 }
485 }
486 *limit = lower_limit;
487 }
488 return true;
489 #endif
490 }
491
492 const char* os::get_current_directory(char *buf, size_t buflen) {
493 return getcwd(buf, buflen);
494 }
495
496 FILE* os::open(int fd, const char* mode) {
497 return ::fdopen(fd, mode);
498 }
499
500 void os::flockfile(FILE* fp) {
501 ::flockfile(fp);
502 }
503
504 void os::funlockfile(FILE* fp) {
505 ::funlockfile(fp);
506 }
507
508 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
509 // which is used to find statically linked in agents.
510 // Parameters:
511 // sym_name: Symbol in library we are looking for
512 // lib_name: Name of library to look in, NULL for shared libs.
513 // is_absolute_path == true if lib_name is absolute path to agent
514 // such as "/a/b/libL.so"
515 // == false if only the base name of the library is passed in
516 // such as "L"
517 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
518 bool is_absolute_path) {
519 char *agent_entry_name;
520 size_t len;
521 size_t name_len;
522 size_t prefix_len = strlen(JNI_LIB_PREFIX);
523 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
524 const char *start;
525
526 if (lib_name != NULL) {
527 name_len = strlen(lib_name);
528 if (is_absolute_path) {
529 // Need to strip path, prefix and suffix
530 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
531 lib_name = ++start;
532 }
533 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
534 return NULL;
535 }
536 lib_name += prefix_len;
537 name_len = strlen(lib_name) - suffix_len;
538 }
539 }
540 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
541 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
542 if (agent_entry_name == NULL) {
543 return NULL;
544 }
545 strcpy(agent_entry_name, sym_name);
546 if (lib_name != NULL) {
547 strcat(agent_entry_name, "_");
548 strncat(agent_entry_name, lib_name, name_len);
549 }
550 return agent_entry_name;
551 }
552
553 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
554 assert(thread == Thread::current(), "thread consistency check");
555
556 ParkEvent * const slp = thread->_SleepEvent ;
557 slp->reset() ;
558 OrderAccess::fence() ;
559
560 if (interruptible) {
561 jlong prevtime = javaTimeNanos();
562
563 for (;;) {
564 if (os::is_interrupted(thread, true)) {
565 return OS_INTRPT;
566 }
567
568 jlong newtime = javaTimeNanos();
569
570 if (newtime - prevtime < 0) {
571 // time moving backwards, should only happen if no monotonic clock
572 // not a guarantee() because JVM should not abort on kernel/glibc bugs
573 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
574 } else {
575 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
576 }
577
578 if (millis <= 0) {
579 return OS_OK;
580 }
581
582 prevtime = newtime;
583
584 {
585 assert(thread->is_Java_thread(), "sanity check");
586 JavaThread *jt = (JavaThread *) thread;
587 ThreadBlockInVM tbivm(jt);
588 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
589
590 jt->set_suspend_equivalent();
591 // cleared by handle_special_suspend_equivalent_condition() or
592 // java_suspend_self() via check_and_wait_while_suspended()
593
594 slp->park(millis);
595
596 // were we externally suspended while we were waiting?
597 jt->check_and_wait_while_suspended();
598 }
599 }
600 } else {
601 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
602 jlong prevtime = javaTimeNanos();
603
604 for (;;) {
605 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
606 // the 1st iteration ...
607 jlong newtime = javaTimeNanos();
608
609 if (newtime - prevtime < 0) {
610 // time moving backwards, should only happen if no monotonic clock
611 // not a guarantee() because JVM should not abort on kernel/glibc bugs
612 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
613 } else {
614 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
615 }
616
617 if (millis <= 0) break ;
618
619 prevtime = newtime;
620 slp->park(millis);
621 }
622 return OS_OK ;
623 }
624 }
625
626 ////////////////////////////////////////////////////////////////////////////////
627 // interrupt support
628
629 void os::interrupt(Thread* thread) {
630 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
631
632 OSThread* osthread = thread->osthread();
633
634 if (!osthread->interrupted()) {
635 osthread->set_interrupted(true);
636 // More than one thread can get here with the same value of osthread,
637 // resulting in multiple notifications. We do, however, want the store
638 // to interrupted() to be visible to other threads before we execute unpark().
639 OrderAccess::fence();
640 ParkEvent * const slp = thread->_SleepEvent ;
641 if (slp != NULL) slp->unpark() ;
642 }
643
644 // For JSR166. Unpark even if interrupt status already was set
645 if (thread->is_Java_thread())
646 ((JavaThread*)thread)->parker()->unpark();
647
648 ParkEvent * ev = thread->_ParkEvent ;
649 if (ev != NULL) ev->unpark() ;
650 }
651
652 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
653 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
654
655 OSThread* osthread = thread->osthread();
656
657 bool interrupted = osthread->interrupted();
658
659 // NOTE that since there is no "lock" around the interrupt and
660 // is_interrupted operations, there is the possibility that the
661 // interrupted flag (in osThread) will be "false" but that the
662 // low-level events will be in the signaled state. This is
663 // intentional. The effect of this is that Object.wait() and
664 // LockSupport.park() will appear to have a spurious wakeup, which
665 // is allowed and not harmful, and the possibility is so rare that
666 // it is not worth the added complexity to add yet another lock.
667 // For the sleep event an explicit reset is performed on entry
668 // to os::sleep, so there is no early return. It has also been
669 // recommended not to put the interrupted flag into the "event"
670 // structure because it hides the issue.
671 if (interrupted && clear_interrupted) {
672 osthread->set_interrupted(false);
673 // consider thread->_SleepEvent->reset() ... optional optimization
674 }
675
676 return interrupted;
677 }
678
679
680
681 static const struct {
682 int sig; const char* name;
683 }
684 g_signal_info[] =
685 {
686 { SIGABRT, "SIGABRT" },
687 #ifdef SIGAIO
688 { SIGAIO, "SIGAIO" },
689 #endif
690 { SIGALRM, "SIGALRM" },
691 #ifdef SIGALRM1
692 { SIGALRM1, "SIGALRM1" },
693 #endif
694 { SIGBUS, "SIGBUS" },
695 #ifdef SIGCANCEL
696 { SIGCANCEL, "SIGCANCEL" },
697 #endif
698 { SIGCHLD, "SIGCHLD" },
699 #ifdef SIGCLD
700 { SIGCLD, "SIGCLD" },
701 #endif
702 { SIGCONT, "SIGCONT" },
703 #ifdef SIGCPUFAIL
704 { SIGCPUFAIL, "SIGCPUFAIL" },
705 #endif
706 #ifdef SIGDANGER
707 { SIGDANGER, "SIGDANGER" },
708 #endif
709 #ifdef SIGDIL
710 { SIGDIL, "SIGDIL" },
711 #endif
712 #ifdef SIGEMT
713 { SIGEMT, "SIGEMT" },
714 #endif
715 { SIGFPE, "SIGFPE" },
716 #ifdef SIGFREEZE
717 { SIGFREEZE, "SIGFREEZE" },
718 #endif
719 #ifdef SIGGFAULT
720 { SIGGFAULT, "SIGGFAULT" },
721 #endif
722 #ifdef SIGGRANT
723 { SIGGRANT, "SIGGRANT" },
724 #endif
725 { SIGHUP, "SIGHUP" },
726 { SIGILL, "SIGILL" },
727 { SIGINT, "SIGINT" },
728 #ifdef SIGIO
729 { SIGIO, "SIGIO" },
730 #endif
731 #ifdef SIGIOINT
732 { SIGIOINT, "SIGIOINT" },
733 #endif
734 #ifdef SIGIOT
735 // SIGIOT is there for BSD compatibility, but on most Unices just a
736 // synonym for SIGABRT. The result should be "SIGABRT", not
737 // "SIGIOT".
738 #if (SIGIOT != SIGABRT )
739 { SIGIOT, "SIGIOT" },
740 #endif
741 #endif
742 #ifdef SIGKAP
743 { SIGKAP, "SIGKAP" },
744 #endif
745 { SIGKILL, "SIGKILL" },
746 #ifdef SIGLOST
747 { SIGLOST, "SIGLOST" },
748 #endif
749 #ifdef SIGLWP
750 { SIGLWP, "SIGLWP" },
751 #endif
752 #ifdef SIGLWPTIMER
753 { SIGLWPTIMER, "SIGLWPTIMER" },
754 #endif
755 #ifdef SIGMIGRATE
756 { SIGMIGRATE, "SIGMIGRATE" },
757 #endif
758 #ifdef SIGMSG
759 { SIGMSG, "SIGMSG" },
760 #endif
761 { SIGPIPE, "SIGPIPE" },
762 #ifdef SIGPOLL
763 { SIGPOLL, "SIGPOLL" },
764 #endif
765 #ifdef SIGPRE
766 { SIGPRE, "SIGPRE" },
767 #endif
768 { SIGPROF, "SIGPROF" },
769 #ifdef SIGPTY
770 { SIGPTY, "SIGPTY" },
771 #endif
772 #ifdef SIGPWR
773 { SIGPWR, "SIGPWR" },
774 #endif
775 { SIGQUIT, "SIGQUIT" },
776 #ifdef SIGRECONFIG
777 { SIGRECONFIG, "SIGRECONFIG" },
778 #endif
779 #ifdef SIGRECOVERY
780 { SIGRECOVERY, "SIGRECOVERY" },
781 #endif
782 #ifdef SIGRESERVE
783 { SIGRESERVE, "SIGRESERVE" },
784 #endif
785 #ifdef SIGRETRACT
786 { SIGRETRACT, "SIGRETRACT" },
787 #endif
788 #ifdef SIGSAK
789 { SIGSAK, "SIGSAK" },
790 #endif
791 { SIGSEGV, "SIGSEGV" },
792 #ifdef SIGSOUND
793 { SIGSOUND, "SIGSOUND" },
794 #endif
795 #ifdef SIGSTKFLT
796 { SIGSTKFLT, "SIGSTKFLT" },
797 #endif
798 { SIGSTOP, "SIGSTOP" },
799 { SIGSYS, "SIGSYS" },
800 #ifdef SIGSYSERROR
801 { SIGSYSERROR, "SIGSYSERROR" },
802 #endif
803 #ifdef SIGTALRM
804 { SIGTALRM, "SIGTALRM" },
805 #endif
806 { SIGTERM, "SIGTERM" },
807 #ifdef SIGTHAW
808 { SIGTHAW, "SIGTHAW" },
809 #endif
810 { SIGTRAP, "SIGTRAP" },
811 #ifdef SIGTSTP
812 { SIGTSTP, "SIGTSTP" },
813 #endif
814 { SIGTTIN, "SIGTTIN" },
815 { SIGTTOU, "SIGTTOU" },
816 #ifdef SIGURG
817 { SIGURG, "SIGURG" },
818 #endif
819 { SIGUSR1, "SIGUSR1" },
820 { SIGUSR2, "SIGUSR2" },
821 #ifdef SIGVIRT
822 { SIGVIRT, "SIGVIRT" },
823 #endif
824 { SIGVTALRM, "SIGVTALRM" },
825 #ifdef SIGWAITING
826 { SIGWAITING, "SIGWAITING" },
827 #endif
828 #ifdef SIGWINCH
829 { SIGWINCH, "SIGWINCH" },
830 #endif
831 #ifdef SIGWINDOW
832 { SIGWINDOW, "SIGWINDOW" },
833 #endif
834 { SIGXCPU, "SIGXCPU" },
835 { SIGXFSZ, "SIGXFSZ" },
836 #ifdef SIGXRES
837 { SIGXRES, "SIGXRES" },
838 #endif
839 { -1, NULL }
840 };
841
842 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
843 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
844
845 const char* ret = NULL;
846
847 #ifdef SIGRTMIN
848 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
849 if (sig == SIGRTMIN) {
850 ret = "SIGRTMIN";
851 } else if (sig == SIGRTMAX) {
852 ret = "SIGRTMAX";
853 } else {
854 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
855 return out;
856 }
857 }
858 #endif
859
860 if (sig > 0) {
861 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
862 if (g_signal_info[idx].sig == sig) {
863 ret = g_signal_info[idx].name;
864 break;
865 }
866 }
867 }
868
869 if (!ret) {
870 if (!is_valid_signal(sig)) {
871 ret = "INVALID";
872 } else {
873 ret = "UNKNOWN";
874 }
875 }
876
877 if (out && outlen > 0) {
878 strncpy(out, ret, outlen);
879 out[outlen - 1] = '\0';
880 }
881 return out;
882 }
883
884 int os::Posix::get_signal_number(const char* signal_name) {
885 char tmp[30];
886 const char* s = signal_name;
887 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
888 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
889 s = tmp;
890 }
891 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
892 if (strcmp(g_signal_info[idx].name, s) == 0) {
893 return g_signal_info[idx].sig;
894 }
895 }
896 return -1;
897 }
898
899 int os::get_signal_number(const char* signal_name) {
900 return os::Posix::get_signal_number(signal_name);
901 }
902
903 // Returns true if signal number is valid.
904 bool os::Posix::is_valid_signal(int sig) {
905 // MacOS not really POSIX compliant: sigaddset does not return
906 // an error for invalid signal numbers. However, MacOS does not
907 // support real time signals and simply seems to have just 33
908 // signals with no holes in the signal range.
909 #ifdef __APPLE__
910 return sig >= 1 && sig < NSIG;
911 #else
912 // Use sigaddset to check for signal validity.
913 sigset_t set;
914 sigemptyset(&set);
915 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
916 return false;
917 }
918 return true;
919 #endif
920 }
921
922 // Returns:
923 // NULL for an invalid signal number
924 // "SIG<num>" for a valid but unknown signal number
925 // signal name otherwise.
926 const char* os::exception_name(int sig, char* buf, size_t size) {
927 if (!os::Posix::is_valid_signal(sig)) {
928 return NULL;
929 }
930 const char* const name = os::Posix::get_signal_name(sig, buf, size);
931 if (strcmp(name, "UNKNOWN") == 0) {
932 jio_snprintf(buf, size, "SIG%d", sig);
933 }
934 return buf;
935 }
936
937 #define NUM_IMPORTANT_SIGS 32
938 // Returns one-line short description of a signal set in a user provided buffer.
939 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
940 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
941 // Note: for shortness, just print out the first 32. That should
942 // cover most of the useful ones, apart from realtime signals.
943 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
944 const int rc = sigismember(set, sig);
945 if (rc == -1 && errno == EINVAL) {
946 buffer[sig-1] = '?';
947 } else {
948 buffer[sig-1] = rc == 0 ? '0' : '1';
949 }
950 }
951 buffer[NUM_IMPORTANT_SIGS] = 0;
952 return buffer;
953 }
954
955 // Prints one-line description of a signal set.
956 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
957 char buf[NUM_IMPORTANT_SIGS + 1];
958 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
959 st->print("%s", buf);
960 }
961
962 // Writes one-line description of a combination of sigaction.sa_flags into a user
963 // provided buffer. Returns that buffer.
964 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
965 char* p = buffer;
966 size_t remaining = size;
967 bool first = true;
968 int idx = 0;
969
970 assert(buffer, "invalid argument");
971
972 if (size == 0) {
973 return buffer;
974 }
975
976 strncpy(buffer, "none", size);
977
978 const struct {
979 // NB: i is an unsigned int here because SA_RESETHAND is on some
980 // systems 0x80000000, which is implicitly unsigned. Assignining
981 // it to an int field would be an overflow in unsigned-to-signed
982 // conversion.
983 unsigned int i;
984 const char* s;
985 } flaginfo [] = {
986 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
987 { SA_ONSTACK, "SA_ONSTACK" },
988 { SA_RESETHAND, "SA_RESETHAND" },
989 { SA_RESTART, "SA_RESTART" },
990 { SA_SIGINFO, "SA_SIGINFO" },
991 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
992 { SA_NODEFER, "SA_NODEFER" },
993 #ifdef AIX
994 { SA_ONSTACK, "SA_ONSTACK" },
995 { SA_OLDSTYLE, "SA_OLDSTYLE" },
996 #endif
997 { 0, NULL }
998 };
999
1000 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
1001 if (flags & flaginfo[idx].i) {
1002 if (first) {
1003 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
1004 first = false;
1005 } else {
1006 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
1007 }
1008 const size_t len = strlen(p);
1009 p += len;
1010 remaining -= len;
1011 }
1012 }
1013
1014 buffer[size - 1] = '\0';
1015
1016 return buffer;
1017 }
1018
1019 // Prints one-line description of a combination of sigaction.sa_flags.
1020 void os::Posix::print_sa_flags(outputStream* st, int flags) {
1021 char buffer[0x100];
1022 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
1023 st->print("%s", buffer);
1024 }
1025
1026 // Helper function for os::Posix::print_siginfo_...():
1027 // return a textual description for signal code.
1028 struct enum_sigcode_desc_t {
1029 const char* s_name;
1030 const char* s_desc;
1031 };
1032
1033 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
1034
1035 const struct {
1036 int sig; int code; const char* s_code; const char* s_desc;
1037 } t1 [] = {
1038 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
1039 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
1040 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
1041 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
1042 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
1043 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
1044 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
1045 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
1046 #if defined(IA64) && defined(LINUX)
1047 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
1048 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
1049 #endif
1050 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
1051 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
1052 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
1053 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
1054 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
1055 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
1056 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
1057 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
1058 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
1059 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
1060 #ifdef AIX
1061 // no explanation found what keyerr would be
1062 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
1063 #endif
1064 #if defined(IA64) && !defined(AIX)
1065 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
1066 #endif
1067 #if defined(__sparc) && defined(SOLARIS)
1068 // define Solaris Sparc M7 ADI SEGV signals
1069 #if !defined(SEGV_ACCADI)
1070 #define SEGV_ACCADI 3
1071 #endif
1072 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
1073 #if !defined(SEGV_ACCDERR)
1074 #define SEGV_ACCDERR 4
1075 #endif
1076 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
1077 #if !defined(SEGV_ACCPERR)
1078 #define SEGV_ACCPERR 5
1079 #endif
1080 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
1081 #endif // defined(__sparc) && defined(SOLARIS)
1082 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
1083 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
1084 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
1085 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
1086 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
1087 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
1088 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
1089 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
1090 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
1091 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
1092 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
1093 #ifdef SIGPOLL
1094 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
1095 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
1096 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
1097 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
1098 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
1099 #endif
1100 { -1, -1, NULL, NULL }
1101 };
1102
1103 // Codes valid in any signal context.
1104 const struct {
1105 int code; const char* s_code; const char* s_desc;
1106 } t2 [] = {
1107 { SI_USER, "SI_USER", "Signal sent by kill()." },
1108 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
1109 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
1110 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
1111 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
1112 // Linux specific
1113 #ifdef SI_TKILL
1114 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
1115 #endif
1116 #ifdef SI_DETHREAD
1117 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
1118 #endif
1119 #ifdef SI_KERNEL
1120 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
1121 #endif
1122 #ifdef SI_SIGIO
1123 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
1124 #endif
1125
1126 #ifdef AIX
1127 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
1128 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
1129 #endif
1130
1131 #ifdef __sun
1132 { SI_NOINFO, "SI_NOINFO", "No signal information" },
1133 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
1134 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
1135 #endif
1136
1137 { -1, NULL, NULL }
1138 };
1139
1140 const char* s_code = NULL;
1141 const char* s_desc = NULL;
1142
1143 for (int i = 0; t1[i].sig != -1; i ++) {
1144 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
1145 s_code = t1[i].s_code;
1146 s_desc = t1[i].s_desc;
1147 break;
1148 }
1149 }
1150
1151 if (s_code == NULL) {
1152 for (int i = 0; t2[i].s_code != NULL; i ++) {
1153 if (t2[i].code == si->si_code) {
1154 s_code = t2[i].s_code;
1155 s_desc = t2[i].s_desc;
1156 }
1157 }
1158 }
1159
1160 if (s_code == NULL) {
1161 out->s_name = "unknown";
1162 out->s_desc = "unknown";
1163 return false;
1164 }
1165
1166 out->s_name = s_code;
1167 out->s_desc = s_desc;
1168
1169 return true;
1170 }
1171
1172 void os::print_siginfo(outputStream* os, const void* si0) {
1173
1174 const siginfo_t* const si = (const siginfo_t*) si0;
1175
1176 char buf[20];
1177 os->print("siginfo:");
1178
1179 if (!si) {
1180 os->print(" <null>");
1181 return;
1182 }
1183
1184 const int sig = si->si_signo;
1185
1186 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1187
1188 enum_sigcode_desc_t ed;
1189 get_signal_code_description(si, &ed);
1190 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1191
1192 if (si->si_errno) {
1193 os->print(", si_errno: %d", si->si_errno);
1194 }
1195
1196 // Output additional information depending on the signal code.
1197
1198 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1199 // so it depends on the context which member to use. For synchronous error signals,
1200 // we print si_addr, unless the signal was sent by another process or thread, in
1201 // which case we print out pid or tid of the sender.
1202 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
1203 const pid_t pid = si->si_pid;
1204 os->print(", si_pid: %ld", (long) pid);
1205 if (IS_VALID_PID(pid)) {
1206 const pid_t me = getpid();
1207 if (me == pid) {
1208 os->print(" (current process)");
1209 }
1210 } else {
1211 os->print(" (invalid)");
1212 }
1213 os->print(", si_uid: %ld", (long) si->si_uid);
1214 if (sig == SIGCHLD) {
1215 os->print(", si_status: %d", si->si_status);
1216 }
1217 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1218 sig == SIGTRAP || sig == SIGFPE) {
1219 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1220 #ifdef SIGPOLL
1221 } else if (sig == SIGPOLL) {
1222 os->print(", si_band: %ld", si->si_band);
1223 #endif
1224 }
1225
1226 }
1227
1228 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1229 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1230 }
1231
1232 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1233 #if defined(AIX)
1234 return Aix::ucontext_get_pc(ctx);
1235 #elif defined(BSD)
1236 return Bsd::ucontext_get_pc(ctx);
1237 #elif defined(LINUX)
1238 return Linux::ucontext_get_pc(ctx);
1239 #elif defined(SOLARIS)
1240 return Solaris::ucontext_get_pc(ctx);
1241 #else
1242 VMError::report_and_die("unimplemented ucontext_get_pc");
1243 #endif
1244 }
1245
1246 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1247 #if defined(AIX)
1248 Aix::ucontext_set_pc(ctx, pc);
1249 #elif defined(BSD)
1250 Bsd::ucontext_set_pc(ctx, pc);
1251 #elif defined(LINUX)
1252 Linux::ucontext_set_pc(ctx, pc);
1253 #elif defined(SOLARIS)
1254 Solaris::ucontext_set_pc(ctx, pc);
1255 #else
1256 VMError::report_and_die("unimplemented ucontext_get_pc");
1257 #endif
1258 }
1259
1260 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1261 size_t stack_size = 0;
1262 size_t guard_size = 0;
1263 int detachstate = 0;
1264 pthread_attr_getstacksize(attr, &stack_size);
1265 pthread_attr_getguardsize(attr, &guard_size);
1266 // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
1267 LINUX_ONLY(stack_size -= guard_size);
1268 pthread_attr_getdetachstate(attr, &detachstate);
1269 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1270 stack_size / 1024, guard_size / 1024,
1271 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1272 return buf;
1273 }
1274
1275 char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
1276
1277 if (filename == NULL || outbuf == NULL || outbuflen < 1) {
1278 assert(false, "os::Posix::realpath: invalid arguments.");
1279 errno = EINVAL;
1280 return NULL;
1281 }
1282
1283 char* result = NULL;
1284
1285 // This assumes platform realpath() is implemented according to POSIX.1-2008.
1286 // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
1287 // output buffer is dynamically allocated and must be ::free()'d by the caller.
1288 char* p = ::realpath(filename, NULL);
1289 if (p != NULL) {
1290 if (strlen(p) < outbuflen) {
1291 strcpy(outbuf, p);
1292 result = outbuf;
1293 } else {
1294 errno = ENAMETOOLONG;
1295 }
1296 ::free(p); // *not* os::free
1297 } else {
1298 // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
1299 // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
1300 // that it complains about the NULL we handed down as user buffer.
1301 // In this case, use the user provided buffer but at least check whether realpath caused
1302 // a memory overwrite.
1303 if (errno == EINVAL) {
1304 outbuf[outbuflen - 1] = '\0';
1305 p = ::realpath(filename, outbuf);
1306 if (p != NULL) {
1307 guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
1308 result = p;
1309 }
1310 }
1311 }
1312 return result;
1313
1314 }
1315
1316
1317 // Check minimum allowable stack sizes for thread creation and to initialize
1318 // the java system classes, including StackOverflowError - depends on page
1319 // size.
1320 // The space needed for frames during startup is platform dependent. It
1321 // depends on word size, platform calling conventions, C frame layout and
1322 // interpreter/C1/C2 design decisions. Therefore this is given in a
1323 // platform (os/cpu) dependent constant.
1324 // To this, space for guard mechanisms is added, which depends on the
1325 // page size which again depends on the concrete system the VM is running
1326 // on. Space for libc guard pages is not included in this size.
1327 jint os::Posix::set_minimum_stack_sizes() {
1328 size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
1329
1330 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
1331 JavaThread::stack_guard_zone_size() +
1332 JavaThread::stack_shadow_zone_size();
1333
1334 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
1335 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
1336
1337 size_t stack_size_in_bytes = ThreadStackSize * K;
1338 if (stack_size_in_bytes != 0 &&
1339 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1340 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1341 // ThreadStackSize so we go with "Java thread stack size" instead
1342 // of "ThreadStackSize" to be more friendly.
1343 tty->print_cr("\nThe Java thread stack size specified is too small. "
1344 "Specify at least " SIZE_FORMAT "k",
1345 _java_thread_min_stack_allowed / K);
1346 return JNI_ERR;
1347 }
1348
1349 // Make the stack size a multiple of the page size so that
1350 // the yellow/red zones can be guarded.
1351 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
1352
1353 // Reminder: a compiler thread is a Java thread.
1354 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
1355 JavaThread::stack_guard_zone_size() +
1356 JavaThread::stack_shadow_zone_size();
1357
1358 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
1359 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
1360
1361 stack_size_in_bytes = CompilerThreadStackSize * K;
1362 if (stack_size_in_bytes != 0 &&
1363 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1364 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1365 "Specify at least " SIZE_FORMAT "k",
1366 _compiler_thread_min_stack_allowed / K);
1367 return JNI_ERR;
1368 }
1369
1370 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1371 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
1372
1373 stack_size_in_bytes = VMThreadStackSize * K;
1374 if (stack_size_in_bytes != 0 &&
1375 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1376 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1377 "Specify at least " SIZE_FORMAT "k",
1378 _vm_internal_thread_min_stack_allowed / K);
1379 return JNI_ERR;
1380 }
1381 return JNI_OK;
1382 }
1383
1384 // Called when creating the thread. The minimum stack sizes have already been calculated
1385 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1386 size_t stack_size;
1387 if (req_stack_size == 0) {
1388 stack_size = default_stack_size(thr_type);
1389 } else {
1390 stack_size = req_stack_size;
1391 }
1392
1393 switch (thr_type) {
1394 case os::java_thread:
1395 // Java threads use ThreadStackSize which default value can be
1396 // changed with the flag -Xss
1397 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1398 // no requested size and we have a more specific default value
1399 stack_size = JavaThread::stack_size_at_create();
1400 }
1401 stack_size = MAX2(stack_size,
1402 _java_thread_min_stack_allowed);
1403 break;
1404 case os::compiler_thread:
1405 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1406 // no requested size and we have a more specific default value
1407 stack_size = (size_t)(CompilerThreadStackSize * K);
1408 }
1409 stack_size = MAX2(stack_size,
1410 _compiler_thread_min_stack_allowed);
1411 break;
1412 case os::vm_thread:
1413 case os::pgc_thread:
1414 case os::cgc_thread:
1415 case os::watcher_thread:
1416 default: // presume the unknown thr_type is a VM internal
1417 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1418 // no requested size and we have a more specific default value
1419 stack_size = (size_t)(VMThreadStackSize * K);
1420 }
1421
1422 stack_size = MAX2(stack_size,
1423 _vm_internal_thread_min_stack_allowed);
1424 break;
1425 }
1426
1427 // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
1428 // Be careful not to round up to 0. Align down in that case.
1429 if (stack_size <= SIZE_MAX - vm_page_size()) {
1430 stack_size = align_up(stack_size, vm_page_size());
1431 } else {
1432 stack_size = align_down(stack_size, vm_page_size());
1433 }
1434
1435 return stack_size;
1436 }
1437
1438 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
1439 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
1440 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
1441
1442 os::ThreadCrashProtection::ThreadCrashProtection() {
1443 }
1444
1445 /*
1446 * See the caveats for this class in os_posix.hpp
1447 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1448 * method and returns false. If none of the signals are raised, returns true.
1449 * The callback is supposed to provide the method that should be protected.
1450 */
1451 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1452 sigset_t saved_sig_mask;
1453
1454 Thread::muxAcquire(&_crash_mux, "CrashProtection");
1455
1456 _protected_thread = Thread::current_or_null();
1457 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
1458
1459 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1460 // since on at least some systems (OS X) siglongjmp will restore the mask
1461 // for the process, not the thread
1462 pthread_sigmask(0, NULL, &saved_sig_mask);
1463 if (sigsetjmp(_jmpbuf, 0) == 0) {
1464 // make sure we can see in the signal handler that we have crash protection
1465 // installed
1466 _crash_protection = this;
1467 cb.call();
1468 // and clear the crash protection
1469 _crash_protection = NULL;
1470 _protected_thread = NULL;
1471 Thread::muxRelease(&_crash_mux);
1472 return true;
1473 }
1474 // this happens when we siglongjmp() back
1475 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1476 _crash_protection = NULL;
1477 _protected_thread = NULL;
1478 Thread::muxRelease(&_crash_mux);
1479 return false;
1480 }
1481
1482 void os::ThreadCrashProtection::restore() {
1483 assert(_crash_protection != NULL, "must have crash protection");
1484 siglongjmp(_jmpbuf, 1);
1485 }
1486
1487 void os::ThreadCrashProtection::check_crash_protection(int sig,
1488 Thread* thread) {
1489
1490 if (thread != NULL &&
1491 thread == _protected_thread &&
1492 _crash_protection != NULL) {
1493
1494 if (sig == SIGSEGV || sig == SIGBUS) {
1495 _crash_protection->restore();
1496 }
1497 }
1498 }
1499
1500 // POSIX unamed semaphores are not supported on OS X.
1501 #ifndef __APPLE__
1502
1503 PosixSemaphore::PosixSemaphore(uint value) {
1504 int ret = sem_init(&_semaphore, 0, value);
1505
1506 guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
1507 }
1508
1509 PosixSemaphore::~PosixSemaphore() {
1510 sem_destroy(&_semaphore);
1511 }
1512
1513 void PosixSemaphore::signal(uint count) {
1514 for (uint i = 0; i < count; i++) {
1515 int ret = sem_post(&_semaphore);
1516
1517 assert_with_errno(ret == 0, "sem_post failed");
1518 }
1519 }
1520
1521 void PosixSemaphore::wait() {
1522 int ret;
1523
1524 do {
1525 ret = sem_wait(&_semaphore);
1526 } while (ret != 0 && errno == EINTR);
1527
1528 assert_with_errno(ret == 0, "sem_wait failed");
1529 }
1530
1531 bool PosixSemaphore::trywait() {
1532 int ret;
1533
1534 do {
1535 ret = sem_trywait(&_semaphore);
1536 } while (ret != 0 && errno == EINTR);
1537
1538 assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
1539
1540 return ret == 0;
1541 }
1542
1543 bool PosixSemaphore::timedwait(struct timespec ts) {
1544 while (true) {
1545 int result = sem_timedwait(&_semaphore, &ts);
1546 if (result == 0) {
1547 return true;
1548 } else if (errno == EINTR) {
1549 continue;
1550 } else if (errno == ETIMEDOUT) {
1551 return false;
1552 } else {
1553 assert_with_errno(false, "timedwait failed");
1554 return false;
1555 }
1556 }
1557 }
1558
1559 #endif // __APPLE__
1560
1561
1562 // Shared pthread_mutex/cond based PlatformEvent implementation.
1563 // Not currently usable by Solaris.
1564
1565 #ifndef SOLARIS
1566
1567 // Shared condattr object for use with relative timed-waits. Will be associated
1568 // with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
1569 // but otherwise whatever default is used by the platform - generally the
1570 // time-of-day clock.
1571 static pthread_condattr_t _condAttr[1];
1572
1573 // Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
1574 // all systems (e.g. FreeBSD) map the default to "normal".
1575 static pthread_mutexattr_t _mutexAttr[1];
1576
1577 // common basic initialization that is always supported
1578 static void pthread_init_common(void) {
1579 int status;
1580 if ((status = pthread_condattr_init(_condAttr)) != 0) {
1581 fatal("pthread_condattr_init: %s", os::strerror(status));
1582 }
1583 if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
1584 fatal("pthread_mutexattr_init: %s", os::strerror(status));
1585 }
1586 if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
1587 fatal("pthread_mutexattr_settype: %s", os::strerror(status));
1588 }
1589 }
1590
1591 // Not all POSIX types and API's are available on all notionally "posix"
1592 // platforms. If we have build-time support then we will check for actual
1593 // runtime support via dlopen/dlsym lookup. This allows for running on an
1594 // older OS version compared to the build platform. But if there is no
1595 // build time support then there cannot be any runtime support as we do not
1596 // know what the runtime types would be (for example clockid_t might be an
1597 // int or int64_t).
1598 //
1599 #ifdef SUPPORTS_CLOCK_MONOTONIC
1600
1601 // This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
1602
1603 static int (*_clock_gettime)(clockid_t, struct timespec *);
1604 static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t);
1605
1606 static bool _use_clock_monotonic_condattr;
1607
1608 // Determine what POSIX API's are present and do appropriate
1609 // configuration.
1610 void os::Posix::init(void) {
1611
1612 // NOTE: no logging available when this is called. Put logging
1613 // statements in init_2().
1614
1615 // Copied from os::Linux::clock_init(). The duplication is temporary.
1616
1617 // 1. Check for CLOCK_MONOTONIC support.
1618
1619 void* handle = NULL;
1620
1621 // For linux we need librt, for other OS we can find
1622 // this function in regular libc.
1623 #ifdef NEEDS_LIBRT
1624 // We do dlopen's in this particular order due to bug in linux
1625 // dynamic loader (see 6348968) leading to crash on exit.
1626 handle = dlopen("librt.so.1", RTLD_LAZY);
1627 if (handle == NULL) {
1628 handle = dlopen("librt.so", RTLD_LAZY);
1629 }
1630 #endif
1631
1632 if (handle == NULL) {
1633 handle = RTLD_DEFAULT;
1634 }
1635
1636 _clock_gettime = NULL;
1637
1638 int (*clock_getres_func)(clockid_t, struct timespec*) =
1639 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1640 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1641 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1642 if (clock_getres_func != NULL && clock_gettime_func != NULL) {
1643 // We assume that if both clock_gettime and clock_getres support
1644 // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
1645 struct timespec res;
1646 struct timespec tp;
1647 if (clock_getres_func(CLOCK_MONOTONIC, &res) == 0 &&
1648 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1649 // Yes, monotonic clock is supported.
1650 _clock_gettime = clock_gettime_func;
1651 } else {
1652 #ifdef NEEDS_LIBRT
1653 // Close librt if there is no monotonic clock.
1654 if (handle != RTLD_DEFAULT) {
1655 dlclose(handle);
1656 }
1657 #endif
1658 }
1659 }
1660
1661 // 2. Check for pthread_condattr_setclock support.
1662
1663 _pthread_condattr_setclock = NULL;
1664
1665 // libpthread is already loaded.
1666 int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
1667 (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
1668 "pthread_condattr_setclock");
1669 if (condattr_setclock_func != NULL) {
1670 _pthread_condattr_setclock = condattr_setclock_func;
1671 }
1672
1673 // Now do general initialization.
1674
1675 pthread_init_common();
1676
1677 int status;
1678 if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
1679 if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
1680 if (status == EINVAL) {
1681 _use_clock_monotonic_condattr = false;
1682 warning("Unable to use monotonic clock with relative timed-waits" \
1683 " - changes to the time-of-day clock may have adverse affects");
1684 } else {
1685 fatal("pthread_condattr_setclock: %s", os::strerror(status));
1686 }
1687 } else {
1688 _use_clock_monotonic_condattr = true;
1689 }
1690 } else {
1691 _use_clock_monotonic_condattr = false;
1692 }
1693 }
1694
1695 void os::Posix::init_2(void) {
1696 log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
1697 (_clock_gettime != NULL ? "" : " not"));
1698 log_info(os)("Use of pthread_condattr_setclock is%s supported",
1699 (_pthread_condattr_setclock != NULL ? "" : " not"));
1700 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
1701 _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
1702 }
1703
1704 #else // !SUPPORTS_CLOCK_MONOTONIC
1705
1706 void os::Posix::init(void) {
1707 pthread_init_common();
1708 }
1709
1710 void os::Posix::init_2(void) {
1711 log_info(os)("Use of CLOCK_MONOTONIC is not supported");
1712 log_info(os)("Use of pthread_condattr_setclock is not supported");
1713 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
1714 }
1715
1716 #endif // SUPPORTS_CLOCK_MONOTONIC
1717
1718 os::PlatformEvent::PlatformEvent() {
1719 int status = pthread_cond_init(_cond, _condAttr);
1720 assert_status(status == 0, status, "cond_init");
1721 status = pthread_mutex_init(_mutex, _mutexAttr);
1722 assert_status(status == 0, status, "mutex_init");
1723 _event = 0;
1724 _nParked = 0;
1725 }
1726
1727 // Utility to convert the given timeout to an absolute timespec
1728 // (based on the appropriate clock) to use with pthread_cond_timewait.
1729 // The clock queried here must be the clock used to manage the
1730 // timeout of the condition variable.
1731 //
1732 // The passed in timeout value is either a relative time in nanoseconds
1733 // or an absolute time in milliseconds. A relative timeout will be
1734 // associated with CLOCK_MONOTONIC if available; otherwise, or if absolute,
1735 // the default time-of-day clock will be used.
1736
1737 // Given time is a 64-bit value and the time_t used in the timespec is
1738 // sometimes a signed-32-bit value we have to watch for overflow if times
1739 // way in the future are given. Further on Solaris versions
1740 // prior to 10 there is a restriction (see cond_timedwait) that the specified
1741 // number of seconds, in abstime, is less than current_time + 100000000.
1742 // As it will be over 20 years before "now + 100000000" will overflow we can
1743 // ignore overflow and just impose a hard-limit on seconds using the value
1744 // of "now + 100000000". This places a limit on the timeout of about 3.17
1745 // years from "now".
1746 //
1747 #define MAX_SECS 100000000
1748
1749 // Calculate a new absolute time that is "timeout" nanoseconds from "now".
1750 // "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
1751 // on which clock is being used).
1752 static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
1753 jlong now_part_sec, jlong unit) {
1754 time_t max_secs = now_sec + MAX_SECS;
1755
1756 jlong seconds = timeout / NANOUNITS;
1757 timeout %= NANOUNITS; // remaining nanos
1758
1759 if (seconds >= MAX_SECS) {
1760 // More seconds than we can add, so pin to max_secs.
1761 abstime->tv_sec = max_secs;
1762 abstime->tv_nsec = 0;
1763 } else {
1764 abstime->tv_sec = now_sec + seconds;
1765 long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
1766 if (nanos >= NANOUNITS) { // overflow
1767 abstime->tv_sec += 1;
1768 nanos -= NANOUNITS;
1769 }
1770 abstime->tv_nsec = nanos;
1771 }
1772 }
1773
1774 // Unpack the given deadline in milliseconds since the epoch, into the given timespec.
1775 // The current time in seconds is also passed in to enforce an upper bound as discussed above.
1776 static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
1777 time_t max_secs = now_sec + MAX_SECS;
1778
1779 jlong seconds = deadline / MILLIUNITS;
1780 jlong millis = deadline % MILLIUNITS;
1781
1782 if (seconds >= max_secs) {
1783 // Absolute seconds exceeds allowed max, so pin to max_secs.
1784 abstime->tv_sec = max_secs;
1785 abstime->tv_nsec = 0;
1786 } else {
1787 abstime->tv_sec = seconds;
1788 abstime->tv_nsec = millis * (NANOUNITS / MILLIUNITS);
1789 }
1790 }
1791
1792 static void to_abstime(timespec* abstime, jlong timeout, bool isAbsolute) {
1793 DEBUG_ONLY(int max_secs = MAX_SECS;)
1794
1795 if (timeout < 0) {
1796 timeout = 0;
1797 }
1798
1799 #ifdef SUPPORTS_CLOCK_MONOTONIC
1800
1801 if (_use_clock_monotonic_condattr && !isAbsolute) {
1802 struct timespec now;
1803 int status = _clock_gettime(CLOCK_MONOTONIC, &now);
1804 assert_status(status == 0, status, "clock_gettime");
1805 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
1806 DEBUG_ONLY(max_secs += now.tv_sec;)
1807 } else {
1808
1809 #else
1810
1811 { // Match the block scope.
1812
1813 #endif // SUPPORTS_CLOCK_MONOTONIC
1814
1815 // Time-of-day clock is all we can reliably use.
1816 struct timeval now;
1817 int status = gettimeofday(&now, NULL);
1818 assert_status(status == 0, errno, "gettimeofday");
1819 if (isAbsolute) {
1820 unpack_abs_time(abstime, timeout, now.tv_sec);
1821 } else {
1822 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
1823 }
1824 DEBUG_ONLY(max_secs += now.tv_sec;)
1825 }
1826
1827 assert(abstime->tv_sec >= 0, "tv_sec < 0");
1828 assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
1829 assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
1830 assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
1831 }
1832
1833 // PlatformEvent
1834 //
1835 // Assumption:
1836 // Only one parker can exist on an event, which is why we allocate
1837 // them per-thread. Multiple unparkers can coexist.
1838 //
1839 // _event serves as a restricted-range semaphore.
1840 // -1 : thread is blocked, i.e. there is a waiter
1841 // 0 : neutral: thread is running or ready,
1842 // could have been signaled after a wait started
1843 // 1 : signaled - thread is running or ready
1844 //
1845 // Having three states allows for some detection of bad usage - see
1846 // comments on unpark().
1847
1848 void os::PlatformEvent::park() { // AKA "down()"
1849 // Transitions for _event:
1850 // -1 => -1 : illegal
1851 // 1 => 0 : pass - return immediately
1852 // 0 => -1 : block; then set _event to 0 before returning
1853
1854 // Invariant: Only the thread associated with the PlatformEvent
1855 // may call park().
1856 assert(_nParked == 0, "invariant");
1857
1858 int v;
1859
1860 // atomically decrement _event
1861 for (;;) {
1862 v = _event;
1863 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1864 }
1865 guarantee(v >= 0, "invariant");
1866
1867 if (v == 0) { // Do this the hard way by blocking ...
1868 int status = pthread_mutex_lock(_mutex);
1869 assert_status(status == 0, status, "mutex_lock");
1870 guarantee(_nParked == 0, "invariant");
1871 ++_nParked;
1872 while (_event < 0) {
1873 // OS-level "spurious wakeups" are ignored
1874 status = pthread_cond_wait(_cond, _mutex);
1875 assert_status(status == 0, status, "cond_wait");
1876 }
1877 --_nParked;
1878
1879 _event = 0;
1880 status = pthread_mutex_unlock(_mutex);
1881 assert_status(status == 0, status, "mutex_unlock");
1882 // Paranoia to ensure our locked and lock-free paths interact
1883 // correctly with each other.
1884 OrderAccess::fence();
1885 }
1886 guarantee(_event >= 0, "invariant");
1887 }
1888
1889 int os::PlatformEvent::park(jlong millis) {
1890 // Transitions for _event:
1891 // -1 => -1 : illegal
1892 // 1 => 0 : pass - return immediately
1893 // 0 => -1 : block; then set _event to 0 before returning
1894
1895 // Invariant: Only the thread associated with the Event/PlatformEvent
1896 // may call park().
1897 assert(_nParked == 0, "invariant");
1898
1899 int v;
1900 // atomically decrement _event
1901 for (;;) {
1902 v = _event;
1903 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1904 }
1905 guarantee(v >= 0, "invariant");
1906
1907 if (v == 0) { // Do this the hard way by blocking ...
1908 struct timespec abst;
1909 // We have to watch for overflow when converting millis to nanos,
1910 // but if millis is that large then we will end up limiting to
1911 // MAX_SECS anyway, so just do that here.
1912 if (millis / MILLIUNITS > MAX_SECS) {
1913 millis = jlong(MAX_SECS) * MILLIUNITS;
1914 }
1915 to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false);
1916
1917 int ret = OS_TIMEOUT;
1918 int status = pthread_mutex_lock(_mutex);
1919 assert_status(status == 0, status, "mutex_lock");
1920 guarantee(_nParked == 0, "invariant");
1921 ++_nParked;
1922
1923 while (_event < 0) {
1924 status = pthread_cond_timedwait(_cond, _mutex, &abst);
1925 assert_status(status == 0 || status == ETIMEDOUT,
1926 status, "cond_timedwait");
1927 // OS-level "spurious wakeups" are ignored unless the archaic
1928 // FilterSpuriousWakeups is set false. That flag should be obsoleted.
1929 if (!FilterSpuriousWakeups) break;
1930 if (status == ETIMEDOUT) break;
1931 }
1932 --_nParked;
1933
1934 if (_event >= 0) {
1935 ret = OS_OK;
1936 }
1937
1938 _event = 0;
1939 status = pthread_mutex_unlock(_mutex);
1940 assert_status(status == 0, status, "mutex_unlock");
1941 // Paranoia to ensure our locked and lock-free paths interact
1942 // correctly with each other.
1943 OrderAccess::fence();
1944 return ret;
1945 }
1946 return OS_OK;
1947 }
1948
1949 void os::PlatformEvent::unpark() {
1950 // Transitions for _event:
1951 // 0 => 1 : just return
1952 // 1 => 1 : just return
1953 // -1 => either 0 or 1; must signal target thread
1954 // That is, we can safely transition _event from -1 to either
1955 // 0 or 1.
1956 // See also: "Semaphores in Plan 9" by Mullender & Cox
1957 //
1958 // Note: Forcing a transition from "-1" to "1" on an unpark() means
1959 // that it will take two back-to-back park() calls for the owning
1960 // thread to block. This has the benefit of forcing a spurious return
1961 // from the first park() call after an unpark() call which will help
1962 // shake out uses of park() and unpark() without checking state conditions
1963 // properly. This spurious return doesn't manifest itself in any user code
1964 // but only in the correctly written condition checking loops of ObjectMonitor,
1965 // Mutex/Monitor, Thread::muxAcquire and os::sleep
1966
1967 if (Atomic::xchg(1, &_event) >= 0) return;
1968
1969 int status = pthread_mutex_lock(_mutex);
1970 assert_status(status == 0, status, "mutex_lock");
1971 int anyWaiters = _nParked;
1972 assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
1973 status = pthread_mutex_unlock(_mutex);
1974 assert_status(status == 0, status, "mutex_unlock");
1975
1976 // Note that we signal() *after* dropping the lock for "immortal" Events.
1977 // This is safe and avoids a common class of futile wakeups. In rare
1978 // circumstances this can cause a thread to return prematurely from
1979 // cond_{timed}wait() but the spurious wakeup is benign and the victim
1980 // will simply re-test the condition and re-park itself.
1981 // This provides particular benefit if the underlying platform does not
1982 // provide wait morphing.
1983
1984 if (anyWaiters != 0) {
1985 status = pthread_cond_signal(_cond);
1986 assert_status(status == 0, status, "cond_signal");
1987 }
1988 }
1989
1990 // JSR166 support
1991
1992 os::PlatformParker::PlatformParker() {
1993 int status;
1994 status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
1995 assert_status(status == 0, status, "cond_init rel");
1996 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
1997 assert_status(status == 0, status, "cond_init abs");
1998 status = pthread_mutex_init(_mutex, _mutexAttr);
1999 assert_status(status == 0, status, "mutex_init");
2000 _cur_index = -1; // mark as unused
2001 }
2002
2003 // Parker::park decrements count if > 0, else does a condvar wait. Unpark
2004 // sets count to 1 and signals condvar. Only one thread ever waits
2005 // on the condvar. Contention seen when trying to park implies that someone
2006 // is unparking you, so don't wait. And spurious returns are fine, so there
2007 // is no need to track notifications.
2008
2009 void Parker::park(bool isAbsolute, jlong time) {
2010
2011 // Optional fast-path check:
2012 // Return immediately if a permit is available.
2013 // We depend on Atomic::xchg() having full barrier semantics
2014 // since we are doing a lock-free update to _counter.
2015 if (Atomic::xchg(0, &_counter) > 0) return;
2016
2017 Thread* thread = Thread::current();
2018 assert(thread->is_Java_thread(), "Must be JavaThread");
2019 JavaThread *jt = (JavaThread *)thread;
2020
2021 // Optional optimization -- avoid state transitions if there's
2022 // an interrupt pending.
2023 if (Thread::is_interrupted(thread, false)) {
2024 return;
2025 }
2026
2027 // Next, demultiplex/decode time arguments
2028 struct timespec absTime;
2029 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
2030 return;
2031 }
2032 if (time > 0) {
2033 to_abstime(&absTime, time, isAbsolute);
2034 }
2035
2036 // Enter safepoint region
2037 // Beware of deadlocks such as 6317397.
2038 // The per-thread Parker:: mutex is a classic leaf-lock.
2039 // In particular a thread must never block on the Threads_lock while
2040 // holding the Parker:: mutex. If safepoints are pending both the
2041 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
2042 ThreadBlockInVM tbivm(jt);
2043
2044 // Don't wait if cannot get lock since interference arises from
2045 // unparking. Also re-check interrupt before trying wait.
2046 if (Thread::is_interrupted(thread, false) ||
2047 pthread_mutex_trylock(_mutex) != 0) {
2048 return;
2049 }
2050
2051 int status;
2052 if (_counter > 0) { // no wait needed
2053 _counter = 0;
2054 status = pthread_mutex_unlock(_mutex);
2055 assert_status(status == 0, status, "invariant");
2056 // Paranoia to ensure our locked and lock-free paths interact
2057 // correctly with each other and Java-level accesses.
2058 OrderAccess::fence();
2059 return;
2060 }
2061
2062 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2063 jt->set_suspend_equivalent();
2064 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2065
2066 assert(_cur_index == -1, "invariant");
2067 if (time == 0) {
2068 _cur_index = REL_INDEX; // arbitrary choice when not timed
2069 status = pthread_cond_wait(&_cond[_cur_index], _mutex);
2070 assert_status(status == 0, status, "cond_timedwait");
2071 }
2072 else {
2073 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
2074 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
2075 assert_status(status == 0 || status == ETIMEDOUT,
2076 status, "cond_timedwait");
2077 }
2078 _cur_index = -1;
2079
2080 _counter = 0;
2081 status = pthread_mutex_unlock(_mutex);
2082 assert_status(status == 0, status, "invariant");
2083 // Paranoia to ensure our locked and lock-free paths interact
2084 // correctly with each other and Java-level accesses.
2085 OrderAccess::fence();
2086
2087 // If externally suspended while waiting, re-suspend
2088 if (jt->handle_special_suspend_equivalent_condition()) {
2089 jt->java_suspend_self();
2090 }
2091 }
2092
2093 void Parker::unpark() {
2094 int status = pthread_mutex_lock(_mutex);
2095 assert_status(status == 0, status, "invariant");
2096 const int s = _counter;
2097 _counter = 1;
2098 // must capture correct index before unlocking
2099 int index = _cur_index;
2100 status = pthread_mutex_unlock(_mutex);
2101 assert_status(status == 0, status, "invariant");
2102
2103 // Note that we signal() *after* dropping the lock for "immortal" Events.
2104 // This is safe and avoids a common class of futile wakeups. In rare
2105 // circumstances this can cause a thread to return prematurely from
2106 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2107 // will simply re-test the condition and re-park itself.
2108 // This provides particular benefit if the underlying platform does not
2109 // provide wait morphing.
2110
2111 if (s < 1 && index != -1) {
2112 // thread is definitely parked
2113 status = pthread_cond_signal(&_cond[index]);
2114 assert_status(status == 0, status, "invariant");
2115 }
2116 }
2117
2118
2119 #endif // !SOLARIS