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 int ret = util_posix_fallocate(fd, 0, (off_t)size);
247 if (ret != 0) {
248 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory. error(%d)", ret));
249 return NULL;
250 }
251
252 int prot = PROT_READ | PROT_WRITE;
253 int flags = MAP_SHARED;
254 if (base != NULL) {
255 flags |= MAP_FIXED;
256 }
257 char* addr = (char*)mmap(base, size, prot, flags, fd, 0);
258
259 if (addr == MAP_FAILED) {
260 warning("Failed mmap to file. (%s)", os::strerror(errno));
261 return NULL;
262 }
263 if (base != NULL && addr != base) {
264 if (!os::release_memory(addr, size)) {
265 warning("Could not release memory on unsuccessful file mapping");
266 }
267 return NULL;
268 }
269 return addr;
270 }
271
272 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
273 assert(fd != -1, "File descriptor is not valid");
274 assert(base != NULL, "Base cannot be NULL");
275
276 return map_memory_to_file(base, size, fd);
277 }
278
279 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
280 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
281 // rather than unmapping and remapping the whole chunk to get requested alignment.
282 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
283 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
284 "Alignment must be a multiple of allocation granularity (page size)");
285 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
286
287 size_t extra_size = size + alignment;
288 assert(extra_size >= size, "overflow, size is too large to allow alignment");
289
290 char* extra_base;
291 if (file_desc != -1) {
292 // For file mapping, we do not call os:reserve_memory(extra_size, NULL, alignment, file_desc) because
293 // we need to deal with shrinking of the file space later when we release extra memory after alignment.
294 // We also cannot called os:reserve_memory() with file_desc set to -1 because on aix we might get SHM memory.
295 // So here to call a helper function while reserve memory for us. After we have a aligned base,
296 // we will replace anonymous mapping with file mapping.
297 extra_base = reserve_mmapped_memory(extra_size, NULL);
298 if (extra_base != NULL) {
299 MemTracker::record_virtual_memory_reserve((address)extra_base, extra_size, CALLER_PC);
300 }
301 } else {
302 extra_base = os::reserve_memory(extra_size, NULL, alignment);
303 }
304
305 if (extra_base == NULL) {
306 return NULL;
307 }
308
309 // Do manual alignment
310 char* aligned_base = align_up(extra_base, alignment);
311
312 // [ | | ]
313 // ^ extra_base
314 // ^ extra_base + begin_offset == aligned_base
315 // extra_base + begin_offset + size ^
316 // extra_base + extra_size ^
317 // |<>| == begin_offset
318 // end_offset == |<>|
319 size_t begin_offset = aligned_base - extra_base;
320 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
321
322 if (begin_offset > 0) {
323 os::release_memory(extra_base, begin_offset);
324 }
325
326 if (end_offset > 0) {
327 os::release_memory(extra_base + begin_offset + size, end_offset);
328 }
329
330 if (file_desc != -1) {
331 // After we have an aligned address, we can replace anonymous mapping with file mapping
332 if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
333 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
334 }
335 MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
336 }
337 return aligned_base;
338 }
339
340 int os::log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
341 return vsnprintf(buf, len, fmt, args);
342 }
343
344 int os::get_fileno(FILE* fp) {
345 return NOT_AIX(::)fileno(fp);
346 }
347
348 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
349 return gmtime_r(clock, res);
350 }
351
352 void os::Posix::print_load_average(outputStream* st) {
353 st->print("load average:");
354 double loadavg[3];
355 os::loadavg(loadavg, 3);
356 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
357 st->cr();
358 }
359
360 void os::Posix::print_rlimit_info(outputStream* st) {
361 st->print("rlimit:");
362 struct rlimit rlim;
363
364 st->print(" STACK ");
365 getrlimit(RLIMIT_STACK, &rlim);
366 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
367 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
368
369 st->print(", CORE ");
370 getrlimit(RLIMIT_CORE, &rlim);
371 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
372 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
373
374 // Isn't there on solaris
375 #if defined(AIX)
376 st->print(", NPROC ");
377 st->print("%d", sysconf(_SC_CHILD_MAX));
378 #elif !defined(SOLARIS)
379 st->print(", NPROC ");
380 getrlimit(RLIMIT_NPROC, &rlim);
381 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
382 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
383 #endif
384
385 st->print(", NOFILE ");
386 getrlimit(RLIMIT_NOFILE, &rlim);
387 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
388 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
389
390 st->print(", AS ");
391 getrlimit(RLIMIT_AS, &rlim);
392 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
393 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
394
395 st->print(", DATA ");
396 getrlimit(RLIMIT_DATA, &rlim);
397 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
398 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
399
400 st->print(", FSIZE ");
401 getrlimit(RLIMIT_FSIZE, &rlim);
402 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
403 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
404
405 st->cr();
406 }
407
408 void os::Posix::print_uname_info(outputStream* st) {
409 // kernel
410 st->print("uname:");
411 struct utsname name;
412 uname(&name);
413 st->print("%s ", name.sysname);
414 #ifdef ASSERT
415 st->print("%s ", name.nodename);
416 #endif
417 st->print("%s ", name.release);
418 st->print("%s ", name.version);
419 st->print("%s", name.machine);
420 st->cr();
421 }
422
423 bool os::get_host_name(char* buf, size_t buflen) {
424 struct utsname name;
425 uname(&name);
426 jio_snprintf(buf, buflen, "%s", name.nodename);
427 return true;
428 }
429
430 bool os::has_allocatable_memory_limit(julong* limit) {
431 struct rlimit rlim;
432 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
433 // if there was an error when calling getrlimit, assume that there is no limitation
434 // on virtual memory.
435 bool result;
436 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
437 result = false;
438 } else {
439 *limit = (julong)rlim.rlim_cur;
440 result = true;
441 }
442 #ifdef _LP64
443 return result;
444 #else
445 // arbitrary virtual space limit for 32 bit Unices found by testing. If
446 // getrlimit above returned a limit, bound it with this limit. Otherwise
447 // directly use it.
448 const julong max_virtual_limit = (julong)3800*M;
449 if (result) {
450 *limit = MIN2(*limit, max_virtual_limit);
451 } else {
452 *limit = max_virtual_limit;
453 }
454
455 // bound by actually allocatable memory. The algorithm uses two bounds, an
456 // upper and a lower limit. The upper limit is the current highest amount of
457 // memory that could not be allocated, the lower limit is the current highest
458 // amount of memory that could be allocated.
459 // The algorithm iteratively refines the result by halving the difference
460 // between these limits, updating either the upper limit (if that value could
461 // not be allocated) or the lower limit (if the that value could be allocated)
462 // until the difference between these limits is "small".
463
464 // the minimum amount of memory we care about allocating.
465 const julong min_allocation_size = M;
466
467 julong upper_limit = *limit;
468
469 // first check a few trivial cases
470 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
471 *limit = upper_limit;
472 } else if (!is_allocatable(min_allocation_size)) {
473 // we found that not even min_allocation_size is allocatable. Return it
474 // anyway. There is no point to search for a better value any more.
475 *limit = min_allocation_size;
476 } else {
477 // perform the binary search.
478 julong lower_limit = min_allocation_size;
479 while ((upper_limit - lower_limit) > min_allocation_size) {
480 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
481 temp_limit = align_down(temp_limit, min_allocation_size);
482 if (is_allocatable(temp_limit)) {
483 lower_limit = temp_limit;
484 } else {
485 upper_limit = temp_limit;
486 }
487 }
488 *limit = lower_limit;
489 }
490 return true;
491 #endif
492 }
493
494 const char* os::get_current_directory(char *buf, size_t buflen) {
495 return getcwd(buf, buflen);
496 }
497
498 FILE* os::open(int fd, const char* mode) {
499 return ::fdopen(fd, mode);
500 }
501
502 void os::flockfile(FILE* fp) {
503 ::flockfile(fp);
504 }
505
506 void os::funlockfile(FILE* fp) {
507 ::funlockfile(fp);
508 }
509
510 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
511 // which is used to find statically linked in agents.
512 // Parameters:
513 // sym_name: Symbol in library we are looking for
514 // lib_name: Name of library to look in, NULL for shared libs.
515 // is_absolute_path == true if lib_name is absolute path to agent
516 // such as "/a/b/libL.so"
517 // == false if only the base name of the library is passed in
518 // such as "L"
519 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
520 bool is_absolute_path) {
521 char *agent_entry_name;
522 size_t len;
523 size_t name_len;
524 size_t prefix_len = strlen(JNI_LIB_PREFIX);
525 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
526 const char *start;
527
528 if (lib_name != NULL) {
529 name_len = strlen(lib_name);
530 if (is_absolute_path) {
531 // Need to strip path, prefix and suffix
532 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
533 lib_name = ++start;
534 }
535 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
536 return NULL;
537 }
538 lib_name += prefix_len;
539 name_len = strlen(lib_name) - suffix_len;
540 }
541 }
542 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
543 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
544 if (agent_entry_name == NULL) {
545 return NULL;
546 }
547 strcpy(agent_entry_name, sym_name);
548 if (lib_name != NULL) {
549 strcat(agent_entry_name, "_");
550 strncat(agent_entry_name, lib_name, name_len);
551 }
552 return agent_entry_name;
553 }
554
555 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
556 assert(thread == Thread::current(), "thread consistency check");
557
558 ParkEvent * const slp = thread->_SleepEvent ;
559 slp->reset() ;
560 OrderAccess::fence() ;
561
562 if (interruptible) {
563 jlong prevtime = javaTimeNanos();
564
565 for (;;) {
566 if (os::is_interrupted(thread, true)) {
567 return OS_INTRPT;
568 }
569
570 jlong newtime = javaTimeNanos();
571
572 if (newtime - prevtime < 0) {
573 // time moving backwards, should only happen if no monotonic clock
574 // not a guarantee() because JVM should not abort on kernel/glibc bugs
575 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
576 } else {
577 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
578 }
579
580 if (millis <= 0) {
581 return OS_OK;
582 }
583
584 prevtime = newtime;
585
586 {
587 assert(thread->is_Java_thread(), "sanity check");
588 JavaThread *jt = (JavaThread *) thread;
589 ThreadBlockInVM tbivm(jt);
590 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
591
592 jt->set_suspend_equivalent();
593 // cleared by handle_special_suspend_equivalent_condition() or
594 // java_suspend_self() via check_and_wait_while_suspended()
595
596 slp->park(millis);
597
598 // were we externally suspended while we were waiting?
599 jt->check_and_wait_while_suspended();
600 }
601 }
602 } else {
603 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
604 jlong prevtime = javaTimeNanos();
605
606 for (;;) {
607 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
608 // the 1st iteration ...
609 jlong newtime = javaTimeNanos();
610
611 if (newtime - prevtime < 0) {
612 // time moving backwards, should only happen if no monotonic clock
613 // not a guarantee() because JVM should not abort on kernel/glibc bugs
614 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
615 } else {
616 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
617 }
618
619 if (millis <= 0) break ;
620
621 prevtime = newtime;
622 slp->park(millis);
623 }
624 return OS_OK ;
625 }
626 }
627
628 ////////////////////////////////////////////////////////////////////////////////
629 // interrupt support
630
631 void os::interrupt(Thread* thread) {
632 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
633
634 OSThread* osthread = thread->osthread();
635
636 if (!osthread->interrupted()) {
637 osthread->set_interrupted(true);
638 // More than one thread can get here with the same value of osthread,
639 // resulting in multiple notifications. We do, however, want the store
640 // to interrupted() to be visible to other threads before we execute unpark().
641 OrderAccess::fence();
642 ParkEvent * const slp = thread->_SleepEvent ;
643 if (slp != NULL) slp->unpark() ;
644 }
645
646 // For JSR166. Unpark even if interrupt status already was set
647 if (thread->is_Java_thread())
648 ((JavaThread*)thread)->parker()->unpark();
649
650 ParkEvent * ev = thread->_ParkEvent ;
651 if (ev != NULL) ev->unpark() ;
652 }
653
654 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
655 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
656
657 OSThread* osthread = thread->osthread();
658
659 bool interrupted = osthread->interrupted();
660
661 // NOTE that since there is no "lock" around the interrupt and
662 // is_interrupted operations, there is the possibility that the
663 // interrupted flag (in osThread) will be "false" but that the
664 // low-level events will be in the signaled state. This is
665 // intentional. The effect of this is that Object.wait() and
666 // LockSupport.park() will appear to have a spurious wakeup, which
667 // is allowed and not harmful, and the possibility is so rare that
668 // it is not worth the added complexity to add yet another lock.
669 // For the sleep event an explicit reset is performed on entry
670 // to os::sleep, so there is no early return. It has also been
671 // recommended not to put the interrupted flag into the "event"
672 // structure because it hides the issue.
673 if (interrupted && clear_interrupted) {
674 osthread->set_interrupted(false);
675 // consider thread->_SleepEvent->reset() ... optional optimization
676 }
677
678 return interrupted;
679 }
680
681
682
683 static const struct {
684 int sig; const char* name;
685 }
686 g_signal_info[] =
687 {
688 { SIGABRT, "SIGABRT" },
689 #ifdef SIGAIO
690 { SIGAIO, "SIGAIO" },
691 #endif
692 { SIGALRM, "SIGALRM" },
693 #ifdef SIGALRM1
694 { SIGALRM1, "SIGALRM1" },
695 #endif
696 { SIGBUS, "SIGBUS" },
697 #ifdef SIGCANCEL
698 { SIGCANCEL, "SIGCANCEL" },
699 #endif
700 { SIGCHLD, "SIGCHLD" },
701 #ifdef SIGCLD
702 { SIGCLD, "SIGCLD" },
703 #endif
704 { SIGCONT, "SIGCONT" },
705 #ifdef SIGCPUFAIL
706 { SIGCPUFAIL, "SIGCPUFAIL" },
707 #endif
708 #ifdef SIGDANGER
709 { SIGDANGER, "SIGDANGER" },
710 #endif
711 #ifdef SIGDIL
712 { SIGDIL, "SIGDIL" },
713 #endif
714 #ifdef SIGEMT
715 { SIGEMT, "SIGEMT" },
716 #endif
717 { SIGFPE, "SIGFPE" },
718 #ifdef SIGFREEZE
719 { SIGFREEZE, "SIGFREEZE" },
720 #endif
721 #ifdef SIGGFAULT
722 { SIGGFAULT, "SIGGFAULT" },
723 #endif
724 #ifdef SIGGRANT
725 { SIGGRANT, "SIGGRANT" },
726 #endif
727 { SIGHUP, "SIGHUP" },
728 { SIGILL, "SIGILL" },
729 { SIGINT, "SIGINT" },
730 #ifdef SIGIO
731 { SIGIO, "SIGIO" },
732 #endif
733 #ifdef SIGIOINT
734 { SIGIOINT, "SIGIOINT" },
735 #endif
736 #ifdef SIGIOT
737 // SIGIOT is there for BSD compatibility, but on most Unices just a
738 // synonym for SIGABRT. The result should be "SIGABRT", not
739 // "SIGIOT".
740 #if (SIGIOT != SIGABRT )
741 { SIGIOT, "SIGIOT" },
742 #endif
743 #endif
744 #ifdef SIGKAP
745 { SIGKAP, "SIGKAP" },
746 #endif
747 { SIGKILL, "SIGKILL" },
748 #ifdef SIGLOST
749 { SIGLOST, "SIGLOST" },
750 #endif
751 #ifdef SIGLWP
752 { SIGLWP, "SIGLWP" },
753 #endif
754 #ifdef SIGLWPTIMER
755 { SIGLWPTIMER, "SIGLWPTIMER" },
756 #endif
757 #ifdef SIGMIGRATE
758 { SIGMIGRATE, "SIGMIGRATE" },
759 #endif
760 #ifdef SIGMSG
761 { SIGMSG, "SIGMSG" },
762 #endif
763 { SIGPIPE, "SIGPIPE" },
764 #ifdef SIGPOLL
765 { SIGPOLL, "SIGPOLL" },
766 #endif
767 #ifdef SIGPRE
768 { SIGPRE, "SIGPRE" },
769 #endif
770 { SIGPROF, "SIGPROF" },
771 #ifdef SIGPTY
772 { SIGPTY, "SIGPTY" },
773 #endif
774 #ifdef SIGPWR
775 { SIGPWR, "SIGPWR" },
776 #endif
777 { SIGQUIT, "SIGQUIT" },
778 #ifdef SIGRECONFIG
779 { SIGRECONFIG, "SIGRECONFIG" },
780 #endif
781 #ifdef SIGRECOVERY
782 { SIGRECOVERY, "SIGRECOVERY" },
783 #endif
784 #ifdef SIGRESERVE
785 { SIGRESERVE, "SIGRESERVE" },
786 #endif
787 #ifdef SIGRETRACT
788 { SIGRETRACT, "SIGRETRACT" },
789 #endif
790 #ifdef SIGSAK
791 { SIGSAK, "SIGSAK" },
792 #endif
793 { SIGSEGV, "SIGSEGV" },
794 #ifdef SIGSOUND
795 { SIGSOUND, "SIGSOUND" },
796 #endif
797 #ifdef SIGSTKFLT
798 { SIGSTKFLT, "SIGSTKFLT" },
799 #endif
800 { SIGSTOP, "SIGSTOP" },
801 { SIGSYS, "SIGSYS" },
802 #ifdef SIGSYSERROR
803 { SIGSYSERROR, "SIGSYSERROR" },
804 #endif
805 #ifdef SIGTALRM
806 { SIGTALRM, "SIGTALRM" },
807 #endif
808 { SIGTERM, "SIGTERM" },
809 #ifdef SIGTHAW
810 { SIGTHAW, "SIGTHAW" },
811 #endif
812 { SIGTRAP, "SIGTRAP" },
813 #ifdef SIGTSTP
814 { SIGTSTP, "SIGTSTP" },
815 #endif
816 { SIGTTIN, "SIGTTIN" },
817 { SIGTTOU, "SIGTTOU" },
818 #ifdef SIGURG
819 { SIGURG, "SIGURG" },
820 #endif
821 { SIGUSR1, "SIGUSR1" },
822 { SIGUSR2, "SIGUSR2" },
823 #ifdef SIGVIRT
824 { SIGVIRT, "SIGVIRT" },
825 #endif
826 { SIGVTALRM, "SIGVTALRM" },
827 #ifdef SIGWAITING
828 { SIGWAITING, "SIGWAITING" },
829 #endif
830 #ifdef SIGWINCH
831 { SIGWINCH, "SIGWINCH" },
832 #endif
833 #ifdef SIGWINDOW
834 { SIGWINDOW, "SIGWINDOW" },
835 #endif
836 { SIGXCPU, "SIGXCPU" },
837 { SIGXFSZ, "SIGXFSZ" },
838 #ifdef SIGXRES
839 { SIGXRES, "SIGXRES" },
840 #endif
841 { -1, NULL }
842 };
843
844 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
845 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
846
847 const char* ret = NULL;
848
849 #ifdef SIGRTMIN
850 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
851 if (sig == SIGRTMIN) {
852 ret = "SIGRTMIN";
853 } else if (sig == SIGRTMAX) {
854 ret = "SIGRTMAX";
855 } else {
856 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
857 return out;
858 }
859 }
860 #endif
861
862 if (sig > 0) {
863 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
864 if (g_signal_info[idx].sig == sig) {
865 ret = g_signal_info[idx].name;
866 break;
867 }
868 }
869 }
870
871 if (!ret) {
872 if (!is_valid_signal(sig)) {
873 ret = "INVALID";
874 } else {
875 ret = "UNKNOWN";
876 }
877 }
878
879 if (out && outlen > 0) {
880 strncpy(out, ret, outlen);
881 out[outlen - 1] = '\0';
882 }
883 return out;
884 }
885
886 int os::Posix::get_signal_number(const char* signal_name) {
887 char tmp[30];
888 const char* s = signal_name;
889 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
890 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
891 s = tmp;
892 }
893 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
894 if (strcmp(g_signal_info[idx].name, s) == 0) {
895 return g_signal_info[idx].sig;
896 }
897 }
898 return -1;
899 }
900
901 int os::get_signal_number(const char* signal_name) {
902 return os::Posix::get_signal_number(signal_name);
903 }
904
905 // Returns true if signal number is valid.
906 bool os::Posix::is_valid_signal(int sig) {
907 // MacOS not really POSIX compliant: sigaddset does not return
908 // an error for invalid signal numbers. However, MacOS does not
909 // support real time signals and simply seems to have just 33
910 // signals with no holes in the signal range.
911 #ifdef __APPLE__
912 return sig >= 1 && sig < NSIG;
913 #else
914 // Use sigaddset to check for signal validity.
915 sigset_t set;
916 sigemptyset(&set);
917 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
918 return false;
919 }
920 return true;
921 #endif
922 }
923
924 // Returns:
925 // NULL for an invalid signal number
926 // "SIG<num>" for a valid but unknown signal number
927 // signal name otherwise.
928 const char* os::exception_name(int sig, char* buf, size_t size) {
929 if (!os::Posix::is_valid_signal(sig)) {
930 return NULL;
931 }
932 const char* const name = os::Posix::get_signal_name(sig, buf, size);
933 if (strcmp(name, "UNKNOWN") == 0) {
934 jio_snprintf(buf, size, "SIG%d", sig);
935 }
936 return buf;
937 }
938
939 #define NUM_IMPORTANT_SIGS 32
940 // Returns one-line short description of a signal set in a user provided buffer.
941 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
942 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
943 // Note: for shortness, just print out the first 32. That should
944 // cover most of the useful ones, apart from realtime signals.
945 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
946 const int rc = sigismember(set, sig);
947 if (rc == -1 && errno == EINVAL) {
948 buffer[sig-1] = '?';
949 } else {
950 buffer[sig-1] = rc == 0 ? '0' : '1';
951 }
952 }
953 buffer[NUM_IMPORTANT_SIGS] = 0;
954 return buffer;
955 }
956
957 // Prints one-line description of a signal set.
958 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
959 char buf[NUM_IMPORTANT_SIGS + 1];
960 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
961 st->print("%s", buf);
962 }
963
964 // Writes one-line description of a combination of sigaction.sa_flags into a user
965 // provided buffer. Returns that buffer.
966 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
967 char* p = buffer;
968 size_t remaining = size;
969 bool first = true;
970 int idx = 0;
971
972 assert(buffer, "invalid argument");
973
974 if (size == 0) {
975 return buffer;
976 }
977
978 strncpy(buffer, "none", size);
979
980 const struct {
981 // NB: i is an unsigned int here because SA_RESETHAND is on some
982 // systems 0x80000000, which is implicitly unsigned. Assignining
983 // it to an int field would be an overflow in unsigned-to-signed
984 // conversion.
985 unsigned int i;
986 const char* s;
987 } flaginfo [] = {
988 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
989 { SA_ONSTACK, "SA_ONSTACK" },
990 { SA_RESETHAND, "SA_RESETHAND" },
991 { SA_RESTART, "SA_RESTART" },
992 { SA_SIGINFO, "SA_SIGINFO" },
993 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
994 { SA_NODEFER, "SA_NODEFER" },
995 #ifdef AIX
996 { SA_ONSTACK, "SA_ONSTACK" },
997 { SA_OLDSTYLE, "SA_OLDSTYLE" },
998 #endif
999 { 0, NULL }
1000 };
1001
1002 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
1003 if (flags & flaginfo[idx].i) {
1004 if (first) {
1005 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
1006 first = false;
1007 } else {
1008 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
1009 }
1010 const size_t len = strlen(p);
1011 p += len;
1012 remaining -= len;
1013 }
1014 }
1015
1016 buffer[size - 1] = '\0';
1017
1018 return buffer;
1019 }
1020
1021 // Prints one-line description of a combination of sigaction.sa_flags.
1022 void os::Posix::print_sa_flags(outputStream* st, int flags) {
1023 char buffer[0x100];
1024 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
1025 st->print("%s", buffer);
1026 }
1027
1028 // Helper function for os::Posix::print_siginfo_...():
1029 // return a textual description for signal code.
1030 struct enum_sigcode_desc_t {
1031 const char* s_name;
1032 const char* s_desc;
1033 };
1034
1035 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
1036
1037 const struct {
1038 int sig; int code; const char* s_code; const char* s_desc;
1039 } t1 [] = {
1040 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
1041 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
1042 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
1043 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
1044 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
1045 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
1046 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
1047 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
1048 #if defined(IA64) && defined(LINUX)
1049 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
1050 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
1051 #endif
1052 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
1053 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
1054 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
1055 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
1056 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
1057 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
1058 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
1059 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
1060 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
1061 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
1062 #ifdef AIX
1063 // no explanation found what keyerr would be
1064 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
1065 #endif
1066 #if defined(IA64) && !defined(AIX)
1067 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
1068 #endif
1069 #if defined(__sparc) && defined(SOLARIS)
1070 // define Solaris Sparc M7 ADI SEGV signals
1071 #if !defined(SEGV_ACCADI)
1072 #define SEGV_ACCADI 3
1073 #endif
1074 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
1075 #if !defined(SEGV_ACCDERR)
1076 #define SEGV_ACCDERR 4
1077 #endif
1078 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
1079 #if !defined(SEGV_ACCPERR)
1080 #define SEGV_ACCPERR 5
1081 #endif
1082 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
1083 #endif // defined(__sparc) && defined(SOLARIS)
1084 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
1085 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
1086 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
1087 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
1088 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
1089 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
1090 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
1091 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
1092 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
1093 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
1094 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
1095 #ifdef SIGPOLL
1096 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
1097 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
1098 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
1099 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
1100 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
1101 #endif
1102 { -1, -1, NULL, NULL }
1103 };
1104
1105 // Codes valid in any signal context.
1106 const struct {
1107 int code; const char* s_code; const char* s_desc;
1108 } t2 [] = {
1109 { SI_USER, "SI_USER", "Signal sent by kill()." },
1110 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
1111 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
1112 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
1113 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
1114 // Linux specific
1115 #ifdef SI_TKILL
1116 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
1117 #endif
1118 #ifdef SI_DETHREAD
1119 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
1120 #endif
1121 #ifdef SI_KERNEL
1122 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
1123 #endif
1124 #ifdef SI_SIGIO
1125 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
1126 #endif
1127
1128 #ifdef AIX
1129 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
1130 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
1131 #endif
1132
1133 #ifdef __sun
1134 { SI_NOINFO, "SI_NOINFO", "No signal information" },
1135 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
1136 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
1137 #endif
1138
1139 { -1, NULL, NULL }
1140 };
1141
1142 const char* s_code = NULL;
1143 const char* s_desc = NULL;
1144
1145 for (int i = 0; t1[i].sig != -1; i ++) {
1146 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
1147 s_code = t1[i].s_code;
1148 s_desc = t1[i].s_desc;
1149 break;
1150 }
1151 }
1152
1153 if (s_code == NULL) {
1154 for (int i = 0; t2[i].s_code != NULL; i ++) {
1155 if (t2[i].code == si->si_code) {
1156 s_code = t2[i].s_code;
1157 s_desc = t2[i].s_desc;
1158 }
1159 }
1160 }
1161
1162 if (s_code == NULL) {
1163 out->s_name = "unknown";
1164 out->s_desc = "unknown";
1165 return false;
1166 }
1167
1168 out->s_name = s_code;
1169 out->s_desc = s_desc;
1170
1171 return true;
1172 }
1173
1174 void os::print_siginfo(outputStream* os, const void* si0) {
1175
1176 const siginfo_t* const si = (const siginfo_t*) si0;
1177
1178 char buf[20];
1179 os->print("siginfo:");
1180
1181 if (!si) {
1182 os->print(" <null>");
1183 return;
1184 }
1185
1186 const int sig = si->si_signo;
1187
1188 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1189
1190 enum_sigcode_desc_t ed;
1191 get_signal_code_description(si, &ed);
1192 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1193
1194 if (si->si_errno) {
1195 os->print(", si_errno: %d", si->si_errno);
1196 }
1197
1198 // Output additional information depending on the signal code.
1199
1200 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1201 // so it depends on the context which member to use. For synchronous error signals,
1202 // we print si_addr, unless the signal was sent by another process or thread, in
1203 // which case we print out pid or tid of the sender.
1204 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
1205 const pid_t pid = si->si_pid;
1206 os->print(", si_pid: %ld", (long) pid);
1207 if (IS_VALID_PID(pid)) {
1208 const pid_t me = getpid();
1209 if (me == pid) {
1210 os->print(" (current process)");
1211 }
1212 } else {
1213 os->print(" (invalid)");
1214 }
1215 os->print(", si_uid: %ld", (long) si->si_uid);
1216 if (sig == SIGCHLD) {
1217 os->print(", si_status: %d", si->si_status);
1218 }
1219 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1220 sig == SIGTRAP || sig == SIGFPE) {
1221 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1222 #ifdef SIGPOLL
1223 } else if (sig == SIGPOLL) {
1224 os->print(", si_band: %ld", si->si_band);
1225 #endif
1226 }
1227
1228 }
1229
1230 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1231 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1232 }
1233
1234 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1235 #if defined(AIX)
1236 return Aix::ucontext_get_pc(ctx);
1237 #elif defined(BSD)
1238 return Bsd::ucontext_get_pc(ctx);
1239 #elif defined(LINUX)
1240 return Linux::ucontext_get_pc(ctx);
1241 #elif defined(SOLARIS)
1242 return Solaris::ucontext_get_pc(ctx);
1243 #else
1244 VMError::report_and_die("unimplemented ucontext_get_pc");
1245 #endif
1246 }
1247
1248 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1249 #if defined(AIX)
1250 Aix::ucontext_set_pc(ctx, pc);
1251 #elif defined(BSD)
1252 Bsd::ucontext_set_pc(ctx, pc);
1253 #elif defined(LINUX)
1254 Linux::ucontext_set_pc(ctx, pc);
1255 #elif defined(SOLARIS)
1256 Solaris::ucontext_set_pc(ctx, pc);
1257 #else
1258 VMError::report_and_die("unimplemented ucontext_get_pc");
1259 #endif
1260 }
1261
1262 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1263 size_t stack_size = 0;
1264 size_t guard_size = 0;
1265 int detachstate = 0;
1266 pthread_attr_getstacksize(attr, &stack_size);
1267 pthread_attr_getguardsize(attr, &guard_size);
1268 // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
1269 LINUX_ONLY(stack_size -= guard_size);
1270 pthread_attr_getdetachstate(attr, &detachstate);
1271 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1272 stack_size / 1024, guard_size / 1024,
1273 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1274 return buf;
1275 }
1276
1277 char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
1278
1279 if (filename == NULL || outbuf == NULL || outbuflen < 1) {
1280 assert(false, "os::Posix::realpath: invalid arguments.");
1281 errno = EINVAL;
1282 return NULL;
1283 }
1284
1285 char* result = NULL;
1286
1287 // This assumes platform realpath() is implemented according to POSIX.1-2008.
1288 // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
1289 // output buffer is dynamically allocated and must be ::free()'d by the caller.
1290 char* p = ::realpath(filename, NULL);
1291 if (p != NULL) {
1292 if (strlen(p) < outbuflen) {
1293 strcpy(outbuf, p);
1294 result = outbuf;
1295 } else {
1296 errno = ENAMETOOLONG;
1297 }
1298 ::free(p); // *not* os::free
1299 } else {
1300 // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
1301 // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
1302 // that it complains about the NULL we handed down as user buffer.
1303 // In this case, use the user provided buffer but at least check whether realpath caused
1304 // a memory overwrite.
1305 if (errno == EINVAL) {
1306 outbuf[outbuflen - 1] = '\0';
1307 p = ::realpath(filename, outbuf);
1308 if (p != NULL) {
1309 guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
1310 result = p;
1311 }
1312 }
1313 }
1314 return result;
1315
1316 }
1317
1318
1319 // Check minimum allowable stack sizes for thread creation and to initialize
1320 // the java system classes, including StackOverflowError - depends on page
1321 // size.
1322 // The space needed for frames during startup is platform dependent. It
1323 // depends on word size, platform calling conventions, C frame layout and
1324 // interpreter/C1/C2 design decisions. Therefore this is given in a
1325 // platform (os/cpu) dependent constant.
1326 // To this, space for guard mechanisms is added, which depends on the
1327 // page size which again depends on the concrete system the VM is running
1328 // on. Space for libc guard pages is not included in this size.
1329 jint os::Posix::set_minimum_stack_sizes() {
1330 size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
1331
1332 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
1333 JavaThread::stack_guard_zone_size() +
1334 JavaThread::stack_shadow_zone_size();
1335
1336 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
1337 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
1338
1339 size_t stack_size_in_bytes = ThreadStackSize * K;
1340 if (stack_size_in_bytes != 0 &&
1341 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1342 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1343 // ThreadStackSize so we go with "Java thread stack size" instead
1344 // of "ThreadStackSize" to be more friendly.
1345 tty->print_cr("\nThe Java thread stack size specified is too small. "
1346 "Specify at least " SIZE_FORMAT "k",
1347 _java_thread_min_stack_allowed / K);
1348 return JNI_ERR;
1349 }
1350
1351 // Make the stack size a multiple of the page size so that
1352 // the yellow/red zones can be guarded.
1353 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
1354
1355 // Reminder: a compiler thread is a Java thread.
1356 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
1357 JavaThread::stack_guard_zone_size() +
1358 JavaThread::stack_shadow_zone_size();
1359
1360 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
1361 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
1362
1363 stack_size_in_bytes = CompilerThreadStackSize * K;
1364 if (stack_size_in_bytes != 0 &&
1365 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1366 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1367 "Specify at least " SIZE_FORMAT "k",
1368 _compiler_thread_min_stack_allowed / K);
1369 return JNI_ERR;
1370 }
1371
1372 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1373 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
1374
1375 stack_size_in_bytes = VMThreadStackSize * K;
1376 if (stack_size_in_bytes != 0 &&
1377 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1378 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1379 "Specify at least " SIZE_FORMAT "k",
1380 _vm_internal_thread_min_stack_allowed / K);
1381 return JNI_ERR;
1382 }
1383 return JNI_OK;
1384 }
1385
1386 // Called when creating the thread. The minimum stack sizes have already been calculated
1387 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1388 size_t stack_size;
1389 if (req_stack_size == 0) {
1390 stack_size = default_stack_size(thr_type);
1391 } else {
1392 stack_size = req_stack_size;
1393 }
1394
1395 switch (thr_type) {
1396 case os::java_thread:
1397 // Java threads use ThreadStackSize which default value can be
1398 // changed with the flag -Xss
1399 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1400 // no requested size and we have a more specific default value
1401 stack_size = JavaThread::stack_size_at_create();
1402 }
1403 stack_size = MAX2(stack_size,
1404 _java_thread_min_stack_allowed);
1405 break;
1406 case os::compiler_thread:
1407 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1408 // no requested size and we have a more specific default value
1409 stack_size = (size_t)(CompilerThreadStackSize * K);
1410 }
1411 stack_size = MAX2(stack_size,
1412 _compiler_thread_min_stack_allowed);
1413 break;
1414 case os::vm_thread:
1415 case os::pgc_thread:
1416 case os::cgc_thread:
1417 case os::watcher_thread:
1418 default: // presume the unknown thr_type is a VM internal
1419 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1420 // no requested size and we have a more specific default value
1421 stack_size = (size_t)(VMThreadStackSize * K);
1422 }
1423
1424 stack_size = MAX2(stack_size,
1425 _vm_internal_thread_min_stack_allowed);
1426 break;
1427 }
1428
1429 // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
1430 // Be careful not to round up to 0. Align down in that case.
1431 if (stack_size <= SIZE_MAX - vm_page_size()) {
1432 stack_size = align_up(stack_size, vm_page_size());
1433 } else {
1434 stack_size = align_down(stack_size, vm_page_size());
1435 }
1436
1437 return stack_size;
1438 }
1439
1440 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
1441 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
1442 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
1443
1444 os::ThreadCrashProtection::ThreadCrashProtection() {
1445 }
1446
1447 /*
1448 * See the caveats for this class in os_posix.hpp
1449 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1450 * method and returns false. If none of the signals are raised, returns true.
1451 * The callback is supposed to provide the method that should be protected.
1452 */
1453 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1454 sigset_t saved_sig_mask;
1455
1456 Thread::muxAcquire(&_crash_mux, "CrashProtection");
1457
1458 _protected_thread = Thread::current_or_null();
1459 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
1460
1461 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1462 // since on at least some systems (OS X) siglongjmp will restore the mask
1463 // for the process, not the thread
1464 pthread_sigmask(0, NULL, &saved_sig_mask);
1465 if (sigsetjmp(_jmpbuf, 0) == 0) {
1466 // make sure we can see in the signal handler that we have crash protection
1467 // installed
1468 _crash_protection = this;
1469 cb.call();
1470 // and clear the crash protection
1471 _crash_protection = NULL;
1472 _protected_thread = NULL;
1473 Thread::muxRelease(&_crash_mux);
1474 return true;
1475 }
1476 // this happens when we siglongjmp() back
1477 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1478 _crash_protection = NULL;
1479 _protected_thread = NULL;
1480 Thread::muxRelease(&_crash_mux);
1481 return false;
1482 }
1483
1484 void os::ThreadCrashProtection::restore() {
1485 assert(_crash_protection != NULL, "must have crash protection");
1486 siglongjmp(_jmpbuf, 1);
1487 }
1488
1489 void os::ThreadCrashProtection::check_crash_protection(int sig,
1490 Thread* thread) {
1491
1492 if (thread != NULL &&
1493 thread == _protected_thread &&
1494 _crash_protection != NULL) {
1495
1496 if (sig == SIGSEGV || sig == SIGBUS) {
1497 _crash_protection->restore();
1498 }
1499 }
1500 }
1501
1502 // POSIX unamed semaphores are not supported on OS X.
1503 #ifndef __APPLE__
1504
1505 PosixSemaphore::PosixSemaphore(uint value) {
1506 int ret = sem_init(&_semaphore, 0, value);
1507
1508 guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
1509 }
1510
1511 PosixSemaphore::~PosixSemaphore() {
1512 sem_destroy(&_semaphore);
1513 }
1514
1515 void PosixSemaphore::signal(uint count) {
1516 for (uint i = 0; i < count; i++) {
1517 int ret = sem_post(&_semaphore);
1518
1519 assert_with_errno(ret == 0, "sem_post failed");
1520 }
1521 }
1522
1523 void PosixSemaphore::wait() {
1524 int ret;
1525
1526 do {
1527 ret = sem_wait(&_semaphore);
1528 } while (ret != 0 && errno == EINTR);
1529
1530 assert_with_errno(ret == 0, "sem_wait failed");
1531 }
1532
1533 bool PosixSemaphore::trywait() {
1534 int ret;
1535
1536 do {
1537 ret = sem_trywait(&_semaphore);
1538 } while (ret != 0 && errno == EINTR);
1539
1540 assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
1541
1542 return ret == 0;
1543 }
1544
1545 bool PosixSemaphore::timedwait(struct timespec ts) {
1546 while (true) {
1547 int result = sem_timedwait(&_semaphore, &ts);
1548 if (result == 0) {
1549 return true;
1550 } else if (errno == EINTR) {
1551 continue;
1552 } else if (errno == ETIMEDOUT) {
1553 return false;
1554 } else {
1555 assert_with_errno(false, "timedwait failed");
1556 return false;
1557 }
1558 }
1559 }
1560
1561 #endif // __APPLE__
1562
1563
1564 // Shared pthread_mutex/cond based PlatformEvent implementation.
1565 // Not currently usable by Solaris.
1566
1567 #ifndef SOLARIS
1568
1569 // Shared condattr object for use with relative timed-waits. Will be associated
1570 // with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
1571 // but otherwise whatever default is used by the platform - generally the
1572 // time-of-day clock.
1573 static pthread_condattr_t _condAttr[1];
1574
1575 // Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
1576 // all systems (e.g. FreeBSD) map the default to "normal".
1577 static pthread_mutexattr_t _mutexAttr[1];
1578
1579 // common basic initialization that is always supported
1580 static void pthread_init_common(void) {
1581 int status;
1582 if ((status = pthread_condattr_init(_condAttr)) != 0) {
1583 fatal("pthread_condattr_init: %s", os::strerror(status));
1584 }
1585 if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
1586 fatal("pthread_mutexattr_init: %s", os::strerror(status));
1587 }
1588 if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
1589 fatal("pthread_mutexattr_settype: %s", os::strerror(status));
1590 }
1591 }
1592
1593 // Not all POSIX types and API's are available on all notionally "posix"
1594 // platforms. If we have build-time support then we will check for actual
1595 // runtime support via dlopen/dlsym lookup. This allows for running on an
1596 // older OS version compared to the build platform. But if there is no
1597 // build time support then there cannot be any runtime support as we do not
1598 // know what the runtime types would be (for example clockid_t might be an
1599 // int or int64_t).
1600 //
1601 #ifdef SUPPORTS_CLOCK_MONOTONIC
1602
1603 // This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
1604
1605 static int (*_clock_gettime)(clockid_t, struct timespec *);
1606 static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t);
1607
1608 static bool _use_clock_monotonic_condattr;
1609
1610 // Determine what POSIX API's are present and do appropriate
1611 // configuration.
1612 void os::Posix::init(void) {
1613
1614 // NOTE: no logging available when this is called. Put logging
1615 // statements in init_2().
1616
1617 // Copied from os::Linux::clock_init(). The duplication is temporary.
1618
1619 // 1. Check for CLOCK_MONOTONIC support.
1620
1621 void* handle = NULL;
1622
1623 // For linux we need librt, for other OS we can find
1624 // this function in regular libc.
1625 #ifdef NEEDS_LIBRT
1626 // We do dlopen's in this particular order due to bug in linux
1627 // dynamic loader (see 6348968) leading to crash on exit.
1628 handle = dlopen("librt.so.1", RTLD_LAZY);
1629 if (handle == NULL) {
1630 handle = dlopen("librt.so", RTLD_LAZY);
1631 }
1632 #endif
1633
1634 if (handle == NULL) {
1635 handle = RTLD_DEFAULT;
1636 }
1637
1638 _clock_gettime = NULL;
1639
1640 int (*clock_getres_func)(clockid_t, struct timespec*) =
1641 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1642 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1643 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1644 if (clock_getres_func != NULL && clock_gettime_func != NULL) {
1645 // We assume that if both clock_gettime and clock_getres support
1646 // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
1647 struct timespec res;
1648 struct timespec tp;
1649 if (clock_getres_func(CLOCK_MONOTONIC, &res) == 0 &&
1650 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1651 // Yes, monotonic clock is supported.
1652 _clock_gettime = clock_gettime_func;
1653 } else {
1654 #ifdef NEEDS_LIBRT
1655 // Close librt if there is no monotonic clock.
1656 if (handle != RTLD_DEFAULT) {
1657 dlclose(handle);
1658 }
1659 #endif
1660 }
1661 }
1662
1663 // 2. Check for pthread_condattr_setclock support.
1664
1665 _pthread_condattr_setclock = NULL;
1666
1667 // libpthread is already loaded.
1668 int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
1669 (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
1670 "pthread_condattr_setclock");
1671 if (condattr_setclock_func != NULL) {
1672 _pthread_condattr_setclock = condattr_setclock_func;
1673 }
1674
1675 // Now do general initialization.
1676
1677 pthread_init_common();
1678
1679 int status;
1680 if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
1681 if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
1682 if (status == EINVAL) {
1683 _use_clock_monotonic_condattr = false;
1684 warning("Unable to use monotonic clock with relative timed-waits" \
1685 " - changes to the time-of-day clock may have adverse affects");
1686 } else {
1687 fatal("pthread_condattr_setclock: %s", os::strerror(status));
1688 }
1689 } else {
1690 _use_clock_monotonic_condattr = true;
1691 }
1692 } else {
1693 _use_clock_monotonic_condattr = false;
1694 }
1695 }
1696
1697 void os::Posix::init_2(void) {
1698 log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
1699 (_clock_gettime != NULL ? "" : " not"));
1700 log_info(os)("Use of pthread_condattr_setclock is%s supported",
1701 (_pthread_condattr_setclock != NULL ? "" : " not"));
1702 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
1703 _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
1704 }
1705
1706 #else // !SUPPORTS_CLOCK_MONOTONIC
1707
1708 void os::Posix::init(void) {
1709 pthread_init_common();
1710 }
1711
1712 void os::Posix::init_2(void) {
1713 log_info(os)("Use of CLOCK_MONOTONIC is not supported");
1714 log_info(os)("Use of pthread_condattr_setclock is not supported");
1715 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
1716 }
1717
1718 #endif // SUPPORTS_CLOCK_MONOTONIC
1719
1720 os::PlatformEvent::PlatformEvent() {
1721 int status = pthread_cond_init(_cond, _condAttr);
1722 assert_status(status == 0, status, "cond_init");
1723 status = pthread_mutex_init(_mutex, _mutexAttr);
1724 assert_status(status == 0, status, "mutex_init");
1725 _event = 0;
1726 _nParked = 0;
1727 }
1728
1729 // Utility to convert the given timeout to an absolute timespec
1730 // (based on the appropriate clock) to use with pthread_cond_timewait.
1731 // The clock queried here must be the clock used to manage the
1732 // timeout of the condition variable.
1733 //
1734 // The passed in timeout value is either a relative time in nanoseconds
1735 // or an absolute time in milliseconds. A relative timeout will be
1736 // associated with CLOCK_MONOTONIC if available; otherwise, or if absolute,
1737 // the default time-of-day clock will be used.
1738
1739 // Given time is a 64-bit value and the time_t used in the timespec is
1740 // sometimes a signed-32-bit value we have to watch for overflow if times
1741 // way in the future are given. Further on Solaris versions
1742 // prior to 10 there is a restriction (see cond_timedwait) that the specified
1743 // number of seconds, in abstime, is less than current_time + 100000000.
1744 // As it will be over 20 years before "now + 100000000" will overflow we can
1745 // ignore overflow and just impose a hard-limit on seconds using the value
1746 // of "now + 100000000". This places a limit on the timeout of about 3.17
1747 // years from "now".
1748 //
1749 #define MAX_SECS 100000000
1750
1751 // Calculate a new absolute time that is "timeout" nanoseconds from "now".
1752 // "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
1753 // on which clock is being used).
1754 static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
1755 jlong now_part_sec, jlong unit) {
1756 time_t max_secs = now_sec + MAX_SECS;
1757
1758 jlong seconds = timeout / NANOUNITS;
1759 timeout %= NANOUNITS; // remaining nanos
1760
1761 if (seconds >= MAX_SECS) {
1762 // More seconds than we can add, so pin to max_secs.
1763 abstime->tv_sec = max_secs;
1764 abstime->tv_nsec = 0;
1765 } else {
1766 abstime->tv_sec = now_sec + seconds;
1767 long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
1768 if (nanos >= NANOUNITS) { // overflow
1769 abstime->tv_sec += 1;
1770 nanos -= NANOUNITS;
1771 }
1772 abstime->tv_nsec = nanos;
1773 }
1774 }
1775
1776 // Unpack the given deadline in milliseconds since the epoch, into the given timespec.
1777 // The current time in seconds is also passed in to enforce an upper bound as discussed above.
1778 static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
1779 time_t max_secs = now_sec + MAX_SECS;
1780
1781 jlong seconds = deadline / MILLIUNITS;
1782 jlong millis = deadline % MILLIUNITS;
1783
1784 if (seconds >= max_secs) {
1785 // Absolute seconds exceeds allowed max, so pin to max_secs.
1786 abstime->tv_sec = max_secs;
1787 abstime->tv_nsec = 0;
1788 } else {
1789 abstime->tv_sec = seconds;
1790 abstime->tv_nsec = millis * (NANOUNITS / MILLIUNITS);
1791 }
1792 }
1793
1794 static void to_abstime(timespec* abstime, jlong timeout, bool isAbsolute) {
1795 DEBUG_ONLY(int max_secs = MAX_SECS;)
1796
1797 if (timeout < 0) {
1798 timeout = 0;
1799 }
1800
1801 #ifdef SUPPORTS_CLOCK_MONOTONIC
1802
1803 if (_use_clock_monotonic_condattr && !isAbsolute) {
1804 struct timespec now;
1805 int status = _clock_gettime(CLOCK_MONOTONIC, &now);
1806 assert_status(status == 0, status, "clock_gettime");
1807 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
1808 DEBUG_ONLY(max_secs += now.tv_sec;)
1809 } else {
1810
1811 #else
1812
1813 { // Match the block scope.
1814
1815 #endif // SUPPORTS_CLOCK_MONOTONIC
1816
1817 // Time-of-day clock is all we can reliably use.
1818 struct timeval now;
1819 int status = gettimeofday(&now, NULL);
1820 assert_status(status == 0, errno, "gettimeofday");
1821 if (isAbsolute) {
1822 unpack_abs_time(abstime, timeout, now.tv_sec);
1823 } else {
1824 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
1825 }
1826 DEBUG_ONLY(max_secs += now.tv_sec;)
1827 }
1828
1829 assert(abstime->tv_sec >= 0, "tv_sec < 0");
1830 assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
1831 assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
1832 assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
1833 }
1834
1835 // PlatformEvent
1836 //
1837 // Assumption:
1838 // Only one parker can exist on an event, which is why we allocate
1839 // them per-thread. Multiple unparkers can coexist.
1840 //
1841 // _event serves as a restricted-range semaphore.
1842 // -1 : thread is blocked, i.e. there is a waiter
1843 // 0 : neutral: thread is running or ready,
1844 // could have been signaled after a wait started
1845 // 1 : signaled - thread is running or ready
1846 //
1847 // Having three states allows for some detection of bad usage - see
1848 // comments on unpark().
1849
1850 void os::PlatformEvent::park() { // AKA "down()"
1851 // Transitions for _event:
1852 // -1 => -1 : illegal
1853 // 1 => 0 : pass - return immediately
1854 // 0 => -1 : block; then set _event to 0 before returning
1855
1856 // Invariant: Only the thread associated with the PlatformEvent
1857 // may call park().
1858 assert(_nParked == 0, "invariant");
1859
1860 int v;
1861
1862 // atomically decrement _event
1863 for (;;) {
1864 v = _event;
1865 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1866 }
1867 guarantee(v >= 0, "invariant");
1868
1869 if (v == 0) { // Do this the hard way by blocking ...
1870 int status = pthread_mutex_lock(_mutex);
1871 assert_status(status == 0, status, "mutex_lock");
1872 guarantee(_nParked == 0, "invariant");
1873 ++_nParked;
1874 while (_event < 0) {
1875 // OS-level "spurious wakeups" are ignored
1876 status = pthread_cond_wait(_cond, _mutex);
1877 assert_status(status == 0, status, "cond_wait");
1878 }
1879 --_nParked;
1880
1881 _event = 0;
1882 status = pthread_mutex_unlock(_mutex);
1883 assert_status(status == 0, status, "mutex_unlock");
1884 // Paranoia to ensure our locked and lock-free paths interact
1885 // correctly with each other.
1886 OrderAccess::fence();
1887 }
1888 guarantee(_event >= 0, "invariant");
1889 }
1890
1891 int os::PlatformEvent::park(jlong millis) {
1892 // Transitions for _event:
1893 // -1 => -1 : illegal
1894 // 1 => 0 : pass - return immediately
1895 // 0 => -1 : block; then set _event to 0 before returning
1896
1897 // Invariant: Only the thread associated with the Event/PlatformEvent
1898 // may call park().
1899 assert(_nParked == 0, "invariant");
1900
1901 int v;
1902 // atomically decrement _event
1903 for (;;) {
1904 v = _event;
1905 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1906 }
1907 guarantee(v >= 0, "invariant");
1908
1909 if (v == 0) { // Do this the hard way by blocking ...
1910 struct timespec abst;
1911 // We have to watch for overflow when converting millis to nanos,
1912 // but if millis is that large then we will end up limiting to
1913 // MAX_SECS anyway, so just do that here.
1914 if (millis / MILLIUNITS > MAX_SECS) {
1915 millis = jlong(MAX_SECS) * MILLIUNITS;
1916 }
1917 to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false);
1918
1919 int ret = OS_TIMEOUT;
1920 int status = pthread_mutex_lock(_mutex);
1921 assert_status(status == 0, status, "mutex_lock");
1922 guarantee(_nParked == 0, "invariant");
1923 ++_nParked;
1924
1925 while (_event < 0) {
1926 status = pthread_cond_timedwait(_cond, _mutex, &abst);
1927 assert_status(status == 0 || status == ETIMEDOUT,
1928 status, "cond_timedwait");
1929 // OS-level "spurious wakeups" are ignored unless the archaic
1930 // FilterSpuriousWakeups is set false. That flag should be obsoleted.
1931 if (!FilterSpuriousWakeups) break;
1932 if (status == ETIMEDOUT) break;
1933 }
1934 --_nParked;
1935
1936 if (_event >= 0) {
1937 ret = OS_OK;
1938 }
1939
1940 _event = 0;
1941 status = pthread_mutex_unlock(_mutex);
1942 assert_status(status == 0, status, "mutex_unlock");
1943 // Paranoia to ensure our locked and lock-free paths interact
1944 // correctly with each other.
1945 OrderAccess::fence();
1946 return ret;
1947 }
1948 return OS_OK;
1949 }
1950
1951 void os::PlatformEvent::unpark() {
1952 // Transitions for _event:
1953 // 0 => 1 : just return
1954 // 1 => 1 : just return
1955 // -1 => either 0 or 1; must signal target thread
1956 // That is, we can safely transition _event from -1 to either
1957 // 0 or 1.
1958 // See also: "Semaphores in Plan 9" by Mullender & Cox
1959 //
1960 // Note: Forcing a transition from "-1" to "1" on an unpark() means
1961 // that it will take two back-to-back park() calls for the owning
1962 // thread to block. This has the benefit of forcing a spurious return
1963 // from the first park() call after an unpark() call which will help
1964 // shake out uses of park() and unpark() without checking state conditions
1965 // properly. This spurious return doesn't manifest itself in any user code
1966 // but only in the correctly written condition checking loops of ObjectMonitor,
1967 // Mutex/Monitor, Thread::muxAcquire and os::sleep
1968
1969 if (Atomic::xchg(1, &_event) >= 0) return;
1970
1971 int status = pthread_mutex_lock(_mutex);
1972 assert_status(status == 0, status, "mutex_lock");
1973 int anyWaiters = _nParked;
1974 assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
1975 status = pthread_mutex_unlock(_mutex);
1976 assert_status(status == 0, status, "mutex_unlock");
1977
1978 // Note that we signal() *after* dropping the lock for "immortal" Events.
1979 // This is safe and avoids a common class of futile wakeups. In rare
1980 // circumstances this can cause a thread to return prematurely from
1981 // cond_{timed}wait() but the spurious wakeup is benign and the victim
1982 // will simply re-test the condition and re-park itself.
1983 // This provides particular benefit if the underlying platform does not
1984 // provide wait morphing.
1985
1986 if (anyWaiters != 0) {
1987 status = pthread_cond_signal(_cond);
1988 assert_status(status == 0, status, "cond_signal");
1989 }
1990 }
1991
1992 // JSR166 support
1993
1994 os::PlatformParker::PlatformParker() {
1995 int status;
1996 status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
1997 assert_status(status == 0, status, "cond_init rel");
1998 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
1999 assert_status(status == 0, status, "cond_init abs");
2000 status = pthread_mutex_init(_mutex, _mutexAttr);
2001 assert_status(status == 0, status, "mutex_init");
2002 _cur_index = -1; // mark as unused
2003 }
2004
2005 // Parker::park decrements count if > 0, else does a condvar wait. Unpark
2006 // sets count to 1 and signals condvar. Only one thread ever waits
2007 // on the condvar. Contention seen when trying to park implies that someone
2008 // is unparking you, so don't wait. And spurious returns are fine, so there
2009 // is no need to track notifications.
2010
2011 void Parker::park(bool isAbsolute, jlong time) {
2012
2013 // Optional fast-path check:
2014 // Return immediately if a permit is available.
2015 // We depend on Atomic::xchg() having full barrier semantics
2016 // since we are doing a lock-free update to _counter.
2017 if (Atomic::xchg(0, &_counter) > 0) return;
2018
2019 Thread* thread = Thread::current();
2020 assert(thread->is_Java_thread(), "Must be JavaThread");
2021 JavaThread *jt = (JavaThread *)thread;
2022
2023 // Optional optimization -- avoid state transitions if there's
2024 // an interrupt pending.
2025 if (Thread::is_interrupted(thread, false)) {
2026 return;
2027 }
2028
2029 // Next, demultiplex/decode time arguments
2030 struct timespec absTime;
2031 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
2032 return;
2033 }
2034 if (time > 0) {
2035 to_abstime(&absTime, time, isAbsolute);
2036 }
2037
2038 // Enter safepoint region
2039 // Beware of deadlocks such as 6317397.
2040 // The per-thread Parker:: mutex is a classic leaf-lock.
2041 // In particular a thread must never block on the Threads_lock while
2042 // holding the Parker:: mutex. If safepoints are pending both the
2043 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
2044 ThreadBlockInVM tbivm(jt);
2045
2046 // Don't wait if cannot get lock since interference arises from
2047 // unparking. Also re-check interrupt before trying wait.
2048 if (Thread::is_interrupted(thread, false) ||
2049 pthread_mutex_trylock(_mutex) != 0) {
2050 return;
2051 }
2052
2053 int status;
2054 if (_counter > 0) { // no wait needed
2055 _counter = 0;
2056 status = pthread_mutex_unlock(_mutex);
2057 assert_status(status == 0, status, "invariant");
2058 // Paranoia to ensure our locked and lock-free paths interact
2059 // correctly with each other and Java-level accesses.
2060 OrderAccess::fence();
2061 return;
2062 }
2063
2064 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2065 jt->set_suspend_equivalent();
2066 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2067
2068 assert(_cur_index == -1, "invariant");
2069 if (time == 0) {
2070 _cur_index = REL_INDEX; // arbitrary choice when not timed
2071 status = pthread_cond_wait(&_cond[_cur_index], _mutex);
2072 assert_status(status == 0, status, "cond_timedwait");
2073 }
2074 else {
2075 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
2076 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
2077 assert_status(status == 0 || status == ETIMEDOUT,
2078 status, "cond_timedwait");
2079 }
2080 _cur_index = -1;
2081
2082 _counter = 0;
2083 status = pthread_mutex_unlock(_mutex);
2084 assert_status(status == 0, status, "invariant");
2085 // Paranoia to ensure our locked and lock-free paths interact
2086 // correctly with each other and Java-level accesses.
2087 OrderAccess::fence();
2088
2089 // If externally suspended while waiting, re-suspend
2090 if (jt->handle_special_suspend_equivalent_condition()) {
2091 jt->java_suspend_self();
2092 }
2093 }
2094
2095 void Parker::unpark() {
2096 int status = pthread_mutex_lock(_mutex);
2097 assert_status(status == 0, status, "invariant");
2098 const int s = _counter;
2099 _counter = 1;
2100 // must capture correct index before unlocking
2101 int index = _cur_index;
2102 status = pthread_mutex_unlock(_mutex);
2103 assert_status(status == 0, status, "invariant");
2104
2105 // Note that we signal() *after* dropping the lock for "immortal" Events.
2106 // This is safe and avoids a common class of futile wakeups. In rare
2107 // circumstances this can cause a thread to return prematurely from
2108 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2109 // will simply re-test the condition and re-park itself.
2110 // This provides particular benefit if the underlying platform does not
2111 // provide wait morphing.
2112
2113 if (s < 1 && index != -1) {
2114 // thread is definitely parked
2115 status = pthread_cond_signal(&_cond[index]);
2116 assert_status(status == 0, status, "invariant");
2117 }
2118 }
2119
2120
2121 #endif // !SOLARIS