1 /*
2 * Copyright (c) 1999, 2018, 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 "logging/log.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "utilities/globalDefinitions.hpp"
29 #include "runtime/frame.inline.hpp"
30 #include "runtime/interfaceSupport.inline.hpp"
31 #include "runtime/os.hpp"
32 #include "services/memTracker.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/formatBuffer.hpp"
35 #include "utilities/macros.hpp"
36 #include "utilities/vmError.hpp"
37
38 #include <dlfcn.h>
39 #include <pthread.h>
40 #include <signal.h>
41 #include <sys/mman.h>
42 #include <sys/resource.h>
43 #include <sys/utsname.h>
44 #include <time.h>
45 #include <unistd.h>
46
47 // Todo: provide a os::get_max_process_id() or similar. Number of processes
48 // may have been configured, can be read more accurately from proc fs etc.
49 #ifndef MAX_PID
50 #define MAX_PID INT_MAX
51 #endif
52 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
53
54 #define ROOT_UID 0
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 size_t os::lasterror(char *buf, size_t len) {
154 if (errno == 0) return 0;
155
156 const char *s = os::strerror(errno);
157 size_t n = ::strlen(s);
158 if (n >= len) {
159 n = len - 1;
160 }
161 ::strncpy(buf, s, n);
162 buf[n] = '\0';
163 return n;
164 }
165
166 bool os::is_debugger_attached() {
167 // not implemented
168 return false;
169 }
170
171 void os::wait_for_keypress_at_exit(void) {
172 // don't do anything on posix platforms
173 return;
174 }
175
176 int os::create_file_for_heap(const char* dir) {
177
178 const char name_template[] = "/jvmheap.XXXXXX";
179
180 char *fullname = (char*)os::malloc((strlen(dir) + strlen(name_template) + 1), mtInternal);
181 if (fullname == NULL) {
182 vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
183 return -1;
184 }
185 (void)strncpy(fullname, dir, strlen(dir)+1);
186 (void)strncat(fullname, name_template, strlen(name_template));
187
188 os::native_path(fullname);
189
190 sigset_t set, oldset;
191 int ret = sigfillset(&set);
192 assert_with_errno(ret == 0, "sigfillset returned error");
193
194 // set the file creation mask.
195 mode_t file_mode = S_IRUSR | S_IWUSR;
196
197 // create a new file.
198 int fd = mkstemp(fullname);
199
200 if (fd < 0) {
201 warning("Could not create file for heap with template %s", fullname);
202 os::free(fullname);
203 return -1;
204 }
205
206 // delete the name from the filesystem. When 'fd' is closed, the file (and space) will be deleted.
207 ret = unlink(fullname);
208 assert_with_errno(ret == 0, "unlink returned error");
209
210 os::free(fullname);
211 return fd;
212 }
213
214 static char* reserve_mmapped_memory(size_t bytes, char* requested_addr) {
215 char * addr;
216 int flags = MAP_PRIVATE NOT_AIX( | MAP_NORESERVE ) | MAP_ANONYMOUS;
217 if (requested_addr != NULL) {
218 assert((uintptr_t)requested_addr % os::vm_page_size() == 0, "Requested address should be aligned to OS page size");
219 flags |= MAP_FIXED;
220 }
221
222 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
223 // touch an uncommitted page. Otherwise, the read/write might
224 // succeed if we have enough swap space to back the physical page.
225 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
226 flags, -1, 0);
227
228 if (addr != MAP_FAILED) {
229 MemTracker::record_virtual_memory_reserve((address)addr, bytes, CALLER_PC);
230 return addr;
231 }
232 return NULL;
233 }
234
235 static int util_posix_fallocate(int fd, off_t offset, off_t len) {
236 #ifdef __APPLE__
237 fstore_t store = { F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, len };
238 // First we try to get a continuous chunk of disk space
239 int ret = fcntl(fd, F_PREALLOCATE, &store);
240 if (ret == -1) {
241 // Maybe we are too fragmented, try to allocate non-continuous range
242 store.fst_flags = F_ALLOCATEALL;
243 ret = fcntl(fd, F_PREALLOCATE, &store);
244 }
245 if(ret != -1) {
246 return ftruncate(fd, len);
247 }
248 return -1;
249 #else
250 return posix_fallocate(fd, offset, len);
251 #endif
252 }
253
254 // Map the given address range to the provided file descriptor.
255 char* os::map_memory_to_file(char* base, size_t size, int fd) {
256 assert(fd != -1, "File descriptor is not valid");
257
258 // allocate space for the file
259 int ret = util_posix_fallocate(fd, 0, (off_t)size);
260 if (ret != 0) {
261 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory. error(%d)", ret));
262 return NULL;
263 }
264
265 int prot = PROT_READ | PROT_WRITE;
266 int flags = MAP_SHARED;
267 if (base != NULL) {
268 flags |= MAP_FIXED;
269 }
270 char* addr = (char*)mmap(base, size, prot, flags, fd, 0);
271
272 if (addr == MAP_FAILED) {
273 warning("Failed mmap to file. (%s)", os::strerror(errno));
274 return NULL;
275 }
276 if (base != NULL && addr != base) {
277 if (!os::release_memory(addr, size)) {
278 warning("Could not release memory on unsuccessful file mapping");
279 }
280 return NULL;
281 }
282 return addr;
283 }
284
285 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
286 assert(fd != -1, "File descriptor is not valid");
287 assert(base != NULL, "Base cannot be NULL");
288
289 return map_memory_to_file(base, size, fd);
290 }
291
292 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
293 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
294 // rather than unmapping and remapping the whole chunk to get requested alignment.
295 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
296 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
297 "Alignment must be a multiple of allocation granularity (page size)");
298 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
299
300 size_t extra_size = size + alignment;
301 assert(extra_size >= size, "overflow, size is too large to allow alignment");
302
303 char* extra_base;
304 if (file_desc != -1) {
305 // For file mapping, we do not call os:reserve_memory(extra_size, NULL, alignment, file_desc) because
306 // we need to deal with shrinking of the file space later when we release extra memory after alignment.
307 // We also cannot called os:reserve_memory() with file_desc set to -1 because on aix we might get SHM memory.
308 // So here to call a helper function while reserve memory for us. After we have a aligned base,
309 // we will replace anonymous mapping with file mapping.
310 extra_base = reserve_mmapped_memory(extra_size, NULL);
311 if (extra_base != NULL) {
312 MemTracker::record_virtual_memory_reserve((address)extra_base, extra_size, CALLER_PC);
313 }
314 } else {
315 extra_base = os::reserve_memory(extra_size, NULL, alignment);
316 }
317
318 if (extra_base == NULL) {
319 return NULL;
320 }
321
322 // Do manual alignment
323 char* aligned_base = align_up(extra_base, alignment);
324
325 // [ | | ]
326 // ^ extra_base
327 // ^ extra_base + begin_offset == aligned_base
328 // extra_base + begin_offset + size ^
329 // extra_base + extra_size ^
330 // |<>| == begin_offset
331 // end_offset == |<>|
332 size_t begin_offset = aligned_base - extra_base;
333 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
334
335 if (begin_offset > 0) {
336 os::release_memory(extra_base, begin_offset);
337 }
338
339 if (end_offset > 0) {
340 os::release_memory(extra_base + begin_offset + size, end_offset);
341 }
342
343 if (file_desc != -1) {
344 // After we have an aligned address, we can replace anonymous mapping with file mapping
345 if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
346 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
347 }
348 MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
349 }
350 return aligned_base;
351 }
352
353 int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
354 // All supported POSIX platforms provide C99 semantics.
355 int result = ::vsnprintf(buf, len, fmt, args);
356 // If an encoding error occurred (result < 0) then it's not clear
357 // whether the buffer is NUL terminated, so ensure it is.
358 if ((result < 0) && (len > 0)) {
359 buf[len - 1] = '\0';
360 }
361 return result;
362 }
363
364 int os::get_fileno(FILE* fp) {
365 return NOT_AIX(::)fileno(fp);
366 }
367
368 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
369 return gmtime_r(clock, res);
370 }
371
372 void os::Posix::print_load_average(outputStream* st) {
373 st->print("load average:");
374 double loadavg[3];
375 os::loadavg(loadavg, 3);
376 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
377 st->cr();
378 }
379
380 void os::Posix::print_rlimit_info(outputStream* st) {
381 st->print("rlimit:");
382 struct rlimit rlim;
383
384 st->print(" STACK ");
385 getrlimit(RLIMIT_STACK, &rlim);
386 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
387 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
388
389 st->print(", CORE ");
390 getrlimit(RLIMIT_CORE, &rlim);
391 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
392 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
393
394 // Isn't there on solaris
395 #if defined(AIX)
396 st->print(", NPROC ");
397 st->print("%d", sysconf(_SC_CHILD_MAX));
398 #elif !defined(SOLARIS)
399 st->print(", NPROC ");
400 getrlimit(RLIMIT_NPROC, &rlim);
401 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
402 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
403 #endif
404
405 st->print(", NOFILE ");
406 getrlimit(RLIMIT_NOFILE, &rlim);
407 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
408 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
409
410 st->print(", AS ");
411 getrlimit(RLIMIT_AS, &rlim);
412 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
413 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
414
415 st->print(", DATA ");
416 getrlimit(RLIMIT_DATA, &rlim);
417 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
418 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
419
420 st->print(", FSIZE ");
421 getrlimit(RLIMIT_FSIZE, &rlim);
422 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
423 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
424
425 st->cr();
426 }
427
428 void os::Posix::print_uname_info(outputStream* st) {
429 // kernel
430 st->print("uname:");
431 struct utsname name;
432 uname(&name);
433 st->print("%s ", name.sysname);
434 #ifdef ASSERT
435 st->print("%s ", name.nodename);
436 #endif
437 st->print("%s ", name.release);
438 st->print("%s ", name.version);
439 st->print("%s", name.machine);
440 st->cr();
441 }
442
443 bool os::get_host_name(char* buf, size_t buflen) {
444 struct utsname name;
445 uname(&name);
446 jio_snprintf(buf, buflen, "%s", name.nodename);
447 return true;
448 }
449
450 bool os::has_allocatable_memory_limit(julong* limit) {
451 struct rlimit rlim;
452 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
453 // if there was an error when calling getrlimit, assume that there is no limitation
454 // on virtual memory.
455 bool result;
456 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
457 result = false;
458 } else {
459 *limit = (julong)rlim.rlim_cur;
460 result = true;
461 }
462 #ifdef _LP64
463 return result;
464 #else
465 // arbitrary virtual space limit for 32 bit Unices found by testing. If
466 // getrlimit above returned a limit, bound it with this limit. Otherwise
467 // directly use it.
468 const julong max_virtual_limit = (julong)3800*M;
469 if (result) {
470 *limit = MIN2(*limit, max_virtual_limit);
471 } else {
472 *limit = max_virtual_limit;
473 }
474
475 // bound by actually allocatable memory. The algorithm uses two bounds, an
476 // upper and a lower limit. The upper limit is the current highest amount of
477 // memory that could not be allocated, the lower limit is the current highest
478 // amount of memory that could be allocated.
479 // The algorithm iteratively refines the result by halving the difference
480 // between these limits, updating either the upper limit (if that value could
481 // not be allocated) or the lower limit (if the that value could be allocated)
482 // until the difference between these limits is "small".
483
484 // the minimum amount of memory we care about allocating.
485 const julong min_allocation_size = M;
486
487 julong upper_limit = *limit;
488
489 // first check a few trivial cases
490 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
491 *limit = upper_limit;
492 } else if (!is_allocatable(min_allocation_size)) {
493 // we found that not even min_allocation_size is allocatable. Return it
494 // anyway. There is no point to search for a better value any more.
495 *limit = min_allocation_size;
496 } else {
497 // perform the binary search.
498 julong lower_limit = min_allocation_size;
499 while ((upper_limit - lower_limit) > min_allocation_size) {
500 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
501 temp_limit = align_down(temp_limit, min_allocation_size);
502 if (is_allocatable(temp_limit)) {
503 lower_limit = temp_limit;
504 } else {
505 upper_limit = temp_limit;
506 }
507 }
508 *limit = lower_limit;
509 }
510 return true;
511 #endif
512 }
513
514 const char* os::get_current_directory(char *buf, size_t buflen) {
515 return getcwd(buf, buflen);
516 }
517
518 FILE* os::open(int fd, const char* mode) {
519 return ::fdopen(fd, mode);
520 }
521
522 void os::flockfile(FILE* fp) {
523 ::flockfile(fp);
524 }
525
526 void os::funlockfile(FILE* fp) {
527 ::funlockfile(fp);
528 }
529
530 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
531 // which is used to find statically linked in agents.
532 // Parameters:
533 // sym_name: Symbol in library we are looking for
534 // lib_name: Name of library to look in, NULL for shared libs.
535 // is_absolute_path == true if lib_name is absolute path to agent
536 // such as "/a/b/libL.so"
537 // == false if only the base name of the library is passed in
538 // such as "L"
539 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
540 bool is_absolute_path) {
541 char *agent_entry_name;
542 size_t len;
543 size_t name_len;
544 size_t prefix_len = strlen(JNI_LIB_PREFIX);
545 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
546 const char *start;
547
548 if (lib_name != NULL) {
549 name_len = strlen(lib_name);
550 if (is_absolute_path) {
551 // Need to strip path, prefix and suffix
552 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
553 lib_name = ++start;
554 }
555 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
556 return NULL;
557 }
558 lib_name += prefix_len;
559 name_len = strlen(lib_name) - suffix_len;
560 }
561 }
562 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
563 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
564 if (agent_entry_name == NULL) {
565 return NULL;
566 }
567 strcpy(agent_entry_name, sym_name);
568 if (lib_name != NULL) {
569 strcat(agent_entry_name, "_");
570 strncat(agent_entry_name, lib_name, name_len);
571 }
572 return agent_entry_name;
573 }
574
575 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
576 assert(thread == Thread::current(), "thread consistency check");
577
578 ParkEvent * const slp = thread->_SleepEvent ;
579 slp->reset() ;
580 OrderAccess::fence() ;
581
582 if (interruptible) {
583 jlong prevtime = javaTimeNanos();
584
585 for (;;) {
586 if (os::is_interrupted(thread, true)) {
587 return OS_INTRPT;
588 }
589
590 jlong newtime = javaTimeNanos();
591
592 if (newtime - prevtime < 0) {
593 // time moving backwards, should only happen if no monotonic clock
594 // not a guarantee() because JVM should not abort on kernel/glibc bugs
595 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
596 } else {
597 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
598 }
599
600 if (millis <= 0) {
601 return OS_OK;
602 }
603
604 prevtime = newtime;
605
606 {
607 assert(thread->is_Java_thread(), "sanity check");
608 JavaThread *jt = (JavaThread *) thread;
609 ThreadBlockInVM tbivm(jt);
610 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
611
612 jt->set_suspend_equivalent();
613 // cleared by handle_special_suspend_equivalent_condition() or
614 // java_suspend_self() via check_and_wait_while_suspended()
615
616 slp->park(millis);
617
618 // were we externally suspended while we were waiting?
619 jt->check_and_wait_while_suspended();
620 }
621 }
622 } else {
623 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
624 jlong prevtime = javaTimeNanos();
625
626 for (;;) {
627 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
628 // the 1st iteration ...
629 jlong newtime = javaTimeNanos();
630
631 if (newtime - prevtime < 0) {
632 // time moving backwards, should only happen if no monotonic clock
633 // not a guarantee() because JVM should not abort on kernel/glibc bugs
634 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
635 } else {
636 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
637 }
638
639 if (millis <= 0) break ;
640
641 prevtime = newtime;
642 slp->park(millis);
643 }
644 return OS_OK ;
645 }
646 }
647
648 ////////////////////////////////////////////////////////////////////////////////
649 // interrupt support
650
651 void os::interrupt(Thread* thread) {
652 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
653
654 OSThread* osthread = thread->osthread();
655
656 if (!osthread->interrupted()) {
657 osthread->set_interrupted(true);
658 // More than one thread can get here with the same value of osthread,
659 // resulting in multiple notifications. We do, however, want the store
660 // to interrupted() to be visible to other threads before we execute unpark().
661 OrderAccess::fence();
662 ParkEvent * const slp = thread->_SleepEvent ;
663 if (slp != NULL) slp->unpark() ;
664 }
665
666 // For JSR166. Unpark even if interrupt status already was set
667 if (thread->is_Java_thread())
668 ((JavaThread*)thread)->parker()->unpark();
669
670 ParkEvent * ev = thread->_ParkEvent ;
671 if (ev != NULL) ev->unpark() ;
672 }
673
674 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
675 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
676
677 OSThread* osthread = thread->osthread();
678
679 bool interrupted = osthread->interrupted();
680
681 // NOTE that since there is no "lock" around the interrupt and
682 // is_interrupted operations, there is the possibility that the
683 // interrupted flag (in osThread) will be "false" but that the
684 // low-level events will be in the signaled state. This is
685 // intentional. The effect of this is that Object.wait() and
686 // LockSupport.park() will appear to have a spurious wakeup, which
687 // is allowed and not harmful, and the possibility is so rare that
688 // it is not worth the added complexity to add yet another lock.
689 // For the sleep event an explicit reset is performed on entry
690 // to os::sleep, so there is no early return. It has also been
691 // recommended not to put the interrupted flag into the "event"
692 // structure because it hides the issue.
693 if (interrupted && clear_interrupted) {
694 osthread->set_interrupted(false);
695 // consider thread->_SleepEvent->reset() ... optional optimization
696 }
697
698 return interrupted;
699 }
700
701
702
703 static const struct {
704 int sig; const char* name;
705 }
706 g_signal_info[] =
707 {
708 { SIGABRT, "SIGABRT" },
709 #ifdef SIGAIO
710 { SIGAIO, "SIGAIO" },
711 #endif
712 { SIGALRM, "SIGALRM" },
713 #ifdef SIGALRM1
714 { SIGALRM1, "SIGALRM1" },
715 #endif
716 { SIGBUS, "SIGBUS" },
717 #ifdef SIGCANCEL
718 { SIGCANCEL, "SIGCANCEL" },
719 #endif
720 { SIGCHLD, "SIGCHLD" },
721 #ifdef SIGCLD
722 { SIGCLD, "SIGCLD" },
723 #endif
724 { SIGCONT, "SIGCONT" },
725 #ifdef SIGCPUFAIL
726 { SIGCPUFAIL, "SIGCPUFAIL" },
727 #endif
728 #ifdef SIGDANGER
729 { SIGDANGER, "SIGDANGER" },
730 #endif
731 #ifdef SIGDIL
732 { SIGDIL, "SIGDIL" },
733 #endif
734 #ifdef SIGEMT
735 { SIGEMT, "SIGEMT" },
736 #endif
737 { SIGFPE, "SIGFPE" },
738 #ifdef SIGFREEZE
739 { SIGFREEZE, "SIGFREEZE" },
740 #endif
741 #ifdef SIGGFAULT
742 { SIGGFAULT, "SIGGFAULT" },
743 #endif
744 #ifdef SIGGRANT
745 { SIGGRANT, "SIGGRANT" },
746 #endif
747 { SIGHUP, "SIGHUP" },
748 { SIGILL, "SIGILL" },
749 { SIGINT, "SIGINT" },
750 #ifdef SIGIO
751 { SIGIO, "SIGIO" },
752 #endif
753 #ifdef SIGIOINT
754 { SIGIOINT, "SIGIOINT" },
755 #endif
756 #ifdef SIGIOT
757 // SIGIOT is there for BSD compatibility, but on most Unices just a
758 // synonym for SIGABRT. The result should be "SIGABRT", not
759 // "SIGIOT".
760 #if (SIGIOT != SIGABRT )
761 { SIGIOT, "SIGIOT" },
762 #endif
763 #endif
764 #ifdef SIGKAP
765 { SIGKAP, "SIGKAP" },
766 #endif
767 { SIGKILL, "SIGKILL" },
768 #ifdef SIGLOST
769 { SIGLOST, "SIGLOST" },
770 #endif
771 #ifdef SIGLWP
772 { SIGLWP, "SIGLWP" },
773 #endif
774 #ifdef SIGLWPTIMER
775 { SIGLWPTIMER, "SIGLWPTIMER" },
776 #endif
777 #ifdef SIGMIGRATE
778 { SIGMIGRATE, "SIGMIGRATE" },
779 #endif
780 #ifdef SIGMSG
781 { SIGMSG, "SIGMSG" },
782 #endif
783 { SIGPIPE, "SIGPIPE" },
784 #ifdef SIGPOLL
785 { SIGPOLL, "SIGPOLL" },
786 #endif
787 #ifdef SIGPRE
788 { SIGPRE, "SIGPRE" },
789 #endif
790 { SIGPROF, "SIGPROF" },
791 #ifdef SIGPTY
792 { SIGPTY, "SIGPTY" },
793 #endif
794 #ifdef SIGPWR
795 { SIGPWR, "SIGPWR" },
796 #endif
797 { SIGQUIT, "SIGQUIT" },
798 #ifdef SIGRECONFIG
799 { SIGRECONFIG, "SIGRECONFIG" },
800 #endif
801 #ifdef SIGRECOVERY
802 { SIGRECOVERY, "SIGRECOVERY" },
803 #endif
804 #ifdef SIGRESERVE
805 { SIGRESERVE, "SIGRESERVE" },
806 #endif
807 #ifdef SIGRETRACT
808 { SIGRETRACT, "SIGRETRACT" },
809 #endif
810 #ifdef SIGSAK
811 { SIGSAK, "SIGSAK" },
812 #endif
813 { SIGSEGV, "SIGSEGV" },
814 #ifdef SIGSOUND
815 { SIGSOUND, "SIGSOUND" },
816 #endif
817 #ifdef SIGSTKFLT
818 { SIGSTKFLT, "SIGSTKFLT" },
819 #endif
820 { SIGSTOP, "SIGSTOP" },
821 { SIGSYS, "SIGSYS" },
822 #ifdef SIGSYSERROR
823 { SIGSYSERROR, "SIGSYSERROR" },
824 #endif
825 #ifdef SIGTALRM
826 { SIGTALRM, "SIGTALRM" },
827 #endif
828 { SIGTERM, "SIGTERM" },
829 #ifdef SIGTHAW
830 { SIGTHAW, "SIGTHAW" },
831 #endif
832 { SIGTRAP, "SIGTRAP" },
833 #ifdef SIGTSTP
834 { SIGTSTP, "SIGTSTP" },
835 #endif
836 { SIGTTIN, "SIGTTIN" },
837 { SIGTTOU, "SIGTTOU" },
838 #ifdef SIGURG
839 { SIGURG, "SIGURG" },
840 #endif
841 { SIGUSR1, "SIGUSR1" },
842 { SIGUSR2, "SIGUSR2" },
843 #ifdef SIGVIRT
844 { SIGVIRT, "SIGVIRT" },
845 #endif
846 { SIGVTALRM, "SIGVTALRM" },
847 #ifdef SIGWAITING
848 { SIGWAITING, "SIGWAITING" },
849 #endif
850 #ifdef SIGWINCH
851 { SIGWINCH, "SIGWINCH" },
852 #endif
853 #ifdef SIGWINDOW
854 { SIGWINDOW, "SIGWINDOW" },
855 #endif
856 { SIGXCPU, "SIGXCPU" },
857 { SIGXFSZ, "SIGXFSZ" },
858 #ifdef SIGXRES
859 { SIGXRES, "SIGXRES" },
860 #endif
861 { -1, NULL }
862 };
863
864 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
865 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
866
867 const char* ret = NULL;
868
869 #ifdef SIGRTMIN
870 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
871 if (sig == SIGRTMIN) {
872 ret = "SIGRTMIN";
873 } else if (sig == SIGRTMAX) {
874 ret = "SIGRTMAX";
875 } else {
876 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
877 return out;
878 }
879 }
880 #endif
881
882 if (sig > 0) {
883 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
884 if (g_signal_info[idx].sig == sig) {
885 ret = g_signal_info[idx].name;
886 break;
887 }
888 }
889 }
890
891 if (!ret) {
892 if (!is_valid_signal(sig)) {
893 ret = "INVALID";
894 } else {
895 ret = "UNKNOWN";
896 }
897 }
898
899 if (out && outlen > 0) {
900 strncpy(out, ret, outlen);
901 out[outlen - 1] = '\0';
902 }
903 return out;
904 }
905
906 int os::Posix::get_signal_number(const char* signal_name) {
907 char tmp[30];
908 const char* s = signal_name;
909 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
910 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
911 s = tmp;
912 }
913 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
914 if (strcmp(g_signal_info[idx].name, s) == 0) {
915 return g_signal_info[idx].sig;
916 }
917 }
918 return -1;
919 }
920
921 int os::get_signal_number(const char* signal_name) {
922 return os::Posix::get_signal_number(signal_name);
923 }
924
925 // Returns true if signal number is valid.
926 bool os::Posix::is_valid_signal(int sig) {
927 // MacOS not really POSIX compliant: sigaddset does not return
928 // an error for invalid signal numbers. However, MacOS does not
929 // support real time signals and simply seems to have just 33
930 // signals with no holes in the signal range.
931 #ifdef __APPLE__
932 return sig >= 1 && sig < NSIG;
933 #else
934 // Use sigaddset to check for signal validity.
935 sigset_t set;
936 sigemptyset(&set);
937 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
938 return false;
939 }
940 return true;
941 #endif
942 }
943
944 bool os::Posix::is_sig_ignored(int sig) {
945 struct sigaction oact;
946 sigaction(sig, (struct sigaction*)NULL, &oact);
947 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
948 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
949 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
950 return true;
951 } else {
952 return false;
953 }
954 }
955
956 // Returns:
957 // NULL for an invalid signal number
958 // "SIG<num>" for a valid but unknown signal number
959 // signal name otherwise.
960 const char* os::exception_name(int sig, char* buf, size_t size) {
961 if (!os::Posix::is_valid_signal(sig)) {
962 return NULL;
963 }
964 const char* const name = os::Posix::get_signal_name(sig, buf, size);
965 if (strcmp(name, "UNKNOWN") == 0) {
966 jio_snprintf(buf, size, "SIG%d", sig);
967 }
968 return buf;
969 }
970
971 #define NUM_IMPORTANT_SIGS 32
972 // Returns one-line short description of a signal set in a user provided buffer.
973 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
974 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
975 // Note: for shortness, just print out the first 32. That should
976 // cover most of the useful ones, apart from realtime signals.
977 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
978 const int rc = sigismember(set, sig);
979 if (rc == -1 && errno == EINVAL) {
980 buffer[sig-1] = '?';
981 } else {
982 buffer[sig-1] = rc == 0 ? '0' : '1';
983 }
984 }
985 buffer[NUM_IMPORTANT_SIGS] = 0;
986 return buffer;
987 }
988
989 // Prints one-line description of a signal set.
990 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
991 char buf[NUM_IMPORTANT_SIGS + 1];
992 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
993 st->print("%s", buf);
994 }
995
996 // Writes one-line description of a combination of sigaction.sa_flags into a user
997 // provided buffer. Returns that buffer.
998 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
999 char* p = buffer;
1000 size_t remaining = size;
1001 bool first = true;
1002 int idx = 0;
1003
1004 assert(buffer, "invalid argument");
1005
1006 if (size == 0) {
1007 return buffer;
1008 }
1009
1010 strncpy(buffer, "none", size);
1011
1012 const struct {
1013 // NB: i is an unsigned int here because SA_RESETHAND is on some
1014 // systems 0x80000000, which is implicitly unsigned. Assignining
1015 // it to an int field would be an overflow in unsigned-to-signed
1016 // conversion.
1017 unsigned int i;
1018 const char* s;
1019 } flaginfo [] = {
1020 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
1021 { SA_ONSTACK, "SA_ONSTACK" },
1022 { SA_RESETHAND, "SA_RESETHAND" },
1023 { SA_RESTART, "SA_RESTART" },
1024 { SA_SIGINFO, "SA_SIGINFO" },
1025 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
1026 { SA_NODEFER, "SA_NODEFER" },
1027 #ifdef AIX
1028 { SA_ONSTACK, "SA_ONSTACK" },
1029 { SA_OLDSTYLE, "SA_OLDSTYLE" },
1030 #endif
1031 { 0, NULL }
1032 };
1033
1034 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
1035 if (flags & flaginfo[idx].i) {
1036 if (first) {
1037 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
1038 first = false;
1039 } else {
1040 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
1041 }
1042 const size_t len = strlen(p);
1043 p += len;
1044 remaining -= len;
1045 }
1046 }
1047
1048 buffer[size - 1] = '\0';
1049
1050 return buffer;
1051 }
1052
1053 // Prints one-line description of a combination of sigaction.sa_flags.
1054 void os::Posix::print_sa_flags(outputStream* st, int flags) {
1055 char buffer[0x100];
1056 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
1057 st->print("%s", buffer);
1058 }
1059
1060 // Helper function for os::Posix::print_siginfo_...():
1061 // return a textual description for signal code.
1062 struct enum_sigcode_desc_t {
1063 const char* s_name;
1064 const char* s_desc;
1065 };
1066
1067 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
1068
1069 const struct {
1070 int sig; int code; const char* s_code; const char* s_desc;
1071 } t1 [] = {
1072 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
1073 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
1074 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
1075 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
1076 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
1077 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
1078 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
1079 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
1080 #if defined(IA64) && defined(LINUX)
1081 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
1082 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
1083 #endif
1084 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
1085 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
1086 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
1087 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
1088 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
1089 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
1090 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
1091 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
1092 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
1093 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
1094 #ifdef AIX
1095 // no explanation found what keyerr would be
1096 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
1097 #endif
1098 #if defined(IA64) && !defined(AIX)
1099 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
1100 #endif
1101 #if defined(__sparc) && defined(SOLARIS)
1102 // define Solaris Sparc M7 ADI SEGV signals
1103 #if !defined(SEGV_ACCADI)
1104 #define SEGV_ACCADI 3
1105 #endif
1106 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
1107 #if !defined(SEGV_ACCDERR)
1108 #define SEGV_ACCDERR 4
1109 #endif
1110 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
1111 #if !defined(SEGV_ACCPERR)
1112 #define SEGV_ACCPERR 5
1113 #endif
1114 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
1115 #endif // defined(__sparc) && defined(SOLARIS)
1116 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
1117 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
1118 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
1119 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
1120 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
1121 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
1122 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
1123 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
1124 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
1125 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
1126 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
1127 #ifdef SIGPOLL
1128 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
1129 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
1130 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
1131 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
1132 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
1133 #endif
1134 { -1, -1, NULL, NULL }
1135 };
1136
1137 // Codes valid in any signal context.
1138 const struct {
1139 int code; const char* s_code; const char* s_desc;
1140 } t2 [] = {
1141 { SI_USER, "SI_USER", "Signal sent by kill()." },
1142 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
1143 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
1144 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
1145 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
1146 // Linux specific
1147 #ifdef SI_TKILL
1148 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
1149 #endif
1150 #ifdef SI_DETHREAD
1151 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
1152 #endif
1153 #ifdef SI_KERNEL
1154 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
1155 #endif
1156 #ifdef SI_SIGIO
1157 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
1158 #endif
1159
1160 #ifdef AIX
1161 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
1162 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
1163 #endif
1164
1165 #ifdef __sun
1166 { SI_NOINFO, "SI_NOINFO", "No signal information" },
1167 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
1168 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
1169 #endif
1170
1171 { -1, NULL, NULL }
1172 };
1173
1174 const char* s_code = NULL;
1175 const char* s_desc = NULL;
1176
1177 for (int i = 0; t1[i].sig != -1; i ++) {
1178 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
1179 s_code = t1[i].s_code;
1180 s_desc = t1[i].s_desc;
1181 break;
1182 }
1183 }
1184
1185 if (s_code == NULL) {
1186 for (int i = 0; t2[i].s_code != NULL; i ++) {
1187 if (t2[i].code == si->si_code) {
1188 s_code = t2[i].s_code;
1189 s_desc = t2[i].s_desc;
1190 }
1191 }
1192 }
1193
1194 if (s_code == NULL) {
1195 out->s_name = "unknown";
1196 out->s_desc = "unknown";
1197 return false;
1198 }
1199
1200 out->s_name = s_code;
1201 out->s_desc = s_desc;
1202
1203 return true;
1204 }
1205
1206 void os::print_siginfo(outputStream* os, const void* si0) {
1207
1208 const siginfo_t* const si = (const siginfo_t*) si0;
1209
1210 char buf[20];
1211 os->print("siginfo:");
1212
1213 if (!si) {
1214 os->print(" <null>");
1215 return;
1216 }
1217
1218 const int sig = si->si_signo;
1219
1220 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1221
1222 enum_sigcode_desc_t ed;
1223 get_signal_code_description(si, &ed);
1224 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1225
1226 if (si->si_errno) {
1227 os->print(", si_errno: %d", si->si_errno);
1228 }
1229
1230 // Output additional information depending on the signal code.
1231
1232 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1233 // so it depends on the context which member to use. For synchronous error signals,
1234 // we print si_addr, unless the signal was sent by another process or thread, in
1235 // which case we print out pid or tid of the sender.
1236 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
1237 const pid_t pid = si->si_pid;
1238 os->print(", si_pid: %ld", (long) pid);
1239 if (IS_VALID_PID(pid)) {
1240 const pid_t me = getpid();
1241 if (me == pid) {
1242 os->print(" (current process)");
1243 }
1244 } else {
1245 os->print(" (invalid)");
1246 }
1247 os->print(", si_uid: %ld", (long) si->si_uid);
1248 if (sig == SIGCHLD) {
1249 os->print(", si_status: %d", si->si_status);
1250 }
1251 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1252 sig == SIGTRAP || sig == SIGFPE) {
1253 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1254 #ifdef SIGPOLL
1255 } else if (sig == SIGPOLL) {
1256 os->print(", si_band: %ld", si->si_band);
1257 #endif
1258 }
1259
1260 }
1261
1262 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1263 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1264 }
1265
1266 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1267 #if defined(AIX)
1268 return Aix::ucontext_get_pc(ctx);
1269 #elif defined(BSD)
1270 return Bsd::ucontext_get_pc(ctx);
1271 #elif defined(LINUX)
1272 return Linux::ucontext_get_pc(ctx);
1273 #elif defined(SOLARIS)
1274 return Solaris::ucontext_get_pc(ctx);
1275 #else
1276 VMError::report_and_die("unimplemented ucontext_get_pc");
1277 #endif
1278 }
1279
1280 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1281 #if defined(AIX)
1282 Aix::ucontext_set_pc(ctx, pc);
1283 #elif defined(BSD)
1284 Bsd::ucontext_set_pc(ctx, pc);
1285 #elif defined(LINUX)
1286 Linux::ucontext_set_pc(ctx, pc);
1287 #elif defined(SOLARIS)
1288 Solaris::ucontext_set_pc(ctx, pc);
1289 #else
1290 VMError::report_and_die("unimplemented ucontext_get_pc");
1291 #endif
1292 }
1293
1294 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1295 size_t stack_size = 0;
1296 size_t guard_size = 0;
1297 int detachstate = 0;
1298 pthread_attr_getstacksize(attr, &stack_size);
1299 pthread_attr_getguardsize(attr, &guard_size);
1300 // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
1301 LINUX_ONLY(stack_size -= guard_size);
1302 pthread_attr_getdetachstate(attr, &detachstate);
1303 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1304 stack_size / 1024, guard_size / 1024,
1305 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1306 return buf;
1307 }
1308
1309 char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
1310
1311 if (filename == NULL || outbuf == NULL || outbuflen < 1) {
1312 assert(false, "os::Posix::realpath: invalid arguments.");
1313 errno = EINVAL;
1314 return NULL;
1315 }
1316
1317 char* result = NULL;
1318
1319 // This assumes platform realpath() is implemented according to POSIX.1-2008.
1320 // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
1321 // output buffer is dynamically allocated and must be ::free()'d by the caller.
1322 char* p = ::realpath(filename, NULL);
1323 if (p != NULL) {
1324 if (strlen(p) < outbuflen) {
1325 strcpy(outbuf, p);
1326 result = outbuf;
1327 } else {
1328 errno = ENAMETOOLONG;
1329 }
1330 ::free(p); // *not* os::free
1331 } else {
1332 // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
1333 // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
1334 // that it complains about the NULL we handed down as user buffer.
1335 // In this case, use the user provided buffer but at least check whether realpath caused
1336 // a memory overwrite.
1337 if (errno == EINVAL) {
1338 outbuf[outbuflen - 1] = '\0';
1339 p = ::realpath(filename, outbuf);
1340 if (p != NULL) {
1341 guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
1342 result = p;
1343 }
1344 }
1345 }
1346 return result;
1347
1348 }
1349
1350 int os::stat(const char *path, struct stat *sbuf) {
1351 return ::stat(path, sbuf);
1352 }
1353
1354 char * os::native_path(char *path) {
1355 return path;
1356 }
1357
1358 // Check minimum allowable stack sizes for thread creation and to initialize
1359 // the java system classes, including StackOverflowError - depends on page
1360 // size.
1361 // The space needed for frames during startup is platform dependent. It
1362 // depends on word size, platform calling conventions, C frame layout and
1363 // interpreter/C1/C2 design decisions. Therefore this is given in a
1364 // platform (os/cpu) dependent constant.
1365 // To this, space for guard mechanisms is added, which depends on the
1366 // page size which again depends on the concrete system the VM is running
1367 // on. Space for libc guard pages is not included in this size.
1368 jint os::Posix::set_minimum_stack_sizes() {
1369 size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
1370
1371 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
1372 JavaThread::stack_guard_zone_size() +
1373 JavaThread::stack_shadow_zone_size();
1374
1375 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
1376 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
1377
1378 size_t stack_size_in_bytes = ThreadStackSize * K;
1379 if (stack_size_in_bytes != 0 &&
1380 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1381 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1382 // ThreadStackSize so we go with "Java thread stack size" instead
1383 // of "ThreadStackSize" to be more friendly.
1384 tty->print_cr("\nThe Java thread stack size specified is too small. "
1385 "Specify at least " SIZE_FORMAT "k",
1386 _java_thread_min_stack_allowed / K);
1387 return JNI_ERR;
1388 }
1389
1390 // Make the stack size a multiple of the page size so that
1391 // the yellow/red zones can be guarded.
1392 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
1393
1394 // Reminder: a compiler thread is a Java thread.
1395 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
1396 JavaThread::stack_guard_zone_size() +
1397 JavaThread::stack_shadow_zone_size();
1398
1399 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
1400 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
1401
1402 stack_size_in_bytes = CompilerThreadStackSize * K;
1403 if (stack_size_in_bytes != 0 &&
1404 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1405 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1406 "Specify at least " SIZE_FORMAT "k",
1407 _compiler_thread_min_stack_allowed / K);
1408 return JNI_ERR;
1409 }
1410
1411 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1412 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
1413
1414 stack_size_in_bytes = VMThreadStackSize * K;
1415 if (stack_size_in_bytes != 0 &&
1416 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1417 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1418 "Specify at least " SIZE_FORMAT "k",
1419 _vm_internal_thread_min_stack_allowed / K);
1420 return JNI_ERR;
1421 }
1422 return JNI_OK;
1423 }
1424
1425 // Called when creating the thread. The minimum stack sizes have already been calculated
1426 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1427 size_t stack_size;
1428 if (req_stack_size == 0) {
1429 stack_size = default_stack_size(thr_type);
1430 } else {
1431 stack_size = req_stack_size;
1432 }
1433
1434 switch (thr_type) {
1435 case os::java_thread:
1436 // Java threads use ThreadStackSize which default value can be
1437 // changed with the flag -Xss
1438 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1439 // no requested size and we have a more specific default value
1440 stack_size = JavaThread::stack_size_at_create();
1441 }
1442 stack_size = MAX2(stack_size,
1443 _java_thread_min_stack_allowed);
1444 break;
1445 case os::compiler_thread:
1446 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1447 // no requested size and we have a more specific default value
1448 stack_size = (size_t)(CompilerThreadStackSize * K);
1449 }
1450 stack_size = MAX2(stack_size,
1451 _compiler_thread_min_stack_allowed);
1452 break;
1453 case os::vm_thread:
1454 case os::pgc_thread:
1455 case os::cgc_thread:
1456 case os::watcher_thread:
1457 default: // presume the unknown thr_type is a VM internal
1458 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1459 // no requested size and we have a more specific default value
1460 stack_size = (size_t)(VMThreadStackSize * K);
1461 }
1462
1463 stack_size = MAX2(stack_size,
1464 _vm_internal_thread_min_stack_allowed);
1465 break;
1466 }
1467
1468 // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
1469 // Be careful not to round up to 0. Align down in that case.
1470 if (stack_size <= SIZE_MAX - vm_page_size()) {
1471 stack_size = align_up(stack_size, vm_page_size());
1472 } else {
1473 stack_size = align_down(stack_size, vm_page_size());
1474 }
1475
1476 return stack_size;
1477 }
1478
1479 bool os::Posix::is_root(uid_t uid){
1480 return ROOT_UID == uid;
1481 }
1482
1483 bool os::Posix::matches_effective_uid_or_root(uid_t uid) {
1484 return is_root(uid) || geteuid() == uid;
1485 }
1486
1487 bool os::Posix::matches_effective_uid_and_gid_or_root(uid_t uid, gid_t gid) {
1488 return is_root(uid) || (geteuid() == uid && getegid() == gid);
1489 }
1490
1491 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
1492 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
1493 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
1494
1495 os::ThreadCrashProtection::ThreadCrashProtection() {
1496 }
1497
1498 /*
1499 * See the caveats for this class in os_posix.hpp
1500 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1501 * method and returns false. If none of the signals are raised, returns true.
1502 * The callback is supposed to provide the method that should be protected.
1503 */
1504 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1505 sigset_t saved_sig_mask;
1506
1507 Thread::muxAcquire(&_crash_mux, "CrashProtection");
1508
1509 _protected_thread = Thread::current_or_null();
1510 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
1511
1512 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1513 // since on at least some systems (OS X) siglongjmp will restore the mask
1514 // for the process, not the thread
1515 pthread_sigmask(0, NULL, &saved_sig_mask);
1516 if (sigsetjmp(_jmpbuf, 0) == 0) {
1517 // make sure we can see in the signal handler that we have crash protection
1518 // installed
1519 _crash_protection = this;
1520 cb.call();
1521 // and clear the crash protection
1522 _crash_protection = NULL;
1523 _protected_thread = NULL;
1524 Thread::muxRelease(&_crash_mux);
1525 return true;
1526 }
1527 // this happens when we siglongjmp() back
1528 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1529 _crash_protection = NULL;
1530 _protected_thread = NULL;
1531 Thread::muxRelease(&_crash_mux);
1532 return false;
1533 }
1534
1535 void os::ThreadCrashProtection::restore() {
1536 assert(_crash_protection != NULL, "must have crash protection");
1537 siglongjmp(_jmpbuf, 1);
1538 }
1539
1540 void os::ThreadCrashProtection::check_crash_protection(int sig,
1541 Thread* thread) {
1542
1543 if (thread != NULL &&
1544 thread == _protected_thread &&
1545 _crash_protection != NULL) {
1546
1547 if (sig == SIGSEGV || sig == SIGBUS) {
1548 _crash_protection->restore();
1549 }
1550 }
1551 }
1552
1553
1554 // Shared pthread_mutex/cond based PlatformEvent implementation.
1555 // Not currently usable by Solaris.
1556
1557 #ifndef SOLARIS
1558
1559 // Shared condattr object for use with relative timed-waits. Will be associated
1560 // with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
1561 // but otherwise whatever default is used by the platform - generally the
1562 // time-of-day clock.
1563 static pthread_condattr_t _condAttr[1];
1564
1565 // Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
1566 // all systems (e.g. FreeBSD) map the default to "normal".
1567 static pthread_mutexattr_t _mutexAttr[1];
1568
1569 // common basic initialization that is always supported
1570 static void pthread_init_common(void) {
1571 int status;
1572 if ((status = pthread_condattr_init(_condAttr)) != 0) {
1573 fatal("pthread_condattr_init: %s", os::strerror(status));
1574 }
1575 if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
1576 fatal("pthread_mutexattr_init: %s", os::strerror(status));
1577 }
1578 if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
1579 fatal("pthread_mutexattr_settype: %s", os::strerror(status));
1580 }
1581 }
1582
1583 // Not all POSIX types and API's are available on all notionally "posix"
1584 // platforms. If we have build-time support then we will check for actual
1585 // runtime support via dlopen/dlsym lookup. This allows for running on an
1586 // older OS version compared to the build platform. But if there is no
1587 // build time support then there cannot be any runtime support as we do not
1588 // know what the runtime types would be (for example clockid_t might be an
1589 // int or int64_t).
1590 //
1591 #ifdef SUPPORTS_CLOCK_MONOTONIC
1592
1593 // This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
1594
1595 static int (*_clock_gettime)(clockid_t, struct timespec *);
1596 static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t);
1597
1598 static bool _use_clock_monotonic_condattr;
1599
1600 // Determine what POSIX API's are present and do appropriate
1601 // configuration.
1602 void os::Posix::init(void) {
1603
1604 // NOTE: no logging available when this is called. Put logging
1605 // statements in init_2().
1606
1607 // Copied from os::Linux::clock_init(). The duplication is temporary.
1608
1609 // 1. Check for CLOCK_MONOTONIC support.
1610
1611 void* handle = NULL;
1612
1613 // For linux we need librt, for other OS we can find
1614 // this function in regular libc.
1615 #ifdef NEEDS_LIBRT
1616 // We do dlopen's in this particular order due to bug in linux
1617 // dynamic loader (see 6348968) leading to crash on exit.
1618 handle = dlopen("librt.so.1", RTLD_LAZY);
1619 if (handle == NULL) {
1620 handle = dlopen("librt.so", RTLD_LAZY);
1621 }
1622 #endif
1623
1624 if (handle == NULL) {
1625 handle = RTLD_DEFAULT;
1626 }
1627
1628 _clock_gettime = NULL;
1629
1630 int (*clock_getres_func)(clockid_t, struct timespec*) =
1631 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1632 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1633 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1634 if (clock_getres_func != NULL && clock_gettime_func != NULL) {
1635 // We assume that if both clock_gettime and clock_getres support
1636 // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
1637 struct timespec res;
1638 struct timespec tp;
1639 if (clock_getres_func(CLOCK_MONOTONIC, &res) == 0 &&
1640 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1641 // Yes, monotonic clock is supported.
1642 _clock_gettime = clock_gettime_func;
1643 } else {
1644 #ifdef NEEDS_LIBRT
1645 // Close librt if there is no monotonic clock.
1646 if (handle != RTLD_DEFAULT) {
1647 dlclose(handle);
1648 }
1649 #endif
1650 }
1651 }
1652
1653 // 2. Check for pthread_condattr_setclock support.
1654
1655 _pthread_condattr_setclock = NULL;
1656
1657 // libpthread is already loaded.
1658 int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
1659 (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
1660 "pthread_condattr_setclock");
1661 if (condattr_setclock_func != NULL) {
1662 _pthread_condattr_setclock = condattr_setclock_func;
1663 }
1664
1665 // Now do general initialization.
1666
1667 pthread_init_common();
1668
1669 int status;
1670 if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
1671 if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
1672 if (status == EINVAL) {
1673 _use_clock_monotonic_condattr = false;
1674 warning("Unable to use monotonic clock with relative timed-waits" \
1675 " - changes to the time-of-day clock may have adverse affects");
1676 } else {
1677 fatal("pthread_condattr_setclock: %s", os::strerror(status));
1678 }
1679 } else {
1680 _use_clock_monotonic_condattr = true;
1681 }
1682 } else {
1683 _use_clock_monotonic_condattr = false;
1684 }
1685 }
1686
1687 void os::Posix::init_2(void) {
1688 log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
1689 (_clock_gettime != NULL ? "" : " not"));
1690 log_info(os)("Use of pthread_condattr_setclock is%s supported",
1691 (_pthread_condattr_setclock != NULL ? "" : " not"));
1692 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
1693 _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
1694 }
1695
1696 #else // !SUPPORTS_CLOCK_MONOTONIC
1697
1698 void os::Posix::init(void) {
1699 pthread_init_common();
1700 }
1701
1702 void os::Posix::init_2(void) {
1703 log_info(os)("Use of CLOCK_MONOTONIC is not supported");
1704 log_info(os)("Use of pthread_condattr_setclock is not supported");
1705 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
1706 }
1707
1708 #endif // SUPPORTS_CLOCK_MONOTONIC
1709
1710 os::PlatformEvent::PlatformEvent() {
1711 int status = pthread_cond_init(_cond, _condAttr);
1712 assert_status(status == 0, status, "cond_init");
1713 status = pthread_mutex_init(_mutex, _mutexAttr);
1714 assert_status(status == 0, status, "mutex_init");
1715 _event = 0;
1716 _nParked = 0;
1717 }
1718
1719 // Utility to convert the given timeout to an absolute timespec
1720 // (based on the appropriate clock) to use with pthread_cond_timewait.
1721 // The clock queried here must be the clock used to manage the
1722 // timeout of the condition variable.
1723 //
1724 // The passed in timeout value is either a relative time in nanoseconds
1725 // or an absolute time in milliseconds. A relative timeout will be
1726 // associated with CLOCK_MONOTONIC if available; otherwise, or if absolute,
1727 // the default time-of-day clock will be used.
1728
1729 // Given time is a 64-bit value and the time_t used in the timespec is
1730 // sometimes a signed-32-bit value we have to watch for overflow if times
1731 // way in the future are given. Further on Solaris versions
1732 // prior to 10 there is a restriction (see cond_timedwait) that the specified
1733 // number of seconds, in abstime, is less than current_time + 100000000.
1734 // As it will be over 20 years before "now + 100000000" will overflow we can
1735 // ignore overflow and just impose a hard-limit on seconds using the value
1736 // of "now + 100000000". This places a limit on the timeout of about 3.17
1737 // years from "now".
1738 //
1739 #define MAX_SECS 100000000
1740
1741 // Calculate a new absolute time that is "timeout" nanoseconds from "now".
1742 // "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
1743 // on which clock is being used).
1744 static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
1745 jlong now_part_sec, jlong unit) {
1746 time_t max_secs = now_sec + MAX_SECS;
1747
1748 jlong seconds = timeout / NANOUNITS;
1749 timeout %= NANOUNITS; // remaining nanos
1750
1751 if (seconds >= MAX_SECS) {
1752 // More seconds than we can add, so pin to max_secs.
1753 abstime->tv_sec = max_secs;
1754 abstime->tv_nsec = 0;
1755 } else {
1756 abstime->tv_sec = now_sec + seconds;
1757 long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
1758 if (nanos >= NANOUNITS) { // overflow
1759 abstime->tv_sec += 1;
1760 nanos -= NANOUNITS;
1761 }
1762 abstime->tv_nsec = nanos;
1763 }
1764 }
1765
1766 // Unpack the given deadline in milliseconds since the epoch, into the given timespec.
1767 // The current time in seconds is also passed in to enforce an upper bound as discussed above.
1768 static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
1769 time_t max_secs = now_sec + MAX_SECS;
1770
1771 jlong seconds = deadline / MILLIUNITS;
1772 jlong millis = deadline % MILLIUNITS;
1773
1774 if (seconds >= max_secs) {
1775 // Absolute seconds exceeds allowed max, so pin to max_secs.
1776 abstime->tv_sec = max_secs;
1777 abstime->tv_nsec = 0;
1778 } else {
1779 abstime->tv_sec = seconds;
1780 abstime->tv_nsec = millis * (NANOUNITS / MILLIUNITS);
1781 }
1782 }
1783
1784 static void to_abstime(timespec* abstime, jlong timeout, bool isAbsolute) {
1785 DEBUG_ONLY(int max_secs = MAX_SECS;)
1786
1787 if (timeout < 0) {
1788 timeout = 0;
1789 }
1790
1791 #ifdef SUPPORTS_CLOCK_MONOTONIC
1792
1793 if (_use_clock_monotonic_condattr && !isAbsolute) {
1794 struct timespec now;
1795 int status = _clock_gettime(CLOCK_MONOTONIC, &now);
1796 assert_status(status == 0, status, "clock_gettime");
1797 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
1798 DEBUG_ONLY(max_secs += now.tv_sec;)
1799 } else {
1800
1801 #else
1802
1803 { // Match the block scope.
1804
1805 #endif // SUPPORTS_CLOCK_MONOTONIC
1806
1807 // Time-of-day clock is all we can reliably use.
1808 struct timeval now;
1809 int status = gettimeofday(&now, NULL);
1810 assert_status(status == 0, errno, "gettimeofday");
1811 if (isAbsolute) {
1812 unpack_abs_time(abstime, timeout, now.tv_sec);
1813 } else {
1814 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
1815 }
1816 DEBUG_ONLY(max_secs += now.tv_sec;)
1817 }
1818
1819 assert(abstime->tv_sec >= 0, "tv_sec < 0");
1820 assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
1821 assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
1822 assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
1823 }
1824
1825 // PlatformEvent
1826 //
1827 // Assumption:
1828 // Only one parker can exist on an event, which is why we allocate
1829 // them per-thread. Multiple unparkers can coexist.
1830 //
1831 // _event serves as a restricted-range semaphore.
1832 // -1 : thread is blocked, i.e. there is a waiter
1833 // 0 : neutral: thread is running or ready,
1834 // could have been signaled after a wait started
1835 // 1 : signaled - thread is running or ready
1836 //
1837 // Having three states allows for some detection of bad usage - see
1838 // comments on unpark().
1839
1840 void os::PlatformEvent::park() { // AKA "down()"
1841 // Transitions for _event:
1842 // -1 => -1 : illegal
1843 // 1 => 0 : pass - return immediately
1844 // 0 => -1 : block; then set _event to 0 before returning
1845
1846 // Invariant: Only the thread associated with the PlatformEvent
1847 // may call park().
1848 assert(_nParked == 0, "invariant");
1849
1850 int v;
1851
1852 // atomically decrement _event
1853 for (;;) {
1854 v = _event;
1855 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1856 }
1857 guarantee(v >= 0, "invariant");
1858
1859 if (v == 0) { // Do this the hard way by blocking ...
1860 int status = pthread_mutex_lock(_mutex);
1861 assert_status(status == 0, status, "mutex_lock");
1862 guarantee(_nParked == 0, "invariant");
1863 ++_nParked;
1864 while (_event < 0) {
1865 // OS-level "spurious wakeups" are ignored
1866 status = pthread_cond_wait(_cond, _mutex);
1867 assert_status(status == 0, status, "cond_wait");
1868 }
1869 --_nParked;
1870
1871 _event = 0;
1872 status = pthread_mutex_unlock(_mutex);
1873 assert_status(status == 0, status, "mutex_unlock");
1874 // Paranoia to ensure our locked and lock-free paths interact
1875 // correctly with each other.
1876 OrderAccess::fence();
1877 }
1878 guarantee(_event >= 0, "invariant");
1879 }
1880
1881 int os::PlatformEvent::park(jlong millis) {
1882 // Transitions for _event:
1883 // -1 => -1 : illegal
1884 // 1 => 0 : pass - return immediately
1885 // 0 => -1 : block; then set _event to 0 before returning
1886
1887 // Invariant: Only the thread associated with the Event/PlatformEvent
1888 // may call park().
1889 assert(_nParked == 0, "invariant");
1890
1891 int v;
1892 // atomically decrement _event
1893 for (;;) {
1894 v = _event;
1895 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1896 }
1897 guarantee(v >= 0, "invariant");
1898
1899 if (v == 0) { // Do this the hard way by blocking ...
1900 struct timespec abst;
1901 // We have to watch for overflow when converting millis to nanos,
1902 // but if millis is that large then we will end up limiting to
1903 // MAX_SECS anyway, so just do that here.
1904 if (millis / MILLIUNITS > MAX_SECS) {
1905 millis = jlong(MAX_SECS) * MILLIUNITS;
1906 }
1907 to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false);
1908
1909 int ret = OS_TIMEOUT;
1910 int status = pthread_mutex_lock(_mutex);
1911 assert_status(status == 0, status, "mutex_lock");
1912 guarantee(_nParked == 0, "invariant");
1913 ++_nParked;
1914
1915 while (_event < 0) {
1916 status = pthread_cond_timedwait(_cond, _mutex, &abst);
1917 assert_status(status == 0 || status == ETIMEDOUT,
1918 status, "cond_timedwait");
1919 // OS-level "spurious wakeups" are ignored unless the archaic
1920 // FilterSpuriousWakeups is set false. That flag should be obsoleted.
1921 if (!FilterSpuriousWakeups) break;
1922 if (status == ETIMEDOUT) break;
1923 }
1924 --_nParked;
1925
1926 if (_event >= 0) {
1927 ret = OS_OK;
1928 }
1929
1930 _event = 0;
1931 status = pthread_mutex_unlock(_mutex);
1932 assert_status(status == 0, status, "mutex_unlock");
1933 // Paranoia to ensure our locked and lock-free paths interact
1934 // correctly with each other.
1935 OrderAccess::fence();
1936 return ret;
1937 }
1938 return OS_OK;
1939 }
1940
1941 void os::PlatformEvent::unpark() {
1942 // Transitions for _event:
1943 // 0 => 1 : just return
1944 // 1 => 1 : just return
1945 // -1 => either 0 or 1; must signal target thread
1946 // That is, we can safely transition _event from -1 to either
1947 // 0 or 1.
1948 // See also: "Semaphores in Plan 9" by Mullender & Cox
1949 //
1950 // Note: Forcing a transition from "-1" to "1" on an unpark() means
1951 // that it will take two back-to-back park() calls for the owning
1952 // thread to block. This has the benefit of forcing a spurious return
1953 // from the first park() call after an unpark() call which will help
1954 // shake out uses of park() and unpark() without checking state conditions
1955 // properly. This spurious return doesn't manifest itself in any user code
1956 // but only in the correctly written condition checking loops of ObjectMonitor,
1957 // Mutex/Monitor, Thread::muxAcquire and os::sleep
1958
1959 if (Atomic::xchg(1, &_event) >= 0) return;
1960
1961 int status = pthread_mutex_lock(_mutex);
1962 assert_status(status == 0, status, "mutex_lock");
1963 int anyWaiters = _nParked;
1964 assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
1965 status = pthread_mutex_unlock(_mutex);
1966 assert_status(status == 0, status, "mutex_unlock");
1967
1968 // Note that we signal() *after* dropping the lock for "immortal" Events.
1969 // This is safe and avoids a common class of futile wakeups. In rare
1970 // circumstances this can cause a thread to return prematurely from
1971 // cond_{timed}wait() but the spurious wakeup is benign and the victim
1972 // will simply re-test the condition and re-park itself.
1973 // This provides particular benefit if the underlying platform does not
1974 // provide wait morphing.
1975
1976 if (anyWaiters != 0) {
1977 status = pthread_cond_signal(_cond);
1978 assert_status(status == 0, status, "cond_signal");
1979 }
1980 }
1981
1982 // JSR166 support
1983
1984 os::PlatformParker::PlatformParker() {
1985 int status;
1986 status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
1987 assert_status(status == 0, status, "cond_init rel");
1988 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
1989 assert_status(status == 0, status, "cond_init abs");
1990 status = pthread_mutex_init(_mutex, _mutexAttr);
1991 assert_status(status == 0, status, "mutex_init");
1992 _cur_index = -1; // mark as unused
1993 }
1994
1995 // Parker::park decrements count if > 0, else does a condvar wait. Unpark
1996 // sets count to 1 and signals condvar. Only one thread ever waits
1997 // on the condvar. Contention seen when trying to park implies that someone
1998 // is unparking you, so don't wait. And spurious returns are fine, so there
1999 // is no need to track notifications.
2000
2001 void Parker::park(bool isAbsolute, jlong time) {
2002
2003 // Optional fast-path check:
2004 // Return immediately if a permit is available.
2005 // We depend on Atomic::xchg() having full barrier semantics
2006 // since we are doing a lock-free update to _counter.
2007 if (Atomic::xchg(0, &_counter) > 0) return;
2008
2009 Thread* thread = Thread::current();
2010 assert(thread->is_Java_thread(), "Must be JavaThread");
2011 JavaThread *jt = (JavaThread *)thread;
2012
2013 // Optional optimization -- avoid state transitions if there's
2014 // an interrupt pending.
2015 if (Thread::is_interrupted(thread, false)) {
2016 return;
2017 }
2018
2019 // Next, demultiplex/decode time arguments
2020 struct timespec absTime;
2021 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
2022 return;
2023 }
2024 if (time > 0) {
2025 to_abstime(&absTime, time, isAbsolute);
2026 }
2027
2028 // Enter safepoint region
2029 // Beware of deadlocks such as 6317397.
2030 // The per-thread Parker:: mutex is a classic leaf-lock.
2031 // In particular a thread must never block on the Threads_lock while
2032 // holding the Parker:: mutex. If safepoints are pending both the
2033 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
2034 ThreadBlockInVM tbivm(jt);
2035
2036 // Don't wait if cannot get lock since interference arises from
2037 // unparking. Also re-check interrupt before trying wait.
2038 if (Thread::is_interrupted(thread, false) ||
2039 pthread_mutex_trylock(_mutex) != 0) {
2040 return;
2041 }
2042
2043 int status;
2044 if (_counter > 0) { // no wait needed
2045 _counter = 0;
2046 status = pthread_mutex_unlock(_mutex);
2047 assert_status(status == 0, status, "invariant");
2048 // Paranoia to ensure our locked and lock-free paths interact
2049 // correctly with each other and Java-level accesses.
2050 OrderAccess::fence();
2051 return;
2052 }
2053
2054 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2055 jt->set_suspend_equivalent();
2056 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2057
2058 assert(_cur_index == -1, "invariant");
2059 if (time == 0) {
2060 _cur_index = REL_INDEX; // arbitrary choice when not timed
2061 status = pthread_cond_wait(&_cond[_cur_index], _mutex);
2062 assert_status(status == 0, status, "cond_timedwait");
2063 }
2064 else {
2065 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
2066 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
2067 assert_status(status == 0 || status == ETIMEDOUT,
2068 status, "cond_timedwait");
2069 }
2070 _cur_index = -1;
2071
2072 _counter = 0;
2073 status = pthread_mutex_unlock(_mutex);
2074 assert_status(status == 0, status, "invariant");
2075 // Paranoia to ensure our locked and lock-free paths interact
2076 // correctly with each other and Java-level accesses.
2077 OrderAccess::fence();
2078
2079 // If externally suspended while waiting, re-suspend
2080 if (jt->handle_special_suspend_equivalent_condition()) {
2081 jt->java_suspend_self();
2082 }
2083 }
2084
2085 void Parker::unpark() {
2086 int status = pthread_mutex_lock(_mutex);
2087 assert_status(status == 0, status, "invariant");
2088 const int s = _counter;
2089 _counter = 1;
2090 // must capture correct index before unlocking
2091 int index = _cur_index;
2092 status = pthread_mutex_unlock(_mutex);
2093 assert_status(status == 0, status, "invariant");
2094
2095 // Note that we signal() *after* dropping the lock for "immortal" Events.
2096 // This is safe and avoids a common class of futile wakeups. In rare
2097 // circumstances this can cause a thread to return prematurely from
2098 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2099 // will simply re-test the condition and re-park itself.
2100 // This provides particular benefit if the underlying platform does not
2101 // provide wait morphing.
2102
2103 if (s < 1 && index != -1) {
2104 // thread is definitely parked
2105 status = pthread_cond_signal(&_cond[index]);
2106 assert_status(status == 0, status, "invariant");
2107 }
2108 }
2109
2110
2111 #endif // !SOLARIS