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 <grp.h>
40 #include <pwd.h>
41 #include <pthread.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 #define ROOT_UID 0
57
58 #ifndef MAP_ANONYMOUS
59 #define MAP_ANONYMOUS MAP_ANON
60 #endif
61
62 #define check_with_errno(check_type, cond, msg) \
63 do { \
64 int err = errno; \
65 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
66 os::errno_name(err)); \
67 } while (false)
68
69 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
70 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
71
72 // Check core dump limit and report possible place where core can be found
73 void os::check_dump_limit(char* buffer, size_t bufferSize) {
74 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
75 jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
76 VMError::record_coredump_status(buffer, false);
77 return;
78 }
79
80 int n;
81 struct rlimit rlim;
82 bool success;
83
84 char core_path[PATH_MAX];
85 n = get_core_path(core_path, PATH_MAX);
86
87 if (n <= 0) {
88 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
89 success = true;
90 #ifdef LINUX
91 } else if (core_path[0] == '"') { // redirect to user process
92 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
93 success = true;
94 #endif
95 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
96 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
97 success = true;
98 } else {
99 switch(rlim.rlim_cur) {
100 case RLIM_INFINITY:
101 jio_snprintf(buffer, bufferSize, "%s", core_path);
102 success = true;
103 break;
104 case 0:
105 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
106 success = false;
107 break;
108 default:
109 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);
110 success = true;
111 break;
112 }
113 }
114
115 VMError::record_coredump_status(buffer, success);
116 }
117
118 int os::get_native_stack(address* stack, int frames, int toSkip) {
119 int frame_idx = 0;
120 int num_of_frames; // number of frames captured
121 frame fr = os::current_frame();
122 while (fr.pc() && frame_idx < frames) {
123 if (toSkip > 0) {
124 toSkip --;
125 } else {
126 stack[frame_idx ++] = fr.pc();
127 }
128 if (fr.fp() == NULL || fr.cb() != NULL ||
129 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
130
131 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
132 fr = os::get_sender_for_C_frame(&fr);
133 } else {
134 break;
135 }
136 }
137 num_of_frames = frame_idx;
138 for (; frame_idx < frames; frame_idx ++) {
139 stack[frame_idx] = NULL;
140 }
141
142 return num_of_frames;
143 }
144
145
146 bool os::unsetenv(const char* name) {
147 assert(name != NULL, "Null pointer");
148 return (::unsetenv(name) == 0);
149 }
150
151 int os::get_last_error() {
152 return errno;
153 }
154
155 bool os::is_debugger_attached() {
156 // not implemented
157 return false;
158 }
159
160 void os::wait_for_keypress_at_exit(void) {
161 // don't do anything on posix platforms
162 return;
163 }
164
165 int os::create_file_for_heap(const char* dir) {
166
167 const char name_template[] = "/jvmheap.XXXXXX";
168
169 char *fullname = (char*)os::malloc((strlen(dir) + strlen(name_template) + 1), mtInternal);
170 if (fullname == NULL) {
171 vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
172 return -1;
173 }
174 (void)strncpy(fullname, dir, strlen(dir)+1);
175 (void)strncat(fullname, name_template, strlen(name_template));
176
177 os::native_path(fullname);
178
179 sigset_t set, oldset;
180 int ret = sigfillset(&set);
181 assert_with_errno(ret == 0, "sigfillset returned error");
182
183 // set the file creation mask.
184 mode_t file_mode = S_IRUSR | S_IWUSR;
185
186 // create a new file.
187 int fd = mkstemp(fullname);
188
189 if (fd < 0) {
190 warning("Could not create file for heap with template %s", fullname);
191 os::free(fullname);
192 return -1;
193 }
194
195 // delete the name from the filesystem. When 'fd' is closed, the file (and space) will be deleted.
196 ret = unlink(fullname);
197 assert_with_errno(ret == 0, "unlink returned error");
198
199 os::free(fullname);
200 return fd;
201 }
202
203 static char* reserve_mmapped_memory(size_t bytes, char* requested_addr) {
204 char * addr;
205 int flags = MAP_PRIVATE NOT_AIX( | MAP_NORESERVE ) | MAP_ANONYMOUS;
206 if (requested_addr != NULL) {
207 assert((uintptr_t)requested_addr % os::vm_page_size() == 0, "Requested address should be aligned to OS page size");
208 flags |= MAP_FIXED;
209 }
210
211 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
212 // touch an uncommitted page. Otherwise, the read/write might
213 // succeed if we have enough swap space to back the physical page.
214 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
215 flags, -1, 0);
216
217 if (addr != MAP_FAILED) {
218 MemTracker::record_virtual_memory_reserve((address)addr, bytes, CALLER_PC);
219 return addr;
220 }
221 return NULL;
222 }
223
224 static int util_posix_fallocate(int fd, off_t offset, off_t len) {
225 #ifdef __APPLE__
226 fstore_t store = { F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, len };
227 // First we try to get a continuous chunk of disk space
228 int ret = fcntl(fd, F_PREALLOCATE, &store);
229 if (ret == -1) {
230 // Maybe we are too fragmented, try to allocate non-continuous range
231 store.fst_flags = F_ALLOCATEALL;
232 ret = fcntl(fd, F_PREALLOCATE, &store);
233 }
234 if(ret != -1) {
235 return ftruncate(fd, len);
236 }
237 return -1;
238 #else
239 return posix_fallocate(fd, offset, len);
240 #endif
241 }
242
243 // Map the given address range to the provided file descriptor.
244 char* os::map_memory_to_file(char* base, size_t size, int fd) {
245 assert(fd != -1, "File descriptor is not valid");
246
247 // allocate space for the file
248 int ret = util_posix_fallocate(fd, 0, (off_t)size);
249 if (ret != 0) {
250 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory. error(%d)", ret));
251 return NULL;
252 }
253
254 int prot = PROT_READ | PROT_WRITE;
255 int flags = MAP_SHARED;
256 if (base != NULL) {
257 flags |= MAP_FIXED;
258 }
259 char* addr = (char*)mmap(base, size, prot, flags, fd, 0);
260
261 if (addr == MAP_FAILED) {
262 warning("Failed mmap to file. (%s)", os::strerror(errno));
263 return NULL;
264 }
265 if (base != NULL && addr != base) {
266 if (!os::release_memory(addr, size)) {
267 warning("Could not release memory on unsuccessful file mapping");
268 }
269 return NULL;
270 }
271 return addr;
272 }
273
274 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
275 assert(fd != -1, "File descriptor is not valid");
276 assert(base != NULL, "Base cannot be NULL");
277
278 return map_memory_to_file(base, size, fd);
279 }
280
281 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
282 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
283 // rather than unmapping and remapping the whole chunk to get requested alignment.
284 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
285 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
286 "Alignment must be a multiple of allocation granularity (page size)");
287 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
288
289 size_t extra_size = size + alignment;
290 assert(extra_size >= size, "overflow, size is too large to allow alignment");
291
292 char* extra_base;
293 if (file_desc != -1) {
294 // For file mapping, we do not call os:reserve_memory(extra_size, NULL, alignment, file_desc) because
295 // we need to deal with shrinking of the file space later when we release extra memory after alignment.
296 // We also cannot called os:reserve_memory() with file_desc set to -1 because on aix we might get SHM memory.
297 // So here to call a helper function while reserve memory for us. After we have a aligned base,
298 // we will replace anonymous mapping with file mapping.
299 extra_base = reserve_mmapped_memory(extra_size, NULL);
300 if (extra_base != NULL) {
301 MemTracker::record_virtual_memory_reserve((address)extra_base, extra_size, CALLER_PC);
302 }
303 } else {
304 extra_base = os::reserve_memory(extra_size, NULL, alignment);
305 }
306
307 if (extra_base == NULL) {
308 return NULL;
309 }
310
311 // Do manual alignment
312 char* aligned_base = align_up(extra_base, alignment);
313
314 // [ | | ]
315 // ^ extra_base
316 // ^ extra_base + begin_offset == aligned_base
317 // extra_base + begin_offset + size ^
318 // extra_base + extra_size ^
319 // |<>| == begin_offset
320 // end_offset == |<>|
321 size_t begin_offset = aligned_base - extra_base;
322 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
323
324 if (begin_offset > 0) {
325 os::release_memory(extra_base, begin_offset);
326 }
327
328 if (end_offset > 0) {
329 os::release_memory(extra_base + begin_offset + size, end_offset);
330 }
331
332 if (file_desc != -1) {
333 // After we have an aligned address, we can replace anonymous mapping with file mapping
334 if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
335 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
336 }
337 MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
338 }
339 return aligned_base;
340 }
341
342 int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
343 // All supported POSIX platforms provide C99 semantics.
344 int result = ::vsnprintf(buf, len, fmt, args);
345 // If an encoding error occurred (result < 0) then it's not clear
346 // whether the buffer is NUL terminated, so ensure it is.
347 if ((result < 0) && (len > 0)) {
348 buf[len - 1] = '\0';
349 }
350 return result;
351 }
352
353 int os::get_fileno(FILE* fp) {
354 return NOT_AIX(::)fileno(fp);
355 }
356
357 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
358 return gmtime_r(clock, res);
359 }
360
361 void os::Posix::print_load_average(outputStream* st) {
362 st->print("load average:");
363 double loadavg[3];
364 os::loadavg(loadavg, 3);
365 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
366 st->cr();
367 }
368
369 void os::Posix::print_rlimit_info(outputStream* st) {
370 st->print("rlimit:");
371 struct rlimit rlim;
372
373 st->print(" STACK ");
374 getrlimit(RLIMIT_STACK, &rlim);
375 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
376 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
377
378 st->print(", CORE ");
379 getrlimit(RLIMIT_CORE, &rlim);
380 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
381 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
382
383 // Isn't there on solaris
384 #if defined(AIX)
385 st->print(", NPROC ");
386 st->print("%d", sysconf(_SC_CHILD_MAX));
387 #elif !defined(SOLARIS)
388 st->print(", NPROC ");
389 getrlimit(RLIMIT_NPROC, &rlim);
390 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
391 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
392 #endif
393
394 st->print(", NOFILE ");
395 getrlimit(RLIMIT_NOFILE, &rlim);
396 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
397 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
398
399 st->print(", AS ");
400 getrlimit(RLIMIT_AS, &rlim);
401 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
402 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
403
404 st->print(", DATA ");
405 getrlimit(RLIMIT_DATA, &rlim);
406 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
407 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
408
409 st->print(", FSIZE ");
410 getrlimit(RLIMIT_FSIZE, &rlim);
411 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
412 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
413
414 st->cr();
415 }
416
417 void os::Posix::print_uname_info(outputStream* st) {
418 // kernel
419 st->print("uname:");
420 struct utsname name;
421 uname(&name);
422 st->print("%s ", name.sysname);
423 #ifdef ASSERT
424 st->print("%s ", name.nodename);
425 #endif
426 st->print("%s ", name.release);
427 st->print("%s ", name.version);
428 st->print("%s", name.machine);
429 st->cr();
430 }
431
432 void os::Posix::print_umask(outputStream* st, mode_t umsk) {
433 st->print((umsk & S_IRUSR) ? "r" : "-");
434 st->print((umsk & S_IWUSR) ? "w" : "-");
435 st->print((umsk & S_IXUSR) ? "x" : "-");
436 st->print((umsk & S_IRGRP) ? "r" : "-");
437 st->print((umsk & S_IWGRP) ? "w" : "-");
438 st->print((umsk & S_IXGRP) ? "x" : "-");
439 st->print((umsk & S_IROTH) ? "r" : "-");
440 st->print((umsk & S_IWOTH) ? "w" : "-");
441 st->print((umsk & S_IXOTH) ? "x" : "-");
442 }
443
444 void os::Posix::print_user_info(outputStream* st) {
445 unsigned id = (unsigned) ::getuid();
446 st->print("uid : %u ", id);
447 id = (unsigned) ::geteuid();
448 st->print("euid : %u ", id);
449 id = (unsigned) ::getgid();
450 st->print("gid : %u ", id);
451 id = (unsigned) ::getegid();
452 st->print_cr("egid : %u", id);
453 st->cr();
454
455 mode_t umsk = ::umask(0);
456 ::umask(umsk);
457 st->print("umask: %04o (", (unsigned) umsk);
458 print_umask(st, umsk);
459 st->print_cr(")");
460 st->cr();
461 }
462
463
464 bool os::get_host_name(char* buf, size_t buflen) {
465 struct utsname name;
466 uname(&name);
467 jio_snprintf(buf, buflen, "%s", name.nodename);
468 return true;
469 }
470
471 bool os::has_allocatable_memory_limit(julong* limit) {
472 struct rlimit rlim;
473 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
474 // if there was an error when calling getrlimit, assume that there is no limitation
475 // on virtual memory.
476 bool result;
477 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
478 result = false;
479 } else {
480 *limit = (julong)rlim.rlim_cur;
481 result = true;
482 }
483 #ifdef _LP64
484 return result;
485 #else
486 // arbitrary virtual space limit for 32 bit Unices found by testing. If
487 // getrlimit above returned a limit, bound it with this limit. Otherwise
488 // directly use it.
489 const julong max_virtual_limit = (julong)3800*M;
490 if (result) {
491 *limit = MIN2(*limit, max_virtual_limit);
492 } else {
493 *limit = max_virtual_limit;
494 }
495
496 // bound by actually allocatable memory. The algorithm uses two bounds, an
497 // upper and a lower limit. The upper limit is the current highest amount of
498 // memory that could not be allocated, the lower limit is the current highest
499 // amount of memory that could be allocated.
500 // The algorithm iteratively refines the result by halving the difference
501 // between these limits, updating either the upper limit (if that value could
502 // not be allocated) or the lower limit (if the that value could be allocated)
503 // until the difference between these limits is "small".
504
505 // the minimum amount of memory we care about allocating.
506 const julong min_allocation_size = M;
507
508 julong upper_limit = *limit;
509
510 // first check a few trivial cases
511 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
512 *limit = upper_limit;
513 } else if (!is_allocatable(min_allocation_size)) {
514 // we found that not even min_allocation_size is allocatable. Return it
515 // anyway. There is no point to search for a better value any more.
516 *limit = min_allocation_size;
517 } else {
518 // perform the binary search.
519 julong lower_limit = min_allocation_size;
520 while ((upper_limit - lower_limit) > min_allocation_size) {
521 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
522 temp_limit = align_down(temp_limit, min_allocation_size);
523 if (is_allocatable(temp_limit)) {
524 lower_limit = temp_limit;
525 } else {
526 upper_limit = temp_limit;
527 }
528 }
529 *limit = lower_limit;
530 }
531 return true;
532 #endif
533 }
534
535 const char* os::get_current_directory(char *buf, size_t buflen) {
536 return getcwd(buf, buflen);
537 }
538
539 FILE* os::open(int fd, const char* mode) {
540 return ::fdopen(fd, mode);
541 }
542
543 void os::flockfile(FILE* fp) {
544 ::flockfile(fp);
545 }
546
547 void os::funlockfile(FILE* fp) {
548 ::funlockfile(fp);
549 }
550
551 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
552 // which is used to find statically linked in agents.
553 // Parameters:
554 // sym_name: Symbol in library we are looking for
555 // lib_name: Name of library to look in, NULL for shared libs.
556 // is_absolute_path == true if lib_name is absolute path to agent
557 // such as "/a/b/libL.so"
558 // == false if only the base name of the library is passed in
559 // such as "L"
560 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
561 bool is_absolute_path) {
562 char *agent_entry_name;
563 size_t len;
564 size_t name_len;
565 size_t prefix_len = strlen(JNI_LIB_PREFIX);
566 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
567 const char *start;
568
569 if (lib_name != NULL) {
570 name_len = strlen(lib_name);
571 if (is_absolute_path) {
572 // Need to strip path, prefix and suffix
573 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
574 lib_name = ++start;
575 }
576 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
577 return NULL;
578 }
579 lib_name += prefix_len;
580 name_len = strlen(lib_name) - suffix_len;
581 }
582 }
583 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
584 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
585 if (agent_entry_name == NULL) {
586 return NULL;
587 }
588 strcpy(agent_entry_name, sym_name);
589 if (lib_name != NULL) {
590 strcat(agent_entry_name, "_");
591 strncat(agent_entry_name, lib_name, name_len);
592 }
593 return agent_entry_name;
594 }
595
596 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
597 assert(thread == Thread::current(), "thread consistency check");
598
599 ParkEvent * const slp = thread->_SleepEvent ;
600 slp->reset() ;
601 OrderAccess::fence() ;
602
603 if (interruptible) {
604 jlong prevtime = javaTimeNanos();
605
606 for (;;) {
607 if (os::is_interrupted(thread, true)) {
608 return OS_INTRPT;
609 }
610
611 jlong newtime = javaTimeNanos();
612
613 if (newtime - prevtime < 0) {
614 // time moving backwards, should only happen if no monotonic clock
615 // not a guarantee() because JVM should not abort on kernel/glibc bugs
616 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
617 } else {
618 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
619 }
620
621 if (millis <= 0) {
622 return OS_OK;
623 }
624
625 prevtime = newtime;
626
627 {
628 assert(thread->is_Java_thread(), "sanity check");
629 JavaThread *jt = (JavaThread *) thread;
630 ThreadBlockInVM tbivm(jt);
631 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
632
633 jt->set_suspend_equivalent();
634 // cleared by handle_special_suspend_equivalent_condition() or
635 // java_suspend_self() via check_and_wait_while_suspended()
636
637 slp->park(millis);
638
639 // were we externally suspended while we were waiting?
640 jt->check_and_wait_while_suspended();
641 }
642 }
643 } else {
644 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
645 jlong prevtime = javaTimeNanos();
646
647 for (;;) {
648 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
649 // the 1st iteration ...
650 jlong newtime = javaTimeNanos();
651
652 if (newtime - prevtime < 0) {
653 // time moving backwards, should only happen if no monotonic clock
654 // not a guarantee() because JVM should not abort on kernel/glibc bugs
655 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
656 } else {
657 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
658 }
659
660 if (millis <= 0) break ;
661
662 prevtime = newtime;
663 slp->park(millis);
664 }
665 return OS_OK ;
666 }
667 }
668
669 ////////////////////////////////////////////////////////////////////////////////
670 // interrupt support
671
672 void os::interrupt(Thread* thread) {
673 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
674
675 OSThread* osthread = thread->osthread();
676
677 if (!osthread->interrupted()) {
678 osthread->set_interrupted(true);
679 // More than one thread can get here with the same value of osthread,
680 // resulting in multiple notifications. We do, however, want the store
681 // to interrupted() to be visible to other threads before we execute unpark().
682 OrderAccess::fence();
683 ParkEvent * const slp = thread->_SleepEvent ;
684 if (slp != NULL) slp->unpark() ;
685 }
686
687 // For JSR166. Unpark even if interrupt status already was set
688 if (thread->is_Java_thread())
689 ((JavaThread*)thread)->parker()->unpark();
690
691 ParkEvent * ev = thread->_ParkEvent ;
692 if (ev != NULL) ev->unpark() ;
693 }
694
695 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
696 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
697
698 OSThread* osthread = thread->osthread();
699
700 bool interrupted = osthread->interrupted();
701
702 // NOTE that since there is no "lock" around the interrupt and
703 // is_interrupted operations, there is the possibility that the
704 // interrupted flag (in osThread) will be "false" but that the
705 // low-level events will be in the signaled state. This is
706 // intentional. The effect of this is that Object.wait() and
707 // LockSupport.park() will appear to have a spurious wakeup, which
708 // is allowed and not harmful, and the possibility is so rare that
709 // it is not worth the added complexity to add yet another lock.
710 // For the sleep event an explicit reset is performed on entry
711 // to os::sleep, so there is no early return. It has also been
712 // recommended not to put the interrupted flag into the "event"
713 // structure because it hides the issue.
714 if (interrupted && clear_interrupted) {
715 osthread->set_interrupted(false);
716 // consider thread->_SleepEvent->reset() ... optional optimization
717 }
718
719 return interrupted;
720 }
721
722
723
724 static const struct {
725 int sig; const char* name;
726 }
727 g_signal_info[] =
728 {
729 { SIGABRT, "SIGABRT" },
730 #ifdef SIGAIO
731 { SIGAIO, "SIGAIO" },
732 #endif
733 { SIGALRM, "SIGALRM" },
734 #ifdef SIGALRM1
735 { SIGALRM1, "SIGALRM1" },
736 #endif
737 { SIGBUS, "SIGBUS" },
738 #ifdef SIGCANCEL
739 { SIGCANCEL, "SIGCANCEL" },
740 #endif
741 { SIGCHLD, "SIGCHLD" },
742 #ifdef SIGCLD
743 { SIGCLD, "SIGCLD" },
744 #endif
745 { SIGCONT, "SIGCONT" },
746 #ifdef SIGCPUFAIL
747 { SIGCPUFAIL, "SIGCPUFAIL" },
748 #endif
749 #ifdef SIGDANGER
750 { SIGDANGER, "SIGDANGER" },
751 #endif
752 #ifdef SIGDIL
753 { SIGDIL, "SIGDIL" },
754 #endif
755 #ifdef SIGEMT
756 { SIGEMT, "SIGEMT" },
757 #endif
758 { SIGFPE, "SIGFPE" },
759 #ifdef SIGFREEZE
760 { SIGFREEZE, "SIGFREEZE" },
761 #endif
762 #ifdef SIGGFAULT
763 { SIGGFAULT, "SIGGFAULT" },
764 #endif
765 #ifdef SIGGRANT
766 { SIGGRANT, "SIGGRANT" },
767 #endif
768 { SIGHUP, "SIGHUP" },
769 { SIGILL, "SIGILL" },
770 { SIGINT, "SIGINT" },
771 #ifdef SIGIO
772 { SIGIO, "SIGIO" },
773 #endif
774 #ifdef SIGIOINT
775 { SIGIOINT, "SIGIOINT" },
776 #endif
777 #ifdef SIGIOT
778 // SIGIOT is there for BSD compatibility, but on most Unices just a
779 // synonym for SIGABRT. The result should be "SIGABRT", not
780 // "SIGIOT".
781 #if (SIGIOT != SIGABRT )
782 { SIGIOT, "SIGIOT" },
783 #endif
784 #endif
785 #ifdef SIGKAP
786 { SIGKAP, "SIGKAP" },
787 #endif
788 { SIGKILL, "SIGKILL" },
789 #ifdef SIGLOST
790 { SIGLOST, "SIGLOST" },
791 #endif
792 #ifdef SIGLWP
793 { SIGLWP, "SIGLWP" },
794 #endif
795 #ifdef SIGLWPTIMER
796 { SIGLWPTIMER, "SIGLWPTIMER" },
797 #endif
798 #ifdef SIGMIGRATE
799 { SIGMIGRATE, "SIGMIGRATE" },
800 #endif
801 #ifdef SIGMSG
802 { SIGMSG, "SIGMSG" },
803 #endif
804 { SIGPIPE, "SIGPIPE" },
805 #ifdef SIGPOLL
806 { SIGPOLL, "SIGPOLL" },
807 #endif
808 #ifdef SIGPRE
809 { SIGPRE, "SIGPRE" },
810 #endif
811 { SIGPROF, "SIGPROF" },
812 #ifdef SIGPTY
813 { SIGPTY, "SIGPTY" },
814 #endif
815 #ifdef SIGPWR
816 { SIGPWR, "SIGPWR" },
817 #endif
818 { SIGQUIT, "SIGQUIT" },
819 #ifdef SIGRECONFIG
820 { SIGRECONFIG, "SIGRECONFIG" },
821 #endif
822 #ifdef SIGRECOVERY
823 { SIGRECOVERY, "SIGRECOVERY" },
824 #endif
825 #ifdef SIGRESERVE
826 { SIGRESERVE, "SIGRESERVE" },
827 #endif
828 #ifdef SIGRETRACT
829 { SIGRETRACT, "SIGRETRACT" },
830 #endif
831 #ifdef SIGSAK
832 { SIGSAK, "SIGSAK" },
833 #endif
834 { SIGSEGV, "SIGSEGV" },
835 #ifdef SIGSOUND
836 { SIGSOUND, "SIGSOUND" },
837 #endif
838 #ifdef SIGSTKFLT
839 { SIGSTKFLT, "SIGSTKFLT" },
840 #endif
841 { SIGSTOP, "SIGSTOP" },
842 { SIGSYS, "SIGSYS" },
843 #ifdef SIGSYSERROR
844 { SIGSYSERROR, "SIGSYSERROR" },
845 #endif
846 #ifdef SIGTALRM
847 { SIGTALRM, "SIGTALRM" },
848 #endif
849 { SIGTERM, "SIGTERM" },
850 #ifdef SIGTHAW
851 { SIGTHAW, "SIGTHAW" },
852 #endif
853 { SIGTRAP, "SIGTRAP" },
854 #ifdef SIGTSTP
855 { SIGTSTP, "SIGTSTP" },
856 #endif
857 { SIGTTIN, "SIGTTIN" },
858 { SIGTTOU, "SIGTTOU" },
859 #ifdef SIGURG
860 { SIGURG, "SIGURG" },
861 #endif
862 { SIGUSR1, "SIGUSR1" },
863 { SIGUSR2, "SIGUSR2" },
864 #ifdef SIGVIRT
865 { SIGVIRT, "SIGVIRT" },
866 #endif
867 { SIGVTALRM, "SIGVTALRM" },
868 #ifdef SIGWAITING
869 { SIGWAITING, "SIGWAITING" },
870 #endif
871 #ifdef SIGWINCH
872 { SIGWINCH, "SIGWINCH" },
873 #endif
874 #ifdef SIGWINDOW
875 { SIGWINDOW, "SIGWINDOW" },
876 #endif
877 { SIGXCPU, "SIGXCPU" },
878 { SIGXFSZ, "SIGXFSZ" },
879 #ifdef SIGXRES
880 { SIGXRES, "SIGXRES" },
881 #endif
882 { -1, NULL }
883 };
884
885 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
886 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
887
888 const char* ret = NULL;
889
890 #ifdef SIGRTMIN
891 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
892 if (sig == SIGRTMIN) {
893 ret = "SIGRTMIN";
894 } else if (sig == SIGRTMAX) {
895 ret = "SIGRTMAX";
896 } else {
897 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
898 return out;
899 }
900 }
901 #endif
902
903 if (sig > 0) {
904 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
905 if (g_signal_info[idx].sig == sig) {
906 ret = g_signal_info[idx].name;
907 break;
908 }
909 }
910 }
911
912 if (!ret) {
913 if (!is_valid_signal(sig)) {
914 ret = "INVALID";
915 } else {
916 ret = "UNKNOWN";
917 }
918 }
919
920 if (out && outlen > 0) {
921 strncpy(out, ret, outlen);
922 out[outlen - 1] = '\0';
923 }
924 return out;
925 }
926
927 int os::Posix::get_signal_number(const char* signal_name) {
928 char tmp[30];
929 const char* s = signal_name;
930 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
931 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
932 s = tmp;
933 }
934 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
935 if (strcmp(g_signal_info[idx].name, s) == 0) {
936 return g_signal_info[idx].sig;
937 }
938 }
939 return -1;
940 }
941
942 int os::get_signal_number(const char* signal_name) {
943 return os::Posix::get_signal_number(signal_name);
944 }
945
946 // Returns true if signal number is valid.
947 bool os::Posix::is_valid_signal(int sig) {
948 // MacOS not really POSIX compliant: sigaddset does not return
949 // an error for invalid signal numbers. However, MacOS does not
950 // support real time signals and simply seems to have just 33
951 // signals with no holes in the signal range.
952 #ifdef __APPLE__
953 return sig >= 1 && sig < NSIG;
954 #else
955 // Use sigaddset to check for signal validity.
956 sigset_t set;
957 sigemptyset(&set);
958 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
959 return false;
960 }
961 return true;
962 #endif
963 }
964
965 bool os::Posix::is_sig_ignored(int sig) {
966 struct sigaction oact;
967 sigaction(sig, (struct sigaction*)NULL, &oact);
968 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
969 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
970 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
971 return true;
972 } else {
973 return false;
974 }
975 }
976
977 // Returns:
978 // NULL for an invalid signal number
979 // "SIG<num>" for a valid but unknown signal number
980 // signal name otherwise.
981 const char* os::exception_name(int sig, char* buf, size_t size) {
982 if (!os::Posix::is_valid_signal(sig)) {
983 return NULL;
984 }
985 const char* const name = os::Posix::get_signal_name(sig, buf, size);
986 if (strcmp(name, "UNKNOWN") == 0) {
987 jio_snprintf(buf, size, "SIG%d", sig);
988 }
989 return buf;
990 }
991
992 #define NUM_IMPORTANT_SIGS 32
993 // Returns one-line short description of a signal set in a user provided buffer.
994 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
995 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
996 // Note: for shortness, just print out the first 32. That should
997 // cover most of the useful ones, apart from realtime signals.
998 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
999 const int rc = sigismember(set, sig);
1000 if (rc == -1 && errno == EINVAL) {
1001 buffer[sig-1] = '?';
1002 } else {
1003 buffer[sig-1] = rc == 0 ? '0' : '1';
1004 }
1005 }
1006 buffer[NUM_IMPORTANT_SIGS] = 0;
1007 return buffer;
1008 }
1009
1010 // Prints one-line description of a signal set.
1011 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
1012 char buf[NUM_IMPORTANT_SIGS + 1];
1013 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
1014 st->print("%s", buf);
1015 }
1016
1017 // Writes one-line description of a combination of sigaction.sa_flags into a user
1018 // provided buffer. Returns that buffer.
1019 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
1020 char* p = buffer;
1021 size_t remaining = size;
1022 bool first = true;
1023 int idx = 0;
1024
1025 assert(buffer, "invalid argument");
1026
1027 if (size == 0) {
1028 return buffer;
1029 }
1030
1031 strncpy(buffer, "none", size);
1032
1033 const struct {
1034 // NB: i is an unsigned int here because SA_RESETHAND is on some
1035 // systems 0x80000000, which is implicitly unsigned. Assignining
1036 // it to an int field would be an overflow in unsigned-to-signed
1037 // conversion.
1038 unsigned int i;
1039 const char* s;
1040 } flaginfo [] = {
1041 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
1042 { SA_ONSTACK, "SA_ONSTACK" },
1043 { SA_RESETHAND, "SA_RESETHAND" },
1044 { SA_RESTART, "SA_RESTART" },
1045 { SA_SIGINFO, "SA_SIGINFO" },
1046 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
1047 { SA_NODEFER, "SA_NODEFER" },
1048 #ifdef AIX
1049 { SA_ONSTACK, "SA_ONSTACK" },
1050 { SA_OLDSTYLE, "SA_OLDSTYLE" },
1051 #endif
1052 { 0, NULL }
1053 };
1054
1055 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
1056 if (flags & flaginfo[idx].i) {
1057 if (first) {
1058 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
1059 first = false;
1060 } else {
1061 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
1062 }
1063 const size_t len = strlen(p);
1064 p += len;
1065 remaining -= len;
1066 }
1067 }
1068
1069 buffer[size - 1] = '\0';
1070
1071 return buffer;
1072 }
1073
1074 // Prints one-line description of a combination of sigaction.sa_flags.
1075 void os::Posix::print_sa_flags(outputStream* st, int flags) {
1076 char buffer[0x100];
1077 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
1078 st->print("%s", buffer);
1079 }
1080
1081 // Helper function for os::Posix::print_siginfo_...():
1082 // return a textual description for signal code.
1083 struct enum_sigcode_desc_t {
1084 const char* s_name;
1085 const char* s_desc;
1086 };
1087
1088 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
1089
1090 const struct {
1091 int sig; int code; const char* s_code; const char* s_desc;
1092 } t1 [] = {
1093 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
1094 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
1095 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
1096 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
1097 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
1098 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
1099 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
1100 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
1101 #if defined(IA64) && defined(LINUX)
1102 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
1103 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
1104 #endif
1105 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
1106 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
1107 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
1108 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
1109 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
1110 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
1111 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
1112 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
1113 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
1114 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
1115 #ifdef AIX
1116 // no explanation found what keyerr would be
1117 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
1118 #endif
1119 #if defined(IA64) && !defined(AIX)
1120 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
1121 #endif
1122 #if defined(__sparc) && defined(SOLARIS)
1123 // define Solaris Sparc M7 ADI SEGV signals
1124 #if !defined(SEGV_ACCADI)
1125 #define SEGV_ACCADI 3
1126 #endif
1127 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
1128 #if !defined(SEGV_ACCDERR)
1129 #define SEGV_ACCDERR 4
1130 #endif
1131 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
1132 #if !defined(SEGV_ACCPERR)
1133 #define SEGV_ACCPERR 5
1134 #endif
1135 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
1136 #endif // defined(__sparc) && defined(SOLARIS)
1137 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
1138 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
1139 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
1140 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
1141 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
1142 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
1143 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
1144 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
1145 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
1146 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
1147 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
1148 #ifdef SIGPOLL
1149 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
1150 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
1151 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
1152 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
1153 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
1154 #endif
1155 { -1, -1, NULL, NULL }
1156 };
1157
1158 // Codes valid in any signal context.
1159 const struct {
1160 int code; const char* s_code; const char* s_desc;
1161 } t2 [] = {
1162 { SI_USER, "SI_USER", "Signal sent by kill()." },
1163 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
1164 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
1165 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
1166 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
1167 // Linux specific
1168 #ifdef SI_TKILL
1169 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
1170 #endif
1171 #ifdef SI_DETHREAD
1172 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
1173 #endif
1174 #ifdef SI_KERNEL
1175 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
1176 #endif
1177 #ifdef SI_SIGIO
1178 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
1179 #endif
1180
1181 #ifdef AIX
1182 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
1183 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
1184 #endif
1185
1186 #ifdef __sun
1187 { SI_NOINFO, "SI_NOINFO", "No signal information" },
1188 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
1189 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
1190 #endif
1191
1192 { -1, NULL, NULL }
1193 };
1194
1195 const char* s_code = NULL;
1196 const char* s_desc = NULL;
1197
1198 for (int i = 0; t1[i].sig != -1; i ++) {
1199 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
1200 s_code = t1[i].s_code;
1201 s_desc = t1[i].s_desc;
1202 break;
1203 }
1204 }
1205
1206 if (s_code == NULL) {
1207 for (int i = 0; t2[i].s_code != NULL; i ++) {
1208 if (t2[i].code == si->si_code) {
1209 s_code = t2[i].s_code;
1210 s_desc = t2[i].s_desc;
1211 }
1212 }
1213 }
1214
1215 if (s_code == NULL) {
1216 out->s_name = "unknown";
1217 out->s_desc = "unknown";
1218 return false;
1219 }
1220
1221 out->s_name = s_code;
1222 out->s_desc = s_desc;
1223
1224 return true;
1225 }
1226
1227 void os::print_siginfo(outputStream* os, const void* si0) {
1228
1229 const siginfo_t* const si = (const siginfo_t*) si0;
1230
1231 char buf[20];
1232 os->print("siginfo:");
1233
1234 if (!si) {
1235 os->print(" <null>");
1236 return;
1237 }
1238
1239 const int sig = si->si_signo;
1240
1241 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1242
1243 enum_sigcode_desc_t ed;
1244 get_signal_code_description(si, &ed);
1245 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1246
1247 if (si->si_errno) {
1248 os->print(", si_errno: %d", si->si_errno);
1249 }
1250
1251 // Output additional information depending on the signal code.
1252
1253 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1254 // so it depends on the context which member to use. For synchronous error signals,
1255 // we print si_addr, unless the signal was sent by another process or thread, in
1256 // which case we print out pid or tid of the sender.
1257 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
1258 const pid_t pid = si->si_pid;
1259 os->print(", si_pid: %ld", (long) pid);
1260 if (IS_VALID_PID(pid)) {
1261 const pid_t me = getpid();
1262 if (me == pid) {
1263 os->print(" (current process)");
1264 }
1265 } else {
1266 os->print(" (invalid)");
1267 }
1268 os->print(", si_uid: %ld", (long) si->si_uid);
1269 if (sig == SIGCHLD) {
1270 os->print(", si_status: %d", si->si_status);
1271 }
1272 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1273 sig == SIGTRAP || sig == SIGFPE) {
1274 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1275 #ifdef SIGPOLL
1276 } else if (sig == SIGPOLL) {
1277 os->print(", si_band: %ld", si->si_band);
1278 #endif
1279 }
1280
1281 }
1282
1283 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1284 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1285 }
1286
1287 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1288 #if defined(AIX)
1289 return Aix::ucontext_get_pc(ctx);
1290 #elif defined(BSD)
1291 return Bsd::ucontext_get_pc(ctx);
1292 #elif defined(LINUX)
1293 return Linux::ucontext_get_pc(ctx);
1294 #elif defined(SOLARIS)
1295 return Solaris::ucontext_get_pc(ctx);
1296 #else
1297 VMError::report_and_die("unimplemented ucontext_get_pc");
1298 #endif
1299 }
1300
1301 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1302 #if defined(AIX)
1303 Aix::ucontext_set_pc(ctx, pc);
1304 #elif defined(BSD)
1305 Bsd::ucontext_set_pc(ctx, pc);
1306 #elif defined(LINUX)
1307 Linux::ucontext_set_pc(ctx, pc);
1308 #elif defined(SOLARIS)
1309 Solaris::ucontext_set_pc(ctx, pc);
1310 #else
1311 VMError::report_and_die("unimplemented ucontext_get_pc");
1312 #endif
1313 }
1314
1315 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1316 size_t stack_size = 0;
1317 size_t guard_size = 0;
1318 int detachstate = 0;
1319 pthread_attr_getstacksize(attr, &stack_size);
1320 pthread_attr_getguardsize(attr, &guard_size);
1321 // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
1322 LINUX_ONLY(stack_size -= guard_size);
1323 pthread_attr_getdetachstate(attr, &detachstate);
1324 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1325 stack_size / 1024, guard_size / 1024,
1326 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1327 return buf;
1328 }
1329
1330 char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
1331
1332 if (filename == NULL || outbuf == NULL || outbuflen < 1) {
1333 assert(false, "os::Posix::realpath: invalid arguments.");
1334 errno = EINVAL;
1335 return NULL;
1336 }
1337
1338 char* result = NULL;
1339
1340 // This assumes platform realpath() is implemented according to POSIX.1-2008.
1341 // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
1342 // output buffer is dynamically allocated and must be ::free()'d by the caller.
1343 char* p = ::realpath(filename, NULL);
1344 if (p != NULL) {
1345 if (strlen(p) < outbuflen) {
1346 strcpy(outbuf, p);
1347 result = outbuf;
1348 } else {
1349 errno = ENAMETOOLONG;
1350 }
1351 ::free(p); // *not* os::free
1352 } else {
1353 // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
1354 // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
1355 // that it complains about the NULL we handed down as user buffer.
1356 // In this case, use the user provided buffer but at least check whether realpath caused
1357 // a memory overwrite.
1358 if (errno == EINVAL) {
1359 outbuf[outbuflen - 1] = '\0';
1360 p = ::realpath(filename, outbuf);
1361 if (p != NULL) {
1362 guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
1363 result = p;
1364 }
1365 }
1366 }
1367 return result;
1368
1369 }
1370
1371 int os::stat(const char *path, struct stat *sbuf) {
1372 return ::stat(path, sbuf);
1373 }
1374
1375 char * os::native_path(char *path) {
1376 return path;
1377 }
1378
1379 // Check minimum allowable stack sizes for thread creation and to initialize
1380 // the java system classes, including StackOverflowError - depends on page
1381 // size.
1382 // The space needed for frames during startup is platform dependent. It
1383 // depends on word size, platform calling conventions, C frame layout and
1384 // interpreter/C1/C2 design decisions. Therefore this is given in a
1385 // platform (os/cpu) dependent constant.
1386 // To this, space for guard mechanisms is added, which depends on the
1387 // page size which again depends on the concrete system the VM is running
1388 // on. Space for libc guard pages is not included in this size.
1389 jint os::Posix::set_minimum_stack_sizes() {
1390 size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
1391
1392 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
1393 JavaThread::stack_guard_zone_size() +
1394 JavaThread::stack_shadow_zone_size();
1395
1396 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
1397 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
1398
1399 size_t stack_size_in_bytes = ThreadStackSize * K;
1400 if (stack_size_in_bytes != 0 &&
1401 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1402 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1403 // ThreadStackSize so we go with "Java thread stack size" instead
1404 // of "ThreadStackSize" to be more friendly.
1405 tty->print_cr("\nThe Java thread stack size specified is too small. "
1406 "Specify at least " SIZE_FORMAT "k",
1407 _java_thread_min_stack_allowed / K);
1408 return JNI_ERR;
1409 }
1410
1411 // Make the stack size a multiple of the page size so that
1412 // the yellow/red zones can be guarded.
1413 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
1414
1415 // Reminder: a compiler thread is a Java thread.
1416 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
1417 JavaThread::stack_guard_zone_size() +
1418 JavaThread::stack_shadow_zone_size();
1419
1420 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
1421 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
1422
1423 stack_size_in_bytes = CompilerThreadStackSize * K;
1424 if (stack_size_in_bytes != 0 &&
1425 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1426 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1427 "Specify at least " SIZE_FORMAT "k",
1428 _compiler_thread_min_stack_allowed / K);
1429 return JNI_ERR;
1430 }
1431
1432 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1433 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
1434
1435 stack_size_in_bytes = VMThreadStackSize * K;
1436 if (stack_size_in_bytes != 0 &&
1437 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1438 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1439 "Specify at least " SIZE_FORMAT "k",
1440 _vm_internal_thread_min_stack_allowed / K);
1441 return JNI_ERR;
1442 }
1443 return JNI_OK;
1444 }
1445
1446 // Called when creating the thread. The minimum stack sizes have already been calculated
1447 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1448 size_t stack_size;
1449 if (req_stack_size == 0) {
1450 stack_size = default_stack_size(thr_type);
1451 } else {
1452 stack_size = req_stack_size;
1453 }
1454
1455 switch (thr_type) {
1456 case os::java_thread:
1457 // Java threads use ThreadStackSize which default value can be
1458 // changed with the flag -Xss
1459 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1460 // no requested size and we have a more specific default value
1461 stack_size = JavaThread::stack_size_at_create();
1462 }
1463 stack_size = MAX2(stack_size,
1464 _java_thread_min_stack_allowed);
1465 break;
1466 case os::compiler_thread:
1467 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1468 // no requested size and we have a more specific default value
1469 stack_size = (size_t)(CompilerThreadStackSize * K);
1470 }
1471 stack_size = MAX2(stack_size,
1472 _compiler_thread_min_stack_allowed);
1473 break;
1474 case os::vm_thread:
1475 case os::pgc_thread:
1476 case os::cgc_thread:
1477 case os::watcher_thread:
1478 default: // presume the unknown thr_type is a VM internal
1479 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1480 // no requested size and we have a more specific default value
1481 stack_size = (size_t)(VMThreadStackSize * K);
1482 }
1483
1484 stack_size = MAX2(stack_size,
1485 _vm_internal_thread_min_stack_allowed);
1486 break;
1487 }
1488
1489 // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
1490 // Be careful not to round up to 0. Align down in that case.
1491 if (stack_size <= SIZE_MAX - vm_page_size()) {
1492 stack_size = align_up(stack_size, vm_page_size());
1493 } else {
1494 stack_size = align_down(stack_size, vm_page_size());
1495 }
1496
1497 return stack_size;
1498 }
1499
1500 bool os::Posix::is_root(uid_t uid){
1501 return ROOT_UID == uid;
1502 }
1503
1504 bool os::Posix::matches_effective_uid_or_root(uid_t uid) {
1505 return is_root(uid) || geteuid() == uid;
1506 }
1507
1508 bool os::Posix::matches_effective_uid_and_gid_or_root(uid_t uid, gid_t gid) {
1509 return is_root(uid) || (geteuid() == uid && getegid() == gid);
1510 }
1511
1512 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
1513 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
1514 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
1515
1516 os::ThreadCrashProtection::ThreadCrashProtection() {
1517 }
1518
1519 /*
1520 * See the caveats for this class in os_posix.hpp
1521 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1522 * method and returns false. If none of the signals are raised, returns true.
1523 * The callback is supposed to provide the method that should be protected.
1524 */
1525 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1526 sigset_t saved_sig_mask;
1527
1528 Thread::muxAcquire(&_crash_mux, "CrashProtection");
1529
1530 _protected_thread = Thread::current_or_null();
1531 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
1532
1533 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1534 // since on at least some systems (OS X) siglongjmp will restore the mask
1535 // for the process, not the thread
1536 pthread_sigmask(0, NULL, &saved_sig_mask);
1537 if (sigsetjmp(_jmpbuf, 0) == 0) {
1538 // make sure we can see in the signal handler that we have crash protection
1539 // installed
1540 _crash_protection = this;
1541 cb.call();
1542 // and clear the crash protection
1543 _crash_protection = NULL;
1544 _protected_thread = NULL;
1545 Thread::muxRelease(&_crash_mux);
1546 return true;
1547 }
1548 // this happens when we siglongjmp() back
1549 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1550 _crash_protection = NULL;
1551 _protected_thread = NULL;
1552 Thread::muxRelease(&_crash_mux);
1553 return false;
1554 }
1555
1556 void os::ThreadCrashProtection::restore() {
1557 assert(_crash_protection != NULL, "must have crash protection");
1558 siglongjmp(_jmpbuf, 1);
1559 }
1560
1561 void os::ThreadCrashProtection::check_crash_protection(int sig,
1562 Thread* thread) {
1563
1564 if (thread != NULL &&
1565 thread == _protected_thread &&
1566 _crash_protection != NULL) {
1567
1568 if (sig == SIGSEGV || sig == SIGBUS) {
1569 _crash_protection->restore();
1570 }
1571 }
1572 }
1573
1574
1575 // Shared pthread_mutex/cond based PlatformEvent implementation.
1576 // Not currently usable by Solaris.
1577
1578 #ifndef SOLARIS
1579
1580 // Shared condattr object for use with relative timed-waits. Will be associated
1581 // with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
1582 // but otherwise whatever default is used by the platform - generally the
1583 // time-of-day clock.
1584 static pthread_condattr_t _condAttr[1];
1585
1586 // Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
1587 // all systems (e.g. FreeBSD) map the default to "normal".
1588 static pthread_mutexattr_t _mutexAttr[1];
1589
1590 // common basic initialization that is always supported
1591 static void pthread_init_common(void) {
1592 int status;
1593 if ((status = pthread_condattr_init(_condAttr)) != 0) {
1594 fatal("pthread_condattr_init: %s", os::strerror(status));
1595 }
1596 if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
1597 fatal("pthread_mutexattr_init: %s", os::strerror(status));
1598 }
1599 if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
1600 fatal("pthread_mutexattr_settype: %s", os::strerror(status));
1601 }
1602 }
1603
1604 // Not all POSIX types and API's are available on all notionally "posix"
1605 // platforms. If we have build-time support then we will check for actual
1606 // runtime support via dlopen/dlsym lookup. This allows for running on an
1607 // older OS version compared to the build platform. But if there is no
1608 // build time support then there cannot be any runtime support as we do not
1609 // know what the runtime types would be (for example clockid_t might be an
1610 // int or int64_t).
1611 //
1612 #ifdef SUPPORTS_CLOCK_MONOTONIC
1613
1614 // This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
1615
1616 static int (*_clock_gettime)(clockid_t, struct timespec *);
1617 static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t);
1618
1619 static bool _use_clock_monotonic_condattr;
1620
1621 // Determine what POSIX API's are present and do appropriate
1622 // configuration.
1623 void os::Posix::init(void) {
1624
1625 // NOTE: no logging available when this is called. Put logging
1626 // statements in init_2().
1627
1628 // Copied from os::Linux::clock_init(). The duplication is temporary.
1629
1630 // 1. Check for CLOCK_MONOTONIC support.
1631
1632 void* handle = NULL;
1633
1634 // For linux we need librt, for other OS we can find
1635 // this function in regular libc.
1636 #ifdef NEEDS_LIBRT
1637 // We do dlopen's in this particular order due to bug in linux
1638 // dynamic loader (see 6348968) leading to crash on exit.
1639 handle = dlopen("librt.so.1", RTLD_LAZY);
1640 if (handle == NULL) {
1641 handle = dlopen("librt.so", RTLD_LAZY);
1642 }
1643 #endif
1644
1645 if (handle == NULL) {
1646 handle = RTLD_DEFAULT;
1647 }
1648
1649 _clock_gettime = NULL;
1650
1651 int (*clock_getres_func)(clockid_t, struct timespec*) =
1652 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1653 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1654 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1655 if (clock_getres_func != NULL && clock_gettime_func != NULL) {
1656 // We assume that if both clock_gettime and clock_getres support
1657 // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
1658 struct timespec res;
1659 struct timespec tp;
1660 if (clock_getres_func(CLOCK_MONOTONIC, &res) == 0 &&
1661 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1662 // Yes, monotonic clock is supported.
1663 _clock_gettime = clock_gettime_func;
1664 } else {
1665 #ifdef NEEDS_LIBRT
1666 // Close librt if there is no monotonic clock.
1667 if (handle != RTLD_DEFAULT) {
1668 dlclose(handle);
1669 }
1670 #endif
1671 }
1672 }
1673
1674 // 2. Check for pthread_condattr_setclock support.
1675
1676 _pthread_condattr_setclock = NULL;
1677
1678 // libpthread is already loaded.
1679 int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
1680 (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
1681 "pthread_condattr_setclock");
1682 if (condattr_setclock_func != NULL) {
1683 _pthread_condattr_setclock = condattr_setclock_func;
1684 }
1685
1686 // Now do general initialization.
1687
1688 pthread_init_common();
1689
1690 int status;
1691 if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
1692 if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
1693 if (status == EINVAL) {
1694 _use_clock_monotonic_condattr = false;
1695 warning("Unable to use monotonic clock with relative timed-waits" \
1696 " - changes to the time-of-day clock may have adverse affects");
1697 } else {
1698 fatal("pthread_condattr_setclock: %s", os::strerror(status));
1699 }
1700 } else {
1701 _use_clock_monotonic_condattr = true;
1702 }
1703 } else {
1704 _use_clock_monotonic_condattr = false;
1705 }
1706 }
1707
1708 void os::Posix::init_2(void) {
1709 log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
1710 (_clock_gettime != NULL ? "" : " not"));
1711 log_info(os)("Use of pthread_condattr_setclock is%s supported",
1712 (_pthread_condattr_setclock != NULL ? "" : " not"));
1713 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
1714 _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
1715 }
1716
1717 #else // !SUPPORTS_CLOCK_MONOTONIC
1718
1719 void os::Posix::init(void) {
1720 pthread_init_common();
1721 }
1722
1723 void os::Posix::init_2(void) {
1724 log_info(os)("Use of CLOCK_MONOTONIC is not supported");
1725 log_info(os)("Use of pthread_condattr_setclock is not supported");
1726 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
1727 }
1728
1729 #endif // SUPPORTS_CLOCK_MONOTONIC
1730
1731 os::PlatformEvent::PlatformEvent() {
1732 int status = pthread_cond_init(_cond, _condAttr);
1733 assert_status(status == 0, status, "cond_init");
1734 status = pthread_mutex_init(_mutex, _mutexAttr);
1735 assert_status(status == 0, status, "mutex_init");
1736 _event = 0;
1737 _nParked = 0;
1738 }
1739
1740 // Utility to convert the given timeout to an absolute timespec
1741 // (based on the appropriate clock) to use with pthread_cond_timewait.
1742 // The clock queried here must be the clock used to manage the
1743 // timeout of the condition variable.
1744 //
1745 // The passed in timeout value is either a relative time in nanoseconds
1746 // or an absolute time in milliseconds. A relative timeout will be
1747 // associated with CLOCK_MONOTONIC if available; otherwise, or if absolute,
1748 // the default time-of-day clock will be used.
1749
1750 // Given time is a 64-bit value and the time_t used in the timespec is
1751 // sometimes a signed-32-bit value we have to watch for overflow if times
1752 // way in the future are given. Further on Solaris versions
1753 // prior to 10 there is a restriction (see cond_timedwait) that the specified
1754 // number of seconds, in abstime, is less than current_time + 100000000.
1755 // As it will be over 20 years before "now + 100000000" will overflow we can
1756 // ignore overflow and just impose a hard-limit on seconds using the value
1757 // of "now + 100000000". This places a limit on the timeout of about 3.17
1758 // years from "now".
1759 //
1760 #define MAX_SECS 100000000
1761
1762 // Calculate a new absolute time that is "timeout" nanoseconds from "now".
1763 // "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
1764 // on which clock is being used).
1765 static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
1766 jlong now_part_sec, jlong unit) {
1767 time_t max_secs = now_sec + MAX_SECS;
1768
1769 jlong seconds = timeout / NANOUNITS;
1770 timeout %= NANOUNITS; // remaining nanos
1771
1772 if (seconds >= MAX_SECS) {
1773 // More seconds than we can add, so pin to max_secs.
1774 abstime->tv_sec = max_secs;
1775 abstime->tv_nsec = 0;
1776 } else {
1777 abstime->tv_sec = now_sec + seconds;
1778 long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
1779 if (nanos >= NANOUNITS) { // overflow
1780 abstime->tv_sec += 1;
1781 nanos -= NANOUNITS;
1782 }
1783 abstime->tv_nsec = nanos;
1784 }
1785 }
1786
1787 // Unpack the given deadline in milliseconds since the epoch, into the given timespec.
1788 // The current time in seconds is also passed in to enforce an upper bound as discussed above.
1789 static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
1790 time_t max_secs = now_sec + MAX_SECS;
1791
1792 jlong seconds = deadline / MILLIUNITS;
1793 jlong millis = deadline % MILLIUNITS;
1794
1795 if (seconds >= max_secs) {
1796 // Absolute seconds exceeds allowed max, so pin to max_secs.
1797 abstime->tv_sec = max_secs;
1798 abstime->tv_nsec = 0;
1799 } else {
1800 abstime->tv_sec = seconds;
1801 abstime->tv_nsec = millis * (NANOUNITS / MILLIUNITS);
1802 }
1803 }
1804
1805 static void to_abstime(timespec* abstime, jlong timeout, bool isAbsolute) {
1806 DEBUG_ONLY(int max_secs = MAX_SECS;)
1807
1808 if (timeout < 0) {
1809 timeout = 0;
1810 }
1811
1812 #ifdef SUPPORTS_CLOCK_MONOTONIC
1813
1814 if (_use_clock_monotonic_condattr && !isAbsolute) {
1815 struct timespec now;
1816 int status = _clock_gettime(CLOCK_MONOTONIC, &now);
1817 assert_status(status == 0, status, "clock_gettime");
1818 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
1819 DEBUG_ONLY(max_secs += now.tv_sec;)
1820 } else {
1821
1822 #else
1823
1824 { // Match the block scope.
1825
1826 #endif // SUPPORTS_CLOCK_MONOTONIC
1827
1828 // Time-of-day clock is all we can reliably use.
1829 struct timeval now;
1830 int status = gettimeofday(&now, NULL);
1831 assert_status(status == 0, errno, "gettimeofday");
1832 if (isAbsolute) {
1833 unpack_abs_time(abstime, timeout, now.tv_sec);
1834 } else {
1835 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
1836 }
1837 DEBUG_ONLY(max_secs += now.tv_sec;)
1838 }
1839
1840 assert(abstime->tv_sec >= 0, "tv_sec < 0");
1841 assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
1842 assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
1843 assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
1844 }
1845
1846 // PlatformEvent
1847 //
1848 // Assumption:
1849 // Only one parker can exist on an event, which is why we allocate
1850 // them per-thread. Multiple unparkers can coexist.
1851 //
1852 // _event serves as a restricted-range semaphore.
1853 // -1 : thread is blocked, i.e. there is a waiter
1854 // 0 : neutral: thread is running or ready,
1855 // could have been signaled after a wait started
1856 // 1 : signaled - thread is running or ready
1857 //
1858 // Having three states allows for some detection of bad usage - see
1859 // comments on unpark().
1860
1861 void os::PlatformEvent::park() { // AKA "down()"
1862 // Transitions for _event:
1863 // -1 => -1 : illegal
1864 // 1 => 0 : pass - return immediately
1865 // 0 => -1 : block; then set _event to 0 before returning
1866
1867 // Invariant: Only the thread associated with the PlatformEvent
1868 // may call park().
1869 assert(_nParked == 0, "invariant");
1870
1871 int v;
1872
1873 // atomically decrement _event
1874 for (;;) {
1875 v = _event;
1876 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1877 }
1878 guarantee(v >= 0, "invariant");
1879
1880 if (v == 0) { // Do this the hard way by blocking ...
1881 int status = pthread_mutex_lock(_mutex);
1882 assert_status(status == 0, status, "mutex_lock");
1883 guarantee(_nParked == 0, "invariant");
1884 ++_nParked;
1885 while (_event < 0) {
1886 // OS-level "spurious wakeups" are ignored
1887 status = pthread_cond_wait(_cond, _mutex);
1888 assert_status(status == 0, status, "cond_wait");
1889 }
1890 --_nParked;
1891
1892 _event = 0;
1893 status = pthread_mutex_unlock(_mutex);
1894 assert_status(status == 0, status, "mutex_unlock");
1895 // Paranoia to ensure our locked and lock-free paths interact
1896 // correctly with each other.
1897 OrderAccess::fence();
1898 }
1899 guarantee(_event >= 0, "invariant");
1900 }
1901
1902 int os::PlatformEvent::park(jlong millis) {
1903 // Transitions for _event:
1904 // -1 => -1 : illegal
1905 // 1 => 0 : pass - return immediately
1906 // 0 => -1 : block; then set _event to 0 before returning
1907
1908 // Invariant: Only the thread associated with the Event/PlatformEvent
1909 // may call park().
1910 assert(_nParked == 0, "invariant");
1911
1912 int v;
1913 // atomically decrement _event
1914 for (;;) {
1915 v = _event;
1916 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1917 }
1918 guarantee(v >= 0, "invariant");
1919
1920 if (v == 0) { // Do this the hard way by blocking ...
1921 struct timespec abst;
1922 // We have to watch for overflow when converting millis to nanos,
1923 // but if millis is that large then we will end up limiting to
1924 // MAX_SECS anyway, so just do that here.
1925 if (millis / MILLIUNITS > MAX_SECS) {
1926 millis = jlong(MAX_SECS) * MILLIUNITS;
1927 }
1928 to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false);
1929
1930 int ret = OS_TIMEOUT;
1931 int status = pthread_mutex_lock(_mutex);
1932 assert_status(status == 0, status, "mutex_lock");
1933 guarantee(_nParked == 0, "invariant");
1934 ++_nParked;
1935
1936 while (_event < 0) {
1937 status = pthread_cond_timedwait(_cond, _mutex, &abst);
1938 assert_status(status == 0 || status == ETIMEDOUT,
1939 status, "cond_timedwait");
1940 // OS-level "spurious wakeups" are ignored unless the archaic
1941 // FilterSpuriousWakeups is set false. That flag should be obsoleted.
1942 if (!FilterSpuriousWakeups) break;
1943 if (status == ETIMEDOUT) break;
1944 }
1945 --_nParked;
1946
1947 if (_event >= 0) {
1948 ret = OS_OK;
1949 }
1950
1951 _event = 0;
1952 status = pthread_mutex_unlock(_mutex);
1953 assert_status(status == 0, status, "mutex_unlock");
1954 // Paranoia to ensure our locked and lock-free paths interact
1955 // correctly with each other.
1956 OrderAccess::fence();
1957 return ret;
1958 }
1959 return OS_OK;
1960 }
1961
1962 void os::PlatformEvent::unpark() {
1963 // Transitions for _event:
1964 // 0 => 1 : just return
1965 // 1 => 1 : just return
1966 // -1 => either 0 or 1; must signal target thread
1967 // That is, we can safely transition _event from -1 to either
1968 // 0 or 1.
1969 // See also: "Semaphores in Plan 9" by Mullender & Cox
1970 //
1971 // Note: Forcing a transition from "-1" to "1" on an unpark() means
1972 // that it will take two back-to-back park() calls for the owning
1973 // thread to block. This has the benefit of forcing a spurious return
1974 // from the first park() call after an unpark() call which will help
1975 // shake out uses of park() and unpark() without checking state conditions
1976 // properly. This spurious return doesn't manifest itself in any user code
1977 // but only in the correctly written condition checking loops of ObjectMonitor,
1978 // Mutex/Monitor, Thread::muxAcquire and os::sleep
1979
1980 if (Atomic::xchg(1, &_event) >= 0) return;
1981
1982 int status = pthread_mutex_lock(_mutex);
1983 assert_status(status == 0, status, "mutex_lock");
1984 int anyWaiters = _nParked;
1985 assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
1986 status = pthread_mutex_unlock(_mutex);
1987 assert_status(status == 0, status, "mutex_unlock");
1988
1989 // Note that we signal() *after* dropping the lock for "immortal" Events.
1990 // This is safe and avoids a common class of futile wakeups. In rare
1991 // circumstances this can cause a thread to return prematurely from
1992 // cond_{timed}wait() but the spurious wakeup is benign and the victim
1993 // will simply re-test the condition and re-park itself.
1994 // This provides particular benefit if the underlying platform does not
1995 // provide wait morphing.
1996
1997 if (anyWaiters != 0) {
1998 status = pthread_cond_signal(_cond);
1999 assert_status(status == 0, status, "cond_signal");
2000 }
2001 }
2002
2003 // JSR166 support
2004
2005 os::PlatformParker::PlatformParker() {
2006 int status;
2007 status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
2008 assert_status(status == 0, status, "cond_init rel");
2009 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
2010 assert_status(status == 0, status, "cond_init abs");
2011 status = pthread_mutex_init(_mutex, _mutexAttr);
2012 assert_status(status == 0, status, "mutex_init");
2013 _cur_index = -1; // mark as unused
2014 }
2015
2016 // Parker::park decrements count if > 0, else does a condvar wait. Unpark
2017 // sets count to 1 and signals condvar. Only one thread ever waits
2018 // on the condvar. Contention seen when trying to park implies that someone
2019 // is unparking you, so don't wait. And spurious returns are fine, so there
2020 // is no need to track notifications.
2021
2022 void Parker::park(bool isAbsolute, jlong time) {
2023
2024 // Optional fast-path check:
2025 // Return immediately if a permit is available.
2026 // We depend on Atomic::xchg() having full barrier semantics
2027 // since we are doing a lock-free update to _counter.
2028 if (Atomic::xchg(0, &_counter) > 0) return;
2029
2030 Thread* thread = Thread::current();
2031 assert(thread->is_Java_thread(), "Must be JavaThread");
2032 JavaThread *jt = (JavaThread *)thread;
2033
2034 // Optional optimization -- avoid state transitions if there's
2035 // an interrupt pending.
2036 if (Thread::is_interrupted(thread, false)) {
2037 return;
2038 }
2039
2040 // Next, demultiplex/decode time arguments
2041 struct timespec absTime;
2042 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
2043 return;
2044 }
2045 if (time > 0) {
2046 to_abstime(&absTime, time, isAbsolute);
2047 }
2048
2049 // Enter safepoint region
2050 // Beware of deadlocks such as 6317397.
2051 // The per-thread Parker:: mutex is a classic leaf-lock.
2052 // In particular a thread must never block on the Threads_lock while
2053 // holding the Parker:: mutex. If safepoints are pending both the
2054 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
2055 ThreadBlockInVM tbivm(jt);
2056
2057 // Don't wait if cannot get lock since interference arises from
2058 // unparking. Also re-check interrupt before trying wait.
2059 if (Thread::is_interrupted(thread, false) ||
2060 pthread_mutex_trylock(_mutex) != 0) {
2061 return;
2062 }
2063
2064 int status;
2065 if (_counter > 0) { // no wait needed
2066 _counter = 0;
2067 status = pthread_mutex_unlock(_mutex);
2068 assert_status(status == 0, status, "invariant");
2069 // Paranoia to ensure our locked and lock-free paths interact
2070 // correctly with each other and Java-level accesses.
2071 OrderAccess::fence();
2072 return;
2073 }
2074
2075 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2076 jt->set_suspend_equivalent();
2077 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2078
2079 assert(_cur_index == -1, "invariant");
2080 if (time == 0) {
2081 _cur_index = REL_INDEX; // arbitrary choice when not timed
2082 status = pthread_cond_wait(&_cond[_cur_index], _mutex);
2083 assert_status(status == 0, status, "cond_timedwait");
2084 }
2085 else {
2086 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
2087 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
2088 assert_status(status == 0 || status == ETIMEDOUT,
2089 status, "cond_timedwait");
2090 }
2091 _cur_index = -1;
2092
2093 _counter = 0;
2094 status = pthread_mutex_unlock(_mutex);
2095 assert_status(status == 0, status, "invariant");
2096 // Paranoia to ensure our locked and lock-free paths interact
2097 // correctly with each other and Java-level accesses.
2098 OrderAccess::fence();
2099
2100 // If externally suspended while waiting, re-suspend
2101 if (jt->handle_special_suspend_equivalent_condition()) {
2102 jt->java_suspend_self();
2103 }
2104 }
2105
2106 void Parker::unpark() {
2107 int status = pthread_mutex_lock(_mutex);
2108 assert_status(status == 0, status, "invariant");
2109 const int s = _counter;
2110 _counter = 1;
2111 // must capture correct index before unlocking
2112 int index = _cur_index;
2113 status = pthread_mutex_unlock(_mutex);
2114 assert_status(status == 0, status, "invariant");
2115
2116 // Note that we signal() *after* dropping the lock for "immortal" Events.
2117 // This is safe and avoids a common class of futile wakeups. In rare
2118 // circumstances this can cause a thread to return prematurely from
2119 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2120 // will simply re-test the condition and re-park itself.
2121 // This provides particular benefit if the underlying platform does not
2122 // provide wait morphing.
2123
2124 if (s < 1 && index != -1) {
2125 // thread is definitely parked
2126 status = pthread_cond_signal(&_cond[index]);
2127 assert_status(status == 0, status, "invariant");
2128 }
2129 }
2130
2131
2132 #endif // !SOLARIS