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 <dirent.h>
39 #include <dlfcn.h>
40 #include <grp.h>
41 #include <pwd.h>
42 #include <pthread.h>
43 #include <signal.h>
44 #include <sys/mman.h>
45 #include <sys/resource.h>
46 #include <sys/utsname.h>
47 #include <time.h>
48 #include <unistd.h>
49
50 // Todo: provide a os::get_max_process_id() or similar. Number of processes
51 // may have been configured, can be read more accurately from proc fs etc.
52 #ifndef MAX_PID
53 #define MAX_PID INT_MAX
54 #endif
55 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
56
57 #define ROOT_UID 0
58
59 #ifndef MAP_ANONYMOUS
60 #define MAP_ANONYMOUS MAP_ANON
61 #endif
62
63 #define check_with_errno(check_type, cond, msg) \
64 do { \
65 int err = errno; \
66 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
67 os::errno_name(err)); \
68 } while (false)
69
70 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
71 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
72
73 // Check core dump limit and report possible place where core can be found
74 void os::check_dump_limit(char* buffer, size_t bufferSize) {
75 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
76 jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
77 VMError::record_coredump_status(buffer, false);
78 return;
79 }
80
81 int n;
82 struct rlimit rlim;
83 bool success;
84
85 char core_path[PATH_MAX];
86 n = get_core_path(core_path, PATH_MAX);
87
88 if (n <= 0) {
89 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
90 success = true;
91 #ifdef LINUX
92 } else if (core_path[0] == '"') { // redirect to user process
93 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
94 success = true;
95 #endif
96 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
97 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
98 success = true;
99 } else {
100 switch(rlim.rlim_cur) {
101 case RLIM_INFINITY:
102 jio_snprintf(buffer, bufferSize, "%s", core_path);
103 success = true;
104 break;
105 case 0:
106 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
107 success = false;
108 break;
109 default:
110 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);
111 success = true;
112 break;
113 }
114 }
115
116 VMError::record_coredump_status(buffer, success);
117 }
118
119 int os::get_native_stack(address* stack, int frames, int toSkip) {
120 int frame_idx = 0;
121 int num_of_frames; // number of frames captured
122 frame fr = os::current_frame();
123 while (fr.pc() && frame_idx < frames) {
124 if (toSkip > 0) {
125 toSkip --;
126 } else {
127 stack[frame_idx ++] = fr.pc();
128 }
129 if (fr.fp() == NULL || fr.cb() != NULL ||
130 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
131
132 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
133 fr = os::get_sender_for_C_frame(&fr);
134 } else {
135 break;
136 }
137 }
138 num_of_frames = frame_idx;
139 for (; frame_idx < frames; frame_idx ++) {
140 stack[frame_idx] = NULL;
141 }
142
143 return num_of_frames;
144 }
145
146
147 bool os::unsetenv(const char* name) {
148 assert(name != NULL, "Null pointer");
149 return (::unsetenv(name) == 0);
150 }
151
152 int os::get_last_error() {
153 return errno;
154 }
155
156 size_t os::lasterror(char *buf, size_t len) {
157 if (errno == 0) return 0;
158
159 const char *s = os::strerror(errno);
160 size_t n = ::strlen(s);
161 if (n >= len) {
162 n = len - 1;
163 }
164 ::strncpy(buf, s, n);
165 buf[n] = '\0';
166 return n;
167 }
168
169 bool os::is_debugger_attached() {
170 // not implemented
171 return false;
172 }
173
174 void os::wait_for_keypress_at_exit(void) {
175 // don't do anything on posix platforms
176 return;
177 }
178
179 int os::create_file_for_heap(const char* dir) {
180
181 const char name_template[] = "/jvmheap.XXXXXX";
182
183 char *fullname = (char*)os::malloc((strlen(dir) + strlen(name_template) + 1), mtInternal);
184 if (fullname == NULL) {
185 vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
186 return -1;
187 }
188 (void)strncpy(fullname, dir, strlen(dir)+1);
189 (void)strncat(fullname, name_template, strlen(name_template));
190
191 os::native_path(fullname);
192
193 sigset_t set, oldset;
194 int ret = sigfillset(&set);
195 assert_with_errno(ret == 0, "sigfillset returned error");
196
197 // set the file creation mask.
198 mode_t file_mode = S_IRUSR | S_IWUSR;
199
200 // create a new file.
201 int fd = mkstemp(fullname);
202
203 if (fd < 0) {
204 warning("Could not create file for heap with template %s", fullname);
205 os::free(fullname);
206 return -1;
207 }
208
209 // delete the name from the filesystem. When 'fd' is closed, the file (and space) will be deleted.
210 ret = unlink(fullname);
211 assert_with_errno(ret == 0, "unlink returned error");
212
213 os::free(fullname);
214 return fd;
215 }
216
217 static char* reserve_mmapped_memory(size_t bytes, char* requested_addr) {
218 char * addr;
219 int flags = MAP_PRIVATE NOT_AIX( | MAP_NORESERVE ) | MAP_ANONYMOUS;
220 if (requested_addr != NULL) {
221 assert((uintptr_t)requested_addr % os::vm_page_size() == 0, "Requested address should be aligned to OS page size");
222 flags |= MAP_FIXED;
223 }
224
225 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
226 // touch an uncommitted page. Otherwise, the read/write might
227 // succeed if we have enough swap space to back the physical page.
228 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
229 flags, -1, 0);
230
231 if (addr != MAP_FAILED) {
232 MemTracker::record_virtual_memory_reserve((address)addr, bytes, CALLER_PC);
233 return addr;
234 }
235 return NULL;
236 }
237
238 static int util_posix_fallocate(int fd, off_t offset, off_t len) {
239 #ifdef __APPLE__
240 fstore_t store = { F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, len };
241 // First we try to get a continuous chunk of disk space
242 int ret = fcntl(fd, F_PREALLOCATE, &store);
243 if (ret == -1) {
244 // Maybe we are too fragmented, try to allocate non-continuous range
245 store.fst_flags = F_ALLOCATEALL;
246 ret = fcntl(fd, F_PREALLOCATE, &store);
247 }
248 if(ret != -1) {
249 return ftruncate(fd, len);
250 }
251 return -1;
252 #else
253 return posix_fallocate(fd, offset, len);
254 #endif
255 }
256
257 // Map the given address range to the provided file descriptor.
258 char* os::map_memory_to_file(char* base, size_t size, int fd) {
259 assert(fd != -1, "File descriptor is not valid");
260
261 // allocate space for the file
262 int ret = util_posix_fallocate(fd, 0, (off_t)size);
263 if (ret != 0) {
264 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory. error(%d)", ret));
265 return NULL;
266 }
267
268 int prot = PROT_READ | PROT_WRITE;
269 int flags = MAP_SHARED;
270 if (base != NULL) {
271 flags |= MAP_FIXED;
272 }
273 char* addr = (char*)mmap(base, size, prot, flags, fd, 0);
274
275 if (addr == MAP_FAILED) {
276 warning("Failed mmap to file. (%s)", os::strerror(errno));
277 return NULL;
278 }
279 if (base != NULL && addr != base) {
280 if (!os::release_memory(addr, size)) {
281 warning("Could not release memory on unsuccessful file mapping");
282 }
283 return NULL;
284 }
285 return addr;
286 }
287
288 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
289 assert(fd != -1, "File descriptor is not valid");
290 assert(base != NULL, "Base cannot be NULL");
291
292 return map_memory_to_file(base, size, fd);
293 }
294
295 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
296 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
297 // rather than unmapping and remapping the whole chunk to get requested alignment.
298 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
299 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
300 "Alignment must be a multiple of allocation granularity (page size)");
301 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
302
303 size_t extra_size = size + alignment;
304 assert(extra_size >= size, "overflow, size is too large to allow alignment");
305
306 char* extra_base;
307 if (file_desc != -1) {
308 // For file mapping, we do not call os:reserve_memory(extra_size, NULL, alignment, file_desc) because
309 // we need to deal with shrinking of the file space later when we release extra memory after alignment.
310 // We also cannot called os:reserve_memory() with file_desc set to -1 because on aix we might get SHM memory.
311 // So here to call a helper function while reserve memory for us. After we have a aligned base,
312 // we will replace anonymous mapping with file mapping.
313 extra_base = reserve_mmapped_memory(extra_size, NULL);
314 if (extra_base != NULL) {
315 MemTracker::record_virtual_memory_reserve((address)extra_base, extra_size, CALLER_PC);
316 }
317 } else {
318 extra_base = os::reserve_memory(extra_size, NULL, alignment);
319 }
320
321 if (extra_base == NULL) {
322 return NULL;
323 }
324
325 // Do manual alignment
326 char* aligned_base = align_up(extra_base, alignment);
327
328 // [ | | ]
329 // ^ extra_base
330 // ^ extra_base + begin_offset == aligned_base
331 // extra_base + begin_offset + size ^
332 // extra_base + extra_size ^
333 // |<>| == begin_offset
334 // end_offset == |<>|
335 size_t begin_offset = aligned_base - extra_base;
336 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
337
338 if (begin_offset > 0) {
339 os::release_memory(extra_base, begin_offset);
340 }
341
342 if (end_offset > 0) {
343 os::release_memory(extra_base + begin_offset + size, end_offset);
344 }
345
346 if (file_desc != -1) {
347 // After we have an aligned address, we can replace anonymous mapping with file mapping
348 if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
349 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
350 }
351 MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
352 }
353 return aligned_base;
354 }
355
356 int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
357 // All supported POSIX platforms provide C99 semantics.
358 int result = ::vsnprintf(buf, len, fmt, args);
359 // If an encoding error occurred (result < 0) then it's not clear
360 // whether the buffer is NUL terminated, so ensure it is.
361 if ((result < 0) && (len > 0)) {
362 buf[len - 1] = '\0';
363 }
364 return result;
365 }
366
367 int os::get_fileno(FILE* fp) {
368 return NOT_AIX(::)fileno(fp);
369 }
370
371 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
372 return gmtime_r(clock, res);
373 }
374
375 void os::Posix::print_load_average(outputStream* st) {
376 st->print("load average:");
377 double loadavg[3];
378 os::loadavg(loadavg, 3);
379 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
380 st->cr();
381 }
382
383 void os::Posix::print_rlimit_info(outputStream* st) {
384 st->print("rlimit:");
385 struct rlimit rlim;
386
387 st->print(" STACK ");
388 getrlimit(RLIMIT_STACK, &rlim);
389 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
390 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
391
392 st->print(", CORE ");
393 getrlimit(RLIMIT_CORE, &rlim);
394 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
395 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
396
397 // Isn't there on solaris
398 #if defined(AIX)
399 st->print(", NPROC ");
400 st->print("%d", sysconf(_SC_CHILD_MAX));
401 #elif !defined(SOLARIS)
402 st->print(", NPROC ");
403 getrlimit(RLIMIT_NPROC, &rlim);
404 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
405 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
406 #endif
407
408 st->print(", NOFILE ");
409 getrlimit(RLIMIT_NOFILE, &rlim);
410 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
411 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
412
413 st->print(", AS ");
414 getrlimit(RLIMIT_AS, &rlim);
415 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
416 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
417
418 st->print(", DATA ");
419 getrlimit(RLIMIT_DATA, &rlim);
420 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
421 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
422
423 st->print(", FSIZE ");
424 getrlimit(RLIMIT_FSIZE, &rlim);
425 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
426 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
427
428 st->cr();
429 }
430
431 void os::Posix::print_uname_info(outputStream* st) {
432 // kernel
433 st->print("uname:");
434 struct utsname name;
435 uname(&name);
436 st->print("%s ", name.sysname);
437 #ifdef ASSERT
438 st->print("%s ", name.nodename);
439 #endif
440 st->print("%s ", name.release);
441 st->print("%s ", name.version);
442 st->print("%s", name.machine);
443 st->cr();
444 }
445
446 void os::Posix::print_umask(outputStream* st, mode_t umsk) {
447 st->print((umsk & S_IRUSR) ? "r" : "-");
448 st->print((umsk & S_IWUSR) ? "w" : "-");
449 st->print((umsk & S_IXUSR) ? "x" : "-");
450 st->print((umsk & S_IRGRP) ? "r" : "-");
451 st->print((umsk & S_IWGRP) ? "w" : "-");
452 st->print((umsk & S_IXGRP) ? "x" : "-");
453 st->print((umsk & S_IROTH) ? "r" : "-");
454 st->print((umsk & S_IWOTH) ? "w" : "-");
455 st->print((umsk & S_IXOTH) ? "x" : "-");
456 }
457
458 void os::Posix::print_user_info(outputStream* st) {
459 unsigned id = (unsigned) ::getuid();
460 st->print("uid : %u ", id);
461 id = (unsigned) ::geteuid();
462 st->print("euid : %u ", id);
463 id = (unsigned) ::getgid();
464 st->print("gid : %u ", id);
465 id = (unsigned) ::getegid();
466 st->print_cr("egid : %u", id);
467 st->cr();
468
469 mode_t umsk = ::umask(0);
470 ::umask(umsk);
471 st->print("umask: %04o (", (unsigned) umsk);
472 print_umask(st, umsk);
473 st->print_cr(")");
474 st->cr();
475 }
476
477
478 bool os::get_host_name(char* buf, size_t buflen) {
479 struct utsname name;
480 uname(&name);
481 jio_snprintf(buf, buflen, "%s", name.nodename);
482 return true;
483 }
484
485 bool os::has_allocatable_memory_limit(julong* limit) {
486 struct rlimit rlim;
487 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
488 // if there was an error when calling getrlimit, assume that there is no limitation
489 // on virtual memory.
490 bool result;
491 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
492 result = false;
493 } else {
494 *limit = (julong)rlim.rlim_cur;
495 result = true;
496 }
497 #ifdef _LP64
498 return result;
499 #else
500 // arbitrary virtual space limit for 32 bit Unices found by testing. If
501 // getrlimit above returned a limit, bound it with this limit. Otherwise
502 // directly use it.
503 const julong max_virtual_limit = (julong)3800*M;
504 if (result) {
505 *limit = MIN2(*limit, max_virtual_limit);
506 } else {
507 *limit = max_virtual_limit;
508 }
509
510 // bound by actually allocatable memory. The algorithm uses two bounds, an
511 // upper and a lower limit. The upper limit is the current highest amount of
512 // memory that could not be allocated, the lower limit is the current highest
513 // amount of memory that could be allocated.
514 // The algorithm iteratively refines the result by halving the difference
515 // between these limits, updating either the upper limit (if that value could
516 // not be allocated) or the lower limit (if the that value could be allocated)
517 // until the difference between these limits is "small".
518
519 // the minimum amount of memory we care about allocating.
520 const julong min_allocation_size = M;
521
522 julong upper_limit = *limit;
523
524 // first check a few trivial cases
525 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
526 *limit = upper_limit;
527 } else if (!is_allocatable(min_allocation_size)) {
528 // we found that not even min_allocation_size is allocatable. Return it
529 // anyway. There is no point to search for a better value any more.
530 *limit = min_allocation_size;
531 } else {
532 // perform the binary search.
533 julong lower_limit = min_allocation_size;
534 while ((upper_limit - lower_limit) > min_allocation_size) {
535 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
536 temp_limit = align_down(temp_limit, min_allocation_size);
537 if (is_allocatable(temp_limit)) {
538 lower_limit = temp_limit;
539 } else {
540 upper_limit = temp_limit;
541 }
542 }
543 *limit = lower_limit;
544 }
545 return true;
546 #endif
547 }
548
549 const char* os::get_current_directory(char *buf, size_t buflen) {
550 return getcwd(buf, buflen);
551 }
552
553 FILE* os::open(int fd, const char* mode) {
554 return ::fdopen(fd, mode);
555 }
556
557 void os::flockfile(FILE* fp) {
558 ::flockfile(fp);
559 }
560
561 void os::funlockfile(FILE* fp) {
562 ::funlockfile(fp);
563 }
564
565 DIR* os::opendir(const char* dirname) {
566 assert(dirname != NULL, "just checking");
567 return ::opendir(dirname);
568 }
569
570 struct dirent* os::readdir(DIR* dirp) {
571 assert(dirp != NULL, "just checking");
572 return ::readdir(dirp);
573 }
574
575 int os::closedir(DIR *dirp) {
576 assert(dirp != NULL, "just checking");
577 return ::closedir(dirp);
578 }
579
580 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
581 // which is used to find statically linked in agents.
582 // Parameters:
583 // sym_name: Symbol in library we are looking for
584 // lib_name: Name of library to look in, NULL for shared libs.
585 // is_absolute_path == true if lib_name is absolute path to agent
586 // such as "/a/b/libL.so"
587 // == false if only the base name of the library is passed in
588 // such as "L"
589 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
590 bool is_absolute_path) {
591 char *agent_entry_name;
592 size_t len;
593 size_t name_len;
594 size_t prefix_len = strlen(JNI_LIB_PREFIX);
595 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
596 const char *start;
597
598 if (lib_name != NULL) {
599 name_len = strlen(lib_name);
600 if (is_absolute_path) {
601 // Need to strip path, prefix and suffix
602 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
603 lib_name = ++start;
604 }
605 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
606 return NULL;
607 }
608 lib_name += prefix_len;
609 name_len = strlen(lib_name) - suffix_len;
610 }
611 }
612 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
613 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
614 if (agent_entry_name == NULL) {
615 return NULL;
616 }
617 strcpy(agent_entry_name, sym_name);
618 if (lib_name != NULL) {
619 strcat(agent_entry_name, "_");
620 strncat(agent_entry_name, lib_name, name_len);
621 }
622 return agent_entry_name;
623 }
624
625 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
626 assert(thread == Thread::current(), "thread consistency check");
627
628 ParkEvent * const slp = thread->_SleepEvent ;
629 slp->reset() ;
630 OrderAccess::fence() ;
631
632 if (interruptible) {
633 jlong prevtime = javaTimeNanos();
634
635 for (;;) {
636 if (os::is_interrupted(thread, true)) {
637 return OS_INTRPT;
638 }
639
640 jlong newtime = javaTimeNanos();
641
642 if (newtime - prevtime < 0) {
643 // time moving backwards, should only happen if no monotonic clock
644 // not a guarantee() because JVM should not abort on kernel/glibc bugs
645 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
646 } else {
647 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
648 }
649
650 if (millis <= 0) {
651 return OS_OK;
652 }
653
654 prevtime = newtime;
655
656 {
657 assert(thread->is_Java_thread(), "sanity check");
658 JavaThread *jt = (JavaThread *) thread;
659 ThreadBlockInVM tbivm(jt);
660 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
661
662 jt->set_suspend_equivalent();
663 // cleared by handle_special_suspend_equivalent_condition() or
664 // java_suspend_self() via check_and_wait_while_suspended()
665
666 slp->park(millis);
667
668 // were we externally suspended while we were waiting?
669 jt->check_and_wait_while_suspended();
670 }
671 }
672 } else {
673 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
674 jlong prevtime = javaTimeNanos();
675
676 for (;;) {
677 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
678 // the 1st iteration ...
679 jlong newtime = javaTimeNanos();
680
681 if (newtime - prevtime < 0) {
682 // time moving backwards, should only happen if no monotonic clock
683 // not a guarantee() because JVM should not abort on kernel/glibc bugs
684 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
685 } else {
686 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
687 }
688
689 if (millis <= 0) break ;
690
691 prevtime = newtime;
692 slp->park(millis);
693 }
694 return OS_OK ;
695 }
696 }
697
698 ////////////////////////////////////////////////////////////////////////////////
699 // interrupt support
700
701 void os::interrupt(Thread* thread) {
702 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
703
704 OSThread* osthread = thread->osthread();
705
706 if (!osthread->interrupted()) {
707 osthread->set_interrupted(true);
708 // More than one thread can get here with the same value of osthread,
709 // resulting in multiple notifications. We do, however, want the store
710 // to interrupted() to be visible to other threads before we execute unpark().
711 OrderAccess::fence();
712 ParkEvent * const slp = thread->_SleepEvent ;
713 if (slp != NULL) slp->unpark() ;
714 }
715
716 // For JSR166. Unpark even if interrupt status already was set
717 if (thread->is_Java_thread())
718 ((JavaThread*)thread)->parker()->unpark();
719
720 ParkEvent * ev = thread->_ParkEvent ;
721 if (ev != NULL) ev->unpark() ;
722 }
723
724 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
725 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
726
727 OSThread* osthread = thread->osthread();
728
729 bool interrupted = osthread->interrupted();
730
731 // NOTE that since there is no "lock" around the interrupt and
732 // is_interrupted operations, there is the possibility that the
733 // interrupted flag (in osThread) will be "false" but that the
734 // low-level events will be in the signaled state. This is
735 // intentional. The effect of this is that Object.wait() and
736 // LockSupport.park() will appear to have a spurious wakeup, which
737 // is allowed and not harmful, and the possibility is so rare that
738 // it is not worth the added complexity to add yet another lock.
739 // For the sleep event an explicit reset is performed on entry
740 // to os::sleep, so there is no early return. It has also been
741 // recommended not to put the interrupted flag into the "event"
742 // structure because it hides the issue.
743 if (interrupted && clear_interrupted) {
744 osthread->set_interrupted(false);
745 // consider thread->_SleepEvent->reset() ... optional optimization
746 }
747
748 return interrupted;
749 }
750
751
752
753 static const struct {
754 int sig; const char* name;
755 }
756 g_signal_info[] =
757 {
758 { SIGABRT, "SIGABRT" },
759 #ifdef SIGAIO
760 { SIGAIO, "SIGAIO" },
761 #endif
762 { SIGALRM, "SIGALRM" },
763 #ifdef SIGALRM1
764 { SIGALRM1, "SIGALRM1" },
765 #endif
766 { SIGBUS, "SIGBUS" },
767 #ifdef SIGCANCEL
768 { SIGCANCEL, "SIGCANCEL" },
769 #endif
770 { SIGCHLD, "SIGCHLD" },
771 #ifdef SIGCLD
772 { SIGCLD, "SIGCLD" },
773 #endif
774 { SIGCONT, "SIGCONT" },
775 #ifdef SIGCPUFAIL
776 { SIGCPUFAIL, "SIGCPUFAIL" },
777 #endif
778 #ifdef SIGDANGER
779 { SIGDANGER, "SIGDANGER" },
780 #endif
781 #ifdef SIGDIL
782 { SIGDIL, "SIGDIL" },
783 #endif
784 #ifdef SIGEMT
785 { SIGEMT, "SIGEMT" },
786 #endif
787 { SIGFPE, "SIGFPE" },
788 #ifdef SIGFREEZE
789 { SIGFREEZE, "SIGFREEZE" },
790 #endif
791 #ifdef SIGGFAULT
792 { SIGGFAULT, "SIGGFAULT" },
793 #endif
794 #ifdef SIGGRANT
795 { SIGGRANT, "SIGGRANT" },
796 #endif
797 { SIGHUP, "SIGHUP" },
798 { SIGILL, "SIGILL" },
799 { SIGINT, "SIGINT" },
800 #ifdef SIGIO
801 { SIGIO, "SIGIO" },
802 #endif
803 #ifdef SIGIOINT
804 { SIGIOINT, "SIGIOINT" },
805 #endif
806 #ifdef SIGIOT
807 // SIGIOT is there for BSD compatibility, but on most Unices just a
808 // synonym for SIGABRT. The result should be "SIGABRT", not
809 // "SIGIOT".
810 #if (SIGIOT != SIGABRT )
811 { SIGIOT, "SIGIOT" },
812 #endif
813 #endif
814 #ifdef SIGKAP
815 { SIGKAP, "SIGKAP" },
816 #endif
817 { SIGKILL, "SIGKILL" },
818 #ifdef SIGLOST
819 { SIGLOST, "SIGLOST" },
820 #endif
821 #ifdef SIGLWP
822 { SIGLWP, "SIGLWP" },
823 #endif
824 #ifdef SIGLWPTIMER
825 { SIGLWPTIMER, "SIGLWPTIMER" },
826 #endif
827 #ifdef SIGMIGRATE
828 { SIGMIGRATE, "SIGMIGRATE" },
829 #endif
830 #ifdef SIGMSG
831 { SIGMSG, "SIGMSG" },
832 #endif
833 { SIGPIPE, "SIGPIPE" },
834 #ifdef SIGPOLL
835 { SIGPOLL, "SIGPOLL" },
836 #endif
837 #ifdef SIGPRE
838 { SIGPRE, "SIGPRE" },
839 #endif
840 { SIGPROF, "SIGPROF" },
841 #ifdef SIGPTY
842 { SIGPTY, "SIGPTY" },
843 #endif
844 #ifdef SIGPWR
845 { SIGPWR, "SIGPWR" },
846 #endif
847 { SIGQUIT, "SIGQUIT" },
848 #ifdef SIGRECONFIG
849 { SIGRECONFIG, "SIGRECONFIG" },
850 #endif
851 #ifdef SIGRECOVERY
852 { SIGRECOVERY, "SIGRECOVERY" },
853 #endif
854 #ifdef SIGRESERVE
855 { SIGRESERVE, "SIGRESERVE" },
856 #endif
857 #ifdef SIGRETRACT
858 { SIGRETRACT, "SIGRETRACT" },
859 #endif
860 #ifdef SIGSAK
861 { SIGSAK, "SIGSAK" },
862 #endif
863 { SIGSEGV, "SIGSEGV" },
864 #ifdef SIGSOUND
865 { SIGSOUND, "SIGSOUND" },
866 #endif
867 #ifdef SIGSTKFLT
868 { SIGSTKFLT, "SIGSTKFLT" },
869 #endif
870 { SIGSTOP, "SIGSTOP" },
871 { SIGSYS, "SIGSYS" },
872 #ifdef SIGSYSERROR
873 { SIGSYSERROR, "SIGSYSERROR" },
874 #endif
875 #ifdef SIGTALRM
876 { SIGTALRM, "SIGTALRM" },
877 #endif
878 { SIGTERM, "SIGTERM" },
879 #ifdef SIGTHAW
880 { SIGTHAW, "SIGTHAW" },
881 #endif
882 { SIGTRAP, "SIGTRAP" },
883 #ifdef SIGTSTP
884 { SIGTSTP, "SIGTSTP" },
885 #endif
886 { SIGTTIN, "SIGTTIN" },
887 { SIGTTOU, "SIGTTOU" },
888 #ifdef SIGURG
889 { SIGURG, "SIGURG" },
890 #endif
891 { SIGUSR1, "SIGUSR1" },
892 { SIGUSR2, "SIGUSR2" },
893 #ifdef SIGVIRT
894 { SIGVIRT, "SIGVIRT" },
895 #endif
896 { SIGVTALRM, "SIGVTALRM" },
897 #ifdef SIGWAITING
898 { SIGWAITING, "SIGWAITING" },
899 #endif
900 #ifdef SIGWINCH
901 { SIGWINCH, "SIGWINCH" },
902 #endif
903 #ifdef SIGWINDOW
904 { SIGWINDOW, "SIGWINDOW" },
905 #endif
906 { SIGXCPU, "SIGXCPU" },
907 { SIGXFSZ, "SIGXFSZ" },
908 #ifdef SIGXRES
909 { SIGXRES, "SIGXRES" },
910 #endif
911 { -1, NULL }
912 };
913
914 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
915 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
916
917 const char* ret = NULL;
918
919 #ifdef SIGRTMIN
920 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
921 if (sig == SIGRTMIN) {
922 ret = "SIGRTMIN";
923 } else if (sig == SIGRTMAX) {
924 ret = "SIGRTMAX";
925 } else {
926 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
927 return out;
928 }
929 }
930 #endif
931
932 if (sig > 0) {
933 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
934 if (g_signal_info[idx].sig == sig) {
935 ret = g_signal_info[idx].name;
936 break;
937 }
938 }
939 }
940
941 if (!ret) {
942 if (!is_valid_signal(sig)) {
943 ret = "INVALID";
944 } else {
945 ret = "UNKNOWN";
946 }
947 }
948
949 if (out && outlen > 0) {
950 strncpy(out, ret, outlen);
951 out[outlen - 1] = '\0';
952 }
953 return out;
954 }
955
956 int os::Posix::get_signal_number(const char* signal_name) {
957 char tmp[30];
958 const char* s = signal_name;
959 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
960 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
961 s = tmp;
962 }
963 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
964 if (strcmp(g_signal_info[idx].name, s) == 0) {
965 return g_signal_info[idx].sig;
966 }
967 }
968 return -1;
969 }
970
971 int os::get_signal_number(const char* signal_name) {
972 return os::Posix::get_signal_number(signal_name);
973 }
974
975 // Returns true if signal number is valid.
976 bool os::Posix::is_valid_signal(int sig) {
977 // MacOS not really POSIX compliant: sigaddset does not return
978 // an error for invalid signal numbers. However, MacOS does not
979 // support real time signals and simply seems to have just 33
980 // signals with no holes in the signal range.
981 #ifdef __APPLE__
982 return sig >= 1 && sig < NSIG;
983 #else
984 // Use sigaddset to check for signal validity.
985 sigset_t set;
986 sigemptyset(&set);
987 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
988 return false;
989 }
990 return true;
991 #endif
992 }
993
994 bool os::Posix::is_sig_ignored(int sig) {
995 struct sigaction oact;
996 sigaction(sig, (struct sigaction*)NULL, &oact);
997 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
998 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
999 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
1000 return true;
1001 } else {
1002 return false;
1003 }
1004 }
1005
1006 // Returns:
1007 // NULL for an invalid signal number
1008 // "SIG<num>" for a valid but unknown signal number
1009 // signal name otherwise.
1010 const char* os::exception_name(int sig, char* buf, size_t size) {
1011 if (!os::Posix::is_valid_signal(sig)) {
1012 return NULL;
1013 }
1014 const char* const name = os::Posix::get_signal_name(sig, buf, size);
1015 if (strcmp(name, "UNKNOWN") == 0) {
1016 jio_snprintf(buf, size, "SIG%d", sig);
1017 }
1018 return buf;
1019 }
1020
1021 #define NUM_IMPORTANT_SIGS 32
1022 // Returns one-line short description of a signal set in a user provided buffer.
1023 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
1024 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
1025 // Note: for shortness, just print out the first 32. That should
1026 // cover most of the useful ones, apart from realtime signals.
1027 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
1028 const int rc = sigismember(set, sig);
1029 if (rc == -1 && errno == EINVAL) {
1030 buffer[sig-1] = '?';
1031 } else {
1032 buffer[sig-1] = rc == 0 ? '0' : '1';
1033 }
1034 }
1035 buffer[NUM_IMPORTANT_SIGS] = 0;
1036 return buffer;
1037 }
1038
1039 // Prints one-line description of a signal set.
1040 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
1041 char buf[NUM_IMPORTANT_SIGS + 1];
1042 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
1043 st->print("%s", buf);
1044 }
1045
1046 // Writes one-line description of a combination of sigaction.sa_flags into a user
1047 // provided buffer. Returns that buffer.
1048 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
1049 char* p = buffer;
1050 size_t remaining = size;
1051 bool first = true;
1052 int idx = 0;
1053
1054 assert(buffer, "invalid argument");
1055
1056 if (size == 0) {
1057 return buffer;
1058 }
1059
1060 strncpy(buffer, "none", size);
1061
1062 const struct {
1063 // NB: i is an unsigned int here because SA_RESETHAND is on some
1064 // systems 0x80000000, which is implicitly unsigned. Assignining
1065 // it to an int field would be an overflow in unsigned-to-signed
1066 // conversion.
1067 unsigned int i;
1068 const char* s;
1069 } flaginfo [] = {
1070 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
1071 { SA_ONSTACK, "SA_ONSTACK" },
1072 { SA_RESETHAND, "SA_RESETHAND" },
1073 { SA_RESTART, "SA_RESTART" },
1074 { SA_SIGINFO, "SA_SIGINFO" },
1075 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
1076 { SA_NODEFER, "SA_NODEFER" },
1077 #ifdef AIX
1078 { SA_ONSTACK, "SA_ONSTACK" },
1079 { SA_OLDSTYLE, "SA_OLDSTYLE" },
1080 #endif
1081 { 0, NULL }
1082 };
1083
1084 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
1085 if (flags & flaginfo[idx].i) {
1086 if (first) {
1087 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
1088 first = false;
1089 } else {
1090 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
1091 }
1092 const size_t len = strlen(p);
1093 p += len;
1094 remaining -= len;
1095 }
1096 }
1097
1098 buffer[size - 1] = '\0';
1099
1100 return buffer;
1101 }
1102
1103 // Prints one-line description of a combination of sigaction.sa_flags.
1104 void os::Posix::print_sa_flags(outputStream* st, int flags) {
1105 char buffer[0x100];
1106 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
1107 st->print("%s", buffer);
1108 }
1109
1110 // Helper function for os::Posix::print_siginfo_...():
1111 // return a textual description for signal code.
1112 struct enum_sigcode_desc_t {
1113 const char* s_name;
1114 const char* s_desc;
1115 };
1116
1117 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
1118
1119 const struct {
1120 int sig; int code; const char* s_code; const char* s_desc;
1121 } t1 [] = {
1122 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
1123 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
1124 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
1125 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
1126 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
1127 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
1128 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
1129 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
1130 #if defined(IA64) && defined(LINUX)
1131 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
1132 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
1133 #endif
1134 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
1135 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
1136 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
1137 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
1138 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
1139 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
1140 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
1141 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
1142 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
1143 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
1144 #ifdef AIX
1145 // no explanation found what keyerr would be
1146 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
1147 #endif
1148 #if defined(IA64) && !defined(AIX)
1149 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
1150 #endif
1151 #if defined(__sparc) && defined(SOLARIS)
1152 // define Solaris Sparc M7 ADI SEGV signals
1153 #if !defined(SEGV_ACCADI)
1154 #define SEGV_ACCADI 3
1155 #endif
1156 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
1157 #if !defined(SEGV_ACCDERR)
1158 #define SEGV_ACCDERR 4
1159 #endif
1160 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
1161 #if !defined(SEGV_ACCPERR)
1162 #define SEGV_ACCPERR 5
1163 #endif
1164 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
1165 #endif // defined(__sparc) && defined(SOLARIS)
1166 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
1167 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
1168 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
1169 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
1170 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
1171 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
1172 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
1173 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
1174 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
1175 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
1176 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
1177 #ifdef SIGPOLL
1178 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
1179 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
1180 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
1181 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
1182 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
1183 #endif
1184 { -1, -1, NULL, NULL }
1185 };
1186
1187 // Codes valid in any signal context.
1188 const struct {
1189 int code; const char* s_code; const char* s_desc;
1190 } t2 [] = {
1191 { SI_USER, "SI_USER", "Signal sent by kill()." },
1192 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
1193 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
1194 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
1195 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
1196 // Linux specific
1197 #ifdef SI_TKILL
1198 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
1199 #endif
1200 #ifdef SI_DETHREAD
1201 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
1202 #endif
1203 #ifdef SI_KERNEL
1204 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
1205 #endif
1206 #ifdef SI_SIGIO
1207 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
1208 #endif
1209
1210 #ifdef AIX
1211 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
1212 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
1213 #endif
1214
1215 #ifdef __sun
1216 { SI_NOINFO, "SI_NOINFO", "No signal information" },
1217 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
1218 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
1219 #endif
1220
1221 { -1, NULL, NULL }
1222 };
1223
1224 const char* s_code = NULL;
1225 const char* s_desc = NULL;
1226
1227 for (int i = 0; t1[i].sig != -1; i ++) {
1228 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
1229 s_code = t1[i].s_code;
1230 s_desc = t1[i].s_desc;
1231 break;
1232 }
1233 }
1234
1235 if (s_code == NULL) {
1236 for (int i = 0; t2[i].s_code != NULL; i ++) {
1237 if (t2[i].code == si->si_code) {
1238 s_code = t2[i].s_code;
1239 s_desc = t2[i].s_desc;
1240 }
1241 }
1242 }
1243
1244 if (s_code == NULL) {
1245 out->s_name = "unknown";
1246 out->s_desc = "unknown";
1247 return false;
1248 }
1249
1250 out->s_name = s_code;
1251 out->s_desc = s_desc;
1252
1253 return true;
1254 }
1255
1256 void os::print_siginfo(outputStream* os, const void* si0) {
1257
1258 const siginfo_t* const si = (const siginfo_t*) si0;
1259
1260 char buf[20];
1261 os->print("siginfo:");
1262
1263 if (!si) {
1264 os->print(" <null>");
1265 return;
1266 }
1267
1268 const int sig = si->si_signo;
1269
1270 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1271
1272 enum_sigcode_desc_t ed;
1273 get_signal_code_description(si, &ed);
1274 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1275
1276 if (si->si_errno) {
1277 os->print(", si_errno: %d", si->si_errno);
1278 }
1279
1280 // Output additional information depending on the signal code.
1281
1282 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1283 // so it depends on the context which member to use. For synchronous error signals,
1284 // we print si_addr, unless the signal was sent by another process or thread, in
1285 // which case we print out pid or tid of the sender.
1286 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
1287 const pid_t pid = si->si_pid;
1288 os->print(", si_pid: %ld", (long) pid);
1289 if (IS_VALID_PID(pid)) {
1290 const pid_t me = getpid();
1291 if (me == pid) {
1292 os->print(" (current process)");
1293 }
1294 } else {
1295 os->print(" (invalid)");
1296 }
1297 os->print(", si_uid: %ld", (long) si->si_uid);
1298 if (sig == SIGCHLD) {
1299 os->print(", si_status: %d", si->si_status);
1300 }
1301 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1302 sig == SIGTRAP || sig == SIGFPE) {
1303 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1304 #ifdef SIGPOLL
1305 } else if (sig == SIGPOLL) {
1306 os->print(", si_band: %ld", si->si_band);
1307 #endif
1308 }
1309
1310 }
1311
1312 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1313 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1314 }
1315
1316 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1317 #if defined(AIX)
1318 return Aix::ucontext_get_pc(ctx);
1319 #elif defined(BSD)
1320 return Bsd::ucontext_get_pc(ctx);
1321 #elif defined(LINUX)
1322 return Linux::ucontext_get_pc(ctx);
1323 #elif defined(SOLARIS)
1324 return Solaris::ucontext_get_pc(ctx);
1325 #else
1326 VMError::report_and_die("unimplemented ucontext_get_pc");
1327 #endif
1328 }
1329
1330 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1331 #if defined(AIX)
1332 Aix::ucontext_set_pc(ctx, pc);
1333 #elif defined(BSD)
1334 Bsd::ucontext_set_pc(ctx, pc);
1335 #elif defined(LINUX)
1336 Linux::ucontext_set_pc(ctx, pc);
1337 #elif defined(SOLARIS)
1338 Solaris::ucontext_set_pc(ctx, pc);
1339 #else
1340 VMError::report_and_die("unimplemented ucontext_get_pc");
1341 #endif
1342 }
1343
1344 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1345 size_t stack_size = 0;
1346 size_t guard_size = 0;
1347 int detachstate = 0;
1348 pthread_attr_getstacksize(attr, &stack_size);
1349 pthread_attr_getguardsize(attr, &guard_size);
1350 // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
1351 LINUX_ONLY(stack_size -= guard_size);
1352 pthread_attr_getdetachstate(attr, &detachstate);
1353 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1354 stack_size / 1024, guard_size / 1024,
1355 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1356 return buf;
1357 }
1358
1359 char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
1360
1361 if (filename == NULL || outbuf == NULL || outbuflen < 1) {
1362 assert(false, "os::Posix::realpath: invalid arguments.");
1363 errno = EINVAL;
1364 return NULL;
1365 }
1366
1367 char* result = NULL;
1368
1369 // This assumes platform realpath() is implemented according to POSIX.1-2008.
1370 // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
1371 // output buffer is dynamically allocated and must be ::free()'d by the caller.
1372 char* p = ::realpath(filename, NULL);
1373 if (p != NULL) {
1374 if (strlen(p) < outbuflen) {
1375 strcpy(outbuf, p);
1376 result = outbuf;
1377 } else {
1378 errno = ENAMETOOLONG;
1379 }
1380 ::free(p); // *not* os::free
1381 } else {
1382 // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
1383 // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
1384 // that it complains about the NULL we handed down as user buffer.
1385 // In this case, use the user provided buffer but at least check whether realpath caused
1386 // a memory overwrite.
1387 if (errno == EINVAL) {
1388 outbuf[outbuflen - 1] = '\0';
1389 p = ::realpath(filename, outbuf);
1390 if (p != NULL) {
1391 guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
1392 result = p;
1393 }
1394 }
1395 }
1396 return result;
1397
1398 }
1399
1400 int os::stat(const char *path, struct stat *sbuf) {
1401 return ::stat(path, sbuf);
1402 }
1403
1404 char * os::native_path(char *path) {
1405 return path;
1406 }
1407
1408 // Check minimum allowable stack sizes for thread creation and to initialize
1409 // the java system classes, including StackOverflowError - depends on page
1410 // size.
1411 // The space needed for frames during startup is platform dependent. It
1412 // depends on word size, platform calling conventions, C frame layout and
1413 // interpreter/C1/C2 design decisions. Therefore this is given in a
1414 // platform (os/cpu) dependent constant.
1415 // To this, space for guard mechanisms is added, which depends on the
1416 // page size which again depends on the concrete system the VM is running
1417 // on. Space for libc guard pages is not included in this size.
1418 jint os::Posix::set_minimum_stack_sizes() {
1419 size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
1420
1421 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
1422 JavaThread::stack_guard_zone_size() +
1423 JavaThread::stack_shadow_zone_size();
1424
1425 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
1426 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
1427
1428 size_t stack_size_in_bytes = ThreadStackSize * K;
1429 if (stack_size_in_bytes != 0 &&
1430 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1431 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1432 // ThreadStackSize so we go with "Java thread stack size" instead
1433 // of "ThreadStackSize" to be more friendly.
1434 tty->print_cr("\nThe Java thread stack size specified is too small. "
1435 "Specify at least " SIZE_FORMAT "k",
1436 _java_thread_min_stack_allowed / K);
1437 return JNI_ERR;
1438 }
1439
1440 // Make the stack size a multiple of the page size so that
1441 // the yellow/red zones can be guarded.
1442 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
1443
1444 // Reminder: a compiler thread is a Java thread.
1445 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
1446 JavaThread::stack_guard_zone_size() +
1447 JavaThread::stack_shadow_zone_size();
1448
1449 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
1450 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
1451
1452 stack_size_in_bytes = CompilerThreadStackSize * K;
1453 if (stack_size_in_bytes != 0 &&
1454 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1455 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1456 "Specify at least " SIZE_FORMAT "k",
1457 _compiler_thread_min_stack_allowed / K);
1458 return JNI_ERR;
1459 }
1460
1461 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1462 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
1463
1464 stack_size_in_bytes = VMThreadStackSize * K;
1465 if (stack_size_in_bytes != 0 &&
1466 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1467 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1468 "Specify at least " SIZE_FORMAT "k",
1469 _vm_internal_thread_min_stack_allowed / K);
1470 return JNI_ERR;
1471 }
1472 return JNI_OK;
1473 }
1474
1475 // Called when creating the thread. The minimum stack sizes have already been calculated
1476 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1477 size_t stack_size;
1478 if (req_stack_size == 0) {
1479 stack_size = default_stack_size(thr_type);
1480 } else {
1481 stack_size = req_stack_size;
1482 }
1483
1484 switch (thr_type) {
1485 case os::java_thread:
1486 // Java threads use ThreadStackSize which default value can be
1487 // changed with the flag -Xss
1488 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1489 // no requested size and we have a more specific default value
1490 stack_size = JavaThread::stack_size_at_create();
1491 }
1492 stack_size = MAX2(stack_size,
1493 _java_thread_min_stack_allowed);
1494 break;
1495 case os::compiler_thread:
1496 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1497 // no requested size and we have a more specific default value
1498 stack_size = (size_t)(CompilerThreadStackSize * K);
1499 }
1500 stack_size = MAX2(stack_size,
1501 _compiler_thread_min_stack_allowed);
1502 break;
1503 case os::vm_thread:
1504 case os::pgc_thread:
1505 case os::cgc_thread:
1506 case os::watcher_thread:
1507 default: // presume the unknown thr_type is a VM internal
1508 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1509 // no requested size and we have a more specific default value
1510 stack_size = (size_t)(VMThreadStackSize * K);
1511 }
1512
1513 stack_size = MAX2(stack_size,
1514 _vm_internal_thread_min_stack_allowed);
1515 break;
1516 }
1517
1518 // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
1519 // Be careful not to round up to 0. Align down in that case.
1520 if (stack_size <= SIZE_MAX - vm_page_size()) {
1521 stack_size = align_up(stack_size, vm_page_size());
1522 } else {
1523 stack_size = align_down(stack_size, vm_page_size());
1524 }
1525
1526 return stack_size;
1527 }
1528
1529 bool os::Posix::is_root(uid_t uid){
1530 return ROOT_UID == uid;
1531 }
1532
1533 bool os::Posix::matches_effective_uid_or_root(uid_t uid) {
1534 return is_root(uid) || geteuid() == uid;
1535 }
1536
1537 bool os::Posix::matches_effective_uid_and_gid_or_root(uid_t uid, gid_t gid) {
1538 return is_root(uid) || (geteuid() == uid && getegid() == gid);
1539 }
1540
1541 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
1542 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
1543 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
1544
1545 os::ThreadCrashProtection::ThreadCrashProtection() {
1546 }
1547
1548 /*
1549 * See the caveats for this class in os_posix.hpp
1550 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1551 * method and returns false. If none of the signals are raised, returns true.
1552 * The callback is supposed to provide the method that should be protected.
1553 */
1554 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1555 sigset_t saved_sig_mask;
1556
1557 Thread::muxAcquire(&_crash_mux, "CrashProtection");
1558
1559 _protected_thread = Thread::current_or_null();
1560 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
1561
1562 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1563 // since on at least some systems (OS X) siglongjmp will restore the mask
1564 // for the process, not the thread
1565 pthread_sigmask(0, NULL, &saved_sig_mask);
1566 if (sigsetjmp(_jmpbuf, 0) == 0) {
1567 // make sure we can see in the signal handler that we have crash protection
1568 // installed
1569 _crash_protection = this;
1570 cb.call();
1571 // and clear the crash protection
1572 _crash_protection = NULL;
1573 _protected_thread = NULL;
1574 Thread::muxRelease(&_crash_mux);
1575 return true;
1576 }
1577 // this happens when we siglongjmp() back
1578 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1579 _crash_protection = NULL;
1580 _protected_thread = NULL;
1581 Thread::muxRelease(&_crash_mux);
1582 return false;
1583 }
1584
1585 void os::ThreadCrashProtection::restore() {
1586 assert(_crash_protection != NULL, "must have crash protection");
1587 siglongjmp(_jmpbuf, 1);
1588 }
1589
1590 void os::ThreadCrashProtection::check_crash_protection(int sig,
1591 Thread* thread) {
1592
1593 if (thread != NULL &&
1594 thread == _protected_thread &&
1595 _crash_protection != NULL) {
1596
1597 if (sig == SIGSEGV || sig == SIGBUS) {
1598 _crash_protection->restore();
1599 }
1600 }
1601 }
1602
1603
1604 // Shared pthread_mutex/cond based PlatformEvent implementation.
1605 // Not currently usable by Solaris.
1606
1607 #ifndef SOLARIS
1608
1609 // Shared condattr object for use with relative timed-waits. Will be associated
1610 // with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
1611 // but otherwise whatever default is used by the platform - generally the
1612 // time-of-day clock.
1613 static pthread_condattr_t _condAttr[1];
1614
1615 // Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
1616 // all systems (e.g. FreeBSD) map the default to "normal".
1617 static pthread_mutexattr_t _mutexAttr[1];
1618
1619 // common basic initialization that is always supported
1620 static void pthread_init_common(void) {
1621 int status;
1622 if ((status = pthread_condattr_init(_condAttr)) != 0) {
1623 fatal("pthread_condattr_init: %s", os::strerror(status));
1624 }
1625 if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
1626 fatal("pthread_mutexattr_init: %s", os::strerror(status));
1627 }
1628 if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
1629 fatal("pthread_mutexattr_settype: %s", os::strerror(status));
1630 }
1631 }
1632
1633 // Not all POSIX types and API's are available on all notionally "posix"
1634 // platforms. If we have build-time support then we will check for actual
1635 // runtime support via dlopen/dlsym lookup. This allows for running on an
1636 // older OS version compared to the build platform. But if there is no
1637 // build time support then there cannot be any runtime support as we do not
1638 // know what the runtime types would be (for example clockid_t might be an
1639 // int or int64_t).
1640 //
1641 #ifdef SUPPORTS_CLOCK_MONOTONIC
1642
1643 // This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
1644
1645 static int (*_clock_gettime)(clockid_t, struct timespec *);
1646 static int (*_clock_getres)(clockid_t, struct timespec *);
1647 static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t);
1648
1649 static bool _use_clock_monotonic_condattr;
1650
1651 // Exported clock functionality
1652
1653 int os::Posix::clock_gettime(clockid_t clock_id, struct timespec *tp) {
1654 return _clock_gettime != NULL ? _clock_gettime(clock_id, tp) : -1;
1655 }
1656
1657 int os::Posix::clock_getres(clockid_t clock_id, struct timespec *tp) {
1658 return _clock_getres != NULL ? _clock_getres(clock_id, tp) : -1;
1659 }
1660
1661 bool os::Posix::supports_monotonic_clock() {
1662 return _clock_gettime != NULL;
1663 }
1664
1665 // Determine what POSIX API's are present and do appropriate
1666 // configuration.
1667 void os::Posix::init(void) {
1668
1669 // NOTE: no logging available when this is called. Put logging
1670 // statements in init_2().
1671
1672 // 1. Check for CLOCK_MONOTONIC support.
1673
1674 void* handle = NULL;
1675
1676 // For linux we need librt, for other OS we can find
1677 // this function in regular libc.
1678 #ifdef NEEDS_LIBRT
1679 // We do dlopen's in this particular order due to bug in linux
1680 // dynamic loader (see 6348968) leading to crash on exit.
1681 handle = dlopen("librt.so.1", RTLD_LAZY);
1682 if (handle == NULL) {
1683 handle = dlopen("librt.so", RTLD_LAZY);
1684 }
1685 #endif
1686
1687 if (handle == NULL) {
1688 handle = RTLD_DEFAULT;
1689 }
1690
1691 _clock_gettime = NULL;
1692 _clock_getres = NULL;
1693
1694 int (*clock_getres_func)(clockid_t, struct timespec*) =
1695 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1696 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1697 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1698 if (clock_getres_func != NULL && clock_gettime_func != NULL) {
1699 // We assume that if both clock_gettime and clock_getres support
1700 // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
1701 struct timespec res;
1702 struct timespec tp;
1703 if (clock_getres_func(CLOCK_MONOTONIC, &res) == 0 &&
1704 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1705 // Yes, monotonic clock is supported.
1706 _clock_gettime = clock_gettime_func;
1707 _clock_getres = clock_getres_func;
1708 } else {
1709 #ifdef NEEDS_LIBRT
1710 // Close librt if there is no monotonic clock.
1711 if (handle != RTLD_DEFAULT) {
1712 dlclose(handle);
1713 }
1714 #endif
1715 }
1716 }
1717
1718 // 2. Check for pthread_condattr_setclock support.
1719
1720 _pthread_condattr_setclock = NULL;
1721
1722 // libpthread is already loaded.
1723 int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
1724 (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
1725 "pthread_condattr_setclock");
1726 if (condattr_setclock_func != NULL) {
1727 _pthread_condattr_setclock = condattr_setclock_func;
1728 }
1729
1730 // Now do general initialization.
1731
1732 pthread_init_common();
1733
1734 int status;
1735 if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
1736 if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
1737 if (status == EINVAL) {
1738 _use_clock_monotonic_condattr = false;
1739 warning("Unable to use monotonic clock with relative timed-waits" \
1740 " - changes to the time-of-day clock may have adverse affects");
1741 } else {
1742 fatal("pthread_condattr_setclock: %s", os::strerror(status));
1743 }
1744 } else {
1745 _use_clock_monotonic_condattr = true;
1746 }
1747 } else {
1748 _use_clock_monotonic_condattr = false;
1749 }
1750 }
1751
1752 void os::Posix::init_2(void) {
1753 log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
1754 (_clock_gettime != NULL ? "" : " not"));
1755 log_info(os)("Use of pthread_condattr_setclock is%s supported",
1756 (_pthread_condattr_setclock != NULL ? "" : " not"));
1757 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
1758 _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
1759 }
1760
1761 #else // !SUPPORTS_CLOCK_MONOTONIC
1762
1763 void os::Posix::init(void) {
1764 pthread_init_common();
1765 }
1766
1767 void os::Posix::init_2(void) {
1768 log_info(os)("Use of CLOCK_MONOTONIC is not supported");
1769 log_info(os)("Use of pthread_condattr_setclock is not supported");
1770 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
1771 }
1772
1773 #endif // SUPPORTS_CLOCK_MONOTONIC
1774
1775 os::PlatformEvent::PlatformEvent() {
1776 int status = pthread_cond_init(_cond, _condAttr);
1777 assert_status(status == 0, status, "cond_init");
1778 status = pthread_mutex_init(_mutex, _mutexAttr);
1779 assert_status(status == 0, status, "mutex_init");
1780 _event = 0;
1781 _nParked = 0;
1782 }
1783
1784 // Utility to convert the given timeout to an absolute timespec
1785 // (based on the appropriate clock) to use with pthread_cond_timewait.
1786 // The clock queried here must be the clock used to manage the
1787 // timeout of the condition variable.
1788 //
1789 // The passed in timeout value is either a relative time in nanoseconds
1790 // or an absolute time in milliseconds. A relative timeout will be
1791 // associated with CLOCK_MONOTONIC if available; otherwise, or if absolute,
1792 // the default time-of-day clock will be used.
1793
1794 // Given time is a 64-bit value and the time_t used in the timespec is
1795 // sometimes a signed-32-bit value we have to watch for overflow if times
1796 // way in the future are given. Further on Solaris versions
1797 // prior to 10 there is a restriction (see cond_timedwait) that the specified
1798 // number of seconds, in abstime, is less than current_time + 100000000.
1799 // As it will be over 20 years before "now + 100000000" will overflow we can
1800 // ignore overflow and just impose a hard-limit on seconds using the value
1801 // of "now + 100000000". This places a limit on the timeout of about 3.17
1802 // years from "now".
1803 //
1804 #define MAX_SECS 100000000
1805
1806 // Calculate a new absolute time that is "timeout" nanoseconds from "now".
1807 // "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
1808 // on which clock is being used).
1809 static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
1810 jlong now_part_sec, jlong unit) {
1811 time_t max_secs = now_sec + MAX_SECS;
1812
1813 jlong seconds = timeout / NANOUNITS;
1814 timeout %= NANOUNITS; // remaining nanos
1815
1816 if (seconds >= MAX_SECS) {
1817 // More seconds than we can add, so pin to max_secs.
1818 abstime->tv_sec = max_secs;
1819 abstime->tv_nsec = 0;
1820 } else {
1821 abstime->tv_sec = now_sec + seconds;
1822 long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
1823 if (nanos >= NANOUNITS) { // overflow
1824 abstime->tv_sec += 1;
1825 nanos -= NANOUNITS;
1826 }
1827 abstime->tv_nsec = nanos;
1828 }
1829 }
1830
1831 // Unpack the given deadline in milliseconds since the epoch, into the given timespec.
1832 // The current time in seconds is also passed in to enforce an upper bound as discussed above.
1833 static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
1834 time_t max_secs = now_sec + MAX_SECS;
1835
1836 jlong seconds = deadline / MILLIUNITS;
1837 jlong millis = deadline % MILLIUNITS;
1838
1839 if (seconds >= max_secs) {
1840 // Absolute seconds exceeds allowed max, so pin to max_secs.
1841 abstime->tv_sec = max_secs;
1842 abstime->tv_nsec = 0;
1843 } else {
1844 abstime->tv_sec = seconds;
1845 abstime->tv_nsec = millis * (NANOUNITS / MILLIUNITS);
1846 }
1847 }
1848
1849 static void to_abstime(timespec* abstime, jlong timeout, bool isAbsolute) {
1850 DEBUG_ONLY(int max_secs = MAX_SECS;)
1851
1852 if (timeout < 0) {
1853 timeout = 0;
1854 }
1855
1856 #ifdef SUPPORTS_CLOCK_MONOTONIC
1857
1858 if (_use_clock_monotonic_condattr && !isAbsolute) {
1859 struct timespec now;
1860 int status = _clock_gettime(CLOCK_MONOTONIC, &now);
1861 assert_status(status == 0, status, "clock_gettime");
1862 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
1863 DEBUG_ONLY(max_secs += now.tv_sec;)
1864 } else {
1865
1866 #else
1867
1868 { // Match the block scope.
1869
1870 #endif // SUPPORTS_CLOCK_MONOTONIC
1871
1872 // Time-of-day clock is all we can reliably use.
1873 struct timeval now;
1874 int status = gettimeofday(&now, NULL);
1875 assert_status(status == 0, errno, "gettimeofday");
1876 if (isAbsolute) {
1877 unpack_abs_time(abstime, timeout, now.tv_sec);
1878 } else {
1879 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
1880 }
1881 DEBUG_ONLY(max_secs += now.tv_sec;)
1882 }
1883
1884 assert(abstime->tv_sec >= 0, "tv_sec < 0");
1885 assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
1886 assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
1887 assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
1888 }
1889
1890 // PlatformEvent
1891 //
1892 // Assumption:
1893 // Only one parker can exist on an event, which is why we allocate
1894 // them per-thread. Multiple unparkers can coexist.
1895 //
1896 // _event serves as a restricted-range semaphore.
1897 // -1 : thread is blocked, i.e. there is a waiter
1898 // 0 : neutral: thread is running or ready,
1899 // could have been signaled after a wait started
1900 // 1 : signaled - thread is running or ready
1901 //
1902 // Having three states allows for some detection of bad usage - see
1903 // comments on unpark().
1904
1905 void os::PlatformEvent::park() { // AKA "down()"
1906 // Transitions for _event:
1907 // -1 => -1 : illegal
1908 // 1 => 0 : pass - return immediately
1909 // 0 => -1 : block; then set _event to 0 before returning
1910
1911 // Invariant: Only the thread associated with the PlatformEvent
1912 // may call park().
1913 assert(_nParked == 0, "invariant");
1914
1915 int v;
1916
1917 // atomically decrement _event
1918 for (;;) {
1919 v = _event;
1920 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1921 }
1922 guarantee(v >= 0, "invariant");
1923
1924 if (v == 0) { // Do this the hard way by blocking ...
1925 int status = pthread_mutex_lock(_mutex);
1926 assert_status(status == 0, status, "mutex_lock");
1927 guarantee(_nParked == 0, "invariant");
1928 ++_nParked;
1929 while (_event < 0) {
1930 // OS-level "spurious wakeups" are ignored
1931 status = pthread_cond_wait(_cond, _mutex);
1932 assert_status(status == 0, status, "cond_wait");
1933 }
1934 --_nParked;
1935
1936 _event = 0;
1937 status = pthread_mutex_unlock(_mutex);
1938 assert_status(status == 0, status, "mutex_unlock");
1939 // Paranoia to ensure our locked and lock-free paths interact
1940 // correctly with each other.
1941 OrderAccess::fence();
1942 }
1943 guarantee(_event >= 0, "invariant");
1944 }
1945
1946 int os::PlatformEvent::park(jlong millis) {
1947 // Transitions for _event:
1948 // -1 => -1 : illegal
1949 // 1 => 0 : pass - return immediately
1950 // 0 => -1 : block; then set _event to 0 before returning
1951
1952 // Invariant: Only the thread associated with the Event/PlatformEvent
1953 // may call park().
1954 assert(_nParked == 0, "invariant");
1955
1956 int v;
1957 // atomically decrement _event
1958 for (;;) {
1959 v = _event;
1960 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1961 }
1962 guarantee(v >= 0, "invariant");
1963
1964 if (v == 0) { // Do this the hard way by blocking ...
1965 struct timespec abst;
1966 // We have to watch for overflow when converting millis to nanos,
1967 // but if millis is that large then we will end up limiting to
1968 // MAX_SECS anyway, so just do that here.
1969 if (millis / MILLIUNITS > MAX_SECS) {
1970 millis = jlong(MAX_SECS) * MILLIUNITS;
1971 }
1972 to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false);
1973
1974 int ret = OS_TIMEOUT;
1975 int status = pthread_mutex_lock(_mutex);
1976 assert_status(status == 0, status, "mutex_lock");
1977 guarantee(_nParked == 0, "invariant");
1978 ++_nParked;
1979
1980 while (_event < 0) {
1981 status = pthread_cond_timedwait(_cond, _mutex, &abst);
1982 assert_status(status == 0 || status == ETIMEDOUT,
1983 status, "cond_timedwait");
1984 // OS-level "spurious wakeups" are ignored unless the archaic
1985 // FilterSpuriousWakeups is set false. That flag should be obsoleted.
1986 if (!FilterSpuriousWakeups) break;
1987 if (status == ETIMEDOUT) break;
1988 }
1989 --_nParked;
1990
1991 if (_event >= 0) {
1992 ret = OS_OK;
1993 }
1994
1995 _event = 0;
1996 status = pthread_mutex_unlock(_mutex);
1997 assert_status(status == 0, status, "mutex_unlock");
1998 // Paranoia to ensure our locked and lock-free paths interact
1999 // correctly with each other.
2000 OrderAccess::fence();
2001 return ret;
2002 }
2003 return OS_OK;
2004 }
2005
2006 void os::PlatformEvent::unpark() {
2007 // Transitions for _event:
2008 // 0 => 1 : just return
2009 // 1 => 1 : just return
2010 // -1 => either 0 or 1; must signal target thread
2011 // That is, we can safely transition _event from -1 to either
2012 // 0 or 1.
2013 // See also: "Semaphores in Plan 9" by Mullender & Cox
2014 //
2015 // Note: Forcing a transition from "-1" to "1" on an unpark() means
2016 // that it will take two back-to-back park() calls for the owning
2017 // thread to block. This has the benefit of forcing a spurious return
2018 // from the first park() call after an unpark() call which will help
2019 // shake out uses of park() and unpark() without checking state conditions
2020 // properly. This spurious return doesn't manifest itself in any user code
2021 // but only in the correctly written condition checking loops of ObjectMonitor,
2022 // Mutex/Monitor, Thread::muxAcquire and os::sleep
2023
2024 if (Atomic::xchg(1, &_event) >= 0) return;
2025
2026 int status = pthread_mutex_lock(_mutex);
2027 assert_status(status == 0, status, "mutex_lock");
2028 int anyWaiters = _nParked;
2029 assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
2030 status = pthread_mutex_unlock(_mutex);
2031 assert_status(status == 0, status, "mutex_unlock");
2032
2033 // Note that we signal() *after* dropping the lock for "immortal" Events.
2034 // This is safe and avoids a common class of futile wakeups. In rare
2035 // circumstances this can cause a thread to return prematurely from
2036 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2037 // will simply re-test the condition and re-park itself.
2038 // This provides particular benefit if the underlying platform does not
2039 // provide wait morphing.
2040
2041 if (anyWaiters != 0) {
2042 status = pthread_cond_signal(_cond);
2043 assert_status(status == 0, status, "cond_signal");
2044 }
2045 }
2046
2047 // JSR166 support
2048
2049 os::PlatformParker::PlatformParker() {
2050 int status;
2051 status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
2052 assert_status(status == 0, status, "cond_init rel");
2053 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
2054 assert_status(status == 0, status, "cond_init abs");
2055 status = pthread_mutex_init(_mutex, _mutexAttr);
2056 assert_status(status == 0, status, "mutex_init");
2057 _cur_index = -1; // mark as unused
2058 }
2059
2060 // Parker::park decrements count if > 0, else does a condvar wait. Unpark
2061 // sets count to 1 and signals condvar. Only one thread ever waits
2062 // on the condvar. Contention seen when trying to park implies that someone
2063 // is unparking you, so don't wait. And spurious returns are fine, so there
2064 // is no need to track notifications.
2065
2066 void Parker::park(bool isAbsolute, jlong time) {
2067
2068 // Optional fast-path check:
2069 // Return immediately if a permit is available.
2070 // We depend on Atomic::xchg() having full barrier semantics
2071 // since we are doing a lock-free update to _counter.
2072 if (Atomic::xchg(0, &_counter) > 0) return;
2073
2074 Thread* thread = Thread::current();
2075 assert(thread->is_Java_thread(), "Must be JavaThread");
2076 JavaThread *jt = (JavaThread *)thread;
2077
2078 // Optional optimization -- avoid state transitions if there's
2079 // an interrupt pending.
2080 if (Thread::is_interrupted(thread, false)) {
2081 return;
2082 }
2083
2084 // Next, demultiplex/decode time arguments
2085 struct timespec absTime;
2086 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
2087 return;
2088 }
2089 if (time > 0) {
2090 to_abstime(&absTime, time, isAbsolute);
2091 }
2092
2093 // Enter safepoint region
2094 // Beware of deadlocks such as 6317397.
2095 // The per-thread Parker:: mutex is a classic leaf-lock.
2096 // In particular a thread must never block on the Threads_lock while
2097 // holding the Parker:: mutex. If safepoints are pending both the
2098 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
2099 ThreadBlockInVM tbivm(jt);
2100
2101 // Don't wait if cannot get lock since interference arises from
2102 // unparking. Also re-check interrupt before trying wait.
2103 if (Thread::is_interrupted(thread, false) ||
2104 pthread_mutex_trylock(_mutex) != 0) {
2105 return;
2106 }
2107
2108 int status;
2109 if (_counter > 0) { // no wait needed
2110 _counter = 0;
2111 status = pthread_mutex_unlock(_mutex);
2112 assert_status(status == 0, status, "invariant");
2113 // Paranoia to ensure our locked and lock-free paths interact
2114 // correctly with each other and Java-level accesses.
2115 OrderAccess::fence();
2116 return;
2117 }
2118
2119 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2120 jt->set_suspend_equivalent();
2121 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2122
2123 assert(_cur_index == -1, "invariant");
2124 if (time == 0) {
2125 _cur_index = REL_INDEX; // arbitrary choice when not timed
2126 status = pthread_cond_wait(&_cond[_cur_index], _mutex);
2127 assert_status(status == 0, status, "cond_timedwait");
2128 }
2129 else {
2130 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
2131 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
2132 assert_status(status == 0 || status == ETIMEDOUT,
2133 status, "cond_timedwait");
2134 }
2135 _cur_index = -1;
2136
2137 _counter = 0;
2138 status = pthread_mutex_unlock(_mutex);
2139 assert_status(status == 0, status, "invariant");
2140 // Paranoia to ensure our locked and lock-free paths interact
2141 // correctly with each other and Java-level accesses.
2142 OrderAccess::fence();
2143
2144 // If externally suspended while waiting, re-suspend
2145 if (jt->handle_special_suspend_equivalent_condition()) {
2146 jt->java_suspend_self();
2147 }
2148 }
2149
2150 void Parker::unpark() {
2151 int status = pthread_mutex_lock(_mutex);
2152 assert_status(status == 0, status, "invariant");
2153 const int s = _counter;
2154 _counter = 1;
2155 // must capture correct index before unlocking
2156 int index = _cur_index;
2157 status = pthread_mutex_unlock(_mutex);
2158 assert_status(status == 0, status, "invariant");
2159
2160 // Note that we signal() *after* dropping the lock for "immortal" Events.
2161 // This is safe and avoids a common class of futile wakeups. In rare
2162 // circumstances this can cause a thread to return prematurely from
2163 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2164 // will simply re-test the condition and re-park itself.
2165 // This provides particular benefit if the underlying platform does not
2166 // provide wait morphing.
2167
2168 if (s < 1 && index != -1) {
2169 // thread is definitely parked
2170 status = pthread_cond_signal(&_cond[index]);
2171 assert_status(status == 0, status, "invariant");
2172 }
2173 }
2174
2175
2176 #endif // !SOLARIS