1 /*
2 * Copyright (c) 1999, 2019, 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 "os_posix.inline.hpp"
29 #include "utilities/globalDefinitions.hpp"
30 #include "runtime/frame.inline.hpp"
31 #include "runtime/interfaceSupport.inline.hpp"
32 #include "services/memTracker.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/events.hpp"
35 #include "utilities/formatBuffer.hpp"
36 #include "utilities/macros.hpp"
37 #include "utilities/vmError.hpp"
38
39 #include <dirent.h>
40 #include <dlfcn.h>
41 #include <grp.h>
42 #include <pwd.h>
43 #include <pthread.h>
44 #include <signal.h>
45 #include <sys/mman.h>
46 #include <sys/resource.h>
47 #include <sys/utsname.h>
48 #include <time.h>
49 #include <unistd.h>
50
51 // Todo: provide a os::get_max_process_id() or similar. Number of processes
52 // may have been configured, can be read more accurately from proc fs etc.
53 #ifndef MAX_PID
54 #define MAX_PID INT_MAX
55 #endif
56 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
57
58 #define ROOT_UID 0
59
60 #ifndef MAP_ANONYMOUS
61 #define MAP_ANONYMOUS MAP_ANON
62 #endif
63
64 #define check_with_errno(check_type, cond, msg) \
65 do { \
66 int err = errno; \
67 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
68 os::errno_name(err)); \
69 } while (false)
70
71 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
72 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
73
74 // Check core dump limit and report possible place where core can be found
75 void os::check_dump_limit(char* buffer, size_t bufferSize) {
76 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
77 jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
78 VMError::record_coredump_status(buffer, false);
79 return;
80 }
81
82 int n;
83 struct rlimit rlim;
84 bool success;
85
86 char core_path[PATH_MAX];
87 n = get_core_path(core_path, PATH_MAX);
88
89 if (n <= 0) {
90 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
91 success = true;
92 #ifdef LINUX
93 } else if (core_path[0] == '"') { // redirect to user process
94 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
95 success = true;
96 #endif
97 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
98 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
99 success = true;
100 } else {
101 switch(rlim.rlim_cur) {
102 case RLIM_INFINITY:
103 jio_snprintf(buffer, bufferSize, "%s", core_path);
104 success = true;
105 break;
106 case 0:
107 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
108 success = false;
109 break;
110 default:
111 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);
112 success = true;
113 break;
114 }
115 }
116
117 VMError::record_coredump_status(buffer, success);
118 }
119
120 int os::get_native_stack(address* stack, int frames, int toSkip) {
121 int frame_idx = 0;
122 int num_of_frames; // number of frames captured
123 frame fr = os::current_frame();
124 while (fr.pc() && frame_idx < frames) {
125 if (toSkip > 0) {
126 toSkip --;
127 } else {
128 stack[frame_idx ++] = fr.pc();
129 }
130 if (fr.fp() == NULL || fr.cb() != NULL ||
131 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
132
133 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
134 fr = os::get_sender_for_C_frame(&fr);
135 } else {
136 break;
137 }
138 }
139 num_of_frames = frame_idx;
140 for (; frame_idx < frames; frame_idx ++) {
141 stack[frame_idx] = NULL;
142 }
143
144 return num_of_frames;
145 }
146
147
148 bool os::unsetenv(const char* name) {
149 assert(name != NULL, "Null pointer");
150 return (::unsetenv(name) == 0);
151 }
152
153 int os::get_last_error() {
154 return errno;
155 }
156
157 size_t os::lasterror(char *buf, size_t len) {
158 if (errno == 0) return 0;
159
160 const char *s = os::strerror(errno);
161 size_t n = ::strlen(s);
162 if (n >= len) {
163 n = len - 1;
164 }
165 ::strncpy(buf, s, n);
166 buf[n] = '\0';
167 return n;
168 }
169
170 bool os::is_debugger_attached() {
171 // not implemented
172 return false;
173 }
174
175 void os::wait_for_keypress_at_exit(void) {
176 // don't do anything on posix platforms
177 return;
178 }
179
180 int os::create_file_for_heap(const char* dir) {
181
182 const char name_template[] = "/jvmheap.XXXXXX";
183
184 size_t fullname_len = strlen(dir) + strlen(name_template);
185 char *fullname = (char*)os::malloc(fullname_len + 1, mtInternal);
186 if (fullname == NULL) {
187 vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
188 return -1;
189 }
190 int n = snprintf(fullname, fullname_len + 1, "%s%s", dir, name_template);
191 assert((size_t)n == fullname_len, "Unexpected number of characters in string");
192
193 os::native_path(fullname);
194
195 // set the file creation mask.
196 mode_t file_mode = S_IRUSR | S_IWUSR;
197
198 // create a new file.
199 int fd = mkstemp(fullname);
200
201 if (fd < 0) {
202 warning("Could not create file for heap with template %s", fullname);
203 os::free(fullname);
204 return -1;
205 }
206
207 // delete the name from the filesystem. When 'fd' is closed, the file (and space) will be deleted.
208 int ret = unlink(fullname);
209 assert_with_errno(ret == 0, "unlink returned error");
210
211 os::free(fullname);
212 return fd;
213 }
214
215 static char* reserve_mmapped_memory(size_t bytes, char* requested_addr) {
216 char * addr;
217 int flags = MAP_PRIVATE NOT_AIX( | MAP_NORESERVE ) | MAP_ANONYMOUS;
218 if (requested_addr != NULL) {
219 assert((uintptr_t)requested_addr % os::vm_page_size() == 0, "Requested address should be aligned to OS page size");
220 flags |= MAP_FIXED;
221 }
222
223 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
224 // touch an uncommitted page. Otherwise, the read/write might
225 // succeed if we have enough swap space to back the physical page.
226 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
227 flags, -1, 0);
228
229 if (addr != MAP_FAILED) {
230 MemTracker::record_virtual_memory_reserve((address)addr, bytes, CALLER_PC);
231 return addr;
232 }
233 return NULL;
234 }
235
236 static int util_posix_fallocate(int fd, off_t offset, off_t len) {
237 #ifdef __APPLE__
238 fstore_t store = { F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, len };
239 // First we try to get a continuous chunk of disk space
240 int ret = fcntl(fd, F_PREALLOCATE, &store);
241 if (ret == -1) {
242 // Maybe we are too fragmented, try to allocate non-continuous range
243 store.fst_flags = F_ALLOCATEALL;
244 ret = fcntl(fd, F_PREALLOCATE, &store);
245 }
246 if(ret != -1) {
247 return ftruncate(fd, len);
248 }
249 return -1;
250 #else
251 return posix_fallocate(fd, offset, len);
252 #endif
253 }
254
255 // Map the given address range to the provided file descriptor.
256 char* os::map_memory_to_file(char* base, size_t size, int fd) {
257 assert(fd != -1, "File descriptor is not valid");
258
259 // allocate space for the file
260 int ret = util_posix_fallocate(fd, 0, (off_t)size);
261 if (ret != 0) {
262 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory. error(%d)", ret));
263 return NULL;
264 }
265
266 int prot = PROT_READ | PROT_WRITE;
267 int flags = MAP_SHARED;
268 if (base != NULL) {
269 flags |= MAP_FIXED;
270 }
271 char* addr = (char*)mmap(base, size, prot, flags, fd, 0);
272
273 if (addr == MAP_FAILED) {
274 warning("Failed mmap to file. (%s)", os::strerror(errno));
275 return NULL;
276 }
277 if (base != NULL && addr != base) {
278 if (!os::release_memory(addr, size)) {
279 warning("Could not release memory on unsuccessful file mapping");
280 }
281 return NULL;
282 }
283 return addr;
284 }
285
286 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
287 assert(fd != -1, "File descriptor is not valid");
288 assert(base != NULL, "Base cannot be NULL");
289
290 return map_memory_to_file(base, size, fd);
291 }
292
293 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
294 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
295 // rather than unmapping and remapping the whole chunk to get requested alignment.
296 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
297 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
298 "Alignment must be a multiple of allocation granularity (page size)");
299 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
300
301 size_t extra_size = size + alignment;
302 assert(extra_size >= size, "overflow, size is too large to allow alignment");
303
304 char* extra_base;
305 if (file_desc != -1) {
306 // For file mapping, we do not call os:reserve_memory(extra_size, NULL, alignment, file_desc) because
307 // we need to deal with shrinking of the file space later when we release extra memory after alignment.
308 // We also cannot called os:reserve_memory() with file_desc set to -1 because on aix we might get SHM memory.
309 // So here to call a helper function while reserve memory for us. After we have a aligned base,
310 // we will replace anonymous mapping with file mapping.
311 extra_base = reserve_mmapped_memory(extra_size, NULL);
312 if (extra_base != NULL) {
313 MemTracker::record_virtual_memory_reserve((address)extra_base, extra_size, CALLER_PC);
314 }
315 } else {
316 extra_base = os::reserve_memory(extra_size, NULL, alignment);
317 }
318
319 if (extra_base == NULL) {
320 return NULL;
321 }
322
323 // Do manual alignment
324 char* aligned_base = align_up(extra_base, alignment);
325
326 // [ | | ]
327 // ^ extra_base
328 // ^ extra_base + begin_offset == aligned_base
329 // extra_base + begin_offset + size ^
330 // extra_base + extra_size ^
331 // |<>| == begin_offset
332 // end_offset == |<>|
333 size_t begin_offset = aligned_base - extra_base;
334 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
335
336 if (begin_offset > 0) {
337 os::release_memory(extra_base, begin_offset);
338 }
339
340 if (end_offset > 0) {
341 os::release_memory(extra_base + begin_offset + size, end_offset);
342 }
343
344 if (file_desc != -1) {
345 // After we have an aligned address, we can replace anonymous mapping with file mapping
346 if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
347 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
348 }
349 MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
350 }
351 return aligned_base;
352 }
353
354 int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
355 // All supported POSIX platforms provide C99 semantics.
356 int result = ::vsnprintf(buf, len, fmt, args);
357 // If an encoding error occurred (result < 0) then it's not clear
358 // whether the buffer is NUL terminated, so ensure it is.
359 if ((result < 0) && (len > 0)) {
360 buf[len - 1] = '\0';
361 }
362 return result;
363 }
364
365 int os::get_fileno(FILE* fp) {
366 return NOT_AIX(::)fileno(fp);
367 }
368
369 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
370 return gmtime_r(clock, res);
371 }
372
373 void os::Posix::print_load_average(outputStream* st) {
374 st->print("load average:");
375 double loadavg[3];
376 int res = os::loadavg(loadavg, 3);
377 if (res != -1) {
378 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
379 } else {
380 st->print(" Unavailable");
381 }
382 st->cr();
383 }
384
385 void os::Posix::print_rlimit_info(outputStream* st) {
386 st->print("rlimit:");
387 struct rlimit rlim;
388
389 st->print(" STACK ");
390 getrlimit(RLIMIT_STACK, &rlim);
391 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
392 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
393
394 st->print(", CORE ");
395 getrlimit(RLIMIT_CORE, &rlim);
396 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
397 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
398
399 // Isn't there on solaris
400 #if defined(AIX)
401 st->print(", NPROC ");
402 st->print("%d", sysconf(_SC_CHILD_MAX));
403 #elif !defined(SOLARIS)
404 st->print(", NPROC ");
405 getrlimit(RLIMIT_NPROC, &rlim);
406 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
407 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
408 #endif
409
410 st->print(", NOFILE ");
411 getrlimit(RLIMIT_NOFILE, &rlim);
412 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
413 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
414
415 st->print(", AS ");
416 getrlimit(RLIMIT_AS, &rlim);
417 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
418 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
419
420 st->print(", DATA ");
421 getrlimit(RLIMIT_DATA, &rlim);
422 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
423 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
424
425 st->print(", FSIZE ");
426 getrlimit(RLIMIT_FSIZE, &rlim);
427 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
428 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
429
430 st->cr();
431 }
432
433 void os::Posix::print_uname_info(outputStream* st) {
434 // kernel
435 st->print("uname:");
436 struct utsname name;
437 uname(&name);
438 st->print("%s ", name.sysname);
439 #ifdef ASSERT
440 st->print("%s ", name.nodename);
441 #endif
442 st->print("%s ", name.release);
443 st->print("%s ", name.version);
444 st->print("%s", name.machine);
445 st->cr();
446 }
447
448 void os::Posix::print_umask(outputStream* st, mode_t umsk) {
449 st->print((umsk & S_IRUSR) ? "r" : "-");
450 st->print((umsk & S_IWUSR) ? "w" : "-");
451 st->print((umsk & S_IXUSR) ? "x" : "-");
452 st->print((umsk & S_IRGRP) ? "r" : "-");
453 st->print((umsk & S_IWGRP) ? "w" : "-");
454 st->print((umsk & S_IXGRP) ? "x" : "-");
455 st->print((umsk & S_IROTH) ? "r" : "-");
456 st->print((umsk & S_IWOTH) ? "w" : "-");
457 st->print((umsk & S_IXOTH) ? "x" : "-");
458 }
459
460 void os::Posix::print_user_info(outputStream* st) {
461 unsigned id = (unsigned) ::getuid();
462 st->print("uid : %u ", id);
463 id = (unsigned) ::geteuid();
464 st->print("euid : %u ", id);
465 id = (unsigned) ::getgid();
466 st->print("gid : %u ", id);
467 id = (unsigned) ::getegid();
468 st->print_cr("egid : %u", id);
469 st->cr();
470
471 mode_t umsk = ::umask(0);
472 ::umask(umsk);
473 st->print("umask: %04o (", (unsigned) umsk);
474 print_umask(st, umsk);
475 st->print_cr(")");
476 st->cr();
477 }
478
479
480 bool os::get_host_name(char* buf, size_t buflen) {
481 struct utsname name;
482 uname(&name);
483 jio_snprintf(buf, buflen, "%s", name.nodename);
484 return true;
485 }
486
487 bool os::has_allocatable_memory_limit(julong* limit) {
488 struct rlimit rlim;
489 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
490 // if there was an error when calling getrlimit, assume that there is no limitation
491 // on virtual memory.
492 bool result;
493 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
494 result = false;
495 } else {
496 *limit = (julong)rlim.rlim_cur;
497 result = true;
498 }
499 #ifdef _LP64
500 return result;
501 #else
502 // arbitrary virtual space limit for 32 bit Unices found by testing. If
503 // getrlimit above returned a limit, bound it with this limit. Otherwise
504 // directly use it.
505 const julong max_virtual_limit = (julong)3800*M;
506 if (result) {
507 *limit = MIN2(*limit, max_virtual_limit);
508 } else {
509 *limit = max_virtual_limit;
510 }
511
512 // bound by actually allocatable memory. The algorithm uses two bounds, an
513 // upper and a lower limit. The upper limit is the current highest amount of
514 // memory that could not be allocated, the lower limit is the current highest
515 // amount of memory that could be allocated.
516 // The algorithm iteratively refines the result by halving the difference
517 // between these limits, updating either the upper limit (if that value could
518 // not be allocated) or the lower limit (if the that value could be allocated)
519 // until the difference between these limits is "small".
520
521 // the minimum amount of memory we care about allocating.
522 const julong min_allocation_size = M;
523
524 julong upper_limit = *limit;
525
526 // first check a few trivial cases
527 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
528 *limit = upper_limit;
529 } else if (!is_allocatable(min_allocation_size)) {
530 // we found that not even min_allocation_size is allocatable. Return it
531 // anyway. There is no point to search for a better value any more.
532 *limit = min_allocation_size;
533 } else {
534 // perform the binary search.
535 julong lower_limit = min_allocation_size;
536 while ((upper_limit - lower_limit) > min_allocation_size) {
537 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
538 temp_limit = align_down(temp_limit, min_allocation_size);
539 if (is_allocatable(temp_limit)) {
540 lower_limit = temp_limit;
541 } else {
542 upper_limit = temp_limit;
543 }
544 }
545 *limit = lower_limit;
546 }
547 return true;
548 #endif
549 }
550
551 const char* os::get_current_directory(char *buf, size_t buflen) {
552 return getcwd(buf, buflen);
553 }
554
555 FILE* os::open(int fd, const char* mode) {
556 return ::fdopen(fd, mode);
557 }
558
559 ssize_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
560 return ::pread(fd, buf, nBytes, offset);
561 }
562
563 void os::flockfile(FILE* fp) {
564 ::flockfile(fp);
565 }
566
567 void os::funlockfile(FILE* fp) {
568 ::funlockfile(fp);
569 }
570
571 DIR* os::opendir(const char* dirname) {
572 assert(dirname != NULL, "just checking");
573 return ::opendir(dirname);
574 }
575
576 struct dirent* os::readdir(DIR* dirp) {
577 assert(dirp != NULL, "just checking");
578 return ::readdir(dirp);
579 }
580
581 int os::closedir(DIR *dirp) {
582 assert(dirp != NULL, "just checking");
583 return ::closedir(dirp);
584 }
585
586 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
587 // which is used to find statically linked in agents.
588 // Parameters:
589 // sym_name: Symbol in library we are looking for
590 // lib_name: Name of library to look in, NULL for shared libs.
591 // is_absolute_path == true if lib_name is absolute path to agent
592 // such as "/a/b/libL.so"
593 // == false if only the base name of the library is passed in
594 // such as "L"
595 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
596 bool is_absolute_path) {
597 char *agent_entry_name;
598 size_t len;
599 size_t name_len;
600 size_t prefix_len = strlen(JNI_LIB_PREFIX);
601 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
602 const char *start;
603
604 if (lib_name != NULL) {
605 name_len = strlen(lib_name);
606 if (is_absolute_path) {
607 // Need to strip path, prefix and suffix
608 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
609 lib_name = ++start;
610 }
611 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
612 return NULL;
613 }
614 lib_name += prefix_len;
615 name_len = strlen(lib_name) - suffix_len;
616 }
617 }
618 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
619 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
620 if (agent_entry_name == NULL) {
621 return NULL;
622 }
623 strcpy(agent_entry_name, sym_name);
624 if (lib_name != NULL) {
625 strcat(agent_entry_name, "_");
626 strncat(agent_entry_name, lib_name, name_len);
627 }
628 return agent_entry_name;
629 }
630
631
632 void os::naked_short_nanosleep(jlong ns) {
633 struct timespec req;
634 assert(ns > -1 && ns < NANOUNITS, "Un-interruptable sleep, short time use only");
635 req.tv_sec = 0;
636 req.tv_nsec = ns;
637 ::nanosleep(&req, NULL);
638 return;
639 }
640
641 void os::naked_short_sleep(jlong ms) {
642 assert(ms < MILLIUNITS, "Un-interruptable sleep, short time use only");
643 os::naked_short_nanosleep(ms * (NANOUNITS / MILLIUNITS));
644 return;
645 }
646
647 static const struct {
648 int sig; const char* name;
649 }
650 g_signal_info[] =
651 {
652 { SIGABRT, "SIGABRT" },
653 #ifdef SIGAIO
654 { SIGAIO, "SIGAIO" },
655 #endif
656 { SIGALRM, "SIGALRM" },
657 #ifdef SIGALRM1
658 { SIGALRM1, "SIGALRM1" },
659 #endif
660 { SIGBUS, "SIGBUS" },
661 #ifdef SIGCANCEL
662 { SIGCANCEL, "SIGCANCEL" },
663 #endif
664 { SIGCHLD, "SIGCHLD" },
665 #ifdef SIGCLD
666 { SIGCLD, "SIGCLD" },
667 #endif
668 { SIGCONT, "SIGCONT" },
669 #ifdef SIGCPUFAIL
670 { SIGCPUFAIL, "SIGCPUFAIL" },
671 #endif
672 #ifdef SIGDANGER
673 { SIGDANGER, "SIGDANGER" },
674 #endif
675 #ifdef SIGDIL
676 { SIGDIL, "SIGDIL" },
677 #endif
678 #ifdef SIGEMT
679 { SIGEMT, "SIGEMT" },
680 #endif
681 { SIGFPE, "SIGFPE" },
682 #ifdef SIGFREEZE
683 { SIGFREEZE, "SIGFREEZE" },
684 #endif
685 #ifdef SIGGFAULT
686 { SIGGFAULT, "SIGGFAULT" },
687 #endif
688 #ifdef SIGGRANT
689 { SIGGRANT, "SIGGRANT" },
690 #endif
691 { SIGHUP, "SIGHUP" },
692 { SIGILL, "SIGILL" },
693 { SIGINT, "SIGINT" },
694 #ifdef SIGIO
695 { SIGIO, "SIGIO" },
696 #endif
697 #ifdef SIGIOINT
698 { SIGIOINT, "SIGIOINT" },
699 #endif
700 #ifdef SIGIOT
701 // SIGIOT is there for BSD compatibility, but on most Unices just a
702 // synonym for SIGABRT. The result should be "SIGABRT", not
703 // "SIGIOT".
704 #if (SIGIOT != SIGABRT )
705 { SIGIOT, "SIGIOT" },
706 #endif
707 #endif
708 #ifdef SIGKAP
709 { SIGKAP, "SIGKAP" },
710 #endif
711 { SIGKILL, "SIGKILL" },
712 #ifdef SIGLOST
713 { SIGLOST, "SIGLOST" },
714 #endif
715 #ifdef SIGLWP
716 { SIGLWP, "SIGLWP" },
717 #endif
718 #ifdef SIGLWPTIMER
719 { SIGLWPTIMER, "SIGLWPTIMER" },
720 #endif
721 #ifdef SIGMIGRATE
722 { SIGMIGRATE, "SIGMIGRATE" },
723 #endif
724 #ifdef SIGMSG
725 { SIGMSG, "SIGMSG" },
726 #endif
727 { SIGPIPE, "SIGPIPE" },
728 #ifdef SIGPOLL
729 { SIGPOLL, "SIGPOLL" },
730 #endif
731 #ifdef SIGPRE
732 { SIGPRE, "SIGPRE" },
733 #endif
734 { SIGPROF, "SIGPROF" },
735 #ifdef SIGPTY
736 { SIGPTY, "SIGPTY" },
737 #endif
738 #ifdef SIGPWR
739 { SIGPWR, "SIGPWR" },
740 #endif
741 { SIGQUIT, "SIGQUIT" },
742 #ifdef SIGRECONFIG
743 { SIGRECONFIG, "SIGRECONFIG" },
744 #endif
745 #ifdef SIGRECOVERY
746 { SIGRECOVERY, "SIGRECOVERY" },
747 #endif
748 #ifdef SIGRESERVE
749 { SIGRESERVE, "SIGRESERVE" },
750 #endif
751 #ifdef SIGRETRACT
752 { SIGRETRACT, "SIGRETRACT" },
753 #endif
754 #ifdef SIGSAK
755 { SIGSAK, "SIGSAK" },
756 #endif
757 { SIGSEGV, "SIGSEGV" },
758 #ifdef SIGSOUND
759 { SIGSOUND, "SIGSOUND" },
760 #endif
761 #ifdef SIGSTKFLT
762 { SIGSTKFLT, "SIGSTKFLT" },
763 #endif
764 { SIGSTOP, "SIGSTOP" },
765 { SIGSYS, "SIGSYS" },
766 #ifdef SIGSYSERROR
767 { SIGSYSERROR, "SIGSYSERROR" },
768 #endif
769 #ifdef SIGTALRM
770 { SIGTALRM, "SIGTALRM" },
771 #endif
772 { SIGTERM, "SIGTERM" },
773 #ifdef SIGTHAW
774 { SIGTHAW, "SIGTHAW" },
775 #endif
776 { SIGTRAP, "SIGTRAP" },
777 #ifdef SIGTSTP
778 { SIGTSTP, "SIGTSTP" },
779 #endif
780 { SIGTTIN, "SIGTTIN" },
781 { SIGTTOU, "SIGTTOU" },
782 #ifdef SIGURG
783 { SIGURG, "SIGURG" },
784 #endif
785 { SIGUSR1, "SIGUSR1" },
786 { SIGUSR2, "SIGUSR2" },
787 #ifdef SIGVIRT
788 { SIGVIRT, "SIGVIRT" },
789 #endif
790 { SIGVTALRM, "SIGVTALRM" },
791 #ifdef SIGWAITING
792 { SIGWAITING, "SIGWAITING" },
793 #endif
794 #ifdef SIGWINCH
795 { SIGWINCH, "SIGWINCH" },
796 #endif
797 #ifdef SIGWINDOW
798 { SIGWINDOW, "SIGWINDOW" },
799 #endif
800 { SIGXCPU, "SIGXCPU" },
801 { SIGXFSZ, "SIGXFSZ" },
802 #ifdef SIGXRES
803 { SIGXRES, "SIGXRES" },
804 #endif
805 { -1, NULL }
806 };
807
808 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
809 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
810
811 const char* ret = NULL;
812
813 #ifdef SIGRTMIN
814 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
815 if (sig == SIGRTMIN) {
816 ret = "SIGRTMIN";
817 } else if (sig == SIGRTMAX) {
818 ret = "SIGRTMAX";
819 } else {
820 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
821 return out;
822 }
823 }
824 #endif
825
826 if (sig > 0) {
827 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
828 if (g_signal_info[idx].sig == sig) {
829 ret = g_signal_info[idx].name;
830 break;
831 }
832 }
833 }
834
835 if (!ret) {
836 if (!is_valid_signal(sig)) {
837 ret = "INVALID";
838 } else {
839 ret = "UNKNOWN";
840 }
841 }
842
843 if (out && outlen > 0) {
844 strncpy(out, ret, outlen);
845 out[outlen - 1] = '\0';
846 }
847 return out;
848 }
849
850 int os::Posix::get_signal_number(const char* signal_name) {
851 char tmp[30];
852 const char* s = signal_name;
853 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
854 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
855 s = tmp;
856 }
857 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
858 if (strcmp(g_signal_info[idx].name, s) == 0) {
859 return g_signal_info[idx].sig;
860 }
861 }
862 return -1;
863 }
864
865 int os::get_signal_number(const char* signal_name) {
866 return os::Posix::get_signal_number(signal_name);
867 }
868
869 // Returns true if signal number is valid.
870 bool os::Posix::is_valid_signal(int sig) {
871 // MacOS not really POSIX compliant: sigaddset does not return
872 // an error for invalid signal numbers. However, MacOS does not
873 // support real time signals and simply seems to have just 33
874 // signals with no holes in the signal range.
875 #ifdef __APPLE__
876 return sig >= 1 && sig < NSIG;
877 #else
878 // Use sigaddset to check for signal validity.
879 sigset_t set;
880 sigemptyset(&set);
881 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
882 return false;
883 }
884 return true;
885 #endif
886 }
887
888 bool os::Posix::is_sig_ignored(int sig) {
889 struct sigaction oact;
890 sigaction(sig, (struct sigaction*)NULL, &oact);
891 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
892 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
893 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
894 return true;
895 } else {
896 return false;
897 }
898 }
899
900 // Returns:
901 // NULL for an invalid signal number
902 // "SIG<num>" for a valid but unknown signal number
903 // signal name otherwise.
904 const char* os::exception_name(int sig, char* buf, size_t size) {
905 if (!os::Posix::is_valid_signal(sig)) {
906 return NULL;
907 }
908 const char* const name = os::Posix::get_signal_name(sig, buf, size);
909 if (strcmp(name, "UNKNOWN") == 0) {
910 jio_snprintf(buf, size, "SIG%d", sig);
911 }
912 return buf;
913 }
914
915 #define NUM_IMPORTANT_SIGS 32
916 // Returns one-line short description of a signal set in a user provided buffer.
917 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
918 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
919 // Note: for shortness, just print out the first 32. That should
920 // cover most of the useful ones, apart from realtime signals.
921 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
922 const int rc = sigismember(set, sig);
923 if (rc == -1 && errno == EINVAL) {
924 buffer[sig-1] = '?';
925 } else {
926 buffer[sig-1] = rc == 0 ? '0' : '1';
927 }
928 }
929 buffer[NUM_IMPORTANT_SIGS] = 0;
930 return buffer;
931 }
932
933 // Prints one-line description of a signal set.
934 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
935 char buf[NUM_IMPORTANT_SIGS + 1];
936 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
937 st->print("%s", buf);
938 }
939
940 // Writes one-line description of a combination of sigaction.sa_flags into a user
941 // provided buffer. Returns that buffer.
942 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
943 char* p = buffer;
944 size_t remaining = size;
945 bool first = true;
946 int idx = 0;
947
948 assert(buffer, "invalid argument");
949
950 if (size == 0) {
951 return buffer;
952 }
953
954 strncpy(buffer, "none", size);
955
956 const struct {
957 // NB: i is an unsigned int here because SA_RESETHAND is on some
958 // systems 0x80000000, which is implicitly unsigned. Assignining
959 // it to an int field would be an overflow in unsigned-to-signed
960 // conversion.
961 unsigned int i;
962 const char* s;
963 } flaginfo [] = {
964 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
965 { SA_ONSTACK, "SA_ONSTACK" },
966 { SA_RESETHAND, "SA_RESETHAND" },
967 { SA_RESTART, "SA_RESTART" },
968 { SA_SIGINFO, "SA_SIGINFO" },
969 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
970 { SA_NODEFER, "SA_NODEFER" },
971 #ifdef AIX
972 { SA_ONSTACK, "SA_ONSTACK" },
973 { SA_OLDSTYLE, "SA_OLDSTYLE" },
974 #endif
975 { 0, NULL }
976 };
977
978 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
979 if (flags & flaginfo[idx].i) {
980 if (first) {
981 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
982 first = false;
983 } else {
984 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
985 }
986 const size_t len = strlen(p);
987 p += len;
988 remaining -= len;
989 }
990 }
991
992 buffer[size - 1] = '\0';
993
994 return buffer;
995 }
996
997 // Prints one-line description of a combination of sigaction.sa_flags.
998 void os::Posix::print_sa_flags(outputStream* st, int flags) {
999 char buffer[0x100];
1000 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
1001 st->print("%s", buffer);
1002 }
1003
1004 // Helper function for os::Posix::print_siginfo_...():
1005 // return a textual description for signal code.
1006 struct enum_sigcode_desc_t {
1007 const char* s_name;
1008 const char* s_desc;
1009 };
1010
1011 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
1012
1013 const struct {
1014 int sig; int code; const char* s_code; const char* s_desc;
1015 } t1 [] = {
1016 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
1017 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
1018 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
1019 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
1020 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
1021 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
1022 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
1023 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
1024 #if defined(IA64) && defined(LINUX)
1025 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
1026 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
1027 #endif
1028 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
1029 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
1030 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
1031 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
1032 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
1033 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
1034 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
1035 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
1036 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
1037 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
1038 #ifdef AIX
1039 // no explanation found what keyerr would be
1040 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
1041 #endif
1042 #if defined(IA64) && !defined(AIX)
1043 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
1044 #endif
1045 #if defined(__sparc) && defined(SOLARIS)
1046 // define Solaris Sparc M7 ADI SEGV signals
1047 #if !defined(SEGV_ACCADI)
1048 #define SEGV_ACCADI 3
1049 #endif
1050 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
1051 #if !defined(SEGV_ACCDERR)
1052 #define SEGV_ACCDERR 4
1053 #endif
1054 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
1055 #if !defined(SEGV_ACCPERR)
1056 #define SEGV_ACCPERR 5
1057 #endif
1058 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
1059 #endif // defined(__sparc) && defined(SOLARIS)
1060 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
1061 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
1062 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
1063 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
1064 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
1065 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
1066 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
1067 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
1068 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
1069 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
1070 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
1071 #ifdef SIGPOLL
1072 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
1073 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
1074 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
1075 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
1076 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
1077 #endif
1078 { -1, -1, NULL, NULL }
1079 };
1080
1081 // Codes valid in any signal context.
1082 const struct {
1083 int code; const char* s_code; const char* s_desc;
1084 } t2 [] = {
1085 { SI_USER, "SI_USER", "Signal sent by kill()." },
1086 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
1087 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
1088 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
1089 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
1090 // Linux specific
1091 #ifdef SI_TKILL
1092 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
1093 #endif
1094 #ifdef SI_DETHREAD
1095 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
1096 #endif
1097 #ifdef SI_KERNEL
1098 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
1099 #endif
1100 #ifdef SI_SIGIO
1101 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
1102 #endif
1103
1104 #ifdef AIX
1105 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
1106 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
1107 #endif
1108
1109 #ifdef __sun
1110 { SI_NOINFO, "SI_NOINFO", "No signal information" },
1111 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
1112 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
1113 #endif
1114
1115 { -1, NULL, NULL }
1116 };
1117
1118 const char* s_code = NULL;
1119 const char* s_desc = NULL;
1120
1121 for (int i = 0; t1[i].sig != -1; i ++) {
1122 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
1123 s_code = t1[i].s_code;
1124 s_desc = t1[i].s_desc;
1125 break;
1126 }
1127 }
1128
1129 if (s_code == NULL) {
1130 for (int i = 0; t2[i].s_code != NULL; i ++) {
1131 if (t2[i].code == si->si_code) {
1132 s_code = t2[i].s_code;
1133 s_desc = t2[i].s_desc;
1134 }
1135 }
1136 }
1137
1138 if (s_code == NULL) {
1139 out->s_name = "unknown";
1140 out->s_desc = "unknown";
1141 return false;
1142 }
1143
1144 out->s_name = s_code;
1145 out->s_desc = s_desc;
1146
1147 return true;
1148 }
1149
1150 bool os::signal_sent_by_kill(const void* siginfo) {
1151 const siginfo_t* const si = (const siginfo_t*)siginfo;
1152 return si->si_code == SI_USER || si->si_code == SI_QUEUE
1153 #ifdef SI_TKILL
1154 || si->si_code == SI_TKILL
1155 #endif
1156 ;
1157 }
1158
1159 void os::print_siginfo(outputStream* os, const void* si0) {
1160
1161 const siginfo_t* const si = (const siginfo_t*) si0;
1162
1163 char buf[20];
1164 os->print("siginfo:");
1165
1166 if (!si) {
1167 os->print(" <null>");
1168 return;
1169 }
1170
1171 const int sig = si->si_signo;
1172
1173 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1174
1175 enum_sigcode_desc_t ed;
1176 get_signal_code_description(si, &ed);
1177 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1178
1179 if (si->si_errno) {
1180 os->print(", si_errno: %d", si->si_errno);
1181 }
1182
1183 // Output additional information depending on the signal code.
1184
1185 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1186 // so it depends on the context which member to use. For synchronous error signals,
1187 // we print si_addr, unless the signal was sent by another process or thread, in
1188 // which case we print out pid or tid of the sender.
1189 if (signal_sent_by_kill(si)) {
1190 const pid_t pid = si->si_pid;
1191 os->print(", si_pid: %ld", (long) pid);
1192 if (IS_VALID_PID(pid)) {
1193 const pid_t me = getpid();
1194 if (me == pid) {
1195 os->print(" (current process)");
1196 }
1197 } else {
1198 os->print(" (invalid)");
1199 }
1200 os->print(", si_uid: %ld", (long) si->si_uid);
1201 if (sig == SIGCHLD) {
1202 os->print(", si_status: %d", si->si_status);
1203 }
1204 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1205 sig == SIGTRAP || sig == SIGFPE) {
1206 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1207 #ifdef SIGPOLL
1208 } else if (sig == SIGPOLL) {
1209 os->print(", si_band: %ld", si->si_band);
1210 #endif
1211 }
1212
1213 }
1214
1215 bool os::signal_thread(Thread* thread, int sig, const char* reason) {
1216 OSThread* osthread = thread->osthread();
1217 if (osthread) {
1218 #if defined (SOLARIS)
1219 // Note: we cannot use pthread_kill on Solaris - not because
1220 // its missing, but because we do not have the pthread_t id.
1221 int status = thr_kill(osthread->thread_id(), sig);
1222 #else
1223 int status = pthread_kill(osthread->pthread_id(), sig);
1224 #endif
1225 if (status == 0) {
1226 Events::log(Thread::current(), "sent signal %d to Thread " INTPTR_FORMAT " because %s.",
1227 sig, p2i(thread), reason);
1228 return true;
1229 }
1230 }
1231 return false;
1232 }
1233
1234 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1235 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1236 }
1237
1238 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1239 #if defined(AIX)
1240 return Aix::ucontext_get_pc(ctx);
1241 #elif defined(BSD)
1242 return Bsd::ucontext_get_pc(ctx);
1243 #elif defined(LINUX)
1244 return Linux::ucontext_get_pc(ctx);
1245 #elif defined(SOLARIS)
1246 return Solaris::ucontext_get_pc(ctx);
1247 #else
1248 VMError::report_and_die("unimplemented ucontext_get_pc");
1249 #endif
1250 }
1251
1252 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1253 #if defined(AIX)
1254 Aix::ucontext_set_pc(ctx, pc);
1255 #elif defined(BSD)
1256 Bsd::ucontext_set_pc(ctx, pc);
1257 #elif defined(LINUX)
1258 Linux::ucontext_set_pc(ctx, pc);
1259 #elif defined(SOLARIS)
1260 Solaris::ucontext_set_pc(ctx, pc);
1261 #else
1262 VMError::report_and_die("unimplemented ucontext_get_pc");
1263 #endif
1264 }
1265
1266 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1267 size_t stack_size = 0;
1268 size_t guard_size = 0;
1269 int detachstate = 0;
1270 pthread_attr_getstacksize(attr, &stack_size);
1271 pthread_attr_getguardsize(attr, &guard_size);
1272 // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
1273 LINUX_ONLY(stack_size -= guard_size);
1274 pthread_attr_getdetachstate(attr, &detachstate);
1275 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1276 stack_size / 1024, guard_size / 1024,
1277 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1278 return buf;
1279 }
1280
1281 char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
1282
1283 if (filename == NULL || outbuf == NULL || outbuflen < 1) {
1284 assert(false, "os::Posix::realpath: invalid arguments.");
1285 errno = EINVAL;
1286 return NULL;
1287 }
1288
1289 char* result = NULL;
1290
1291 // This assumes platform realpath() is implemented according to POSIX.1-2008.
1292 // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
1293 // output buffer is dynamically allocated and must be ::free()'d by the caller.
1294 char* p = ::realpath(filename, NULL);
1295 if (p != NULL) {
1296 if (strlen(p) < outbuflen) {
1297 strcpy(outbuf, p);
1298 result = outbuf;
1299 } else {
1300 errno = ENAMETOOLONG;
1301 }
1302 ::free(p); // *not* os::free
1303 } else {
1304 // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
1305 // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
1306 // that it complains about the NULL we handed down as user buffer.
1307 // In this case, use the user provided buffer but at least check whether realpath caused
1308 // a memory overwrite.
1309 if (errno == EINVAL) {
1310 outbuf[outbuflen - 1] = '\0';
1311 p = ::realpath(filename, outbuf);
1312 if (p != NULL) {
1313 guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
1314 result = p;
1315 }
1316 }
1317 }
1318 return result;
1319
1320 }
1321
1322 int os::stat(const char *path, struct stat *sbuf) {
1323 return ::stat(path, sbuf);
1324 }
1325
1326 char * os::native_path(char *path) {
1327 return path;
1328 }
1329
1330 bool os::same_files(const char* file1, const char* file2) {
1331 if (strcmp(file1, file2) == 0) {
1332 return true;
1333 }
1334
1335 bool is_same = false;
1336 struct stat st1;
1337 struct stat st2;
1338
1339 if (os::stat(file1, &st1) < 0) {
1340 return false;
1341 }
1342
1343 if (os::stat(file2, &st2) < 0) {
1344 return false;
1345 }
1346
1347 if (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino) {
1348 // same files
1349 is_same = true;
1350 }
1351 return is_same;
1352 }
1353
1354 // Check minimum allowable stack sizes for thread creation and to initialize
1355 // the java system classes, including StackOverflowError - depends on page
1356 // size.
1357 // The space needed for frames during startup is platform dependent. It
1358 // depends on word size, platform calling conventions, C frame layout and
1359 // interpreter/C1/C2 design decisions. Therefore this is given in a
1360 // platform (os/cpu) dependent constant.
1361 // To this, space for guard mechanisms is added, which depends on the
1362 // page size which again depends on the concrete system the VM is running
1363 // on. Space for libc guard pages is not included in this size.
1364 jint os::Posix::set_minimum_stack_sizes() {
1365 size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
1366
1367 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
1368 JavaThread::stack_guard_zone_size() +
1369 JavaThread::stack_shadow_zone_size();
1370
1371 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
1372 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
1373
1374 size_t stack_size_in_bytes = ThreadStackSize * K;
1375 if (stack_size_in_bytes != 0 &&
1376 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1377 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1378 // ThreadStackSize so we go with "Java thread stack size" instead
1379 // of "ThreadStackSize" to be more friendly.
1380 tty->print_cr("\nThe Java thread stack size specified is too small. "
1381 "Specify at least " SIZE_FORMAT "k",
1382 _java_thread_min_stack_allowed / K);
1383 return JNI_ERR;
1384 }
1385
1386 // Make the stack size a multiple of the page size so that
1387 // the yellow/red zones can be guarded.
1388 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
1389
1390 // Reminder: a compiler thread is a Java thread.
1391 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
1392 JavaThread::stack_guard_zone_size() +
1393 JavaThread::stack_shadow_zone_size();
1394
1395 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
1396 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
1397
1398 stack_size_in_bytes = CompilerThreadStackSize * K;
1399 if (stack_size_in_bytes != 0 &&
1400 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1401 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1402 "Specify at least " SIZE_FORMAT "k",
1403 _compiler_thread_min_stack_allowed / K);
1404 return JNI_ERR;
1405 }
1406
1407 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1408 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
1409
1410 stack_size_in_bytes = VMThreadStackSize * K;
1411 if (stack_size_in_bytes != 0 &&
1412 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1413 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1414 "Specify at least " SIZE_FORMAT "k",
1415 _vm_internal_thread_min_stack_allowed / K);
1416 return JNI_ERR;
1417 }
1418 return JNI_OK;
1419 }
1420
1421 // Called when creating the thread. The minimum stack sizes have already been calculated
1422 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1423 size_t stack_size;
1424 if (req_stack_size == 0) {
1425 stack_size = default_stack_size(thr_type);
1426 } else {
1427 stack_size = req_stack_size;
1428 }
1429
1430 switch (thr_type) {
1431 case os::java_thread:
1432 // Java threads use ThreadStackSize which default value can be
1433 // changed with the flag -Xss
1434 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1435 // no requested size and we have a more specific default value
1436 stack_size = JavaThread::stack_size_at_create();
1437 }
1438 stack_size = MAX2(stack_size,
1439 _java_thread_min_stack_allowed);
1440 break;
1441 case os::compiler_thread:
1442 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1443 // no requested size and we have a more specific default value
1444 stack_size = (size_t)(CompilerThreadStackSize * K);
1445 }
1446 stack_size = MAX2(stack_size,
1447 _compiler_thread_min_stack_allowed);
1448 break;
1449 case os::vm_thread:
1450 case os::pgc_thread:
1451 case os::cgc_thread:
1452 case os::watcher_thread:
1453 default: // presume the unknown thr_type is a VM internal
1454 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1455 // no requested size and we have a more specific default value
1456 stack_size = (size_t)(VMThreadStackSize * K);
1457 }
1458
1459 stack_size = MAX2(stack_size,
1460 _vm_internal_thread_min_stack_allowed);
1461 break;
1462 }
1463
1464 // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
1465 // Be careful not to round up to 0. Align down in that case.
1466 if (stack_size <= SIZE_MAX - vm_page_size()) {
1467 stack_size = align_up(stack_size, vm_page_size());
1468 } else {
1469 stack_size = align_down(stack_size, vm_page_size());
1470 }
1471
1472 return stack_size;
1473 }
1474
1475 bool os::Posix::is_root(uid_t uid){
1476 return ROOT_UID == uid;
1477 }
1478
1479 bool os::Posix::matches_effective_uid_or_root(uid_t uid) {
1480 return is_root(uid) || geteuid() == uid;
1481 }
1482
1483 bool os::Posix::matches_effective_uid_and_gid_or_root(uid_t uid, gid_t gid) {
1484 return is_root(uid) || (geteuid() == uid && getegid() == gid);
1485 }
1486
1487 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
1488 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
1489 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
1490
1491 os::ThreadCrashProtection::ThreadCrashProtection() {
1492 }
1493
1494 /*
1495 * See the caveats for this class in os_posix.hpp
1496 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1497 * method and returns false. If none of the signals are raised, returns true.
1498 * The callback is supposed to provide the method that should be protected.
1499 */
1500 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1501 sigset_t saved_sig_mask;
1502
1503 Thread::muxAcquire(&_crash_mux, "CrashProtection");
1504
1505 _protected_thread = Thread::current_or_null();
1506 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
1507
1508 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1509 // since on at least some systems (OS X) siglongjmp will restore the mask
1510 // for the process, not the thread
1511 pthread_sigmask(0, NULL, &saved_sig_mask);
1512 if (sigsetjmp(_jmpbuf, 0) == 0) {
1513 // make sure we can see in the signal handler that we have crash protection
1514 // installed
1515 _crash_protection = this;
1516 cb.call();
1517 // and clear the crash protection
1518 _crash_protection = NULL;
1519 _protected_thread = NULL;
1520 Thread::muxRelease(&_crash_mux);
1521 return true;
1522 }
1523 // this happens when we siglongjmp() back
1524 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1525 _crash_protection = NULL;
1526 _protected_thread = NULL;
1527 Thread::muxRelease(&_crash_mux);
1528 return false;
1529 }
1530
1531 void os::ThreadCrashProtection::restore() {
1532 assert(_crash_protection != NULL, "must have crash protection");
1533 siglongjmp(_jmpbuf, 1);
1534 }
1535
1536 void os::ThreadCrashProtection::check_crash_protection(int sig,
1537 Thread* thread) {
1538
1539 if (thread != NULL &&
1540 thread == _protected_thread &&
1541 _crash_protection != NULL) {
1542
1543 if (sig == SIGSEGV || sig == SIGBUS) {
1544 _crash_protection->restore();
1545 }
1546 }
1547 }
1548
1549 // Shared clock/time and other supporting routines for pthread_mutex/cond
1550 // initialization. This is enabled on Solaris but only some of the clock/time
1551 // functionality is actually used there.
1552
1553 // Shared condattr object for use with relative timed-waits. Will be associated
1554 // with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
1555 // but otherwise whatever default is used by the platform - generally the
1556 // time-of-day clock.
1557 static pthread_condattr_t _condAttr[1];
1558
1559 // Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
1560 // all systems (e.g. FreeBSD) map the default to "normal".
1561 static pthread_mutexattr_t _mutexAttr[1];
1562
1563 // common basic initialization that is always supported
1564 static void pthread_init_common(void) {
1565 int status;
1566 if ((status = pthread_condattr_init(_condAttr)) != 0) {
1567 fatal("pthread_condattr_init: %s", os::strerror(status));
1568 }
1569 if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
1570 fatal("pthread_mutexattr_init: %s", os::strerror(status));
1571 }
1572 if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
1573 fatal("pthread_mutexattr_settype: %s", os::strerror(status));
1574 }
1575 // Solaris has it's own PlatformMutex, distinct from the one for POSIX.
1576 NOT_SOLARIS(os::PlatformMutex::init();)
1577 }
1578
1579 #ifndef SOLARIS
1580 sigset_t sigs;
1581 struct sigaction sigact[NSIG];
1582
1583 struct sigaction* os::Posix::get_preinstalled_handler(int sig) {
1584 if (sigismember(&sigs, sig)) {
1585 return &sigact[sig];
1586 }
1587 return NULL;
1588 }
1589
1590 void os::Posix::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
1591 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
1592 sigact[sig] = oldAct;
1593 sigaddset(&sigs, sig);
1594 }
1595 #endif
1596
1597 // Not all POSIX types and API's are available on all notionally "posix"
1598 // platforms. If we have build-time support then we will check for actual
1599 // runtime support via dlopen/dlsym lookup. This allows for running on an
1600 // older OS version compared to the build platform. But if there is no
1601 // build time support then there cannot be any runtime support as we do not
1602 // know what the runtime types would be (for example clockid_t might be an
1603 // int or int64_t).
1604 //
1605 #ifdef SUPPORTS_CLOCK_MONOTONIC
1606
1607 // This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
1608
1609 int (*os::Posix::_clock_gettime)(clockid_t, struct timespec *) = NULL;
1610 int (*os::Posix::_clock_getres)(clockid_t, struct timespec *) = NULL;
1611
1612 static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t) = NULL;
1613
1614 static bool _use_clock_monotonic_condattr = false;
1615
1616 // Determine what POSIX API's are present and do appropriate
1617 // configuration.
1618 void os::Posix::init(void) {
1619
1620 // NOTE: no logging available when this is called. Put logging
1621 // statements in init_2().
1622
1623 // 1. Check for CLOCK_MONOTONIC support.
1624
1625 void* handle = NULL;
1626
1627 // For linux we need librt, for other OS we can find
1628 // this function in regular libc.
1629 #ifdef NEEDS_LIBRT
1630 // We do dlopen's in this particular order due to bug in linux
1631 // dynamic loader (see 6348968) leading to crash on exit.
1632 handle = dlopen("librt.so.1", RTLD_LAZY);
1633 if (handle == NULL) {
1634 handle = dlopen("librt.so", RTLD_LAZY);
1635 }
1636 #endif
1637
1638 if (handle == NULL) {
1639 handle = RTLD_DEFAULT;
1640 }
1641
1642 int (*clock_getres_func)(clockid_t, struct timespec*) =
1643 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1644 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1645 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1646 if (clock_getres_func != NULL && clock_gettime_func != NULL) {
1647 // We assume that if both clock_gettime and clock_getres support
1648 // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
1649 struct timespec res;
1650 struct timespec tp;
1651 if (clock_getres_func(CLOCK_MONOTONIC, &res) == 0 &&
1652 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1653 // Yes, monotonic clock is supported.
1654 _clock_gettime = clock_gettime_func;
1655 _clock_getres = clock_getres_func;
1656 } else {
1657 #ifdef NEEDS_LIBRT
1658 // Close librt if there is no monotonic clock.
1659 if (handle != RTLD_DEFAULT) {
1660 dlclose(handle);
1661 }
1662 #endif
1663 }
1664 }
1665
1666 // 2. Check for pthread_condattr_setclock support.
1667
1668 // libpthread is already loaded.
1669 int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
1670 (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
1671 "pthread_condattr_setclock");
1672 if (condattr_setclock_func != NULL) {
1673 _pthread_condattr_setclock = condattr_setclock_func;
1674 }
1675
1676 // Now do general initialization.
1677
1678 pthread_init_common();
1679
1680 #ifndef SOLARIS
1681 int status;
1682 if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
1683 if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
1684 if (status == EINVAL) {
1685 _use_clock_monotonic_condattr = false;
1686 warning("Unable to use monotonic clock with relative timed-waits" \
1687 " - changes to the time-of-day clock may have adverse affects");
1688 } else {
1689 fatal("pthread_condattr_setclock: %s", os::strerror(status));
1690 }
1691 } else {
1692 _use_clock_monotonic_condattr = true;
1693 }
1694 }
1695 #endif // !SOLARIS
1696
1697 }
1698
1699 void os::Posix::init_2(void) {
1700 #ifndef SOLARIS
1701 log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
1702 (_clock_gettime != NULL ? "" : " not"));
1703 log_info(os)("Use of pthread_condattr_setclock is%s supported",
1704 (_pthread_condattr_setclock != NULL ? "" : " not"));
1705 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
1706 _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
1707 sigemptyset(&sigs);
1708 #endif // !SOLARIS
1709 }
1710
1711 #else // !SUPPORTS_CLOCK_MONOTONIC
1712
1713 void os::Posix::init(void) {
1714 pthread_init_common();
1715 }
1716
1717 void os::Posix::init_2(void) {
1718 #ifndef SOLARIS
1719 log_info(os)("Use of CLOCK_MONOTONIC is not supported");
1720 log_info(os)("Use of pthread_condattr_setclock is not supported");
1721 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
1722 sigemptyset(&sigs);
1723 #endif // !SOLARIS
1724 }
1725
1726 #endif // SUPPORTS_CLOCK_MONOTONIC
1727
1728 // Utility to convert the given timeout to an absolute timespec
1729 // (based on the appropriate clock) to use with pthread_cond_timewait,
1730 // and sem_timedwait().
1731 // The clock queried here must be the clock used to manage the
1732 // timeout of the condition variable or semaphore.
1733 //
1734 // The passed in timeout value is either a relative time in nanoseconds
1735 // or an absolute time in milliseconds. A relative timeout will be
1736 // associated with CLOCK_MONOTONIC if available, unless the real-time clock
1737 // is explicitly requested; otherwise, or if absolute,
1738 // the default time-of-day clock will be used.
1739
1740 // Given time is a 64-bit value and the time_t used in the timespec is
1741 // sometimes a signed-32-bit value we have to watch for overflow if times
1742 // way in the future are given. Further on Solaris versions
1743 // prior to 10 there is a restriction (see cond_timedwait) that the specified
1744 // number of seconds, in abstime, is less than current_time + 100000000.
1745 // As it will be over 20 years before "now + 100000000" will overflow we can
1746 // ignore overflow and just impose a hard-limit on seconds using the value
1747 // of "now + 100000000". This places a limit on the timeout of about 3.17
1748 // years from "now".
1749 //
1750 #define MAX_SECS 100000000
1751
1752 // Calculate a new absolute time that is "timeout" nanoseconds from "now".
1753 // "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
1754 // on which clock API is being used).
1755 static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
1756 jlong now_part_sec, jlong unit) {
1757 time_t max_secs = now_sec + MAX_SECS;
1758
1759 jlong seconds = timeout / NANOUNITS;
1760 timeout %= NANOUNITS; // remaining nanos
1761
1762 if (seconds >= MAX_SECS) {
1763 // More seconds than we can add, so pin to max_secs.
1764 abstime->tv_sec = max_secs;
1765 abstime->tv_nsec = 0;
1766 } else {
1767 abstime->tv_sec = now_sec + seconds;
1768 long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
1769 if (nanos >= NANOUNITS) { // overflow
1770 abstime->tv_sec += 1;
1771 nanos -= NANOUNITS;
1772 }
1773 abstime->tv_nsec = nanos;
1774 }
1775 }
1776
1777 // Unpack the given deadline in milliseconds since the epoch, into the given timespec.
1778 // The current time in seconds is also passed in to enforce an upper bound as discussed above.
1779 // This is only used with gettimeofday, when clock_gettime is not available.
1780 static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
1781 time_t max_secs = now_sec + MAX_SECS;
1782
1783 jlong seconds = deadline / MILLIUNITS;
1784 jlong millis = deadline % MILLIUNITS;
1785
1786 if (seconds >= max_secs) {
1787 // Absolute seconds exceeds allowed max, so pin to max_secs.
1788 abstime->tv_sec = max_secs;
1789 abstime->tv_nsec = 0;
1790 } else {
1791 abstime->tv_sec = seconds;
1792 abstime->tv_nsec = millis * (NANOUNITS / MILLIUNITS);
1793 }
1794 }
1795
1796 static jlong millis_to_nanos(jlong millis) {
1797 // We have to watch for overflow when converting millis to nanos,
1798 // but if millis is that large then we will end up limiting to
1799 // MAX_SECS anyway, so just do that here.
1800 if (millis / MILLIUNITS > MAX_SECS) {
1801 millis = jlong(MAX_SECS) * MILLIUNITS;
1802 }
1803 return millis * (NANOUNITS / MILLIUNITS);
1804 }
1805
1806 static void to_abstime(timespec* abstime, jlong timeout,
1807 bool isAbsolute, bool isRealtime) {
1808 DEBUG_ONLY(int max_secs = MAX_SECS;)
1809
1810 if (timeout < 0) {
1811 timeout = 0;
1812 }
1813
1814 #ifdef SUPPORTS_CLOCK_MONOTONIC
1815
1816 clockid_t clock = CLOCK_MONOTONIC;
1817 // need to ensure we have a runtime check for clock_gettime support
1818 if (!isAbsolute && os::Posix::supports_monotonic_clock()) {
1819 if (!_use_clock_monotonic_condattr || isRealtime) {
1820 clock = CLOCK_REALTIME;
1821 }
1822 struct timespec now;
1823 int status = os::Posix::clock_gettime(clock, &now);
1824 assert_status(status == 0, status, "clock_gettime");
1825 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
1826 DEBUG_ONLY(max_secs += now.tv_sec;)
1827 } else {
1828
1829 #else
1830
1831 { // Match the block scope.
1832
1833 #endif // SUPPORTS_CLOCK_MONOTONIC
1834
1835 // Time-of-day clock is all we can reliably use.
1836 struct timeval now;
1837 int status = gettimeofday(&now, NULL);
1838 assert_status(status == 0, errno, "gettimeofday");
1839 if (isAbsolute) {
1840 unpack_abs_time(abstime, timeout, now.tv_sec);
1841 } else {
1842 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
1843 }
1844 DEBUG_ONLY(max_secs += now.tv_sec;)
1845 }
1846
1847 assert(abstime->tv_sec >= 0, "tv_sec < 0");
1848 assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
1849 assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
1850 assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
1851 }
1852
1853 // Create an absolute time 'millis' milliseconds in the future, using the
1854 // real-time (time-of-day) clock. Used by PosixSemaphore.
1855 void os::Posix::to_RTC_abstime(timespec* abstime, int64_t millis) {
1856 to_abstime(abstime, millis_to_nanos(millis),
1857 false /* not absolute */,
1858 true /* use real-time clock */);
1859 }
1860
1861 // Shared pthread_mutex/cond based PlatformEvent implementation.
1862 // Not currently usable by Solaris.
1863
1864 #ifndef SOLARIS
1865
1866 // PlatformEvent
1867 //
1868 // Assumption:
1869 // Only one parker can exist on an event, which is why we allocate
1870 // them per-thread. Multiple unparkers can coexist.
1871 //
1872 // _event serves as a restricted-range semaphore.
1873 // -1 : thread is blocked, i.e. there is a waiter
1874 // 0 : neutral: thread is running or ready,
1875 // could have been signaled after a wait started
1876 // 1 : signaled - thread is running or ready
1877 //
1878 // Having three states allows for some detection of bad usage - see
1879 // comments on unpark().
1880
1881 os::PlatformEvent::PlatformEvent() {
1882 int status = pthread_cond_init(_cond, _condAttr);
1883 assert_status(status == 0, status, "cond_init");
1884 status = pthread_mutex_init(_mutex, _mutexAttr);
1885 assert_status(status == 0, status, "mutex_init");
1886 _event = 0;
1887 _nParked = 0;
1888 }
1889
1890 void os::PlatformEvent::park() { // AKA "down()"
1891 // Transitions for _event:
1892 // -1 => -1 : illegal
1893 // 1 => 0 : pass - return immediately
1894 // 0 => -1 : block; then set _event to 0 before returning
1895
1896 // Invariant: Only the thread associated with the PlatformEvent
1897 // may call park().
1898 assert(_nParked == 0, "invariant");
1899
1900 int v;
1901
1902 // atomically decrement _event
1903 for (;;) {
1904 v = _event;
1905 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1906 }
1907 guarantee(v >= 0, "invariant");
1908
1909 if (v == 0) { // Do this the hard way by blocking ...
1910 int status = pthread_mutex_lock(_mutex);
1911 assert_status(status == 0, status, "mutex_lock");
1912 guarantee(_nParked == 0, "invariant");
1913 ++_nParked;
1914 while (_event < 0) {
1915 // OS-level "spurious wakeups" are ignored
1916 status = pthread_cond_wait(_cond, _mutex);
1917 assert_status(status == 0, status, "cond_wait");
1918 }
1919 --_nParked;
1920
1921 _event = 0;
1922 status = pthread_mutex_unlock(_mutex);
1923 assert_status(status == 0, status, "mutex_unlock");
1924 // Paranoia to ensure our locked and lock-free paths interact
1925 // correctly with each other.
1926 OrderAccess::fence();
1927 }
1928 guarantee(_event >= 0, "invariant");
1929 }
1930
1931 int os::PlatformEvent::park(jlong millis) {
1932 // Transitions for _event:
1933 // -1 => -1 : illegal
1934 // 1 => 0 : pass - return immediately
1935 // 0 => -1 : block; then set _event to 0 before returning
1936
1937 // Invariant: Only the thread associated with the Event/PlatformEvent
1938 // may call park().
1939 assert(_nParked == 0, "invariant");
1940
1941 int v;
1942 // atomically decrement _event
1943 for (;;) {
1944 v = _event;
1945 if (Atomic::cmpxchg(v - 1, &_event, v) == v) break;
1946 }
1947 guarantee(v >= 0, "invariant");
1948
1949 if (v == 0) { // Do this the hard way by blocking ...
1950 struct timespec abst;
1951 to_abstime(&abst, millis_to_nanos(millis), false, false);
1952
1953 int ret = OS_TIMEOUT;
1954 int status = pthread_mutex_lock(_mutex);
1955 assert_status(status == 0, status, "mutex_lock");
1956 guarantee(_nParked == 0, "invariant");
1957 ++_nParked;
1958
1959 while (_event < 0) {
1960 status = pthread_cond_timedwait(_cond, _mutex, &abst);
1961 assert_status(status == 0 || status == ETIMEDOUT,
1962 status, "cond_timedwait");
1963 // OS-level "spurious wakeups" are ignored unless the archaic
1964 // FilterSpuriousWakeups is set false. That flag should be obsoleted.
1965 if (!FilterSpuriousWakeups) break;
1966 if (status == ETIMEDOUT) break;
1967 }
1968 --_nParked;
1969
1970 if (_event >= 0) {
1971 ret = OS_OK;
1972 }
1973
1974 _event = 0;
1975 status = pthread_mutex_unlock(_mutex);
1976 assert_status(status == 0, status, "mutex_unlock");
1977 // Paranoia to ensure our locked and lock-free paths interact
1978 // correctly with each other.
1979 OrderAccess::fence();
1980 return ret;
1981 }
1982 return OS_OK;
1983 }
1984
1985 void os::PlatformEvent::unpark() {
1986 // Transitions for _event:
1987 // 0 => 1 : just return
1988 // 1 => 1 : just return
1989 // -1 => either 0 or 1; must signal target thread
1990 // That is, we can safely transition _event from -1 to either
1991 // 0 or 1.
1992 // See also: "Semaphores in Plan 9" by Mullender & Cox
1993 //
1994 // Note: Forcing a transition from "-1" to "1" on an unpark() means
1995 // that it will take two back-to-back park() calls for the owning
1996 // thread to block. This has the benefit of forcing a spurious return
1997 // from the first park() call after an unpark() call which will help
1998 // shake out uses of park() and unpark() without checking state conditions
1999 // properly. This spurious return doesn't manifest itself in any user code
2000 // but only in the correctly written condition checking loops of ObjectMonitor,
2001 // Mutex/Monitor, Thread::muxAcquire and JavaThread::sleep
2002
2003 if (Atomic::xchg(1, &_event) >= 0) return;
2004
2005 int status = pthread_mutex_lock(_mutex);
2006 assert_status(status == 0, status, "mutex_lock");
2007 int anyWaiters = _nParked;
2008 assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
2009 status = pthread_mutex_unlock(_mutex);
2010 assert_status(status == 0, status, "mutex_unlock");
2011
2012 // Note that we signal() *after* dropping the lock for "immortal" Events.
2013 // This is safe and avoids a common class of futile wakeups. In rare
2014 // circumstances this can cause a thread to return prematurely from
2015 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2016 // will simply re-test the condition and re-park itself.
2017 // This provides particular benefit if the underlying platform does not
2018 // provide wait morphing.
2019
2020 if (anyWaiters != 0) {
2021 status = pthread_cond_signal(_cond);
2022 assert_status(status == 0, status, "cond_signal");
2023 }
2024 }
2025
2026 // JSR166 support
2027
2028 os::PlatformParker::PlatformParker() {
2029 int status;
2030 status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
2031 assert_status(status == 0, status, "cond_init rel");
2032 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
2033 assert_status(status == 0, status, "cond_init abs");
2034 status = pthread_mutex_init(_mutex, _mutexAttr);
2035 assert_status(status == 0, status, "mutex_init");
2036 _cur_index = -1; // mark as unused
2037 }
2038
2039 // Parker::park decrements count if > 0, else does a condvar wait. Unpark
2040 // sets count to 1 and signals condvar. Only one thread ever waits
2041 // on the condvar. Contention seen when trying to park implies that someone
2042 // is unparking you, so don't wait. And spurious returns are fine, so there
2043 // is no need to track notifications.
2044
2045 void Parker::park(bool isAbsolute, jlong time) {
2046
2047 // Optional fast-path check:
2048 // Return immediately if a permit is available.
2049 // We depend on Atomic::xchg() having full barrier semantics
2050 // since we are doing a lock-free update to _counter.
2051 if (Atomic::xchg(0, &_counter) > 0) return;
2052
2053 Thread* thread = Thread::current();
2054 assert(thread->is_Java_thread(), "Must be JavaThread");
2055 JavaThread *jt = (JavaThread *)thread;
2056
2057 // Optional optimization -- avoid state transitions if there's
2058 // an interrupt pending.
2059 if (jt->is_interrupted(false)) {
2060 return;
2061 }
2062
2063 // Next, demultiplex/decode time arguments
2064 struct timespec absTime;
2065 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
2066 return;
2067 }
2068 if (time > 0) {
2069 to_abstime(&absTime, time, isAbsolute, false);
2070 }
2071
2072 // Enter safepoint region
2073 // Beware of deadlocks such as 6317397.
2074 // The per-thread Parker:: mutex is a classic leaf-lock.
2075 // In particular a thread must never block on the Threads_lock while
2076 // holding the Parker:: mutex. If safepoints are pending both the
2077 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
2078 ThreadBlockInVM tbivm(jt);
2079
2080 // Don't wait if cannot get lock since interference arises from
2081 // unparking. Also re-check interrupt before trying wait.
2082 if (jt->is_interrupted(false) ||
2083 pthread_mutex_trylock(_mutex) != 0) {
2084 return;
2085 }
2086
2087 int status;
2088 if (_counter > 0) { // no wait needed
2089 _counter = 0;
2090 status = pthread_mutex_unlock(_mutex);
2091 assert_status(status == 0, status, "invariant");
2092 // Paranoia to ensure our locked and lock-free paths interact
2093 // correctly with each other and Java-level accesses.
2094 OrderAccess::fence();
2095 return;
2096 }
2097
2098 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2099 jt->set_suspend_equivalent();
2100 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2101
2102 assert(_cur_index == -1, "invariant");
2103 if (time == 0) {
2104 _cur_index = REL_INDEX; // arbitrary choice when not timed
2105 status = pthread_cond_wait(&_cond[_cur_index], _mutex);
2106 assert_status(status == 0, status, "cond_timedwait");
2107 }
2108 else {
2109 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
2110 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
2111 assert_status(status == 0 || status == ETIMEDOUT,
2112 status, "cond_timedwait");
2113 }
2114 _cur_index = -1;
2115
2116 _counter = 0;
2117 status = pthread_mutex_unlock(_mutex);
2118 assert_status(status == 0, status, "invariant");
2119 // Paranoia to ensure our locked and lock-free paths interact
2120 // correctly with each other and Java-level accesses.
2121 OrderAccess::fence();
2122
2123 // If externally suspended while waiting, re-suspend
2124 if (jt->handle_special_suspend_equivalent_condition()) {
2125 jt->java_suspend_self();
2126 }
2127 }
2128
2129 void Parker::unpark() {
2130 int status = pthread_mutex_lock(_mutex);
2131 assert_status(status == 0, status, "invariant");
2132 const int s = _counter;
2133 _counter = 1;
2134 // must capture correct index before unlocking
2135 int index = _cur_index;
2136 status = pthread_mutex_unlock(_mutex);
2137 assert_status(status == 0, status, "invariant");
2138
2139 // Note that we signal() *after* dropping the lock for "immortal" Events.
2140 // This is safe and avoids a common class of futile wakeups. In rare
2141 // circumstances this can cause a thread to return prematurely from
2142 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2143 // will simply re-test the condition and re-park itself.
2144 // This provides particular benefit if the underlying platform does not
2145 // provide wait morphing.
2146
2147 if (s < 1 && index != -1) {
2148 // thread is definitely parked
2149 status = pthread_cond_signal(&_cond[index]);
2150 assert_status(status == 0, status, "invariant");
2151 }
2152 }
2153
2154 // Platform Mutex/Monitor implementation
2155
2156 #if PLATFORM_MONITOR_IMPL_INDIRECT
2157
2158 os::PlatformMutex::Mutex::Mutex() : _next(NULL) {
2159 int status = pthread_mutex_init(&_mutex, _mutexAttr);
2160 assert_status(status == 0, status, "mutex_init");
2161 }
2162
2163 os::PlatformMutex::Mutex::~Mutex() {
2164 int status = pthread_mutex_destroy(&_mutex);
2165 assert_status(status == 0, status, "mutex_destroy");
2166 }
2167
2168 pthread_mutex_t os::PlatformMutex::_freelist_lock;
2169 os::PlatformMutex::Mutex* os::PlatformMutex::_mutex_freelist = NULL;
2170
2171 void os::PlatformMutex::init() {
2172 int status = pthread_mutex_init(&_freelist_lock, _mutexAttr);
2173 assert_status(status == 0, status, "freelist lock init");
2174 }
2175
2176 struct os::PlatformMutex::WithFreeListLocked : public StackObj {
2177 WithFreeListLocked() {
2178 int status = pthread_mutex_lock(&_freelist_lock);
2179 assert_status(status == 0, status, "freelist lock");
2180 }
2181
2182 ~WithFreeListLocked() {
2183 int status = pthread_mutex_unlock(&_freelist_lock);
2184 assert_status(status == 0, status, "freelist unlock");
2185 }
2186 };
2187
2188 os::PlatformMutex::PlatformMutex() {
2189 {
2190 WithFreeListLocked wfl;
2191 _impl = _mutex_freelist;
2192 if (_impl != NULL) {
2193 _mutex_freelist = _impl->_next;
2194 _impl->_next = NULL;
2195 return;
2196 }
2197 }
2198 _impl = new Mutex();
2199 }
2200
2201 os::PlatformMutex::~PlatformMutex() {
2202 WithFreeListLocked wfl;
2203 assert(_impl->_next == NULL, "invariant");
2204 _impl->_next = _mutex_freelist;
2205 _mutex_freelist = _impl;
2206 }
2207
2208 os::PlatformMonitor::Cond::Cond() : _next(NULL) {
2209 int status = pthread_cond_init(&_cond, _condAttr);
2210 assert_status(status == 0, status, "cond_init");
2211 }
2212
2213 os::PlatformMonitor::Cond::~Cond() {
2214 int status = pthread_cond_destroy(&_cond);
2215 assert_status(status == 0, status, "cond_destroy");
2216 }
2217
2218 os::PlatformMonitor::Cond* os::PlatformMonitor::_cond_freelist = NULL;
2219
2220 os::PlatformMonitor::PlatformMonitor() {
2221 {
2222 WithFreeListLocked wfl;
2223 _impl = _cond_freelist;
2224 if (_impl != NULL) {
2225 _cond_freelist = _impl->_next;
2226 _impl->_next = NULL;
2227 return;
2228 }
2229 }
2230 _impl = new Cond();
2231 }
2232
2233 os::PlatformMonitor::~PlatformMonitor() {
2234 WithFreeListLocked wfl;
2235 assert(_impl->_next == NULL, "invariant");
2236 _impl->_next = _cond_freelist;
2237 _cond_freelist = _impl;
2238 }
2239
2240 #else
2241
2242 os::PlatformMutex::PlatformMutex() {
2243 int status = pthread_mutex_init(&_mutex, _mutexAttr);
2244 assert_status(status == 0, status, "mutex_init");
2245 }
2246
2247 os::PlatformMutex::~PlatformMutex() {
2248 int status = pthread_mutex_destroy(&_mutex);
2249 assert_status(status == 0, status, "mutex_destroy");
2250 }
2251
2252 os::PlatformMonitor::PlatformMonitor() {
2253 int status = pthread_cond_init(&_cond, _condAttr);
2254 assert_status(status == 0, status, "cond_init");
2255 }
2256
2257 os::PlatformMonitor::~PlatformMonitor() {
2258 int status = pthread_cond_destroy(&_cond);
2259 assert_status(status == 0, status, "cond_destroy");
2260 }
2261
2262 #endif // PLATFORM_MONITOR_IMPL_INDIRECT
2263
2264 // Must already be locked
2265 int os::PlatformMonitor::wait(jlong millis) {
2266 assert(millis >= 0, "negative timeout");
2267 if (millis > 0) {
2268 struct timespec abst;
2269 // We have to watch for overflow when converting millis to nanos,
2270 // but if millis is that large then we will end up limiting to
2271 // MAX_SECS anyway, so just do that here.
2272 if (millis / MILLIUNITS > MAX_SECS) {
2273 millis = jlong(MAX_SECS) * MILLIUNITS;
2274 }
2275 to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false, false);
2276
2277 int ret = OS_TIMEOUT;
2278 int status = pthread_cond_timedwait(cond(), mutex(), &abst);
2279 assert_status(status == 0 || status == ETIMEDOUT,
2280 status, "cond_timedwait");
2281 if (status == 0) {
2282 ret = OS_OK;
2283 }
2284 return ret;
2285 } else {
2286 int status = pthread_cond_wait(cond(), mutex());
2287 assert_status(status == 0, status, "cond_wait");
2288 return OS_OK;
2289 }
2290 }
2291
2292 #endif // !SOLARIS