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