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