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 "runtime/orderAccess.hpp"
34 #include "utilities/align.hpp"
35 #include "utilities/events.hpp"
36 #include "utilities/formatBuffer.hpp"
37 #include "utilities/macros.hpp"
38 #include "utilities/vmError.hpp"
39
40 #include <dirent.h>
41 #include <dlfcn.h>
42 #include <grp.h>
43 #include <pwd.h>
44 #include <pthread.h>
45 #include <signal.h>
46 #include <sys/mman.h>
47 #include <sys/resource.h>
48 #include <sys/utsname.h>
49 #include <time.h>
50 #include <unistd.h>
51
52 // Todo: provide a os::get_max_process_id() or similar. Number of processes
53 // may have been configured, can be read more accurately from proc fs etc.
54 #ifndef MAX_PID
55 #define MAX_PID INT_MAX
56 #endif
57 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
58
59 #define ROOT_UID 0
60
61 #ifndef MAP_ANONYMOUS
62 #define MAP_ANONYMOUS MAP_ANON
63 #endif
64
65 #define check_with_errno(check_type, cond, msg) \
66 do { \
67 int err = errno; \
68 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
69 os::errno_name(err)); \
70 } while (false)
71
72 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
73 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
74
75 // Check core dump limit and report possible place where core can be found
76 void os::check_dump_limit(char* buffer, size_t bufferSize) {
77 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
78 jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
79 VMError::record_coredump_status(buffer, false);
80 return;
81 }
82
83 int n;
84 struct rlimit rlim;
85 bool success;
86
87 char core_path[PATH_MAX];
88 n = get_core_path(core_path, PATH_MAX);
89
90 if (n <= 0) {
91 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
92 success = true;
93 #ifdef LINUX
94 } else if (core_path[0] == '"') { // redirect to user process
95 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
96 success = true;
97 #endif
98 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
99 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
100 success = true;
101 } else {
102 switch(rlim.rlim_cur) {
103 case RLIM_INFINITY:
104 jio_snprintf(buffer, bufferSize, "%s", core_path);
105 success = true;
106 break;
107 case 0:
108 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
109 success = false;
110 break;
111 default:
112 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);
113 success = true;
114 break;
115 }
116 }
117
118 VMError::record_coredump_status(buffer, success);
119 }
120
121 int os::get_native_stack(address* stack, int frames, int toSkip) {
122 int frame_idx = 0;
123 int num_of_frames; // number of frames captured
124 frame fr = os::current_frame();
125 while (fr.pc() && frame_idx < frames) {
126 if (toSkip > 0) {
127 toSkip --;
128 } else {
129 stack[frame_idx ++] = fr.pc();
130 }
131 if (fr.fp() == NULL || fr.cb() != NULL ||
132 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
133
134 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
135 fr = os::get_sender_for_C_frame(&fr);
136 } else {
137 break;
138 }
139 }
140 num_of_frames = frame_idx;
141 for (; frame_idx < frames; frame_idx ++) {
142 stack[frame_idx] = NULL;
143 }
144
145 return num_of_frames;
146 }
147
148
149 bool os::unsetenv(const char* name) {
150 assert(name != NULL, "Null pointer");
151 return (::unsetenv(name) == 0);
152 }
153
154 int os::get_last_error() {
155 return errno;
156 }
157
158 size_t os::lasterror(char *buf, size_t len) {
159 if (errno == 0) return 0;
160
161 const char *s = os::strerror(errno);
162 size_t n = ::strlen(s);
163 if (n >= len) {
164 n = len - 1;
165 }
166 ::strncpy(buf, s, n);
167 buf[n] = '\0';
168 return n;
169 }
170
171 void os::wait_for_keypress_at_exit(void) {
172 // don't do anything on posix platforms
173 return;
174 }
175
176 int os::create_file_for_heap(const char* dir) {
177
178 const char name_template[] = "/jvmheap.XXXXXX";
179
180 size_t fullname_len = strlen(dir) + strlen(name_template);
181 char *fullname = (char*)os::malloc(fullname_len + 1, mtInternal);
182 if (fullname == NULL) {
183 vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
184 return -1;
185 }
186 int n = snprintf(fullname, fullname_len + 1, "%s%s", dir, name_template);
187 assert((size_t)n == fullname_len, "Unexpected number of characters in string");
188
189 os::native_path(fullname);
190
191 // set the file creation mask.
192 mode_t file_mode = S_IRUSR | S_IWUSR;
193
194 // create a new file.
195 int fd = mkstemp(fullname);
196
197 if (fd < 0) {
198 warning("Could not create file for heap with template %s", fullname);
199 os::free(fullname);
200 return -1;
201 }
202
203 // delete the name from the filesystem. When 'fd' is closed, the file (and space) will be deleted.
204 int ret = unlink(fullname);
205 assert_with_errno(ret == 0, "unlink returned error");
206
207 os::free(fullname);
208 return fd;
209 }
210
211 static char* reserve_mmapped_memory(size_t bytes, char* requested_addr) {
212 char * addr;
213 int flags = MAP_PRIVATE NOT_AIX( | MAP_NORESERVE ) | MAP_ANONYMOUS;
214 if (requested_addr != NULL) {
215 assert((uintptr_t)requested_addr % os::vm_page_size() == 0, "Requested address should be aligned to OS page size");
216 flags |= MAP_FIXED;
217 }
218
219 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
220 // touch an uncommitted page. Otherwise, the read/write might
221 // succeed if we have enough swap space to back the physical page.
222 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
223 flags, -1, 0);
224
225 if (addr != MAP_FAILED) {
226 MemTracker::record_virtual_memory_reserve((address)addr, bytes, CALLER_PC);
227 return addr;
228 }
229 return NULL;
230 }
231
232 static int util_posix_fallocate(int fd, off_t offset, off_t len) {
233 #ifdef __APPLE__
234 fstore_t store = { F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, len };
235 // First we try to get a continuous chunk of disk space
236 int ret = fcntl(fd, F_PREALLOCATE, &store);
237 if (ret == -1) {
238 // Maybe we are too fragmented, try to allocate non-continuous range
239 store.fst_flags = F_ALLOCATEALL;
240 ret = fcntl(fd, F_PREALLOCATE, &store);
241 }
242 if(ret != -1) {
243 return ftruncate(fd, len);
244 }
245 return -1;
246 #else
247 return posix_fallocate(fd, offset, len);
248 #endif
249 }
250
251 // Map the given address range to the provided file descriptor.
252 char* os::map_memory_to_file(char* base, size_t size, int fd) {
253 assert(fd != -1, "File descriptor is not valid");
254
255 // allocate space for the file
256 int ret = util_posix_fallocate(fd, 0, (off_t)size);
257 if (ret != 0) {
258 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory. error(%d)", ret));
259 return NULL;
260 }
261
262 int prot = PROT_READ | PROT_WRITE;
263 int flags = MAP_SHARED;
264 if (base != NULL) {
265 flags |= MAP_FIXED;
266 }
267 char* addr = (char*)mmap(base, size, prot, flags, fd, 0);
268
269 if (addr == MAP_FAILED) {
270 warning("Failed mmap to file. (%s)", os::strerror(errno));
271 return NULL;
272 }
273 if (base != NULL && addr != base) {
274 if (!os::release_memory(addr, size)) {
275 warning("Could not release memory on unsuccessful file mapping");
276 }
277 return NULL;
278 }
279 return addr;
280 }
281
282 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
283 assert(fd != -1, "File descriptor is not valid");
284 assert(base != NULL, "Base cannot be NULL");
285
286 return map_memory_to_file(base, size, fd);
287 }
288
289 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
290 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
291 // rather than unmapping and remapping the whole chunk to get requested alignment.
292 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
293 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
294 "Alignment must be a multiple of allocation granularity (page size)");
295 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
296
297 size_t extra_size = size + alignment;
298 assert(extra_size >= size, "overflow, size is too large to allow alignment");
299
300 char* extra_base;
301 if (file_desc != -1) {
302 // For file mapping, we do not call os:reserve_memory(extra_size, NULL, alignment, file_desc) because
303 // we need to deal with shrinking of the file space later when we release extra memory after alignment.
304 // We also cannot called os:reserve_memory() with file_desc set to -1 because on aix we might get SHM memory.
305 // So here to call a helper function while reserve memory for us. After we have a aligned base,
306 // we will replace anonymous mapping with file mapping.
307 extra_base = reserve_mmapped_memory(extra_size, NULL);
308 if (extra_base != NULL) {
309 MemTracker::record_virtual_memory_reserve((address)extra_base, extra_size, CALLER_PC);
310 }
311 } else {
312 extra_base = os::reserve_memory(extra_size, NULL, alignment);
313 }
314
315 if (extra_base == NULL) {
316 return NULL;
317 }
318
319 // Do manual alignment
320 char* aligned_base = align_up(extra_base, alignment);
321
322 // [ | | ]
323 // ^ extra_base
324 // ^ extra_base + begin_offset == aligned_base
325 // extra_base + begin_offset + size ^
326 // extra_base + extra_size ^
327 // |<>| == begin_offset
328 // end_offset == |<>|
329 size_t begin_offset = aligned_base - extra_base;
330 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
331
332 if (begin_offset > 0) {
333 os::release_memory(extra_base, begin_offset);
334 }
335
336 if (end_offset > 0) {
337 os::release_memory(extra_base + begin_offset + size, end_offset);
338 }
339
340 if (file_desc != -1) {
341 // After we have an aligned address, we can replace anonymous mapping with file mapping
342 if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
343 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
344 }
345 MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
346 }
347 return aligned_base;
348 }
349
350 int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
351 // All supported POSIX platforms provide C99 semantics.
352 int result = ::vsnprintf(buf, len, fmt, args);
353 // If an encoding error occurred (result < 0) then it's not clear
354 // whether the buffer is NUL terminated, so ensure it is.
355 if ((result < 0) && (len > 0)) {
356 buf[len - 1] = '\0';
357 }
358 return result;
359 }
360
361 int os::get_fileno(FILE* fp) {
362 return NOT_AIX(::)fileno(fp);
363 }
364
365 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
366 return gmtime_r(clock, res);
367 }
368
369 void os::Posix::print_load_average(outputStream* st) {
370 st->print("load average:");
371 double loadavg[3];
372 int res = os::loadavg(loadavg, 3);
373 if (res != -1) {
374 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
375 } else {
376 st->print(" Unavailable");
377 }
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 #ifdef SIGINFO
690 { SIGINFO, "SIGINFO" },
691 #endif
692 { SIGINT, "SIGINT" },
693 #ifdef SIGIO
694 { SIGIO, "SIGIO" },
695 #endif
696 #ifdef SIGIOINT
697 { SIGIOINT, "SIGIOINT" },
698 #endif
699 #ifdef SIGIOT
700 // SIGIOT is there for BSD compatibility, but on most Unices just a
701 // synonym for SIGABRT. The result should be "SIGABRT", not
702 // "SIGIOT".
703 #if (SIGIOT != SIGABRT )
704 { SIGIOT, "SIGIOT" },
705 #endif
706 #endif
707 #ifdef SIGKAP
708 { SIGKAP, "SIGKAP" },
709 #endif
710 { SIGKILL, "SIGKILL" },
711 #ifdef SIGLOST
712 { SIGLOST, "SIGLOST" },
713 #endif
714 #ifdef SIGLWP
715 { SIGLWP, "SIGLWP" },
716 #endif
717 #ifdef SIGLWPTIMER
718 { SIGLWPTIMER, "SIGLWPTIMER" },
719 #endif
720 #ifdef SIGMIGRATE
721 { SIGMIGRATE, "SIGMIGRATE" },
722 #endif
723 #ifdef SIGMSG
724 { SIGMSG, "SIGMSG" },
725 #endif
726 { SIGPIPE, "SIGPIPE" },
727 #ifdef SIGPOLL
728 { SIGPOLL, "SIGPOLL" },
729 #endif
730 #ifdef SIGPRE
731 { SIGPRE, "SIGPRE" },
732 #endif
733 { SIGPROF, "SIGPROF" },
734 #ifdef SIGPTY
735 { SIGPTY, "SIGPTY" },
736 #endif
737 #ifdef SIGPWR
738 { SIGPWR, "SIGPWR" },
739 #endif
740 { SIGQUIT, "SIGQUIT" },
741 #ifdef SIGRECONFIG
742 { SIGRECONFIG, "SIGRECONFIG" },
743 #endif
744 #ifdef SIGRECOVERY
745 { SIGRECOVERY, "SIGRECOVERY" },
746 #endif
747 #ifdef SIGRESERVE
748 { SIGRESERVE, "SIGRESERVE" },
749 #endif
750 #ifdef SIGRETRACT
751 { SIGRETRACT, "SIGRETRACT" },
752 #endif
753 #ifdef SIGSAK
754 { SIGSAK, "SIGSAK" },
755 #endif
756 { SIGSEGV, "SIGSEGV" },
757 #ifdef SIGSOUND
758 { SIGSOUND, "SIGSOUND" },
759 #endif
760 #ifdef SIGSTKFLT
761 { SIGSTKFLT, "SIGSTKFLT" },
762 #endif
763 { SIGSTOP, "SIGSTOP" },
764 { SIGSYS, "SIGSYS" },
765 #ifdef SIGSYSERROR
766 { SIGSYSERROR, "SIGSYSERROR" },
767 #endif
768 #ifdef SIGTALRM
769 { SIGTALRM, "SIGTALRM" },
770 #endif
771 { SIGTERM, "SIGTERM" },
772 #ifdef SIGTHAW
773 { SIGTHAW, "SIGTHAW" },
774 #endif
775 { SIGTRAP, "SIGTRAP" },
776 #ifdef SIGTSTP
777 { SIGTSTP, "SIGTSTP" },
778 #endif
779 { SIGTTIN, "SIGTTIN" },
780 { SIGTTOU, "SIGTTOU" },
781 #ifdef SIGURG
782 { SIGURG, "SIGURG" },
783 #endif
784 { SIGUSR1, "SIGUSR1" },
785 { SIGUSR2, "SIGUSR2" },
786 #ifdef SIGVIRT
787 { SIGVIRT, "SIGVIRT" },
788 #endif
789 { SIGVTALRM, "SIGVTALRM" },
790 #ifdef SIGWAITING
791 { SIGWAITING, "SIGWAITING" },
792 #endif
793 #ifdef SIGWINCH
794 { SIGWINCH, "SIGWINCH" },
795 #endif
796 #ifdef SIGWINDOW
797 { SIGWINDOW, "SIGWINDOW" },
798 #endif
799 { SIGXCPU, "SIGXCPU" },
800 { SIGXFSZ, "SIGXFSZ" },
801 #ifdef SIGXRES
802 { SIGXRES, "SIGXRES" },
803 #endif
804 { -1, NULL }
805 };
806
807 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
808 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
809
810 const char* ret = NULL;
811
812 #ifdef SIGRTMIN
813 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
814 if (sig == SIGRTMIN) {
815 ret = "SIGRTMIN";
816 } else if (sig == SIGRTMAX) {
817 ret = "SIGRTMAX";
818 } else {
819 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
820 return out;
821 }
822 }
823 #endif
824
825 if (sig > 0) {
826 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
827 if (g_signal_info[idx].sig == sig) {
828 ret = g_signal_info[idx].name;
829 break;
830 }
831 }
832 }
833
834 if (!ret) {
835 if (!is_valid_signal(sig)) {
836 ret = "INVALID";
837 } else {
838 ret = "UNKNOWN";
839 }
840 }
841
842 if (out && outlen > 0) {
843 strncpy(out, ret, outlen);
844 out[outlen - 1] = '\0';
845 }
846 return out;
847 }
848
849 int os::Posix::get_signal_number(const char* signal_name) {
850 char tmp[30];
851 const char* s = signal_name;
852 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
853 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
854 s = tmp;
855 }
856 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
857 if (strcmp(g_signal_info[idx].name, s) == 0) {
858 return g_signal_info[idx].sig;
859 }
860 }
861 return -1;
862 }
863
864 int os::get_signal_number(const char* signal_name) {
865 return os::Posix::get_signal_number(signal_name);
866 }
867
868 // Returns true if signal number is valid.
869 bool os::Posix::is_valid_signal(int sig) {
870 // MacOS not really POSIX compliant: sigaddset does not return
871 // an error for invalid signal numbers. However, MacOS does not
872 // support real time signals and simply seems to have just 33
873 // signals with no holes in the signal range.
874 #ifdef __APPLE__
875 return sig >= 1 && sig < NSIG;
876 #else
877 // Use sigaddset to check for signal validity.
878 sigset_t set;
879 sigemptyset(&set);
880 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
881 return false;
882 }
883 return true;
884 #endif
885 }
886
887 bool os::Posix::is_sig_ignored(int sig) {
888 struct sigaction oact;
889 sigaction(sig, (struct sigaction*)NULL, &oact);
890 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
891 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
892 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
893 return true;
894 } else {
895 return false;
896 }
897 }
898
899 // Returns:
900 // NULL for an invalid signal number
901 // "SIG<num>" for a valid but unknown signal number
902 // signal name otherwise.
903 const char* os::exception_name(int sig, char* buf, size_t size) {
904 if (!os::Posix::is_valid_signal(sig)) {
905 return NULL;
906 }
907 const char* const name = os::Posix::get_signal_name(sig, buf, size);
908 if (strcmp(name, "UNKNOWN") == 0) {
909 jio_snprintf(buf, size, "SIG%d", sig);
910 }
911 return buf;
912 }
913
914 #define NUM_IMPORTANT_SIGS 32
915 // Returns one-line short description of a signal set in a user provided buffer.
916 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
917 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
918 // Note: for shortness, just print out the first 32. That should
919 // cover most of the useful ones, apart from realtime signals.
920 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
921 const int rc = sigismember(set, sig);
922 if (rc == -1 && errno == EINVAL) {
923 buffer[sig-1] = '?';
924 } else {
925 buffer[sig-1] = rc == 0 ? '0' : '1';
926 }
927 }
928 buffer[NUM_IMPORTANT_SIGS] = 0;
929 return buffer;
930 }
931
932 // Prints one-line description of a signal set.
933 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
934 char buf[NUM_IMPORTANT_SIGS + 1];
935 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
936 st->print("%s", buf);
937 }
938
939 // Writes one-line description of a combination of sigaction.sa_flags into a user
940 // provided buffer. Returns that buffer.
941 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
942 char* p = buffer;
943 size_t remaining = size;
944 bool first = true;
945 int idx = 0;
946
947 assert(buffer, "invalid argument");
948
949 if (size == 0) {
950 return buffer;
951 }
952
953 strncpy(buffer, "none", size);
954
955 const struct {
956 // NB: i is an unsigned int here because SA_RESETHAND is on some
957 // systems 0x80000000, which is implicitly unsigned. Assignining
958 // it to an int field would be an overflow in unsigned-to-signed
959 // conversion.
960 unsigned int i;
961 const char* s;
962 } flaginfo [] = {
963 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
964 { SA_ONSTACK, "SA_ONSTACK" },
965 { SA_RESETHAND, "SA_RESETHAND" },
966 { SA_RESTART, "SA_RESTART" },
967 { SA_SIGINFO, "SA_SIGINFO" },
968 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
969 { SA_NODEFER, "SA_NODEFER" },
970 #ifdef AIX
971 { SA_ONSTACK, "SA_ONSTACK" },
972 { SA_OLDSTYLE, "SA_OLDSTYLE" },
973 #endif
974 { 0, NULL }
975 };
976
977 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
978 if (flags & flaginfo[idx].i) {
979 if (first) {
980 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
981 first = false;
982 } else {
983 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
984 }
985 const size_t len = strlen(p);
986 p += len;
987 remaining -= len;
988 }
989 }
990
991 buffer[size - 1] = '\0';
992
993 return buffer;
994 }
995
996 // Prints one-line description of a combination of sigaction.sa_flags.
997 void os::Posix::print_sa_flags(outputStream* st, int flags) {
998 char buffer[0x100];
999 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
1000 st->print("%s", buffer);
1001 }
1002
1003 // Helper function for os::Posix::print_siginfo_...():
1004 // return a textual description for signal code.
1005 struct enum_sigcode_desc_t {
1006 const char* s_name;
1007 const char* s_desc;
1008 };
1009
1010 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
1011
1012 const struct {
1013 int sig; int code; const char* s_code; const char* s_desc;
1014 } t1 [] = {
1015 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
1016 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
1017 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
1018 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
1019 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
1020 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
1021 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
1022 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
1023 #if defined(IA64) && defined(LINUX)
1024 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
1025 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
1026 #endif
1027 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
1028 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
1029 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
1030 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
1031 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
1032 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
1033 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
1034 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
1035 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
1036 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
1037 #ifdef AIX
1038 // no explanation found what keyerr would be
1039 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
1040 #endif
1041 #if defined(IA64) && !defined(AIX)
1042 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
1043 #endif
1044 #if defined(__sparc) && defined(SOLARIS)
1045 // define Solaris Sparc M7 ADI SEGV signals
1046 #if !defined(SEGV_ACCADI)
1047 #define SEGV_ACCADI 3
1048 #endif
1049 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
1050 #if !defined(SEGV_ACCDERR)
1051 #define SEGV_ACCDERR 4
1052 #endif
1053 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
1054 #if !defined(SEGV_ACCPERR)
1055 #define SEGV_ACCPERR 5
1056 #endif
1057 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
1058 #endif // defined(__sparc) && defined(SOLARIS)
1059 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
1060 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
1061 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
1062 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
1063 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
1064 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
1065 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
1066 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
1067 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
1068 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
1069 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
1070 #ifdef SIGPOLL
1071 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
1072 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
1073 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
1074 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
1075 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
1076 #endif
1077 { -1, -1, NULL, NULL }
1078 };
1079
1080 // Codes valid in any signal context.
1081 const struct {
1082 int code; const char* s_code; const char* s_desc;
1083 } t2 [] = {
1084 { SI_USER, "SI_USER", "Signal sent by kill()." },
1085 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
1086 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
1087 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
1088 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
1089 // Linux specific
1090 #ifdef SI_TKILL
1091 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
1092 #endif
1093 #ifdef SI_DETHREAD
1094 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
1095 #endif
1096 #ifdef SI_KERNEL
1097 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
1098 #endif
1099 #ifdef SI_SIGIO
1100 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
1101 #endif
1102
1103 #ifdef AIX
1104 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
1105 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
1106 #endif
1107
1108 #ifdef __sun
1109 { SI_NOINFO, "SI_NOINFO", "No signal information" },
1110 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
1111 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
1112 #endif
1113
1114 { -1, NULL, NULL }
1115 };
1116
1117 const char* s_code = NULL;
1118 const char* s_desc = NULL;
1119
1120 for (int i = 0; t1[i].sig != -1; i ++) {
1121 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
1122 s_code = t1[i].s_code;
1123 s_desc = t1[i].s_desc;
1124 break;
1125 }
1126 }
1127
1128 if (s_code == NULL) {
1129 for (int i = 0; t2[i].s_code != NULL; i ++) {
1130 if (t2[i].code == si->si_code) {
1131 s_code = t2[i].s_code;
1132 s_desc = t2[i].s_desc;
1133 }
1134 }
1135 }
1136
1137 if (s_code == NULL) {
1138 out->s_name = "unknown";
1139 out->s_desc = "unknown";
1140 return false;
1141 }
1142
1143 out->s_name = s_code;
1144 out->s_desc = s_desc;
1145
1146 return true;
1147 }
1148
1149 bool os::signal_sent_by_kill(const void* siginfo) {
1150 const siginfo_t* const si = (const siginfo_t*)siginfo;
1151 return si->si_code == SI_USER || si->si_code == SI_QUEUE
1152 #ifdef SI_TKILL
1153 || si->si_code == SI_TKILL
1154 #endif
1155 ;
1156 }
1157
1158 void os::print_siginfo(outputStream* os, const void* si0) {
1159
1160 const siginfo_t* const si = (const siginfo_t*) si0;
1161
1162 char buf[20];
1163 os->print("siginfo:");
1164
1165 if (!si) {
1166 os->print(" <null>");
1167 return;
1168 }
1169
1170 const int sig = si->si_signo;
1171
1172 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1173
1174 enum_sigcode_desc_t ed;
1175 get_signal_code_description(si, &ed);
1176 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1177
1178 if (si->si_errno) {
1179 os->print(", si_errno: %d", si->si_errno);
1180 }
1181
1182 // Output additional information depending on the signal code.
1183
1184 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1185 // so it depends on the context which member to use. For synchronous error signals,
1186 // we print si_addr, unless the signal was sent by another process or thread, in
1187 // which case we print out pid or tid of the sender.
1188 if (signal_sent_by_kill(si)) {
1189 const pid_t pid = si->si_pid;
1190 os->print(", si_pid: %ld", (long) pid);
1191 if (IS_VALID_PID(pid)) {
1192 const pid_t me = getpid();
1193 if (me == pid) {
1194 os->print(" (current process)");
1195 }
1196 } else {
1197 os->print(" (invalid)");
1198 }
1199 os->print(", si_uid: %ld", (long) si->si_uid);
1200 if (sig == SIGCHLD) {
1201 os->print(", si_status: %d", si->si_status);
1202 }
1203 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1204 sig == SIGTRAP || sig == SIGFPE) {
1205 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1206 #ifdef SIGPOLL
1207 } else if (sig == SIGPOLL) {
1208 os->print(", si_band: %ld", si->si_band);
1209 #endif
1210 }
1211
1212 }
1213
1214 bool os::signal_thread(Thread* thread, int sig, const char* reason) {
1215 OSThread* osthread = thread->osthread();
1216 if (osthread) {
1217 #if defined (SOLARIS)
1218 // Note: we cannot use pthread_kill on Solaris - not because
1219 // its missing, but because we do not have the pthread_t id.
1220 int status = thr_kill(osthread->thread_id(), sig);
1221 #else
1222 int status = pthread_kill(osthread->pthread_id(), sig);
1223 #endif
1224 if (status == 0) {
1225 Events::log(Thread::current(), "sent signal %d to Thread " INTPTR_FORMAT " because %s.",
1226 sig, p2i(thread), reason);
1227 return true;
1228 }
1229 }
1230 return false;
1231 }
1232
1233 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1234 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1235 }
1236
1237 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1238 #if defined(AIX)
1239 return Aix::ucontext_get_pc(ctx);
1240 #elif defined(BSD)
1241 return Bsd::ucontext_get_pc(ctx);
1242 #elif defined(LINUX)
1243 return Linux::ucontext_get_pc(ctx);
1244 #elif defined(SOLARIS)
1245 return Solaris::ucontext_get_pc(ctx);
1246 #else
1247 VMError::report_and_die("unimplemented ucontext_get_pc");
1248 #endif
1249 }
1250
1251 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1252 #if defined(AIX)
1253 Aix::ucontext_set_pc(ctx, pc);
1254 #elif defined(BSD)
1255 Bsd::ucontext_set_pc(ctx, pc);
1256 #elif defined(LINUX)
1257 Linux::ucontext_set_pc(ctx, pc);
1258 #elif defined(SOLARIS)
1259 Solaris::ucontext_set_pc(ctx, pc);
1260 #else
1261 VMError::report_and_die("unimplemented ucontext_get_pc");
1262 #endif
1263 }
1264
1265 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1266 size_t stack_size = 0;
1267 size_t guard_size = 0;
1268 int detachstate = 0;
1269 pthread_attr_getstacksize(attr, &stack_size);
1270 pthread_attr_getguardsize(attr, &guard_size);
1271 // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
1272 LINUX_ONLY(stack_size -= guard_size);
1273 pthread_attr_getdetachstate(attr, &detachstate);
1274 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1275 stack_size / 1024, guard_size / 1024,
1276 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1277 return buf;
1278 }
1279
1280 char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
1281
1282 if (filename == NULL || outbuf == NULL || outbuflen < 1) {
1283 assert(false, "os::Posix::realpath: invalid arguments.");
1284 errno = EINVAL;
1285 return NULL;
1286 }
1287
1288 char* result = NULL;
1289
1290 // This assumes platform realpath() is implemented according to POSIX.1-2008.
1291 // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
1292 // output buffer is dynamically allocated and must be ::free()'d by the caller.
1293 char* p = ::realpath(filename, NULL);
1294 if (p != NULL) {
1295 if (strlen(p) < outbuflen) {
1296 strcpy(outbuf, p);
1297 result = outbuf;
1298 } else {
1299 errno = ENAMETOOLONG;
1300 }
1301 ::free(p); // *not* os::free
1302 } else {
1303 // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
1304 // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
1305 // that it complains about the NULL we handed down as user buffer.
1306 // In this case, use the user provided buffer but at least check whether realpath caused
1307 // a memory overwrite.
1308 if (errno == EINVAL) {
1309 outbuf[outbuflen - 1] = '\0';
1310 p = ::realpath(filename, outbuf);
1311 if (p != NULL) {
1312 guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
1313 result = p;
1314 }
1315 }
1316 }
1317 return result;
1318
1319 }
1320
1321 int os::stat(const char *path, struct stat *sbuf) {
1322 return ::stat(path, sbuf);
1323 }
1324
1325 char * os::native_path(char *path) {
1326 return path;
1327 }
1328
1329 bool os::same_files(const char* file1, const char* file2) {
1330 if (strcmp(file1, file2) == 0) {
1331 return true;
1332 }
1333
1334 bool is_same = false;
1335 struct stat st1;
1336 struct stat st2;
1337
1338 if (os::stat(file1, &st1) < 0) {
1339 return false;
1340 }
1341
1342 if (os::stat(file2, &st2) < 0) {
1343 return false;
1344 }
1345
1346 if (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino) {
1347 // same files
1348 is_same = true;
1349 }
1350 return is_same;
1351 }
1352
1353 // Check minimum allowable stack sizes for thread creation and to initialize
1354 // the java system classes, including StackOverflowError - depends on page
1355 // size.
1356 // The space needed for frames during startup is platform dependent. It
1357 // depends on word size, platform calling conventions, C frame layout and
1358 // interpreter/C1/C2 design decisions. Therefore this is given in a
1359 // platform (os/cpu) dependent constant.
1360 // To this, space for guard mechanisms is added, which depends on the
1361 // page size which again depends on the concrete system the VM is running
1362 // on. Space for libc guard pages is not included in this size.
1363 jint os::Posix::set_minimum_stack_sizes() {
1364 size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
1365
1366 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
1367 JavaThread::stack_guard_zone_size() +
1368 JavaThread::stack_shadow_zone_size();
1369
1370 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
1371 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
1372
1373 size_t stack_size_in_bytes = ThreadStackSize * K;
1374 if (stack_size_in_bytes != 0 &&
1375 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1376 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1377 // ThreadStackSize so we go with "Java thread stack size" instead
1378 // of "ThreadStackSize" to be more friendly.
1379 tty->print_cr("\nThe Java thread stack size specified is too small. "
1380 "Specify at least " SIZE_FORMAT "k",
1381 _java_thread_min_stack_allowed / K);
1382 return JNI_ERR;
1383 }
1384
1385 // Make the stack size a multiple of the page size so that
1386 // the yellow/red zones can be guarded.
1387 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
1388
1389 // Reminder: a compiler thread is a Java thread.
1390 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
1391 JavaThread::stack_guard_zone_size() +
1392 JavaThread::stack_shadow_zone_size();
1393
1394 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
1395 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
1396
1397 stack_size_in_bytes = CompilerThreadStackSize * K;
1398 if (stack_size_in_bytes != 0 &&
1399 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1400 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1401 "Specify at least " SIZE_FORMAT "k",
1402 _compiler_thread_min_stack_allowed / K);
1403 return JNI_ERR;
1404 }
1405
1406 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1407 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
1408
1409 stack_size_in_bytes = VMThreadStackSize * K;
1410 if (stack_size_in_bytes != 0 &&
1411 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1412 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1413 "Specify at least " SIZE_FORMAT "k",
1414 _vm_internal_thread_min_stack_allowed / K);
1415 return JNI_ERR;
1416 }
1417 return JNI_OK;
1418 }
1419
1420 // Called when creating the thread. The minimum stack sizes have already been calculated
1421 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1422 size_t stack_size;
1423 if (req_stack_size == 0) {
1424 stack_size = default_stack_size(thr_type);
1425 } else {
1426 stack_size = req_stack_size;
1427 }
1428
1429 switch (thr_type) {
1430 case os::java_thread:
1431 // Java threads use ThreadStackSize which default value can be
1432 // changed with the flag -Xss
1433 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1434 // no requested size and we have a more specific default value
1435 stack_size = JavaThread::stack_size_at_create();
1436 }
1437 stack_size = MAX2(stack_size,
1438 _java_thread_min_stack_allowed);
1439 break;
1440 case os::compiler_thread:
1441 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1442 // no requested size and we have a more specific default value
1443 stack_size = (size_t)(CompilerThreadStackSize * K);
1444 }
1445 stack_size = MAX2(stack_size,
1446 _compiler_thread_min_stack_allowed);
1447 break;
1448 case os::vm_thread:
1449 case os::pgc_thread:
1450 case os::cgc_thread:
1451 case os::watcher_thread:
1452 default: // presume the unknown thr_type is a VM internal
1453 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1454 // no requested size and we have a more specific default value
1455 stack_size = (size_t)(VMThreadStackSize * K);
1456 }
1457
1458 stack_size = MAX2(stack_size,
1459 _vm_internal_thread_min_stack_allowed);
1460 break;
1461 }
1462
1463 // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
1464 // Be careful not to round up to 0. Align down in that case.
1465 if (stack_size <= SIZE_MAX - vm_page_size()) {
1466 stack_size = align_up(stack_size, vm_page_size());
1467 } else {
1468 stack_size = align_down(stack_size, vm_page_size());
1469 }
1470
1471 return stack_size;
1472 }
1473
1474 bool os::Posix::is_root(uid_t uid){
1475 return ROOT_UID == uid;
1476 }
1477
1478 bool os::Posix::matches_effective_uid_or_root(uid_t uid) {
1479 return is_root(uid) || geteuid() == uid;
1480 }
1481
1482 bool os::Posix::matches_effective_uid_and_gid_or_root(uid_t uid, gid_t gid) {
1483 return is_root(uid) || (geteuid() == uid && getegid() == gid);
1484 }
1485
1486 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
1487 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
1488 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
1489
1490 os::ThreadCrashProtection::ThreadCrashProtection() {
1491 }
1492
1493 /*
1494 * See the caveats for this class in os_posix.hpp
1495 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1496 * method and returns false. If none of the signals are raised, returns true.
1497 * The callback is supposed to provide the method that should be protected.
1498 */
1499 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1500 sigset_t saved_sig_mask;
1501
1502 Thread::muxAcquire(&_crash_mux, "CrashProtection");
1503
1504 _protected_thread = Thread::current_or_null();
1505 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
1506
1507 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1508 // since on at least some systems (OS X) siglongjmp will restore the mask
1509 // for the process, not the thread
1510 pthread_sigmask(0, NULL, &saved_sig_mask);
1511 if (sigsetjmp(_jmpbuf, 0) == 0) {
1512 // make sure we can see in the signal handler that we have crash protection
1513 // installed
1514 _crash_protection = this;
1515 cb.call();
1516 // and clear the crash protection
1517 _crash_protection = NULL;
1518 _protected_thread = NULL;
1519 Thread::muxRelease(&_crash_mux);
1520 return true;
1521 }
1522 // this happens when we siglongjmp() back
1523 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1524 _crash_protection = NULL;
1525 _protected_thread = NULL;
1526 Thread::muxRelease(&_crash_mux);
1527 return false;
1528 }
1529
1530 void os::ThreadCrashProtection::restore() {
1531 assert(_crash_protection != NULL, "must have crash protection");
1532 siglongjmp(_jmpbuf, 1);
1533 }
1534
1535 void os::ThreadCrashProtection::check_crash_protection(int sig,
1536 Thread* thread) {
1537
1538 if (thread != NULL &&
1539 thread == _protected_thread &&
1540 _crash_protection != NULL) {
1541
1542 if (sig == SIGSEGV || sig == SIGBUS) {
1543 _crash_protection->restore();
1544 }
1545 }
1546 }
1547
1548 // Shared clock/time and other supporting routines for pthread_mutex/cond
1549 // initialization. This is enabled on Solaris but only some of the clock/time
1550 // functionality is actually used there.
1551
1552 // Shared condattr object for use with relative timed-waits. Will be associated
1553 // with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
1554 // but otherwise whatever default is used by the platform - generally the
1555 // time-of-day clock.
1556 static pthread_condattr_t _condAttr[1];
1557
1558 // Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
1559 // all systems (e.g. FreeBSD) map the default to "normal".
1560 static pthread_mutexattr_t _mutexAttr[1];
1561
1562 // common basic initialization that is always supported
1563 static void pthread_init_common(void) {
1564 int status;
1565 if ((status = pthread_condattr_init(_condAttr)) != 0) {
1566 fatal("pthread_condattr_init: %s", os::strerror(status));
1567 }
1568 if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
1569 fatal("pthread_mutexattr_init: %s", os::strerror(status));
1570 }
1571 if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
1572 fatal("pthread_mutexattr_settype: %s", os::strerror(status));
1573 }
1574 // Solaris has it's own PlatformMutex, distinct from the one for POSIX.
1575 NOT_SOLARIS(os::PlatformMutex::init();)
1576 }
1577
1578 #ifndef SOLARIS
1579 sigset_t sigs;
1580 struct sigaction sigact[NSIG];
1581
1582 struct sigaction* os::Posix::get_preinstalled_handler(int sig) {
1583 if (sigismember(&sigs, sig)) {
1584 return &sigact[sig];
1585 }
1586 return NULL;
1587 }
1588
1589 void os::Posix::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
1590 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
1591 sigact[sig] = oldAct;
1592 sigaddset(&sigs, sig);
1593 }
1594 #endif
1595
1596 // Not all POSIX types and API's are available on all notionally "posix"
1597 // platforms. If we have build-time support then we will check for actual
1598 // runtime support via dlopen/dlsym lookup. This allows for running on an
1599 // older OS version compared to the build platform. But if there is no
1600 // build time support then there cannot be any runtime support as we do not
1601 // know what the runtime types would be (for example clockid_t might be an
1602 // int or int64_t).
1603 //
1604 #ifdef SUPPORTS_CLOCK_MONOTONIC
1605
1606 // This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
1607
1608 int (*os::Posix::_clock_gettime)(clockid_t, struct timespec *) = NULL;
1609 int (*os::Posix::_clock_getres)(clockid_t, struct timespec *) = NULL;
1610
1611 static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t) = NULL;
1612
1613 static bool _use_clock_monotonic_condattr = false;
1614
1615 // Determine what POSIX API's are present and do appropriate
1616 // configuration.
1617 void os::Posix::init(void) {
1618
1619 // NOTE: no logging available when this is called. Put logging
1620 // statements in init_2().
1621
1622 // 1. Check for CLOCK_MONOTONIC support.
1623
1624 void* handle = NULL;
1625
1626 // For linux we need librt, for other OS we can find
1627 // this function in regular libc.
1628 #ifdef NEEDS_LIBRT
1629 // We do dlopen's in this particular order due to bug in linux
1630 // dynamic loader (see 6348968) leading to crash on exit.
1631 handle = dlopen("librt.so.1", RTLD_LAZY);
1632 if (handle == NULL) {
1633 handle = dlopen("librt.so", RTLD_LAZY);
1634 }
1635 #endif
1636
1637 if (handle == NULL) {
1638 handle = RTLD_DEFAULT;
1639 }
1640
1641 int (*clock_getres_func)(clockid_t, struct timespec*) =
1642 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1643 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1644 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1645 if (clock_getres_func != NULL && clock_gettime_func != NULL) {
1646 // We assume that if both clock_gettime and clock_getres support
1647 // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
1648 struct timespec res;
1649 struct timespec tp;
1650 if (clock_getres_func(CLOCK_MONOTONIC, &res) == 0 &&
1651 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1652 // Yes, monotonic clock is supported.
1653 _clock_gettime = clock_gettime_func;
1654 _clock_getres = clock_getres_func;
1655 } else {
1656 #ifdef NEEDS_LIBRT
1657 // Close librt if there is no monotonic clock.
1658 if (handle != RTLD_DEFAULT) {
1659 dlclose(handle);
1660 }
1661 #endif
1662 }
1663 }
1664
1665 // 2. Check for pthread_condattr_setclock support.
1666
1667 // libpthread is already loaded.
1668 int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
1669 (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
1670 "pthread_condattr_setclock");
1671 if (condattr_setclock_func != NULL) {
1672 _pthread_condattr_setclock = condattr_setclock_func;
1673 }
1674
1675 // Now do general initialization.
1676
1677 pthread_init_common();
1678
1679 #ifndef SOLARIS
1680 int status;
1681 if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
1682 if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
1683 if (status == EINVAL) {
1684 _use_clock_monotonic_condattr = false;
1685 warning("Unable to use monotonic clock with relative timed-waits" \
1686 " - changes to the time-of-day clock may have adverse affects");
1687 } else {
1688 fatal("pthread_condattr_setclock: %s", os::strerror(status));
1689 }
1690 } else {
1691 _use_clock_monotonic_condattr = true;
1692 }
1693 }
1694 #endif // !SOLARIS
1695
1696 }
1697
1698 void os::Posix::init_2(void) {
1699 #ifndef SOLARIS
1700 log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
1701 (_clock_gettime != NULL ? "" : " not"));
1702 log_info(os)("Use of pthread_condattr_setclock is%s supported",
1703 (_pthread_condattr_setclock != NULL ? "" : " not"));
1704 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
1705 _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
1706 sigemptyset(&sigs);
1707 #endif // !SOLARIS
1708 }
1709
1710 #else // !SUPPORTS_CLOCK_MONOTONIC
1711
1712 void os::Posix::init(void) {
1713 pthread_init_common();
1714 }
1715
1716 void os::Posix::init_2(void) {
1717 #ifndef SOLARIS
1718 log_info(os)("Use of CLOCK_MONOTONIC is not supported");
1719 log_info(os)("Use of pthread_condattr_setclock is not supported");
1720 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
1721 sigemptyset(&sigs);
1722 #endif // !SOLARIS
1723 }
1724
1725 #endif // SUPPORTS_CLOCK_MONOTONIC
1726
1727 // Utility to convert the given timeout to an absolute timespec
1728 // (based on the appropriate clock) to use with pthread_cond_timewait,
1729 // and sem_timedwait().
1730 // The clock queried here must be the clock used to manage the
1731 // timeout of the condition variable or semaphore.
1732 //
1733 // The passed in timeout value is either a relative time in nanoseconds
1734 // or an absolute time in milliseconds. A relative timeout will be
1735 // associated with CLOCK_MONOTONIC if available, unless the real-time clock
1736 // is explicitly requested; otherwise, or if absolute,
1737 // the default time-of-day clock will be used.
1738
1739 // Given time is a 64-bit value and the time_t used in the timespec is
1740 // sometimes a signed-32-bit value we have to watch for overflow if times
1741 // way in the future are given. Further on Solaris versions
1742 // prior to 10 there is a restriction (see cond_timedwait) that the specified
1743 // number of seconds, in abstime, is less than current_time + 100000000.
1744 // As it will be over 20 years before "now + 100000000" will overflow we can
1745 // ignore overflow and just impose a hard-limit on seconds using the value
1746 // of "now + 100000000". This places a limit on the timeout of about 3.17
1747 // years from "now".
1748 //
1749 #define MAX_SECS 100000000
1750
1751 // Calculate a new absolute time that is "timeout" nanoseconds from "now".
1752 // "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
1753 // on which clock API is being used).
1754 static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
1755 jlong now_part_sec, jlong unit) {
1756 time_t max_secs = now_sec + MAX_SECS;
1757
1758 jlong seconds = timeout / NANOUNITS;
1759 timeout %= NANOUNITS; // remaining nanos
1760
1761 if (seconds >= MAX_SECS) {
1762 // More seconds than we can add, so pin to max_secs.
1763 abstime->tv_sec = max_secs;
1764 abstime->tv_nsec = 0;
1765 } else {
1766 abstime->tv_sec = now_sec + seconds;
1767 long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
1768 if (nanos >= NANOUNITS) { // overflow
1769 abstime->tv_sec += 1;
1770 nanos -= NANOUNITS;
1771 }
1772 abstime->tv_nsec = nanos;
1773 }
1774 }
1775
1776 // Unpack the given deadline in milliseconds since the epoch, into the given timespec.
1777 // The current time in seconds is also passed in to enforce an upper bound as discussed above.
1778 // This is only used with gettimeofday, when clock_gettime is not available.
1779 static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
1780 time_t max_secs = now_sec + MAX_SECS;
1781
1782 jlong seconds = deadline / MILLIUNITS;
1783 jlong millis = deadline % MILLIUNITS;
1784
1785 if (seconds >= max_secs) {
1786 // Absolute seconds exceeds allowed max, so pin to max_secs.
1787 abstime->tv_sec = max_secs;
1788 abstime->tv_nsec = 0;
1789 } else {
1790 abstime->tv_sec = seconds;
1791 abstime->tv_nsec = millis * (NANOUNITS / MILLIUNITS);
1792 }
1793 }
1794
1795 static jlong millis_to_nanos(jlong millis) {
1796 // We have to watch for overflow when converting millis to nanos,
1797 // but if millis is that large then we will end up limiting to
1798 // MAX_SECS anyway, so just do that here.
1799 if (millis / MILLIUNITS > MAX_SECS) {
1800 millis = jlong(MAX_SECS) * MILLIUNITS;
1801 }
1802 return millis * (NANOUNITS / MILLIUNITS);
1803 }
1804
1805 static void to_abstime(timespec* abstime, jlong timeout,
1806 bool isAbsolute, bool isRealtime) {
1807 DEBUG_ONLY(int max_secs = MAX_SECS;)
1808
1809 if (timeout < 0) {
1810 timeout = 0;
1811 }
1812
1813 #ifdef SUPPORTS_CLOCK_MONOTONIC
1814
1815 clockid_t clock = CLOCK_MONOTONIC;
1816 // need to ensure we have a runtime check for clock_gettime support
1817 if (!isAbsolute && os::Posix::supports_monotonic_clock()) {
1818 if (!_use_clock_monotonic_condattr || isRealtime) {
1819 clock = CLOCK_REALTIME;
1820 }
1821 struct timespec now;
1822 int status = os::Posix::clock_gettime(clock, &now);
1823 assert_status(status == 0, status, "clock_gettime");
1824 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
1825 DEBUG_ONLY(max_secs += now.tv_sec;)
1826 } else {
1827
1828 #else
1829
1830 { // Match the block scope.
1831
1832 #endif // SUPPORTS_CLOCK_MONOTONIC
1833
1834 // Time-of-day clock is all we can reliably use.
1835 struct timeval now;
1836 int status = gettimeofday(&now, NULL);
1837 assert_status(status == 0, errno, "gettimeofday");
1838 if (isAbsolute) {
1839 unpack_abs_time(abstime, timeout, now.tv_sec);
1840 } else {
1841 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
1842 }
1843 DEBUG_ONLY(max_secs += now.tv_sec;)
1844 }
1845
1846 assert(abstime->tv_sec >= 0, "tv_sec < 0");
1847 assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
1848 assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
1849 assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
1850 }
1851
1852 // Create an absolute time 'millis' milliseconds in the future, using the
1853 // real-time (time-of-day) clock. Used by PosixSemaphore.
1854 void os::Posix::to_RTC_abstime(timespec* abstime, int64_t millis) {
1855 to_abstime(abstime, millis_to_nanos(millis),
1856 false /* not absolute */,
1857 true /* use real-time clock */);
1858 }
1859
1860 // Shared pthread_mutex/cond based PlatformEvent implementation.
1861 // Not currently usable by Solaris.
1862
1863 #ifndef SOLARIS
1864
1865 // PlatformEvent
1866 //
1867 // Assumption:
1868 // Only one parker can exist on an event, which is why we allocate
1869 // them per-thread. Multiple unparkers can coexist.
1870 //
1871 // _event serves as a restricted-range semaphore.
1872 // -1 : thread is blocked, i.e. there is a waiter
1873 // 0 : neutral: thread is running or ready,
1874 // could have been signaled after a wait started
1875 // 1 : signaled - thread is running or ready
1876 //
1877 // Having three states allows for some detection of bad usage - see
1878 // comments on unpark().
1879
1880 os::PlatformEvent::PlatformEvent() {
1881 int status = pthread_cond_init(_cond, _condAttr);
1882 assert_status(status == 0, status, "cond_init");
1883 status = pthread_mutex_init(_mutex, _mutexAttr);
1884 assert_status(status == 0, status, "mutex_init");
1885 _event = 0;
1886 _nParked = 0;
1887 }
1888
1889 void os::PlatformEvent::park() { // AKA "down()"
1890 // Transitions for _event:
1891 // -1 => -1 : illegal
1892 // 1 => 0 : pass - return immediately
1893 // 0 => -1 : block; then set _event to 0 before returning
1894
1895 // Invariant: Only the thread associated with the PlatformEvent
1896 // may call park().
1897 assert(_nParked == 0, "invariant");
1898
1899 int v;
1900
1901 // atomically decrement _event
1902 for (;;) {
1903 v = _event;
1904 if (Atomic::cmpxchg(&_event, v, v - 1) == v) break;
1905 }
1906 guarantee(v >= 0, "invariant");
1907
1908 if (v == 0) { // Do this the hard way by blocking ...
1909 int status = pthread_mutex_lock(_mutex);
1910 assert_status(status == 0, status, "mutex_lock");
1911 guarantee(_nParked == 0, "invariant");
1912 ++_nParked;
1913 while (_event < 0) {
1914 // OS-level "spurious wakeups" are ignored
1915 status = pthread_cond_wait(_cond, _mutex);
1916 assert_status(status == 0, status, "cond_wait");
1917 }
1918 --_nParked;
1919
1920 _event = 0;
1921 status = pthread_mutex_unlock(_mutex);
1922 assert_status(status == 0, status, "mutex_unlock");
1923 // Paranoia to ensure our locked and lock-free paths interact
1924 // correctly with each other.
1925 OrderAccess::fence();
1926 }
1927 guarantee(_event >= 0, "invariant");
1928 }
1929
1930 int os::PlatformEvent::park(jlong millis) {
1931 // Transitions for _event:
1932 // -1 => -1 : illegal
1933 // 1 => 0 : pass - return immediately
1934 // 0 => -1 : block; then set _event to 0 before returning
1935
1936 // Invariant: Only the thread associated with the Event/PlatformEvent
1937 // may call park().
1938 assert(_nParked == 0, "invariant");
1939
1940 int v;
1941 // atomically decrement _event
1942 for (;;) {
1943 v = _event;
1944 if (Atomic::cmpxchg(&_event, v, v - 1) == v) break;
1945 }
1946 guarantee(v >= 0, "invariant");
1947
1948 if (v == 0) { // Do this the hard way by blocking ...
1949 struct timespec abst;
1950 to_abstime(&abst, millis_to_nanos(millis), false, false);
1951
1952 int ret = OS_TIMEOUT;
1953 int status = pthread_mutex_lock(_mutex);
1954 assert_status(status == 0, status, "mutex_lock");
1955 guarantee(_nParked == 0, "invariant");
1956 ++_nParked;
1957
1958 while (_event < 0) {
1959 status = pthread_cond_timedwait(_cond, _mutex, &abst);
1960 assert_status(status == 0 || status == ETIMEDOUT,
1961 status, "cond_timedwait");
1962 // OS-level "spurious wakeups" are ignored unless the archaic
1963 // FilterSpuriousWakeups is set false. That flag should be obsoleted.
1964 if (!FilterSpuriousWakeups) break;
1965 if (status == ETIMEDOUT) break;
1966 }
1967 --_nParked;
1968
1969 if (_event >= 0) {
1970 ret = OS_OK;
1971 }
1972
1973 _event = 0;
1974 status = pthread_mutex_unlock(_mutex);
1975 assert_status(status == 0, status, "mutex_unlock");
1976 // Paranoia to ensure our locked and lock-free paths interact
1977 // correctly with each other.
1978 OrderAccess::fence();
1979 return ret;
1980 }
1981 return OS_OK;
1982 }
1983
1984 void os::PlatformEvent::unpark() {
1985 // Transitions for _event:
1986 // 0 => 1 : just return
1987 // 1 => 1 : just return
1988 // -1 => either 0 or 1; must signal target thread
1989 // That is, we can safely transition _event from -1 to either
1990 // 0 or 1.
1991 // See also: "Semaphores in Plan 9" by Mullender & Cox
1992 //
1993 // Note: Forcing a transition from "-1" to "1" on an unpark() means
1994 // that it will take two back-to-back park() calls for the owning
1995 // thread to block. This has the benefit of forcing a spurious return
1996 // from the first park() call after an unpark() call which will help
1997 // shake out uses of park() and unpark() without checking state conditions
1998 // properly. This spurious return doesn't manifest itself in any user code
1999 // but only in the correctly written condition checking loops of ObjectMonitor,
2000 // Mutex/Monitor, Thread::muxAcquire and JavaThread::sleep
2001
2002 if (Atomic::xchg(&_event, 1) >= 0) return;
2003
2004 int status = pthread_mutex_lock(_mutex);
2005 assert_status(status == 0, status, "mutex_lock");
2006 int anyWaiters = _nParked;
2007 assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
2008 status = pthread_mutex_unlock(_mutex);
2009 assert_status(status == 0, status, "mutex_unlock");
2010
2011 // Note that we signal() *after* dropping the lock for "immortal" Events.
2012 // This is safe and avoids a common class of futile wakeups. In rare
2013 // circumstances this can cause a thread to return prematurely from
2014 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2015 // will simply re-test the condition and re-park itself.
2016 // This provides particular benefit if the underlying platform does not
2017 // provide wait morphing.
2018
2019 if (anyWaiters != 0) {
2020 status = pthread_cond_signal(_cond);
2021 assert_status(status == 0, status, "cond_signal");
2022 }
2023 }
2024
2025 // JSR166 support
2026
2027 os::PlatformParker::PlatformParker() {
2028 int status;
2029 status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
2030 assert_status(status == 0, status, "cond_init rel");
2031 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
2032 assert_status(status == 0, status, "cond_init abs");
2033 status = pthread_mutex_init(_mutex, _mutexAttr);
2034 assert_status(status == 0, status, "mutex_init");
2035 _cur_index = -1; // mark as unused
2036 }
2037
2038 // Parker::park decrements count if > 0, else does a condvar wait. Unpark
2039 // sets count to 1 and signals condvar. Only one thread ever waits
2040 // on the condvar. Contention seen when trying to park implies that someone
2041 // is unparking you, so don't wait. And spurious returns are fine, so there
2042 // is no need to track notifications.
2043
2044 void Parker::park(bool isAbsolute, jlong time) {
2045
2046 // Optional fast-path check:
2047 // Return immediately if a permit is available.
2048 // We depend on Atomic::xchg() having full barrier semantics
2049 // since we are doing a lock-free update to _counter.
2050 if (Atomic::xchg(&_counter, 0) > 0) return;
2051
2052 Thread* thread = Thread::current();
2053 assert(thread->is_Java_thread(), "Must be JavaThread");
2054 JavaThread *jt = (JavaThread *)thread;
2055
2056 // Optional optimization -- avoid state transitions if there's
2057 // an interrupt pending.
2058 if (jt->is_interrupted(false)) {
2059 return;
2060 }
2061
2062 // Next, demultiplex/decode time arguments
2063 struct timespec absTime;
2064 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
2065 return;
2066 }
2067 if (time > 0) {
2068 to_abstime(&absTime, time, isAbsolute, false);
2069 }
2070
2071 // Enter safepoint region
2072 // Beware of deadlocks such as 6317397.
2073 // The per-thread Parker:: mutex is a classic leaf-lock.
2074 // In particular a thread must never block on the Threads_lock while
2075 // holding the Parker:: mutex. If safepoints are pending both the
2076 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
2077 ThreadBlockInVM tbivm(jt);
2078
2079 // Can't access interrupt state now that we are _thread_blocked. If we've
2080 // been interrupted since we checked above then _counter will be > 0.
2081
2082 // Don't wait if cannot get lock since interference arises from
2083 // unparking.
2084 if (pthread_mutex_trylock(_mutex) != 0) {
2085 return;
2086 }
2087
2088 int status;
2089 if (_counter > 0) { // no wait needed
2090 _counter = 0;
2091 status = pthread_mutex_unlock(_mutex);
2092 assert_status(status == 0, status, "invariant");
2093 // Paranoia to ensure our locked and lock-free paths interact
2094 // correctly with each other and Java-level accesses.
2095 OrderAccess::fence();
2096 return;
2097 }
2098
2099 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2100 jt->set_suspend_equivalent();
2101 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2102
2103 assert(_cur_index == -1, "invariant");
2104 if (time == 0) {
2105 _cur_index = REL_INDEX; // arbitrary choice when not timed
2106 status = pthread_cond_wait(&_cond[_cur_index], _mutex);
2107 assert_status(status == 0, status, "cond_timedwait");
2108 }
2109 else {
2110 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
2111 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
2112 assert_status(status == 0 || status == ETIMEDOUT,
2113 status, "cond_timedwait");
2114 }
2115 _cur_index = -1;
2116
2117 _counter = 0;
2118 status = pthread_mutex_unlock(_mutex);
2119 assert_status(status == 0, status, "invariant");
2120 // Paranoia to ensure our locked and lock-free paths interact
2121 // correctly with each other and Java-level accesses.
2122 OrderAccess::fence();
2123
2124 // If externally suspended while waiting, re-suspend
2125 if (jt->handle_special_suspend_equivalent_condition()) {
2126 jt->java_suspend_self();
2127 }
2128 }
2129
2130 void Parker::unpark() {
2131 int status = pthread_mutex_lock(_mutex);
2132 assert_status(status == 0, status, "invariant");
2133 const int s = _counter;
2134 _counter = 1;
2135 // must capture correct index before unlocking
2136 int index = _cur_index;
2137 status = pthread_mutex_unlock(_mutex);
2138 assert_status(status == 0, status, "invariant");
2139
2140 // Note that we signal() *after* dropping the lock for "immortal" Events.
2141 // This is safe and avoids a common class of futile wakeups. In rare
2142 // circumstances this can cause a thread to return prematurely from
2143 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2144 // will simply re-test the condition and re-park itself.
2145 // This provides particular benefit if the underlying platform does not
2146 // provide wait morphing.
2147
2148 if (s < 1 && index != -1) {
2149 // thread is definitely parked
2150 status = pthread_cond_signal(&_cond[index]);
2151 assert_status(status == 0, status, "invariant");
2152 }
2153 }
2154
2155 // Platform Mutex/Monitor implementation
2156
2157 #if PLATFORM_MONITOR_IMPL_INDIRECT
2158
2159 os::PlatformMutex::Mutex::Mutex() : _next(NULL) {
2160 int status = pthread_mutex_init(&_mutex, _mutexAttr);
2161 assert_status(status == 0, status, "mutex_init");
2162 }
2163
2164 os::PlatformMutex::Mutex::~Mutex() {
2165 int status = pthread_mutex_destroy(&_mutex);
2166 assert_status(status == 0, status, "mutex_destroy");
2167 }
2168
2169 pthread_mutex_t os::PlatformMutex::_freelist_lock;
2170 os::PlatformMutex::Mutex* os::PlatformMutex::_mutex_freelist = NULL;
2171
2172 void os::PlatformMutex::init() {
2173 int status = pthread_mutex_init(&_freelist_lock, _mutexAttr);
2174 assert_status(status == 0, status, "freelist lock init");
2175 }
2176
2177 struct os::PlatformMutex::WithFreeListLocked : public StackObj {
2178 WithFreeListLocked() {
2179 int status = pthread_mutex_lock(&_freelist_lock);
2180 assert_status(status == 0, status, "freelist lock");
2181 }
2182
2183 ~WithFreeListLocked() {
2184 int status = pthread_mutex_unlock(&_freelist_lock);
2185 assert_status(status == 0, status, "freelist unlock");
2186 }
2187 };
2188
2189 os::PlatformMutex::PlatformMutex() {
2190 {
2191 WithFreeListLocked wfl;
2192 _impl = _mutex_freelist;
2193 if (_impl != NULL) {
2194 _mutex_freelist = _impl->_next;
2195 _impl->_next = NULL;
2196 return;
2197 }
2198 }
2199 _impl = new Mutex();
2200 }
2201
2202 os::PlatformMutex::~PlatformMutex() {
2203 WithFreeListLocked wfl;
2204 assert(_impl->_next == NULL, "invariant");
2205 _impl->_next = _mutex_freelist;
2206 _mutex_freelist = _impl;
2207 }
2208
2209 os::PlatformMonitor::Cond::Cond() : _next(NULL) {
2210 int status = pthread_cond_init(&_cond, _condAttr);
2211 assert_status(status == 0, status, "cond_init");
2212 }
2213
2214 os::PlatformMonitor::Cond::~Cond() {
2215 int status = pthread_cond_destroy(&_cond);
2216 assert_status(status == 0, status, "cond_destroy");
2217 }
2218
2219 os::PlatformMonitor::Cond* os::PlatformMonitor::_cond_freelist = NULL;
2220
2221 os::PlatformMonitor::PlatformMonitor() {
2222 {
2223 WithFreeListLocked wfl;
2224 _impl = _cond_freelist;
2225 if (_impl != NULL) {
2226 _cond_freelist = _impl->_next;
2227 _impl->_next = NULL;
2228 return;
2229 }
2230 }
2231 _impl = new Cond();
2232 }
2233
2234 os::PlatformMonitor::~PlatformMonitor() {
2235 WithFreeListLocked wfl;
2236 assert(_impl->_next == NULL, "invariant");
2237 _impl->_next = _cond_freelist;
2238 _cond_freelist = _impl;
2239 }
2240
2241 #else
2242
2243 os::PlatformMutex::PlatformMutex() {
2244 int status = pthread_mutex_init(&_mutex, _mutexAttr);
2245 assert_status(status == 0, status, "mutex_init");
2246 }
2247
2248 os::PlatformMutex::~PlatformMutex() {
2249 int status = pthread_mutex_destroy(&_mutex);
2250 assert_status(status == 0, status, "mutex_destroy");
2251 }
2252
2253 os::PlatformMonitor::PlatformMonitor() {
2254 int status = pthread_cond_init(&_cond, _condAttr);
2255 assert_status(status == 0, status, "cond_init");
2256 }
2257
2258 os::PlatformMonitor::~PlatformMonitor() {
2259 int status = pthread_cond_destroy(&_cond);
2260 assert_status(status == 0, status, "cond_destroy");
2261 }
2262
2263 #endif // PLATFORM_MONITOR_IMPL_INDIRECT
2264
2265 // Must already be locked
2266 int os::PlatformMonitor::wait(jlong millis) {
2267 assert(millis >= 0, "negative timeout");
2268 if (millis > 0) {
2269 struct timespec abst;
2270 // We have to watch for overflow when converting millis to nanos,
2271 // but if millis is that large then we will end up limiting to
2272 // MAX_SECS anyway, so just do that here.
2273 if (millis / MILLIUNITS > MAX_SECS) {
2274 millis = jlong(MAX_SECS) * MILLIUNITS;
2275 }
2276 to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false, false);
2277
2278 int ret = OS_TIMEOUT;
2279 int status = pthread_cond_timedwait(cond(), mutex(), &abst);
2280 assert_status(status == 0 || status == ETIMEDOUT,
2281 status, "cond_timedwait");
2282 if (status == 0) {
2283 ret = OS_OK;
2284 }
2285 return ret;
2286 } else {
2287 int status = pthread_cond_wait(cond(), mutex());
2288 assert_status(status == 0, status, "cond_wait");
2289 return OS_OK;
2290 }
2291 }
2292
2293 #endif // !SOLARIS