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/atomic.hpp"
34 #include "runtime/orderAccess.hpp"
35 #include "utilities/align.hpp"
36 #include "utilities/events.hpp"
37 #include "utilities/formatBuffer.hpp"
38 #include "utilities/macros.hpp"
39 #include "utilities/vmError.hpp"
40
41 #include <dirent.h>
42 #include <dlfcn.h>
43 #include <grp.h>
44 #include <pwd.h>
45 #include <pthread.h>
46 #include <signal.h>
47 #include <sys/mman.h>
48 #include <sys/resource.h>
49 #include <sys/utsname.h>
50 #include <time.h>
51 #include <unistd.h>
52 #include <utmpx.h>
53
54 // Todo: provide a os::get_max_process_id() or similar. Number of processes
55 // may have been configured, can be read more accurately from proc fs etc.
56 #ifndef MAX_PID
57 #define MAX_PID INT_MAX
58 #endif
59 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
60
61 #define ROOT_UID 0
62
63 #ifndef MAP_ANONYMOUS
64 #define MAP_ANONYMOUS MAP_ANON
65 #endif
66
67 #define check_with_errno(check_type, cond, msg) \
68 do { \
69 int err = errno; \
70 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
71 os::errno_name(err)); \
72 } while (false)
73
74 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
75 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
76
77 // Check core dump limit and report possible place where core can be found
78 void os::check_dump_limit(char* buffer, size_t bufferSize) {
79 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
80 jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
81 VMError::record_coredump_status(buffer, false);
82 return;
83 }
84
85 int n;
86 struct rlimit rlim;
87 bool success;
88
89 char core_path[PATH_MAX];
90 n = get_core_path(core_path, PATH_MAX);
91
92 if (n <= 0) {
93 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
94 success = true;
95 #ifdef LINUX
96 } else if (core_path[0] == '"') { // redirect to user process
97 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
98 success = true;
99 #endif
100 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
101 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
102 success = true;
103 } else {
104 switch(rlim.rlim_cur) {
105 case RLIM_INFINITY:
106 jio_snprintf(buffer, bufferSize, "%s", core_path);
107 success = true;
108 break;
109 case 0:
110 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
111 success = false;
112 break;
113 default:
114 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);
115 success = true;
116 break;
117 }
118 }
119
120 VMError::record_coredump_status(buffer, success);
121 }
122
123 int os::get_native_stack(address* stack, int frames, int toSkip) {
124 int frame_idx = 0;
125 int num_of_frames; // number of frames captured
126 frame fr = os::current_frame();
127 while (fr.pc() && frame_idx < frames) {
128 if (toSkip > 0) {
129 toSkip --;
130 } else {
131 stack[frame_idx ++] = fr.pc();
132 }
133 if (fr.fp() == NULL || fr.cb() != NULL ||
134 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
135
136 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
137 fr = os::get_sender_for_C_frame(&fr);
138 } else {
139 break;
140 }
141 }
142 num_of_frames = frame_idx;
143 for (; frame_idx < frames; frame_idx ++) {
144 stack[frame_idx] = NULL;
145 }
146
147 return num_of_frames;
148 }
149
150
151 bool os::unsetenv(const char* name) {
152 assert(name != NULL, "Null pointer");
153 return (::unsetenv(name) == 0);
154 }
155
156 int os::get_last_error() {
157 return errno;
158 }
159
160 size_t os::lasterror(char *buf, size_t len) {
161 if (errno == 0) return 0;
162
163 const char *s = os::strerror(errno);
164 size_t n = ::strlen(s);
165 if (n >= len) {
166 n = len - 1;
167 }
168 ::strncpy(buf, s, n);
169 buf[n] = '\0';
170 return n;
171 }
172
173 void os::wait_for_keypress_at_exit(void) {
174 // don't do anything on posix platforms
175 return;
176 }
177
178 int os::create_file_for_heap(const char* dir) {
179 int fd;
180
181 #ifdef O_TMPFILE
182 char* native_dir = os::strdup(dir);
183 if (native_dir == NULL) {
184 vm_exit_during_initialization(err_msg("strdup failed during creation of backing file for heap (%s)", os::strerror(errno)));
185 return -1;
186 }
187 os::native_path(native_dir);
188 fd = os::open(dir, O_TMPFILE | O_RDWR, S_IRUSR | S_IWUSR);
189 os::free(native_dir);
190
191 if (fd == -1)
192 #endif
193 {
194 const char name_template[] = "/jvmheap.XXXXXX";
195
196 size_t fullname_len = strlen(dir) + strlen(name_template);
197 char *fullname = (char*)os::malloc(fullname_len + 1, mtInternal);
198 if (fullname == NULL) {
199 vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
200 return -1;
201 }
202 int n = snprintf(fullname, fullname_len + 1, "%s%s", dir, name_template);
203 assert((size_t)n == fullname_len, "Unexpected number of characters in string");
204
205 os::native_path(fullname);
206
207 // create a new file.
208 fd = mkstemp(fullname);
209
210 if (fd < 0) {
211 warning("Could not create file for heap with template %s", fullname);
212 os::free(fullname);
213 return -1;
214 } else {
215 // delete the name from the filesystem. When 'fd' is closed, the file (and space) will be deleted.
216 int ret = unlink(fullname);
217 assert_with_errno(ret == 0, "unlink returned error");
218 }
219
220 os::free(fullname);
221 }
222
223 return fd;
224 }
225
226 static char* reserve_mmapped_memory(size_t bytes, char* requested_addr) {
227 char * addr;
228 int flags = MAP_PRIVATE NOT_AIX( | MAP_NORESERVE ) | MAP_ANONYMOUS;
229 if (requested_addr != NULL) {
230 assert((uintptr_t)requested_addr % os::vm_page_size() == 0, "Requested address should be aligned to OS page size");
231 flags |= MAP_FIXED;
232 }
233
234 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
235 // touch an uncommitted page. Otherwise, the read/write might
236 // succeed if we have enough swap space to back the physical page.
237 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
238 flags, -1, 0);
239
240 if (addr != MAP_FAILED) {
241 MemTracker::record_virtual_memory_reserve((address)addr, bytes, CALLER_PC);
242 return addr;
243 }
244 return NULL;
245 }
246
247 static int util_posix_fallocate(int fd, off_t offset, off_t len) {
248 #ifdef __APPLE__
249 fstore_t store = { F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, len };
250 // First we try to get a continuous chunk of disk space
251 int ret = fcntl(fd, F_PREALLOCATE, &store);
252 if (ret == -1) {
253 // Maybe we are too fragmented, try to allocate non-continuous range
254 store.fst_flags = F_ALLOCATEALL;
255 ret = fcntl(fd, F_PREALLOCATE, &store);
256 }
257 if(ret != -1) {
258 return ftruncate(fd, len);
259 }
260 return -1;
261 #else
262 return posix_fallocate(fd, offset, len);
263 #endif
264 }
265
266 // Map the given address range to the provided file descriptor.
267 char* os::map_memory_to_file(char* base, size_t size, int fd) {
268 assert(fd != -1, "File descriptor is not valid");
269
270 // allocate space for the file
271 int ret = util_posix_fallocate(fd, 0, (off_t)size);
272 if (ret != 0) {
273 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory. error(%d)", ret));
274 return NULL;
275 }
276
277 int prot = PROT_READ | PROT_WRITE;
278 int flags = MAP_SHARED;
279 if (base != NULL) {
280 flags |= MAP_FIXED;
281 }
282 char* addr = (char*)mmap(base, size, prot, flags, fd, 0);
283
284 if (addr == MAP_FAILED) {
285 warning("Failed mmap to file. (%s)", os::strerror(errno));
286 return NULL;
287 }
288 if (base != NULL && addr != base) {
289 if (!os::release_memory(addr, size)) {
290 warning("Could not release memory on unsuccessful file mapping");
291 }
292 return NULL;
293 }
294 return addr;
295 }
296
297 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
298 assert(fd != -1, "File descriptor is not valid");
299 assert(base != NULL, "Base cannot be NULL");
300
301 return map_memory_to_file(base, size, fd);
302 }
303
304 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
305 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
306 // rather than unmapping and remapping the whole chunk to get requested alignment.
307 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
308 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
309 "Alignment must be a multiple of allocation granularity (page size)");
310 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
311
312 size_t extra_size = size + alignment;
313 assert(extra_size >= size, "overflow, size is too large to allow alignment");
314
315 char* extra_base;
316 if (file_desc != -1) {
317 // For file mapping, we do not call os:reserve_memory(extra_size, NULL, alignment, file_desc) because
318 // we need to deal with shrinking of the file space later when we release extra memory after alignment.
319 // We also cannot called os:reserve_memory() with file_desc set to -1 because on aix we might get SHM memory.
320 // So here to call a helper function while reserve memory for us. After we have a aligned base,
321 // we will replace anonymous mapping with file mapping.
322 extra_base = reserve_mmapped_memory(extra_size, NULL);
323 if (extra_base != NULL) {
324 MemTracker::record_virtual_memory_reserve((address)extra_base, extra_size, CALLER_PC);
325 }
326 } else {
327 extra_base = os::reserve_memory(extra_size, NULL, alignment);
328 }
329
330 if (extra_base == NULL) {
331 return NULL;
332 }
333
334 // Do manual alignment
335 char* aligned_base = align_up(extra_base, alignment);
336
337 // [ | | ]
338 // ^ extra_base
339 // ^ extra_base + begin_offset == aligned_base
340 // extra_base + begin_offset + size ^
341 // extra_base + extra_size ^
342 // |<>| == begin_offset
343 // end_offset == |<>|
344 size_t begin_offset = aligned_base - extra_base;
345 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
346
347 if (begin_offset > 0) {
348 os::release_memory(extra_base, begin_offset);
349 }
350
351 if (end_offset > 0) {
352 os::release_memory(extra_base + begin_offset + size, end_offset);
353 }
354
355 if (file_desc != -1) {
356 // After we have an aligned address, we can replace anonymous mapping with file mapping
357 if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
358 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
359 }
360 MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
361 }
362 return aligned_base;
363 }
364
365 int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
366 // All supported POSIX platforms provide C99 semantics.
367 int result = ::vsnprintf(buf, len, fmt, args);
368 // If an encoding error occurred (result < 0) then it's not clear
369 // whether the buffer is NUL terminated, so ensure it is.
370 if ((result < 0) && (len > 0)) {
371 buf[len - 1] = '\0';
372 }
373 return result;
374 }
375
376 int os::get_fileno(FILE* fp) {
377 return NOT_AIX(::)fileno(fp);
378 }
379
380 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
381 return gmtime_r(clock, res);
382 }
383
384 void os::Posix::print_load_average(outputStream* st) {
385 st->print("load average:");
386 double loadavg[3];
387 int res = os::loadavg(loadavg, 3);
388 if (res != -1) {
389 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
390 } else {
391 st->print(" Unavailable");
392 }
393 st->cr();
394 }
395
396 // boot/uptime information;
397 // unfortunately it does not work on macOS and Linux because the utx chain has no entry
398 // for reboot at least on my test machines
399 void os::Posix::print_uptime_info(outputStream* st) {
400 int bootsec = -1;
401 int currsec = time(NULL);
402 struct utmpx* ent;
403 setutxent();
404 while ((ent = getutxent())) {
405 if (!strcmp("system boot", ent->ut_line)) {
406 bootsec = ent->ut_tv.tv_sec;
407 break;
408 }
409 }
410
411 if (bootsec != -1) {
412 os::print_dhm(st, "OS uptime:", (long) (currsec-bootsec));
413 }
414 }
415
416
417 void os::Posix::print_rlimit_info(outputStream* st) {
418 st->print("rlimit:");
419 struct rlimit rlim;
420
421 st->print(" STACK ");
422 getrlimit(RLIMIT_STACK, &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->print(", CORE ");
427 getrlimit(RLIMIT_CORE, &rlim);
428 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
429 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
430
431 // Isn't there on solaris
432 #if defined(AIX)
433 st->print(", NPROC ");
434 st->print("%d", sysconf(_SC_CHILD_MAX));
435 st->print(", THREADS ");
436 getrlimit(RLIMIT_THREADS, &rlim);
437 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
438 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
439 #elif !defined(SOLARIS)
440 st->print(", NPROC ");
441 getrlimit(RLIMIT_NPROC, &rlim);
442 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
443 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
444 #endif
445
446 st->print(", NOFILE ");
447 getrlimit(RLIMIT_NOFILE, &rlim);
448 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
449 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
450
451 st->print(", AS ");
452 getrlimit(RLIMIT_AS, &rlim);
453 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
454 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
455
456 st->print(", CPU ");
457 getrlimit(RLIMIT_CPU, &rlim);
458 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
459 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
460
461 st->print(", DATA ");
462 getrlimit(RLIMIT_DATA, &rlim);
463 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
464 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
465
466 st->print(", FSIZE ");
467 getrlimit(RLIMIT_FSIZE, &rlim);
468 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
469 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
470
471 st->cr();
472 }
473
474 void os::Posix::print_uname_info(outputStream* st) {
475 // kernel
476 st->print("uname:");
477 struct utsname name;
478 uname(&name);
479 st->print("%s ", name.sysname);
480 #ifdef ASSERT
481 st->print("%s ", name.nodename);
482 #endif
483 st->print("%s ", name.release);
484 st->print("%s ", name.version);
485 st->print("%s", name.machine);
486 st->cr();
487 }
488
489 void os::Posix::print_umask(outputStream* st, mode_t umsk) {
490 st->print((umsk & S_IRUSR) ? "r" : "-");
491 st->print((umsk & S_IWUSR) ? "w" : "-");
492 st->print((umsk & S_IXUSR) ? "x" : "-");
493 st->print((umsk & S_IRGRP) ? "r" : "-");
494 st->print((umsk & S_IWGRP) ? "w" : "-");
495 st->print((umsk & S_IXGRP) ? "x" : "-");
496 st->print((umsk & S_IROTH) ? "r" : "-");
497 st->print((umsk & S_IWOTH) ? "w" : "-");
498 st->print((umsk & S_IXOTH) ? "x" : "-");
499 }
500
501 void os::Posix::print_user_info(outputStream* st) {
502 unsigned id = (unsigned) ::getuid();
503 st->print("uid : %u ", id);
504 id = (unsigned) ::geteuid();
505 st->print("euid : %u ", id);
506 id = (unsigned) ::getgid();
507 st->print("gid : %u ", id);
508 id = (unsigned) ::getegid();
509 st->print_cr("egid : %u", id);
510 st->cr();
511
512 mode_t umsk = ::umask(0);
513 ::umask(umsk);
514 st->print("umask: %04o (", (unsigned) umsk);
515 print_umask(st, umsk);
516 st->print_cr(")");
517 st->cr();
518 }
519
520
521 bool os::get_host_name(char* buf, size_t buflen) {
522 struct utsname name;
523 uname(&name);
524 jio_snprintf(buf, buflen, "%s", name.nodename);
525 return true;
526 }
527
528 bool os::has_allocatable_memory_limit(julong* limit) {
529 struct rlimit rlim;
530 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
531 // if there was an error when calling getrlimit, assume that there is no limitation
532 // on virtual memory.
533 bool result;
534 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
535 result = false;
536 } else {
537 *limit = (julong)rlim.rlim_cur;
538 result = true;
539 }
540 #ifdef _LP64
541 return result;
542 #else
543 // arbitrary virtual space limit for 32 bit Unices found by testing. If
544 // getrlimit above returned a limit, bound it with this limit. Otherwise
545 // directly use it.
546 const julong max_virtual_limit = (julong)3800*M;
547 if (result) {
548 *limit = MIN2(*limit, max_virtual_limit);
549 } else {
550 *limit = max_virtual_limit;
551 }
552
553 // bound by actually allocatable memory. The algorithm uses two bounds, an
554 // upper and a lower limit. The upper limit is the current highest amount of
555 // memory that could not be allocated, the lower limit is the current highest
556 // amount of memory that could be allocated.
557 // The algorithm iteratively refines the result by halving the difference
558 // between these limits, updating either the upper limit (if that value could
559 // not be allocated) or the lower limit (if the that value could be allocated)
560 // until the difference between these limits is "small".
561
562 // the minimum amount of memory we care about allocating.
563 const julong min_allocation_size = M;
564
565 julong upper_limit = *limit;
566
567 // first check a few trivial cases
568 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
569 *limit = upper_limit;
570 } else if (!is_allocatable(min_allocation_size)) {
571 // we found that not even min_allocation_size is allocatable. Return it
572 // anyway. There is no point to search for a better value any more.
573 *limit = min_allocation_size;
574 } else {
575 // perform the binary search.
576 julong lower_limit = min_allocation_size;
577 while ((upper_limit - lower_limit) > min_allocation_size) {
578 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
579 temp_limit = align_down(temp_limit, min_allocation_size);
580 if (is_allocatable(temp_limit)) {
581 lower_limit = temp_limit;
582 } else {
583 upper_limit = temp_limit;
584 }
585 }
586 *limit = lower_limit;
587 }
588 return true;
589 #endif
590 }
591
592 const char* os::get_current_directory(char *buf, size_t buflen) {
593 return getcwd(buf, buflen);
594 }
595
596 FILE* os::open(int fd, const char* mode) {
597 return ::fdopen(fd, mode);
598 }
599
600 ssize_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
601 return ::pread(fd, buf, nBytes, offset);
602 }
603
604 void os::flockfile(FILE* fp) {
605 ::flockfile(fp);
606 }
607
608 void os::funlockfile(FILE* fp) {
609 ::funlockfile(fp);
610 }
611
612 DIR* os::opendir(const char* dirname) {
613 assert(dirname != NULL, "just checking");
614 return ::opendir(dirname);
615 }
616
617 struct dirent* os::readdir(DIR* dirp) {
618 assert(dirp != NULL, "just checking");
619 return ::readdir(dirp);
620 }
621
622 int os::closedir(DIR *dirp) {
623 assert(dirp != NULL, "just checking");
624 return ::closedir(dirp);
625 }
626
627 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
628 // which is used to find statically linked in agents.
629 // Parameters:
630 // sym_name: Symbol in library we are looking for
631 // lib_name: Name of library to look in, NULL for shared libs.
632 // is_absolute_path == true if lib_name is absolute path to agent
633 // such as "/a/b/libL.so"
634 // == false if only the base name of the library is passed in
635 // such as "L"
636 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
637 bool is_absolute_path) {
638 char *agent_entry_name;
639 size_t len;
640 size_t name_len;
641 size_t prefix_len = strlen(JNI_LIB_PREFIX);
642 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
643 const char *start;
644
645 if (lib_name != NULL) {
646 name_len = strlen(lib_name);
647 if (is_absolute_path) {
648 // Need to strip path, prefix and suffix
649 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
650 lib_name = ++start;
651 }
652 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
653 return NULL;
654 }
655 lib_name += prefix_len;
656 name_len = strlen(lib_name) - suffix_len;
657 }
658 }
659 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
660 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
661 if (agent_entry_name == NULL) {
662 return NULL;
663 }
664 strcpy(agent_entry_name, sym_name);
665 if (lib_name != NULL) {
666 strcat(agent_entry_name, "_");
667 strncat(agent_entry_name, lib_name, name_len);
668 }
669 return agent_entry_name;
670 }
671
672
673 void os::naked_short_nanosleep(jlong ns) {
674 struct timespec req;
675 assert(ns > -1 && ns < NANOUNITS, "Un-interruptable sleep, short time use only");
676 req.tv_sec = 0;
677 req.tv_nsec = ns;
678 ::nanosleep(&req, NULL);
679 return;
680 }
681
682 void os::naked_short_sleep(jlong ms) {
683 assert(ms < MILLIUNITS, "Un-interruptable sleep, short time use only");
684 os::naked_short_nanosleep(ms * (NANOUNITS / MILLIUNITS));
685 return;
686 }
687
688 static const struct {
689 int sig; const char* name;
690 }
691 g_signal_info[] =
692 {
693 { SIGABRT, "SIGABRT" },
694 #ifdef SIGAIO
695 { SIGAIO, "SIGAIO" },
696 #endif
697 { SIGALRM, "SIGALRM" },
698 #ifdef SIGALRM1
699 { SIGALRM1, "SIGALRM1" },
700 #endif
701 { SIGBUS, "SIGBUS" },
702 #ifdef SIGCANCEL
703 { SIGCANCEL, "SIGCANCEL" },
704 #endif
705 { SIGCHLD, "SIGCHLD" },
706 #ifdef SIGCLD
707 { SIGCLD, "SIGCLD" },
708 #endif
709 { SIGCONT, "SIGCONT" },
710 #ifdef SIGCPUFAIL
711 { SIGCPUFAIL, "SIGCPUFAIL" },
712 #endif
713 #ifdef SIGDANGER
714 { SIGDANGER, "SIGDANGER" },
715 #endif
716 #ifdef SIGDIL
717 { SIGDIL, "SIGDIL" },
718 #endif
719 #ifdef SIGEMT
720 { SIGEMT, "SIGEMT" },
721 #endif
722 { SIGFPE, "SIGFPE" },
723 #ifdef SIGFREEZE
724 { SIGFREEZE, "SIGFREEZE" },
725 #endif
726 #ifdef SIGGFAULT
727 { SIGGFAULT, "SIGGFAULT" },
728 #endif
729 #ifdef SIGGRANT
730 { SIGGRANT, "SIGGRANT" },
731 #endif
732 { SIGHUP, "SIGHUP" },
733 { SIGILL, "SIGILL" },
734 #ifdef SIGINFO
735 { SIGINFO, "SIGINFO" },
736 #endif
737 { SIGINT, "SIGINT" },
738 #ifdef SIGIO
739 { SIGIO, "SIGIO" },
740 #endif
741 #ifdef SIGIOINT
742 { SIGIOINT, "SIGIOINT" },
743 #endif
744 #ifdef SIGIOT
745 // SIGIOT is there for BSD compatibility, but on most Unices just a
746 // synonym for SIGABRT. The result should be "SIGABRT", not
747 // "SIGIOT".
748 #if (SIGIOT != SIGABRT )
749 { SIGIOT, "SIGIOT" },
750 #endif
751 #endif
752 #ifdef SIGKAP
753 { SIGKAP, "SIGKAP" },
754 #endif
755 { SIGKILL, "SIGKILL" },
756 #ifdef SIGLOST
757 { SIGLOST, "SIGLOST" },
758 #endif
759 #ifdef SIGLWP
760 { SIGLWP, "SIGLWP" },
761 #endif
762 #ifdef SIGLWPTIMER
763 { SIGLWPTIMER, "SIGLWPTIMER" },
764 #endif
765 #ifdef SIGMIGRATE
766 { SIGMIGRATE, "SIGMIGRATE" },
767 #endif
768 #ifdef SIGMSG
769 { SIGMSG, "SIGMSG" },
770 #endif
771 { SIGPIPE, "SIGPIPE" },
772 #ifdef SIGPOLL
773 { SIGPOLL, "SIGPOLL" },
774 #endif
775 #ifdef SIGPRE
776 { SIGPRE, "SIGPRE" },
777 #endif
778 { SIGPROF, "SIGPROF" },
779 #ifdef SIGPTY
780 { SIGPTY, "SIGPTY" },
781 #endif
782 #ifdef SIGPWR
783 { SIGPWR, "SIGPWR" },
784 #endif
785 { SIGQUIT, "SIGQUIT" },
786 #ifdef SIGRECONFIG
787 { SIGRECONFIG, "SIGRECONFIG" },
788 #endif
789 #ifdef SIGRECOVERY
790 { SIGRECOVERY, "SIGRECOVERY" },
791 #endif
792 #ifdef SIGRESERVE
793 { SIGRESERVE, "SIGRESERVE" },
794 #endif
795 #ifdef SIGRETRACT
796 { SIGRETRACT, "SIGRETRACT" },
797 #endif
798 #ifdef SIGSAK
799 { SIGSAK, "SIGSAK" },
800 #endif
801 { SIGSEGV, "SIGSEGV" },
802 #ifdef SIGSOUND
803 { SIGSOUND, "SIGSOUND" },
804 #endif
805 #ifdef SIGSTKFLT
806 { SIGSTKFLT, "SIGSTKFLT" },
807 #endif
808 { SIGSTOP, "SIGSTOP" },
809 { SIGSYS, "SIGSYS" },
810 #ifdef SIGSYSERROR
811 { SIGSYSERROR, "SIGSYSERROR" },
812 #endif
813 #ifdef SIGTALRM
814 { SIGTALRM, "SIGTALRM" },
815 #endif
816 { SIGTERM, "SIGTERM" },
817 #ifdef SIGTHAW
818 { SIGTHAW, "SIGTHAW" },
819 #endif
820 { SIGTRAP, "SIGTRAP" },
821 #ifdef SIGTSTP
822 { SIGTSTP, "SIGTSTP" },
823 #endif
824 { SIGTTIN, "SIGTTIN" },
825 { SIGTTOU, "SIGTTOU" },
826 #ifdef SIGURG
827 { SIGURG, "SIGURG" },
828 #endif
829 { SIGUSR1, "SIGUSR1" },
830 { SIGUSR2, "SIGUSR2" },
831 #ifdef SIGVIRT
832 { SIGVIRT, "SIGVIRT" },
833 #endif
834 { SIGVTALRM, "SIGVTALRM" },
835 #ifdef SIGWAITING
836 { SIGWAITING, "SIGWAITING" },
837 #endif
838 #ifdef SIGWINCH
839 { SIGWINCH, "SIGWINCH" },
840 #endif
841 #ifdef SIGWINDOW
842 { SIGWINDOW, "SIGWINDOW" },
843 #endif
844 { SIGXCPU, "SIGXCPU" },
845 { SIGXFSZ, "SIGXFSZ" },
846 #ifdef SIGXRES
847 { SIGXRES, "SIGXRES" },
848 #endif
849 { -1, NULL }
850 };
851
852 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
853 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
854
855 const char* ret = NULL;
856
857 #ifdef SIGRTMIN
858 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
859 if (sig == SIGRTMIN) {
860 ret = "SIGRTMIN";
861 } else if (sig == SIGRTMAX) {
862 ret = "SIGRTMAX";
863 } else {
864 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
865 return out;
866 }
867 }
868 #endif
869
870 if (sig > 0) {
871 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
872 if (g_signal_info[idx].sig == sig) {
873 ret = g_signal_info[idx].name;
874 break;
875 }
876 }
877 }
878
879 if (!ret) {
880 if (!is_valid_signal(sig)) {
881 ret = "INVALID";
882 } else {
883 ret = "UNKNOWN";
884 }
885 }
886
887 if (out && outlen > 0) {
888 strncpy(out, ret, outlen);
889 out[outlen - 1] = '\0';
890 }
891 return out;
892 }
893
894 int os::Posix::get_signal_number(const char* signal_name) {
895 char tmp[30];
896 const char* s = signal_name;
897 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
898 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
899 s = tmp;
900 }
901 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
902 if (strcmp(g_signal_info[idx].name, s) == 0) {
903 return g_signal_info[idx].sig;
904 }
905 }
906 return -1;
907 }
908
909 int os::get_signal_number(const char* signal_name) {
910 return os::Posix::get_signal_number(signal_name);
911 }
912
913 // Returns true if signal number is valid.
914 bool os::Posix::is_valid_signal(int sig) {
915 // MacOS not really POSIX compliant: sigaddset does not return
916 // an error for invalid signal numbers. However, MacOS does not
917 // support real time signals and simply seems to have just 33
918 // signals with no holes in the signal range.
919 #ifdef __APPLE__
920 return sig >= 1 && sig < NSIG;
921 #else
922 // Use sigaddset to check for signal validity.
923 sigset_t set;
924 sigemptyset(&set);
925 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
926 return false;
927 }
928 return true;
929 #endif
930 }
931
932 bool os::Posix::is_sig_ignored(int sig) {
933 struct sigaction oact;
934 sigaction(sig, (struct sigaction*)NULL, &oact);
935 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
936 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
937 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
938 return true;
939 } else {
940 return false;
941 }
942 }
943
944 // Returns:
945 // NULL for an invalid signal number
946 // "SIG<num>" for a valid but unknown signal number
947 // signal name otherwise.
948 const char* os::exception_name(int sig, char* buf, size_t size) {
949 if (!os::Posix::is_valid_signal(sig)) {
950 return NULL;
951 }
952 const char* const name = os::Posix::get_signal_name(sig, buf, size);
953 if (strcmp(name, "UNKNOWN") == 0) {
954 jio_snprintf(buf, size, "SIG%d", sig);
955 }
956 return buf;
957 }
958
959 #define NUM_IMPORTANT_SIGS 32
960 // Returns one-line short description of a signal set in a user provided buffer.
961 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
962 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
963 // Note: for shortness, just print out the first 32. That should
964 // cover most of the useful ones, apart from realtime signals.
965 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
966 const int rc = sigismember(set, sig);
967 if (rc == -1 && errno == EINVAL) {
968 buffer[sig-1] = '?';
969 } else {
970 buffer[sig-1] = rc == 0 ? '0' : '1';
971 }
972 }
973 buffer[NUM_IMPORTANT_SIGS] = 0;
974 return buffer;
975 }
976
977 // Prints one-line description of a signal set.
978 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
979 char buf[NUM_IMPORTANT_SIGS + 1];
980 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
981 st->print("%s", buf);
982 }
983
984 // Writes one-line description of a combination of sigaction.sa_flags into a user
985 // provided buffer. Returns that buffer.
986 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
987 char* p = buffer;
988 size_t remaining = size;
989 bool first = true;
990 int idx = 0;
991
992 assert(buffer, "invalid argument");
993
994 if (size == 0) {
995 return buffer;
996 }
997
998 strncpy(buffer, "none", size);
999
1000 const struct {
1001 // NB: i is an unsigned int here because SA_RESETHAND is on some
1002 // systems 0x80000000, which is implicitly unsigned. Assignining
1003 // it to an int field would be an overflow in unsigned-to-signed
1004 // conversion.
1005 unsigned int i;
1006 const char* s;
1007 } flaginfo [] = {
1008 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
1009 { SA_ONSTACK, "SA_ONSTACK" },
1010 { SA_RESETHAND, "SA_RESETHAND" },
1011 { SA_RESTART, "SA_RESTART" },
1012 { SA_SIGINFO, "SA_SIGINFO" },
1013 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
1014 { SA_NODEFER, "SA_NODEFER" },
1015 #ifdef AIX
1016 { SA_ONSTACK, "SA_ONSTACK" },
1017 { SA_OLDSTYLE, "SA_OLDSTYLE" },
1018 #endif
1019 { 0, NULL }
1020 };
1021
1022 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
1023 if (flags & flaginfo[idx].i) {
1024 if (first) {
1025 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
1026 first = false;
1027 } else {
1028 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
1029 }
1030 const size_t len = strlen(p);
1031 p += len;
1032 remaining -= len;
1033 }
1034 }
1035
1036 buffer[size - 1] = '\0';
1037
1038 return buffer;
1039 }
1040
1041 // Prints one-line description of a combination of sigaction.sa_flags.
1042 void os::Posix::print_sa_flags(outputStream* st, int flags) {
1043 char buffer[0x100];
1044 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
1045 st->print("%s", buffer);
1046 }
1047
1048 // Helper function for os::Posix::print_siginfo_...():
1049 // return a textual description for signal code.
1050 struct enum_sigcode_desc_t {
1051 const char* s_name;
1052 const char* s_desc;
1053 };
1054
1055 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
1056
1057 const struct {
1058 int sig; int code; const char* s_code; const char* s_desc;
1059 } t1 [] = {
1060 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
1061 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
1062 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
1063 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
1064 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
1065 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
1066 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
1067 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
1068 #if defined(IA64) && defined(LINUX)
1069 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
1070 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
1071 #endif
1072 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
1073 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
1074 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
1075 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
1076 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
1077 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
1078 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
1079 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
1080 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
1081 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
1082 #ifdef AIX
1083 // no explanation found what keyerr would be
1084 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
1085 #endif
1086 #if defined(IA64) && !defined(AIX)
1087 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
1088 #endif
1089 #if defined(__sparc) && defined(SOLARIS)
1090 // define Solaris Sparc M7 ADI SEGV signals
1091 #if !defined(SEGV_ACCADI)
1092 #define SEGV_ACCADI 3
1093 #endif
1094 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
1095 #if !defined(SEGV_ACCDERR)
1096 #define SEGV_ACCDERR 4
1097 #endif
1098 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
1099 #if !defined(SEGV_ACCPERR)
1100 #define SEGV_ACCPERR 5
1101 #endif
1102 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
1103 #endif // defined(__sparc) && defined(SOLARIS)
1104 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
1105 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
1106 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
1107 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
1108 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
1109 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
1110 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
1111 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
1112 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
1113 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
1114 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
1115 #ifdef SIGPOLL
1116 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
1117 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
1118 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
1119 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
1120 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
1121 #endif
1122 { -1, -1, NULL, NULL }
1123 };
1124
1125 // Codes valid in any signal context.
1126 const struct {
1127 int code; const char* s_code; const char* s_desc;
1128 } t2 [] = {
1129 { SI_USER, "SI_USER", "Signal sent by kill()." },
1130 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
1131 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
1132 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
1133 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
1134 // Linux specific
1135 #ifdef SI_TKILL
1136 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
1137 #endif
1138 #ifdef SI_DETHREAD
1139 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
1140 #endif
1141 #ifdef SI_KERNEL
1142 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
1143 #endif
1144 #ifdef SI_SIGIO
1145 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
1146 #endif
1147
1148 #ifdef AIX
1149 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
1150 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
1151 #endif
1152
1153 #ifdef __sun
1154 { SI_NOINFO, "SI_NOINFO", "No signal information" },
1155 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
1156 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
1157 #endif
1158
1159 { -1, NULL, NULL }
1160 };
1161
1162 const char* s_code = NULL;
1163 const char* s_desc = NULL;
1164
1165 for (int i = 0; t1[i].sig != -1; i ++) {
1166 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
1167 s_code = t1[i].s_code;
1168 s_desc = t1[i].s_desc;
1169 break;
1170 }
1171 }
1172
1173 if (s_code == NULL) {
1174 for (int i = 0; t2[i].s_code != NULL; i ++) {
1175 if (t2[i].code == si->si_code) {
1176 s_code = t2[i].s_code;
1177 s_desc = t2[i].s_desc;
1178 }
1179 }
1180 }
1181
1182 if (s_code == NULL) {
1183 out->s_name = "unknown";
1184 out->s_desc = "unknown";
1185 return false;
1186 }
1187
1188 out->s_name = s_code;
1189 out->s_desc = s_desc;
1190
1191 return true;
1192 }
1193
1194 bool os::signal_sent_by_kill(const void* siginfo) {
1195 const siginfo_t* const si = (const siginfo_t*)siginfo;
1196 return si->si_code == SI_USER || si->si_code == SI_QUEUE
1197 #ifdef SI_TKILL
1198 || si->si_code == SI_TKILL
1199 #endif
1200 ;
1201 }
1202
1203 void os::print_siginfo(outputStream* os, const void* si0) {
1204
1205 const siginfo_t* const si = (const siginfo_t*) si0;
1206
1207 char buf[20];
1208 os->print("siginfo:");
1209
1210 if (!si) {
1211 os->print(" <null>");
1212 return;
1213 }
1214
1215 const int sig = si->si_signo;
1216
1217 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1218
1219 enum_sigcode_desc_t ed;
1220 get_signal_code_description(si, &ed);
1221 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1222
1223 if (si->si_errno) {
1224 os->print(", si_errno: %d", si->si_errno);
1225 }
1226
1227 // Output additional information depending on the signal code.
1228
1229 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1230 // so it depends on the context which member to use. For synchronous error signals,
1231 // we print si_addr, unless the signal was sent by another process or thread, in
1232 // which case we print out pid or tid of the sender.
1233 if (signal_sent_by_kill(si)) {
1234 const pid_t pid = si->si_pid;
1235 os->print(", si_pid: %ld", (long) pid);
1236 if (IS_VALID_PID(pid)) {
1237 const pid_t me = getpid();
1238 if (me == pid) {
1239 os->print(" (current process)");
1240 }
1241 } else {
1242 os->print(" (invalid)");
1243 }
1244 os->print(", si_uid: %ld", (long) si->si_uid);
1245 if (sig == SIGCHLD) {
1246 os->print(", si_status: %d", si->si_status);
1247 }
1248 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1249 sig == SIGTRAP || sig == SIGFPE) {
1250 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1251 #ifdef SIGPOLL
1252 } else if (sig == SIGPOLL) {
1253 os->print(", si_band: %ld", si->si_band);
1254 #endif
1255 }
1256
1257 }
1258
1259 bool os::signal_thread(Thread* thread, int sig, const char* reason) {
1260 OSThread* osthread = thread->osthread();
1261 if (osthread) {
1262 #if defined (SOLARIS)
1263 // Note: we cannot use pthread_kill on Solaris - not because
1264 // its missing, but because we do not have the pthread_t id.
1265 int status = thr_kill(osthread->thread_id(), sig);
1266 #else
1267 int status = pthread_kill(osthread->pthread_id(), sig);
1268 #endif
1269 if (status == 0) {
1270 Events::log(Thread::current(), "sent signal %d to Thread " INTPTR_FORMAT " because %s.",
1271 sig, p2i(thread), reason);
1272 return true;
1273 }
1274 }
1275 return false;
1276 }
1277
1278 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1279 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1280 }
1281
1282 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1283 #if defined(AIX)
1284 return Aix::ucontext_get_pc(ctx);
1285 #elif defined(BSD)
1286 return Bsd::ucontext_get_pc(ctx);
1287 #elif defined(LINUX)
1288 return Linux::ucontext_get_pc(ctx);
1289 #elif defined(SOLARIS)
1290 return Solaris::ucontext_get_pc(ctx);
1291 #else
1292 VMError::report_and_die("unimplemented ucontext_get_pc");
1293 #endif
1294 }
1295
1296 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1297 #if defined(AIX)
1298 Aix::ucontext_set_pc(ctx, pc);
1299 #elif defined(BSD)
1300 Bsd::ucontext_set_pc(ctx, pc);
1301 #elif defined(LINUX)
1302 Linux::ucontext_set_pc(ctx, pc);
1303 #elif defined(SOLARIS)
1304 Solaris::ucontext_set_pc(ctx, pc);
1305 #else
1306 VMError::report_and_die("unimplemented ucontext_get_pc");
1307 #endif
1308 }
1309
1310 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1311 size_t stack_size = 0;
1312 size_t guard_size = 0;
1313 int detachstate = 0;
1314 pthread_attr_getstacksize(attr, &stack_size);
1315 pthread_attr_getguardsize(attr, &guard_size);
1316 // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
1317 LINUX_ONLY(stack_size -= guard_size);
1318 pthread_attr_getdetachstate(attr, &detachstate);
1319 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1320 stack_size / 1024, guard_size / 1024,
1321 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1322 return buf;
1323 }
1324
1325 char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
1326
1327 if (filename == NULL || outbuf == NULL || outbuflen < 1) {
1328 assert(false, "os::Posix::realpath: invalid arguments.");
1329 errno = EINVAL;
1330 return NULL;
1331 }
1332
1333 char* result = NULL;
1334
1335 // This assumes platform realpath() is implemented according to POSIX.1-2008.
1336 // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
1337 // output buffer is dynamically allocated and must be ::free()'d by the caller.
1338 char* p = ::realpath(filename, NULL);
1339 if (p != NULL) {
1340 if (strlen(p) < outbuflen) {
1341 strcpy(outbuf, p);
1342 result = outbuf;
1343 } else {
1344 errno = ENAMETOOLONG;
1345 }
1346 ::free(p); // *not* os::free
1347 } else {
1348 // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
1349 // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
1350 // that it complains about the NULL we handed down as user buffer.
1351 // In this case, use the user provided buffer but at least check whether realpath caused
1352 // a memory overwrite.
1353 if (errno == EINVAL) {
1354 outbuf[outbuflen - 1] = '\0';
1355 p = ::realpath(filename, outbuf);
1356 if (p != NULL) {
1357 guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
1358 result = p;
1359 }
1360 }
1361 }
1362 return result;
1363
1364 }
1365
1366 int os::stat(const char *path, struct stat *sbuf) {
1367 return ::stat(path, sbuf);
1368 }
1369
1370 char * os::native_path(char *path) {
1371 return path;
1372 }
1373
1374 bool os::same_files(const char* file1, const char* file2) {
1375 if (strcmp(file1, file2) == 0) {
1376 return true;
1377 }
1378
1379 bool is_same = false;
1380 struct stat st1;
1381 struct stat st2;
1382
1383 if (os::stat(file1, &st1) < 0) {
1384 return false;
1385 }
1386
1387 if (os::stat(file2, &st2) < 0) {
1388 return false;
1389 }
1390
1391 if (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino) {
1392 // same files
1393 is_same = true;
1394 }
1395 return is_same;
1396 }
1397
1398 // Check minimum allowable stack sizes for thread creation and to initialize
1399 // the java system classes, including StackOverflowError - depends on page
1400 // size.
1401 // The space needed for frames during startup is platform dependent. It
1402 // depends on word size, platform calling conventions, C frame layout and
1403 // interpreter/C1/C2 design decisions. Therefore this is given in a
1404 // platform (os/cpu) dependent constant.
1405 // To this, space for guard mechanisms is added, which depends on the
1406 // page size which again depends on the concrete system the VM is running
1407 // on. Space for libc guard pages is not included in this size.
1408 jint os::Posix::set_minimum_stack_sizes() {
1409 size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
1410
1411 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
1412 JavaThread::stack_guard_zone_size() +
1413 JavaThread::stack_shadow_zone_size();
1414
1415 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
1416 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
1417
1418 size_t stack_size_in_bytes = ThreadStackSize * K;
1419 if (stack_size_in_bytes != 0 &&
1420 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1421 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1422 // ThreadStackSize so we go with "Java thread stack size" instead
1423 // of "ThreadStackSize" to be more friendly.
1424 tty->print_cr("\nThe Java thread stack size specified is too small. "
1425 "Specify at least " SIZE_FORMAT "k",
1426 _java_thread_min_stack_allowed / K);
1427 return JNI_ERR;
1428 }
1429
1430 // Make the stack size a multiple of the page size so that
1431 // the yellow/red zones can be guarded.
1432 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
1433
1434 // Reminder: a compiler thread is a Java thread.
1435 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
1436 JavaThread::stack_guard_zone_size() +
1437 JavaThread::stack_shadow_zone_size();
1438
1439 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
1440 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
1441
1442 stack_size_in_bytes = CompilerThreadStackSize * K;
1443 if (stack_size_in_bytes != 0 &&
1444 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1445 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1446 "Specify at least " SIZE_FORMAT "k",
1447 _compiler_thread_min_stack_allowed / K);
1448 return JNI_ERR;
1449 }
1450
1451 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1452 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
1453
1454 stack_size_in_bytes = VMThreadStackSize * K;
1455 if (stack_size_in_bytes != 0 &&
1456 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1457 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1458 "Specify at least " SIZE_FORMAT "k",
1459 _vm_internal_thread_min_stack_allowed / K);
1460 return JNI_ERR;
1461 }
1462 return JNI_OK;
1463 }
1464
1465 // Called when creating the thread. The minimum stack sizes have already been calculated
1466 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1467 size_t stack_size;
1468 if (req_stack_size == 0) {
1469 stack_size = default_stack_size(thr_type);
1470 } else {
1471 stack_size = req_stack_size;
1472 }
1473
1474 switch (thr_type) {
1475 case os::java_thread:
1476 // Java threads use ThreadStackSize which default value can be
1477 // changed with the flag -Xss
1478 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1479 // no requested size and we have a more specific default value
1480 stack_size = JavaThread::stack_size_at_create();
1481 }
1482 stack_size = MAX2(stack_size,
1483 _java_thread_min_stack_allowed);
1484 break;
1485 case os::compiler_thread:
1486 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1487 // no requested size and we have a more specific default value
1488 stack_size = (size_t)(CompilerThreadStackSize * K);
1489 }
1490 stack_size = MAX2(stack_size,
1491 _compiler_thread_min_stack_allowed);
1492 break;
1493 case os::vm_thread:
1494 case os::pgc_thread:
1495 case os::cgc_thread:
1496 case os::watcher_thread:
1497 default: // presume the unknown thr_type is a VM internal
1498 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1499 // no requested size and we have a more specific default value
1500 stack_size = (size_t)(VMThreadStackSize * K);
1501 }
1502
1503 stack_size = MAX2(stack_size,
1504 _vm_internal_thread_min_stack_allowed);
1505 break;
1506 }
1507
1508 // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
1509 // Be careful not to round up to 0. Align down in that case.
1510 if (stack_size <= SIZE_MAX - vm_page_size()) {
1511 stack_size = align_up(stack_size, vm_page_size());
1512 } else {
1513 stack_size = align_down(stack_size, vm_page_size());
1514 }
1515
1516 return stack_size;
1517 }
1518
1519 bool os::Posix::is_root(uid_t uid){
1520 return ROOT_UID == uid;
1521 }
1522
1523 bool os::Posix::matches_effective_uid_or_root(uid_t uid) {
1524 return is_root(uid) || geteuid() == uid;
1525 }
1526
1527 bool os::Posix::matches_effective_uid_and_gid_or_root(uid_t uid, gid_t gid) {
1528 return is_root(uid) || (geteuid() == uid && getegid() == gid);
1529 }
1530
1531 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
1532 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
1533 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
1534
1535 os::ThreadCrashProtection::ThreadCrashProtection() {
1536 }
1537
1538 /*
1539 * See the caveats for this class in os_posix.hpp
1540 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1541 * method and returns false. If none of the signals are raised, returns true.
1542 * The callback is supposed to provide the method that should be protected.
1543 */
1544 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1545 sigset_t saved_sig_mask;
1546
1547 Thread::muxAcquire(&_crash_mux, "CrashProtection");
1548
1549 _protected_thread = Thread::current_or_null();
1550 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
1551
1552 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1553 // since on at least some systems (OS X) siglongjmp will restore the mask
1554 // for the process, not the thread
1555 pthread_sigmask(0, NULL, &saved_sig_mask);
1556 if (sigsetjmp(_jmpbuf, 0) == 0) {
1557 // make sure we can see in the signal handler that we have crash protection
1558 // installed
1559 _crash_protection = this;
1560 cb.call();
1561 // and clear the crash protection
1562 _crash_protection = NULL;
1563 _protected_thread = NULL;
1564 Thread::muxRelease(&_crash_mux);
1565 return true;
1566 }
1567 // this happens when we siglongjmp() back
1568 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1569 _crash_protection = NULL;
1570 _protected_thread = NULL;
1571 Thread::muxRelease(&_crash_mux);
1572 return false;
1573 }
1574
1575 void os::ThreadCrashProtection::restore() {
1576 assert(_crash_protection != NULL, "must have crash protection");
1577 siglongjmp(_jmpbuf, 1);
1578 }
1579
1580 void os::ThreadCrashProtection::check_crash_protection(int sig,
1581 Thread* thread) {
1582
1583 if (thread != NULL &&
1584 thread == _protected_thread &&
1585 _crash_protection != NULL) {
1586
1587 if (sig == SIGSEGV || sig == SIGBUS) {
1588 _crash_protection->restore();
1589 }
1590 }
1591 }
1592
1593 // Shared clock/time and other supporting routines for pthread_mutex/cond
1594 // initialization. This is enabled on Solaris but only some of the clock/time
1595 // functionality is actually used there.
1596
1597 // Shared condattr object for use with relative timed-waits. Will be associated
1598 // with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
1599 // but otherwise whatever default is used by the platform - generally the
1600 // time-of-day clock.
1601 static pthread_condattr_t _condAttr[1];
1602
1603 // Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
1604 // all systems (e.g. FreeBSD) map the default to "normal".
1605 static pthread_mutexattr_t _mutexAttr[1];
1606
1607 // common basic initialization that is always supported
1608 static void pthread_init_common(void) {
1609 int status;
1610 if ((status = pthread_condattr_init(_condAttr)) != 0) {
1611 fatal("pthread_condattr_init: %s", os::strerror(status));
1612 }
1613 if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
1614 fatal("pthread_mutexattr_init: %s", os::strerror(status));
1615 }
1616 if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
1617 fatal("pthread_mutexattr_settype: %s", os::strerror(status));
1618 }
1619 // Solaris has it's own PlatformMutex, distinct from the one for POSIX.
1620 NOT_SOLARIS(os::PlatformMutex::init();)
1621 }
1622
1623 #ifndef SOLARIS
1624 sigset_t sigs;
1625 struct sigaction sigact[NSIG];
1626
1627 struct sigaction* os::Posix::get_preinstalled_handler(int sig) {
1628 if (sigismember(&sigs, sig)) {
1629 return &sigact[sig];
1630 }
1631 return NULL;
1632 }
1633
1634 void os::Posix::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
1635 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
1636 sigact[sig] = oldAct;
1637 sigaddset(&sigs, sig);
1638 }
1639 #endif
1640
1641 // Not all POSIX types and API's are available on all notionally "posix"
1642 // platforms. If we have build-time support then we will check for actual
1643 // runtime support via dlopen/dlsym lookup. This allows for running on an
1644 // older OS version compared to the build platform. But if there is no
1645 // build time support then there cannot be any runtime support as we do not
1646 // know what the runtime types would be (for example clockid_t might be an
1647 // int or int64_t).
1648 //
1649 #ifdef SUPPORTS_CLOCK_MONOTONIC
1650
1651 // This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
1652
1653 int (*os::Posix::_clock_gettime)(clockid_t, struct timespec *) = NULL;
1654 int (*os::Posix::_clock_getres)(clockid_t, struct timespec *) = NULL;
1655
1656 static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t) = NULL;
1657
1658 static bool _use_clock_monotonic_condattr = false;
1659
1660 // Determine what POSIX API's are present and do appropriate
1661 // configuration.
1662 void os::Posix::init(void) {
1663
1664 // NOTE: no logging available when this is called. Put logging
1665 // statements in init_2().
1666
1667 // 1. Check for CLOCK_MONOTONIC support.
1668
1669 void* handle = NULL;
1670
1671 // For linux we need librt, for other OS we can find
1672 // this function in regular libc.
1673 #ifdef NEEDS_LIBRT
1674 // We do dlopen's in this particular order due to bug in linux
1675 // dynamic loader (see 6348968) leading to crash on exit.
1676 handle = dlopen("librt.so.1", RTLD_LAZY);
1677 if (handle == NULL) {
1678 handle = dlopen("librt.so", RTLD_LAZY);
1679 }
1680 #endif
1681
1682 if (handle == NULL) {
1683 handle = RTLD_DEFAULT;
1684 }
1685
1686 int (*clock_getres_func)(clockid_t, struct timespec*) =
1687 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1688 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1689 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1690 if (clock_getres_func != NULL && clock_gettime_func != NULL) {
1691 // We assume that if both clock_gettime and clock_getres support
1692 // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
1693 struct timespec res;
1694 struct timespec tp;
1695 if (clock_getres_func(CLOCK_MONOTONIC, &res) == 0 &&
1696 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1697 // Yes, monotonic clock is supported.
1698 _clock_gettime = clock_gettime_func;
1699 _clock_getres = clock_getres_func;
1700 } else {
1701 #ifdef NEEDS_LIBRT
1702 // Close librt if there is no monotonic clock.
1703 if (handle != RTLD_DEFAULT) {
1704 dlclose(handle);
1705 }
1706 #endif
1707 }
1708 }
1709
1710 // 2. Check for pthread_condattr_setclock support.
1711
1712 // libpthread is already loaded.
1713 int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
1714 (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
1715 "pthread_condattr_setclock");
1716 if (condattr_setclock_func != NULL) {
1717 _pthread_condattr_setclock = condattr_setclock_func;
1718 }
1719
1720 // Now do general initialization.
1721
1722 pthread_init_common();
1723
1724 #ifndef SOLARIS
1725 int status;
1726 if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
1727 if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
1728 if (status == EINVAL) {
1729 _use_clock_monotonic_condattr = false;
1730 warning("Unable to use monotonic clock with relative timed-waits" \
1731 " - changes to the time-of-day clock may have adverse affects");
1732 } else {
1733 fatal("pthread_condattr_setclock: %s", os::strerror(status));
1734 }
1735 } else {
1736 _use_clock_monotonic_condattr = true;
1737 }
1738 }
1739 #endif // !SOLARIS
1740
1741 }
1742
1743 void os::Posix::init_2(void) {
1744 #ifndef SOLARIS
1745 log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
1746 (_clock_gettime != NULL ? "" : " not"));
1747 log_info(os)("Use of pthread_condattr_setclock is%s supported",
1748 (_pthread_condattr_setclock != NULL ? "" : " not"));
1749 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
1750 _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
1751 sigemptyset(&sigs);
1752 #endif // !SOLARIS
1753 }
1754
1755 #else // !SUPPORTS_CLOCK_MONOTONIC
1756
1757 void os::Posix::init(void) {
1758 pthread_init_common();
1759 }
1760
1761 void os::Posix::init_2(void) {
1762 #ifndef SOLARIS
1763 log_info(os)("Use of CLOCK_MONOTONIC is not supported");
1764 log_info(os)("Use of pthread_condattr_setclock is not supported");
1765 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
1766 sigemptyset(&sigs);
1767 #endif // !SOLARIS
1768 }
1769
1770 #endif // SUPPORTS_CLOCK_MONOTONIC
1771
1772 // Utility to convert the given timeout to an absolute timespec
1773 // (based on the appropriate clock) to use with pthread_cond_timewait,
1774 // and sem_timedwait().
1775 // The clock queried here must be the clock used to manage the
1776 // timeout of the condition variable or semaphore.
1777 //
1778 // The passed in timeout value is either a relative time in nanoseconds
1779 // or an absolute time in milliseconds. A relative timeout will be
1780 // associated with CLOCK_MONOTONIC if available, unless the real-time clock
1781 // is explicitly requested; otherwise, or if absolute,
1782 // the default time-of-day clock will be used.
1783
1784 // Given time is a 64-bit value and the time_t used in the timespec is
1785 // sometimes a signed-32-bit value we have to watch for overflow if times
1786 // way in the future are given. Further on Solaris versions
1787 // prior to 10 there is a restriction (see cond_timedwait) that the specified
1788 // number of seconds, in abstime, is less than current_time + 100000000.
1789 // As it will be over 20 years before "now + 100000000" will overflow we can
1790 // ignore overflow and just impose a hard-limit on seconds using the value
1791 // of "now + 100000000". This places a limit on the timeout of about 3.17
1792 // years from "now".
1793 //
1794 #define MAX_SECS 100000000
1795
1796 // Calculate a new absolute time that is "timeout" nanoseconds from "now".
1797 // "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
1798 // on which clock API is being used).
1799 static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
1800 jlong now_part_sec, jlong unit) {
1801 time_t max_secs = now_sec + MAX_SECS;
1802
1803 jlong seconds = timeout / NANOUNITS;
1804 timeout %= NANOUNITS; // remaining nanos
1805
1806 if (seconds >= MAX_SECS) {
1807 // More seconds than we can add, so pin to max_secs.
1808 abstime->tv_sec = max_secs;
1809 abstime->tv_nsec = 0;
1810 } else {
1811 abstime->tv_sec = now_sec + seconds;
1812 long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
1813 if (nanos >= NANOUNITS) { // overflow
1814 abstime->tv_sec += 1;
1815 nanos -= NANOUNITS;
1816 }
1817 abstime->tv_nsec = nanos;
1818 }
1819 }
1820
1821 // Unpack the given deadline in milliseconds since the epoch, into the given timespec.
1822 // The current time in seconds is also passed in to enforce an upper bound as discussed above.
1823 // This is only used with gettimeofday, when clock_gettime is not available.
1824 static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
1825 time_t max_secs = now_sec + MAX_SECS;
1826
1827 jlong seconds = deadline / MILLIUNITS;
1828 jlong millis = deadline % MILLIUNITS;
1829
1830 if (seconds >= max_secs) {
1831 // Absolute seconds exceeds allowed max, so pin to max_secs.
1832 abstime->tv_sec = max_secs;
1833 abstime->tv_nsec = 0;
1834 } else {
1835 abstime->tv_sec = seconds;
1836 abstime->tv_nsec = millis * (NANOUNITS / MILLIUNITS);
1837 }
1838 }
1839
1840 static jlong millis_to_nanos(jlong millis) {
1841 // We have to watch for overflow when converting millis to nanos,
1842 // but if millis is that large then we will end up limiting to
1843 // MAX_SECS anyway, so just do that here.
1844 if (millis / MILLIUNITS > MAX_SECS) {
1845 millis = jlong(MAX_SECS) * MILLIUNITS;
1846 }
1847 return millis * (NANOUNITS / MILLIUNITS);
1848 }
1849
1850 static void to_abstime(timespec* abstime, jlong timeout,
1851 bool isAbsolute, bool isRealtime) {
1852 DEBUG_ONLY(int max_secs = MAX_SECS;)
1853
1854 if (timeout < 0) {
1855 timeout = 0;
1856 }
1857
1858 #ifdef SUPPORTS_CLOCK_MONOTONIC
1859
1860 clockid_t clock = CLOCK_MONOTONIC;
1861 // need to ensure we have a runtime check for clock_gettime support
1862 if (!isAbsolute && os::Posix::supports_monotonic_clock()) {
1863 if (!_use_clock_monotonic_condattr || isRealtime) {
1864 clock = CLOCK_REALTIME;
1865 }
1866 struct timespec now;
1867 int status = os::Posix::clock_gettime(clock, &now);
1868 assert_status(status == 0, status, "clock_gettime");
1869 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
1870 DEBUG_ONLY(max_secs += now.tv_sec;)
1871 } else {
1872
1873 #else
1874
1875 { // Match the block scope.
1876
1877 #endif // SUPPORTS_CLOCK_MONOTONIC
1878
1879 // Time-of-day clock is all we can reliably use.
1880 struct timeval now;
1881 int status = gettimeofday(&now, NULL);
1882 assert_status(status == 0, errno, "gettimeofday");
1883 if (isAbsolute) {
1884 unpack_abs_time(abstime, timeout, now.tv_sec);
1885 } else {
1886 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
1887 }
1888 DEBUG_ONLY(max_secs += now.tv_sec;)
1889 }
1890
1891 assert(abstime->tv_sec >= 0, "tv_sec < 0");
1892 assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
1893 assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
1894 assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
1895 }
1896
1897 // Create an absolute time 'millis' milliseconds in the future, using the
1898 // real-time (time-of-day) clock. Used by PosixSemaphore.
1899 void os::Posix::to_RTC_abstime(timespec* abstime, int64_t millis) {
1900 to_abstime(abstime, millis_to_nanos(millis),
1901 false /* not absolute */,
1902 true /* use real-time clock */);
1903 }
1904
1905 // Shared pthread_mutex/cond based PlatformEvent implementation.
1906 // Not currently usable by Solaris.
1907
1908 #ifndef SOLARIS
1909
1910 // PlatformEvent
1911 //
1912 // Assumption:
1913 // Only one parker can exist on an event, which is why we allocate
1914 // them per-thread. Multiple unparkers can coexist.
1915 //
1916 // _event serves as a restricted-range semaphore.
1917 // -1 : thread is blocked, i.e. there is a waiter
1918 // 0 : neutral: thread is running or ready,
1919 // could have been signaled after a wait started
1920 // 1 : signaled - thread is running or ready
1921 //
1922 // Having three states allows for some detection of bad usage - see
1923 // comments on unpark().
1924
1925 os::PlatformEvent::PlatformEvent() {
1926 int status = pthread_cond_init(_cond, _condAttr);
1927 assert_status(status == 0, status, "cond_init");
1928 status = pthread_mutex_init(_mutex, _mutexAttr);
1929 assert_status(status == 0, status, "mutex_init");
1930 _event = 0;
1931 _nParked = 0;
1932 }
1933
1934 void os::PlatformEvent::park() { // AKA "down()"
1935 // Transitions for _event:
1936 // -1 => -1 : illegal
1937 // 1 => 0 : pass - return immediately
1938 // 0 => -1 : block; then set _event to 0 before returning
1939
1940 // Invariant: Only the thread associated with the PlatformEvent
1941 // may call park().
1942 assert(_nParked == 0, "invariant");
1943
1944 int v;
1945
1946 // atomically decrement _event
1947 for (;;) {
1948 v = _event;
1949 if (Atomic::cmpxchg(&_event, v, v - 1) == v) break;
1950 }
1951 guarantee(v >= 0, "invariant");
1952
1953 if (v == 0) { // Do this the hard way by blocking ...
1954 int status = pthread_mutex_lock(_mutex);
1955 assert_status(status == 0, status, "mutex_lock");
1956 guarantee(_nParked == 0, "invariant");
1957 ++_nParked;
1958 while (_event < 0) {
1959 // OS-level "spurious wakeups" are ignored
1960 status = pthread_cond_wait(_cond, _mutex);
1961 assert_status(status == 0, status, "cond_wait");
1962 }
1963 --_nParked;
1964
1965 _event = 0;
1966 status = pthread_mutex_unlock(_mutex);
1967 assert_status(status == 0, status, "mutex_unlock");
1968 // Paranoia to ensure our locked and lock-free paths interact
1969 // correctly with each other.
1970 OrderAccess::fence();
1971 }
1972 guarantee(_event >= 0, "invariant");
1973 }
1974
1975 int os::PlatformEvent::park(jlong millis) {
1976 // Transitions for _event:
1977 // -1 => -1 : illegal
1978 // 1 => 0 : pass - return immediately
1979 // 0 => -1 : block; then set _event to 0 before returning
1980
1981 // Invariant: Only the thread associated with the Event/PlatformEvent
1982 // may call park().
1983 assert(_nParked == 0, "invariant");
1984
1985 int v;
1986 // atomically decrement _event
1987 for (;;) {
1988 v = _event;
1989 if (Atomic::cmpxchg(&_event, v, v - 1) == v) break;
1990 }
1991 guarantee(v >= 0, "invariant");
1992
1993 if (v == 0) { // Do this the hard way by blocking ...
1994 struct timespec abst;
1995 to_abstime(&abst, millis_to_nanos(millis), false, false);
1996
1997 int ret = OS_TIMEOUT;
1998 int status = pthread_mutex_lock(_mutex);
1999 assert_status(status == 0, status, "mutex_lock");
2000 guarantee(_nParked == 0, "invariant");
2001 ++_nParked;
2002
2003 while (_event < 0) {
2004 status = pthread_cond_timedwait(_cond, _mutex, &abst);
2005 assert_status(status == 0 || status == ETIMEDOUT,
2006 status, "cond_timedwait");
2007 // OS-level "spurious wakeups" are ignored unless the archaic
2008 // FilterSpuriousWakeups is set false. That flag should be obsoleted.
2009 if (!FilterSpuriousWakeups) break;
2010 if (status == ETIMEDOUT) break;
2011 }
2012 --_nParked;
2013
2014 if (_event >= 0) {
2015 ret = OS_OK;
2016 }
2017
2018 _event = 0;
2019 status = pthread_mutex_unlock(_mutex);
2020 assert_status(status == 0, status, "mutex_unlock");
2021 // Paranoia to ensure our locked and lock-free paths interact
2022 // correctly with each other.
2023 OrderAccess::fence();
2024 return ret;
2025 }
2026 return OS_OK;
2027 }
2028
2029 void os::PlatformEvent::unpark() {
2030 // Transitions for _event:
2031 // 0 => 1 : just return
2032 // 1 => 1 : just return
2033 // -1 => either 0 or 1; must signal target thread
2034 // That is, we can safely transition _event from -1 to either
2035 // 0 or 1.
2036 // See also: "Semaphores in Plan 9" by Mullender & Cox
2037 //
2038 // Note: Forcing a transition from "-1" to "1" on an unpark() means
2039 // that it will take two back-to-back park() calls for the owning
2040 // thread to block. This has the benefit of forcing a spurious return
2041 // from the first park() call after an unpark() call which will help
2042 // shake out uses of park() and unpark() without checking state conditions
2043 // properly. This spurious return doesn't manifest itself in any user code
2044 // but only in the correctly written condition checking loops of ObjectMonitor,
2045 // Mutex/Monitor, Thread::muxAcquire and JavaThread::sleep
2046
2047 if (Atomic::xchg(&_event, 1) >= 0) return;
2048
2049 int status = pthread_mutex_lock(_mutex);
2050 assert_status(status == 0, status, "mutex_lock");
2051 int anyWaiters = _nParked;
2052 assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
2053 status = pthread_mutex_unlock(_mutex);
2054 assert_status(status == 0, status, "mutex_unlock");
2055
2056 // Note that we signal() *after* dropping the lock for "immortal" Events.
2057 // This is safe and avoids a common class of futile wakeups. In rare
2058 // circumstances this can cause a thread to return prematurely from
2059 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2060 // will simply re-test the condition and re-park itself.
2061 // This provides particular benefit if the underlying platform does not
2062 // provide wait morphing.
2063
2064 if (anyWaiters != 0) {
2065 status = pthread_cond_signal(_cond);
2066 assert_status(status == 0, status, "cond_signal");
2067 }
2068 }
2069
2070 // JSR166 support
2071
2072 os::PlatformParker::PlatformParker() {
2073 int status;
2074 status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
2075 assert_status(status == 0, status, "cond_init rel");
2076 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
2077 assert_status(status == 0, status, "cond_init abs");
2078 status = pthread_mutex_init(_mutex, _mutexAttr);
2079 assert_status(status == 0, status, "mutex_init");
2080 _cur_index = -1; // mark as unused
2081 }
2082
2083 // Parker::park decrements count if > 0, else does a condvar wait. Unpark
2084 // sets count to 1 and signals condvar. Only one thread ever waits
2085 // on the condvar. Contention seen when trying to park implies that someone
2086 // is unparking you, so don't wait. And spurious returns are fine, so there
2087 // is no need to track notifications.
2088
2089 void Parker::park(bool isAbsolute, jlong time) {
2090
2091 // Optional fast-path check:
2092 // Return immediately if a permit is available.
2093 // We depend on Atomic::xchg() having full barrier semantics
2094 // since we are doing a lock-free update to _counter.
2095 if (Atomic::xchg(&_counter, 0) > 0) return;
2096
2097 Thread* thread = Thread::current();
2098 assert(thread->is_Java_thread(), "Must be JavaThread");
2099 JavaThread *jt = (JavaThread *)thread;
2100
2101 // Optional optimization -- avoid state transitions if there's
2102 // an interrupt pending.
2103 if (jt->is_interrupted(false)) {
2104 return;
2105 }
2106
2107 // Next, demultiplex/decode time arguments
2108 struct timespec absTime;
2109 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
2110 return;
2111 }
2112 if (time > 0) {
2113 to_abstime(&absTime, time, isAbsolute, false);
2114 }
2115
2116 // Enter safepoint region
2117 // Beware of deadlocks such as 6317397.
2118 // The per-thread Parker:: mutex is a classic leaf-lock.
2119 // In particular a thread must never block on the Threads_lock while
2120 // holding the Parker:: mutex. If safepoints are pending both the
2121 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
2122 ThreadBlockInVM tbivm(jt);
2123
2124 // Can't access interrupt state now that we are _thread_blocked. If we've
2125 // been interrupted since we checked above then _counter will be > 0.
2126
2127 // Don't wait if cannot get lock since interference arises from
2128 // unparking.
2129 if (pthread_mutex_trylock(_mutex) != 0) {
2130 return;
2131 }
2132
2133 int status;
2134 if (_counter > 0) { // no wait needed
2135 _counter = 0;
2136 status = pthread_mutex_unlock(_mutex);
2137 assert_status(status == 0, status, "invariant");
2138 // Paranoia to ensure our locked and lock-free paths interact
2139 // correctly with each other and Java-level accesses.
2140 OrderAccess::fence();
2141 return;
2142 }
2143
2144 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2145 jt->set_suspend_equivalent();
2146 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2147
2148 assert(_cur_index == -1, "invariant");
2149 if (time == 0) {
2150 _cur_index = REL_INDEX; // arbitrary choice when not timed
2151 status = pthread_cond_wait(&_cond[_cur_index], _mutex);
2152 assert_status(status == 0, status, "cond_timedwait");
2153 }
2154 else {
2155 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
2156 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
2157 assert_status(status == 0 || status == ETIMEDOUT,
2158 status, "cond_timedwait");
2159 }
2160 _cur_index = -1;
2161
2162 _counter = 0;
2163 status = pthread_mutex_unlock(_mutex);
2164 assert_status(status == 0, status, "invariant");
2165 // Paranoia to ensure our locked and lock-free paths interact
2166 // correctly with each other and Java-level accesses.
2167 OrderAccess::fence();
2168
2169 // If externally suspended while waiting, re-suspend
2170 if (jt->handle_special_suspend_equivalent_condition()) {
2171 jt->java_suspend_self();
2172 }
2173 }
2174
2175 void Parker::unpark() {
2176 int status = pthread_mutex_lock(_mutex);
2177 assert_status(status == 0, status, "invariant");
2178 const int s = _counter;
2179 _counter = 1;
2180 // must capture correct index before unlocking
2181 int index = _cur_index;
2182 status = pthread_mutex_unlock(_mutex);
2183 assert_status(status == 0, status, "invariant");
2184
2185 // Note that we signal() *after* dropping the lock for "immortal" Events.
2186 // This is safe and avoids a common class of futile wakeups. In rare
2187 // circumstances this can cause a thread to return prematurely from
2188 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2189 // will simply re-test the condition and re-park itself.
2190 // This provides particular benefit if the underlying platform does not
2191 // provide wait morphing.
2192
2193 if (s < 1 && index != -1) {
2194 // thread is definitely parked
2195 status = pthread_cond_signal(&_cond[index]);
2196 assert_status(status == 0, status, "invariant");
2197 }
2198 }
2199
2200 // Platform Mutex/Monitor implementation
2201
2202 #if PLATFORM_MONITOR_IMPL_INDIRECT
2203
2204 os::PlatformMutex::Mutex::Mutex() : _next(NULL) {
2205 int status = pthread_mutex_init(&_mutex, _mutexAttr);
2206 assert_status(status == 0, status, "mutex_init");
2207 }
2208
2209 os::PlatformMutex::Mutex::~Mutex() {
2210 int status = pthread_mutex_destroy(&_mutex);
2211 assert_status(status == 0, status, "mutex_destroy");
2212 }
2213
2214 pthread_mutex_t os::PlatformMutex::_freelist_lock;
2215 os::PlatformMutex::Mutex* os::PlatformMutex::_mutex_freelist = NULL;
2216
2217 void os::PlatformMutex::init() {
2218 int status = pthread_mutex_init(&_freelist_lock, _mutexAttr);
2219 assert_status(status == 0, status, "freelist lock init");
2220 }
2221
2222 struct os::PlatformMutex::WithFreeListLocked : public StackObj {
2223 WithFreeListLocked() {
2224 int status = pthread_mutex_lock(&_freelist_lock);
2225 assert_status(status == 0, status, "freelist lock");
2226 }
2227
2228 ~WithFreeListLocked() {
2229 int status = pthread_mutex_unlock(&_freelist_lock);
2230 assert_status(status == 0, status, "freelist unlock");
2231 }
2232 };
2233
2234 os::PlatformMutex::PlatformMutex() {
2235 {
2236 WithFreeListLocked wfl;
2237 _impl = _mutex_freelist;
2238 if (_impl != NULL) {
2239 _mutex_freelist = _impl->_next;
2240 _impl->_next = NULL;
2241 return;
2242 }
2243 }
2244 _impl = new Mutex();
2245 }
2246
2247 os::PlatformMutex::~PlatformMutex() {
2248 WithFreeListLocked wfl;
2249 assert(_impl->_next == NULL, "invariant");
2250 _impl->_next = _mutex_freelist;
2251 _mutex_freelist = _impl;
2252 }
2253
2254 os::PlatformMonitor::Cond::Cond() : _next(NULL) {
2255 int status = pthread_cond_init(&_cond, _condAttr);
2256 assert_status(status == 0, status, "cond_init");
2257 }
2258
2259 os::PlatformMonitor::Cond::~Cond() {
2260 int status = pthread_cond_destroy(&_cond);
2261 assert_status(status == 0, status, "cond_destroy");
2262 }
2263
2264 os::PlatformMonitor::Cond* os::PlatformMonitor::_cond_freelist = NULL;
2265
2266 os::PlatformMonitor::PlatformMonitor() {
2267 {
2268 WithFreeListLocked wfl;
2269 _impl = _cond_freelist;
2270 if (_impl != NULL) {
2271 _cond_freelist = _impl->_next;
2272 _impl->_next = NULL;
2273 return;
2274 }
2275 }
2276 _impl = new Cond();
2277 }
2278
2279 os::PlatformMonitor::~PlatformMonitor() {
2280 WithFreeListLocked wfl;
2281 assert(_impl->_next == NULL, "invariant");
2282 _impl->_next = _cond_freelist;
2283 _cond_freelist = _impl;
2284 }
2285
2286 #else
2287
2288 os::PlatformMutex::PlatformMutex() {
2289 int status = pthread_mutex_init(&_mutex, _mutexAttr);
2290 assert_status(status == 0, status, "mutex_init");
2291 }
2292
2293 os::PlatformMutex::~PlatformMutex() {
2294 int status = pthread_mutex_destroy(&_mutex);
2295 assert_status(status == 0, status, "mutex_destroy");
2296 }
2297
2298 os::PlatformMonitor::PlatformMonitor() {
2299 int status = pthread_cond_init(&_cond, _condAttr);
2300 assert_status(status == 0, status, "cond_init");
2301 }
2302
2303 os::PlatformMonitor::~PlatformMonitor() {
2304 int status = pthread_cond_destroy(&_cond);
2305 assert_status(status == 0, status, "cond_destroy");
2306 }
2307
2308 #endif // PLATFORM_MONITOR_IMPL_INDIRECT
2309
2310 // Must already be locked
2311 int os::PlatformMonitor::wait(jlong millis) {
2312 assert(millis >= 0, "negative timeout");
2313 if (millis > 0) {
2314 struct timespec abst;
2315 // We have to watch for overflow when converting millis to nanos,
2316 // but if millis is that large then we will end up limiting to
2317 // MAX_SECS anyway, so just do that here.
2318 if (millis / MILLIUNITS > MAX_SECS) {
2319 millis = jlong(MAX_SECS) * MILLIUNITS;
2320 }
2321 to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false, false);
2322
2323 int ret = OS_TIMEOUT;
2324 int status = pthread_cond_timedwait(cond(), mutex(), &abst);
2325 assert_status(status == 0 || status == ETIMEDOUT,
2326 status, "cond_timedwait");
2327 if (status == 0) {
2328 ret = OS_OK;
2329 }
2330 return ret;
2331 } else {
2332 int status = pthread_cond_wait(cond(), mutex());
2333 assert_status(status == 0, status, "cond_wait");
2334 return OS_OK;
2335 }
2336 }
2337
2338 #endif // !SOLARIS