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