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 #ifndef O_TMPFILE
68 #ifdef __O_TMPFILE
69 #define O_TMPFILE __O_TMPFILE
70 #endif
71 #endif
72
73 #define check_with_errno(check_type, cond, msg) \
74 do { \
75 int err = errno; \
76 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
77 os::errno_name(err)); \
78 } while (false)
79
80 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
81 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
82
83 // Check core dump limit and report possible place where core can be found
84 void os::check_dump_limit(char* buffer, size_t bufferSize) {
85 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
86 jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
87 VMError::record_coredump_status(buffer, false);
88 return;
89 }
90
91 int n;
92 struct rlimit rlim;
93 bool success;
94
95 char core_path[PATH_MAX];
96 n = get_core_path(core_path, PATH_MAX);
97
98 if (n <= 0) {
99 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
100 success = true;
101 #ifdef LINUX
102 } else if (core_path[0] == '"') { // redirect to user process
103 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
104 success = true;
105 #endif
106 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
107 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
108 success = true;
109 } else {
110 switch(rlim.rlim_cur) {
111 case RLIM_INFINITY:
112 jio_snprintf(buffer, bufferSize, "%s", core_path);
113 success = true;
114 break;
115 case 0:
116 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
117 success = false;
118 break;
119 default:
120 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);
121 success = true;
122 break;
123 }
124 }
125
126 VMError::record_coredump_status(buffer, success);
127 }
128
129 int os::get_native_stack(address* stack, int frames, int toSkip) {
130 int frame_idx = 0;
131 int num_of_frames; // number of frames captured
132 frame fr = os::current_frame();
133 while (fr.pc() && frame_idx < frames) {
134 if (toSkip > 0) {
135 toSkip --;
136 } else {
137 stack[frame_idx ++] = fr.pc();
138 }
139 if (fr.fp() == NULL || fr.cb() != NULL ||
140 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
141
142 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
143 fr = os::get_sender_for_C_frame(&fr);
144 } else {
145 break;
146 }
147 }
148 num_of_frames = frame_idx;
149 for (; frame_idx < frames; frame_idx ++) {
150 stack[frame_idx] = NULL;
151 }
152
153 return num_of_frames;
154 }
155
156
157 bool os::unsetenv(const char* name) {
158 assert(name != NULL, "Null pointer");
159 return (::unsetenv(name) == 0);
160 }
161
162 int os::get_last_error() {
163 return errno;
164 }
165
166 size_t os::lasterror(char *buf, size_t len) {
167 if (errno == 0) return 0;
168
169 const char *s = os::strerror(errno);
170 size_t n = ::strlen(s);
171 if (n >= len) {
172 n = len - 1;
173 }
174 ::strncpy(buf, s, n);
175 buf[n] = '\0';
176 return n;
177 }
178
179 void os::wait_for_keypress_at_exit(void) {
180 // don't do anything on posix platforms
181 return;
182 }
183
184 int os::create_file_for_heap(const char* dir) {
185 char* native_dir = os::strdup(dir);
186 if (native_dir == NULL) {
187 vm_exit_during_initialization(err_msg("strdup failed during creation of backing file for heap (%s)", os::strerror(errno)));
188 return -1;
189 }
190 os::native_path(native_dir);
191 int fd = os::open(dir, O_TMPFILE | O_RDWR, S_IRUSR | S_IWUSR);
192 os::free(native_dir);
193
194 if (fd == -1) {
195 const char name_template[] = "/jvmheap.XXXXXX";
196
197 size_t fullname_len = strlen(dir) + strlen(name_template);
198 char *fullname = (char*)os::malloc(fullname_len + 1, mtInternal);
199 if (fullname == NULL) {
200 vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
201 return -1;
202 }
203 int n = snprintf(fullname, fullname_len + 1, "%s%s", dir, name_template);
204 assert((size_t)n == fullname_len, "Unexpected number of characters in string");
205
206 os::native_path(fullname);
207
208 // create a new file.
209 fd = mkstemp(fullname);
210
211 if (fd < 0) {
212 warning("Could not create file for heap with template %s", fullname);
213 os::free(fullname);
214 return -1;
215 } else {
216 // delete the name from the filesystem. When 'fd' is closed, the file (and space) will be deleted.
217 int ret = unlink(fullname);
218 assert_with_errno(ret == 0, "unlink returned error");
219 }
220
221 os::free(fullname);
222 }
223
224 return fd;
225 }
226
227 static char* reserve_mmapped_memory(size_t bytes, char* requested_addr) {
228 char * addr;
229 int flags = MAP_PRIVATE NOT_AIX( | MAP_NORESERVE ) | MAP_ANONYMOUS;
230 if (requested_addr != NULL) {
231 assert((uintptr_t)requested_addr % os::vm_page_size() == 0, "Requested address should be aligned to OS page size");
232 flags |= MAP_FIXED;
233 }
234
235 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
236 // touch an uncommitted page. Otherwise, the read/write might
237 // succeed if we have enough swap space to back the physical page.
238 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
239 flags, -1, 0);
240
241 if (addr != MAP_FAILED) {
242 MemTracker::record_virtual_memory_reserve((address)addr, bytes, CALLER_PC);
243 return addr;
244 }
245 return NULL;
246 }
247
248 static int util_posix_fallocate(int fd, off_t offset, off_t len) {
249 #ifdef __APPLE__
250 fstore_t store = { F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, len };
251 // First we try to get a continuous chunk of disk space
252 int ret = fcntl(fd, F_PREALLOCATE, &store);
253 if (ret == -1) {
254 // Maybe we are too fragmented, try to allocate non-continuous range
255 store.fst_flags = F_ALLOCATEALL;
256 ret = fcntl(fd, F_PREALLOCATE, &store);
257 }
258 if(ret != -1) {
259 return ftruncate(fd, len);
260 }
261 return -1;
262 #else
263 return posix_fallocate(fd, offset, len);
264 #endif
265 }
266
267 // Map the given address range to the provided file descriptor.
268 char* os::map_memory_to_file(char* base, size_t size, int fd) {
269 assert(fd != -1, "File descriptor is not valid");
270
271 // allocate space for the file
272 int ret = util_posix_fallocate(fd, 0, (off_t)size);
273 if (ret != 0) {
274 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory. error(%d)", ret));
275 return NULL;
276 }
277
278 int prot = PROT_READ | PROT_WRITE;
279 int flags = MAP_SHARED;
280 if (base != NULL) {
281 flags |= MAP_FIXED;
282 }
283 char* addr = (char*)mmap(base, size, prot, flags, fd, 0);
284
285 if (addr == MAP_FAILED) {
286 warning("Failed mmap to file. (%s)", os::strerror(errno));
287 return NULL;
288 }
289 if (base != NULL && addr != base) {
290 if (!os::release_memory(addr, size)) {
291 warning("Could not release memory on unsuccessful file mapping");
292 }
293 return NULL;
294 }
295 return addr;
296 }
297
298 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
299 assert(fd != -1, "File descriptor is not valid");
300 assert(base != NULL, "Base cannot be NULL");
301
302 return map_memory_to_file(base, size, fd);
303 }
304
305 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
306 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
307 // rather than unmapping and remapping the whole chunk to get requested alignment.
308 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
309 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
310 "Alignment must be a multiple of allocation granularity (page size)");
311 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
312
313 size_t extra_size = size + alignment;
314 assert(extra_size >= size, "overflow, size is too large to allow alignment");
315
316 char* extra_base;
317 if (file_desc != -1) {
318 // For file mapping, we do not call os:reserve_memory(extra_size, NULL, alignment, file_desc) because
319 // we need to deal with shrinking of the file space later when we release extra memory after alignment.
320 // We also cannot called os:reserve_memory() with file_desc set to -1 because on aix we might get SHM memory.
321 // So here to call a helper function while reserve memory for us. After we have a aligned base,
322 // we will replace anonymous mapping with file mapping.
323 extra_base = reserve_mmapped_memory(extra_size, NULL);
324 if (extra_base != NULL) {
325 MemTracker::record_virtual_memory_reserve((address)extra_base, extra_size, CALLER_PC);
326 }
327 } else {
328 extra_base = os::reserve_memory(extra_size, NULL, alignment);
329 }
330
331 if (extra_base == NULL) {
332 return NULL;
333 }
334
335 // Do manual alignment
336 char* aligned_base = align_up(extra_base, alignment);
337
338 // [ | | ]
339 // ^ extra_base
340 // ^ extra_base + begin_offset == aligned_base
341 // extra_base + begin_offset + size ^
342 // extra_base + extra_size ^
343 // |<>| == begin_offset
344 // end_offset == |<>|
345 size_t begin_offset = aligned_base - extra_base;
346 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
347
348 if (begin_offset > 0) {
349 os::release_memory(extra_base, begin_offset);
350 }
351
352 if (end_offset > 0) {
353 os::release_memory(extra_base + begin_offset + size, end_offset);
354 }
355
356 if (file_desc != -1) {
357 // After we have an aligned address, we can replace anonymous mapping with file mapping
358 if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
359 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
360 }
361 MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
362 }
363 return aligned_base;
364 }
365
366 int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
367 // All supported POSIX platforms provide C99 semantics.
368 int result = ::vsnprintf(buf, len, fmt, args);
369 // If an encoding error occurred (result < 0) then it's not clear
370 // whether the buffer is NUL terminated, so ensure it is.
371 if ((result < 0) && (len > 0)) {
372 buf[len - 1] = '\0';
373 }
374 return result;
375 }
376
377 int os::get_fileno(FILE* fp) {
378 return NOT_AIX(::)fileno(fp);
379 }
380
381 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
382 return gmtime_r(clock, res);
383 }
384
385 void os::Posix::print_load_average(outputStream* st) {
386 st->print("load average:");
387 double loadavg[3];
388 int res = os::loadavg(loadavg, 3);
389 if (res != -1) {
390 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
391 } else {
392 st->print(" Unavailable");
393 }
394 st->cr();
395 }
396
397 // boot/uptime information;
398 // unfortunately it does not work on macOS and Linux because the utx chain has no entry
399 // for reboot at least on my test machines
400 void os::Posix::print_uptime_info(outputStream* st) {
401 int bootsec = -1;
402 int currsec = time(NULL);
403 struct utmpx* ent;
404 setutxent();
405 while ((ent = getutxent())) {
406 if (!strcmp("system boot", ent->ut_line)) {
407 bootsec = ent->ut_tv.tv_sec;
408 break;
409 }
410 }
411
412 if (bootsec != -1) {
413 os::print_dhm(st, "OS uptime:", (long) (currsec-bootsec));
414 }
415 }
416
417
418 void os::Posix::print_rlimit_info(outputStream* st) {
419 st->print("rlimit:");
420 struct rlimit rlim;
421
422 st->print(" STACK ");
423 getrlimit(RLIMIT_STACK, &rlim);
424 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
425 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
426
427 st->print(", CORE ");
428 getrlimit(RLIMIT_CORE, &rlim);
429 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
430 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
431
432 // Isn't there on solaris
433 #if defined(AIX)
434 st->print(", NPROC ");
435 st->print("%d", sysconf(_SC_CHILD_MAX));
436 st->print(", THREADS ");
437 getrlimit(RLIMIT_THREADS, &rlim);
438 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
439 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
440 #elif !defined(SOLARIS)
441 st->print(", NPROC ");
442 getrlimit(RLIMIT_NPROC, &rlim);
443 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
444 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
445 #endif
446
447 st->print(", NOFILE ");
448 getrlimit(RLIMIT_NOFILE, &rlim);
449 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
450 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
451
452 st->print(", AS ");
453 getrlimit(RLIMIT_AS, &rlim);
454 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
455 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
456
457 st->print(", CPU ");
458 getrlimit(RLIMIT_CPU, &rlim);
459 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
460 else st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur));
461
462 st->print(", DATA ");
463 getrlimit(RLIMIT_DATA, &rlim);
464 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
465 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
466
467 st->print(", FSIZE ");
468 getrlimit(RLIMIT_FSIZE, &rlim);
469 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
470 else st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024);
471
472 st->cr();
473 }
474
475 void os::Posix::print_uname_info(outputStream* st) {
476 // kernel
477 st->print("uname:");
478 struct utsname name;
479 uname(&name);
480 st->print("%s ", name.sysname);
481 #ifdef ASSERT
482 st->print("%s ", name.nodename);
483 #endif
484 st->print("%s ", name.release);
485 st->print("%s ", name.version);
486 st->print("%s", name.machine);
487 st->cr();
488 }
489
490 void os::Posix::print_umask(outputStream* st, mode_t umsk) {
491 st->print((umsk & S_IRUSR) ? "r" : "-");
492 st->print((umsk & S_IWUSR) ? "w" : "-");
493 st->print((umsk & S_IXUSR) ? "x" : "-");
494 st->print((umsk & S_IRGRP) ? "r" : "-");
495 st->print((umsk & S_IWGRP) ? "w" : "-");
496 st->print((umsk & S_IXGRP) ? "x" : "-");
497 st->print((umsk & S_IROTH) ? "r" : "-");
498 st->print((umsk & S_IWOTH) ? "w" : "-");
499 st->print((umsk & S_IXOTH) ? "x" : "-");
500 }
501
502 void os::Posix::print_user_info(outputStream* st) {
503 unsigned id = (unsigned) ::getuid();
504 st->print("uid : %u ", id);
505 id = (unsigned) ::geteuid();
506 st->print("euid : %u ", id);
507 id = (unsigned) ::getgid();
508 st->print("gid : %u ", id);
509 id = (unsigned) ::getegid();
510 st->print_cr("egid : %u", id);
511 st->cr();
512
513 mode_t umsk = ::umask(0);
514 ::umask(umsk);
515 st->print("umask: %04o (", (unsigned) umsk);
516 print_umask(st, umsk);
517 st->print_cr(")");
518 st->cr();
519 }
520
521
522 bool os::get_host_name(char* buf, size_t buflen) {
523 struct utsname name;
524 uname(&name);
525 jio_snprintf(buf, buflen, "%s", name.nodename);
526 return true;
527 }
528
529 bool os::has_allocatable_memory_limit(julong* limit) {
530 struct rlimit rlim;
531 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
532 // if there was an error when calling getrlimit, assume that there is no limitation
533 // on virtual memory.
534 bool result;
535 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
536 result = false;
537 } else {
538 *limit = (julong)rlim.rlim_cur;
539 result = true;
540 }
541 #ifdef _LP64
542 return result;
543 #else
544 // arbitrary virtual space limit for 32 bit Unices found by testing. If
545 // getrlimit above returned a limit, bound it with this limit. Otherwise
546 // directly use it.
547 const julong max_virtual_limit = (julong)3800*M;
548 if (result) {
549 *limit = MIN2(*limit, max_virtual_limit);
550 } else {
551 *limit = max_virtual_limit;
552 }
553
554 // bound by actually allocatable memory. The algorithm uses two bounds, an
555 // upper and a lower limit. The upper limit is the current highest amount of
556 // memory that could not be allocated, the lower limit is the current highest
557 // amount of memory that could be allocated.
558 // The algorithm iteratively refines the result by halving the difference
559 // between these limits, updating either the upper limit (if that value could
560 // not be allocated) or the lower limit (if the that value could be allocated)
561 // until the difference between these limits is "small".
562
563 // the minimum amount of memory we care about allocating.
564 const julong min_allocation_size = M;
565
566 julong upper_limit = *limit;
567
568 // first check a few trivial cases
569 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
570 *limit = upper_limit;
571 } else if (!is_allocatable(min_allocation_size)) {
572 // we found that not even min_allocation_size is allocatable. Return it
573 // anyway. There is no point to search for a better value any more.
574 *limit = min_allocation_size;
575 } else {
576 // perform the binary search.
577 julong lower_limit = min_allocation_size;
578 while ((upper_limit - lower_limit) > min_allocation_size) {
579 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
580 temp_limit = align_down(temp_limit, min_allocation_size);
581 if (is_allocatable(temp_limit)) {
582 lower_limit = temp_limit;
583 } else {
584 upper_limit = temp_limit;
585 }
586 }
587 *limit = lower_limit;
588 }
589 return true;
590 #endif
591 }
592
593 const char* os::get_current_directory(char *buf, size_t buflen) {
594 return getcwd(buf, buflen);
595 }
596
597 FILE* os::open(int fd, const char* mode) {
598 return ::fdopen(fd, mode);
599 }
600
601 ssize_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
602 return ::pread(fd, buf, nBytes, offset);
603 }
604
605 void os::flockfile(FILE* fp) {
606 ::flockfile(fp);
607 }
608
609 void os::funlockfile(FILE* fp) {
610 ::funlockfile(fp);
611 }
612
613 DIR* os::opendir(const char* dirname) {
614 assert(dirname != NULL, "just checking");
615 return ::opendir(dirname);
616 }
617
618 struct dirent* os::readdir(DIR* dirp) {
619 assert(dirp != NULL, "just checking");
620 return ::readdir(dirp);
621 }
622
623 int os::closedir(DIR *dirp) {
624 assert(dirp != NULL, "just checking");
625 return ::closedir(dirp);
626 }
627
628 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
629 // which is used to find statically linked in agents.
630 // Parameters:
631 // sym_name: Symbol in library we are looking for
632 // lib_name: Name of library to look in, NULL for shared libs.
633 // is_absolute_path == true if lib_name is absolute path to agent
634 // such as "/a/b/libL.so"
635 // == false if only the base name of the library is passed in
636 // such as "L"
637 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
638 bool is_absolute_path) {
639 char *agent_entry_name;
640 size_t len;
641 size_t name_len;
642 size_t prefix_len = strlen(JNI_LIB_PREFIX);
643 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
644 const char *start;
645
646 if (lib_name != NULL) {
647 name_len = strlen(lib_name);
648 if (is_absolute_path) {
649 // Need to strip path, prefix and suffix
650 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
651 lib_name = ++start;
652 }
653 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
654 return NULL;
655 }
656 lib_name += prefix_len;
657 name_len = strlen(lib_name) - suffix_len;
658 }
659 }
660 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
661 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
662 if (agent_entry_name == NULL) {
663 return NULL;
664 }
665 strcpy(agent_entry_name, sym_name);
666 if (lib_name != NULL) {
667 strcat(agent_entry_name, "_");
668 strncat(agent_entry_name, lib_name, name_len);
669 }
670 return agent_entry_name;
671 }
672
673
674 void os::naked_short_nanosleep(jlong ns) {
675 struct timespec req;
676 assert(ns > -1 && ns < NANOUNITS, "Un-interruptable sleep, short time use only");
677 req.tv_sec = 0;
678 req.tv_nsec = ns;
679 ::nanosleep(&req, NULL);
680 return;
681 }
682
683 void os::naked_short_sleep(jlong ms) {
684 assert(ms < MILLIUNITS, "Un-interruptable sleep, short time use only");
685 os::naked_short_nanosleep(ms * (NANOUNITS / MILLIUNITS));
686 return;
687 }
688
689 static const struct {
690 int sig; const char* name;
691 }
692 g_signal_info[] =
693 {
694 { SIGABRT, "SIGABRT" },
695 #ifdef SIGAIO
696 { SIGAIO, "SIGAIO" },
697 #endif
698 { SIGALRM, "SIGALRM" },
699 #ifdef SIGALRM1
700 { SIGALRM1, "SIGALRM1" },
701 #endif
702 { SIGBUS, "SIGBUS" },
703 #ifdef SIGCANCEL
704 { SIGCANCEL, "SIGCANCEL" },
705 #endif
706 { SIGCHLD, "SIGCHLD" },
707 #ifdef SIGCLD
708 { SIGCLD, "SIGCLD" },
709 #endif
710 { SIGCONT, "SIGCONT" },
711 #ifdef SIGCPUFAIL
712 { SIGCPUFAIL, "SIGCPUFAIL" },
713 #endif
714 #ifdef SIGDANGER
715 { SIGDANGER, "SIGDANGER" },
716 #endif
717 #ifdef SIGDIL
718 { SIGDIL, "SIGDIL" },
719 #endif
720 #ifdef SIGEMT
721 { SIGEMT, "SIGEMT" },
722 #endif
723 { SIGFPE, "SIGFPE" },
724 #ifdef SIGFREEZE
725 { SIGFREEZE, "SIGFREEZE" },
726 #endif
727 #ifdef SIGGFAULT
728 { SIGGFAULT, "SIGGFAULT" },
729 #endif
730 #ifdef SIGGRANT
731 { SIGGRANT, "SIGGRANT" },
732 #endif
733 { SIGHUP, "SIGHUP" },
734 { SIGILL, "SIGILL" },
735 #ifdef SIGINFO
736 { SIGINFO, "SIGINFO" },
737 #endif
738 { SIGINT, "SIGINT" },
739 #ifdef SIGIO
740 { SIGIO, "SIGIO" },
741 #endif
742 #ifdef SIGIOINT
743 { SIGIOINT, "SIGIOINT" },
744 #endif
745 #ifdef SIGIOT
746 // SIGIOT is there for BSD compatibility, but on most Unices just a
747 // synonym for SIGABRT. The result should be "SIGABRT", not
748 // "SIGIOT".
749 #if (SIGIOT != SIGABRT )
750 { SIGIOT, "SIGIOT" },
751 #endif
752 #endif
753 #ifdef SIGKAP
754 { SIGKAP, "SIGKAP" },
755 #endif
756 { SIGKILL, "SIGKILL" },
757 #ifdef SIGLOST
758 { SIGLOST, "SIGLOST" },
759 #endif
760 #ifdef SIGLWP
761 { SIGLWP, "SIGLWP" },
762 #endif
763 #ifdef SIGLWPTIMER
764 { SIGLWPTIMER, "SIGLWPTIMER" },
765 #endif
766 #ifdef SIGMIGRATE
767 { SIGMIGRATE, "SIGMIGRATE" },
768 #endif
769 #ifdef SIGMSG
770 { SIGMSG, "SIGMSG" },
771 #endif
772 { SIGPIPE, "SIGPIPE" },
773 #ifdef SIGPOLL
774 { SIGPOLL, "SIGPOLL" },
775 #endif
776 #ifdef SIGPRE
777 { SIGPRE, "SIGPRE" },
778 #endif
779 { SIGPROF, "SIGPROF" },
780 #ifdef SIGPTY
781 { SIGPTY, "SIGPTY" },
782 #endif
783 #ifdef SIGPWR
784 { SIGPWR, "SIGPWR" },
785 #endif
786 { SIGQUIT, "SIGQUIT" },
787 #ifdef SIGRECONFIG
788 { SIGRECONFIG, "SIGRECONFIG" },
789 #endif
790 #ifdef SIGRECOVERY
791 { SIGRECOVERY, "SIGRECOVERY" },
792 #endif
793 #ifdef SIGRESERVE
794 { SIGRESERVE, "SIGRESERVE" },
795 #endif
796 #ifdef SIGRETRACT
797 { SIGRETRACT, "SIGRETRACT" },
798 #endif
799 #ifdef SIGSAK
800 { SIGSAK, "SIGSAK" },
801 #endif
802 { SIGSEGV, "SIGSEGV" },
803 #ifdef SIGSOUND
804 { SIGSOUND, "SIGSOUND" },
805 #endif
806 #ifdef SIGSTKFLT
807 { SIGSTKFLT, "SIGSTKFLT" },
808 #endif
809 { SIGSTOP, "SIGSTOP" },
810 { SIGSYS, "SIGSYS" },
811 #ifdef SIGSYSERROR
812 { SIGSYSERROR, "SIGSYSERROR" },
813 #endif
814 #ifdef SIGTALRM
815 { SIGTALRM, "SIGTALRM" },
816 #endif
817 { SIGTERM, "SIGTERM" },
818 #ifdef SIGTHAW
819 { SIGTHAW, "SIGTHAW" },
820 #endif
821 { SIGTRAP, "SIGTRAP" },
822 #ifdef SIGTSTP
823 { SIGTSTP, "SIGTSTP" },
824 #endif
825 { SIGTTIN, "SIGTTIN" },
826 { SIGTTOU, "SIGTTOU" },
827 #ifdef SIGURG
828 { SIGURG, "SIGURG" },
829 #endif
830 { SIGUSR1, "SIGUSR1" },
831 { SIGUSR2, "SIGUSR2" },
832 #ifdef SIGVIRT
833 { SIGVIRT, "SIGVIRT" },
834 #endif
835 { SIGVTALRM, "SIGVTALRM" },
836 #ifdef SIGWAITING
837 { SIGWAITING, "SIGWAITING" },
838 #endif
839 #ifdef SIGWINCH
840 { SIGWINCH, "SIGWINCH" },
841 #endif
842 #ifdef SIGWINDOW
843 { SIGWINDOW, "SIGWINDOW" },
844 #endif
845 { SIGXCPU, "SIGXCPU" },
846 { SIGXFSZ, "SIGXFSZ" },
847 #ifdef SIGXRES
848 { SIGXRES, "SIGXRES" },
849 #endif
850 { -1, NULL }
851 };
852
853 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
854 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
855
856 const char* ret = NULL;
857
858 #ifdef SIGRTMIN
859 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
860 if (sig == SIGRTMIN) {
861 ret = "SIGRTMIN";
862 } else if (sig == SIGRTMAX) {
863 ret = "SIGRTMAX";
864 } else {
865 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
866 return out;
867 }
868 }
869 #endif
870
871 if (sig > 0) {
872 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
873 if (g_signal_info[idx].sig == sig) {
874 ret = g_signal_info[idx].name;
875 break;
876 }
877 }
878 }
879
880 if (!ret) {
881 if (!is_valid_signal(sig)) {
882 ret = "INVALID";
883 } else {
884 ret = "UNKNOWN";
885 }
886 }
887
888 if (out && outlen > 0) {
889 strncpy(out, ret, outlen);
890 out[outlen - 1] = '\0';
891 }
892 return out;
893 }
894
895 int os::Posix::get_signal_number(const char* signal_name) {
896 char tmp[30];
897 const char* s = signal_name;
898 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
899 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
900 s = tmp;
901 }
902 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
903 if (strcmp(g_signal_info[idx].name, s) == 0) {
904 return g_signal_info[idx].sig;
905 }
906 }
907 return -1;
908 }
909
910 int os::get_signal_number(const char* signal_name) {
911 return os::Posix::get_signal_number(signal_name);
912 }
913
914 // Returns true if signal number is valid.
915 bool os::Posix::is_valid_signal(int sig) {
916 // MacOS not really POSIX compliant: sigaddset does not return
917 // an error for invalid signal numbers. However, MacOS does not
918 // support real time signals and simply seems to have just 33
919 // signals with no holes in the signal range.
920 #ifdef __APPLE__
921 return sig >= 1 && sig < NSIG;
922 #else
923 // Use sigaddset to check for signal validity.
924 sigset_t set;
925 sigemptyset(&set);
926 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
927 return false;
928 }
929 return true;
930 #endif
931 }
932
933 bool os::Posix::is_sig_ignored(int sig) {
934 struct sigaction oact;
935 sigaction(sig, (struct sigaction*)NULL, &oact);
936 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
937 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
938 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
939 return true;
940 } else {
941 return false;
942 }
943 }
944
945 // Returns:
946 // NULL for an invalid signal number
947 // "SIG<num>" for a valid but unknown signal number
948 // signal name otherwise.
949 const char* os::exception_name(int sig, char* buf, size_t size) {
950 if (!os::Posix::is_valid_signal(sig)) {
951 return NULL;
952 }
953 const char* const name = os::Posix::get_signal_name(sig, buf, size);
954 if (strcmp(name, "UNKNOWN") == 0) {
955 jio_snprintf(buf, size, "SIG%d", sig);
956 }
957 return buf;
958 }
959
960 #define NUM_IMPORTANT_SIGS 32
961 // Returns one-line short description of a signal set in a user provided buffer.
962 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
963 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
964 // Note: for shortness, just print out the first 32. That should
965 // cover most of the useful ones, apart from realtime signals.
966 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
967 const int rc = sigismember(set, sig);
968 if (rc == -1 && errno == EINVAL) {
969 buffer[sig-1] = '?';
970 } else {
971 buffer[sig-1] = rc == 0 ? '0' : '1';
972 }
973 }
974 buffer[NUM_IMPORTANT_SIGS] = 0;
975 return buffer;
976 }
977
978 // Prints one-line description of a signal set.
979 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
980 char buf[NUM_IMPORTANT_SIGS + 1];
981 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
982 st->print("%s", buf);
983 }
984
985 // Writes one-line description of a combination of sigaction.sa_flags into a user
986 // provided buffer. Returns that buffer.
987 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
988 char* p = buffer;
989 size_t remaining = size;
990 bool first = true;
991 int idx = 0;
992
993 assert(buffer, "invalid argument");
994
995 if (size == 0) {
996 return buffer;
997 }
998
999 strncpy(buffer, "none", size);
1000
1001 const struct {
1002 // NB: i is an unsigned int here because SA_RESETHAND is on some
1003 // systems 0x80000000, which is implicitly unsigned. Assignining
1004 // it to an int field would be an overflow in unsigned-to-signed
1005 // conversion.
1006 unsigned int i;
1007 const char* s;
1008 } flaginfo [] = {
1009 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
1010 { SA_ONSTACK, "SA_ONSTACK" },
1011 { SA_RESETHAND, "SA_RESETHAND" },
1012 { SA_RESTART, "SA_RESTART" },
1013 { SA_SIGINFO, "SA_SIGINFO" },
1014 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
1015 { SA_NODEFER, "SA_NODEFER" },
1016 #ifdef AIX
1017 { SA_ONSTACK, "SA_ONSTACK" },
1018 { SA_OLDSTYLE, "SA_OLDSTYLE" },
1019 #endif
1020 { 0, NULL }
1021 };
1022
1023 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
1024 if (flags & flaginfo[idx].i) {
1025 if (first) {
1026 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
1027 first = false;
1028 } else {
1029 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
1030 }
1031 const size_t len = strlen(p);
1032 p += len;
1033 remaining -= len;
1034 }
1035 }
1036
1037 buffer[size - 1] = '\0';
1038
1039 return buffer;
1040 }
1041
1042 // Prints one-line description of a combination of sigaction.sa_flags.
1043 void os::Posix::print_sa_flags(outputStream* st, int flags) {
1044 char buffer[0x100];
1045 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
1046 st->print("%s", buffer);
1047 }
1048
1049 // Helper function for os::Posix::print_siginfo_...():
1050 // return a textual description for signal code.
1051 struct enum_sigcode_desc_t {
1052 const char* s_name;
1053 const char* s_desc;
1054 };
1055
1056 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
1057
1058 const struct {
1059 int sig; int code; const char* s_code; const char* s_desc;
1060 } t1 [] = {
1061 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
1062 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
1063 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
1064 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
1065 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
1066 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
1067 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
1068 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
1069 #if defined(IA64) && defined(LINUX)
1070 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
1071 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
1072 #endif
1073 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
1074 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
1075 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
1076 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
1077 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
1078 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
1079 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
1080 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
1081 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
1082 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
1083 #ifdef AIX
1084 // no explanation found what keyerr would be
1085 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
1086 #endif
1087 #if defined(IA64) && !defined(AIX)
1088 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
1089 #endif
1090 #if defined(__sparc) && defined(SOLARIS)
1091 // define Solaris Sparc M7 ADI SEGV signals
1092 #if !defined(SEGV_ACCADI)
1093 #define SEGV_ACCADI 3
1094 #endif
1095 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
1096 #if !defined(SEGV_ACCDERR)
1097 #define SEGV_ACCDERR 4
1098 #endif
1099 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
1100 #if !defined(SEGV_ACCPERR)
1101 #define SEGV_ACCPERR 5
1102 #endif
1103 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
1104 #endif // defined(__sparc) && defined(SOLARIS)
1105 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
1106 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
1107 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
1108 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
1109 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
1110 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
1111 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
1112 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
1113 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
1114 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
1115 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
1116 #ifdef SIGPOLL
1117 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
1118 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
1119 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
1120 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
1121 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
1122 #endif
1123 { -1, -1, NULL, NULL }
1124 };
1125
1126 // Codes valid in any signal context.
1127 const struct {
1128 int code; const char* s_code; const char* s_desc;
1129 } t2 [] = {
1130 { SI_USER, "SI_USER", "Signal sent by kill()." },
1131 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
1132 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
1133 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
1134 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
1135 // Linux specific
1136 #ifdef SI_TKILL
1137 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
1138 #endif
1139 #ifdef SI_DETHREAD
1140 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
1141 #endif
1142 #ifdef SI_KERNEL
1143 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
1144 #endif
1145 #ifdef SI_SIGIO
1146 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
1147 #endif
1148
1149 #ifdef AIX
1150 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
1151 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
1152 #endif
1153
1154 #ifdef __sun
1155 { SI_NOINFO, "SI_NOINFO", "No signal information" },
1156 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
1157 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
1158 #endif
1159
1160 { -1, NULL, NULL }
1161 };
1162
1163 const char* s_code = NULL;
1164 const char* s_desc = NULL;
1165
1166 for (int i = 0; t1[i].sig != -1; i ++) {
1167 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
1168 s_code = t1[i].s_code;
1169 s_desc = t1[i].s_desc;
1170 break;
1171 }
1172 }
1173
1174 if (s_code == NULL) {
1175 for (int i = 0; t2[i].s_code != NULL; i ++) {
1176 if (t2[i].code == si->si_code) {
1177 s_code = t2[i].s_code;
1178 s_desc = t2[i].s_desc;
1179 }
1180 }
1181 }
1182
1183 if (s_code == NULL) {
1184 out->s_name = "unknown";
1185 out->s_desc = "unknown";
1186 return false;
1187 }
1188
1189 out->s_name = s_code;
1190 out->s_desc = s_desc;
1191
1192 return true;
1193 }
1194
1195 bool os::signal_sent_by_kill(const void* siginfo) {
1196 const siginfo_t* const si = (const siginfo_t*)siginfo;
1197 return si->si_code == SI_USER || si->si_code == SI_QUEUE
1198 #ifdef SI_TKILL
1199 || si->si_code == SI_TKILL
1200 #endif
1201 ;
1202 }
1203
1204 void os::print_siginfo(outputStream* os, const void* si0) {
1205
1206 const siginfo_t* const si = (const siginfo_t*) si0;
1207
1208 char buf[20];
1209 os->print("siginfo:");
1210
1211 if (!si) {
1212 os->print(" <null>");
1213 return;
1214 }
1215
1216 const int sig = si->si_signo;
1217
1218 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1219
1220 enum_sigcode_desc_t ed;
1221 get_signal_code_description(si, &ed);
1222 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1223
1224 if (si->si_errno) {
1225 os->print(", si_errno: %d", si->si_errno);
1226 }
1227
1228 // Output additional information depending on the signal code.
1229
1230 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1231 // so it depends on the context which member to use. For synchronous error signals,
1232 // we print si_addr, unless the signal was sent by another process or thread, in
1233 // which case we print out pid or tid of the sender.
1234 if (signal_sent_by_kill(si)) {
1235 const pid_t pid = si->si_pid;
1236 os->print(", si_pid: %ld", (long) pid);
1237 if (IS_VALID_PID(pid)) {
1238 const pid_t me = getpid();
1239 if (me == pid) {
1240 os->print(" (current process)");
1241 }
1242 } else {
1243 os->print(" (invalid)");
1244 }
1245 os->print(", si_uid: %ld", (long) si->si_uid);
1246 if (sig == SIGCHLD) {
1247 os->print(", si_status: %d", si->si_status);
1248 }
1249 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1250 sig == SIGTRAP || sig == SIGFPE) {
1251 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1252 #ifdef SIGPOLL
1253 } else if (sig == SIGPOLL) {
1254 os->print(", si_band: %ld", si->si_band);
1255 #endif
1256 }
1257
1258 }
1259
1260 bool os::signal_thread(Thread* thread, int sig, const char* reason) {
1261 OSThread* osthread = thread->osthread();
1262 if (osthread) {
1263 #if defined (SOLARIS)
1264 // Note: we cannot use pthread_kill on Solaris - not because
1265 // its missing, but because we do not have the pthread_t id.
1266 int status = thr_kill(osthread->thread_id(), sig);
1267 #else
1268 int status = pthread_kill(osthread->pthread_id(), sig);
1269 #endif
1270 if (status == 0) {
1271 Events::log(Thread::current(), "sent signal %d to Thread " INTPTR_FORMAT " because %s.",
1272 sig, p2i(thread), reason);
1273 return true;
1274 }
1275 }
1276 return false;
1277 }
1278
1279 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1280 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1281 }
1282
1283 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1284 #if defined(AIX)
1285 return Aix::ucontext_get_pc(ctx);
1286 #elif defined(BSD)
1287 return Bsd::ucontext_get_pc(ctx);
1288 #elif defined(LINUX)
1289 return Linux::ucontext_get_pc(ctx);
1290 #elif defined(SOLARIS)
1291 return Solaris::ucontext_get_pc(ctx);
1292 #else
1293 VMError::report_and_die("unimplemented ucontext_get_pc");
1294 #endif
1295 }
1296
1297 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1298 #if defined(AIX)
1299 Aix::ucontext_set_pc(ctx, pc);
1300 #elif defined(BSD)
1301 Bsd::ucontext_set_pc(ctx, pc);
1302 #elif defined(LINUX)
1303 Linux::ucontext_set_pc(ctx, pc);
1304 #elif defined(SOLARIS)
1305 Solaris::ucontext_set_pc(ctx, pc);
1306 #else
1307 VMError::report_and_die("unimplemented ucontext_get_pc");
1308 #endif
1309 }
1310
1311 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1312 size_t stack_size = 0;
1313 size_t guard_size = 0;
1314 int detachstate = 0;
1315 pthread_attr_getstacksize(attr, &stack_size);
1316 pthread_attr_getguardsize(attr, &guard_size);
1317 // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
1318 LINUX_ONLY(stack_size -= guard_size);
1319 pthread_attr_getdetachstate(attr, &detachstate);
1320 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1321 stack_size / 1024, guard_size / 1024,
1322 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1323 return buf;
1324 }
1325
1326 char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
1327
1328 if (filename == NULL || outbuf == NULL || outbuflen < 1) {
1329 assert(false, "os::Posix::realpath: invalid arguments.");
1330 errno = EINVAL;
1331 return NULL;
1332 }
1333
1334 char* result = NULL;
1335
1336 // This assumes platform realpath() is implemented according to POSIX.1-2008.
1337 // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
1338 // output buffer is dynamically allocated and must be ::free()'d by the caller.
1339 char* p = ::realpath(filename, NULL);
1340 if (p != NULL) {
1341 if (strlen(p) < outbuflen) {
1342 strcpy(outbuf, p);
1343 result = outbuf;
1344 } else {
1345 errno = ENAMETOOLONG;
1346 }
1347 ::free(p); // *not* os::free
1348 } else {
1349 // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
1350 // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
1351 // that it complains about the NULL we handed down as user buffer.
1352 // In this case, use the user provided buffer but at least check whether realpath caused
1353 // a memory overwrite.
1354 if (errno == EINVAL) {
1355 outbuf[outbuflen - 1] = '\0';
1356 p = ::realpath(filename, outbuf);
1357 if (p != NULL) {
1358 guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
1359 result = p;
1360 }
1361 }
1362 }
1363 return result;
1364
1365 }
1366
1367 int os::stat(const char *path, struct stat *sbuf) {
1368 return ::stat(path, sbuf);
1369 }
1370
1371 char * os::native_path(char *path) {
1372 return path;
1373 }
1374
1375 bool os::same_files(const char* file1, const char* file2) {
1376 if (strcmp(file1, file2) == 0) {
1377 return true;
1378 }
1379
1380 bool is_same = false;
1381 struct stat st1;
1382 struct stat st2;
1383
1384 if (os::stat(file1, &st1) < 0) {
1385 return false;
1386 }
1387
1388 if (os::stat(file2, &st2) < 0) {
1389 return false;
1390 }
1391
1392 if (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino) {
1393 // same files
1394 is_same = true;
1395 }
1396 return is_same;
1397 }
1398
1399 // Check minimum allowable stack sizes for thread creation and to initialize
1400 // the java system classes, including StackOverflowError - depends on page
1401 // size.
1402 // The space needed for frames during startup is platform dependent. It
1403 // depends on word size, platform calling conventions, C frame layout and
1404 // interpreter/C1/C2 design decisions. Therefore this is given in a
1405 // platform (os/cpu) dependent constant.
1406 // To this, space for guard mechanisms is added, which depends on the
1407 // page size which again depends on the concrete system the VM is running
1408 // on. Space for libc guard pages is not included in this size.
1409 jint os::Posix::set_minimum_stack_sizes() {
1410 size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
1411
1412 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
1413 JavaThread::stack_guard_zone_size() +
1414 JavaThread::stack_shadow_zone_size();
1415
1416 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
1417 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
1418
1419 size_t stack_size_in_bytes = ThreadStackSize * K;
1420 if (stack_size_in_bytes != 0 &&
1421 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1422 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1423 // ThreadStackSize so we go with "Java thread stack size" instead
1424 // of "ThreadStackSize" to be more friendly.
1425 tty->print_cr("\nThe Java thread stack size specified is too small. "
1426 "Specify at least " SIZE_FORMAT "k",
1427 _java_thread_min_stack_allowed / K);
1428 return JNI_ERR;
1429 }
1430
1431 // Make the stack size a multiple of the page size so that
1432 // the yellow/red zones can be guarded.
1433 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
1434
1435 // Reminder: a compiler thread is a Java thread.
1436 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
1437 JavaThread::stack_guard_zone_size() +
1438 JavaThread::stack_shadow_zone_size();
1439
1440 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
1441 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
1442
1443 stack_size_in_bytes = CompilerThreadStackSize * K;
1444 if (stack_size_in_bytes != 0 &&
1445 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1446 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1447 "Specify at least " SIZE_FORMAT "k",
1448 _compiler_thread_min_stack_allowed / K);
1449 return JNI_ERR;
1450 }
1451
1452 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1453 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
1454
1455 stack_size_in_bytes = VMThreadStackSize * K;
1456 if (stack_size_in_bytes != 0 &&
1457 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1458 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1459 "Specify at least " SIZE_FORMAT "k",
1460 _vm_internal_thread_min_stack_allowed / K);
1461 return JNI_ERR;
1462 }
1463 return JNI_OK;
1464 }
1465
1466 // Called when creating the thread. The minimum stack sizes have already been calculated
1467 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1468 size_t stack_size;
1469 if (req_stack_size == 0) {
1470 stack_size = default_stack_size(thr_type);
1471 } else {
1472 stack_size = req_stack_size;
1473 }
1474
1475 switch (thr_type) {
1476 case os::java_thread:
1477 // Java threads use ThreadStackSize which default value can be
1478 // changed with the flag -Xss
1479 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1480 // no requested size and we have a more specific default value
1481 stack_size = JavaThread::stack_size_at_create();
1482 }
1483 stack_size = MAX2(stack_size,
1484 _java_thread_min_stack_allowed);
1485 break;
1486 case os::compiler_thread:
1487 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1488 // no requested size and we have a more specific default value
1489 stack_size = (size_t)(CompilerThreadStackSize * K);
1490 }
1491 stack_size = MAX2(stack_size,
1492 _compiler_thread_min_stack_allowed);
1493 break;
1494 case os::vm_thread:
1495 case os::pgc_thread:
1496 case os::cgc_thread:
1497 case os::watcher_thread:
1498 default: // presume the unknown thr_type is a VM internal
1499 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1500 // no requested size and we have a more specific default value
1501 stack_size = (size_t)(VMThreadStackSize * K);
1502 }
1503
1504 stack_size = MAX2(stack_size,
1505 _vm_internal_thread_min_stack_allowed);
1506 break;
1507 }
1508
1509 // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
1510 // Be careful not to round up to 0. Align down in that case.
1511 if (stack_size <= SIZE_MAX - vm_page_size()) {
1512 stack_size = align_up(stack_size, vm_page_size());
1513 } else {
1514 stack_size = align_down(stack_size, vm_page_size());
1515 }
1516
1517 return stack_size;
1518 }
1519
1520 bool os::Posix::is_root(uid_t uid){
1521 return ROOT_UID == uid;
1522 }
1523
1524 bool os::Posix::matches_effective_uid_or_root(uid_t uid) {
1525 return is_root(uid) || geteuid() == uid;
1526 }
1527
1528 bool os::Posix::matches_effective_uid_and_gid_or_root(uid_t uid, gid_t gid) {
1529 return is_root(uid) || (geteuid() == uid && getegid() == gid);
1530 }
1531
1532 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
1533 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
1534 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
1535
1536 os::ThreadCrashProtection::ThreadCrashProtection() {
1537 }
1538
1539 /*
1540 * See the caveats for this class in os_posix.hpp
1541 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1542 * method and returns false. If none of the signals are raised, returns true.
1543 * The callback is supposed to provide the method that should be protected.
1544 */
1545 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1546 sigset_t saved_sig_mask;
1547
1548 Thread::muxAcquire(&_crash_mux, "CrashProtection");
1549
1550 _protected_thread = Thread::current_or_null();
1551 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
1552
1553 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1554 // since on at least some systems (OS X) siglongjmp will restore the mask
1555 // for the process, not the thread
1556 pthread_sigmask(0, NULL, &saved_sig_mask);
1557 if (sigsetjmp(_jmpbuf, 0) == 0) {
1558 // make sure we can see in the signal handler that we have crash protection
1559 // installed
1560 _crash_protection = this;
1561 cb.call();
1562 // and clear the crash protection
1563 _crash_protection = NULL;
1564 _protected_thread = NULL;
1565 Thread::muxRelease(&_crash_mux);
1566 return true;
1567 }
1568 // this happens when we siglongjmp() back
1569 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1570 _crash_protection = NULL;
1571 _protected_thread = NULL;
1572 Thread::muxRelease(&_crash_mux);
1573 return false;
1574 }
1575
1576 void os::ThreadCrashProtection::restore() {
1577 assert(_crash_protection != NULL, "must have crash protection");
1578 siglongjmp(_jmpbuf, 1);
1579 }
1580
1581 void os::ThreadCrashProtection::check_crash_protection(int sig,
1582 Thread* thread) {
1583
1584 if (thread != NULL &&
1585 thread == _protected_thread &&
1586 _crash_protection != NULL) {
1587
1588 if (sig == SIGSEGV || sig == SIGBUS) {
1589 _crash_protection->restore();
1590 }
1591 }
1592 }
1593
1594 // Shared clock/time and other supporting routines for pthread_mutex/cond
1595 // initialization. This is enabled on Solaris but only some of the clock/time
1596 // functionality is actually used there.
1597
1598 // Shared condattr object for use with relative timed-waits. Will be associated
1599 // with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
1600 // but otherwise whatever default is used by the platform - generally the
1601 // time-of-day clock.
1602 static pthread_condattr_t _condAttr[1];
1603
1604 // Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
1605 // all systems (e.g. FreeBSD) map the default to "normal".
1606 static pthread_mutexattr_t _mutexAttr[1];
1607
1608 // common basic initialization that is always supported
1609 static void pthread_init_common(void) {
1610 int status;
1611 if ((status = pthread_condattr_init(_condAttr)) != 0) {
1612 fatal("pthread_condattr_init: %s", os::strerror(status));
1613 }
1614 if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
1615 fatal("pthread_mutexattr_init: %s", os::strerror(status));
1616 }
1617 if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
1618 fatal("pthread_mutexattr_settype: %s", os::strerror(status));
1619 }
1620 // Solaris has it's own PlatformMutex, distinct from the one for POSIX.
1621 NOT_SOLARIS(os::PlatformMutex::init();)
1622 }
1623
1624 #ifndef SOLARIS
1625 sigset_t sigs;
1626 struct sigaction sigact[NSIG];
1627
1628 struct sigaction* os::Posix::get_preinstalled_handler(int sig) {
1629 if (sigismember(&sigs, sig)) {
1630 return &sigact[sig];
1631 }
1632 return NULL;
1633 }
1634
1635 void os::Posix::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
1636 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
1637 sigact[sig] = oldAct;
1638 sigaddset(&sigs, sig);
1639 }
1640 #endif
1641
1642 // Not all POSIX types and API's are available on all notionally "posix"
1643 // platforms. If we have build-time support then we will check for actual
1644 // runtime support via dlopen/dlsym lookup. This allows for running on an
1645 // older OS version compared to the build platform. But if there is no
1646 // build time support then there cannot be any runtime support as we do not
1647 // know what the runtime types would be (for example clockid_t might be an
1648 // int or int64_t).
1649 //
1650 #ifdef SUPPORTS_CLOCK_MONOTONIC
1651
1652 // This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
1653
1654 int (*os::Posix::_clock_gettime)(clockid_t, struct timespec *) = NULL;
1655 int (*os::Posix::_clock_getres)(clockid_t, struct timespec *) = NULL;
1656
1657 static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t) = NULL;
1658
1659 static bool _use_clock_monotonic_condattr = false;
1660
1661 // Determine what POSIX API's are present and do appropriate
1662 // configuration.
1663 void os::Posix::init(void) {
1664
1665 // NOTE: no logging available when this is called. Put logging
1666 // statements in init_2().
1667
1668 // 1. Check for CLOCK_MONOTONIC support.
1669
1670 void* handle = NULL;
1671
1672 // For linux we need librt, for other OS we can find
1673 // this function in regular libc.
1674 #ifdef NEEDS_LIBRT
1675 // We do dlopen's in this particular order due to bug in linux
1676 // dynamic loader (see 6348968) leading to crash on exit.
1677 handle = dlopen("librt.so.1", RTLD_LAZY);
1678 if (handle == NULL) {
1679 handle = dlopen("librt.so", RTLD_LAZY);
1680 }
1681 #endif
1682
1683 if (handle == NULL) {
1684 handle = RTLD_DEFAULT;
1685 }
1686
1687 int (*clock_getres_func)(clockid_t, struct timespec*) =
1688 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1689 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1690 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1691 if (clock_getres_func != NULL && clock_gettime_func != NULL) {
1692 // We assume that if both clock_gettime and clock_getres support
1693 // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
1694 struct timespec res;
1695 struct timespec tp;
1696 if (clock_getres_func(CLOCK_MONOTONIC, &res) == 0 &&
1697 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1698 // Yes, monotonic clock is supported.
1699 _clock_gettime = clock_gettime_func;
1700 _clock_getres = clock_getres_func;
1701 } else {
1702 #ifdef NEEDS_LIBRT
1703 // Close librt if there is no monotonic clock.
1704 if (handle != RTLD_DEFAULT) {
1705 dlclose(handle);
1706 }
1707 #endif
1708 }
1709 }
1710
1711 // 2. Check for pthread_condattr_setclock support.
1712
1713 // libpthread is already loaded.
1714 int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
1715 (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
1716 "pthread_condattr_setclock");
1717 if (condattr_setclock_func != NULL) {
1718 _pthread_condattr_setclock = condattr_setclock_func;
1719 }
1720
1721 // Now do general initialization.
1722
1723 pthread_init_common();
1724
1725 #ifndef SOLARIS
1726 int status;
1727 if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
1728 if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
1729 if (status == EINVAL) {
1730 _use_clock_monotonic_condattr = false;
1731 warning("Unable to use monotonic clock with relative timed-waits" \
1732 " - changes to the time-of-day clock may have adverse affects");
1733 } else {
1734 fatal("pthread_condattr_setclock: %s", os::strerror(status));
1735 }
1736 } else {
1737 _use_clock_monotonic_condattr = true;
1738 }
1739 }
1740 #endif // !SOLARIS
1741
1742 }
1743
1744 void os::Posix::init_2(void) {
1745 #ifndef SOLARIS
1746 log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
1747 (_clock_gettime != NULL ? "" : " not"));
1748 log_info(os)("Use of pthread_condattr_setclock is%s supported",
1749 (_pthread_condattr_setclock != NULL ? "" : " not"));
1750 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
1751 _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
1752 sigemptyset(&sigs);
1753 #endif // !SOLARIS
1754 }
1755
1756 #else // !SUPPORTS_CLOCK_MONOTONIC
1757
1758 void os::Posix::init(void) {
1759 pthread_init_common();
1760 }
1761
1762 void os::Posix::init_2(void) {
1763 #ifndef SOLARIS
1764 log_info(os)("Use of CLOCK_MONOTONIC is not supported");
1765 log_info(os)("Use of pthread_condattr_setclock is not supported");
1766 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
1767 sigemptyset(&sigs);
1768 #endif // !SOLARIS
1769 }
1770
1771 #endif // SUPPORTS_CLOCK_MONOTONIC
1772
1773 // Utility to convert the given timeout to an absolute timespec
1774 // (based on the appropriate clock) to use with pthread_cond_timewait,
1775 // and sem_timedwait().
1776 // The clock queried here must be the clock used to manage the
1777 // timeout of the condition variable or semaphore.
1778 //
1779 // The passed in timeout value is either a relative time in nanoseconds
1780 // or an absolute time in milliseconds. A relative timeout will be
1781 // associated with CLOCK_MONOTONIC if available, unless the real-time clock
1782 // is explicitly requested; otherwise, or if absolute,
1783 // the default time-of-day clock will be used.
1784
1785 // Given time is a 64-bit value and the time_t used in the timespec is
1786 // sometimes a signed-32-bit value we have to watch for overflow if times
1787 // way in the future are given. Further on Solaris versions
1788 // prior to 10 there is a restriction (see cond_timedwait) that the specified
1789 // number of seconds, in abstime, is less than current_time + 100000000.
1790 // As it will be over 20 years before "now + 100000000" will overflow we can
1791 // ignore overflow and just impose a hard-limit on seconds using the value
1792 // of "now + 100000000". This places a limit on the timeout of about 3.17
1793 // years from "now".
1794 //
1795 #define MAX_SECS 100000000
1796
1797 // Calculate a new absolute time that is "timeout" nanoseconds from "now".
1798 // "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
1799 // on which clock API is being used).
1800 static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
1801 jlong now_part_sec, jlong unit) {
1802 time_t max_secs = now_sec + MAX_SECS;
1803
1804 jlong seconds = timeout / NANOUNITS;
1805 timeout %= NANOUNITS; // remaining nanos
1806
1807 if (seconds >= MAX_SECS) {
1808 // More seconds than we can add, so pin to max_secs.
1809 abstime->tv_sec = max_secs;
1810 abstime->tv_nsec = 0;
1811 } else {
1812 abstime->tv_sec = now_sec + seconds;
1813 long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
1814 if (nanos >= NANOUNITS) { // overflow
1815 abstime->tv_sec += 1;
1816 nanos -= NANOUNITS;
1817 }
1818 abstime->tv_nsec = nanos;
1819 }
1820 }
1821
1822 // Unpack the given deadline in milliseconds since the epoch, into the given timespec.
1823 // The current time in seconds is also passed in to enforce an upper bound as discussed above.
1824 // This is only used with gettimeofday, when clock_gettime is not available.
1825 static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
1826 time_t max_secs = now_sec + MAX_SECS;
1827
1828 jlong seconds = deadline / MILLIUNITS;
1829 jlong millis = deadline % MILLIUNITS;
1830
1831 if (seconds >= max_secs) {
1832 // Absolute seconds exceeds allowed max, so pin to max_secs.
1833 abstime->tv_sec = max_secs;
1834 abstime->tv_nsec = 0;
1835 } else {
1836 abstime->tv_sec = seconds;
1837 abstime->tv_nsec = millis * (NANOUNITS / MILLIUNITS);
1838 }
1839 }
1840
1841 static jlong millis_to_nanos(jlong millis) {
1842 // We have to watch for overflow when converting millis to nanos,
1843 // but if millis is that large then we will end up limiting to
1844 // MAX_SECS anyway, so just do that here.
1845 if (millis / MILLIUNITS > MAX_SECS) {
1846 millis = jlong(MAX_SECS) * MILLIUNITS;
1847 }
1848 return millis * (NANOUNITS / MILLIUNITS);
1849 }
1850
1851 static void to_abstime(timespec* abstime, jlong timeout,
1852 bool isAbsolute, bool isRealtime) {
1853 DEBUG_ONLY(int max_secs = MAX_SECS;)
1854
1855 if (timeout < 0) {
1856 timeout = 0;
1857 }
1858
1859 #ifdef SUPPORTS_CLOCK_MONOTONIC
1860
1861 clockid_t clock = CLOCK_MONOTONIC;
1862 // need to ensure we have a runtime check for clock_gettime support
1863 if (!isAbsolute && os::Posix::supports_monotonic_clock()) {
1864 if (!_use_clock_monotonic_condattr || isRealtime) {
1865 clock = CLOCK_REALTIME;
1866 }
1867 struct timespec now;
1868 int status = os::Posix::clock_gettime(clock, &now);
1869 assert_status(status == 0, status, "clock_gettime");
1870 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
1871 DEBUG_ONLY(max_secs += now.tv_sec;)
1872 } else {
1873
1874 #else
1875
1876 { // Match the block scope.
1877
1878 #endif // SUPPORTS_CLOCK_MONOTONIC
1879
1880 // Time-of-day clock is all we can reliably use.
1881 struct timeval now;
1882 int status = gettimeofday(&now, NULL);
1883 assert_status(status == 0, errno, "gettimeofday");
1884 if (isAbsolute) {
1885 unpack_abs_time(abstime, timeout, now.tv_sec);
1886 } else {
1887 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
1888 }
1889 DEBUG_ONLY(max_secs += now.tv_sec;)
1890 }
1891
1892 assert(abstime->tv_sec >= 0, "tv_sec < 0");
1893 assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
1894 assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
1895 assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
1896 }
1897
1898 // Create an absolute time 'millis' milliseconds in the future, using the
1899 // real-time (time-of-day) clock. Used by PosixSemaphore.
1900 void os::Posix::to_RTC_abstime(timespec* abstime, int64_t millis) {
1901 to_abstime(abstime, millis_to_nanos(millis),
1902 false /* not absolute */,
1903 true /* use real-time clock */);
1904 }
1905
1906 // Shared pthread_mutex/cond based PlatformEvent implementation.
1907 // Not currently usable by Solaris.
1908
1909 #ifndef SOLARIS
1910
1911 // PlatformEvent
1912 //
1913 // Assumption:
1914 // Only one parker can exist on an event, which is why we allocate
1915 // them per-thread. Multiple unparkers can coexist.
1916 //
1917 // _event serves as a restricted-range semaphore.
1918 // -1 : thread is blocked, i.e. there is a waiter
1919 // 0 : neutral: thread is running or ready,
1920 // could have been signaled after a wait started
1921 // 1 : signaled - thread is running or ready
1922 //
1923 // Having three states allows for some detection of bad usage - see
1924 // comments on unpark().
1925
1926 os::PlatformEvent::PlatformEvent() {
1927 int status = pthread_cond_init(_cond, _condAttr);
1928 assert_status(status == 0, status, "cond_init");
1929 status = pthread_mutex_init(_mutex, _mutexAttr);
1930 assert_status(status == 0, status, "mutex_init");
1931 _event = 0;
1932 _nParked = 0;
1933 }
1934
1935 void os::PlatformEvent::park() { // AKA "down()"
1936 // Transitions for _event:
1937 // -1 => -1 : illegal
1938 // 1 => 0 : pass - return immediately
1939 // 0 => -1 : block; then set _event to 0 before returning
1940
1941 // Invariant: Only the thread associated with the PlatformEvent
1942 // may call park().
1943 assert(_nParked == 0, "invariant");
1944
1945 int v;
1946
1947 // atomically decrement _event
1948 for (;;) {
1949 v = _event;
1950 if (Atomic::cmpxchg(&_event, v, v - 1) == v) break;
1951 }
1952 guarantee(v >= 0, "invariant");
1953
1954 if (v == 0) { // Do this the hard way by blocking ...
1955 int status = pthread_mutex_lock(_mutex);
1956 assert_status(status == 0, status, "mutex_lock");
1957 guarantee(_nParked == 0, "invariant");
1958 ++_nParked;
1959 while (_event < 0) {
1960 // OS-level "spurious wakeups" are ignored
1961 status = pthread_cond_wait(_cond, _mutex);
1962 assert_status(status == 0, status, "cond_wait");
1963 }
1964 --_nParked;
1965
1966 _event = 0;
1967 status = pthread_mutex_unlock(_mutex);
1968 assert_status(status == 0, status, "mutex_unlock");
1969 // Paranoia to ensure our locked and lock-free paths interact
1970 // correctly with each other.
1971 OrderAccess::fence();
1972 }
1973 guarantee(_event >= 0, "invariant");
1974 }
1975
1976 int os::PlatformEvent::park(jlong millis) {
1977 // Transitions for _event:
1978 // -1 => -1 : illegal
1979 // 1 => 0 : pass - return immediately
1980 // 0 => -1 : block; then set _event to 0 before returning
1981
1982 // Invariant: Only the thread associated with the Event/PlatformEvent
1983 // may call park().
1984 assert(_nParked == 0, "invariant");
1985
1986 int v;
1987 // atomically decrement _event
1988 for (;;) {
1989 v = _event;
1990 if (Atomic::cmpxchg(&_event, v, v - 1) == v) break;
1991 }
1992 guarantee(v >= 0, "invariant");
1993
1994 if (v == 0) { // Do this the hard way by blocking ...
1995 struct timespec abst;
1996 to_abstime(&abst, millis_to_nanos(millis), false, false);
1997
1998 int ret = OS_TIMEOUT;
1999 int status = pthread_mutex_lock(_mutex);
2000 assert_status(status == 0, status, "mutex_lock");
2001 guarantee(_nParked == 0, "invariant");
2002 ++_nParked;
2003
2004 while (_event < 0) {
2005 status = pthread_cond_timedwait(_cond, _mutex, &abst);
2006 assert_status(status == 0 || status == ETIMEDOUT,
2007 status, "cond_timedwait");
2008 // OS-level "spurious wakeups" are ignored unless the archaic
2009 // FilterSpuriousWakeups is set false. That flag should be obsoleted.
2010 if (!FilterSpuriousWakeups) break;
2011 if (status == ETIMEDOUT) break;
2012 }
2013 --_nParked;
2014
2015 if (_event >= 0) {
2016 ret = OS_OK;
2017 }
2018
2019 _event = 0;
2020 status = pthread_mutex_unlock(_mutex);
2021 assert_status(status == 0, status, "mutex_unlock");
2022 // Paranoia to ensure our locked and lock-free paths interact
2023 // correctly with each other.
2024 OrderAccess::fence();
2025 return ret;
2026 }
2027 return OS_OK;
2028 }
2029
2030 void os::PlatformEvent::unpark() {
2031 // Transitions for _event:
2032 // 0 => 1 : just return
2033 // 1 => 1 : just return
2034 // -1 => either 0 or 1; must signal target thread
2035 // That is, we can safely transition _event from -1 to either
2036 // 0 or 1.
2037 // See also: "Semaphores in Plan 9" by Mullender & Cox
2038 //
2039 // Note: Forcing a transition from "-1" to "1" on an unpark() means
2040 // that it will take two back-to-back park() calls for the owning
2041 // thread to block. This has the benefit of forcing a spurious return
2042 // from the first park() call after an unpark() call which will help
2043 // shake out uses of park() and unpark() without checking state conditions
2044 // properly. This spurious return doesn't manifest itself in any user code
2045 // but only in the correctly written condition checking loops of ObjectMonitor,
2046 // Mutex/Monitor, Thread::muxAcquire and JavaThread::sleep
2047
2048 if (Atomic::xchg(&_event, 1) >= 0) return;
2049
2050 int status = pthread_mutex_lock(_mutex);
2051 assert_status(status == 0, status, "mutex_lock");
2052 int anyWaiters = _nParked;
2053 assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
2054 status = pthread_mutex_unlock(_mutex);
2055 assert_status(status == 0, status, "mutex_unlock");
2056
2057 // Note that we signal() *after* dropping the lock for "immortal" Events.
2058 // This is safe and avoids a common class of futile wakeups. In rare
2059 // circumstances this can cause a thread to return prematurely from
2060 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2061 // will simply re-test the condition and re-park itself.
2062 // This provides particular benefit if the underlying platform does not
2063 // provide wait morphing.
2064
2065 if (anyWaiters != 0) {
2066 status = pthread_cond_signal(_cond);
2067 assert_status(status == 0, status, "cond_signal");
2068 }
2069 }
2070
2071 // JSR166 support
2072
2073 os::PlatformParker::PlatformParker() {
2074 int status;
2075 status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
2076 assert_status(status == 0, status, "cond_init rel");
2077 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
2078 assert_status(status == 0, status, "cond_init abs");
2079 status = pthread_mutex_init(_mutex, _mutexAttr);
2080 assert_status(status == 0, status, "mutex_init");
2081 _cur_index = -1; // mark as unused
2082 }
2083
2084 // Parker::park decrements count if > 0, else does a condvar wait. Unpark
2085 // sets count to 1 and signals condvar. Only one thread ever waits
2086 // on the condvar. Contention seen when trying to park implies that someone
2087 // is unparking you, so don't wait. And spurious returns are fine, so there
2088 // is no need to track notifications.
2089
2090 void Parker::park(bool isAbsolute, jlong time) {
2091
2092 // Optional fast-path check:
2093 // Return immediately if a permit is available.
2094 // We depend on Atomic::xchg() having full barrier semantics
2095 // since we are doing a lock-free update to _counter.
2096 if (Atomic::xchg(&_counter, 0) > 0) return;
2097
2098 Thread* thread = Thread::current();
2099 assert(thread->is_Java_thread(), "Must be JavaThread");
2100 JavaThread *jt = (JavaThread *)thread;
2101
2102 // Optional optimization -- avoid state transitions if there's
2103 // an interrupt pending.
2104 if (jt->is_interrupted(false)) {
2105 return;
2106 }
2107
2108 // Next, demultiplex/decode time arguments
2109 struct timespec absTime;
2110 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
2111 return;
2112 }
2113 if (time > 0) {
2114 to_abstime(&absTime, time, isAbsolute, false);
2115 }
2116
2117 // Enter safepoint region
2118 // Beware of deadlocks such as 6317397.
2119 // The per-thread Parker:: mutex is a classic leaf-lock.
2120 // In particular a thread must never block on the Threads_lock while
2121 // holding the Parker:: mutex. If safepoints are pending both the
2122 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
2123 ThreadBlockInVM tbivm(jt);
2124
2125 // Can't access interrupt state now that we are _thread_blocked. If we've
2126 // been interrupted since we checked above then _counter will be > 0.
2127
2128 // Don't wait if cannot get lock since interference arises from
2129 // unparking.
2130 if (pthread_mutex_trylock(_mutex) != 0) {
2131 return;
2132 }
2133
2134 int status;
2135 if (_counter > 0) { // no wait needed
2136 _counter = 0;
2137 status = pthread_mutex_unlock(_mutex);
2138 assert_status(status == 0, status, "invariant");
2139 // Paranoia to ensure our locked and lock-free paths interact
2140 // correctly with each other and Java-level accesses.
2141 OrderAccess::fence();
2142 return;
2143 }
2144
2145 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2146 jt->set_suspend_equivalent();
2147 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2148
2149 assert(_cur_index == -1, "invariant");
2150 if (time == 0) {
2151 _cur_index = REL_INDEX; // arbitrary choice when not timed
2152 status = pthread_cond_wait(&_cond[_cur_index], _mutex);
2153 assert_status(status == 0, status, "cond_timedwait");
2154 }
2155 else {
2156 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
2157 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
2158 assert_status(status == 0 || status == ETIMEDOUT,
2159 status, "cond_timedwait");
2160 }
2161 _cur_index = -1;
2162
2163 _counter = 0;
2164 status = pthread_mutex_unlock(_mutex);
2165 assert_status(status == 0, status, "invariant");
2166 // Paranoia to ensure our locked and lock-free paths interact
2167 // correctly with each other and Java-level accesses.
2168 OrderAccess::fence();
2169
2170 // If externally suspended while waiting, re-suspend
2171 if (jt->handle_special_suspend_equivalent_condition()) {
2172 jt->java_suspend_self();
2173 }
2174 }
2175
2176 void Parker::unpark() {
2177 int status = pthread_mutex_lock(_mutex);
2178 assert_status(status == 0, status, "invariant");
2179 const int s = _counter;
2180 _counter = 1;
2181 // must capture correct index before unlocking
2182 int index = _cur_index;
2183 status = pthread_mutex_unlock(_mutex);
2184 assert_status(status == 0, status, "invariant");
2185
2186 // Note that we signal() *after* dropping the lock for "immortal" Events.
2187 // This is safe and avoids a common class of futile wakeups. In rare
2188 // circumstances this can cause a thread to return prematurely from
2189 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2190 // will simply re-test the condition and re-park itself.
2191 // This provides particular benefit if the underlying platform does not
2192 // provide wait morphing.
2193
2194 if (s < 1 && index != -1) {
2195 // thread is definitely parked
2196 status = pthread_cond_signal(&_cond[index]);
2197 assert_status(status == 0, status, "invariant");
2198 }
2199 }
2200
2201 // Platform Mutex/Monitor implementation
2202
2203 #if PLATFORM_MONITOR_IMPL_INDIRECT
2204
2205 os::PlatformMutex::Mutex::Mutex() : _next(NULL) {
2206 int status = pthread_mutex_init(&_mutex, _mutexAttr);
2207 assert_status(status == 0, status, "mutex_init");
2208 }
2209
2210 os::PlatformMutex::Mutex::~Mutex() {
2211 int status = pthread_mutex_destroy(&_mutex);
2212 assert_status(status == 0, status, "mutex_destroy");
2213 }
2214
2215 pthread_mutex_t os::PlatformMutex::_freelist_lock;
2216 os::PlatformMutex::Mutex* os::PlatformMutex::_mutex_freelist = NULL;
2217
2218 void os::PlatformMutex::init() {
2219 int status = pthread_mutex_init(&_freelist_lock, _mutexAttr);
2220 assert_status(status == 0, status, "freelist lock init");
2221 }
2222
2223 struct os::PlatformMutex::WithFreeListLocked : public StackObj {
2224 WithFreeListLocked() {
2225 int status = pthread_mutex_lock(&_freelist_lock);
2226 assert_status(status == 0, status, "freelist lock");
2227 }
2228
2229 ~WithFreeListLocked() {
2230 int status = pthread_mutex_unlock(&_freelist_lock);
2231 assert_status(status == 0, status, "freelist unlock");
2232 }
2233 };
2234
2235 os::PlatformMutex::PlatformMutex() {
2236 {
2237 WithFreeListLocked wfl;
2238 _impl = _mutex_freelist;
2239 if (_impl != NULL) {
2240 _mutex_freelist = _impl->_next;
2241 _impl->_next = NULL;
2242 return;
2243 }
2244 }
2245 _impl = new Mutex();
2246 }
2247
2248 os::PlatformMutex::~PlatformMutex() {
2249 WithFreeListLocked wfl;
2250 assert(_impl->_next == NULL, "invariant");
2251 _impl->_next = _mutex_freelist;
2252 _mutex_freelist = _impl;
2253 }
2254
2255 os::PlatformMonitor::Cond::Cond() : _next(NULL) {
2256 int status = pthread_cond_init(&_cond, _condAttr);
2257 assert_status(status == 0, status, "cond_init");
2258 }
2259
2260 os::PlatformMonitor::Cond::~Cond() {
2261 int status = pthread_cond_destroy(&_cond);
2262 assert_status(status == 0, status, "cond_destroy");
2263 }
2264
2265 os::PlatformMonitor::Cond* os::PlatformMonitor::_cond_freelist = NULL;
2266
2267 os::PlatformMonitor::PlatformMonitor() {
2268 {
2269 WithFreeListLocked wfl;
2270 _impl = _cond_freelist;
2271 if (_impl != NULL) {
2272 _cond_freelist = _impl->_next;
2273 _impl->_next = NULL;
2274 return;
2275 }
2276 }
2277 _impl = new Cond();
2278 }
2279
2280 os::PlatformMonitor::~PlatformMonitor() {
2281 WithFreeListLocked wfl;
2282 assert(_impl->_next == NULL, "invariant");
2283 _impl->_next = _cond_freelist;
2284 _cond_freelist = _impl;
2285 }
2286
2287 #else
2288
2289 os::PlatformMutex::PlatformMutex() {
2290 int status = pthread_mutex_init(&_mutex, _mutexAttr);
2291 assert_status(status == 0, status, "mutex_init");
2292 }
2293
2294 os::PlatformMutex::~PlatformMutex() {
2295 int status = pthread_mutex_destroy(&_mutex);
2296 assert_status(status == 0, status, "mutex_destroy");
2297 }
2298
2299 os::PlatformMonitor::PlatformMonitor() {
2300 int status = pthread_cond_init(&_cond, _condAttr);
2301 assert_status(status == 0, status, "cond_init");
2302 }
2303
2304 os::PlatformMonitor::~PlatformMonitor() {
2305 int status = pthread_cond_destroy(&_cond);
2306 assert_status(status == 0, status, "cond_destroy");
2307 }
2308
2309 #endif // PLATFORM_MONITOR_IMPL_INDIRECT
2310
2311 // Must already be locked
2312 int os::PlatformMonitor::wait(jlong millis) {
2313 assert(millis >= 0, "negative timeout");
2314 if (millis > 0) {
2315 struct timespec abst;
2316 // We have to watch for overflow when converting millis to nanos,
2317 // but if millis is that large then we will end up limiting to
2318 // MAX_SECS anyway, so just do that here.
2319 if (millis / MILLIUNITS > MAX_SECS) {
2320 millis = jlong(MAX_SECS) * MILLIUNITS;
2321 }
2322 to_abstime(&abst, millis * (NANOUNITS / MILLIUNITS), false, false);
2323
2324 int ret = OS_TIMEOUT;
2325 int status = pthread_cond_timedwait(cond(), mutex(), &abst);
2326 assert_status(status == 0 || status == ETIMEDOUT,
2327 status, "cond_timedwait");
2328 if (status == 0) {
2329 ret = OS_OK;
2330 }
2331 return ret;
2332 } else {
2333 int status = pthread_cond_wait(cond(), mutex());
2334 assert_status(status == 0, status, "cond_wait");
2335 return OS_OK;
2336 }
2337 }
2338
2339 #endif // !SOLARIS