1 /*
2 * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "jvm.h"
26 #include "logging/log.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "os_posix.inline.hpp"
29 #include "utilities/globalDefinitions.hpp"
30 #include "runtime/frame.inline.hpp"
31 #include "runtime/interfaceSupport.inline.hpp"
32 #include "services/memTracker.hpp"
33 #include "runtime/atomic.hpp"
34 #include "runtime/orderAccess.hpp"
35 #include "utilities/align.hpp"
36 #include "utilities/events.hpp"
37 #include "utilities/formatBuffer.hpp"
38 #include "utilities/macros.hpp"
39 #include "utilities/vmError.hpp"
40
41 #include <dirent.h>
42 #include <dlfcn.h>
43 #include <grp.h>
44 #include <pwd.h>
45 #include <pthread.h>
46 #include <signal.h>
47 #include <sys/mman.h>
48 #include <sys/resource.h>
49 #include <sys/utsname.h>
50 #include <time.h>
51 #include <unistd.h>
52 #include <utmpx.h>
53
54 // Todo: provide a os::get_max_process_id() or similar. Number of processes
55 // may have been configured, can be read more accurately from proc fs etc.
56 #ifndef MAX_PID
57 #define MAX_PID INT_MAX
58 #endif
59 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
60
61 #define ROOT_UID 0
62
63 #ifndef MAP_ANONYMOUS
64 #define MAP_ANONYMOUS MAP_ANON
65 #endif
66
67 #define check_with_errno(check_type, cond, msg) \
68 do { \
69 int err = errno; \
70 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
71 os::errno_name(err)); \
72 } while (false)
73
74 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
75 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
76
77 // Check core dump limit and report possible place where core can be found
78 void os::check_dump_limit(char* buffer, size_t bufferSize) {
79 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
80 jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
81 VMError::record_coredump_status(buffer, false);
82 return;
83 }
84
85 int n;
86 struct rlimit rlim;
87 bool success;
88
89 char core_path[PATH_MAX];
90 n = get_core_path(core_path, PATH_MAX);
91
92 if (n <= 0) {
93 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
94 success = true;
95 #ifdef LINUX
96 } else if (core_path[0] == '"') { // redirect to user process
97 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
98 success = true;
99 #endif
100 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
101 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
102 success = true;
103 } else {
104 switch(rlim.rlim_cur) {
105 case RLIM_INFINITY:
106 jio_snprintf(buffer, bufferSize, "%s", core_path);
107 success = true;
108 break;
109 case 0:
110 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
111 success = false;
112 break;
113 default:
114 jio_snprintf(buffer, bufferSize, "%s (max size " UINT64_FORMAT " kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", core_path, uint64_t(rlim.rlim_cur) / 1024);
115 success = true;
116 break;
117 }
118 }
119
120 VMError::record_coredump_status(buffer, success);
121 }
122
123 int os::get_native_stack(address* stack, int frames, int toSkip) {
124 int frame_idx = 0;
125 int num_of_frames; // number of frames captured
126 frame fr = os::current_frame();
127 while (fr.pc() && frame_idx < frames) {
128 if (toSkip > 0) {
129 toSkip --;
130 } else {
131 stack[frame_idx ++] = fr.pc();
132 }
133 if (fr.fp() == NULL || fr.cb() != NULL ||
134 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
135
136 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
137 fr = os::get_sender_for_C_frame(&fr);
138 } else {
139 break;
140 }
141 }
142 num_of_frames = frame_idx;
143 for (; frame_idx < frames; frame_idx ++) {
144 stack[frame_idx] = NULL;
145 }
146
147 return num_of_frames;
148 }
149
150
151 bool os::unsetenv(const char* name) {
152 assert(name != NULL, "Null pointer");
153 return (::unsetenv(name) == 0);
154 }
155
156 int os::get_last_error() {
157 return errno;
158 }
159
160 size_t os::lasterror(char *buf, size_t len) {
161 if (errno == 0) return 0;
162
163 const char *s = os::strerror(errno);
164 size_t n = ::strlen(s);
165 if (n >= len) {
166 n = len - 1;
167 }
168 ::strncpy(buf, s, n);
169 buf[n] = '\0';
170 return n;
171 }
172
173 void os::wait_for_keypress_at_exit(void) {
174 // don't do anything on posix platforms
175 return;
176 }
177
178 int os::create_file_for_heap(const char* dir) {
179 int fd;
180
181 #if defined(LINUX) && defined(O_TMPFILE)
182 char* native_dir = os::strdup(dir);
183 if (native_dir == NULL) {
184 vm_exit_during_initialization(err_msg("strdup failed during creation of backing file for heap (%s)", os::strerror(errno)));
185 return -1;
186 }
187 os::native_path(native_dir);
188 fd = os::open(dir, O_TMPFILE | O_RDWR, S_IRUSR | S_IWUSR);
189 os::free(native_dir);
190
191 if (fd == -1)
192 #endif
193 {
194 const char name_template[] = "/jvmheap.XXXXXX";
195
196 size_t fullname_len = strlen(dir) + strlen(name_template);
197 char *fullname = (char*)os::malloc(fullname_len + 1, mtInternal);
198 if (fullname == NULL) {
199 vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
200 return -1;
201 }
202 int n = snprintf(fullname, fullname_len + 1, "%s%s", dir, name_template);
203 assert((size_t)n == fullname_len, "Unexpected number of characters in string");
204
205 os::native_path(fullname);
206
207 // create a new file.
208 fd = mkstemp(fullname);
209
210 if (fd < 0) {
211 warning("Could not create file for heap with template %s", fullname);
212 os::free(fullname);
213 return -1;
214 } else {
215 // delete the name from the filesystem. When 'fd' is closed, the file (and space) will be deleted.
216 int ret = unlink(fullname);
217 assert_with_errno(ret == 0, "unlink returned error");
218 }
219
220 os::free(fullname);
221 }
222
223 return fd;
224 }
225
226 static char* reserve_mmapped_memory(size_t bytes, char* requested_addr) {
227 char * addr;
228 int flags = MAP_PRIVATE NOT_AIX( | MAP_NORESERVE ) | MAP_ANONYMOUS;
229 if (requested_addr != NULL) {
230 assert((uintptr_t)requested_addr % os::vm_page_size() == 0, "Requested address should be aligned to OS page size");
231 flags |= MAP_FIXED;
232 }
233
234 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
235 // touch an uncommitted page. Otherwise, the read/write might
236 // succeed if we have enough swap space to back the physical page.
237 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
238 flags, -1, 0);
239
240 if (addr != MAP_FAILED) {
241 MemTracker::record_virtual_memory_reserve((address)addr, bytes, CALLER_PC);
242 return addr;
243 }
244 return NULL;
245 }
246
247 static int util_posix_fallocate(int fd, off_t offset, off_t len) {
248 #ifdef __APPLE__
249 fstore_t store = { F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, len };
250 // First we try to get a continuous chunk of disk space
251 int ret = fcntl(fd, F_PREALLOCATE, &store);
252 if (ret == -1) {
253 // Maybe we are too fragmented, try to allocate non-continuous range
254 store.fst_flags = F_ALLOCATEALL;
255 ret = fcntl(fd, F_PREALLOCATE, &store);
256 }
257 if(ret != -1) {
258 return ftruncate(fd, len);
259 }
260 return -1;
261 #else
262 return posix_fallocate(fd, offset, len);
263 #endif
264 }
265
266 // Map the given address range to the provided file descriptor.
267 char* os::map_memory_to_file(char* base, size_t size, int fd) {
268 assert(fd != -1, "File descriptor is not valid");
269
270 // allocate space for the file
271 int ret = util_posix_fallocate(fd, 0, (off_t)size);
272 if (ret != 0) {
273 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory. error(%d)", ret));
274 return NULL;
275 }
276
277 int prot = PROT_READ | PROT_WRITE;
278 int flags = MAP_SHARED;
279 if (base != NULL) {
280 flags |= MAP_FIXED;
281 }
282 char* addr = (char*)mmap(base, size, prot, flags, fd, 0);
283
284 if (addr == MAP_FAILED) {
285 warning("Failed mmap to file. (%s)", os::strerror(errno));
286 return NULL;
287 }
288 if (base != NULL && addr != base) {
289 if (!os::release_memory(addr, size)) {
290 warning("Could not release memory on unsuccessful file mapping");
291 }
292 return NULL;
293 }
294 return addr;
295 }
296
297 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
298 assert(fd != -1, "File descriptor is not valid");
299 assert(base != NULL, "Base cannot be NULL");
300
301 return map_memory_to_file(base, size, fd);
302 }
303
304 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
305 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
306 // rather than unmapping and remapping the whole chunk to get requested alignment.
307 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
308 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
309 "Alignment must be a multiple of allocation granularity (page size)");
310 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
311
312 size_t extra_size = size + alignment;
313 assert(extra_size >= size, "overflow, size is too large to allow alignment");
314
315 char* extra_base;
316 if (file_desc != -1) {
317 // For file mapping, we do not call os:reserve_memory(extra_size, NULL, alignment, file_desc) because
318 // we need to deal with shrinking of the file space later when we release extra memory after alignment.
319 // We also cannot called os:reserve_memory() with file_desc set to -1 because on aix we might get SHM memory.
320 // So here to call a helper function while reserve memory for us. After we have a aligned base,
321 // we will replace anonymous mapping with file mapping.
322 extra_base = reserve_mmapped_memory(extra_size, NULL);
323 if (extra_base != NULL) {
324 MemTracker::record_virtual_memory_reserve((address)extra_base, extra_size, CALLER_PC);
325 }
326 } else {
327 extra_base = os::reserve_memory(extra_size, NULL, alignment);
328 }
329
330 if (extra_base == NULL) {
331 return NULL;
332 }
333
334 // Do manual alignment
335 char* aligned_base = align_up(extra_base, alignment);
336
337 // [ | | ]
338 // ^ extra_base
339 // ^ extra_base + begin_offset == aligned_base
340 // extra_base + begin_offset + size ^
341 // extra_base + extra_size ^
342 // |<>| == begin_offset
343 // end_offset == |<>|
344 size_t begin_offset = aligned_base - extra_base;
345 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
346
347 if (begin_offset > 0) {
348 os::release_memory(extra_base, begin_offset);
349 }
350
351 if (end_offset > 0) {
352 os::release_memory(extra_base + begin_offset + size, end_offset);
353 }
354
355 if (file_desc != -1) {
356 // After we have an aligned address, we can replace anonymous mapping with file mapping
357 if (replace_existing_mapping_with_file_mapping(aligned_base, size, file_desc) == NULL) {
358 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
359 }
360 MemTracker::record_virtual_memory_commit((address)aligned_base, size, CALLER_PC);
361 }
362 return aligned_base;
363 }
364
365 // On Posix platforms, reservations are done using mmap which can be released in parts. So splitting is a no-op.
366 void os::split_reserved_memory(char *base, size_t size, size_t split) {
367 char* const split_address = base + split;
368 assert(size > 0, "Sanity");
369 assert(size > split, "Sanity");
370 assert(split > 0, "Sanity");
371 assert(is_aligned(base, os::vm_allocation_granularity()), "Sanity");
372 assert(is_aligned(split_address, os::vm_allocation_granularity()), "Sanity");
373 }
374
375 int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
376 // All supported POSIX platforms provide C99 semantics.
377 int result = ::vsnprintf(buf, len, fmt, args);
378 // If an encoding error occurred (result < 0) then it's not clear
379 // whether the buffer is NUL terminated, so ensure it is.
380 if ((result < 0) && (len > 0)) {
381 buf[len - 1] = '\0';
382 }
383 return result;
384 }
385
386 int os::get_fileno(FILE* fp) {
387 return NOT_AIX(::)fileno(fp);
388 }
389
390 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
391 return gmtime_r(clock, res);
392 }
393
394 void os::Posix::print_load_average(outputStream* st) {
395 st->print("load average:");
396 double loadavg[3];
397 int res = os::loadavg(loadavg, 3);
398 if (res != -1) {
399 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
400 } else {
401 st->print(" Unavailable");
402 }
403 st->cr();
404 }
405
406 // boot/uptime information;
407 // unfortunately it does not work on macOS and Linux because the utx chain has no entry
408 // for reboot at least on my test machines
409 void os::Posix::print_uptime_info(outputStream* st) {
410 int bootsec = -1;
411 int currsec = time(NULL);
412 struct utmpx* ent;
413 setutxent();
414 while ((ent = getutxent())) {
415 if (!strcmp("system boot", ent->ut_line)) {
416 bootsec = ent->ut_tv.tv_sec;
417 break;
418 }
419 }
420
421 if (bootsec != -1) {
422 os::print_dhm(st, "OS uptime:", (long) (currsec-bootsec));
423 }
424 }
425
426 static void print_rlimit(outputStream* st, const char* msg,
427 int resource, bool output_k = false) {
428 struct rlimit rlim;
429
430 st->print(" %s ", msg);
431 int res = getrlimit(resource, &rlim);
432 if (res == -1) {
433 st->print("could not obtain value");
434 } else {
435 // soft limit
436 if (rlim.rlim_cur == RLIM_INFINITY) { st->print("infinity"); }
437 else {
438 if (output_k) { st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_cur) / 1024); }
439 else { st->print(UINT64_FORMAT, uint64_t(rlim.rlim_cur)); }
440 }
441 // hard limit
442 st->print("/");
443 if (rlim.rlim_max == RLIM_INFINITY) { st->print("infinity"); }
444 else {
445 if (output_k) { st->print(UINT64_FORMAT "k", uint64_t(rlim.rlim_max) / 1024); }
446 else { st->print(UINT64_FORMAT, uint64_t(rlim.rlim_max)); }
447 }
448 }
449 }
450
451 void os::Posix::print_rlimit_info(outputStream* st) {
452 st->print("rlimit (soft/hard):");
453 print_rlimit(st, "STACK", RLIMIT_STACK, true);
454 print_rlimit(st, ", CORE", RLIMIT_CORE, true);
455
456 #if defined(AIX)
457 st->print(", NPROC ");
458 st->print("%d", sysconf(_SC_CHILD_MAX));
459
460 print_rlimit(st, ", THREADS", RLIMIT_THREADS);
461 #elif !defined(SOLARIS)
462 print_rlimit(st, ", NPROC", RLIMIT_NPROC);
463 #endif
464
465 print_rlimit(st, ", NOFILE", RLIMIT_NOFILE);
466 print_rlimit(st, ", AS", RLIMIT_AS, true);
467 print_rlimit(st, ", CPU", RLIMIT_CPU);
468 print_rlimit(st, ", DATA", RLIMIT_DATA, true);
469
470 // maximum size of files that the process may create
471 print_rlimit(st, ", FSIZE", RLIMIT_FSIZE, true);
472
473 #if defined(LINUX) || defined(__APPLE__)
474 // maximum number of bytes of memory that may be locked into RAM
475 // (rounded down to the nearest multiple of system pagesize)
476 print_rlimit(st, ", MEMLOCK", RLIMIT_MEMLOCK, true);
477 #endif
478
479 #if defined(SOLARIS)
480 // maximum size of mapped address space of a process in bytes;
481 // if the limit is exceeded, mmap and brk fail
482 print_rlimit(st, ", VMEM", RLIMIT_VMEM, true);
483 #endif
484
485 // MacOS; The maximum size (in bytes) to which a process's resident set size may grow.
486 #if defined(__APPLE__)
487 print_rlimit(st, ", RSS", RLIMIT_RSS, true);
488 #endif
489
490 st->cr();
491 }
492
493 void os::Posix::print_uname_info(outputStream* st) {
494 // kernel
495 st->print("uname:");
496 struct utsname name;
497 uname(&name);
498 st->print("%s ", name.sysname);
499 #ifdef ASSERT
500 st->print("%s ", name.nodename);
501 #endif
502 st->print("%s ", name.release);
503 st->print("%s ", name.version);
504 st->print("%s", name.machine);
505 st->cr();
506 }
507
508 void os::Posix::print_umask(outputStream* st, mode_t umsk) {
509 st->print((umsk & S_IRUSR) ? "r" : "-");
510 st->print((umsk & S_IWUSR) ? "w" : "-");
511 st->print((umsk & S_IXUSR) ? "x" : "-");
512 st->print((umsk & S_IRGRP) ? "r" : "-");
513 st->print((umsk & S_IWGRP) ? "w" : "-");
514 st->print((umsk & S_IXGRP) ? "x" : "-");
515 st->print((umsk & S_IROTH) ? "r" : "-");
516 st->print((umsk & S_IWOTH) ? "w" : "-");
517 st->print((umsk & S_IXOTH) ? "x" : "-");
518 }
519
520 void os::Posix::print_user_info(outputStream* st) {
521 unsigned id = (unsigned) ::getuid();
522 st->print("uid : %u ", id);
523 id = (unsigned) ::geteuid();
524 st->print("euid : %u ", id);
525 id = (unsigned) ::getgid();
526 st->print("gid : %u ", id);
527 id = (unsigned) ::getegid();
528 st->print_cr("egid : %u", id);
529 st->cr();
530
531 mode_t umsk = ::umask(0);
532 ::umask(umsk);
533 st->print("umask: %04o (", (unsigned) umsk);
534 print_umask(st, umsk);
535 st->print_cr(")");
536 st->cr();
537 }
538
539
540 bool os::get_host_name(char* buf, size_t buflen) {
541 struct utsname name;
542 uname(&name);
543 jio_snprintf(buf, buflen, "%s", name.nodename);
544 return true;
545 }
546
547 bool os::has_allocatable_memory_limit(julong* limit) {
548 struct rlimit rlim;
549 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
550 // if there was an error when calling getrlimit, assume that there is no limitation
551 // on virtual memory.
552 bool result;
553 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
554 result = false;
555 } else {
556 *limit = (julong)rlim.rlim_cur;
557 result = true;
558 }
559 #ifdef _LP64
560 return result;
561 #else
562 // arbitrary virtual space limit for 32 bit Unices found by testing. If
563 // getrlimit above returned a limit, bound it with this limit. Otherwise
564 // directly use it.
565 const julong max_virtual_limit = (julong)3800*M;
566 if (result) {
567 *limit = MIN2(*limit, max_virtual_limit);
568 } else {
569 *limit = max_virtual_limit;
570 }
571
572 // bound by actually allocatable memory. The algorithm uses two bounds, an
573 // upper and a lower limit. The upper limit is the current highest amount of
574 // memory that could not be allocated, the lower limit is the current highest
575 // amount of memory that could be allocated.
576 // The algorithm iteratively refines the result by halving the difference
577 // between these limits, updating either the upper limit (if that value could
578 // not be allocated) or the lower limit (if the that value could be allocated)
579 // until the difference between these limits is "small".
580
581 // the minimum amount of memory we care about allocating.
582 const julong min_allocation_size = M;
583
584 julong upper_limit = *limit;
585
586 // first check a few trivial cases
587 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
588 *limit = upper_limit;
589 } else if (!is_allocatable(min_allocation_size)) {
590 // we found that not even min_allocation_size is allocatable. Return it
591 // anyway. There is no point to search for a better value any more.
592 *limit = min_allocation_size;
593 } else {
594 // perform the binary search.
595 julong lower_limit = min_allocation_size;
596 while ((upper_limit - lower_limit) > min_allocation_size) {
597 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
598 temp_limit = align_down(temp_limit, min_allocation_size);
599 if (is_allocatable(temp_limit)) {
600 lower_limit = temp_limit;
601 } else {
602 upper_limit = temp_limit;
603 }
604 }
605 *limit = lower_limit;
606 }
607 return true;
608 #endif
609 }
610
611 const char* os::get_current_directory(char *buf, size_t buflen) {
612 return getcwd(buf, buflen);
613 }
614
615 FILE* os::open(int fd, const char* mode) {
616 return ::fdopen(fd, mode);
617 }
618
619 ssize_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
620 return ::pread(fd, buf, nBytes, offset);
621 }
622
623 void os::flockfile(FILE* fp) {
624 ::flockfile(fp);
625 }
626
627 void os::funlockfile(FILE* fp) {
628 ::funlockfile(fp);
629 }
630
631 DIR* os::opendir(const char* dirname) {
632 assert(dirname != NULL, "just checking");
633 return ::opendir(dirname);
634 }
635
636 struct dirent* os::readdir(DIR* dirp) {
637 assert(dirp != NULL, "just checking");
638 return ::readdir(dirp);
639 }
640
641 int os::closedir(DIR *dirp) {
642 assert(dirp != NULL, "just checking");
643 return ::closedir(dirp);
644 }
645
646 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
647 // which is used to find statically linked in agents.
648 // Parameters:
649 // sym_name: Symbol in library we are looking for
650 // lib_name: Name of library to look in, NULL for shared libs.
651 // is_absolute_path == true if lib_name is absolute path to agent
652 // such as "/a/b/libL.so"
653 // == false if only the base name of the library is passed in
654 // such as "L"
655 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
656 bool is_absolute_path) {
657 char *agent_entry_name;
658 size_t len;
659 size_t name_len;
660 size_t prefix_len = strlen(JNI_LIB_PREFIX);
661 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
662 const char *start;
663
664 if (lib_name != NULL) {
665 name_len = strlen(lib_name);
666 if (is_absolute_path) {
667 // Need to strip path, prefix and suffix
668 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
669 lib_name = ++start;
670 }
671 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
672 return NULL;
673 }
674 lib_name += prefix_len;
675 name_len = strlen(lib_name) - suffix_len;
676 }
677 }
678 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
679 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
680 if (agent_entry_name == NULL) {
681 return NULL;
682 }
683 strcpy(agent_entry_name, sym_name);
684 if (lib_name != NULL) {
685 strcat(agent_entry_name, "_");
686 strncat(agent_entry_name, lib_name, name_len);
687 }
688 return agent_entry_name;
689 }
690
691
692 void os::naked_short_nanosleep(jlong ns) {
693 struct timespec req;
694 assert(ns > -1 && ns < NANOUNITS, "Un-interruptable sleep, short time use only");
695 req.tv_sec = 0;
696 req.tv_nsec = ns;
697 ::nanosleep(&req, NULL);
698 return;
699 }
700
701 void os::naked_short_sleep(jlong ms) {
702 assert(ms < MILLIUNITS, "Un-interruptable sleep, short time use only");
703 os::naked_short_nanosleep(millis_to_nanos(ms));
704 return;
705 }
706
707 static const struct {
708 int sig; const char* name;
709 }
710 g_signal_info[] =
711 {
712 { SIGABRT, "SIGABRT" },
713 #ifdef SIGAIO
714 { SIGAIO, "SIGAIO" },
715 #endif
716 { SIGALRM, "SIGALRM" },
717 #ifdef SIGALRM1
718 { SIGALRM1, "SIGALRM1" },
719 #endif
720 { SIGBUS, "SIGBUS" },
721 #ifdef SIGCANCEL
722 { SIGCANCEL, "SIGCANCEL" },
723 #endif
724 { SIGCHLD, "SIGCHLD" },
725 #ifdef SIGCLD
726 { SIGCLD, "SIGCLD" },
727 #endif
728 { SIGCONT, "SIGCONT" },
729 #ifdef SIGCPUFAIL
730 { SIGCPUFAIL, "SIGCPUFAIL" },
731 #endif
732 #ifdef SIGDANGER
733 { SIGDANGER, "SIGDANGER" },
734 #endif
735 #ifdef SIGDIL
736 { SIGDIL, "SIGDIL" },
737 #endif
738 #ifdef SIGEMT
739 { SIGEMT, "SIGEMT" },
740 #endif
741 { SIGFPE, "SIGFPE" },
742 #ifdef SIGFREEZE
743 { SIGFREEZE, "SIGFREEZE" },
744 #endif
745 #ifdef SIGGFAULT
746 { SIGGFAULT, "SIGGFAULT" },
747 #endif
748 #ifdef SIGGRANT
749 { SIGGRANT, "SIGGRANT" },
750 #endif
751 { SIGHUP, "SIGHUP" },
752 { SIGILL, "SIGILL" },
753 #ifdef SIGINFO
754 { SIGINFO, "SIGINFO" },
755 #endif
756 { SIGINT, "SIGINT" },
757 #ifdef SIGIO
758 { SIGIO, "SIGIO" },
759 #endif
760 #ifdef SIGIOINT
761 { SIGIOINT, "SIGIOINT" },
762 #endif
763 #ifdef SIGIOT
764 // SIGIOT is there for BSD compatibility, but on most Unices just a
765 // synonym for SIGABRT. The result should be "SIGABRT", not
766 // "SIGIOT".
767 #if (SIGIOT != SIGABRT )
768 { SIGIOT, "SIGIOT" },
769 #endif
770 #endif
771 #ifdef SIGKAP
772 { SIGKAP, "SIGKAP" },
773 #endif
774 { SIGKILL, "SIGKILL" },
775 #ifdef SIGLOST
776 { SIGLOST, "SIGLOST" },
777 #endif
778 #ifdef SIGLWP
779 { SIGLWP, "SIGLWP" },
780 #endif
781 #ifdef SIGLWPTIMER
782 { SIGLWPTIMER, "SIGLWPTIMER" },
783 #endif
784 #ifdef SIGMIGRATE
785 { SIGMIGRATE, "SIGMIGRATE" },
786 #endif
787 #ifdef SIGMSG
788 { SIGMSG, "SIGMSG" },
789 #endif
790 { SIGPIPE, "SIGPIPE" },
791 #ifdef SIGPOLL
792 { SIGPOLL, "SIGPOLL" },
793 #endif
794 #ifdef SIGPRE
795 { SIGPRE, "SIGPRE" },
796 #endif
797 { SIGPROF, "SIGPROF" },
798 #ifdef SIGPTY
799 { SIGPTY, "SIGPTY" },
800 #endif
801 #ifdef SIGPWR
802 { SIGPWR, "SIGPWR" },
803 #endif
804 { SIGQUIT, "SIGQUIT" },
805 #ifdef SIGRECONFIG
806 { SIGRECONFIG, "SIGRECONFIG" },
807 #endif
808 #ifdef SIGRECOVERY
809 { SIGRECOVERY, "SIGRECOVERY" },
810 #endif
811 #ifdef SIGRESERVE
812 { SIGRESERVE, "SIGRESERVE" },
813 #endif
814 #ifdef SIGRETRACT
815 { SIGRETRACT, "SIGRETRACT" },
816 #endif
817 #ifdef SIGSAK
818 { SIGSAK, "SIGSAK" },
819 #endif
820 { SIGSEGV, "SIGSEGV" },
821 #ifdef SIGSOUND
822 { SIGSOUND, "SIGSOUND" },
823 #endif
824 #ifdef SIGSTKFLT
825 { SIGSTKFLT, "SIGSTKFLT" },
826 #endif
827 { SIGSTOP, "SIGSTOP" },
828 { SIGSYS, "SIGSYS" },
829 #ifdef SIGSYSERROR
830 { SIGSYSERROR, "SIGSYSERROR" },
831 #endif
832 #ifdef SIGTALRM
833 { SIGTALRM, "SIGTALRM" },
834 #endif
835 { SIGTERM, "SIGTERM" },
836 #ifdef SIGTHAW
837 { SIGTHAW, "SIGTHAW" },
838 #endif
839 { SIGTRAP, "SIGTRAP" },
840 #ifdef SIGTSTP
841 { SIGTSTP, "SIGTSTP" },
842 #endif
843 { SIGTTIN, "SIGTTIN" },
844 { SIGTTOU, "SIGTTOU" },
845 #ifdef SIGURG
846 { SIGURG, "SIGURG" },
847 #endif
848 { SIGUSR1, "SIGUSR1" },
849 { SIGUSR2, "SIGUSR2" },
850 #ifdef SIGVIRT
851 { SIGVIRT, "SIGVIRT" },
852 #endif
853 { SIGVTALRM, "SIGVTALRM" },
854 #ifdef SIGWAITING
855 { SIGWAITING, "SIGWAITING" },
856 #endif
857 #ifdef SIGWINCH
858 { SIGWINCH, "SIGWINCH" },
859 #endif
860 #ifdef SIGWINDOW
861 { SIGWINDOW, "SIGWINDOW" },
862 #endif
863 { SIGXCPU, "SIGXCPU" },
864 { SIGXFSZ, "SIGXFSZ" },
865 #ifdef SIGXRES
866 { SIGXRES, "SIGXRES" },
867 #endif
868 { -1, NULL }
869 };
870
871 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
872 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
873
874 const char* ret = NULL;
875
876 #ifdef SIGRTMIN
877 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
878 if (sig == SIGRTMIN) {
879 ret = "SIGRTMIN";
880 } else if (sig == SIGRTMAX) {
881 ret = "SIGRTMAX";
882 } else {
883 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
884 return out;
885 }
886 }
887 #endif
888
889 if (sig > 0) {
890 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
891 if (g_signal_info[idx].sig == sig) {
892 ret = g_signal_info[idx].name;
893 break;
894 }
895 }
896 }
897
898 if (!ret) {
899 if (!is_valid_signal(sig)) {
900 ret = "INVALID";
901 } else {
902 ret = "UNKNOWN";
903 }
904 }
905
906 if (out && outlen > 0) {
907 strncpy(out, ret, outlen);
908 out[outlen - 1] = '\0';
909 }
910 return out;
911 }
912
913 int os::Posix::get_signal_number(const char* signal_name) {
914 char tmp[30];
915 const char* s = signal_name;
916 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
917 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
918 s = tmp;
919 }
920 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
921 if (strcmp(g_signal_info[idx].name, s) == 0) {
922 return g_signal_info[idx].sig;
923 }
924 }
925 return -1;
926 }
927
928 int os::get_signal_number(const char* signal_name) {
929 return os::Posix::get_signal_number(signal_name);
930 }
931
932 // Returns true if signal number is valid.
933 bool os::Posix::is_valid_signal(int sig) {
934 // MacOS not really POSIX compliant: sigaddset does not return
935 // an error for invalid signal numbers. However, MacOS does not
936 // support real time signals and simply seems to have just 33
937 // signals with no holes in the signal range.
938 #ifdef __APPLE__
939 return sig >= 1 && sig < NSIG;
940 #else
941 // Use sigaddset to check for signal validity.
942 sigset_t set;
943 sigemptyset(&set);
944 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
945 return false;
946 }
947 return true;
948 #endif
949 }
950
951 bool os::Posix::is_sig_ignored(int sig) {
952 struct sigaction oact;
953 sigaction(sig, (struct sigaction*)NULL, &oact);
954 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
955 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
956 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
957 return true;
958 } else {
959 return false;
960 }
961 }
962
963 // Returns:
964 // NULL for an invalid signal number
965 // "SIG<num>" for a valid but unknown signal number
966 // signal name otherwise.
967 const char* os::exception_name(int sig, char* buf, size_t size) {
968 if (!os::Posix::is_valid_signal(sig)) {
969 return NULL;
970 }
971 const char* const name = os::Posix::get_signal_name(sig, buf, size);
972 if (strcmp(name, "UNKNOWN") == 0) {
973 jio_snprintf(buf, size, "SIG%d", sig);
974 }
975 return buf;
976 }
977
978 #define NUM_IMPORTANT_SIGS 32
979 // Returns one-line short description of a signal set in a user provided buffer.
980 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
981 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
982 // Note: for shortness, just print out the first 32. That should
983 // cover most of the useful ones, apart from realtime signals.
984 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
985 const int rc = sigismember(set, sig);
986 if (rc == -1 && errno == EINVAL) {
987 buffer[sig-1] = '?';
988 } else {
989 buffer[sig-1] = rc == 0 ? '0' : '1';
990 }
991 }
992 buffer[NUM_IMPORTANT_SIGS] = 0;
993 return buffer;
994 }
995
996 // Prints one-line description of a signal set.
997 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
998 char buf[NUM_IMPORTANT_SIGS + 1];
999 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
1000 st->print("%s", buf);
1001 }
1002
1003 // Writes one-line description of a combination of sigaction.sa_flags into a user
1004 // provided buffer. Returns that buffer.
1005 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
1006 char* p = buffer;
1007 size_t remaining = size;
1008 bool first = true;
1009 int idx = 0;
1010
1011 assert(buffer, "invalid argument");
1012
1013 if (size == 0) {
1014 return buffer;
1015 }
1016
1017 strncpy(buffer, "none", size);
1018
1019 const struct {
1020 // NB: i is an unsigned int here because SA_RESETHAND is on some
1021 // systems 0x80000000, which is implicitly unsigned. Assignining
1022 // it to an int field would be an overflow in unsigned-to-signed
1023 // conversion.
1024 unsigned int i;
1025 const char* s;
1026 } flaginfo [] = {
1027 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
1028 { SA_ONSTACK, "SA_ONSTACK" },
1029 { SA_RESETHAND, "SA_RESETHAND" },
1030 { SA_RESTART, "SA_RESTART" },
1031 { SA_SIGINFO, "SA_SIGINFO" },
1032 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
1033 { SA_NODEFER, "SA_NODEFER" },
1034 #ifdef AIX
1035 { SA_ONSTACK, "SA_ONSTACK" },
1036 { SA_OLDSTYLE, "SA_OLDSTYLE" },
1037 #endif
1038 { 0, NULL }
1039 };
1040
1041 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
1042 if (flags & flaginfo[idx].i) {
1043 if (first) {
1044 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
1045 first = false;
1046 } else {
1047 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
1048 }
1049 const size_t len = strlen(p);
1050 p += len;
1051 remaining -= len;
1052 }
1053 }
1054
1055 buffer[size - 1] = '\0';
1056
1057 return buffer;
1058 }
1059
1060 // Prints one-line description of a combination of sigaction.sa_flags.
1061 void os::Posix::print_sa_flags(outputStream* st, int flags) {
1062 char buffer[0x100];
1063 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
1064 st->print("%s", buffer);
1065 }
1066
1067 // Helper function for os::Posix::print_siginfo_...():
1068 // return a textual description for signal code.
1069 struct enum_sigcode_desc_t {
1070 const char* s_name;
1071 const char* s_desc;
1072 };
1073
1074 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
1075
1076 const struct {
1077 int sig; int code; const char* s_code; const char* s_desc;
1078 } t1 [] = {
1079 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
1080 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
1081 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
1082 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
1083 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
1084 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
1085 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
1086 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
1087 #if defined(IA64) && defined(LINUX)
1088 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
1089 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
1090 #endif
1091 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
1092 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
1093 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
1094 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
1095 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
1096 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
1097 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
1098 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
1099 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
1100 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
1101 #ifdef AIX
1102 // no explanation found what keyerr would be
1103 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
1104 #endif
1105 #if defined(IA64) && !defined(AIX)
1106 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
1107 #endif
1108 #if defined(__sparc) && defined(SOLARIS)
1109 // define Solaris Sparc M7 ADI SEGV signals
1110 #if !defined(SEGV_ACCADI)
1111 #define SEGV_ACCADI 3
1112 #endif
1113 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
1114 #if !defined(SEGV_ACCDERR)
1115 #define SEGV_ACCDERR 4
1116 #endif
1117 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
1118 #if !defined(SEGV_ACCPERR)
1119 #define SEGV_ACCPERR 5
1120 #endif
1121 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
1122 #endif // defined(__sparc) && defined(SOLARIS)
1123 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
1124 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
1125 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
1126 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
1127 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
1128 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
1129 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
1130 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
1131 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
1132 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
1133 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
1134 #ifdef SIGPOLL
1135 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
1136 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
1137 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
1138 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
1139 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
1140 #endif
1141 { -1, -1, NULL, NULL }
1142 };
1143
1144 // Codes valid in any signal context.
1145 const struct {
1146 int code; const char* s_code; const char* s_desc;
1147 } t2 [] = {
1148 { SI_USER, "SI_USER", "Signal sent by kill()." },
1149 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
1150 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
1151 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
1152 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
1153 // Linux specific
1154 #ifdef SI_TKILL
1155 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
1156 #endif
1157 #ifdef SI_DETHREAD
1158 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
1159 #endif
1160 #ifdef SI_KERNEL
1161 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
1162 #endif
1163 #ifdef SI_SIGIO
1164 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
1165 #endif
1166
1167 #ifdef AIX
1168 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
1169 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
1170 #endif
1171
1172 #ifdef __sun
1173 { SI_NOINFO, "SI_NOINFO", "No signal information" },
1174 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
1175 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
1176 #endif
1177
1178 { -1, NULL, NULL }
1179 };
1180
1181 const char* s_code = NULL;
1182 const char* s_desc = NULL;
1183
1184 for (int i = 0; t1[i].sig != -1; i ++) {
1185 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
1186 s_code = t1[i].s_code;
1187 s_desc = t1[i].s_desc;
1188 break;
1189 }
1190 }
1191
1192 if (s_code == NULL) {
1193 for (int i = 0; t2[i].s_code != NULL; i ++) {
1194 if (t2[i].code == si->si_code) {
1195 s_code = t2[i].s_code;
1196 s_desc = t2[i].s_desc;
1197 }
1198 }
1199 }
1200
1201 if (s_code == NULL) {
1202 out->s_name = "unknown";
1203 out->s_desc = "unknown";
1204 return false;
1205 }
1206
1207 out->s_name = s_code;
1208 out->s_desc = s_desc;
1209
1210 return true;
1211 }
1212
1213 bool os::signal_sent_by_kill(const void* siginfo) {
1214 const siginfo_t* const si = (const siginfo_t*)siginfo;
1215 return si->si_code == SI_USER || si->si_code == SI_QUEUE
1216 #ifdef SI_TKILL
1217 || si->si_code == SI_TKILL
1218 #endif
1219 ;
1220 }
1221
1222 void os::print_siginfo(outputStream* os, const void* si0) {
1223
1224 const siginfo_t* const si = (const siginfo_t*) si0;
1225
1226 char buf[20];
1227 os->print("siginfo:");
1228
1229 if (!si) {
1230 os->print(" <null>");
1231 return;
1232 }
1233
1234 const int sig = si->si_signo;
1235
1236 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1237
1238 enum_sigcode_desc_t ed;
1239 get_signal_code_description(si, &ed);
1240 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1241
1242 if (si->si_errno) {
1243 os->print(", si_errno: %d", si->si_errno);
1244 }
1245
1246 // Output additional information depending on the signal code.
1247
1248 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1249 // so it depends on the context which member to use. For synchronous error signals,
1250 // we print si_addr, unless the signal was sent by another process or thread, in
1251 // which case we print out pid or tid of the sender.
1252 if (signal_sent_by_kill(si)) {
1253 const pid_t pid = si->si_pid;
1254 os->print(", si_pid: %ld", (long) pid);
1255 if (IS_VALID_PID(pid)) {
1256 const pid_t me = getpid();
1257 if (me == pid) {
1258 os->print(" (current process)");
1259 }
1260 } else {
1261 os->print(" (invalid)");
1262 }
1263 os->print(", si_uid: %ld", (long) si->si_uid);
1264 if (sig == SIGCHLD) {
1265 os->print(", si_status: %d", si->si_status);
1266 }
1267 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1268 sig == SIGTRAP || sig == SIGFPE) {
1269 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1270 #ifdef SIGPOLL
1271 } else if (sig == SIGPOLL) {
1272 os->print(", si_band: %ld", si->si_band);
1273 #endif
1274 }
1275
1276 }
1277
1278 bool os::signal_thread(Thread* thread, int sig, const char* reason) {
1279 OSThread* osthread = thread->osthread();
1280 if (osthread) {
1281 #if defined (SOLARIS)
1282 // Note: we cannot use pthread_kill on Solaris - not because
1283 // its missing, but because we do not have the pthread_t id.
1284 int status = thr_kill(osthread->thread_id(), sig);
1285 #else
1286 int status = pthread_kill(osthread->pthread_id(), sig);
1287 #endif
1288 if (status == 0) {
1289 Events::log(Thread::current(), "sent signal %d to Thread " INTPTR_FORMAT " because %s.",
1290 sig, p2i(thread), reason);
1291 return true;
1292 }
1293 }
1294 return false;
1295 }
1296
1297 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1298 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1299 }
1300
1301 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1302 #if defined(AIX)
1303 return Aix::ucontext_get_pc(ctx);
1304 #elif defined(BSD)
1305 return Bsd::ucontext_get_pc(ctx);
1306 #elif defined(LINUX)
1307 return Linux::ucontext_get_pc(ctx);
1308 #elif defined(SOLARIS)
1309 return Solaris::ucontext_get_pc(ctx);
1310 #else
1311 VMError::report_and_die("unimplemented ucontext_get_pc");
1312 #endif
1313 }
1314
1315 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1316 #if defined(AIX)
1317 Aix::ucontext_set_pc(ctx, pc);
1318 #elif defined(BSD)
1319 Bsd::ucontext_set_pc(ctx, pc);
1320 #elif defined(LINUX)
1321 Linux::ucontext_set_pc(ctx, pc);
1322 #elif defined(SOLARIS)
1323 Solaris::ucontext_set_pc(ctx, pc);
1324 #else
1325 VMError::report_and_die("unimplemented ucontext_get_pc");
1326 #endif
1327 }
1328
1329 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1330 size_t stack_size = 0;
1331 size_t guard_size = 0;
1332 int detachstate = 0;
1333 pthread_attr_getstacksize(attr, &stack_size);
1334 pthread_attr_getguardsize(attr, &guard_size);
1335 // Work around linux NPTL implementation error, see also os::create_thread() in os_linux.cpp.
1336 LINUX_ONLY(stack_size -= guard_size);
1337 pthread_attr_getdetachstate(attr, &detachstate);
1338 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1339 stack_size / 1024, guard_size / 1024,
1340 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1341 return buf;
1342 }
1343
1344 char* os::Posix::realpath(const char* filename, char* outbuf, size_t outbuflen) {
1345
1346 if (filename == NULL || outbuf == NULL || outbuflen < 1) {
1347 assert(false, "os::Posix::realpath: invalid arguments.");
1348 errno = EINVAL;
1349 return NULL;
1350 }
1351
1352 char* result = NULL;
1353
1354 // This assumes platform realpath() is implemented according to POSIX.1-2008.
1355 // POSIX.1-2008 allows to specify NULL for the output buffer, in which case
1356 // output buffer is dynamically allocated and must be ::free()'d by the caller.
1357 char* p = ::realpath(filename, NULL);
1358 if (p != NULL) {
1359 if (strlen(p) < outbuflen) {
1360 strcpy(outbuf, p);
1361 result = outbuf;
1362 } else {
1363 errno = ENAMETOOLONG;
1364 }
1365 ::free(p); // *not* os::free
1366 } else {
1367 // Fallback for platforms struggling with modern Posix standards (AIX 5.3, 6.1). If realpath
1368 // returns EINVAL, this may indicate that realpath is not POSIX.1-2008 compatible and
1369 // that it complains about the NULL we handed down as user buffer.
1370 // In this case, use the user provided buffer but at least check whether realpath caused
1371 // a memory overwrite.
1372 if (errno == EINVAL) {
1373 outbuf[outbuflen - 1] = '\0';
1374 p = ::realpath(filename, outbuf);
1375 if (p != NULL) {
1376 guarantee(outbuf[outbuflen - 1] == '\0', "realpath buffer overwrite detected.");
1377 result = p;
1378 }
1379 }
1380 }
1381 return result;
1382
1383 }
1384
1385 int os::stat(const char *path, struct stat *sbuf) {
1386 return ::stat(path, sbuf);
1387 }
1388
1389 char * os::native_path(char *path) {
1390 return path;
1391 }
1392
1393 bool os::same_files(const char* file1, const char* file2) {
1394 if (strcmp(file1, file2) == 0) {
1395 return true;
1396 }
1397
1398 bool is_same = false;
1399 struct stat st1;
1400 struct stat st2;
1401
1402 if (os::stat(file1, &st1) < 0) {
1403 return false;
1404 }
1405
1406 if (os::stat(file2, &st2) < 0) {
1407 return false;
1408 }
1409
1410 if (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino) {
1411 // same files
1412 is_same = true;
1413 }
1414 return is_same;
1415 }
1416
1417 // Check minimum allowable stack sizes for thread creation and to initialize
1418 // the java system classes, including StackOverflowError - depends on page
1419 // size.
1420 // The space needed for frames during startup is platform dependent. It
1421 // depends on word size, platform calling conventions, C frame layout and
1422 // interpreter/C1/C2 design decisions. Therefore this is given in a
1423 // platform (os/cpu) dependent constant.
1424 // To this, space for guard mechanisms is added, which depends on the
1425 // page size which again depends on the concrete system the VM is running
1426 // on. Space for libc guard pages is not included in this size.
1427 jint os::Posix::set_minimum_stack_sizes() {
1428 size_t os_min_stack_allowed = SOLARIS_ONLY(thr_min_stack()) NOT_SOLARIS(PTHREAD_STACK_MIN);
1429
1430 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
1431 JavaThread::stack_guard_zone_size() +
1432 JavaThread::stack_shadow_zone_size();
1433
1434 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
1435 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, os_min_stack_allowed);
1436
1437 size_t stack_size_in_bytes = ThreadStackSize * K;
1438 if (stack_size_in_bytes != 0 &&
1439 stack_size_in_bytes < _java_thread_min_stack_allowed) {
1440 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
1441 // ThreadStackSize so we go with "Java thread stack size" instead
1442 // of "ThreadStackSize" to be more friendly.
1443 tty->print_cr("\nThe Java thread stack size specified is too small. "
1444 "Specify at least " SIZE_FORMAT "k",
1445 _java_thread_min_stack_allowed / K);
1446 return JNI_ERR;
1447 }
1448
1449 // Make the stack size a multiple of the page size so that
1450 // the yellow/red zones can be guarded.
1451 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
1452
1453 // Reminder: a compiler thread is a Java thread.
1454 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
1455 JavaThread::stack_guard_zone_size() +
1456 JavaThread::stack_shadow_zone_size();
1457
1458 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
1459 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, os_min_stack_allowed);
1460
1461 stack_size_in_bytes = CompilerThreadStackSize * K;
1462 if (stack_size_in_bytes != 0 &&
1463 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
1464 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
1465 "Specify at least " SIZE_FORMAT "k",
1466 _compiler_thread_min_stack_allowed / K);
1467 return JNI_ERR;
1468 }
1469
1470 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
1471 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, os_min_stack_allowed);
1472
1473 stack_size_in_bytes = VMThreadStackSize * K;
1474 if (stack_size_in_bytes != 0 &&
1475 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
1476 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
1477 "Specify at least " SIZE_FORMAT "k",
1478 _vm_internal_thread_min_stack_allowed / K);
1479 return JNI_ERR;
1480 }
1481 return JNI_OK;
1482 }
1483
1484 // Called when creating the thread. The minimum stack sizes have already been calculated
1485 size_t os::Posix::get_initial_stack_size(ThreadType thr_type, size_t req_stack_size) {
1486 size_t stack_size;
1487 if (req_stack_size == 0) {
1488 stack_size = default_stack_size(thr_type);
1489 } else {
1490 stack_size = req_stack_size;
1491 }
1492
1493 switch (thr_type) {
1494 case os::java_thread:
1495 // Java threads use ThreadStackSize which default value can be
1496 // changed with the flag -Xss
1497 if (req_stack_size == 0 && JavaThread::stack_size_at_create() > 0) {
1498 // no requested size and we have a more specific default value
1499 stack_size = JavaThread::stack_size_at_create();
1500 }
1501 stack_size = MAX2(stack_size,
1502 _java_thread_min_stack_allowed);
1503 break;
1504 case os::compiler_thread:
1505 if (req_stack_size == 0 && CompilerThreadStackSize > 0) {
1506 // no requested size and we have a more specific default value
1507 stack_size = (size_t)(CompilerThreadStackSize * K);
1508 }
1509 stack_size = MAX2(stack_size,
1510 _compiler_thread_min_stack_allowed);
1511 break;
1512 case os::vm_thread:
1513 case os::pgc_thread:
1514 case os::cgc_thread:
1515 case os::watcher_thread:
1516 default: // presume the unknown thr_type is a VM internal
1517 if (req_stack_size == 0 && VMThreadStackSize > 0) {
1518 // no requested size and we have a more specific default value
1519 stack_size = (size_t)(VMThreadStackSize * K);
1520 }
1521
1522 stack_size = MAX2(stack_size,
1523 _vm_internal_thread_min_stack_allowed);
1524 break;
1525 }
1526
1527 // pthread_attr_setstacksize() may require that the size be rounded up to the OS page size.
1528 // Be careful not to round up to 0. Align down in that case.
1529 if (stack_size <= SIZE_MAX - vm_page_size()) {
1530 stack_size = align_up(stack_size, vm_page_size());
1531 } else {
1532 stack_size = align_down(stack_size, vm_page_size());
1533 }
1534
1535 return stack_size;
1536 }
1537
1538 bool os::Posix::is_root(uid_t uid){
1539 return ROOT_UID == uid;
1540 }
1541
1542 bool os::Posix::matches_effective_uid_or_root(uid_t uid) {
1543 return is_root(uid) || geteuid() == uid;
1544 }
1545
1546 bool os::Posix::matches_effective_uid_and_gid_or_root(uid_t uid, gid_t gid) {
1547 return is_root(uid) || (geteuid() == uid && getegid() == gid);
1548 }
1549
1550 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
1551 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
1552 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
1553
1554 os::ThreadCrashProtection::ThreadCrashProtection() {
1555 }
1556
1557 /*
1558 * See the caveats for this class in os_posix.hpp
1559 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1560 * method and returns false. If none of the signals are raised, returns true.
1561 * The callback is supposed to provide the method that should be protected.
1562 */
1563 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1564 sigset_t saved_sig_mask;
1565
1566 Thread::muxAcquire(&_crash_mux, "CrashProtection");
1567
1568 _protected_thread = Thread::current_or_null();
1569 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
1570
1571 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1572 // since on at least some systems (OS X) siglongjmp will restore the mask
1573 // for the process, not the thread
1574 pthread_sigmask(0, NULL, &saved_sig_mask);
1575 if (sigsetjmp(_jmpbuf, 0) == 0) {
1576 // make sure we can see in the signal handler that we have crash protection
1577 // installed
1578 _crash_protection = this;
1579 cb.call();
1580 // and clear the crash protection
1581 _crash_protection = NULL;
1582 _protected_thread = NULL;
1583 Thread::muxRelease(&_crash_mux);
1584 return true;
1585 }
1586 // this happens when we siglongjmp() back
1587 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1588 _crash_protection = NULL;
1589 _protected_thread = NULL;
1590 Thread::muxRelease(&_crash_mux);
1591 return false;
1592 }
1593
1594 void os::ThreadCrashProtection::restore() {
1595 assert(_crash_protection != NULL, "must have crash protection");
1596 siglongjmp(_jmpbuf, 1);
1597 }
1598
1599 void os::ThreadCrashProtection::check_crash_protection(int sig,
1600 Thread* thread) {
1601
1602 if (thread != NULL &&
1603 thread == _protected_thread &&
1604 _crash_protection != NULL) {
1605
1606 if (sig == SIGSEGV || sig == SIGBUS) {
1607 _crash_protection->restore();
1608 }
1609 }
1610 }
1611
1612 // Shared clock/time and other supporting routines for pthread_mutex/cond
1613 // initialization. This is enabled on Solaris but only some of the clock/time
1614 // functionality is actually used there.
1615
1616 // Shared condattr object for use with relative timed-waits. Will be associated
1617 // with CLOCK_MONOTONIC if available to avoid issues with time-of-day changes,
1618 // but otherwise whatever default is used by the platform - generally the
1619 // time-of-day clock.
1620 static pthread_condattr_t _condAttr[1];
1621
1622 // Shared mutexattr to explicitly set the type to PTHREAD_MUTEX_NORMAL as not
1623 // all systems (e.g. FreeBSD) map the default to "normal".
1624 static pthread_mutexattr_t _mutexAttr[1];
1625
1626 // common basic initialization that is always supported
1627 static void pthread_init_common(void) {
1628 int status;
1629 if ((status = pthread_condattr_init(_condAttr)) != 0) {
1630 fatal("pthread_condattr_init: %s", os::strerror(status));
1631 }
1632 if ((status = pthread_mutexattr_init(_mutexAttr)) != 0) {
1633 fatal("pthread_mutexattr_init: %s", os::strerror(status));
1634 }
1635 if ((status = pthread_mutexattr_settype(_mutexAttr, PTHREAD_MUTEX_NORMAL)) != 0) {
1636 fatal("pthread_mutexattr_settype: %s", os::strerror(status));
1637 }
1638 // Solaris has it's own PlatformMutex, distinct from the one for POSIX.
1639 NOT_SOLARIS(os::PlatformMutex::init();)
1640 }
1641
1642 #ifndef SOLARIS
1643 sigset_t sigs;
1644 struct sigaction sigact[NSIG];
1645
1646 struct sigaction* os::Posix::get_preinstalled_handler(int sig) {
1647 if (sigismember(&sigs, sig)) {
1648 return &sigact[sig];
1649 }
1650 return NULL;
1651 }
1652
1653 void os::Posix::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
1654 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
1655 sigact[sig] = oldAct;
1656 sigaddset(&sigs, sig);
1657 }
1658 #endif
1659
1660 // Not all POSIX types and API's are available on all notionally "posix"
1661 // platforms. If we have build-time support then we will check for actual
1662 // runtime support via dlopen/dlsym lookup. This allows for running on an
1663 // older OS version compared to the build platform. But if there is no
1664 // build time support then there cannot be any runtime support as we do not
1665 // know what the runtime types would be (for example clockid_t might be an
1666 // int or int64_t).
1667 //
1668 #ifdef SUPPORTS_CLOCK_MONOTONIC
1669
1670 // This means we have clockid_t, clock_gettime et al and CLOCK_MONOTONIC
1671
1672 int (*os::Posix::_clock_gettime)(clockid_t, struct timespec *) = NULL;
1673 int (*os::Posix::_clock_getres)(clockid_t, struct timespec *) = NULL;
1674
1675 static int (*_pthread_condattr_setclock)(pthread_condattr_t *, clockid_t) = NULL;
1676
1677 static bool _use_clock_monotonic_condattr = false;
1678
1679 // Determine what POSIX API's are present and do appropriate
1680 // configuration.
1681 void os::Posix::init(void) {
1682
1683 // NOTE: no logging available when this is called. Put logging
1684 // statements in init_2().
1685
1686 // 1. Check for CLOCK_MONOTONIC support.
1687
1688 void* handle = NULL;
1689
1690 // For linux we need librt, for other OS we can find
1691 // this function in regular libc.
1692 #ifdef NEEDS_LIBRT
1693 // We do dlopen's in this particular order due to bug in linux
1694 // dynamic loader (see 6348968) leading to crash on exit.
1695 handle = dlopen("librt.so.1", RTLD_LAZY);
1696 if (handle == NULL) {
1697 handle = dlopen("librt.so", RTLD_LAZY);
1698 }
1699 #endif
1700
1701 if (handle == NULL) {
1702 handle = RTLD_DEFAULT;
1703 }
1704
1705 int (*clock_getres_func)(clockid_t, struct timespec*) =
1706 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
1707 int (*clock_gettime_func)(clockid_t, struct timespec*) =
1708 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
1709 if (clock_getres_func != NULL && clock_gettime_func != NULL) {
1710 // We assume that if both clock_gettime and clock_getres support
1711 // CLOCK_MONOTONIC then the OS provides true high-res monotonic clock.
1712 struct timespec res;
1713 struct timespec tp;
1714 if (clock_getres_func(CLOCK_MONOTONIC, &res) == 0 &&
1715 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
1716 // Yes, monotonic clock is supported.
1717 _clock_gettime = clock_gettime_func;
1718 _clock_getres = clock_getres_func;
1719 } else {
1720 #ifdef NEEDS_LIBRT
1721 // Close librt if there is no monotonic clock.
1722 if (handle != RTLD_DEFAULT) {
1723 dlclose(handle);
1724 }
1725 #endif
1726 }
1727 }
1728
1729 // 2. Check for pthread_condattr_setclock support.
1730
1731 // libpthread is already loaded.
1732 int (*condattr_setclock_func)(pthread_condattr_t*, clockid_t) =
1733 (int (*)(pthread_condattr_t*, clockid_t))dlsym(RTLD_DEFAULT,
1734 "pthread_condattr_setclock");
1735 if (condattr_setclock_func != NULL) {
1736 _pthread_condattr_setclock = condattr_setclock_func;
1737 }
1738
1739 // Now do general initialization.
1740
1741 pthread_init_common();
1742
1743 #ifndef SOLARIS
1744 int status;
1745 if (_pthread_condattr_setclock != NULL && _clock_gettime != NULL) {
1746 if ((status = _pthread_condattr_setclock(_condAttr, CLOCK_MONOTONIC)) != 0) {
1747 if (status == EINVAL) {
1748 _use_clock_monotonic_condattr = false;
1749 warning("Unable to use monotonic clock with relative timed-waits" \
1750 " - changes to the time-of-day clock may have adverse affects");
1751 } else {
1752 fatal("pthread_condattr_setclock: %s", os::strerror(status));
1753 }
1754 } else {
1755 _use_clock_monotonic_condattr = true;
1756 }
1757 }
1758 #endif // !SOLARIS
1759
1760 }
1761
1762 void os::Posix::init_2(void) {
1763 #ifndef SOLARIS
1764 log_info(os)("Use of CLOCK_MONOTONIC is%s supported",
1765 (_clock_gettime != NULL ? "" : " not"));
1766 log_info(os)("Use of pthread_condattr_setclock is%s supported",
1767 (_pthread_condattr_setclock != NULL ? "" : " not"));
1768 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with %s",
1769 _use_clock_monotonic_condattr ? "CLOCK_MONOTONIC" : "the default clock");
1770 sigemptyset(&sigs);
1771 #endif // !SOLARIS
1772 }
1773
1774 #else // !SUPPORTS_CLOCK_MONOTONIC
1775
1776 void os::Posix::init(void) {
1777 pthread_init_common();
1778 }
1779
1780 void os::Posix::init_2(void) {
1781 #ifndef SOLARIS
1782 log_info(os)("Use of CLOCK_MONOTONIC is not supported");
1783 log_info(os)("Use of pthread_condattr_setclock is not supported");
1784 log_info(os)("Relative timed-wait using pthread_cond_timedwait is associated with the default clock");
1785 sigemptyset(&sigs);
1786 #endif // !SOLARIS
1787 }
1788
1789 #endif // SUPPORTS_CLOCK_MONOTONIC
1790
1791 // Utility to convert the given timeout to an absolute timespec
1792 // (based on the appropriate clock) to use with pthread_cond_timewait,
1793 // and sem_timedwait().
1794 // The clock queried here must be the clock used to manage the
1795 // timeout of the condition variable or semaphore.
1796 //
1797 // The passed in timeout value is either a relative time in nanoseconds
1798 // or an absolute time in milliseconds. A relative timeout will be
1799 // associated with CLOCK_MONOTONIC if available, unless the real-time clock
1800 // is explicitly requested; otherwise, or if absolute,
1801 // the default time-of-day clock will be used.
1802
1803 // Given time is a 64-bit value and the time_t used in the timespec is
1804 // sometimes a signed-32-bit value we have to watch for overflow if times
1805 // way in the future are given. Further on Solaris versions
1806 // prior to 10 there is a restriction (see cond_timedwait) that the specified
1807 // number of seconds, in abstime, is less than current_time + 100000000.
1808 // As it will be over 20 years before "now + 100000000" will overflow we can
1809 // ignore overflow and just impose a hard-limit on seconds using the value
1810 // of "now + 100000000". This places a limit on the timeout of about 3.17
1811 // years from "now".
1812 //
1813 #define MAX_SECS 100000000
1814
1815 // Calculate a new absolute time that is "timeout" nanoseconds from "now".
1816 // "unit" indicates the unit of "now_part_sec" (may be nanos or micros depending
1817 // on which clock API is being used).
1818 static void calc_rel_time(timespec* abstime, jlong timeout, jlong now_sec,
1819 jlong now_part_sec, jlong unit) {
1820 time_t max_secs = now_sec + MAX_SECS;
1821
1822 jlong seconds = timeout / NANOUNITS;
1823 timeout %= NANOUNITS; // remaining nanos
1824
1825 if (seconds >= MAX_SECS) {
1826 // More seconds than we can add, so pin to max_secs.
1827 abstime->tv_sec = max_secs;
1828 abstime->tv_nsec = 0;
1829 } else {
1830 abstime->tv_sec = now_sec + seconds;
1831 long nanos = (now_part_sec * (NANOUNITS / unit)) + timeout;
1832 if (nanos >= NANOUNITS) { // overflow
1833 abstime->tv_sec += 1;
1834 nanos -= NANOUNITS;
1835 }
1836 abstime->tv_nsec = nanos;
1837 }
1838 }
1839
1840 // Unpack the given deadline in milliseconds since the epoch, into the given timespec.
1841 // The current time in seconds is also passed in to enforce an upper bound as discussed above.
1842 // This is only used with gettimeofday, when clock_gettime is not available.
1843 static void unpack_abs_time(timespec* abstime, jlong deadline, jlong now_sec) {
1844 time_t max_secs = now_sec + MAX_SECS;
1845
1846 jlong seconds = deadline / MILLIUNITS;
1847 jlong millis = deadline % MILLIUNITS;
1848
1849 if (seconds >= max_secs) {
1850 // Absolute seconds exceeds allowed max, so pin to max_secs.
1851 abstime->tv_sec = max_secs;
1852 abstime->tv_nsec = 0;
1853 } else {
1854 abstime->tv_sec = seconds;
1855 abstime->tv_nsec = millis_to_nanos(millis);
1856 }
1857 }
1858
1859 static jlong millis_to_nanos_bounded(jlong millis) {
1860 // We have to watch for overflow when converting millis to nanos,
1861 // but if millis is that large then we will end up limiting to
1862 // MAX_SECS anyway, so just do that here.
1863 if (millis / MILLIUNITS > MAX_SECS) {
1864 millis = jlong(MAX_SECS) * MILLIUNITS;
1865 }
1866 return millis_to_nanos(millis);
1867 }
1868
1869 static void to_abstime(timespec* abstime, jlong timeout,
1870 bool isAbsolute, bool isRealtime) {
1871 DEBUG_ONLY(int max_secs = MAX_SECS;)
1872
1873 if (timeout < 0) {
1874 timeout = 0;
1875 }
1876
1877 #ifdef SUPPORTS_CLOCK_MONOTONIC
1878
1879 clockid_t clock = CLOCK_MONOTONIC;
1880 // need to ensure we have a runtime check for clock_gettime support
1881 if (!isAbsolute && os::Posix::supports_monotonic_clock()) {
1882 if (!_use_clock_monotonic_condattr || isRealtime) {
1883 clock = CLOCK_REALTIME;
1884 }
1885 struct timespec now;
1886 int status = os::Posix::clock_gettime(clock, &now);
1887 assert_status(status == 0, status, "clock_gettime");
1888 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_nsec, NANOUNITS);
1889 DEBUG_ONLY(max_secs += now.tv_sec;)
1890 } else {
1891
1892 #else
1893
1894 { // Match the block scope.
1895
1896 #endif // SUPPORTS_CLOCK_MONOTONIC
1897
1898 // Time-of-day clock is all we can reliably use.
1899 struct timeval now;
1900 int status = gettimeofday(&now, NULL);
1901 assert_status(status == 0, errno, "gettimeofday");
1902 if (isAbsolute) {
1903 unpack_abs_time(abstime, timeout, now.tv_sec);
1904 } else {
1905 calc_rel_time(abstime, timeout, now.tv_sec, now.tv_usec, MICROUNITS);
1906 }
1907 DEBUG_ONLY(max_secs += now.tv_sec;)
1908 }
1909
1910 assert(abstime->tv_sec >= 0, "tv_sec < 0");
1911 assert(abstime->tv_sec <= max_secs, "tv_sec > max_secs");
1912 assert(abstime->tv_nsec >= 0, "tv_nsec < 0");
1913 assert(abstime->tv_nsec < NANOUNITS, "tv_nsec >= NANOUNITS");
1914 }
1915
1916 // Create an absolute time 'millis' milliseconds in the future, using the
1917 // real-time (time-of-day) clock. Used by PosixSemaphore.
1918 void os::Posix::to_RTC_abstime(timespec* abstime, int64_t millis) {
1919 to_abstime(abstime, millis_to_nanos_bounded(millis),
1920 false /* not absolute */,
1921 true /* use real-time clock */);
1922 }
1923
1924 // Shared pthread_mutex/cond based PlatformEvent implementation.
1925 // Not currently usable by Solaris.
1926
1927 #ifndef SOLARIS
1928
1929 // PlatformEvent
1930 //
1931 // Assumption:
1932 // Only one parker can exist on an event, which is why we allocate
1933 // them per-thread. Multiple unparkers can coexist.
1934 //
1935 // _event serves as a restricted-range semaphore.
1936 // -1 : thread is blocked, i.e. there is a waiter
1937 // 0 : neutral: thread is running or ready,
1938 // could have been signaled after a wait started
1939 // 1 : signaled - thread is running or ready
1940 //
1941 // Having three states allows for some detection of bad usage - see
1942 // comments on unpark().
1943
1944 os::PlatformEvent::PlatformEvent() {
1945 int status = pthread_cond_init(_cond, _condAttr);
1946 assert_status(status == 0, status, "cond_init");
1947 status = pthread_mutex_init(_mutex, _mutexAttr);
1948 assert_status(status == 0, status, "mutex_init");
1949 _event = 0;
1950 _nParked = 0;
1951 }
1952
1953 void os::PlatformEvent::park() { // AKA "down()"
1954 // Transitions for _event:
1955 // -1 => -1 : illegal
1956 // 1 => 0 : pass - return immediately
1957 // 0 => -1 : block; then set _event to 0 before returning
1958
1959 // Invariant: Only the thread associated with the PlatformEvent
1960 // may call park().
1961 assert(_nParked == 0, "invariant");
1962
1963 int v;
1964
1965 // atomically decrement _event
1966 for (;;) {
1967 v = _event;
1968 if (Atomic::cmpxchg(&_event, v, v - 1) == v) break;
1969 }
1970 guarantee(v >= 0, "invariant");
1971
1972 if (v == 0) { // Do this the hard way by blocking ...
1973 int status = pthread_mutex_lock(_mutex);
1974 assert_status(status == 0, status, "mutex_lock");
1975 guarantee(_nParked == 0, "invariant");
1976 ++_nParked;
1977 while (_event < 0) {
1978 // OS-level "spurious wakeups" are ignored
1979 status = pthread_cond_wait(_cond, _mutex);
1980 assert_status(status == 0 MACOS_ONLY(|| status == ETIMEDOUT),
1981 status, "cond_wait");
1982 }
1983 --_nParked;
1984
1985 _event = 0;
1986 status = pthread_mutex_unlock(_mutex);
1987 assert_status(status == 0, status, "mutex_unlock");
1988 // Paranoia to ensure our locked and lock-free paths interact
1989 // correctly with each other.
1990 OrderAccess::fence();
1991 }
1992 guarantee(_event >= 0, "invariant");
1993 }
1994
1995 int os::PlatformEvent::park(jlong millis) {
1996 // Transitions for _event:
1997 // -1 => -1 : illegal
1998 // 1 => 0 : pass - return immediately
1999 // 0 => -1 : block; then set _event to 0 before returning
2000
2001 // Invariant: Only the thread associated with the Event/PlatformEvent
2002 // may call park().
2003 assert(_nParked == 0, "invariant");
2004
2005 int v;
2006 // atomically decrement _event
2007 for (;;) {
2008 v = _event;
2009 if (Atomic::cmpxchg(&_event, v, v - 1) == v) break;
2010 }
2011 guarantee(v >= 0, "invariant");
2012
2013 if (v == 0) { // Do this the hard way by blocking ...
2014 struct timespec abst;
2015 to_abstime(&abst, millis_to_nanos_bounded(millis), false, false);
2016
2017 int ret = OS_TIMEOUT;
2018 int status = pthread_mutex_lock(_mutex);
2019 assert_status(status == 0, status, "mutex_lock");
2020 guarantee(_nParked == 0, "invariant");
2021 ++_nParked;
2022
2023 while (_event < 0) {
2024 status = pthread_cond_timedwait(_cond, _mutex, &abst);
2025 assert_status(status == 0 || status == ETIMEDOUT,
2026 status, "cond_timedwait");
2027 // OS-level "spurious wakeups" are ignored unless the archaic
2028 // FilterSpuriousWakeups is set false. That flag should be obsoleted.
2029 if (!FilterSpuriousWakeups) break;
2030 if (status == ETIMEDOUT) break;
2031 }
2032 --_nParked;
2033
2034 if (_event >= 0) {
2035 ret = OS_OK;
2036 }
2037
2038 _event = 0;
2039 status = pthread_mutex_unlock(_mutex);
2040 assert_status(status == 0, status, "mutex_unlock");
2041 // Paranoia to ensure our locked and lock-free paths interact
2042 // correctly with each other.
2043 OrderAccess::fence();
2044 return ret;
2045 }
2046 return OS_OK;
2047 }
2048
2049 void os::PlatformEvent::unpark() {
2050 // Transitions for _event:
2051 // 0 => 1 : just return
2052 // 1 => 1 : just return
2053 // -1 => either 0 or 1; must signal target thread
2054 // That is, we can safely transition _event from -1 to either
2055 // 0 or 1.
2056 // See also: "Semaphores in Plan 9" by Mullender & Cox
2057 //
2058 // Note: Forcing a transition from "-1" to "1" on an unpark() means
2059 // that it will take two back-to-back park() calls for the owning
2060 // thread to block. This has the benefit of forcing a spurious return
2061 // from the first park() call after an unpark() call which will help
2062 // shake out uses of park() and unpark() without checking state conditions
2063 // properly. This spurious return doesn't manifest itself in any user code
2064 // but only in the correctly written condition checking loops of ObjectMonitor,
2065 // Mutex/Monitor, Thread::muxAcquire and JavaThread::sleep
2066
2067 if (Atomic::xchg(&_event, 1) >= 0) return;
2068
2069 int status = pthread_mutex_lock(_mutex);
2070 assert_status(status == 0, status, "mutex_lock");
2071 int anyWaiters = _nParked;
2072 assert(anyWaiters == 0 || anyWaiters == 1, "invariant");
2073 status = pthread_mutex_unlock(_mutex);
2074 assert_status(status == 0, status, "mutex_unlock");
2075
2076 // Note that we signal() *after* dropping the lock for "immortal" Events.
2077 // This is safe and avoids a common class of futile wakeups. In rare
2078 // circumstances this can cause a thread to return prematurely from
2079 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2080 // will simply re-test the condition and re-park itself.
2081 // This provides particular benefit if the underlying platform does not
2082 // provide wait morphing.
2083
2084 if (anyWaiters != 0) {
2085 status = pthread_cond_signal(_cond);
2086 assert_status(status == 0, status, "cond_signal");
2087 }
2088 }
2089
2090 // JSR166 support
2091
2092 os::PlatformParker::PlatformParker() {
2093 int status;
2094 status = pthread_cond_init(&_cond[REL_INDEX], _condAttr);
2095 assert_status(status == 0, status, "cond_init rel");
2096 status = pthread_cond_init(&_cond[ABS_INDEX], NULL);
2097 assert_status(status == 0, status, "cond_init abs");
2098 status = pthread_mutex_init(_mutex, _mutexAttr);
2099 assert_status(status == 0, status, "mutex_init");
2100 _cur_index = -1; // mark as unused
2101 }
2102
2103 // Parker::park decrements count if > 0, else does a condvar wait. Unpark
2104 // sets count to 1 and signals condvar. Only one thread ever waits
2105 // on the condvar. Contention seen when trying to park implies that someone
2106 // is unparking you, so don't wait. And spurious returns are fine, so there
2107 // is no need to track notifications.
2108
2109 void Parker::park(bool isAbsolute, jlong time) {
2110
2111 // Optional fast-path check:
2112 // Return immediately if a permit is available.
2113 // We depend on Atomic::xchg() having full barrier semantics
2114 // since we are doing a lock-free update to _counter.
2115 if (Atomic::xchg(&_counter, 0) > 0) return;
2116
2117 Thread* thread = Thread::current();
2118 assert(thread->is_Java_thread(), "Must be JavaThread");
2119 JavaThread *jt = (JavaThread *)thread;
2120
2121 // Optional optimization -- avoid state transitions if there's
2122 // an interrupt pending.
2123 if (jt->is_interrupted(false)) {
2124 return;
2125 }
2126
2127 // Next, demultiplex/decode time arguments
2128 struct timespec absTime;
2129 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
2130 return;
2131 }
2132 if (time > 0) {
2133 to_abstime(&absTime, time, isAbsolute, false);
2134 }
2135
2136 // Enter safepoint region
2137 // Beware of deadlocks such as 6317397.
2138 // The per-thread Parker:: mutex is a classic leaf-lock.
2139 // In particular a thread must never block on the Threads_lock while
2140 // holding the Parker:: mutex. If safepoints are pending both the
2141 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
2142 ThreadBlockInVM tbivm(jt);
2143
2144 // Can't access interrupt state now that we are _thread_blocked. If we've
2145 // been interrupted since we checked above then _counter will be > 0.
2146
2147 // Don't wait if cannot get lock since interference arises from
2148 // unparking.
2149 if (pthread_mutex_trylock(_mutex) != 0) {
2150 return;
2151 }
2152
2153 int status;
2154 if (_counter > 0) { // no wait needed
2155 _counter = 0;
2156 status = pthread_mutex_unlock(_mutex);
2157 assert_status(status == 0, status, "invariant");
2158 // Paranoia to ensure our locked and lock-free paths interact
2159 // correctly with each other and Java-level accesses.
2160 OrderAccess::fence();
2161 return;
2162 }
2163
2164 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2165 jt->set_suspend_equivalent();
2166 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2167
2168 assert(_cur_index == -1, "invariant");
2169 if (time == 0) {
2170 _cur_index = REL_INDEX; // arbitrary choice when not timed
2171 status = pthread_cond_wait(&_cond[_cur_index], _mutex);
2172 assert_status(status == 0 MACOS_ONLY(|| status == ETIMEDOUT),
2173 status, "cond_wait");
2174 }
2175 else {
2176 _cur_index = isAbsolute ? ABS_INDEX : REL_INDEX;
2177 status = pthread_cond_timedwait(&_cond[_cur_index], _mutex, &absTime);
2178 assert_status(status == 0 || status == ETIMEDOUT,
2179 status, "cond_timedwait");
2180 }
2181 _cur_index = -1;
2182
2183 _counter = 0;
2184 status = pthread_mutex_unlock(_mutex);
2185 assert_status(status == 0, status, "invariant");
2186 // Paranoia to ensure our locked and lock-free paths interact
2187 // correctly with each other and Java-level accesses.
2188 OrderAccess::fence();
2189
2190 // If externally suspended while waiting, re-suspend
2191 if (jt->handle_special_suspend_equivalent_condition()) {
2192 jt->java_suspend_self();
2193 }
2194 }
2195
2196 void Parker::unpark() {
2197 int status = pthread_mutex_lock(_mutex);
2198 assert_status(status == 0, status, "invariant");
2199 const int s = _counter;
2200 _counter = 1;
2201 // must capture correct index before unlocking
2202 int index = _cur_index;
2203 status = pthread_mutex_unlock(_mutex);
2204 assert_status(status == 0, status, "invariant");
2205
2206 // Note that we signal() *after* dropping the lock for "immortal" Events.
2207 // This is safe and avoids a common class of futile wakeups. In rare
2208 // circumstances this can cause a thread to return prematurely from
2209 // cond_{timed}wait() but the spurious wakeup is benign and the victim
2210 // will simply re-test the condition and re-park itself.
2211 // This provides particular benefit if the underlying platform does not
2212 // provide wait morphing.
2213
2214 if (s < 1 && index != -1) {
2215 // thread is definitely parked
2216 status = pthread_cond_signal(&_cond[index]);
2217 assert_status(status == 0, status, "invariant");
2218 }
2219 }
2220
2221 // Platform Mutex/Monitor implementation
2222
2223 #if PLATFORM_MONITOR_IMPL_INDIRECT
2224
2225 os::PlatformMutex::Mutex::Mutex() : _next(NULL) {
2226 int status = pthread_mutex_init(&_mutex, _mutexAttr);
2227 assert_status(status == 0, status, "mutex_init");
2228 }
2229
2230 os::PlatformMutex::Mutex::~Mutex() {
2231 int status = pthread_mutex_destroy(&_mutex);
2232 assert_status(status == 0, status, "mutex_destroy");
2233 }
2234
2235 pthread_mutex_t os::PlatformMutex::_freelist_lock;
2236 os::PlatformMutex::Mutex* os::PlatformMutex::_mutex_freelist = NULL;
2237
2238 void os::PlatformMutex::init() {
2239 int status = pthread_mutex_init(&_freelist_lock, _mutexAttr);
2240 assert_status(status == 0, status, "freelist lock init");
2241 }
2242
2243 struct os::PlatformMutex::WithFreeListLocked : public StackObj {
2244 WithFreeListLocked() {
2245 int status = pthread_mutex_lock(&_freelist_lock);
2246 assert_status(status == 0, status, "freelist lock");
2247 }
2248
2249 ~WithFreeListLocked() {
2250 int status = pthread_mutex_unlock(&_freelist_lock);
2251 assert_status(status == 0, status, "freelist unlock");
2252 }
2253 };
2254
2255 os::PlatformMutex::PlatformMutex() {
2256 {
2257 WithFreeListLocked wfl;
2258 _impl = _mutex_freelist;
2259 if (_impl != NULL) {
2260 _mutex_freelist = _impl->_next;
2261 _impl->_next = NULL;
2262 return;
2263 }
2264 }
2265 _impl = new Mutex();
2266 }
2267
2268 os::PlatformMutex::~PlatformMutex() {
2269 WithFreeListLocked wfl;
2270 assert(_impl->_next == NULL, "invariant");
2271 _impl->_next = _mutex_freelist;
2272 _mutex_freelist = _impl;
2273 }
2274
2275 os::PlatformMonitor::Cond::Cond() : _next(NULL) {
2276 int status = pthread_cond_init(&_cond, _condAttr);
2277 assert_status(status == 0, status, "cond_init");
2278 }
2279
2280 os::PlatformMonitor::Cond::~Cond() {
2281 int status = pthread_cond_destroy(&_cond);
2282 assert_status(status == 0, status, "cond_destroy");
2283 }
2284
2285 os::PlatformMonitor::Cond* os::PlatformMonitor::_cond_freelist = NULL;
2286
2287 os::PlatformMonitor::PlatformMonitor() {
2288 {
2289 WithFreeListLocked wfl;
2290 _impl = _cond_freelist;
2291 if (_impl != NULL) {
2292 _cond_freelist = _impl->_next;
2293 _impl->_next = NULL;
2294 return;
2295 }
2296 }
2297 _impl = new Cond();
2298 }
2299
2300 os::PlatformMonitor::~PlatformMonitor() {
2301 WithFreeListLocked wfl;
2302 assert(_impl->_next == NULL, "invariant");
2303 _impl->_next = _cond_freelist;
2304 _cond_freelist = _impl;
2305 }
2306
2307 #else
2308
2309 os::PlatformMutex::PlatformMutex() {
2310 int status = pthread_mutex_init(&_mutex, _mutexAttr);
2311 assert_status(status == 0, status, "mutex_init");
2312 }
2313
2314 os::PlatformMutex::~PlatformMutex() {
2315 int status = pthread_mutex_destroy(&_mutex);
2316 assert_status(status == 0, status, "mutex_destroy");
2317 }
2318
2319 os::PlatformMonitor::PlatformMonitor() {
2320 int status = pthread_cond_init(&_cond, _condAttr);
2321 assert_status(status == 0, status, "cond_init");
2322 }
2323
2324 os::PlatformMonitor::~PlatformMonitor() {
2325 int status = pthread_cond_destroy(&_cond);
2326 assert_status(status == 0, status, "cond_destroy");
2327 }
2328
2329 #endif // PLATFORM_MONITOR_IMPL_INDIRECT
2330
2331 // Must already be locked
2332 int os::PlatformMonitor::wait(jlong millis) {
2333 assert(millis >= 0, "negative timeout");
2334 if (millis > 0) {
2335 struct timespec abst;
2336 // We have to watch for overflow when converting millis to nanos,
2337 // but if millis is that large then we will end up limiting to
2338 // MAX_SECS anyway, so just do that here.
2339 if (millis / MILLIUNITS > MAX_SECS) {
2340 millis = jlong(MAX_SECS) * MILLIUNITS;
2341 }
2342 to_abstime(&abst, millis_to_nanos(millis), false, false);
2343
2344 int ret = OS_TIMEOUT;
2345 int status = pthread_cond_timedwait(cond(), mutex(), &abst);
2346 assert_status(status == 0 || status == ETIMEDOUT,
2347 status, "cond_timedwait");
2348 if (status == 0) {
2349 ret = OS_OK;
2350 }
2351 return ret;
2352 } else {
2353 int status = pthread_cond_wait(cond(), mutex());
2354 assert_status(status == 0 MACOS_ONLY(|| status == ETIMEDOUT),
2355 status, "cond_wait");
2356 return OS_OK;
2357 }
2358 }
2359
2360 #endif // !SOLARIS