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