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