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