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