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