1 /* 2 * Copyright (c) 1999, 2013, 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 // no precompiled headers 26 #include "classfile/classLoader.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "classfile/vmSymbols.hpp" 29 #include "code/icBuffer.hpp" 30 #include "code/vtableStubs.hpp" 31 #include "compiler/compileBroker.hpp" 32 #include "compiler/disassembler.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "jvm_bsd.h" 35 #include "memory/allocation.inline.hpp" 36 #include "memory/filemap.hpp" 37 #include "mutex_bsd.inline.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "os_share_bsd.hpp" 40 #include "prims/jniFastGetField.hpp" 41 #include "prims/jvm.h" 42 #include "prims/jvm_misc.hpp" 43 #include "runtime/arguments.hpp" 44 #include "runtime/extendedPC.hpp" 45 #include "runtime/globals.hpp" 46 #include "runtime/interfaceSupport.hpp" 47 #include "runtime/java.hpp" 48 #include "runtime/javaCalls.hpp" 49 #include "runtime/mutexLocker.hpp" 50 #include "runtime/objectMonitor.hpp" 51 #include "runtime/osThread.hpp" 52 #include "runtime/perfMemory.hpp" 53 #include "runtime/sharedRuntime.hpp" 54 #include "runtime/statSampler.hpp" 55 #include "runtime/stubRoutines.hpp" 56 #include "runtime/thread.inline.hpp" 57 #include "runtime/threadCritical.hpp" 58 #include "runtime/timer.hpp" 59 #include "services/attachListener.hpp" 60 #include "services/memTracker.hpp" 61 #include "services/runtimeService.hpp" 62 #include "utilities/decoder.hpp" 63 #include "utilities/defaultStream.hpp" 64 #include "utilities/events.hpp" 65 #include "utilities/growableArray.hpp" 66 #include "utilities/vmError.hpp" 67 68 // put OS-includes here 69 # include <sys/types.h> 70 # include <sys/mman.h> 71 # include <sys/stat.h> 72 # include <sys/select.h> 73 # include <pthread.h> 74 # include <signal.h> 75 # include <errno.h> 76 # include <dlfcn.h> 77 # include <stdio.h> 78 # include <unistd.h> 79 # include <sys/resource.h> 80 # include <pthread.h> 81 # include <sys/stat.h> 82 # include <sys/time.h> 83 # include <sys/times.h> 84 # include <sys/utsname.h> 85 # include <sys/socket.h> 86 # include <sys/wait.h> 87 # include <time.h> 88 # include <pwd.h> 89 # include <poll.h> 90 # include <semaphore.h> 91 # include <fcntl.h> 92 # include <string.h> 93 # include <sys/param.h> 94 # include <sys/sysctl.h> 95 # include <sys/ipc.h> 96 # include <sys/shm.h> 97 #ifndef __APPLE__ 98 # include <link.h> 99 #endif 100 # include <stdint.h> 101 # include <inttypes.h> 102 # include <sys/ioctl.h> 103 104 #if defined(__FreeBSD__) || defined(__NetBSD__) 105 # include <elf.h> 106 #endif 107 108 #ifdef __APPLE__ 109 # include <mach/mach.h> // semaphore_* API 110 # include <mach-o/dyld.h> 111 # include <sys/proc_info.h> 112 # include <objc/objc-auto.h> 113 #endif 114 115 #ifndef MAP_ANONYMOUS 116 #define MAP_ANONYMOUS MAP_ANON 117 #endif 118 119 #define MAX_PATH (2 * K) 120 121 // for timer info max values which include all bits 122 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 123 124 #define LARGEPAGES_BIT (1 << 6) 125 //////////////////////////////////////////////////////////////////////////////// 126 // global variables 127 julong os::Bsd::_physical_memory = 0; 128 129 130 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; 131 pthread_t os::Bsd::_main_thread; 132 int os::Bsd::_page_size = -1; 133 134 static jlong initial_time_count=0; 135 136 static int clock_tics_per_sec = 100; 137 138 // For diagnostics to print a message once. see run_periodic_checks 139 static sigset_t check_signal_done; 140 static bool check_signals = true; 141 142 static pid_t _initial_pid = 0; 143 144 /* Signal number used to suspend/resume a thread */ 145 146 /* do not use any signal number less than SIGSEGV, see 4355769 */ 147 static int SR_signum = SIGUSR2; 148 sigset_t SR_sigset; 149 150 151 //////////////////////////////////////////////////////////////////////////////// 152 // utility functions 153 154 static int SR_initialize(); 155 156 julong os::available_memory() { 157 return Bsd::available_memory(); 158 } 159 160 julong os::Bsd::available_memory() { 161 // XXXBSD: this is just a stopgap implementation 162 return physical_memory() >> 2; 163 } 164 165 julong os::physical_memory() { 166 return Bsd::physical_memory(); 167 } 168 169 //////////////////////////////////////////////////////////////////////////////// 170 // environment support 171 172 bool os::getenv(const char* name, char* buf, int len) { 173 const char* val = ::getenv(name); 174 if (val != NULL && strlen(val) < (size_t)len) { 175 strcpy(buf, val); 176 return true; 177 } 178 if (len > 0) buf[0] = 0; // return a null string 179 return false; 180 } 181 182 183 // Return true if user is running as root. 184 185 bool os::have_special_privileges() { 186 static bool init = false; 187 static bool privileges = false; 188 if (!init) { 189 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 190 init = true; 191 } 192 return privileges; 193 } 194 195 196 197 // Cpu architecture string 198 #if defined(ZERO) 199 static char cpu_arch[] = ZERO_LIBARCH; 200 #elif defined(IA64) 201 static char cpu_arch[] = "ia64"; 202 #elif defined(IA32) 203 static char cpu_arch[] = "i386"; 204 #elif defined(AMD64) 205 static char cpu_arch[] = "amd64"; 206 #elif defined(ARM) 207 static char cpu_arch[] = "arm"; 208 #elif defined(PPC) 209 static char cpu_arch[] = "ppc"; 210 #elif defined(SPARC) 211 # ifdef _LP64 212 static char cpu_arch[] = "sparcv9"; 213 # else 214 static char cpu_arch[] = "sparc"; 215 # endif 216 #else 217 #error Add appropriate cpu_arch setting 218 #endif 219 220 // Compiler variant 221 #ifdef COMPILER2 222 #define COMPILER_VARIANT "server" 223 #else 224 #define COMPILER_VARIANT "client" 225 #endif 226 227 228 void os::Bsd::initialize_system_info() { 229 int mib[2]; 230 size_t len; 231 int cpu_val; 232 julong mem_val; 233 234 /* get processors count via hw.ncpus sysctl */ 235 mib[0] = CTL_HW; 236 mib[1] = HW_NCPU; 237 len = sizeof(cpu_val); 238 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) { 239 assert(len == sizeof(cpu_val), "unexpected data size"); 240 set_processor_count(cpu_val); 241 } 242 else { 243 set_processor_count(1); // fallback 244 } 245 246 /* get physical memory via hw.memsize sysctl (hw.memsize is used 247 * since it returns a 64 bit value) 248 */ 249 mib[0] = CTL_HW; 250 mib[1] = HW_MEMSIZE; 251 len = sizeof(mem_val); 252 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) { 253 assert(len == sizeof(mem_val), "unexpected data size"); 254 _physical_memory = mem_val; 255 } else { 256 _physical_memory = 256*1024*1024; // fallback (XXXBSD?) 257 } 258 259 #ifdef __OpenBSD__ 260 { 261 // limit _physical_memory memory view on OpenBSD since 262 // datasize rlimit restricts us anyway. 263 struct rlimit limits; 264 getrlimit(RLIMIT_DATA, &limits); 265 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur); 266 } 267 #endif 268 } 269 270 #ifdef __APPLE__ 271 static const char *get_home() { 272 const char *home_dir = ::getenv("HOME"); 273 if ((home_dir == NULL) || (*home_dir == '\0')) { 274 struct passwd *passwd_info = getpwuid(geteuid()); 275 if (passwd_info != NULL) { 276 home_dir = passwd_info->pw_dir; 277 } 278 } 279 280 return home_dir; 281 } 282 #endif 283 284 void os::init_system_properties_values() { 285 // char arch[12]; 286 // sysinfo(SI_ARCHITECTURE, arch, sizeof(arch)); 287 288 // The next steps are taken in the product version: 289 // 290 // Obtain the JAVA_HOME value from the location of libjvm.so. 291 // This library should be located at: 292 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so. 293 // 294 // If "/jre/lib/" appears at the right place in the path, then we 295 // assume libjvm.so is installed in a JDK and we use this path. 296 // 297 // Otherwise exit with message: "Could not create the Java virtual machine." 298 // 299 // The following extra steps are taken in the debugging version: 300 // 301 // If "/jre/lib/" does NOT appear at the right place in the path 302 // instead of exit check for $JAVA_HOME environment variable. 303 // 304 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 305 // then we append a fake suffix "hotspot/libjvm.so" to this path so 306 // it looks like libjvm.so is installed there 307 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 308 // 309 // Otherwise exit. 310 // 311 // Important note: if the location of libjvm.so changes this 312 // code needs to be changed accordingly. 313 314 // The next few definitions allow the code to be verbatim: 315 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal) 316 #define getenv(n) ::getenv(n) 317 318 /* 319 * See ld(1): 320 * The linker uses the following search paths to locate required 321 * shared libraries: 322 * 1: ... 323 * ... 324 * 7: The default directories, normally /lib and /usr/lib. 325 */ 326 #ifndef DEFAULT_LIBPATH 327 #define DEFAULT_LIBPATH "/lib:/usr/lib" 328 #endif 329 330 #define EXTENSIONS_DIR "/lib/ext" 331 #define ENDORSED_DIR "/lib/endorsed" 332 #define REG_DIR "/usr/java/packages" 333 334 #ifdef __APPLE__ 335 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions" 336 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java" 337 const char *user_home_dir = get_home(); 338 // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir 339 int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) + 340 sizeof(SYS_EXTENSIONS_DIRS); 341 #endif 342 343 { 344 /* sysclasspath, java_home, dll_dir */ 345 { 346 char *home_path; 347 char *dll_path; 348 char *pslash; 349 char buf[MAXPATHLEN]; 350 os::jvm_path(buf, sizeof(buf)); 351 352 // Found the full path to libjvm.so. 353 // Now cut the path to <java_home>/jre if we can. 354 *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */ 355 pslash = strrchr(buf, '/'); 356 if (pslash != NULL) 357 *pslash = '\0'; /* get rid of /{client|server|hotspot} */ 358 dll_path = malloc(strlen(buf) + 1); 359 if (dll_path == NULL) 360 return; 361 strcpy(dll_path, buf); 362 Arguments::set_dll_dir(dll_path); 363 364 if (pslash != NULL) { 365 pslash = strrchr(buf, '/'); 366 if (pslash != NULL) { 367 *pslash = '\0'; /* get rid of /<arch> (/lib on macosx) */ 368 #ifndef __APPLE__ 369 pslash = strrchr(buf, '/'); 370 if (pslash != NULL) 371 *pslash = '\0'; /* get rid of /lib */ 372 #endif 373 } 374 } 375 376 home_path = malloc(strlen(buf) + 1); 377 if (home_path == NULL) 378 return; 379 strcpy(home_path, buf); 380 Arguments::set_java_home(home_path); 381 382 if (!set_boot_path('/', ':')) 383 return; 384 } 385 386 /* 387 * Where to look for native libraries 388 * 389 * Note: Due to a legacy implementation, most of the library path 390 * is set in the launcher. This was to accomodate linking restrictions 391 * on legacy Bsd implementations (which are no longer supported). 392 * Eventually, all the library path setting will be done here. 393 * 394 * However, to prevent the proliferation of improperly built native 395 * libraries, the new path component /usr/java/packages is added here. 396 * Eventually, all the library path setting will be done here. 397 */ 398 { 399 char *ld_library_path; 400 401 /* 402 * Construct the invariant part of ld_library_path. Note that the 403 * space for the colon and the trailing null are provided by the 404 * nulls included by the sizeof operator (so actually we allocate 405 * a byte more than necessary). 406 */ 407 #ifdef __APPLE__ 408 ld_library_path = (char *) malloc(system_ext_size); 409 sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir); 410 #else 411 ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") + 412 strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH)); 413 sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch); 414 #endif 415 416 /* 417 * Get the user setting of LD_LIBRARY_PATH, and prepended it. It 418 * should always exist (until the legacy problem cited above is 419 * addressed). 420 */ 421 #ifdef __APPLE__ 422 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper 423 char *l = getenv("JAVA_LIBRARY_PATH"); 424 if (l != NULL) { 425 char *t = ld_library_path; 426 /* That's +1 for the colon and +1 for the trailing '\0' */ 427 ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1); 428 sprintf(ld_library_path, "%s:%s", l, t); 429 free(t); 430 } 431 432 char *v = getenv("DYLD_LIBRARY_PATH"); 433 #else 434 char *v = getenv("LD_LIBRARY_PATH"); 435 #endif 436 if (v != NULL) { 437 char *t = ld_library_path; 438 /* That's +1 for the colon and +1 for the trailing '\0' */ 439 ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1); 440 sprintf(ld_library_path, "%s:%s", v, t); 441 free(t); 442 } 443 444 #ifdef __APPLE__ 445 // Apple's Java6 has "." at the beginning of java.library.path. 446 // OpenJDK on Windows has "." at the end of java.library.path. 447 // OpenJDK on Linux and Solaris don't have "." in java.library.path 448 // at all. To ease the transition from Apple's Java6 to OpenJDK7, 449 // "." is appended to the end of java.library.path. Yes, this 450 // could cause a change in behavior, but Apple's Java6 behavior 451 // can be achieved by putting "." at the beginning of the 452 // JAVA_LIBRARY_PATH environment variable. 453 { 454 char *t = ld_library_path; 455 // that's +3 for appending ":." and the trailing '\0' 456 ld_library_path = (char *) malloc(strlen(t) + 3); 457 sprintf(ld_library_path, "%s:%s", t, "."); 458 free(t); 459 } 460 #endif 461 462 Arguments::set_library_path(ld_library_path); 463 } 464 465 /* 466 * Extensions directories. 467 * 468 * Note that the space for the colon and the trailing null are provided 469 * by the nulls included by the sizeof operator (so actually one byte more 470 * than necessary is allocated). 471 */ 472 { 473 #ifdef __APPLE__ 474 char *buf = malloc(strlen(Arguments::get_java_home()) + 475 sizeof(EXTENSIONS_DIR) + system_ext_size); 476 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" 477 SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home()); 478 #else 479 char *buf = malloc(strlen(Arguments::get_java_home()) + 480 sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR)); 481 sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR, 482 Arguments::get_java_home()); 483 #endif 484 485 Arguments::set_ext_dirs(buf); 486 } 487 488 /* Endorsed standards default directory. */ 489 { 490 char * buf; 491 buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR)); 492 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); 493 Arguments::set_endorsed_dirs(buf); 494 } 495 } 496 497 #ifdef __APPLE__ 498 #undef SYS_EXTENSIONS_DIR 499 #endif 500 #undef malloc 501 #undef getenv 502 #undef EXTENSIONS_DIR 503 #undef ENDORSED_DIR 504 505 // Done 506 return; 507 } 508 509 //////////////////////////////////////////////////////////////////////////////// 510 // breakpoint support 511 512 void os::breakpoint() { 513 BREAKPOINT; 514 } 515 516 extern "C" void breakpoint() { 517 // use debugger to set breakpoint here 518 } 519 520 //////////////////////////////////////////////////////////////////////////////// 521 // signal support 522 523 debug_only(static bool signal_sets_initialized = false); 524 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 525 526 bool os::Bsd::is_sig_ignored(int sig) { 527 struct sigaction oact; 528 sigaction(sig, (struct sigaction*)NULL, &oact); 529 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 530 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 531 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) 532 return true; 533 else 534 return false; 535 } 536 537 void os::Bsd::signal_sets_init() { 538 // Should also have an assertion stating we are still single-threaded. 539 assert(!signal_sets_initialized, "Already initialized"); 540 // Fill in signals that are necessarily unblocked for all threads in 541 // the VM. Currently, we unblock the following signals: 542 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 543 // by -Xrs (=ReduceSignalUsage)); 544 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 545 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 546 // the dispositions or masks wrt these signals. 547 // Programs embedding the VM that want to use the above signals for their 548 // own purposes must, at this time, use the "-Xrs" option to prevent 549 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 550 // (See bug 4345157, and other related bugs). 551 // In reality, though, unblocking these signals is really a nop, since 552 // these signals are not blocked by default. 553 sigemptyset(&unblocked_sigs); 554 sigemptyset(&allowdebug_blocked_sigs); 555 sigaddset(&unblocked_sigs, SIGILL); 556 sigaddset(&unblocked_sigs, SIGSEGV); 557 sigaddset(&unblocked_sigs, SIGBUS); 558 sigaddset(&unblocked_sigs, SIGFPE); 559 sigaddset(&unblocked_sigs, SR_signum); 560 561 if (!ReduceSignalUsage) { 562 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 563 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 564 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); 565 } 566 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 567 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 568 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); 569 } 570 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 571 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 572 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); 573 } 574 } 575 // Fill in signals that are blocked by all but the VM thread. 576 sigemptyset(&vm_sigs); 577 if (!ReduceSignalUsage) 578 sigaddset(&vm_sigs, BREAK_SIGNAL); 579 debug_only(signal_sets_initialized = true); 580 581 } 582 583 // These are signals that are unblocked while a thread is running Java. 584 // (For some reason, they get blocked by default.) 585 sigset_t* os::Bsd::unblocked_signals() { 586 assert(signal_sets_initialized, "Not initialized"); 587 return &unblocked_sigs; 588 } 589 590 // These are the signals that are blocked while a (non-VM) thread is 591 // running Java. Only the VM thread handles these signals. 592 sigset_t* os::Bsd::vm_signals() { 593 assert(signal_sets_initialized, "Not initialized"); 594 return &vm_sigs; 595 } 596 597 // These are signals that are blocked during cond_wait to allow debugger in 598 sigset_t* os::Bsd::allowdebug_blocked_signals() { 599 assert(signal_sets_initialized, "Not initialized"); 600 return &allowdebug_blocked_sigs; 601 } 602 603 void os::Bsd::hotspot_sigmask(Thread* thread) { 604 605 //Save caller's signal mask before setting VM signal mask 606 sigset_t caller_sigmask; 607 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 608 609 OSThread* osthread = thread->osthread(); 610 osthread->set_caller_sigmask(caller_sigmask); 611 612 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); 613 614 if (!ReduceSignalUsage) { 615 if (thread->is_VM_thread()) { 616 // Only the VM thread handles BREAK_SIGNAL ... 617 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 618 } else { 619 // ... all other threads block BREAK_SIGNAL 620 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 621 } 622 } 623 } 624 625 626 ////////////////////////////////////////////////////////////////////////////// 627 // create new thread 628 629 static address highest_vm_reserved_address(); 630 631 // check if it's safe to start a new thread 632 static bool _thread_safety_check(Thread* thread) { 633 return true; 634 } 635 636 #ifdef __APPLE__ 637 // library handle for calling objc_registerThreadWithCollector() 638 // without static linking to the libobjc library 639 #define OBJC_LIB "/usr/lib/libobjc.dylib" 640 #define OBJC_GCREGISTER "objc_registerThreadWithCollector" 641 typedef void (*objc_registerThreadWithCollector_t)(); 642 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction; 643 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL; 644 #endif 645 646 #ifdef __APPLE__ 647 static uint64_t locate_unique_thread_id() { 648 // Additional thread_id used to correlate threads in SA 649 thread_identifier_info_data_t m_ident_info; 650 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT; 651 652 thread_info(::mach_thread_self(), THREAD_IDENTIFIER_INFO, 653 (thread_info_t) &m_ident_info, &count); 654 return m_ident_info.thread_id; 655 } 656 #endif 657 658 // Thread start routine for all newly created threads 659 static void *java_start(Thread *thread) { 660 // Try to randomize the cache line index of hot stack frames. 661 // This helps when threads of the same stack traces evict each other's 662 // cache lines. The threads can be either from the same JVM instance, or 663 // from different JVM instances. The benefit is especially true for 664 // processors with hyperthreading technology. 665 static int counter = 0; 666 int pid = os::current_process_id(); 667 alloca(((pid ^ counter++) & 7) * 128); 668 669 ThreadLocalStorage::set_thread(thread); 670 671 OSThread* osthread = thread->osthread(); 672 Monitor* sync = osthread->startThread_lock(); 673 674 // non floating stack BsdThreads needs extra check, see above 675 if (!_thread_safety_check(thread)) { 676 // notify parent thread 677 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 678 osthread->set_state(ZOMBIE); 679 sync->notify_all(); 680 return NULL; 681 } 682 683 #ifdef __APPLE__ 684 // thread_id is mach thread on macos 685 osthread->set_thread_id(::mach_thread_self()); 686 osthread->set_unique_thread_id(locate_unique_thread_id()); 687 #else 688 // thread_id is pthread_id on BSD 689 osthread->set_thread_id(::pthread_self()); 690 #endif 691 // initialize signal mask for this thread 692 os::Bsd::hotspot_sigmask(thread); 693 694 // initialize floating point control register 695 os::Bsd::init_thread_fpu_state(); 696 697 #ifdef __APPLE__ 698 // register thread with objc gc 699 if (objc_registerThreadWithCollectorFunction != NULL) { 700 objc_registerThreadWithCollectorFunction(); 701 } 702 #endif 703 704 // handshaking with parent thread 705 { 706 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 707 708 // notify parent thread 709 osthread->set_state(INITIALIZED); 710 sync->notify_all(); 711 712 // wait until os::start_thread() 713 while (osthread->get_state() == INITIALIZED) { 714 sync->wait(Mutex::_no_safepoint_check_flag); 715 } 716 } 717 718 // call one more level start routine 719 thread->run(); 720 721 return 0; 722 } 723 724 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { 725 assert(thread->osthread() == NULL, "caller responsible"); 726 727 // Allocate the OSThread object 728 OSThread* osthread = new OSThread(NULL, NULL); 729 if (osthread == NULL) { 730 return false; 731 } 732 733 // set the correct thread state 734 osthread->set_thread_type(thr_type); 735 736 // Initial state is ALLOCATED but not INITIALIZED 737 osthread->set_state(ALLOCATED); 738 739 thread->set_osthread(osthread); 740 741 // init thread attributes 742 pthread_attr_t attr; 743 pthread_attr_init(&attr); 744 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 745 746 // stack size 747 if (os::Bsd::supports_variable_stack_size()) { 748 // calculate stack size if it's not specified by caller 749 if (stack_size == 0) { 750 stack_size = os::Bsd::default_stack_size(thr_type); 751 752 switch (thr_type) { 753 case os::java_thread: 754 // Java threads use ThreadStackSize which default value can be 755 // changed with the flag -Xss 756 assert (JavaThread::stack_size_at_create() > 0, "this should be set"); 757 stack_size = JavaThread::stack_size_at_create(); 758 break; 759 case os::compiler_thread: 760 if (CompilerThreadStackSize > 0) { 761 stack_size = (size_t)(CompilerThreadStackSize * K); 762 break; 763 } // else fall through: 764 // use VMThreadStackSize if CompilerThreadStackSize is not defined 765 case os::vm_thread: 766 case os::pgc_thread: 767 case os::cgc_thread: 768 case os::watcher_thread: 769 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 770 break; 771 } 772 } 773 774 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); 775 pthread_attr_setstacksize(&attr, stack_size); 776 } else { 777 // let pthread_create() pick the default value. 778 } 779 780 ThreadState state; 781 782 { 783 pthread_t tid; 784 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 785 786 pthread_attr_destroy(&attr); 787 788 if (ret != 0) { 789 if (PrintMiscellaneous && (Verbose || WizardMode)) { 790 perror("pthread_create()"); 791 } 792 // Need to clean up stuff we've allocated so far 793 thread->set_osthread(NULL); 794 delete osthread; 795 return false; 796 } 797 798 // Store pthread info into the OSThread 799 osthread->set_pthread_id(tid); 800 801 // Wait until child thread is either initialized or aborted 802 { 803 Monitor* sync_with_child = osthread->startThread_lock(); 804 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 805 while ((state = osthread->get_state()) == ALLOCATED) { 806 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 807 } 808 } 809 810 } 811 812 // Aborted due to thread limit being reached 813 if (state == ZOMBIE) { 814 thread->set_osthread(NULL); 815 delete osthread; 816 return false; 817 } 818 819 // The thread is returned suspended (in state INITIALIZED), 820 // and is started higher up in the call chain 821 assert(state == INITIALIZED, "race condition"); 822 return true; 823 } 824 825 ///////////////////////////////////////////////////////////////////////////// 826 // attach existing thread 827 828 // bootstrap the main thread 829 bool os::create_main_thread(JavaThread* thread) { 830 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); 831 return create_attached_thread(thread); 832 } 833 834 bool os::create_attached_thread(JavaThread* thread) { 835 #ifdef ASSERT 836 thread->verify_not_published(); 837 #endif 838 839 // Allocate the OSThread object 840 OSThread* osthread = new OSThread(NULL, NULL); 841 842 if (osthread == NULL) { 843 return false; 844 } 845 846 // Store pthread info into the OSThread 847 #ifdef __APPLE__ 848 osthread->set_thread_id(::mach_thread_self()); 849 osthread->set_unique_thread_id(locate_unique_thread_id()); 850 #else 851 osthread->set_thread_id(::pthread_self()); 852 #endif 853 osthread->set_pthread_id(::pthread_self()); 854 855 // initialize floating point control register 856 os::Bsd::init_thread_fpu_state(); 857 858 // Initial thread state is RUNNABLE 859 osthread->set_state(RUNNABLE); 860 861 thread->set_osthread(osthread); 862 863 // initialize signal mask for this thread 864 // and save the caller's signal mask 865 os::Bsd::hotspot_sigmask(thread); 866 867 return true; 868 } 869 870 void os::pd_start_thread(Thread* thread) { 871 OSThread * osthread = thread->osthread(); 872 assert(osthread->get_state() != INITIALIZED, "just checking"); 873 Monitor* sync_with_child = osthread->startThread_lock(); 874 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 875 sync_with_child->notify(); 876 } 877 878 // Free Bsd resources related to the OSThread 879 void os::free_thread(OSThread* osthread) { 880 assert(osthread != NULL, "osthread not set"); 881 882 if (Thread::current()->osthread() == osthread) { 883 // Restore caller's signal mask 884 sigset_t sigmask = osthread->caller_sigmask(); 885 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 886 } 887 888 delete osthread; 889 } 890 891 ////////////////////////////////////////////////////////////////////////////// 892 // thread local storage 893 894 int os::allocate_thread_local_storage() { 895 pthread_key_t key; 896 int rslt = pthread_key_create(&key, NULL); 897 assert(rslt == 0, "cannot allocate thread local storage"); 898 return (int)key; 899 } 900 901 // Note: This is currently not used by VM, as we don't destroy TLS key 902 // on VM exit. 903 void os::free_thread_local_storage(int index) { 904 int rslt = pthread_key_delete((pthread_key_t)index); 905 assert(rslt == 0, "invalid index"); 906 } 907 908 void os::thread_local_storage_at_put(int index, void* value) { 909 int rslt = pthread_setspecific((pthread_key_t)index, value); 910 assert(rslt == 0, "pthread_setspecific failed"); 911 } 912 913 extern "C" Thread* get_thread() { 914 return ThreadLocalStorage::thread(); 915 } 916 917 918 //////////////////////////////////////////////////////////////////////////////// 919 // time support 920 921 // Time since start-up in seconds to a fine granularity. 922 // Used by VMSelfDestructTimer and the MemProfiler. 923 double os::elapsedTime() { 924 925 return (double)(os::elapsed_counter()) * 0.000001; 926 } 927 928 jlong os::elapsed_counter() { 929 timeval time; 930 int status = gettimeofday(&time, NULL); 931 return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count; 932 } 933 934 jlong os::elapsed_frequency() { 935 return (1000 * 1000); 936 } 937 938 // XXX: For now, code this as if BSD does not support vtime. 939 bool os::supports_vtime() { return false; } 940 bool os::enable_vtime() { return false; } 941 bool os::vtime_enabled() { return false; } 942 double os::elapsedVTime() { 943 // better than nothing, but not much 944 return elapsedTime(); 945 } 946 947 jlong os::javaTimeMillis() { 948 timeval time; 949 int status = gettimeofday(&time, NULL); 950 assert(status != -1, "bsd error"); 951 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 952 } 953 954 #ifndef CLOCK_MONOTONIC 955 #define CLOCK_MONOTONIC (1) 956 #endif 957 958 #ifdef __APPLE__ 959 void os::Bsd::clock_init() { 960 // XXXDARWIN: Investigate replacement monotonic clock 961 } 962 #else 963 void os::Bsd::clock_init() { 964 struct timespec res; 965 struct timespec tp; 966 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && 967 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { 968 // yes, monotonic clock is supported 969 _clock_gettime = ::clock_gettime; 970 } 971 } 972 #endif 973 974 975 jlong os::javaTimeNanos() { 976 if (Bsd::supports_monotonic_clock()) { 977 struct timespec tp; 978 int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp); 979 assert(status == 0, "gettime error"); 980 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 981 return result; 982 } else { 983 timeval time; 984 int status = gettimeofday(&time, NULL); 985 assert(status != -1, "bsd error"); 986 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 987 return 1000 * usecs; 988 } 989 } 990 991 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 992 if (Bsd::supports_monotonic_clock()) { 993 info_ptr->max_value = ALL_64_BITS; 994 995 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 996 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 997 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 998 } else { 999 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1000 info_ptr->max_value = ALL_64_BITS; 1001 1002 // gettimeofday is a real time clock so it skips 1003 info_ptr->may_skip_backward = true; 1004 info_ptr->may_skip_forward = true; 1005 } 1006 1007 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1008 } 1009 1010 // Return the real, user, and system times in seconds from an 1011 // arbitrary fixed point in the past. 1012 bool os::getTimesSecs(double* process_real_time, 1013 double* process_user_time, 1014 double* process_system_time) { 1015 struct tms ticks; 1016 clock_t real_ticks = times(&ticks); 1017 1018 if (real_ticks == (clock_t) (-1)) { 1019 return false; 1020 } else { 1021 double ticks_per_second = (double) clock_tics_per_sec; 1022 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1023 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1024 *process_real_time = ((double) real_ticks) / ticks_per_second; 1025 1026 return true; 1027 } 1028 } 1029 1030 1031 char * os::local_time_string(char *buf, size_t buflen) { 1032 struct tm t; 1033 time_t long_time; 1034 time(&long_time); 1035 localtime_r(&long_time, &t); 1036 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1037 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1038 t.tm_hour, t.tm_min, t.tm_sec); 1039 return buf; 1040 } 1041 1042 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1043 return localtime_r(clock, res); 1044 } 1045 1046 //////////////////////////////////////////////////////////////////////////////// 1047 // runtime exit support 1048 1049 // Note: os::shutdown() might be called very early during initialization, or 1050 // called from signal handler. Before adding something to os::shutdown(), make 1051 // sure it is async-safe and can handle partially initialized VM. 1052 void os::shutdown() { 1053 1054 // allow PerfMemory to attempt cleanup of any persistent resources 1055 perfMemory_exit(); 1056 1057 // needs to remove object in file system 1058 AttachListener::abort(); 1059 1060 // flush buffered output, finish log files 1061 ostream_abort(); 1062 1063 // Check for abort hook 1064 abort_hook_t abort_hook = Arguments::abort_hook(); 1065 if (abort_hook != NULL) { 1066 abort_hook(); 1067 } 1068 1069 } 1070 1071 // Note: os::abort() might be called very early during initialization, or 1072 // called from signal handler. Before adding something to os::abort(), make 1073 // sure it is async-safe and can handle partially initialized VM. 1074 void os::abort(bool dump_core) { 1075 os::shutdown(); 1076 if (dump_core) { 1077 #ifndef PRODUCT 1078 fdStream out(defaultStream::output_fd()); 1079 out.print_raw("Current thread is "); 1080 char buf[16]; 1081 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1082 out.print_raw_cr(buf); 1083 out.print_raw_cr("Dumping core ..."); 1084 #endif 1085 ::abort(); // dump core 1086 } 1087 1088 ::exit(1); 1089 } 1090 1091 // Die immediately, no exit hook, no abort hook, no cleanup. 1092 void os::die() { 1093 // _exit() on BsdThreads only kills current thread 1094 ::abort(); 1095 } 1096 1097 // unused on bsd for now. 1098 void os::set_error_file(const char *logfile) {} 1099 1100 1101 // This method is a copy of JDK's sysGetLastErrorString 1102 // from src/solaris/hpi/src/system_md.c 1103 1104 size_t os::lasterror(char *buf, size_t len) { 1105 1106 if (errno == 0) return 0; 1107 1108 const char *s = ::strerror(errno); 1109 size_t n = ::strlen(s); 1110 if (n >= len) { 1111 n = len - 1; 1112 } 1113 ::strncpy(buf, s, n); 1114 buf[n] = '\0'; 1115 return n; 1116 } 1117 1118 intx os::current_thread_id() { 1119 #ifdef __APPLE__ 1120 return (intx)::mach_thread_self(); 1121 #else 1122 return (intx)::pthread_self(); 1123 #endif 1124 } 1125 int os::current_process_id() { 1126 1127 // Under the old bsd thread library, bsd gives each thread 1128 // its own process id. Because of this each thread will return 1129 // a different pid if this method were to return the result 1130 // of getpid(2). Bsd provides no api that returns the pid 1131 // of the launcher thread for the vm. This implementation 1132 // returns a unique pid, the pid of the launcher thread 1133 // that starts the vm 'process'. 1134 1135 // Under the NPTL, getpid() returns the same pid as the 1136 // launcher thread rather than a unique pid per thread. 1137 // Use gettid() if you want the old pre NPTL behaviour. 1138 1139 // if you are looking for the result of a call to getpid() that 1140 // returns a unique pid for the calling thread, then look at the 1141 // OSThread::thread_id() method in osThread_bsd.hpp file 1142 1143 return (int)(_initial_pid ? _initial_pid : getpid()); 1144 } 1145 1146 // DLL functions 1147 1148 #define JNI_LIB_PREFIX "lib" 1149 #ifdef __APPLE__ 1150 #define JNI_LIB_SUFFIX ".dylib" 1151 #else 1152 #define JNI_LIB_SUFFIX ".so" 1153 #endif 1154 1155 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } 1156 1157 // This must be hard coded because it's the system's temporary 1158 // directory not the java application's temp directory, ala java.io.tmpdir. 1159 #ifdef __APPLE__ 1160 // macosx has a secure per-user temporary directory 1161 char temp_path_storage[PATH_MAX]; 1162 const char* os::get_temp_directory() { 1163 static char *temp_path = NULL; 1164 if (temp_path == NULL) { 1165 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX); 1166 if (pathSize == 0 || pathSize > PATH_MAX) { 1167 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage)); 1168 } 1169 temp_path = temp_path_storage; 1170 } 1171 return temp_path; 1172 } 1173 #else /* __APPLE__ */ 1174 const char* os::get_temp_directory() { return "/tmp"; } 1175 #endif /* __APPLE__ */ 1176 1177 static bool file_exists(const char* filename) { 1178 struct stat statbuf; 1179 if (filename == NULL || strlen(filename) == 0) { 1180 return false; 1181 } 1182 return os::stat(filename, &statbuf) == 0; 1183 } 1184 1185 bool os::dll_build_name(char* buffer, size_t buflen, 1186 const char* pname, const char* fname) { 1187 bool retval = false; 1188 // Copied from libhpi 1189 const size_t pnamelen = pname ? strlen(pname) : 0; 1190 1191 // Return error on buffer overflow. 1192 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { 1193 return retval; 1194 } 1195 1196 if (pnamelen == 0) { 1197 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); 1198 retval = true; 1199 } else if (strchr(pname, *os::path_separator()) != NULL) { 1200 int n; 1201 char** pelements = split_path(pname, &n); 1202 if (pelements == NULL) { 1203 return false; 1204 } 1205 for (int i = 0 ; i < n ; i++) { 1206 // Really shouldn't be NULL, but check can't hurt 1207 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1208 continue; // skip the empty path values 1209 } 1210 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, 1211 pelements[i], fname); 1212 if (file_exists(buffer)) { 1213 retval = true; 1214 break; 1215 } 1216 } 1217 // release the storage 1218 for (int i = 0 ; i < n ; i++) { 1219 if (pelements[i] != NULL) { 1220 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal); 1221 } 1222 } 1223 if (pelements != NULL) { 1224 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal); 1225 } 1226 } else { 1227 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); 1228 retval = true; 1229 } 1230 return retval; 1231 } 1232 1233 // check if addr is inside libjvm.so 1234 bool os::address_is_in_vm(address addr) { 1235 static address libjvm_base_addr; 1236 Dl_info dlinfo; 1237 1238 if (libjvm_base_addr == NULL) { 1239 dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo); 1240 libjvm_base_addr = (address)dlinfo.dli_fbase; 1241 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1242 } 1243 1244 if (dladdr((void *)addr, &dlinfo)) { 1245 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1246 } 1247 1248 return false; 1249 } 1250 1251 1252 #define MACH_MAXSYMLEN 256 1253 1254 bool os::dll_address_to_function_name(address addr, char *buf, 1255 int buflen, int *offset) { 1256 Dl_info dlinfo; 1257 char localbuf[MACH_MAXSYMLEN]; 1258 1259 // dladdr will find names of dynamic functions only, but does 1260 // it set dli_fbase with mach_header address when it "fails" ? 1261 if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) { 1262 if (buf != NULL) { 1263 if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { 1264 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1265 } 1266 } 1267 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1268 return true; 1269 } else if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != 0) { 1270 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1271 buf, buflen, offset, dlinfo.dli_fname)) { 1272 return true; 1273 } 1274 } 1275 1276 // Handle non-dymanic manually: 1277 if (dlinfo.dli_fbase != NULL && 1278 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) { 1279 if(!Decoder::demangle(localbuf, buf, buflen)) { 1280 jio_snprintf(buf, buflen, "%s", localbuf); 1281 } 1282 return true; 1283 } 1284 if (buf != NULL) buf[0] = '\0'; 1285 if (offset != NULL) *offset = -1; 1286 return false; 1287 } 1288 1289 // ported from solaris version 1290 bool os::dll_address_to_library_name(address addr, char* buf, 1291 int buflen, int* offset) { 1292 Dl_info dlinfo; 1293 1294 if (dladdr((void*)addr, &dlinfo)){ 1295 if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1296 if (offset) *offset = addr - (address)dlinfo.dli_fbase; 1297 return true; 1298 } else { 1299 if (buf) buf[0] = '\0'; 1300 if (offset) *offset = -1; 1301 return false; 1302 } 1303 } 1304 1305 // Loads .dll/.so and 1306 // in case of error it checks if .dll/.so was built for the 1307 // same architecture as Hotspot is running on 1308 1309 #ifdef __APPLE__ 1310 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1311 void * result= ::dlopen(filename, RTLD_LAZY); 1312 if (result != NULL) { 1313 // Successful loading 1314 return result; 1315 } 1316 1317 // Read system error message into ebuf 1318 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1319 ebuf[ebuflen-1]='\0'; 1320 1321 return NULL; 1322 } 1323 #else 1324 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) 1325 { 1326 void * result= ::dlopen(filename, RTLD_LAZY); 1327 if (result != NULL) { 1328 // Successful loading 1329 return result; 1330 } 1331 1332 Elf32_Ehdr elf_head; 1333 1334 // Read system error message into ebuf 1335 // It may or may not be overwritten below 1336 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1337 ebuf[ebuflen-1]='\0'; 1338 int diag_msg_max_length=ebuflen-strlen(ebuf); 1339 char* diag_msg_buf=ebuf+strlen(ebuf); 1340 1341 if (diag_msg_max_length==0) { 1342 // No more space in ebuf for additional diagnostics message 1343 return NULL; 1344 } 1345 1346 1347 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1348 1349 if (file_descriptor < 0) { 1350 // Can't open library, report dlerror() message 1351 return NULL; 1352 } 1353 1354 bool failed_to_read_elf_head= 1355 (sizeof(elf_head)!= 1356 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ; 1357 1358 ::close(file_descriptor); 1359 if (failed_to_read_elf_head) { 1360 // file i/o error - report dlerror() msg 1361 return NULL; 1362 } 1363 1364 typedef struct { 1365 Elf32_Half code; // Actual value as defined in elf.h 1366 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1367 char elf_class; // 32 or 64 bit 1368 char endianess; // MSB or LSB 1369 char* name; // String representation 1370 } arch_t; 1371 1372 #ifndef EM_486 1373 #define EM_486 6 /* Intel 80486 */ 1374 #endif 1375 1376 #ifndef EM_MIPS_RS3_LE 1377 #define EM_MIPS_RS3_LE 10 /* MIPS */ 1378 #endif 1379 1380 #ifndef EM_PPC64 1381 #define EM_PPC64 21 /* PowerPC64 */ 1382 #endif 1383 1384 #ifndef EM_S390 1385 #define EM_S390 22 /* IBM System/390 */ 1386 #endif 1387 1388 #ifndef EM_IA_64 1389 #define EM_IA_64 50 /* HP/Intel IA-64 */ 1390 #endif 1391 1392 #ifndef EM_X86_64 1393 #define EM_X86_64 62 /* AMD x86-64 */ 1394 #endif 1395 1396 static const arch_t arch_array[]={ 1397 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1398 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1399 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1400 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1401 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1402 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1403 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1404 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1405 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1406 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1407 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1408 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1409 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1410 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1411 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1412 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} 1413 }; 1414 1415 #if (defined IA32) 1416 static Elf32_Half running_arch_code=EM_386; 1417 #elif (defined AMD64) 1418 static Elf32_Half running_arch_code=EM_X86_64; 1419 #elif (defined IA64) 1420 static Elf32_Half running_arch_code=EM_IA_64; 1421 #elif (defined __sparc) && (defined _LP64) 1422 static Elf32_Half running_arch_code=EM_SPARCV9; 1423 #elif (defined __sparc) && (!defined _LP64) 1424 static Elf32_Half running_arch_code=EM_SPARC; 1425 #elif (defined __powerpc64__) 1426 static Elf32_Half running_arch_code=EM_PPC64; 1427 #elif (defined __powerpc__) 1428 static Elf32_Half running_arch_code=EM_PPC; 1429 #elif (defined ARM) 1430 static Elf32_Half running_arch_code=EM_ARM; 1431 #elif (defined S390) 1432 static Elf32_Half running_arch_code=EM_S390; 1433 #elif (defined ALPHA) 1434 static Elf32_Half running_arch_code=EM_ALPHA; 1435 #elif (defined MIPSEL) 1436 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1437 #elif (defined PARISC) 1438 static Elf32_Half running_arch_code=EM_PARISC; 1439 #elif (defined MIPS) 1440 static Elf32_Half running_arch_code=EM_MIPS; 1441 #elif (defined M68K) 1442 static Elf32_Half running_arch_code=EM_68K; 1443 #else 1444 #error Method os::dll_load requires that one of following is defined:\ 1445 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K 1446 #endif 1447 1448 // Identify compatability class for VM's architecture and library's architecture 1449 // Obtain string descriptions for architectures 1450 1451 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1452 int running_arch_index=-1; 1453 1454 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) { 1455 if (running_arch_code == arch_array[i].code) { 1456 running_arch_index = i; 1457 } 1458 if (lib_arch.code == arch_array[i].code) { 1459 lib_arch.compat_class = arch_array[i].compat_class; 1460 lib_arch.name = arch_array[i].name; 1461 } 1462 } 1463 1464 assert(running_arch_index != -1, 1465 "Didn't find running architecture code (running_arch_code) in arch_array"); 1466 if (running_arch_index == -1) { 1467 // Even though running architecture detection failed 1468 // we may still continue with reporting dlerror() message 1469 return NULL; 1470 } 1471 1472 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1473 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1474 return NULL; 1475 } 1476 1477 #ifndef S390 1478 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1479 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1480 return NULL; 1481 } 1482 #endif // !S390 1483 1484 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1485 if ( lib_arch.name!=NULL ) { 1486 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1487 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1488 lib_arch.name, arch_array[running_arch_index].name); 1489 } else { 1490 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1491 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1492 lib_arch.code, 1493 arch_array[running_arch_index].name); 1494 } 1495 } 1496 1497 return NULL; 1498 } 1499 #endif /* !__APPLE__ */ 1500 1501 // XXX: Do we need a lock around this as per Linux? 1502 void* os::dll_lookup(void* handle, const char* name) { 1503 return dlsym(handle, name); 1504 } 1505 1506 1507 static bool _print_ascii_file(const char* filename, outputStream* st) { 1508 int fd = ::open(filename, O_RDONLY); 1509 if (fd == -1) { 1510 return false; 1511 } 1512 1513 char buf[32]; 1514 int bytes; 1515 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { 1516 st->print_raw(buf, bytes); 1517 } 1518 1519 ::close(fd); 1520 1521 return true; 1522 } 1523 1524 void os::print_dll_info(outputStream *st) { 1525 st->print_cr("Dynamic libraries:"); 1526 #ifdef RTLD_DI_LINKMAP 1527 Dl_info dli; 1528 void *handle; 1529 Link_map *map; 1530 Link_map *p; 1531 1532 if (!dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli)) { 1533 st->print_cr("Error: Cannot print dynamic libraries."); 1534 return; 1535 } 1536 handle = dlopen(dli.dli_fname, RTLD_LAZY); 1537 if (handle == NULL) { 1538 st->print_cr("Error: Cannot print dynamic libraries."); 1539 return; 1540 } 1541 dlinfo(handle, RTLD_DI_LINKMAP, &map); 1542 if (map == NULL) { 1543 st->print_cr("Error: Cannot print dynamic libraries."); 1544 return; 1545 } 1546 1547 while (map->l_prev != NULL) 1548 map = map->l_prev; 1549 1550 while (map != NULL) { 1551 st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name); 1552 map = map->l_next; 1553 } 1554 1555 dlclose(handle); 1556 #elif defined(__APPLE__) 1557 uint32_t count; 1558 uint32_t i; 1559 1560 count = _dyld_image_count(); 1561 for (i = 1; i < count; i++) { 1562 const char *name = _dyld_get_image_name(i); 1563 intptr_t slide = _dyld_get_image_vmaddr_slide(i); 1564 st->print_cr(PTR_FORMAT " \t%s", slide, name); 1565 } 1566 #else 1567 st->print_cr("Error: Cannot print dynamic libraries."); 1568 #endif 1569 } 1570 1571 void os::print_os_info_brief(outputStream* st) { 1572 st->print("Bsd"); 1573 1574 os::Posix::print_uname_info(st); 1575 } 1576 1577 void os::print_os_info(outputStream* st) { 1578 st->print("OS:"); 1579 st->print("Bsd"); 1580 1581 os::Posix::print_uname_info(st); 1582 1583 os::Posix::print_rlimit_info(st); 1584 1585 os::Posix::print_load_average(st); 1586 } 1587 1588 void os::pd_print_cpu_info(outputStream* st) { 1589 // Nothing to do for now. 1590 } 1591 1592 void os::print_memory_info(outputStream* st) { 1593 1594 st->print("Memory:"); 1595 st->print(" %dk page", os::vm_page_size()>>10); 1596 1597 st->print(", physical " UINT64_FORMAT "k", 1598 os::physical_memory() >> 10); 1599 st->print("(" UINT64_FORMAT "k free)", 1600 os::available_memory() >> 10); 1601 st->cr(); 1602 1603 // meminfo 1604 st->print("\n/proc/meminfo:\n"); 1605 _print_ascii_file("/proc/meminfo", st); 1606 st->cr(); 1607 } 1608 1609 // Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific 1610 // but they're the same for all the bsd arch that we support 1611 // and they're the same for solaris but there's no common place to put this. 1612 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR", 1613 "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG", 1614 "ILL_COPROC", "ILL_BADSTK" }; 1615 1616 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV", 1617 "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES", 1618 "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" }; 1619 1620 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" }; 1621 1622 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" }; 1623 1624 void os::print_siginfo(outputStream* st, void* siginfo) { 1625 st->print("siginfo:"); 1626 1627 const int buflen = 100; 1628 char buf[buflen]; 1629 siginfo_t *si = (siginfo_t*)siginfo; 1630 st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen)); 1631 if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) { 1632 st->print("si_errno=%s", buf); 1633 } else { 1634 st->print("si_errno=%d", si->si_errno); 1635 } 1636 const int c = si->si_code; 1637 assert(c > 0, "unexpected si_code"); 1638 switch (si->si_signo) { 1639 case SIGILL: 1640 st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]); 1641 st->print(", si_addr=" PTR_FORMAT, si->si_addr); 1642 break; 1643 case SIGFPE: 1644 st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]); 1645 st->print(", si_addr=" PTR_FORMAT, si->si_addr); 1646 break; 1647 case SIGSEGV: 1648 st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]); 1649 st->print(", si_addr=" PTR_FORMAT, si->si_addr); 1650 break; 1651 case SIGBUS: 1652 st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]); 1653 st->print(", si_addr=" PTR_FORMAT, si->si_addr); 1654 break; 1655 default: 1656 st->print(", si_code=%d", si->si_code); 1657 // no si_addr 1658 } 1659 1660 if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && 1661 UseSharedSpaces) { 1662 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1663 if (mapinfo->is_in_shared_space(si->si_addr)) { 1664 st->print("\n\nError accessing class data sharing archive." \ 1665 " Mapped file inaccessible during execution, " \ 1666 " possible disk/network problem."); 1667 } 1668 } 1669 st->cr(); 1670 } 1671 1672 1673 static void print_signal_handler(outputStream* st, int sig, 1674 char* buf, size_t buflen); 1675 1676 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 1677 st->print_cr("Signal Handlers:"); 1678 print_signal_handler(st, SIGSEGV, buf, buflen); 1679 print_signal_handler(st, SIGBUS , buf, buflen); 1680 print_signal_handler(st, SIGFPE , buf, buflen); 1681 print_signal_handler(st, SIGPIPE, buf, buflen); 1682 print_signal_handler(st, SIGXFSZ, buf, buflen); 1683 print_signal_handler(st, SIGILL , buf, buflen); 1684 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); 1685 print_signal_handler(st, SR_signum, buf, buflen); 1686 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 1687 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 1688 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 1689 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 1690 } 1691 1692 static char saved_jvm_path[MAXPATHLEN] = {0}; 1693 1694 // Find the full path to the current module, libjvm 1695 void os::jvm_path(char *buf, jint buflen) { 1696 // Error checking. 1697 if (buflen < MAXPATHLEN) { 1698 assert(false, "must use a large-enough buffer"); 1699 buf[0] = '\0'; 1700 return; 1701 } 1702 // Lazy resolve the path to current module. 1703 if (saved_jvm_path[0] != 0) { 1704 strcpy(buf, saved_jvm_path); 1705 return; 1706 } 1707 1708 char dli_fname[MAXPATHLEN]; 1709 bool ret = dll_address_to_library_name( 1710 CAST_FROM_FN_PTR(address, os::jvm_path), 1711 dli_fname, sizeof(dli_fname), NULL); 1712 assert(ret != 0, "cannot locate libjvm"); 1713 char *rp = realpath(dli_fname, buf); 1714 if (rp == NULL) 1715 return; 1716 1717 if (Arguments::created_by_gamma_launcher()) { 1718 // Support for the gamma launcher. Typical value for buf is 1719 // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm". If "/jre/lib/" appears at 1720 // the right place in the string, then assume we are installed in a JDK and 1721 // we're done. Otherwise, check for a JAVA_HOME environment variable and 1722 // construct a path to the JVM being overridden. 1723 1724 const char *p = buf + strlen(buf) - 1; 1725 for (int count = 0; p > buf && count < 5; ++count) { 1726 for (--p; p > buf && *p != '/'; --p) 1727 /* empty */ ; 1728 } 1729 1730 if (strncmp(p, "/jre/lib/", 9) != 0) { 1731 // Look for JAVA_HOME in the environment. 1732 char* java_home_var = ::getenv("JAVA_HOME"); 1733 if (java_home_var != NULL && java_home_var[0] != 0) { 1734 char* jrelib_p; 1735 int len; 1736 1737 // Check the current module name "libjvm" 1738 p = strrchr(buf, '/'); 1739 assert(strstr(p, "/libjvm") == p, "invalid library name"); 1740 1741 rp = realpath(java_home_var, buf); 1742 if (rp == NULL) 1743 return; 1744 1745 // determine if this is a legacy image or modules image 1746 // modules image doesn't have "jre" subdirectory 1747 len = strlen(buf); 1748 jrelib_p = buf + len; 1749 1750 // Add the appropriate library subdir 1751 snprintf(jrelib_p, buflen-len, "/jre/lib"); 1752 if (0 != access(buf, F_OK)) { 1753 snprintf(jrelib_p, buflen-len, "/lib"); 1754 } 1755 1756 // Add the appropriate client or server subdir 1757 len = strlen(buf); 1758 jrelib_p = buf + len; 1759 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT); 1760 if (0 != access(buf, F_OK)) { 1761 snprintf(jrelib_p, buflen-len, ""); 1762 } 1763 1764 // If the path exists within JAVA_HOME, add the JVM library name 1765 // to complete the path to JVM being overridden. Otherwise fallback 1766 // to the path to the current library. 1767 if (0 == access(buf, F_OK)) { 1768 // Use current module name "libjvm" 1769 len = strlen(buf); 1770 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX); 1771 } else { 1772 // Fall back to path of current library 1773 rp = realpath(dli_fname, buf); 1774 if (rp == NULL) 1775 return; 1776 } 1777 } 1778 } 1779 } 1780 1781 strcpy(saved_jvm_path, buf); 1782 } 1783 1784 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 1785 // no prefix required, not even "_" 1786 } 1787 1788 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 1789 // no suffix required 1790 } 1791 1792 //////////////////////////////////////////////////////////////////////////////// 1793 // sun.misc.Signal support 1794 1795 static volatile jint sigint_count = 0; 1796 1797 static void 1798 UserHandler(int sig, void *siginfo, void *context) { 1799 // 4511530 - sem_post is serialized and handled by the manager thread. When 1800 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 1801 // don't want to flood the manager thread with sem_post requests. 1802 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) 1803 return; 1804 1805 // Ctrl-C is pressed during error reporting, likely because the error 1806 // handler fails to abort. Let VM die immediately. 1807 if (sig == SIGINT && is_error_reported()) { 1808 os::die(); 1809 } 1810 1811 os::signal_notify(sig); 1812 } 1813 1814 void* os::user_handler() { 1815 return CAST_FROM_FN_PTR(void*, UserHandler); 1816 } 1817 1818 extern "C" { 1819 typedef void (*sa_handler_t)(int); 1820 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1821 } 1822 1823 void* os::signal(int signal_number, void* handler) { 1824 struct sigaction sigAct, oldSigAct; 1825 1826 sigfillset(&(sigAct.sa_mask)); 1827 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 1828 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 1829 1830 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 1831 // -1 means registration failed 1832 return (void *)-1; 1833 } 1834 1835 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 1836 } 1837 1838 void os::signal_raise(int signal_number) { 1839 ::raise(signal_number); 1840 } 1841 1842 /* 1843 * The following code is moved from os.cpp for making this 1844 * code platform specific, which it is by its very nature. 1845 */ 1846 1847 // Will be modified when max signal is changed to be dynamic 1848 int os::sigexitnum_pd() { 1849 return NSIG; 1850 } 1851 1852 // a counter for each possible signal value 1853 static volatile jint pending_signals[NSIG+1] = { 0 }; 1854 1855 // Bsd(POSIX) specific hand shaking semaphore. 1856 #ifdef __APPLE__ 1857 static semaphore_t sig_sem; 1858 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) 1859 #define SEM_WAIT(sem) semaphore_wait(sem); 1860 #define SEM_POST(sem) semaphore_signal(sem); 1861 #else 1862 static sem_t sig_sem; 1863 #define SEM_INIT(sem, value) sem_init(&sem, 0, value) 1864 #define SEM_WAIT(sem) sem_wait(&sem); 1865 #define SEM_POST(sem) sem_post(&sem); 1866 #endif 1867 1868 void os::signal_init_pd() { 1869 // Initialize signal structures 1870 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 1871 1872 // Initialize signal semaphore 1873 ::SEM_INIT(sig_sem, 0); 1874 } 1875 1876 void os::signal_notify(int sig) { 1877 Atomic::inc(&pending_signals[sig]); 1878 ::SEM_POST(sig_sem); 1879 } 1880 1881 static int check_pending_signals(bool wait) { 1882 Atomic::store(0, &sigint_count); 1883 for (;;) { 1884 for (int i = 0; i < NSIG + 1; i++) { 1885 jint n = pending_signals[i]; 1886 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 1887 return i; 1888 } 1889 } 1890 if (!wait) { 1891 return -1; 1892 } 1893 JavaThread *thread = JavaThread::current(); 1894 ThreadBlockInVM tbivm(thread); 1895 1896 bool threadIsSuspended; 1897 do { 1898 thread->set_suspend_equivalent(); 1899 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 1900 ::SEM_WAIT(sig_sem); 1901 1902 // were we externally suspended while we were waiting? 1903 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 1904 if (threadIsSuspended) { 1905 // 1906 // The semaphore has been incremented, but while we were waiting 1907 // another thread suspended us. We don't want to continue running 1908 // while suspended because that would surprise the thread that 1909 // suspended us. 1910 // 1911 ::SEM_POST(sig_sem); 1912 1913 thread->java_suspend_self(); 1914 } 1915 } while (threadIsSuspended); 1916 } 1917 } 1918 1919 int os::signal_lookup() { 1920 return check_pending_signals(false); 1921 } 1922 1923 int os::signal_wait() { 1924 return check_pending_signals(true); 1925 } 1926 1927 //////////////////////////////////////////////////////////////////////////////// 1928 // Virtual Memory 1929 1930 int os::vm_page_size() { 1931 // Seems redundant as all get out 1932 assert(os::Bsd::page_size() != -1, "must call os::init"); 1933 return os::Bsd::page_size(); 1934 } 1935 1936 // Solaris allocates memory by pages. 1937 int os::vm_allocation_granularity() { 1938 assert(os::Bsd::page_size() != -1, "must call os::init"); 1939 return os::Bsd::page_size(); 1940 } 1941 1942 // Rationale behind this function: 1943 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 1944 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 1945 // samples for JITted code. Here we create private executable mapping over the code cache 1946 // and then we can use standard (well, almost, as mapping can change) way to provide 1947 // info for the reporting script by storing timestamp and location of symbol 1948 void bsd_wrap_code(char* base, size_t size) { 1949 static volatile jint cnt = 0; 1950 1951 if (!UseOprofile) { 1952 return; 1953 } 1954 1955 char buf[PATH_MAX + 1]; 1956 int num = Atomic::add(1, &cnt); 1957 1958 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", 1959 os::get_temp_directory(), os::current_process_id(), num); 1960 unlink(buf); 1961 1962 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 1963 1964 if (fd != -1) { 1965 off_t rv = ::lseek(fd, size-2, SEEK_SET); 1966 if (rv != (off_t)-1) { 1967 if (::write(fd, "", 1) == 1) { 1968 mmap(base, size, 1969 PROT_READ|PROT_WRITE|PROT_EXEC, 1970 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 1971 } 1972 } 1973 ::close(fd); 1974 unlink(buf); 1975 } 1976 } 1977 1978 // NOTE: Bsd kernel does not really reserve the pages for us. 1979 // All it does is to check if there are enough free pages 1980 // left at the time of mmap(). This could be a potential 1981 // problem. 1982 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 1983 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 1984 #ifdef __OpenBSD__ 1985 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 1986 return ::mprotect(addr, size, prot) == 0; 1987 #else 1988 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 1989 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 1990 return res != (uintptr_t) MAP_FAILED; 1991 #endif 1992 } 1993 1994 1995 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 1996 bool exec) { 1997 return commit_memory(addr, size, exec); 1998 } 1999 2000 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2001 } 2002 2003 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2004 ::madvise(addr, bytes, MADV_DONTNEED); 2005 } 2006 2007 void os::numa_make_global(char *addr, size_t bytes) { 2008 } 2009 2010 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2011 } 2012 2013 bool os::numa_topology_changed() { return false; } 2014 2015 size_t os::numa_get_groups_num() { 2016 return 1; 2017 } 2018 2019 int os::numa_get_group_id() { 2020 return 0; 2021 } 2022 2023 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2024 if (size > 0) { 2025 ids[0] = 0; 2026 return 1; 2027 } 2028 return 0; 2029 } 2030 2031 bool os::get_page_info(char *start, page_info* info) { 2032 return false; 2033 } 2034 2035 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { 2036 return end; 2037 } 2038 2039 2040 bool os::pd_uncommit_memory(char* addr, size_t size) { 2041 #ifdef __OpenBSD__ 2042 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2043 return ::mprotect(addr, size, PROT_NONE) == 0; 2044 #else 2045 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2046 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2047 return res != (uintptr_t) MAP_FAILED; 2048 #endif 2049 } 2050 2051 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2052 return os::commit_memory(addr, size); 2053 } 2054 2055 // If this is a growable mapping, remove the guard pages entirely by 2056 // munmap()ping them. If not, just call uncommit_memory(). 2057 bool os::remove_stack_guard_pages(char* addr, size_t size) { 2058 return os::uncommit_memory(addr, size); 2059 } 2060 2061 static address _highest_vm_reserved_address = NULL; 2062 2063 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 2064 // at 'requested_addr'. If there are existing memory mappings at the same 2065 // location, however, they will be overwritten. If 'fixed' is false, 2066 // 'requested_addr' is only treated as a hint, the return value may or 2067 // may not start from the requested address. Unlike Bsd mmap(), this 2068 // function returns NULL to indicate failure. 2069 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 2070 char * addr; 2071 int flags; 2072 2073 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 2074 if (fixed) { 2075 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); 2076 flags |= MAP_FIXED; 2077 } 2078 2079 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 2080 // touch an uncommitted page. Otherwise, the read/write might 2081 // succeed if we have enough swap space to back the physical page. 2082 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 2083 flags, -1, 0); 2084 2085 if (addr != MAP_FAILED) { 2086 // anon_mmap() should only get called during VM initialization, 2087 // don't need lock (actually we can skip locking even it can be called 2088 // from multiple threads, because _highest_vm_reserved_address is just a 2089 // hint about the upper limit of non-stack memory regions.) 2090 if ((address)addr + bytes > _highest_vm_reserved_address) { 2091 _highest_vm_reserved_address = (address)addr + bytes; 2092 } 2093 } 2094 2095 return addr == MAP_FAILED ? NULL : addr; 2096 } 2097 2098 // Don't update _highest_vm_reserved_address, because there might be memory 2099 // regions above addr + size. If so, releasing a memory region only creates 2100 // a hole in the address space, it doesn't help prevent heap-stack collision. 2101 // 2102 static int anon_munmap(char * addr, size_t size) { 2103 return ::munmap(addr, size) == 0; 2104 } 2105 2106 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 2107 size_t alignment_hint) { 2108 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 2109 } 2110 2111 bool os::pd_release_memory(char* addr, size_t size) { 2112 return anon_munmap(addr, size); 2113 } 2114 2115 static address highest_vm_reserved_address() { 2116 return _highest_vm_reserved_address; 2117 } 2118 2119 static bool bsd_mprotect(char* addr, size_t size, int prot) { 2120 // Bsd wants the mprotect address argument to be page aligned. 2121 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); 2122 2123 // According to SUSv3, mprotect() should only be used with mappings 2124 // established by mmap(), and mmap() always maps whole pages. Unaligned 2125 // 'addr' likely indicates problem in the VM (e.g. trying to change 2126 // protection of malloc'ed or statically allocated memory). Check the 2127 // caller if you hit this assert. 2128 assert(addr == bottom, "sanity check"); 2129 2130 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); 2131 return ::mprotect(bottom, size, prot) == 0; 2132 } 2133 2134 // Set protections specified 2135 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 2136 bool is_committed) { 2137 unsigned int p = 0; 2138 switch (prot) { 2139 case MEM_PROT_NONE: p = PROT_NONE; break; 2140 case MEM_PROT_READ: p = PROT_READ; break; 2141 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 2142 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 2143 default: 2144 ShouldNotReachHere(); 2145 } 2146 // is_committed is unused. 2147 return bsd_mprotect(addr, bytes, p); 2148 } 2149 2150 bool os::guard_memory(char* addr, size_t size) { 2151 return bsd_mprotect(addr, size, PROT_NONE); 2152 } 2153 2154 bool os::unguard_memory(char* addr, size_t size) { 2155 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); 2156 } 2157 2158 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { 2159 return false; 2160 } 2161 2162 /* 2163 * Set the coredump_filter bits to include largepages in core dump (bit 6) 2164 * 2165 * From the coredump_filter documentation: 2166 * 2167 * - (bit 0) anonymous private memory 2168 * - (bit 1) anonymous shared memory 2169 * - (bit 2) file-backed private memory 2170 * - (bit 3) file-backed shared memory 2171 * - (bit 4) ELF header pages in file-backed private memory areas (it is 2172 * effective only if the bit 2 is cleared) 2173 * - (bit 5) hugetlb private memory 2174 * - (bit 6) hugetlb shared memory 2175 */ 2176 static void set_coredump_filter(void) { 2177 FILE *f; 2178 long cdm; 2179 2180 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { 2181 return; 2182 } 2183 2184 if (fscanf(f, "%lx", &cdm) != 1) { 2185 fclose(f); 2186 return; 2187 } 2188 2189 rewind(f); 2190 2191 if ((cdm & LARGEPAGES_BIT) == 0) { 2192 cdm |= LARGEPAGES_BIT; 2193 fprintf(f, "%#lx", cdm); 2194 } 2195 2196 fclose(f); 2197 } 2198 2199 // Large page support 2200 2201 static size_t _large_page_size = 0; 2202 2203 void os::large_page_init() { 2204 } 2205 2206 2207 char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) { 2208 // "exec" is passed in but not used. Creating the shared image for 2209 // the code cache doesn't have an SHM_X executable permission to check. 2210 assert(UseLargePages && UseSHM, "only for SHM large pages"); 2211 2212 key_t key = IPC_PRIVATE; 2213 char *addr; 2214 2215 bool warn_on_failure = UseLargePages && 2216 (!FLAG_IS_DEFAULT(UseLargePages) || 2217 !FLAG_IS_DEFAULT(LargePageSizeInBytes) 2218 ); 2219 char msg[128]; 2220 2221 // Create a large shared memory region to attach to based on size. 2222 // Currently, size is the total size of the heap 2223 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); 2224 if (shmid == -1) { 2225 // Possible reasons for shmget failure: 2226 // 1. shmmax is too small for Java heap. 2227 // > check shmmax value: cat /proc/sys/kernel/shmmax 2228 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 2229 // 2. not enough large page memory. 2230 // > check available large pages: cat /proc/meminfo 2231 // > increase amount of large pages: 2232 // echo new_value > /proc/sys/vm/nr_hugepages 2233 // Note 1: different Bsd may use different name for this property, 2234 // e.g. on Redhat AS-3 it is "hugetlb_pool". 2235 // Note 2: it's possible there's enough physical memory available but 2236 // they are so fragmented after a long run that they can't 2237 // coalesce into large pages. Try to reserve large pages when 2238 // the system is still "fresh". 2239 if (warn_on_failure) { 2240 jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno); 2241 warning(msg); 2242 } 2243 return NULL; 2244 } 2245 2246 // attach to the region 2247 addr = (char*)shmat(shmid, req_addr, 0); 2248 int err = errno; 2249 2250 // Remove shmid. If shmat() is successful, the actual shared memory segment 2251 // will be deleted when it's detached by shmdt() or when the process 2252 // terminates. If shmat() is not successful this will remove the shared 2253 // segment immediately. 2254 shmctl(shmid, IPC_RMID, NULL); 2255 2256 if ((intptr_t)addr == -1) { 2257 if (warn_on_failure) { 2258 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err); 2259 warning(msg); 2260 } 2261 return NULL; 2262 } 2263 2264 // The memory is committed 2265 address pc = CALLER_PC; 2266 MemTracker::record_virtual_memory_reserve((address)addr, bytes, pc); 2267 MemTracker::record_virtual_memory_commit((address)addr, bytes, pc); 2268 2269 return addr; 2270 } 2271 2272 bool os::release_memory_special(char* base, size_t bytes) { 2273 // detaching the SHM segment will also delete it, see reserve_memory_special() 2274 int rslt = shmdt(base); 2275 if (rslt == 0) { 2276 MemTracker::record_virtual_memory_uncommit((address)base, bytes); 2277 MemTracker::record_virtual_memory_release((address)base, bytes); 2278 return true; 2279 } else { 2280 return false; 2281 } 2282 2283 } 2284 2285 size_t os::large_page_size() { 2286 return _large_page_size; 2287 } 2288 2289 // HugeTLBFS allows application to commit large page memory on demand; 2290 // with SysV SHM the entire memory region must be allocated as shared 2291 // memory. 2292 bool os::can_commit_large_page_memory() { 2293 return UseHugeTLBFS; 2294 } 2295 2296 bool os::can_execute_large_page_memory() { 2297 return UseHugeTLBFS; 2298 } 2299 2300 // Reserve memory at an arbitrary address, only if that area is 2301 // available (and not reserved for something else). 2302 2303 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 2304 const int max_tries = 10; 2305 char* base[max_tries]; 2306 size_t size[max_tries]; 2307 const size_t gap = 0x000000; 2308 2309 // Assert only that the size is a multiple of the page size, since 2310 // that's all that mmap requires, and since that's all we really know 2311 // about at this low abstraction level. If we need higher alignment, 2312 // we can either pass an alignment to this method or verify alignment 2313 // in one of the methods further up the call chain. See bug 5044738. 2314 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 2315 2316 // Repeatedly allocate blocks until the block is allocated at the 2317 // right spot. Give up after max_tries. Note that reserve_memory() will 2318 // automatically update _highest_vm_reserved_address if the call is 2319 // successful. The variable tracks the highest memory address every reserved 2320 // by JVM. It is used to detect heap-stack collision if running with 2321 // fixed-stack BsdThreads. Because here we may attempt to reserve more 2322 // space than needed, it could confuse the collision detecting code. To 2323 // solve the problem, save current _highest_vm_reserved_address and 2324 // calculate the correct value before return. 2325 address old_highest = _highest_vm_reserved_address; 2326 2327 // Bsd mmap allows caller to pass an address as hint; give it a try first, 2328 // if kernel honors the hint then we can return immediately. 2329 char * addr = anon_mmap(requested_addr, bytes, false); 2330 if (addr == requested_addr) { 2331 return requested_addr; 2332 } 2333 2334 if (addr != NULL) { 2335 // mmap() is successful but it fails to reserve at the requested address 2336 anon_munmap(addr, bytes); 2337 } 2338 2339 int i; 2340 for (i = 0; i < max_tries; ++i) { 2341 base[i] = reserve_memory(bytes); 2342 2343 if (base[i] != NULL) { 2344 // Is this the block we wanted? 2345 if (base[i] == requested_addr) { 2346 size[i] = bytes; 2347 break; 2348 } 2349 2350 // Does this overlap the block we wanted? Give back the overlapped 2351 // parts and try again. 2352 2353 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; 2354 if (top_overlap >= 0 && top_overlap < bytes) { 2355 unmap_memory(base[i], top_overlap); 2356 base[i] += top_overlap; 2357 size[i] = bytes - top_overlap; 2358 } else { 2359 size_t bottom_overlap = base[i] + bytes - requested_addr; 2360 if (bottom_overlap >= 0 && bottom_overlap < bytes) { 2361 unmap_memory(requested_addr, bottom_overlap); 2362 size[i] = bytes - bottom_overlap; 2363 } else { 2364 size[i] = bytes; 2365 } 2366 } 2367 } 2368 } 2369 2370 // Give back the unused reserved pieces. 2371 2372 for (int j = 0; j < i; ++j) { 2373 if (base[j] != NULL) { 2374 unmap_memory(base[j], size[j]); 2375 } 2376 } 2377 2378 if (i < max_tries) { 2379 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); 2380 return requested_addr; 2381 } else { 2382 _highest_vm_reserved_address = old_highest; 2383 return NULL; 2384 } 2385 } 2386 2387 size_t os::read(int fd, void *buf, unsigned int nBytes) { 2388 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); 2389 } 2390 2391 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation. 2392 // Solaris uses poll(), bsd uses park(). 2393 // Poll() is likely a better choice, assuming that Thread.interrupt() 2394 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with 2395 // SIGSEGV, see 4355769. 2396 2397 int os::sleep(Thread* thread, jlong millis, bool interruptible) { 2398 assert(thread == Thread::current(), "thread consistency check"); 2399 2400 ParkEvent * const slp = thread->_SleepEvent ; 2401 slp->reset() ; 2402 OrderAccess::fence() ; 2403 2404 if (interruptible) { 2405 jlong prevtime = javaTimeNanos(); 2406 2407 for (;;) { 2408 if (os::is_interrupted(thread, true)) { 2409 return OS_INTRPT; 2410 } 2411 2412 jlong newtime = javaTimeNanos(); 2413 2414 if (newtime - prevtime < 0) { 2415 // time moving backwards, should only happen if no monotonic clock 2416 // not a guarantee() because JVM should not abort on kernel/glibc bugs 2417 assert(!Bsd::supports_monotonic_clock(), "time moving backwards"); 2418 } else { 2419 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC; 2420 } 2421 2422 if(millis <= 0) { 2423 return OS_OK; 2424 } 2425 2426 prevtime = newtime; 2427 2428 { 2429 assert(thread->is_Java_thread(), "sanity check"); 2430 JavaThread *jt = (JavaThread *) thread; 2431 ThreadBlockInVM tbivm(jt); 2432 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */); 2433 2434 jt->set_suspend_equivalent(); 2435 // cleared by handle_special_suspend_equivalent_condition() or 2436 // java_suspend_self() via check_and_wait_while_suspended() 2437 2438 slp->park(millis); 2439 2440 // were we externally suspended while we were waiting? 2441 jt->check_and_wait_while_suspended(); 2442 } 2443 } 2444 } else { 2445 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 2446 jlong prevtime = javaTimeNanos(); 2447 2448 for (;;) { 2449 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on 2450 // the 1st iteration ... 2451 jlong newtime = javaTimeNanos(); 2452 2453 if (newtime - prevtime < 0) { 2454 // time moving backwards, should only happen if no monotonic clock 2455 // not a guarantee() because JVM should not abort on kernel/glibc bugs 2456 assert(!Bsd::supports_monotonic_clock(), "time moving backwards"); 2457 } else { 2458 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC; 2459 } 2460 2461 if(millis <= 0) break ; 2462 2463 prevtime = newtime; 2464 slp->park(millis); 2465 } 2466 return OS_OK ; 2467 } 2468 } 2469 2470 int os::naked_sleep() { 2471 // %% make the sleep time an integer flag. for now use 1 millisec. 2472 return os::sleep(Thread::current(), 1, false); 2473 } 2474 2475 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 2476 void os::infinite_sleep() { 2477 while (true) { // sleep forever ... 2478 ::sleep(100); // ... 100 seconds at a time 2479 } 2480 } 2481 2482 // Used to convert frequent JVM_Yield() to nops 2483 bool os::dont_yield() { 2484 return DontYieldALot; 2485 } 2486 2487 void os::yield() { 2488 sched_yield(); 2489 } 2490 2491 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;} 2492 2493 void os::yield_all(int attempts) { 2494 // Yields to all threads, including threads with lower priorities 2495 // Threads on Bsd are all with same priority. The Solaris style 2496 // os::yield_all() with nanosleep(1ms) is not necessary. 2497 sched_yield(); 2498 } 2499 2500 // Called from the tight loops to possibly influence time-sharing heuristics 2501 void os::loop_breaker(int attempts) { 2502 os::yield_all(attempts); 2503 } 2504 2505 //////////////////////////////////////////////////////////////////////////////// 2506 // thread priority support 2507 2508 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER 2509 // only supports dynamic priority, static priority must be zero. For real-time 2510 // applications, Bsd supports SCHED_RR which allows static priority (1-99). 2511 // However, for large multi-threaded applications, SCHED_RR is not only slower 2512 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 2513 // of 5 runs - Sep 2005). 2514 // 2515 // The following code actually changes the niceness of kernel-thread/LWP. It 2516 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 2517 // not the entire user process, and user level threads are 1:1 mapped to kernel 2518 // threads. It has always been the case, but could change in the future. For 2519 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 2520 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 2521 2522 #if !defined(__APPLE__) 2523 int os::java_to_os_priority[CriticalPriority + 1] = { 2524 19, // 0 Entry should never be used 2525 2526 0, // 1 MinPriority 2527 3, // 2 2528 6, // 3 2529 2530 10, // 4 2531 15, // 5 NormPriority 2532 18, // 6 2533 2534 21, // 7 2535 25, // 8 2536 28, // 9 NearMaxPriority 2537 2538 31, // 10 MaxPriority 2539 2540 31 // 11 CriticalPriority 2541 }; 2542 #else 2543 /* Using Mach high-level priority assignments */ 2544 int os::java_to_os_priority[CriticalPriority + 1] = { 2545 0, // 0 Entry should never be used (MINPRI_USER) 2546 2547 27, // 1 MinPriority 2548 28, // 2 2549 29, // 3 2550 2551 30, // 4 2552 31, // 5 NormPriority (BASEPRI_DEFAULT) 2553 32, // 6 2554 2555 33, // 7 2556 34, // 8 2557 35, // 9 NearMaxPriority 2558 2559 36, // 10 MaxPriority 2560 2561 36 // 11 CriticalPriority 2562 }; 2563 #endif 2564 2565 static int prio_init() { 2566 if (ThreadPriorityPolicy == 1) { 2567 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 2568 // if effective uid is not root. Perhaps, a more elegant way of doing 2569 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 2570 if (geteuid() != 0) { 2571 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 2572 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); 2573 } 2574 ThreadPriorityPolicy = 0; 2575 } 2576 } 2577 if (UseCriticalJavaThreadPriority) { 2578 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 2579 } 2580 return 0; 2581 } 2582 2583 OSReturn os::set_native_priority(Thread* thread, int newpri) { 2584 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK; 2585 2586 #ifdef __OpenBSD__ 2587 // OpenBSD pthread_setprio starves low priority threads 2588 return OS_OK; 2589 #elif defined(__FreeBSD__) 2590 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); 2591 #elif defined(__APPLE__) || defined(__NetBSD__) 2592 struct sched_param sp; 2593 int policy; 2594 pthread_t self = pthread_self(); 2595 2596 if (pthread_getschedparam(self, &policy, &sp) != 0) 2597 return OS_ERR; 2598 2599 sp.sched_priority = newpri; 2600 if (pthread_setschedparam(self, policy, &sp) != 0) 2601 return OS_ERR; 2602 2603 return OS_OK; 2604 #else 2605 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 2606 return (ret == 0) ? OS_OK : OS_ERR; 2607 #endif 2608 } 2609 2610 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { 2611 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) { 2612 *priority_ptr = java_to_os_priority[NormPriority]; 2613 return OS_OK; 2614 } 2615 2616 errno = 0; 2617 #if defined(__OpenBSD__) || defined(__FreeBSD__) 2618 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); 2619 #elif defined(__APPLE__) || defined(__NetBSD__) 2620 int policy; 2621 struct sched_param sp; 2622 2623 pthread_getschedparam(pthread_self(), &policy, &sp); 2624 *priority_ptr = sp.sched_priority; 2625 #else 2626 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 2627 #endif 2628 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 2629 } 2630 2631 // Hint to the underlying OS that a task switch would not be good. 2632 // Void return because it's a hint and can fail. 2633 void os::hint_no_preempt() {} 2634 2635 //////////////////////////////////////////////////////////////////////////////// 2636 // suspend/resume support 2637 2638 // the low-level signal-based suspend/resume support is a remnant from the 2639 // old VM-suspension that used to be for java-suspension, safepoints etc, 2640 // within hotspot. Now there is a single use-case for this: 2641 // - calling get_thread_pc() on the VMThread by the flat-profiler task 2642 // that runs in the watcher thread. 2643 // The remaining code is greatly simplified from the more general suspension 2644 // code that used to be used. 2645 // 2646 // The protocol is quite simple: 2647 // - suspend: 2648 // - sends a signal to the target thread 2649 // - polls the suspend state of the osthread using a yield loop 2650 // - target thread signal handler (SR_handler) sets suspend state 2651 // and blocks in sigsuspend until continued 2652 // - resume: 2653 // - sets target osthread state to continue 2654 // - sends signal to end the sigsuspend loop in the SR_handler 2655 // 2656 // Note that the SR_lock plays no role in this suspend/resume protocol. 2657 // 2658 2659 static void resume_clear_context(OSThread *osthread) { 2660 osthread->set_ucontext(NULL); 2661 osthread->set_siginfo(NULL); 2662 2663 // notify the suspend action is completed, we have now resumed 2664 osthread->sr.clear_suspended(); 2665 } 2666 2667 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { 2668 osthread->set_ucontext(context); 2669 osthread->set_siginfo(siginfo); 2670 } 2671 2672 // 2673 // Handler function invoked when a thread's execution is suspended or 2674 // resumed. We have to be careful that only async-safe functions are 2675 // called here (Note: most pthread functions are not async safe and 2676 // should be avoided.) 2677 // 2678 // Note: sigwait() is a more natural fit than sigsuspend() from an 2679 // interface point of view, but sigwait() prevents the signal hander 2680 // from being run. libpthread would get very confused by not having 2681 // its signal handlers run and prevents sigwait()'s use with the 2682 // mutex granting granting signal. 2683 // 2684 // Currently only ever called on the VMThread 2685 // 2686 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 2687 // Save and restore errno to avoid confusing native code with EINTR 2688 // after sigsuspend. 2689 int old_errno = errno; 2690 2691 Thread* thread = Thread::current(); 2692 OSThread* osthread = thread->osthread(); 2693 assert(thread->is_VM_thread(), "Must be VMThread"); 2694 // read current suspend action 2695 int action = osthread->sr.suspend_action(); 2696 if (action == os::Bsd::SuspendResume::SR_SUSPEND) { 2697 suspend_save_context(osthread, siginfo, context); 2698 2699 // Notify the suspend action is about to be completed. do_suspend() 2700 // waits until SR_SUSPENDED is set and then returns. We will wait 2701 // here for a resume signal and that completes the suspend-other 2702 // action. do_suspend/do_resume is always called as a pair from 2703 // the same thread - so there are no races 2704 2705 // notify the caller 2706 osthread->sr.set_suspended(); 2707 2708 sigset_t suspend_set; // signals for sigsuspend() 2709 2710 // get current set of blocked signals and unblock resume signal 2711 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 2712 sigdelset(&suspend_set, SR_signum); 2713 2714 // wait here until we are resumed 2715 do { 2716 sigsuspend(&suspend_set); 2717 // ignore all returns until we get a resume signal 2718 } while (osthread->sr.suspend_action() != os::Bsd::SuspendResume::SR_CONTINUE); 2719 2720 resume_clear_context(osthread); 2721 2722 } else { 2723 assert(action == os::Bsd::SuspendResume::SR_CONTINUE, "unexpected sr action"); 2724 // nothing special to do - just leave the handler 2725 } 2726 2727 errno = old_errno; 2728 } 2729 2730 2731 static int SR_initialize() { 2732 struct sigaction act; 2733 char *s; 2734 /* Get signal number to use for suspend/resume */ 2735 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 2736 int sig = ::strtol(s, 0, 10); 2737 if (sig > 0 || sig < NSIG) { 2738 SR_signum = sig; 2739 } 2740 } 2741 2742 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 2743 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 2744 2745 sigemptyset(&SR_sigset); 2746 sigaddset(&SR_sigset, SR_signum); 2747 2748 /* Set up signal handler for suspend/resume */ 2749 act.sa_flags = SA_RESTART|SA_SIGINFO; 2750 act.sa_handler = (void (*)(int)) SR_handler; 2751 2752 // SR_signum is blocked by default. 2753 // 4528190 - We also need to block pthread restart signal (32 on all 2754 // supported Bsd platforms). Note that BsdThreads need to block 2755 // this signal for all threads to work properly. So we don't have 2756 // to use hard-coded signal number when setting up the mask. 2757 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 2758 2759 if (sigaction(SR_signum, &act, 0) == -1) { 2760 return -1; 2761 } 2762 2763 // Save signal flag 2764 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); 2765 return 0; 2766 } 2767 2768 2769 // returns true on success and false on error - really an error is fatal 2770 // but this seems the normal response to library errors 2771 static bool do_suspend(OSThread* osthread) { 2772 // mark as suspended and send signal 2773 osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_SUSPEND); 2774 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2775 assert_status(status == 0, status, "pthread_kill"); 2776 2777 // check status and wait until notified of suspension 2778 if (status == 0) { 2779 for (int i = 0; !osthread->sr.is_suspended(); i++) { 2780 os::yield_all(i); 2781 } 2782 osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE); 2783 return true; 2784 } 2785 else { 2786 osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE); 2787 return false; 2788 } 2789 } 2790 2791 static void do_resume(OSThread* osthread) { 2792 assert(osthread->sr.is_suspended(), "thread should be suspended"); 2793 osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_CONTINUE); 2794 2795 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2796 assert_status(status == 0, status, "pthread_kill"); 2797 // check status and wait unit notified of resumption 2798 if (status == 0) { 2799 for (int i = 0; osthread->sr.is_suspended(); i++) { 2800 os::yield_all(i); 2801 } 2802 } 2803 osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE); 2804 } 2805 2806 //////////////////////////////////////////////////////////////////////////////// 2807 // interrupt support 2808 2809 void os::interrupt(Thread* thread) { 2810 assert(Thread::current() == thread || Threads_lock->owned_by_self(), 2811 "possibility of dangling Thread pointer"); 2812 2813 OSThread* osthread = thread->osthread(); 2814 2815 if (!osthread->interrupted()) { 2816 osthread->set_interrupted(true); 2817 // More than one thread can get here with the same value of osthread, 2818 // resulting in multiple notifications. We do, however, want the store 2819 // to interrupted() to be visible to other threads before we execute unpark(). 2820 OrderAccess::fence(); 2821 ParkEvent * const slp = thread->_SleepEvent ; 2822 if (slp != NULL) slp->unpark() ; 2823 } 2824 2825 // For JSR166. Unpark even if interrupt status already was set 2826 if (thread->is_Java_thread()) 2827 ((JavaThread*)thread)->parker()->unpark(); 2828 2829 ParkEvent * ev = thread->_ParkEvent ; 2830 if (ev != NULL) ev->unpark() ; 2831 2832 } 2833 2834 bool os::is_interrupted(Thread* thread, bool clear_interrupted) { 2835 assert(Thread::current() == thread || Threads_lock->owned_by_self(), 2836 "possibility of dangling Thread pointer"); 2837 2838 OSThread* osthread = thread->osthread(); 2839 2840 bool interrupted = osthread->interrupted(); 2841 2842 if (interrupted && clear_interrupted) { 2843 osthread->set_interrupted(false); 2844 // consider thread->_SleepEvent->reset() ... optional optimization 2845 } 2846 2847 return interrupted; 2848 } 2849 2850 /////////////////////////////////////////////////////////////////////////////////// 2851 // signal handling (except suspend/resume) 2852 2853 // This routine may be used by user applications as a "hook" to catch signals. 2854 // The user-defined signal handler must pass unrecognized signals to this 2855 // routine, and if it returns true (non-zero), then the signal handler must 2856 // return immediately. If the flag "abort_if_unrecognized" is true, then this 2857 // routine will never retun false (zero), but instead will execute a VM panic 2858 // routine kill the process. 2859 // 2860 // If this routine returns false, it is OK to call it again. This allows 2861 // the user-defined signal handler to perform checks either before or after 2862 // the VM performs its own checks. Naturally, the user code would be making 2863 // a serious error if it tried to handle an exception (such as a null check 2864 // or breakpoint) that the VM was generating for its own correct operation. 2865 // 2866 // This routine may recognize any of the following kinds of signals: 2867 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 2868 // It should be consulted by handlers for any of those signals. 2869 // 2870 // The caller of this routine must pass in the three arguments supplied 2871 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 2872 // field of the structure passed to sigaction(). This routine assumes that 2873 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 2874 // 2875 // Note that the VM will print warnings if it detects conflicting signal 2876 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 2877 // 2878 extern "C" JNIEXPORT int 2879 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, 2880 void* ucontext, int abort_if_unrecognized); 2881 2882 void signalHandler(int sig, siginfo_t* info, void* uc) { 2883 assert(info != NULL && uc != NULL, "it must be old kernel"); 2884 int orig_errno = errno; // Preserve errno value over signal handler. 2885 JVM_handle_bsd_signal(sig, info, uc, true); 2886 errno = orig_errno; 2887 } 2888 2889 2890 // This boolean allows users to forward their own non-matching signals 2891 // to JVM_handle_bsd_signal, harmlessly. 2892 bool os::Bsd::signal_handlers_are_installed = false; 2893 2894 // For signal-chaining 2895 struct sigaction os::Bsd::sigact[MAXSIGNUM]; 2896 unsigned int os::Bsd::sigs = 0; 2897 bool os::Bsd::libjsig_is_loaded = false; 2898 typedef struct sigaction *(*get_signal_t)(int); 2899 get_signal_t os::Bsd::get_signal_action = NULL; 2900 2901 struct sigaction* os::Bsd::get_chained_signal_action(int sig) { 2902 struct sigaction *actp = NULL; 2903 2904 if (libjsig_is_loaded) { 2905 // Retrieve the old signal handler from libjsig 2906 actp = (*get_signal_action)(sig); 2907 } 2908 if (actp == NULL) { 2909 // Retrieve the preinstalled signal handler from jvm 2910 actp = get_preinstalled_handler(sig); 2911 } 2912 2913 return actp; 2914 } 2915 2916 static bool call_chained_handler(struct sigaction *actp, int sig, 2917 siginfo_t *siginfo, void *context) { 2918 // Call the old signal handler 2919 if (actp->sa_handler == SIG_DFL) { 2920 // It's more reasonable to let jvm treat it as an unexpected exception 2921 // instead of taking the default action. 2922 return false; 2923 } else if (actp->sa_handler != SIG_IGN) { 2924 if ((actp->sa_flags & SA_NODEFER) == 0) { 2925 // automaticlly block the signal 2926 sigaddset(&(actp->sa_mask), sig); 2927 } 2928 2929 sa_handler_t hand; 2930 sa_sigaction_t sa; 2931 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 2932 // retrieve the chained handler 2933 if (siginfo_flag_set) { 2934 sa = actp->sa_sigaction; 2935 } else { 2936 hand = actp->sa_handler; 2937 } 2938 2939 if ((actp->sa_flags & SA_RESETHAND) != 0) { 2940 actp->sa_handler = SIG_DFL; 2941 } 2942 2943 // try to honor the signal mask 2944 sigset_t oset; 2945 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 2946 2947 // call into the chained handler 2948 if (siginfo_flag_set) { 2949 (*sa)(sig, siginfo, context); 2950 } else { 2951 (*hand)(sig); 2952 } 2953 2954 // restore the signal mask 2955 pthread_sigmask(SIG_SETMASK, &oset, 0); 2956 } 2957 // Tell jvm's signal handler the signal is taken care of. 2958 return true; 2959 } 2960 2961 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { 2962 bool chained = false; 2963 // signal-chaining 2964 if (UseSignalChaining) { 2965 struct sigaction *actp = get_chained_signal_action(sig); 2966 if (actp != NULL) { 2967 chained = call_chained_handler(actp, sig, siginfo, context); 2968 } 2969 } 2970 return chained; 2971 } 2972 2973 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { 2974 if ((( (unsigned int)1 << sig ) & sigs) != 0) { 2975 return &sigact[sig]; 2976 } 2977 return NULL; 2978 } 2979 2980 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 2981 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 2982 sigact[sig] = oldAct; 2983 sigs |= (unsigned int)1 << sig; 2984 } 2985 2986 // for diagnostic 2987 int os::Bsd::sigflags[MAXSIGNUM]; 2988 2989 int os::Bsd::get_our_sigflags(int sig) { 2990 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 2991 return sigflags[sig]; 2992 } 2993 2994 void os::Bsd::set_our_sigflags(int sig, int flags) { 2995 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 2996 sigflags[sig] = flags; 2997 } 2998 2999 void os::Bsd::set_signal_handler(int sig, bool set_installed) { 3000 // Check for overwrite. 3001 struct sigaction oldAct; 3002 sigaction(sig, (struct sigaction*)NULL, &oldAct); 3003 3004 void* oldhand = oldAct.sa_sigaction 3005 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3006 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3007 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 3008 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 3009 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 3010 if (AllowUserSignalHandlers || !set_installed) { 3011 // Do not overwrite; user takes responsibility to forward to us. 3012 return; 3013 } else if (UseSignalChaining) { 3014 // save the old handler in jvm 3015 save_preinstalled_handler(sig, oldAct); 3016 // libjsig also interposes the sigaction() call below and saves the 3017 // old sigaction on it own. 3018 } else { 3019 fatal(err_msg("Encountered unexpected pre-existing sigaction handler " 3020 "%#lx for signal %d.", (long)oldhand, sig)); 3021 } 3022 } 3023 3024 struct sigaction sigAct; 3025 sigfillset(&(sigAct.sa_mask)); 3026 sigAct.sa_handler = SIG_DFL; 3027 if (!set_installed) { 3028 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3029 } else { 3030 sigAct.sa_sigaction = signalHandler; 3031 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3032 } 3033 // Save flags, which are set by ours 3034 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3035 sigflags[sig] = sigAct.sa_flags; 3036 3037 int ret = sigaction(sig, &sigAct, &oldAct); 3038 assert(ret == 0, "check"); 3039 3040 void* oldhand2 = oldAct.sa_sigaction 3041 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3042 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3043 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 3044 } 3045 3046 // install signal handlers for signals that HotSpot needs to 3047 // handle in order to support Java-level exception handling. 3048 3049 void os::Bsd::install_signal_handlers() { 3050 if (!signal_handlers_are_installed) { 3051 signal_handlers_are_installed = true; 3052 3053 // signal-chaining 3054 typedef void (*signal_setting_t)(); 3055 signal_setting_t begin_signal_setting = NULL; 3056 signal_setting_t end_signal_setting = NULL; 3057 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3058 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 3059 if (begin_signal_setting != NULL) { 3060 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3061 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 3062 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 3063 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 3064 libjsig_is_loaded = true; 3065 assert(UseSignalChaining, "should enable signal-chaining"); 3066 } 3067 if (libjsig_is_loaded) { 3068 // Tell libjsig jvm is setting signal handlers 3069 (*begin_signal_setting)(); 3070 } 3071 3072 set_signal_handler(SIGSEGV, true); 3073 set_signal_handler(SIGPIPE, true); 3074 set_signal_handler(SIGBUS, true); 3075 set_signal_handler(SIGILL, true); 3076 set_signal_handler(SIGFPE, true); 3077 set_signal_handler(SIGXFSZ, true); 3078 3079 #if defined(__APPLE__) 3080 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including 3081 // signals caught and handled by the JVM. To work around this, we reset the mach task 3082 // signal handler that's placed on our process by CrashReporter. This disables 3083 // CrashReporter-based reporting. 3084 // 3085 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes 3086 // on caught fatal signals. 3087 // 3088 // Additionally, gdb installs both standard BSD signal handlers, and mach exception 3089 // handlers. By replacing the existing task exception handler, we disable gdb's mach 3090 // exception handling, while leaving the standard BSD signal handlers functional. 3091 kern_return_t kr; 3092 kr = task_set_exception_ports(mach_task_self(), 3093 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, 3094 MACH_PORT_NULL, 3095 EXCEPTION_STATE_IDENTITY, 3096 MACHINE_THREAD_STATE); 3097 3098 assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); 3099 #endif 3100 3101 if (libjsig_is_loaded) { 3102 // Tell libjsig jvm finishes setting signal handlers 3103 (*end_signal_setting)(); 3104 } 3105 3106 // We don't activate signal checker if libjsig is in place, we trust ourselves 3107 // and if UserSignalHandler is installed all bets are off 3108 if (CheckJNICalls) { 3109 if (libjsig_is_loaded) { 3110 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 3111 check_signals = false; 3112 } 3113 if (AllowUserSignalHandlers) { 3114 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 3115 check_signals = false; 3116 } 3117 } 3118 } 3119 } 3120 3121 3122 ///// 3123 // glibc on Bsd platform uses non-documented flag 3124 // to indicate, that some special sort of signal 3125 // trampoline is used. 3126 // We will never set this flag, and we should 3127 // ignore this flag in our diagnostic 3128 #ifdef SIGNIFICANT_SIGNAL_MASK 3129 #undef SIGNIFICANT_SIGNAL_MASK 3130 #endif 3131 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 3132 3133 static const char* get_signal_handler_name(address handler, 3134 char* buf, int buflen) { 3135 int offset; 3136 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 3137 if (found) { 3138 // skip directory names 3139 const char *p1, *p2; 3140 p1 = buf; 3141 size_t len = strlen(os::file_separator()); 3142 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 3143 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 3144 } else { 3145 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 3146 } 3147 return buf; 3148 } 3149 3150 static void print_signal_handler(outputStream* st, int sig, 3151 char* buf, size_t buflen) { 3152 struct sigaction sa; 3153 3154 sigaction(sig, NULL, &sa); 3155 3156 // See comment for SIGNIFICANT_SIGNAL_MASK define 3157 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3158 3159 st->print("%s: ", os::exception_name(sig, buf, buflen)); 3160 3161 address handler = (sa.sa_flags & SA_SIGINFO) 3162 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 3163 : CAST_FROM_FN_PTR(address, sa.sa_handler); 3164 3165 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 3166 st->print("SIG_DFL"); 3167 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 3168 st->print("SIG_IGN"); 3169 } else { 3170 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 3171 } 3172 3173 st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask); 3174 3175 address rh = VMError::get_resetted_sighandler(sig); 3176 // May be, handler was resetted by VMError? 3177 if(rh != NULL) { 3178 handler = rh; 3179 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 3180 } 3181 3182 st->print(", sa_flags=" PTR32_FORMAT, sa.sa_flags); 3183 3184 // Check: is it our handler? 3185 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 3186 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 3187 // It is our signal handler 3188 // check for flags, reset system-used one! 3189 if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3190 st->print( 3191 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 3192 os::Bsd::get_our_sigflags(sig)); 3193 } 3194 } 3195 st->cr(); 3196 } 3197 3198 3199 #define DO_SIGNAL_CHECK(sig) \ 3200 if (!sigismember(&check_signal_done, sig)) \ 3201 os::Bsd::check_signal_handler(sig) 3202 3203 // This method is a periodic task to check for misbehaving JNI applications 3204 // under CheckJNI, we can add any periodic checks here 3205 3206 void os::run_periodic_checks() { 3207 3208 if (check_signals == false) return; 3209 3210 // SEGV and BUS if overridden could potentially prevent 3211 // generation of hs*.log in the event of a crash, debugging 3212 // such a case can be very challenging, so we absolutely 3213 // check the following for a good measure: 3214 DO_SIGNAL_CHECK(SIGSEGV); 3215 DO_SIGNAL_CHECK(SIGILL); 3216 DO_SIGNAL_CHECK(SIGFPE); 3217 DO_SIGNAL_CHECK(SIGBUS); 3218 DO_SIGNAL_CHECK(SIGPIPE); 3219 DO_SIGNAL_CHECK(SIGXFSZ); 3220 3221 3222 // ReduceSignalUsage allows the user to override these handlers 3223 // see comments at the very top and jvm_solaris.h 3224 if (!ReduceSignalUsage) { 3225 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 3226 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 3227 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 3228 DO_SIGNAL_CHECK(BREAK_SIGNAL); 3229 } 3230 3231 DO_SIGNAL_CHECK(SR_signum); 3232 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); 3233 } 3234 3235 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 3236 3237 static os_sigaction_t os_sigaction = NULL; 3238 3239 void os::Bsd::check_signal_handler(int sig) { 3240 char buf[O_BUFLEN]; 3241 address jvmHandler = NULL; 3242 3243 3244 struct sigaction act; 3245 if (os_sigaction == NULL) { 3246 // only trust the default sigaction, in case it has been interposed 3247 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 3248 if (os_sigaction == NULL) return; 3249 } 3250 3251 os_sigaction(sig, (struct sigaction*)NULL, &act); 3252 3253 3254 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3255 3256 address thisHandler = (act.sa_flags & SA_SIGINFO) 3257 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 3258 : CAST_FROM_FN_PTR(address, act.sa_handler) ; 3259 3260 3261 switch(sig) { 3262 case SIGSEGV: 3263 case SIGBUS: 3264 case SIGFPE: 3265 case SIGPIPE: 3266 case SIGILL: 3267 case SIGXFSZ: 3268 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 3269 break; 3270 3271 case SHUTDOWN1_SIGNAL: 3272 case SHUTDOWN2_SIGNAL: 3273 case SHUTDOWN3_SIGNAL: 3274 case BREAK_SIGNAL: 3275 jvmHandler = (address)user_handler(); 3276 break; 3277 3278 case INTERRUPT_SIGNAL: 3279 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); 3280 break; 3281 3282 default: 3283 if (sig == SR_signum) { 3284 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 3285 } else { 3286 return; 3287 } 3288 break; 3289 } 3290 3291 if (thisHandler != jvmHandler) { 3292 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 3293 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 3294 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 3295 // No need to check this sig any longer 3296 sigaddset(&check_signal_done, sig); 3297 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3298 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 3299 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); 3300 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); 3301 // No need to check this sig any longer 3302 sigaddset(&check_signal_done, sig); 3303 } 3304 3305 // Dump all the signal 3306 if (sigismember(&check_signal_done, sig)) { 3307 print_signal_handlers(tty, buf, O_BUFLEN); 3308 } 3309 } 3310 3311 extern void report_error(char* file_name, int line_no, char* title, char* format, ...); 3312 3313 extern bool signal_name(int signo, char* buf, size_t len); 3314 3315 const char* os::exception_name(int exception_code, char* buf, size_t size) { 3316 if (0 < exception_code && exception_code <= SIGRTMAX) { 3317 // signal 3318 if (!signal_name(exception_code, buf, size)) { 3319 jio_snprintf(buf, size, "SIG%d", exception_code); 3320 } 3321 return buf; 3322 } else { 3323 return NULL; 3324 } 3325 } 3326 3327 // this is called _before_ the most of global arguments have been parsed 3328 void os::init(void) { 3329 char dummy; /* used to get a guess on initial stack address */ 3330 // first_hrtime = gethrtime(); 3331 3332 // With BsdThreads the JavaMain thread pid (primordial thread) 3333 // is different than the pid of the java launcher thread. 3334 // So, on Bsd, the launcher thread pid is passed to the VM 3335 // via the sun.java.launcher.pid property. 3336 // Use this property instead of getpid() if it was correctly passed. 3337 // See bug 6351349. 3338 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); 3339 3340 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); 3341 3342 clock_tics_per_sec = CLK_TCK; 3343 3344 init_random(1234567); 3345 3346 ThreadCritical::initialize(); 3347 3348 Bsd::set_page_size(getpagesize()); 3349 if (Bsd::page_size() == -1) { 3350 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)", 3351 strerror(errno))); 3352 } 3353 init_page_sizes((size_t) Bsd::page_size()); 3354 3355 Bsd::initialize_system_info(); 3356 3357 // main_thread points to the aboriginal thread 3358 Bsd::_main_thread = pthread_self(); 3359 3360 Bsd::clock_init(); 3361 initial_time_count = os::elapsed_counter(); 3362 3363 #ifdef __APPLE__ 3364 // XXXDARWIN 3365 // Work around the unaligned VM callbacks in hotspot's 3366 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on 3367 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces 3368 // alignment when doing symbol lookup. To work around this, we force early 3369 // binding of all symbols now, thus binding when alignment is known-good. 3370 _dyld_bind_fully_image_containing_address((const void *) &os::init); 3371 #endif 3372 } 3373 3374 // To install functions for atexit system call 3375 extern "C" { 3376 static void perfMemory_exit_helper() { 3377 perfMemory_exit(); 3378 } 3379 } 3380 3381 // this is called _after_ the global arguments have been parsed 3382 jint os::init_2(void) 3383 { 3384 // Allocate a single page and mark it as readable for safepoint polling 3385 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3386 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" ); 3387 3388 os::set_polling_page( polling_page ); 3389 3390 #ifndef PRODUCT 3391 if(Verbose && PrintMiscellaneous) 3392 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page); 3393 #endif 3394 3395 if (!UseMembar) { 3396 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3397 guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page"); 3398 os::set_memory_serialize_page( mem_serialize_page ); 3399 3400 #ifndef PRODUCT 3401 if(Verbose && PrintMiscellaneous) 3402 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page); 3403 #endif 3404 } 3405 3406 os::large_page_init(); 3407 3408 // initialize suspend/resume support - must do this before signal_sets_init() 3409 if (SR_initialize() != 0) { 3410 perror("SR_initialize failed"); 3411 return JNI_ERR; 3412 } 3413 3414 Bsd::signal_sets_init(); 3415 Bsd::install_signal_handlers(); 3416 3417 // Check minimum allowable stack size for thread creation and to initialize 3418 // the java system classes, including StackOverflowError - depends on page 3419 // size. Add a page for compiler2 recursion in main thread. 3420 // Add in 2*BytesPerWord times page size to account for VM stack during 3421 // class initialization depending on 32 or 64 bit VM. 3422 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, 3423 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ 3424 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); 3425 3426 size_t threadStackSizeInBytes = ThreadStackSize * K; 3427 if (threadStackSizeInBytes != 0 && 3428 threadStackSizeInBytes < os::Bsd::min_stack_allowed) { 3429 tty->print_cr("\nThe stack size specified is too small, " 3430 "Specify at least %dk", 3431 os::Bsd::min_stack_allowed/ K); 3432 return JNI_ERR; 3433 } 3434 3435 // Make the stack size a multiple of the page size so that 3436 // the yellow/red zones can be guarded. 3437 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 3438 vm_page_size())); 3439 3440 if (MaxFDLimit) { 3441 // set the number of file descriptors to max. print out error 3442 // if getrlimit/setrlimit fails but continue regardless. 3443 struct rlimit nbr_files; 3444 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 3445 if (status != 0) { 3446 if (PrintMiscellaneous && (Verbose || WizardMode)) 3447 perror("os::init_2 getrlimit failed"); 3448 } else { 3449 nbr_files.rlim_cur = nbr_files.rlim_max; 3450 3451 #ifdef __APPLE__ 3452 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if 3453 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must 3454 // be used instead 3455 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); 3456 #endif 3457 3458 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 3459 if (status != 0) { 3460 if (PrintMiscellaneous && (Verbose || WizardMode)) 3461 perror("os::init_2 setrlimit failed"); 3462 } 3463 } 3464 } 3465 3466 // at-exit methods are called in the reverse order of their registration. 3467 // atexit functions are called on return from main or as a result of a 3468 // call to exit(3C). There can be only 32 of these functions registered 3469 // and atexit() does not set errno. 3470 3471 if (PerfAllowAtExitRegistration) { 3472 // only register atexit functions if PerfAllowAtExitRegistration is set. 3473 // atexit functions can be delayed until process exit time, which 3474 // can be problematic for embedded VM situations. Embedded VMs should 3475 // call DestroyJavaVM() to assure that VM resources are released. 3476 3477 // note: perfMemory_exit_helper atexit function may be removed in 3478 // the future if the appropriate cleanup code can be added to the 3479 // VM_Exit VMOperation's doit method. 3480 if (atexit(perfMemory_exit_helper) != 0) { 3481 warning("os::init2 atexit(perfMemory_exit_helper) failed"); 3482 } 3483 } 3484 3485 // initialize thread priority policy 3486 prio_init(); 3487 3488 #ifdef __APPLE__ 3489 // dynamically link to objective c gc registration 3490 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY); 3491 if (handleLibObjc != NULL) { 3492 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER); 3493 } 3494 #endif 3495 3496 return JNI_OK; 3497 } 3498 3499 // this is called at the end of vm_initialization 3500 void os::init_3(void) { } 3501 3502 // Mark the polling page as unreadable 3503 void os::make_polling_page_unreadable(void) { 3504 if( !guard_memory((char*)_polling_page, Bsd::page_size()) ) 3505 fatal("Could not disable polling page"); 3506 }; 3507 3508 // Mark the polling page as readable 3509 void os::make_polling_page_readable(void) { 3510 if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { 3511 fatal("Could not enable polling page"); 3512 } 3513 }; 3514 3515 int os::active_processor_count() { 3516 return _processor_count; 3517 } 3518 3519 void os::set_native_thread_name(const char *name) { 3520 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5 3521 // This is only supported in Snow Leopard and beyond 3522 if (name != NULL) { 3523 // Add a "Java: " prefix to the name 3524 char buf[MAXTHREADNAMESIZE]; 3525 snprintf(buf, sizeof(buf), "Java: %s", name); 3526 pthread_setname_np(buf); 3527 } 3528 #endif 3529 } 3530 3531 bool os::distribute_processes(uint length, uint* distribution) { 3532 // Not yet implemented. 3533 return false; 3534 } 3535 3536 bool os::bind_to_processor(uint processor_id) { 3537 // Not yet implemented. 3538 return false; 3539 } 3540 3541 /// 3542 3543 // Suspends the target using the signal mechanism and then grabs the PC before 3544 // resuming the target. Used by the flat-profiler only 3545 ExtendedPC os::get_thread_pc(Thread* thread) { 3546 // Make sure that it is called by the watcher for the VMThread 3547 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 3548 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 3549 3550 ExtendedPC epc; 3551 3552 OSThread* osthread = thread->osthread(); 3553 if (do_suspend(osthread)) { 3554 if (osthread->ucontext() != NULL) { 3555 epc = os::Bsd::ucontext_get_pc(osthread->ucontext()); 3556 } else { 3557 // NULL context is unexpected, double-check this is the VMThread 3558 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 3559 } 3560 do_resume(osthread); 3561 } 3562 // failure means pthread_kill failed for some reason - arguably this is 3563 // a fatal problem, but such problems are ignored elsewhere 3564 3565 return epc; 3566 } 3567 3568 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime) 3569 { 3570 return pthread_cond_timedwait(_cond, _mutex, _abstime); 3571 } 3572 3573 //////////////////////////////////////////////////////////////////////////////// 3574 // debug support 3575 3576 bool os::find(address addr, outputStream* st) { 3577 Dl_info dlinfo; 3578 memset(&dlinfo, 0, sizeof(dlinfo)); 3579 if (dladdr(addr, &dlinfo)) { 3580 st->print(PTR_FORMAT ": ", addr); 3581 if (dlinfo.dli_sname != NULL) { 3582 st->print("%s+%#x", dlinfo.dli_sname, 3583 addr - (intptr_t)dlinfo.dli_saddr); 3584 } else if (dlinfo.dli_fname) { 3585 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); 3586 } else { 3587 st->print("<absolute address>"); 3588 } 3589 if (dlinfo.dli_fname) { 3590 st->print(" in %s", dlinfo.dli_fname); 3591 } 3592 if (dlinfo.dli_fbase) { 3593 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); 3594 } 3595 st->cr(); 3596 3597 if (Verbose) { 3598 // decode some bytes around the PC 3599 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 3600 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 3601 address lowest = (address) dlinfo.dli_sname; 3602 if (!lowest) lowest = (address) dlinfo.dli_fbase; 3603 if (begin < lowest) begin = lowest; 3604 Dl_info dlinfo2; 3605 if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr 3606 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) 3607 end = (address) dlinfo2.dli_saddr; 3608 Disassembler::decode(begin, end, st); 3609 } 3610 return true; 3611 } 3612 return false; 3613 } 3614 3615 //////////////////////////////////////////////////////////////////////////////// 3616 // misc 3617 3618 // This does not do anything on Bsd. This is basically a hook for being 3619 // able to use structured exception handling (thread-local exception filters) 3620 // on, e.g., Win32. 3621 void 3622 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, 3623 JavaCallArguments* args, Thread* thread) { 3624 f(value, method, args, thread); 3625 } 3626 3627 void os::print_statistics() { 3628 } 3629 3630 int os::message_box(const char* title, const char* message) { 3631 int i; 3632 fdStream err(defaultStream::error_fd()); 3633 for (i = 0; i < 78; i++) err.print_raw("="); 3634 err.cr(); 3635 err.print_raw_cr(title); 3636 for (i = 0; i < 78; i++) err.print_raw("-"); 3637 err.cr(); 3638 err.print_raw_cr(message); 3639 for (i = 0; i < 78; i++) err.print_raw("="); 3640 err.cr(); 3641 3642 char buf[16]; 3643 // Prevent process from exiting upon "read error" without consuming all CPU 3644 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 3645 3646 return buf[0] == 'y' || buf[0] == 'Y'; 3647 } 3648 3649 int os::stat(const char *path, struct stat *sbuf) { 3650 char pathbuf[MAX_PATH]; 3651 if (strlen(path) > MAX_PATH - 1) { 3652 errno = ENAMETOOLONG; 3653 return -1; 3654 } 3655 os::native_path(strcpy(pathbuf, path)); 3656 return ::stat(pathbuf, sbuf); 3657 } 3658 3659 bool os::check_heap(bool force) { 3660 return true; 3661 } 3662 3663 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) { 3664 return ::vsnprintf(buf, count, format, args); 3665 } 3666 3667 // Is a (classpath) directory empty? 3668 bool os::dir_is_empty(const char* path) { 3669 DIR *dir = NULL; 3670 struct dirent *ptr; 3671 3672 dir = opendir(path); 3673 if (dir == NULL) return true; 3674 3675 /* Scan the directory */ 3676 bool result = true; 3677 char buf[sizeof(struct dirent) + MAX_PATH]; 3678 while (result && (ptr = ::readdir(dir)) != NULL) { 3679 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 3680 result = false; 3681 } 3682 } 3683 closedir(dir); 3684 return result; 3685 } 3686 3687 // This code originates from JDK's sysOpen and open64_w 3688 // from src/solaris/hpi/src/system_md.c 3689 3690 #ifndef O_DELETE 3691 #define O_DELETE 0x10000 3692 #endif 3693 3694 // Open a file. Unlink the file immediately after open returns 3695 // if the specified oflag has the O_DELETE flag set. 3696 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c 3697 3698 int os::open(const char *path, int oflag, int mode) { 3699 3700 if (strlen(path) > MAX_PATH - 1) { 3701 errno = ENAMETOOLONG; 3702 return -1; 3703 } 3704 int fd; 3705 int o_delete = (oflag & O_DELETE); 3706 oflag = oflag & ~O_DELETE; 3707 3708 fd = ::open(path, oflag, mode); 3709 if (fd == -1) return -1; 3710 3711 //If the open succeeded, the file might still be a directory 3712 { 3713 struct stat buf; 3714 int ret = ::fstat(fd, &buf); 3715 int st_mode = buf.st_mode; 3716 3717 if (ret != -1) { 3718 if ((st_mode & S_IFMT) == S_IFDIR) { 3719 errno = EISDIR; 3720 ::close(fd); 3721 return -1; 3722 } 3723 } else { 3724 ::close(fd); 3725 return -1; 3726 } 3727 } 3728 3729 /* 3730 * All file descriptors that are opened in the JVM and not 3731 * specifically destined for a subprocess should have the 3732 * close-on-exec flag set. If we don't set it, then careless 3rd 3733 * party native code might fork and exec without closing all 3734 * appropriate file descriptors (e.g. as we do in closeDescriptors in 3735 * UNIXProcess.c), and this in turn might: 3736 * 3737 * - cause end-of-file to fail to be detected on some file 3738 * descriptors, resulting in mysterious hangs, or 3739 * 3740 * - might cause an fopen in the subprocess to fail on a system 3741 * suffering from bug 1085341. 3742 * 3743 * (Yes, the default setting of the close-on-exec flag is a Unix 3744 * design flaw) 3745 * 3746 * See: 3747 * 1085341: 32-bit stdio routines should support file descriptors >255 3748 * 4843136: (process) pipe file descriptor from Runtime.exec not being closed 3749 * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 3750 */ 3751 #ifdef FD_CLOEXEC 3752 { 3753 int flags = ::fcntl(fd, F_GETFD); 3754 if (flags != -1) 3755 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 3756 } 3757 #endif 3758 3759 if (o_delete != 0) { 3760 ::unlink(path); 3761 } 3762 return fd; 3763 } 3764 3765 3766 // create binary file, rewriting existing file if required 3767 int os::create_binary_file(const char* path, bool rewrite_existing) { 3768 int oflags = O_WRONLY | O_CREAT; 3769 if (!rewrite_existing) { 3770 oflags |= O_EXCL; 3771 } 3772 return ::open(path, oflags, S_IREAD | S_IWRITE); 3773 } 3774 3775 // return current position of file pointer 3776 jlong os::current_file_offset(int fd) { 3777 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); 3778 } 3779 3780 // move file pointer to the specified offset 3781 jlong os::seek_to_file_offset(int fd, jlong offset) { 3782 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); 3783 } 3784 3785 // This code originates from JDK's sysAvailable 3786 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 3787 3788 int os::available(int fd, jlong *bytes) { 3789 jlong cur, end; 3790 int mode; 3791 struct stat buf; 3792 3793 if (::fstat(fd, &buf) >= 0) { 3794 mode = buf.st_mode; 3795 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 3796 /* 3797 * XXX: is the following call interruptible? If so, this might 3798 * need to go through the INTERRUPT_IO() wrapper as for other 3799 * blocking, interruptible calls in this file. 3800 */ 3801 int n; 3802 if (::ioctl(fd, FIONREAD, &n) >= 0) { 3803 *bytes = n; 3804 return 1; 3805 } 3806 } 3807 } 3808 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { 3809 return 0; 3810 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { 3811 return 0; 3812 } else if (::lseek(fd, cur, SEEK_SET) == -1) { 3813 return 0; 3814 } 3815 *bytes = end - cur; 3816 return 1; 3817 } 3818 3819 int os::socket_available(int fd, jint *pbytes) { 3820 if (fd < 0) 3821 return OS_OK; 3822 3823 int ret; 3824 3825 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret); 3826 3827 //%% note ioctl can return 0 when successful, JVM_SocketAvailable 3828 // is expected to return 0 on failure and 1 on success to the jdk. 3829 3830 return (ret == OS_ERR) ? 0 : 1; 3831 } 3832 3833 // Map a block of memory. 3834 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 3835 char *addr, size_t bytes, bool read_only, 3836 bool allow_exec) { 3837 int prot; 3838 int flags; 3839 3840 if (read_only) { 3841 prot = PROT_READ; 3842 flags = MAP_SHARED; 3843 } else { 3844 prot = PROT_READ | PROT_WRITE; 3845 flags = MAP_PRIVATE; 3846 } 3847 3848 if (allow_exec) { 3849 prot |= PROT_EXEC; 3850 } 3851 3852 if (addr != NULL) { 3853 flags |= MAP_FIXED; 3854 } 3855 3856 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 3857 fd, file_offset); 3858 if (mapped_address == MAP_FAILED) { 3859 return NULL; 3860 } 3861 return mapped_address; 3862 } 3863 3864 3865 // Remap a block of memory. 3866 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 3867 char *addr, size_t bytes, bool read_only, 3868 bool allow_exec) { 3869 // same as map_memory() on this OS 3870 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 3871 allow_exec); 3872 } 3873 3874 3875 // Unmap a block of memory. 3876 bool os::pd_unmap_memory(char* addr, size_t bytes) { 3877 return munmap(addr, bytes) == 0; 3878 } 3879 3880 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 3881 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 3882 // of a thread. 3883 // 3884 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 3885 // the fast estimate available on the platform. 3886 3887 jlong os::current_thread_cpu_time() { 3888 #ifdef __APPLE__ 3889 return os::thread_cpu_time(Thread::current(), true /* user + sys */); 3890 #else 3891 Unimplemented(); 3892 return 0; 3893 #endif 3894 } 3895 3896 jlong os::thread_cpu_time(Thread* thread) { 3897 #ifdef __APPLE__ 3898 return os::thread_cpu_time(thread, true /* user + sys */); 3899 #else 3900 Unimplemented(); 3901 return 0; 3902 #endif 3903 } 3904 3905 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 3906 #ifdef __APPLE__ 3907 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); 3908 #else 3909 Unimplemented(); 3910 return 0; 3911 #endif 3912 } 3913 3914 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 3915 #ifdef __APPLE__ 3916 struct thread_basic_info tinfo; 3917 mach_msg_type_number_t tcount = THREAD_INFO_MAX; 3918 kern_return_t kr; 3919 thread_t mach_thread; 3920 3921 mach_thread = thread->osthread()->thread_id(); 3922 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); 3923 if (kr != KERN_SUCCESS) 3924 return -1; 3925 3926 if (user_sys_cpu_time) { 3927 jlong nanos; 3928 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; 3929 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; 3930 return nanos; 3931 } else { 3932 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); 3933 } 3934 #else 3935 Unimplemented(); 3936 return 0; 3937 #endif 3938 } 3939 3940 3941 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 3942 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 3943 info_ptr->may_skip_backward = false; // elapsed time not wall time 3944 info_ptr->may_skip_forward = false; // elapsed time not wall time 3945 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 3946 } 3947 3948 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 3949 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 3950 info_ptr->may_skip_backward = false; // elapsed time not wall time 3951 info_ptr->may_skip_forward = false; // elapsed time not wall time 3952 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 3953 } 3954 3955 bool os::is_thread_cpu_time_supported() { 3956 #ifdef __APPLE__ 3957 return true; 3958 #else 3959 return false; 3960 #endif 3961 } 3962 3963 // System loadavg support. Returns -1 if load average cannot be obtained. 3964 // Bsd doesn't yet have a (official) notion of processor sets, 3965 // so just return the system wide load average. 3966 int os::loadavg(double loadavg[], int nelem) { 3967 return ::getloadavg(loadavg, nelem); 3968 } 3969 3970 void os::pause() { 3971 char filename[MAX_PATH]; 3972 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 3973 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); 3974 } else { 3975 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 3976 } 3977 3978 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 3979 if (fd != -1) { 3980 struct stat buf; 3981 ::close(fd); 3982 while (::stat(filename, &buf) == 0) { 3983 (void)::poll(NULL, 0, 100); 3984 } 3985 } else { 3986 jio_fprintf(stderr, 3987 "Could not open pause file '%s', continuing immediately.\n", filename); 3988 } 3989 } 3990 3991 3992 // Refer to the comments in os_solaris.cpp park-unpark. 3993 // 3994 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 3995 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 3996 // For specifics regarding the bug see GLIBC BUGID 261237 : 3997 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 3998 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 3999 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 4000 // is used. (The simple C test-case provided in the GLIBC bug report manifests the 4001 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 4002 // and monitorenter when we're using 1-0 locking. All those operations may result in 4003 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 4004 // of libpthread avoids the problem, but isn't practical. 4005 // 4006 // Possible remedies: 4007 // 4008 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 4009 // This is palliative and probabilistic, however. If the thread is preempted 4010 // between the call to compute_abstime() and pthread_cond_timedwait(), more 4011 // than the minimum period may have passed, and the abstime may be stale (in the 4012 // past) resultin in a hang. Using this technique reduces the odds of a hang 4013 // but the JVM is still vulnerable, particularly on heavily loaded systems. 4014 // 4015 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 4016 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set 4017 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 4018 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant 4019 // thread. 4020 // 4021 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 4022 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 4023 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). 4024 // This also works well. In fact it avoids kernel-level scalability impediments 4025 // on certain platforms that don't handle lots of active pthread_cond_timedwait() 4026 // timers in a graceful fashion. 4027 // 4028 // 4. When the abstime value is in the past it appears that control returns 4029 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 4030 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we 4031 // can avoid the problem by reinitializing the condvar -- by cond_destroy() 4032 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). 4033 // It may be possible to avoid reinitialization by checking the return 4034 // value from pthread_cond_timedwait(). In addition to reinitializing the 4035 // condvar we must establish the invariant that cond_signal() is only called 4036 // within critical sections protected by the adjunct mutex. This prevents 4037 // cond_signal() from "seeing" a condvar that's in the midst of being 4038 // reinitialized or that is corrupt. Sadly, this invariant obviates the 4039 // desirable signal-after-unlock optimization that avoids futile context switching. 4040 // 4041 // I'm also concerned that some versions of NTPL might allocate an auxilliary 4042 // structure when a condvar is used or initialized. cond_destroy() would 4043 // release the helper structure. Our reinitialize-after-timedwait fix 4044 // put excessive stress on malloc/free and locks protecting the c-heap. 4045 // 4046 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 4047 // It may be possible to refine (4) by checking the kernel and NTPL verisons 4048 // and only enabling the work-around for vulnerable environments. 4049 4050 // utility to compute the abstime argument to timedwait: 4051 // millis is the relative timeout time 4052 // abstime will be the absolute timeout time 4053 // TODO: replace compute_abstime() with unpackTime() 4054 4055 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) { 4056 if (millis < 0) millis = 0; 4057 struct timeval now; 4058 int status = gettimeofday(&now, NULL); 4059 assert(status == 0, "gettimeofday"); 4060 jlong seconds = millis / 1000; 4061 millis %= 1000; 4062 if (seconds > 50000000) { // see man cond_timedwait(3T) 4063 seconds = 50000000; 4064 } 4065 abstime->tv_sec = now.tv_sec + seconds; 4066 long usec = now.tv_usec + millis * 1000; 4067 if (usec >= 1000000) { 4068 abstime->tv_sec += 1; 4069 usec -= 1000000; 4070 } 4071 abstime->tv_nsec = usec * 1000; 4072 return abstime; 4073 } 4074 4075 4076 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately. 4077 // Conceptually TryPark() should be equivalent to park(0). 4078 4079 int os::PlatformEvent::TryPark() { 4080 for (;;) { 4081 const int v = _Event ; 4082 guarantee ((v == 0) || (v == 1), "invariant") ; 4083 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ; 4084 } 4085 } 4086 4087 void os::PlatformEvent::park() { // AKA "down()" 4088 // Invariant: Only the thread associated with the Event/PlatformEvent 4089 // may call park(). 4090 // TODO: assert that _Assoc != NULL or _Assoc == Self 4091 int v ; 4092 for (;;) { 4093 v = _Event ; 4094 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; 4095 } 4096 guarantee (v >= 0, "invariant") ; 4097 if (v == 0) { 4098 // Do this the hard way by blocking ... 4099 int status = pthread_mutex_lock(_mutex); 4100 assert_status(status == 0, status, "mutex_lock"); 4101 guarantee (_nParked == 0, "invariant") ; 4102 ++ _nParked ; 4103 while (_Event < 0) { 4104 status = pthread_cond_wait(_cond, _mutex); 4105 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 4106 // Treat this the same as if the wait was interrupted 4107 if (status == ETIMEDOUT) { status = EINTR; } 4108 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 4109 } 4110 -- _nParked ; 4111 4112 _Event = 0 ; 4113 status = pthread_mutex_unlock(_mutex); 4114 assert_status(status == 0, status, "mutex_unlock"); 4115 // Paranoia to ensure our locked and lock-free paths interact 4116 // correctly with each other. 4117 OrderAccess::fence(); 4118 } 4119 guarantee (_Event >= 0, "invariant") ; 4120 } 4121 4122 int os::PlatformEvent::park(jlong millis) { 4123 guarantee (_nParked == 0, "invariant") ; 4124 4125 int v ; 4126 for (;;) { 4127 v = _Event ; 4128 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; 4129 } 4130 guarantee (v >= 0, "invariant") ; 4131 if (v != 0) return OS_OK ; 4132 4133 // We do this the hard way, by blocking the thread. 4134 // Consider enforcing a minimum timeout value. 4135 struct timespec abst; 4136 compute_abstime(&abst, millis); 4137 4138 int ret = OS_TIMEOUT; 4139 int status = pthread_mutex_lock(_mutex); 4140 assert_status(status == 0, status, "mutex_lock"); 4141 guarantee (_nParked == 0, "invariant") ; 4142 ++_nParked ; 4143 4144 // Object.wait(timo) will return because of 4145 // (a) notification 4146 // (b) timeout 4147 // (c) thread.interrupt 4148 // 4149 // Thread.interrupt and object.notify{All} both call Event::set. 4150 // That is, we treat thread.interrupt as a special case of notification. 4151 // The underlying Solaris implementation, cond_timedwait, admits 4152 // spurious/premature wakeups, but the JLS/JVM spec prevents the 4153 // JVM from making those visible to Java code. As such, we must 4154 // filter out spurious wakeups. We assume all ETIME returns are valid. 4155 // 4156 // TODO: properly differentiate simultaneous notify+interrupt. 4157 // In that case, we should propagate the notify to another waiter. 4158 4159 while (_Event < 0) { 4160 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst); 4161 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4162 pthread_cond_destroy (_cond); 4163 pthread_cond_init (_cond, NULL) ; 4164 } 4165 assert_status(status == 0 || status == EINTR || 4166 status == ETIMEDOUT, 4167 status, "cond_timedwait"); 4168 if (!FilterSpuriousWakeups) break ; // previous semantics 4169 if (status == ETIMEDOUT) break ; 4170 // We consume and ignore EINTR and spurious wakeups. 4171 } 4172 --_nParked ; 4173 if (_Event >= 0) { 4174 ret = OS_OK; 4175 } 4176 _Event = 0 ; 4177 status = pthread_mutex_unlock(_mutex); 4178 assert_status(status == 0, status, "mutex_unlock"); 4179 assert (_nParked == 0, "invariant") ; 4180 // Paranoia to ensure our locked and lock-free paths interact 4181 // correctly with each other. 4182 OrderAccess::fence(); 4183 return ret; 4184 } 4185 4186 void os::PlatformEvent::unpark() { 4187 // Transitions for _Event: 4188 // 0 :=> 1 4189 // 1 :=> 1 4190 // -1 :=> either 0 or 1; must signal target thread 4191 // That is, we can safely transition _Event from -1 to either 4192 // 0 or 1. Forcing 1 is slightly more efficient for back-to-back 4193 // unpark() calls. 4194 // See also: "Semaphores in Plan 9" by Mullender & Cox 4195 // 4196 // Note: Forcing a transition from "-1" to "1" on an unpark() means 4197 // that it will take two back-to-back park() calls for the owning 4198 // thread to block. This has the benefit of forcing a spurious return 4199 // from the first park() call after an unpark() call which will help 4200 // shake out uses of park() and unpark() without condition variables. 4201 4202 if (Atomic::xchg(1, &_Event) >= 0) return; 4203 4204 // Wait for the thread associated with the event to vacate 4205 int status = pthread_mutex_lock(_mutex); 4206 assert_status(status == 0, status, "mutex_lock"); 4207 int AnyWaiters = _nParked; 4208 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 4209 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 4210 AnyWaiters = 0; 4211 pthread_cond_signal(_cond); 4212 } 4213 status = pthread_mutex_unlock(_mutex); 4214 assert_status(status == 0, status, "mutex_unlock"); 4215 if (AnyWaiters != 0) { 4216 status = pthread_cond_signal(_cond); 4217 assert_status(status == 0, status, "cond_signal"); 4218 } 4219 4220 // Note that we signal() _after dropping the lock for "immortal" Events. 4221 // This is safe and avoids a common class of futile wakeups. In rare 4222 // circumstances this can cause a thread to return prematurely from 4223 // cond_{timed}wait() but the spurious wakeup is benign and the victim will 4224 // simply re-test the condition and re-park itself. 4225 } 4226 4227 4228 // JSR166 4229 // ------------------------------------------------------- 4230 4231 /* 4232 * The solaris and bsd implementations of park/unpark are fairly 4233 * conservative for now, but can be improved. They currently use a 4234 * mutex/condvar pair, plus a a count. 4235 * Park decrements count if > 0, else does a condvar wait. Unpark 4236 * sets count to 1 and signals condvar. Only one thread ever waits 4237 * on the condvar. Contention seen when trying to park implies that someone 4238 * is unparking you, so don't wait. And spurious returns are fine, so there 4239 * is no need to track notifications. 4240 */ 4241 4242 #define MAX_SECS 100000000 4243 /* 4244 * This code is common to bsd and solaris and will be moved to a 4245 * common place in dolphin. 4246 * 4247 * The passed in time value is either a relative time in nanoseconds 4248 * or an absolute time in milliseconds. Either way it has to be unpacked 4249 * into suitable seconds and nanoseconds components and stored in the 4250 * given timespec structure. 4251 * Given time is a 64-bit value and the time_t used in the timespec is only 4252 * a signed-32-bit value (except on 64-bit Bsd) we have to watch for 4253 * overflow if times way in the future are given. Further on Solaris versions 4254 * prior to 10 there is a restriction (see cond_timedwait) that the specified 4255 * number of seconds, in abstime, is less than current_time + 100,000,000. 4256 * As it will be 28 years before "now + 100000000" will overflow we can 4257 * ignore overflow and just impose a hard-limit on seconds using the value 4258 * of "now + 100,000,000". This places a limit on the timeout of about 3.17 4259 * years from "now". 4260 */ 4261 4262 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { 4263 assert (time > 0, "convertTime"); 4264 4265 struct timeval now; 4266 int status = gettimeofday(&now, NULL); 4267 assert(status == 0, "gettimeofday"); 4268 4269 time_t max_secs = now.tv_sec + MAX_SECS; 4270 4271 if (isAbsolute) { 4272 jlong secs = time / 1000; 4273 if (secs > max_secs) { 4274 absTime->tv_sec = max_secs; 4275 } 4276 else { 4277 absTime->tv_sec = secs; 4278 } 4279 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 4280 } 4281 else { 4282 jlong secs = time / NANOSECS_PER_SEC; 4283 if (secs >= MAX_SECS) { 4284 absTime->tv_sec = max_secs; 4285 absTime->tv_nsec = 0; 4286 } 4287 else { 4288 absTime->tv_sec = now.tv_sec + secs; 4289 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 4290 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 4291 absTime->tv_nsec -= NANOSECS_PER_SEC; 4292 ++absTime->tv_sec; // note: this must be <= max_secs 4293 } 4294 } 4295 } 4296 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 4297 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 4298 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 4299 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 4300 } 4301 4302 void Parker::park(bool isAbsolute, jlong time) { 4303 // Ideally we'd do something useful while spinning, such 4304 // as calling unpackTime(). 4305 4306 // Optional fast-path check: 4307 // Return immediately if a permit is available. 4308 // We depend on Atomic::xchg() having full barrier semantics 4309 // since we are doing a lock-free update to _counter. 4310 if (Atomic::xchg(0, &_counter) > 0) return; 4311 4312 Thread* thread = Thread::current(); 4313 assert(thread->is_Java_thread(), "Must be JavaThread"); 4314 JavaThread *jt = (JavaThread *)thread; 4315 4316 // Optional optimization -- avoid state transitions if there's an interrupt pending. 4317 // Check interrupt before trying to wait 4318 if (Thread::is_interrupted(thread, false)) { 4319 return; 4320 } 4321 4322 // Next, demultiplex/decode time arguments 4323 struct timespec absTime; 4324 if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all 4325 return; 4326 } 4327 if (time > 0) { 4328 unpackTime(&absTime, isAbsolute, time); 4329 } 4330 4331 4332 // Enter safepoint region 4333 // Beware of deadlocks such as 6317397. 4334 // The per-thread Parker:: mutex is a classic leaf-lock. 4335 // In particular a thread must never block on the Threads_lock while 4336 // holding the Parker:: mutex. If safepoints are pending both the 4337 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 4338 ThreadBlockInVM tbivm(jt); 4339 4340 // Don't wait if cannot get lock since interference arises from 4341 // unblocking. Also. check interrupt before trying wait 4342 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 4343 return; 4344 } 4345 4346 int status ; 4347 if (_counter > 0) { // no wait needed 4348 _counter = 0; 4349 status = pthread_mutex_unlock(_mutex); 4350 assert (status == 0, "invariant") ; 4351 // Paranoia to ensure our locked and lock-free paths interact 4352 // correctly with each other and Java-level accesses. 4353 OrderAccess::fence(); 4354 return; 4355 } 4356 4357 #ifdef ASSERT 4358 // Don't catch signals while blocked; let the running threads have the signals. 4359 // (This allows a debugger to break into the running thread.) 4360 sigset_t oldsigs; 4361 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); 4362 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 4363 #endif 4364 4365 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 4366 jt->set_suspend_equivalent(); 4367 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 4368 4369 if (time == 0) { 4370 status = pthread_cond_wait (_cond, _mutex) ; 4371 } else { 4372 status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ; 4373 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4374 pthread_cond_destroy (_cond) ; 4375 pthread_cond_init (_cond, NULL); 4376 } 4377 } 4378 assert_status(status == 0 || status == EINTR || 4379 status == ETIMEDOUT, 4380 status, "cond_timedwait"); 4381 4382 #ifdef ASSERT 4383 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 4384 #endif 4385 4386 _counter = 0 ; 4387 status = pthread_mutex_unlock(_mutex) ; 4388 assert_status(status == 0, status, "invariant") ; 4389 // Paranoia to ensure our locked and lock-free paths interact 4390 // correctly with each other and Java-level accesses. 4391 OrderAccess::fence(); 4392 4393 // If externally suspended while waiting, re-suspend 4394 if (jt->handle_special_suspend_equivalent_condition()) { 4395 jt->java_suspend_self(); 4396 } 4397 } 4398 4399 void Parker::unpark() { 4400 int s, status ; 4401 status = pthread_mutex_lock(_mutex); 4402 assert (status == 0, "invariant") ; 4403 s = _counter; 4404 _counter = 1; 4405 if (s < 1) { 4406 if (WorkAroundNPTLTimedWaitHang) { 4407 status = pthread_cond_signal (_cond) ; 4408 assert (status == 0, "invariant") ; 4409 status = pthread_mutex_unlock(_mutex); 4410 assert (status == 0, "invariant") ; 4411 } else { 4412 status = pthread_mutex_unlock(_mutex); 4413 assert (status == 0, "invariant") ; 4414 status = pthread_cond_signal (_cond) ; 4415 assert (status == 0, "invariant") ; 4416 } 4417 } else { 4418 pthread_mutex_unlock(_mutex); 4419 assert (status == 0, "invariant") ; 4420 } 4421 } 4422 4423 4424 /* Darwin has no "environ" in a dynamic library. */ 4425 #ifdef __APPLE__ 4426 #include <crt_externs.h> 4427 #define environ (*_NSGetEnviron()) 4428 #else 4429 extern char** environ; 4430 #endif 4431 4432 // Run the specified command in a separate process. Return its exit value, 4433 // or -1 on failure (e.g. can't fork a new process). 4434 // Unlike system(), this function can be called from signal handler. It 4435 // doesn't block SIGINT et al. 4436 int os::fork_and_exec(char* cmd) { 4437 const char * argv[4] = {"sh", "-c", cmd, NULL}; 4438 4439 // fork() in BsdThreads/NPTL is not async-safe. It needs to run 4440 // pthread_atfork handlers and reset pthread library. All we need is a 4441 // separate process to execve. Make a direct syscall to fork process. 4442 // On IA64 there's no fork syscall, we have to use fork() and hope for 4443 // the best... 4444 pid_t pid = fork(); 4445 4446 if (pid < 0) { 4447 // fork failed 4448 return -1; 4449 4450 } else if (pid == 0) { 4451 // child process 4452 4453 // execve() in BsdThreads will call pthread_kill_other_threads_np() 4454 // first to kill every thread on the thread list. Because this list is 4455 // not reset by fork() (see notes above), execve() will instead kill 4456 // every thread in the parent process. We know this is the only thread 4457 // in the new process, so make a system call directly. 4458 // IA64 should use normal execve() from glibc to match the glibc fork() 4459 // above. 4460 execve("/bin/sh", (char* const*)argv, environ); 4461 4462 // execve failed 4463 _exit(-1); 4464 4465 } else { 4466 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 4467 // care about the actual exit code, for now. 4468 4469 int status; 4470 4471 // Wait for the child process to exit. This returns immediately if 4472 // the child has already exited. */ 4473 while (waitpid(pid, &status, 0) < 0) { 4474 switch (errno) { 4475 case ECHILD: return 0; 4476 case EINTR: break; 4477 default: return -1; 4478 } 4479 } 4480 4481 if (WIFEXITED(status)) { 4482 // The child exited normally; get its exit code. 4483 return WEXITSTATUS(status); 4484 } else if (WIFSIGNALED(status)) { 4485 // The child exited because of a signal 4486 // The best value to return is 0x80 + signal number, 4487 // because that is what all Unix shells do, and because 4488 // it allows callers to distinguish between process exit and 4489 // process death by signal. 4490 return 0x80 + WTERMSIG(status); 4491 } else { 4492 // Unknown exit code; pass it through 4493 return status; 4494 } 4495 } 4496 } 4497 4498 // is_headless_jre() 4499 // 4500 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 4501 // in order to report if we are running in a headless jre 4502 // 4503 // Since JDK8 xawt/libmawt.so was moved into the same directory 4504 // as libawt.so, and renamed libawt_xawt.so 4505 // 4506 bool os::is_headless_jre() { 4507 struct stat statbuf; 4508 char buf[MAXPATHLEN]; 4509 char libmawtpath[MAXPATHLEN]; 4510 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX; 4511 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX; 4512 char *p; 4513 4514 // Get path to libjvm.so 4515 os::jvm_path(buf, sizeof(buf)); 4516 4517 // Get rid of libjvm.so 4518 p = strrchr(buf, '/'); 4519 if (p == NULL) return false; 4520 else *p = '\0'; 4521 4522 // Get rid of client or server 4523 p = strrchr(buf, '/'); 4524 if (p == NULL) return false; 4525 else *p = '\0'; 4526 4527 // check xawt/libmawt.so 4528 strcpy(libmawtpath, buf); 4529 strcat(libmawtpath, xawtstr); 4530 if (::stat(libmawtpath, &statbuf) == 0) return false; 4531 4532 // check libawt_xawt.so 4533 strcpy(libmawtpath, buf); 4534 strcat(libmawtpath, new_xawtstr); 4535 if (::stat(libmawtpath, &statbuf) == 0) return false; 4536 4537 return true; 4538 } 4539 4540 // Get the default path to the core file 4541 // Returns the length of the string 4542 int os::get_core_path(char* buffer, size_t bufferSize) { 4543 int n = jio_snprintf(buffer, bufferSize, "/cores"); 4544 4545 // Truncate if theoretical string was longer than bufferSize 4546 n = MIN2(n, (int)bufferSize); 4547 4548 return n; 4549 }