1 /* 2 * Copyright (c) 1999, 2014, 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 # include <sys/syscall.h> 104 105 #if defined(__FreeBSD__) || defined(__NetBSD__) 106 # include <elf.h> 107 #endif 108 109 #ifdef __APPLE__ 110 # include <mach/mach.h> // semaphore_* API 111 # include <mach-o/dyld.h> 112 # include <sys/proc_info.h> 113 # include <objc/objc-auto.h> 114 #endif 115 116 #ifndef MAP_ANONYMOUS 117 #define MAP_ANONYMOUS MAP_ANON 118 #endif 119 120 #define MAX_PATH (2 * K) 121 122 // for timer info max values which include all bits 123 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 124 125 #define LARGEPAGES_BIT (1 << 6) 126 //////////////////////////////////////////////////////////////////////////////// 127 // global variables 128 julong os::Bsd::_physical_memory = 0; 129 130 131 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; 132 pthread_t os::Bsd::_main_thread; 133 int os::Bsd::_page_size = -1; 134 135 static jlong initial_time_count=0; 136 137 static int clock_tics_per_sec = 100; 138 139 // For diagnostics to print a message once. see run_periodic_checks 140 static sigset_t check_signal_done; 141 static bool check_signals = true; 142 143 static pid_t _initial_pid = 0; 144 145 /* Signal number used to suspend/resume a thread */ 146 147 /* do not use any signal number less than SIGSEGV, see 4355769 */ 148 static int SR_signum = SIGUSR2; 149 sigset_t SR_sigset; 150 151 152 //////////////////////////////////////////////////////////////////////////////// 153 // utility functions 154 155 static int SR_initialize(); 156 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time); 157 158 julong os::available_memory() { 159 return Bsd::available_memory(); 160 } 161 162 // available here means free 163 julong os::Bsd::available_memory() { 164 uint64_t available = physical_memory() >> 2; 165 #ifdef __APPLE__ 166 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT; 167 vm_statistics64_data_t vmstat; 168 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64, 169 (host_info64_t)&vmstat, &count); 170 assert(kerr == KERN_SUCCESS, 171 "host_statistics64 failed - check mach_host_self() and count"); 172 if (kerr == KERN_SUCCESS) { 173 available = vmstat.free_count * os::vm_page_size(); 174 } 175 #endif 176 return available; 177 } 178 179 julong os::physical_memory() { 180 return Bsd::physical_memory(); 181 } 182 183 //////////////////////////////////////////////////////////////////////////////// 184 // environment support 185 186 bool os::getenv(const char* name, char* buf, int len) { 187 const char* val = ::getenv(name); 188 if (val != NULL && strlen(val) < (size_t)len) { 189 strcpy(buf, val); 190 return true; 191 } 192 if (len > 0) buf[0] = 0; // return a null string 193 return false; 194 } 195 196 197 // Return true if user is running as root. 198 199 bool os::have_special_privileges() { 200 static bool init = false; 201 static bool privileges = false; 202 if (!init) { 203 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 204 init = true; 205 } 206 return privileges; 207 } 208 209 210 211 // Cpu architecture string 212 #if defined(ZERO) 213 static char cpu_arch[] = ZERO_LIBARCH; 214 #elif defined(IA64) 215 static char cpu_arch[] = "ia64"; 216 #elif defined(IA32) 217 static char cpu_arch[] = "i386"; 218 #elif defined(AMD64) 219 static char cpu_arch[] = "amd64"; 220 #elif defined(ARM) 221 static char cpu_arch[] = "arm"; 222 #elif defined(PPC32) 223 static char cpu_arch[] = "ppc"; 224 #elif defined(SPARC) 225 # ifdef _LP64 226 static char cpu_arch[] = "sparcv9"; 227 # else 228 static char cpu_arch[] = "sparc"; 229 # endif 230 #else 231 #error Add appropriate cpu_arch setting 232 #endif 233 234 // Compiler variant 235 #ifdef COMPILER2 236 #define COMPILER_VARIANT "server" 237 #else 238 #define COMPILER_VARIANT "client" 239 #endif 240 241 242 void os::Bsd::initialize_system_info() { 243 int mib[2]; 244 size_t len; 245 int cpu_val; 246 julong mem_val; 247 248 /* get processors count via hw.ncpus sysctl */ 249 mib[0] = CTL_HW; 250 mib[1] = HW_NCPU; 251 len = sizeof(cpu_val); 252 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) { 253 assert(len == sizeof(cpu_val), "unexpected data size"); 254 set_processor_count(cpu_val); 255 } 256 else { 257 set_processor_count(1); // fallback 258 } 259 260 /* get physical memory via hw.memsize sysctl (hw.memsize is used 261 * since it returns a 64 bit value) 262 */ 263 mib[0] = CTL_HW; 264 265 #if defined (HW_MEMSIZE) // Apple 266 mib[1] = HW_MEMSIZE; 267 #elif defined(HW_PHYSMEM) // Most of BSD 268 mib[1] = HW_PHYSMEM; 269 #elif defined(HW_REALMEM) // Old FreeBSD 270 mib[1] = HW_REALMEM; 271 #else 272 #error No ways to get physmem 273 #endif 274 275 len = sizeof(mem_val); 276 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) { 277 assert(len == sizeof(mem_val), "unexpected data size"); 278 _physical_memory = mem_val; 279 } else { 280 _physical_memory = 256*1024*1024; // fallback (XXXBSD?) 281 } 282 283 #ifdef __OpenBSD__ 284 { 285 // limit _physical_memory memory view on OpenBSD since 286 // datasize rlimit restricts us anyway. 287 struct rlimit limits; 288 getrlimit(RLIMIT_DATA, &limits); 289 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur); 290 } 291 #endif 292 } 293 294 #ifdef __APPLE__ 295 static const char *get_home() { 296 const char *home_dir = ::getenv("HOME"); 297 if ((home_dir == NULL) || (*home_dir == '\0')) { 298 struct passwd *passwd_info = getpwuid(geteuid()); 299 if (passwd_info != NULL) { 300 home_dir = passwd_info->pw_dir; 301 } 302 } 303 304 return home_dir; 305 } 306 #endif 307 308 void os::init_system_properties_values() { 309 // char arch[12]; 310 // sysinfo(SI_ARCHITECTURE, arch, sizeof(arch)); 311 312 // The next steps are taken in the product version: 313 // 314 // Obtain the JAVA_HOME value from the location of libjvm.so. 315 // This library should be located at: 316 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so. 317 // 318 // If "/jre/lib/" appears at the right place in the path, then we 319 // assume libjvm.so is installed in a JDK and we use this path. 320 // 321 // Otherwise exit with message: "Could not create the Java virtual machine." 322 // 323 // The following extra steps are taken in the debugging version: 324 // 325 // If "/jre/lib/" does NOT appear at the right place in the path 326 // instead of exit check for $JAVA_HOME environment variable. 327 // 328 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 329 // then we append a fake suffix "hotspot/libjvm.so" to this path so 330 // it looks like libjvm.so is installed there 331 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 332 // 333 // Otherwise exit. 334 // 335 // Important note: if the location of libjvm.so changes this 336 // code needs to be changed accordingly. 337 338 // The next few definitions allow the code to be verbatim: 339 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal) 340 #define getenv(n) ::getenv(n) 341 342 /* 343 * See ld(1): 344 * The linker uses the following search paths to locate required 345 * shared libraries: 346 * 1: ... 347 * ... 348 * 7: The default directories, normally /lib and /usr/lib. 349 */ 350 #ifndef DEFAULT_LIBPATH 351 #define DEFAULT_LIBPATH "/lib:/usr/lib" 352 #endif 353 354 #define EXTENSIONS_DIR "/lib/ext" 355 #define ENDORSED_DIR "/lib/endorsed" 356 #define REG_DIR "/usr/java/packages" 357 358 #ifdef __APPLE__ 359 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions" 360 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java" 361 const char *user_home_dir = get_home(); 362 // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir 363 int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) + 364 sizeof(SYS_EXTENSIONS_DIRS); 365 #endif 366 367 { 368 /* sysclasspath, java_home, dll_dir */ 369 { 370 char *home_path; 371 char *dll_path; 372 char *pslash; 373 char buf[MAXPATHLEN]; 374 os::jvm_path(buf, sizeof(buf)); 375 376 // Found the full path to libjvm.so. 377 // Now cut the path to <java_home>/jre if we can. 378 *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */ 379 pslash = strrchr(buf, '/'); 380 if (pslash != NULL) 381 *pslash = '\0'; /* get rid of /{client|server|hotspot} */ 382 dll_path = malloc(strlen(buf) + 1); 383 if (dll_path == NULL) 384 return; 385 strcpy(dll_path, buf); 386 Arguments::set_dll_dir(dll_path); 387 388 if (pslash != NULL) { 389 pslash = strrchr(buf, '/'); 390 if (pslash != NULL) { 391 *pslash = '\0'; /* get rid of /<arch> (/lib on macosx) */ 392 #ifndef __APPLE__ 393 pslash = strrchr(buf, '/'); 394 if (pslash != NULL) 395 *pslash = '\0'; /* get rid of /lib */ 396 #endif 397 } 398 } 399 400 home_path = malloc(strlen(buf) + 1); 401 if (home_path == NULL) 402 return; 403 strcpy(home_path, buf); 404 Arguments::set_java_home(home_path); 405 406 if (!set_boot_path('/', ':')) 407 return; 408 } 409 410 /* 411 * Where to look for native libraries 412 * 413 * Note: Due to a legacy implementation, most of the library path 414 * is set in the launcher. This was to accomodate linking restrictions 415 * on legacy Bsd implementations (which are no longer supported). 416 * Eventually, all the library path setting will be done here. 417 * 418 * However, to prevent the proliferation of improperly built native 419 * libraries, the new path component /usr/java/packages is added here. 420 * Eventually, all the library path setting will be done here. 421 */ 422 { 423 char *ld_library_path; 424 425 /* 426 * Construct the invariant part of ld_library_path. Note that the 427 * space for the colon and the trailing null are provided by the 428 * nulls included by the sizeof operator (so actually we allocate 429 * a byte more than necessary). 430 */ 431 #ifdef __APPLE__ 432 ld_library_path = (char *) malloc(system_ext_size); 433 sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir); 434 #else 435 ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") + 436 strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH)); 437 sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch); 438 #endif 439 440 /* 441 * Get the user setting of LD_LIBRARY_PATH, and prepended it. It 442 * should always exist (until the legacy problem cited above is 443 * addressed). 444 */ 445 #ifdef __APPLE__ 446 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper 447 char *l = getenv("JAVA_LIBRARY_PATH"); 448 if (l != NULL) { 449 char *t = ld_library_path; 450 /* That's +1 for the colon and +1 for the trailing '\0' */ 451 ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1); 452 sprintf(ld_library_path, "%s:%s", l, t); 453 free(t); 454 } 455 456 char *v = getenv("DYLD_LIBRARY_PATH"); 457 #else 458 char *v = getenv("LD_LIBRARY_PATH"); 459 #endif 460 if (v != NULL) { 461 char *t = ld_library_path; 462 /* That's +1 for the colon and +1 for the trailing '\0' */ 463 ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1); 464 sprintf(ld_library_path, "%s:%s", v, t); 465 free(t); 466 } 467 468 #ifdef __APPLE__ 469 // Apple's Java6 has "." at the beginning of java.library.path. 470 // OpenJDK on Windows has "." at the end of java.library.path. 471 // OpenJDK on Linux and Solaris don't have "." in java.library.path 472 // at all. To ease the transition from Apple's Java6 to OpenJDK7, 473 // "." is appended to the end of java.library.path. Yes, this 474 // could cause a change in behavior, but Apple's Java6 behavior 475 // can be achieved by putting "." at the beginning of the 476 // JAVA_LIBRARY_PATH environment variable. 477 { 478 char *t = ld_library_path; 479 // that's +3 for appending ":." and the trailing '\0' 480 ld_library_path = (char *) malloc(strlen(t) + 3); 481 sprintf(ld_library_path, "%s:%s", t, "."); 482 free(t); 483 } 484 #endif 485 486 Arguments::set_library_path(ld_library_path); 487 } 488 489 /* 490 * Extensions directories. 491 * 492 * Note that the space for the colon and the trailing null are provided 493 * by the nulls included by the sizeof operator (so actually one byte more 494 * than necessary is allocated). 495 */ 496 { 497 #ifdef __APPLE__ 498 char *buf = malloc(strlen(Arguments::get_java_home()) + 499 sizeof(EXTENSIONS_DIR) + system_ext_size); 500 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" 501 SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home()); 502 #else 503 char *buf = malloc(strlen(Arguments::get_java_home()) + 504 sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR)); 505 sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR, 506 Arguments::get_java_home()); 507 #endif 508 509 Arguments::set_ext_dirs(buf); 510 } 511 512 /* Endorsed standards default directory. */ 513 { 514 char * buf; 515 buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR)); 516 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); 517 Arguments::set_endorsed_dirs(buf); 518 } 519 } 520 521 #ifdef __APPLE__ 522 #undef SYS_EXTENSIONS_DIR 523 #endif 524 #undef malloc 525 #undef getenv 526 #undef EXTENSIONS_DIR 527 #undef ENDORSED_DIR 528 529 // Done 530 return; 531 } 532 533 //////////////////////////////////////////////////////////////////////////////// 534 // breakpoint support 535 536 void os::breakpoint() { 537 BREAKPOINT; 538 } 539 540 extern "C" void breakpoint() { 541 // use debugger to set breakpoint here 542 } 543 544 //////////////////////////////////////////////////////////////////////////////// 545 // signal support 546 547 debug_only(static bool signal_sets_initialized = false); 548 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 549 550 bool os::Bsd::is_sig_ignored(int sig) { 551 struct sigaction oact; 552 sigaction(sig, (struct sigaction*)NULL, &oact); 553 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 554 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 555 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) 556 return true; 557 else 558 return false; 559 } 560 561 void os::Bsd::signal_sets_init() { 562 // Should also have an assertion stating we are still single-threaded. 563 assert(!signal_sets_initialized, "Already initialized"); 564 // Fill in signals that are necessarily unblocked for all threads in 565 // the VM. Currently, we unblock the following signals: 566 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 567 // by -Xrs (=ReduceSignalUsage)); 568 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 569 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 570 // the dispositions or masks wrt these signals. 571 // Programs embedding the VM that want to use the above signals for their 572 // own purposes must, at this time, use the "-Xrs" option to prevent 573 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 574 // (See bug 4345157, and other related bugs). 575 // In reality, though, unblocking these signals is really a nop, since 576 // these signals are not blocked by default. 577 sigemptyset(&unblocked_sigs); 578 sigemptyset(&allowdebug_blocked_sigs); 579 sigaddset(&unblocked_sigs, SIGILL); 580 sigaddset(&unblocked_sigs, SIGSEGV); 581 sigaddset(&unblocked_sigs, SIGBUS); 582 sigaddset(&unblocked_sigs, SIGFPE); 583 sigaddset(&unblocked_sigs, SR_signum); 584 585 if (!ReduceSignalUsage) { 586 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 587 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 588 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); 589 } 590 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 591 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 592 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); 593 } 594 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 595 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 596 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); 597 } 598 } 599 // Fill in signals that are blocked by all but the VM thread. 600 sigemptyset(&vm_sigs); 601 if (!ReduceSignalUsage) 602 sigaddset(&vm_sigs, BREAK_SIGNAL); 603 debug_only(signal_sets_initialized = true); 604 605 } 606 607 // These are signals that are unblocked while a thread is running Java. 608 // (For some reason, they get blocked by default.) 609 sigset_t* os::Bsd::unblocked_signals() { 610 assert(signal_sets_initialized, "Not initialized"); 611 return &unblocked_sigs; 612 } 613 614 // These are the signals that are blocked while a (non-VM) thread is 615 // running Java. Only the VM thread handles these signals. 616 sigset_t* os::Bsd::vm_signals() { 617 assert(signal_sets_initialized, "Not initialized"); 618 return &vm_sigs; 619 } 620 621 // These are signals that are blocked during cond_wait to allow debugger in 622 sigset_t* os::Bsd::allowdebug_blocked_signals() { 623 assert(signal_sets_initialized, "Not initialized"); 624 return &allowdebug_blocked_sigs; 625 } 626 627 void os::Bsd::hotspot_sigmask(Thread* thread) { 628 629 //Save caller's signal mask before setting VM signal mask 630 sigset_t caller_sigmask; 631 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 632 633 OSThread* osthread = thread->osthread(); 634 osthread->set_caller_sigmask(caller_sigmask); 635 636 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); 637 638 if (!ReduceSignalUsage) { 639 if (thread->is_VM_thread()) { 640 // Only the VM thread handles BREAK_SIGNAL ... 641 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 642 } else { 643 // ... all other threads block BREAK_SIGNAL 644 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 645 } 646 } 647 } 648 649 650 ////////////////////////////////////////////////////////////////////////////// 651 // create new thread 652 653 // check if it's safe to start a new thread 654 static bool _thread_safety_check(Thread* thread) { 655 return true; 656 } 657 658 #ifdef __APPLE__ 659 // library handle for calling objc_registerThreadWithCollector() 660 // without static linking to the libobjc library 661 #define OBJC_LIB "/usr/lib/libobjc.dylib" 662 #define OBJC_GCREGISTER "objc_registerThreadWithCollector" 663 typedef void (*objc_registerThreadWithCollector_t)(); 664 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction; 665 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL; 666 #endif 667 668 #ifdef __APPLE__ 669 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) { 670 // Additional thread_id used to correlate threads in SA 671 thread_identifier_info_data_t m_ident_info; 672 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT; 673 674 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO, 675 (thread_info_t) &m_ident_info, &count); 676 677 return m_ident_info.thread_id; 678 } 679 #endif 680 681 // Thread start routine for all newly created threads 682 static void *java_start(Thread *thread) { 683 // Try to randomize the cache line index of hot stack frames. 684 // This helps when threads of the same stack traces evict each other's 685 // cache lines. The threads can be either from the same JVM instance, or 686 // from different JVM instances. The benefit is especially true for 687 // processors with hyperthreading technology. 688 static int counter = 0; 689 int pid = os::current_process_id(); 690 alloca(((pid ^ counter++) & 7) * 128); 691 692 ThreadLocalStorage::set_thread(thread); 693 694 OSThread* osthread = thread->osthread(); 695 Monitor* sync = osthread->startThread_lock(); 696 697 // non floating stack BsdThreads needs extra check, see above 698 if (!_thread_safety_check(thread)) { 699 // notify parent thread 700 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 701 osthread->set_state(ZOMBIE); 702 sync->notify_all(); 703 return NULL; 704 } 705 706 osthread->set_thread_id(os::Bsd::gettid()); 707 708 #ifdef __APPLE__ 709 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 710 guarantee(unique_thread_id != 0, "unique thread id was not found"); 711 osthread->set_unique_thread_id(unique_thread_id); 712 #endif 713 // initialize signal mask for this thread 714 os::Bsd::hotspot_sigmask(thread); 715 716 // initialize floating point control register 717 os::Bsd::init_thread_fpu_state(); 718 719 #ifdef __APPLE__ 720 // register thread with objc gc 721 if (objc_registerThreadWithCollectorFunction != NULL) { 722 objc_registerThreadWithCollectorFunction(); 723 } 724 #endif 725 726 // handshaking with parent thread 727 { 728 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 729 730 // notify parent thread 731 osthread->set_state(INITIALIZED); 732 sync->notify_all(); 733 734 // wait until os::start_thread() 735 while (osthread->get_state() == INITIALIZED) { 736 sync->wait(Mutex::_no_safepoint_check_flag); 737 } 738 } 739 740 // call one more level start routine 741 thread->run(); 742 743 return 0; 744 } 745 746 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { 747 assert(thread->osthread() == NULL, "caller responsible"); 748 749 // Allocate the OSThread object 750 OSThread* osthread = new OSThread(NULL, NULL); 751 if (osthread == NULL) { 752 return false; 753 } 754 755 // set the correct thread state 756 osthread->set_thread_type(thr_type); 757 758 // Initial state is ALLOCATED but not INITIALIZED 759 osthread->set_state(ALLOCATED); 760 761 thread->set_osthread(osthread); 762 763 // init thread attributes 764 pthread_attr_t attr; 765 pthread_attr_init(&attr); 766 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 767 768 // stack size 769 if (os::Bsd::supports_variable_stack_size()) { 770 // calculate stack size if it's not specified by caller 771 if (stack_size == 0) { 772 stack_size = os::Bsd::default_stack_size(thr_type); 773 774 switch (thr_type) { 775 case os::java_thread: 776 // Java threads use ThreadStackSize which default value can be 777 // changed with the flag -Xss 778 assert (JavaThread::stack_size_at_create() > 0, "this should be set"); 779 stack_size = JavaThread::stack_size_at_create(); 780 break; 781 case os::compiler_thread: 782 if (CompilerThreadStackSize > 0) { 783 stack_size = (size_t)(CompilerThreadStackSize * K); 784 break; 785 } // else fall through: 786 // use VMThreadStackSize if CompilerThreadStackSize is not defined 787 case os::vm_thread: 788 case os::pgc_thread: 789 case os::cgc_thread: 790 case os::watcher_thread: 791 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 792 break; 793 } 794 } 795 796 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); 797 pthread_attr_setstacksize(&attr, stack_size); 798 } else { 799 // let pthread_create() pick the default value. 800 } 801 802 ThreadState state; 803 804 { 805 pthread_t tid; 806 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 807 808 pthread_attr_destroy(&attr); 809 810 if (ret != 0) { 811 if (PrintMiscellaneous && (Verbose || WizardMode)) { 812 perror("pthread_create()"); 813 } 814 // Need to clean up stuff we've allocated so far 815 thread->set_osthread(NULL); 816 delete osthread; 817 return false; 818 } 819 820 // Store pthread info into the OSThread 821 osthread->set_pthread_id(tid); 822 823 // Wait until child thread is either initialized or aborted 824 { 825 Monitor* sync_with_child = osthread->startThread_lock(); 826 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 827 while ((state = osthread->get_state()) == ALLOCATED) { 828 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 829 } 830 } 831 832 } 833 834 // Aborted due to thread limit being reached 835 if (state == ZOMBIE) { 836 thread->set_osthread(NULL); 837 delete osthread; 838 return false; 839 } 840 841 // The thread is returned suspended (in state INITIALIZED), 842 // and is started higher up in the call chain 843 assert(state == INITIALIZED, "race condition"); 844 return true; 845 } 846 847 ///////////////////////////////////////////////////////////////////////////// 848 // attach existing thread 849 850 // bootstrap the main thread 851 bool os::create_main_thread(JavaThread* thread) { 852 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); 853 return create_attached_thread(thread); 854 } 855 856 bool os::create_attached_thread(JavaThread* thread) { 857 #ifdef ASSERT 858 thread->verify_not_published(); 859 #endif 860 861 // Allocate the OSThread object 862 OSThread* osthread = new OSThread(NULL, NULL); 863 864 if (osthread == NULL) { 865 return false; 866 } 867 868 osthread->set_thread_id(os::Bsd::gettid()); 869 870 // Store pthread info into the OSThread 871 #ifdef __APPLE__ 872 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 873 guarantee(unique_thread_id != 0, "just checking"); 874 osthread->set_unique_thread_id(unique_thread_id); 875 #endif 876 osthread->set_pthread_id(::pthread_self()); 877 878 // initialize floating point control register 879 os::Bsd::init_thread_fpu_state(); 880 881 // Initial thread state is RUNNABLE 882 osthread->set_state(RUNNABLE); 883 884 thread->set_osthread(osthread); 885 886 // initialize signal mask for this thread 887 // and save the caller's signal mask 888 os::Bsd::hotspot_sigmask(thread); 889 890 return true; 891 } 892 893 void os::pd_start_thread(Thread* thread) { 894 OSThread * osthread = thread->osthread(); 895 assert(osthread->get_state() != INITIALIZED, "just checking"); 896 Monitor* sync_with_child = osthread->startThread_lock(); 897 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 898 sync_with_child->notify(); 899 } 900 901 // Free Bsd resources related to the OSThread 902 void os::free_thread(OSThread* osthread) { 903 assert(osthread != NULL, "osthread not set"); 904 905 if (Thread::current()->osthread() == osthread) { 906 // Restore caller's signal mask 907 sigset_t sigmask = osthread->caller_sigmask(); 908 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 909 } 910 911 delete osthread; 912 } 913 914 ////////////////////////////////////////////////////////////////////////////// 915 // thread local storage 916 917 int os::allocate_thread_local_storage() { 918 pthread_key_t key; 919 int rslt = pthread_key_create(&key, NULL); 920 assert(rslt == 0, "cannot allocate thread local storage"); 921 return (int)key; 922 } 923 924 // Note: This is currently not used by VM, as we don't destroy TLS key 925 // on VM exit. 926 void os::free_thread_local_storage(int index) { 927 int rslt = pthread_key_delete((pthread_key_t)index); 928 assert(rslt == 0, "invalid index"); 929 } 930 931 void os::thread_local_storage_at_put(int index, void* value) { 932 int rslt = pthread_setspecific((pthread_key_t)index, value); 933 assert(rslt == 0, "pthread_setspecific failed"); 934 } 935 936 extern "C" Thread* get_thread() { 937 return ThreadLocalStorage::thread(); 938 } 939 940 941 //////////////////////////////////////////////////////////////////////////////// 942 // time support 943 944 // Time since start-up in seconds to a fine granularity. 945 // Used by VMSelfDestructTimer and the MemProfiler. 946 double os::elapsedTime() { 947 948 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); 949 } 950 951 jlong os::elapsed_counter() { 952 return javaTimeNanos() - initial_time_count; 953 } 954 955 jlong os::elapsed_frequency() { 956 return NANOSECS_PER_SEC; // nanosecond resolution 957 } 958 959 bool os::supports_vtime() { return true; } 960 bool os::enable_vtime() { return false; } 961 bool os::vtime_enabled() { return false; } 962 963 double os::elapsedVTime() { 964 // better than nothing, but not much 965 return elapsedTime(); 966 } 967 968 jlong os::javaTimeMillis() { 969 timeval time; 970 int status = gettimeofday(&time, NULL); 971 assert(status != -1, "bsd error"); 972 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 973 } 974 975 #ifndef CLOCK_MONOTONIC 976 #define CLOCK_MONOTONIC (1) 977 #endif 978 979 #ifdef __APPLE__ 980 void os::Bsd::clock_init() { 981 // XXXDARWIN: Investigate replacement monotonic clock 982 } 983 #else 984 void os::Bsd::clock_init() { 985 struct timespec res; 986 struct timespec tp; 987 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && 988 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { 989 // yes, monotonic clock is supported 990 _clock_gettime = ::clock_gettime; 991 } 992 } 993 #endif 994 995 996 jlong os::javaTimeNanos() { 997 if (os::supports_monotonic_clock()) { 998 struct timespec tp; 999 int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp); 1000 assert(status == 0, "gettime error"); 1001 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1002 return result; 1003 } else { 1004 timeval time; 1005 int status = gettimeofday(&time, NULL); 1006 assert(status != -1, "bsd error"); 1007 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1008 return 1000 * usecs; 1009 } 1010 } 1011 1012 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1013 if (os::supports_monotonic_clock()) { 1014 info_ptr->max_value = ALL_64_BITS; 1015 1016 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1017 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1018 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1019 } else { 1020 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1021 info_ptr->max_value = ALL_64_BITS; 1022 1023 // gettimeofday is a real time clock so it skips 1024 info_ptr->may_skip_backward = true; 1025 info_ptr->may_skip_forward = true; 1026 } 1027 1028 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1029 } 1030 1031 // Return the real, user, and system times in seconds from an 1032 // arbitrary fixed point in the past. 1033 bool os::getTimesSecs(double* process_real_time, 1034 double* process_user_time, 1035 double* process_system_time) { 1036 struct tms ticks; 1037 clock_t real_ticks = times(&ticks); 1038 1039 if (real_ticks == (clock_t) (-1)) { 1040 return false; 1041 } else { 1042 double ticks_per_second = (double) clock_tics_per_sec; 1043 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1044 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1045 *process_real_time = ((double) real_ticks) / ticks_per_second; 1046 1047 return true; 1048 } 1049 } 1050 1051 1052 char * os::local_time_string(char *buf, size_t buflen) { 1053 struct tm t; 1054 time_t long_time; 1055 time(&long_time); 1056 localtime_r(&long_time, &t); 1057 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1058 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1059 t.tm_hour, t.tm_min, t.tm_sec); 1060 return buf; 1061 } 1062 1063 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1064 return localtime_r(clock, res); 1065 } 1066 1067 //////////////////////////////////////////////////////////////////////////////// 1068 // runtime exit support 1069 1070 // Note: os::shutdown() might be called very early during initialization, or 1071 // called from signal handler. Before adding something to os::shutdown(), make 1072 // sure it is async-safe and can handle partially initialized VM. 1073 void os::shutdown() { 1074 1075 // allow PerfMemory to attempt cleanup of any persistent resources 1076 perfMemory_exit(); 1077 1078 // needs to remove object in file system 1079 AttachListener::abort(); 1080 1081 // flush buffered output, finish log files 1082 ostream_abort(); 1083 1084 // Check for abort hook 1085 abort_hook_t abort_hook = Arguments::abort_hook(); 1086 if (abort_hook != NULL) { 1087 abort_hook(); 1088 } 1089 1090 } 1091 1092 // Note: os::abort() might be called very early during initialization, or 1093 // called from signal handler. Before adding something to os::abort(), make 1094 // sure it is async-safe and can handle partially initialized VM. 1095 void os::abort(bool dump_core) { 1096 os::shutdown(); 1097 if (dump_core) { 1098 #ifndef PRODUCT 1099 fdStream out(defaultStream::output_fd()); 1100 out.print_raw("Current thread is "); 1101 char buf[16]; 1102 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1103 out.print_raw_cr(buf); 1104 out.print_raw_cr("Dumping core ..."); 1105 #endif 1106 ::abort(); // dump core 1107 } 1108 1109 ::exit(1); 1110 } 1111 1112 // Die immediately, no exit hook, no abort hook, no cleanup. 1113 void os::die() { 1114 // _exit() on BsdThreads only kills current thread 1115 ::abort(); 1116 } 1117 1118 // unused on bsd for now. 1119 void os::set_error_file(const char *logfile) {} 1120 1121 1122 // This method is a copy of JDK's sysGetLastErrorString 1123 // from src/solaris/hpi/src/system_md.c 1124 1125 size_t os::lasterror(char *buf, size_t len) { 1126 1127 if (errno == 0) return 0; 1128 1129 const char *s = ::strerror(errno); 1130 size_t n = ::strlen(s); 1131 if (n >= len) { 1132 n = len - 1; 1133 } 1134 ::strncpy(buf, s, n); 1135 buf[n] = '\0'; 1136 return n; 1137 } 1138 1139 // Information of current thread in variety of formats 1140 pid_t os::Bsd::gettid() { 1141 int retval = -1; 1142 1143 #ifdef __APPLE__ //XNU kernel 1144 // despite the fact mach port is actually not a thread id use it 1145 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4 1146 retval = ::pthread_mach_thread_np(::pthread_self()); 1147 guarantee(retval != 0, "just checking"); 1148 return retval; 1149 1150 #elif __FreeBSD__ 1151 retval = syscall(SYS_thr_self); 1152 #elif __OpenBSD__ 1153 retval = syscall(SYS_getthrid); 1154 #elif __NetBSD__ 1155 retval = (pid_t) syscall(SYS__lwp_self); 1156 #endif 1157 1158 if (retval == -1) { 1159 return getpid(); 1160 } 1161 } 1162 1163 intx os::current_thread_id() { 1164 #ifdef __APPLE__ 1165 return (intx)::pthread_mach_thread_np(::pthread_self()); 1166 #else 1167 return (intx)::pthread_self(); 1168 #endif 1169 } 1170 1171 int os::current_process_id() { 1172 1173 // Under the old bsd thread library, bsd gives each thread 1174 // its own process id. Because of this each thread will return 1175 // a different pid if this method were to return the result 1176 // of getpid(2). Bsd provides no api that returns the pid 1177 // of the launcher thread for the vm. This implementation 1178 // returns a unique pid, the pid of the launcher thread 1179 // that starts the vm 'process'. 1180 1181 // Under the NPTL, getpid() returns the same pid as the 1182 // launcher thread rather than a unique pid per thread. 1183 // Use gettid() if you want the old pre NPTL behaviour. 1184 1185 // if you are looking for the result of a call to getpid() that 1186 // returns a unique pid for the calling thread, then look at the 1187 // OSThread::thread_id() method in osThread_bsd.hpp file 1188 1189 return (int)(_initial_pid ? _initial_pid : getpid()); 1190 } 1191 1192 // DLL functions 1193 1194 #define JNI_LIB_PREFIX "lib" 1195 #ifdef __APPLE__ 1196 #define JNI_LIB_SUFFIX ".dylib" 1197 #else 1198 #define JNI_LIB_SUFFIX ".so" 1199 #endif 1200 1201 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } 1202 1203 // This must be hard coded because it's the system's temporary 1204 // directory not the java application's temp directory, ala java.io.tmpdir. 1205 #ifdef __APPLE__ 1206 // macosx has a secure per-user temporary directory 1207 char temp_path_storage[PATH_MAX]; 1208 const char* os::get_temp_directory() { 1209 static char *temp_path = NULL; 1210 if (temp_path == NULL) { 1211 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX); 1212 if (pathSize == 0 || pathSize > PATH_MAX) { 1213 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage)); 1214 } 1215 temp_path = temp_path_storage; 1216 } 1217 return temp_path; 1218 } 1219 #else /* __APPLE__ */ 1220 const char* os::get_temp_directory() { return "/tmp"; } 1221 #endif /* __APPLE__ */ 1222 1223 static bool file_exists(const char* filename) { 1224 struct stat statbuf; 1225 if (filename == NULL || strlen(filename) == 0) { 1226 return false; 1227 } 1228 return os::stat(filename, &statbuf) == 0; 1229 } 1230 1231 bool os::dll_build_name(char* buffer, size_t buflen, 1232 const char* pname, const char* fname) { 1233 bool retval = false; 1234 // Copied from libhpi 1235 const size_t pnamelen = pname ? strlen(pname) : 0; 1236 1237 // Return error on buffer overflow. 1238 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { 1239 return retval; 1240 } 1241 1242 if (pnamelen == 0) { 1243 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); 1244 retval = true; 1245 } else if (strchr(pname, *os::path_separator()) != NULL) { 1246 int n; 1247 char** pelements = split_path(pname, &n); 1248 if (pelements == NULL) { 1249 return false; 1250 } 1251 for (int i = 0 ; i < n ; i++) { 1252 // Really shouldn't be NULL, but check can't hurt 1253 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1254 continue; // skip the empty path values 1255 } 1256 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, 1257 pelements[i], fname); 1258 if (file_exists(buffer)) { 1259 retval = true; 1260 break; 1261 } 1262 } 1263 // release the storage 1264 for (int i = 0 ; i < n ; i++) { 1265 if (pelements[i] != NULL) { 1266 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal); 1267 } 1268 } 1269 if (pelements != NULL) { 1270 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal); 1271 } 1272 } else { 1273 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); 1274 retval = true; 1275 } 1276 return retval; 1277 } 1278 1279 // check if addr is inside libjvm.so 1280 bool os::address_is_in_vm(address addr) { 1281 static address libjvm_base_addr; 1282 Dl_info dlinfo; 1283 1284 if (libjvm_base_addr == NULL) { 1285 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1286 libjvm_base_addr = (address)dlinfo.dli_fbase; 1287 } 1288 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1289 } 1290 1291 if (dladdr((void *)addr, &dlinfo) != 0) { 1292 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1293 } 1294 1295 return false; 1296 } 1297 1298 1299 #define MACH_MAXSYMLEN 256 1300 1301 bool os::dll_address_to_function_name(address addr, char *buf, 1302 int buflen, int *offset) { 1303 // buf is not optional, but offset is optional 1304 assert(buf != NULL, "sanity check"); 1305 1306 Dl_info dlinfo; 1307 char localbuf[MACH_MAXSYMLEN]; 1308 1309 if (dladdr((void*)addr, &dlinfo) != 0) { 1310 // see if we have a matching symbol 1311 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1312 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { 1313 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1314 } 1315 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1316 return true; 1317 } 1318 // no matching symbol so try for just file info 1319 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1320 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1321 buf, buflen, offset, dlinfo.dli_fname)) { 1322 return true; 1323 } 1324 } 1325 1326 // Handle non-dynamic manually: 1327 if (dlinfo.dli_fbase != NULL && 1328 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, 1329 dlinfo.dli_fbase)) { 1330 if (!Decoder::demangle(localbuf, buf, buflen)) { 1331 jio_snprintf(buf, buflen, "%s", localbuf); 1332 } 1333 return true; 1334 } 1335 } 1336 buf[0] = '\0'; 1337 if (offset != NULL) *offset = -1; 1338 return false; 1339 } 1340 1341 // ported from solaris version 1342 bool os::dll_address_to_library_name(address addr, char* buf, 1343 int buflen, int* offset) { 1344 // buf is not optional, but offset is optional 1345 assert(buf != NULL, "sanity check"); 1346 1347 Dl_info dlinfo; 1348 1349 if (dladdr((void*)addr, &dlinfo) != 0) { 1350 if (dlinfo.dli_fname != NULL) { 1351 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1352 } 1353 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1354 *offset = addr - (address)dlinfo.dli_fbase; 1355 } 1356 return true; 1357 } 1358 1359 buf[0] = '\0'; 1360 if (offset) *offset = -1; 1361 return false; 1362 } 1363 1364 // Loads .dll/.so and 1365 // in case of error it checks if .dll/.so was built for the 1366 // same architecture as Hotspot is running on 1367 1368 #ifdef __APPLE__ 1369 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1370 void * result= ::dlopen(filename, RTLD_LAZY); 1371 if (result != NULL) { 1372 // Successful loading 1373 return result; 1374 } 1375 1376 // Read system error message into ebuf 1377 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1378 ebuf[ebuflen-1]='\0'; 1379 1380 return NULL; 1381 } 1382 #else 1383 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) 1384 { 1385 void * result= ::dlopen(filename, RTLD_LAZY); 1386 if (result != NULL) { 1387 // Successful loading 1388 return result; 1389 } 1390 1391 Elf32_Ehdr elf_head; 1392 1393 // Read system error message into ebuf 1394 // It may or may not be overwritten below 1395 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1396 ebuf[ebuflen-1]='\0'; 1397 int diag_msg_max_length=ebuflen-strlen(ebuf); 1398 char* diag_msg_buf=ebuf+strlen(ebuf); 1399 1400 if (diag_msg_max_length==0) { 1401 // No more space in ebuf for additional diagnostics message 1402 return NULL; 1403 } 1404 1405 1406 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1407 1408 if (file_descriptor < 0) { 1409 // Can't open library, report dlerror() message 1410 return NULL; 1411 } 1412 1413 bool failed_to_read_elf_head= 1414 (sizeof(elf_head)!= 1415 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ; 1416 1417 ::close(file_descriptor); 1418 if (failed_to_read_elf_head) { 1419 // file i/o error - report dlerror() msg 1420 return NULL; 1421 } 1422 1423 typedef struct { 1424 Elf32_Half code; // Actual value as defined in elf.h 1425 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1426 char elf_class; // 32 or 64 bit 1427 char endianess; // MSB or LSB 1428 char* name; // String representation 1429 } arch_t; 1430 1431 #ifndef EM_486 1432 #define EM_486 6 /* Intel 80486 */ 1433 #endif 1434 1435 #ifndef EM_MIPS_RS3_LE 1436 #define EM_MIPS_RS3_LE 10 /* MIPS */ 1437 #endif 1438 1439 #ifndef EM_PPC64 1440 #define EM_PPC64 21 /* PowerPC64 */ 1441 #endif 1442 1443 #ifndef EM_S390 1444 #define EM_S390 22 /* IBM System/390 */ 1445 #endif 1446 1447 #ifndef EM_IA_64 1448 #define EM_IA_64 50 /* HP/Intel IA-64 */ 1449 #endif 1450 1451 #ifndef EM_X86_64 1452 #define EM_X86_64 62 /* AMD x86-64 */ 1453 #endif 1454 1455 static const arch_t arch_array[]={ 1456 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1457 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1458 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1459 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1460 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1461 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1462 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1463 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1464 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1465 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1466 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1467 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1468 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1469 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1470 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1471 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} 1472 }; 1473 1474 #if (defined IA32) 1475 static Elf32_Half running_arch_code=EM_386; 1476 #elif (defined AMD64) 1477 static Elf32_Half running_arch_code=EM_X86_64; 1478 #elif (defined IA64) 1479 static Elf32_Half running_arch_code=EM_IA_64; 1480 #elif (defined __sparc) && (defined _LP64) 1481 static Elf32_Half running_arch_code=EM_SPARCV9; 1482 #elif (defined __sparc) && (!defined _LP64) 1483 static Elf32_Half running_arch_code=EM_SPARC; 1484 #elif (defined __powerpc64__) 1485 static Elf32_Half running_arch_code=EM_PPC64; 1486 #elif (defined __powerpc__) 1487 static Elf32_Half running_arch_code=EM_PPC; 1488 #elif (defined ARM) 1489 static Elf32_Half running_arch_code=EM_ARM; 1490 #elif (defined S390) 1491 static Elf32_Half running_arch_code=EM_S390; 1492 #elif (defined ALPHA) 1493 static Elf32_Half running_arch_code=EM_ALPHA; 1494 #elif (defined MIPSEL) 1495 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1496 #elif (defined PARISC) 1497 static Elf32_Half running_arch_code=EM_PARISC; 1498 #elif (defined MIPS) 1499 static Elf32_Half running_arch_code=EM_MIPS; 1500 #elif (defined M68K) 1501 static Elf32_Half running_arch_code=EM_68K; 1502 #else 1503 #error Method os::dll_load requires that one of following is defined:\ 1504 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K 1505 #endif 1506 1507 // Identify compatability class for VM's architecture and library's architecture 1508 // Obtain string descriptions for architectures 1509 1510 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1511 int running_arch_index=-1; 1512 1513 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) { 1514 if (running_arch_code == arch_array[i].code) { 1515 running_arch_index = i; 1516 } 1517 if (lib_arch.code == arch_array[i].code) { 1518 lib_arch.compat_class = arch_array[i].compat_class; 1519 lib_arch.name = arch_array[i].name; 1520 } 1521 } 1522 1523 assert(running_arch_index != -1, 1524 "Didn't find running architecture code (running_arch_code) in arch_array"); 1525 if (running_arch_index == -1) { 1526 // Even though running architecture detection failed 1527 // we may still continue with reporting dlerror() message 1528 return NULL; 1529 } 1530 1531 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1532 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1533 return NULL; 1534 } 1535 1536 #ifndef S390 1537 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1538 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1539 return NULL; 1540 } 1541 #endif // !S390 1542 1543 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1544 if ( lib_arch.name!=NULL ) { 1545 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1546 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1547 lib_arch.name, arch_array[running_arch_index].name); 1548 } else { 1549 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1550 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1551 lib_arch.code, 1552 arch_array[running_arch_index].name); 1553 } 1554 } 1555 1556 return NULL; 1557 } 1558 #endif /* !__APPLE__ */ 1559 1560 void* os::get_default_process_handle() { 1561 #ifdef __APPLE__ 1562 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY 1563 // to avoid finding unexpected symbols on second (or later) 1564 // loads of a library. 1565 return (void*)::dlopen(NULL, RTLD_FIRST); 1566 #else 1567 return (void*)::dlopen(NULL, RTLD_LAZY); 1568 #endif 1569 } 1570 1571 // XXX: Do we need a lock around this as per Linux? 1572 void* os::dll_lookup(void* handle, const char* name) { 1573 return dlsym(handle, name); 1574 } 1575 1576 1577 static bool _print_ascii_file(const char* filename, outputStream* st) { 1578 int fd = ::open(filename, O_RDONLY); 1579 if (fd == -1) { 1580 return false; 1581 } 1582 1583 char buf[32]; 1584 int bytes; 1585 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { 1586 st->print_raw(buf, bytes); 1587 } 1588 1589 ::close(fd); 1590 1591 return true; 1592 } 1593 1594 void os::print_dll_info(outputStream *st) { 1595 st->print_cr("Dynamic libraries:"); 1596 #ifdef RTLD_DI_LINKMAP 1597 Dl_info dli; 1598 void *handle; 1599 Link_map *map; 1600 Link_map *p; 1601 1602 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 || 1603 dli.dli_fname == NULL) { 1604 st->print_cr("Error: Cannot print dynamic libraries."); 1605 return; 1606 } 1607 handle = dlopen(dli.dli_fname, RTLD_LAZY); 1608 if (handle == NULL) { 1609 st->print_cr("Error: Cannot print dynamic libraries."); 1610 return; 1611 } 1612 dlinfo(handle, RTLD_DI_LINKMAP, &map); 1613 if (map == NULL) { 1614 st->print_cr("Error: Cannot print dynamic libraries."); 1615 return; 1616 } 1617 1618 while (map->l_prev != NULL) 1619 map = map->l_prev; 1620 1621 while (map != NULL) { 1622 st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name); 1623 map = map->l_next; 1624 } 1625 1626 dlclose(handle); 1627 #elif defined(__APPLE__) 1628 uint32_t count; 1629 uint32_t i; 1630 1631 count = _dyld_image_count(); 1632 for (i = 1; i < count; i++) { 1633 const char *name = _dyld_get_image_name(i); 1634 intptr_t slide = _dyld_get_image_vmaddr_slide(i); 1635 st->print_cr(PTR_FORMAT " \t%s", slide, name); 1636 } 1637 #else 1638 st->print_cr("Error: Cannot print dynamic libraries."); 1639 #endif 1640 } 1641 1642 void os::print_os_info_brief(outputStream* st) { 1643 st->print("Bsd"); 1644 1645 os::Posix::print_uname_info(st); 1646 } 1647 1648 void os::print_os_info(outputStream* st) { 1649 st->print("OS:"); 1650 st->print("Bsd"); 1651 1652 os::Posix::print_uname_info(st); 1653 1654 os::Posix::print_rlimit_info(st); 1655 1656 os::Posix::print_load_average(st); 1657 } 1658 1659 void os::pd_print_cpu_info(outputStream* st) { 1660 // Nothing to do for now. 1661 } 1662 1663 void os::print_memory_info(outputStream* st) { 1664 1665 st->print("Memory:"); 1666 st->print(" %dk page", os::vm_page_size()>>10); 1667 1668 st->print(", physical " UINT64_FORMAT "k", 1669 os::physical_memory() >> 10); 1670 st->print("(" UINT64_FORMAT "k free)", 1671 os::available_memory() >> 10); 1672 st->cr(); 1673 1674 // meminfo 1675 st->print("\n/proc/meminfo:\n"); 1676 _print_ascii_file("/proc/meminfo", st); 1677 st->cr(); 1678 } 1679 1680 void os::print_siginfo(outputStream* st, void* siginfo) { 1681 const siginfo_t* si = (const siginfo_t*)siginfo; 1682 1683 os::Posix::print_siginfo_brief(st, si); 1684 1685 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && 1686 UseSharedSpaces) { 1687 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1688 if (mapinfo->is_in_shared_space(si->si_addr)) { 1689 st->print("\n\nError accessing class data sharing archive." \ 1690 " Mapped file inaccessible during execution, " \ 1691 " possible disk/network problem."); 1692 } 1693 } 1694 st->cr(); 1695 } 1696 1697 1698 static void print_signal_handler(outputStream* st, int sig, 1699 char* buf, size_t buflen); 1700 1701 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 1702 st->print_cr("Signal Handlers:"); 1703 print_signal_handler(st, SIGSEGV, buf, buflen); 1704 print_signal_handler(st, SIGBUS , buf, buflen); 1705 print_signal_handler(st, SIGFPE , buf, buflen); 1706 print_signal_handler(st, SIGPIPE, buf, buflen); 1707 print_signal_handler(st, SIGXFSZ, buf, buflen); 1708 print_signal_handler(st, SIGILL , buf, buflen); 1709 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); 1710 print_signal_handler(st, SR_signum, buf, buflen); 1711 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 1712 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 1713 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 1714 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 1715 } 1716 1717 static char saved_jvm_path[MAXPATHLEN] = {0}; 1718 1719 // Find the full path to the current module, libjvm 1720 void os::jvm_path(char *buf, jint buflen) { 1721 // Error checking. 1722 if (buflen < MAXPATHLEN) { 1723 assert(false, "must use a large-enough buffer"); 1724 buf[0] = '\0'; 1725 return; 1726 } 1727 // Lazy resolve the path to current module. 1728 if (saved_jvm_path[0] != 0) { 1729 strcpy(buf, saved_jvm_path); 1730 return; 1731 } 1732 1733 char dli_fname[MAXPATHLEN]; 1734 bool ret = dll_address_to_library_name( 1735 CAST_FROM_FN_PTR(address, os::jvm_path), 1736 dli_fname, sizeof(dli_fname), NULL); 1737 assert(ret, "cannot locate libjvm"); 1738 char *rp = NULL; 1739 if (ret && dli_fname[0] != '\0') { 1740 rp = realpath(dli_fname, buf); 1741 } 1742 if (rp == NULL) 1743 return; 1744 1745 if (Arguments::sun_java_launcher_is_altjvm()) { 1746 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 1747 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so" 1748 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/" 1749 // appears at the right place in the string, then assume we are 1750 // installed in a JDK and we're done. Otherwise, check for a 1751 // JAVA_HOME environment variable and construct a path to the JVM 1752 // being overridden. 1753 1754 const char *p = buf + strlen(buf) - 1; 1755 for (int count = 0; p > buf && count < 5; ++count) { 1756 for (--p; p > buf && *p != '/'; --p) 1757 /* empty */ ; 1758 } 1759 1760 if (strncmp(p, "/jre/lib/", 9) != 0) { 1761 // Look for JAVA_HOME in the environment. 1762 char* java_home_var = ::getenv("JAVA_HOME"); 1763 if (java_home_var != NULL && java_home_var[0] != 0) { 1764 char* jrelib_p; 1765 int len; 1766 1767 // Check the current module name "libjvm" 1768 p = strrchr(buf, '/'); 1769 assert(strstr(p, "/libjvm") == p, "invalid library name"); 1770 1771 rp = realpath(java_home_var, buf); 1772 if (rp == NULL) 1773 return; 1774 1775 // determine if this is a legacy image or modules image 1776 // modules image doesn't have "jre" subdirectory 1777 len = strlen(buf); 1778 jrelib_p = buf + len; 1779 1780 // Add the appropriate library subdir 1781 snprintf(jrelib_p, buflen-len, "/jre/lib"); 1782 if (0 != access(buf, F_OK)) { 1783 snprintf(jrelib_p, buflen-len, "/lib"); 1784 } 1785 1786 // Add the appropriate client or server subdir 1787 len = strlen(buf); 1788 jrelib_p = buf + len; 1789 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT); 1790 if (0 != access(buf, F_OK)) { 1791 snprintf(jrelib_p, buflen-len, "%s", ""); 1792 } 1793 1794 // If the path exists within JAVA_HOME, add the JVM library name 1795 // to complete the path to JVM being overridden. Otherwise fallback 1796 // to the path to the current library. 1797 if (0 == access(buf, F_OK)) { 1798 // Use current module name "libjvm" 1799 len = strlen(buf); 1800 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX); 1801 } else { 1802 // Fall back to path of current library 1803 rp = realpath(dli_fname, buf); 1804 if (rp == NULL) 1805 return; 1806 } 1807 } 1808 } 1809 } 1810 1811 strcpy(saved_jvm_path, buf); 1812 } 1813 1814 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 1815 // no prefix required, not even "_" 1816 } 1817 1818 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 1819 // no suffix required 1820 } 1821 1822 //////////////////////////////////////////////////////////////////////////////// 1823 // sun.misc.Signal support 1824 1825 static volatile jint sigint_count = 0; 1826 1827 static void 1828 UserHandler(int sig, void *siginfo, void *context) { 1829 // 4511530 - sem_post is serialized and handled by the manager thread. When 1830 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 1831 // don't want to flood the manager thread with sem_post requests. 1832 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) 1833 return; 1834 1835 // Ctrl-C is pressed during error reporting, likely because the error 1836 // handler fails to abort. Let VM die immediately. 1837 if (sig == SIGINT && is_error_reported()) { 1838 os::die(); 1839 } 1840 1841 os::signal_notify(sig); 1842 } 1843 1844 void* os::user_handler() { 1845 return CAST_FROM_FN_PTR(void*, UserHandler); 1846 } 1847 1848 extern "C" { 1849 typedef void (*sa_handler_t)(int); 1850 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1851 } 1852 1853 void* os::signal(int signal_number, void* handler) { 1854 struct sigaction sigAct, oldSigAct; 1855 1856 sigfillset(&(sigAct.sa_mask)); 1857 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 1858 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 1859 1860 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 1861 // -1 means registration failed 1862 return (void *)-1; 1863 } 1864 1865 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 1866 } 1867 1868 void os::signal_raise(int signal_number) { 1869 ::raise(signal_number); 1870 } 1871 1872 /* 1873 * The following code is moved from os.cpp for making this 1874 * code platform specific, which it is by its very nature. 1875 */ 1876 1877 // Will be modified when max signal is changed to be dynamic 1878 int os::sigexitnum_pd() { 1879 return NSIG; 1880 } 1881 1882 // a counter for each possible signal value 1883 static volatile jint pending_signals[NSIG+1] = { 0 }; 1884 1885 // Bsd(POSIX) specific hand shaking semaphore. 1886 #ifdef __APPLE__ 1887 typedef semaphore_t os_semaphore_t; 1888 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) 1889 #define SEM_WAIT(sem) semaphore_wait(sem) 1890 #define SEM_POST(sem) semaphore_signal(sem) 1891 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem) 1892 #else 1893 typedef sem_t os_semaphore_t; 1894 #define SEM_INIT(sem, value) sem_init(&sem, 0, value) 1895 #define SEM_WAIT(sem) sem_wait(&sem) 1896 #define SEM_POST(sem) sem_post(&sem) 1897 #define SEM_DESTROY(sem) sem_destroy(&sem) 1898 #endif 1899 1900 class Semaphore : public StackObj { 1901 public: 1902 Semaphore(); 1903 ~Semaphore(); 1904 void signal(); 1905 void wait(); 1906 bool trywait(); 1907 bool timedwait(unsigned int sec, int nsec); 1908 private: 1909 jlong currenttime() const; 1910 os_semaphore_t _semaphore; 1911 }; 1912 1913 Semaphore::Semaphore() : _semaphore(0) { 1914 SEM_INIT(_semaphore, 0); 1915 } 1916 1917 Semaphore::~Semaphore() { 1918 SEM_DESTROY(_semaphore); 1919 } 1920 1921 void Semaphore::signal() { 1922 SEM_POST(_semaphore); 1923 } 1924 1925 void Semaphore::wait() { 1926 SEM_WAIT(_semaphore); 1927 } 1928 1929 jlong Semaphore::currenttime() const { 1930 struct timeval tv; 1931 gettimeofday(&tv, NULL); 1932 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000); 1933 } 1934 1935 #ifdef __APPLE__ 1936 bool Semaphore::trywait() { 1937 return timedwait(0, 0); 1938 } 1939 1940 bool Semaphore::timedwait(unsigned int sec, int nsec) { 1941 kern_return_t kr = KERN_ABORTED; 1942 mach_timespec_t waitspec; 1943 waitspec.tv_sec = sec; 1944 waitspec.tv_nsec = nsec; 1945 1946 jlong starttime = currenttime(); 1947 1948 kr = semaphore_timedwait(_semaphore, waitspec); 1949 while (kr == KERN_ABORTED) { 1950 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec; 1951 1952 jlong current = currenttime(); 1953 jlong passedtime = current - starttime; 1954 1955 if (passedtime >= totalwait) { 1956 waitspec.tv_sec = 0; 1957 waitspec.tv_nsec = 0; 1958 } else { 1959 jlong waittime = totalwait - (current - starttime); 1960 waitspec.tv_sec = waittime / NANOSECS_PER_SEC; 1961 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC; 1962 } 1963 1964 kr = semaphore_timedwait(_semaphore, waitspec); 1965 } 1966 1967 return kr == KERN_SUCCESS; 1968 } 1969 1970 #else 1971 1972 bool Semaphore::trywait() { 1973 return sem_trywait(&_semaphore) == 0; 1974 } 1975 1976 bool Semaphore::timedwait(unsigned int sec, int nsec) { 1977 struct timespec ts; 1978 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec); 1979 1980 while (1) { 1981 int result = sem_timedwait(&_semaphore, &ts); 1982 if (result == 0) { 1983 return true; 1984 } else if (errno == EINTR) { 1985 continue; 1986 } else if (errno == ETIMEDOUT) { 1987 return false; 1988 } else { 1989 return false; 1990 } 1991 } 1992 } 1993 1994 #endif // __APPLE__ 1995 1996 static os_semaphore_t sig_sem; 1997 static Semaphore sr_semaphore; 1998 1999 void os::signal_init_pd() { 2000 // Initialize signal structures 2001 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2002 2003 // Initialize signal semaphore 2004 ::SEM_INIT(sig_sem, 0); 2005 } 2006 2007 void os::signal_notify(int sig) { 2008 Atomic::inc(&pending_signals[sig]); 2009 ::SEM_POST(sig_sem); 2010 } 2011 2012 static int check_pending_signals(bool wait) { 2013 Atomic::store(0, &sigint_count); 2014 for (;;) { 2015 for (int i = 0; i < NSIG + 1; i++) { 2016 jint n = pending_signals[i]; 2017 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2018 return i; 2019 } 2020 } 2021 if (!wait) { 2022 return -1; 2023 } 2024 JavaThread *thread = JavaThread::current(); 2025 ThreadBlockInVM tbivm(thread); 2026 2027 bool threadIsSuspended; 2028 do { 2029 thread->set_suspend_equivalent(); 2030 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2031 ::SEM_WAIT(sig_sem); 2032 2033 // were we externally suspended while we were waiting? 2034 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2035 if (threadIsSuspended) { 2036 // 2037 // The semaphore has been incremented, but while we were waiting 2038 // another thread suspended us. We don't want to continue running 2039 // while suspended because that would surprise the thread that 2040 // suspended us. 2041 // 2042 ::SEM_POST(sig_sem); 2043 2044 thread->java_suspend_self(); 2045 } 2046 } while (threadIsSuspended); 2047 } 2048 } 2049 2050 int os::signal_lookup() { 2051 return check_pending_signals(false); 2052 } 2053 2054 int os::signal_wait() { 2055 return check_pending_signals(true); 2056 } 2057 2058 //////////////////////////////////////////////////////////////////////////////// 2059 // Virtual Memory 2060 2061 int os::vm_page_size() { 2062 // Seems redundant as all get out 2063 assert(os::Bsd::page_size() != -1, "must call os::init"); 2064 return os::Bsd::page_size(); 2065 } 2066 2067 // Solaris allocates memory by pages. 2068 int os::vm_allocation_granularity() { 2069 assert(os::Bsd::page_size() != -1, "must call os::init"); 2070 return os::Bsd::page_size(); 2071 } 2072 2073 // Rationale behind this function: 2074 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2075 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2076 // samples for JITted code. Here we create private executable mapping over the code cache 2077 // and then we can use standard (well, almost, as mapping can change) way to provide 2078 // info for the reporting script by storing timestamp and location of symbol 2079 void bsd_wrap_code(char* base, size_t size) { 2080 static volatile jint cnt = 0; 2081 2082 if (!UseOprofile) { 2083 return; 2084 } 2085 2086 char buf[PATH_MAX + 1]; 2087 int num = Atomic::add(1, &cnt); 2088 2089 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", 2090 os::get_temp_directory(), os::current_process_id(), num); 2091 unlink(buf); 2092 2093 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2094 2095 if (fd != -1) { 2096 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2097 if (rv != (off_t)-1) { 2098 if (::write(fd, "", 1) == 1) { 2099 mmap(base, size, 2100 PROT_READ|PROT_WRITE|PROT_EXEC, 2101 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2102 } 2103 } 2104 ::close(fd); 2105 unlink(buf); 2106 } 2107 } 2108 2109 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2110 int err) { 2111 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2112 ", %d) failed; error='%s' (errno=%d)", addr, size, exec, 2113 strerror(err), err); 2114 } 2115 2116 // NOTE: Bsd kernel does not really reserve the pages for us. 2117 // All it does is to check if there are enough free pages 2118 // left at the time of mmap(). This could be a potential 2119 // problem. 2120 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2121 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2122 #ifdef __OpenBSD__ 2123 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2124 if (::mprotect(addr, size, prot) == 0) { 2125 return true; 2126 } 2127 #else 2128 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2129 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2130 if (res != (uintptr_t) MAP_FAILED) { 2131 return true; 2132 } 2133 #endif 2134 2135 // Warn about any commit errors we see in non-product builds just 2136 // in case mmap() doesn't work as described on the man page. 2137 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);) 2138 2139 return false; 2140 } 2141 2142 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2143 bool exec) { 2144 // alignment_hint is ignored on this OS 2145 return pd_commit_memory(addr, size, exec); 2146 } 2147 2148 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2149 const char* mesg) { 2150 assert(mesg != NULL, "mesg must be specified"); 2151 if (!pd_commit_memory(addr, size, exec)) { 2152 // add extra info in product mode for vm_exit_out_of_memory(): 2153 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);) 2154 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg); 2155 } 2156 } 2157 2158 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2159 size_t alignment_hint, bool exec, 2160 const char* mesg) { 2161 // alignment_hint is ignored on this OS 2162 pd_commit_memory_or_exit(addr, size, exec, mesg); 2163 } 2164 2165 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2166 } 2167 2168 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2169 ::madvise(addr, bytes, MADV_DONTNEED); 2170 } 2171 2172 void os::numa_make_global(char *addr, size_t bytes) { 2173 } 2174 2175 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2176 } 2177 2178 bool os::numa_topology_changed() { return false; } 2179 2180 size_t os::numa_get_groups_num() { 2181 return 1; 2182 } 2183 2184 int os::numa_get_group_id() { 2185 return 0; 2186 } 2187 2188 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2189 if (size > 0) { 2190 ids[0] = 0; 2191 return 1; 2192 } 2193 return 0; 2194 } 2195 2196 bool os::get_page_info(char *start, page_info* info) { 2197 return false; 2198 } 2199 2200 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { 2201 return end; 2202 } 2203 2204 2205 bool os::pd_uncommit_memory(char* addr, size_t size) { 2206 #ifdef __OpenBSD__ 2207 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2208 return ::mprotect(addr, size, PROT_NONE) == 0; 2209 #else 2210 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2211 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2212 return res != (uintptr_t) MAP_FAILED; 2213 #endif 2214 } 2215 2216 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2217 return os::commit_memory(addr, size, !ExecMem); 2218 } 2219 2220 // If this is a growable mapping, remove the guard pages entirely by 2221 // munmap()ping them. If not, just call uncommit_memory(). 2222 bool os::remove_stack_guard_pages(char* addr, size_t size) { 2223 return os::uncommit_memory(addr, size); 2224 } 2225 2226 static address _highest_vm_reserved_address = NULL; 2227 2228 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 2229 // at 'requested_addr'. If there are existing memory mappings at the same 2230 // location, however, they will be overwritten. If 'fixed' is false, 2231 // 'requested_addr' is only treated as a hint, the return value may or 2232 // may not start from the requested address. Unlike Bsd mmap(), this 2233 // function returns NULL to indicate failure. 2234 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 2235 char * addr; 2236 int flags; 2237 2238 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 2239 if (fixed) { 2240 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); 2241 flags |= MAP_FIXED; 2242 } 2243 2244 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 2245 // touch an uncommitted page. Otherwise, the read/write might 2246 // succeed if we have enough swap space to back the physical page. 2247 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 2248 flags, -1, 0); 2249 2250 if (addr != MAP_FAILED) { 2251 // anon_mmap() should only get called during VM initialization, 2252 // don't need lock (actually we can skip locking even it can be called 2253 // from multiple threads, because _highest_vm_reserved_address is just a 2254 // hint about the upper limit of non-stack memory regions.) 2255 if ((address)addr + bytes > _highest_vm_reserved_address) { 2256 _highest_vm_reserved_address = (address)addr + bytes; 2257 } 2258 } 2259 2260 return addr == MAP_FAILED ? NULL : addr; 2261 } 2262 2263 // Don't update _highest_vm_reserved_address, because there might be memory 2264 // regions above addr + size. If so, releasing a memory region only creates 2265 // a hole in the address space, it doesn't help prevent heap-stack collision. 2266 // 2267 static int anon_munmap(char * addr, size_t size) { 2268 return ::munmap(addr, size) == 0; 2269 } 2270 2271 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 2272 size_t alignment_hint) { 2273 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 2274 } 2275 2276 bool os::pd_release_memory(char* addr, size_t size) { 2277 return anon_munmap(addr, size); 2278 } 2279 2280 static bool bsd_mprotect(char* addr, size_t size, int prot) { 2281 // Bsd wants the mprotect address argument to be page aligned. 2282 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); 2283 2284 // According to SUSv3, mprotect() should only be used with mappings 2285 // established by mmap(), and mmap() always maps whole pages. Unaligned 2286 // 'addr' likely indicates problem in the VM (e.g. trying to change 2287 // protection of malloc'ed or statically allocated memory). Check the 2288 // caller if you hit this assert. 2289 assert(addr == bottom, "sanity check"); 2290 2291 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); 2292 return ::mprotect(bottom, size, prot) == 0; 2293 } 2294 2295 // Set protections specified 2296 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 2297 bool is_committed) { 2298 unsigned int p = 0; 2299 switch (prot) { 2300 case MEM_PROT_NONE: p = PROT_NONE; break; 2301 case MEM_PROT_READ: p = PROT_READ; break; 2302 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 2303 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 2304 default: 2305 ShouldNotReachHere(); 2306 } 2307 // is_committed is unused. 2308 return bsd_mprotect(addr, bytes, p); 2309 } 2310 2311 bool os::guard_memory(char* addr, size_t size) { 2312 return bsd_mprotect(addr, size, PROT_NONE); 2313 } 2314 2315 bool os::unguard_memory(char* addr, size_t size) { 2316 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); 2317 } 2318 2319 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { 2320 return false; 2321 } 2322 2323 // Large page support 2324 2325 static size_t _large_page_size = 0; 2326 2327 void os::large_page_init() { 2328 } 2329 2330 2331 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) { 2332 fatal("This code is not used or maintained."); 2333 2334 // "exec" is passed in but not used. Creating the shared image for 2335 // the code cache doesn't have an SHM_X executable permission to check. 2336 assert(UseLargePages && UseSHM, "only for SHM large pages"); 2337 2338 key_t key = IPC_PRIVATE; 2339 char *addr; 2340 2341 bool warn_on_failure = UseLargePages && 2342 (!FLAG_IS_DEFAULT(UseLargePages) || 2343 !FLAG_IS_DEFAULT(LargePageSizeInBytes) 2344 ); 2345 char msg[128]; 2346 2347 // Create a large shared memory region to attach to based on size. 2348 // Currently, size is the total size of the heap 2349 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); 2350 if (shmid == -1) { 2351 // Possible reasons for shmget failure: 2352 // 1. shmmax is too small for Java heap. 2353 // > check shmmax value: cat /proc/sys/kernel/shmmax 2354 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 2355 // 2. not enough large page memory. 2356 // > check available large pages: cat /proc/meminfo 2357 // > increase amount of large pages: 2358 // echo new_value > /proc/sys/vm/nr_hugepages 2359 // Note 1: different Bsd may use different name for this property, 2360 // e.g. on Redhat AS-3 it is "hugetlb_pool". 2361 // Note 2: it's possible there's enough physical memory available but 2362 // they are so fragmented after a long run that they can't 2363 // coalesce into large pages. Try to reserve large pages when 2364 // the system is still "fresh". 2365 if (warn_on_failure) { 2366 jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno); 2367 warning(msg); 2368 } 2369 return NULL; 2370 } 2371 2372 // attach to the region 2373 addr = (char*)shmat(shmid, req_addr, 0); 2374 int err = errno; 2375 2376 // Remove shmid. If shmat() is successful, the actual shared memory segment 2377 // will be deleted when it's detached by shmdt() or when the process 2378 // terminates. If shmat() is not successful this will remove the shared 2379 // segment immediately. 2380 shmctl(shmid, IPC_RMID, NULL); 2381 2382 if ((intptr_t)addr == -1) { 2383 if (warn_on_failure) { 2384 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err); 2385 warning(msg); 2386 } 2387 return NULL; 2388 } 2389 2390 // The memory is committed 2391 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, mtNone, CALLER_PC); 2392 2393 return addr; 2394 } 2395 2396 bool os::release_memory_special(char* base, size_t bytes) { 2397 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 2398 // detaching the SHM segment will also delete it, see reserve_memory_special() 2399 int rslt = shmdt(base); 2400 if (rslt == 0) { 2401 tkr.record((address)base, bytes); 2402 return true; 2403 } else { 2404 tkr.discard(); 2405 return false; 2406 } 2407 2408 } 2409 2410 size_t os::large_page_size() { 2411 return _large_page_size; 2412 } 2413 2414 // HugeTLBFS allows application to commit large page memory on demand; 2415 // with SysV SHM the entire memory region must be allocated as shared 2416 // memory. 2417 bool os::can_commit_large_page_memory() { 2418 return UseHugeTLBFS; 2419 } 2420 2421 bool os::can_execute_large_page_memory() { 2422 return UseHugeTLBFS; 2423 } 2424 2425 // Reserve memory at an arbitrary address, only if that area is 2426 // available (and not reserved for something else). 2427 2428 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 2429 const int max_tries = 10; 2430 char* base[max_tries]; 2431 size_t size[max_tries]; 2432 const size_t gap = 0x000000; 2433 2434 // Assert only that the size is a multiple of the page size, since 2435 // that's all that mmap requires, and since that's all we really know 2436 // about at this low abstraction level. If we need higher alignment, 2437 // we can either pass an alignment to this method or verify alignment 2438 // in one of the methods further up the call chain. See bug 5044738. 2439 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 2440 2441 // Repeatedly allocate blocks until the block is allocated at the 2442 // right spot. Give up after max_tries. Note that reserve_memory() will 2443 // automatically update _highest_vm_reserved_address if the call is 2444 // successful. The variable tracks the highest memory address every reserved 2445 // by JVM. It is used to detect heap-stack collision if running with 2446 // fixed-stack BsdThreads. Because here we may attempt to reserve more 2447 // space than needed, it could confuse the collision detecting code. To 2448 // solve the problem, save current _highest_vm_reserved_address and 2449 // calculate the correct value before return. 2450 address old_highest = _highest_vm_reserved_address; 2451 2452 // Bsd mmap allows caller to pass an address as hint; give it a try first, 2453 // if kernel honors the hint then we can return immediately. 2454 char * addr = anon_mmap(requested_addr, bytes, false); 2455 if (addr == requested_addr) { 2456 return requested_addr; 2457 } 2458 2459 if (addr != NULL) { 2460 // mmap() is successful but it fails to reserve at the requested address 2461 anon_munmap(addr, bytes); 2462 } 2463 2464 int i; 2465 for (i = 0; i < max_tries; ++i) { 2466 base[i] = reserve_memory(bytes); 2467 2468 if (base[i] != NULL) { 2469 // Is this the block we wanted? 2470 if (base[i] == requested_addr) { 2471 size[i] = bytes; 2472 break; 2473 } 2474 2475 // Does this overlap the block we wanted? Give back the overlapped 2476 // parts and try again. 2477 2478 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; 2479 if (top_overlap >= 0 && top_overlap < bytes) { 2480 unmap_memory(base[i], top_overlap); 2481 base[i] += top_overlap; 2482 size[i] = bytes - top_overlap; 2483 } else { 2484 size_t bottom_overlap = base[i] + bytes - requested_addr; 2485 if (bottom_overlap >= 0 && bottom_overlap < bytes) { 2486 unmap_memory(requested_addr, bottom_overlap); 2487 size[i] = bytes - bottom_overlap; 2488 } else { 2489 size[i] = bytes; 2490 } 2491 } 2492 } 2493 } 2494 2495 // Give back the unused reserved pieces. 2496 2497 for (int j = 0; j < i; ++j) { 2498 if (base[j] != NULL) { 2499 unmap_memory(base[j], size[j]); 2500 } 2501 } 2502 2503 if (i < max_tries) { 2504 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); 2505 return requested_addr; 2506 } else { 2507 _highest_vm_reserved_address = old_highest; 2508 return NULL; 2509 } 2510 } 2511 2512 size_t os::read(int fd, void *buf, unsigned int nBytes) { 2513 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); 2514 } 2515 2516 void os::naked_short_sleep(jlong ms) { 2517 struct timespec req; 2518 2519 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 2520 req.tv_sec = 0; 2521 if (ms > 0) { 2522 req.tv_nsec = (ms % 1000) * 1000000; 2523 } 2524 else { 2525 req.tv_nsec = 1; 2526 } 2527 2528 nanosleep(&req, NULL); 2529 2530 return; 2531 } 2532 2533 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 2534 void os::infinite_sleep() { 2535 while (true) { // sleep forever ... 2536 ::sleep(100); // ... 100 seconds at a time 2537 } 2538 } 2539 2540 // Used to convert frequent JVM_Yield() to nops 2541 bool os::dont_yield() { 2542 return DontYieldALot; 2543 } 2544 2545 void os::yield() { 2546 sched_yield(); 2547 } 2548 2549 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;} 2550 2551 void os::yield_all(int attempts) { 2552 // Yields to all threads, including threads with lower priorities 2553 // Threads on Bsd are all with same priority. The Solaris style 2554 // os::yield_all() with nanosleep(1ms) is not necessary. 2555 sched_yield(); 2556 } 2557 2558 // Called from the tight loops to possibly influence time-sharing heuristics 2559 void os::loop_breaker(int attempts) { 2560 os::yield_all(attempts); 2561 } 2562 2563 //////////////////////////////////////////////////////////////////////////////// 2564 // thread priority support 2565 2566 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER 2567 // only supports dynamic priority, static priority must be zero. For real-time 2568 // applications, Bsd supports SCHED_RR which allows static priority (1-99). 2569 // However, for large multi-threaded applications, SCHED_RR is not only slower 2570 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 2571 // of 5 runs - Sep 2005). 2572 // 2573 // The following code actually changes the niceness of kernel-thread/LWP. It 2574 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 2575 // not the entire user process, and user level threads are 1:1 mapped to kernel 2576 // threads. It has always been the case, but could change in the future. For 2577 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 2578 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 2579 2580 #if !defined(__APPLE__) 2581 int os::java_to_os_priority[CriticalPriority + 1] = { 2582 19, // 0 Entry should never be used 2583 2584 0, // 1 MinPriority 2585 3, // 2 2586 6, // 3 2587 2588 10, // 4 2589 15, // 5 NormPriority 2590 18, // 6 2591 2592 21, // 7 2593 25, // 8 2594 28, // 9 NearMaxPriority 2595 2596 31, // 10 MaxPriority 2597 2598 31 // 11 CriticalPriority 2599 }; 2600 #else 2601 /* Using Mach high-level priority assignments */ 2602 int os::java_to_os_priority[CriticalPriority + 1] = { 2603 0, // 0 Entry should never be used (MINPRI_USER) 2604 2605 27, // 1 MinPriority 2606 28, // 2 2607 29, // 3 2608 2609 30, // 4 2610 31, // 5 NormPriority (BASEPRI_DEFAULT) 2611 32, // 6 2612 2613 33, // 7 2614 34, // 8 2615 35, // 9 NearMaxPriority 2616 2617 36, // 10 MaxPriority 2618 2619 36 // 11 CriticalPriority 2620 }; 2621 #endif 2622 2623 static int prio_init() { 2624 if (ThreadPriorityPolicy == 1) { 2625 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 2626 // if effective uid is not root. Perhaps, a more elegant way of doing 2627 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 2628 if (geteuid() != 0) { 2629 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 2630 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); 2631 } 2632 ThreadPriorityPolicy = 0; 2633 } 2634 } 2635 if (UseCriticalJavaThreadPriority) { 2636 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 2637 } 2638 return 0; 2639 } 2640 2641 OSReturn os::set_native_priority(Thread* thread, int newpri) { 2642 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK; 2643 2644 #ifdef __OpenBSD__ 2645 // OpenBSD pthread_setprio starves low priority threads 2646 return OS_OK; 2647 #elif defined(__FreeBSD__) 2648 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); 2649 #elif defined(__APPLE__) || defined(__NetBSD__) 2650 struct sched_param sp; 2651 int policy; 2652 pthread_t self = pthread_self(); 2653 2654 if (pthread_getschedparam(self, &policy, &sp) != 0) 2655 return OS_ERR; 2656 2657 sp.sched_priority = newpri; 2658 if (pthread_setschedparam(self, policy, &sp) != 0) 2659 return OS_ERR; 2660 2661 return OS_OK; 2662 #else 2663 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 2664 return (ret == 0) ? OS_OK : OS_ERR; 2665 #endif 2666 } 2667 2668 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { 2669 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) { 2670 *priority_ptr = java_to_os_priority[NormPriority]; 2671 return OS_OK; 2672 } 2673 2674 errno = 0; 2675 #if defined(__OpenBSD__) || defined(__FreeBSD__) 2676 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); 2677 #elif defined(__APPLE__) || defined(__NetBSD__) 2678 int policy; 2679 struct sched_param sp; 2680 2681 pthread_getschedparam(pthread_self(), &policy, &sp); 2682 *priority_ptr = sp.sched_priority; 2683 #else 2684 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 2685 #endif 2686 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 2687 } 2688 2689 // Hint to the underlying OS that a task switch would not be good. 2690 // Void return because it's a hint and can fail. 2691 void os::hint_no_preempt() {} 2692 2693 //////////////////////////////////////////////////////////////////////////////// 2694 // suspend/resume support 2695 2696 // the low-level signal-based suspend/resume support is a remnant from the 2697 // old VM-suspension that used to be for java-suspension, safepoints etc, 2698 // within hotspot. Now there is a single use-case for this: 2699 // - calling get_thread_pc() on the VMThread by the flat-profiler task 2700 // that runs in the watcher thread. 2701 // The remaining code is greatly simplified from the more general suspension 2702 // code that used to be used. 2703 // 2704 // The protocol is quite simple: 2705 // - suspend: 2706 // - sends a signal to the target thread 2707 // - polls the suspend state of the osthread using a yield loop 2708 // - target thread signal handler (SR_handler) sets suspend state 2709 // and blocks in sigsuspend until continued 2710 // - resume: 2711 // - sets target osthread state to continue 2712 // - sends signal to end the sigsuspend loop in the SR_handler 2713 // 2714 // Note that the SR_lock plays no role in this suspend/resume protocol. 2715 // 2716 2717 static void resume_clear_context(OSThread *osthread) { 2718 osthread->set_ucontext(NULL); 2719 osthread->set_siginfo(NULL); 2720 } 2721 2722 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { 2723 osthread->set_ucontext(context); 2724 osthread->set_siginfo(siginfo); 2725 } 2726 2727 // 2728 // Handler function invoked when a thread's execution is suspended or 2729 // resumed. We have to be careful that only async-safe functions are 2730 // called here (Note: most pthread functions are not async safe and 2731 // should be avoided.) 2732 // 2733 // Note: sigwait() is a more natural fit than sigsuspend() from an 2734 // interface point of view, but sigwait() prevents the signal hander 2735 // from being run. libpthread would get very confused by not having 2736 // its signal handlers run and prevents sigwait()'s use with the 2737 // mutex granting granting signal. 2738 // 2739 // Currently only ever called on the VMThread or JavaThread 2740 // 2741 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 2742 // Save and restore errno to avoid confusing native code with EINTR 2743 // after sigsuspend. 2744 int old_errno = errno; 2745 2746 Thread* thread = Thread::current(); 2747 OSThread* osthread = thread->osthread(); 2748 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 2749 2750 os::SuspendResume::State current = osthread->sr.state(); 2751 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 2752 suspend_save_context(osthread, siginfo, context); 2753 2754 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 2755 os::SuspendResume::State state = osthread->sr.suspended(); 2756 if (state == os::SuspendResume::SR_SUSPENDED) { 2757 sigset_t suspend_set; // signals for sigsuspend() 2758 2759 // get current set of blocked signals and unblock resume signal 2760 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 2761 sigdelset(&suspend_set, SR_signum); 2762 2763 sr_semaphore.signal(); 2764 // wait here until we are resumed 2765 while (1) { 2766 sigsuspend(&suspend_set); 2767 2768 os::SuspendResume::State result = osthread->sr.running(); 2769 if (result == os::SuspendResume::SR_RUNNING) { 2770 sr_semaphore.signal(); 2771 break; 2772 } else if (result != os::SuspendResume::SR_SUSPENDED) { 2773 ShouldNotReachHere(); 2774 } 2775 } 2776 2777 } else if (state == os::SuspendResume::SR_RUNNING) { 2778 // request was cancelled, continue 2779 } else { 2780 ShouldNotReachHere(); 2781 } 2782 2783 resume_clear_context(osthread); 2784 } else if (current == os::SuspendResume::SR_RUNNING) { 2785 // request was cancelled, continue 2786 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 2787 // ignore 2788 } else { 2789 // ignore 2790 } 2791 2792 errno = old_errno; 2793 } 2794 2795 2796 static int SR_initialize() { 2797 struct sigaction act; 2798 char *s; 2799 /* Get signal number to use for suspend/resume */ 2800 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 2801 int sig = ::strtol(s, 0, 10); 2802 if (sig > 0 || sig < NSIG) { 2803 SR_signum = sig; 2804 } 2805 } 2806 2807 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 2808 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 2809 2810 sigemptyset(&SR_sigset); 2811 sigaddset(&SR_sigset, SR_signum); 2812 2813 /* Set up signal handler for suspend/resume */ 2814 act.sa_flags = SA_RESTART|SA_SIGINFO; 2815 act.sa_handler = (void (*)(int)) SR_handler; 2816 2817 // SR_signum is blocked by default. 2818 // 4528190 - We also need to block pthread restart signal (32 on all 2819 // supported Bsd platforms). Note that BsdThreads need to block 2820 // this signal for all threads to work properly. So we don't have 2821 // to use hard-coded signal number when setting up the mask. 2822 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 2823 2824 if (sigaction(SR_signum, &act, 0) == -1) { 2825 return -1; 2826 } 2827 2828 // Save signal flag 2829 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); 2830 return 0; 2831 } 2832 2833 static int sr_notify(OSThread* osthread) { 2834 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2835 assert_status(status == 0, status, "pthread_kill"); 2836 return status; 2837 } 2838 2839 // "Randomly" selected value for how long we want to spin 2840 // before bailing out on suspending a thread, also how often 2841 // we send a signal to a thread we want to resume 2842 static const int RANDOMLY_LARGE_INTEGER = 1000000; 2843 static const int RANDOMLY_LARGE_INTEGER2 = 100; 2844 2845 // returns true on success and false on error - really an error is fatal 2846 // but this seems the normal response to library errors 2847 static bool do_suspend(OSThread* osthread) { 2848 assert(osthread->sr.is_running(), "thread should be running"); 2849 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 2850 2851 // mark as suspended and send signal 2852 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 2853 // failed to switch, state wasn't running? 2854 ShouldNotReachHere(); 2855 return false; 2856 } 2857 2858 if (sr_notify(osthread) != 0) { 2859 ShouldNotReachHere(); 2860 } 2861 2862 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 2863 while (true) { 2864 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2865 break; 2866 } else { 2867 // timeout 2868 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 2869 if (cancelled == os::SuspendResume::SR_RUNNING) { 2870 return false; 2871 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 2872 // make sure that we consume the signal on the semaphore as well 2873 sr_semaphore.wait(); 2874 break; 2875 } else { 2876 ShouldNotReachHere(); 2877 return false; 2878 } 2879 } 2880 } 2881 2882 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 2883 return true; 2884 } 2885 2886 static void do_resume(OSThread* osthread) { 2887 assert(osthread->sr.is_suspended(), "thread should be suspended"); 2888 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 2889 2890 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 2891 // failed to switch to WAKEUP_REQUEST 2892 ShouldNotReachHere(); 2893 return; 2894 } 2895 2896 while (true) { 2897 if (sr_notify(osthread) == 0) { 2898 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2899 if (osthread->sr.is_running()) { 2900 return; 2901 } 2902 } 2903 } else { 2904 ShouldNotReachHere(); 2905 } 2906 } 2907 2908 guarantee(osthread->sr.is_running(), "Must be running!"); 2909 } 2910 2911 /////////////////////////////////////////////////////////////////////////////////// 2912 // signal handling (except suspend/resume) 2913 2914 // This routine may be used by user applications as a "hook" to catch signals. 2915 // The user-defined signal handler must pass unrecognized signals to this 2916 // routine, and if it returns true (non-zero), then the signal handler must 2917 // return immediately. If the flag "abort_if_unrecognized" is true, then this 2918 // routine will never retun false (zero), but instead will execute a VM panic 2919 // routine kill the process. 2920 // 2921 // If this routine returns false, it is OK to call it again. This allows 2922 // the user-defined signal handler to perform checks either before or after 2923 // the VM performs its own checks. Naturally, the user code would be making 2924 // a serious error if it tried to handle an exception (such as a null check 2925 // or breakpoint) that the VM was generating for its own correct operation. 2926 // 2927 // This routine may recognize any of the following kinds of signals: 2928 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 2929 // It should be consulted by handlers for any of those signals. 2930 // 2931 // The caller of this routine must pass in the three arguments supplied 2932 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 2933 // field of the structure passed to sigaction(). This routine assumes that 2934 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 2935 // 2936 // Note that the VM will print warnings if it detects conflicting signal 2937 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 2938 // 2939 extern "C" JNIEXPORT int 2940 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, 2941 void* ucontext, int abort_if_unrecognized); 2942 2943 void signalHandler(int sig, siginfo_t* info, void* uc) { 2944 assert(info != NULL && uc != NULL, "it must be old kernel"); 2945 int orig_errno = errno; // Preserve errno value over signal handler. 2946 JVM_handle_bsd_signal(sig, info, uc, true); 2947 errno = orig_errno; 2948 } 2949 2950 2951 // This boolean allows users to forward their own non-matching signals 2952 // to JVM_handle_bsd_signal, harmlessly. 2953 bool os::Bsd::signal_handlers_are_installed = false; 2954 2955 // For signal-chaining 2956 struct sigaction os::Bsd::sigact[MAXSIGNUM]; 2957 unsigned int os::Bsd::sigs = 0; 2958 bool os::Bsd::libjsig_is_loaded = false; 2959 typedef struct sigaction *(*get_signal_t)(int); 2960 get_signal_t os::Bsd::get_signal_action = NULL; 2961 2962 struct sigaction* os::Bsd::get_chained_signal_action(int sig) { 2963 struct sigaction *actp = NULL; 2964 2965 if (libjsig_is_loaded) { 2966 // Retrieve the old signal handler from libjsig 2967 actp = (*get_signal_action)(sig); 2968 } 2969 if (actp == NULL) { 2970 // Retrieve the preinstalled signal handler from jvm 2971 actp = get_preinstalled_handler(sig); 2972 } 2973 2974 return actp; 2975 } 2976 2977 static bool call_chained_handler(struct sigaction *actp, int sig, 2978 siginfo_t *siginfo, void *context) { 2979 // Call the old signal handler 2980 if (actp->sa_handler == SIG_DFL) { 2981 // It's more reasonable to let jvm treat it as an unexpected exception 2982 // instead of taking the default action. 2983 return false; 2984 } else if (actp->sa_handler != SIG_IGN) { 2985 if ((actp->sa_flags & SA_NODEFER) == 0) { 2986 // automaticlly block the signal 2987 sigaddset(&(actp->sa_mask), sig); 2988 } 2989 2990 sa_handler_t hand; 2991 sa_sigaction_t sa; 2992 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 2993 // retrieve the chained handler 2994 if (siginfo_flag_set) { 2995 sa = actp->sa_sigaction; 2996 } else { 2997 hand = actp->sa_handler; 2998 } 2999 3000 if ((actp->sa_flags & SA_RESETHAND) != 0) { 3001 actp->sa_handler = SIG_DFL; 3002 } 3003 3004 // try to honor the signal mask 3005 sigset_t oset; 3006 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 3007 3008 // call into the chained handler 3009 if (siginfo_flag_set) { 3010 (*sa)(sig, siginfo, context); 3011 } else { 3012 (*hand)(sig); 3013 } 3014 3015 // restore the signal mask 3016 pthread_sigmask(SIG_SETMASK, &oset, 0); 3017 } 3018 // Tell jvm's signal handler the signal is taken care of. 3019 return true; 3020 } 3021 3022 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { 3023 bool chained = false; 3024 // signal-chaining 3025 if (UseSignalChaining) { 3026 struct sigaction *actp = get_chained_signal_action(sig); 3027 if (actp != NULL) { 3028 chained = call_chained_handler(actp, sig, siginfo, context); 3029 } 3030 } 3031 return chained; 3032 } 3033 3034 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { 3035 if ((( (unsigned int)1 << sig ) & sigs) != 0) { 3036 return &sigact[sig]; 3037 } 3038 return NULL; 3039 } 3040 3041 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 3042 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3043 sigact[sig] = oldAct; 3044 sigs |= (unsigned int)1 << sig; 3045 } 3046 3047 // for diagnostic 3048 int os::Bsd::sigflags[MAXSIGNUM]; 3049 3050 int os::Bsd::get_our_sigflags(int sig) { 3051 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3052 return sigflags[sig]; 3053 } 3054 3055 void os::Bsd::set_our_sigflags(int sig, int flags) { 3056 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3057 sigflags[sig] = flags; 3058 } 3059 3060 void os::Bsd::set_signal_handler(int sig, bool set_installed) { 3061 // Check for overwrite. 3062 struct sigaction oldAct; 3063 sigaction(sig, (struct sigaction*)NULL, &oldAct); 3064 3065 void* oldhand = oldAct.sa_sigaction 3066 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3067 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3068 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 3069 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 3070 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 3071 if (AllowUserSignalHandlers || !set_installed) { 3072 // Do not overwrite; user takes responsibility to forward to us. 3073 return; 3074 } else if (UseSignalChaining) { 3075 // save the old handler in jvm 3076 save_preinstalled_handler(sig, oldAct); 3077 // libjsig also interposes the sigaction() call below and saves the 3078 // old sigaction on it own. 3079 } else { 3080 fatal(err_msg("Encountered unexpected pre-existing sigaction handler " 3081 "%#lx for signal %d.", (long)oldhand, sig)); 3082 } 3083 } 3084 3085 struct sigaction sigAct; 3086 sigfillset(&(sigAct.sa_mask)); 3087 sigAct.sa_handler = SIG_DFL; 3088 if (!set_installed) { 3089 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3090 } else { 3091 sigAct.sa_sigaction = signalHandler; 3092 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3093 } 3094 #if __APPLE__ 3095 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV 3096 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages" 3097 // if the signal handler declares it will handle it on alternate stack. 3098 // Notice we only declare we will handle it on alt stack, but we are not 3099 // actually going to use real alt stack - this is just a workaround. 3100 // Please see ux_exception.c, method catch_mach_exception_raise for details 3101 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c 3102 if (sig == SIGSEGV) { 3103 sigAct.sa_flags |= SA_ONSTACK; 3104 } 3105 #endif 3106 3107 // Save flags, which are set by ours 3108 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3109 sigflags[sig] = sigAct.sa_flags; 3110 3111 int ret = sigaction(sig, &sigAct, &oldAct); 3112 assert(ret == 0, "check"); 3113 3114 void* oldhand2 = oldAct.sa_sigaction 3115 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3116 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3117 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 3118 } 3119 3120 // install signal handlers for signals that HotSpot needs to 3121 // handle in order to support Java-level exception handling. 3122 3123 void os::Bsd::install_signal_handlers() { 3124 if (!signal_handlers_are_installed) { 3125 signal_handlers_are_installed = true; 3126 3127 // signal-chaining 3128 typedef void (*signal_setting_t)(); 3129 signal_setting_t begin_signal_setting = NULL; 3130 signal_setting_t end_signal_setting = NULL; 3131 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3132 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 3133 if (begin_signal_setting != NULL) { 3134 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3135 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 3136 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 3137 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 3138 libjsig_is_loaded = true; 3139 assert(UseSignalChaining, "should enable signal-chaining"); 3140 } 3141 if (libjsig_is_loaded) { 3142 // Tell libjsig jvm is setting signal handlers 3143 (*begin_signal_setting)(); 3144 } 3145 3146 set_signal_handler(SIGSEGV, true); 3147 set_signal_handler(SIGPIPE, true); 3148 set_signal_handler(SIGBUS, true); 3149 set_signal_handler(SIGILL, true); 3150 set_signal_handler(SIGFPE, true); 3151 set_signal_handler(SIGXFSZ, true); 3152 3153 #if defined(__APPLE__) 3154 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including 3155 // signals caught and handled by the JVM. To work around this, we reset the mach task 3156 // signal handler that's placed on our process by CrashReporter. This disables 3157 // CrashReporter-based reporting. 3158 // 3159 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes 3160 // on caught fatal signals. 3161 // 3162 // Additionally, gdb installs both standard BSD signal handlers, and mach exception 3163 // handlers. By replacing the existing task exception handler, we disable gdb's mach 3164 // exception handling, while leaving the standard BSD signal handlers functional. 3165 kern_return_t kr; 3166 kr = task_set_exception_ports(mach_task_self(), 3167 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, 3168 MACH_PORT_NULL, 3169 EXCEPTION_STATE_IDENTITY, 3170 MACHINE_THREAD_STATE); 3171 3172 assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); 3173 #endif 3174 3175 if (libjsig_is_loaded) { 3176 // Tell libjsig jvm finishes setting signal handlers 3177 (*end_signal_setting)(); 3178 } 3179 3180 // We don't activate signal checker if libjsig is in place, we trust ourselves 3181 // and if UserSignalHandler is installed all bets are off 3182 if (CheckJNICalls) { 3183 if (libjsig_is_loaded) { 3184 if (PrintJNIResolving) { 3185 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 3186 } 3187 check_signals = false; 3188 } 3189 if (AllowUserSignalHandlers) { 3190 if (PrintJNIResolving) { 3191 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 3192 } 3193 check_signals = false; 3194 } 3195 } 3196 } 3197 } 3198 3199 3200 ///// 3201 // glibc on Bsd platform uses non-documented flag 3202 // to indicate, that some special sort of signal 3203 // trampoline is used. 3204 // We will never set this flag, and we should 3205 // ignore this flag in our diagnostic 3206 #ifdef SIGNIFICANT_SIGNAL_MASK 3207 #undef SIGNIFICANT_SIGNAL_MASK 3208 #endif 3209 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 3210 3211 static const char* get_signal_handler_name(address handler, 3212 char* buf, int buflen) { 3213 int offset; 3214 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 3215 if (found) { 3216 // skip directory names 3217 const char *p1, *p2; 3218 p1 = buf; 3219 size_t len = strlen(os::file_separator()); 3220 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 3221 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 3222 } else { 3223 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 3224 } 3225 return buf; 3226 } 3227 3228 static void print_signal_handler(outputStream* st, int sig, 3229 char* buf, size_t buflen) { 3230 struct sigaction sa; 3231 3232 sigaction(sig, NULL, &sa); 3233 3234 // See comment for SIGNIFICANT_SIGNAL_MASK define 3235 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3236 3237 st->print("%s: ", os::exception_name(sig, buf, buflen)); 3238 3239 address handler = (sa.sa_flags & SA_SIGINFO) 3240 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 3241 : CAST_FROM_FN_PTR(address, sa.sa_handler); 3242 3243 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 3244 st->print("SIG_DFL"); 3245 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 3246 st->print("SIG_IGN"); 3247 } else { 3248 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 3249 } 3250 3251 st->print(", sa_mask[0]="); 3252 os::Posix::print_signal_set_short(st, &sa.sa_mask); 3253 3254 address rh = VMError::get_resetted_sighandler(sig); 3255 // May be, handler was resetted by VMError? 3256 if(rh != NULL) { 3257 handler = rh; 3258 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 3259 } 3260 3261 st->print(", sa_flags="); 3262 os::Posix::print_sa_flags(st, sa.sa_flags); 3263 3264 // Check: is it our handler? 3265 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 3266 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 3267 // It is our signal handler 3268 // check for flags, reset system-used one! 3269 if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3270 st->print( 3271 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 3272 os::Bsd::get_our_sigflags(sig)); 3273 } 3274 } 3275 st->cr(); 3276 } 3277 3278 3279 #define DO_SIGNAL_CHECK(sig) \ 3280 if (!sigismember(&check_signal_done, sig)) \ 3281 os::Bsd::check_signal_handler(sig) 3282 3283 // This method is a periodic task to check for misbehaving JNI applications 3284 // under CheckJNI, we can add any periodic checks here 3285 3286 void os::run_periodic_checks() { 3287 3288 if (check_signals == false) return; 3289 3290 // SEGV and BUS if overridden could potentially prevent 3291 // generation of hs*.log in the event of a crash, debugging 3292 // such a case can be very challenging, so we absolutely 3293 // check the following for a good measure: 3294 DO_SIGNAL_CHECK(SIGSEGV); 3295 DO_SIGNAL_CHECK(SIGILL); 3296 DO_SIGNAL_CHECK(SIGFPE); 3297 DO_SIGNAL_CHECK(SIGBUS); 3298 DO_SIGNAL_CHECK(SIGPIPE); 3299 DO_SIGNAL_CHECK(SIGXFSZ); 3300 3301 3302 // ReduceSignalUsage allows the user to override these handlers 3303 // see comments at the very top and jvm_solaris.h 3304 if (!ReduceSignalUsage) { 3305 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 3306 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 3307 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 3308 DO_SIGNAL_CHECK(BREAK_SIGNAL); 3309 } 3310 3311 DO_SIGNAL_CHECK(SR_signum); 3312 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); 3313 } 3314 3315 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 3316 3317 static os_sigaction_t os_sigaction = NULL; 3318 3319 void os::Bsd::check_signal_handler(int sig) { 3320 char buf[O_BUFLEN]; 3321 address jvmHandler = NULL; 3322 3323 3324 struct sigaction act; 3325 if (os_sigaction == NULL) { 3326 // only trust the default sigaction, in case it has been interposed 3327 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 3328 if (os_sigaction == NULL) return; 3329 } 3330 3331 os_sigaction(sig, (struct sigaction*)NULL, &act); 3332 3333 3334 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3335 3336 address thisHandler = (act.sa_flags & SA_SIGINFO) 3337 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 3338 : CAST_FROM_FN_PTR(address, act.sa_handler) ; 3339 3340 3341 switch(sig) { 3342 case SIGSEGV: 3343 case SIGBUS: 3344 case SIGFPE: 3345 case SIGPIPE: 3346 case SIGILL: 3347 case SIGXFSZ: 3348 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 3349 break; 3350 3351 case SHUTDOWN1_SIGNAL: 3352 case SHUTDOWN2_SIGNAL: 3353 case SHUTDOWN3_SIGNAL: 3354 case BREAK_SIGNAL: 3355 jvmHandler = (address)user_handler(); 3356 break; 3357 3358 case INTERRUPT_SIGNAL: 3359 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); 3360 break; 3361 3362 default: 3363 if (sig == SR_signum) { 3364 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 3365 } else { 3366 return; 3367 } 3368 break; 3369 } 3370 3371 if (thisHandler != jvmHandler) { 3372 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 3373 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 3374 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 3375 // No need to check this sig any longer 3376 sigaddset(&check_signal_done, sig); 3377 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 3378 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 3379 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 3380 exception_name(sig, buf, O_BUFLEN)); 3381 } 3382 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3383 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 3384 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); 3385 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); 3386 // No need to check this sig any longer 3387 sigaddset(&check_signal_done, sig); 3388 } 3389 3390 // Dump all the signal 3391 if (sigismember(&check_signal_done, sig)) { 3392 print_signal_handlers(tty, buf, O_BUFLEN); 3393 } 3394 } 3395 3396 extern void report_error(char* file_name, int line_no, char* title, char* format, ...); 3397 3398 extern bool signal_name(int signo, char* buf, size_t len); 3399 3400 const char* os::exception_name(int exception_code, char* buf, size_t size) { 3401 if (0 < exception_code && exception_code <= SIGRTMAX) { 3402 // signal 3403 if (!signal_name(exception_code, buf, size)) { 3404 jio_snprintf(buf, size, "SIG%d", exception_code); 3405 } 3406 return buf; 3407 } else { 3408 return NULL; 3409 } 3410 } 3411 3412 // this is called _before_ the most of global arguments have been parsed 3413 void os::init(void) { 3414 char dummy; /* used to get a guess on initial stack address */ 3415 // first_hrtime = gethrtime(); 3416 3417 // With BsdThreads the JavaMain thread pid (primordial thread) 3418 // is different than the pid of the java launcher thread. 3419 // So, on Bsd, the launcher thread pid is passed to the VM 3420 // via the sun.java.launcher.pid property. 3421 // Use this property instead of getpid() if it was correctly passed. 3422 // See bug 6351349. 3423 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); 3424 3425 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); 3426 3427 clock_tics_per_sec = CLK_TCK; 3428 3429 init_random(1234567); 3430 3431 ThreadCritical::initialize(); 3432 3433 Bsd::set_page_size(getpagesize()); 3434 if (Bsd::page_size() == -1) { 3435 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)", 3436 strerror(errno))); 3437 } 3438 init_page_sizes((size_t) Bsd::page_size()); 3439 3440 Bsd::initialize_system_info(); 3441 3442 // main_thread points to the aboriginal thread 3443 Bsd::_main_thread = pthread_self(); 3444 3445 Bsd::clock_init(); 3446 initial_time_count = javaTimeNanos(); 3447 3448 #ifdef __APPLE__ 3449 // XXXDARWIN 3450 // Work around the unaligned VM callbacks in hotspot's 3451 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on 3452 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces 3453 // alignment when doing symbol lookup. To work around this, we force early 3454 // binding of all symbols now, thus binding when alignment is known-good. 3455 _dyld_bind_fully_image_containing_address((const void *) &os::init); 3456 #endif 3457 } 3458 3459 // To install functions for atexit system call 3460 extern "C" { 3461 static void perfMemory_exit_helper() { 3462 perfMemory_exit(); 3463 } 3464 } 3465 3466 // this is called _after_ the global arguments have been parsed 3467 jint os::init_2(void) 3468 { 3469 // Allocate a single page and mark it as readable for safepoint polling 3470 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3471 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" ); 3472 3473 os::set_polling_page( polling_page ); 3474 3475 #ifndef PRODUCT 3476 if(Verbose && PrintMiscellaneous) 3477 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page); 3478 #endif 3479 3480 if (!UseMembar) { 3481 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3482 guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 3483 os::set_memory_serialize_page( mem_serialize_page ); 3484 3485 #ifndef PRODUCT 3486 if(Verbose && PrintMiscellaneous) 3487 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page); 3488 #endif 3489 } 3490 3491 // initialize suspend/resume support - must do this before signal_sets_init() 3492 if (SR_initialize() != 0) { 3493 perror("SR_initialize failed"); 3494 return JNI_ERR; 3495 } 3496 3497 Bsd::signal_sets_init(); 3498 Bsd::install_signal_handlers(); 3499 3500 // Check minimum allowable stack size for thread creation and to initialize 3501 // the java system classes, including StackOverflowError - depends on page 3502 // size. Add a page for compiler2 recursion in main thread. 3503 // Add in 2*BytesPerWord times page size to account for VM stack during 3504 // class initialization depending on 32 or 64 bit VM. 3505 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, 3506 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ 3507 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); 3508 3509 size_t threadStackSizeInBytes = ThreadStackSize * K; 3510 if (threadStackSizeInBytes != 0 && 3511 threadStackSizeInBytes < os::Bsd::min_stack_allowed) { 3512 tty->print_cr("\nThe stack size specified is too small, " 3513 "Specify at least %dk", 3514 os::Bsd::min_stack_allowed/ K); 3515 return JNI_ERR; 3516 } 3517 3518 // Make the stack size a multiple of the page size so that 3519 // the yellow/red zones can be guarded. 3520 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 3521 vm_page_size())); 3522 3523 if (MaxFDLimit) { 3524 // set the number of file descriptors to max. print out error 3525 // if getrlimit/setrlimit fails but continue regardless. 3526 struct rlimit nbr_files; 3527 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 3528 if (status != 0) { 3529 if (PrintMiscellaneous && (Verbose || WizardMode)) 3530 perror("os::init_2 getrlimit failed"); 3531 } else { 3532 nbr_files.rlim_cur = nbr_files.rlim_max; 3533 3534 #ifdef __APPLE__ 3535 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if 3536 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must 3537 // be used instead 3538 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); 3539 #endif 3540 3541 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 3542 if (status != 0) { 3543 if (PrintMiscellaneous && (Verbose || WizardMode)) 3544 perror("os::init_2 setrlimit failed"); 3545 } 3546 } 3547 } 3548 3549 // at-exit methods are called in the reverse order of their registration. 3550 // atexit functions are called on return from main or as a result of a 3551 // call to exit(3C). There can be only 32 of these functions registered 3552 // and atexit() does not set errno. 3553 3554 if (PerfAllowAtExitRegistration) { 3555 // only register atexit functions if PerfAllowAtExitRegistration is set. 3556 // atexit functions can be delayed until process exit time, which 3557 // can be problematic for embedded VM situations. Embedded VMs should 3558 // call DestroyJavaVM() to assure that VM resources are released. 3559 3560 // note: perfMemory_exit_helper atexit function may be removed in 3561 // the future if the appropriate cleanup code can be added to the 3562 // VM_Exit VMOperation's doit method. 3563 if (atexit(perfMemory_exit_helper) != 0) { 3564 warning("os::init2 atexit(perfMemory_exit_helper) failed"); 3565 } 3566 } 3567 3568 // initialize thread priority policy 3569 prio_init(); 3570 3571 #ifdef __APPLE__ 3572 // dynamically link to objective c gc registration 3573 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY); 3574 if (handleLibObjc != NULL) { 3575 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER); 3576 } 3577 #endif 3578 3579 return JNI_OK; 3580 } 3581 3582 // this is called at the end of vm_initialization 3583 void os::init_3(void) { } 3584 3585 // Mark the polling page as unreadable 3586 void os::make_polling_page_unreadable(void) { 3587 if( !guard_memory((char*)_polling_page, Bsd::page_size()) ) 3588 fatal("Could not disable polling page"); 3589 }; 3590 3591 // Mark the polling page as readable 3592 void os::make_polling_page_readable(void) { 3593 if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { 3594 fatal("Could not enable polling page"); 3595 } 3596 }; 3597 3598 int os::active_processor_count() { 3599 return _processor_count; 3600 } 3601 3602 void os::set_native_thread_name(const char *name) { 3603 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5 3604 // This is only supported in Snow Leopard and beyond 3605 if (name != NULL) { 3606 // Add a "Java: " prefix to the name 3607 char buf[MAXTHREADNAMESIZE]; 3608 snprintf(buf, sizeof(buf), "Java: %s", name); 3609 pthread_setname_np(buf); 3610 } 3611 #endif 3612 } 3613 3614 bool os::distribute_processes(uint length, uint* distribution) { 3615 // Not yet implemented. 3616 return false; 3617 } 3618 3619 bool os::bind_to_processor(uint processor_id) { 3620 // Not yet implemented. 3621 return false; 3622 } 3623 3624 void os::SuspendedThreadTask::internal_do_task() { 3625 if (do_suspend(_thread->osthread())) { 3626 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 3627 do_task(context); 3628 do_resume(_thread->osthread()); 3629 } 3630 } 3631 3632 /// 3633 class PcFetcher : public os::SuspendedThreadTask { 3634 public: 3635 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 3636 ExtendedPC result(); 3637 protected: 3638 void do_task(const os::SuspendedThreadTaskContext& context); 3639 private: 3640 ExtendedPC _epc; 3641 }; 3642 3643 ExtendedPC PcFetcher::result() { 3644 guarantee(is_done(), "task is not done yet."); 3645 return _epc; 3646 } 3647 3648 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 3649 Thread* thread = context.thread(); 3650 OSThread* osthread = thread->osthread(); 3651 if (osthread->ucontext() != NULL) { 3652 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext()); 3653 } else { 3654 // NULL context is unexpected, double-check this is the VMThread 3655 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 3656 } 3657 } 3658 3659 // Suspends the target using the signal mechanism and then grabs the PC before 3660 // resuming the target. Used by the flat-profiler only 3661 ExtendedPC os::get_thread_pc(Thread* thread) { 3662 // Make sure that it is called by the watcher for the VMThread 3663 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 3664 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 3665 3666 PcFetcher fetcher(thread); 3667 fetcher.run(); 3668 return fetcher.result(); 3669 } 3670 3671 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime) 3672 { 3673 return pthread_cond_timedwait(_cond, _mutex, _abstime); 3674 } 3675 3676 //////////////////////////////////////////////////////////////////////////////// 3677 // debug support 3678 3679 bool os::find(address addr, outputStream* st) { 3680 Dl_info dlinfo; 3681 memset(&dlinfo, 0, sizeof(dlinfo)); 3682 if (dladdr(addr, &dlinfo) != 0) { 3683 st->print(PTR_FORMAT ": ", addr); 3684 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 3685 st->print("%s+%#x", dlinfo.dli_sname, 3686 addr - (intptr_t)dlinfo.dli_saddr); 3687 } else if (dlinfo.dli_fbase != NULL) { 3688 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); 3689 } else { 3690 st->print("<absolute address>"); 3691 } 3692 if (dlinfo.dli_fname != NULL) { 3693 st->print(" in %s", dlinfo.dli_fname); 3694 } 3695 if (dlinfo.dli_fbase != NULL) { 3696 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); 3697 } 3698 st->cr(); 3699 3700 if (Verbose) { 3701 // decode some bytes around the PC 3702 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 3703 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 3704 address lowest = (address) dlinfo.dli_sname; 3705 if (!lowest) lowest = (address) dlinfo.dli_fbase; 3706 if (begin < lowest) begin = lowest; 3707 Dl_info dlinfo2; 3708 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 3709 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) 3710 end = (address) dlinfo2.dli_saddr; 3711 Disassembler::decode(begin, end, st); 3712 } 3713 return true; 3714 } 3715 return false; 3716 } 3717 3718 //////////////////////////////////////////////////////////////////////////////// 3719 // misc 3720 3721 // This does not do anything on Bsd. This is basically a hook for being 3722 // able to use structured exception handling (thread-local exception filters) 3723 // on, e.g., Win32. 3724 void 3725 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, 3726 JavaCallArguments* args, Thread* thread) { 3727 f(value, method, args, thread); 3728 } 3729 3730 void os::print_statistics() { 3731 } 3732 3733 int os::message_box(const char* title, const char* message) { 3734 int i; 3735 fdStream err(defaultStream::error_fd()); 3736 for (i = 0; i < 78; i++) err.print_raw("="); 3737 err.cr(); 3738 err.print_raw_cr(title); 3739 for (i = 0; i < 78; i++) err.print_raw("-"); 3740 err.cr(); 3741 err.print_raw_cr(message); 3742 for (i = 0; i < 78; i++) err.print_raw("="); 3743 err.cr(); 3744 3745 char buf[16]; 3746 // Prevent process from exiting upon "read error" without consuming all CPU 3747 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 3748 3749 return buf[0] == 'y' || buf[0] == 'Y'; 3750 } 3751 3752 int os::stat(const char *path, struct stat *sbuf) { 3753 char pathbuf[MAX_PATH]; 3754 if (strlen(path) > MAX_PATH - 1) { 3755 errno = ENAMETOOLONG; 3756 return -1; 3757 } 3758 os::native_path(strcpy(pathbuf, path)); 3759 return ::stat(pathbuf, sbuf); 3760 } 3761 3762 bool os::check_heap(bool force) { 3763 return true; 3764 } 3765 3766 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) { 3767 return ::vsnprintf(buf, count, format, args); 3768 } 3769 3770 // Is a (classpath) directory empty? 3771 bool os::dir_is_empty(const char* path) { 3772 DIR *dir = NULL; 3773 struct dirent *ptr; 3774 3775 dir = opendir(path); 3776 if (dir == NULL) return true; 3777 3778 /* Scan the directory */ 3779 bool result = true; 3780 char buf[sizeof(struct dirent) + MAX_PATH]; 3781 while (result && (ptr = ::readdir(dir)) != NULL) { 3782 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 3783 result = false; 3784 } 3785 } 3786 closedir(dir); 3787 return result; 3788 } 3789 3790 // This code originates from JDK's sysOpen and open64_w 3791 // from src/solaris/hpi/src/system_md.c 3792 3793 #ifndef O_DELETE 3794 #define O_DELETE 0x10000 3795 #endif 3796 3797 // Open a file. Unlink the file immediately after open returns 3798 // if the specified oflag has the O_DELETE flag set. 3799 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c 3800 3801 int os::open(const char *path, int oflag, int mode) { 3802 3803 if (strlen(path) > MAX_PATH - 1) { 3804 errno = ENAMETOOLONG; 3805 return -1; 3806 } 3807 int fd; 3808 int o_delete = (oflag & O_DELETE); 3809 oflag = oflag & ~O_DELETE; 3810 3811 fd = ::open(path, oflag, mode); 3812 if (fd == -1) return -1; 3813 3814 //If the open succeeded, the file might still be a directory 3815 { 3816 struct stat buf; 3817 int ret = ::fstat(fd, &buf); 3818 int st_mode = buf.st_mode; 3819 3820 if (ret != -1) { 3821 if ((st_mode & S_IFMT) == S_IFDIR) { 3822 errno = EISDIR; 3823 ::close(fd); 3824 return -1; 3825 } 3826 } else { 3827 ::close(fd); 3828 return -1; 3829 } 3830 } 3831 3832 /* 3833 * All file descriptors that are opened in the JVM and not 3834 * specifically destined for a subprocess should have the 3835 * close-on-exec flag set. If we don't set it, then careless 3rd 3836 * party native code might fork and exec without closing all 3837 * appropriate file descriptors (e.g. as we do in closeDescriptors in 3838 * UNIXProcess.c), and this in turn might: 3839 * 3840 * - cause end-of-file to fail to be detected on some file 3841 * descriptors, resulting in mysterious hangs, or 3842 * 3843 * - might cause an fopen in the subprocess to fail on a system 3844 * suffering from bug 1085341. 3845 * 3846 * (Yes, the default setting of the close-on-exec flag is a Unix 3847 * design flaw) 3848 * 3849 * See: 3850 * 1085341: 32-bit stdio routines should support file descriptors >255 3851 * 4843136: (process) pipe file descriptor from Runtime.exec not being closed 3852 * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 3853 */ 3854 #ifdef FD_CLOEXEC 3855 { 3856 int flags = ::fcntl(fd, F_GETFD); 3857 if (flags != -1) 3858 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 3859 } 3860 #endif 3861 3862 if (o_delete != 0) { 3863 ::unlink(path); 3864 } 3865 return fd; 3866 } 3867 3868 3869 // create binary file, rewriting existing file if required 3870 int os::create_binary_file(const char* path, bool rewrite_existing) { 3871 int oflags = O_WRONLY | O_CREAT; 3872 if (!rewrite_existing) { 3873 oflags |= O_EXCL; 3874 } 3875 return ::open(path, oflags, S_IREAD | S_IWRITE); 3876 } 3877 3878 // return current position of file pointer 3879 jlong os::current_file_offset(int fd) { 3880 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); 3881 } 3882 3883 // move file pointer to the specified offset 3884 jlong os::seek_to_file_offset(int fd, jlong offset) { 3885 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); 3886 } 3887 3888 // This code originates from JDK's sysAvailable 3889 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 3890 3891 int os::available(int fd, jlong *bytes) { 3892 jlong cur, end; 3893 int mode; 3894 struct stat buf; 3895 3896 if (::fstat(fd, &buf) >= 0) { 3897 mode = buf.st_mode; 3898 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 3899 /* 3900 * XXX: is the following call interruptible? If so, this might 3901 * need to go through the INTERRUPT_IO() wrapper as for other 3902 * blocking, interruptible calls in this file. 3903 */ 3904 int n; 3905 if (::ioctl(fd, FIONREAD, &n) >= 0) { 3906 *bytes = n; 3907 return 1; 3908 } 3909 } 3910 } 3911 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { 3912 return 0; 3913 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { 3914 return 0; 3915 } else if (::lseek(fd, cur, SEEK_SET) == -1) { 3916 return 0; 3917 } 3918 *bytes = end - cur; 3919 return 1; 3920 } 3921 3922 int os::socket_available(int fd, jint *pbytes) { 3923 if (fd < 0) 3924 return OS_OK; 3925 3926 int ret; 3927 3928 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret); 3929 3930 //%% note ioctl can return 0 when successful, JVM_SocketAvailable 3931 // is expected to return 0 on failure and 1 on success to the jdk. 3932 3933 return (ret == OS_ERR) ? 0 : 1; 3934 } 3935 3936 // Map a block of memory. 3937 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 3938 char *addr, size_t bytes, bool read_only, 3939 bool allow_exec) { 3940 int prot; 3941 int flags; 3942 3943 if (read_only) { 3944 prot = PROT_READ; 3945 flags = MAP_SHARED; 3946 } else { 3947 prot = PROT_READ | PROT_WRITE; 3948 flags = MAP_PRIVATE; 3949 } 3950 3951 if (allow_exec) { 3952 prot |= PROT_EXEC; 3953 } 3954 3955 if (addr != NULL) { 3956 flags |= MAP_FIXED; 3957 } 3958 3959 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 3960 fd, file_offset); 3961 if (mapped_address == MAP_FAILED) { 3962 return NULL; 3963 } 3964 return mapped_address; 3965 } 3966 3967 3968 // Remap a block of memory. 3969 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 3970 char *addr, size_t bytes, bool read_only, 3971 bool allow_exec) { 3972 // same as map_memory() on this OS 3973 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 3974 allow_exec); 3975 } 3976 3977 3978 // Unmap a block of memory. 3979 bool os::pd_unmap_memory(char* addr, size_t bytes) { 3980 return munmap(addr, bytes) == 0; 3981 } 3982 3983 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 3984 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 3985 // of a thread. 3986 // 3987 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 3988 // the fast estimate available on the platform. 3989 3990 jlong os::current_thread_cpu_time() { 3991 #ifdef __APPLE__ 3992 return os::thread_cpu_time(Thread::current(), true /* user + sys */); 3993 #else 3994 Unimplemented(); 3995 return 0; 3996 #endif 3997 } 3998 3999 jlong os::thread_cpu_time(Thread* thread) { 4000 #ifdef __APPLE__ 4001 return os::thread_cpu_time(thread, true /* user + sys */); 4002 #else 4003 Unimplemented(); 4004 return 0; 4005 #endif 4006 } 4007 4008 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 4009 #ifdef __APPLE__ 4010 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); 4011 #else 4012 Unimplemented(); 4013 return 0; 4014 #endif 4015 } 4016 4017 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 4018 #ifdef __APPLE__ 4019 struct thread_basic_info tinfo; 4020 mach_msg_type_number_t tcount = THREAD_INFO_MAX; 4021 kern_return_t kr; 4022 thread_t mach_thread; 4023 4024 mach_thread = thread->osthread()->thread_id(); 4025 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); 4026 if (kr != KERN_SUCCESS) 4027 return -1; 4028 4029 if (user_sys_cpu_time) { 4030 jlong nanos; 4031 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; 4032 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; 4033 return nanos; 4034 } else { 4035 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); 4036 } 4037 #else 4038 Unimplemented(); 4039 return 0; 4040 #endif 4041 } 4042 4043 4044 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4045 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4046 info_ptr->may_skip_backward = false; // elapsed time not wall time 4047 info_ptr->may_skip_forward = false; // elapsed time not wall time 4048 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4049 } 4050 4051 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4052 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4053 info_ptr->may_skip_backward = false; // elapsed time not wall time 4054 info_ptr->may_skip_forward = false; // elapsed time not wall time 4055 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4056 } 4057 4058 bool os::is_thread_cpu_time_supported() { 4059 #ifdef __APPLE__ 4060 return true; 4061 #else 4062 return false; 4063 #endif 4064 } 4065 4066 // System loadavg support. Returns -1 if load average cannot be obtained. 4067 // Bsd doesn't yet have a (official) notion of processor sets, 4068 // so just return the system wide load average. 4069 int os::loadavg(double loadavg[], int nelem) { 4070 return ::getloadavg(loadavg, nelem); 4071 } 4072 4073 void os::pause() { 4074 char filename[MAX_PATH]; 4075 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 4076 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); 4077 } else { 4078 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 4079 } 4080 4081 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 4082 if (fd != -1) { 4083 struct stat buf; 4084 ::close(fd); 4085 while (::stat(filename, &buf) == 0) { 4086 (void)::poll(NULL, 0, 100); 4087 } 4088 } else { 4089 jio_fprintf(stderr, 4090 "Could not open pause file '%s', continuing immediately.\n", filename); 4091 } 4092 } 4093 4094 4095 // Refer to the comments in os_solaris.cpp park-unpark. 4096 // 4097 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 4098 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 4099 // For specifics regarding the bug see GLIBC BUGID 261237 : 4100 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 4101 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 4102 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 4103 // is used. (The simple C test-case provided in the GLIBC bug report manifests the 4104 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 4105 // and monitorenter when we're using 1-0 locking. All those operations may result in 4106 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 4107 // of libpthread avoids the problem, but isn't practical. 4108 // 4109 // Possible remedies: 4110 // 4111 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 4112 // This is palliative and probabilistic, however. If the thread is preempted 4113 // between the call to compute_abstime() and pthread_cond_timedwait(), more 4114 // than the minimum period may have passed, and the abstime may be stale (in the 4115 // past) resultin in a hang. Using this technique reduces the odds of a hang 4116 // but the JVM is still vulnerable, particularly on heavily loaded systems. 4117 // 4118 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 4119 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set 4120 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 4121 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant 4122 // thread. 4123 // 4124 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 4125 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 4126 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). 4127 // This also works well. In fact it avoids kernel-level scalability impediments 4128 // on certain platforms that don't handle lots of active pthread_cond_timedwait() 4129 // timers in a graceful fashion. 4130 // 4131 // 4. When the abstime value is in the past it appears that control returns 4132 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 4133 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we 4134 // can avoid the problem by reinitializing the condvar -- by cond_destroy() 4135 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). 4136 // It may be possible to avoid reinitialization by checking the return 4137 // value from pthread_cond_timedwait(). In addition to reinitializing the 4138 // condvar we must establish the invariant that cond_signal() is only called 4139 // within critical sections protected by the adjunct mutex. This prevents 4140 // cond_signal() from "seeing" a condvar that's in the midst of being 4141 // reinitialized or that is corrupt. Sadly, this invariant obviates the 4142 // desirable signal-after-unlock optimization that avoids futile context switching. 4143 // 4144 // I'm also concerned that some versions of NTPL might allocate an auxilliary 4145 // structure when a condvar is used or initialized. cond_destroy() would 4146 // release the helper structure. Our reinitialize-after-timedwait fix 4147 // put excessive stress on malloc/free and locks protecting the c-heap. 4148 // 4149 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 4150 // It may be possible to refine (4) by checking the kernel and NTPL verisons 4151 // and only enabling the work-around for vulnerable environments. 4152 4153 // utility to compute the abstime argument to timedwait: 4154 // millis is the relative timeout time 4155 // abstime will be the absolute timeout time 4156 // TODO: replace compute_abstime() with unpackTime() 4157 4158 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) { 4159 if (millis < 0) millis = 0; 4160 struct timeval now; 4161 int status = gettimeofday(&now, NULL); 4162 assert(status == 0, "gettimeofday"); 4163 jlong seconds = millis / 1000; 4164 millis %= 1000; 4165 if (seconds > 50000000) { // see man cond_timedwait(3T) 4166 seconds = 50000000; 4167 } 4168 abstime->tv_sec = now.tv_sec + seconds; 4169 long usec = now.tv_usec + millis * 1000; 4170 if (usec >= 1000000) { 4171 abstime->tv_sec += 1; 4172 usec -= 1000000; 4173 } 4174 abstime->tv_nsec = usec * 1000; 4175 return abstime; 4176 } 4177 4178 4179 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately. 4180 // Conceptually TryPark() should be equivalent to park(0). 4181 4182 int os::PlatformEvent::TryPark() { 4183 for (;;) { 4184 const int v = _Event ; 4185 guarantee ((v == 0) || (v == 1), "invariant") ; 4186 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ; 4187 } 4188 } 4189 4190 void os::PlatformEvent::park() { // AKA "down()" 4191 // Invariant: Only the thread associated with the Event/PlatformEvent 4192 // may call park(). 4193 // TODO: assert that _Assoc != NULL or _Assoc == Self 4194 int v ; 4195 for (;;) { 4196 v = _Event ; 4197 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; 4198 } 4199 guarantee (v >= 0, "invariant") ; 4200 if (v == 0) { 4201 // Do this the hard way by blocking ... 4202 int status = pthread_mutex_lock(_mutex); 4203 assert_status(status == 0, status, "mutex_lock"); 4204 guarantee (_nParked == 0, "invariant") ; 4205 ++ _nParked ; 4206 while (_Event < 0) { 4207 status = pthread_cond_wait(_cond, _mutex); 4208 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 4209 // Treat this the same as if the wait was interrupted 4210 if (status == ETIMEDOUT) { status = EINTR; } 4211 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 4212 } 4213 -- _nParked ; 4214 4215 _Event = 0 ; 4216 status = pthread_mutex_unlock(_mutex); 4217 assert_status(status == 0, status, "mutex_unlock"); 4218 // Paranoia to ensure our locked and lock-free paths interact 4219 // correctly with each other. 4220 OrderAccess::fence(); 4221 } 4222 guarantee (_Event >= 0, "invariant") ; 4223 } 4224 4225 int os::PlatformEvent::park(jlong millis) { 4226 guarantee (_nParked == 0, "invariant") ; 4227 4228 int v ; 4229 for (;;) { 4230 v = _Event ; 4231 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; 4232 } 4233 guarantee (v >= 0, "invariant") ; 4234 if (v != 0) return OS_OK ; 4235 4236 // We do this the hard way, by blocking the thread. 4237 // Consider enforcing a minimum timeout value. 4238 struct timespec abst; 4239 compute_abstime(&abst, millis); 4240 4241 int ret = OS_TIMEOUT; 4242 int status = pthread_mutex_lock(_mutex); 4243 assert_status(status == 0, status, "mutex_lock"); 4244 guarantee (_nParked == 0, "invariant") ; 4245 ++_nParked ; 4246 4247 // Object.wait(timo) will return because of 4248 // (a) notification 4249 // (b) timeout 4250 // (c) thread.interrupt 4251 // 4252 // Thread.interrupt and object.notify{All} both call Event::set. 4253 // That is, we treat thread.interrupt as a special case of notification. 4254 // The underlying Solaris implementation, cond_timedwait, admits 4255 // spurious/premature wakeups, but the JLS/JVM spec prevents the 4256 // JVM from making those visible to Java code. As such, we must 4257 // filter out spurious wakeups. We assume all ETIME returns are valid. 4258 // 4259 // TODO: properly differentiate simultaneous notify+interrupt. 4260 // In that case, we should propagate the notify to another waiter. 4261 4262 while (_Event < 0) { 4263 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst); 4264 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4265 pthread_cond_destroy (_cond); 4266 pthread_cond_init (_cond, NULL) ; 4267 } 4268 assert_status(status == 0 || status == EINTR || 4269 status == ETIMEDOUT, 4270 status, "cond_timedwait"); 4271 if (!FilterSpuriousWakeups) break ; // previous semantics 4272 if (status == ETIMEDOUT) break ; 4273 // We consume and ignore EINTR and spurious wakeups. 4274 } 4275 --_nParked ; 4276 if (_Event >= 0) { 4277 ret = OS_OK; 4278 } 4279 _Event = 0 ; 4280 status = pthread_mutex_unlock(_mutex); 4281 assert_status(status == 0, status, "mutex_unlock"); 4282 assert (_nParked == 0, "invariant") ; 4283 // Paranoia to ensure our locked and lock-free paths interact 4284 // correctly with each other. 4285 OrderAccess::fence(); 4286 return ret; 4287 } 4288 4289 void os::PlatformEvent::unpark() { 4290 // Transitions for _Event: 4291 // 0 :=> 1 4292 // 1 :=> 1 4293 // -1 :=> either 0 or 1; must signal target thread 4294 // That is, we can safely transition _Event from -1 to either 4295 // 0 or 1. Forcing 1 is slightly more efficient for back-to-back 4296 // unpark() calls. 4297 // See also: "Semaphores in Plan 9" by Mullender & Cox 4298 // 4299 // Note: Forcing a transition from "-1" to "1" on an unpark() means 4300 // that it will take two back-to-back park() calls for the owning 4301 // thread to block. This has the benefit of forcing a spurious return 4302 // from the first park() call after an unpark() call which will help 4303 // shake out uses of park() and unpark() without condition variables. 4304 4305 if (Atomic::xchg(1, &_Event) >= 0) return; 4306 4307 // Wait for the thread associated with the event to vacate 4308 int status = pthread_mutex_lock(_mutex); 4309 assert_status(status == 0, status, "mutex_lock"); 4310 int AnyWaiters = _nParked; 4311 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 4312 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 4313 AnyWaiters = 0; 4314 pthread_cond_signal(_cond); 4315 } 4316 status = pthread_mutex_unlock(_mutex); 4317 assert_status(status == 0, status, "mutex_unlock"); 4318 if (AnyWaiters != 0) { 4319 status = pthread_cond_signal(_cond); 4320 assert_status(status == 0, status, "cond_signal"); 4321 } 4322 4323 // Note that we signal() _after dropping the lock for "immortal" Events. 4324 // This is safe and avoids a common class of futile wakeups. In rare 4325 // circumstances this can cause a thread to return prematurely from 4326 // cond_{timed}wait() but the spurious wakeup is benign and the victim will 4327 // simply re-test the condition and re-park itself. 4328 } 4329 4330 4331 // JSR166 4332 // ------------------------------------------------------- 4333 4334 /* 4335 * The solaris and bsd implementations of park/unpark are fairly 4336 * conservative for now, but can be improved. They currently use a 4337 * mutex/condvar pair, plus a a count. 4338 * Park decrements count if > 0, else does a condvar wait. Unpark 4339 * sets count to 1 and signals condvar. Only one thread ever waits 4340 * on the condvar. Contention seen when trying to park implies that someone 4341 * is unparking you, so don't wait. And spurious returns are fine, so there 4342 * is no need to track notifications. 4343 */ 4344 4345 #define MAX_SECS 100000000 4346 /* 4347 * This code is common to bsd and solaris and will be moved to a 4348 * common place in dolphin. 4349 * 4350 * The passed in time value is either a relative time in nanoseconds 4351 * or an absolute time in milliseconds. Either way it has to be unpacked 4352 * into suitable seconds and nanoseconds components and stored in the 4353 * given timespec structure. 4354 * Given time is a 64-bit value and the time_t used in the timespec is only 4355 * a signed-32-bit value (except on 64-bit Bsd) we have to watch for 4356 * overflow if times way in the future are given. Further on Solaris versions 4357 * prior to 10 there is a restriction (see cond_timedwait) that the specified 4358 * number of seconds, in abstime, is less than current_time + 100,000,000. 4359 * As it will be 28 years before "now + 100000000" will overflow we can 4360 * ignore overflow and just impose a hard-limit on seconds using the value 4361 * of "now + 100,000,000". This places a limit on the timeout of about 3.17 4362 * years from "now". 4363 */ 4364 4365 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { 4366 assert (time > 0, "convertTime"); 4367 4368 struct timeval now; 4369 int status = gettimeofday(&now, NULL); 4370 assert(status == 0, "gettimeofday"); 4371 4372 time_t max_secs = now.tv_sec + MAX_SECS; 4373 4374 if (isAbsolute) { 4375 jlong secs = time / 1000; 4376 if (secs > max_secs) { 4377 absTime->tv_sec = max_secs; 4378 } 4379 else { 4380 absTime->tv_sec = secs; 4381 } 4382 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 4383 } 4384 else { 4385 jlong secs = time / NANOSECS_PER_SEC; 4386 if (secs >= MAX_SECS) { 4387 absTime->tv_sec = max_secs; 4388 absTime->tv_nsec = 0; 4389 } 4390 else { 4391 absTime->tv_sec = now.tv_sec + secs; 4392 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 4393 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 4394 absTime->tv_nsec -= NANOSECS_PER_SEC; 4395 ++absTime->tv_sec; // note: this must be <= max_secs 4396 } 4397 } 4398 } 4399 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 4400 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 4401 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 4402 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 4403 } 4404 4405 void Parker::park(bool isAbsolute, jlong time) { 4406 // Ideally we'd do something useful while spinning, such 4407 // as calling unpackTime(). 4408 4409 // Optional fast-path check: 4410 // Return immediately if a permit is available. 4411 // We depend on Atomic::xchg() having full barrier semantics 4412 // since we are doing a lock-free update to _counter. 4413 if (Atomic::xchg(0, &_counter) > 0) return; 4414 4415 Thread* thread = Thread::current(); 4416 assert(thread->is_Java_thread(), "Must be JavaThread"); 4417 JavaThread *jt = (JavaThread *)thread; 4418 4419 // Optional optimization -- avoid state transitions if there's an interrupt pending. 4420 // Check interrupt before trying to wait 4421 if (Thread::is_interrupted(thread, false)) { 4422 return; 4423 } 4424 4425 // Next, demultiplex/decode time arguments 4426 struct timespec absTime; 4427 if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all 4428 return; 4429 } 4430 if (time > 0) { 4431 unpackTime(&absTime, isAbsolute, time); 4432 } 4433 4434 4435 // Enter safepoint region 4436 // Beware of deadlocks such as 6317397. 4437 // The per-thread Parker:: mutex is a classic leaf-lock. 4438 // In particular a thread must never block on the Threads_lock while 4439 // holding the Parker:: mutex. If safepoints are pending both the 4440 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 4441 ThreadBlockInVM tbivm(jt); 4442 4443 // Don't wait if cannot get lock since interference arises from 4444 // unblocking. Also. check interrupt before trying wait 4445 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 4446 return; 4447 } 4448 4449 int status ; 4450 if (_counter > 0) { // no wait needed 4451 _counter = 0; 4452 status = pthread_mutex_unlock(_mutex); 4453 assert (status == 0, "invariant") ; 4454 // Paranoia to ensure our locked and lock-free paths interact 4455 // correctly with each other and Java-level accesses. 4456 OrderAccess::fence(); 4457 return; 4458 } 4459 4460 #ifdef ASSERT 4461 // Don't catch signals while blocked; let the running threads have the signals. 4462 // (This allows a debugger to break into the running thread.) 4463 sigset_t oldsigs; 4464 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); 4465 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 4466 #endif 4467 4468 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 4469 jt->set_suspend_equivalent(); 4470 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 4471 4472 if (time == 0) { 4473 status = pthread_cond_wait (_cond, _mutex) ; 4474 } else { 4475 status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ; 4476 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4477 pthread_cond_destroy (_cond) ; 4478 pthread_cond_init (_cond, NULL); 4479 } 4480 } 4481 assert_status(status == 0 || status == EINTR || 4482 status == ETIMEDOUT, 4483 status, "cond_timedwait"); 4484 4485 #ifdef ASSERT 4486 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 4487 #endif 4488 4489 _counter = 0 ; 4490 status = pthread_mutex_unlock(_mutex) ; 4491 assert_status(status == 0, status, "invariant") ; 4492 // Paranoia to ensure our locked and lock-free paths interact 4493 // correctly with each other and Java-level accesses. 4494 OrderAccess::fence(); 4495 4496 // If externally suspended while waiting, re-suspend 4497 if (jt->handle_special_suspend_equivalent_condition()) { 4498 jt->java_suspend_self(); 4499 } 4500 } 4501 4502 void Parker::unpark() { 4503 int s, status ; 4504 status = pthread_mutex_lock(_mutex); 4505 assert (status == 0, "invariant") ; 4506 s = _counter; 4507 _counter = 1; 4508 if (s < 1) { 4509 if (WorkAroundNPTLTimedWaitHang) { 4510 status = pthread_cond_signal (_cond) ; 4511 assert (status == 0, "invariant") ; 4512 status = pthread_mutex_unlock(_mutex); 4513 assert (status == 0, "invariant") ; 4514 } else { 4515 status = pthread_mutex_unlock(_mutex); 4516 assert (status == 0, "invariant") ; 4517 status = pthread_cond_signal (_cond) ; 4518 assert (status == 0, "invariant") ; 4519 } 4520 } else { 4521 pthread_mutex_unlock(_mutex); 4522 assert (status == 0, "invariant") ; 4523 } 4524 } 4525 4526 4527 /* Darwin has no "environ" in a dynamic library. */ 4528 #ifdef __APPLE__ 4529 #include <crt_externs.h> 4530 #define environ (*_NSGetEnviron()) 4531 #else 4532 extern char** environ; 4533 #endif 4534 4535 // Run the specified command in a separate process. Return its exit value, 4536 // or -1 on failure (e.g. can't fork a new process). 4537 // Unlike system(), this function can be called from signal handler. It 4538 // doesn't block SIGINT et al. 4539 int os::fork_and_exec(char* cmd) { 4540 const char * argv[4] = {"sh", "-c", cmd, NULL}; 4541 4542 // fork() in BsdThreads/NPTL is not async-safe. It needs to run 4543 // pthread_atfork handlers and reset pthread library. All we need is a 4544 // separate process to execve. Make a direct syscall to fork process. 4545 // On IA64 there's no fork syscall, we have to use fork() and hope for 4546 // the best... 4547 pid_t pid = fork(); 4548 4549 if (pid < 0) { 4550 // fork failed 4551 return -1; 4552 4553 } else if (pid == 0) { 4554 // child process 4555 4556 // execve() in BsdThreads will call pthread_kill_other_threads_np() 4557 // first to kill every thread on the thread list. Because this list is 4558 // not reset by fork() (see notes above), execve() will instead kill 4559 // every thread in the parent process. We know this is the only thread 4560 // in the new process, so make a system call directly. 4561 // IA64 should use normal execve() from glibc to match the glibc fork() 4562 // above. 4563 execve("/bin/sh", (char* const*)argv, environ); 4564 4565 // execve failed 4566 _exit(-1); 4567 4568 } else { 4569 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 4570 // care about the actual exit code, for now. 4571 4572 int status; 4573 4574 // Wait for the child process to exit. This returns immediately if 4575 // the child has already exited. */ 4576 while (waitpid(pid, &status, 0) < 0) { 4577 switch (errno) { 4578 case ECHILD: return 0; 4579 case EINTR: break; 4580 default: return -1; 4581 } 4582 } 4583 4584 if (WIFEXITED(status)) { 4585 // The child exited normally; get its exit code. 4586 return WEXITSTATUS(status); 4587 } else if (WIFSIGNALED(status)) { 4588 // The child exited because of a signal 4589 // The best value to return is 0x80 + signal number, 4590 // because that is what all Unix shells do, and because 4591 // it allows callers to distinguish between process exit and 4592 // process death by signal. 4593 return 0x80 + WTERMSIG(status); 4594 } else { 4595 // Unknown exit code; pass it through 4596 return status; 4597 } 4598 } 4599 } 4600 4601 // is_headless_jre() 4602 // 4603 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 4604 // in order to report if we are running in a headless jre 4605 // 4606 // Since JDK8 xawt/libmawt.so was moved into the same directory 4607 // as libawt.so, and renamed libawt_xawt.so 4608 // 4609 bool os::is_headless_jre() { 4610 #ifdef __APPLE__ 4611 // We no longer build headless-only on Mac OS X 4612 return false; 4613 #else 4614 struct stat statbuf; 4615 char buf[MAXPATHLEN]; 4616 char libmawtpath[MAXPATHLEN]; 4617 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX; 4618 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX; 4619 char *p; 4620 4621 // Get path to libjvm.so 4622 os::jvm_path(buf, sizeof(buf)); 4623 4624 // Get rid of libjvm.so 4625 p = strrchr(buf, '/'); 4626 if (p == NULL) return false; 4627 else *p = '\0'; 4628 4629 // Get rid of client or server 4630 p = strrchr(buf, '/'); 4631 if (p == NULL) return false; 4632 else *p = '\0'; 4633 4634 // check xawt/libmawt.so 4635 strcpy(libmawtpath, buf); 4636 strcat(libmawtpath, xawtstr); 4637 if (::stat(libmawtpath, &statbuf) == 0) return false; 4638 4639 // check libawt_xawt.so 4640 strcpy(libmawtpath, buf); 4641 strcat(libmawtpath, new_xawtstr); 4642 if (::stat(libmawtpath, &statbuf) == 0) return false; 4643 4644 return true; 4645 #endif 4646 } 4647 4648 // Get the default path to the core file 4649 // Returns the length of the string 4650 int os::get_core_path(char* buffer, size_t bufferSize) { 4651 int n = jio_snprintf(buffer, bufferSize, "/cores"); 4652 4653 // Truncate if theoretical string was longer than bufferSize 4654 n = MIN2(n, (int)bufferSize); 4655 4656 return n; 4657 } 4658 4659 #ifndef PRODUCT 4660 void TestReserveMemorySpecial_test() { 4661 // No tests available for this platform 4662 } 4663 #endif