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_bsd.inline.hpp" 40 #include "os_share_bsd.hpp" 41 #include "prims/jniFastGetField.hpp" 42 #include "prims/jvm.h" 43 #include "prims/jvm_misc.hpp" 44 #include "runtime/arguments.hpp" 45 #include "runtime/atomic.inline.hpp" 46 #include "runtime/extendedPC.hpp" 47 #include "runtime/globals.hpp" 48 #include "runtime/interfaceSupport.hpp" 49 #include "runtime/java.hpp" 50 #include "runtime/javaCalls.hpp" 51 #include "runtime/mutexLocker.hpp" 52 #include "runtime/objectMonitor.hpp" 53 #include "runtime/orderAccess.inline.hpp" 54 #include "runtime/osThread.hpp" 55 #include "runtime/perfMemory.hpp" 56 #include "runtime/sharedRuntime.hpp" 57 #include "runtime/statSampler.hpp" 58 #include "runtime/stubRoutines.hpp" 59 #include "runtime/thread.inline.hpp" 60 #include "runtime/threadCritical.hpp" 61 #include "runtime/timer.hpp" 62 #include "services/attachListener.hpp" 63 #include "services/memTracker.hpp" 64 #include "services/runtimeService.hpp" 65 #include "utilities/decoder.hpp" 66 #include "utilities/defaultStream.hpp" 67 #include "utilities/events.hpp" 68 #include "utilities/growableArray.hpp" 69 #include "utilities/vmError.hpp" 70 71 // put OS-includes here 72 # include <sys/types.h> 73 # include <sys/mman.h> 74 # include <sys/stat.h> 75 # include <sys/select.h> 76 # include <pthread.h> 77 # include <signal.h> 78 # include <errno.h> 79 # include <dlfcn.h> 80 # include <stdio.h> 81 # include <unistd.h> 82 # include <sys/resource.h> 83 # include <pthread.h> 84 # include <sys/stat.h> 85 # include <sys/time.h> 86 # include <sys/times.h> 87 # include <sys/utsname.h> 88 # include <sys/socket.h> 89 # include <sys/wait.h> 90 # include <time.h> 91 # include <pwd.h> 92 # include <poll.h> 93 # include <semaphore.h> 94 # include <fcntl.h> 95 # include <string.h> 96 # include <sys/param.h> 97 # include <sys/sysctl.h> 98 # include <sys/ipc.h> 99 # include <sys/shm.h> 100 #ifndef __APPLE__ 101 # include <link.h> 102 #endif 103 # include <stdint.h> 104 # include <inttypes.h> 105 # include <sys/ioctl.h> 106 # include <sys/syscall.h> 107 108 #if defined(__FreeBSD__) || defined(__NetBSD__) 109 #include <elf.h> 110 #endif 111 112 #ifdef __APPLE__ 113 #include <mach/mach.h> // semaphore_* API 114 #include <mach-o/dyld.h> 115 #include <sys/proc_info.h> 116 #include <objc/objc-auto.h> 117 #endif 118 119 #ifndef MAP_ANONYMOUS 120 #define MAP_ANONYMOUS MAP_ANON 121 #endif 122 123 #define MAX_PATH (2 * K) 124 125 // for timer info max values which include all bits 126 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 127 128 #define LARGEPAGES_BIT (1 << 6) 129 130 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 131 132 //////////////////////////////////////////////////////////////////////////////// 133 // global variables 134 julong os::Bsd::_physical_memory = 0; 135 136 #ifdef __APPLE__ 137 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0}; 138 volatile uint64_t os::Bsd::_max_abstime = 0; 139 #else 140 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; 141 #endif 142 pthread_t os::Bsd::_main_thread; 143 int os::Bsd::_page_size = -1; 144 145 static jlong initial_time_count=0; 146 147 static int clock_tics_per_sec = 100; 148 149 // For diagnostics to print a message once. see run_periodic_checks 150 static sigset_t check_signal_done; 151 static bool check_signals = true; 152 153 static pid_t _initial_pid = 0; 154 155 // Signal number used to suspend/resume a thread 156 157 // do not use any signal number less than SIGSEGV, see 4355769 158 static int SR_signum = SIGUSR2; 159 sigset_t SR_sigset; 160 161 162 //////////////////////////////////////////////////////////////////////////////// 163 // utility functions 164 165 static int SR_initialize(); 166 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time); 167 168 julong os::available_memory() { 169 return Bsd::available_memory(); 170 } 171 172 // available here means free 173 julong os::Bsd::available_memory() { 174 uint64_t available = physical_memory() >> 2; 175 #ifdef __APPLE__ 176 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT; 177 vm_statistics64_data_t vmstat; 178 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64, 179 (host_info64_t)&vmstat, &count); 180 assert(kerr == KERN_SUCCESS, 181 "host_statistics64 failed - check mach_host_self() and count"); 182 if (kerr == KERN_SUCCESS) { 183 available = vmstat.free_count * os::vm_page_size(); 184 } 185 #endif 186 return available; 187 } 188 189 julong os::physical_memory() { 190 return Bsd::physical_memory(); 191 } 192 193 //////////////////////////////////////////////////////////////////////////////// 194 // environment support 195 196 bool os::getenv(const char* name, char* buf, int len) { 197 const char* val = ::getenv(name); 198 if (val != NULL && strlen(val) < (size_t)len) { 199 strcpy(buf, val); 200 return true; 201 } 202 if (len > 0) buf[0] = 0; // return a null string 203 return false; 204 } 205 206 207 // Return true if user is running as root. 208 209 bool os::have_special_privileges() { 210 static bool init = false; 211 static bool privileges = false; 212 if (!init) { 213 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 214 init = true; 215 } 216 return privileges; 217 } 218 219 220 221 // Cpu architecture string 222 #if defined(ZERO) 223 static char cpu_arch[] = ZERO_LIBARCH; 224 #elif defined(IA64) 225 static char cpu_arch[] = "ia64"; 226 #elif defined(IA32) 227 static char cpu_arch[] = "i386"; 228 #elif defined(AMD64) 229 static char cpu_arch[] = "amd64"; 230 #elif defined(ARM) 231 static char cpu_arch[] = "arm"; 232 #elif defined(PPC32) 233 static char cpu_arch[] = "ppc"; 234 #elif defined(SPARC) 235 #ifdef _LP64 236 static char cpu_arch[] = "sparcv9"; 237 #else 238 static char cpu_arch[] = "sparc"; 239 #endif 240 #else 241 #error Add appropriate cpu_arch setting 242 #endif 243 244 // Compiler variant 245 #ifdef COMPILER2 246 #define COMPILER_VARIANT "server" 247 #else 248 #define COMPILER_VARIANT "client" 249 #endif 250 251 252 void os::Bsd::initialize_system_info() { 253 int mib[2]; 254 size_t len; 255 int cpu_val; 256 julong mem_val; 257 258 // get processors count via hw.ncpus sysctl 259 mib[0] = CTL_HW; 260 mib[1] = HW_NCPU; 261 len = sizeof(cpu_val); 262 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) { 263 assert(len == sizeof(cpu_val), "unexpected data size"); 264 set_processor_count(cpu_val); 265 } else { 266 set_processor_count(1); // fallback 267 } 268 269 // get physical memory via hw.memsize sysctl (hw.memsize is used 270 // since it returns a 64 bit value) 271 mib[0] = CTL_HW; 272 273 #if defined (HW_MEMSIZE) // Apple 274 mib[1] = HW_MEMSIZE; 275 #elif defined(HW_PHYSMEM) // Most of BSD 276 mib[1] = HW_PHYSMEM; 277 #elif defined(HW_REALMEM) // Old FreeBSD 278 mib[1] = HW_REALMEM; 279 #else 280 #error No ways to get physmem 281 #endif 282 283 len = sizeof(mem_val); 284 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) { 285 assert(len == sizeof(mem_val), "unexpected data size"); 286 _physical_memory = mem_val; 287 } else { 288 _physical_memory = 256 * 1024 * 1024; // fallback (XXXBSD?) 289 } 290 291 #ifdef __OpenBSD__ 292 { 293 // limit _physical_memory memory view on OpenBSD since 294 // datasize rlimit restricts us anyway. 295 struct rlimit limits; 296 getrlimit(RLIMIT_DATA, &limits); 297 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur); 298 } 299 #endif 300 } 301 302 #ifdef __APPLE__ 303 static const char *get_home() { 304 const char *home_dir = ::getenv("HOME"); 305 if ((home_dir == NULL) || (*home_dir == '\0')) { 306 struct passwd *passwd_info = getpwuid(geteuid()); 307 if (passwd_info != NULL) { 308 home_dir = passwd_info->pw_dir; 309 } 310 } 311 312 return home_dir; 313 } 314 #endif 315 316 void os::init_system_properties_values() { 317 // The next steps are taken in the product version: 318 // 319 // Obtain the JAVA_HOME value from the location of libjvm.so. 320 // This library should be located at: 321 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so. 322 // 323 // If "/jre/lib/" appears at the right place in the path, then we 324 // assume libjvm.so is installed in a JDK and we use this path. 325 // 326 // Otherwise exit with message: "Could not create the Java virtual machine." 327 // 328 // The following extra steps are taken in the debugging version: 329 // 330 // If "/jre/lib/" does NOT appear at the right place in the path 331 // instead of exit check for $JAVA_HOME environment variable. 332 // 333 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 334 // then we append a fake suffix "hotspot/libjvm.so" to this path so 335 // it looks like libjvm.so is installed there 336 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 337 // 338 // Otherwise exit. 339 // 340 // Important note: if the location of libjvm.so changes this 341 // code needs to be changed accordingly. 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 #ifndef DEFAULT_LIBPATH 350 #define DEFAULT_LIBPATH "/lib:/usr/lib" 351 #endif 352 353 // Base path of extensions installed on the system. 354 #define SYS_EXT_DIR "/usr/java/packages" 355 #define EXTENSIONS_DIR "/lib/ext" 356 357 #ifndef __APPLE__ 358 359 // Buffer that fits several sprintfs. 360 // Note that the space for the colon and the trailing null are provided 361 // by the nulls included by the sizeof operator. 362 const size_t bufsize = 363 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. 364 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir 365 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 366 367 // sysclasspath, java_home, dll_dir 368 { 369 char *pslash; 370 os::jvm_path(buf, bufsize); 371 372 // Found the full path to libjvm.so. 373 // Now cut the path to <java_home>/jre if we can. 374 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 375 pslash = strrchr(buf, '/'); 376 if (pslash != NULL) { 377 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 378 } 379 Arguments::set_dll_dir(buf); 380 381 if (pslash != NULL) { 382 pslash = strrchr(buf, '/'); 383 if (pslash != NULL) { 384 *pslash = '\0'; // Get rid of /<arch>. 385 pslash = strrchr(buf, '/'); 386 if (pslash != NULL) { 387 *pslash = '\0'; // Get rid of /lib. 388 } 389 } 390 } 391 Arguments::set_java_home(buf); 392 set_boot_path('/', ':'); 393 } 394 395 // Where to look for native libraries. 396 // 397 // Note: Due to a legacy implementation, most of the library path 398 // is set in the launcher. This was to accomodate linking restrictions 399 // on legacy Bsd implementations (which are no longer supported). 400 // Eventually, all the library path setting will be done here. 401 // 402 // However, to prevent the proliferation of improperly built native 403 // libraries, the new path component /usr/java/packages is added here. 404 // Eventually, all the library path setting will be done here. 405 { 406 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 407 // should always exist (until the legacy problem cited above is 408 // addressed). 409 const char *v = ::getenv("LD_LIBRARY_PATH"); 410 const char *v_colon = ":"; 411 if (v == NULL) { v = ""; v_colon = ""; } 412 // That's +1 for the colon and +1 for the trailing '\0'. 413 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 414 strlen(v) + 1 + 415 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1, 416 mtInternal); 417 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch); 418 Arguments::set_library_path(ld_library_path); 419 FREE_C_HEAP_ARRAY(char, ld_library_path); 420 } 421 422 // Extensions directories. 423 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 424 Arguments::set_ext_dirs(buf); 425 426 FREE_C_HEAP_ARRAY(char, buf); 427 428 #else // __APPLE__ 429 430 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions" 431 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java" 432 433 const char *user_home_dir = get_home(); 434 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir. 435 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) + 436 sizeof(SYS_EXTENSIONS_DIRS); 437 438 // Buffer that fits several sprintfs. 439 // Note that the space for the colon and the trailing null are provided 440 // by the nulls included by the sizeof operator. 441 const size_t bufsize = 442 MAX2((size_t)MAXPATHLEN, // for dll_dir & friends. 443 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir 444 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 445 446 // sysclasspath, java_home, dll_dir 447 { 448 char *pslash; 449 os::jvm_path(buf, bufsize); 450 451 // Found the full path to libjvm.so. 452 // Now cut the path to <java_home>/jre if we can. 453 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 454 pslash = strrchr(buf, '/'); 455 if (pslash != NULL) { 456 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 457 } 458 Arguments::set_dll_dir(buf); 459 460 if (pslash != NULL) { 461 pslash = strrchr(buf, '/'); 462 if (pslash != NULL) { 463 *pslash = '\0'; // Get rid of /lib. 464 } 465 } 466 Arguments::set_java_home(buf); 467 set_boot_path('/', ':'); 468 } 469 470 // Where to look for native libraries. 471 // 472 // Note: Due to a legacy implementation, most of the library path 473 // is set in the launcher. This was to accomodate linking restrictions 474 // on legacy Bsd implementations (which are no longer supported). 475 // Eventually, all the library path setting will be done here. 476 // 477 // However, to prevent the proliferation of improperly built native 478 // libraries, the new path component /usr/java/packages is added here. 479 // Eventually, all the library path setting will be done here. 480 { 481 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 482 // should always exist (until the legacy problem cited above is 483 // addressed). 484 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code 485 // can specify a directory inside an app wrapper 486 const char *l = ::getenv("JAVA_LIBRARY_PATH"); 487 const char *l_colon = ":"; 488 if (l == NULL) { l = ""; l_colon = ""; } 489 490 const char *v = ::getenv("DYLD_LIBRARY_PATH"); 491 const char *v_colon = ":"; 492 if (v == NULL) { v = ""; v_colon = ""; } 493 494 // Apple's Java6 has "." at the beginning of java.library.path. 495 // OpenJDK on Windows has "." at the end of java.library.path. 496 // OpenJDK on Linux and Solaris don't have "." in java.library.path 497 // at all. To ease the transition from Apple's Java6 to OpenJDK7, 498 // "." is appended to the end of java.library.path. Yes, this 499 // could cause a change in behavior, but Apple's Java6 behavior 500 // can be achieved by putting "." at the beginning of the 501 // JAVA_LIBRARY_PATH environment variable. 502 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 503 strlen(v) + 1 + strlen(l) + 1 + 504 system_ext_size + 3, 505 mtInternal); 506 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.", 507 v, v_colon, l, l_colon, user_home_dir); 508 Arguments::set_library_path(ld_library_path); 509 FREE_C_HEAP_ARRAY(char, ld_library_path); 510 } 511 512 // Extensions directories. 513 // 514 // Note that the space for the colon and the trailing null are provided 515 // by the nulls included by the sizeof operator (so actually one byte more 516 // than necessary is allocated). 517 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, 518 user_home_dir, Arguments::get_java_home()); 519 Arguments::set_ext_dirs(buf); 520 521 FREE_C_HEAP_ARRAY(char, buf); 522 523 #undef SYS_EXTENSIONS_DIR 524 #undef SYS_EXTENSIONS_DIRS 525 526 #endif // __APPLE__ 527 528 #undef SYS_EXT_DIR 529 #undef EXTENSIONS_DIR 530 } 531 532 //////////////////////////////////////////////////////////////////////////////// 533 // breakpoint support 534 535 void os::breakpoint() { 536 BREAKPOINT; 537 } 538 539 extern "C" void breakpoint() { 540 // use debugger to set breakpoint here 541 } 542 543 //////////////////////////////////////////////////////////////////////////////// 544 // signal support 545 546 debug_only(static bool signal_sets_initialized = false); 547 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 548 549 bool os::Bsd::is_sig_ignored(int sig) { 550 struct sigaction oact; 551 sigaction(sig, (struct sigaction*)NULL, &oact); 552 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 553 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 554 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) { 555 return true; 556 } else { 557 return false; 558 } 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 } 604 debug_only(signal_sets_initialized = true); 605 606 } 607 608 // These are signals that are unblocked while a thread is running Java. 609 // (For some reason, they get blocked by default.) 610 sigset_t* os::Bsd::unblocked_signals() { 611 assert(signal_sets_initialized, "Not initialized"); 612 return &unblocked_sigs; 613 } 614 615 // These are the signals that are blocked while a (non-VM) thread is 616 // running Java. Only the VM thread handles these signals. 617 sigset_t* os::Bsd::vm_signals() { 618 assert(signal_sets_initialized, "Not initialized"); 619 return &vm_sigs; 620 } 621 622 // These are signals that are blocked during cond_wait to allow debugger in 623 sigset_t* os::Bsd::allowdebug_blocked_signals() { 624 assert(signal_sets_initialized, "Not initialized"); 625 return &allowdebug_blocked_sigs; 626 } 627 628 void os::Bsd::hotspot_sigmask(Thread* thread) { 629 630 //Save caller's signal mask before setting VM signal mask 631 sigset_t caller_sigmask; 632 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 633 634 OSThread* osthread = thread->osthread(); 635 osthread->set_caller_sigmask(caller_sigmask); 636 637 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); 638 639 if (!ReduceSignalUsage) { 640 if (thread->is_VM_thread()) { 641 // Only the VM thread handles BREAK_SIGNAL ... 642 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 643 } else { 644 // ... all other threads block BREAK_SIGNAL 645 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 646 } 647 } 648 } 649 650 651 ////////////////////////////////////////////////////////////////////////////// 652 // create new thread 653 654 // check if it's safe to start a new thread 655 static bool _thread_safety_check(Thread* thread) { 656 return true; 657 } 658 659 #ifdef __APPLE__ 660 // library handle for calling objc_registerThreadWithCollector() 661 // without static linking to the libobjc library 662 #define OBJC_LIB "/usr/lib/libobjc.dylib" 663 #define OBJC_GCREGISTER "objc_registerThreadWithCollector" 664 typedef void (*objc_registerThreadWithCollector_t)(); 665 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction; 666 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL; 667 #endif 668 669 #ifdef __APPLE__ 670 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) { 671 // Additional thread_id used to correlate threads in SA 672 thread_identifier_info_data_t m_ident_info; 673 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT; 674 675 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO, 676 (thread_info_t) &m_ident_info, &count); 677 678 return m_ident_info.thread_id; 679 } 680 #endif 681 682 // Thread start routine for all newly created threads 683 static void *java_start(Thread *thread) { 684 // Try to randomize the cache line index of hot stack frames. 685 // This helps when threads of the same stack traces evict each other's 686 // cache lines. The threads can be either from the same JVM instance, or 687 // from different JVM instances. The benefit is especially true for 688 // processors with hyperthreading technology. 689 static int counter = 0; 690 int pid = os::current_process_id(); 691 alloca(((pid ^ counter++) & 7) * 128); 692 693 ThreadLocalStorage::set_thread(thread); 694 695 OSThread* osthread = thread->osthread(); 696 Monitor* sync = osthread->startThread_lock(); 697 698 // non floating stack BsdThreads needs extra check, see above 699 if (!_thread_safety_check(thread)) { 700 // notify parent thread 701 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 702 osthread->set_state(ZOMBIE); 703 sync->notify_all(); 704 return NULL; 705 } 706 707 osthread->set_thread_id(os::Bsd::gettid()); 708 709 #ifdef __APPLE__ 710 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 711 guarantee(unique_thread_id != 0, "unique thread id was not found"); 712 osthread->set_unique_thread_id(unique_thread_id); 713 #endif 714 // initialize signal mask for this thread 715 os::Bsd::hotspot_sigmask(thread); 716 717 // initialize floating point control register 718 os::Bsd::init_thread_fpu_state(); 719 720 #ifdef __APPLE__ 721 // register thread with objc gc 722 if (objc_registerThreadWithCollectorFunction != NULL) { 723 objc_registerThreadWithCollectorFunction(); 724 } 725 #endif 726 727 // handshaking with parent thread 728 { 729 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 730 731 // notify parent thread 732 osthread->set_state(INITIALIZED); 733 sync->notify_all(); 734 735 // wait until os::start_thread() 736 while (osthread->get_state() == INITIALIZED) { 737 sync->wait(Mutex::_no_safepoint_check_flag); 738 } 739 } 740 741 // call one more level start routine 742 thread->run(); 743 744 return 0; 745 } 746 747 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { 748 assert(thread->osthread() == NULL, "caller responsible"); 749 750 // Allocate the OSThread object 751 OSThread* osthread = new OSThread(NULL, NULL); 752 if (osthread == NULL) { 753 return false; 754 } 755 756 // set the correct thread state 757 osthread->set_thread_type(thr_type); 758 759 // Initial state is ALLOCATED but not INITIALIZED 760 osthread->set_state(ALLOCATED); 761 762 thread->set_osthread(osthread); 763 764 // init thread attributes 765 pthread_attr_t attr; 766 pthread_attr_init(&attr); 767 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 768 769 // stack size 770 if (os::Bsd::supports_variable_stack_size()) { 771 // calculate stack size if it's not specified by caller 772 if (stack_size == 0) { 773 stack_size = os::Bsd::default_stack_size(thr_type); 774 775 switch (thr_type) { 776 case os::java_thread: 777 // Java threads use ThreadStackSize which default value can be 778 // changed with the flag -Xss 779 assert(JavaThread::stack_size_at_create() > 0, "this should be set"); 780 stack_size = JavaThread::stack_size_at_create(); 781 break; 782 case os::compiler_thread: 783 if (CompilerThreadStackSize > 0) { 784 stack_size = (size_t)(CompilerThreadStackSize * K); 785 break; 786 } // else fall through: 787 // use VMThreadStackSize if CompilerThreadStackSize is not defined 788 case os::vm_thread: 789 case os::pgc_thread: 790 case os::cgc_thread: 791 case os::watcher_thread: 792 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 793 break; 794 } 795 } 796 797 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); 798 pthread_attr_setstacksize(&attr, stack_size); 799 } else { 800 // let pthread_create() pick the default value. 801 } 802 803 ThreadState state; 804 805 { 806 pthread_t tid; 807 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 808 809 pthread_attr_destroy(&attr); 810 811 if (ret != 0) { 812 if (PrintMiscellaneous && (Verbose || WizardMode)) { 813 perror("pthread_create()"); 814 } 815 // Need to clean up stuff we've allocated so far 816 thread->set_osthread(NULL); 817 delete osthread; 818 return false; 819 } 820 821 // Store pthread info into the OSThread 822 osthread->set_pthread_id(tid); 823 824 // Wait until child thread is either initialized or aborted 825 { 826 Monitor* sync_with_child = osthread->startThread_lock(); 827 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 828 while ((state = osthread->get_state()) == ALLOCATED) { 829 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 830 } 831 } 832 833 } 834 835 // Aborted due to thread limit being reached 836 if (state == ZOMBIE) { 837 thread->set_osthread(NULL); 838 delete osthread; 839 return false; 840 } 841 842 // The thread is returned suspended (in state INITIALIZED), 843 // and is started higher up in the call chain 844 assert(state == INITIALIZED, "race condition"); 845 return true; 846 } 847 848 ///////////////////////////////////////////////////////////////////////////// 849 // attach existing thread 850 851 // bootstrap the main thread 852 bool os::create_main_thread(JavaThread* thread) { 853 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); 854 return create_attached_thread(thread); 855 } 856 857 bool os::create_attached_thread(JavaThread* thread) { 858 #ifdef ASSERT 859 thread->verify_not_published(); 860 #endif 861 862 // Allocate the OSThread object 863 OSThread* osthread = new OSThread(NULL, NULL); 864 865 if (osthread == NULL) { 866 return false; 867 } 868 869 osthread->set_thread_id(os::Bsd::gettid()); 870 871 // Store pthread info into the OSThread 872 #ifdef __APPLE__ 873 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 874 guarantee(unique_thread_id != 0, "just checking"); 875 osthread->set_unique_thread_id(unique_thread_id); 876 #endif 877 osthread->set_pthread_id(::pthread_self()); 878 879 // initialize floating point control register 880 os::Bsd::init_thread_fpu_state(); 881 882 // Initial thread state is RUNNABLE 883 osthread->set_state(RUNNABLE); 884 885 thread->set_osthread(osthread); 886 887 // initialize signal mask for this thread 888 // and save the caller's signal mask 889 os::Bsd::hotspot_sigmask(thread); 890 891 return true; 892 } 893 894 void os::pd_start_thread(Thread* thread) { 895 OSThread * osthread = thread->osthread(); 896 assert(osthread->get_state() != INITIALIZED, "just checking"); 897 Monitor* sync_with_child = osthread->startThread_lock(); 898 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 899 sync_with_child->notify(); 900 } 901 902 // Free Bsd resources related to the OSThread 903 void os::free_thread(OSThread* osthread) { 904 assert(osthread != NULL, "osthread not set"); 905 906 if (Thread::current()->osthread() == osthread) { 907 // Restore caller's signal mask 908 sigset_t sigmask = osthread->caller_sigmask(); 909 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 910 } 911 912 delete osthread; 913 } 914 915 ////////////////////////////////////////////////////////////////////////////// 916 // thread local storage 917 918 // Restore the thread pointer if the destructor is called. This is in case 919 // someone from JNI code sets up a destructor with pthread_key_create to run 920 // detachCurrentThread on thread death. Unless we restore the thread pointer we 921 // will hang or crash. When detachCurrentThread is called the key will be set 922 // to null and we will not be called again. If detachCurrentThread is never 923 // called we could loop forever depending on the pthread implementation. 924 static void restore_thread_pointer(void* p) { 925 Thread* thread = (Thread*) p; 926 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread); 927 } 928 929 int os::allocate_thread_local_storage() { 930 pthread_key_t key; 931 int rslt = pthread_key_create(&key, restore_thread_pointer); 932 assert(rslt == 0, "cannot allocate thread local storage"); 933 return (int)key; 934 } 935 936 // Note: This is currently not used by VM, as we don't destroy TLS key 937 // on VM exit. 938 void os::free_thread_local_storage(int index) { 939 int rslt = pthread_key_delete((pthread_key_t)index); 940 assert(rslt == 0, "invalid index"); 941 } 942 943 void os::thread_local_storage_at_put(int index, void* value) { 944 int rslt = pthread_setspecific((pthread_key_t)index, value); 945 assert(rslt == 0, "pthread_setspecific failed"); 946 } 947 948 extern "C" Thread* get_thread() { 949 return ThreadLocalStorage::thread(); 950 } 951 952 953 //////////////////////////////////////////////////////////////////////////////// 954 // time support 955 956 // Time since start-up in seconds to a fine granularity. 957 // Used by VMSelfDestructTimer and the MemProfiler. 958 double os::elapsedTime() { 959 960 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); 961 } 962 963 jlong os::elapsed_counter() { 964 return javaTimeNanos() - initial_time_count; 965 } 966 967 jlong os::elapsed_frequency() { 968 return NANOSECS_PER_SEC; // nanosecond resolution 969 } 970 971 bool os::supports_vtime() { return true; } 972 bool os::enable_vtime() { return false; } 973 bool os::vtime_enabled() { return false; } 974 975 double os::elapsedVTime() { 976 // better than nothing, but not much 977 return elapsedTime(); 978 } 979 980 jlong os::javaTimeMillis() { 981 timeval time; 982 int status = gettimeofday(&time, NULL); 983 assert(status != -1, "bsd error"); 984 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 985 } 986 987 #ifndef __APPLE__ 988 #ifndef CLOCK_MONOTONIC 989 #define CLOCK_MONOTONIC (1) 990 #endif 991 #endif 992 993 #ifdef __APPLE__ 994 void os::Bsd::clock_init() { 995 mach_timebase_info(&_timebase_info); 996 } 997 #else 998 void os::Bsd::clock_init() { 999 struct timespec res; 1000 struct timespec tp; 1001 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && 1002 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { 1003 // yes, monotonic clock is supported 1004 _clock_gettime = ::clock_gettime; 1005 } 1006 } 1007 #endif 1008 1009 1010 1011 #ifdef __APPLE__ 1012 1013 jlong os::javaTimeNanos() { 1014 const uint64_t tm = mach_absolute_time(); 1015 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom; 1016 const uint64_t prev = Bsd::_max_abstime; 1017 if (now <= prev) { 1018 return prev; // same or retrograde time; 1019 } 1020 const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev); 1021 assert(obsv >= prev, "invariant"); // Monotonicity 1022 // If the CAS succeeded then we're done and return "now". 1023 // If the CAS failed and the observed value "obsv" is >= now then 1024 // we should return "obsv". If the CAS failed and now > obsv > prv then 1025 // some other thread raced this thread and installed a new value, in which case 1026 // we could either (a) retry the entire operation, (b) retry trying to install now 1027 // or (c) just return obsv. We use (c). No loop is required although in some cases 1028 // we might discard a higher "now" value in deference to a slightly lower but freshly 1029 // installed obsv value. That's entirely benign -- it admits no new orderings compared 1030 // to (a) or (b) -- and greatly reduces coherence traffic. 1031 // We might also condition (c) on the magnitude of the delta between obsv and now. 1032 // Avoiding excessive CAS operations to hot RW locations is critical. 1033 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate 1034 return (prev == obsv) ? now : obsv; 1035 } 1036 1037 #else // __APPLE__ 1038 1039 jlong os::javaTimeNanos() { 1040 if (os::supports_monotonic_clock()) { 1041 struct timespec tp; 1042 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp); 1043 assert(status == 0, "gettime error"); 1044 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1045 return result; 1046 } else { 1047 timeval time; 1048 int status = gettimeofday(&time, NULL); 1049 assert(status != -1, "bsd error"); 1050 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1051 return 1000 * usecs; 1052 } 1053 } 1054 1055 #endif // __APPLE__ 1056 1057 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1058 if (os::supports_monotonic_clock()) { 1059 info_ptr->max_value = ALL_64_BITS; 1060 1061 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1062 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1063 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1064 } else { 1065 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1066 info_ptr->max_value = ALL_64_BITS; 1067 1068 // gettimeofday is a real time clock so it skips 1069 info_ptr->may_skip_backward = true; 1070 info_ptr->may_skip_forward = true; 1071 } 1072 1073 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1074 } 1075 1076 // Return the real, user, and system times in seconds from an 1077 // arbitrary fixed point in the past. 1078 bool os::getTimesSecs(double* process_real_time, 1079 double* process_user_time, 1080 double* process_system_time) { 1081 struct tms ticks; 1082 clock_t real_ticks = times(&ticks); 1083 1084 if (real_ticks == (clock_t) (-1)) { 1085 return false; 1086 } else { 1087 double ticks_per_second = (double) clock_tics_per_sec; 1088 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1089 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1090 *process_real_time = ((double) real_ticks) / ticks_per_second; 1091 1092 return true; 1093 } 1094 } 1095 1096 1097 char * os::local_time_string(char *buf, size_t buflen) { 1098 struct tm t; 1099 time_t long_time; 1100 time(&long_time); 1101 localtime_r(&long_time, &t); 1102 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1103 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1104 t.tm_hour, t.tm_min, t.tm_sec); 1105 return buf; 1106 } 1107 1108 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1109 return localtime_r(clock, res); 1110 } 1111 1112 //////////////////////////////////////////////////////////////////////////////// 1113 // runtime exit support 1114 1115 // Note: os::shutdown() might be called very early during initialization, or 1116 // called from signal handler. Before adding something to os::shutdown(), make 1117 // sure it is async-safe and can handle partially initialized VM. 1118 void os::shutdown() { 1119 1120 // allow PerfMemory to attempt cleanup of any persistent resources 1121 perfMemory_exit(); 1122 1123 // needs to remove object in file system 1124 AttachListener::abort(); 1125 1126 // flush buffered output, finish log files 1127 ostream_abort(); 1128 1129 // Check for abort hook 1130 abort_hook_t abort_hook = Arguments::abort_hook(); 1131 if (abort_hook != NULL) { 1132 abort_hook(); 1133 } 1134 1135 } 1136 1137 // Note: os::abort() might be called very early during initialization, or 1138 // called from signal handler. Before adding something to os::abort(), make 1139 // sure it is async-safe and can handle partially initialized VM. 1140 void os::abort(bool dump_core) { 1141 os::shutdown(); 1142 if (dump_core) { 1143 #ifndef PRODUCT 1144 fdStream out(defaultStream::output_fd()); 1145 out.print_raw("Current thread is "); 1146 char buf[16]; 1147 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1148 out.print_raw_cr(buf); 1149 out.print_raw_cr("Dumping core ..."); 1150 #endif 1151 ::abort(); // dump core 1152 } 1153 1154 ::exit(1); 1155 } 1156 1157 // Die immediately, no exit hook, no abort hook, no cleanup. 1158 void os::die() { 1159 // _exit() on BsdThreads only kills current thread 1160 ::abort(); 1161 } 1162 1163 // This method is a copy of JDK's sysGetLastErrorString 1164 // from src/solaris/hpi/src/system_md.c 1165 1166 size_t os::lasterror(char *buf, size_t len) { 1167 if (errno == 0) return 0; 1168 1169 const char *s = ::strerror(errno); 1170 size_t n = ::strlen(s); 1171 if (n >= len) { 1172 n = len - 1; 1173 } 1174 ::strncpy(buf, s, n); 1175 buf[n] = '\0'; 1176 return n; 1177 } 1178 1179 // Information of current thread in variety of formats 1180 pid_t os::Bsd::gettid() { 1181 int retval = -1; 1182 1183 #ifdef __APPLE__ //XNU kernel 1184 // despite the fact mach port is actually not a thread id use it 1185 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4 1186 retval = ::pthread_mach_thread_np(::pthread_self()); 1187 guarantee(retval != 0, "just checking"); 1188 return retval; 1189 1190 #elif __FreeBSD__ 1191 retval = syscall(SYS_thr_self); 1192 #elif __OpenBSD__ 1193 retval = syscall(SYS_getthrid); 1194 #elif __NetBSD__ 1195 retval = (pid_t) syscall(SYS__lwp_self); 1196 #endif 1197 1198 if (retval == -1) { 1199 return getpid(); 1200 } 1201 } 1202 1203 intx os::current_thread_id() { 1204 #ifdef __APPLE__ 1205 return (intx)::pthread_mach_thread_np(::pthread_self()); 1206 #else 1207 return (intx)::pthread_self(); 1208 #endif 1209 } 1210 1211 int os::current_process_id() { 1212 1213 // Under the old bsd thread library, bsd gives each thread 1214 // its own process id. Because of this each thread will return 1215 // a different pid if this method were to return the result 1216 // of getpid(2). Bsd provides no api that returns the pid 1217 // of the launcher thread for the vm. This implementation 1218 // returns a unique pid, the pid of the launcher thread 1219 // that starts the vm 'process'. 1220 1221 // Under the NPTL, getpid() returns the same pid as the 1222 // launcher thread rather than a unique pid per thread. 1223 // Use gettid() if you want the old pre NPTL behaviour. 1224 1225 // if you are looking for the result of a call to getpid() that 1226 // returns a unique pid for the calling thread, then look at the 1227 // OSThread::thread_id() method in osThread_bsd.hpp file 1228 1229 return (int)(_initial_pid ? _initial_pid : getpid()); 1230 } 1231 1232 // DLL functions 1233 1234 #define JNI_LIB_PREFIX "lib" 1235 #ifdef __APPLE__ 1236 #define JNI_LIB_SUFFIX ".dylib" 1237 #else 1238 #define JNI_LIB_SUFFIX ".so" 1239 #endif 1240 1241 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } 1242 1243 // This must be hard coded because it's the system's temporary 1244 // directory not the java application's temp directory, ala java.io.tmpdir. 1245 #ifdef __APPLE__ 1246 // macosx has a secure per-user temporary directory 1247 char temp_path_storage[PATH_MAX]; 1248 const char* os::get_temp_directory() { 1249 static char *temp_path = NULL; 1250 if (temp_path == NULL) { 1251 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX); 1252 if (pathSize == 0 || pathSize > PATH_MAX) { 1253 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage)); 1254 } 1255 temp_path = temp_path_storage; 1256 } 1257 return temp_path; 1258 } 1259 #else // __APPLE__ 1260 const char* os::get_temp_directory() { return "/tmp"; } 1261 #endif // __APPLE__ 1262 1263 static bool file_exists(const char* filename) { 1264 struct stat statbuf; 1265 if (filename == NULL || strlen(filename) == 0) { 1266 return false; 1267 } 1268 return os::stat(filename, &statbuf) == 0; 1269 } 1270 1271 bool os::dll_build_name(char* buffer, size_t buflen, 1272 const char* pname, const char* fname) { 1273 bool retval = false; 1274 // Copied from libhpi 1275 const size_t pnamelen = pname ? strlen(pname) : 0; 1276 1277 // Return error on buffer overflow. 1278 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { 1279 return retval; 1280 } 1281 1282 if (pnamelen == 0) { 1283 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); 1284 retval = true; 1285 } else if (strchr(pname, *os::path_separator()) != NULL) { 1286 int n; 1287 char** pelements = split_path(pname, &n); 1288 if (pelements == NULL) { 1289 return false; 1290 } 1291 for (int i = 0; i < n; i++) { 1292 // Really shouldn't be NULL, but check can't hurt 1293 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1294 continue; // skip the empty path values 1295 } 1296 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, 1297 pelements[i], fname); 1298 if (file_exists(buffer)) { 1299 retval = true; 1300 break; 1301 } 1302 } 1303 // release the storage 1304 for (int i = 0; i < n; i++) { 1305 if (pelements[i] != NULL) { 1306 FREE_C_HEAP_ARRAY(char, pelements[i]); 1307 } 1308 } 1309 if (pelements != NULL) { 1310 FREE_C_HEAP_ARRAY(char*, pelements); 1311 } 1312 } else { 1313 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); 1314 retval = true; 1315 } 1316 return retval; 1317 } 1318 1319 // check if addr is inside libjvm.so 1320 bool os::address_is_in_vm(address addr) { 1321 static address libjvm_base_addr; 1322 Dl_info dlinfo; 1323 1324 if (libjvm_base_addr == NULL) { 1325 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1326 libjvm_base_addr = (address)dlinfo.dli_fbase; 1327 } 1328 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1329 } 1330 1331 if (dladdr((void *)addr, &dlinfo) != 0) { 1332 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1333 } 1334 1335 return false; 1336 } 1337 1338 1339 #define MACH_MAXSYMLEN 256 1340 1341 bool os::dll_address_to_function_name(address addr, char *buf, 1342 int buflen, int *offset) { 1343 // buf is not optional, but offset is optional 1344 assert(buf != NULL, "sanity check"); 1345 1346 Dl_info dlinfo; 1347 char localbuf[MACH_MAXSYMLEN]; 1348 1349 if (dladdr((void*)addr, &dlinfo) != 0) { 1350 // see if we have a matching symbol 1351 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1352 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { 1353 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1354 } 1355 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1356 return true; 1357 } 1358 // no matching symbol so try for just file info 1359 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1360 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1361 buf, buflen, offset, dlinfo.dli_fname)) { 1362 return true; 1363 } 1364 } 1365 1366 // Handle non-dynamic manually: 1367 if (dlinfo.dli_fbase != NULL && 1368 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) { 1369 if (!Decoder::demangle(localbuf, buf, buflen)) { 1370 jio_snprintf(buf, buflen, "%s", localbuf); 1371 } 1372 return true; 1373 } 1374 } 1375 buf[0] = '\0'; 1376 if (offset != NULL) *offset = -1; 1377 return false; 1378 } 1379 1380 // ported from solaris version 1381 bool os::dll_address_to_library_name(address addr, char* buf, 1382 int buflen, int* offset) { 1383 // buf is not optional, but offset is optional 1384 assert(buf != NULL, "sanity check"); 1385 1386 Dl_info dlinfo; 1387 1388 if (dladdr((void*)addr, &dlinfo) != 0) { 1389 if (dlinfo.dli_fname != NULL) { 1390 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1391 } 1392 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1393 *offset = addr - (address)dlinfo.dli_fbase; 1394 } 1395 return true; 1396 } 1397 1398 buf[0] = '\0'; 1399 if (offset) *offset = -1; 1400 return false; 1401 } 1402 1403 // Loads .dll/.so and 1404 // in case of error it checks if .dll/.so was built for the 1405 // same architecture as Hotspot is running on 1406 1407 #ifdef __APPLE__ 1408 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1409 void * result= ::dlopen(filename, RTLD_LAZY); 1410 if (result != NULL) { 1411 // Successful loading 1412 return result; 1413 } 1414 1415 // Read system error message into ebuf 1416 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1417 ebuf[ebuflen-1]='\0'; 1418 1419 return NULL; 1420 } 1421 #else 1422 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1423 void * result= ::dlopen(filename, RTLD_LAZY); 1424 if (result != NULL) { 1425 // Successful loading 1426 return result; 1427 } 1428 1429 Elf32_Ehdr elf_head; 1430 1431 // Read system error message into ebuf 1432 // It may or may not be overwritten below 1433 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1434 ebuf[ebuflen-1]='\0'; 1435 int diag_msg_max_length=ebuflen-strlen(ebuf); 1436 char* diag_msg_buf=ebuf+strlen(ebuf); 1437 1438 if (diag_msg_max_length==0) { 1439 // No more space in ebuf for additional diagnostics message 1440 return NULL; 1441 } 1442 1443 1444 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1445 1446 if (file_descriptor < 0) { 1447 // Can't open library, report dlerror() message 1448 return NULL; 1449 } 1450 1451 bool failed_to_read_elf_head= 1452 (sizeof(elf_head)!= 1453 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1454 1455 ::close(file_descriptor); 1456 if (failed_to_read_elf_head) { 1457 // file i/o error - report dlerror() msg 1458 return NULL; 1459 } 1460 1461 typedef struct { 1462 Elf32_Half code; // Actual value as defined in elf.h 1463 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1464 char elf_class; // 32 or 64 bit 1465 char endianess; // MSB or LSB 1466 char* name; // String representation 1467 } arch_t; 1468 1469 #ifndef EM_486 1470 #define EM_486 6 /* Intel 80486 */ 1471 #endif 1472 1473 #ifndef EM_MIPS_RS3_LE 1474 #define EM_MIPS_RS3_LE 10 /* MIPS */ 1475 #endif 1476 1477 #ifndef EM_PPC64 1478 #define EM_PPC64 21 /* PowerPC64 */ 1479 #endif 1480 1481 #ifndef EM_S390 1482 #define EM_S390 22 /* IBM System/390 */ 1483 #endif 1484 1485 #ifndef EM_IA_64 1486 #define EM_IA_64 50 /* HP/Intel IA-64 */ 1487 #endif 1488 1489 #ifndef EM_X86_64 1490 #define EM_X86_64 62 /* AMD x86-64 */ 1491 #endif 1492 1493 static const arch_t arch_array[]={ 1494 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1495 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1496 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1497 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1498 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1499 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1500 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1501 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1502 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1503 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1504 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1505 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1506 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1507 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1508 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1509 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} 1510 }; 1511 1512 #if (defined IA32) 1513 static Elf32_Half running_arch_code=EM_386; 1514 #elif (defined AMD64) 1515 static Elf32_Half running_arch_code=EM_X86_64; 1516 #elif (defined IA64) 1517 static Elf32_Half running_arch_code=EM_IA_64; 1518 #elif (defined __sparc) && (defined _LP64) 1519 static Elf32_Half running_arch_code=EM_SPARCV9; 1520 #elif (defined __sparc) && (!defined _LP64) 1521 static Elf32_Half running_arch_code=EM_SPARC; 1522 #elif (defined __powerpc64__) 1523 static Elf32_Half running_arch_code=EM_PPC64; 1524 #elif (defined __powerpc__) 1525 static Elf32_Half running_arch_code=EM_PPC; 1526 #elif (defined ARM) 1527 static Elf32_Half running_arch_code=EM_ARM; 1528 #elif (defined S390) 1529 static Elf32_Half running_arch_code=EM_S390; 1530 #elif (defined ALPHA) 1531 static Elf32_Half running_arch_code=EM_ALPHA; 1532 #elif (defined MIPSEL) 1533 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1534 #elif (defined PARISC) 1535 static Elf32_Half running_arch_code=EM_PARISC; 1536 #elif (defined MIPS) 1537 static Elf32_Half running_arch_code=EM_MIPS; 1538 #elif (defined M68K) 1539 static Elf32_Half running_arch_code=EM_68K; 1540 #else 1541 #error Method os::dll_load requires that one of following is defined:\ 1542 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K 1543 #endif 1544 1545 // Identify compatability class for VM's architecture and library's architecture 1546 // Obtain string descriptions for architectures 1547 1548 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1549 int running_arch_index=-1; 1550 1551 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1552 if (running_arch_code == arch_array[i].code) { 1553 running_arch_index = i; 1554 } 1555 if (lib_arch.code == arch_array[i].code) { 1556 lib_arch.compat_class = arch_array[i].compat_class; 1557 lib_arch.name = arch_array[i].name; 1558 } 1559 } 1560 1561 assert(running_arch_index != -1, 1562 "Didn't find running architecture code (running_arch_code) in arch_array"); 1563 if (running_arch_index == -1) { 1564 // Even though running architecture detection failed 1565 // we may still continue with reporting dlerror() message 1566 return NULL; 1567 } 1568 1569 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1570 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1571 return NULL; 1572 } 1573 1574 #ifndef S390 1575 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1576 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1577 return NULL; 1578 } 1579 #endif // !S390 1580 1581 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1582 if (lib_arch.name!=NULL) { 1583 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1584 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1585 lib_arch.name, arch_array[running_arch_index].name); 1586 } else { 1587 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1588 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1589 lib_arch.code, 1590 arch_array[running_arch_index].name); 1591 } 1592 } 1593 1594 return NULL; 1595 } 1596 #endif // !__APPLE__ 1597 1598 void* os::get_default_process_handle() { 1599 #ifdef __APPLE__ 1600 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY 1601 // to avoid finding unexpected symbols on second (or later) 1602 // loads of a library. 1603 return (void*)::dlopen(NULL, RTLD_FIRST); 1604 #else 1605 return (void*)::dlopen(NULL, RTLD_LAZY); 1606 #endif 1607 } 1608 1609 // XXX: Do we need a lock around this as per Linux? 1610 void* os::dll_lookup(void* handle, const char* name) { 1611 return dlsym(handle, name); 1612 } 1613 1614 1615 static bool _print_ascii_file(const char* filename, outputStream* st) { 1616 int fd = ::open(filename, O_RDONLY); 1617 if (fd == -1) { 1618 return false; 1619 } 1620 1621 char buf[32]; 1622 int bytes; 1623 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { 1624 st->print_raw(buf, bytes); 1625 } 1626 1627 ::close(fd); 1628 1629 return true; 1630 } 1631 1632 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) { 1633 outputStream * out = (outputStream *) param; 1634 out->print_cr(PTR_FORMAT " \t%s", base_address, name); 1635 return 0; 1636 } 1637 1638 void os::print_dll_info(outputStream *st) { 1639 st->print_cr("Dynamic libraries:"); 1640 if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) { 1641 st->print_cr("Error: Cannot print dynamic libraries."); 1642 } 1643 } 1644 1645 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1646 #ifdef RTLD_DI_LINKMAP 1647 Dl_info dli; 1648 void *handle; 1649 Link_map *map; 1650 Link_map *p; 1651 1652 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 || 1653 dli.dli_fname == NULL) { 1654 return 1; 1655 } 1656 handle = dlopen(dli.dli_fname, RTLD_LAZY); 1657 if (handle == NULL) { 1658 return 1; 1659 } 1660 dlinfo(handle, RTLD_DI_LINKMAP, &map); 1661 if (map == NULL) { 1662 dlclose(handle); 1663 return 1; 1664 } 1665 1666 while (map->l_prev != NULL) 1667 map = map->l_prev; 1668 1669 while (map != NULL) { 1670 // Value for top_address is returned as 0 since we don't have any information about module size 1671 if (callback(map->l_name, (address)map->l_addr, (address)0, param)) { 1672 dlclose(handle); 1673 return 1; 1674 } 1675 map = map->l_next; 1676 } 1677 1678 dlclose(handle); 1679 #elif defined(__APPLE__) 1680 for (uint32_t i = 1; i < _dyld_image_count(); i++) { 1681 // Value for top_address is returned as 0 since we don't have any information about module size 1682 if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) { 1683 return 1; 1684 } 1685 } 1686 return 0; 1687 #else 1688 return 1; 1689 #endif 1690 } 1691 1692 void os::print_os_info_brief(outputStream* st) { 1693 st->print("Bsd"); 1694 1695 os::Posix::print_uname_info(st); 1696 } 1697 1698 void os::print_os_info(outputStream* st) { 1699 st->print("OS:"); 1700 st->print("Bsd"); 1701 1702 os::Posix::print_uname_info(st); 1703 1704 os::Posix::print_rlimit_info(st); 1705 1706 os::Posix::print_load_average(st); 1707 } 1708 1709 void os::pd_print_cpu_info(outputStream* st) { 1710 // Nothing to do for now. 1711 } 1712 1713 void os::print_memory_info(outputStream* st) { 1714 1715 st->print("Memory:"); 1716 st->print(" %dk page", os::vm_page_size()>>10); 1717 1718 st->print(", physical " UINT64_FORMAT "k", 1719 os::physical_memory() >> 10); 1720 st->print("(" UINT64_FORMAT "k free)", 1721 os::available_memory() >> 10); 1722 st->cr(); 1723 1724 // meminfo 1725 st->print("\n/proc/meminfo:\n"); 1726 _print_ascii_file("/proc/meminfo", st); 1727 st->cr(); 1728 } 1729 1730 void os::print_siginfo(outputStream* st, void* siginfo) { 1731 const siginfo_t* si = (const siginfo_t*)siginfo; 1732 1733 os::Posix::print_siginfo_brief(st, si); 1734 1735 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && 1736 UseSharedSpaces) { 1737 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1738 if (mapinfo->is_in_shared_space(si->si_addr)) { 1739 st->print("\n\nError accessing class data sharing archive." \ 1740 " Mapped file inaccessible during execution, " \ 1741 " possible disk/network problem."); 1742 } 1743 } 1744 st->cr(); 1745 } 1746 1747 1748 static void print_signal_handler(outputStream* st, int sig, 1749 char* buf, size_t buflen); 1750 1751 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 1752 st->print_cr("Signal Handlers:"); 1753 print_signal_handler(st, SIGSEGV, buf, buflen); 1754 print_signal_handler(st, SIGBUS , buf, buflen); 1755 print_signal_handler(st, SIGFPE , buf, buflen); 1756 print_signal_handler(st, SIGPIPE, buf, buflen); 1757 print_signal_handler(st, SIGXFSZ, buf, buflen); 1758 print_signal_handler(st, SIGILL , buf, buflen); 1759 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); 1760 print_signal_handler(st, SR_signum, buf, buflen); 1761 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 1762 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 1763 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 1764 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 1765 } 1766 1767 static char saved_jvm_path[MAXPATHLEN] = {0}; 1768 1769 // Find the full path to the current module, libjvm 1770 void os::jvm_path(char *buf, jint buflen) { 1771 // Error checking. 1772 if (buflen < MAXPATHLEN) { 1773 assert(false, "must use a large-enough buffer"); 1774 buf[0] = '\0'; 1775 return; 1776 } 1777 // Lazy resolve the path to current module. 1778 if (saved_jvm_path[0] != 0) { 1779 strcpy(buf, saved_jvm_path); 1780 return; 1781 } 1782 1783 char dli_fname[MAXPATHLEN]; 1784 bool ret = dll_address_to_library_name( 1785 CAST_FROM_FN_PTR(address, os::jvm_path), 1786 dli_fname, sizeof(dli_fname), NULL); 1787 assert(ret, "cannot locate libjvm"); 1788 char *rp = NULL; 1789 if (ret && dli_fname[0] != '\0') { 1790 rp = realpath(dli_fname, buf); 1791 } 1792 if (rp == NULL) { 1793 return; 1794 } 1795 1796 if (Arguments::sun_java_launcher_is_altjvm()) { 1797 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 1798 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so" 1799 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/" 1800 // appears at the right place in the string, then assume we are 1801 // installed in a JDK and we're done. Otherwise, check for a 1802 // JAVA_HOME environment variable and construct a path to the JVM 1803 // being overridden. 1804 1805 const char *p = buf + strlen(buf) - 1; 1806 for (int count = 0; p > buf && count < 5; ++count) { 1807 for (--p; p > buf && *p != '/'; --p) 1808 /* empty */ ; 1809 } 1810 1811 if (strncmp(p, "/jre/lib/", 9) != 0) { 1812 // Look for JAVA_HOME in the environment. 1813 char* java_home_var = ::getenv("JAVA_HOME"); 1814 if (java_home_var != NULL && java_home_var[0] != 0) { 1815 char* jrelib_p; 1816 int len; 1817 1818 // Check the current module name "libjvm" 1819 p = strrchr(buf, '/'); 1820 assert(strstr(p, "/libjvm") == p, "invalid library name"); 1821 1822 rp = realpath(java_home_var, buf); 1823 if (rp == NULL) { 1824 return; 1825 } 1826 1827 // determine if this is a legacy image or modules image 1828 // modules image doesn't have "jre" subdirectory 1829 len = strlen(buf); 1830 assert(len < buflen, "Ran out of buffer space"); 1831 jrelib_p = buf + len; 1832 1833 // Add the appropriate library subdir 1834 snprintf(jrelib_p, buflen-len, "/jre/lib"); 1835 if (0 != access(buf, F_OK)) { 1836 snprintf(jrelib_p, buflen-len, "/lib"); 1837 } 1838 1839 // Add the appropriate client or server subdir 1840 len = strlen(buf); 1841 jrelib_p = buf + len; 1842 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT); 1843 if (0 != access(buf, F_OK)) { 1844 snprintf(jrelib_p, buflen-len, "%s", ""); 1845 } 1846 1847 // If the path exists within JAVA_HOME, add the JVM library name 1848 // to complete the path to JVM being overridden. Otherwise fallback 1849 // to the path to the current library. 1850 if (0 == access(buf, F_OK)) { 1851 // Use current module name "libjvm" 1852 len = strlen(buf); 1853 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX); 1854 } else { 1855 // Fall back to path of current library 1856 rp = realpath(dli_fname, buf); 1857 if (rp == NULL) { 1858 return; 1859 } 1860 } 1861 } 1862 } 1863 } 1864 1865 strncpy(saved_jvm_path, buf, MAXPATHLEN); 1866 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 1867 } 1868 1869 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 1870 // no prefix required, not even "_" 1871 } 1872 1873 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 1874 // no suffix required 1875 } 1876 1877 //////////////////////////////////////////////////////////////////////////////// 1878 // sun.misc.Signal support 1879 1880 static volatile jint sigint_count = 0; 1881 1882 static void UserHandler(int sig, void *siginfo, void *context) { 1883 // 4511530 - sem_post is serialized and handled by the manager thread. When 1884 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 1885 // don't want to flood the manager thread with sem_post requests. 1886 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 1887 return; 1888 } 1889 1890 // Ctrl-C is pressed during error reporting, likely because the error 1891 // handler fails to abort. Let VM die immediately. 1892 if (sig == SIGINT && is_error_reported()) { 1893 os::die(); 1894 } 1895 1896 os::signal_notify(sig); 1897 } 1898 1899 void* os::user_handler() { 1900 return CAST_FROM_FN_PTR(void*, UserHandler); 1901 } 1902 1903 extern "C" { 1904 typedef void (*sa_handler_t)(int); 1905 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1906 } 1907 1908 void* os::signal(int signal_number, void* handler) { 1909 struct sigaction sigAct, oldSigAct; 1910 1911 sigfillset(&(sigAct.sa_mask)); 1912 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 1913 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 1914 1915 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 1916 // -1 means registration failed 1917 return (void *)-1; 1918 } 1919 1920 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 1921 } 1922 1923 void os::signal_raise(int signal_number) { 1924 ::raise(signal_number); 1925 } 1926 1927 // The following code is moved from os.cpp for making this 1928 // code platform specific, which it is by its very nature. 1929 1930 // Will be modified when max signal is changed to be dynamic 1931 int os::sigexitnum_pd() { 1932 return NSIG; 1933 } 1934 1935 // a counter for each possible signal value 1936 static volatile jint pending_signals[NSIG+1] = { 0 }; 1937 1938 // Bsd(POSIX) specific hand shaking semaphore. 1939 #ifdef __APPLE__ 1940 typedef semaphore_t os_semaphore_t; 1941 1942 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) 1943 #define SEM_WAIT(sem) semaphore_wait(sem) 1944 #define SEM_POST(sem) semaphore_signal(sem) 1945 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem) 1946 #else 1947 typedef sem_t os_semaphore_t; 1948 1949 #define SEM_INIT(sem, value) sem_init(&sem, 0, value) 1950 #define SEM_WAIT(sem) sem_wait(&sem) 1951 #define SEM_POST(sem) sem_post(&sem) 1952 #define SEM_DESTROY(sem) sem_destroy(&sem) 1953 #endif 1954 1955 class Semaphore : public StackObj { 1956 public: 1957 Semaphore(); 1958 ~Semaphore(); 1959 void signal(); 1960 void wait(); 1961 bool trywait(); 1962 bool timedwait(unsigned int sec, int nsec); 1963 private: 1964 jlong currenttime() const; 1965 os_semaphore_t _semaphore; 1966 }; 1967 1968 Semaphore::Semaphore() : _semaphore(0) { 1969 SEM_INIT(_semaphore, 0); 1970 } 1971 1972 Semaphore::~Semaphore() { 1973 SEM_DESTROY(_semaphore); 1974 } 1975 1976 void Semaphore::signal() { 1977 SEM_POST(_semaphore); 1978 } 1979 1980 void Semaphore::wait() { 1981 SEM_WAIT(_semaphore); 1982 } 1983 1984 jlong Semaphore::currenttime() const { 1985 struct timeval tv; 1986 gettimeofday(&tv, NULL); 1987 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000); 1988 } 1989 1990 #ifdef __APPLE__ 1991 bool Semaphore::trywait() { 1992 return timedwait(0, 0); 1993 } 1994 1995 bool Semaphore::timedwait(unsigned int sec, int nsec) { 1996 kern_return_t kr = KERN_ABORTED; 1997 mach_timespec_t waitspec; 1998 waitspec.tv_sec = sec; 1999 waitspec.tv_nsec = nsec; 2000 2001 jlong starttime = currenttime(); 2002 2003 kr = semaphore_timedwait(_semaphore, waitspec); 2004 while (kr == KERN_ABORTED) { 2005 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec; 2006 2007 jlong current = currenttime(); 2008 jlong passedtime = current - starttime; 2009 2010 if (passedtime >= totalwait) { 2011 waitspec.tv_sec = 0; 2012 waitspec.tv_nsec = 0; 2013 } else { 2014 jlong waittime = totalwait - (current - starttime); 2015 waitspec.tv_sec = waittime / NANOSECS_PER_SEC; 2016 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC; 2017 } 2018 2019 kr = semaphore_timedwait(_semaphore, waitspec); 2020 } 2021 2022 return kr == KERN_SUCCESS; 2023 } 2024 2025 #else 2026 2027 bool Semaphore::trywait() { 2028 return sem_trywait(&_semaphore) == 0; 2029 } 2030 2031 bool Semaphore::timedwait(unsigned int sec, int nsec) { 2032 struct timespec ts; 2033 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec); 2034 2035 while (1) { 2036 int result = sem_timedwait(&_semaphore, &ts); 2037 if (result == 0) { 2038 return true; 2039 } else if (errno == EINTR) { 2040 continue; 2041 } else if (errno == ETIMEDOUT) { 2042 return false; 2043 } else { 2044 return false; 2045 } 2046 } 2047 } 2048 2049 #endif // __APPLE__ 2050 2051 static os_semaphore_t sig_sem; 2052 static Semaphore sr_semaphore; 2053 2054 void os::signal_init_pd() { 2055 // Initialize signal structures 2056 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2057 2058 // Initialize signal semaphore 2059 ::SEM_INIT(sig_sem, 0); 2060 } 2061 2062 void os::signal_notify(int sig) { 2063 Atomic::inc(&pending_signals[sig]); 2064 ::SEM_POST(sig_sem); 2065 } 2066 2067 static int check_pending_signals(bool wait) { 2068 Atomic::store(0, &sigint_count); 2069 for (;;) { 2070 for (int i = 0; i < NSIG + 1; i++) { 2071 jint n = pending_signals[i]; 2072 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2073 return i; 2074 } 2075 } 2076 if (!wait) { 2077 return -1; 2078 } 2079 JavaThread *thread = JavaThread::current(); 2080 ThreadBlockInVM tbivm(thread); 2081 2082 bool threadIsSuspended; 2083 do { 2084 thread->set_suspend_equivalent(); 2085 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2086 ::SEM_WAIT(sig_sem); 2087 2088 // were we externally suspended while we were waiting? 2089 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2090 if (threadIsSuspended) { 2091 // The semaphore has been incremented, but while we were waiting 2092 // another thread suspended us. We don't want to continue running 2093 // while suspended because that would surprise the thread that 2094 // suspended us. 2095 ::SEM_POST(sig_sem); 2096 2097 thread->java_suspend_self(); 2098 } 2099 } while (threadIsSuspended); 2100 } 2101 } 2102 2103 int os::signal_lookup() { 2104 return check_pending_signals(false); 2105 } 2106 2107 int os::signal_wait() { 2108 return check_pending_signals(true); 2109 } 2110 2111 //////////////////////////////////////////////////////////////////////////////// 2112 // Virtual Memory 2113 2114 int os::vm_page_size() { 2115 // Seems redundant as all get out 2116 assert(os::Bsd::page_size() != -1, "must call os::init"); 2117 return os::Bsd::page_size(); 2118 } 2119 2120 // Solaris allocates memory by pages. 2121 int os::vm_allocation_granularity() { 2122 assert(os::Bsd::page_size() != -1, "must call os::init"); 2123 return os::Bsd::page_size(); 2124 } 2125 2126 // Rationale behind this function: 2127 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2128 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2129 // samples for JITted code. Here we create private executable mapping over the code cache 2130 // and then we can use standard (well, almost, as mapping can change) way to provide 2131 // info for the reporting script by storing timestamp and location of symbol 2132 void bsd_wrap_code(char* base, size_t size) { 2133 static volatile jint cnt = 0; 2134 2135 if (!UseOprofile) { 2136 return; 2137 } 2138 2139 char buf[PATH_MAX + 1]; 2140 int num = Atomic::add(1, &cnt); 2141 2142 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", 2143 os::get_temp_directory(), os::current_process_id(), num); 2144 unlink(buf); 2145 2146 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2147 2148 if (fd != -1) { 2149 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2150 if (rv != (off_t)-1) { 2151 if (::write(fd, "", 1) == 1) { 2152 mmap(base, size, 2153 PROT_READ|PROT_WRITE|PROT_EXEC, 2154 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2155 } 2156 } 2157 ::close(fd); 2158 unlink(buf); 2159 } 2160 } 2161 2162 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2163 int err) { 2164 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2165 ", %d) failed; error='%s' (errno=%d)", addr, size, exec, 2166 strerror(err), err); 2167 } 2168 2169 // NOTE: Bsd kernel does not really reserve the pages for us. 2170 // All it does is to check if there are enough free pages 2171 // left at the time of mmap(). This could be a potential 2172 // problem. 2173 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2174 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2175 #ifdef __OpenBSD__ 2176 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2177 if (::mprotect(addr, size, prot) == 0) { 2178 return true; 2179 } 2180 #else 2181 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2182 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2183 if (res != (uintptr_t) MAP_FAILED) { 2184 return true; 2185 } 2186 #endif 2187 2188 // Warn about any commit errors we see in non-product builds just 2189 // in case mmap() doesn't work as described on the man page. 2190 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);) 2191 2192 return false; 2193 } 2194 2195 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2196 bool exec) { 2197 // alignment_hint is ignored on this OS 2198 return pd_commit_memory(addr, size, exec); 2199 } 2200 2201 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2202 const char* mesg) { 2203 assert(mesg != NULL, "mesg must be specified"); 2204 if (!pd_commit_memory(addr, size, exec)) { 2205 // add extra info in product mode for vm_exit_out_of_memory(): 2206 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);) 2207 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg); 2208 } 2209 } 2210 2211 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2212 size_t alignment_hint, bool exec, 2213 const char* mesg) { 2214 // alignment_hint is ignored on this OS 2215 pd_commit_memory_or_exit(addr, size, exec, mesg); 2216 } 2217 2218 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2219 } 2220 2221 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2222 ::madvise(addr, bytes, MADV_DONTNEED); 2223 } 2224 2225 void os::numa_make_global(char *addr, size_t bytes) { 2226 } 2227 2228 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2229 } 2230 2231 bool os::numa_topology_changed() { return false; } 2232 2233 size_t os::numa_get_groups_num() { 2234 return 1; 2235 } 2236 2237 int os::numa_get_group_id() { 2238 return 0; 2239 } 2240 2241 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2242 if (size > 0) { 2243 ids[0] = 0; 2244 return 1; 2245 } 2246 return 0; 2247 } 2248 2249 bool os::get_page_info(char *start, page_info* info) { 2250 return false; 2251 } 2252 2253 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { 2254 return end; 2255 } 2256 2257 2258 bool os::pd_uncommit_memory(char* addr, size_t size) { 2259 #ifdef __OpenBSD__ 2260 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2261 return ::mprotect(addr, size, PROT_NONE) == 0; 2262 #else 2263 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2264 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2265 return res != (uintptr_t) MAP_FAILED; 2266 #endif 2267 } 2268 2269 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2270 return os::commit_memory(addr, size, !ExecMem); 2271 } 2272 2273 // If this is a growable mapping, remove the guard pages entirely by 2274 // munmap()ping them. If not, just call uncommit_memory(). 2275 bool os::remove_stack_guard_pages(char* addr, size_t size) { 2276 return os::uncommit_memory(addr, size); 2277 } 2278 2279 static address _highest_vm_reserved_address = NULL; 2280 2281 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 2282 // at 'requested_addr'. If there are existing memory mappings at the same 2283 // location, however, they will be overwritten. If 'fixed' is false, 2284 // 'requested_addr' is only treated as a hint, the return value may or 2285 // may not start from the requested address. Unlike Bsd mmap(), this 2286 // function returns NULL to indicate failure. 2287 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 2288 char * addr; 2289 int flags; 2290 2291 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 2292 if (fixed) { 2293 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); 2294 flags |= MAP_FIXED; 2295 } 2296 2297 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 2298 // touch an uncommitted page. Otherwise, the read/write might 2299 // succeed if we have enough swap space to back the physical page. 2300 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 2301 flags, -1, 0); 2302 2303 if (addr != MAP_FAILED) { 2304 // anon_mmap() should only get called during VM initialization, 2305 // don't need lock (actually we can skip locking even it can be called 2306 // from multiple threads, because _highest_vm_reserved_address is just a 2307 // hint about the upper limit of non-stack memory regions.) 2308 if ((address)addr + bytes > _highest_vm_reserved_address) { 2309 _highest_vm_reserved_address = (address)addr + bytes; 2310 } 2311 } 2312 2313 return addr == MAP_FAILED ? NULL : addr; 2314 } 2315 2316 // Don't update _highest_vm_reserved_address, because there might be memory 2317 // regions above addr + size. If so, releasing a memory region only creates 2318 // a hole in the address space, it doesn't help prevent heap-stack collision. 2319 // 2320 static int anon_munmap(char * addr, size_t size) { 2321 return ::munmap(addr, size) == 0; 2322 } 2323 2324 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 2325 size_t alignment_hint) { 2326 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 2327 } 2328 2329 bool os::pd_release_memory(char* addr, size_t size) { 2330 return anon_munmap(addr, size); 2331 } 2332 2333 static bool bsd_mprotect(char* addr, size_t size, int prot) { 2334 // Bsd wants the mprotect address argument to be page aligned. 2335 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); 2336 2337 // According to SUSv3, mprotect() should only be used with mappings 2338 // established by mmap(), and mmap() always maps whole pages. Unaligned 2339 // 'addr' likely indicates problem in the VM (e.g. trying to change 2340 // protection of malloc'ed or statically allocated memory). Check the 2341 // caller if you hit this assert. 2342 assert(addr == bottom, "sanity check"); 2343 2344 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); 2345 return ::mprotect(bottom, size, prot) == 0; 2346 } 2347 2348 // Set protections specified 2349 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 2350 bool is_committed) { 2351 unsigned int p = 0; 2352 switch (prot) { 2353 case MEM_PROT_NONE: p = PROT_NONE; break; 2354 case MEM_PROT_READ: p = PROT_READ; break; 2355 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 2356 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 2357 default: 2358 ShouldNotReachHere(); 2359 } 2360 // is_committed is unused. 2361 return bsd_mprotect(addr, bytes, p); 2362 } 2363 2364 bool os::guard_memory(char* addr, size_t size) { 2365 return bsd_mprotect(addr, size, PROT_NONE); 2366 } 2367 2368 bool os::unguard_memory(char* addr, size_t size) { 2369 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); 2370 } 2371 2372 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { 2373 return false; 2374 } 2375 2376 // Large page support 2377 2378 static size_t _large_page_size = 0; 2379 2380 void os::large_page_init() { 2381 } 2382 2383 2384 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) { 2385 fatal("This code is not used or maintained."); 2386 2387 // "exec" is passed in but not used. Creating the shared image for 2388 // the code cache doesn't have an SHM_X executable permission to check. 2389 assert(UseLargePages && UseSHM, "only for SHM large pages"); 2390 2391 key_t key = IPC_PRIVATE; 2392 char *addr; 2393 2394 bool warn_on_failure = UseLargePages && 2395 (!FLAG_IS_DEFAULT(UseLargePages) || 2396 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 2397 2398 // Create a large shared memory region to attach to based on size. 2399 // Currently, size is the total size of the heap 2400 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); 2401 if (shmid == -1) { 2402 // Possible reasons for shmget failure: 2403 // 1. shmmax is too small for Java heap. 2404 // > check shmmax value: cat /proc/sys/kernel/shmmax 2405 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 2406 // 2. not enough large page memory. 2407 // > check available large pages: cat /proc/meminfo 2408 // > increase amount of large pages: 2409 // echo new_value > /proc/sys/vm/nr_hugepages 2410 // Note 1: different Bsd may use different name for this property, 2411 // e.g. on Redhat AS-3 it is "hugetlb_pool". 2412 // Note 2: it's possible there's enough physical memory available but 2413 // they are so fragmented after a long run that they can't 2414 // coalesce into large pages. Try to reserve large pages when 2415 // the system is still "fresh". 2416 if (warn_on_failure) { 2417 warning("Failed to reserve shared memory (errno = %d).", errno); 2418 } 2419 return NULL; 2420 } 2421 2422 // attach to the region 2423 addr = (char*)shmat(shmid, req_addr, 0); 2424 int err = errno; 2425 2426 // Remove shmid. If shmat() is successful, the actual shared memory segment 2427 // will be deleted when it's detached by shmdt() or when the process 2428 // terminates. If shmat() is not successful this will remove the shared 2429 // segment immediately. 2430 shmctl(shmid, IPC_RMID, NULL); 2431 2432 if ((intptr_t)addr == -1) { 2433 if (warn_on_failure) { 2434 warning("Failed to attach shared memory (errno = %d).", err); 2435 } 2436 return NULL; 2437 } 2438 2439 // The memory is committed 2440 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 2441 2442 return addr; 2443 } 2444 2445 bool os::release_memory_special(char* base, size_t bytes) { 2446 if (MemTracker::tracking_level() > NMT_minimal) { 2447 Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 2448 // detaching the SHM segment will also delete it, see reserve_memory_special() 2449 int rslt = shmdt(base); 2450 if (rslt == 0) { 2451 tkr.record((address)base, bytes); 2452 return true; 2453 } else { 2454 return false; 2455 } 2456 } else { 2457 return shmdt(base) == 0; 2458 } 2459 } 2460 2461 size_t os::large_page_size() { 2462 return _large_page_size; 2463 } 2464 2465 // HugeTLBFS allows application to commit large page memory on demand; 2466 // with SysV SHM the entire memory region must be allocated as shared 2467 // memory. 2468 bool os::can_commit_large_page_memory() { 2469 return UseHugeTLBFS; 2470 } 2471 2472 bool os::can_execute_large_page_memory() { 2473 return UseHugeTLBFS; 2474 } 2475 2476 // Reserve memory at an arbitrary address, only if that area is 2477 // available (and not reserved for something else). 2478 2479 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 2480 const int max_tries = 10; 2481 char* base[max_tries]; 2482 size_t size[max_tries]; 2483 const size_t gap = 0x000000; 2484 2485 // Assert only that the size is a multiple of the page size, since 2486 // that's all that mmap requires, and since that's all we really know 2487 // about at this low abstraction level. If we need higher alignment, 2488 // we can either pass an alignment to this method or verify alignment 2489 // in one of the methods further up the call chain. See bug 5044738. 2490 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 2491 2492 // Repeatedly allocate blocks until the block is allocated at the 2493 // right spot. Give up after max_tries. Note that reserve_memory() will 2494 // automatically update _highest_vm_reserved_address if the call is 2495 // successful. The variable tracks the highest memory address every reserved 2496 // by JVM. It is used to detect heap-stack collision if running with 2497 // fixed-stack BsdThreads. Because here we may attempt to reserve more 2498 // space than needed, it could confuse the collision detecting code. To 2499 // solve the problem, save current _highest_vm_reserved_address and 2500 // calculate the correct value before return. 2501 address old_highest = _highest_vm_reserved_address; 2502 2503 // Bsd mmap allows caller to pass an address as hint; give it a try first, 2504 // if kernel honors the hint then we can return immediately. 2505 char * addr = anon_mmap(requested_addr, bytes, false); 2506 if (addr == requested_addr) { 2507 return requested_addr; 2508 } 2509 2510 if (addr != NULL) { 2511 // mmap() is successful but it fails to reserve at the requested address 2512 anon_munmap(addr, bytes); 2513 } 2514 2515 int i; 2516 for (i = 0; i < max_tries; ++i) { 2517 base[i] = reserve_memory(bytes); 2518 2519 if (base[i] != NULL) { 2520 // Is this the block we wanted? 2521 if (base[i] == requested_addr) { 2522 size[i] = bytes; 2523 break; 2524 } 2525 2526 // Does this overlap the block we wanted? Give back the overlapped 2527 // parts and try again. 2528 2529 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; 2530 if (top_overlap >= 0 && top_overlap < bytes) { 2531 unmap_memory(base[i], top_overlap); 2532 base[i] += top_overlap; 2533 size[i] = bytes - top_overlap; 2534 } else { 2535 size_t bottom_overlap = base[i] + bytes - requested_addr; 2536 if (bottom_overlap >= 0 && bottom_overlap < bytes) { 2537 unmap_memory(requested_addr, bottom_overlap); 2538 size[i] = bytes - bottom_overlap; 2539 } else { 2540 size[i] = bytes; 2541 } 2542 } 2543 } 2544 } 2545 2546 // Give back the unused reserved pieces. 2547 2548 for (int j = 0; j < i; ++j) { 2549 if (base[j] != NULL) { 2550 unmap_memory(base[j], size[j]); 2551 } 2552 } 2553 2554 if (i < max_tries) { 2555 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); 2556 return requested_addr; 2557 } else { 2558 _highest_vm_reserved_address = old_highest; 2559 return NULL; 2560 } 2561 } 2562 2563 size_t os::read(int fd, void *buf, unsigned int nBytes) { 2564 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); 2565 } 2566 2567 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 2568 RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset)); 2569 } 2570 2571 void os::naked_short_sleep(jlong ms) { 2572 struct timespec req; 2573 2574 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 2575 req.tv_sec = 0; 2576 if (ms > 0) { 2577 req.tv_nsec = (ms % 1000) * 1000000; 2578 } else { 2579 req.tv_nsec = 1; 2580 } 2581 2582 nanosleep(&req, NULL); 2583 2584 return; 2585 } 2586 2587 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 2588 void os::infinite_sleep() { 2589 while (true) { // sleep forever ... 2590 ::sleep(100); // ... 100 seconds at a time 2591 } 2592 } 2593 2594 // Used to convert frequent JVM_Yield() to nops 2595 bool os::dont_yield() { 2596 return DontYieldALot; 2597 } 2598 2599 void os::naked_yield() { 2600 sched_yield(); 2601 } 2602 2603 //////////////////////////////////////////////////////////////////////////////// 2604 // thread priority support 2605 2606 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER 2607 // only supports dynamic priority, static priority must be zero. For real-time 2608 // applications, Bsd supports SCHED_RR which allows static priority (1-99). 2609 // However, for large multi-threaded applications, SCHED_RR is not only slower 2610 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 2611 // of 5 runs - Sep 2005). 2612 // 2613 // The following code actually changes the niceness of kernel-thread/LWP. It 2614 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 2615 // not the entire user process, and user level threads are 1:1 mapped to kernel 2616 // threads. It has always been the case, but could change in the future. For 2617 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 2618 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 2619 2620 #if !defined(__APPLE__) 2621 int os::java_to_os_priority[CriticalPriority + 1] = { 2622 19, // 0 Entry should never be used 2623 2624 0, // 1 MinPriority 2625 3, // 2 2626 6, // 3 2627 2628 10, // 4 2629 15, // 5 NormPriority 2630 18, // 6 2631 2632 21, // 7 2633 25, // 8 2634 28, // 9 NearMaxPriority 2635 2636 31, // 10 MaxPriority 2637 2638 31 // 11 CriticalPriority 2639 }; 2640 #else 2641 // Using Mach high-level priority assignments 2642 int os::java_to_os_priority[CriticalPriority + 1] = { 2643 0, // 0 Entry should never be used (MINPRI_USER) 2644 2645 27, // 1 MinPriority 2646 28, // 2 2647 29, // 3 2648 2649 30, // 4 2650 31, // 5 NormPriority (BASEPRI_DEFAULT) 2651 32, // 6 2652 2653 33, // 7 2654 34, // 8 2655 35, // 9 NearMaxPriority 2656 2657 36, // 10 MaxPriority 2658 2659 36 // 11 CriticalPriority 2660 }; 2661 #endif 2662 2663 static int prio_init() { 2664 if (ThreadPriorityPolicy == 1) { 2665 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 2666 // if effective uid is not root. Perhaps, a more elegant way of doing 2667 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 2668 if (geteuid() != 0) { 2669 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 2670 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); 2671 } 2672 ThreadPriorityPolicy = 0; 2673 } 2674 } 2675 if (UseCriticalJavaThreadPriority) { 2676 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 2677 } 2678 return 0; 2679 } 2680 2681 OSReturn os::set_native_priority(Thread* thread, int newpri) { 2682 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 2683 2684 #ifdef __OpenBSD__ 2685 // OpenBSD pthread_setprio starves low priority threads 2686 return OS_OK; 2687 #elif defined(__FreeBSD__) 2688 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); 2689 #elif defined(__APPLE__) || defined(__NetBSD__) 2690 struct sched_param sp; 2691 int policy; 2692 pthread_t self = pthread_self(); 2693 2694 if (pthread_getschedparam(self, &policy, &sp) != 0) { 2695 return OS_ERR; 2696 } 2697 2698 sp.sched_priority = newpri; 2699 if (pthread_setschedparam(self, policy, &sp) != 0) { 2700 return OS_ERR; 2701 } 2702 2703 return OS_OK; 2704 #else 2705 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 2706 return (ret == 0) ? OS_OK : OS_ERR; 2707 #endif 2708 } 2709 2710 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { 2711 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 2712 *priority_ptr = java_to_os_priority[NormPriority]; 2713 return OS_OK; 2714 } 2715 2716 errno = 0; 2717 #if defined(__OpenBSD__) || defined(__FreeBSD__) 2718 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); 2719 #elif defined(__APPLE__) || defined(__NetBSD__) 2720 int policy; 2721 struct sched_param sp; 2722 2723 pthread_getschedparam(pthread_self(), &policy, &sp); 2724 *priority_ptr = sp.sched_priority; 2725 #else 2726 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 2727 #endif 2728 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 2729 } 2730 2731 // Hint to the underlying OS that a task switch would not be good. 2732 // Void return because it's a hint and can fail. 2733 void os::hint_no_preempt() {} 2734 2735 //////////////////////////////////////////////////////////////////////////////// 2736 // suspend/resume support 2737 2738 // the low-level signal-based suspend/resume support is a remnant from the 2739 // old VM-suspension that used to be for java-suspension, safepoints etc, 2740 // within hotspot. Now there is a single use-case for this: 2741 // - calling get_thread_pc() on the VMThread by the flat-profiler task 2742 // that runs in the watcher thread. 2743 // The remaining code is greatly simplified from the more general suspension 2744 // code that used to be used. 2745 // 2746 // The protocol is quite simple: 2747 // - suspend: 2748 // - sends a signal to the target thread 2749 // - polls the suspend state of the osthread using a yield loop 2750 // - target thread signal handler (SR_handler) sets suspend state 2751 // and blocks in sigsuspend until continued 2752 // - resume: 2753 // - sets target osthread state to continue 2754 // - sends signal to end the sigsuspend loop in the SR_handler 2755 // 2756 // Note that the SR_lock plays no role in this suspend/resume protocol. 2757 2758 static void resume_clear_context(OSThread *osthread) { 2759 osthread->set_ucontext(NULL); 2760 osthread->set_siginfo(NULL); 2761 } 2762 2763 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { 2764 osthread->set_ucontext(context); 2765 osthread->set_siginfo(siginfo); 2766 } 2767 2768 // Handler function invoked when a thread's execution is suspended or 2769 // resumed. We have to be careful that only async-safe functions are 2770 // called here (Note: most pthread functions are not async safe and 2771 // should be avoided.) 2772 // 2773 // Note: sigwait() is a more natural fit than sigsuspend() from an 2774 // interface point of view, but sigwait() prevents the signal hander 2775 // from being run. libpthread would get very confused by not having 2776 // its signal handlers run and prevents sigwait()'s use with the 2777 // mutex granting granting signal. 2778 // 2779 // Currently only ever called on the VMThread or JavaThread 2780 // 2781 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 2782 // Save and restore errno to avoid confusing native code with EINTR 2783 // after sigsuspend. 2784 int old_errno = errno; 2785 2786 Thread* thread = Thread::current(); 2787 OSThread* osthread = thread->osthread(); 2788 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 2789 2790 os::SuspendResume::State current = osthread->sr.state(); 2791 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 2792 suspend_save_context(osthread, siginfo, context); 2793 2794 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 2795 os::SuspendResume::State state = osthread->sr.suspended(); 2796 if (state == os::SuspendResume::SR_SUSPENDED) { 2797 sigset_t suspend_set; // signals for sigsuspend() 2798 2799 // get current set of blocked signals and unblock resume signal 2800 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 2801 sigdelset(&suspend_set, SR_signum); 2802 2803 sr_semaphore.signal(); 2804 // wait here until we are resumed 2805 while (1) { 2806 sigsuspend(&suspend_set); 2807 2808 os::SuspendResume::State result = osthread->sr.running(); 2809 if (result == os::SuspendResume::SR_RUNNING) { 2810 sr_semaphore.signal(); 2811 break; 2812 } else if (result != os::SuspendResume::SR_SUSPENDED) { 2813 ShouldNotReachHere(); 2814 } 2815 } 2816 2817 } else if (state == os::SuspendResume::SR_RUNNING) { 2818 // request was cancelled, continue 2819 } else { 2820 ShouldNotReachHere(); 2821 } 2822 2823 resume_clear_context(osthread); 2824 } else if (current == os::SuspendResume::SR_RUNNING) { 2825 // request was cancelled, continue 2826 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 2827 // ignore 2828 } else { 2829 // ignore 2830 } 2831 2832 errno = old_errno; 2833 } 2834 2835 2836 static int SR_initialize() { 2837 struct sigaction act; 2838 char *s; 2839 // Get signal number to use for suspend/resume 2840 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 2841 int sig = ::strtol(s, 0, 10); 2842 if (sig > 0 || sig < NSIG) { 2843 SR_signum = sig; 2844 } 2845 } 2846 2847 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 2848 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 2849 2850 sigemptyset(&SR_sigset); 2851 sigaddset(&SR_sigset, SR_signum); 2852 2853 // Set up signal handler for suspend/resume 2854 act.sa_flags = SA_RESTART|SA_SIGINFO; 2855 act.sa_handler = (void (*)(int)) SR_handler; 2856 2857 // SR_signum is blocked by default. 2858 // 4528190 - We also need to block pthread restart signal (32 on all 2859 // supported Bsd platforms). Note that BsdThreads need to block 2860 // this signal for all threads to work properly. So we don't have 2861 // to use hard-coded signal number when setting up the mask. 2862 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 2863 2864 if (sigaction(SR_signum, &act, 0) == -1) { 2865 return -1; 2866 } 2867 2868 // Save signal flag 2869 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); 2870 return 0; 2871 } 2872 2873 static int sr_notify(OSThread* osthread) { 2874 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2875 assert_status(status == 0, status, "pthread_kill"); 2876 return status; 2877 } 2878 2879 // "Randomly" selected value for how long we want to spin 2880 // before bailing out on suspending a thread, also how often 2881 // we send a signal to a thread we want to resume 2882 static const int RANDOMLY_LARGE_INTEGER = 1000000; 2883 static const int RANDOMLY_LARGE_INTEGER2 = 100; 2884 2885 // returns true on success and false on error - really an error is fatal 2886 // but this seems the normal response to library errors 2887 static bool do_suspend(OSThread* osthread) { 2888 assert(osthread->sr.is_running(), "thread should be running"); 2889 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 2890 2891 // mark as suspended and send signal 2892 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 2893 // failed to switch, state wasn't running? 2894 ShouldNotReachHere(); 2895 return false; 2896 } 2897 2898 if (sr_notify(osthread) != 0) { 2899 ShouldNotReachHere(); 2900 } 2901 2902 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 2903 while (true) { 2904 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2905 break; 2906 } else { 2907 // timeout 2908 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 2909 if (cancelled == os::SuspendResume::SR_RUNNING) { 2910 return false; 2911 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 2912 // make sure that we consume the signal on the semaphore as well 2913 sr_semaphore.wait(); 2914 break; 2915 } else { 2916 ShouldNotReachHere(); 2917 return false; 2918 } 2919 } 2920 } 2921 2922 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 2923 return true; 2924 } 2925 2926 static void do_resume(OSThread* osthread) { 2927 assert(osthread->sr.is_suspended(), "thread should be suspended"); 2928 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 2929 2930 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 2931 // failed to switch to WAKEUP_REQUEST 2932 ShouldNotReachHere(); 2933 return; 2934 } 2935 2936 while (true) { 2937 if (sr_notify(osthread) == 0) { 2938 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2939 if (osthread->sr.is_running()) { 2940 return; 2941 } 2942 } 2943 } else { 2944 ShouldNotReachHere(); 2945 } 2946 } 2947 2948 guarantee(osthread->sr.is_running(), "Must be running!"); 2949 } 2950 2951 /////////////////////////////////////////////////////////////////////////////////// 2952 // signal handling (except suspend/resume) 2953 2954 // This routine may be used by user applications as a "hook" to catch signals. 2955 // The user-defined signal handler must pass unrecognized signals to this 2956 // routine, and if it returns true (non-zero), then the signal handler must 2957 // return immediately. If the flag "abort_if_unrecognized" is true, then this 2958 // routine will never retun false (zero), but instead will execute a VM panic 2959 // routine kill the process. 2960 // 2961 // If this routine returns false, it is OK to call it again. This allows 2962 // the user-defined signal handler to perform checks either before or after 2963 // the VM performs its own checks. Naturally, the user code would be making 2964 // a serious error if it tried to handle an exception (such as a null check 2965 // or breakpoint) that the VM was generating for its own correct operation. 2966 // 2967 // This routine may recognize any of the following kinds of signals: 2968 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 2969 // It should be consulted by handlers for any of those signals. 2970 // 2971 // The caller of this routine must pass in the three arguments supplied 2972 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 2973 // field of the structure passed to sigaction(). This routine assumes that 2974 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 2975 // 2976 // Note that the VM will print warnings if it detects conflicting signal 2977 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 2978 // 2979 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, 2980 void* ucontext, 2981 int abort_if_unrecognized); 2982 2983 void signalHandler(int sig, siginfo_t* info, void* uc) { 2984 assert(info != NULL && uc != NULL, "it must be old kernel"); 2985 int orig_errno = errno; // Preserve errno value over signal handler. 2986 JVM_handle_bsd_signal(sig, info, uc, true); 2987 errno = orig_errno; 2988 } 2989 2990 2991 // This boolean allows users to forward their own non-matching signals 2992 // to JVM_handle_bsd_signal, harmlessly. 2993 bool os::Bsd::signal_handlers_are_installed = false; 2994 2995 // For signal-chaining 2996 struct sigaction os::Bsd::sigact[MAXSIGNUM]; 2997 unsigned int os::Bsd::sigs = 0; 2998 bool os::Bsd::libjsig_is_loaded = false; 2999 typedef struct sigaction *(*get_signal_t)(int); 3000 get_signal_t os::Bsd::get_signal_action = NULL; 3001 3002 struct sigaction* os::Bsd::get_chained_signal_action(int sig) { 3003 struct sigaction *actp = NULL; 3004 3005 if (libjsig_is_loaded) { 3006 // Retrieve the old signal handler from libjsig 3007 actp = (*get_signal_action)(sig); 3008 } 3009 if (actp == NULL) { 3010 // Retrieve the preinstalled signal handler from jvm 3011 actp = get_preinstalled_handler(sig); 3012 } 3013 3014 return actp; 3015 } 3016 3017 static bool call_chained_handler(struct sigaction *actp, int sig, 3018 siginfo_t *siginfo, void *context) { 3019 // Call the old signal handler 3020 if (actp->sa_handler == SIG_DFL) { 3021 // It's more reasonable to let jvm treat it as an unexpected exception 3022 // instead of taking the default action. 3023 return false; 3024 } else if (actp->sa_handler != SIG_IGN) { 3025 if ((actp->sa_flags & SA_NODEFER) == 0) { 3026 // automaticlly block the signal 3027 sigaddset(&(actp->sa_mask), sig); 3028 } 3029 3030 sa_handler_t hand; 3031 sa_sigaction_t sa; 3032 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 3033 // retrieve the chained handler 3034 if (siginfo_flag_set) { 3035 sa = actp->sa_sigaction; 3036 } else { 3037 hand = actp->sa_handler; 3038 } 3039 3040 if ((actp->sa_flags & SA_RESETHAND) != 0) { 3041 actp->sa_handler = SIG_DFL; 3042 } 3043 3044 // try to honor the signal mask 3045 sigset_t oset; 3046 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 3047 3048 // call into the chained handler 3049 if (siginfo_flag_set) { 3050 (*sa)(sig, siginfo, context); 3051 } else { 3052 (*hand)(sig); 3053 } 3054 3055 // restore the signal mask 3056 pthread_sigmask(SIG_SETMASK, &oset, 0); 3057 } 3058 // Tell jvm's signal handler the signal is taken care of. 3059 return true; 3060 } 3061 3062 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { 3063 bool chained = false; 3064 // signal-chaining 3065 if (UseSignalChaining) { 3066 struct sigaction *actp = get_chained_signal_action(sig); 3067 if (actp != NULL) { 3068 chained = call_chained_handler(actp, sig, siginfo, context); 3069 } 3070 } 3071 return chained; 3072 } 3073 3074 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { 3075 if ((((unsigned int)1 << sig) & sigs) != 0) { 3076 return &sigact[sig]; 3077 } 3078 return NULL; 3079 } 3080 3081 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 3082 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3083 sigact[sig] = oldAct; 3084 sigs |= (unsigned int)1 << sig; 3085 } 3086 3087 // for diagnostic 3088 int os::Bsd::sigflags[MAXSIGNUM]; 3089 3090 int os::Bsd::get_our_sigflags(int sig) { 3091 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3092 return sigflags[sig]; 3093 } 3094 3095 void os::Bsd::set_our_sigflags(int sig, int flags) { 3096 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3097 sigflags[sig] = flags; 3098 } 3099 3100 void os::Bsd::set_signal_handler(int sig, bool set_installed) { 3101 // Check for overwrite. 3102 struct sigaction oldAct; 3103 sigaction(sig, (struct sigaction*)NULL, &oldAct); 3104 3105 void* oldhand = oldAct.sa_sigaction 3106 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3107 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3108 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 3109 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 3110 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 3111 if (AllowUserSignalHandlers || !set_installed) { 3112 // Do not overwrite; user takes responsibility to forward to us. 3113 return; 3114 } else if (UseSignalChaining) { 3115 // save the old handler in jvm 3116 save_preinstalled_handler(sig, oldAct); 3117 // libjsig also interposes the sigaction() call below and saves the 3118 // old sigaction on it own. 3119 } else { 3120 fatal(err_msg("Encountered unexpected pre-existing sigaction handler " 3121 "%#lx for signal %d.", (long)oldhand, sig)); 3122 } 3123 } 3124 3125 struct sigaction sigAct; 3126 sigfillset(&(sigAct.sa_mask)); 3127 sigAct.sa_handler = SIG_DFL; 3128 if (!set_installed) { 3129 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3130 } else { 3131 sigAct.sa_sigaction = signalHandler; 3132 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3133 } 3134 #ifdef __APPLE__ 3135 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV 3136 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages" 3137 // if the signal handler declares it will handle it on alternate stack. 3138 // Notice we only declare we will handle it on alt stack, but we are not 3139 // actually going to use real alt stack - this is just a workaround. 3140 // Please see ux_exception.c, method catch_mach_exception_raise for details 3141 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c 3142 if (sig == SIGSEGV) { 3143 sigAct.sa_flags |= SA_ONSTACK; 3144 } 3145 #endif 3146 3147 // Save flags, which are set by ours 3148 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3149 sigflags[sig] = sigAct.sa_flags; 3150 3151 int ret = sigaction(sig, &sigAct, &oldAct); 3152 assert(ret == 0, "check"); 3153 3154 void* oldhand2 = oldAct.sa_sigaction 3155 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3156 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3157 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 3158 } 3159 3160 // install signal handlers for signals that HotSpot needs to 3161 // handle in order to support Java-level exception handling. 3162 3163 void os::Bsd::install_signal_handlers() { 3164 if (!signal_handlers_are_installed) { 3165 signal_handlers_are_installed = true; 3166 3167 // signal-chaining 3168 typedef void (*signal_setting_t)(); 3169 signal_setting_t begin_signal_setting = NULL; 3170 signal_setting_t end_signal_setting = NULL; 3171 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3172 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 3173 if (begin_signal_setting != NULL) { 3174 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3175 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 3176 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 3177 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 3178 libjsig_is_loaded = true; 3179 assert(UseSignalChaining, "should enable signal-chaining"); 3180 } 3181 if (libjsig_is_loaded) { 3182 // Tell libjsig jvm is setting signal handlers 3183 (*begin_signal_setting)(); 3184 } 3185 3186 set_signal_handler(SIGSEGV, true); 3187 set_signal_handler(SIGPIPE, true); 3188 set_signal_handler(SIGBUS, true); 3189 set_signal_handler(SIGILL, true); 3190 set_signal_handler(SIGFPE, true); 3191 set_signal_handler(SIGXFSZ, true); 3192 3193 #if defined(__APPLE__) 3194 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including 3195 // signals caught and handled by the JVM. To work around this, we reset the mach task 3196 // signal handler that's placed on our process by CrashReporter. This disables 3197 // CrashReporter-based reporting. 3198 // 3199 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes 3200 // on caught fatal signals. 3201 // 3202 // Additionally, gdb installs both standard BSD signal handlers, and mach exception 3203 // handlers. By replacing the existing task exception handler, we disable gdb's mach 3204 // exception handling, while leaving the standard BSD signal handlers functional. 3205 kern_return_t kr; 3206 kr = task_set_exception_ports(mach_task_self(), 3207 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, 3208 MACH_PORT_NULL, 3209 EXCEPTION_STATE_IDENTITY, 3210 MACHINE_THREAD_STATE); 3211 3212 assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); 3213 #endif 3214 3215 if (libjsig_is_loaded) { 3216 // Tell libjsig jvm finishes setting signal handlers 3217 (*end_signal_setting)(); 3218 } 3219 3220 // We don't activate signal checker if libjsig is in place, we trust ourselves 3221 // and if UserSignalHandler is installed all bets are off 3222 if (CheckJNICalls) { 3223 if (libjsig_is_loaded) { 3224 if (PrintJNIResolving) { 3225 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 3226 } 3227 check_signals = false; 3228 } 3229 if (AllowUserSignalHandlers) { 3230 if (PrintJNIResolving) { 3231 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 3232 } 3233 check_signals = false; 3234 } 3235 } 3236 } 3237 } 3238 3239 3240 ///// 3241 // glibc on Bsd platform uses non-documented flag 3242 // to indicate, that some special sort of signal 3243 // trampoline is used. 3244 // We will never set this flag, and we should 3245 // ignore this flag in our diagnostic 3246 #ifdef SIGNIFICANT_SIGNAL_MASK 3247 #undef SIGNIFICANT_SIGNAL_MASK 3248 #endif 3249 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 3250 3251 static const char* get_signal_handler_name(address handler, 3252 char* buf, int buflen) { 3253 int offset; 3254 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 3255 if (found) { 3256 // skip directory names 3257 const char *p1, *p2; 3258 p1 = buf; 3259 size_t len = strlen(os::file_separator()); 3260 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 3261 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 3262 } else { 3263 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 3264 } 3265 return buf; 3266 } 3267 3268 static void print_signal_handler(outputStream* st, int sig, 3269 char* buf, size_t buflen) { 3270 struct sigaction sa; 3271 3272 sigaction(sig, NULL, &sa); 3273 3274 // See comment for SIGNIFICANT_SIGNAL_MASK define 3275 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3276 3277 st->print("%s: ", os::exception_name(sig, buf, buflen)); 3278 3279 address handler = (sa.sa_flags & SA_SIGINFO) 3280 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 3281 : CAST_FROM_FN_PTR(address, sa.sa_handler); 3282 3283 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 3284 st->print("SIG_DFL"); 3285 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 3286 st->print("SIG_IGN"); 3287 } else { 3288 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 3289 } 3290 3291 st->print(", sa_mask[0]="); 3292 os::Posix::print_signal_set_short(st, &sa.sa_mask); 3293 3294 address rh = VMError::get_resetted_sighandler(sig); 3295 // May be, handler was resetted by VMError? 3296 if (rh != NULL) { 3297 handler = rh; 3298 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 3299 } 3300 3301 st->print(", sa_flags="); 3302 os::Posix::print_sa_flags(st, sa.sa_flags); 3303 3304 // Check: is it our handler? 3305 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 3306 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 3307 // It is our signal handler 3308 // check for flags, reset system-used one! 3309 if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3310 st->print( 3311 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 3312 os::Bsd::get_our_sigflags(sig)); 3313 } 3314 } 3315 st->cr(); 3316 } 3317 3318 3319 #define DO_SIGNAL_CHECK(sig) \ 3320 do { \ 3321 if (!sigismember(&check_signal_done, sig)) { \ 3322 os::Bsd::check_signal_handler(sig); \ 3323 } \ 3324 } while (0) 3325 3326 // This method is a periodic task to check for misbehaving JNI applications 3327 // under CheckJNI, we can add any periodic checks here 3328 3329 void os::run_periodic_checks() { 3330 3331 if (check_signals == false) return; 3332 3333 // SEGV and BUS if overridden could potentially prevent 3334 // generation of hs*.log in the event of a crash, debugging 3335 // such a case can be very challenging, so we absolutely 3336 // check the following for a good measure: 3337 DO_SIGNAL_CHECK(SIGSEGV); 3338 DO_SIGNAL_CHECK(SIGILL); 3339 DO_SIGNAL_CHECK(SIGFPE); 3340 DO_SIGNAL_CHECK(SIGBUS); 3341 DO_SIGNAL_CHECK(SIGPIPE); 3342 DO_SIGNAL_CHECK(SIGXFSZ); 3343 3344 3345 // ReduceSignalUsage allows the user to override these handlers 3346 // see comments at the very top and jvm_solaris.h 3347 if (!ReduceSignalUsage) { 3348 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 3349 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 3350 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 3351 DO_SIGNAL_CHECK(BREAK_SIGNAL); 3352 } 3353 3354 DO_SIGNAL_CHECK(SR_signum); 3355 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); 3356 } 3357 3358 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 3359 3360 static os_sigaction_t os_sigaction = NULL; 3361 3362 void os::Bsd::check_signal_handler(int sig) { 3363 char buf[O_BUFLEN]; 3364 address jvmHandler = NULL; 3365 3366 3367 struct sigaction act; 3368 if (os_sigaction == NULL) { 3369 // only trust the default sigaction, in case it has been interposed 3370 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 3371 if (os_sigaction == NULL) return; 3372 } 3373 3374 os_sigaction(sig, (struct sigaction*)NULL, &act); 3375 3376 3377 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3378 3379 address thisHandler = (act.sa_flags & SA_SIGINFO) 3380 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 3381 : CAST_FROM_FN_PTR(address, act.sa_handler); 3382 3383 3384 switch (sig) { 3385 case SIGSEGV: 3386 case SIGBUS: 3387 case SIGFPE: 3388 case SIGPIPE: 3389 case SIGILL: 3390 case SIGXFSZ: 3391 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 3392 break; 3393 3394 case SHUTDOWN1_SIGNAL: 3395 case SHUTDOWN2_SIGNAL: 3396 case SHUTDOWN3_SIGNAL: 3397 case BREAK_SIGNAL: 3398 jvmHandler = (address)user_handler(); 3399 break; 3400 3401 case INTERRUPT_SIGNAL: 3402 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); 3403 break; 3404 3405 default: 3406 if (sig == SR_signum) { 3407 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 3408 } else { 3409 return; 3410 } 3411 break; 3412 } 3413 3414 if (thisHandler != jvmHandler) { 3415 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 3416 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 3417 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 3418 // No need to check this sig any longer 3419 sigaddset(&check_signal_done, sig); 3420 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 3421 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 3422 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 3423 exception_name(sig, buf, O_BUFLEN)); 3424 } 3425 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3426 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 3427 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); 3428 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); 3429 // No need to check this sig any longer 3430 sigaddset(&check_signal_done, sig); 3431 } 3432 3433 // Dump all the signal 3434 if (sigismember(&check_signal_done, sig)) { 3435 print_signal_handlers(tty, buf, O_BUFLEN); 3436 } 3437 } 3438 3439 extern void report_error(char* file_name, int line_no, char* title, 3440 char* format, ...); 3441 3442 extern bool signal_name(int signo, char* buf, size_t len); 3443 3444 const char* os::exception_name(int exception_code, char* buf, size_t size) { 3445 if (0 < exception_code && exception_code <= SIGRTMAX) { 3446 // signal 3447 if (!signal_name(exception_code, buf, size)) { 3448 jio_snprintf(buf, size, "SIG%d", exception_code); 3449 } 3450 return buf; 3451 } else { 3452 return NULL; 3453 } 3454 } 3455 3456 // this is called _before_ the most of global arguments have been parsed 3457 void os::init(void) { 3458 char dummy; // used to get a guess on initial stack address 3459 // first_hrtime = gethrtime(); 3460 3461 // With BsdThreads the JavaMain thread pid (primordial thread) 3462 // is different than the pid of the java launcher thread. 3463 // So, on Bsd, the launcher thread pid is passed to the VM 3464 // via the sun.java.launcher.pid property. 3465 // Use this property instead of getpid() if it was correctly passed. 3466 // See bug 6351349. 3467 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); 3468 3469 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); 3470 3471 clock_tics_per_sec = CLK_TCK; 3472 3473 init_random(1234567); 3474 3475 ThreadCritical::initialize(); 3476 3477 Bsd::set_page_size(getpagesize()); 3478 if (Bsd::page_size() == -1) { 3479 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)", 3480 strerror(errno))); 3481 } 3482 init_page_sizes((size_t) Bsd::page_size()); 3483 3484 Bsd::initialize_system_info(); 3485 3486 // main_thread points to the aboriginal thread 3487 Bsd::_main_thread = pthread_self(); 3488 3489 Bsd::clock_init(); 3490 initial_time_count = javaTimeNanos(); 3491 3492 #ifdef __APPLE__ 3493 // XXXDARWIN 3494 // Work around the unaligned VM callbacks in hotspot's 3495 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on 3496 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces 3497 // alignment when doing symbol lookup. To work around this, we force early 3498 // binding of all symbols now, thus binding when alignment is known-good. 3499 _dyld_bind_fully_image_containing_address((const void *) &os::init); 3500 #endif 3501 } 3502 3503 // To install functions for atexit system call 3504 extern "C" { 3505 static void perfMemory_exit_helper() { 3506 perfMemory_exit(); 3507 } 3508 } 3509 3510 // this is called _after_ the global arguments have been parsed 3511 jint os::init_2(void) { 3512 // Allocate a single page and mark it as readable for safepoint polling 3513 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3514 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page"); 3515 3516 os::set_polling_page(polling_page); 3517 3518 #ifndef PRODUCT 3519 if (Verbose && PrintMiscellaneous) { 3520 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", 3521 (intptr_t)polling_page); 3522 } 3523 #endif 3524 3525 if (!UseMembar) { 3526 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3527 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 3528 os::set_memory_serialize_page(mem_serialize_page); 3529 3530 #ifndef PRODUCT 3531 if (Verbose && PrintMiscellaneous) { 3532 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", 3533 (intptr_t)mem_serialize_page); 3534 } 3535 #endif 3536 } 3537 3538 // initialize suspend/resume support - must do this before signal_sets_init() 3539 if (SR_initialize() != 0) { 3540 perror("SR_initialize failed"); 3541 return JNI_ERR; 3542 } 3543 3544 Bsd::signal_sets_init(); 3545 Bsd::install_signal_handlers(); 3546 3547 // Check minimum allowable stack size for thread creation and to initialize 3548 // the java system classes, including StackOverflowError - depends on page 3549 // size. Add a page for compiler2 recursion in main thread. 3550 // Add in 2*BytesPerWord times page size to account for VM stack during 3551 // class initialization depending on 32 or 64 bit VM. 3552 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, 3553 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ 3554 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); 3555 3556 size_t threadStackSizeInBytes = ThreadStackSize * K; 3557 if (threadStackSizeInBytes != 0 && 3558 threadStackSizeInBytes < os::Bsd::min_stack_allowed) { 3559 tty->print_cr("\nThe stack size specified is too small, " 3560 "Specify at least %dk", 3561 os::Bsd::min_stack_allowed/ K); 3562 return JNI_ERR; 3563 } 3564 3565 // Make the stack size a multiple of the page size so that 3566 // the yellow/red zones can be guarded. 3567 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 3568 vm_page_size())); 3569 3570 if (MaxFDLimit) { 3571 // set the number of file descriptors to max. print out error 3572 // if getrlimit/setrlimit fails but continue regardless. 3573 struct rlimit nbr_files; 3574 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 3575 if (status != 0) { 3576 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3577 perror("os::init_2 getrlimit failed"); 3578 } 3579 } else { 3580 nbr_files.rlim_cur = nbr_files.rlim_max; 3581 3582 #ifdef __APPLE__ 3583 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if 3584 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must 3585 // be used instead 3586 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); 3587 #endif 3588 3589 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 3590 if (status != 0) { 3591 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3592 perror("os::init_2 setrlimit failed"); 3593 } 3594 } 3595 } 3596 } 3597 3598 // at-exit methods are called in the reverse order of their registration. 3599 // atexit functions are called on return from main or as a result of a 3600 // call to exit(3C). There can be only 32 of these functions registered 3601 // and atexit() does not set errno. 3602 3603 if (PerfAllowAtExitRegistration) { 3604 // only register atexit functions if PerfAllowAtExitRegistration is set. 3605 // atexit functions can be delayed until process exit time, which 3606 // can be problematic for embedded VM situations. Embedded VMs should 3607 // call DestroyJavaVM() to assure that VM resources are released. 3608 3609 // note: perfMemory_exit_helper atexit function may be removed in 3610 // the future if the appropriate cleanup code can be added to the 3611 // VM_Exit VMOperation's doit method. 3612 if (atexit(perfMemory_exit_helper) != 0) { 3613 warning("os::init2 atexit(perfMemory_exit_helper) failed"); 3614 } 3615 } 3616 3617 // initialize thread priority policy 3618 prio_init(); 3619 3620 #ifdef __APPLE__ 3621 // dynamically link to objective c gc registration 3622 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY); 3623 if (handleLibObjc != NULL) { 3624 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER); 3625 } 3626 #endif 3627 3628 return JNI_OK; 3629 } 3630 3631 // Mark the polling page as unreadable 3632 void os::make_polling_page_unreadable(void) { 3633 if (!guard_memory((char*)_polling_page, Bsd::page_size())) { 3634 fatal("Could not disable polling page"); 3635 } 3636 } 3637 3638 // Mark the polling page as readable 3639 void os::make_polling_page_readable(void) { 3640 if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { 3641 fatal("Could not enable polling page"); 3642 } 3643 } 3644 3645 int os::active_processor_count() { 3646 return _processor_count; 3647 } 3648 3649 void os::set_native_thread_name(const char *name) { 3650 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5 3651 // This is only supported in Snow Leopard and beyond 3652 if (name != NULL) { 3653 // Add a "Java: " prefix to the name 3654 char buf[MAXTHREADNAMESIZE]; 3655 snprintf(buf, sizeof(buf), "Java: %s", name); 3656 pthread_setname_np(buf); 3657 } 3658 #endif 3659 } 3660 3661 bool os::distribute_processes(uint length, uint* distribution) { 3662 // Not yet implemented. 3663 return false; 3664 } 3665 3666 bool os::bind_to_processor(uint processor_id) { 3667 // Not yet implemented. 3668 return false; 3669 } 3670 3671 void os::SuspendedThreadTask::internal_do_task() { 3672 if (do_suspend(_thread->osthread())) { 3673 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 3674 do_task(context); 3675 do_resume(_thread->osthread()); 3676 } 3677 } 3678 3679 /// 3680 class PcFetcher : public os::SuspendedThreadTask { 3681 public: 3682 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 3683 ExtendedPC result(); 3684 protected: 3685 void do_task(const os::SuspendedThreadTaskContext& context); 3686 private: 3687 ExtendedPC _epc; 3688 }; 3689 3690 ExtendedPC PcFetcher::result() { 3691 guarantee(is_done(), "task is not done yet."); 3692 return _epc; 3693 } 3694 3695 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 3696 Thread* thread = context.thread(); 3697 OSThread* osthread = thread->osthread(); 3698 if (osthread->ucontext() != NULL) { 3699 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext()); 3700 } else { 3701 // NULL context is unexpected, double-check this is the VMThread 3702 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 3703 } 3704 } 3705 3706 // Suspends the target using the signal mechanism and then grabs the PC before 3707 // resuming the target. Used by the flat-profiler only 3708 ExtendedPC os::get_thread_pc(Thread* thread) { 3709 // Make sure that it is called by the watcher for the VMThread 3710 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 3711 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 3712 3713 PcFetcher fetcher(thread); 3714 fetcher.run(); 3715 return fetcher.result(); 3716 } 3717 3718 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, 3719 pthread_mutex_t *_mutex, 3720 const struct timespec *_abstime) { 3721 return pthread_cond_timedwait(_cond, _mutex, _abstime); 3722 } 3723 3724 //////////////////////////////////////////////////////////////////////////////// 3725 // debug support 3726 3727 bool os::find(address addr, outputStream* st) { 3728 Dl_info dlinfo; 3729 memset(&dlinfo, 0, sizeof(dlinfo)); 3730 if (dladdr(addr, &dlinfo) != 0) { 3731 st->print(PTR_FORMAT ": ", addr); 3732 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 3733 st->print("%s+%#x", dlinfo.dli_sname, 3734 addr - (intptr_t)dlinfo.dli_saddr); 3735 } else if (dlinfo.dli_fbase != NULL) { 3736 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); 3737 } else { 3738 st->print("<absolute address>"); 3739 } 3740 if (dlinfo.dli_fname != NULL) { 3741 st->print(" in %s", dlinfo.dli_fname); 3742 } 3743 if (dlinfo.dli_fbase != NULL) { 3744 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); 3745 } 3746 st->cr(); 3747 3748 if (Verbose) { 3749 // decode some bytes around the PC 3750 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 3751 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 3752 address lowest = (address) dlinfo.dli_sname; 3753 if (!lowest) lowest = (address) dlinfo.dli_fbase; 3754 if (begin < lowest) begin = lowest; 3755 Dl_info dlinfo2; 3756 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 3757 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 3758 end = (address) dlinfo2.dli_saddr; 3759 } 3760 Disassembler::decode(begin, end, st); 3761 } 3762 return true; 3763 } 3764 return false; 3765 } 3766 3767 //////////////////////////////////////////////////////////////////////////////// 3768 // misc 3769 3770 // This does not do anything on Bsd. This is basically a hook for being 3771 // able to use structured exception handling (thread-local exception filters) 3772 // on, e.g., Win32. 3773 void os::os_exception_wrapper(java_call_t f, JavaValue* value, 3774 methodHandle* method, JavaCallArguments* args, 3775 Thread* thread) { 3776 f(value, method, args, thread); 3777 } 3778 3779 void os::print_statistics() { 3780 } 3781 3782 int os::message_box(const char* title, const char* message) { 3783 int i; 3784 fdStream err(defaultStream::error_fd()); 3785 for (i = 0; i < 78; i++) err.print_raw("="); 3786 err.cr(); 3787 err.print_raw_cr(title); 3788 for (i = 0; i < 78; i++) err.print_raw("-"); 3789 err.cr(); 3790 err.print_raw_cr(message); 3791 for (i = 0; i < 78; i++) err.print_raw("="); 3792 err.cr(); 3793 3794 char buf[16]; 3795 // Prevent process from exiting upon "read error" without consuming all CPU 3796 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 3797 3798 return buf[0] == 'y' || buf[0] == 'Y'; 3799 } 3800 3801 int os::stat(const char *path, struct stat *sbuf) { 3802 char pathbuf[MAX_PATH]; 3803 if (strlen(path) > MAX_PATH - 1) { 3804 errno = ENAMETOOLONG; 3805 return -1; 3806 } 3807 os::native_path(strcpy(pathbuf, path)); 3808 return ::stat(pathbuf, sbuf); 3809 } 3810 3811 bool os::check_heap(bool force) { 3812 return true; 3813 } 3814 3815 // Is a (classpath) directory empty? 3816 bool os::dir_is_empty(const char* path) { 3817 DIR *dir = NULL; 3818 struct dirent *ptr; 3819 3820 dir = opendir(path); 3821 if (dir == NULL) return true; 3822 3823 // Scan the directory 3824 bool result = true; 3825 char buf[sizeof(struct dirent) + MAX_PATH]; 3826 while (result && (ptr = ::readdir(dir)) != NULL) { 3827 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 3828 result = false; 3829 } 3830 } 3831 closedir(dir); 3832 return result; 3833 } 3834 3835 // This code originates from JDK's sysOpen and open64_w 3836 // from src/solaris/hpi/src/system_md.c 3837 3838 int os::open(const char *path, int oflag, int mode) { 3839 if (strlen(path) > MAX_PATH - 1) { 3840 errno = ENAMETOOLONG; 3841 return -1; 3842 } 3843 int fd; 3844 3845 fd = ::open(path, oflag, mode); 3846 if (fd == -1) return -1; 3847 3848 // If the open succeeded, the file might still be a directory 3849 { 3850 struct stat buf; 3851 int ret = ::fstat(fd, &buf); 3852 int st_mode = buf.st_mode; 3853 3854 if (ret != -1) { 3855 if ((st_mode & S_IFMT) == S_IFDIR) { 3856 errno = EISDIR; 3857 ::close(fd); 3858 return -1; 3859 } 3860 } else { 3861 ::close(fd); 3862 return -1; 3863 } 3864 } 3865 3866 // All file descriptors that are opened in the JVM and not 3867 // specifically destined for a subprocess should have the 3868 // close-on-exec flag set. If we don't set it, then careless 3rd 3869 // party native code might fork and exec without closing all 3870 // appropriate file descriptors (e.g. as we do in closeDescriptors in 3871 // UNIXProcess.c), and this in turn might: 3872 // 3873 // - cause end-of-file to fail to be detected on some file 3874 // descriptors, resulting in mysterious hangs, or 3875 // 3876 // - might cause an fopen in the subprocess to fail on a system 3877 // suffering from bug 1085341. 3878 // 3879 // (Yes, the default setting of the close-on-exec flag is a Unix 3880 // design flaw) 3881 // 3882 // See: 3883 // 1085341: 32-bit stdio routines should support file descriptors >255 3884 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 3885 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 3886 // 3887 #ifdef FD_CLOEXEC 3888 { 3889 int flags = ::fcntl(fd, F_GETFD); 3890 if (flags != -1) { 3891 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 3892 } 3893 } 3894 #endif 3895 3896 return fd; 3897 } 3898 3899 3900 // create binary file, rewriting existing file if required 3901 int os::create_binary_file(const char* path, bool rewrite_existing) { 3902 int oflags = O_WRONLY | O_CREAT; 3903 if (!rewrite_existing) { 3904 oflags |= O_EXCL; 3905 } 3906 return ::open(path, oflags, S_IREAD | S_IWRITE); 3907 } 3908 3909 // return current position of file pointer 3910 jlong os::current_file_offset(int fd) { 3911 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); 3912 } 3913 3914 // move file pointer to the specified offset 3915 jlong os::seek_to_file_offset(int fd, jlong offset) { 3916 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); 3917 } 3918 3919 // This code originates from JDK's sysAvailable 3920 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 3921 3922 int os::available(int fd, jlong *bytes) { 3923 jlong cur, end; 3924 int mode; 3925 struct stat buf; 3926 3927 if (::fstat(fd, &buf) >= 0) { 3928 mode = buf.st_mode; 3929 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 3930 // XXX: is the following call interruptible? If so, this might 3931 // need to go through the INTERRUPT_IO() wrapper as for other 3932 // blocking, interruptible calls in this file. 3933 int n; 3934 if (::ioctl(fd, FIONREAD, &n) >= 0) { 3935 *bytes = n; 3936 return 1; 3937 } 3938 } 3939 } 3940 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { 3941 return 0; 3942 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { 3943 return 0; 3944 } else if (::lseek(fd, cur, SEEK_SET) == -1) { 3945 return 0; 3946 } 3947 *bytes = end - cur; 3948 return 1; 3949 } 3950 3951 // Map a block of memory. 3952 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 3953 char *addr, size_t bytes, bool read_only, 3954 bool allow_exec) { 3955 int prot; 3956 int flags; 3957 3958 if (read_only) { 3959 prot = PROT_READ; 3960 flags = MAP_SHARED; 3961 } else { 3962 prot = PROT_READ | PROT_WRITE; 3963 flags = MAP_PRIVATE; 3964 } 3965 3966 if (allow_exec) { 3967 prot |= PROT_EXEC; 3968 } 3969 3970 if (addr != NULL) { 3971 flags |= MAP_FIXED; 3972 } 3973 3974 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 3975 fd, file_offset); 3976 if (mapped_address == MAP_FAILED) { 3977 return NULL; 3978 } 3979 return mapped_address; 3980 } 3981 3982 3983 // Remap a block of memory. 3984 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 3985 char *addr, size_t bytes, bool read_only, 3986 bool allow_exec) { 3987 // same as map_memory() on this OS 3988 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 3989 allow_exec); 3990 } 3991 3992 3993 // Unmap a block of memory. 3994 bool os::pd_unmap_memory(char* addr, size_t bytes) { 3995 return munmap(addr, bytes) == 0; 3996 } 3997 3998 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 3999 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 4000 // of a thread. 4001 // 4002 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 4003 // the fast estimate available on the platform. 4004 4005 jlong os::current_thread_cpu_time() { 4006 #ifdef __APPLE__ 4007 return os::thread_cpu_time(Thread::current(), true /* user + sys */); 4008 #else 4009 Unimplemented(); 4010 return 0; 4011 #endif 4012 } 4013 4014 jlong os::thread_cpu_time(Thread* thread) { 4015 #ifdef __APPLE__ 4016 return os::thread_cpu_time(thread, true /* user + sys */); 4017 #else 4018 Unimplemented(); 4019 return 0; 4020 #endif 4021 } 4022 4023 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 4024 #ifdef __APPLE__ 4025 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); 4026 #else 4027 Unimplemented(); 4028 return 0; 4029 #endif 4030 } 4031 4032 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 4033 #ifdef __APPLE__ 4034 struct thread_basic_info tinfo; 4035 mach_msg_type_number_t tcount = THREAD_INFO_MAX; 4036 kern_return_t kr; 4037 thread_t mach_thread; 4038 4039 mach_thread = thread->osthread()->thread_id(); 4040 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); 4041 if (kr != KERN_SUCCESS) { 4042 return -1; 4043 } 4044 4045 if (user_sys_cpu_time) { 4046 jlong nanos; 4047 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; 4048 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; 4049 return nanos; 4050 } else { 4051 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); 4052 } 4053 #else 4054 Unimplemented(); 4055 return 0; 4056 #endif 4057 } 4058 4059 4060 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4061 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4062 info_ptr->may_skip_backward = false; // elapsed time not wall time 4063 info_ptr->may_skip_forward = false; // elapsed time not wall time 4064 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4065 } 4066 4067 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4068 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4069 info_ptr->may_skip_backward = false; // elapsed time not wall time 4070 info_ptr->may_skip_forward = false; // elapsed time not wall time 4071 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4072 } 4073 4074 bool os::is_thread_cpu_time_supported() { 4075 #ifdef __APPLE__ 4076 return true; 4077 #else 4078 return false; 4079 #endif 4080 } 4081 4082 // System loadavg support. Returns -1 if load average cannot be obtained. 4083 // Bsd doesn't yet have a (official) notion of processor sets, 4084 // so just return the system wide load average. 4085 int os::loadavg(double loadavg[], int nelem) { 4086 return ::getloadavg(loadavg, nelem); 4087 } 4088 4089 void os::pause() { 4090 char filename[MAX_PATH]; 4091 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 4092 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); 4093 } else { 4094 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 4095 } 4096 4097 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 4098 if (fd != -1) { 4099 struct stat buf; 4100 ::close(fd); 4101 while (::stat(filename, &buf) == 0) { 4102 (void)::poll(NULL, 0, 100); 4103 } 4104 } else { 4105 jio_fprintf(stderr, 4106 "Could not open pause file '%s', continuing immediately.\n", filename); 4107 } 4108 } 4109 4110 4111 // Refer to the comments in os_solaris.cpp park-unpark. The next two 4112 // comment paragraphs are worth repeating here: 4113 // 4114 // Assumption: 4115 // Only one parker can exist on an event, which is why we allocate 4116 // them per-thread. Multiple unparkers can coexist. 4117 // 4118 // _Event serves as a restricted-range semaphore. 4119 // -1 : thread is blocked, i.e. there is a waiter 4120 // 0 : neutral: thread is running or ready, 4121 // could have been signaled after a wait started 4122 // 1 : signaled - thread is running or ready 4123 // 4124 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 4125 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 4126 // For specifics regarding the bug see GLIBC BUGID 261237 : 4127 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 4128 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 4129 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 4130 // is used. (The simple C test-case provided in the GLIBC bug report manifests the 4131 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 4132 // and monitorenter when we're using 1-0 locking. All those operations may result in 4133 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 4134 // of libpthread avoids the problem, but isn't practical. 4135 // 4136 // Possible remedies: 4137 // 4138 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 4139 // This is palliative and probabilistic, however. If the thread is preempted 4140 // between the call to compute_abstime() and pthread_cond_timedwait(), more 4141 // than the minimum period may have passed, and the abstime may be stale (in the 4142 // past) resultin in a hang. Using this technique reduces the odds of a hang 4143 // but the JVM is still vulnerable, particularly on heavily loaded systems. 4144 // 4145 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 4146 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set 4147 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 4148 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant 4149 // thread. 4150 // 4151 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 4152 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 4153 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). 4154 // This also works well. In fact it avoids kernel-level scalability impediments 4155 // on certain platforms that don't handle lots of active pthread_cond_timedwait() 4156 // timers in a graceful fashion. 4157 // 4158 // 4. When the abstime value is in the past it appears that control returns 4159 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 4160 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we 4161 // can avoid the problem by reinitializing the condvar -- by cond_destroy() 4162 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). 4163 // It may be possible to avoid reinitialization by checking the return 4164 // value from pthread_cond_timedwait(). In addition to reinitializing the 4165 // condvar we must establish the invariant that cond_signal() is only called 4166 // within critical sections protected by the adjunct mutex. This prevents 4167 // cond_signal() from "seeing" a condvar that's in the midst of being 4168 // reinitialized or that is corrupt. Sadly, this invariant obviates the 4169 // desirable signal-after-unlock optimization that avoids futile context switching. 4170 // 4171 // I'm also concerned that some versions of NTPL might allocate an auxilliary 4172 // structure when a condvar is used or initialized. cond_destroy() would 4173 // release the helper structure. Our reinitialize-after-timedwait fix 4174 // put excessive stress on malloc/free and locks protecting the c-heap. 4175 // 4176 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 4177 // It may be possible to refine (4) by checking the kernel and NTPL verisons 4178 // and only enabling the work-around for vulnerable environments. 4179 4180 // utility to compute the abstime argument to timedwait: 4181 // millis is the relative timeout time 4182 // abstime will be the absolute timeout time 4183 // TODO: replace compute_abstime() with unpackTime() 4184 4185 static struct timespec* compute_abstime(struct timespec* abstime, 4186 jlong millis) { 4187 if (millis < 0) millis = 0; 4188 struct timeval now; 4189 int status = gettimeofday(&now, NULL); 4190 assert(status == 0, "gettimeofday"); 4191 jlong seconds = millis / 1000; 4192 millis %= 1000; 4193 if (seconds > 50000000) { // see man cond_timedwait(3T) 4194 seconds = 50000000; 4195 } 4196 abstime->tv_sec = now.tv_sec + seconds; 4197 long usec = now.tv_usec + millis * 1000; 4198 if (usec >= 1000000) { 4199 abstime->tv_sec += 1; 4200 usec -= 1000000; 4201 } 4202 abstime->tv_nsec = usec * 1000; 4203 return abstime; 4204 } 4205 4206 void os::PlatformEvent::park() { // AKA "down()" 4207 // Transitions for _Event: 4208 // -1 => -1 : illegal 4209 // 1 => 0 : pass - return immediately 4210 // 0 => -1 : block; then set _Event to 0 before returning 4211 4212 // Invariant: Only the thread associated with the Event/PlatformEvent 4213 // may call park(). 4214 // TODO: assert that _Assoc != NULL or _Assoc == Self 4215 assert(_nParked == 0, "invariant"); 4216 4217 int v; 4218 for (;;) { 4219 v = _Event; 4220 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4221 } 4222 guarantee(v >= 0, "invariant"); 4223 if (v == 0) { 4224 // Do this the hard way by blocking ... 4225 int status = pthread_mutex_lock(_mutex); 4226 assert_status(status == 0, status, "mutex_lock"); 4227 guarantee(_nParked == 0, "invariant"); 4228 ++_nParked; 4229 while (_Event < 0) { 4230 status = pthread_cond_wait(_cond, _mutex); 4231 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 4232 // Treat this the same as if the wait was interrupted 4233 if (status == ETIMEDOUT) { status = EINTR; } 4234 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 4235 } 4236 --_nParked; 4237 4238 _Event = 0; 4239 status = pthread_mutex_unlock(_mutex); 4240 assert_status(status == 0, status, "mutex_unlock"); 4241 // Paranoia to ensure our locked and lock-free paths interact 4242 // correctly with each other. 4243 OrderAccess::fence(); 4244 } 4245 guarantee(_Event >= 0, "invariant"); 4246 } 4247 4248 int os::PlatformEvent::park(jlong millis) { 4249 // Transitions for _Event: 4250 // -1 => -1 : illegal 4251 // 1 => 0 : pass - return immediately 4252 // 0 => -1 : block; then set _Event to 0 before returning 4253 4254 guarantee(_nParked == 0, "invariant"); 4255 4256 int v; 4257 for (;;) { 4258 v = _Event; 4259 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4260 } 4261 guarantee(v >= 0, "invariant"); 4262 if (v != 0) return OS_OK; 4263 4264 // We do this the hard way, by blocking the thread. 4265 // Consider enforcing a minimum timeout value. 4266 struct timespec abst; 4267 compute_abstime(&abst, millis); 4268 4269 int ret = OS_TIMEOUT; 4270 int status = pthread_mutex_lock(_mutex); 4271 assert_status(status == 0, status, "mutex_lock"); 4272 guarantee(_nParked == 0, "invariant"); 4273 ++_nParked; 4274 4275 // Object.wait(timo) will return because of 4276 // (a) notification 4277 // (b) timeout 4278 // (c) thread.interrupt 4279 // 4280 // Thread.interrupt and object.notify{All} both call Event::set. 4281 // That is, we treat thread.interrupt as a special case of notification. 4282 // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false. 4283 // We assume all ETIME returns are valid. 4284 // 4285 // TODO: properly differentiate simultaneous notify+interrupt. 4286 // In that case, we should propagate the notify to another waiter. 4287 4288 while (_Event < 0) { 4289 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst); 4290 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4291 pthread_cond_destroy(_cond); 4292 pthread_cond_init(_cond, NULL); 4293 } 4294 assert_status(status == 0 || status == EINTR || 4295 status == ETIMEDOUT, 4296 status, "cond_timedwait"); 4297 if (!FilterSpuriousWakeups) break; // previous semantics 4298 if (status == ETIMEDOUT) break; 4299 // We consume and ignore EINTR and spurious wakeups. 4300 } 4301 --_nParked; 4302 if (_Event >= 0) { 4303 ret = OS_OK; 4304 } 4305 _Event = 0; 4306 status = pthread_mutex_unlock(_mutex); 4307 assert_status(status == 0, status, "mutex_unlock"); 4308 assert(_nParked == 0, "invariant"); 4309 // Paranoia to ensure our locked and lock-free paths interact 4310 // correctly with each other. 4311 OrderAccess::fence(); 4312 return ret; 4313 } 4314 4315 void os::PlatformEvent::unpark() { 4316 // Transitions for _Event: 4317 // 0 => 1 : just return 4318 // 1 => 1 : just return 4319 // -1 => either 0 or 1; must signal target thread 4320 // That is, we can safely transition _Event from -1 to either 4321 // 0 or 1. 4322 // See also: "Semaphores in Plan 9" by Mullender & Cox 4323 // 4324 // Note: Forcing a transition from "-1" to "1" on an unpark() means 4325 // that it will take two back-to-back park() calls for the owning 4326 // thread to block. This has the benefit of forcing a spurious return 4327 // from the first park() call after an unpark() call which will help 4328 // shake out uses of park() and unpark() without condition variables. 4329 4330 if (Atomic::xchg(1, &_Event) >= 0) return; 4331 4332 // Wait for the thread associated with the event to vacate 4333 int status = pthread_mutex_lock(_mutex); 4334 assert_status(status == 0, status, "mutex_lock"); 4335 int AnyWaiters = _nParked; 4336 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 4337 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 4338 AnyWaiters = 0; 4339 pthread_cond_signal(_cond); 4340 } 4341 status = pthread_mutex_unlock(_mutex); 4342 assert_status(status == 0, status, "mutex_unlock"); 4343 if (AnyWaiters != 0) { 4344 // Note that we signal() *after* dropping the lock for "immortal" Events. 4345 // This is safe and avoids a common class of futile wakeups. In rare 4346 // circumstances this can cause a thread to return prematurely from 4347 // cond_{timed}wait() but the spurious wakeup is benign and the victim 4348 // will simply re-test the condition and re-park itself. 4349 // This provides particular benefit if the underlying platform does not 4350 // provide wait morphing. 4351 status = pthread_cond_signal(_cond); 4352 assert_status(status == 0, status, "cond_signal"); 4353 } 4354 } 4355 4356 4357 // JSR166 4358 // ------------------------------------------------------- 4359 4360 // The solaris and bsd implementations of park/unpark are fairly 4361 // conservative for now, but can be improved. They currently use a 4362 // mutex/condvar pair, plus a a count. 4363 // Park decrements count if > 0, else does a condvar wait. Unpark 4364 // sets count to 1 and signals condvar. Only one thread ever waits 4365 // on the condvar. Contention seen when trying to park implies that someone 4366 // is unparking you, so don't wait. And spurious returns are fine, so there 4367 // is no need to track notifications. 4368 4369 #define MAX_SECS 100000000 4370 4371 // This code is common to bsd and solaris and will be moved to a 4372 // common place in dolphin. 4373 // 4374 // The passed in time value is either a relative time in nanoseconds 4375 // or an absolute time in milliseconds. Either way it has to be unpacked 4376 // into suitable seconds and nanoseconds components and stored in the 4377 // given timespec structure. 4378 // Given time is a 64-bit value and the time_t used in the timespec is only 4379 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for 4380 // overflow if times way in the future are given. Further on Solaris versions 4381 // prior to 10 there is a restriction (see cond_timedwait) that the specified 4382 // number of seconds, in abstime, is less than current_time + 100,000,000. 4383 // As it will be 28 years before "now + 100000000" will overflow we can 4384 // ignore overflow and just impose a hard-limit on seconds using the value 4385 // of "now + 100,000,000". This places a limit on the timeout of about 3.17 4386 // years from "now". 4387 4388 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { 4389 assert(time > 0, "convertTime"); 4390 4391 struct timeval now; 4392 int status = gettimeofday(&now, NULL); 4393 assert(status == 0, "gettimeofday"); 4394 4395 time_t max_secs = now.tv_sec + MAX_SECS; 4396 4397 if (isAbsolute) { 4398 jlong secs = time / 1000; 4399 if (secs > max_secs) { 4400 absTime->tv_sec = max_secs; 4401 } else { 4402 absTime->tv_sec = secs; 4403 } 4404 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 4405 } else { 4406 jlong secs = time / NANOSECS_PER_SEC; 4407 if (secs >= MAX_SECS) { 4408 absTime->tv_sec = max_secs; 4409 absTime->tv_nsec = 0; 4410 } else { 4411 absTime->tv_sec = now.tv_sec + secs; 4412 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 4413 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 4414 absTime->tv_nsec -= NANOSECS_PER_SEC; 4415 ++absTime->tv_sec; // note: this must be <= max_secs 4416 } 4417 } 4418 } 4419 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 4420 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 4421 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 4422 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 4423 } 4424 4425 void Parker::park(bool isAbsolute, jlong time) { 4426 // Ideally we'd do something useful while spinning, such 4427 // as calling unpackTime(). 4428 4429 // Optional fast-path check: 4430 // Return immediately if a permit is available. 4431 // We depend on Atomic::xchg() having full barrier semantics 4432 // since we are doing a lock-free update to _counter. 4433 if (Atomic::xchg(0, &_counter) > 0) return; 4434 4435 Thread* thread = Thread::current(); 4436 assert(thread->is_Java_thread(), "Must be JavaThread"); 4437 JavaThread *jt = (JavaThread *)thread; 4438 4439 // Optional optimization -- avoid state transitions if there's an interrupt pending. 4440 // Check interrupt before trying to wait 4441 if (Thread::is_interrupted(thread, false)) { 4442 return; 4443 } 4444 4445 // Next, demultiplex/decode time arguments 4446 struct timespec absTime; 4447 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all 4448 return; 4449 } 4450 if (time > 0) { 4451 unpackTime(&absTime, isAbsolute, time); 4452 } 4453 4454 4455 // Enter safepoint region 4456 // Beware of deadlocks such as 6317397. 4457 // The per-thread Parker:: mutex is a classic leaf-lock. 4458 // In particular a thread must never block on the Threads_lock while 4459 // holding the Parker:: mutex. If safepoints are pending both the 4460 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 4461 ThreadBlockInVM tbivm(jt); 4462 4463 // Don't wait if cannot get lock since interference arises from 4464 // unblocking. Also. check interrupt before trying wait 4465 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 4466 return; 4467 } 4468 4469 int status; 4470 if (_counter > 0) { // no wait needed 4471 _counter = 0; 4472 status = pthread_mutex_unlock(_mutex); 4473 assert(status == 0, "invariant"); 4474 // Paranoia to ensure our locked and lock-free paths interact 4475 // correctly with each other and Java-level accesses. 4476 OrderAccess::fence(); 4477 return; 4478 } 4479 4480 #ifdef ASSERT 4481 // Don't catch signals while blocked; let the running threads have the signals. 4482 // (This allows a debugger to break into the running thread.) 4483 sigset_t oldsigs; 4484 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); 4485 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 4486 #endif 4487 4488 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 4489 jt->set_suspend_equivalent(); 4490 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 4491 4492 if (time == 0) { 4493 status = pthread_cond_wait(_cond, _mutex); 4494 } else { 4495 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &absTime); 4496 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4497 pthread_cond_destroy(_cond); 4498 pthread_cond_init(_cond, NULL); 4499 } 4500 } 4501 assert_status(status == 0 || status == EINTR || 4502 status == ETIMEDOUT, 4503 status, "cond_timedwait"); 4504 4505 #ifdef ASSERT 4506 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 4507 #endif 4508 4509 _counter = 0; 4510 status = pthread_mutex_unlock(_mutex); 4511 assert_status(status == 0, status, "invariant"); 4512 // Paranoia to ensure our locked and lock-free paths interact 4513 // correctly with each other and Java-level accesses. 4514 OrderAccess::fence(); 4515 4516 // If externally suspended while waiting, re-suspend 4517 if (jt->handle_special_suspend_equivalent_condition()) { 4518 jt->java_suspend_self(); 4519 } 4520 } 4521 4522 void Parker::unpark() { 4523 int status = pthread_mutex_lock(_mutex); 4524 assert(status == 0, "invariant"); 4525 const int s = _counter; 4526 _counter = 1; 4527 if (s < 1) { 4528 if (WorkAroundNPTLTimedWaitHang) { 4529 status = pthread_cond_signal(_cond); 4530 assert(status == 0, "invariant"); 4531 status = pthread_mutex_unlock(_mutex); 4532 assert(status == 0, "invariant"); 4533 } else { 4534 status = pthread_mutex_unlock(_mutex); 4535 assert(status == 0, "invariant"); 4536 status = pthread_cond_signal(_cond); 4537 assert(status == 0, "invariant"); 4538 } 4539 } else { 4540 pthread_mutex_unlock(_mutex); 4541 assert(status == 0, "invariant"); 4542 } 4543 } 4544 4545 4546 // Darwin has no "environ" in a dynamic library. 4547 #ifdef __APPLE__ 4548 #include <crt_externs.h> 4549 #define environ (*_NSGetEnviron()) 4550 #else 4551 extern char** environ; 4552 #endif 4553 4554 // Run the specified command in a separate process. Return its exit value, 4555 // or -1 on failure (e.g. can't fork a new process). 4556 // Unlike system(), this function can be called from signal handler. It 4557 // doesn't block SIGINT et al. 4558 int os::fork_and_exec(char* cmd) { 4559 const char * argv[4] = {"sh", "-c", cmd, NULL}; 4560 4561 // fork() in BsdThreads/NPTL is not async-safe. It needs to run 4562 // pthread_atfork handlers and reset pthread library. All we need is a 4563 // separate process to execve. Make a direct syscall to fork process. 4564 // On IA64 there's no fork syscall, we have to use fork() and hope for 4565 // the best... 4566 pid_t pid = fork(); 4567 4568 if (pid < 0) { 4569 // fork failed 4570 return -1; 4571 4572 } else if (pid == 0) { 4573 // child process 4574 4575 // execve() in BsdThreads will call pthread_kill_other_threads_np() 4576 // first to kill every thread on the thread list. Because this list is 4577 // not reset by fork() (see notes above), execve() will instead kill 4578 // every thread in the parent process. We know this is the only thread 4579 // in the new process, so make a system call directly. 4580 // IA64 should use normal execve() from glibc to match the glibc fork() 4581 // above. 4582 execve("/bin/sh", (char* const*)argv, environ); 4583 4584 // execve failed 4585 _exit(-1); 4586 4587 } else { 4588 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 4589 // care about the actual exit code, for now. 4590 4591 int status; 4592 4593 // Wait for the child process to exit. This returns immediately if 4594 // the child has already exited. */ 4595 while (waitpid(pid, &status, 0) < 0) { 4596 switch (errno) { 4597 case ECHILD: return 0; 4598 case EINTR: break; 4599 default: return -1; 4600 } 4601 } 4602 4603 if (WIFEXITED(status)) { 4604 // The child exited normally; get its exit code. 4605 return WEXITSTATUS(status); 4606 } else if (WIFSIGNALED(status)) { 4607 // The child exited because of a signal 4608 // The best value to return is 0x80 + signal number, 4609 // because that is what all Unix shells do, and because 4610 // it allows callers to distinguish between process exit and 4611 // process death by signal. 4612 return 0x80 + WTERMSIG(status); 4613 } else { 4614 // Unknown exit code; pass it through 4615 return status; 4616 } 4617 } 4618 } 4619 4620 // is_headless_jre() 4621 // 4622 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 4623 // in order to report if we are running in a headless jre 4624 // 4625 // Since JDK8 xawt/libmawt.so was moved into the same directory 4626 // as libawt.so, and renamed libawt_xawt.so 4627 // 4628 bool os::is_headless_jre() { 4629 #ifdef __APPLE__ 4630 // We no longer build headless-only on Mac OS X 4631 return false; 4632 #else 4633 struct stat statbuf; 4634 char buf[MAXPATHLEN]; 4635 char libmawtpath[MAXPATHLEN]; 4636 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX; 4637 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX; 4638 char *p; 4639 4640 // Get path to libjvm.so 4641 os::jvm_path(buf, sizeof(buf)); 4642 4643 // Get rid of libjvm.so 4644 p = strrchr(buf, '/'); 4645 if (p == NULL) { 4646 return false; 4647 } else { 4648 *p = '\0'; 4649 } 4650 4651 // Get rid of client or server 4652 p = strrchr(buf, '/'); 4653 if (p == NULL) { 4654 return false; 4655 } else { 4656 *p = '\0'; 4657 } 4658 4659 // check xawt/libmawt.so 4660 strcpy(libmawtpath, buf); 4661 strcat(libmawtpath, xawtstr); 4662 if (::stat(libmawtpath, &statbuf) == 0) return false; 4663 4664 // check libawt_xawt.so 4665 strcpy(libmawtpath, buf); 4666 strcat(libmawtpath, new_xawtstr); 4667 if (::stat(libmawtpath, &statbuf) == 0) return false; 4668 4669 return true; 4670 #endif 4671 } 4672 4673 // Get the default path to the core file 4674 // Returns the length of the string 4675 int os::get_core_path(char* buffer, size_t bufferSize) { 4676 int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id()); 4677 4678 // Truncate if theoretical string was longer than bufferSize 4679 n = MIN2(n, (int)bufferSize); 4680 4681 return n; 4682 } 4683 4684 #ifndef PRODUCT 4685 void TestReserveMemorySpecial_test() { 4686 // No tests available for this platform 4687 } 4688 #endif