1 /* 2 * Copyright (c) 1999, 2015, 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 "semaphore_bsd.hpp" 63 #include "services/attachListener.hpp" 64 #include "services/memTracker.hpp" 65 #include "services/runtimeService.hpp" 66 #include "utilities/decoder.hpp" 67 #include "utilities/defaultStream.hpp" 68 #include "utilities/events.hpp" 69 #include "utilities/growableArray.hpp" 70 #include "utilities/vmError.hpp" 71 72 // put OS-includes here 73 # include <sys/types.h> 74 # include <sys/mman.h> 75 # include <sys/stat.h> 76 # include <sys/select.h> 77 # include <pthread.h> 78 # include <signal.h> 79 # include <errno.h> 80 # include <dlfcn.h> 81 # include <stdio.h> 82 # include <unistd.h> 83 # include <sys/resource.h> 84 # include <pthread.h> 85 # include <sys/stat.h> 86 # include <sys/time.h> 87 # include <sys/times.h> 88 # include <sys/utsname.h> 89 # include <sys/socket.h> 90 # include <sys/wait.h> 91 # include <time.h> 92 # include <pwd.h> 93 # include <poll.h> 94 # include <semaphore.h> 95 # include <fcntl.h> 96 # include <string.h> 97 # include <sys/param.h> 98 # include <sys/sysctl.h> 99 # include <sys/ipc.h> 100 # include <sys/shm.h> 101 #ifndef __APPLE__ 102 # include <link.h> 103 #endif 104 # include <stdint.h> 105 # include <inttypes.h> 106 # include <sys/ioctl.h> 107 # include <sys/syscall.h> 108 109 #if defined(__FreeBSD__) || defined(__NetBSD__) 110 #include <elf.h> 111 #endif 112 113 #ifdef __APPLE__ 114 #include <mach/mach.h> // semaphore_* API 115 #include <mach-o/dyld.h> 116 #include <sys/proc_info.h> 117 #include <objc/objc-auto.h> 118 #endif 119 120 #ifndef MAP_ANONYMOUS 121 #define MAP_ANONYMOUS MAP_ANON 122 #endif 123 124 #define MAX_PATH (2 * K) 125 126 // for timer info max values which include all bits 127 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 128 129 #define LARGEPAGES_BIT (1 << 6) 130 131 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 132 133 //////////////////////////////////////////////////////////////////////////////// 134 // global variables 135 julong os::Bsd::_physical_memory = 0; 136 137 #ifdef __APPLE__ 138 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0}; 139 volatile uint64_t os::Bsd::_max_abstime = 0; 140 #else 141 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; 142 #endif 143 pthread_t os::Bsd::_main_thread; 144 int os::Bsd::_page_size = -1; 145 146 static jlong initial_time_count=0; 147 148 static int clock_tics_per_sec = 100; 149 150 // For diagnostics to print a message once. see run_periodic_checks 151 static sigset_t check_signal_done; 152 static bool check_signals = true; 153 154 static pid_t _initial_pid = 0; 155 156 // Signal number used to suspend/resume a thread 157 158 // do not use any signal number less than SIGSEGV, see 4355769 159 static int SR_signum = SIGUSR2; 160 sigset_t SR_sigset; 161 162 163 //////////////////////////////////////////////////////////////////////////////// 164 // utility functions 165 166 static int SR_initialize(); 167 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time); 168 169 julong os::available_memory() { 170 return Bsd::available_memory(); 171 } 172 173 // available here means free 174 julong os::Bsd::available_memory() { 175 uint64_t available = physical_memory() >> 2; 176 #ifdef __APPLE__ 177 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT; 178 vm_statistics64_data_t vmstat; 179 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64, 180 (host_info64_t)&vmstat, &count); 181 assert(kerr == KERN_SUCCESS, 182 "host_statistics64 failed - check mach_host_self() and count"); 183 if (kerr == KERN_SUCCESS) { 184 available = vmstat.free_count * os::vm_page_size(); 185 } 186 #endif 187 return available; 188 } 189 190 julong os::physical_memory() { 191 return Bsd::physical_memory(); 192 } 193 194 // Return true if user is running as root. 195 196 bool os::have_special_privileges() { 197 static bool init = false; 198 static bool privileges = false; 199 if (!init) { 200 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 201 init = true; 202 } 203 return privileges; 204 } 205 206 207 208 // Cpu architecture string 209 #if defined(ZERO) 210 static char cpu_arch[] = ZERO_LIBARCH; 211 #elif defined(IA64) 212 static char cpu_arch[] = "ia64"; 213 #elif defined(IA32) 214 static char cpu_arch[] = "i386"; 215 #elif defined(AMD64) 216 static char cpu_arch[] = "amd64"; 217 #elif defined(ARM) 218 static char cpu_arch[] = "arm"; 219 #elif defined(PPC32) 220 static char cpu_arch[] = "ppc"; 221 #elif defined(SPARC) 222 #ifdef _LP64 223 static char cpu_arch[] = "sparcv9"; 224 #else 225 static char cpu_arch[] = "sparc"; 226 #endif 227 #else 228 #error Add appropriate cpu_arch setting 229 #endif 230 231 // Compiler variant 232 #ifdef COMPILER2 233 #define COMPILER_VARIANT "server" 234 #else 235 #define COMPILER_VARIANT "client" 236 #endif 237 238 239 void os::Bsd::initialize_system_info() { 240 int mib[2]; 241 size_t len; 242 int cpu_val; 243 julong mem_val; 244 245 // get processors count via hw.ncpus sysctl 246 mib[0] = CTL_HW; 247 mib[1] = HW_NCPU; 248 len = sizeof(cpu_val); 249 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) { 250 assert(len == sizeof(cpu_val), "unexpected data size"); 251 set_processor_count(cpu_val); 252 } else { 253 set_processor_count(1); // fallback 254 } 255 256 // get physical memory via hw.memsize sysctl (hw.memsize is used 257 // since it returns a 64 bit value) 258 mib[0] = CTL_HW; 259 260 #if defined (HW_MEMSIZE) // Apple 261 mib[1] = HW_MEMSIZE; 262 #elif defined(HW_PHYSMEM) // Most of BSD 263 mib[1] = HW_PHYSMEM; 264 #elif defined(HW_REALMEM) // Old FreeBSD 265 mib[1] = HW_REALMEM; 266 #else 267 #error No ways to get physmem 268 #endif 269 270 len = sizeof(mem_val); 271 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) { 272 assert(len == sizeof(mem_val), "unexpected data size"); 273 _physical_memory = mem_val; 274 } else { 275 _physical_memory = 256 * 1024 * 1024; // fallback (XXXBSD?) 276 } 277 278 #ifdef __OpenBSD__ 279 { 280 // limit _physical_memory memory view on OpenBSD since 281 // datasize rlimit restricts us anyway. 282 struct rlimit limits; 283 getrlimit(RLIMIT_DATA, &limits); 284 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur); 285 } 286 #endif 287 } 288 289 #ifdef __APPLE__ 290 static const char *get_home() { 291 const char *home_dir = ::getenv("HOME"); 292 if ((home_dir == NULL) || (*home_dir == '\0')) { 293 struct passwd *passwd_info = getpwuid(geteuid()); 294 if (passwd_info != NULL) { 295 home_dir = passwd_info->pw_dir; 296 } 297 } 298 299 return home_dir; 300 } 301 #endif 302 303 void os::init_system_properties_values() { 304 // The next steps are taken in the product version: 305 // 306 // Obtain the JAVA_HOME value from the location of libjvm.so. 307 // This library should be located at: 308 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so. 309 // 310 // If "/jre/lib/" appears at the right place in the path, then we 311 // assume libjvm.so is installed in a JDK and we use this path. 312 // 313 // Otherwise exit with message: "Could not create the Java virtual machine." 314 // 315 // The following extra steps are taken in the debugging version: 316 // 317 // If "/jre/lib/" does NOT appear at the right place in the path 318 // instead of exit check for $JAVA_HOME environment variable. 319 // 320 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 321 // then we append a fake suffix "hotspot/libjvm.so" to this path so 322 // it looks like libjvm.so is installed there 323 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 324 // 325 // Otherwise exit. 326 // 327 // Important note: if the location of libjvm.so changes this 328 // code needs to be changed accordingly. 329 330 // See ld(1): 331 // The linker uses the following search paths to locate required 332 // shared libraries: 333 // 1: ... 334 // ... 335 // 7: The default directories, normally /lib and /usr/lib. 336 #ifndef DEFAULT_LIBPATH 337 #define DEFAULT_LIBPATH "/lib:/usr/lib" 338 #endif 339 340 // Base path of extensions installed on the system. 341 #define SYS_EXT_DIR "/usr/java/packages" 342 #define EXTENSIONS_DIR "/lib/ext" 343 344 #ifndef __APPLE__ 345 346 // Buffer that fits several sprintfs. 347 // Note that the space for the colon and the trailing null are provided 348 // by the nulls included by the sizeof operator. 349 const size_t bufsize = 350 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. 351 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir 352 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 353 354 // sysclasspath, java_home, dll_dir 355 { 356 char *pslash; 357 os::jvm_path(buf, bufsize); 358 359 // Found the full path to libjvm.so. 360 // Now cut the path to <java_home>/jre if we can. 361 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 362 pslash = strrchr(buf, '/'); 363 if (pslash != NULL) { 364 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 365 } 366 Arguments::set_dll_dir(buf); 367 368 if (pslash != NULL) { 369 pslash = strrchr(buf, '/'); 370 if (pslash != NULL) { 371 *pslash = '\0'; // Get rid of /<arch>. 372 pslash = strrchr(buf, '/'); 373 if (pslash != NULL) { 374 *pslash = '\0'; // Get rid of /lib. 375 } 376 } 377 } 378 Arguments::set_java_home(buf); 379 set_boot_path('/', ':'); 380 } 381 382 // Where to look for native libraries. 383 // 384 // Note: Due to a legacy implementation, most of the library path 385 // is set in the launcher. This was to accomodate linking restrictions 386 // on legacy Bsd implementations (which are no longer supported). 387 // Eventually, all the library path setting will be done here. 388 // 389 // However, to prevent the proliferation of improperly built native 390 // libraries, the new path component /usr/java/packages is added here. 391 // Eventually, all the library path setting will be done here. 392 { 393 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 394 // should always exist (until the legacy problem cited above is 395 // addressed). 396 const char *v = ::getenv("LD_LIBRARY_PATH"); 397 const char *v_colon = ":"; 398 if (v == NULL) { v = ""; v_colon = ""; } 399 // That's +1 for the colon and +1 for the trailing '\0'. 400 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 401 strlen(v) + 1 + 402 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1, 403 mtInternal); 404 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch); 405 Arguments::set_library_path(ld_library_path); 406 FREE_C_HEAP_ARRAY(char, ld_library_path); 407 } 408 409 // Extensions directories. 410 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 411 Arguments::set_ext_dirs(buf); 412 413 FREE_C_HEAP_ARRAY(char, buf); 414 415 #else // __APPLE__ 416 417 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions" 418 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java" 419 420 const char *user_home_dir = get_home(); 421 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir. 422 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) + 423 sizeof(SYS_EXTENSIONS_DIRS); 424 425 // Buffer that fits several sprintfs. 426 // Note that the space for the colon and the trailing null are provided 427 // by the nulls included by the sizeof operator. 428 const size_t bufsize = 429 MAX2((size_t)MAXPATHLEN, // for dll_dir & friends. 430 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir 431 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 432 433 // sysclasspath, java_home, dll_dir 434 { 435 char *pslash; 436 os::jvm_path(buf, bufsize); 437 438 // Found the full path to libjvm.so. 439 // Now cut the path to <java_home>/jre if we can. 440 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 441 pslash = strrchr(buf, '/'); 442 if (pslash != NULL) { 443 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 444 } 445 Arguments::set_dll_dir(buf); 446 447 if (pslash != NULL) { 448 pslash = strrchr(buf, '/'); 449 if (pslash != NULL) { 450 *pslash = '\0'; // Get rid of /lib. 451 } 452 } 453 Arguments::set_java_home(buf); 454 set_boot_path('/', ':'); 455 } 456 457 // Where to look for native libraries. 458 // 459 // Note: Due to a legacy implementation, most of the library path 460 // is set in the launcher. This was to accomodate linking restrictions 461 // on legacy Bsd implementations (which are no longer supported). 462 // Eventually, all the library path setting will be done here. 463 // 464 // However, to prevent the proliferation of improperly built native 465 // libraries, the new path component /usr/java/packages is added here. 466 // Eventually, all the library path setting will be done here. 467 { 468 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 469 // should always exist (until the legacy problem cited above is 470 // addressed). 471 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code 472 // can specify a directory inside an app wrapper 473 const char *l = ::getenv("JAVA_LIBRARY_PATH"); 474 const char *l_colon = ":"; 475 if (l == NULL) { l = ""; l_colon = ""; } 476 477 const char *v = ::getenv("DYLD_LIBRARY_PATH"); 478 const char *v_colon = ":"; 479 if (v == NULL) { v = ""; v_colon = ""; } 480 481 // Apple's Java6 has "." at the beginning of java.library.path. 482 // OpenJDK on Windows has "." at the end of java.library.path. 483 // OpenJDK on Linux and Solaris don't have "." in java.library.path 484 // at all. To ease the transition from Apple's Java6 to OpenJDK7, 485 // "." is appended to the end of java.library.path. Yes, this 486 // could cause a change in behavior, but Apple's Java6 behavior 487 // can be achieved by putting "." at the beginning of the 488 // JAVA_LIBRARY_PATH environment variable. 489 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 490 strlen(v) + 1 + strlen(l) + 1 + 491 system_ext_size + 3, 492 mtInternal); 493 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.", 494 v, v_colon, l, l_colon, user_home_dir); 495 Arguments::set_library_path(ld_library_path); 496 FREE_C_HEAP_ARRAY(char, ld_library_path); 497 } 498 499 // Extensions directories. 500 // 501 // Note that the space for the colon and the trailing null are provided 502 // by the nulls included by the sizeof operator (so actually one byte more 503 // than necessary is allocated). 504 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, 505 user_home_dir, Arguments::get_java_home()); 506 Arguments::set_ext_dirs(buf); 507 508 FREE_C_HEAP_ARRAY(char, buf); 509 510 #undef SYS_EXTENSIONS_DIR 511 #undef SYS_EXTENSIONS_DIRS 512 513 #endif // __APPLE__ 514 515 #undef SYS_EXT_DIR 516 #undef EXTENSIONS_DIR 517 } 518 519 //////////////////////////////////////////////////////////////////////////////// 520 // breakpoint support 521 522 void os::breakpoint() { 523 BREAKPOINT; 524 } 525 526 extern "C" void breakpoint() { 527 // use debugger to set breakpoint here 528 } 529 530 //////////////////////////////////////////////////////////////////////////////// 531 // signal support 532 533 debug_only(static bool signal_sets_initialized = false); 534 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 535 536 bool os::Bsd::is_sig_ignored(int sig) { 537 struct sigaction oact; 538 sigaction(sig, (struct sigaction*)NULL, &oact); 539 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 540 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 541 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) { 542 return true; 543 } else { 544 return false; 545 } 546 } 547 548 void os::Bsd::signal_sets_init() { 549 // Should also have an assertion stating we are still single-threaded. 550 assert(!signal_sets_initialized, "Already initialized"); 551 // Fill in signals that are necessarily unblocked for all threads in 552 // the VM. Currently, we unblock the following signals: 553 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 554 // by -Xrs (=ReduceSignalUsage)); 555 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 556 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 557 // the dispositions or masks wrt these signals. 558 // Programs embedding the VM that want to use the above signals for their 559 // own purposes must, at this time, use the "-Xrs" option to prevent 560 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 561 // (See bug 4345157, and other related bugs). 562 // In reality, though, unblocking these signals is really a nop, since 563 // these signals are not blocked by default. 564 sigemptyset(&unblocked_sigs); 565 sigemptyset(&allowdebug_blocked_sigs); 566 sigaddset(&unblocked_sigs, SIGILL); 567 sigaddset(&unblocked_sigs, SIGSEGV); 568 sigaddset(&unblocked_sigs, SIGBUS); 569 sigaddset(&unblocked_sigs, SIGFPE); 570 sigaddset(&unblocked_sigs, SR_signum); 571 572 if (!ReduceSignalUsage) { 573 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 574 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 575 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); 576 } 577 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 578 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 579 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); 580 } 581 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 582 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 583 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); 584 } 585 } 586 // Fill in signals that are blocked by all but the VM thread. 587 sigemptyset(&vm_sigs); 588 if (!ReduceSignalUsage) { 589 sigaddset(&vm_sigs, BREAK_SIGNAL); 590 } 591 debug_only(signal_sets_initialized = true); 592 593 } 594 595 // These are signals that are unblocked while a thread is running Java. 596 // (For some reason, they get blocked by default.) 597 sigset_t* os::Bsd::unblocked_signals() { 598 assert(signal_sets_initialized, "Not initialized"); 599 return &unblocked_sigs; 600 } 601 602 // These are the signals that are blocked while a (non-VM) thread is 603 // running Java. Only the VM thread handles these signals. 604 sigset_t* os::Bsd::vm_signals() { 605 assert(signal_sets_initialized, "Not initialized"); 606 return &vm_sigs; 607 } 608 609 // These are signals that are blocked during cond_wait to allow debugger in 610 sigset_t* os::Bsd::allowdebug_blocked_signals() { 611 assert(signal_sets_initialized, "Not initialized"); 612 return &allowdebug_blocked_sigs; 613 } 614 615 void os::Bsd::hotspot_sigmask(Thread* thread) { 616 617 //Save caller's signal mask before setting VM signal mask 618 sigset_t caller_sigmask; 619 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 620 621 OSThread* osthread = thread->osthread(); 622 osthread->set_caller_sigmask(caller_sigmask); 623 624 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); 625 626 if (!ReduceSignalUsage) { 627 if (thread->is_VM_thread()) { 628 // Only the VM thread handles BREAK_SIGNAL ... 629 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 630 } else { 631 // ... all other threads block BREAK_SIGNAL 632 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 633 } 634 } 635 } 636 637 638 ////////////////////////////////////////////////////////////////////////////// 639 // create new thread 640 641 #ifdef __APPLE__ 642 // library handle for calling objc_registerThreadWithCollector() 643 // without static linking to the libobjc library 644 #define OBJC_LIB "/usr/lib/libobjc.dylib" 645 #define OBJC_GCREGISTER "objc_registerThreadWithCollector" 646 typedef void (*objc_registerThreadWithCollector_t)(); 647 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction; 648 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL; 649 #endif 650 651 #ifdef __APPLE__ 652 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) { 653 // Additional thread_id used to correlate threads in SA 654 thread_identifier_info_data_t m_ident_info; 655 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT; 656 657 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO, 658 (thread_info_t) &m_ident_info, &count); 659 660 return m_ident_info.thread_id; 661 } 662 #endif 663 664 // Thread start routine for all newly created threads 665 static void *java_start(Thread *thread) { 666 // Try to randomize the cache line index of hot stack frames. 667 // This helps when threads of the same stack traces evict each other's 668 // cache lines. The threads can be either from the same JVM instance, or 669 // from different JVM instances. The benefit is especially true for 670 // processors with hyperthreading technology. 671 static int counter = 0; 672 int pid = os::current_process_id(); 673 alloca(((pid ^ counter++) & 7) * 128); 674 675 ThreadLocalStorage::set_thread(thread); 676 677 OSThread* osthread = thread->osthread(); 678 Monitor* sync = osthread->startThread_lock(); 679 680 osthread->set_thread_id(os::Bsd::gettid()); 681 682 #ifdef __APPLE__ 683 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 684 guarantee(unique_thread_id != 0, "unique thread id was not found"); 685 osthread->set_unique_thread_id(unique_thread_id); 686 #endif 687 // initialize signal mask for this thread 688 os::Bsd::hotspot_sigmask(thread); 689 690 // initialize floating point control register 691 os::Bsd::init_thread_fpu_state(); 692 693 #ifdef __APPLE__ 694 // register thread with objc gc 695 if (objc_registerThreadWithCollectorFunction != NULL) { 696 objc_registerThreadWithCollectorFunction(); 697 } 698 #endif 699 700 // handshaking with parent thread 701 { 702 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 703 704 // notify parent thread 705 osthread->set_state(INITIALIZED); 706 sync->notify_all(); 707 708 // wait until os::start_thread() 709 while (osthread->get_state() == INITIALIZED) { 710 sync->wait(Mutex::_no_safepoint_check_flag); 711 } 712 } 713 714 // call one more level start routine 715 thread->run(); 716 717 return 0; 718 } 719 720 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { 721 assert(thread->osthread() == NULL, "caller responsible"); 722 723 // Allocate the OSThread object 724 OSThread* osthread = new OSThread(NULL, NULL); 725 if (osthread == NULL) { 726 return false; 727 } 728 729 // set the correct thread state 730 osthread->set_thread_type(thr_type); 731 732 // Initial state is ALLOCATED but not INITIALIZED 733 osthread->set_state(ALLOCATED); 734 735 thread->set_osthread(osthread); 736 737 // init thread attributes 738 pthread_attr_t attr; 739 pthread_attr_init(&attr); 740 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 741 742 // calculate stack size if it's not specified by caller 743 if (stack_size == 0) { 744 stack_size = os::Bsd::default_stack_size(thr_type); 745 746 switch (thr_type) { 747 case os::java_thread: 748 // Java threads use ThreadStackSize which default value can be 749 // changed with the flag -Xss 750 assert(JavaThread::stack_size_at_create() > 0, "this should be set"); 751 stack_size = JavaThread::stack_size_at_create(); 752 break; 753 case os::compiler_thread: 754 if (CompilerThreadStackSize > 0) { 755 stack_size = (size_t)(CompilerThreadStackSize * K); 756 break; 757 } // else fall through: 758 // use VMThreadStackSize if CompilerThreadStackSize is not defined 759 case os::vm_thread: 760 case os::pgc_thread: 761 case os::cgc_thread: 762 case os::watcher_thread: 763 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 764 break; 765 } 766 } 767 768 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); 769 pthread_attr_setstacksize(&attr, stack_size); 770 771 ThreadState state; 772 773 { 774 pthread_t tid; 775 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 776 777 pthread_attr_destroy(&attr); 778 779 if (ret != 0) { 780 if (PrintMiscellaneous && (Verbose || WizardMode)) { 781 perror("pthread_create()"); 782 } 783 // Need to clean up stuff we've allocated so far 784 thread->set_osthread(NULL); 785 delete osthread; 786 return false; 787 } 788 789 // Store pthread info into the OSThread 790 osthread->set_pthread_id(tid); 791 792 // Wait until child thread is either initialized or aborted 793 { 794 Monitor* sync_with_child = osthread->startThread_lock(); 795 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 796 while ((state = osthread->get_state()) == ALLOCATED) { 797 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 798 } 799 } 800 801 } 802 803 // Aborted due to thread limit being reached 804 if (state == ZOMBIE) { 805 thread->set_osthread(NULL); 806 delete osthread; 807 return false; 808 } 809 810 // The thread is returned suspended (in state INITIALIZED), 811 // and is started higher up in the call chain 812 assert(state == INITIALIZED, "race condition"); 813 return true; 814 } 815 816 ///////////////////////////////////////////////////////////////////////////// 817 // attach existing thread 818 819 // bootstrap the main thread 820 bool os::create_main_thread(JavaThread* thread) { 821 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); 822 return create_attached_thread(thread); 823 } 824 825 bool os::create_attached_thread(JavaThread* thread) { 826 #ifdef ASSERT 827 thread->verify_not_published(); 828 #endif 829 830 // Allocate the OSThread object 831 OSThread* osthread = new OSThread(NULL, NULL); 832 833 if (osthread == NULL) { 834 return false; 835 } 836 837 osthread->set_thread_id(os::Bsd::gettid()); 838 839 // Store pthread info into the OSThread 840 #ifdef __APPLE__ 841 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 842 guarantee(unique_thread_id != 0, "just checking"); 843 osthread->set_unique_thread_id(unique_thread_id); 844 #endif 845 osthread->set_pthread_id(::pthread_self()); 846 847 // initialize floating point control register 848 os::Bsd::init_thread_fpu_state(); 849 850 // Initial thread state is RUNNABLE 851 osthread->set_state(RUNNABLE); 852 853 thread->set_osthread(osthread); 854 855 // initialize signal mask for this thread 856 // and save the caller's signal mask 857 os::Bsd::hotspot_sigmask(thread); 858 859 return true; 860 } 861 862 void os::pd_start_thread(Thread* thread) { 863 OSThread * osthread = thread->osthread(); 864 assert(osthread->get_state() != INITIALIZED, "just checking"); 865 Monitor* sync_with_child = osthread->startThread_lock(); 866 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 867 sync_with_child->notify(); 868 } 869 870 // Free Bsd resources related to the OSThread 871 void os::free_thread(OSThread* osthread) { 872 assert(osthread != NULL, "osthread not set"); 873 874 if (Thread::current()->osthread() == osthread) { 875 // Restore caller's signal mask 876 sigset_t sigmask = osthread->caller_sigmask(); 877 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 878 } 879 880 delete osthread; 881 } 882 883 ////////////////////////////////////////////////////////////////////////////// 884 // thread local storage 885 886 // Restore the thread pointer if the destructor is called. This is in case 887 // someone from JNI code sets up a destructor with pthread_key_create to run 888 // detachCurrentThread on thread death. Unless we restore the thread pointer we 889 // will hang or crash. When detachCurrentThread is called the key will be set 890 // to null and we will not be called again. If detachCurrentThread is never 891 // called we could loop forever depending on the pthread implementation. 892 static void restore_thread_pointer(void* p) { 893 Thread* thread = (Thread*) p; 894 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread); 895 } 896 897 int os::allocate_thread_local_storage() { 898 pthread_key_t key; 899 int rslt = pthread_key_create(&key, restore_thread_pointer); 900 assert(rslt == 0, "cannot allocate thread local storage"); 901 return (int)key; 902 } 903 904 // Note: This is currently not used by VM, as we don't destroy TLS key 905 // on VM exit. 906 void os::free_thread_local_storage(int index) { 907 int rslt = pthread_key_delete((pthread_key_t)index); 908 assert(rslt == 0, "invalid index"); 909 } 910 911 void os::thread_local_storage_at_put(int index, void* value) { 912 int rslt = pthread_setspecific((pthread_key_t)index, value); 913 assert(rslt == 0, "pthread_setspecific failed"); 914 } 915 916 extern "C" Thread* get_thread() { 917 return ThreadLocalStorage::thread(); 918 } 919 920 921 //////////////////////////////////////////////////////////////////////////////// 922 // time support 923 924 // Time since start-up in seconds to a fine granularity. 925 // Used by VMSelfDestructTimer and the MemProfiler. 926 double os::elapsedTime() { 927 928 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); 929 } 930 931 jlong os::elapsed_counter() { 932 return javaTimeNanos() - initial_time_count; 933 } 934 935 jlong os::elapsed_frequency() { 936 return NANOSECS_PER_SEC; // nanosecond resolution 937 } 938 939 bool os::supports_vtime() { return true; } 940 bool os::enable_vtime() { return false; } 941 bool os::vtime_enabled() { return false; } 942 943 double os::elapsedVTime() { 944 // better than nothing, but not much 945 return elapsedTime(); 946 } 947 948 jlong os::javaTimeMillis() { 949 timeval time; 950 int status = gettimeofday(&time, NULL); 951 assert(status != -1, "bsd error"); 952 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 953 } 954 955 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) { 956 timeval time; 957 int status = gettimeofday(&time, NULL); 958 assert(status != -1, "bsd error"); 959 seconds = jlong(time.tv_sec); 960 nanos = jlong(time.tv_usec) * 1000; 961 } 962 963 #ifndef __APPLE__ 964 #ifndef CLOCK_MONOTONIC 965 #define CLOCK_MONOTONIC (1) 966 #endif 967 #endif 968 969 #ifdef __APPLE__ 970 void os::Bsd::clock_init() { 971 mach_timebase_info(&_timebase_info); 972 } 973 #else 974 void os::Bsd::clock_init() { 975 struct timespec res; 976 struct timespec tp; 977 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && 978 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { 979 // yes, monotonic clock is supported 980 _clock_gettime = ::clock_gettime; 981 } 982 } 983 #endif 984 985 986 987 #ifdef __APPLE__ 988 989 jlong os::javaTimeNanos() { 990 const uint64_t tm = mach_absolute_time(); 991 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom; 992 const uint64_t prev = Bsd::_max_abstime; 993 if (now <= prev) { 994 return prev; // same or retrograde time; 995 } 996 const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev); 997 assert(obsv >= prev, "invariant"); // Monotonicity 998 // If the CAS succeeded then we're done and return "now". 999 // If the CAS failed and the observed value "obsv" is >= now then 1000 // we should return "obsv". If the CAS failed and now > obsv > prv then 1001 // some other thread raced this thread and installed a new value, in which case 1002 // we could either (a) retry the entire operation, (b) retry trying to install now 1003 // or (c) just return obsv. We use (c). No loop is required although in some cases 1004 // we might discard a higher "now" value in deference to a slightly lower but freshly 1005 // installed obsv value. That's entirely benign -- it admits no new orderings compared 1006 // to (a) or (b) -- and greatly reduces coherence traffic. 1007 // We might also condition (c) on the magnitude of the delta between obsv and now. 1008 // Avoiding excessive CAS operations to hot RW locations is critical. 1009 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate 1010 return (prev == obsv) ? now : obsv; 1011 } 1012 1013 #else // __APPLE__ 1014 1015 jlong os::javaTimeNanos() { 1016 if (os::supports_monotonic_clock()) { 1017 struct timespec tp; 1018 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp); 1019 assert(status == 0, "gettime error"); 1020 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1021 return result; 1022 } else { 1023 timeval time; 1024 int status = gettimeofday(&time, NULL); 1025 assert(status != -1, "bsd error"); 1026 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1027 return 1000 * usecs; 1028 } 1029 } 1030 1031 #endif // __APPLE__ 1032 1033 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1034 if (os::supports_monotonic_clock()) { 1035 info_ptr->max_value = ALL_64_BITS; 1036 1037 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1038 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1039 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1040 } else { 1041 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1042 info_ptr->max_value = ALL_64_BITS; 1043 1044 // gettimeofday is a real time clock so it skips 1045 info_ptr->may_skip_backward = true; 1046 info_ptr->may_skip_forward = true; 1047 } 1048 1049 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1050 } 1051 1052 // Return the real, user, and system times in seconds from an 1053 // arbitrary fixed point in the past. 1054 bool os::getTimesSecs(double* process_real_time, 1055 double* process_user_time, 1056 double* process_system_time) { 1057 struct tms ticks; 1058 clock_t real_ticks = times(&ticks); 1059 1060 if (real_ticks == (clock_t) (-1)) { 1061 return false; 1062 } else { 1063 double ticks_per_second = (double) clock_tics_per_sec; 1064 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1065 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1066 *process_real_time = ((double) real_ticks) / ticks_per_second; 1067 1068 return true; 1069 } 1070 } 1071 1072 1073 char * os::local_time_string(char *buf, size_t buflen) { 1074 struct tm t; 1075 time_t long_time; 1076 time(&long_time); 1077 localtime_r(&long_time, &t); 1078 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1079 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1080 t.tm_hour, t.tm_min, t.tm_sec); 1081 return buf; 1082 } 1083 1084 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1085 return localtime_r(clock, res); 1086 } 1087 1088 //////////////////////////////////////////////////////////////////////////////// 1089 // runtime exit support 1090 1091 // Note: os::shutdown() might be called very early during initialization, or 1092 // called from signal handler. Before adding something to os::shutdown(), make 1093 // sure it is async-safe and can handle partially initialized VM. 1094 void os::shutdown() { 1095 1096 // allow PerfMemory to attempt cleanup of any persistent resources 1097 perfMemory_exit(); 1098 1099 // needs to remove object in file system 1100 AttachListener::abort(); 1101 1102 // flush buffered output, finish log files 1103 ostream_abort(); 1104 1105 // Check for abort hook 1106 abort_hook_t abort_hook = Arguments::abort_hook(); 1107 if (abort_hook != NULL) { 1108 abort_hook(); 1109 } 1110 1111 } 1112 1113 // Note: os::abort() might be called very early during initialization, or 1114 // called from signal handler. Before adding something to os::abort(), make 1115 // sure it is async-safe and can handle partially initialized VM. 1116 void os::abort(bool dump_core, void* siginfo, void* context) { 1117 os::shutdown(); 1118 if (dump_core) { 1119 #ifndef PRODUCT 1120 fdStream out(defaultStream::output_fd()); 1121 out.print_raw("Current thread is "); 1122 char buf[16]; 1123 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1124 out.print_raw_cr(buf); 1125 out.print_raw_cr("Dumping core ..."); 1126 #endif 1127 ::abort(); // dump core 1128 } 1129 1130 ::exit(1); 1131 } 1132 1133 // Die immediately, no exit hook, no abort hook, no cleanup. 1134 void os::die() { 1135 // _exit() on BsdThreads only kills current thread 1136 ::abort(); 1137 } 1138 1139 // This method is a copy of JDK's sysGetLastErrorString 1140 // from src/solaris/hpi/src/system_md.c 1141 1142 size_t os::lasterror(char *buf, size_t len) { 1143 if (errno == 0) return 0; 1144 1145 const char *s = ::strerror(errno); 1146 size_t n = ::strlen(s); 1147 if (n >= len) { 1148 n = len - 1; 1149 } 1150 ::strncpy(buf, s, n); 1151 buf[n] = '\0'; 1152 return n; 1153 } 1154 1155 // Information of current thread in variety of formats 1156 pid_t os::Bsd::gettid() { 1157 int retval = -1; 1158 1159 #ifdef __APPLE__ //XNU kernel 1160 // despite the fact mach port is actually not a thread id use it 1161 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4 1162 retval = ::pthread_mach_thread_np(::pthread_self()); 1163 guarantee(retval != 0, "just checking"); 1164 return retval; 1165 1166 #else 1167 #ifdef __FreeBSD__ 1168 retval = syscall(SYS_thr_self); 1169 #else 1170 #ifdef __OpenBSD__ 1171 retval = syscall(SYS_getthrid); 1172 #else 1173 #ifdef __NetBSD__ 1174 retval = (pid_t) syscall(SYS__lwp_self); 1175 #endif 1176 #endif 1177 #endif 1178 #endif 1179 1180 if (retval == -1) { 1181 return getpid(); 1182 } 1183 } 1184 1185 intx os::current_thread_id() { 1186 #ifdef __APPLE__ 1187 return (intx)::pthread_mach_thread_np(::pthread_self()); 1188 #else 1189 return (intx)::pthread_self(); 1190 #endif 1191 } 1192 1193 int os::current_process_id() { 1194 1195 // Under the old bsd thread library, bsd gives each thread 1196 // its own process id. Because of this each thread will return 1197 // a different pid if this method were to return the result 1198 // of getpid(2). Bsd provides no api that returns the pid 1199 // of the launcher thread for the vm. This implementation 1200 // returns a unique pid, the pid of the launcher thread 1201 // that starts the vm 'process'. 1202 1203 // Under the NPTL, getpid() returns the same pid as the 1204 // launcher thread rather than a unique pid per thread. 1205 // Use gettid() if you want the old pre NPTL behaviour. 1206 1207 // if you are looking for the result of a call to getpid() that 1208 // returns a unique pid for the calling thread, then look at the 1209 // OSThread::thread_id() method in osThread_bsd.hpp file 1210 1211 return (int)(_initial_pid ? _initial_pid : getpid()); 1212 } 1213 1214 // DLL functions 1215 1216 #define JNI_LIB_PREFIX "lib" 1217 #ifdef __APPLE__ 1218 #define JNI_LIB_SUFFIX ".dylib" 1219 #else 1220 #define JNI_LIB_SUFFIX ".so" 1221 #endif 1222 1223 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } 1224 1225 // This must be hard coded because it's the system's temporary 1226 // directory not the java application's temp directory, ala java.io.tmpdir. 1227 #ifdef __APPLE__ 1228 // macosx has a secure per-user temporary directory 1229 char temp_path_storage[PATH_MAX]; 1230 const char* os::get_temp_directory() { 1231 static char *temp_path = NULL; 1232 if (temp_path == NULL) { 1233 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX); 1234 if (pathSize == 0 || pathSize > PATH_MAX) { 1235 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage)); 1236 } 1237 temp_path = temp_path_storage; 1238 } 1239 return temp_path; 1240 } 1241 #else // __APPLE__ 1242 const char* os::get_temp_directory() { return "/tmp"; } 1243 #endif // __APPLE__ 1244 1245 static bool file_exists(const char* filename) { 1246 struct stat statbuf; 1247 if (filename == NULL || strlen(filename) == 0) { 1248 return false; 1249 } 1250 return os::stat(filename, &statbuf) == 0; 1251 } 1252 1253 bool os::dll_build_name(char* buffer, size_t buflen, 1254 const char* pname, const char* fname) { 1255 bool retval = false; 1256 // Copied from libhpi 1257 const size_t pnamelen = pname ? strlen(pname) : 0; 1258 1259 // Return error on buffer overflow. 1260 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { 1261 return retval; 1262 } 1263 1264 if (pnamelen == 0) { 1265 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); 1266 retval = true; 1267 } else if (strchr(pname, *os::path_separator()) != NULL) { 1268 int n; 1269 char** pelements = split_path(pname, &n); 1270 if (pelements == NULL) { 1271 return false; 1272 } 1273 for (int i = 0; i < n; i++) { 1274 // Really shouldn't be NULL, but check can't hurt 1275 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1276 continue; // skip the empty path values 1277 } 1278 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, 1279 pelements[i], fname); 1280 if (file_exists(buffer)) { 1281 retval = true; 1282 break; 1283 } 1284 } 1285 // release the storage 1286 for (int i = 0; i < n; i++) { 1287 if (pelements[i] != NULL) { 1288 FREE_C_HEAP_ARRAY(char, pelements[i]); 1289 } 1290 } 1291 if (pelements != NULL) { 1292 FREE_C_HEAP_ARRAY(char*, pelements); 1293 } 1294 } else { 1295 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); 1296 retval = true; 1297 } 1298 return retval; 1299 } 1300 1301 // check if addr is inside libjvm.so 1302 bool os::address_is_in_vm(address addr) { 1303 static address libjvm_base_addr; 1304 Dl_info dlinfo; 1305 1306 if (libjvm_base_addr == NULL) { 1307 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1308 libjvm_base_addr = (address)dlinfo.dli_fbase; 1309 } 1310 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1311 } 1312 1313 if (dladdr((void *)addr, &dlinfo) != 0) { 1314 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1315 } 1316 1317 return false; 1318 } 1319 1320 1321 #define MACH_MAXSYMLEN 256 1322 1323 bool os::dll_address_to_function_name(address addr, char *buf, 1324 int buflen, int *offset, 1325 bool demangle) { 1326 // buf is not optional, but offset is optional 1327 assert(buf != NULL, "sanity check"); 1328 1329 Dl_info dlinfo; 1330 char localbuf[MACH_MAXSYMLEN]; 1331 1332 if (dladdr((void*)addr, &dlinfo) != 0) { 1333 // see if we have a matching symbol 1334 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1335 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) { 1336 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1337 } 1338 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1339 return true; 1340 } 1341 // no matching symbol so try for just file info 1342 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1343 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1344 buf, buflen, offset, dlinfo.dli_fname, demangle)) { 1345 return true; 1346 } 1347 } 1348 1349 // Handle non-dynamic manually: 1350 if (dlinfo.dli_fbase != NULL && 1351 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, 1352 dlinfo.dli_fbase)) { 1353 if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) { 1354 jio_snprintf(buf, buflen, "%s", localbuf); 1355 } 1356 return true; 1357 } 1358 } 1359 buf[0] = '\0'; 1360 if (offset != NULL) *offset = -1; 1361 return false; 1362 } 1363 1364 // ported from solaris version 1365 bool os::dll_address_to_library_name(address addr, char* buf, 1366 int buflen, int* offset) { 1367 // buf is not optional, but offset is optional 1368 assert(buf != NULL, "sanity check"); 1369 1370 Dl_info dlinfo; 1371 1372 if (dladdr((void*)addr, &dlinfo) != 0) { 1373 if (dlinfo.dli_fname != NULL) { 1374 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1375 } 1376 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1377 *offset = addr - (address)dlinfo.dli_fbase; 1378 } 1379 return true; 1380 } 1381 1382 buf[0] = '\0'; 1383 if (offset) *offset = -1; 1384 return false; 1385 } 1386 1387 // Loads .dll/.so and 1388 // in case of error it checks if .dll/.so was built for the 1389 // same architecture as Hotspot is running on 1390 1391 #ifdef __APPLE__ 1392 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1393 void * result= ::dlopen(filename, RTLD_LAZY); 1394 if (result != NULL) { 1395 // Successful loading 1396 return result; 1397 } 1398 1399 // Read system error message into ebuf 1400 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1401 ebuf[ebuflen-1]='\0'; 1402 1403 return NULL; 1404 } 1405 #else 1406 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1407 void * result= ::dlopen(filename, RTLD_LAZY); 1408 if (result != NULL) { 1409 // Successful loading 1410 return result; 1411 } 1412 1413 Elf32_Ehdr elf_head; 1414 1415 // Read system error message into ebuf 1416 // It may or may not be overwritten below 1417 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1418 ebuf[ebuflen-1]='\0'; 1419 int diag_msg_max_length=ebuflen-strlen(ebuf); 1420 char* diag_msg_buf=ebuf+strlen(ebuf); 1421 1422 if (diag_msg_max_length==0) { 1423 // No more space in ebuf for additional diagnostics message 1424 return NULL; 1425 } 1426 1427 1428 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1429 1430 if (file_descriptor < 0) { 1431 // Can't open library, report dlerror() message 1432 return NULL; 1433 } 1434 1435 bool failed_to_read_elf_head= 1436 (sizeof(elf_head)!= 1437 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1438 1439 ::close(file_descriptor); 1440 if (failed_to_read_elf_head) { 1441 // file i/o error - report dlerror() msg 1442 return NULL; 1443 } 1444 1445 typedef struct { 1446 Elf32_Half code; // Actual value as defined in elf.h 1447 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1448 char elf_class; // 32 or 64 bit 1449 char endianess; // MSB or LSB 1450 char* name; // String representation 1451 } arch_t; 1452 1453 #ifndef EM_486 1454 #define EM_486 6 /* Intel 80486 */ 1455 #endif 1456 1457 #ifndef EM_MIPS_RS3_LE 1458 #define EM_MIPS_RS3_LE 10 /* MIPS */ 1459 #endif 1460 1461 #ifndef EM_PPC64 1462 #define EM_PPC64 21 /* PowerPC64 */ 1463 #endif 1464 1465 #ifndef EM_S390 1466 #define EM_S390 22 /* IBM System/390 */ 1467 #endif 1468 1469 #ifndef EM_IA_64 1470 #define EM_IA_64 50 /* HP/Intel IA-64 */ 1471 #endif 1472 1473 #ifndef EM_X86_64 1474 #define EM_X86_64 62 /* AMD x86-64 */ 1475 #endif 1476 1477 static const arch_t arch_array[]={ 1478 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1479 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1480 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1481 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1482 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1483 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1484 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1485 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1486 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1487 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1488 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1489 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1490 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1491 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1492 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1493 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} 1494 }; 1495 1496 #if (defined IA32) 1497 static Elf32_Half running_arch_code=EM_386; 1498 #elif (defined AMD64) 1499 static Elf32_Half running_arch_code=EM_X86_64; 1500 #elif (defined IA64) 1501 static Elf32_Half running_arch_code=EM_IA_64; 1502 #elif (defined __sparc) && (defined _LP64) 1503 static Elf32_Half running_arch_code=EM_SPARCV9; 1504 #elif (defined __sparc) && (!defined _LP64) 1505 static Elf32_Half running_arch_code=EM_SPARC; 1506 #elif (defined __powerpc64__) 1507 static Elf32_Half running_arch_code=EM_PPC64; 1508 #elif (defined __powerpc__) 1509 static Elf32_Half running_arch_code=EM_PPC; 1510 #elif (defined ARM) 1511 static Elf32_Half running_arch_code=EM_ARM; 1512 #elif (defined S390) 1513 static Elf32_Half running_arch_code=EM_S390; 1514 #elif (defined ALPHA) 1515 static Elf32_Half running_arch_code=EM_ALPHA; 1516 #elif (defined MIPSEL) 1517 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1518 #elif (defined PARISC) 1519 static Elf32_Half running_arch_code=EM_PARISC; 1520 #elif (defined MIPS) 1521 static Elf32_Half running_arch_code=EM_MIPS; 1522 #elif (defined M68K) 1523 static Elf32_Half running_arch_code=EM_68K; 1524 #else 1525 #error Method os::dll_load requires that one of following is defined:\ 1526 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K 1527 #endif 1528 1529 // Identify compatability class for VM's architecture and library's architecture 1530 // Obtain string descriptions for architectures 1531 1532 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1533 int running_arch_index=-1; 1534 1535 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1536 if (running_arch_code == arch_array[i].code) { 1537 running_arch_index = i; 1538 } 1539 if (lib_arch.code == arch_array[i].code) { 1540 lib_arch.compat_class = arch_array[i].compat_class; 1541 lib_arch.name = arch_array[i].name; 1542 } 1543 } 1544 1545 assert(running_arch_index != -1, 1546 "Didn't find running architecture code (running_arch_code) in arch_array"); 1547 if (running_arch_index == -1) { 1548 // Even though running architecture detection failed 1549 // we may still continue with reporting dlerror() message 1550 return NULL; 1551 } 1552 1553 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1554 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1555 return NULL; 1556 } 1557 1558 #ifndef S390 1559 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1560 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1561 return NULL; 1562 } 1563 #endif // !S390 1564 1565 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1566 if (lib_arch.name!=NULL) { 1567 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1568 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1569 lib_arch.name, arch_array[running_arch_index].name); 1570 } else { 1571 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1572 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1573 lib_arch.code, 1574 arch_array[running_arch_index].name); 1575 } 1576 } 1577 1578 return NULL; 1579 } 1580 #endif // !__APPLE__ 1581 1582 void* os::get_default_process_handle() { 1583 #ifdef __APPLE__ 1584 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY 1585 // to avoid finding unexpected symbols on second (or later) 1586 // loads of a library. 1587 return (void*)::dlopen(NULL, RTLD_FIRST); 1588 #else 1589 return (void*)::dlopen(NULL, RTLD_LAZY); 1590 #endif 1591 } 1592 1593 // XXX: Do we need a lock around this as per Linux? 1594 void* os::dll_lookup(void* handle, const char* name) { 1595 return dlsym(handle, name); 1596 } 1597 1598 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) { 1599 outputStream * out = (outputStream *) param; 1600 out->print_cr(PTR_FORMAT " \t%s", base_address, name); 1601 return 0; 1602 } 1603 1604 void os::print_dll_info(outputStream *st) { 1605 st->print_cr("Dynamic libraries:"); 1606 if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) { 1607 st->print_cr("Error: Cannot print dynamic libraries."); 1608 } 1609 } 1610 1611 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1612 #ifdef RTLD_DI_LINKMAP 1613 Dl_info dli; 1614 void *handle; 1615 Link_map *map; 1616 Link_map *p; 1617 1618 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 || 1619 dli.dli_fname == NULL) { 1620 return 1; 1621 } 1622 handle = dlopen(dli.dli_fname, RTLD_LAZY); 1623 if (handle == NULL) { 1624 return 1; 1625 } 1626 dlinfo(handle, RTLD_DI_LINKMAP, &map); 1627 if (map == NULL) { 1628 dlclose(handle); 1629 return 1; 1630 } 1631 1632 while (map->l_prev != NULL) 1633 map = map->l_prev; 1634 1635 while (map != NULL) { 1636 // Value for top_address is returned as 0 since we don't have any information about module size 1637 if (callback(map->l_name, (address)map->l_addr, (address)0, param)) { 1638 dlclose(handle); 1639 return 1; 1640 } 1641 map = map->l_next; 1642 } 1643 1644 dlclose(handle); 1645 #elif defined(__APPLE__) 1646 for (uint32_t i = 1; i < _dyld_image_count(); i++) { 1647 // Value for top_address is returned as 0 since we don't have any information about module size 1648 if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) { 1649 return 1; 1650 } 1651 } 1652 return 0; 1653 #else 1654 return 1; 1655 #endif 1656 } 1657 1658 void os::get_summary_os_info(char* buf, size_t buflen) { 1659 // These buffers are small because we want this to be brief 1660 // and not use a lot of stack while generating the hs_err file. 1661 char os[100]; 1662 size_t size = sizeof(os); 1663 int mib_kern[] = { CTL_KERN, KERN_OSTYPE }; 1664 if (sysctl(mib_kern, 2, os, &size, NULL, 0) < 0) { 1665 #ifdef __APPLE__ 1666 strncpy(os, "Darwin", sizeof(os)); 1667 #elif __OpenBSD__ 1668 strncpy(os, "OpenBSD", sizeof(os)); 1669 #else 1670 strncpy(os, "BSD", sizeof(os)); 1671 #endif 1672 } 1673 1674 char release[100]; 1675 size = sizeof(release); 1676 int mib_release[] = { CTL_KERN, KERN_OSRELEASE }; 1677 if (sysctl(mib_release, 2, release, &size, NULL, 0) < 0) { 1678 // if error, leave blank 1679 strncpy(release, "", sizeof(release)); 1680 } 1681 snprintf(buf, buflen, "%s %s", os, release); 1682 } 1683 1684 void os::print_os_info_brief(outputStream* st) { 1685 os::Posix::print_uname_info(st); 1686 } 1687 1688 void os::print_os_info(outputStream* st) { 1689 st->print("OS:"); 1690 1691 os::Posix::print_uname_info(st); 1692 1693 os::Posix::print_rlimit_info(st); 1694 1695 os::Posix::print_load_average(st); 1696 } 1697 1698 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) { 1699 // Nothing to do for now. 1700 } 1701 1702 void os::get_summary_cpu_info(char* buf, size_t buflen) { 1703 unsigned int mhz; 1704 size_t size = sizeof(mhz); 1705 int mib[] = { CTL_HW, HW_CPU_FREQ }; 1706 if (sysctl(mib, 2, &mhz, &size, NULL, 0) < 0) { 1707 mhz = 1; // looks like an error but can be divided by 1708 } else { 1709 mhz /= 1000000; // reported in millions 1710 } 1711 1712 char model[100]; 1713 size = sizeof(model); 1714 int mib_model[] = { CTL_HW, HW_MODEL }; 1715 if (sysctl(mib_model, 2, model, &size, NULL, 0) < 0) { 1716 strncpy(model, cpu_arch, sizeof(model)); 1717 } 1718 1719 char machine[100]; 1720 size = sizeof(machine); 1721 int mib_machine[] = { CTL_HW, HW_MACHINE }; 1722 if (sysctl(mib_machine, 2, machine, &size, NULL, 0) < 0) { 1723 strncpy(machine, "", sizeof(machine)); 1724 } 1725 1726 snprintf(buf, buflen, "%s %s %d MHz", model, machine, mhz); 1727 } 1728 1729 void os::print_memory_info(outputStream* st) { 1730 1731 st->print("Memory:"); 1732 st->print(" %dk page", os::vm_page_size()>>10); 1733 1734 st->print(", physical " UINT64_FORMAT "k", 1735 os::physical_memory() >> 10); 1736 st->print("(" UINT64_FORMAT "k free)", 1737 os::available_memory() >> 10); 1738 st->cr(); 1739 } 1740 1741 void os::print_siginfo(outputStream* st, void* siginfo) { 1742 const siginfo_t* si = (const siginfo_t*)siginfo; 1743 1744 os::Posix::print_siginfo_brief(st, si); 1745 1746 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && 1747 UseSharedSpaces) { 1748 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1749 if (mapinfo->is_in_shared_space(si->si_addr)) { 1750 st->print("\n\nError accessing class data sharing archive." \ 1751 " Mapped file inaccessible during execution, " \ 1752 " possible disk/network problem."); 1753 } 1754 } 1755 st->cr(); 1756 } 1757 1758 1759 static void print_signal_handler(outputStream* st, int sig, 1760 char* buf, size_t buflen); 1761 1762 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 1763 st->print_cr("Signal Handlers:"); 1764 print_signal_handler(st, SIGSEGV, buf, buflen); 1765 print_signal_handler(st, SIGBUS , buf, buflen); 1766 print_signal_handler(st, SIGFPE , buf, buflen); 1767 print_signal_handler(st, SIGPIPE, buf, buflen); 1768 print_signal_handler(st, SIGXFSZ, buf, buflen); 1769 print_signal_handler(st, SIGILL , buf, buflen); 1770 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); 1771 print_signal_handler(st, SR_signum, buf, buflen); 1772 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 1773 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 1774 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 1775 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 1776 } 1777 1778 static char saved_jvm_path[MAXPATHLEN] = {0}; 1779 1780 // Find the full path to the current module, libjvm 1781 void os::jvm_path(char *buf, jint buflen) { 1782 // Error checking. 1783 if (buflen < MAXPATHLEN) { 1784 assert(false, "must use a large-enough buffer"); 1785 buf[0] = '\0'; 1786 return; 1787 } 1788 // Lazy resolve the path to current module. 1789 if (saved_jvm_path[0] != 0) { 1790 strcpy(buf, saved_jvm_path); 1791 return; 1792 } 1793 1794 char dli_fname[MAXPATHLEN]; 1795 bool ret = dll_address_to_library_name( 1796 CAST_FROM_FN_PTR(address, os::jvm_path), 1797 dli_fname, sizeof(dli_fname), NULL); 1798 assert(ret, "cannot locate libjvm"); 1799 char *rp = NULL; 1800 if (ret && dli_fname[0] != '\0') { 1801 rp = realpath(dli_fname, buf); 1802 } 1803 if (rp == NULL) { 1804 return; 1805 } 1806 1807 if (Arguments::sun_java_launcher_is_altjvm()) { 1808 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 1809 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so" 1810 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/" 1811 // appears at the right place in the string, then assume we are 1812 // installed in a JDK and we're done. Otherwise, check for a 1813 // JAVA_HOME environment variable and construct a path to the JVM 1814 // being overridden. 1815 1816 const char *p = buf + strlen(buf) - 1; 1817 for (int count = 0; p > buf && count < 5; ++count) { 1818 for (--p; p > buf && *p != '/'; --p) 1819 /* empty */ ; 1820 } 1821 1822 if (strncmp(p, "/jre/lib/", 9) != 0) { 1823 // Look for JAVA_HOME in the environment. 1824 char* java_home_var = ::getenv("JAVA_HOME"); 1825 if (java_home_var != NULL && java_home_var[0] != 0) { 1826 char* jrelib_p; 1827 int len; 1828 1829 // Check the current module name "libjvm" 1830 p = strrchr(buf, '/'); 1831 assert(strstr(p, "/libjvm") == p, "invalid library name"); 1832 1833 rp = realpath(java_home_var, buf); 1834 if (rp == NULL) { 1835 return; 1836 } 1837 1838 // determine if this is a legacy image or modules image 1839 // modules image doesn't have "jre" subdirectory 1840 len = strlen(buf); 1841 assert(len < buflen, "Ran out of buffer space"); 1842 jrelib_p = buf + len; 1843 1844 // Add the appropriate library subdir 1845 snprintf(jrelib_p, buflen-len, "/jre/lib"); 1846 if (0 != access(buf, F_OK)) { 1847 snprintf(jrelib_p, buflen-len, "/lib"); 1848 } 1849 1850 // Add the appropriate client or server subdir 1851 len = strlen(buf); 1852 jrelib_p = buf + len; 1853 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT); 1854 if (0 != access(buf, F_OK)) { 1855 snprintf(jrelib_p, buflen-len, "%s", ""); 1856 } 1857 1858 // If the path exists within JAVA_HOME, add the JVM library name 1859 // to complete the path to JVM being overridden. Otherwise fallback 1860 // to the path to the current library. 1861 if (0 == access(buf, F_OK)) { 1862 // Use current module name "libjvm" 1863 len = strlen(buf); 1864 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX); 1865 } else { 1866 // Fall back to path of current library 1867 rp = realpath(dli_fname, buf); 1868 if (rp == NULL) { 1869 return; 1870 } 1871 } 1872 } 1873 } 1874 } 1875 1876 strncpy(saved_jvm_path, buf, MAXPATHLEN); 1877 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 1878 } 1879 1880 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 1881 // no prefix required, not even "_" 1882 } 1883 1884 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 1885 // no suffix required 1886 } 1887 1888 //////////////////////////////////////////////////////////////////////////////// 1889 // sun.misc.Signal support 1890 1891 static volatile jint sigint_count = 0; 1892 1893 static void UserHandler(int sig, void *siginfo, void *context) { 1894 // 4511530 - sem_post is serialized and handled by the manager thread. When 1895 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 1896 // don't want to flood the manager thread with sem_post requests. 1897 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 1898 return; 1899 } 1900 1901 // Ctrl-C is pressed during error reporting, likely because the error 1902 // handler fails to abort. Let VM die immediately. 1903 if (sig == SIGINT && is_error_reported()) { 1904 os::die(); 1905 } 1906 1907 os::signal_notify(sig); 1908 } 1909 1910 void* os::user_handler() { 1911 return CAST_FROM_FN_PTR(void*, UserHandler); 1912 } 1913 1914 extern "C" { 1915 typedef void (*sa_handler_t)(int); 1916 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1917 } 1918 1919 void* os::signal(int signal_number, void* handler) { 1920 struct sigaction sigAct, oldSigAct; 1921 1922 sigfillset(&(sigAct.sa_mask)); 1923 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 1924 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 1925 1926 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 1927 // -1 means registration failed 1928 return (void *)-1; 1929 } 1930 1931 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 1932 } 1933 1934 void os::signal_raise(int signal_number) { 1935 ::raise(signal_number); 1936 } 1937 1938 // The following code is moved from os.cpp for making this 1939 // code platform specific, which it is by its very nature. 1940 1941 // Will be modified when max signal is changed to be dynamic 1942 int os::sigexitnum_pd() { 1943 return NSIG; 1944 } 1945 1946 // a counter for each possible signal value 1947 static volatile jint pending_signals[NSIG+1] = { 0 }; 1948 1949 // Bsd(POSIX) specific hand shaking semaphore. 1950 #ifdef __APPLE__ 1951 typedef semaphore_t os_semaphore_t; 1952 1953 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) 1954 #define SEM_WAIT(sem) semaphore_wait(sem) 1955 #define SEM_POST(sem) semaphore_signal(sem) 1956 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem) 1957 #else 1958 typedef sem_t os_semaphore_t; 1959 1960 #define SEM_INIT(sem, value) sem_init(&sem, 0, value) 1961 #define SEM_WAIT(sem) sem_wait(&sem) 1962 #define SEM_POST(sem) sem_post(&sem) 1963 #define SEM_DESTROY(sem) sem_destroy(&sem) 1964 #endif 1965 1966 #ifdef __APPLE__ 1967 // OS X doesn't support unamed POSIX semaphores, so the implementation in os_posix.cpp can't be used. 1968 1969 static const char* sem_init_strerror(kern_return_t value) { 1970 switch (value) { 1971 case KERN_INVALID_ARGUMENT: return "Invalid argument"; 1972 case KERN_RESOURCE_SHORTAGE: return "Resource shortage"; 1973 default: return "Unknown"; 1974 } 1975 } 1976 1977 OSXSemaphore::OSXSemaphore(uint value) { 1978 kern_return_t ret = SEM_INIT(_semaphore, value); 1979 1980 guarantee(ret == KERN_SUCCESS, "Failed to create semaphore: %s", sem_init_strerror(ret)); 1981 } 1982 1983 OSXSemaphore::~OSXSemaphore() { 1984 SEM_DESTROY(_semaphore); 1985 } 1986 1987 void OSXSemaphore::signal(uint count) { 1988 for (uint i = 0; i < count; i++) { 1989 kern_return_t ret = SEM_POST(_semaphore); 1990 1991 assert(ret == KERN_SUCCESS, "Failed to signal semaphore"); 1992 } 1993 } 1994 1995 void OSXSemaphore::wait() { 1996 kern_return_t ret; 1997 while ((ret = SEM_WAIT(_semaphore)) == KERN_ABORTED) { 1998 // Semaphore was interrupted. Retry. 1999 } 2000 assert(ret == KERN_SUCCESS, "Failed to wait on semaphore"); 2001 } 2002 2003 jlong OSXSemaphore::currenttime() { 2004 struct timeval tv; 2005 gettimeofday(&tv, NULL); 2006 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000); 2007 } 2008 2009 bool OSXSemaphore::trywait() { 2010 return timedwait(0, 0); 2011 } 2012 2013 bool OSXSemaphore::timedwait(unsigned int sec, int nsec) { 2014 kern_return_t kr = KERN_ABORTED; 2015 mach_timespec_t waitspec; 2016 waitspec.tv_sec = sec; 2017 waitspec.tv_nsec = nsec; 2018 2019 jlong starttime = currenttime(); 2020 2021 kr = semaphore_timedwait(_semaphore, waitspec); 2022 while (kr == KERN_ABORTED) { 2023 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec; 2024 2025 jlong current = currenttime(); 2026 jlong passedtime = current - starttime; 2027 2028 if (passedtime >= totalwait) { 2029 waitspec.tv_sec = 0; 2030 waitspec.tv_nsec = 0; 2031 } else { 2032 jlong waittime = totalwait - (current - starttime); 2033 waitspec.tv_sec = waittime / NANOSECS_PER_SEC; 2034 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC; 2035 } 2036 2037 kr = semaphore_timedwait(_semaphore, waitspec); 2038 } 2039 2040 return kr == KERN_SUCCESS; 2041 } 2042 2043 #else 2044 // Use POSIX implementation of semaphores. 2045 2046 struct timespec PosixSemaphore::create_timespec(unsigned int sec, int nsec) { 2047 struct timespec ts; 2048 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec); 2049 2050 return ts; 2051 } 2052 2053 #endif // __APPLE__ 2054 2055 static os_semaphore_t sig_sem; 2056 2057 #ifdef __APPLE__ 2058 static OSXSemaphore sr_semaphore; 2059 #else 2060 static PosixSemaphore sr_semaphore; 2061 #endif 2062 2063 void os::signal_init_pd() { 2064 // Initialize signal structures 2065 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2066 2067 // Initialize signal semaphore 2068 ::SEM_INIT(sig_sem, 0); 2069 } 2070 2071 void os::signal_notify(int sig) { 2072 Atomic::inc(&pending_signals[sig]); 2073 ::SEM_POST(sig_sem); 2074 } 2075 2076 static int check_pending_signals(bool wait) { 2077 Atomic::store(0, &sigint_count); 2078 for (;;) { 2079 for (int i = 0; i < NSIG + 1; i++) { 2080 jint n = pending_signals[i]; 2081 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2082 return i; 2083 } 2084 } 2085 if (!wait) { 2086 return -1; 2087 } 2088 JavaThread *thread = JavaThread::current(); 2089 ThreadBlockInVM tbivm(thread); 2090 2091 bool threadIsSuspended; 2092 do { 2093 thread->set_suspend_equivalent(); 2094 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2095 ::SEM_WAIT(sig_sem); 2096 2097 // were we externally suspended while we were waiting? 2098 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2099 if (threadIsSuspended) { 2100 // The semaphore has been incremented, but while we were waiting 2101 // another thread suspended us. We don't want to continue running 2102 // while suspended because that would surprise the thread that 2103 // suspended us. 2104 ::SEM_POST(sig_sem); 2105 2106 thread->java_suspend_self(); 2107 } 2108 } while (threadIsSuspended); 2109 } 2110 } 2111 2112 int os::signal_lookup() { 2113 return check_pending_signals(false); 2114 } 2115 2116 int os::signal_wait() { 2117 return check_pending_signals(true); 2118 } 2119 2120 //////////////////////////////////////////////////////////////////////////////// 2121 // Virtual Memory 2122 2123 int os::vm_page_size() { 2124 // Seems redundant as all get out 2125 assert(os::Bsd::page_size() != -1, "must call os::init"); 2126 return os::Bsd::page_size(); 2127 } 2128 2129 // Solaris allocates memory by pages. 2130 int os::vm_allocation_granularity() { 2131 assert(os::Bsd::page_size() != -1, "must call os::init"); 2132 return os::Bsd::page_size(); 2133 } 2134 2135 // Rationale behind this function: 2136 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2137 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2138 // samples for JITted code. Here we create private executable mapping over the code cache 2139 // and then we can use standard (well, almost, as mapping can change) way to provide 2140 // info for the reporting script by storing timestamp and location of symbol 2141 void bsd_wrap_code(char* base, size_t size) { 2142 static volatile jint cnt = 0; 2143 2144 if (!UseOprofile) { 2145 return; 2146 } 2147 2148 char buf[PATH_MAX + 1]; 2149 int num = Atomic::add(1, &cnt); 2150 2151 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", 2152 os::get_temp_directory(), os::current_process_id(), num); 2153 unlink(buf); 2154 2155 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2156 2157 if (fd != -1) { 2158 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2159 if (rv != (off_t)-1) { 2160 if (::write(fd, "", 1) == 1) { 2161 mmap(base, size, 2162 PROT_READ|PROT_WRITE|PROT_EXEC, 2163 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2164 } 2165 } 2166 ::close(fd); 2167 unlink(buf); 2168 } 2169 } 2170 2171 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2172 int err) { 2173 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2174 ", %d) failed; error='%s' (errno=%d)", addr, size, exec, 2175 strerror(err), err); 2176 } 2177 2178 // NOTE: Bsd kernel does not really reserve the pages for us. 2179 // All it does is to check if there are enough free pages 2180 // left at the time of mmap(). This could be a potential 2181 // problem. 2182 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2183 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2184 #ifdef __OpenBSD__ 2185 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2186 if (::mprotect(addr, size, prot) == 0) { 2187 return true; 2188 } 2189 #else 2190 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2191 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2192 if (res != (uintptr_t) MAP_FAILED) { 2193 return true; 2194 } 2195 #endif 2196 2197 // Warn about any commit errors we see in non-product builds just 2198 // in case mmap() doesn't work as described on the man page. 2199 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);) 2200 2201 return false; 2202 } 2203 2204 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2205 bool exec) { 2206 // alignment_hint is ignored on this OS 2207 return pd_commit_memory(addr, size, exec); 2208 } 2209 2210 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2211 const char* mesg) { 2212 assert(mesg != NULL, "mesg must be specified"); 2213 if (!pd_commit_memory(addr, size, exec)) { 2214 // add extra info in product mode for vm_exit_out_of_memory(): 2215 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);) 2216 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2217 } 2218 } 2219 2220 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2221 size_t alignment_hint, bool exec, 2222 const char* mesg) { 2223 // alignment_hint is ignored on this OS 2224 pd_commit_memory_or_exit(addr, size, exec, mesg); 2225 } 2226 2227 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2228 } 2229 2230 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2231 ::madvise(addr, bytes, MADV_DONTNEED); 2232 } 2233 2234 void os::numa_make_global(char *addr, size_t bytes) { 2235 } 2236 2237 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2238 } 2239 2240 bool os::numa_topology_changed() { return false; } 2241 2242 size_t os::numa_get_groups_num() { 2243 return 1; 2244 } 2245 2246 int os::numa_get_group_id() { 2247 return 0; 2248 } 2249 2250 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2251 if (size > 0) { 2252 ids[0] = 0; 2253 return 1; 2254 } 2255 return 0; 2256 } 2257 2258 bool os::get_page_info(char *start, page_info* info) { 2259 return false; 2260 } 2261 2262 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { 2263 return end; 2264 } 2265 2266 2267 bool os::pd_uncommit_memory(char* addr, size_t size) { 2268 #ifdef __OpenBSD__ 2269 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2270 return ::mprotect(addr, size, PROT_NONE) == 0; 2271 #else 2272 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2273 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2274 return res != (uintptr_t) MAP_FAILED; 2275 #endif 2276 } 2277 2278 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2279 return os::commit_memory(addr, size, !ExecMem); 2280 } 2281 2282 // If this is a growable mapping, remove the guard pages entirely by 2283 // munmap()ping them. If not, just call uncommit_memory(). 2284 bool os::remove_stack_guard_pages(char* addr, size_t size) { 2285 return os::uncommit_memory(addr, size); 2286 } 2287 2288 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 2289 // at 'requested_addr'. If there are existing memory mappings at the same 2290 // location, however, they will be overwritten. If 'fixed' is false, 2291 // 'requested_addr' is only treated as a hint, the return value may or 2292 // may not start from the requested address. Unlike Bsd mmap(), this 2293 // function returns NULL to indicate failure. 2294 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 2295 char * addr; 2296 int flags; 2297 2298 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 2299 if (fixed) { 2300 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); 2301 flags |= MAP_FIXED; 2302 } 2303 2304 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 2305 // touch an uncommitted page. Otherwise, the read/write might 2306 // succeed if we have enough swap space to back the physical page. 2307 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 2308 flags, -1, 0); 2309 2310 return addr == MAP_FAILED ? NULL : addr; 2311 } 2312 2313 static int anon_munmap(char * addr, size_t size) { 2314 return ::munmap(addr, size) == 0; 2315 } 2316 2317 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 2318 size_t alignment_hint) { 2319 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 2320 } 2321 2322 bool os::pd_release_memory(char* addr, size_t size) { 2323 return anon_munmap(addr, size); 2324 } 2325 2326 static bool bsd_mprotect(char* addr, size_t size, int prot) { 2327 // Bsd wants the mprotect address argument to be page aligned. 2328 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); 2329 2330 // According to SUSv3, mprotect() should only be used with mappings 2331 // established by mmap(), and mmap() always maps whole pages. Unaligned 2332 // 'addr' likely indicates problem in the VM (e.g. trying to change 2333 // protection of malloc'ed or statically allocated memory). Check the 2334 // caller if you hit this assert. 2335 assert(addr == bottom, "sanity check"); 2336 2337 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); 2338 return ::mprotect(bottom, size, prot) == 0; 2339 } 2340 2341 // Set protections specified 2342 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 2343 bool is_committed) { 2344 unsigned int p = 0; 2345 switch (prot) { 2346 case MEM_PROT_NONE: p = PROT_NONE; break; 2347 case MEM_PROT_READ: p = PROT_READ; break; 2348 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 2349 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 2350 default: 2351 ShouldNotReachHere(); 2352 } 2353 // is_committed is unused. 2354 return bsd_mprotect(addr, bytes, p); 2355 } 2356 2357 bool os::guard_memory(char* addr, size_t size) { 2358 return bsd_mprotect(addr, size, PROT_NONE); 2359 } 2360 2361 bool os::unguard_memory(char* addr, size_t size) { 2362 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); 2363 } 2364 2365 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { 2366 return false; 2367 } 2368 2369 // Large page support 2370 2371 static size_t _large_page_size = 0; 2372 2373 void os::large_page_init() { 2374 } 2375 2376 2377 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) { 2378 fatal("This code is not used or maintained."); 2379 2380 // "exec" is passed in but not used. Creating the shared image for 2381 // the code cache doesn't have an SHM_X executable permission to check. 2382 assert(UseLargePages && UseSHM, "only for SHM large pages"); 2383 2384 key_t key = IPC_PRIVATE; 2385 char *addr; 2386 2387 bool warn_on_failure = UseLargePages && 2388 (!FLAG_IS_DEFAULT(UseLargePages) || 2389 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 2390 2391 // Create a large shared memory region to attach to based on size. 2392 // Currently, size is the total size of the heap 2393 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); 2394 if (shmid == -1) { 2395 // Possible reasons for shmget failure: 2396 // 1. shmmax is too small for Java heap. 2397 // > check shmmax value: cat /proc/sys/kernel/shmmax 2398 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 2399 // 2. not enough large page memory. 2400 // > check available large pages: cat /proc/meminfo 2401 // > increase amount of large pages: 2402 // echo new_value > /proc/sys/vm/nr_hugepages 2403 // Note 1: different Bsd may use different name for this property, 2404 // e.g. on Redhat AS-3 it is "hugetlb_pool". 2405 // Note 2: it's possible there's enough physical memory available but 2406 // they are so fragmented after a long run that they can't 2407 // coalesce into large pages. Try to reserve large pages when 2408 // the system is still "fresh". 2409 if (warn_on_failure) { 2410 warning("Failed to reserve shared memory (errno = %d).", errno); 2411 } 2412 return NULL; 2413 } 2414 2415 // attach to the region 2416 addr = (char*)shmat(shmid, req_addr, 0); 2417 int err = errno; 2418 2419 // Remove shmid. If shmat() is successful, the actual shared memory segment 2420 // will be deleted when it's detached by shmdt() or when the process 2421 // terminates. If shmat() is not successful this will remove the shared 2422 // segment immediately. 2423 shmctl(shmid, IPC_RMID, NULL); 2424 2425 if ((intptr_t)addr == -1) { 2426 if (warn_on_failure) { 2427 warning("Failed to attach shared memory (errno = %d).", err); 2428 } 2429 return NULL; 2430 } 2431 2432 // The memory is committed 2433 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 2434 2435 return addr; 2436 } 2437 2438 bool os::release_memory_special(char* base, size_t bytes) { 2439 if (MemTracker::tracking_level() > NMT_minimal) { 2440 Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 2441 // detaching the SHM segment will also delete it, see reserve_memory_special() 2442 int rslt = shmdt(base); 2443 if (rslt == 0) { 2444 tkr.record((address)base, bytes); 2445 return true; 2446 } else { 2447 return false; 2448 } 2449 } else { 2450 return shmdt(base) == 0; 2451 } 2452 } 2453 2454 size_t os::large_page_size() { 2455 return _large_page_size; 2456 } 2457 2458 // HugeTLBFS allows application to commit large page memory on demand; 2459 // with SysV SHM the entire memory region must be allocated as shared 2460 // memory. 2461 bool os::can_commit_large_page_memory() { 2462 return UseHugeTLBFS; 2463 } 2464 2465 bool os::can_execute_large_page_memory() { 2466 return UseHugeTLBFS; 2467 } 2468 2469 // Reserve memory at an arbitrary address, only if that area is 2470 // available (and not reserved for something else). 2471 2472 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 2473 const int max_tries = 10; 2474 char* base[max_tries]; 2475 size_t size[max_tries]; 2476 const size_t gap = 0x000000; 2477 2478 // Assert only that the size is a multiple of the page size, since 2479 // that's all that mmap requires, and since that's all we really know 2480 // about at this low abstraction level. If we need higher alignment, 2481 // we can either pass an alignment to this method or verify alignment 2482 // in one of the methods further up the call chain. See bug 5044738. 2483 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 2484 2485 // Repeatedly allocate blocks until the block is allocated at the 2486 // right spot. 2487 2488 // Bsd mmap allows caller to pass an address as hint; give it a try first, 2489 // if kernel honors the hint then we can return immediately. 2490 char * addr = anon_mmap(requested_addr, bytes, false); 2491 if (addr == requested_addr) { 2492 return requested_addr; 2493 } 2494 2495 if (addr != NULL) { 2496 // mmap() is successful but it fails to reserve at the requested address 2497 anon_munmap(addr, bytes); 2498 } 2499 2500 int i; 2501 for (i = 0; i < max_tries; ++i) { 2502 base[i] = reserve_memory(bytes); 2503 2504 if (base[i] != NULL) { 2505 // Is this the block we wanted? 2506 if (base[i] == requested_addr) { 2507 size[i] = bytes; 2508 break; 2509 } 2510 2511 // Does this overlap the block we wanted? Give back the overlapped 2512 // parts and try again. 2513 2514 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; 2515 if (top_overlap >= 0 && top_overlap < bytes) { 2516 unmap_memory(base[i], top_overlap); 2517 base[i] += top_overlap; 2518 size[i] = bytes - top_overlap; 2519 } else { 2520 size_t bottom_overlap = base[i] + bytes - requested_addr; 2521 if (bottom_overlap >= 0 && bottom_overlap < bytes) { 2522 unmap_memory(requested_addr, bottom_overlap); 2523 size[i] = bytes - bottom_overlap; 2524 } else { 2525 size[i] = bytes; 2526 } 2527 } 2528 } 2529 } 2530 2531 // Give back the unused reserved pieces. 2532 2533 for (int j = 0; j < i; ++j) { 2534 if (base[j] != NULL) { 2535 unmap_memory(base[j], size[j]); 2536 } 2537 } 2538 2539 if (i < max_tries) { 2540 return requested_addr; 2541 } else { 2542 return NULL; 2543 } 2544 } 2545 2546 size_t os::read(int fd, void *buf, unsigned int nBytes) { 2547 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); 2548 } 2549 2550 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 2551 RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset)); 2552 } 2553 2554 void os::naked_short_sleep(jlong ms) { 2555 struct timespec req; 2556 2557 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 2558 req.tv_sec = 0; 2559 if (ms > 0) { 2560 req.tv_nsec = (ms % 1000) * 1000000; 2561 } else { 2562 req.tv_nsec = 1; 2563 } 2564 2565 nanosleep(&req, NULL); 2566 2567 return; 2568 } 2569 2570 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 2571 void os::infinite_sleep() { 2572 while (true) { // sleep forever ... 2573 ::sleep(100); // ... 100 seconds at a time 2574 } 2575 } 2576 2577 // Used to convert frequent JVM_Yield() to nops 2578 bool os::dont_yield() { 2579 return DontYieldALot; 2580 } 2581 2582 void os::naked_yield() { 2583 sched_yield(); 2584 } 2585 2586 //////////////////////////////////////////////////////////////////////////////// 2587 // thread priority support 2588 2589 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER 2590 // only supports dynamic priority, static priority must be zero. For real-time 2591 // applications, Bsd supports SCHED_RR which allows static priority (1-99). 2592 // However, for large multi-threaded applications, SCHED_RR is not only slower 2593 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 2594 // of 5 runs - Sep 2005). 2595 // 2596 // The following code actually changes the niceness of kernel-thread/LWP. It 2597 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 2598 // not the entire user process, and user level threads are 1:1 mapped to kernel 2599 // threads. It has always been the case, but could change in the future. For 2600 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 2601 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 2602 2603 #if !defined(__APPLE__) 2604 int os::java_to_os_priority[CriticalPriority + 1] = { 2605 19, // 0 Entry should never be used 2606 2607 0, // 1 MinPriority 2608 3, // 2 2609 6, // 3 2610 2611 10, // 4 2612 15, // 5 NormPriority 2613 18, // 6 2614 2615 21, // 7 2616 25, // 8 2617 28, // 9 NearMaxPriority 2618 2619 31, // 10 MaxPriority 2620 2621 31 // 11 CriticalPriority 2622 }; 2623 #else 2624 // Using Mach high-level priority assignments 2625 int os::java_to_os_priority[CriticalPriority + 1] = { 2626 0, // 0 Entry should never be used (MINPRI_USER) 2627 2628 27, // 1 MinPriority 2629 28, // 2 2630 29, // 3 2631 2632 30, // 4 2633 31, // 5 NormPriority (BASEPRI_DEFAULT) 2634 32, // 6 2635 2636 33, // 7 2637 34, // 8 2638 35, // 9 NearMaxPriority 2639 2640 36, // 10 MaxPriority 2641 2642 36 // 11 CriticalPriority 2643 }; 2644 #endif 2645 2646 static int prio_init() { 2647 if (ThreadPriorityPolicy == 1) { 2648 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 2649 // if effective uid is not root. Perhaps, a more elegant way of doing 2650 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 2651 if (geteuid() != 0) { 2652 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 2653 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); 2654 } 2655 ThreadPriorityPolicy = 0; 2656 } 2657 } 2658 if (UseCriticalJavaThreadPriority) { 2659 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 2660 } 2661 return 0; 2662 } 2663 2664 OSReturn os::set_native_priority(Thread* thread, int newpri) { 2665 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 2666 2667 #ifdef __OpenBSD__ 2668 // OpenBSD pthread_setprio starves low priority threads 2669 return OS_OK; 2670 #elif defined(__FreeBSD__) 2671 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); 2672 #elif defined(__APPLE__) || defined(__NetBSD__) 2673 struct sched_param sp; 2674 int policy; 2675 pthread_t self = pthread_self(); 2676 2677 if (pthread_getschedparam(self, &policy, &sp) != 0) { 2678 return OS_ERR; 2679 } 2680 2681 sp.sched_priority = newpri; 2682 if (pthread_setschedparam(self, policy, &sp) != 0) { 2683 return OS_ERR; 2684 } 2685 2686 return OS_OK; 2687 #else 2688 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 2689 return (ret == 0) ? OS_OK : OS_ERR; 2690 #endif 2691 } 2692 2693 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { 2694 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 2695 *priority_ptr = java_to_os_priority[NormPriority]; 2696 return OS_OK; 2697 } 2698 2699 errno = 0; 2700 #if defined(__OpenBSD__) || defined(__FreeBSD__) 2701 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); 2702 #elif defined(__APPLE__) || defined(__NetBSD__) 2703 int policy; 2704 struct sched_param sp; 2705 2706 pthread_getschedparam(pthread_self(), &policy, &sp); 2707 *priority_ptr = sp.sched_priority; 2708 #else 2709 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 2710 #endif 2711 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 2712 } 2713 2714 // Hint to the underlying OS that a task switch would not be good. 2715 // Void return because it's a hint and can fail. 2716 void os::hint_no_preempt() {} 2717 2718 //////////////////////////////////////////////////////////////////////////////// 2719 // suspend/resume support 2720 2721 // the low-level signal-based suspend/resume support is a remnant from the 2722 // old VM-suspension that used to be for java-suspension, safepoints etc, 2723 // within hotspot. Now there is a single use-case for this: 2724 // - calling get_thread_pc() on the VMThread by the flat-profiler task 2725 // that runs in the watcher thread. 2726 // The remaining code is greatly simplified from the more general suspension 2727 // code that used to be used. 2728 // 2729 // The protocol is quite simple: 2730 // - suspend: 2731 // - sends a signal to the target thread 2732 // - polls the suspend state of the osthread using a yield loop 2733 // - target thread signal handler (SR_handler) sets suspend state 2734 // and blocks in sigsuspend until continued 2735 // - resume: 2736 // - sets target osthread state to continue 2737 // - sends signal to end the sigsuspend loop in the SR_handler 2738 // 2739 // Note that the SR_lock plays no role in this suspend/resume protocol. 2740 2741 static void resume_clear_context(OSThread *osthread) { 2742 osthread->set_ucontext(NULL); 2743 osthread->set_siginfo(NULL); 2744 } 2745 2746 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { 2747 osthread->set_ucontext(context); 2748 osthread->set_siginfo(siginfo); 2749 } 2750 2751 // Handler function invoked when a thread's execution is suspended or 2752 // resumed. We have to be careful that only async-safe functions are 2753 // called here (Note: most pthread functions are not async safe and 2754 // should be avoided.) 2755 // 2756 // Note: sigwait() is a more natural fit than sigsuspend() from an 2757 // interface point of view, but sigwait() prevents the signal hander 2758 // from being run. libpthread would get very confused by not having 2759 // its signal handlers run and prevents sigwait()'s use with the 2760 // mutex granting granting signal. 2761 // 2762 // Currently only ever called on the VMThread or JavaThread 2763 // 2764 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 2765 // Save and restore errno to avoid confusing native code with EINTR 2766 // after sigsuspend. 2767 int old_errno = errno; 2768 2769 Thread* thread = Thread::current(); 2770 OSThread* osthread = thread->osthread(); 2771 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 2772 2773 os::SuspendResume::State current = osthread->sr.state(); 2774 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 2775 suspend_save_context(osthread, siginfo, context); 2776 2777 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 2778 os::SuspendResume::State state = osthread->sr.suspended(); 2779 if (state == os::SuspendResume::SR_SUSPENDED) { 2780 sigset_t suspend_set; // signals for sigsuspend() 2781 2782 // get current set of blocked signals and unblock resume signal 2783 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 2784 sigdelset(&suspend_set, SR_signum); 2785 2786 sr_semaphore.signal(); 2787 // wait here until we are resumed 2788 while (1) { 2789 sigsuspend(&suspend_set); 2790 2791 os::SuspendResume::State result = osthread->sr.running(); 2792 if (result == os::SuspendResume::SR_RUNNING) { 2793 sr_semaphore.signal(); 2794 break; 2795 } else if (result != os::SuspendResume::SR_SUSPENDED) { 2796 ShouldNotReachHere(); 2797 } 2798 } 2799 2800 } else if (state == os::SuspendResume::SR_RUNNING) { 2801 // request was cancelled, continue 2802 } else { 2803 ShouldNotReachHere(); 2804 } 2805 2806 resume_clear_context(osthread); 2807 } else if (current == os::SuspendResume::SR_RUNNING) { 2808 // request was cancelled, continue 2809 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 2810 // ignore 2811 } else { 2812 // ignore 2813 } 2814 2815 errno = old_errno; 2816 } 2817 2818 2819 static int SR_initialize() { 2820 struct sigaction act; 2821 char *s; 2822 // Get signal number to use for suspend/resume 2823 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 2824 int sig = ::strtol(s, 0, 10); 2825 if (sig > 0 || sig < NSIG) { 2826 SR_signum = sig; 2827 } 2828 } 2829 2830 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 2831 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 2832 2833 sigemptyset(&SR_sigset); 2834 sigaddset(&SR_sigset, SR_signum); 2835 2836 // Set up signal handler for suspend/resume 2837 act.sa_flags = SA_RESTART|SA_SIGINFO; 2838 act.sa_handler = (void (*)(int)) SR_handler; 2839 2840 // SR_signum is blocked by default. 2841 // 4528190 - We also need to block pthread restart signal (32 on all 2842 // supported Bsd platforms). Note that BsdThreads need to block 2843 // this signal for all threads to work properly. So we don't have 2844 // to use hard-coded signal number when setting up the mask. 2845 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 2846 2847 if (sigaction(SR_signum, &act, 0) == -1) { 2848 return -1; 2849 } 2850 2851 // Save signal flag 2852 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); 2853 return 0; 2854 } 2855 2856 static int sr_notify(OSThread* osthread) { 2857 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2858 assert_status(status == 0, status, "pthread_kill"); 2859 return status; 2860 } 2861 2862 // "Randomly" selected value for how long we want to spin 2863 // before bailing out on suspending a thread, also how often 2864 // we send a signal to a thread we want to resume 2865 static const int RANDOMLY_LARGE_INTEGER = 1000000; 2866 static const int RANDOMLY_LARGE_INTEGER2 = 100; 2867 2868 // returns true on success and false on error - really an error is fatal 2869 // but this seems the normal response to library errors 2870 static bool do_suspend(OSThread* osthread) { 2871 assert(osthread->sr.is_running(), "thread should be running"); 2872 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 2873 2874 // mark as suspended and send signal 2875 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 2876 // failed to switch, state wasn't running? 2877 ShouldNotReachHere(); 2878 return false; 2879 } 2880 2881 if (sr_notify(osthread) != 0) { 2882 ShouldNotReachHere(); 2883 } 2884 2885 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 2886 while (true) { 2887 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2888 break; 2889 } else { 2890 // timeout 2891 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 2892 if (cancelled == os::SuspendResume::SR_RUNNING) { 2893 return false; 2894 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 2895 // make sure that we consume the signal on the semaphore as well 2896 sr_semaphore.wait(); 2897 break; 2898 } else { 2899 ShouldNotReachHere(); 2900 return false; 2901 } 2902 } 2903 } 2904 2905 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 2906 return true; 2907 } 2908 2909 static void do_resume(OSThread* osthread) { 2910 assert(osthread->sr.is_suspended(), "thread should be suspended"); 2911 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 2912 2913 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 2914 // failed to switch to WAKEUP_REQUEST 2915 ShouldNotReachHere(); 2916 return; 2917 } 2918 2919 while (true) { 2920 if (sr_notify(osthread) == 0) { 2921 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2922 if (osthread->sr.is_running()) { 2923 return; 2924 } 2925 } 2926 } else { 2927 ShouldNotReachHere(); 2928 } 2929 } 2930 2931 guarantee(osthread->sr.is_running(), "Must be running!"); 2932 } 2933 2934 /////////////////////////////////////////////////////////////////////////////////// 2935 // signal handling (except suspend/resume) 2936 2937 // This routine may be used by user applications as a "hook" to catch signals. 2938 // The user-defined signal handler must pass unrecognized signals to this 2939 // routine, and if it returns true (non-zero), then the signal handler must 2940 // return immediately. If the flag "abort_if_unrecognized" is true, then this 2941 // routine will never retun false (zero), but instead will execute a VM panic 2942 // routine kill the process. 2943 // 2944 // If this routine returns false, it is OK to call it again. This allows 2945 // the user-defined signal handler to perform checks either before or after 2946 // the VM performs its own checks. Naturally, the user code would be making 2947 // a serious error if it tried to handle an exception (such as a null check 2948 // or breakpoint) that the VM was generating for its own correct operation. 2949 // 2950 // This routine may recognize any of the following kinds of signals: 2951 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 2952 // It should be consulted by handlers for any of those signals. 2953 // 2954 // The caller of this routine must pass in the three arguments supplied 2955 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 2956 // field of the structure passed to sigaction(). This routine assumes that 2957 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 2958 // 2959 // Note that the VM will print warnings if it detects conflicting signal 2960 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 2961 // 2962 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, 2963 void* ucontext, 2964 int abort_if_unrecognized); 2965 2966 void signalHandler(int sig, siginfo_t* info, void* uc) { 2967 assert(info != NULL && uc != NULL, "it must be old kernel"); 2968 int orig_errno = errno; // Preserve errno value over signal handler. 2969 JVM_handle_bsd_signal(sig, info, uc, true); 2970 errno = orig_errno; 2971 } 2972 2973 2974 // This boolean allows users to forward their own non-matching signals 2975 // to JVM_handle_bsd_signal, harmlessly. 2976 bool os::Bsd::signal_handlers_are_installed = false; 2977 2978 // For signal-chaining 2979 struct sigaction os::Bsd::sigact[MAXSIGNUM]; 2980 unsigned int os::Bsd::sigs = 0; 2981 bool os::Bsd::libjsig_is_loaded = false; 2982 typedef struct sigaction *(*get_signal_t)(int); 2983 get_signal_t os::Bsd::get_signal_action = NULL; 2984 2985 struct sigaction* os::Bsd::get_chained_signal_action(int sig) { 2986 struct sigaction *actp = NULL; 2987 2988 if (libjsig_is_loaded) { 2989 // Retrieve the old signal handler from libjsig 2990 actp = (*get_signal_action)(sig); 2991 } 2992 if (actp == NULL) { 2993 // Retrieve the preinstalled signal handler from jvm 2994 actp = get_preinstalled_handler(sig); 2995 } 2996 2997 return actp; 2998 } 2999 3000 static bool call_chained_handler(struct sigaction *actp, int sig, 3001 siginfo_t *siginfo, void *context) { 3002 // Call the old signal handler 3003 if (actp->sa_handler == SIG_DFL) { 3004 // It's more reasonable to let jvm treat it as an unexpected exception 3005 // instead of taking the default action. 3006 return false; 3007 } else if (actp->sa_handler != SIG_IGN) { 3008 if ((actp->sa_flags & SA_NODEFER) == 0) { 3009 // automaticlly block the signal 3010 sigaddset(&(actp->sa_mask), sig); 3011 } 3012 3013 sa_handler_t hand; 3014 sa_sigaction_t sa; 3015 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 3016 // retrieve the chained handler 3017 if (siginfo_flag_set) { 3018 sa = actp->sa_sigaction; 3019 } else { 3020 hand = actp->sa_handler; 3021 } 3022 3023 if ((actp->sa_flags & SA_RESETHAND) != 0) { 3024 actp->sa_handler = SIG_DFL; 3025 } 3026 3027 // try to honor the signal mask 3028 sigset_t oset; 3029 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 3030 3031 // call into the chained handler 3032 if (siginfo_flag_set) { 3033 (*sa)(sig, siginfo, context); 3034 } else { 3035 (*hand)(sig); 3036 } 3037 3038 // restore the signal mask 3039 pthread_sigmask(SIG_SETMASK, &oset, 0); 3040 } 3041 // Tell jvm's signal handler the signal is taken care of. 3042 return true; 3043 } 3044 3045 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { 3046 bool chained = false; 3047 // signal-chaining 3048 if (UseSignalChaining) { 3049 struct sigaction *actp = get_chained_signal_action(sig); 3050 if (actp != NULL) { 3051 chained = call_chained_handler(actp, sig, siginfo, context); 3052 } 3053 } 3054 return chained; 3055 } 3056 3057 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { 3058 if ((((unsigned int)1 << sig) & sigs) != 0) { 3059 return &sigact[sig]; 3060 } 3061 return NULL; 3062 } 3063 3064 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 3065 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3066 sigact[sig] = oldAct; 3067 sigs |= (unsigned int)1 << sig; 3068 } 3069 3070 // for diagnostic 3071 int os::Bsd::sigflags[MAXSIGNUM]; 3072 3073 int os::Bsd::get_our_sigflags(int sig) { 3074 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3075 return sigflags[sig]; 3076 } 3077 3078 void os::Bsd::set_our_sigflags(int sig, int flags) { 3079 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3080 sigflags[sig] = flags; 3081 } 3082 3083 void os::Bsd::set_signal_handler(int sig, bool set_installed) { 3084 // Check for overwrite. 3085 struct sigaction oldAct; 3086 sigaction(sig, (struct sigaction*)NULL, &oldAct); 3087 3088 void* oldhand = oldAct.sa_sigaction 3089 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3090 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3091 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 3092 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 3093 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 3094 if (AllowUserSignalHandlers || !set_installed) { 3095 // Do not overwrite; user takes responsibility to forward to us. 3096 return; 3097 } else if (UseSignalChaining) { 3098 // save the old handler in jvm 3099 save_preinstalled_handler(sig, oldAct); 3100 // libjsig also interposes the sigaction() call below and saves the 3101 // old sigaction on it own. 3102 } else { 3103 fatal("Encountered unexpected pre-existing sigaction handler " 3104 "%#lx for signal %d.", (long)oldhand, sig); 3105 } 3106 } 3107 3108 struct sigaction sigAct; 3109 sigfillset(&(sigAct.sa_mask)); 3110 sigAct.sa_handler = SIG_DFL; 3111 if (!set_installed) { 3112 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3113 } else { 3114 sigAct.sa_sigaction = signalHandler; 3115 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3116 } 3117 #ifdef __APPLE__ 3118 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV 3119 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages" 3120 // if the signal handler declares it will handle it on alternate stack. 3121 // Notice we only declare we will handle it on alt stack, but we are not 3122 // actually going to use real alt stack - this is just a workaround. 3123 // Please see ux_exception.c, method catch_mach_exception_raise for details 3124 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c 3125 if (sig == SIGSEGV) { 3126 sigAct.sa_flags |= SA_ONSTACK; 3127 } 3128 #endif 3129 3130 // Save flags, which are set by ours 3131 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3132 sigflags[sig] = sigAct.sa_flags; 3133 3134 int ret = sigaction(sig, &sigAct, &oldAct); 3135 assert(ret == 0, "check"); 3136 3137 void* oldhand2 = oldAct.sa_sigaction 3138 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3139 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3140 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 3141 } 3142 3143 // install signal handlers for signals that HotSpot needs to 3144 // handle in order to support Java-level exception handling. 3145 3146 void os::Bsd::install_signal_handlers() { 3147 if (!signal_handlers_are_installed) { 3148 signal_handlers_are_installed = true; 3149 3150 // signal-chaining 3151 typedef void (*signal_setting_t)(); 3152 signal_setting_t begin_signal_setting = NULL; 3153 signal_setting_t end_signal_setting = NULL; 3154 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3155 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 3156 if (begin_signal_setting != NULL) { 3157 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3158 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 3159 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 3160 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 3161 libjsig_is_loaded = true; 3162 assert(UseSignalChaining, "should enable signal-chaining"); 3163 } 3164 if (libjsig_is_loaded) { 3165 // Tell libjsig jvm is setting signal handlers 3166 (*begin_signal_setting)(); 3167 } 3168 3169 set_signal_handler(SIGSEGV, true); 3170 set_signal_handler(SIGPIPE, true); 3171 set_signal_handler(SIGBUS, true); 3172 set_signal_handler(SIGILL, true); 3173 set_signal_handler(SIGFPE, true); 3174 set_signal_handler(SIGXFSZ, true); 3175 3176 #if defined(__APPLE__) 3177 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including 3178 // signals caught and handled by the JVM. To work around this, we reset the mach task 3179 // signal handler that's placed on our process by CrashReporter. This disables 3180 // CrashReporter-based reporting. 3181 // 3182 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes 3183 // on caught fatal signals. 3184 // 3185 // Additionally, gdb installs both standard BSD signal handlers, and mach exception 3186 // handlers. By replacing the existing task exception handler, we disable gdb's mach 3187 // exception handling, while leaving the standard BSD signal handlers functional. 3188 kern_return_t kr; 3189 kr = task_set_exception_ports(mach_task_self(), 3190 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, 3191 MACH_PORT_NULL, 3192 EXCEPTION_STATE_IDENTITY, 3193 MACHINE_THREAD_STATE); 3194 3195 assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); 3196 #endif 3197 3198 if (libjsig_is_loaded) { 3199 // Tell libjsig jvm finishes setting signal handlers 3200 (*end_signal_setting)(); 3201 } 3202 3203 // We don't activate signal checker if libjsig is in place, we trust ourselves 3204 // and if UserSignalHandler is installed all bets are off 3205 if (CheckJNICalls) { 3206 if (libjsig_is_loaded) { 3207 if (PrintJNIResolving) { 3208 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 3209 } 3210 check_signals = false; 3211 } 3212 if (AllowUserSignalHandlers) { 3213 if (PrintJNIResolving) { 3214 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 3215 } 3216 check_signals = false; 3217 } 3218 } 3219 } 3220 } 3221 3222 3223 ///// 3224 // glibc on Bsd platform uses non-documented flag 3225 // to indicate, that some special sort of signal 3226 // trampoline is used. 3227 // We will never set this flag, and we should 3228 // ignore this flag in our diagnostic 3229 #ifdef SIGNIFICANT_SIGNAL_MASK 3230 #undef SIGNIFICANT_SIGNAL_MASK 3231 #endif 3232 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 3233 3234 static const char* get_signal_handler_name(address handler, 3235 char* buf, int buflen) { 3236 int offset; 3237 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 3238 if (found) { 3239 // skip directory names 3240 const char *p1, *p2; 3241 p1 = buf; 3242 size_t len = strlen(os::file_separator()); 3243 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 3244 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 3245 } else { 3246 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 3247 } 3248 return buf; 3249 } 3250 3251 static void print_signal_handler(outputStream* st, int sig, 3252 char* buf, size_t buflen) { 3253 struct sigaction sa; 3254 3255 sigaction(sig, NULL, &sa); 3256 3257 // See comment for SIGNIFICANT_SIGNAL_MASK define 3258 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3259 3260 st->print("%s: ", os::exception_name(sig, buf, buflen)); 3261 3262 address handler = (sa.sa_flags & SA_SIGINFO) 3263 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 3264 : CAST_FROM_FN_PTR(address, sa.sa_handler); 3265 3266 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 3267 st->print("SIG_DFL"); 3268 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 3269 st->print("SIG_IGN"); 3270 } else { 3271 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 3272 } 3273 3274 st->print(", sa_mask[0]="); 3275 os::Posix::print_signal_set_short(st, &sa.sa_mask); 3276 3277 address rh = VMError::get_resetted_sighandler(sig); 3278 // May be, handler was resetted by VMError? 3279 if (rh != NULL) { 3280 handler = rh; 3281 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 3282 } 3283 3284 st->print(", sa_flags="); 3285 os::Posix::print_sa_flags(st, sa.sa_flags); 3286 3287 // Check: is it our handler? 3288 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 3289 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 3290 // It is our signal handler 3291 // check for flags, reset system-used one! 3292 if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3293 st->print( 3294 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 3295 os::Bsd::get_our_sigflags(sig)); 3296 } 3297 } 3298 st->cr(); 3299 } 3300 3301 3302 #define DO_SIGNAL_CHECK(sig) \ 3303 do { \ 3304 if (!sigismember(&check_signal_done, sig)) { \ 3305 os::Bsd::check_signal_handler(sig); \ 3306 } \ 3307 } while (0) 3308 3309 // This method is a periodic task to check for misbehaving JNI applications 3310 // under CheckJNI, we can add any periodic checks here 3311 3312 void os::run_periodic_checks() { 3313 3314 if (check_signals == false) return; 3315 3316 // SEGV and BUS if overridden could potentially prevent 3317 // generation of hs*.log in the event of a crash, debugging 3318 // such a case can be very challenging, so we absolutely 3319 // check the following for a good measure: 3320 DO_SIGNAL_CHECK(SIGSEGV); 3321 DO_SIGNAL_CHECK(SIGILL); 3322 DO_SIGNAL_CHECK(SIGFPE); 3323 DO_SIGNAL_CHECK(SIGBUS); 3324 DO_SIGNAL_CHECK(SIGPIPE); 3325 DO_SIGNAL_CHECK(SIGXFSZ); 3326 3327 3328 // ReduceSignalUsage allows the user to override these handlers 3329 // see comments at the very top and jvm_solaris.h 3330 if (!ReduceSignalUsage) { 3331 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 3332 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 3333 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 3334 DO_SIGNAL_CHECK(BREAK_SIGNAL); 3335 } 3336 3337 DO_SIGNAL_CHECK(SR_signum); 3338 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); 3339 } 3340 3341 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 3342 3343 static os_sigaction_t os_sigaction = NULL; 3344 3345 void os::Bsd::check_signal_handler(int sig) { 3346 char buf[O_BUFLEN]; 3347 address jvmHandler = NULL; 3348 3349 3350 struct sigaction act; 3351 if (os_sigaction == NULL) { 3352 // only trust the default sigaction, in case it has been interposed 3353 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 3354 if (os_sigaction == NULL) return; 3355 } 3356 3357 os_sigaction(sig, (struct sigaction*)NULL, &act); 3358 3359 3360 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3361 3362 address thisHandler = (act.sa_flags & SA_SIGINFO) 3363 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 3364 : CAST_FROM_FN_PTR(address, act.sa_handler); 3365 3366 3367 switch (sig) { 3368 case SIGSEGV: 3369 case SIGBUS: 3370 case SIGFPE: 3371 case SIGPIPE: 3372 case SIGILL: 3373 case SIGXFSZ: 3374 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 3375 break; 3376 3377 case SHUTDOWN1_SIGNAL: 3378 case SHUTDOWN2_SIGNAL: 3379 case SHUTDOWN3_SIGNAL: 3380 case BREAK_SIGNAL: 3381 jvmHandler = (address)user_handler(); 3382 break; 3383 3384 case INTERRUPT_SIGNAL: 3385 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); 3386 break; 3387 3388 default: 3389 if (sig == SR_signum) { 3390 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 3391 } else { 3392 return; 3393 } 3394 break; 3395 } 3396 3397 if (thisHandler != jvmHandler) { 3398 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 3399 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 3400 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 3401 // No need to check this sig any longer 3402 sigaddset(&check_signal_done, sig); 3403 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 3404 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 3405 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 3406 exception_name(sig, buf, O_BUFLEN)); 3407 } 3408 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3409 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 3410 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); 3411 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); 3412 // No need to check this sig any longer 3413 sigaddset(&check_signal_done, sig); 3414 } 3415 3416 // Dump all the signal 3417 if (sigismember(&check_signal_done, sig)) { 3418 print_signal_handlers(tty, buf, O_BUFLEN); 3419 } 3420 } 3421 3422 extern void report_error(char* file_name, int line_no, char* title, 3423 char* format, ...); 3424 3425 extern bool signal_name(int signo, char* buf, size_t len); 3426 3427 const char* os::exception_name(int exception_code, char* buf, size_t size) { 3428 if (0 < exception_code && exception_code <= SIGRTMAX) { 3429 // signal 3430 if (!signal_name(exception_code, buf, size)) { 3431 jio_snprintf(buf, size, "SIG%d", exception_code); 3432 } 3433 return buf; 3434 } else { 3435 return NULL; 3436 } 3437 } 3438 3439 // this is called _before_ the most of global arguments have been parsed 3440 void os::init(void) { 3441 char dummy; // used to get a guess on initial stack address 3442 // first_hrtime = gethrtime(); 3443 3444 // With BsdThreads the JavaMain thread pid (primordial thread) 3445 // is different than the pid of the java launcher thread. 3446 // So, on Bsd, the launcher thread pid is passed to the VM 3447 // via the sun.java.launcher.pid property. 3448 // Use this property instead of getpid() if it was correctly passed. 3449 // See bug 6351349. 3450 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); 3451 3452 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); 3453 3454 clock_tics_per_sec = CLK_TCK; 3455 3456 init_random(1234567); 3457 3458 ThreadCritical::initialize(); 3459 3460 Bsd::set_page_size(getpagesize()); 3461 if (Bsd::page_size() == -1) { 3462 fatal("os_bsd.cpp: os::init: sysconf failed (%s)", strerror(errno)); 3463 } 3464 init_page_sizes((size_t) Bsd::page_size()); 3465 3466 Bsd::initialize_system_info(); 3467 3468 // main_thread points to the aboriginal thread 3469 Bsd::_main_thread = pthread_self(); 3470 3471 Bsd::clock_init(); 3472 initial_time_count = javaTimeNanos(); 3473 3474 #ifdef __APPLE__ 3475 // XXXDARWIN 3476 // Work around the unaligned VM callbacks in hotspot's 3477 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on 3478 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces 3479 // alignment when doing symbol lookup. To work around this, we force early 3480 // binding of all symbols now, thus binding when alignment is known-good. 3481 _dyld_bind_fully_image_containing_address((const void *) &os::init); 3482 #endif 3483 } 3484 3485 // To install functions for atexit system call 3486 extern "C" { 3487 static void perfMemory_exit_helper() { 3488 perfMemory_exit(); 3489 } 3490 } 3491 3492 // this is called _after_ the global arguments have been parsed 3493 jint os::init_2(void) { 3494 // Allocate a single page and mark it as readable for safepoint polling 3495 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3496 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page"); 3497 3498 os::set_polling_page(polling_page); 3499 3500 #ifndef PRODUCT 3501 if (Verbose && PrintMiscellaneous) { 3502 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", 3503 (intptr_t)polling_page); 3504 } 3505 #endif 3506 3507 if (!UseMembar) { 3508 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3509 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 3510 os::set_memory_serialize_page(mem_serialize_page); 3511 3512 #ifndef PRODUCT 3513 if (Verbose && PrintMiscellaneous) { 3514 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", 3515 (intptr_t)mem_serialize_page); 3516 } 3517 #endif 3518 } 3519 3520 // initialize suspend/resume support - must do this before signal_sets_init() 3521 if (SR_initialize() != 0) { 3522 perror("SR_initialize failed"); 3523 return JNI_ERR; 3524 } 3525 3526 Bsd::signal_sets_init(); 3527 Bsd::install_signal_handlers(); 3528 3529 // Check minimum allowable stack size for thread creation and to initialize 3530 // the java system classes, including StackOverflowError - depends on page 3531 // size. Add a page for compiler2 recursion in main thread. 3532 // Add in 2*BytesPerWord times page size to account for VM stack during 3533 // class initialization depending on 32 or 64 bit VM. 3534 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, 3535 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ 3536 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); 3537 3538 size_t threadStackSizeInBytes = ThreadStackSize * K; 3539 if (threadStackSizeInBytes != 0 && 3540 threadStackSizeInBytes < os::Bsd::min_stack_allowed) { 3541 tty->print_cr("\nThe stack size specified is too small, " 3542 "Specify at least %dk", 3543 os::Bsd::min_stack_allowed/ K); 3544 return JNI_ERR; 3545 } 3546 3547 // Make the stack size a multiple of the page size so that 3548 // the yellow/red zones can be guarded. 3549 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 3550 vm_page_size())); 3551 3552 if (MaxFDLimit) { 3553 // set the number of file descriptors to max. print out error 3554 // if getrlimit/setrlimit fails but continue regardless. 3555 struct rlimit nbr_files; 3556 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 3557 if (status != 0) { 3558 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3559 perror("os::init_2 getrlimit failed"); 3560 } 3561 } else { 3562 nbr_files.rlim_cur = nbr_files.rlim_max; 3563 3564 #ifdef __APPLE__ 3565 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if 3566 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must 3567 // be used instead 3568 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); 3569 #endif 3570 3571 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 3572 if (status != 0) { 3573 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3574 perror("os::init_2 setrlimit failed"); 3575 } 3576 } 3577 } 3578 } 3579 3580 // at-exit methods are called in the reverse order of their registration. 3581 // atexit functions are called on return from main or as a result of a 3582 // call to exit(3C). There can be only 32 of these functions registered 3583 // and atexit() does not set errno. 3584 3585 if (PerfAllowAtExitRegistration) { 3586 // only register atexit functions if PerfAllowAtExitRegistration is set. 3587 // atexit functions can be delayed until process exit time, which 3588 // can be problematic for embedded VM situations. Embedded VMs should 3589 // call DestroyJavaVM() to assure that VM resources are released. 3590 3591 // note: perfMemory_exit_helper atexit function may be removed in 3592 // the future if the appropriate cleanup code can be added to the 3593 // VM_Exit VMOperation's doit method. 3594 if (atexit(perfMemory_exit_helper) != 0) { 3595 warning("os::init2 atexit(perfMemory_exit_helper) failed"); 3596 } 3597 } 3598 3599 // initialize thread priority policy 3600 prio_init(); 3601 3602 #ifdef __APPLE__ 3603 // dynamically link to objective c gc registration 3604 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY); 3605 if (handleLibObjc != NULL) { 3606 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER); 3607 } 3608 #endif 3609 3610 return JNI_OK; 3611 } 3612 3613 // Mark the polling page as unreadable 3614 void os::make_polling_page_unreadable(void) { 3615 if (!guard_memory((char*)_polling_page, Bsd::page_size())) { 3616 fatal("Could not disable polling page"); 3617 } 3618 } 3619 3620 // Mark the polling page as readable 3621 void os::make_polling_page_readable(void) { 3622 if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { 3623 fatal("Could not enable polling page"); 3624 } 3625 } 3626 3627 int os::active_processor_count() { 3628 return _processor_count; 3629 } 3630 3631 void os::set_native_thread_name(const char *name) { 3632 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5 3633 // This is only supported in Snow Leopard and beyond 3634 if (name != NULL) { 3635 // Add a "Java: " prefix to the name 3636 char buf[MAXTHREADNAMESIZE]; 3637 snprintf(buf, sizeof(buf), "Java: %s", name); 3638 pthread_setname_np(buf); 3639 } 3640 #endif 3641 } 3642 3643 bool os::distribute_processes(uint length, uint* distribution) { 3644 // Not yet implemented. 3645 return false; 3646 } 3647 3648 bool os::bind_to_processor(uint processor_id) { 3649 // Not yet implemented. 3650 return false; 3651 } 3652 3653 void os::SuspendedThreadTask::internal_do_task() { 3654 if (do_suspend(_thread->osthread())) { 3655 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 3656 do_task(context); 3657 do_resume(_thread->osthread()); 3658 } 3659 } 3660 3661 /// 3662 class PcFetcher : public os::SuspendedThreadTask { 3663 public: 3664 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 3665 ExtendedPC result(); 3666 protected: 3667 void do_task(const os::SuspendedThreadTaskContext& context); 3668 private: 3669 ExtendedPC _epc; 3670 }; 3671 3672 ExtendedPC PcFetcher::result() { 3673 guarantee(is_done(), "task is not done yet."); 3674 return _epc; 3675 } 3676 3677 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 3678 Thread* thread = context.thread(); 3679 OSThread* osthread = thread->osthread(); 3680 if (osthread->ucontext() != NULL) { 3681 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext()); 3682 } else { 3683 // NULL context is unexpected, double-check this is the VMThread 3684 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 3685 } 3686 } 3687 3688 // Suspends the target using the signal mechanism and then grabs the PC before 3689 // resuming the target. Used by the flat-profiler only 3690 ExtendedPC os::get_thread_pc(Thread* thread) { 3691 // Make sure that it is called by the watcher for the VMThread 3692 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 3693 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 3694 3695 PcFetcher fetcher(thread); 3696 fetcher.run(); 3697 return fetcher.result(); 3698 } 3699 3700 //////////////////////////////////////////////////////////////////////////////// 3701 // debug support 3702 3703 bool os::find(address addr, outputStream* st) { 3704 Dl_info dlinfo; 3705 memset(&dlinfo, 0, sizeof(dlinfo)); 3706 if (dladdr(addr, &dlinfo) != 0) { 3707 st->print(PTR_FORMAT ": ", addr); 3708 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 3709 st->print("%s+%#x", dlinfo.dli_sname, 3710 addr - (intptr_t)dlinfo.dli_saddr); 3711 } else if (dlinfo.dli_fbase != NULL) { 3712 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); 3713 } else { 3714 st->print("<absolute address>"); 3715 } 3716 if (dlinfo.dli_fname != NULL) { 3717 st->print(" in %s", dlinfo.dli_fname); 3718 } 3719 if (dlinfo.dli_fbase != NULL) { 3720 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); 3721 } 3722 st->cr(); 3723 3724 if (Verbose) { 3725 // decode some bytes around the PC 3726 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 3727 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 3728 address lowest = (address) dlinfo.dli_sname; 3729 if (!lowest) lowest = (address) dlinfo.dli_fbase; 3730 if (begin < lowest) begin = lowest; 3731 Dl_info dlinfo2; 3732 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 3733 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 3734 end = (address) dlinfo2.dli_saddr; 3735 } 3736 Disassembler::decode(begin, end, st); 3737 } 3738 return true; 3739 } 3740 return false; 3741 } 3742 3743 //////////////////////////////////////////////////////////////////////////////// 3744 // misc 3745 3746 // This does not do anything on Bsd. This is basically a hook for being 3747 // able to use structured exception handling (thread-local exception filters) 3748 // on, e.g., Win32. 3749 void os::os_exception_wrapper(java_call_t f, JavaValue* value, 3750 methodHandle* method, JavaCallArguments* args, 3751 Thread* thread) { 3752 f(value, method, args, thread); 3753 } 3754 3755 void os::print_statistics() { 3756 } 3757 3758 int os::message_box(const char* title, const char* message) { 3759 int i; 3760 fdStream err(defaultStream::error_fd()); 3761 for (i = 0; i < 78; i++) err.print_raw("="); 3762 err.cr(); 3763 err.print_raw_cr(title); 3764 for (i = 0; i < 78; i++) err.print_raw("-"); 3765 err.cr(); 3766 err.print_raw_cr(message); 3767 for (i = 0; i < 78; i++) err.print_raw("="); 3768 err.cr(); 3769 3770 char buf[16]; 3771 // Prevent process from exiting upon "read error" without consuming all CPU 3772 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 3773 3774 return buf[0] == 'y' || buf[0] == 'Y'; 3775 } 3776 3777 int os::stat(const char *path, struct stat *sbuf) { 3778 char pathbuf[MAX_PATH]; 3779 if (strlen(path) > MAX_PATH - 1) { 3780 errno = ENAMETOOLONG; 3781 return -1; 3782 } 3783 os::native_path(strcpy(pathbuf, path)); 3784 return ::stat(pathbuf, sbuf); 3785 } 3786 3787 bool os::check_heap(bool force) { 3788 return true; 3789 } 3790 3791 // Is a (classpath) directory empty? 3792 bool os::dir_is_empty(const char* path) { 3793 DIR *dir = NULL; 3794 struct dirent *ptr; 3795 3796 dir = opendir(path); 3797 if (dir == NULL) return true; 3798 3799 // Scan the directory 3800 bool result = true; 3801 char buf[sizeof(struct dirent) + MAX_PATH]; 3802 while (result && (ptr = ::readdir(dir)) != NULL) { 3803 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 3804 result = false; 3805 } 3806 } 3807 closedir(dir); 3808 return result; 3809 } 3810 3811 // This code originates from JDK's sysOpen and open64_w 3812 // from src/solaris/hpi/src/system_md.c 3813 3814 int os::open(const char *path, int oflag, int mode) { 3815 if (strlen(path) > MAX_PATH - 1) { 3816 errno = ENAMETOOLONG; 3817 return -1; 3818 } 3819 int fd; 3820 3821 fd = ::open(path, oflag, mode); 3822 if (fd == -1) return -1; 3823 3824 // If the open succeeded, the file might still be a directory 3825 { 3826 struct stat buf; 3827 int ret = ::fstat(fd, &buf); 3828 int st_mode = buf.st_mode; 3829 3830 if (ret != -1) { 3831 if ((st_mode & S_IFMT) == S_IFDIR) { 3832 errno = EISDIR; 3833 ::close(fd); 3834 return -1; 3835 } 3836 } else { 3837 ::close(fd); 3838 return -1; 3839 } 3840 } 3841 3842 // All file descriptors that are opened in the JVM and not 3843 // specifically destined for a subprocess should have the 3844 // close-on-exec flag set. If we don't set it, then careless 3rd 3845 // party native code might fork and exec without closing all 3846 // appropriate file descriptors (e.g. as we do in closeDescriptors in 3847 // UNIXProcess.c), and this in turn might: 3848 // 3849 // - cause end-of-file to fail to be detected on some file 3850 // descriptors, resulting in mysterious hangs, or 3851 // 3852 // - might cause an fopen in the subprocess to fail on a system 3853 // suffering from bug 1085341. 3854 // 3855 // (Yes, the default setting of the close-on-exec flag is a Unix 3856 // design flaw) 3857 // 3858 // See: 3859 // 1085341: 32-bit stdio routines should support file descriptors >255 3860 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 3861 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 3862 // 3863 #ifdef FD_CLOEXEC 3864 { 3865 int flags = ::fcntl(fd, F_GETFD); 3866 if (flags != -1) { 3867 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 3868 } 3869 } 3870 #endif 3871 3872 return fd; 3873 } 3874 3875 3876 // create binary file, rewriting existing file if required 3877 int os::create_binary_file(const char* path, bool rewrite_existing) { 3878 int oflags = O_WRONLY | O_CREAT; 3879 if (!rewrite_existing) { 3880 oflags |= O_EXCL; 3881 } 3882 return ::open(path, oflags, S_IREAD | S_IWRITE); 3883 } 3884 3885 // return current position of file pointer 3886 jlong os::current_file_offset(int fd) { 3887 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); 3888 } 3889 3890 // move file pointer to the specified offset 3891 jlong os::seek_to_file_offset(int fd, jlong offset) { 3892 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); 3893 } 3894 3895 // This code originates from JDK's sysAvailable 3896 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 3897 3898 int os::available(int fd, jlong *bytes) { 3899 jlong cur, end; 3900 int mode; 3901 struct stat buf; 3902 3903 if (::fstat(fd, &buf) >= 0) { 3904 mode = buf.st_mode; 3905 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 3906 // XXX: is the following call interruptible? If so, this might 3907 // need to go through the INTERRUPT_IO() wrapper as for other 3908 // blocking, interruptible calls in this file. 3909 int n; 3910 if (::ioctl(fd, FIONREAD, &n) >= 0) { 3911 *bytes = n; 3912 return 1; 3913 } 3914 } 3915 } 3916 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { 3917 return 0; 3918 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { 3919 return 0; 3920 } else if (::lseek(fd, cur, SEEK_SET) == -1) { 3921 return 0; 3922 } 3923 *bytes = end - cur; 3924 return 1; 3925 } 3926 3927 // Map a block of memory. 3928 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 3929 char *addr, size_t bytes, bool read_only, 3930 bool allow_exec) { 3931 int prot; 3932 int flags; 3933 3934 if (read_only) { 3935 prot = PROT_READ; 3936 flags = MAP_SHARED; 3937 } else { 3938 prot = PROT_READ | PROT_WRITE; 3939 flags = MAP_PRIVATE; 3940 } 3941 3942 if (allow_exec) { 3943 prot |= PROT_EXEC; 3944 } 3945 3946 if (addr != NULL) { 3947 flags |= MAP_FIXED; 3948 } 3949 3950 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 3951 fd, file_offset); 3952 if (mapped_address == MAP_FAILED) { 3953 return NULL; 3954 } 3955 return mapped_address; 3956 } 3957 3958 3959 // Remap a block of memory. 3960 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 3961 char *addr, size_t bytes, bool read_only, 3962 bool allow_exec) { 3963 // same as map_memory() on this OS 3964 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 3965 allow_exec); 3966 } 3967 3968 3969 // Unmap a block of memory. 3970 bool os::pd_unmap_memory(char* addr, size_t bytes) { 3971 return munmap(addr, bytes) == 0; 3972 } 3973 3974 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 3975 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 3976 // of a thread. 3977 // 3978 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 3979 // the fast estimate available on the platform. 3980 3981 jlong os::current_thread_cpu_time() { 3982 #ifdef __APPLE__ 3983 return os::thread_cpu_time(Thread::current(), true /* user + sys */); 3984 #else 3985 Unimplemented(); 3986 return 0; 3987 #endif 3988 } 3989 3990 jlong os::thread_cpu_time(Thread* thread) { 3991 #ifdef __APPLE__ 3992 return os::thread_cpu_time(thread, true /* user + sys */); 3993 #else 3994 Unimplemented(); 3995 return 0; 3996 #endif 3997 } 3998 3999 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 4000 #ifdef __APPLE__ 4001 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); 4002 #else 4003 Unimplemented(); 4004 return 0; 4005 #endif 4006 } 4007 4008 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 4009 #ifdef __APPLE__ 4010 struct thread_basic_info tinfo; 4011 mach_msg_type_number_t tcount = THREAD_INFO_MAX; 4012 kern_return_t kr; 4013 thread_t mach_thread; 4014 4015 mach_thread = thread->osthread()->thread_id(); 4016 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); 4017 if (kr != KERN_SUCCESS) { 4018 return -1; 4019 } 4020 4021 if (user_sys_cpu_time) { 4022 jlong nanos; 4023 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; 4024 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; 4025 return nanos; 4026 } else { 4027 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); 4028 } 4029 #else 4030 Unimplemented(); 4031 return 0; 4032 #endif 4033 } 4034 4035 4036 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4037 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4038 info_ptr->may_skip_backward = false; // elapsed time not wall time 4039 info_ptr->may_skip_forward = false; // elapsed time not wall time 4040 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4041 } 4042 4043 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4044 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4045 info_ptr->may_skip_backward = false; // elapsed time not wall time 4046 info_ptr->may_skip_forward = false; // elapsed time not wall time 4047 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4048 } 4049 4050 bool os::is_thread_cpu_time_supported() { 4051 #ifdef __APPLE__ 4052 return true; 4053 #else 4054 return false; 4055 #endif 4056 } 4057 4058 // System loadavg support. Returns -1 if load average cannot be obtained. 4059 // Bsd doesn't yet have a (official) notion of processor sets, 4060 // so just return the system wide load average. 4061 int os::loadavg(double loadavg[], int nelem) { 4062 return ::getloadavg(loadavg, nelem); 4063 } 4064 4065 void os::pause() { 4066 char filename[MAX_PATH]; 4067 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 4068 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); 4069 } else { 4070 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 4071 } 4072 4073 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 4074 if (fd != -1) { 4075 struct stat buf; 4076 ::close(fd); 4077 while (::stat(filename, &buf) == 0) { 4078 (void)::poll(NULL, 0, 100); 4079 } 4080 } else { 4081 jio_fprintf(stderr, 4082 "Could not open pause file '%s', continuing immediately.\n", filename); 4083 } 4084 } 4085 4086 4087 // Refer to the comments in os_solaris.cpp park-unpark. The next two 4088 // comment paragraphs are worth repeating here: 4089 // 4090 // Assumption: 4091 // Only one parker can exist on an event, which is why we allocate 4092 // them per-thread. Multiple unparkers can coexist. 4093 // 4094 // _Event serves as a restricted-range semaphore. 4095 // -1 : thread is blocked, i.e. there is a waiter 4096 // 0 : neutral: thread is running or ready, 4097 // could have been signaled after a wait started 4098 // 1 : signaled - thread is running or ready 4099 // 4100 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 4101 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 4102 // For specifics regarding the bug see GLIBC BUGID 261237 : 4103 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 4104 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 4105 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 4106 // is used. (The simple C test-case provided in the GLIBC bug report manifests the 4107 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 4108 // and monitorenter when we're using 1-0 locking. All those operations may result in 4109 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 4110 // of libpthread avoids the problem, but isn't practical. 4111 // 4112 // Possible remedies: 4113 // 4114 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 4115 // This is palliative and probabilistic, however. If the thread is preempted 4116 // between the call to compute_abstime() and pthread_cond_timedwait(), more 4117 // than the minimum period may have passed, and the abstime may be stale (in the 4118 // past) resultin in a hang. Using this technique reduces the odds of a hang 4119 // but the JVM is still vulnerable, particularly on heavily loaded systems. 4120 // 4121 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 4122 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set 4123 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 4124 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant 4125 // thread. 4126 // 4127 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 4128 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 4129 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). 4130 // This also works well. In fact it avoids kernel-level scalability impediments 4131 // on certain platforms that don't handle lots of active pthread_cond_timedwait() 4132 // timers in a graceful fashion. 4133 // 4134 // 4. When the abstime value is in the past it appears that control returns 4135 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 4136 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we 4137 // can avoid the problem by reinitializing the condvar -- by cond_destroy() 4138 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). 4139 // It may be possible to avoid reinitialization by checking the return 4140 // value from pthread_cond_timedwait(). In addition to reinitializing the 4141 // condvar we must establish the invariant that cond_signal() is only called 4142 // within critical sections protected by the adjunct mutex. This prevents 4143 // cond_signal() from "seeing" a condvar that's in the midst of being 4144 // reinitialized or that is corrupt. Sadly, this invariant obviates the 4145 // desirable signal-after-unlock optimization that avoids futile context switching. 4146 // 4147 // I'm also concerned that some versions of NTPL might allocate an auxilliary 4148 // structure when a condvar is used or initialized. cond_destroy() would 4149 // release the helper structure. Our reinitialize-after-timedwait fix 4150 // put excessive stress on malloc/free and locks protecting the c-heap. 4151 // 4152 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 4153 // It may be possible to refine (4) by checking the kernel and NTPL verisons 4154 // and only enabling the work-around for vulnerable environments. 4155 4156 // utility to compute the abstime argument to timedwait: 4157 // millis is the relative timeout time 4158 // abstime will be the absolute timeout time 4159 // TODO: replace compute_abstime() with unpackTime() 4160 4161 static struct timespec* compute_abstime(struct timespec* abstime, 4162 jlong millis) { 4163 if (millis < 0) millis = 0; 4164 struct timeval now; 4165 int status = gettimeofday(&now, NULL); 4166 assert(status == 0, "gettimeofday"); 4167 jlong seconds = millis / 1000; 4168 millis %= 1000; 4169 if (seconds > 50000000) { // see man cond_timedwait(3T) 4170 seconds = 50000000; 4171 } 4172 abstime->tv_sec = now.tv_sec + seconds; 4173 long usec = now.tv_usec + millis * 1000; 4174 if (usec >= 1000000) { 4175 abstime->tv_sec += 1; 4176 usec -= 1000000; 4177 } 4178 abstime->tv_nsec = usec * 1000; 4179 return abstime; 4180 } 4181 4182 void os::PlatformEvent::park() { // AKA "down()" 4183 // Transitions for _Event: 4184 // -1 => -1 : illegal 4185 // 1 => 0 : pass - return immediately 4186 // 0 => -1 : block; then set _Event to 0 before returning 4187 4188 // Invariant: Only the thread associated with the Event/PlatformEvent 4189 // may call park(). 4190 // TODO: assert that _Assoc != NULL or _Assoc == Self 4191 assert(_nParked == 0, "invariant"); 4192 4193 int v; 4194 for (;;) { 4195 v = _Event; 4196 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4197 } 4198 guarantee(v >= 0, "invariant"); 4199 if (v == 0) { 4200 // Do this the hard way by blocking ... 4201 int status = pthread_mutex_lock(_mutex); 4202 assert_status(status == 0, status, "mutex_lock"); 4203 guarantee(_nParked == 0, "invariant"); 4204 ++_nParked; 4205 while (_Event < 0) { 4206 status = pthread_cond_wait(_cond, _mutex); 4207 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 4208 // Treat this the same as if the wait was interrupted 4209 if (status == ETIMEDOUT) { status = EINTR; } 4210 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 4211 } 4212 --_nParked; 4213 4214 _Event = 0; 4215 status = pthread_mutex_unlock(_mutex); 4216 assert_status(status == 0, status, "mutex_unlock"); 4217 // Paranoia to ensure our locked and lock-free paths interact 4218 // correctly with each other. 4219 OrderAccess::fence(); 4220 } 4221 guarantee(_Event >= 0, "invariant"); 4222 } 4223 4224 int os::PlatformEvent::park(jlong millis) { 4225 // Transitions for _Event: 4226 // -1 => -1 : illegal 4227 // 1 => 0 : pass - return immediately 4228 // 0 => -1 : block; then set _Event to 0 before returning 4229 4230 guarantee(_nParked == 0, "invariant"); 4231 4232 int v; 4233 for (;;) { 4234 v = _Event; 4235 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4236 } 4237 guarantee(v >= 0, "invariant"); 4238 if (v != 0) return OS_OK; 4239 4240 // We do this the hard way, by blocking the thread. 4241 // Consider enforcing a minimum timeout value. 4242 struct timespec abst; 4243 compute_abstime(&abst, millis); 4244 4245 int ret = OS_TIMEOUT; 4246 int status = pthread_mutex_lock(_mutex); 4247 assert_status(status == 0, status, "mutex_lock"); 4248 guarantee(_nParked == 0, "invariant"); 4249 ++_nParked; 4250 4251 // Object.wait(timo) will return because of 4252 // (a) notification 4253 // (b) timeout 4254 // (c) thread.interrupt 4255 // 4256 // Thread.interrupt and object.notify{All} both call Event::set. 4257 // That is, we treat thread.interrupt as a special case of notification. 4258 // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false. 4259 // We assume all ETIME returns are valid. 4260 // 4261 // TODO: properly differentiate simultaneous notify+interrupt. 4262 // In that case, we should propagate the notify to another waiter. 4263 4264 while (_Event < 0) { 4265 status = pthread_cond_timedwait(_cond, _mutex, &abst); 4266 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4267 pthread_cond_destroy(_cond); 4268 pthread_cond_init(_cond, NULL); 4269 } 4270 assert_status(status == 0 || status == EINTR || 4271 status == ETIMEDOUT, 4272 status, "cond_timedwait"); 4273 if (!FilterSpuriousWakeups) break; // previous semantics 4274 if (status == ETIMEDOUT) break; 4275 // We consume and ignore EINTR and spurious wakeups. 4276 } 4277 --_nParked; 4278 if (_Event >= 0) { 4279 ret = OS_OK; 4280 } 4281 _Event = 0; 4282 status = pthread_mutex_unlock(_mutex); 4283 assert_status(status == 0, status, "mutex_unlock"); 4284 assert(_nParked == 0, "invariant"); 4285 // Paranoia to ensure our locked and lock-free paths interact 4286 // correctly with each other. 4287 OrderAccess::fence(); 4288 return ret; 4289 } 4290 4291 void os::PlatformEvent::unpark() { 4292 // Transitions for _Event: 4293 // 0 => 1 : just return 4294 // 1 => 1 : just return 4295 // -1 => either 0 or 1; must signal target thread 4296 // That is, we can safely transition _Event from -1 to either 4297 // 0 or 1. 4298 // See also: "Semaphores in Plan 9" by Mullender & Cox 4299 // 4300 // Note: Forcing a transition from "-1" to "1" on an unpark() means 4301 // that it will take two back-to-back park() calls for the owning 4302 // thread to block. This has the benefit of forcing a spurious return 4303 // from the first park() call after an unpark() call which will help 4304 // shake out uses of park() and unpark() without condition variables. 4305 4306 if (Atomic::xchg(1, &_Event) >= 0) return; 4307 4308 // Wait for the thread associated with the event to vacate 4309 int status = pthread_mutex_lock(_mutex); 4310 assert_status(status == 0, status, "mutex_lock"); 4311 int AnyWaiters = _nParked; 4312 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 4313 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 4314 AnyWaiters = 0; 4315 pthread_cond_signal(_cond); 4316 } 4317 status = pthread_mutex_unlock(_mutex); 4318 assert_status(status == 0, status, "mutex_unlock"); 4319 if (AnyWaiters != 0) { 4320 // Note that we signal() *after* dropping the lock for "immortal" Events. 4321 // This is safe and avoids a common class of futile wakeups. In rare 4322 // circumstances this can cause a thread to return prematurely from 4323 // cond_{timed}wait() but the spurious wakeup is benign and the victim 4324 // will simply re-test the condition and re-park itself. 4325 // This provides particular benefit if the underlying platform does not 4326 // provide wait morphing. 4327 status = pthread_cond_signal(_cond); 4328 assert_status(status == 0, status, "cond_signal"); 4329 } 4330 } 4331 4332 4333 // JSR166 4334 // ------------------------------------------------------- 4335 4336 // The solaris and bsd implementations of park/unpark are fairly 4337 // conservative for now, but can be improved. They currently use a 4338 // mutex/condvar pair, plus a a count. 4339 // Park decrements count if > 0, else does a condvar wait. Unpark 4340 // sets count to 1 and signals condvar. Only one thread ever waits 4341 // on the condvar. Contention seen when trying to park implies that someone 4342 // is unparking you, so don't wait. And spurious returns are fine, so there 4343 // is no need to track notifications. 4344 4345 #define MAX_SECS 100000000 4346 4347 // This code is common to bsd and solaris and will be moved to a 4348 // common place in dolphin. 4349 // 4350 // The passed in time value is either a relative time in nanoseconds 4351 // or an absolute time in milliseconds. Either way it has to be unpacked 4352 // into suitable seconds and nanoseconds components and stored in the 4353 // given timespec structure. 4354 // Given time is a 64-bit value and the time_t used in the timespec is only 4355 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for 4356 // overflow if times way in the future are given. Further on Solaris versions 4357 // prior to 10 there is a restriction (see cond_timedwait) that the specified 4358 // number of seconds, in abstime, is less than current_time + 100,000,000. 4359 // As it will be 28 years before "now + 100000000" will overflow we can 4360 // ignore overflow and just impose a hard-limit on seconds using the value 4361 // of "now + 100,000,000". This places a limit on the timeout of about 3.17 4362 // years from "now". 4363 4364 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { 4365 assert(time > 0, "convertTime"); 4366 4367 struct timeval now; 4368 int status = gettimeofday(&now, NULL); 4369 assert(status == 0, "gettimeofday"); 4370 4371 time_t max_secs = now.tv_sec + MAX_SECS; 4372 4373 if (isAbsolute) { 4374 jlong secs = time / 1000; 4375 if (secs > max_secs) { 4376 absTime->tv_sec = max_secs; 4377 } else { 4378 absTime->tv_sec = secs; 4379 } 4380 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 4381 } else { 4382 jlong secs = time / NANOSECS_PER_SEC; 4383 if (secs >= MAX_SECS) { 4384 absTime->tv_sec = max_secs; 4385 absTime->tv_nsec = 0; 4386 } else { 4387 absTime->tv_sec = now.tv_sec + secs; 4388 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 4389 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 4390 absTime->tv_nsec -= NANOSECS_PER_SEC; 4391 ++absTime->tv_sec; // note: this must be <= max_secs 4392 } 4393 } 4394 } 4395 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 4396 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 4397 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 4398 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 4399 } 4400 4401 void Parker::park(bool isAbsolute, jlong time) { 4402 // Ideally we'd do something useful while spinning, such 4403 // as calling unpackTime(). 4404 4405 // Optional fast-path check: 4406 // Return immediately if a permit is available. 4407 // We depend on Atomic::xchg() having full barrier semantics 4408 // since we are doing a lock-free update to _counter. 4409 if (Atomic::xchg(0, &_counter) > 0) return; 4410 4411 Thread* thread = Thread::current(); 4412 assert(thread->is_Java_thread(), "Must be JavaThread"); 4413 JavaThread *jt = (JavaThread *)thread; 4414 4415 // Optional optimization -- avoid state transitions if there's an interrupt pending. 4416 // Check interrupt before trying to wait 4417 if (Thread::is_interrupted(thread, false)) { 4418 return; 4419 } 4420 4421 // Next, demultiplex/decode time arguments 4422 struct timespec absTime; 4423 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all 4424 return; 4425 } 4426 if (time > 0) { 4427 unpackTime(&absTime, isAbsolute, time); 4428 } 4429 4430 4431 // Enter safepoint region 4432 // Beware of deadlocks such as 6317397. 4433 // The per-thread Parker:: mutex is a classic leaf-lock. 4434 // In particular a thread must never block on the Threads_lock while 4435 // holding the Parker:: mutex. If safepoints are pending both the 4436 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 4437 ThreadBlockInVM tbivm(jt); 4438 4439 // Don't wait if cannot get lock since interference arises from 4440 // unblocking. Also. check interrupt before trying wait 4441 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 4442 return; 4443 } 4444 4445 int status; 4446 if (_counter > 0) { // no wait needed 4447 _counter = 0; 4448 status = pthread_mutex_unlock(_mutex); 4449 assert(status == 0, "invariant"); 4450 // Paranoia to ensure our locked and lock-free paths interact 4451 // correctly with each other and Java-level accesses. 4452 OrderAccess::fence(); 4453 return; 4454 } 4455 4456 #ifdef ASSERT 4457 // Don't catch signals while blocked; let the running threads have the signals. 4458 // (This allows a debugger to break into the running thread.) 4459 sigset_t oldsigs; 4460 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); 4461 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 4462 #endif 4463 4464 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 4465 jt->set_suspend_equivalent(); 4466 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 4467 4468 if (time == 0) { 4469 status = pthread_cond_wait(_cond, _mutex); 4470 } else { 4471 status = pthread_cond_timedwait(_cond, _mutex, &absTime); 4472 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4473 pthread_cond_destroy(_cond); 4474 pthread_cond_init(_cond, NULL); 4475 } 4476 } 4477 assert_status(status == 0 || status == EINTR || 4478 status == ETIMEDOUT, 4479 status, "cond_timedwait"); 4480 4481 #ifdef ASSERT 4482 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 4483 #endif 4484 4485 _counter = 0; 4486 status = pthread_mutex_unlock(_mutex); 4487 assert_status(status == 0, status, "invariant"); 4488 // Paranoia to ensure our locked and lock-free paths interact 4489 // correctly with each other and Java-level accesses. 4490 OrderAccess::fence(); 4491 4492 // If externally suspended while waiting, re-suspend 4493 if (jt->handle_special_suspend_equivalent_condition()) { 4494 jt->java_suspend_self(); 4495 } 4496 } 4497 4498 void Parker::unpark() { 4499 int status = pthread_mutex_lock(_mutex); 4500 assert(status == 0, "invariant"); 4501 const int s = _counter; 4502 _counter = 1; 4503 if (s < 1) { 4504 if (WorkAroundNPTLTimedWaitHang) { 4505 status = pthread_cond_signal(_cond); 4506 assert(status == 0, "invariant"); 4507 status = pthread_mutex_unlock(_mutex); 4508 assert(status == 0, "invariant"); 4509 } else { 4510 status = pthread_mutex_unlock(_mutex); 4511 assert(status == 0, "invariant"); 4512 status = pthread_cond_signal(_cond); 4513 assert(status == 0, "invariant"); 4514 } 4515 } else { 4516 pthread_mutex_unlock(_mutex); 4517 assert(status == 0, "invariant"); 4518 } 4519 } 4520 4521 4522 // Darwin has no "environ" in a dynamic library. 4523 #ifdef __APPLE__ 4524 #include <crt_externs.h> 4525 #define environ (*_NSGetEnviron()) 4526 #else 4527 extern char** environ; 4528 #endif 4529 4530 // Run the specified command in a separate process. Return its exit value, 4531 // or -1 on failure (e.g. can't fork a new process). 4532 // Unlike system(), this function can be called from signal handler. It 4533 // doesn't block SIGINT et al. 4534 int os::fork_and_exec(char* cmd) { 4535 const char * argv[4] = {"sh", "-c", cmd, NULL}; 4536 4537 // fork() in BsdThreads/NPTL is not async-safe. It needs to run 4538 // pthread_atfork handlers and reset pthread library. All we need is a 4539 // separate process to execve. Make a direct syscall to fork process. 4540 // On IA64 there's no fork syscall, we have to use fork() and hope for 4541 // the best... 4542 pid_t pid = fork(); 4543 4544 if (pid < 0) { 4545 // fork failed 4546 return -1; 4547 4548 } else if (pid == 0) { 4549 // child process 4550 4551 // execve() in BsdThreads will call pthread_kill_other_threads_np() 4552 // first to kill every thread on the thread list. Because this list is 4553 // not reset by fork() (see notes above), execve() will instead kill 4554 // every thread in the parent process. We know this is the only thread 4555 // in the new process, so make a system call directly. 4556 // IA64 should use normal execve() from glibc to match the glibc fork() 4557 // above. 4558 execve("/bin/sh", (char* const*)argv, environ); 4559 4560 // execve failed 4561 _exit(-1); 4562 4563 } else { 4564 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 4565 // care about the actual exit code, for now. 4566 4567 int status; 4568 4569 // Wait for the child process to exit. This returns immediately if 4570 // the child has already exited. */ 4571 while (waitpid(pid, &status, 0) < 0) { 4572 switch (errno) { 4573 case ECHILD: return 0; 4574 case EINTR: break; 4575 default: return -1; 4576 } 4577 } 4578 4579 if (WIFEXITED(status)) { 4580 // The child exited normally; get its exit code. 4581 return WEXITSTATUS(status); 4582 } else if (WIFSIGNALED(status)) { 4583 // The child exited because of a signal 4584 // The best value to return is 0x80 + signal number, 4585 // because that is what all Unix shells do, and because 4586 // it allows callers to distinguish between process exit and 4587 // process death by signal. 4588 return 0x80 + WTERMSIG(status); 4589 } else { 4590 // Unknown exit code; pass it through 4591 return status; 4592 } 4593 } 4594 } 4595 4596 // is_headless_jre() 4597 // 4598 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 4599 // in order to report if we are running in a headless jre 4600 // 4601 // Since JDK8 xawt/libmawt.so was moved into the same directory 4602 // as libawt.so, and renamed libawt_xawt.so 4603 // 4604 bool os::is_headless_jre() { 4605 #ifdef __APPLE__ 4606 // We no longer build headless-only on Mac OS X 4607 return false; 4608 #else 4609 struct stat statbuf; 4610 char buf[MAXPATHLEN]; 4611 char libmawtpath[MAXPATHLEN]; 4612 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX; 4613 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX; 4614 char *p; 4615 4616 // Get path to libjvm.so 4617 os::jvm_path(buf, sizeof(buf)); 4618 4619 // Get rid of libjvm.so 4620 p = strrchr(buf, '/'); 4621 if (p == NULL) { 4622 return false; 4623 } else { 4624 *p = '\0'; 4625 } 4626 4627 // Get rid of client or server 4628 p = strrchr(buf, '/'); 4629 if (p == NULL) { 4630 return false; 4631 } else { 4632 *p = '\0'; 4633 } 4634 4635 // check xawt/libmawt.so 4636 strcpy(libmawtpath, buf); 4637 strcat(libmawtpath, xawtstr); 4638 if (::stat(libmawtpath, &statbuf) == 0) return false; 4639 4640 // check libawt_xawt.so 4641 strcpy(libmawtpath, buf); 4642 strcat(libmawtpath, new_xawtstr); 4643 if (::stat(libmawtpath, &statbuf) == 0) return false; 4644 4645 return true; 4646 #endif 4647 } 4648 4649 // Get the default path to the core file 4650 // Returns the length of the string 4651 int os::get_core_path(char* buffer, size_t bufferSize) { 4652 int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id()); 4653 4654 // Truncate if theoretical string was longer than bufferSize 4655 n = MIN2(n, (int)bufferSize); 4656 4657 return n; 4658 } 4659 4660 #ifndef PRODUCT 4661 void TestReserveMemorySpecial_test() { 4662 // No tests available for this platform 4663 } 4664 #endif