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 "services/attachListener.hpp" 63 #include "services/memTracker.hpp" 64 #include "services/runtimeService.hpp" 65 #include "utilities/decoder.hpp" 66 #include "utilities/defaultStream.hpp" 67 #include "utilities/events.hpp" 68 #include "utilities/growableArray.hpp" 69 #include "utilities/vmError.hpp" 70 71 // put OS-includes here 72 # include <sys/types.h> 73 # include <sys/mman.h> 74 # include <sys/stat.h> 75 # include <sys/select.h> 76 # include <pthread.h> 77 # include <signal.h> 78 # include <errno.h> 79 # include <dlfcn.h> 80 # include <stdio.h> 81 # include <unistd.h> 82 # include <sys/resource.h> 83 # include <pthread.h> 84 # include <sys/stat.h> 85 # include <sys/time.h> 86 # include <sys/times.h> 87 # include <sys/utsname.h> 88 # include <sys/socket.h> 89 # include <sys/wait.h> 90 # include <time.h> 91 # include <pwd.h> 92 # include <poll.h> 93 # include <semaphore.h> 94 # include <fcntl.h> 95 # include <string.h> 96 # include <sys/param.h> 97 # include <sys/sysctl.h> 98 # include <sys/ipc.h> 99 # include <sys/shm.h> 100 #ifndef __APPLE__ 101 # include <link.h> 102 #endif 103 # include <stdint.h> 104 # include <inttypes.h> 105 # include <sys/ioctl.h> 106 # include <sys/syscall.h> 107 108 #if defined(__FreeBSD__) || defined(__NetBSD__) 109 #include <elf.h> 110 #endif 111 112 #ifdef __APPLE__ 113 #include <mach/mach.h> // semaphore_* API 114 #include <mach-o/dyld.h> 115 #include <sys/proc_info.h> 116 #include <objc/objc-auto.h> 117 #endif 118 119 #ifndef MAP_ANONYMOUS 120 #define MAP_ANONYMOUS MAP_ANON 121 #endif 122 123 #define MAX_PATH (2 * K) 124 125 // for timer info max values which include all bits 126 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 127 128 #define LARGEPAGES_BIT (1 << 6) 129 130 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 131 132 //////////////////////////////////////////////////////////////////////////////// 133 // global variables 134 julong os::Bsd::_physical_memory = 0; 135 136 #ifdef __APPLE__ 137 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0}; 138 volatile uint64_t os::Bsd::_max_abstime = 0; 139 #else 140 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; 141 #endif 142 pthread_t os::Bsd::_main_thread; 143 int os::Bsd::_page_size = -1; 144 145 static jlong initial_time_count=0; 146 147 static int clock_tics_per_sec = 100; 148 149 // For diagnostics to print a message once. see run_periodic_checks 150 static sigset_t check_signal_done; 151 static bool check_signals = true; 152 153 static pid_t _initial_pid = 0; 154 155 // Signal number used to suspend/resume a thread 156 157 // do not use any signal number less than SIGSEGV, see 4355769 158 static int SR_signum = SIGUSR2; 159 sigset_t SR_sigset; 160 161 162 //////////////////////////////////////////////////////////////////////////////// 163 // utility functions 164 165 static int SR_initialize(); 166 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time); 167 168 julong os::available_memory() { 169 return Bsd::available_memory(); 170 } 171 172 // available here means free 173 julong os::Bsd::available_memory() { 174 uint64_t available = physical_memory() >> 2; 175 #ifdef __APPLE__ 176 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT; 177 vm_statistics64_data_t vmstat; 178 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64, 179 (host_info64_t)&vmstat, &count); 180 assert(kerr == KERN_SUCCESS, 181 "host_statistics64 failed - check mach_host_self() and count"); 182 if (kerr == KERN_SUCCESS) { 183 available = vmstat.free_count * os::vm_page_size(); 184 } 185 #endif 186 return available; 187 } 188 189 julong os::physical_memory() { 190 return Bsd::physical_memory(); 191 } 192 193 // Return true if user is running as root. 194 195 bool os::have_special_privileges() { 196 static bool init = false; 197 static bool privileges = false; 198 if (!init) { 199 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 200 init = true; 201 } 202 return privileges; 203 } 204 205 206 207 // Cpu architecture string 208 #if defined(ZERO) 209 static char cpu_arch[] = ZERO_LIBARCH; 210 #elif defined(IA64) 211 static char cpu_arch[] = "ia64"; 212 #elif defined(IA32) 213 static char cpu_arch[] = "i386"; 214 #elif defined(AMD64) 215 static char cpu_arch[] = "amd64"; 216 #elif defined(ARM) 217 static char cpu_arch[] = "arm"; 218 #elif defined(PPC32) 219 static char cpu_arch[] = "ppc"; 220 #elif defined(SPARC) 221 #ifdef _LP64 222 static char cpu_arch[] = "sparcv9"; 223 #else 224 static char cpu_arch[] = "sparc"; 225 #endif 226 #else 227 #error Add appropriate cpu_arch setting 228 #endif 229 230 // Compiler variant 231 #ifdef COMPILER2 232 #define COMPILER_VARIANT "server" 233 #else 234 #define COMPILER_VARIANT "client" 235 #endif 236 237 238 void os::Bsd::initialize_system_info() { 239 int mib[2]; 240 size_t len; 241 int cpu_val; 242 julong mem_val; 243 244 // get processors count via hw.ncpus sysctl 245 mib[0] = CTL_HW; 246 mib[1] = HW_NCPU; 247 len = sizeof(cpu_val); 248 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) { 249 assert(len == sizeof(cpu_val), "unexpected data size"); 250 set_processor_count(cpu_val); 251 } else { 252 set_processor_count(1); // fallback 253 } 254 255 // get physical memory via hw.memsize sysctl (hw.memsize is used 256 // since it returns a 64 bit value) 257 mib[0] = CTL_HW; 258 259 #if defined (HW_MEMSIZE) // Apple 260 mib[1] = HW_MEMSIZE; 261 #elif defined(HW_PHYSMEM) // Most of BSD 262 mib[1] = HW_PHYSMEM; 263 #elif defined(HW_REALMEM) // Old FreeBSD 264 mib[1] = HW_REALMEM; 265 #else 266 #error No ways to get physmem 267 #endif 268 269 len = sizeof(mem_val); 270 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) { 271 assert(len == sizeof(mem_val), "unexpected data size"); 272 _physical_memory = mem_val; 273 } else { 274 _physical_memory = 256 * 1024 * 1024; // fallback (XXXBSD?) 275 } 276 277 #ifdef __OpenBSD__ 278 { 279 // limit _physical_memory memory view on OpenBSD since 280 // datasize rlimit restricts us anyway. 281 struct rlimit limits; 282 getrlimit(RLIMIT_DATA, &limits); 283 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur); 284 } 285 #endif 286 } 287 288 #ifdef __APPLE__ 289 static const char *get_home() { 290 const char *home_dir = ::getenv("HOME"); 291 if ((home_dir == NULL) || (*home_dir == '\0')) { 292 struct passwd *passwd_info = getpwuid(geteuid()); 293 if (passwd_info != NULL) { 294 home_dir = passwd_info->pw_dir; 295 } 296 } 297 298 return home_dir; 299 } 300 #endif 301 302 void os::init_system_properties_values() { 303 // The next steps are taken in the product version: 304 // 305 // Obtain the JAVA_HOME value from the location of libjvm.so. 306 // This library should be located at: 307 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so. 308 // 309 // If "/jre/lib/" appears at the right place in the path, then we 310 // assume libjvm.so is installed in a JDK and we use this path. 311 // 312 // Otherwise exit with message: "Could not create the Java virtual machine." 313 // 314 // The following extra steps are taken in the debugging version: 315 // 316 // If "/jre/lib/" does NOT appear at the right place in the path 317 // instead of exit check for $JAVA_HOME environment variable. 318 // 319 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 320 // then we append a fake suffix "hotspot/libjvm.so" to this path so 321 // it looks like libjvm.so is installed there 322 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 323 // 324 // Otherwise exit. 325 // 326 // Important note: if the location of libjvm.so changes this 327 // code needs to be changed accordingly. 328 329 // See ld(1): 330 // The linker uses the following search paths to locate required 331 // shared libraries: 332 // 1: ... 333 // ... 334 // 7: The default directories, normally /lib and /usr/lib. 335 #ifndef DEFAULT_LIBPATH 336 #define DEFAULT_LIBPATH "/lib:/usr/lib" 337 #endif 338 339 // Base path of extensions installed on the system. 340 #define SYS_EXT_DIR "/usr/java/packages" 341 #define EXTENSIONS_DIR "/lib/ext" 342 343 #ifndef __APPLE__ 344 345 // Buffer that fits several sprintfs. 346 // Note that the space for the colon and the trailing null are provided 347 // by the nulls included by the sizeof operator. 348 const size_t bufsize = 349 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. 350 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir 351 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 352 353 // sysclasspath, java_home, dll_dir 354 { 355 char *pslash; 356 os::jvm_path(buf, bufsize); 357 358 // Found the full path to libjvm.so. 359 // Now cut the path to <java_home>/jre if we can. 360 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 361 pslash = strrchr(buf, '/'); 362 if (pslash != NULL) { 363 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 364 } 365 Arguments::set_dll_dir(buf); 366 367 if (pslash != NULL) { 368 pslash = strrchr(buf, '/'); 369 if (pslash != NULL) { 370 *pslash = '\0'; // Get rid of /<arch>. 371 pslash = strrchr(buf, '/'); 372 if (pslash != NULL) { 373 *pslash = '\0'; // Get rid of /lib. 374 } 375 } 376 } 377 Arguments::set_java_home(buf); 378 set_boot_path('/', ':'); 379 } 380 381 // Where to look for native libraries. 382 // 383 // Note: Due to a legacy implementation, most of the library path 384 // is set in the launcher. This was to accomodate linking restrictions 385 // on legacy Bsd implementations (which are no longer supported). 386 // Eventually, all the library path setting will be done here. 387 // 388 // However, to prevent the proliferation of improperly built native 389 // libraries, the new path component /usr/java/packages is added here. 390 // Eventually, all the library path setting will be done here. 391 { 392 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 393 // should always exist (until the legacy problem cited above is 394 // addressed). 395 const char *v = ::getenv("LD_LIBRARY_PATH"); 396 const char *v_colon = ":"; 397 if (v == NULL) { v = ""; v_colon = ""; } 398 // That's +1 for the colon and +1 for the trailing '\0'. 399 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 400 strlen(v) + 1 + 401 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1, 402 mtInternal); 403 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch); 404 Arguments::set_library_path(ld_library_path); 405 FREE_C_HEAP_ARRAY(char, ld_library_path); 406 } 407 408 // Extensions directories. 409 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 410 Arguments::set_ext_dirs(buf); 411 412 FREE_C_HEAP_ARRAY(char, buf); 413 414 #else // __APPLE__ 415 416 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions" 417 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java" 418 419 const char *user_home_dir = get_home(); 420 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir. 421 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) + 422 sizeof(SYS_EXTENSIONS_DIRS); 423 424 // Buffer that fits several sprintfs. 425 // Note that the space for the colon and the trailing null are provided 426 // by the nulls included by the sizeof operator. 427 const size_t bufsize = 428 MAX2((size_t)MAXPATHLEN, // for dll_dir & friends. 429 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir 430 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 431 432 // sysclasspath, java_home, dll_dir 433 { 434 char *pslash; 435 os::jvm_path(buf, bufsize); 436 437 // Found the full path to libjvm.so. 438 // Now cut the path to <java_home>/jre if we can. 439 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 440 pslash = strrchr(buf, '/'); 441 if (pslash != NULL) { 442 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 443 } 444 Arguments::set_dll_dir(buf); 445 446 if (pslash != NULL) { 447 pslash = strrchr(buf, '/'); 448 if (pslash != NULL) { 449 *pslash = '\0'; // Get rid of /lib. 450 } 451 } 452 Arguments::set_java_home(buf); 453 set_boot_path('/', ':'); 454 } 455 456 // Where to look for native libraries. 457 // 458 // Note: Due to a legacy implementation, most of the library path 459 // is set in the launcher. This was to accomodate linking restrictions 460 // on legacy Bsd implementations (which are no longer supported). 461 // Eventually, all the library path setting will be done here. 462 // 463 // However, to prevent the proliferation of improperly built native 464 // libraries, the new path component /usr/java/packages is added here. 465 // Eventually, all the library path setting will be done here. 466 { 467 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 468 // should always exist (until the legacy problem cited above is 469 // addressed). 470 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code 471 // can specify a directory inside an app wrapper 472 const char *l = ::getenv("JAVA_LIBRARY_PATH"); 473 const char *l_colon = ":"; 474 if (l == NULL) { l = ""; l_colon = ""; } 475 476 const char *v = ::getenv("DYLD_LIBRARY_PATH"); 477 const char *v_colon = ":"; 478 if (v == NULL) { v = ""; v_colon = ""; } 479 480 // Apple's Java6 has "." at the beginning of java.library.path. 481 // OpenJDK on Windows has "." at the end of java.library.path. 482 // OpenJDK on Linux and Solaris don't have "." in java.library.path 483 // at all. To ease the transition from Apple's Java6 to OpenJDK7, 484 // "." is appended to the end of java.library.path. Yes, this 485 // could cause a change in behavior, but Apple's Java6 behavior 486 // can be achieved by putting "." at the beginning of the 487 // JAVA_LIBRARY_PATH environment variable. 488 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 489 strlen(v) + 1 + strlen(l) + 1 + 490 system_ext_size + 3, 491 mtInternal); 492 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.", 493 v, v_colon, l, l_colon, user_home_dir); 494 Arguments::set_library_path(ld_library_path); 495 FREE_C_HEAP_ARRAY(char, ld_library_path); 496 } 497 498 // Extensions directories. 499 // 500 // Note that the space for the colon and the trailing null are provided 501 // by the nulls included by the sizeof operator (so actually one byte more 502 // than necessary is allocated). 503 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, 504 user_home_dir, Arguments::get_java_home()); 505 Arguments::set_ext_dirs(buf); 506 507 FREE_C_HEAP_ARRAY(char, buf); 508 509 #undef SYS_EXTENSIONS_DIR 510 #undef SYS_EXTENSIONS_DIRS 511 512 #endif // __APPLE__ 513 514 #undef SYS_EXT_DIR 515 #undef EXTENSIONS_DIR 516 } 517 518 //////////////////////////////////////////////////////////////////////////////// 519 // breakpoint support 520 521 void os::breakpoint() { 522 BREAKPOINT; 523 } 524 525 extern "C" void breakpoint() { 526 // use debugger to set breakpoint here 527 } 528 529 //////////////////////////////////////////////////////////////////////////////// 530 // signal support 531 532 debug_only(static bool signal_sets_initialized = false); 533 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 534 535 bool os::Bsd::is_sig_ignored(int sig) { 536 struct sigaction oact; 537 sigaction(sig, (struct sigaction*)NULL, &oact); 538 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 539 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 540 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) { 541 return true; 542 } else { 543 return false; 544 } 545 } 546 547 void os::Bsd::signal_sets_init() { 548 // Should also have an assertion stating we are still single-threaded. 549 assert(!signal_sets_initialized, "Already initialized"); 550 // Fill in signals that are necessarily unblocked for all threads in 551 // the VM. Currently, we unblock the following signals: 552 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 553 // by -Xrs (=ReduceSignalUsage)); 554 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 555 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 556 // the dispositions or masks wrt these signals. 557 // Programs embedding the VM that want to use the above signals for their 558 // own purposes must, at this time, use the "-Xrs" option to prevent 559 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 560 // (See bug 4345157, and other related bugs). 561 // In reality, though, unblocking these signals is really a nop, since 562 // these signals are not blocked by default. 563 sigemptyset(&unblocked_sigs); 564 sigemptyset(&allowdebug_blocked_sigs); 565 sigaddset(&unblocked_sigs, SIGILL); 566 sigaddset(&unblocked_sigs, SIGSEGV); 567 sigaddset(&unblocked_sigs, SIGBUS); 568 sigaddset(&unblocked_sigs, SIGFPE); 569 sigaddset(&unblocked_sigs, SR_signum); 570 571 if (!ReduceSignalUsage) { 572 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 573 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 574 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); 575 } 576 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 577 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 578 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); 579 } 580 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 581 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 582 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); 583 } 584 } 585 // Fill in signals that are blocked by all but the VM thread. 586 sigemptyset(&vm_sigs); 587 if (!ReduceSignalUsage) { 588 sigaddset(&vm_sigs, BREAK_SIGNAL); 589 } 590 debug_only(signal_sets_initialized = true); 591 592 } 593 594 // These are signals that are unblocked while a thread is running Java. 595 // (For some reason, they get blocked by default.) 596 sigset_t* os::Bsd::unblocked_signals() { 597 assert(signal_sets_initialized, "Not initialized"); 598 return &unblocked_sigs; 599 } 600 601 // These are the signals that are blocked while a (non-VM) thread is 602 // running Java. Only the VM thread handles these signals. 603 sigset_t* os::Bsd::vm_signals() { 604 assert(signal_sets_initialized, "Not initialized"); 605 return &vm_sigs; 606 } 607 608 // These are signals that are blocked during cond_wait to allow debugger in 609 sigset_t* os::Bsd::allowdebug_blocked_signals() { 610 assert(signal_sets_initialized, "Not initialized"); 611 return &allowdebug_blocked_sigs; 612 } 613 614 void os::Bsd::hotspot_sigmask(Thread* thread) { 615 616 //Save caller's signal mask before setting VM signal mask 617 sigset_t caller_sigmask; 618 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 619 620 OSThread* osthread = thread->osthread(); 621 osthread->set_caller_sigmask(caller_sigmask); 622 623 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); 624 625 if (!ReduceSignalUsage) { 626 if (thread->is_VM_thread()) { 627 // Only the VM thread handles BREAK_SIGNAL ... 628 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 629 } else { 630 // ... all other threads block BREAK_SIGNAL 631 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 632 } 633 } 634 } 635 636 637 ////////////////////////////////////////////////////////////////////////////// 638 // create new thread 639 640 // check if it's safe to start a new thread 641 static bool _thread_safety_check(Thread* thread) { 642 return true; 643 } 644 645 #ifdef __APPLE__ 646 // library handle for calling objc_registerThreadWithCollector() 647 // without static linking to the libobjc library 648 #define OBJC_LIB "/usr/lib/libobjc.dylib" 649 #define OBJC_GCREGISTER "objc_registerThreadWithCollector" 650 typedef void (*objc_registerThreadWithCollector_t)(); 651 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction; 652 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL; 653 #endif 654 655 #ifdef __APPLE__ 656 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) { 657 // Additional thread_id used to correlate threads in SA 658 thread_identifier_info_data_t m_ident_info; 659 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT; 660 661 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO, 662 (thread_info_t) &m_ident_info, &count); 663 664 return m_ident_info.thread_id; 665 } 666 #endif 667 668 // Thread start routine for all newly created threads 669 static void *java_start(Thread *thread) { 670 // Try to randomize the cache line index of hot stack frames. 671 // This helps when threads of the same stack traces evict each other's 672 // cache lines. The threads can be either from the same JVM instance, or 673 // from different JVM instances. The benefit is especially true for 674 // processors with hyperthreading technology. 675 static int counter = 0; 676 int pid = os::current_process_id(); 677 alloca(((pid ^ counter++) & 7) * 128); 678 679 ThreadLocalStorage::set_thread(thread); 680 681 OSThread* osthread = thread->osthread(); 682 Monitor* sync = osthread->startThread_lock(); 683 684 // non floating stack BsdThreads needs extra check, see above 685 if (!_thread_safety_check(thread)) { 686 // notify parent thread 687 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 688 osthread->set_state(ZOMBIE); 689 sync->notify_all(); 690 return NULL; 691 } 692 693 osthread->set_thread_id(os::Bsd::gettid()); 694 695 #ifdef __APPLE__ 696 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 697 guarantee(unique_thread_id != 0, "unique thread id was not found"); 698 osthread->set_unique_thread_id(unique_thread_id); 699 #endif 700 // initialize signal mask for this thread 701 os::Bsd::hotspot_sigmask(thread); 702 703 // initialize floating point control register 704 os::Bsd::init_thread_fpu_state(); 705 706 #ifdef __APPLE__ 707 // register thread with objc gc 708 if (objc_registerThreadWithCollectorFunction != NULL) { 709 objc_registerThreadWithCollectorFunction(); 710 } 711 #endif 712 713 // handshaking with parent thread 714 { 715 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 716 717 // notify parent thread 718 osthread->set_state(INITIALIZED); 719 sync->notify_all(); 720 721 // wait until os::start_thread() 722 while (osthread->get_state() == INITIALIZED) { 723 sync->wait(Mutex::_no_safepoint_check_flag); 724 } 725 } 726 727 // call one more level start routine 728 thread->run(); 729 730 return 0; 731 } 732 733 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { 734 assert(thread->osthread() == NULL, "caller responsible"); 735 736 // Allocate the OSThread object 737 OSThread* osthread = new OSThread(NULL, NULL); 738 if (osthread == NULL) { 739 return false; 740 } 741 742 // set the correct thread state 743 osthread->set_thread_type(thr_type); 744 745 // Initial state is ALLOCATED but not INITIALIZED 746 osthread->set_state(ALLOCATED); 747 748 thread->set_osthread(osthread); 749 750 // init thread attributes 751 pthread_attr_t attr; 752 pthread_attr_init(&attr); 753 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 754 755 // stack size 756 if (os::Bsd::supports_variable_stack_size()) { 757 // calculate stack size if it's not specified by caller 758 if (stack_size == 0) { 759 stack_size = os::Bsd::default_stack_size(thr_type); 760 761 switch (thr_type) { 762 case os::java_thread: 763 // Java threads use ThreadStackSize which default value can be 764 // changed with the flag -Xss 765 assert(JavaThread::stack_size_at_create() > 0, "this should be set"); 766 stack_size = JavaThread::stack_size_at_create(); 767 break; 768 case os::compiler_thread: 769 if (CompilerThreadStackSize > 0) { 770 stack_size = (size_t)(CompilerThreadStackSize * K); 771 break; 772 } // else fall through: 773 // use VMThreadStackSize if CompilerThreadStackSize is not defined 774 case os::vm_thread: 775 case os::pgc_thread: 776 case os::cgc_thread: 777 case os::watcher_thread: 778 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 779 break; 780 } 781 } 782 783 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); 784 pthread_attr_setstacksize(&attr, stack_size); 785 } else { 786 // let pthread_create() pick the default value. 787 } 788 789 ThreadState state; 790 791 { 792 pthread_t tid; 793 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 794 795 pthread_attr_destroy(&attr); 796 797 if (ret != 0) { 798 if (PrintMiscellaneous && (Verbose || WizardMode)) { 799 perror("pthread_create()"); 800 } 801 // Need to clean up stuff we've allocated so far 802 thread->set_osthread(NULL); 803 delete osthread; 804 return false; 805 } 806 807 // Store pthread info into the OSThread 808 osthread->set_pthread_id(tid); 809 810 // Wait until child thread is either initialized or aborted 811 { 812 Monitor* sync_with_child = osthread->startThread_lock(); 813 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 814 while ((state = osthread->get_state()) == ALLOCATED) { 815 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 816 } 817 } 818 819 } 820 821 // Aborted due to thread limit being reached 822 if (state == ZOMBIE) { 823 thread->set_osthread(NULL); 824 delete osthread; 825 return false; 826 } 827 828 // The thread is returned suspended (in state INITIALIZED), 829 // and is started higher up in the call chain 830 assert(state == INITIALIZED, "race condition"); 831 return true; 832 } 833 834 ///////////////////////////////////////////////////////////////////////////// 835 // attach existing thread 836 837 // bootstrap the main thread 838 bool os::create_main_thread(JavaThread* thread) { 839 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); 840 return create_attached_thread(thread); 841 } 842 843 bool os::create_attached_thread(JavaThread* thread) { 844 #ifdef ASSERT 845 thread->verify_not_published(); 846 #endif 847 848 // Allocate the OSThread object 849 OSThread* osthread = new OSThread(NULL, NULL); 850 851 if (osthread == NULL) { 852 return false; 853 } 854 855 osthread->set_thread_id(os::Bsd::gettid()); 856 857 // Store pthread info into the OSThread 858 #ifdef __APPLE__ 859 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 860 guarantee(unique_thread_id != 0, "just checking"); 861 osthread->set_unique_thread_id(unique_thread_id); 862 #endif 863 osthread->set_pthread_id(::pthread_self()); 864 865 // initialize floating point control register 866 os::Bsd::init_thread_fpu_state(); 867 868 // Initial thread state is RUNNABLE 869 osthread->set_state(RUNNABLE); 870 871 thread->set_osthread(osthread); 872 873 // initialize signal mask for this thread 874 // and save the caller's signal mask 875 os::Bsd::hotspot_sigmask(thread); 876 877 return true; 878 } 879 880 void os::pd_start_thread(Thread* thread) { 881 OSThread * osthread = thread->osthread(); 882 assert(osthread->get_state() != INITIALIZED, "just checking"); 883 Monitor* sync_with_child = osthread->startThread_lock(); 884 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 885 sync_with_child->notify(); 886 } 887 888 // Free Bsd resources related to the OSThread 889 void os::free_thread(OSThread* osthread) { 890 assert(osthread != NULL, "osthread not set"); 891 892 if (Thread::current()->osthread() == osthread) { 893 // Restore caller's signal mask 894 sigset_t sigmask = osthread->caller_sigmask(); 895 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 896 } 897 898 delete osthread; 899 } 900 901 ////////////////////////////////////////////////////////////////////////////// 902 // thread local storage 903 904 // Restore the thread pointer if the destructor is called. This is in case 905 // someone from JNI code sets up a destructor with pthread_key_create to run 906 // detachCurrentThread on thread death. Unless we restore the thread pointer we 907 // will hang or crash. When detachCurrentThread is called the key will be set 908 // to null and we will not be called again. If detachCurrentThread is never 909 // called we could loop forever depending on the pthread implementation. 910 static void restore_thread_pointer(void* p) { 911 Thread* thread = (Thread*) p; 912 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread); 913 } 914 915 int os::allocate_thread_local_storage() { 916 pthread_key_t key; 917 int rslt = pthread_key_create(&key, restore_thread_pointer); 918 assert(rslt == 0, "cannot allocate thread local storage"); 919 return (int)key; 920 } 921 922 // Note: This is currently not used by VM, as we don't destroy TLS key 923 // on VM exit. 924 void os::free_thread_local_storage(int index) { 925 int rslt = pthread_key_delete((pthread_key_t)index); 926 assert(rslt == 0, "invalid index"); 927 } 928 929 void os::thread_local_storage_at_put(int index, void* value) { 930 int rslt = pthread_setspecific((pthread_key_t)index, value); 931 assert(rslt == 0, "pthread_setspecific failed"); 932 } 933 934 extern "C" Thread* get_thread() { 935 return ThreadLocalStorage::thread(); 936 } 937 938 939 //////////////////////////////////////////////////////////////////////////////// 940 // time support 941 942 // Time since start-up in seconds to a fine granularity. 943 // Used by VMSelfDestructTimer and the MemProfiler. 944 double os::elapsedTime() { 945 946 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); 947 } 948 949 jlong os::elapsed_counter() { 950 return javaTimeNanos() - initial_time_count; 951 } 952 953 jlong os::elapsed_frequency() { 954 return NANOSECS_PER_SEC; // nanosecond resolution 955 } 956 957 bool os::supports_vtime() { return true; } 958 bool os::enable_vtime() { return false; } 959 bool os::vtime_enabled() { return false; } 960 961 double os::elapsedVTime() { 962 // better than nothing, but not much 963 return elapsedTime(); 964 } 965 966 jlong os::javaTimeMillis() { 967 timeval time; 968 int status = gettimeofday(&time, NULL); 969 assert(status != -1, "bsd error"); 970 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 971 } 972 973 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) { 974 timeval time; 975 int status = gettimeofday(&time, NULL); 976 assert(status != -1, "bsd error"); 977 seconds = jlong(time.tv_sec); 978 nanos = jlong(time.tv_usec) * 1000; 979 } 980 981 #ifndef __APPLE__ 982 #ifndef CLOCK_MONOTONIC 983 #define CLOCK_MONOTONIC (1) 984 #endif 985 #endif 986 987 #ifdef __APPLE__ 988 void os::Bsd::clock_init() { 989 mach_timebase_info(&_timebase_info); 990 } 991 #else 992 void os::Bsd::clock_init() { 993 struct timespec res; 994 struct timespec tp; 995 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && 996 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { 997 // yes, monotonic clock is supported 998 _clock_gettime = ::clock_gettime; 999 } 1000 } 1001 #endif 1002 1003 1004 1005 #ifdef __APPLE__ 1006 1007 jlong os::javaTimeNanos() { 1008 const uint64_t tm = mach_absolute_time(); 1009 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom; 1010 const uint64_t prev = Bsd::_max_abstime; 1011 if (now <= prev) { 1012 return prev; // same or retrograde time; 1013 } 1014 const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev); 1015 assert(obsv >= prev, "invariant"); // Monotonicity 1016 // If the CAS succeeded then we're done and return "now". 1017 // If the CAS failed and the observed value "obsv" is >= now then 1018 // we should return "obsv". If the CAS failed and now > obsv > prv then 1019 // some other thread raced this thread and installed a new value, in which case 1020 // we could either (a) retry the entire operation, (b) retry trying to install now 1021 // or (c) just return obsv. We use (c). No loop is required although in some cases 1022 // we might discard a higher "now" value in deference to a slightly lower but freshly 1023 // installed obsv value. That's entirely benign -- it admits no new orderings compared 1024 // to (a) or (b) -- and greatly reduces coherence traffic. 1025 // We might also condition (c) on the magnitude of the delta between obsv and now. 1026 // Avoiding excessive CAS operations to hot RW locations is critical. 1027 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate 1028 return (prev == obsv) ? now : obsv; 1029 } 1030 1031 #else // __APPLE__ 1032 1033 jlong os::javaTimeNanos() { 1034 if (os::supports_monotonic_clock()) { 1035 struct timespec tp; 1036 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp); 1037 assert(status == 0, "gettime error"); 1038 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1039 return result; 1040 } else { 1041 timeval time; 1042 int status = gettimeofday(&time, NULL); 1043 assert(status != -1, "bsd error"); 1044 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1045 return 1000 * usecs; 1046 } 1047 } 1048 1049 #endif // __APPLE__ 1050 1051 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1052 if (os::supports_monotonic_clock()) { 1053 info_ptr->max_value = ALL_64_BITS; 1054 1055 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1056 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1057 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1058 } else { 1059 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1060 info_ptr->max_value = ALL_64_BITS; 1061 1062 // gettimeofday is a real time clock so it skips 1063 info_ptr->may_skip_backward = true; 1064 info_ptr->may_skip_forward = true; 1065 } 1066 1067 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1068 } 1069 1070 // Return the real, user, and system times in seconds from an 1071 // arbitrary fixed point in the past. 1072 bool os::getTimesSecs(double* process_real_time, 1073 double* process_user_time, 1074 double* process_system_time) { 1075 struct tms ticks; 1076 clock_t real_ticks = times(&ticks); 1077 1078 if (real_ticks == (clock_t) (-1)) { 1079 return false; 1080 } else { 1081 double ticks_per_second = (double) clock_tics_per_sec; 1082 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1083 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1084 *process_real_time = ((double) real_ticks) / ticks_per_second; 1085 1086 return true; 1087 } 1088 } 1089 1090 1091 char * os::local_time_string(char *buf, size_t buflen) { 1092 struct tm t; 1093 time_t long_time; 1094 time(&long_time); 1095 localtime_r(&long_time, &t); 1096 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1097 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1098 t.tm_hour, t.tm_min, t.tm_sec); 1099 return buf; 1100 } 1101 1102 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1103 return localtime_r(clock, res); 1104 } 1105 1106 //////////////////////////////////////////////////////////////////////////////// 1107 // runtime exit support 1108 1109 // Note: os::shutdown() might be called very early during initialization, or 1110 // called from signal handler. Before adding something to os::shutdown(), make 1111 // sure it is async-safe and can handle partially initialized VM. 1112 void os::shutdown() { 1113 1114 // allow PerfMemory to attempt cleanup of any persistent resources 1115 perfMemory_exit(); 1116 1117 // needs to remove object in file system 1118 AttachListener::abort(); 1119 1120 // flush buffered output, finish log files 1121 ostream_abort(); 1122 1123 // Check for abort hook 1124 abort_hook_t abort_hook = Arguments::abort_hook(); 1125 if (abort_hook != NULL) { 1126 abort_hook(); 1127 } 1128 1129 } 1130 1131 // Note: os::abort() might be called very early during initialization, or 1132 // called from signal handler. Before adding something to os::abort(), make 1133 // sure it is async-safe and can handle partially initialized VM. 1134 void os::abort(bool dump_core) { 1135 os::shutdown(); 1136 if (dump_core) { 1137 #ifndef PRODUCT 1138 fdStream out(defaultStream::output_fd()); 1139 out.print_raw("Current thread is "); 1140 char buf[16]; 1141 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1142 out.print_raw_cr(buf); 1143 out.print_raw_cr("Dumping core ..."); 1144 #endif 1145 ::abort(); // dump core 1146 } 1147 1148 ::exit(1); 1149 } 1150 1151 // Die immediately, no exit hook, no abort hook, no cleanup. 1152 void os::die() { 1153 // _exit() on BsdThreads only kills current thread 1154 ::abort(); 1155 } 1156 1157 // This method is a copy of JDK's sysGetLastErrorString 1158 // from src/solaris/hpi/src/system_md.c 1159 1160 size_t os::lasterror(char *buf, size_t len) { 1161 if (errno == 0) return 0; 1162 1163 const char *s = ::strerror(errno); 1164 size_t n = ::strlen(s); 1165 if (n >= len) { 1166 n = len - 1; 1167 } 1168 ::strncpy(buf, s, n); 1169 buf[n] = '\0'; 1170 return n; 1171 } 1172 1173 // Information of current thread in variety of formats 1174 pid_t os::Bsd::gettid() { 1175 int retval = -1; 1176 1177 #ifdef __APPLE__ //XNU kernel 1178 // despite the fact mach port is actually not a thread id use it 1179 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4 1180 retval = ::pthread_mach_thread_np(::pthread_self()); 1181 guarantee(retval != 0, "just checking"); 1182 return retval; 1183 1184 #elif __FreeBSD__ 1185 retval = syscall(SYS_thr_self); 1186 #elif __OpenBSD__ 1187 retval = syscall(SYS_getthrid); 1188 #elif __NetBSD__ 1189 retval = (pid_t) syscall(SYS__lwp_self); 1190 #endif 1191 1192 if (retval == -1) { 1193 return getpid(); 1194 } 1195 } 1196 1197 intx os::current_thread_id() { 1198 #ifdef __APPLE__ 1199 return (intx)::pthread_mach_thread_np(::pthread_self()); 1200 #else 1201 return (intx)::pthread_self(); 1202 #endif 1203 } 1204 1205 int os::current_process_id() { 1206 1207 // Under the old bsd thread library, bsd gives each thread 1208 // its own process id. Because of this each thread will return 1209 // a different pid if this method were to return the result 1210 // of getpid(2). Bsd provides no api that returns the pid 1211 // of the launcher thread for the vm. This implementation 1212 // returns a unique pid, the pid of the launcher thread 1213 // that starts the vm 'process'. 1214 1215 // Under the NPTL, getpid() returns the same pid as the 1216 // launcher thread rather than a unique pid per thread. 1217 // Use gettid() if you want the old pre NPTL behaviour. 1218 1219 // if you are looking for the result of a call to getpid() that 1220 // returns a unique pid for the calling thread, then look at the 1221 // OSThread::thread_id() method in osThread_bsd.hpp file 1222 1223 return (int)(_initial_pid ? _initial_pid : getpid()); 1224 } 1225 1226 // DLL functions 1227 1228 #define JNI_LIB_PREFIX "lib" 1229 #ifdef __APPLE__ 1230 #define JNI_LIB_SUFFIX ".dylib" 1231 #else 1232 #define JNI_LIB_SUFFIX ".so" 1233 #endif 1234 1235 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } 1236 1237 // This must be hard coded because it's the system's temporary 1238 // directory not the java application's temp directory, ala java.io.tmpdir. 1239 #ifdef __APPLE__ 1240 // macosx has a secure per-user temporary directory 1241 char temp_path_storage[PATH_MAX]; 1242 const char* os::get_temp_directory() { 1243 static char *temp_path = NULL; 1244 if (temp_path == NULL) { 1245 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX); 1246 if (pathSize == 0 || pathSize > PATH_MAX) { 1247 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage)); 1248 } 1249 temp_path = temp_path_storage; 1250 } 1251 return temp_path; 1252 } 1253 #else // __APPLE__ 1254 const char* os::get_temp_directory() { return "/tmp"; } 1255 #endif // __APPLE__ 1256 1257 static bool file_exists(const char* filename) { 1258 struct stat statbuf; 1259 if (filename == NULL || strlen(filename) == 0) { 1260 return false; 1261 } 1262 return os::stat(filename, &statbuf) == 0; 1263 } 1264 1265 bool os::dll_build_name(char* buffer, size_t buflen, 1266 const char* pname, const char* fname) { 1267 bool retval = false; 1268 // Copied from libhpi 1269 const size_t pnamelen = pname ? strlen(pname) : 0; 1270 1271 // Return error on buffer overflow. 1272 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { 1273 return retval; 1274 } 1275 1276 if (pnamelen == 0) { 1277 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); 1278 retval = true; 1279 } else if (strchr(pname, *os::path_separator()) != NULL) { 1280 int n; 1281 char** pelements = split_path(pname, &n); 1282 if (pelements == NULL) { 1283 return false; 1284 } 1285 for (int i = 0; i < n; i++) { 1286 // Really shouldn't be NULL, but check can't hurt 1287 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1288 continue; // skip the empty path values 1289 } 1290 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, 1291 pelements[i], fname); 1292 if (file_exists(buffer)) { 1293 retval = true; 1294 break; 1295 } 1296 } 1297 // release the storage 1298 for (int i = 0; i < n; i++) { 1299 if (pelements[i] != NULL) { 1300 FREE_C_HEAP_ARRAY(char, pelements[i]); 1301 } 1302 } 1303 if (pelements != NULL) { 1304 FREE_C_HEAP_ARRAY(char*, pelements); 1305 } 1306 } else { 1307 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); 1308 retval = true; 1309 } 1310 return retval; 1311 } 1312 1313 // check if addr is inside libjvm.so 1314 bool os::address_is_in_vm(address addr) { 1315 static address libjvm_base_addr; 1316 Dl_info dlinfo; 1317 1318 if (libjvm_base_addr == NULL) { 1319 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1320 libjvm_base_addr = (address)dlinfo.dli_fbase; 1321 } 1322 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1323 } 1324 1325 if (dladdr((void *)addr, &dlinfo) != 0) { 1326 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1327 } 1328 1329 return false; 1330 } 1331 1332 1333 #define MACH_MAXSYMLEN 256 1334 1335 bool os::dll_address_to_function_name(address addr, char *buf, 1336 int buflen, int *offset) { 1337 // buf is not optional, but offset is optional 1338 assert(buf != NULL, "sanity check"); 1339 1340 Dl_info dlinfo; 1341 char localbuf[MACH_MAXSYMLEN]; 1342 1343 if (dladdr((void*)addr, &dlinfo) != 0) { 1344 // see if we have a matching symbol 1345 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1346 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { 1347 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1348 } 1349 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1350 return true; 1351 } 1352 // no matching symbol so try for just file info 1353 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1354 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1355 buf, buflen, offset, dlinfo.dli_fname)) { 1356 return true; 1357 } 1358 } 1359 1360 // Handle non-dynamic manually: 1361 if (dlinfo.dli_fbase != NULL && 1362 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) { 1363 if (!Decoder::demangle(localbuf, buf, buflen)) { 1364 jio_snprintf(buf, buflen, "%s", localbuf); 1365 } 1366 return true; 1367 } 1368 } 1369 buf[0] = '\0'; 1370 if (offset != NULL) *offset = -1; 1371 return false; 1372 } 1373 1374 // ported from solaris version 1375 bool os::dll_address_to_library_name(address addr, char* buf, 1376 int buflen, int* offset) { 1377 // buf is not optional, but offset is optional 1378 assert(buf != NULL, "sanity check"); 1379 1380 Dl_info dlinfo; 1381 1382 if (dladdr((void*)addr, &dlinfo) != 0) { 1383 if (dlinfo.dli_fname != NULL) { 1384 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1385 } 1386 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1387 *offset = addr - (address)dlinfo.dli_fbase; 1388 } 1389 return true; 1390 } 1391 1392 buf[0] = '\0'; 1393 if (offset) *offset = -1; 1394 return false; 1395 } 1396 1397 // Loads .dll/.so and 1398 // in case of error it checks if .dll/.so was built for the 1399 // same architecture as Hotspot is running on 1400 1401 #ifdef __APPLE__ 1402 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1403 void * result= ::dlopen(filename, RTLD_LAZY); 1404 if (result != NULL) { 1405 // Successful loading 1406 return result; 1407 } 1408 1409 // Read system error message into ebuf 1410 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1411 ebuf[ebuflen-1]='\0'; 1412 1413 return NULL; 1414 } 1415 #else 1416 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1417 void * result= ::dlopen(filename, RTLD_LAZY); 1418 if (result != NULL) { 1419 // Successful loading 1420 return result; 1421 } 1422 1423 Elf32_Ehdr elf_head; 1424 1425 // Read system error message into ebuf 1426 // It may or may not be overwritten below 1427 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1428 ebuf[ebuflen-1]='\0'; 1429 int diag_msg_max_length=ebuflen-strlen(ebuf); 1430 char* diag_msg_buf=ebuf+strlen(ebuf); 1431 1432 if (diag_msg_max_length==0) { 1433 // No more space in ebuf for additional diagnostics message 1434 return NULL; 1435 } 1436 1437 1438 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1439 1440 if (file_descriptor < 0) { 1441 // Can't open library, report dlerror() message 1442 return NULL; 1443 } 1444 1445 bool failed_to_read_elf_head= 1446 (sizeof(elf_head)!= 1447 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1448 1449 ::close(file_descriptor); 1450 if (failed_to_read_elf_head) { 1451 // file i/o error - report dlerror() msg 1452 return NULL; 1453 } 1454 1455 typedef struct { 1456 Elf32_Half code; // Actual value as defined in elf.h 1457 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1458 char elf_class; // 32 or 64 bit 1459 char endianess; // MSB or LSB 1460 char* name; // String representation 1461 } arch_t; 1462 1463 #ifndef EM_486 1464 #define EM_486 6 /* Intel 80486 */ 1465 #endif 1466 1467 #ifndef EM_MIPS_RS3_LE 1468 #define EM_MIPS_RS3_LE 10 /* MIPS */ 1469 #endif 1470 1471 #ifndef EM_PPC64 1472 #define EM_PPC64 21 /* PowerPC64 */ 1473 #endif 1474 1475 #ifndef EM_S390 1476 #define EM_S390 22 /* IBM System/390 */ 1477 #endif 1478 1479 #ifndef EM_IA_64 1480 #define EM_IA_64 50 /* HP/Intel IA-64 */ 1481 #endif 1482 1483 #ifndef EM_X86_64 1484 #define EM_X86_64 62 /* AMD x86-64 */ 1485 #endif 1486 1487 static const arch_t arch_array[]={ 1488 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1489 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1490 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1491 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1492 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1493 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1494 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1495 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1496 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1497 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1498 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1499 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1500 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1501 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1502 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1503 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} 1504 }; 1505 1506 #if (defined IA32) 1507 static Elf32_Half running_arch_code=EM_386; 1508 #elif (defined AMD64) 1509 static Elf32_Half running_arch_code=EM_X86_64; 1510 #elif (defined IA64) 1511 static Elf32_Half running_arch_code=EM_IA_64; 1512 #elif (defined __sparc) && (defined _LP64) 1513 static Elf32_Half running_arch_code=EM_SPARCV9; 1514 #elif (defined __sparc) && (!defined _LP64) 1515 static Elf32_Half running_arch_code=EM_SPARC; 1516 #elif (defined __powerpc64__) 1517 static Elf32_Half running_arch_code=EM_PPC64; 1518 #elif (defined __powerpc__) 1519 static Elf32_Half running_arch_code=EM_PPC; 1520 #elif (defined ARM) 1521 static Elf32_Half running_arch_code=EM_ARM; 1522 #elif (defined S390) 1523 static Elf32_Half running_arch_code=EM_S390; 1524 #elif (defined ALPHA) 1525 static Elf32_Half running_arch_code=EM_ALPHA; 1526 #elif (defined MIPSEL) 1527 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1528 #elif (defined PARISC) 1529 static Elf32_Half running_arch_code=EM_PARISC; 1530 #elif (defined MIPS) 1531 static Elf32_Half running_arch_code=EM_MIPS; 1532 #elif (defined M68K) 1533 static Elf32_Half running_arch_code=EM_68K; 1534 #else 1535 #error Method os::dll_load requires that one of following is defined:\ 1536 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K 1537 #endif 1538 1539 // Identify compatability class for VM's architecture and library's architecture 1540 // Obtain string descriptions for architectures 1541 1542 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1543 int running_arch_index=-1; 1544 1545 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1546 if (running_arch_code == arch_array[i].code) { 1547 running_arch_index = i; 1548 } 1549 if (lib_arch.code == arch_array[i].code) { 1550 lib_arch.compat_class = arch_array[i].compat_class; 1551 lib_arch.name = arch_array[i].name; 1552 } 1553 } 1554 1555 assert(running_arch_index != -1, 1556 "Didn't find running architecture code (running_arch_code) in arch_array"); 1557 if (running_arch_index == -1) { 1558 // Even though running architecture detection failed 1559 // we may still continue with reporting dlerror() message 1560 return NULL; 1561 } 1562 1563 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1564 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1565 return NULL; 1566 } 1567 1568 #ifndef S390 1569 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1570 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1571 return NULL; 1572 } 1573 #endif // !S390 1574 1575 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1576 if (lib_arch.name!=NULL) { 1577 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1578 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1579 lib_arch.name, arch_array[running_arch_index].name); 1580 } else { 1581 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1582 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1583 lib_arch.code, 1584 arch_array[running_arch_index].name); 1585 } 1586 } 1587 1588 return NULL; 1589 } 1590 #endif // !__APPLE__ 1591 1592 void* os::get_default_process_handle() { 1593 #ifdef __APPLE__ 1594 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY 1595 // to avoid finding unexpected symbols on second (or later) 1596 // loads of a library. 1597 return (void*)::dlopen(NULL, RTLD_FIRST); 1598 #else 1599 return (void*)::dlopen(NULL, RTLD_LAZY); 1600 #endif 1601 } 1602 1603 // XXX: Do we need a lock around this as per Linux? 1604 void* os::dll_lookup(void* handle, const char* name) { 1605 return dlsym(handle, name); 1606 } 1607 1608 1609 static bool _print_ascii_file(const char* filename, outputStream* st) { 1610 int fd = ::open(filename, O_RDONLY); 1611 if (fd == -1) { 1612 return false; 1613 } 1614 1615 char buf[32]; 1616 int bytes; 1617 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { 1618 st->print_raw(buf, bytes); 1619 } 1620 1621 ::close(fd); 1622 1623 return true; 1624 } 1625 1626 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) { 1627 outputStream * out = (outputStream *) param; 1628 out->print_cr(PTR_FORMAT " \t%s", base_address, name); 1629 return 0; 1630 } 1631 1632 void os::print_dll_info(outputStream *st) { 1633 st->print_cr("Dynamic libraries:"); 1634 if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) { 1635 st->print_cr("Error: Cannot print dynamic libraries."); 1636 } 1637 } 1638 1639 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1640 #ifdef RTLD_DI_LINKMAP 1641 Dl_info dli; 1642 void *handle; 1643 Link_map *map; 1644 Link_map *p; 1645 1646 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 || 1647 dli.dli_fname == NULL) { 1648 return 1; 1649 } 1650 handle = dlopen(dli.dli_fname, RTLD_LAZY); 1651 if (handle == NULL) { 1652 return 1; 1653 } 1654 dlinfo(handle, RTLD_DI_LINKMAP, &map); 1655 if (map == NULL) { 1656 dlclose(handle); 1657 return 1; 1658 } 1659 1660 while (map->l_prev != NULL) 1661 map = map->l_prev; 1662 1663 while (map != NULL) { 1664 // Value for top_address is returned as 0 since we don't have any information about module size 1665 if (callback(map->l_name, (address)map->l_addr, (address)0, param)) { 1666 dlclose(handle); 1667 return 1; 1668 } 1669 map = map->l_next; 1670 } 1671 1672 dlclose(handle); 1673 #elif defined(__APPLE__) 1674 for (uint32_t i = 1; i < _dyld_image_count(); i++) { 1675 // Value for top_address is returned as 0 since we don't have any information about module size 1676 if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) { 1677 return 1; 1678 } 1679 } 1680 return 0; 1681 #else 1682 return 1; 1683 #endif 1684 } 1685 1686 void os::print_os_info_brief(outputStream* st) { 1687 st->print("Bsd"); 1688 1689 os::Posix::print_uname_info(st); 1690 } 1691 1692 void os::print_os_info(outputStream* st) { 1693 st->print("OS:"); 1694 st->print("Bsd"); 1695 1696 os::Posix::print_uname_info(st); 1697 1698 os::Posix::print_rlimit_info(st); 1699 1700 os::Posix::print_load_average(st); 1701 } 1702 1703 void os::pd_print_cpu_info(outputStream* st) { 1704 // Nothing to do for now. 1705 } 1706 1707 void os::print_memory_info(outputStream* st) { 1708 1709 st->print("Memory:"); 1710 st->print(" %dk page", os::vm_page_size()>>10); 1711 1712 st->print(", physical " UINT64_FORMAT "k", 1713 os::physical_memory() >> 10); 1714 st->print("(" UINT64_FORMAT "k free)", 1715 os::available_memory() >> 10); 1716 st->cr(); 1717 1718 // meminfo 1719 st->print("\n/proc/meminfo:\n"); 1720 _print_ascii_file("/proc/meminfo", st); 1721 st->cr(); 1722 } 1723 1724 void os::print_siginfo(outputStream* st, void* siginfo) { 1725 const siginfo_t* si = (const siginfo_t*)siginfo; 1726 1727 os::Posix::print_siginfo_brief(st, si); 1728 1729 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && 1730 UseSharedSpaces) { 1731 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1732 if (mapinfo->is_in_shared_space(si->si_addr)) { 1733 st->print("\n\nError accessing class data sharing archive." \ 1734 " Mapped file inaccessible during execution, " \ 1735 " possible disk/network problem."); 1736 } 1737 } 1738 st->cr(); 1739 } 1740 1741 1742 static void print_signal_handler(outputStream* st, int sig, 1743 char* buf, size_t buflen); 1744 1745 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 1746 st->print_cr("Signal Handlers:"); 1747 print_signal_handler(st, SIGSEGV, buf, buflen); 1748 print_signal_handler(st, SIGBUS , buf, buflen); 1749 print_signal_handler(st, SIGFPE , buf, buflen); 1750 print_signal_handler(st, SIGPIPE, buf, buflen); 1751 print_signal_handler(st, SIGXFSZ, buf, buflen); 1752 print_signal_handler(st, SIGILL , buf, buflen); 1753 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); 1754 print_signal_handler(st, SR_signum, buf, buflen); 1755 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 1756 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 1757 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 1758 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 1759 } 1760 1761 static char saved_jvm_path[MAXPATHLEN] = {0}; 1762 1763 // Find the full path to the current module, libjvm 1764 void os::jvm_path(char *buf, jint buflen) { 1765 // Error checking. 1766 if (buflen < MAXPATHLEN) { 1767 assert(false, "must use a large-enough buffer"); 1768 buf[0] = '\0'; 1769 return; 1770 } 1771 // Lazy resolve the path to current module. 1772 if (saved_jvm_path[0] != 0) { 1773 strcpy(buf, saved_jvm_path); 1774 return; 1775 } 1776 1777 char dli_fname[MAXPATHLEN]; 1778 bool ret = dll_address_to_library_name( 1779 CAST_FROM_FN_PTR(address, os::jvm_path), 1780 dli_fname, sizeof(dli_fname), NULL); 1781 assert(ret, "cannot locate libjvm"); 1782 char *rp = NULL; 1783 if (ret && dli_fname[0] != '\0') { 1784 rp = realpath(dli_fname, buf); 1785 } 1786 if (rp == NULL) { 1787 return; 1788 } 1789 1790 if (Arguments::sun_java_launcher_is_altjvm()) { 1791 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 1792 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so" 1793 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/" 1794 // appears at the right place in the string, then assume we are 1795 // installed in a JDK and we're done. Otherwise, check for a 1796 // JAVA_HOME environment variable and construct a path to the JVM 1797 // being overridden. 1798 1799 const char *p = buf + strlen(buf) - 1; 1800 for (int count = 0; p > buf && count < 5; ++count) { 1801 for (--p; p > buf && *p != '/'; --p) 1802 /* empty */ ; 1803 } 1804 1805 if (strncmp(p, "/jre/lib/", 9) != 0) { 1806 // Look for JAVA_HOME in the environment. 1807 char* java_home_var = ::getenv("JAVA_HOME"); 1808 if (java_home_var != NULL && java_home_var[0] != 0) { 1809 char* jrelib_p; 1810 int len; 1811 1812 // Check the current module name "libjvm" 1813 p = strrchr(buf, '/'); 1814 assert(strstr(p, "/libjvm") == p, "invalid library name"); 1815 1816 rp = realpath(java_home_var, buf); 1817 if (rp == NULL) { 1818 return; 1819 } 1820 1821 // determine if this is a legacy image or modules image 1822 // modules image doesn't have "jre" subdirectory 1823 len = strlen(buf); 1824 assert(len < buflen, "Ran out of buffer space"); 1825 jrelib_p = buf + len; 1826 1827 // Add the appropriate library subdir 1828 snprintf(jrelib_p, buflen-len, "/jre/lib"); 1829 if (0 != access(buf, F_OK)) { 1830 snprintf(jrelib_p, buflen-len, "/lib"); 1831 } 1832 1833 // Add the appropriate client or server subdir 1834 len = strlen(buf); 1835 jrelib_p = buf + len; 1836 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT); 1837 if (0 != access(buf, F_OK)) { 1838 snprintf(jrelib_p, buflen-len, "%s", ""); 1839 } 1840 1841 // If the path exists within JAVA_HOME, add the JVM library name 1842 // to complete the path to JVM being overridden. Otherwise fallback 1843 // to the path to the current library. 1844 if (0 == access(buf, F_OK)) { 1845 // Use current module name "libjvm" 1846 len = strlen(buf); 1847 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX); 1848 } else { 1849 // Fall back to path of current library 1850 rp = realpath(dli_fname, buf); 1851 if (rp == NULL) { 1852 return; 1853 } 1854 } 1855 } 1856 } 1857 } 1858 1859 strncpy(saved_jvm_path, buf, MAXPATHLEN); 1860 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 1861 } 1862 1863 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 1864 // no prefix required, not even "_" 1865 } 1866 1867 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 1868 // no suffix required 1869 } 1870 1871 //////////////////////////////////////////////////////////////////////////////// 1872 // sun.misc.Signal support 1873 1874 static volatile jint sigint_count = 0; 1875 1876 static void UserHandler(int sig, void *siginfo, void *context) { 1877 // 4511530 - sem_post is serialized and handled by the manager thread. When 1878 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 1879 // don't want to flood the manager thread with sem_post requests. 1880 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 1881 return; 1882 } 1883 1884 // Ctrl-C is pressed during error reporting, likely because the error 1885 // handler fails to abort. Let VM die immediately. 1886 if (sig == SIGINT && is_error_reported()) { 1887 os::die(); 1888 } 1889 1890 os::signal_notify(sig); 1891 } 1892 1893 void* os::user_handler() { 1894 return CAST_FROM_FN_PTR(void*, UserHandler); 1895 } 1896 1897 extern "C" { 1898 typedef void (*sa_handler_t)(int); 1899 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1900 } 1901 1902 void* os::signal(int signal_number, void* handler) { 1903 struct sigaction sigAct, oldSigAct; 1904 1905 sigfillset(&(sigAct.sa_mask)); 1906 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 1907 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 1908 1909 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 1910 // -1 means registration failed 1911 return (void *)-1; 1912 } 1913 1914 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 1915 } 1916 1917 void os::signal_raise(int signal_number) { 1918 ::raise(signal_number); 1919 } 1920 1921 // The following code is moved from os.cpp for making this 1922 // code platform specific, which it is by its very nature. 1923 1924 // Will be modified when max signal is changed to be dynamic 1925 int os::sigexitnum_pd() { 1926 return NSIG; 1927 } 1928 1929 // a counter for each possible signal value 1930 static volatile jint pending_signals[NSIG+1] = { 0 }; 1931 1932 // Bsd(POSIX) specific hand shaking semaphore. 1933 #ifdef __APPLE__ 1934 typedef semaphore_t os_semaphore_t; 1935 1936 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) 1937 #define SEM_WAIT(sem) semaphore_wait(sem) 1938 #define SEM_POST(sem) semaphore_signal(sem) 1939 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem) 1940 #else 1941 typedef sem_t os_semaphore_t; 1942 1943 #define SEM_INIT(sem, value) sem_init(&sem, 0, value) 1944 #define SEM_WAIT(sem) sem_wait(&sem) 1945 #define SEM_POST(sem) sem_post(&sem) 1946 #define SEM_DESTROY(sem) sem_destroy(&sem) 1947 #endif 1948 1949 class Semaphore : public StackObj { 1950 public: 1951 Semaphore(); 1952 ~Semaphore(); 1953 void signal(); 1954 void wait(); 1955 bool trywait(); 1956 bool timedwait(unsigned int sec, int nsec); 1957 private: 1958 jlong currenttime() const; 1959 os_semaphore_t _semaphore; 1960 }; 1961 1962 Semaphore::Semaphore() : _semaphore(0) { 1963 SEM_INIT(_semaphore, 0); 1964 } 1965 1966 Semaphore::~Semaphore() { 1967 SEM_DESTROY(_semaphore); 1968 } 1969 1970 void Semaphore::signal() { 1971 SEM_POST(_semaphore); 1972 } 1973 1974 void Semaphore::wait() { 1975 SEM_WAIT(_semaphore); 1976 } 1977 1978 jlong Semaphore::currenttime() const { 1979 struct timeval tv; 1980 gettimeofday(&tv, NULL); 1981 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000); 1982 } 1983 1984 #ifdef __APPLE__ 1985 bool Semaphore::trywait() { 1986 return timedwait(0, 0); 1987 } 1988 1989 bool Semaphore::timedwait(unsigned int sec, int nsec) { 1990 kern_return_t kr = KERN_ABORTED; 1991 mach_timespec_t waitspec; 1992 waitspec.tv_sec = sec; 1993 waitspec.tv_nsec = nsec; 1994 1995 jlong starttime = currenttime(); 1996 1997 kr = semaphore_timedwait(_semaphore, waitspec); 1998 while (kr == KERN_ABORTED) { 1999 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec; 2000 2001 jlong current = currenttime(); 2002 jlong passedtime = current - starttime; 2003 2004 if (passedtime >= totalwait) { 2005 waitspec.tv_sec = 0; 2006 waitspec.tv_nsec = 0; 2007 } else { 2008 jlong waittime = totalwait - (current - starttime); 2009 waitspec.tv_sec = waittime / NANOSECS_PER_SEC; 2010 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC; 2011 } 2012 2013 kr = semaphore_timedwait(_semaphore, waitspec); 2014 } 2015 2016 return kr == KERN_SUCCESS; 2017 } 2018 2019 #else 2020 2021 bool Semaphore::trywait() { 2022 return sem_trywait(&_semaphore) == 0; 2023 } 2024 2025 bool Semaphore::timedwait(unsigned int sec, int nsec) { 2026 struct timespec ts; 2027 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec); 2028 2029 while (1) { 2030 int result = sem_timedwait(&_semaphore, &ts); 2031 if (result == 0) { 2032 return true; 2033 } else if (errno == EINTR) { 2034 continue; 2035 } else if (errno == ETIMEDOUT) { 2036 return false; 2037 } else { 2038 return false; 2039 } 2040 } 2041 } 2042 2043 #endif // __APPLE__ 2044 2045 static os_semaphore_t sig_sem; 2046 static Semaphore sr_semaphore; 2047 2048 void os::signal_init_pd() { 2049 // Initialize signal structures 2050 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2051 2052 // Initialize signal semaphore 2053 ::SEM_INIT(sig_sem, 0); 2054 } 2055 2056 void os::signal_notify(int sig) { 2057 Atomic::inc(&pending_signals[sig]); 2058 ::SEM_POST(sig_sem); 2059 } 2060 2061 static int check_pending_signals(bool wait) { 2062 Atomic::store(0, &sigint_count); 2063 for (;;) { 2064 for (int i = 0; i < NSIG + 1; i++) { 2065 jint n = pending_signals[i]; 2066 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2067 return i; 2068 } 2069 } 2070 if (!wait) { 2071 return -1; 2072 } 2073 JavaThread *thread = JavaThread::current(); 2074 ThreadBlockInVM tbivm(thread); 2075 2076 bool threadIsSuspended; 2077 do { 2078 thread->set_suspend_equivalent(); 2079 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2080 ::SEM_WAIT(sig_sem); 2081 2082 // were we externally suspended while we were waiting? 2083 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2084 if (threadIsSuspended) { 2085 // The semaphore has been incremented, but while we were waiting 2086 // another thread suspended us. We don't want to continue running 2087 // while suspended because that would surprise the thread that 2088 // suspended us. 2089 ::SEM_POST(sig_sem); 2090 2091 thread->java_suspend_self(); 2092 } 2093 } while (threadIsSuspended); 2094 } 2095 } 2096 2097 int os::signal_lookup() { 2098 return check_pending_signals(false); 2099 } 2100 2101 int os::signal_wait() { 2102 return check_pending_signals(true); 2103 } 2104 2105 //////////////////////////////////////////////////////////////////////////////// 2106 // Virtual Memory 2107 2108 int os::vm_page_size() { 2109 // Seems redundant as all get out 2110 assert(os::Bsd::page_size() != -1, "must call os::init"); 2111 return os::Bsd::page_size(); 2112 } 2113 2114 // Solaris allocates memory by pages. 2115 int os::vm_allocation_granularity() { 2116 assert(os::Bsd::page_size() != -1, "must call os::init"); 2117 return os::Bsd::page_size(); 2118 } 2119 2120 // Rationale behind this function: 2121 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2122 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2123 // samples for JITted code. Here we create private executable mapping over the code cache 2124 // and then we can use standard (well, almost, as mapping can change) way to provide 2125 // info for the reporting script by storing timestamp and location of symbol 2126 void bsd_wrap_code(char* base, size_t size) { 2127 static volatile jint cnt = 0; 2128 2129 if (!UseOprofile) { 2130 return; 2131 } 2132 2133 char buf[PATH_MAX + 1]; 2134 int num = Atomic::add(1, &cnt); 2135 2136 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", 2137 os::get_temp_directory(), os::current_process_id(), num); 2138 unlink(buf); 2139 2140 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2141 2142 if (fd != -1) { 2143 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2144 if (rv != (off_t)-1) { 2145 if (::write(fd, "", 1) == 1) { 2146 mmap(base, size, 2147 PROT_READ|PROT_WRITE|PROT_EXEC, 2148 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2149 } 2150 } 2151 ::close(fd); 2152 unlink(buf); 2153 } 2154 } 2155 2156 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2157 int err) { 2158 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2159 ", %d) failed; error='%s' (errno=%d)", addr, size, exec, 2160 strerror(err), err); 2161 } 2162 2163 // NOTE: Bsd kernel does not really reserve the pages for us. 2164 // All it does is to check if there are enough free pages 2165 // left at the time of mmap(). This could be a potential 2166 // problem. 2167 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2168 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2169 #ifdef __OpenBSD__ 2170 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2171 if (::mprotect(addr, size, prot) == 0) { 2172 return true; 2173 } 2174 #else 2175 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2176 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2177 if (res != (uintptr_t) MAP_FAILED) { 2178 return true; 2179 } 2180 #endif 2181 2182 // Warn about any commit errors we see in non-product builds just 2183 // in case mmap() doesn't work as described on the man page. 2184 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);) 2185 2186 return false; 2187 } 2188 2189 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2190 bool exec) { 2191 // alignment_hint is ignored on this OS 2192 return pd_commit_memory(addr, size, exec); 2193 } 2194 2195 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2196 const char* mesg) { 2197 assert(mesg != NULL, "mesg must be specified"); 2198 if (!pd_commit_memory(addr, size, exec)) { 2199 // add extra info in product mode for vm_exit_out_of_memory(): 2200 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);) 2201 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg); 2202 } 2203 } 2204 2205 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2206 size_t alignment_hint, bool exec, 2207 const char* mesg) { 2208 // alignment_hint is ignored on this OS 2209 pd_commit_memory_or_exit(addr, size, exec, mesg); 2210 } 2211 2212 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2213 } 2214 2215 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2216 ::madvise(addr, bytes, MADV_DONTNEED); 2217 } 2218 2219 void os::numa_make_global(char *addr, size_t bytes) { 2220 } 2221 2222 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2223 } 2224 2225 bool os::numa_topology_changed() { return false; } 2226 2227 size_t os::numa_get_groups_num() { 2228 return 1; 2229 } 2230 2231 int os::numa_get_group_id() { 2232 return 0; 2233 } 2234 2235 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2236 if (size > 0) { 2237 ids[0] = 0; 2238 return 1; 2239 } 2240 return 0; 2241 } 2242 2243 bool os::get_page_info(char *start, page_info* info) { 2244 return false; 2245 } 2246 2247 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { 2248 return end; 2249 } 2250 2251 2252 bool os::pd_uncommit_memory(char* addr, size_t size) { 2253 #ifdef __OpenBSD__ 2254 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2255 return ::mprotect(addr, size, PROT_NONE) == 0; 2256 #else 2257 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2258 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2259 return res != (uintptr_t) MAP_FAILED; 2260 #endif 2261 } 2262 2263 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2264 return os::commit_memory(addr, size, !ExecMem); 2265 } 2266 2267 // If this is a growable mapping, remove the guard pages entirely by 2268 // munmap()ping them. If not, just call uncommit_memory(). 2269 bool os::remove_stack_guard_pages(char* addr, size_t size) { 2270 return os::uncommit_memory(addr, size); 2271 } 2272 2273 static address _highest_vm_reserved_address = NULL; 2274 2275 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 2276 // at 'requested_addr'. If there are existing memory mappings at the same 2277 // location, however, they will be overwritten. If 'fixed' is false, 2278 // 'requested_addr' is only treated as a hint, the return value may or 2279 // may not start from the requested address. Unlike Bsd mmap(), this 2280 // function returns NULL to indicate failure. 2281 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 2282 char * addr; 2283 int flags; 2284 2285 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 2286 if (fixed) { 2287 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); 2288 flags |= MAP_FIXED; 2289 } 2290 2291 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 2292 // touch an uncommitted page. Otherwise, the read/write might 2293 // succeed if we have enough swap space to back the physical page. 2294 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 2295 flags, -1, 0); 2296 2297 if (addr != MAP_FAILED) { 2298 // anon_mmap() should only get called during VM initialization, 2299 // don't need lock (actually we can skip locking even it can be called 2300 // from multiple threads, because _highest_vm_reserved_address is just a 2301 // hint about the upper limit of non-stack memory regions.) 2302 if ((address)addr + bytes > _highest_vm_reserved_address) { 2303 _highest_vm_reserved_address = (address)addr + bytes; 2304 } 2305 } 2306 2307 return addr == MAP_FAILED ? NULL : addr; 2308 } 2309 2310 // Don't update _highest_vm_reserved_address, because there might be memory 2311 // regions above addr + size. If so, releasing a memory region only creates 2312 // a hole in the address space, it doesn't help prevent heap-stack collision. 2313 // 2314 static int anon_munmap(char * addr, size_t size) { 2315 return ::munmap(addr, size) == 0; 2316 } 2317 2318 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 2319 size_t alignment_hint) { 2320 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 2321 } 2322 2323 bool os::pd_release_memory(char* addr, size_t size) { 2324 return anon_munmap(addr, size); 2325 } 2326 2327 static bool bsd_mprotect(char* addr, size_t size, int prot) { 2328 // Bsd wants the mprotect address argument to be page aligned. 2329 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); 2330 2331 // According to SUSv3, mprotect() should only be used with mappings 2332 // established by mmap(), and mmap() always maps whole pages. Unaligned 2333 // 'addr' likely indicates problem in the VM (e.g. trying to change 2334 // protection of malloc'ed or statically allocated memory). Check the 2335 // caller if you hit this assert. 2336 assert(addr == bottom, "sanity check"); 2337 2338 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); 2339 return ::mprotect(bottom, size, prot) == 0; 2340 } 2341 2342 // Set protections specified 2343 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 2344 bool is_committed) { 2345 unsigned int p = 0; 2346 switch (prot) { 2347 case MEM_PROT_NONE: p = PROT_NONE; break; 2348 case MEM_PROT_READ: p = PROT_READ; break; 2349 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 2350 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 2351 default: 2352 ShouldNotReachHere(); 2353 } 2354 // is_committed is unused. 2355 return bsd_mprotect(addr, bytes, p); 2356 } 2357 2358 bool os::guard_memory(char* addr, size_t size) { 2359 return bsd_mprotect(addr, size, PROT_NONE); 2360 } 2361 2362 bool os::unguard_memory(char* addr, size_t size) { 2363 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); 2364 } 2365 2366 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { 2367 return false; 2368 } 2369 2370 // Large page support 2371 2372 static size_t _large_page_size = 0; 2373 2374 void os::large_page_init() { 2375 } 2376 2377 2378 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) { 2379 fatal("This code is not used or maintained."); 2380 2381 // "exec" is passed in but not used. Creating the shared image for 2382 // the code cache doesn't have an SHM_X executable permission to check. 2383 assert(UseLargePages && UseSHM, "only for SHM large pages"); 2384 2385 key_t key = IPC_PRIVATE; 2386 char *addr; 2387 2388 bool warn_on_failure = UseLargePages && 2389 (!FLAG_IS_DEFAULT(UseLargePages) || 2390 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 2391 2392 // Create a large shared memory region to attach to based on size. 2393 // Currently, size is the total size of the heap 2394 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); 2395 if (shmid == -1) { 2396 // Possible reasons for shmget failure: 2397 // 1. shmmax is too small for Java heap. 2398 // > check shmmax value: cat /proc/sys/kernel/shmmax 2399 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 2400 // 2. not enough large page memory. 2401 // > check available large pages: cat /proc/meminfo 2402 // > increase amount of large pages: 2403 // echo new_value > /proc/sys/vm/nr_hugepages 2404 // Note 1: different Bsd may use different name for this property, 2405 // e.g. on Redhat AS-3 it is "hugetlb_pool". 2406 // Note 2: it's possible there's enough physical memory available but 2407 // they are so fragmented after a long run that they can't 2408 // coalesce into large pages. Try to reserve large pages when 2409 // the system is still "fresh". 2410 if (warn_on_failure) { 2411 warning("Failed to reserve shared memory (errno = %d).", errno); 2412 } 2413 return NULL; 2414 } 2415 2416 // attach to the region 2417 addr = (char*)shmat(shmid, req_addr, 0); 2418 int err = errno; 2419 2420 // Remove shmid. If shmat() is successful, the actual shared memory segment 2421 // will be deleted when it's detached by shmdt() or when the process 2422 // terminates. If shmat() is not successful this will remove the shared 2423 // segment immediately. 2424 shmctl(shmid, IPC_RMID, NULL); 2425 2426 if ((intptr_t)addr == -1) { 2427 if (warn_on_failure) { 2428 warning("Failed to attach shared memory (errno = %d).", err); 2429 } 2430 return NULL; 2431 } 2432 2433 // The memory is committed 2434 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 2435 2436 return addr; 2437 } 2438 2439 bool os::release_memory_special(char* base, size_t bytes) { 2440 if (MemTracker::tracking_level() > NMT_minimal) { 2441 Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 2442 // detaching the SHM segment will also delete it, see reserve_memory_special() 2443 int rslt = shmdt(base); 2444 if (rslt == 0) { 2445 tkr.record((address)base, bytes); 2446 return true; 2447 } else { 2448 return false; 2449 } 2450 } else { 2451 return shmdt(base) == 0; 2452 } 2453 } 2454 2455 size_t os::large_page_size() { 2456 return _large_page_size; 2457 } 2458 2459 // HugeTLBFS allows application to commit large page memory on demand; 2460 // with SysV SHM the entire memory region must be allocated as shared 2461 // memory. 2462 bool os::can_commit_large_page_memory() { 2463 return UseHugeTLBFS; 2464 } 2465 2466 bool os::can_execute_large_page_memory() { 2467 return UseHugeTLBFS; 2468 } 2469 2470 // Reserve memory at an arbitrary address, only if that area is 2471 // available (and not reserved for something else). 2472 2473 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 2474 const int max_tries = 10; 2475 char* base[max_tries]; 2476 size_t size[max_tries]; 2477 const size_t gap = 0x000000; 2478 2479 // Assert only that the size is a multiple of the page size, since 2480 // that's all that mmap requires, and since that's all we really know 2481 // about at this low abstraction level. If we need higher alignment, 2482 // we can either pass an alignment to this method or verify alignment 2483 // in one of the methods further up the call chain. See bug 5044738. 2484 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 2485 2486 // Repeatedly allocate blocks until the block is allocated at the 2487 // right spot. Give up after max_tries. Note that reserve_memory() will 2488 // automatically update _highest_vm_reserved_address if the call is 2489 // successful. The variable tracks the highest memory address every reserved 2490 // by JVM. It is used to detect heap-stack collision if running with 2491 // fixed-stack BsdThreads. Because here we may attempt to reserve more 2492 // space than needed, it could confuse the collision detecting code. To 2493 // solve the problem, save current _highest_vm_reserved_address and 2494 // calculate the correct value before return. 2495 address old_highest = _highest_vm_reserved_address; 2496 2497 // Bsd mmap allows caller to pass an address as hint; give it a try first, 2498 // if kernel honors the hint then we can return immediately. 2499 char * addr = anon_mmap(requested_addr, bytes, false); 2500 if (addr == requested_addr) { 2501 return requested_addr; 2502 } 2503 2504 if (addr != NULL) { 2505 // mmap() is successful but it fails to reserve at the requested address 2506 anon_munmap(addr, bytes); 2507 } 2508 2509 int i; 2510 for (i = 0; i < max_tries; ++i) { 2511 base[i] = reserve_memory(bytes); 2512 2513 if (base[i] != NULL) { 2514 // Is this the block we wanted? 2515 if (base[i] == requested_addr) { 2516 size[i] = bytes; 2517 break; 2518 } 2519 2520 // Does this overlap the block we wanted? Give back the overlapped 2521 // parts and try again. 2522 2523 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; 2524 if (top_overlap >= 0 && top_overlap < bytes) { 2525 unmap_memory(base[i], top_overlap); 2526 base[i] += top_overlap; 2527 size[i] = bytes - top_overlap; 2528 } else { 2529 size_t bottom_overlap = base[i] + bytes - requested_addr; 2530 if (bottom_overlap >= 0 && bottom_overlap < bytes) { 2531 unmap_memory(requested_addr, bottom_overlap); 2532 size[i] = bytes - bottom_overlap; 2533 } else { 2534 size[i] = bytes; 2535 } 2536 } 2537 } 2538 } 2539 2540 // Give back the unused reserved pieces. 2541 2542 for (int j = 0; j < i; ++j) { 2543 if (base[j] != NULL) { 2544 unmap_memory(base[j], size[j]); 2545 } 2546 } 2547 2548 if (i < max_tries) { 2549 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); 2550 return requested_addr; 2551 } else { 2552 _highest_vm_reserved_address = old_highest; 2553 return NULL; 2554 } 2555 } 2556 2557 size_t os::read(int fd, void *buf, unsigned int nBytes) { 2558 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); 2559 } 2560 2561 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 2562 RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset)); 2563 } 2564 2565 void os::naked_short_sleep(jlong ms) { 2566 struct timespec req; 2567 2568 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 2569 req.tv_sec = 0; 2570 if (ms > 0) { 2571 req.tv_nsec = (ms % 1000) * 1000000; 2572 } else { 2573 req.tv_nsec = 1; 2574 } 2575 2576 nanosleep(&req, NULL); 2577 2578 return; 2579 } 2580 2581 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 2582 void os::infinite_sleep() { 2583 while (true) { // sleep forever ... 2584 ::sleep(100); // ... 100 seconds at a time 2585 } 2586 } 2587 2588 // Used to convert frequent JVM_Yield() to nops 2589 bool os::dont_yield() { 2590 return DontYieldALot; 2591 } 2592 2593 void os::naked_yield() { 2594 sched_yield(); 2595 } 2596 2597 //////////////////////////////////////////////////////////////////////////////// 2598 // thread priority support 2599 2600 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER 2601 // only supports dynamic priority, static priority must be zero. For real-time 2602 // applications, Bsd supports SCHED_RR which allows static priority (1-99). 2603 // However, for large multi-threaded applications, SCHED_RR is not only slower 2604 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 2605 // of 5 runs - Sep 2005). 2606 // 2607 // The following code actually changes the niceness of kernel-thread/LWP. It 2608 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 2609 // not the entire user process, and user level threads are 1:1 mapped to kernel 2610 // threads. It has always been the case, but could change in the future. For 2611 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 2612 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 2613 2614 #if !defined(__APPLE__) 2615 int os::java_to_os_priority[CriticalPriority + 1] = { 2616 19, // 0 Entry should never be used 2617 2618 0, // 1 MinPriority 2619 3, // 2 2620 6, // 3 2621 2622 10, // 4 2623 15, // 5 NormPriority 2624 18, // 6 2625 2626 21, // 7 2627 25, // 8 2628 28, // 9 NearMaxPriority 2629 2630 31, // 10 MaxPriority 2631 2632 31 // 11 CriticalPriority 2633 }; 2634 #else 2635 // Using Mach high-level priority assignments 2636 int os::java_to_os_priority[CriticalPriority + 1] = { 2637 0, // 0 Entry should never be used (MINPRI_USER) 2638 2639 27, // 1 MinPriority 2640 28, // 2 2641 29, // 3 2642 2643 30, // 4 2644 31, // 5 NormPriority (BASEPRI_DEFAULT) 2645 32, // 6 2646 2647 33, // 7 2648 34, // 8 2649 35, // 9 NearMaxPriority 2650 2651 36, // 10 MaxPriority 2652 2653 36 // 11 CriticalPriority 2654 }; 2655 #endif 2656 2657 static int prio_init() { 2658 if (ThreadPriorityPolicy == 1) { 2659 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 2660 // if effective uid is not root. Perhaps, a more elegant way of doing 2661 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 2662 if (geteuid() != 0) { 2663 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 2664 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); 2665 } 2666 ThreadPriorityPolicy = 0; 2667 } 2668 } 2669 if (UseCriticalJavaThreadPriority) { 2670 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 2671 } 2672 return 0; 2673 } 2674 2675 OSReturn os::set_native_priority(Thread* thread, int newpri) { 2676 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 2677 2678 #ifdef __OpenBSD__ 2679 // OpenBSD pthread_setprio starves low priority threads 2680 return OS_OK; 2681 #elif defined(__FreeBSD__) 2682 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); 2683 #elif defined(__APPLE__) || defined(__NetBSD__) 2684 struct sched_param sp; 2685 int policy; 2686 pthread_t self = pthread_self(); 2687 2688 if (pthread_getschedparam(self, &policy, &sp) != 0) { 2689 return OS_ERR; 2690 } 2691 2692 sp.sched_priority = newpri; 2693 if (pthread_setschedparam(self, policy, &sp) != 0) { 2694 return OS_ERR; 2695 } 2696 2697 return OS_OK; 2698 #else 2699 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 2700 return (ret == 0) ? OS_OK : OS_ERR; 2701 #endif 2702 } 2703 2704 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { 2705 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 2706 *priority_ptr = java_to_os_priority[NormPriority]; 2707 return OS_OK; 2708 } 2709 2710 errno = 0; 2711 #if defined(__OpenBSD__) || defined(__FreeBSD__) 2712 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); 2713 #elif defined(__APPLE__) || defined(__NetBSD__) 2714 int policy; 2715 struct sched_param sp; 2716 2717 pthread_getschedparam(pthread_self(), &policy, &sp); 2718 *priority_ptr = sp.sched_priority; 2719 #else 2720 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 2721 #endif 2722 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 2723 } 2724 2725 // Hint to the underlying OS that a task switch would not be good. 2726 // Void return because it's a hint and can fail. 2727 void os::hint_no_preempt() {} 2728 2729 //////////////////////////////////////////////////////////////////////////////// 2730 // suspend/resume support 2731 2732 // the low-level signal-based suspend/resume support is a remnant from the 2733 // old VM-suspension that used to be for java-suspension, safepoints etc, 2734 // within hotspot. Now there is a single use-case for this: 2735 // - calling get_thread_pc() on the VMThread by the flat-profiler task 2736 // that runs in the watcher thread. 2737 // The remaining code is greatly simplified from the more general suspension 2738 // code that used to be used. 2739 // 2740 // The protocol is quite simple: 2741 // - suspend: 2742 // - sends a signal to the target thread 2743 // - polls the suspend state of the osthread using a yield loop 2744 // - target thread signal handler (SR_handler) sets suspend state 2745 // and blocks in sigsuspend until continued 2746 // - resume: 2747 // - sets target osthread state to continue 2748 // - sends signal to end the sigsuspend loop in the SR_handler 2749 // 2750 // Note that the SR_lock plays no role in this suspend/resume protocol. 2751 2752 static void resume_clear_context(OSThread *osthread) { 2753 osthread->set_ucontext(NULL); 2754 osthread->set_siginfo(NULL); 2755 } 2756 2757 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { 2758 osthread->set_ucontext(context); 2759 osthread->set_siginfo(siginfo); 2760 } 2761 2762 // Handler function invoked when a thread's execution is suspended or 2763 // resumed. We have to be careful that only async-safe functions are 2764 // called here (Note: most pthread functions are not async safe and 2765 // should be avoided.) 2766 // 2767 // Note: sigwait() is a more natural fit than sigsuspend() from an 2768 // interface point of view, but sigwait() prevents the signal hander 2769 // from being run. libpthread would get very confused by not having 2770 // its signal handlers run and prevents sigwait()'s use with the 2771 // mutex granting granting signal. 2772 // 2773 // Currently only ever called on the VMThread or JavaThread 2774 // 2775 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 2776 // Save and restore errno to avoid confusing native code with EINTR 2777 // after sigsuspend. 2778 int old_errno = errno; 2779 2780 Thread* thread = Thread::current(); 2781 OSThread* osthread = thread->osthread(); 2782 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 2783 2784 os::SuspendResume::State current = osthread->sr.state(); 2785 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 2786 suspend_save_context(osthread, siginfo, context); 2787 2788 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 2789 os::SuspendResume::State state = osthread->sr.suspended(); 2790 if (state == os::SuspendResume::SR_SUSPENDED) { 2791 sigset_t suspend_set; // signals for sigsuspend() 2792 2793 // get current set of blocked signals and unblock resume signal 2794 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 2795 sigdelset(&suspend_set, SR_signum); 2796 2797 sr_semaphore.signal(); 2798 // wait here until we are resumed 2799 while (1) { 2800 sigsuspend(&suspend_set); 2801 2802 os::SuspendResume::State result = osthread->sr.running(); 2803 if (result == os::SuspendResume::SR_RUNNING) { 2804 sr_semaphore.signal(); 2805 break; 2806 } else if (result != os::SuspendResume::SR_SUSPENDED) { 2807 ShouldNotReachHere(); 2808 } 2809 } 2810 2811 } else if (state == os::SuspendResume::SR_RUNNING) { 2812 // request was cancelled, continue 2813 } else { 2814 ShouldNotReachHere(); 2815 } 2816 2817 resume_clear_context(osthread); 2818 } else if (current == os::SuspendResume::SR_RUNNING) { 2819 // request was cancelled, continue 2820 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 2821 // ignore 2822 } else { 2823 // ignore 2824 } 2825 2826 errno = old_errno; 2827 } 2828 2829 2830 static int SR_initialize() { 2831 struct sigaction act; 2832 char *s; 2833 // Get signal number to use for suspend/resume 2834 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 2835 int sig = ::strtol(s, 0, 10); 2836 if (sig > 0 || sig < NSIG) { 2837 SR_signum = sig; 2838 } 2839 } 2840 2841 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 2842 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 2843 2844 sigemptyset(&SR_sigset); 2845 sigaddset(&SR_sigset, SR_signum); 2846 2847 // Set up signal handler for suspend/resume 2848 act.sa_flags = SA_RESTART|SA_SIGINFO; 2849 act.sa_handler = (void (*)(int)) SR_handler; 2850 2851 // SR_signum is blocked by default. 2852 // 4528190 - We also need to block pthread restart signal (32 on all 2853 // supported Bsd platforms). Note that BsdThreads need to block 2854 // this signal for all threads to work properly. So we don't have 2855 // to use hard-coded signal number when setting up the mask. 2856 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 2857 2858 if (sigaction(SR_signum, &act, 0) == -1) { 2859 return -1; 2860 } 2861 2862 // Save signal flag 2863 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); 2864 return 0; 2865 } 2866 2867 static int sr_notify(OSThread* osthread) { 2868 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2869 assert_status(status == 0, status, "pthread_kill"); 2870 return status; 2871 } 2872 2873 // "Randomly" selected value for how long we want to spin 2874 // before bailing out on suspending a thread, also how often 2875 // we send a signal to a thread we want to resume 2876 static const int RANDOMLY_LARGE_INTEGER = 1000000; 2877 static const int RANDOMLY_LARGE_INTEGER2 = 100; 2878 2879 // returns true on success and false on error - really an error is fatal 2880 // but this seems the normal response to library errors 2881 static bool do_suspend(OSThread* osthread) { 2882 assert(osthread->sr.is_running(), "thread should be running"); 2883 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 2884 2885 // mark as suspended and send signal 2886 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 2887 // failed to switch, state wasn't running? 2888 ShouldNotReachHere(); 2889 return false; 2890 } 2891 2892 if (sr_notify(osthread) != 0) { 2893 ShouldNotReachHere(); 2894 } 2895 2896 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 2897 while (true) { 2898 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2899 break; 2900 } else { 2901 // timeout 2902 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 2903 if (cancelled == os::SuspendResume::SR_RUNNING) { 2904 return false; 2905 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 2906 // make sure that we consume the signal on the semaphore as well 2907 sr_semaphore.wait(); 2908 break; 2909 } else { 2910 ShouldNotReachHere(); 2911 return false; 2912 } 2913 } 2914 } 2915 2916 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 2917 return true; 2918 } 2919 2920 static void do_resume(OSThread* osthread) { 2921 assert(osthread->sr.is_suspended(), "thread should be suspended"); 2922 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 2923 2924 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 2925 // failed to switch to WAKEUP_REQUEST 2926 ShouldNotReachHere(); 2927 return; 2928 } 2929 2930 while (true) { 2931 if (sr_notify(osthread) == 0) { 2932 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2933 if (osthread->sr.is_running()) { 2934 return; 2935 } 2936 } 2937 } else { 2938 ShouldNotReachHere(); 2939 } 2940 } 2941 2942 guarantee(osthread->sr.is_running(), "Must be running!"); 2943 } 2944 2945 /////////////////////////////////////////////////////////////////////////////////// 2946 // signal handling (except suspend/resume) 2947 2948 // This routine may be used by user applications as a "hook" to catch signals. 2949 // The user-defined signal handler must pass unrecognized signals to this 2950 // routine, and if it returns true (non-zero), then the signal handler must 2951 // return immediately. If the flag "abort_if_unrecognized" is true, then this 2952 // routine will never retun false (zero), but instead will execute a VM panic 2953 // routine kill the process. 2954 // 2955 // If this routine returns false, it is OK to call it again. This allows 2956 // the user-defined signal handler to perform checks either before or after 2957 // the VM performs its own checks. Naturally, the user code would be making 2958 // a serious error if it tried to handle an exception (such as a null check 2959 // or breakpoint) that the VM was generating for its own correct operation. 2960 // 2961 // This routine may recognize any of the following kinds of signals: 2962 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 2963 // It should be consulted by handlers for any of those signals. 2964 // 2965 // The caller of this routine must pass in the three arguments supplied 2966 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 2967 // field of the structure passed to sigaction(). This routine assumes that 2968 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 2969 // 2970 // Note that the VM will print warnings if it detects conflicting signal 2971 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 2972 // 2973 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, 2974 void* ucontext, 2975 int abort_if_unrecognized); 2976 2977 void signalHandler(int sig, siginfo_t* info, void* uc) { 2978 assert(info != NULL && uc != NULL, "it must be old kernel"); 2979 int orig_errno = errno; // Preserve errno value over signal handler. 2980 JVM_handle_bsd_signal(sig, info, uc, true); 2981 errno = orig_errno; 2982 } 2983 2984 2985 // This boolean allows users to forward their own non-matching signals 2986 // to JVM_handle_bsd_signal, harmlessly. 2987 bool os::Bsd::signal_handlers_are_installed = false; 2988 2989 // For signal-chaining 2990 struct sigaction os::Bsd::sigact[MAXSIGNUM]; 2991 unsigned int os::Bsd::sigs = 0; 2992 bool os::Bsd::libjsig_is_loaded = false; 2993 typedef struct sigaction *(*get_signal_t)(int); 2994 get_signal_t os::Bsd::get_signal_action = NULL; 2995 2996 struct sigaction* os::Bsd::get_chained_signal_action(int sig) { 2997 struct sigaction *actp = NULL; 2998 2999 if (libjsig_is_loaded) { 3000 // Retrieve the old signal handler from libjsig 3001 actp = (*get_signal_action)(sig); 3002 } 3003 if (actp == NULL) { 3004 // Retrieve the preinstalled signal handler from jvm 3005 actp = get_preinstalled_handler(sig); 3006 } 3007 3008 return actp; 3009 } 3010 3011 static bool call_chained_handler(struct sigaction *actp, int sig, 3012 siginfo_t *siginfo, void *context) { 3013 // Call the old signal handler 3014 if (actp->sa_handler == SIG_DFL) { 3015 // It's more reasonable to let jvm treat it as an unexpected exception 3016 // instead of taking the default action. 3017 return false; 3018 } else if (actp->sa_handler != SIG_IGN) { 3019 if ((actp->sa_flags & SA_NODEFER) == 0) { 3020 // automaticlly block the signal 3021 sigaddset(&(actp->sa_mask), sig); 3022 } 3023 3024 sa_handler_t hand; 3025 sa_sigaction_t sa; 3026 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 3027 // retrieve the chained handler 3028 if (siginfo_flag_set) { 3029 sa = actp->sa_sigaction; 3030 } else { 3031 hand = actp->sa_handler; 3032 } 3033 3034 if ((actp->sa_flags & SA_RESETHAND) != 0) { 3035 actp->sa_handler = SIG_DFL; 3036 } 3037 3038 // try to honor the signal mask 3039 sigset_t oset; 3040 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 3041 3042 // call into the chained handler 3043 if (siginfo_flag_set) { 3044 (*sa)(sig, siginfo, context); 3045 } else { 3046 (*hand)(sig); 3047 } 3048 3049 // restore the signal mask 3050 pthread_sigmask(SIG_SETMASK, &oset, 0); 3051 } 3052 // Tell jvm's signal handler the signal is taken care of. 3053 return true; 3054 } 3055 3056 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { 3057 bool chained = false; 3058 // signal-chaining 3059 if (UseSignalChaining) { 3060 struct sigaction *actp = get_chained_signal_action(sig); 3061 if (actp != NULL) { 3062 chained = call_chained_handler(actp, sig, siginfo, context); 3063 } 3064 } 3065 return chained; 3066 } 3067 3068 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { 3069 if ((((unsigned int)1 << sig) & sigs) != 0) { 3070 return &sigact[sig]; 3071 } 3072 return NULL; 3073 } 3074 3075 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 3076 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3077 sigact[sig] = oldAct; 3078 sigs |= (unsigned int)1 << sig; 3079 } 3080 3081 // for diagnostic 3082 int os::Bsd::sigflags[MAXSIGNUM]; 3083 3084 int os::Bsd::get_our_sigflags(int sig) { 3085 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3086 return sigflags[sig]; 3087 } 3088 3089 void os::Bsd::set_our_sigflags(int sig, int flags) { 3090 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3091 sigflags[sig] = flags; 3092 } 3093 3094 void os::Bsd::set_signal_handler(int sig, bool set_installed) { 3095 // Check for overwrite. 3096 struct sigaction oldAct; 3097 sigaction(sig, (struct sigaction*)NULL, &oldAct); 3098 3099 void* oldhand = oldAct.sa_sigaction 3100 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3101 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3102 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 3103 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 3104 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 3105 if (AllowUserSignalHandlers || !set_installed) { 3106 // Do not overwrite; user takes responsibility to forward to us. 3107 return; 3108 } else if (UseSignalChaining) { 3109 // save the old handler in jvm 3110 save_preinstalled_handler(sig, oldAct); 3111 // libjsig also interposes the sigaction() call below and saves the 3112 // old sigaction on it own. 3113 } else { 3114 fatal(err_msg("Encountered unexpected pre-existing sigaction handler " 3115 "%#lx for signal %d.", (long)oldhand, sig)); 3116 } 3117 } 3118 3119 struct sigaction sigAct; 3120 sigfillset(&(sigAct.sa_mask)); 3121 sigAct.sa_handler = SIG_DFL; 3122 if (!set_installed) { 3123 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3124 } else { 3125 sigAct.sa_sigaction = signalHandler; 3126 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3127 } 3128 #ifdef __APPLE__ 3129 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV 3130 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages" 3131 // if the signal handler declares it will handle it on alternate stack. 3132 // Notice we only declare we will handle it on alt stack, but we are not 3133 // actually going to use real alt stack - this is just a workaround. 3134 // Please see ux_exception.c, method catch_mach_exception_raise for details 3135 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c 3136 if (sig == SIGSEGV) { 3137 sigAct.sa_flags |= SA_ONSTACK; 3138 } 3139 #endif 3140 3141 // Save flags, which are set by ours 3142 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3143 sigflags[sig] = sigAct.sa_flags; 3144 3145 int ret = sigaction(sig, &sigAct, &oldAct); 3146 assert(ret == 0, "check"); 3147 3148 void* oldhand2 = oldAct.sa_sigaction 3149 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3150 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3151 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 3152 } 3153 3154 // install signal handlers for signals that HotSpot needs to 3155 // handle in order to support Java-level exception handling. 3156 3157 void os::Bsd::install_signal_handlers() { 3158 if (!signal_handlers_are_installed) { 3159 signal_handlers_are_installed = true; 3160 3161 // signal-chaining 3162 typedef void (*signal_setting_t)(); 3163 signal_setting_t begin_signal_setting = NULL; 3164 signal_setting_t end_signal_setting = NULL; 3165 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3166 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 3167 if (begin_signal_setting != NULL) { 3168 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3169 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 3170 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 3171 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 3172 libjsig_is_loaded = true; 3173 assert(UseSignalChaining, "should enable signal-chaining"); 3174 } 3175 if (libjsig_is_loaded) { 3176 // Tell libjsig jvm is setting signal handlers 3177 (*begin_signal_setting)(); 3178 } 3179 3180 set_signal_handler(SIGSEGV, true); 3181 set_signal_handler(SIGPIPE, true); 3182 set_signal_handler(SIGBUS, true); 3183 set_signal_handler(SIGILL, true); 3184 set_signal_handler(SIGFPE, true); 3185 set_signal_handler(SIGXFSZ, true); 3186 3187 #if defined(__APPLE__) 3188 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including 3189 // signals caught and handled by the JVM. To work around this, we reset the mach task 3190 // signal handler that's placed on our process by CrashReporter. This disables 3191 // CrashReporter-based reporting. 3192 // 3193 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes 3194 // on caught fatal signals. 3195 // 3196 // Additionally, gdb installs both standard BSD signal handlers, and mach exception 3197 // handlers. By replacing the existing task exception handler, we disable gdb's mach 3198 // exception handling, while leaving the standard BSD signal handlers functional. 3199 kern_return_t kr; 3200 kr = task_set_exception_ports(mach_task_self(), 3201 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, 3202 MACH_PORT_NULL, 3203 EXCEPTION_STATE_IDENTITY, 3204 MACHINE_THREAD_STATE); 3205 3206 assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); 3207 #endif 3208 3209 if (libjsig_is_loaded) { 3210 // Tell libjsig jvm finishes setting signal handlers 3211 (*end_signal_setting)(); 3212 } 3213 3214 // We don't activate signal checker if libjsig is in place, we trust ourselves 3215 // and if UserSignalHandler is installed all bets are off 3216 if (CheckJNICalls) { 3217 if (libjsig_is_loaded) { 3218 if (PrintJNIResolving) { 3219 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 3220 } 3221 check_signals = false; 3222 } 3223 if (AllowUserSignalHandlers) { 3224 if (PrintJNIResolving) { 3225 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 3226 } 3227 check_signals = false; 3228 } 3229 } 3230 } 3231 } 3232 3233 3234 ///// 3235 // glibc on Bsd platform uses non-documented flag 3236 // to indicate, that some special sort of signal 3237 // trampoline is used. 3238 // We will never set this flag, and we should 3239 // ignore this flag in our diagnostic 3240 #ifdef SIGNIFICANT_SIGNAL_MASK 3241 #undef SIGNIFICANT_SIGNAL_MASK 3242 #endif 3243 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 3244 3245 static const char* get_signal_handler_name(address handler, 3246 char* buf, int buflen) { 3247 int offset; 3248 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 3249 if (found) { 3250 // skip directory names 3251 const char *p1, *p2; 3252 p1 = buf; 3253 size_t len = strlen(os::file_separator()); 3254 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 3255 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 3256 } else { 3257 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 3258 } 3259 return buf; 3260 } 3261 3262 static void print_signal_handler(outputStream* st, int sig, 3263 char* buf, size_t buflen) { 3264 struct sigaction sa; 3265 3266 sigaction(sig, NULL, &sa); 3267 3268 // See comment for SIGNIFICANT_SIGNAL_MASK define 3269 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3270 3271 st->print("%s: ", os::exception_name(sig, buf, buflen)); 3272 3273 address handler = (sa.sa_flags & SA_SIGINFO) 3274 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 3275 : CAST_FROM_FN_PTR(address, sa.sa_handler); 3276 3277 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 3278 st->print("SIG_DFL"); 3279 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 3280 st->print("SIG_IGN"); 3281 } else { 3282 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 3283 } 3284 3285 st->print(", sa_mask[0]="); 3286 os::Posix::print_signal_set_short(st, &sa.sa_mask); 3287 3288 address rh = VMError::get_resetted_sighandler(sig); 3289 // May be, handler was resetted by VMError? 3290 if (rh != NULL) { 3291 handler = rh; 3292 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 3293 } 3294 3295 st->print(", sa_flags="); 3296 os::Posix::print_sa_flags(st, sa.sa_flags); 3297 3298 // Check: is it our handler? 3299 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 3300 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 3301 // It is our signal handler 3302 // check for flags, reset system-used one! 3303 if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3304 st->print( 3305 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 3306 os::Bsd::get_our_sigflags(sig)); 3307 } 3308 } 3309 st->cr(); 3310 } 3311 3312 3313 #define DO_SIGNAL_CHECK(sig) \ 3314 do { \ 3315 if (!sigismember(&check_signal_done, sig)) { \ 3316 os::Bsd::check_signal_handler(sig); \ 3317 } \ 3318 } while (0) 3319 3320 // This method is a periodic task to check for misbehaving JNI applications 3321 // under CheckJNI, we can add any periodic checks here 3322 3323 void os::run_periodic_checks() { 3324 3325 if (check_signals == false) return; 3326 3327 // SEGV and BUS if overridden could potentially prevent 3328 // generation of hs*.log in the event of a crash, debugging 3329 // such a case can be very challenging, so we absolutely 3330 // check the following for a good measure: 3331 DO_SIGNAL_CHECK(SIGSEGV); 3332 DO_SIGNAL_CHECK(SIGILL); 3333 DO_SIGNAL_CHECK(SIGFPE); 3334 DO_SIGNAL_CHECK(SIGBUS); 3335 DO_SIGNAL_CHECK(SIGPIPE); 3336 DO_SIGNAL_CHECK(SIGXFSZ); 3337 3338 3339 // ReduceSignalUsage allows the user to override these handlers 3340 // see comments at the very top and jvm_solaris.h 3341 if (!ReduceSignalUsage) { 3342 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 3343 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 3344 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 3345 DO_SIGNAL_CHECK(BREAK_SIGNAL); 3346 } 3347 3348 DO_SIGNAL_CHECK(SR_signum); 3349 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); 3350 } 3351 3352 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 3353 3354 static os_sigaction_t os_sigaction = NULL; 3355 3356 void os::Bsd::check_signal_handler(int sig) { 3357 char buf[O_BUFLEN]; 3358 address jvmHandler = NULL; 3359 3360 3361 struct sigaction act; 3362 if (os_sigaction == NULL) { 3363 // only trust the default sigaction, in case it has been interposed 3364 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 3365 if (os_sigaction == NULL) return; 3366 } 3367 3368 os_sigaction(sig, (struct sigaction*)NULL, &act); 3369 3370 3371 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3372 3373 address thisHandler = (act.sa_flags & SA_SIGINFO) 3374 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 3375 : CAST_FROM_FN_PTR(address, act.sa_handler); 3376 3377 3378 switch (sig) { 3379 case SIGSEGV: 3380 case SIGBUS: 3381 case SIGFPE: 3382 case SIGPIPE: 3383 case SIGILL: 3384 case SIGXFSZ: 3385 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 3386 break; 3387 3388 case SHUTDOWN1_SIGNAL: 3389 case SHUTDOWN2_SIGNAL: 3390 case SHUTDOWN3_SIGNAL: 3391 case BREAK_SIGNAL: 3392 jvmHandler = (address)user_handler(); 3393 break; 3394 3395 case INTERRUPT_SIGNAL: 3396 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); 3397 break; 3398 3399 default: 3400 if (sig == SR_signum) { 3401 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 3402 } else { 3403 return; 3404 } 3405 break; 3406 } 3407 3408 if (thisHandler != jvmHandler) { 3409 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 3410 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 3411 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 3412 // No need to check this sig any longer 3413 sigaddset(&check_signal_done, sig); 3414 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 3415 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 3416 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 3417 exception_name(sig, buf, O_BUFLEN)); 3418 } 3419 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3420 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 3421 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); 3422 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); 3423 // No need to check this sig any longer 3424 sigaddset(&check_signal_done, sig); 3425 } 3426 3427 // Dump all the signal 3428 if (sigismember(&check_signal_done, sig)) { 3429 print_signal_handlers(tty, buf, O_BUFLEN); 3430 } 3431 } 3432 3433 extern void report_error(char* file_name, int line_no, char* title, 3434 char* format, ...); 3435 3436 extern bool signal_name(int signo, char* buf, size_t len); 3437 3438 const char* os::exception_name(int exception_code, char* buf, size_t size) { 3439 if (0 < exception_code && exception_code <= SIGRTMAX) { 3440 // signal 3441 if (!signal_name(exception_code, buf, size)) { 3442 jio_snprintf(buf, size, "SIG%d", exception_code); 3443 } 3444 return buf; 3445 } else { 3446 return NULL; 3447 } 3448 } 3449 3450 // this is called _before_ the most of global arguments have been parsed 3451 void os::init(void) { 3452 char dummy; // used to get a guess on initial stack address 3453 // first_hrtime = gethrtime(); 3454 3455 // With BsdThreads the JavaMain thread pid (primordial thread) 3456 // is different than the pid of the java launcher thread. 3457 // So, on Bsd, the launcher thread pid is passed to the VM 3458 // via the sun.java.launcher.pid property. 3459 // Use this property instead of getpid() if it was correctly passed. 3460 // See bug 6351349. 3461 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); 3462 3463 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); 3464 3465 clock_tics_per_sec = CLK_TCK; 3466 3467 init_random(1234567); 3468 3469 ThreadCritical::initialize(); 3470 3471 Bsd::set_page_size(getpagesize()); 3472 if (Bsd::page_size() == -1) { 3473 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)", 3474 strerror(errno))); 3475 } 3476 init_page_sizes((size_t) Bsd::page_size()); 3477 3478 Bsd::initialize_system_info(); 3479 3480 // main_thread points to the aboriginal thread 3481 Bsd::_main_thread = pthread_self(); 3482 3483 Bsd::clock_init(); 3484 initial_time_count = javaTimeNanos(); 3485 3486 #ifdef __APPLE__ 3487 // XXXDARWIN 3488 // Work around the unaligned VM callbacks in hotspot's 3489 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on 3490 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces 3491 // alignment when doing symbol lookup. To work around this, we force early 3492 // binding of all symbols now, thus binding when alignment is known-good. 3493 _dyld_bind_fully_image_containing_address((const void *) &os::init); 3494 #endif 3495 } 3496 3497 // To install functions for atexit system call 3498 extern "C" { 3499 static void perfMemory_exit_helper() { 3500 perfMemory_exit(); 3501 } 3502 } 3503 3504 // this is called _after_ the global arguments have been parsed 3505 jint os::init_2(void) { 3506 // Allocate a single page and mark it as readable for safepoint polling 3507 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3508 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page"); 3509 3510 os::set_polling_page(polling_page); 3511 3512 #ifndef PRODUCT 3513 if (Verbose && PrintMiscellaneous) { 3514 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", 3515 (intptr_t)polling_page); 3516 } 3517 #endif 3518 3519 if (!UseMembar) { 3520 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3521 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 3522 os::set_memory_serialize_page(mem_serialize_page); 3523 3524 #ifndef PRODUCT 3525 if (Verbose && PrintMiscellaneous) { 3526 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", 3527 (intptr_t)mem_serialize_page); 3528 } 3529 #endif 3530 } 3531 3532 // initialize suspend/resume support - must do this before signal_sets_init() 3533 if (SR_initialize() != 0) { 3534 perror("SR_initialize failed"); 3535 return JNI_ERR; 3536 } 3537 3538 Bsd::signal_sets_init(); 3539 Bsd::install_signal_handlers(); 3540 3541 // Check minimum allowable stack size for thread creation and to initialize 3542 // the java system classes, including StackOverflowError - depends on page 3543 // size. Add a page for compiler2 recursion in main thread. 3544 // Add in 2*BytesPerWord times page size to account for VM stack during 3545 // class initialization depending on 32 or 64 bit VM. 3546 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, 3547 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ 3548 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); 3549 3550 size_t threadStackSizeInBytes = ThreadStackSize * K; 3551 if (threadStackSizeInBytes != 0 && 3552 threadStackSizeInBytes < os::Bsd::min_stack_allowed) { 3553 tty->print_cr("\nThe stack size specified is too small, " 3554 "Specify at least %dk", 3555 os::Bsd::min_stack_allowed/ K); 3556 return JNI_ERR; 3557 } 3558 3559 // Make the stack size a multiple of the page size so that 3560 // the yellow/red zones can be guarded. 3561 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 3562 vm_page_size())); 3563 3564 if (MaxFDLimit) { 3565 // set the number of file descriptors to max. print out error 3566 // if getrlimit/setrlimit fails but continue regardless. 3567 struct rlimit nbr_files; 3568 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 3569 if (status != 0) { 3570 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3571 perror("os::init_2 getrlimit failed"); 3572 } 3573 } else { 3574 nbr_files.rlim_cur = nbr_files.rlim_max; 3575 3576 #ifdef __APPLE__ 3577 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if 3578 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must 3579 // be used instead 3580 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); 3581 #endif 3582 3583 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 3584 if (status != 0) { 3585 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3586 perror("os::init_2 setrlimit failed"); 3587 } 3588 } 3589 } 3590 } 3591 3592 // at-exit methods are called in the reverse order of their registration. 3593 // atexit functions are called on return from main or as a result of a 3594 // call to exit(3C). There can be only 32 of these functions registered 3595 // and atexit() does not set errno. 3596 3597 if (PerfAllowAtExitRegistration) { 3598 // only register atexit functions if PerfAllowAtExitRegistration is set. 3599 // atexit functions can be delayed until process exit time, which 3600 // can be problematic for embedded VM situations. Embedded VMs should 3601 // call DestroyJavaVM() to assure that VM resources are released. 3602 3603 // note: perfMemory_exit_helper atexit function may be removed in 3604 // the future if the appropriate cleanup code can be added to the 3605 // VM_Exit VMOperation's doit method. 3606 if (atexit(perfMemory_exit_helper) != 0) { 3607 warning("os::init2 atexit(perfMemory_exit_helper) failed"); 3608 } 3609 } 3610 3611 // initialize thread priority policy 3612 prio_init(); 3613 3614 #ifdef __APPLE__ 3615 // dynamically link to objective c gc registration 3616 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY); 3617 if (handleLibObjc != NULL) { 3618 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER); 3619 } 3620 #endif 3621 3622 return JNI_OK; 3623 } 3624 3625 // Mark the polling page as unreadable 3626 void os::make_polling_page_unreadable(void) { 3627 if (!guard_memory((char*)_polling_page, Bsd::page_size())) { 3628 fatal("Could not disable polling page"); 3629 } 3630 } 3631 3632 // Mark the polling page as readable 3633 void os::make_polling_page_readable(void) { 3634 if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { 3635 fatal("Could not enable polling page"); 3636 } 3637 } 3638 3639 int os::active_processor_count() { 3640 return _processor_count; 3641 } 3642 3643 void os::set_native_thread_name(const char *name) { 3644 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5 3645 // This is only supported in Snow Leopard and beyond 3646 if (name != NULL) { 3647 // Add a "Java: " prefix to the name 3648 char buf[MAXTHREADNAMESIZE]; 3649 snprintf(buf, sizeof(buf), "Java: %s", name); 3650 pthread_setname_np(buf); 3651 } 3652 #endif 3653 } 3654 3655 bool os::distribute_processes(uint length, uint* distribution) { 3656 // Not yet implemented. 3657 return false; 3658 } 3659 3660 bool os::bind_to_processor(uint processor_id) { 3661 // Not yet implemented. 3662 return false; 3663 } 3664 3665 void os::SuspendedThreadTask::internal_do_task() { 3666 if (do_suspend(_thread->osthread())) { 3667 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 3668 do_task(context); 3669 do_resume(_thread->osthread()); 3670 } 3671 } 3672 3673 /// 3674 class PcFetcher : public os::SuspendedThreadTask { 3675 public: 3676 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 3677 ExtendedPC result(); 3678 protected: 3679 void do_task(const os::SuspendedThreadTaskContext& context); 3680 private: 3681 ExtendedPC _epc; 3682 }; 3683 3684 ExtendedPC PcFetcher::result() { 3685 guarantee(is_done(), "task is not done yet."); 3686 return _epc; 3687 } 3688 3689 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 3690 Thread* thread = context.thread(); 3691 OSThread* osthread = thread->osthread(); 3692 if (osthread->ucontext() != NULL) { 3693 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext()); 3694 } else { 3695 // NULL context is unexpected, double-check this is the VMThread 3696 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 3697 } 3698 } 3699 3700 // Suspends the target using the signal mechanism and then grabs the PC before 3701 // resuming the target. Used by the flat-profiler only 3702 ExtendedPC os::get_thread_pc(Thread* thread) { 3703 // Make sure that it is called by the watcher for the VMThread 3704 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 3705 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 3706 3707 PcFetcher fetcher(thread); 3708 fetcher.run(); 3709 return fetcher.result(); 3710 } 3711 3712 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, 3713 pthread_mutex_t *_mutex, 3714 const struct timespec *_abstime) { 3715 return pthread_cond_timedwait(_cond, _mutex, _abstime); 3716 } 3717 3718 //////////////////////////////////////////////////////////////////////////////// 3719 // debug support 3720 3721 bool os::find(address addr, outputStream* st) { 3722 Dl_info dlinfo; 3723 memset(&dlinfo, 0, sizeof(dlinfo)); 3724 if (dladdr(addr, &dlinfo) != 0) { 3725 st->print(PTR_FORMAT ": ", addr); 3726 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 3727 st->print("%s+%#x", dlinfo.dli_sname, 3728 addr - (intptr_t)dlinfo.dli_saddr); 3729 } else if (dlinfo.dli_fbase != NULL) { 3730 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); 3731 } else { 3732 st->print("<absolute address>"); 3733 } 3734 if (dlinfo.dli_fname != NULL) { 3735 st->print(" in %s", dlinfo.dli_fname); 3736 } 3737 if (dlinfo.dli_fbase != NULL) { 3738 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); 3739 } 3740 st->cr(); 3741 3742 if (Verbose) { 3743 // decode some bytes around the PC 3744 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 3745 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 3746 address lowest = (address) dlinfo.dli_sname; 3747 if (!lowest) lowest = (address) dlinfo.dli_fbase; 3748 if (begin < lowest) begin = lowest; 3749 Dl_info dlinfo2; 3750 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 3751 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 3752 end = (address) dlinfo2.dli_saddr; 3753 } 3754 Disassembler::decode(begin, end, st); 3755 } 3756 return true; 3757 } 3758 return false; 3759 } 3760 3761 //////////////////////////////////////////////////////////////////////////////// 3762 // misc 3763 3764 // This does not do anything on Bsd. This is basically a hook for being 3765 // able to use structured exception handling (thread-local exception filters) 3766 // on, e.g., Win32. 3767 void os::os_exception_wrapper(java_call_t f, JavaValue* value, 3768 methodHandle* method, JavaCallArguments* args, 3769 Thread* thread) { 3770 f(value, method, args, thread); 3771 } 3772 3773 void os::print_statistics() { 3774 } 3775 3776 int os::message_box(const char* title, const char* message) { 3777 int i; 3778 fdStream err(defaultStream::error_fd()); 3779 for (i = 0; i < 78; i++) err.print_raw("="); 3780 err.cr(); 3781 err.print_raw_cr(title); 3782 for (i = 0; i < 78; i++) err.print_raw("-"); 3783 err.cr(); 3784 err.print_raw_cr(message); 3785 for (i = 0; i < 78; i++) err.print_raw("="); 3786 err.cr(); 3787 3788 char buf[16]; 3789 // Prevent process from exiting upon "read error" without consuming all CPU 3790 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 3791 3792 return buf[0] == 'y' || buf[0] == 'Y'; 3793 } 3794 3795 int os::stat(const char *path, struct stat *sbuf) { 3796 char pathbuf[MAX_PATH]; 3797 if (strlen(path) > MAX_PATH - 1) { 3798 errno = ENAMETOOLONG; 3799 return -1; 3800 } 3801 os::native_path(strcpy(pathbuf, path)); 3802 return ::stat(pathbuf, sbuf); 3803 } 3804 3805 bool os::check_heap(bool force) { 3806 return true; 3807 } 3808 3809 // Is a (classpath) directory empty? 3810 bool os::dir_is_empty(const char* path) { 3811 DIR *dir = NULL; 3812 struct dirent *ptr; 3813 3814 dir = opendir(path); 3815 if (dir == NULL) return true; 3816 3817 // Scan the directory 3818 bool result = true; 3819 char buf[sizeof(struct dirent) + MAX_PATH]; 3820 while (result && (ptr = ::readdir(dir)) != NULL) { 3821 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 3822 result = false; 3823 } 3824 } 3825 closedir(dir); 3826 return result; 3827 } 3828 3829 // This code originates from JDK's sysOpen and open64_w 3830 // from src/solaris/hpi/src/system_md.c 3831 3832 int os::open(const char *path, int oflag, int mode) { 3833 if (strlen(path) > MAX_PATH - 1) { 3834 errno = ENAMETOOLONG; 3835 return -1; 3836 } 3837 int fd; 3838 3839 fd = ::open(path, oflag, mode); 3840 if (fd == -1) return -1; 3841 3842 // If the open succeeded, the file might still be a directory 3843 { 3844 struct stat buf; 3845 int ret = ::fstat(fd, &buf); 3846 int st_mode = buf.st_mode; 3847 3848 if (ret != -1) { 3849 if ((st_mode & S_IFMT) == S_IFDIR) { 3850 errno = EISDIR; 3851 ::close(fd); 3852 return -1; 3853 } 3854 } else { 3855 ::close(fd); 3856 return -1; 3857 } 3858 } 3859 3860 // All file descriptors that are opened in the JVM and not 3861 // specifically destined for a subprocess should have the 3862 // close-on-exec flag set. If we don't set it, then careless 3rd 3863 // party native code might fork and exec without closing all 3864 // appropriate file descriptors (e.g. as we do in closeDescriptors in 3865 // UNIXProcess.c), and this in turn might: 3866 // 3867 // - cause end-of-file to fail to be detected on some file 3868 // descriptors, resulting in mysterious hangs, or 3869 // 3870 // - might cause an fopen in the subprocess to fail on a system 3871 // suffering from bug 1085341. 3872 // 3873 // (Yes, the default setting of the close-on-exec flag is a Unix 3874 // design flaw) 3875 // 3876 // See: 3877 // 1085341: 32-bit stdio routines should support file descriptors >255 3878 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 3879 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 3880 // 3881 #ifdef FD_CLOEXEC 3882 { 3883 int flags = ::fcntl(fd, F_GETFD); 3884 if (flags != -1) { 3885 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 3886 } 3887 } 3888 #endif 3889 3890 return fd; 3891 } 3892 3893 3894 // create binary file, rewriting existing file if required 3895 int os::create_binary_file(const char* path, bool rewrite_existing) { 3896 int oflags = O_WRONLY | O_CREAT; 3897 if (!rewrite_existing) { 3898 oflags |= O_EXCL; 3899 } 3900 return ::open(path, oflags, S_IREAD | S_IWRITE); 3901 } 3902 3903 // return current position of file pointer 3904 jlong os::current_file_offset(int fd) { 3905 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); 3906 } 3907 3908 // move file pointer to the specified offset 3909 jlong os::seek_to_file_offset(int fd, jlong offset) { 3910 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); 3911 } 3912 3913 // This code originates from JDK's sysAvailable 3914 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 3915 3916 int os::available(int fd, jlong *bytes) { 3917 jlong cur, end; 3918 int mode; 3919 struct stat buf; 3920 3921 if (::fstat(fd, &buf) >= 0) { 3922 mode = buf.st_mode; 3923 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 3924 // XXX: is the following call interruptible? If so, this might 3925 // need to go through the INTERRUPT_IO() wrapper as for other 3926 // blocking, interruptible calls in this file. 3927 int n; 3928 if (::ioctl(fd, FIONREAD, &n) >= 0) { 3929 *bytes = n; 3930 return 1; 3931 } 3932 } 3933 } 3934 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { 3935 return 0; 3936 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { 3937 return 0; 3938 } else if (::lseek(fd, cur, SEEK_SET) == -1) { 3939 return 0; 3940 } 3941 *bytes = end - cur; 3942 return 1; 3943 } 3944 3945 // Map a block of memory. 3946 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 3947 char *addr, size_t bytes, bool read_only, 3948 bool allow_exec) { 3949 int prot; 3950 int flags; 3951 3952 if (read_only) { 3953 prot = PROT_READ; 3954 flags = MAP_SHARED; 3955 } else { 3956 prot = PROT_READ | PROT_WRITE; 3957 flags = MAP_PRIVATE; 3958 } 3959 3960 if (allow_exec) { 3961 prot |= PROT_EXEC; 3962 } 3963 3964 if (addr != NULL) { 3965 flags |= MAP_FIXED; 3966 } 3967 3968 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 3969 fd, file_offset); 3970 if (mapped_address == MAP_FAILED) { 3971 return NULL; 3972 } 3973 return mapped_address; 3974 } 3975 3976 3977 // Remap a block of memory. 3978 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 3979 char *addr, size_t bytes, bool read_only, 3980 bool allow_exec) { 3981 // same as map_memory() on this OS 3982 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 3983 allow_exec); 3984 } 3985 3986 3987 // Unmap a block of memory. 3988 bool os::pd_unmap_memory(char* addr, size_t bytes) { 3989 return munmap(addr, bytes) == 0; 3990 } 3991 3992 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 3993 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 3994 // of a thread. 3995 // 3996 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 3997 // the fast estimate available on the platform. 3998 3999 jlong os::current_thread_cpu_time() { 4000 #ifdef __APPLE__ 4001 return os::thread_cpu_time(Thread::current(), true /* user + sys */); 4002 #else 4003 Unimplemented(); 4004 return 0; 4005 #endif 4006 } 4007 4008 jlong os::thread_cpu_time(Thread* thread) { 4009 #ifdef __APPLE__ 4010 return os::thread_cpu_time(thread, true /* user + sys */); 4011 #else 4012 Unimplemented(); 4013 return 0; 4014 #endif 4015 } 4016 4017 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 4018 #ifdef __APPLE__ 4019 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); 4020 #else 4021 Unimplemented(); 4022 return 0; 4023 #endif 4024 } 4025 4026 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 4027 #ifdef __APPLE__ 4028 struct thread_basic_info tinfo; 4029 mach_msg_type_number_t tcount = THREAD_INFO_MAX; 4030 kern_return_t kr; 4031 thread_t mach_thread; 4032 4033 mach_thread = thread->osthread()->thread_id(); 4034 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); 4035 if (kr != KERN_SUCCESS) { 4036 return -1; 4037 } 4038 4039 if (user_sys_cpu_time) { 4040 jlong nanos; 4041 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; 4042 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; 4043 return nanos; 4044 } else { 4045 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); 4046 } 4047 #else 4048 Unimplemented(); 4049 return 0; 4050 #endif 4051 } 4052 4053 4054 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4055 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4056 info_ptr->may_skip_backward = false; // elapsed time not wall time 4057 info_ptr->may_skip_forward = false; // elapsed time not wall time 4058 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4059 } 4060 4061 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4062 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4063 info_ptr->may_skip_backward = false; // elapsed time not wall time 4064 info_ptr->may_skip_forward = false; // elapsed time not wall time 4065 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4066 } 4067 4068 bool os::is_thread_cpu_time_supported() { 4069 #ifdef __APPLE__ 4070 return true; 4071 #else 4072 return false; 4073 #endif 4074 } 4075 4076 // System loadavg support. Returns -1 if load average cannot be obtained. 4077 // Bsd doesn't yet have a (official) notion of processor sets, 4078 // so just return the system wide load average. 4079 int os::loadavg(double loadavg[], int nelem) { 4080 return ::getloadavg(loadavg, nelem); 4081 } 4082 4083 void os::pause() { 4084 char filename[MAX_PATH]; 4085 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 4086 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); 4087 } else { 4088 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 4089 } 4090 4091 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 4092 if (fd != -1) { 4093 struct stat buf; 4094 ::close(fd); 4095 while (::stat(filename, &buf) == 0) { 4096 (void)::poll(NULL, 0, 100); 4097 } 4098 } else { 4099 jio_fprintf(stderr, 4100 "Could not open pause file '%s', continuing immediately.\n", filename); 4101 } 4102 } 4103 4104 4105 // Refer to the comments in os_solaris.cpp park-unpark. The next two 4106 // comment paragraphs are worth repeating here: 4107 // 4108 // Assumption: 4109 // Only one parker can exist on an event, which is why we allocate 4110 // them per-thread. Multiple unparkers can coexist. 4111 // 4112 // _Event serves as a restricted-range semaphore. 4113 // -1 : thread is blocked, i.e. there is a waiter 4114 // 0 : neutral: thread is running or ready, 4115 // could have been signaled after a wait started 4116 // 1 : signaled - thread is running or ready 4117 // 4118 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 4119 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 4120 // For specifics regarding the bug see GLIBC BUGID 261237 : 4121 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 4122 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 4123 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 4124 // is used. (The simple C test-case provided in the GLIBC bug report manifests the 4125 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 4126 // and monitorenter when we're using 1-0 locking. All those operations may result in 4127 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 4128 // of libpthread avoids the problem, but isn't practical. 4129 // 4130 // Possible remedies: 4131 // 4132 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 4133 // This is palliative and probabilistic, however. If the thread is preempted 4134 // between the call to compute_abstime() and pthread_cond_timedwait(), more 4135 // than the minimum period may have passed, and the abstime may be stale (in the 4136 // past) resultin in a hang. Using this technique reduces the odds of a hang 4137 // but the JVM is still vulnerable, particularly on heavily loaded systems. 4138 // 4139 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 4140 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set 4141 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 4142 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant 4143 // thread. 4144 // 4145 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 4146 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 4147 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). 4148 // This also works well. In fact it avoids kernel-level scalability impediments 4149 // on certain platforms that don't handle lots of active pthread_cond_timedwait() 4150 // timers in a graceful fashion. 4151 // 4152 // 4. When the abstime value is in the past it appears that control returns 4153 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 4154 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we 4155 // can avoid the problem by reinitializing the condvar -- by cond_destroy() 4156 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). 4157 // It may be possible to avoid reinitialization by checking the return 4158 // value from pthread_cond_timedwait(). In addition to reinitializing the 4159 // condvar we must establish the invariant that cond_signal() is only called 4160 // within critical sections protected by the adjunct mutex. This prevents 4161 // cond_signal() from "seeing" a condvar that's in the midst of being 4162 // reinitialized or that is corrupt. Sadly, this invariant obviates the 4163 // desirable signal-after-unlock optimization that avoids futile context switching. 4164 // 4165 // I'm also concerned that some versions of NTPL might allocate an auxilliary 4166 // structure when a condvar is used or initialized. cond_destroy() would 4167 // release the helper structure. Our reinitialize-after-timedwait fix 4168 // put excessive stress on malloc/free and locks protecting the c-heap. 4169 // 4170 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 4171 // It may be possible to refine (4) by checking the kernel and NTPL verisons 4172 // and only enabling the work-around for vulnerable environments. 4173 4174 // utility to compute the abstime argument to timedwait: 4175 // millis is the relative timeout time 4176 // abstime will be the absolute timeout time 4177 // TODO: replace compute_abstime() with unpackTime() 4178 4179 static struct timespec* compute_abstime(struct timespec* abstime, 4180 jlong millis) { 4181 if (millis < 0) millis = 0; 4182 struct timeval now; 4183 int status = gettimeofday(&now, NULL); 4184 assert(status == 0, "gettimeofday"); 4185 jlong seconds = millis / 1000; 4186 millis %= 1000; 4187 if (seconds > 50000000) { // see man cond_timedwait(3T) 4188 seconds = 50000000; 4189 } 4190 abstime->tv_sec = now.tv_sec + seconds; 4191 long usec = now.tv_usec + millis * 1000; 4192 if (usec >= 1000000) { 4193 abstime->tv_sec += 1; 4194 usec -= 1000000; 4195 } 4196 abstime->tv_nsec = usec * 1000; 4197 return abstime; 4198 } 4199 4200 void os::PlatformEvent::park() { // AKA "down()" 4201 // Transitions for _Event: 4202 // -1 => -1 : illegal 4203 // 1 => 0 : pass - return immediately 4204 // 0 => -1 : block; then set _Event to 0 before returning 4205 4206 // Invariant: Only the thread associated with the Event/PlatformEvent 4207 // may call park(). 4208 // TODO: assert that _Assoc != NULL or _Assoc == Self 4209 assert(_nParked == 0, "invariant"); 4210 4211 int v; 4212 for (;;) { 4213 v = _Event; 4214 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4215 } 4216 guarantee(v >= 0, "invariant"); 4217 if (v == 0) { 4218 // Do this the hard way by blocking ... 4219 int status = pthread_mutex_lock(_mutex); 4220 assert_status(status == 0, status, "mutex_lock"); 4221 guarantee(_nParked == 0, "invariant"); 4222 ++_nParked; 4223 while (_Event < 0) { 4224 status = pthread_cond_wait(_cond, _mutex); 4225 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 4226 // Treat this the same as if the wait was interrupted 4227 if (status == ETIMEDOUT) { status = EINTR; } 4228 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 4229 } 4230 --_nParked; 4231 4232 _Event = 0; 4233 status = pthread_mutex_unlock(_mutex); 4234 assert_status(status == 0, status, "mutex_unlock"); 4235 // Paranoia to ensure our locked and lock-free paths interact 4236 // correctly with each other. 4237 OrderAccess::fence(); 4238 } 4239 guarantee(_Event >= 0, "invariant"); 4240 } 4241 4242 int os::PlatformEvent::park(jlong millis) { 4243 // Transitions for _Event: 4244 // -1 => -1 : illegal 4245 // 1 => 0 : pass - return immediately 4246 // 0 => -1 : block; then set _Event to 0 before returning 4247 4248 guarantee(_nParked == 0, "invariant"); 4249 4250 int v; 4251 for (;;) { 4252 v = _Event; 4253 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4254 } 4255 guarantee(v >= 0, "invariant"); 4256 if (v != 0) return OS_OK; 4257 4258 // We do this the hard way, by blocking the thread. 4259 // Consider enforcing a minimum timeout value. 4260 struct timespec abst; 4261 compute_abstime(&abst, millis); 4262 4263 int ret = OS_TIMEOUT; 4264 int status = pthread_mutex_lock(_mutex); 4265 assert_status(status == 0, status, "mutex_lock"); 4266 guarantee(_nParked == 0, "invariant"); 4267 ++_nParked; 4268 4269 // Object.wait(timo) will return because of 4270 // (a) notification 4271 // (b) timeout 4272 // (c) thread.interrupt 4273 // 4274 // Thread.interrupt and object.notify{All} both call Event::set. 4275 // That is, we treat thread.interrupt as a special case of notification. 4276 // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false. 4277 // We assume all ETIME returns are valid. 4278 // 4279 // TODO: properly differentiate simultaneous notify+interrupt. 4280 // In that case, we should propagate the notify to another waiter. 4281 4282 while (_Event < 0) { 4283 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst); 4284 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4285 pthread_cond_destroy(_cond); 4286 pthread_cond_init(_cond, NULL); 4287 } 4288 assert_status(status == 0 || status == EINTR || 4289 status == ETIMEDOUT, 4290 status, "cond_timedwait"); 4291 if (!FilterSpuriousWakeups) break; // previous semantics 4292 if (status == ETIMEDOUT) break; 4293 // We consume and ignore EINTR and spurious wakeups. 4294 } 4295 --_nParked; 4296 if (_Event >= 0) { 4297 ret = OS_OK; 4298 } 4299 _Event = 0; 4300 status = pthread_mutex_unlock(_mutex); 4301 assert_status(status == 0, status, "mutex_unlock"); 4302 assert(_nParked == 0, "invariant"); 4303 // Paranoia to ensure our locked and lock-free paths interact 4304 // correctly with each other. 4305 OrderAccess::fence(); 4306 return ret; 4307 } 4308 4309 void os::PlatformEvent::unpark() { 4310 // Transitions for _Event: 4311 // 0 => 1 : just return 4312 // 1 => 1 : just return 4313 // -1 => either 0 or 1; must signal target thread 4314 // That is, we can safely transition _Event from -1 to either 4315 // 0 or 1. 4316 // See also: "Semaphores in Plan 9" by Mullender & Cox 4317 // 4318 // Note: Forcing a transition from "-1" to "1" on an unpark() means 4319 // that it will take two back-to-back park() calls for the owning 4320 // thread to block. This has the benefit of forcing a spurious return 4321 // from the first park() call after an unpark() call which will help 4322 // shake out uses of park() and unpark() without condition variables. 4323 4324 if (Atomic::xchg(1, &_Event) >= 0) return; 4325 4326 // Wait for the thread associated with the event to vacate 4327 int status = pthread_mutex_lock(_mutex); 4328 assert_status(status == 0, status, "mutex_lock"); 4329 int AnyWaiters = _nParked; 4330 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 4331 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 4332 AnyWaiters = 0; 4333 pthread_cond_signal(_cond); 4334 } 4335 status = pthread_mutex_unlock(_mutex); 4336 assert_status(status == 0, status, "mutex_unlock"); 4337 if (AnyWaiters != 0) { 4338 // Note that we signal() *after* dropping the lock for "immortal" Events. 4339 // This is safe and avoids a common class of futile wakeups. In rare 4340 // circumstances this can cause a thread to return prematurely from 4341 // cond_{timed}wait() but the spurious wakeup is benign and the victim 4342 // will simply re-test the condition and re-park itself. 4343 // This provides particular benefit if the underlying platform does not 4344 // provide wait morphing. 4345 status = pthread_cond_signal(_cond); 4346 assert_status(status == 0, status, "cond_signal"); 4347 } 4348 } 4349 4350 4351 // JSR166 4352 // ------------------------------------------------------- 4353 4354 // The solaris and bsd implementations of park/unpark are fairly 4355 // conservative for now, but can be improved. They currently use a 4356 // mutex/condvar pair, plus a a count. 4357 // Park decrements count if > 0, else does a condvar wait. Unpark 4358 // sets count to 1 and signals condvar. Only one thread ever waits 4359 // on the condvar. Contention seen when trying to park implies that someone 4360 // is unparking you, so don't wait. And spurious returns are fine, so there 4361 // is no need to track notifications. 4362 4363 #define MAX_SECS 100000000 4364 4365 // This code is common to bsd and solaris and will be moved to a 4366 // common place in dolphin. 4367 // 4368 // The passed in time value is either a relative time in nanoseconds 4369 // or an absolute time in milliseconds. Either way it has to be unpacked 4370 // into suitable seconds and nanoseconds components and stored in the 4371 // given timespec structure. 4372 // Given time is a 64-bit value and the time_t used in the timespec is only 4373 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for 4374 // overflow if times way in the future are given. Further on Solaris versions 4375 // prior to 10 there is a restriction (see cond_timedwait) that the specified 4376 // number of seconds, in abstime, is less than current_time + 100,000,000. 4377 // As it will be 28 years before "now + 100000000" will overflow we can 4378 // ignore overflow and just impose a hard-limit on seconds using the value 4379 // of "now + 100,000,000". This places a limit on the timeout of about 3.17 4380 // years from "now". 4381 4382 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { 4383 assert(time > 0, "convertTime"); 4384 4385 struct timeval now; 4386 int status = gettimeofday(&now, NULL); 4387 assert(status == 0, "gettimeofday"); 4388 4389 time_t max_secs = now.tv_sec + MAX_SECS; 4390 4391 if (isAbsolute) { 4392 jlong secs = time / 1000; 4393 if (secs > max_secs) { 4394 absTime->tv_sec = max_secs; 4395 } else { 4396 absTime->tv_sec = secs; 4397 } 4398 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 4399 } else { 4400 jlong secs = time / NANOSECS_PER_SEC; 4401 if (secs >= MAX_SECS) { 4402 absTime->tv_sec = max_secs; 4403 absTime->tv_nsec = 0; 4404 } else { 4405 absTime->tv_sec = now.tv_sec + secs; 4406 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 4407 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 4408 absTime->tv_nsec -= NANOSECS_PER_SEC; 4409 ++absTime->tv_sec; // note: this must be <= max_secs 4410 } 4411 } 4412 } 4413 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 4414 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 4415 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 4416 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 4417 } 4418 4419 void Parker::park(bool isAbsolute, jlong time) { 4420 // Ideally we'd do something useful while spinning, such 4421 // as calling unpackTime(). 4422 4423 // Optional fast-path check: 4424 // Return immediately if a permit is available. 4425 // We depend on Atomic::xchg() having full barrier semantics 4426 // since we are doing a lock-free update to _counter. 4427 if (Atomic::xchg(0, &_counter) > 0) return; 4428 4429 Thread* thread = Thread::current(); 4430 assert(thread->is_Java_thread(), "Must be JavaThread"); 4431 JavaThread *jt = (JavaThread *)thread; 4432 4433 // Optional optimization -- avoid state transitions if there's an interrupt pending. 4434 // Check interrupt before trying to wait 4435 if (Thread::is_interrupted(thread, false)) { 4436 return; 4437 } 4438 4439 // Next, demultiplex/decode time arguments 4440 struct timespec absTime; 4441 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all 4442 return; 4443 } 4444 if (time > 0) { 4445 unpackTime(&absTime, isAbsolute, time); 4446 } 4447 4448 4449 // Enter safepoint region 4450 // Beware of deadlocks such as 6317397. 4451 // The per-thread Parker:: mutex is a classic leaf-lock. 4452 // In particular a thread must never block on the Threads_lock while 4453 // holding the Parker:: mutex. If safepoints are pending both the 4454 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 4455 ThreadBlockInVM tbivm(jt); 4456 4457 // Don't wait if cannot get lock since interference arises from 4458 // unblocking. Also. check interrupt before trying wait 4459 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 4460 return; 4461 } 4462 4463 int status; 4464 if (_counter > 0) { // no wait needed 4465 _counter = 0; 4466 status = pthread_mutex_unlock(_mutex); 4467 assert(status == 0, "invariant"); 4468 // Paranoia to ensure our locked and lock-free paths interact 4469 // correctly with each other and Java-level accesses. 4470 OrderAccess::fence(); 4471 return; 4472 } 4473 4474 #ifdef ASSERT 4475 // Don't catch signals while blocked; let the running threads have the signals. 4476 // (This allows a debugger to break into the running thread.) 4477 sigset_t oldsigs; 4478 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); 4479 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 4480 #endif 4481 4482 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 4483 jt->set_suspend_equivalent(); 4484 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 4485 4486 if (time == 0) { 4487 status = pthread_cond_wait(_cond, _mutex); 4488 } else { 4489 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &absTime); 4490 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4491 pthread_cond_destroy(_cond); 4492 pthread_cond_init(_cond, NULL); 4493 } 4494 } 4495 assert_status(status == 0 || status == EINTR || 4496 status == ETIMEDOUT, 4497 status, "cond_timedwait"); 4498 4499 #ifdef ASSERT 4500 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 4501 #endif 4502 4503 _counter = 0; 4504 status = pthread_mutex_unlock(_mutex); 4505 assert_status(status == 0, status, "invariant"); 4506 // Paranoia to ensure our locked and lock-free paths interact 4507 // correctly with each other and Java-level accesses. 4508 OrderAccess::fence(); 4509 4510 // If externally suspended while waiting, re-suspend 4511 if (jt->handle_special_suspend_equivalent_condition()) { 4512 jt->java_suspend_self(); 4513 } 4514 } 4515 4516 void Parker::unpark() { 4517 int status = pthread_mutex_lock(_mutex); 4518 assert(status == 0, "invariant"); 4519 const int s = _counter; 4520 _counter = 1; 4521 if (s < 1) { 4522 if (WorkAroundNPTLTimedWaitHang) { 4523 status = pthread_cond_signal(_cond); 4524 assert(status == 0, "invariant"); 4525 status = pthread_mutex_unlock(_mutex); 4526 assert(status == 0, "invariant"); 4527 } else { 4528 status = pthread_mutex_unlock(_mutex); 4529 assert(status == 0, "invariant"); 4530 status = pthread_cond_signal(_cond); 4531 assert(status == 0, "invariant"); 4532 } 4533 } else { 4534 pthread_mutex_unlock(_mutex); 4535 assert(status == 0, "invariant"); 4536 } 4537 } 4538 4539 4540 // Darwin has no "environ" in a dynamic library. 4541 #ifdef __APPLE__ 4542 #include <crt_externs.h> 4543 #define environ (*_NSGetEnviron()) 4544 #else 4545 extern char** environ; 4546 #endif 4547 4548 // Run the specified command in a separate process. Return its exit value, 4549 // or -1 on failure (e.g. can't fork a new process). 4550 // Unlike system(), this function can be called from signal handler. It 4551 // doesn't block SIGINT et al. 4552 int os::fork_and_exec(char* cmd) { 4553 const char * argv[4] = {"sh", "-c", cmd, NULL}; 4554 4555 // fork() in BsdThreads/NPTL is not async-safe. It needs to run 4556 // pthread_atfork handlers and reset pthread library. All we need is a 4557 // separate process to execve. Make a direct syscall to fork process. 4558 // On IA64 there's no fork syscall, we have to use fork() and hope for 4559 // the best... 4560 pid_t pid = fork(); 4561 4562 if (pid < 0) { 4563 // fork failed 4564 return -1; 4565 4566 } else if (pid == 0) { 4567 // child process 4568 4569 // execve() in BsdThreads will call pthread_kill_other_threads_np() 4570 // first to kill every thread on the thread list. Because this list is 4571 // not reset by fork() (see notes above), execve() will instead kill 4572 // every thread in the parent process. We know this is the only thread 4573 // in the new process, so make a system call directly. 4574 // IA64 should use normal execve() from glibc to match the glibc fork() 4575 // above. 4576 execve("/bin/sh", (char* const*)argv, environ); 4577 4578 // execve failed 4579 _exit(-1); 4580 4581 } else { 4582 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 4583 // care about the actual exit code, for now. 4584 4585 int status; 4586 4587 // Wait for the child process to exit. This returns immediately if 4588 // the child has already exited. */ 4589 while (waitpid(pid, &status, 0) < 0) { 4590 switch (errno) { 4591 case ECHILD: return 0; 4592 case EINTR: break; 4593 default: return -1; 4594 } 4595 } 4596 4597 if (WIFEXITED(status)) { 4598 // The child exited normally; get its exit code. 4599 return WEXITSTATUS(status); 4600 } else if (WIFSIGNALED(status)) { 4601 // The child exited because of a signal 4602 // The best value to return is 0x80 + signal number, 4603 // because that is what all Unix shells do, and because 4604 // it allows callers to distinguish between process exit and 4605 // process death by signal. 4606 return 0x80 + WTERMSIG(status); 4607 } else { 4608 // Unknown exit code; pass it through 4609 return status; 4610 } 4611 } 4612 } 4613 4614 // is_headless_jre() 4615 // 4616 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 4617 // in order to report if we are running in a headless jre 4618 // 4619 // Since JDK8 xawt/libmawt.so was moved into the same directory 4620 // as libawt.so, and renamed libawt_xawt.so 4621 // 4622 bool os::is_headless_jre() { 4623 #ifdef __APPLE__ 4624 // We no longer build headless-only on Mac OS X 4625 return false; 4626 #else 4627 struct stat statbuf; 4628 char buf[MAXPATHLEN]; 4629 char libmawtpath[MAXPATHLEN]; 4630 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX; 4631 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX; 4632 char *p; 4633 4634 // Get path to libjvm.so 4635 os::jvm_path(buf, sizeof(buf)); 4636 4637 // Get rid of libjvm.so 4638 p = strrchr(buf, '/'); 4639 if (p == NULL) { 4640 return false; 4641 } else { 4642 *p = '\0'; 4643 } 4644 4645 // Get rid of client or server 4646 p = strrchr(buf, '/'); 4647 if (p == NULL) { 4648 return false; 4649 } else { 4650 *p = '\0'; 4651 } 4652 4653 // check xawt/libmawt.so 4654 strcpy(libmawtpath, buf); 4655 strcat(libmawtpath, xawtstr); 4656 if (::stat(libmawtpath, &statbuf) == 0) return false; 4657 4658 // check libawt_xawt.so 4659 strcpy(libmawtpath, buf); 4660 strcat(libmawtpath, new_xawtstr); 4661 if (::stat(libmawtpath, &statbuf) == 0) return false; 4662 4663 return true; 4664 #endif 4665 } 4666 4667 // Get the default path to the core file 4668 // Returns the length of the string 4669 int os::get_core_path(char* buffer, size_t bufferSize) { 4670 int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id()); 4671 4672 // Truncate if theoretical string was longer than bufferSize 4673 n = MIN2(n, (int)bufferSize); 4674 4675 return n; 4676 } 4677 4678 #ifndef PRODUCT 4679 void TestReserveMemorySpecial_test() { 4680 // No tests available for this platform 4681 } 4682 #endif