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