1 /* 2 * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 // no precompiled headers 26 #include "classfile/classLoader.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "classfile/vmSymbols.hpp" 29 #include "code/icBuffer.hpp" 30 #include "code/vtableStubs.hpp" 31 #include "compiler/compileBroker.hpp" 32 #include "compiler/disassembler.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "jvm_bsd.h" 35 #include "memory/allocation.inline.hpp" 36 #include "memory/filemap.hpp" 37 #include "mutex_bsd.inline.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "os_bsd.inline.hpp" 40 #include "os_share_bsd.hpp" 41 #include "prims/jniFastGetField.hpp" 42 #include "prims/jvm.h" 43 #include "prims/jvm_misc.hpp" 44 #include "runtime/arguments.hpp" 45 #include "runtime/atomic.inline.hpp" 46 #include "runtime/extendedPC.hpp" 47 #include "runtime/globals.hpp" 48 #include "runtime/interfaceSupport.hpp" 49 #include "runtime/java.hpp" 50 #include "runtime/javaCalls.hpp" 51 #include "runtime/mutexLocker.hpp" 52 #include "runtime/objectMonitor.hpp" 53 #include "runtime/orderAccess.inline.hpp" 54 #include "runtime/osThread.hpp" 55 #include "runtime/perfMemory.hpp" 56 #include "runtime/sharedRuntime.hpp" 57 #include "runtime/statSampler.hpp" 58 #include "runtime/stubRoutines.hpp" 59 #include "runtime/thread.inline.hpp" 60 #include "runtime/threadCritical.hpp" 61 #include "runtime/timer.hpp" 62 #include "services/attachListener.hpp" 63 #include "services/memTracker.hpp" 64 #include "services/runtimeService.hpp" 65 #include "utilities/decoder.hpp" 66 #include "utilities/defaultStream.hpp" 67 #include "utilities/events.hpp" 68 #include "utilities/growableArray.hpp" 69 #include "utilities/vmError.hpp" 70 71 // put OS-includes here 72 # include <sys/types.h> 73 # include <sys/mman.h> 74 # include <sys/stat.h> 75 # include <sys/select.h> 76 # include <pthread.h> 77 # include <signal.h> 78 # include <errno.h> 79 # include <dlfcn.h> 80 # include <stdio.h> 81 # include <unistd.h> 82 # include <sys/resource.h> 83 # include <pthread.h> 84 # include <sys/stat.h> 85 # include <sys/time.h> 86 # include <sys/times.h> 87 # include <sys/utsname.h> 88 # include <sys/socket.h> 89 # include <sys/wait.h> 90 # include <time.h> 91 # include <pwd.h> 92 # include <poll.h> 93 # include <semaphore.h> 94 # include <fcntl.h> 95 # include <string.h> 96 # include <sys/param.h> 97 # include <sys/sysctl.h> 98 # include <sys/ipc.h> 99 # include <sys/shm.h> 100 #ifndef __APPLE__ 101 # include <link.h> 102 #endif 103 # include <stdint.h> 104 # include <inttypes.h> 105 # include <sys/ioctl.h> 106 # include <sys/syscall.h> 107 108 #if defined(__FreeBSD__) || defined(__NetBSD__) 109 #include <elf.h> 110 #endif 111 112 #ifdef __APPLE__ 113 #include <mach/mach.h> // semaphore_* API 114 #include <mach-o/dyld.h> 115 #include <sys/proc_info.h> 116 #include <objc/objc-auto.h> 117 #endif 118 119 #ifndef MAP_ANONYMOUS 120 #define MAP_ANONYMOUS MAP_ANON 121 #endif 122 123 #define MAX_PATH (2 * K) 124 125 // for timer info max values which include all bits 126 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 127 128 #define LARGEPAGES_BIT (1 << 6) 129 130 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 131 132 //////////////////////////////////////////////////////////////////////////////// 133 // global variables 134 julong os::Bsd::_physical_memory = 0; 135 136 #ifdef __APPLE__ 137 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0}; 138 volatile uint64_t os::Bsd::_max_abstime = 0; 139 #else 140 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; 141 #endif 142 pthread_t os::Bsd::_main_thread; 143 int os::Bsd::_page_size = -1; 144 145 static jlong initial_time_count=0; 146 147 static int clock_tics_per_sec = 100; 148 149 // For diagnostics to print a message once. see run_periodic_checks 150 static sigset_t check_signal_done; 151 static bool check_signals = true; 152 153 static pid_t _initial_pid = 0; 154 155 // Signal number used to suspend/resume a thread 156 157 // do not use any signal number less than SIGSEGV, see 4355769 158 static int SR_signum = SIGUSR2; 159 sigset_t SR_sigset; 160 161 162 //////////////////////////////////////////////////////////////////////////////// 163 // utility functions 164 165 static int SR_initialize(); 166 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time); 167 168 julong os::available_memory() { 169 return Bsd::available_memory(); 170 } 171 172 // available here means free 173 julong os::Bsd::available_memory() { 174 uint64_t available = physical_memory() >> 2; 175 #ifdef __APPLE__ 176 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT; 177 vm_statistics64_data_t vmstat; 178 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64, 179 (host_info64_t)&vmstat, &count); 180 assert(kerr == KERN_SUCCESS, 181 "host_statistics64 failed - check mach_host_self() and count"); 182 if (kerr == KERN_SUCCESS) { 183 available = vmstat.free_count * os::vm_page_size(); 184 } 185 #endif 186 return available; 187 } 188 189 julong os::physical_memory() { 190 return Bsd::physical_memory(); 191 } 192 193 // Return true if user is running as root. 194 195 bool os::have_special_privileges() { 196 static bool init = false; 197 static bool privileges = false; 198 if (!init) { 199 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 200 init = true; 201 } 202 return privileges; 203 } 204 205 206 207 // Cpu architecture string 208 #if defined(ZERO) 209 static char cpu_arch[] = ZERO_LIBARCH; 210 #elif defined(IA64) 211 static char cpu_arch[] = "ia64"; 212 #elif defined(IA32) 213 static char cpu_arch[] = "i386"; 214 #elif defined(AMD64) 215 static char cpu_arch[] = "amd64"; 216 #elif defined(ARM) 217 static char cpu_arch[] = "arm"; 218 #elif defined(PPC32) 219 static char cpu_arch[] = "ppc"; 220 #elif defined(SPARC) 221 #ifdef _LP64 222 static char cpu_arch[] = "sparcv9"; 223 #else 224 static char cpu_arch[] = "sparc"; 225 #endif 226 #else 227 #error Add appropriate cpu_arch setting 228 #endif 229 230 // Compiler variant 231 #ifdef COMPILER2 232 #define COMPILER_VARIANT "server" 233 #else 234 #define COMPILER_VARIANT "client" 235 #endif 236 237 238 void os::Bsd::initialize_system_info() { 239 int mib[2]; 240 size_t len; 241 int cpu_val; 242 julong mem_val; 243 244 // get processors count via hw.ncpus sysctl 245 mib[0] = CTL_HW; 246 mib[1] = HW_NCPU; 247 len = sizeof(cpu_val); 248 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) { 249 assert(len == sizeof(cpu_val), "unexpected data size"); 250 set_processor_count(cpu_val); 251 } else { 252 set_processor_count(1); // fallback 253 } 254 255 // get physical memory via hw.memsize sysctl (hw.memsize is used 256 // since it returns a 64 bit value) 257 mib[0] = CTL_HW; 258 259 #if defined (HW_MEMSIZE) // Apple 260 mib[1] = HW_MEMSIZE; 261 #elif defined(HW_PHYSMEM) // Most of BSD 262 mib[1] = HW_PHYSMEM; 263 #elif defined(HW_REALMEM) // Old FreeBSD 264 mib[1] = HW_REALMEM; 265 #else 266 #error No ways to get physmem 267 #endif 268 269 len = sizeof(mem_val); 270 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) { 271 assert(len == sizeof(mem_val), "unexpected data size"); 272 _physical_memory = mem_val; 273 } else { 274 _physical_memory = 256 * 1024 * 1024; // fallback (XXXBSD?) 275 } 276 277 #ifdef __OpenBSD__ 278 { 279 // limit _physical_memory memory view on OpenBSD since 280 // datasize rlimit restricts us anyway. 281 struct rlimit limits; 282 getrlimit(RLIMIT_DATA, &limits); 283 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur); 284 } 285 #endif 286 } 287 288 #ifdef __APPLE__ 289 static const char *get_home() { 290 const char *home_dir = ::getenv("HOME"); 291 if ((home_dir == NULL) || (*home_dir == '\0')) { 292 struct passwd *passwd_info = getpwuid(geteuid()); 293 if (passwd_info != NULL) { 294 home_dir = passwd_info->pw_dir; 295 } 296 } 297 298 return home_dir; 299 } 300 #endif 301 302 void os::init_system_properties_values() { 303 // The next steps are taken in the product version: 304 // 305 // Obtain the JAVA_HOME value from the location of libjvm.so. 306 // This library should be located at: 307 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so. 308 // 309 // If "/jre/lib/" appears at the right place in the path, then we 310 // assume libjvm.so is installed in a JDK and we use this path. 311 // 312 // Otherwise exit with message: "Could not create the Java virtual machine." 313 // 314 // The following extra steps are taken in the debugging version: 315 // 316 // If "/jre/lib/" does NOT appear at the right place in the path 317 // instead of exit check for $JAVA_HOME environment variable. 318 // 319 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 320 // then we append a fake suffix "hotspot/libjvm.so" to this path so 321 // it looks like libjvm.so is installed there 322 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 323 // 324 // Otherwise exit. 325 // 326 // Important note: if the location of libjvm.so changes this 327 // code needs to be changed accordingly. 328 329 // See ld(1): 330 // The linker uses the following search paths to locate required 331 // shared libraries: 332 // 1: ... 333 // ... 334 // 7: The default directories, normally /lib and /usr/lib. 335 #ifndef DEFAULT_LIBPATH 336 #define DEFAULT_LIBPATH "/lib:/usr/lib" 337 #endif 338 339 // Base path of extensions installed on the system. 340 #define SYS_EXT_DIR "/usr/java/packages" 341 #define EXTENSIONS_DIR "/lib/ext" 342 343 #ifndef __APPLE__ 344 345 // Buffer that fits several sprintfs. 346 // Note that the space for the colon and the trailing null are provided 347 // by the nulls included by the sizeof operator. 348 const size_t bufsize = 349 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. 350 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir 351 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 352 353 // sysclasspath, java_home, dll_dir 354 { 355 char *pslash; 356 os::jvm_path(buf, bufsize); 357 358 // Found the full path to libjvm.so. 359 // Now cut the path to <java_home>/jre if we can. 360 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 361 pslash = strrchr(buf, '/'); 362 if (pslash != NULL) { 363 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 364 } 365 Arguments::set_dll_dir(buf); 366 367 if (pslash != NULL) { 368 pslash = strrchr(buf, '/'); 369 if (pslash != NULL) { 370 *pslash = '\0'; // Get rid of /<arch>. 371 pslash = strrchr(buf, '/'); 372 if (pslash != NULL) { 373 *pslash = '\0'; // Get rid of /lib. 374 } 375 } 376 } 377 Arguments::set_java_home(buf); 378 set_boot_path('/', ':'); 379 } 380 381 // Where to look for native libraries. 382 // 383 // Note: Due to a legacy implementation, most of the library path 384 // is set in the launcher. This was to accomodate linking restrictions 385 // on legacy Bsd implementations (which are no longer supported). 386 // Eventually, all the library path setting will be done here. 387 // 388 // However, to prevent the proliferation of improperly built native 389 // libraries, the new path component /usr/java/packages is added here. 390 // Eventually, all the library path setting will be done here. 391 { 392 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 393 // should always exist (until the legacy problem cited above is 394 // addressed). 395 const char *v = ::getenv("LD_LIBRARY_PATH"); 396 const char *v_colon = ":"; 397 if (v == NULL) { v = ""; v_colon = ""; } 398 // That's +1 for the colon and +1 for the trailing '\0'. 399 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 400 strlen(v) + 1 + 401 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1, 402 mtInternal); 403 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch); 404 Arguments::set_library_path(ld_library_path); 405 FREE_C_HEAP_ARRAY(char, ld_library_path); 406 } 407 408 // Extensions directories. 409 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 410 Arguments::set_ext_dirs(buf); 411 412 FREE_C_HEAP_ARRAY(char, buf); 413 414 #else // __APPLE__ 415 416 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions" 417 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java" 418 419 const char *user_home_dir = get_home(); 420 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir. 421 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) + 422 sizeof(SYS_EXTENSIONS_DIRS); 423 424 // Buffer that fits several sprintfs. 425 // Note that the space for the colon and the trailing null are provided 426 // by the nulls included by the sizeof operator. 427 const size_t bufsize = 428 MAX2((size_t)MAXPATHLEN, // for dll_dir & friends. 429 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir 430 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 431 432 // sysclasspath, java_home, dll_dir 433 { 434 char *pslash; 435 os::jvm_path(buf, bufsize); 436 437 // Found the full path to libjvm.so. 438 // Now cut the path to <java_home>/jre if we can. 439 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 440 pslash = strrchr(buf, '/'); 441 if (pslash != NULL) { 442 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 443 } 444 Arguments::set_dll_dir(buf); 445 446 if (pslash != NULL) { 447 pslash = strrchr(buf, '/'); 448 if (pslash != NULL) { 449 *pslash = '\0'; // Get rid of /lib. 450 } 451 } 452 Arguments::set_java_home(buf); 453 set_boot_path('/', ':'); 454 } 455 456 // Where to look for native libraries. 457 // 458 // Note: Due to a legacy implementation, most of the library path 459 // is set in the launcher. This was to accomodate linking restrictions 460 // on legacy Bsd implementations (which are no longer supported). 461 // Eventually, all the library path setting will be done here. 462 // 463 // However, to prevent the proliferation of improperly built native 464 // libraries, the new path component /usr/java/packages is added here. 465 // Eventually, all the library path setting will be done here. 466 { 467 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 468 // should always exist (until the legacy problem cited above is 469 // addressed). 470 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code 471 // can specify a directory inside an app wrapper 472 const char *l = ::getenv("JAVA_LIBRARY_PATH"); 473 const char *l_colon = ":"; 474 if (l == NULL) { l = ""; l_colon = ""; } 475 476 const char *v = ::getenv("DYLD_LIBRARY_PATH"); 477 const char *v_colon = ":"; 478 if (v == NULL) { v = ""; v_colon = ""; } 479 480 // Apple's Java6 has "." at the beginning of java.library.path. 481 // OpenJDK on Windows has "." at the end of java.library.path. 482 // OpenJDK on Linux and Solaris don't have "." in java.library.path 483 // at all. To ease the transition from Apple's Java6 to OpenJDK7, 484 // "." is appended to the end of java.library.path. Yes, this 485 // could cause a change in behavior, but Apple's Java6 behavior 486 // can be achieved by putting "." at the beginning of the 487 // JAVA_LIBRARY_PATH environment variable. 488 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 489 strlen(v) + 1 + strlen(l) + 1 + 490 system_ext_size + 3, 491 mtInternal); 492 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.", 493 v, v_colon, l, l_colon, user_home_dir); 494 Arguments::set_library_path(ld_library_path); 495 FREE_C_HEAP_ARRAY(char, ld_library_path); 496 } 497 498 // Extensions directories. 499 // 500 // Note that the space for the colon and the trailing null are provided 501 // by the nulls included by the sizeof operator (so actually one byte more 502 // than necessary is allocated). 503 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, 504 user_home_dir, Arguments::get_java_home()); 505 Arguments::set_ext_dirs(buf); 506 507 FREE_C_HEAP_ARRAY(char, buf); 508 509 #undef SYS_EXTENSIONS_DIR 510 #undef SYS_EXTENSIONS_DIRS 511 512 #endif // __APPLE__ 513 514 #undef SYS_EXT_DIR 515 #undef EXTENSIONS_DIR 516 } 517 518 //////////////////////////////////////////////////////////////////////////////// 519 // breakpoint support 520 521 void os::breakpoint() { 522 BREAKPOINT; 523 } 524 525 extern "C" void breakpoint() { 526 // use debugger to set breakpoint here 527 } 528 529 //////////////////////////////////////////////////////////////////////////////// 530 // signal support 531 532 debug_only(static bool signal_sets_initialized = false); 533 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 534 535 bool os::Bsd::is_sig_ignored(int sig) { 536 struct sigaction oact; 537 sigaction(sig, (struct sigaction*)NULL, &oact); 538 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 539 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 540 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) { 541 return true; 542 } else { 543 return false; 544 } 545 } 546 547 void os::Bsd::signal_sets_init() { 548 // Should also have an assertion stating we are still single-threaded. 549 assert(!signal_sets_initialized, "Already initialized"); 550 // Fill in signals that are necessarily unblocked for all threads in 551 // the VM. Currently, we unblock the following signals: 552 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 553 // by -Xrs (=ReduceSignalUsage)); 554 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 555 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 556 // the dispositions or masks wrt these signals. 557 // Programs embedding the VM that want to use the above signals for their 558 // own purposes must, at this time, use the "-Xrs" option to prevent 559 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 560 // (See bug 4345157, and other related bugs). 561 // In reality, though, unblocking these signals is really a nop, since 562 // these signals are not blocked by default. 563 sigemptyset(&unblocked_sigs); 564 sigemptyset(&allowdebug_blocked_sigs); 565 sigaddset(&unblocked_sigs, SIGILL); 566 sigaddset(&unblocked_sigs, SIGSEGV); 567 sigaddset(&unblocked_sigs, SIGBUS); 568 sigaddset(&unblocked_sigs, SIGFPE); 569 sigaddset(&unblocked_sigs, SR_signum); 570 571 if (!ReduceSignalUsage) { 572 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 573 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 574 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); 575 } 576 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 577 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 578 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); 579 } 580 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 581 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 582 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); 583 } 584 } 585 // Fill in signals that are blocked by all but the VM thread. 586 sigemptyset(&vm_sigs); 587 if (!ReduceSignalUsage) { 588 sigaddset(&vm_sigs, BREAK_SIGNAL); 589 } 590 debug_only(signal_sets_initialized = true); 591 592 } 593 594 // These are signals that are unblocked while a thread is running Java. 595 // (For some reason, they get blocked by default.) 596 sigset_t* os::Bsd::unblocked_signals() { 597 assert(signal_sets_initialized, "Not initialized"); 598 return &unblocked_sigs; 599 } 600 601 // These are the signals that are blocked while a (non-VM) thread is 602 // running Java. Only the VM thread handles these signals. 603 sigset_t* os::Bsd::vm_signals() { 604 assert(signal_sets_initialized, "Not initialized"); 605 return &vm_sigs; 606 } 607 608 // These are signals that are blocked during cond_wait to allow debugger in 609 sigset_t* os::Bsd::allowdebug_blocked_signals() { 610 assert(signal_sets_initialized, "Not initialized"); 611 return &allowdebug_blocked_sigs; 612 } 613 614 void os::Bsd::hotspot_sigmask(Thread* thread) { 615 616 //Save caller's signal mask before setting VM signal mask 617 sigset_t caller_sigmask; 618 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 619 620 OSThread* osthread = thread->osthread(); 621 osthread->set_caller_sigmask(caller_sigmask); 622 623 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); 624 625 if (!ReduceSignalUsage) { 626 if (thread->is_VM_thread()) { 627 // Only the VM thread handles BREAK_SIGNAL ... 628 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 629 } else { 630 // ... all other threads block BREAK_SIGNAL 631 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 632 } 633 } 634 } 635 636 637 ////////////////////////////////////////////////////////////////////////////// 638 // create new thread 639 640 // check if it's safe to start a new thread 641 static bool _thread_safety_check(Thread* thread) { 642 return true; 643 } 644 645 #ifdef __APPLE__ 646 // library handle for calling objc_registerThreadWithCollector() 647 // without static linking to the libobjc library 648 #define OBJC_LIB "/usr/lib/libobjc.dylib" 649 #define OBJC_GCREGISTER "objc_registerThreadWithCollector" 650 typedef void (*objc_registerThreadWithCollector_t)(); 651 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction; 652 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL; 653 #endif 654 655 #ifdef __APPLE__ 656 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) { 657 // Additional thread_id used to correlate threads in SA 658 thread_identifier_info_data_t m_ident_info; 659 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT; 660 661 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO, 662 (thread_info_t) &m_ident_info, &count); 663 664 return m_ident_info.thread_id; 665 } 666 #endif 667 668 // Thread start routine for all newly created threads 669 static void *java_start(Thread *thread) { 670 // Try to randomize the cache line index of hot stack frames. 671 // This helps when threads of the same stack traces evict each other's 672 // cache lines. The threads can be either from the same JVM instance, or 673 // from different JVM instances. The benefit is especially true for 674 // processors with hyperthreading technology. 675 static int counter = 0; 676 int pid = os::current_process_id(); 677 alloca(((pid ^ counter++) & 7) * 128); 678 679 ThreadLocalStorage::set_thread(thread); 680 681 OSThread* osthread = thread->osthread(); 682 Monitor* sync = osthread->startThread_lock(); 683 684 // non floating stack BsdThreads needs extra check, see above 685 if (!_thread_safety_check(thread)) { 686 // notify parent thread 687 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 688 osthread->set_state(ZOMBIE); 689 sync->notify_all(); 690 return NULL; 691 } 692 693 osthread->set_thread_id(os::Bsd::gettid()); 694 695 #ifdef __APPLE__ 696 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 697 guarantee(unique_thread_id != 0, "unique thread id was not found"); 698 osthread->set_unique_thread_id(unique_thread_id); 699 #endif 700 // initialize signal mask for this thread 701 os::Bsd::hotspot_sigmask(thread); 702 703 // initialize floating point control register 704 os::Bsd::init_thread_fpu_state(); 705 706 #ifdef __APPLE__ 707 // register thread with objc gc 708 if (objc_registerThreadWithCollectorFunction != NULL) { 709 objc_registerThreadWithCollectorFunction(); 710 } 711 #endif 712 713 // handshaking with parent thread 714 { 715 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 716 717 // notify parent thread 718 osthread->set_state(INITIALIZED); 719 sync->notify_all(); 720 721 // wait until os::start_thread() 722 while (osthread->get_state() == INITIALIZED) { 723 sync->wait(Mutex::_no_safepoint_check_flag); 724 } 725 } 726 727 // call one more level start routine 728 thread->run(); 729 730 return 0; 731 } 732 733 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { 734 assert(thread->osthread() == NULL, "caller responsible"); 735 736 // Allocate the OSThread object 737 OSThread* osthread = new OSThread(NULL, NULL); 738 if (osthread == NULL) { 739 return false; 740 } 741 742 // set the correct thread state 743 osthread->set_thread_type(thr_type); 744 745 // Initial state is ALLOCATED but not INITIALIZED 746 osthread->set_state(ALLOCATED); 747 748 thread->set_osthread(osthread); 749 750 // init thread attributes 751 pthread_attr_t attr; 752 pthread_attr_init(&attr); 753 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 754 755 // stack size 756 if (os::Bsd::supports_variable_stack_size()) { 757 // calculate stack size if it's not specified by caller 758 if (stack_size == 0) { 759 stack_size = os::Bsd::default_stack_size(thr_type); 760 761 switch (thr_type) { 762 case os::java_thread: 763 // Java threads use ThreadStackSize which default value can be 764 // changed with the flag -Xss 765 assert(JavaThread::stack_size_at_create() > 0, "this should be set"); 766 stack_size = JavaThread::stack_size_at_create(); 767 break; 768 case os::compiler_thread: 769 if (CompilerThreadStackSize > 0) { 770 stack_size = (size_t)(CompilerThreadStackSize * K); 771 break; 772 } // else fall through: 773 // use VMThreadStackSize if CompilerThreadStackSize is not defined 774 case os::vm_thread: 775 case os::pgc_thread: 776 case os::cgc_thread: 777 case os::watcher_thread: 778 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 779 break; 780 } 781 } 782 783 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); 784 pthread_attr_setstacksize(&attr, stack_size); 785 } else { 786 // let pthread_create() pick the default value. 787 } 788 789 ThreadState state; 790 791 { 792 pthread_t tid; 793 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 794 795 pthread_attr_destroy(&attr); 796 797 if (ret != 0) { 798 if (PrintMiscellaneous && (Verbose || WizardMode)) { 799 perror("pthread_create()"); 800 } 801 // Need to clean up stuff we've allocated so far 802 thread->set_osthread(NULL); 803 delete osthread; 804 return false; 805 } 806 807 // Store pthread info into the OSThread 808 osthread->set_pthread_id(tid); 809 810 // Wait until child thread is either initialized or aborted 811 { 812 Monitor* sync_with_child = osthread->startThread_lock(); 813 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 814 while ((state = osthread->get_state()) == ALLOCATED) { 815 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 816 } 817 } 818 819 } 820 821 // Aborted due to thread limit being reached 822 if (state == ZOMBIE) { 823 thread->set_osthread(NULL); 824 delete osthread; 825 return false; 826 } 827 828 // The thread is returned suspended (in state INITIALIZED), 829 // and is started higher up in the call chain 830 assert(state == INITIALIZED, "race condition"); 831 return true; 832 } 833 834 ///////////////////////////////////////////////////////////////////////////// 835 // attach existing thread 836 837 // bootstrap the main thread 838 bool os::create_main_thread(JavaThread* thread) { 839 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); 840 return create_attached_thread(thread); 841 } 842 843 bool os::create_attached_thread(JavaThread* thread) { 844 #ifdef ASSERT 845 thread->verify_not_published(); 846 #endif 847 848 // Allocate the OSThread object 849 OSThread* osthread = new OSThread(NULL, NULL); 850 851 if (osthread == NULL) { 852 return false; 853 } 854 855 osthread->set_thread_id(os::Bsd::gettid()); 856 857 // Store pthread info into the OSThread 858 #ifdef __APPLE__ 859 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 860 guarantee(unique_thread_id != 0, "just checking"); 861 osthread->set_unique_thread_id(unique_thread_id); 862 #endif 863 osthread->set_pthread_id(::pthread_self()); 864 865 // initialize floating point control register 866 os::Bsd::init_thread_fpu_state(); 867 868 // Initial thread state is RUNNABLE 869 osthread->set_state(RUNNABLE); 870 871 thread->set_osthread(osthread); 872 873 // initialize signal mask for this thread 874 // and save the caller's signal mask 875 os::Bsd::hotspot_sigmask(thread); 876 877 return true; 878 } 879 880 void os::pd_start_thread(Thread* thread) { 881 OSThread * osthread = thread->osthread(); 882 assert(osthread->get_state() != INITIALIZED, "just checking"); 883 Monitor* sync_with_child = osthread->startThread_lock(); 884 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 885 sync_with_child->notify(); 886 } 887 888 // Free Bsd resources related to the OSThread 889 void os::free_thread(OSThread* osthread) { 890 assert(osthread != NULL, "osthread not set"); 891 892 if (Thread::current()->osthread() == osthread) { 893 // Restore caller's signal mask 894 sigset_t sigmask = osthread->caller_sigmask(); 895 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 896 } 897 898 delete osthread; 899 } 900 901 ////////////////////////////////////////////////////////////////////////////// 902 // thread local storage 903 904 // Restore the thread pointer if the destructor is called. This is in case 905 // someone from JNI code sets up a destructor with pthread_key_create to run 906 // detachCurrentThread on thread death. Unless we restore the thread pointer we 907 // will hang or crash. When detachCurrentThread is called the key will be set 908 // to null and we will not be called again. If detachCurrentThread is never 909 // called we could loop forever depending on the pthread implementation. 910 static void restore_thread_pointer(void* p) { 911 Thread* thread = (Thread*) p; 912 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread); 913 } 914 915 int os::allocate_thread_local_storage() { 916 pthread_key_t key; 917 int rslt = pthread_key_create(&key, restore_thread_pointer); 918 assert(rslt == 0, "cannot allocate thread local storage"); 919 return (int)key; 920 } 921 922 // Note: This is currently not used by VM, as we don't destroy TLS key 923 // on VM exit. 924 void os::free_thread_local_storage(int index) { 925 int rslt = pthread_key_delete((pthread_key_t)index); 926 assert(rslt == 0, "invalid index"); 927 } 928 929 void os::thread_local_storage_at_put(int index, void* value) { 930 int rslt = pthread_setspecific((pthread_key_t)index, value); 931 assert(rslt == 0, "pthread_setspecific failed"); 932 } 933 934 extern "C" Thread* get_thread() { 935 return ThreadLocalStorage::thread(); 936 } 937 938 939 //////////////////////////////////////////////////////////////////////////////// 940 // time support 941 942 // Time since start-up in seconds to a fine granularity. 943 // Used by VMSelfDestructTimer and the MemProfiler. 944 double os::elapsedTime() { 945 946 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); 947 } 948 949 jlong os::elapsed_counter() { 950 return javaTimeNanos() - initial_time_count; 951 } 952 953 jlong os::elapsed_frequency() { 954 return NANOSECS_PER_SEC; // nanosecond resolution 955 } 956 957 bool os::supports_vtime() { return true; } 958 bool os::enable_vtime() { return false; } 959 bool os::vtime_enabled() { return false; } 960 961 double os::elapsedVTime() { 962 // better than nothing, but not much 963 return elapsedTime(); 964 } 965 966 jlong os::javaTimeMillis() { 967 timeval time; 968 int status = gettimeofday(&time, NULL); 969 assert(status != -1, "bsd error"); 970 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 971 } 972 973 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) { 974 timeval time; 975 int status = gettimeofday(&time, NULL); 976 assert(status != -1, "bsd error"); 977 seconds = jlong(time.tv_sec); 978 nanos = jlong(time.tv_usec) * 1000; 979 } 980 981 #ifndef __APPLE__ 982 #ifndef CLOCK_MONOTONIC 983 #define CLOCK_MONOTONIC (1) 984 #endif 985 #endif 986 987 #ifdef __APPLE__ 988 void os::Bsd::clock_init() { 989 mach_timebase_info(&_timebase_info); 990 } 991 #else 992 void os::Bsd::clock_init() { 993 struct timespec res; 994 struct timespec tp; 995 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && 996 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { 997 // yes, monotonic clock is supported 998 _clock_gettime = ::clock_gettime; 999 } 1000 } 1001 #endif 1002 1003 1004 1005 #ifdef __APPLE__ 1006 1007 jlong os::javaTimeNanos() { 1008 const uint64_t tm = mach_absolute_time(); 1009 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom; 1010 const uint64_t prev = Bsd::_max_abstime; 1011 if (now <= prev) { 1012 return prev; // same or retrograde time; 1013 } 1014 const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev); 1015 assert(obsv >= prev, "invariant"); // Monotonicity 1016 // If the CAS succeeded then we're done and return "now". 1017 // If the CAS failed and the observed value "obsv" is >= now then 1018 // we should return "obsv". If the CAS failed and now > obsv > prv then 1019 // some other thread raced this thread and installed a new value, in which case 1020 // we could either (a) retry the entire operation, (b) retry trying to install now 1021 // or (c) just return obsv. We use (c). No loop is required although in some cases 1022 // we might discard a higher "now" value in deference to a slightly lower but freshly 1023 // installed obsv value. That's entirely benign -- it admits no new orderings compared 1024 // to (a) or (b) -- and greatly reduces coherence traffic. 1025 // We might also condition (c) on the magnitude of the delta between obsv and now. 1026 // Avoiding excessive CAS operations to hot RW locations is critical. 1027 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate 1028 return (prev == obsv) ? now : obsv; 1029 } 1030 1031 #else // __APPLE__ 1032 1033 jlong os::javaTimeNanos() { 1034 if (os::supports_monotonic_clock()) { 1035 struct timespec tp; 1036 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp); 1037 assert(status == 0, "gettime error"); 1038 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1039 return result; 1040 } else { 1041 timeval time; 1042 int status = gettimeofday(&time, NULL); 1043 assert(status != -1, "bsd error"); 1044 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1045 return 1000 * usecs; 1046 } 1047 } 1048 1049 #endif // __APPLE__ 1050 1051 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1052 if (os::supports_monotonic_clock()) { 1053 info_ptr->max_value = ALL_64_BITS; 1054 1055 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1056 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1057 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1058 } else { 1059 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1060 info_ptr->max_value = ALL_64_BITS; 1061 1062 // gettimeofday is a real time clock so it skips 1063 info_ptr->may_skip_backward = true; 1064 info_ptr->may_skip_forward = true; 1065 } 1066 1067 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1068 } 1069 1070 // Return the real, user, and system times in seconds from an 1071 // arbitrary fixed point in the past. 1072 bool os::getTimesSecs(double* process_real_time, 1073 double* process_user_time, 1074 double* process_system_time) { 1075 struct tms ticks; 1076 clock_t real_ticks = times(&ticks); 1077 1078 if (real_ticks == (clock_t) (-1)) { 1079 return false; 1080 } else { 1081 double ticks_per_second = (double) clock_tics_per_sec; 1082 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1083 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1084 *process_real_time = ((double) real_ticks) / ticks_per_second; 1085 1086 return true; 1087 } 1088 } 1089 1090 1091 char * os::local_time_string(char *buf, size_t buflen) { 1092 struct tm t; 1093 time_t long_time; 1094 time(&long_time); 1095 localtime_r(&long_time, &t); 1096 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1097 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1098 t.tm_hour, t.tm_min, t.tm_sec); 1099 return buf; 1100 } 1101 1102 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1103 return localtime_r(clock, res); 1104 } 1105 1106 //////////////////////////////////////////////////////////////////////////////// 1107 // runtime exit support 1108 1109 // Note: os::shutdown() might be called very early during initialization, or 1110 // called from signal handler. Before adding something to os::shutdown(), make 1111 // sure it is async-safe and can handle partially initialized VM. 1112 void os::shutdown() { 1113 1114 // allow PerfMemory to attempt cleanup of any persistent resources 1115 perfMemory_exit(); 1116 1117 // needs to remove object in file system 1118 AttachListener::abort(); 1119 1120 // flush buffered output, finish log files 1121 ostream_abort(); 1122 1123 // Check for abort hook 1124 abort_hook_t abort_hook = Arguments::abort_hook(); 1125 if (abort_hook != NULL) { 1126 abort_hook(); 1127 } 1128 1129 } 1130 1131 // Note: os::abort() might be called very early during initialization, or 1132 // called from signal handler. Before adding something to os::abort(), make 1133 // sure it is async-safe and can handle partially initialized VM. 1134 void os::abort(bool dump_core) { 1135 abort(dump_core, NULL, NULL); 1136 } 1137 1138 void os::abort(bool dump_core, void* siginfo, void* context) { 1139 os::shutdown(); 1140 if (dump_core) { 1141 #ifndef PRODUCT 1142 fdStream out(defaultStream::output_fd()); 1143 out.print_raw("Current thread is "); 1144 char buf[16]; 1145 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1146 out.print_raw_cr(buf); 1147 out.print_raw_cr("Dumping core ..."); 1148 #endif 1149 ::abort(); // dump core 1150 } 1151 1152 ::exit(1); 1153 } 1154 1155 // Die immediately, no exit hook, no abort hook, no cleanup. 1156 void os::die() { 1157 // _exit() on BsdThreads only kills current thread 1158 ::abort(); 1159 } 1160 1161 // This method is a copy of JDK's sysGetLastErrorString 1162 // from src/solaris/hpi/src/system_md.c 1163 1164 size_t os::lasterror(char *buf, size_t len) { 1165 if (errno == 0) return 0; 1166 1167 const char *s = ::strerror(errno); 1168 size_t n = ::strlen(s); 1169 if (n >= len) { 1170 n = len - 1; 1171 } 1172 ::strncpy(buf, s, n); 1173 buf[n] = '\0'; 1174 return n; 1175 } 1176 1177 // Information of current thread in variety of formats 1178 pid_t os::Bsd::gettid() { 1179 int retval = -1; 1180 1181 #ifdef __APPLE__ //XNU kernel 1182 // despite the fact mach port is actually not a thread id use it 1183 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4 1184 retval = ::pthread_mach_thread_np(::pthread_self()); 1185 guarantee(retval != 0, "just checking"); 1186 return retval; 1187 1188 #else 1189 #ifdef __FreeBSD__ 1190 retval = syscall(SYS_thr_self); 1191 #else 1192 #ifdef __OpenBSD__ 1193 retval = syscall(SYS_getthrid); 1194 #else 1195 #ifdef __NetBSD__ 1196 retval = (pid_t) syscall(SYS__lwp_self); 1197 #endif 1198 #endif 1199 #endif 1200 #endif 1201 1202 if (retval == -1) { 1203 return getpid(); 1204 } 1205 } 1206 1207 intx os::current_thread_id() { 1208 #ifdef __APPLE__ 1209 return (intx)::pthread_mach_thread_np(::pthread_self()); 1210 #else 1211 return (intx)::pthread_self(); 1212 #endif 1213 } 1214 1215 int os::current_process_id() { 1216 1217 // Under the old bsd thread library, bsd gives each thread 1218 // its own process id. Because of this each thread will return 1219 // a different pid if this method were to return the result 1220 // of getpid(2). Bsd provides no api that returns the pid 1221 // of the launcher thread for the vm. This implementation 1222 // returns a unique pid, the pid of the launcher thread 1223 // that starts the vm 'process'. 1224 1225 // Under the NPTL, getpid() returns the same pid as the 1226 // launcher thread rather than a unique pid per thread. 1227 // Use gettid() if you want the old pre NPTL behaviour. 1228 1229 // if you are looking for the result of a call to getpid() that 1230 // returns a unique pid for the calling thread, then look at the 1231 // OSThread::thread_id() method in osThread_bsd.hpp file 1232 1233 return (int)(_initial_pid ? _initial_pid : getpid()); 1234 } 1235 1236 // DLL functions 1237 1238 #define JNI_LIB_PREFIX "lib" 1239 #ifdef __APPLE__ 1240 #define JNI_LIB_SUFFIX ".dylib" 1241 #else 1242 #define JNI_LIB_SUFFIX ".so" 1243 #endif 1244 1245 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } 1246 1247 // This must be hard coded because it's the system's temporary 1248 // directory not the java application's temp directory, ala java.io.tmpdir. 1249 #ifdef __APPLE__ 1250 // macosx has a secure per-user temporary directory 1251 char temp_path_storage[PATH_MAX]; 1252 const char* os::get_temp_directory() { 1253 static char *temp_path = NULL; 1254 if (temp_path == NULL) { 1255 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX); 1256 if (pathSize == 0 || pathSize > PATH_MAX) { 1257 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage)); 1258 } 1259 temp_path = temp_path_storage; 1260 } 1261 return temp_path; 1262 } 1263 #else // __APPLE__ 1264 const char* os::get_temp_directory() { return "/tmp"; } 1265 #endif // __APPLE__ 1266 1267 static bool file_exists(const char* filename) { 1268 struct stat statbuf; 1269 if (filename == NULL || strlen(filename) == 0) { 1270 return false; 1271 } 1272 return os::stat(filename, &statbuf) == 0; 1273 } 1274 1275 bool os::dll_build_name(char* buffer, size_t buflen, 1276 const char* pname, const char* fname) { 1277 bool retval = false; 1278 // Copied from libhpi 1279 const size_t pnamelen = pname ? strlen(pname) : 0; 1280 1281 // Return error on buffer overflow. 1282 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { 1283 return retval; 1284 } 1285 1286 if (pnamelen == 0) { 1287 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); 1288 retval = true; 1289 } else if (strchr(pname, *os::path_separator()) != NULL) { 1290 int n; 1291 char** pelements = split_path(pname, &n); 1292 if (pelements == NULL) { 1293 return false; 1294 } 1295 for (int i = 0; i < n; i++) { 1296 // Really shouldn't be NULL, but check can't hurt 1297 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1298 continue; // skip the empty path values 1299 } 1300 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, 1301 pelements[i], fname); 1302 if (file_exists(buffer)) { 1303 retval = true; 1304 break; 1305 } 1306 } 1307 // release the storage 1308 for (int i = 0; i < n; i++) { 1309 if (pelements[i] != NULL) { 1310 FREE_C_HEAP_ARRAY(char, pelements[i]); 1311 } 1312 } 1313 if (pelements != NULL) { 1314 FREE_C_HEAP_ARRAY(char*, pelements); 1315 } 1316 } else { 1317 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); 1318 retval = true; 1319 } 1320 return retval; 1321 } 1322 1323 // check if addr is inside libjvm.so 1324 bool os::address_is_in_vm(address addr) { 1325 static address libjvm_base_addr; 1326 Dl_info dlinfo; 1327 1328 if (libjvm_base_addr == NULL) { 1329 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1330 libjvm_base_addr = (address)dlinfo.dli_fbase; 1331 } 1332 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1333 } 1334 1335 if (dladdr((void *)addr, &dlinfo) != 0) { 1336 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1337 } 1338 1339 return false; 1340 } 1341 1342 1343 #define MACH_MAXSYMLEN 256 1344 1345 bool os::dll_address_to_function_name(address addr, char *buf, 1346 int buflen, int *offset) { 1347 // buf is not optional, but offset is optional 1348 assert(buf != NULL, "sanity check"); 1349 1350 Dl_info dlinfo; 1351 char localbuf[MACH_MAXSYMLEN]; 1352 1353 if (dladdr((void*)addr, &dlinfo) != 0) { 1354 // see if we have a matching symbol 1355 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1356 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { 1357 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1358 } 1359 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1360 return true; 1361 } 1362 // no matching symbol so try for just file info 1363 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1364 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1365 buf, buflen, offset, dlinfo.dli_fname)) { 1366 return true; 1367 } 1368 } 1369 1370 // Handle non-dynamic manually: 1371 if (dlinfo.dli_fbase != NULL && 1372 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) { 1373 if (!Decoder::demangle(localbuf, buf, buflen)) { 1374 jio_snprintf(buf, buflen, "%s", localbuf); 1375 } 1376 return true; 1377 } 1378 } 1379 buf[0] = '\0'; 1380 if (offset != NULL) *offset = -1; 1381 return false; 1382 } 1383 1384 // ported from solaris version 1385 bool os::dll_address_to_library_name(address addr, char* buf, 1386 int buflen, int* offset) { 1387 // buf is not optional, but offset is optional 1388 assert(buf != NULL, "sanity check"); 1389 1390 Dl_info dlinfo; 1391 1392 if (dladdr((void*)addr, &dlinfo) != 0) { 1393 if (dlinfo.dli_fname != NULL) { 1394 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1395 } 1396 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1397 *offset = addr - (address)dlinfo.dli_fbase; 1398 } 1399 return true; 1400 } 1401 1402 buf[0] = '\0'; 1403 if (offset) *offset = -1; 1404 return false; 1405 } 1406 1407 // Loads .dll/.so and 1408 // in case of error it checks if .dll/.so was built for the 1409 // same architecture as Hotspot is running on 1410 1411 #ifdef __APPLE__ 1412 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1413 void * result= ::dlopen(filename, RTLD_LAZY); 1414 if (result != NULL) { 1415 // Successful loading 1416 return result; 1417 } 1418 1419 // Read system error message into ebuf 1420 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1421 ebuf[ebuflen-1]='\0'; 1422 1423 return NULL; 1424 } 1425 #else 1426 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1427 void * result= ::dlopen(filename, RTLD_LAZY); 1428 if (result != NULL) { 1429 // Successful loading 1430 return result; 1431 } 1432 1433 Elf32_Ehdr elf_head; 1434 1435 // Read system error message into ebuf 1436 // It may or may not be overwritten below 1437 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1438 ebuf[ebuflen-1]='\0'; 1439 int diag_msg_max_length=ebuflen-strlen(ebuf); 1440 char* diag_msg_buf=ebuf+strlen(ebuf); 1441 1442 if (diag_msg_max_length==0) { 1443 // No more space in ebuf for additional diagnostics message 1444 return NULL; 1445 } 1446 1447 1448 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1449 1450 if (file_descriptor < 0) { 1451 // Can't open library, report dlerror() message 1452 return NULL; 1453 } 1454 1455 bool failed_to_read_elf_head= 1456 (sizeof(elf_head)!= 1457 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1458 1459 ::close(file_descriptor); 1460 if (failed_to_read_elf_head) { 1461 // file i/o error - report dlerror() msg 1462 return NULL; 1463 } 1464 1465 typedef struct { 1466 Elf32_Half code; // Actual value as defined in elf.h 1467 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1468 char elf_class; // 32 or 64 bit 1469 char endianess; // MSB or LSB 1470 char* name; // String representation 1471 } arch_t; 1472 1473 #ifndef EM_486 1474 #define EM_486 6 /* Intel 80486 */ 1475 #endif 1476 1477 #ifndef EM_MIPS_RS3_LE 1478 #define EM_MIPS_RS3_LE 10 /* MIPS */ 1479 #endif 1480 1481 #ifndef EM_PPC64 1482 #define EM_PPC64 21 /* PowerPC64 */ 1483 #endif 1484 1485 #ifndef EM_S390 1486 #define EM_S390 22 /* IBM System/390 */ 1487 #endif 1488 1489 #ifndef EM_IA_64 1490 #define EM_IA_64 50 /* HP/Intel IA-64 */ 1491 #endif 1492 1493 #ifndef EM_X86_64 1494 #define EM_X86_64 62 /* AMD x86-64 */ 1495 #endif 1496 1497 static const arch_t arch_array[]={ 1498 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1499 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1500 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1501 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1502 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1503 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1504 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1505 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1506 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1507 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1508 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1509 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1510 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1511 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1512 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1513 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} 1514 }; 1515 1516 #if (defined IA32) 1517 static Elf32_Half running_arch_code=EM_386; 1518 #elif (defined AMD64) 1519 static Elf32_Half running_arch_code=EM_X86_64; 1520 #elif (defined IA64) 1521 static Elf32_Half running_arch_code=EM_IA_64; 1522 #elif (defined __sparc) && (defined _LP64) 1523 static Elf32_Half running_arch_code=EM_SPARCV9; 1524 #elif (defined __sparc) && (!defined _LP64) 1525 static Elf32_Half running_arch_code=EM_SPARC; 1526 #elif (defined __powerpc64__) 1527 static Elf32_Half running_arch_code=EM_PPC64; 1528 #elif (defined __powerpc__) 1529 static Elf32_Half running_arch_code=EM_PPC; 1530 #elif (defined ARM) 1531 static Elf32_Half running_arch_code=EM_ARM; 1532 #elif (defined S390) 1533 static Elf32_Half running_arch_code=EM_S390; 1534 #elif (defined ALPHA) 1535 static Elf32_Half running_arch_code=EM_ALPHA; 1536 #elif (defined MIPSEL) 1537 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1538 #elif (defined PARISC) 1539 static Elf32_Half running_arch_code=EM_PARISC; 1540 #elif (defined MIPS) 1541 static Elf32_Half running_arch_code=EM_MIPS; 1542 #elif (defined M68K) 1543 static Elf32_Half running_arch_code=EM_68K; 1544 #else 1545 #error Method os::dll_load requires that one of following is defined:\ 1546 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K 1547 #endif 1548 1549 // Identify compatability class for VM's architecture and library's architecture 1550 // Obtain string descriptions for architectures 1551 1552 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1553 int running_arch_index=-1; 1554 1555 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1556 if (running_arch_code == arch_array[i].code) { 1557 running_arch_index = i; 1558 } 1559 if (lib_arch.code == arch_array[i].code) { 1560 lib_arch.compat_class = arch_array[i].compat_class; 1561 lib_arch.name = arch_array[i].name; 1562 } 1563 } 1564 1565 assert(running_arch_index != -1, 1566 "Didn't find running architecture code (running_arch_code) in arch_array"); 1567 if (running_arch_index == -1) { 1568 // Even though running architecture detection failed 1569 // we may still continue with reporting dlerror() message 1570 return NULL; 1571 } 1572 1573 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1574 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1575 return NULL; 1576 } 1577 1578 #ifndef S390 1579 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1580 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1581 return NULL; 1582 } 1583 #endif // !S390 1584 1585 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1586 if (lib_arch.name!=NULL) { 1587 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1588 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1589 lib_arch.name, arch_array[running_arch_index].name); 1590 } else { 1591 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1592 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1593 lib_arch.code, 1594 arch_array[running_arch_index].name); 1595 } 1596 } 1597 1598 return NULL; 1599 } 1600 #endif // !__APPLE__ 1601 1602 void* os::get_default_process_handle() { 1603 #ifdef __APPLE__ 1604 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY 1605 // to avoid finding unexpected symbols on second (or later) 1606 // loads of a library. 1607 return (void*)::dlopen(NULL, RTLD_FIRST); 1608 #else 1609 return (void*)::dlopen(NULL, RTLD_LAZY); 1610 #endif 1611 } 1612 1613 // XXX: Do we need a lock around this as per Linux? 1614 void* os::dll_lookup(void* handle, const char* name) { 1615 return dlsym(handle, name); 1616 } 1617 1618 1619 static bool _print_ascii_file(const char* filename, outputStream* st) { 1620 int fd = ::open(filename, O_RDONLY); 1621 if (fd == -1) { 1622 return false; 1623 } 1624 1625 char buf[32]; 1626 int bytes; 1627 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { 1628 st->print_raw(buf, bytes); 1629 } 1630 1631 ::close(fd); 1632 1633 return true; 1634 } 1635 1636 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) { 1637 outputStream * out = (outputStream *) param; 1638 out->print_cr(PTR_FORMAT " \t%s", base_address, name); 1639 return 0; 1640 } 1641 1642 void os::print_dll_info(outputStream *st) { 1643 st->print_cr("Dynamic libraries:"); 1644 if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) { 1645 st->print_cr("Error: Cannot print dynamic libraries."); 1646 } 1647 } 1648 1649 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1650 #ifdef RTLD_DI_LINKMAP 1651 Dl_info dli; 1652 void *handle; 1653 Link_map *map; 1654 Link_map *p; 1655 1656 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 || 1657 dli.dli_fname == NULL) { 1658 return 1; 1659 } 1660 handle = dlopen(dli.dli_fname, RTLD_LAZY); 1661 if (handle == NULL) { 1662 return 1; 1663 } 1664 dlinfo(handle, RTLD_DI_LINKMAP, &map); 1665 if (map == NULL) { 1666 dlclose(handle); 1667 return 1; 1668 } 1669 1670 while (map->l_prev != NULL) 1671 map = map->l_prev; 1672 1673 while (map != NULL) { 1674 // Value for top_address is returned as 0 since we don't have any information about module size 1675 if (callback(map->l_name, (address)map->l_addr, (address)0, param)) { 1676 dlclose(handle); 1677 return 1; 1678 } 1679 map = map->l_next; 1680 } 1681 1682 dlclose(handle); 1683 #elif defined(__APPLE__) 1684 for (uint32_t i = 1; i < _dyld_image_count(); i++) { 1685 // Value for top_address is returned as 0 since we don't have any information about module size 1686 if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) { 1687 return 1; 1688 } 1689 } 1690 return 0; 1691 #else 1692 return 1; 1693 #endif 1694 } 1695 1696 void os::print_os_info_brief(outputStream* st) { 1697 st->print("Bsd"); 1698 1699 os::Posix::print_uname_info(st); 1700 } 1701 1702 void os::print_os_info(outputStream* st) { 1703 st->print("OS:"); 1704 st->print("Bsd"); 1705 1706 os::Posix::print_uname_info(st); 1707 1708 os::Posix::print_rlimit_info(st); 1709 1710 os::Posix::print_load_average(st); 1711 } 1712 1713 void os::pd_print_cpu_info(outputStream* st) { 1714 // Nothing to do for now. 1715 } 1716 1717 void os::print_memory_info(outputStream* st) { 1718 1719 st->print("Memory:"); 1720 st->print(" %dk page", os::vm_page_size()>>10); 1721 1722 st->print(", physical " UINT64_FORMAT "k", 1723 os::physical_memory() >> 10); 1724 st->print("(" UINT64_FORMAT "k free)", 1725 os::available_memory() >> 10); 1726 st->cr(); 1727 1728 // meminfo 1729 st->print("\n/proc/meminfo:\n"); 1730 _print_ascii_file("/proc/meminfo", st); 1731 st->cr(); 1732 } 1733 1734 void os::print_siginfo(outputStream* st, void* siginfo) { 1735 const siginfo_t* si = (const siginfo_t*)siginfo; 1736 1737 os::Posix::print_siginfo_brief(st, si); 1738 1739 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && 1740 UseSharedSpaces) { 1741 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1742 if (mapinfo->is_in_shared_space(si->si_addr)) { 1743 st->print("\n\nError accessing class data sharing archive." \ 1744 " Mapped file inaccessible during execution, " \ 1745 " possible disk/network problem."); 1746 } 1747 } 1748 st->cr(); 1749 } 1750 1751 1752 static void print_signal_handler(outputStream* st, int sig, 1753 char* buf, size_t buflen); 1754 1755 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 1756 st->print_cr("Signal Handlers:"); 1757 print_signal_handler(st, SIGSEGV, buf, buflen); 1758 print_signal_handler(st, SIGBUS , buf, buflen); 1759 print_signal_handler(st, SIGFPE , buf, buflen); 1760 print_signal_handler(st, SIGPIPE, buf, buflen); 1761 print_signal_handler(st, SIGXFSZ, buf, buflen); 1762 print_signal_handler(st, SIGILL , buf, buflen); 1763 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); 1764 print_signal_handler(st, SR_signum, buf, buflen); 1765 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 1766 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 1767 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 1768 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 1769 } 1770 1771 static char saved_jvm_path[MAXPATHLEN] = {0}; 1772 1773 // Find the full path to the current module, libjvm 1774 void os::jvm_path(char *buf, jint buflen) { 1775 // Error checking. 1776 if (buflen < MAXPATHLEN) { 1777 assert(false, "must use a large-enough buffer"); 1778 buf[0] = '\0'; 1779 return; 1780 } 1781 // Lazy resolve the path to current module. 1782 if (saved_jvm_path[0] != 0) { 1783 strcpy(buf, saved_jvm_path); 1784 return; 1785 } 1786 1787 char dli_fname[MAXPATHLEN]; 1788 bool ret = dll_address_to_library_name( 1789 CAST_FROM_FN_PTR(address, os::jvm_path), 1790 dli_fname, sizeof(dli_fname), NULL); 1791 assert(ret, "cannot locate libjvm"); 1792 char *rp = NULL; 1793 if (ret && dli_fname[0] != '\0') { 1794 rp = realpath(dli_fname, buf); 1795 } 1796 if (rp == NULL) { 1797 return; 1798 } 1799 1800 if (Arguments::sun_java_launcher_is_altjvm()) { 1801 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 1802 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so" 1803 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/" 1804 // appears at the right place in the string, then assume we are 1805 // installed in a JDK and we're done. Otherwise, check for a 1806 // JAVA_HOME environment variable and construct a path to the JVM 1807 // being overridden. 1808 1809 const char *p = buf + strlen(buf) - 1; 1810 for (int count = 0; p > buf && count < 5; ++count) { 1811 for (--p; p > buf && *p != '/'; --p) 1812 /* empty */ ; 1813 } 1814 1815 if (strncmp(p, "/jre/lib/", 9) != 0) { 1816 // Look for JAVA_HOME in the environment. 1817 char* java_home_var = ::getenv("JAVA_HOME"); 1818 if (java_home_var != NULL && java_home_var[0] != 0) { 1819 char* jrelib_p; 1820 int len; 1821 1822 // Check the current module name "libjvm" 1823 p = strrchr(buf, '/'); 1824 assert(strstr(p, "/libjvm") == p, "invalid library name"); 1825 1826 rp = realpath(java_home_var, buf); 1827 if (rp == NULL) { 1828 return; 1829 } 1830 1831 // determine if this is a legacy image or modules image 1832 // modules image doesn't have "jre" subdirectory 1833 len = strlen(buf); 1834 assert(len < buflen, "Ran out of buffer space"); 1835 jrelib_p = buf + len; 1836 1837 // Add the appropriate library subdir 1838 snprintf(jrelib_p, buflen-len, "/jre/lib"); 1839 if (0 != access(buf, F_OK)) { 1840 snprintf(jrelib_p, buflen-len, "/lib"); 1841 } 1842 1843 // Add the appropriate client or server subdir 1844 len = strlen(buf); 1845 jrelib_p = buf + len; 1846 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT); 1847 if (0 != access(buf, F_OK)) { 1848 snprintf(jrelib_p, buflen-len, "%s", ""); 1849 } 1850 1851 // If the path exists within JAVA_HOME, add the JVM library name 1852 // to complete the path to JVM being overridden. Otherwise fallback 1853 // to the path to the current library. 1854 if (0 == access(buf, F_OK)) { 1855 // Use current module name "libjvm" 1856 len = strlen(buf); 1857 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX); 1858 } else { 1859 // Fall back to path of current library 1860 rp = realpath(dli_fname, buf); 1861 if (rp == NULL) { 1862 return; 1863 } 1864 } 1865 } 1866 } 1867 } 1868 1869 strncpy(saved_jvm_path, buf, MAXPATHLEN); 1870 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 1871 } 1872 1873 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 1874 // no prefix required, not even "_" 1875 } 1876 1877 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 1878 // no suffix required 1879 } 1880 1881 //////////////////////////////////////////////////////////////////////////////// 1882 // sun.misc.Signal support 1883 1884 static volatile jint sigint_count = 0; 1885 1886 static void UserHandler(int sig, void *siginfo, void *context) { 1887 // 4511530 - sem_post is serialized and handled by the manager thread. When 1888 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 1889 // don't want to flood the manager thread with sem_post requests. 1890 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 1891 return; 1892 } 1893 1894 // Ctrl-C is pressed during error reporting, likely because the error 1895 // handler fails to abort. Let VM die immediately. 1896 if (sig == SIGINT && is_error_reported()) { 1897 os::die(); 1898 } 1899 1900 os::signal_notify(sig); 1901 } 1902 1903 void* os::user_handler() { 1904 return CAST_FROM_FN_PTR(void*, UserHandler); 1905 } 1906 1907 extern "C" { 1908 typedef void (*sa_handler_t)(int); 1909 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1910 } 1911 1912 void* os::signal(int signal_number, void* handler) { 1913 struct sigaction sigAct, oldSigAct; 1914 1915 sigfillset(&(sigAct.sa_mask)); 1916 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 1917 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 1918 1919 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 1920 // -1 means registration failed 1921 return (void *)-1; 1922 } 1923 1924 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 1925 } 1926 1927 void os::signal_raise(int signal_number) { 1928 ::raise(signal_number); 1929 } 1930 1931 // The following code is moved from os.cpp for making this 1932 // code platform specific, which it is by its very nature. 1933 1934 // Will be modified when max signal is changed to be dynamic 1935 int os::sigexitnum_pd() { 1936 return NSIG; 1937 } 1938 1939 // a counter for each possible signal value 1940 static volatile jint pending_signals[NSIG+1] = { 0 }; 1941 1942 // Bsd(POSIX) specific hand shaking semaphore. 1943 #ifdef __APPLE__ 1944 typedef semaphore_t os_semaphore_t; 1945 1946 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) 1947 #define SEM_WAIT(sem) semaphore_wait(sem) 1948 #define SEM_POST(sem) semaphore_signal(sem) 1949 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem) 1950 #else 1951 typedef sem_t os_semaphore_t; 1952 1953 #define SEM_INIT(sem, value) sem_init(&sem, 0, value) 1954 #define SEM_WAIT(sem) sem_wait(&sem) 1955 #define SEM_POST(sem) sem_post(&sem) 1956 #define SEM_DESTROY(sem) sem_destroy(&sem) 1957 #endif 1958 1959 class Semaphore : public StackObj { 1960 public: 1961 Semaphore(); 1962 ~Semaphore(); 1963 void signal(); 1964 void wait(); 1965 bool trywait(); 1966 bool timedwait(unsigned int sec, int nsec); 1967 private: 1968 jlong currenttime() const; 1969 os_semaphore_t _semaphore; 1970 }; 1971 1972 Semaphore::Semaphore() : _semaphore(0) { 1973 SEM_INIT(_semaphore, 0); 1974 } 1975 1976 Semaphore::~Semaphore() { 1977 SEM_DESTROY(_semaphore); 1978 } 1979 1980 void Semaphore::signal() { 1981 SEM_POST(_semaphore); 1982 } 1983 1984 void Semaphore::wait() { 1985 SEM_WAIT(_semaphore); 1986 } 1987 1988 jlong Semaphore::currenttime() const { 1989 struct timeval tv; 1990 gettimeofday(&tv, NULL); 1991 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000); 1992 } 1993 1994 #ifdef __APPLE__ 1995 bool Semaphore::trywait() { 1996 return timedwait(0, 0); 1997 } 1998 1999 bool Semaphore::timedwait(unsigned int sec, int nsec) { 2000 kern_return_t kr = KERN_ABORTED; 2001 mach_timespec_t waitspec; 2002 waitspec.tv_sec = sec; 2003 waitspec.tv_nsec = nsec; 2004 2005 jlong starttime = currenttime(); 2006 2007 kr = semaphore_timedwait(_semaphore, waitspec); 2008 while (kr == KERN_ABORTED) { 2009 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec; 2010 2011 jlong current = currenttime(); 2012 jlong passedtime = current - starttime; 2013 2014 if (passedtime >= totalwait) { 2015 waitspec.tv_sec = 0; 2016 waitspec.tv_nsec = 0; 2017 } else { 2018 jlong waittime = totalwait - (current - starttime); 2019 waitspec.tv_sec = waittime / NANOSECS_PER_SEC; 2020 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC; 2021 } 2022 2023 kr = semaphore_timedwait(_semaphore, waitspec); 2024 } 2025 2026 return kr == KERN_SUCCESS; 2027 } 2028 2029 #else 2030 2031 bool Semaphore::trywait() { 2032 return sem_trywait(&_semaphore) == 0; 2033 } 2034 2035 bool Semaphore::timedwait(unsigned int sec, int nsec) { 2036 struct timespec ts; 2037 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec); 2038 2039 while (1) { 2040 int result = sem_timedwait(&_semaphore, &ts); 2041 if (result == 0) { 2042 return true; 2043 } else if (errno == EINTR) { 2044 continue; 2045 } else if (errno == ETIMEDOUT) { 2046 return false; 2047 } else { 2048 return false; 2049 } 2050 } 2051 } 2052 2053 #endif // __APPLE__ 2054 2055 static os_semaphore_t sig_sem; 2056 static Semaphore sr_semaphore; 2057 2058 void os::signal_init_pd() { 2059 // Initialize signal structures 2060 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2061 2062 // Initialize signal semaphore 2063 ::SEM_INIT(sig_sem, 0); 2064 } 2065 2066 void os::signal_notify(int sig) { 2067 Atomic::inc(&pending_signals[sig]); 2068 ::SEM_POST(sig_sem); 2069 } 2070 2071 static int check_pending_signals(bool wait) { 2072 Atomic::store(0, &sigint_count); 2073 for (;;) { 2074 for (int i = 0; i < NSIG + 1; i++) { 2075 jint n = pending_signals[i]; 2076 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2077 return i; 2078 } 2079 } 2080 if (!wait) { 2081 return -1; 2082 } 2083 JavaThread *thread = JavaThread::current(); 2084 ThreadBlockInVM tbivm(thread); 2085 2086 bool threadIsSuspended; 2087 do { 2088 thread->set_suspend_equivalent(); 2089 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2090 ::SEM_WAIT(sig_sem); 2091 2092 // were we externally suspended while we were waiting? 2093 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2094 if (threadIsSuspended) { 2095 // The semaphore has been incremented, but while we were waiting 2096 // another thread suspended us. We don't want to continue running 2097 // while suspended because that would surprise the thread that 2098 // suspended us. 2099 ::SEM_POST(sig_sem); 2100 2101 thread->java_suspend_self(); 2102 } 2103 } while (threadIsSuspended); 2104 } 2105 } 2106 2107 int os::signal_lookup() { 2108 return check_pending_signals(false); 2109 } 2110 2111 int os::signal_wait() { 2112 return check_pending_signals(true); 2113 } 2114 2115 //////////////////////////////////////////////////////////////////////////////// 2116 // Virtual Memory 2117 2118 int os::vm_page_size() { 2119 // Seems redundant as all get out 2120 assert(os::Bsd::page_size() != -1, "must call os::init"); 2121 return os::Bsd::page_size(); 2122 } 2123 2124 // Solaris allocates memory by pages. 2125 int os::vm_allocation_granularity() { 2126 assert(os::Bsd::page_size() != -1, "must call os::init"); 2127 return os::Bsd::page_size(); 2128 } 2129 2130 // Rationale behind this function: 2131 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2132 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2133 // samples for JITted code. Here we create private executable mapping over the code cache 2134 // and then we can use standard (well, almost, as mapping can change) way to provide 2135 // info for the reporting script by storing timestamp and location of symbol 2136 void bsd_wrap_code(char* base, size_t size) { 2137 static volatile jint cnt = 0; 2138 2139 if (!UseOprofile) { 2140 return; 2141 } 2142 2143 char buf[PATH_MAX + 1]; 2144 int num = Atomic::add(1, &cnt); 2145 2146 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", 2147 os::get_temp_directory(), os::current_process_id(), num); 2148 unlink(buf); 2149 2150 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2151 2152 if (fd != -1) { 2153 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2154 if (rv != (off_t)-1) { 2155 if (::write(fd, "", 1) == 1) { 2156 mmap(base, size, 2157 PROT_READ|PROT_WRITE|PROT_EXEC, 2158 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2159 } 2160 } 2161 ::close(fd); 2162 unlink(buf); 2163 } 2164 } 2165 2166 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2167 int err) { 2168 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2169 ", %d) failed; error='%s' (errno=%d)", addr, size, exec, 2170 strerror(err), err); 2171 } 2172 2173 // NOTE: Bsd kernel does not really reserve the pages for us. 2174 // All it does is to check if there are enough free pages 2175 // left at the time of mmap(). This could be a potential 2176 // problem. 2177 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2178 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2179 #ifdef __OpenBSD__ 2180 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2181 if (::mprotect(addr, size, prot) == 0) { 2182 return true; 2183 } 2184 #else 2185 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2186 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2187 if (res != (uintptr_t) MAP_FAILED) { 2188 return true; 2189 } 2190 #endif 2191 2192 // Warn about any commit errors we see in non-product builds just 2193 // in case mmap() doesn't work as described on the man page. 2194 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);) 2195 2196 return false; 2197 } 2198 2199 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2200 bool exec) { 2201 // alignment_hint is ignored on this OS 2202 return pd_commit_memory(addr, size, exec); 2203 } 2204 2205 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2206 const char* mesg) { 2207 assert(mesg != NULL, "mesg must be specified"); 2208 if (!pd_commit_memory(addr, size, exec)) { 2209 // add extra info in product mode for vm_exit_out_of_memory(): 2210 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);) 2211 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg); 2212 } 2213 } 2214 2215 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2216 size_t alignment_hint, bool exec, 2217 const char* mesg) { 2218 // alignment_hint is ignored on this OS 2219 pd_commit_memory_or_exit(addr, size, exec, mesg); 2220 } 2221 2222 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2223 } 2224 2225 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2226 ::madvise(addr, bytes, MADV_DONTNEED); 2227 } 2228 2229 void os::numa_make_global(char *addr, size_t bytes) { 2230 } 2231 2232 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2233 } 2234 2235 bool os::numa_topology_changed() { return false; } 2236 2237 size_t os::numa_get_groups_num() { 2238 return 1; 2239 } 2240 2241 int os::numa_get_group_id() { 2242 return 0; 2243 } 2244 2245 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2246 if (size > 0) { 2247 ids[0] = 0; 2248 return 1; 2249 } 2250 return 0; 2251 } 2252 2253 bool os::get_page_info(char *start, page_info* info) { 2254 return false; 2255 } 2256 2257 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { 2258 return end; 2259 } 2260 2261 2262 bool os::pd_uncommit_memory(char* addr, size_t size) { 2263 #ifdef __OpenBSD__ 2264 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2265 return ::mprotect(addr, size, PROT_NONE) == 0; 2266 #else 2267 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2268 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2269 return res != (uintptr_t) MAP_FAILED; 2270 #endif 2271 } 2272 2273 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2274 return os::commit_memory(addr, size, !ExecMem); 2275 } 2276 2277 // If this is a growable mapping, remove the guard pages entirely by 2278 // munmap()ping them. If not, just call uncommit_memory(). 2279 bool os::remove_stack_guard_pages(char* addr, size_t size) { 2280 return os::uncommit_memory(addr, size); 2281 } 2282 2283 static address _highest_vm_reserved_address = NULL; 2284 2285 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 2286 // at 'requested_addr'. If there are existing memory mappings at the same 2287 // location, however, they will be overwritten. If 'fixed' is false, 2288 // 'requested_addr' is only treated as a hint, the return value may or 2289 // may not start from the requested address. Unlike Bsd mmap(), this 2290 // function returns NULL to indicate failure. 2291 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 2292 char * addr; 2293 int flags; 2294 2295 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 2296 if (fixed) { 2297 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); 2298 flags |= MAP_FIXED; 2299 } 2300 2301 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 2302 // touch an uncommitted page. Otherwise, the read/write might 2303 // succeed if we have enough swap space to back the physical page. 2304 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 2305 flags, -1, 0); 2306 2307 if (addr != MAP_FAILED) { 2308 // anon_mmap() should only get called during VM initialization, 2309 // don't need lock (actually we can skip locking even it can be called 2310 // from multiple threads, because _highest_vm_reserved_address is just a 2311 // hint about the upper limit of non-stack memory regions.) 2312 if ((address)addr + bytes > _highest_vm_reserved_address) { 2313 _highest_vm_reserved_address = (address)addr + bytes; 2314 } 2315 } 2316 2317 return addr == MAP_FAILED ? NULL : addr; 2318 } 2319 2320 // Don't update _highest_vm_reserved_address, because there might be memory 2321 // regions above addr + size. If so, releasing a memory region only creates 2322 // a hole in the address space, it doesn't help prevent heap-stack collision. 2323 // 2324 static int anon_munmap(char * addr, size_t size) { 2325 return ::munmap(addr, size) == 0; 2326 } 2327 2328 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 2329 size_t alignment_hint) { 2330 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 2331 } 2332 2333 bool os::pd_release_memory(char* addr, size_t size) { 2334 return anon_munmap(addr, size); 2335 } 2336 2337 static bool bsd_mprotect(char* addr, size_t size, int prot) { 2338 // Bsd wants the mprotect address argument to be page aligned. 2339 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); 2340 2341 // According to SUSv3, mprotect() should only be used with mappings 2342 // established by mmap(), and mmap() always maps whole pages. Unaligned 2343 // 'addr' likely indicates problem in the VM (e.g. trying to change 2344 // protection of malloc'ed or statically allocated memory). Check the 2345 // caller if you hit this assert. 2346 assert(addr == bottom, "sanity check"); 2347 2348 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); 2349 return ::mprotect(bottom, size, prot) == 0; 2350 } 2351 2352 // Set protections specified 2353 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 2354 bool is_committed) { 2355 unsigned int p = 0; 2356 switch (prot) { 2357 case MEM_PROT_NONE: p = PROT_NONE; break; 2358 case MEM_PROT_READ: p = PROT_READ; break; 2359 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 2360 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 2361 default: 2362 ShouldNotReachHere(); 2363 } 2364 // is_committed is unused. 2365 return bsd_mprotect(addr, bytes, p); 2366 } 2367 2368 bool os::guard_memory(char* addr, size_t size) { 2369 return bsd_mprotect(addr, size, PROT_NONE); 2370 } 2371 2372 bool os::unguard_memory(char* addr, size_t size) { 2373 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); 2374 } 2375 2376 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { 2377 return false; 2378 } 2379 2380 // Large page support 2381 2382 static size_t _large_page_size = 0; 2383 2384 void os::large_page_init() { 2385 } 2386 2387 2388 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) { 2389 fatal("This code is not used or maintained."); 2390 2391 // "exec" is passed in but not used. Creating the shared image for 2392 // the code cache doesn't have an SHM_X executable permission to check. 2393 assert(UseLargePages && UseSHM, "only for SHM large pages"); 2394 2395 key_t key = IPC_PRIVATE; 2396 char *addr; 2397 2398 bool warn_on_failure = UseLargePages && 2399 (!FLAG_IS_DEFAULT(UseLargePages) || 2400 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 2401 2402 // Create a large shared memory region to attach to based on size. 2403 // Currently, size is the total size of the heap 2404 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); 2405 if (shmid == -1) { 2406 // Possible reasons for shmget failure: 2407 // 1. shmmax is too small for Java heap. 2408 // > check shmmax value: cat /proc/sys/kernel/shmmax 2409 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 2410 // 2. not enough large page memory. 2411 // > check available large pages: cat /proc/meminfo 2412 // > increase amount of large pages: 2413 // echo new_value > /proc/sys/vm/nr_hugepages 2414 // Note 1: different Bsd may use different name for this property, 2415 // e.g. on Redhat AS-3 it is "hugetlb_pool". 2416 // Note 2: it's possible there's enough physical memory available but 2417 // they are so fragmented after a long run that they can't 2418 // coalesce into large pages. Try to reserve large pages when 2419 // the system is still "fresh". 2420 if (warn_on_failure) { 2421 warning("Failed to reserve shared memory (errno = %d).", errno); 2422 } 2423 return NULL; 2424 } 2425 2426 // attach to the region 2427 addr = (char*)shmat(shmid, req_addr, 0); 2428 int err = errno; 2429 2430 // Remove shmid. If shmat() is successful, the actual shared memory segment 2431 // will be deleted when it's detached by shmdt() or when the process 2432 // terminates. If shmat() is not successful this will remove the shared 2433 // segment immediately. 2434 shmctl(shmid, IPC_RMID, NULL); 2435 2436 if ((intptr_t)addr == -1) { 2437 if (warn_on_failure) { 2438 warning("Failed to attach shared memory (errno = %d).", err); 2439 } 2440 return NULL; 2441 } 2442 2443 // The memory is committed 2444 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 2445 2446 return addr; 2447 } 2448 2449 bool os::release_memory_special(char* base, size_t bytes) { 2450 if (MemTracker::tracking_level() > NMT_minimal) { 2451 Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 2452 // detaching the SHM segment will also delete it, see reserve_memory_special() 2453 int rslt = shmdt(base); 2454 if (rslt == 0) { 2455 tkr.record((address)base, bytes); 2456 return true; 2457 } else { 2458 return false; 2459 } 2460 } else { 2461 return shmdt(base) == 0; 2462 } 2463 } 2464 2465 size_t os::large_page_size() { 2466 return _large_page_size; 2467 } 2468 2469 // HugeTLBFS allows application to commit large page memory on demand; 2470 // with SysV SHM the entire memory region must be allocated as shared 2471 // memory. 2472 bool os::can_commit_large_page_memory() { 2473 return UseHugeTLBFS; 2474 } 2475 2476 bool os::can_execute_large_page_memory() { 2477 return UseHugeTLBFS; 2478 } 2479 2480 // Reserve memory at an arbitrary address, only if that area is 2481 // available (and not reserved for something else). 2482 2483 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 2484 const int max_tries = 10; 2485 char* base[max_tries]; 2486 size_t size[max_tries]; 2487 const size_t gap = 0x000000; 2488 2489 // Assert only that the size is a multiple of the page size, since 2490 // that's all that mmap requires, and since that's all we really know 2491 // about at this low abstraction level. If we need higher alignment, 2492 // we can either pass an alignment to this method or verify alignment 2493 // in one of the methods further up the call chain. See bug 5044738. 2494 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 2495 2496 // Repeatedly allocate blocks until the block is allocated at the 2497 // right spot. Give up after max_tries. Note that reserve_memory() will 2498 // automatically update _highest_vm_reserved_address if the call is 2499 // successful. The variable tracks the highest memory address every reserved 2500 // by JVM. It is used to detect heap-stack collision if running with 2501 // fixed-stack BsdThreads. Because here we may attempt to reserve more 2502 // space than needed, it could confuse the collision detecting code. To 2503 // solve the problem, save current _highest_vm_reserved_address and 2504 // calculate the correct value before return. 2505 address old_highest = _highest_vm_reserved_address; 2506 2507 // Bsd mmap allows caller to pass an address as hint; give it a try first, 2508 // if kernel honors the hint then we can return immediately. 2509 char * addr = anon_mmap(requested_addr, bytes, false); 2510 if (addr == requested_addr) { 2511 return requested_addr; 2512 } 2513 2514 if (addr != NULL) { 2515 // mmap() is successful but it fails to reserve at the requested address 2516 anon_munmap(addr, bytes); 2517 } 2518 2519 int i; 2520 for (i = 0; i < max_tries; ++i) { 2521 base[i] = reserve_memory(bytes); 2522 2523 if (base[i] != NULL) { 2524 // Is this the block we wanted? 2525 if (base[i] == requested_addr) { 2526 size[i] = bytes; 2527 break; 2528 } 2529 2530 // Does this overlap the block we wanted? Give back the overlapped 2531 // parts and try again. 2532 2533 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; 2534 if (top_overlap >= 0 && top_overlap < bytes) { 2535 unmap_memory(base[i], top_overlap); 2536 base[i] += top_overlap; 2537 size[i] = bytes - top_overlap; 2538 } else { 2539 size_t bottom_overlap = base[i] + bytes - requested_addr; 2540 if (bottom_overlap >= 0 && bottom_overlap < bytes) { 2541 unmap_memory(requested_addr, bottom_overlap); 2542 size[i] = bytes - bottom_overlap; 2543 } else { 2544 size[i] = bytes; 2545 } 2546 } 2547 } 2548 } 2549 2550 // Give back the unused reserved pieces. 2551 2552 for (int j = 0; j < i; ++j) { 2553 if (base[j] != NULL) { 2554 unmap_memory(base[j], size[j]); 2555 } 2556 } 2557 2558 if (i < max_tries) { 2559 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); 2560 return requested_addr; 2561 } else { 2562 _highest_vm_reserved_address = old_highest; 2563 return NULL; 2564 } 2565 } 2566 2567 size_t os::read(int fd, void *buf, unsigned int nBytes) { 2568 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); 2569 } 2570 2571 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 2572 RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset)); 2573 } 2574 2575 void os::naked_short_sleep(jlong ms) { 2576 struct timespec req; 2577 2578 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 2579 req.tv_sec = 0; 2580 if (ms > 0) { 2581 req.tv_nsec = (ms % 1000) * 1000000; 2582 } else { 2583 req.tv_nsec = 1; 2584 } 2585 2586 nanosleep(&req, NULL); 2587 2588 return; 2589 } 2590 2591 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 2592 void os::infinite_sleep() { 2593 while (true) { // sleep forever ... 2594 ::sleep(100); // ... 100 seconds at a time 2595 } 2596 } 2597 2598 // Used to convert frequent JVM_Yield() to nops 2599 bool os::dont_yield() { 2600 return DontYieldALot; 2601 } 2602 2603 void os::naked_yield() { 2604 sched_yield(); 2605 } 2606 2607 //////////////////////////////////////////////////////////////////////////////// 2608 // thread priority support 2609 2610 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER 2611 // only supports dynamic priority, static priority must be zero. For real-time 2612 // applications, Bsd supports SCHED_RR which allows static priority (1-99). 2613 // However, for large multi-threaded applications, SCHED_RR is not only slower 2614 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 2615 // of 5 runs - Sep 2005). 2616 // 2617 // The following code actually changes the niceness of kernel-thread/LWP. It 2618 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 2619 // not the entire user process, and user level threads are 1:1 mapped to kernel 2620 // threads. It has always been the case, but could change in the future. For 2621 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 2622 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 2623 2624 #if !defined(__APPLE__) 2625 int os::java_to_os_priority[CriticalPriority + 1] = { 2626 19, // 0 Entry should never be used 2627 2628 0, // 1 MinPriority 2629 3, // 2 2630 6, // 3 2631 2632 10, // 4 2633 15, // 5 NormPriority 2634 18, // 6 2635 2636 21, // 7 2637 25, // 8 2638 28, // 9 NearMaxPriority 2639 2640 31, // 10 MaxPriority 2641 2642 31 // 11 CriticalPriority 2643 }; 2644 #else 2645 // Using Mach high-level priority assignments 2646 int os::java_to_os_priority[CriticalPriority + 1] = { 2647 0, // 0 Entry should never be used (MINPRI_USER) 2648 2649 27, // 1 MinPriority 2650 28, // 2 2651 29, // 3 2652 2653 30, // 4 2654 31, // 5 NormPriority (BASEPRI_DEFAULT) 2655 32, // 6 2656 2657 33, // 7 2658 34, // 8 2659 35, // 9 NearMaxPriority 2660 2661 36, // 10 MaxPriority 2662 2663 36 // 11 CriticalPriority 2664 }; 2665 #endif 2666 2667 static int prio_init() { 2668 if (ThreadPriorityPolicy == 1) { 2669 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 2670 // if effective uid is not root. Perhaps, a more elegant way of doing 2671 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 2672 if (geteuid() != 0) { 2673 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 2674 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); 2675 } 2676 ThreadPriorityPolicy = 0; 2677 } 2678 } 2679 if (UseCriticalJavaThreadPriority) { 2680 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 2681 } 2682 return 0; 2683 } 2684 2685 OSReturn os::set_native_priority(Thread* thread, int newpri) { 2686 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 2687 2688 #ifdef __OpenBSD__ 2689 // OpenBSD pthread_setprio starves low priority threads 2690 return OS_OK; 2691 #elif defined(__FreeBSD__) 2692 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); 2693 #elif defined(__APPLE__) || defined(__NetBSD__) 2694 struct sched_param sp; 2695 int policy; 2696 pthread_t self = pthread_self(); 2697 2698 if (pthread_getschedparam(self, &policy, &sp) != 0) { 2699 return OS_ERR; 2700 } 2701 2702 sp.sched_priority = newpri; 2703 if (pthread_setschedparam(self, policy, &sp) != 0) { 2704 return OS_ERR; 2705 } 2706 2707 return OS_OK; 2708 #else 2709 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 2710 return (ret == 0) ? OS_OK : OS_ERR; 2711 #endif 2712 } 2713 2714 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { 2715 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 2716 *priority_ptr = java_to_os_priority[NormPriority]; 2717 return OS_OK; 2718 } 2719 2720 errno = 0; 2721 #if defined(__OpenBSD__) || defined(__FreeBSD__) 2722 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); 2723 #elif defined(__APPLE__) || defined(__NetBSD__) 2724 int policy; 2725 struct sched_param sp; 2726 2727 pthread_getschedparam(pthread_self(), &policy, &sp); 2728 *priority_ptr = sp.sched_priority; 2729 #else 2730 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 2731 #endif 2732 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 2733 } 2734 2735 // Hint to the underlying OS that a task switch would not be good. 2736 // Void return because it's a hint and can fail. 2737 void os::hint_no_preempt() {} 2738 2739 //////////////////////////////////////////////////////////////////////////////// 2740 // suspend/resume support 2741 2742 // the low-level signal-based suspend/resume support is a remnant from the 2743 // old VM-suspension that used to be for java-suspension, safepoints etc, 2744 // within hotspot. Now there is a single use-case for this: 2745 // - calling get_thread_pc() on the VMThread by the flat-profiler task 2746 // that runs in the watcher thread. 2747 // The remaining code is greatly simplified from the more general suspension 2748 // code that used to be used. 2749 // 2750 // The protocol is quite simple: 2751 // - suspend: 2752 // - sends a signal to the target thread 2753 // - polls the suspend state of the osthread using a yield loop 2754 // - target thread signal handler (SR_handler) sets suspend state 2755 // and blocks in sigsuspend until continued 2756 // - resume: 2757 // - sets target osthread state to continue 2758 // - sends signal to end the sigsuspend loop in the SR_handler 2759 // 2760 // Note that the SR_lock plays no role in this suspend/resume protocol. 2761 2762 static void resume_clear_context(OSThread *osthread) { 2763 osthread->set_ucontext(NULL); 2764 osthread->set_siginfo(NULL); 2765 } 2766 2767 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { 2768 osthread->set_ucontext(context); 2769 osthread->set_siginfo(siginfo); 2770 } 2771 2772 // Handler function invoked when a thread's execution is suspended or 2773 // resumed. We have to be careful that only async-safe functions are 2774 // called here (Note: most pthread functions are not async safe and 2775 // should be avoided.) 2776 // 2777 // Note: sigwait() is a more natural fit than sigsuspend() from an 2778 // interface point of view, but sigwait() prevents the signal hander 2779 // from being run. libpthread would get very confused by not having 2780 // its signal handlers run and prevents sigwait()'s use with the 2781 // mutex granting granting signal. 2782 // 2783 // Currently only ever called on the VMThread or JavaThread 2784 // 2785 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 2786 // Save and restore errno to avoid confusing native code with EINTR 2787 // after sigsuspend. 2788 int old_errno = errno; 2789 2790 Thread* thread = Thread::current(); 2791 OSThread* osthread = thread->osthread(); 2792 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 2793 2794 os::SuspendResume::State current = osthread->sr.state(); 2795 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 2796 suspend_save_context(osthread, siginfo, context); 2797 2798 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 2799 os::SuspendResume::State state = osthread->sr.suspended(); 2800 if (state == os::SuspendResume::SR_SUSPENDED) { 2801 sigset_t suspend_set; // signals for sigsuspend() 2802 2803 // get current set of blocked signals and unblock resume signal 2804 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 2805 sigdelset(&suspend_set, SR_signum); 2806 2807 sr_semaphore.signal(); 2808 // wait here until we are resumed 2809 while (1) { 2810 sigsuspend(&suspend_set); 2811 2812 os::SuspendResume::State result = osthread->sr.running(); 2813 if (result == os::SuspendResume::SR_RUNNING) { 2814 sr_semaphore.signal(); 2815 break; 2816 } else if (result != os::SuspendResume::SR_SUSPENDED) { 2817 ShouldNotReachHere(); 2818 } 2819 } 2820 2821 } else if (state == os::SuspendResume::SR_RUNNING) { 2822 // request was cancelled, continue 2823 } else { 2824 ShouldNotReachHere(); 2825 } 2826 2827 resume_clear_context(osthread); 2828 } else if (current == os::SuspendResume::SR_RUNNING) { 2829 // request was cancelled, continue 2830 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 2831 // ignore 2832 } else { 2833 // ignore 2834 } 2835 2836 errno = old_errno; 2837 } 2838 2839 2840 static int SR_initialize() { 2841 struct sigaction act; 2842 char *s; 2843 // Get signal number to use for suspend/resume 2844 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 2845 int sig = ::strtol(s, 0, 10); 2846 if (sig > 0 || sig < NSIG) { 2847 SR_signum = sig; 2848 } 2849 } 2850 2851 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 2852 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 2853 2854 sigemptyset(&SR_sigset); 2855 sigaddset(&SR_sigset, SR_signum); 2856 2857 // Set up signal handler for suspend/resume 2858 act.sa_flags = SA_RESTART|SA_SIGINFO; 2859 act.sa_handler = (void (*)(int)) SR_handler; 2860 2861 // SR_signum is blocked by default. 2862 // 4528190 - We also need to block pthread restart signal (32 on all 2863 // supported Bsd platforms). Note that BsdThreads need to block 2864 // this signal for all threads to work properly. So we don't have 2865 // to use hard-coded signal number when setting up the mask. 2866 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 2867 2868 if (sigaction(SR_signum, &act, 0) == -1) { 2869 return -1; 2870 } 2871 2872 // Save signal flag 2873 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); 2874 return 0; 2875 } 2876 2877 static int sr_notify(OSThread* osthread) { 2878 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2879 assert_status(status == 0, status, "pthread_kill"); 2880 return status; 2881 } 2882 2883 // "Randomly" selected value for how long we want to spin 2884 // before bailing out on suspending a thread, also how often 2885 // we send a signal to a thread we want to resume 2886 static const int RANDOMLY_LARGE_INTEGER = 1000000; 2887 static const int RANDOMLY_LARGE_INTEGER2 = 100; 2888 2889 // returns true on success and false on error - really an error is fatal 2890 // but this seems the normal response to library errors 2891 static bool do_suspend(OSThread* osthread) { 2892 assert(osthread->sr.is_running(), "thread should be running"); 2893 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 2894 2895 // mark as suspended and send signal 2896 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 2897 // failed to switch, state wasn't running? 2898 ShouldNotReachHere(); 2899 return false; 2900 } 2901 2902 if (sr_notify(osthread) != 0) { 2903 ShouldNotReachHere(); 2904 } 2905 2906 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 2907 while (true) { 2908 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2909 break; 2910 } else { 2911 // timeout 2912 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 2913 if (cancelled == os::SuspendResume::SR_RUNNING) { 2914 return false; 2915 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 2916 // make sure that we consume the signal on the semaphore as well 2917 sr_semaphore.wait(); 2918 break; 2919 } else { 2920 ShouldNotReachHere(); 2921 return false; 2922 } 2923 } 2924 } 2925 2926 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 2927 return true; 2928 } 2929 2930 static void do_resume(OSThread* osthread) { 2931 assert(osthread->sr.is_suspended(), "thread should be suspended"); 2932 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 2933 2934 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 2935 // failed to switch to WAKEUP_REQUEST 2936 ShouldNotReachHere(); 2937 return; 2938 } 2939 2940 while (true) { 2941 if (sr_notify(osthread) == 0) { 2942 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2943 if (osthread->sr.is_running()) { 2944 return; 2945 } 2946 } 2947 } else { 2948 ShouldNotReachHere(); 2949 } 2950 } 2951 2952 guarantee(osthread->sr.is_running(), "Must be running!"); 2953 } 2954 2955 /////////////////////////////////////////////////////////////////////////////////// 2956 // signal handling (except suspend/resume) 2957 2958 // This routine may be used by user applications as a "hook" to catch signals. 2959 // The user-defined signal handler must pass unrecognized signals to this 2960 // routine, and if it returns true (non-zero), then the signal handler must 2961 // return immediately. If the flag "abort_if_unrecognized" is true, then this 2962 // routine will never retun false (zero), but instead will execute a VM panic 2963 // routine kill the process. 2964 // 2965 // If this routine returns false, it is OK to call it again. This allows 2966 // the user-defined signal handler to perform checks either before or after 2967 // the VM performs its own checks. Naturally, the user code would be making 2968 // a serious error if it tried to handle an exception (such as a null check 2969 // or breakpoint) that the VM was generating for its own correct operation. 2970 // 2971 // This routine may recognize any of the following kinds of signals: 2972 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 2973 // It should be consulted by handlers for any of those signals. 2974 // 2975 // The caller of this routine must pass in the three arguments supplied 2976 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 2977 // field of the structure passed to sigaction(). This routine assumes that 2978 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 2979 // 2980 // Note that the VM will print warnings if it detects conflicting signal 2981 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 2982 // 2983 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, 2984 void* ucontext, 2985 int abort_if_unrecognized); 2986 2987 void signalHandler(int sig, siginfo_t* info, void* uc) { 2988 assert(info != NULL && uc != NULL, "it must be old kernel"); 2989 int orig_errno = errno; // Preserve errno value over signal handler. 2990 JVM_handle_bsd_signal(sig, info, uc, true); 2991 errno = orig_errno; 2992 } 2993 2994 2995 // This boolean allows users to forward their own non-matching signals 2996 // to JVM_handle_bsd_signal, harmlessly. 2997 bool os::Bsd::signal_handlers_are_installed = false; 2998 2999 // For signal-chaining 3000 struct sigaction os::Bsd::sigact[MAXSIGNUM]; 3001 unsigned int os::Bsd::sigs = 0; 3002 bool os::Bsd::libjsig_is_loaded = false; 3003 typedef struct sigaction *(*get_signal_t)(int); 3004 get_signal_t os::Bsd::get_signal_action = NULL; 3005 3006 struct sigaction* os::Bsd::get_chained_signal_action(int sig) { 3007 struct sigaction *actp = NULL; 3008 3009 if (libjsig_is_loaded) { 3010 // Retrieve the old signal handler from libjsig 3011 actp = (*get_signal_action)(sig); 3012 } 3013 if (actp == NULL) { 3014 // Retrieve the preinstalled signal handler from jvm 3015 actp = get_preinstalled_handler(sig); 3016 } 3017 3018 return actp; 3019 } 3020 3021 static bool call_chained_handler(struct sigaction *actp, int sig, 3022 siginfo_t *siginfo, void *context) { 3023 // Call the old signal handler 3024 if (actp->sa_handler == SIG_DFL) { 3025 // It's more reasonable to let jvm treat it as an unexpected exception 3026 // instead of taking the default action. 3027 return false; 3028 } else if (actp->sa_handler != SIG_IGN) { 3029 if ((actp->sa_flags & SA_NODEFER) == 0) { 3030 // automaticlly block the signal 3031 sigaddset(&(actp->sa_mask), sig); 3032 } 3033 3034 sa_handler_t hand; 3035 sa_sigaction_t sa; 3036 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 3037 // retrieve the chained handler 3038 if (siginfo_flag_set) { 3039 sa = actp->sa_sigaction; 3040 } else { 3041 hand = actp->sa_handler; 3042 } 3043 3044 if ((actp->sa_flags & SA_RESETHAND) != 0) { 3045 actp->sa_handler = SIG_DFL; 3046 } 3047 3048 // try to honor the signal mask 3049 sigset_t oset; 3050 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 3051 3052 // call into the chained handler 3053 if (siginfo_flag_set) { 3054 (*sa)(sig, siginfo, context); 3055 } else { 3056 (*hand)(sig); 3057 } 3058 3059 // restore the signal mask 3060 pthread_sigmask(SIG_SETMASK, &oset, 0); 3061 } 3062 // Tell jvm's signal handler the signal is taken care of. 3063 return true; 3064 } 3065 3066 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { 3067 bool chained = false; 3068 // signal-chaining 3069 if (UseSignalChaining) { 3070 struct sigaction *actp = get_chained_signal_action(sig); 3071 if (actp != NULL) { 3072 chained = call_chained_handler(actp, sig, siginfo, context); 3073 } 3074 } 3075 return chained; 3076 } 3077 3078 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { 3079 if ((((unsigned int)1 << sig) & sigs) != 0) { 3080 return &sigact[sig]; 3081 } 3082 return NULL; 3083 } 3084 3085 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 3086 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3087 sigact[sig] = oldAct; 3088 sigs |= (unsigned int)1 << sig; 3089 } 3090 3091 // for diagnostic 3092 int os::Bsd::sigflags[MAXSIGNUM]; 3093 3094 int os::Bsd::get_our_sigflags(int sig) { 3095 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3096 return sigflags[sig]; 3097 } 3098 3099 void os::Bsd::set_our_sigflags(int sig, int flags) { 3100 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3101 sigflags[sig] = flags; 3102 } 3103 3104 void os::Bsd::set_signal_handler(int sig, bool set_installed) { 3105 // Check for overwrite. 3106 struct sigaction oldAct; 3107 sigaction(sig, (struct sigaction*)NULL, &oldAct); 3108 3109 void* oldhand = oldAct.sa_sigaction 3110 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3111 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3112 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 3113 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 3114 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 3115 if (AllowUserSignalHandlers || !set_installed) { 3116 // Do not overwrite; user takes responsibility to forward to us. 3117 return; 3118 } else if (UseSignalChaining) { 3119 // save the old handler in jvm 3120 save_preinstalled_handler(sig, oldAct); 3121 // libjsig also interposes the sigaction() call below and saves the 3122 // old sigaction on it own. 3123 } else { 3124 fatal(err_msg("Encountered unexpected pre-existing sigaction handler " 3125 "%#lx for signal %d.", (long)oldhand, sig)); 3126 } 3127 } 3128 3129 struct sigaction sigAct; 3130 sigfillset(&(sigAct.sa_mask)); 3131 sigAct.sa_handler = SIG_DFL; 3132 if (!set_installed) { 3133 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3134 } else { 3135 sigAct.sa_sigaction = signalHandler; 3136 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3137 } 3138 #ifdef __APPLE__ 3139 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV 3140 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages" 3141 // if the signal handler declares it will handle it on alternate stack. 3142 // Notice we only declare we will handle it on alt stack, but we are not 3143 // actually going to use real alt stack - this is just a workaround. 3144 // Please see ux_exception.c, method catch_mach_exception_raise for details 3145 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c 3146 if (sig == SIGSEGV) { 3147 sigAct.sa_flags |= SA_ONSTACK; 3148 } 3149 #endif 3150 3151 // Save flags, which are set by ours 3152 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3153 sigflags[sig] = sigAct.sa_flags; 3154 3155 int ret = sigaction(sig, &sigAct, &oldAct); 3156 assert(ret == 0, "check"); 3157 3158 void* oldhand2 = oldAct.sa_sigaction 3159 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3160 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3161 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 3162 } 3163 3164 // install signal handlers for signals that HotSpot needs to 3165 // handle in order to support Java-level exception handling. 3166 3167 void os::Bsd::install_signal_handlers() { 3168 if (!signal_handlers_are_installed) { 3169 signal_handlers_are_installed = true; 3170 3171 // signal-chaining 3172 typedef void (*signal_setting_t)(); 3173 signal_setting_t begin_signal_setting = NULL; 3174 signal_setting_t end_signal_setting = NULL; 3175 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3176 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 3177 if (begin_signal_setting != NULL) { 3178 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3179 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 3180 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 3181 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 3182 libjsig_is_loaded = true; 3183 assert(UseSignalChaining, "should enable signal-chaining"); 3184 } 3185 if (libjsig_is_loaded) { 3186 // Tell libjsig jvm is setting signal handlers 3187 (*begin_signal_setting)(); 3188 } 3189 3190 set_signal_handler(SIGSEGV, true); 3191 set_signal_handler(SIGPIPE, true); 3192 set_signal_handler(SIGBUS, true); 3193 set_signal_handler(SIGILL, true); 3194 set_signal_handler(SIGFPE, true); 3195 set_signal_handler(SIGXFSZ, true); 3196 3197 #if defined(__APPLE__) 3198 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including 3199 // signals caught and handled by the JVM. To work around this, we reset the mach task 3200 // signal handler that's placed on our process by CrashReporter. This disables 3201 // CrashReporter-based reporting. 3202 // 3203 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes 3204 // on caught fatal signals. 3205 // 3206 // Additionally, gdb installs both standard BSD signal handlers, and mach exception 3207 // handlers. By replacing the existing task exception handler, we disable gdb's mach 3208 // exception handling, while leaving the standard BSD signal handlers functional. 3209 kern_return_t kr; 3210 kr = task_set_exception_ports(mach_task_self(), 3211 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, 3212 MACH_PORT_NULL, 3213 EXCEPTION_STATE_IDENTITY, 3214 MACHINE_THREAD_STATE); 3215 3216 assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); 3217 #endif 3218 3219 if (libjsig_is_loaded) { 3220 // Tell libjsig jvm finishes setting signal handlers 3221 (*end_signal_setting)(); 3222 } 3223 3224 // We don't activate signal checker if libjsig is in place, we trust ourselves 3225 // and if UserSignalHandler is installed all bets are off 3226 if (CheckJNICalls) { 3227 if (libjsig_is_loaded) { 3228 if (PrintJNIResolving) { 3229 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 3230 } 3231 check_signals = false; 3232 } 3233 if (AllowUserSignalHandlers) { 3234 if (PrintJNIResolving) { 3235 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 3236 } 3237 check_signals = false; 3238 } 3239 } 3240 } 3241 } 3242 3243 3244 ///// 3245 // glibc on Bsd platform uses non-documented flag 3246 // to indicate, that some special sort of signal 3247 // trampoline is used. 3248 // We will never set this flag, and we should 3249 // ignore this flag in our diagnostic 3250 #ifdef SIGNIFICANT_SIGNAL_MASK 3251 #undef SIGNIFICANT_SIGNAL_MASK 3252 #endif 3253 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 3254 3255 static const char* get_signal_handler_name(address handler, 3256 char* buf, int buflen) { 3257 int offset; 3258 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 3259 if (found) { 3260 // skip directory names 3261 const char *p1, *p2; 3262 p1 = buf; 3263 size_t len = strlen(os::file_separator()); 3264 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 3265 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 3266 } else { 3267 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 3268 } 3269 return buf; 3270 } 3271 3272 static void print_signal_handler(outputStream* st, int sig, 3273 char* buf, size_t buflen) { 3274 struct sigaction sa; 3275 3276 sigaction(sig, NULL, &sa); 3277 3278 // See comment for SIGNIFICANT_SIGNAL_MASK define 3279 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3280 3281 st->print("%s: ", os::exception_name(sig, buf, buflen)); 3282 3283 address handler = (sa.sa_flags & SA_SIGINFO) 3284 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 3285 : CAST_FROM_FN_PTR(address, sa.sa_handler); 3286 3287 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 3288 st->print("SIG_DFL"); 3289 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 3290 st->print("SIG_IGN"); 3291 } else { 3292 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 3293 } 3294 3295 st->print(", sa_mask[0]="); 3296 os::Posix::print_signal_set_short(st, &sa.sa_mask); 3297 3298 address rh = VMError::get_resetted_sighandler(sig); 3299 // May be, handler was resetted by VMError? 3300 if (rh != NULL) { 3301 handler = rh; 3302 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 3303 } 3304 3305 st->print(", sa_flags="); 3306 os::Posix::print_sa_flags(st, sa.sa_flags); 3307 3308 // Check: is it our handler? 3309 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 3310 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 3311 // It is our signal handler 3312 // check for flags, reset system-used one! 3313 if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3314 st->print( 3315 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 3316 os::Bsd::get_our_sigflags(sig)); 3317 } 3318 } 3319 st->cr(); 3320 } 3321 3322 3323 #define DO_SIGNAL_CHECK(sig) \ 3324 do { \ 3325 if (!sigismember(&check_signal_done, sig)) { \ 3326 os::Bsd::check_signal_handler(sig); \ 3327 } \ 3328 } while (0) 3329 3330 // This method is a periodic task to check for misbehaving JNI applications 3331 // under CheckJNI, we can add any periodic checks here 3332 3333 void os::run_periodic_checks() { 3334 3335 if (check_signals == false) return; 3336 3337 // SEGV and BUS if overridden could potentially prevent 3338 // generation of hs*.log in the event of a crash, debugging 3339 // such a case can be very challenging, so we absolutely 3340 // check the following for a good measure: 3341 DO_SIGNAL_CHECK(SIGSEGV); 3342 DO_SIGNAL_CHECK(SIGILL); 3343 DO_SIGNAL_CHECK(SIGFPE); 3344 DO_SIGNAL_CHECK(SIGBUS); 3345 DO_SIGNAL_CHECK(SIGPIPE); 3346 DO_SIGNAL_CHECK(SIGXFSZ); 3347 3348 3349 // ReduceSignalUsage allows the user to override these handlers 3350 // see comments at the very top and jvm_solaris.h 3351 if (!ReduceSignalUsage) { 3352 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 3353 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 3354 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 3355 DO_SIGNAL_CHECK(BREAK_SIGNAL); 3356 } 3357 3358 DO_SIGNAL_CHECK(SR_signum); 3359 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); 3360 } 3361 3362 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 3363 3364 static os_sigaction_t os_sigaction = NULL; 3365 3366 void os::Bsd::check_signal_handler(int sig) { 3367 char buf[O_BUFLEN]; 3368 address jvmHandler = NULL; 3369 3370 3371 struct sigaction act; 3372 if (os_sigaction == NULL) { 3373 // only trust the default sigaction, in case it has been interposed 3374 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 3375 if (os_sigaction == NULL) return; 3376 } 3377 3378 os_sigaction(sig, (struct sigaction*)NULL, &act); 3379 3380 3381 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3382 3383 address thisHandler = (act.sa_flags & SA_SIGINFO) 3384 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 3385 : CAST_FROM_FN_PTR(address, act.sa_handler); 3386 3387 3388 switch (sig) { 3389 case SIGSEGV: 3390 case SIGBUS: 3391 case SIGFPE: 3392 case SIGPIPE: 3393 case SIGILL: 3394 case SIGXFSZ: 3395 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 3396 break; 3397 3398 case SHUTDOWN1_SIGNAL: 3399 case SHUTDOWN2_SIGNAL: 3400 case SHUTDOWN3_SIGNAL: 3401 case BREAK_SIGNAL: 3402 jvmHandler = (address)user_handler(); 3403 break; 3404 3405 case INTERRUPT_SIGNAL: 3406 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); 3407 break; 3408 3409 default: 3410 if (sig == SR_signum) { 3411 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 3412 } else { 3413 return; 3414 } 3415 break; 3416 } 3417 3418 if (thisHandler != jvmHandler) { 3419 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 3420 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 3421 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 3422 // No need to check this sig any longer 3423 sigaddset(&check_signal_done, sig); 3424 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 3425 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 3426 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 3427 exception_name(sig, buf, O_BUFLEN)); 3428 } 3429 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3430 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 3431 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); 3432 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); 3433 // No need to check this sig any longer 3434 sigaddset(&check_signal_done, sig); 3435 } 3436 3437 // Dump all the signal 3438 if (sigismember(&check_signal_done, sig)) { 3439 print_signal_handlers(tty, buf, O_BUFLEN); 3440 } 3441 } 3442 3443 extern void report_error(char* file_name, int line_no, char* title, 3444 char* format, ...); 3445 3446 extern bool signal_name(int signo, char* buf, size_t len); 3447 3448 const char* os::exception_name(int exception_code, char* buf, size_t size) { 3449 if (0 < exception_code && exception_code <= SIGRTMAX) { 3450 // signal 3451 if (!signal_name(exception_code, buf, size)) { 3452 jio_snprintf(buf, size, "SIG%d", exception_code); 3453 } 3454 return buf; 3455 } else { 3456 return NULL; 3457 } 3458 } 3459 3460 // this is called _before_ the most of global arguments have been parsed 3461 void os::init(void) { 3462 char dummy; // used to get a guess on initial stack address 3463 // first_hrtime = gethrtime(); 3464 3465 // With BsdThreads the JavaMain thread pid (primordial thread) 3466 // is different than the pid of the java launcher thread. 3467 // So, on Bsd, the launcher thread pid is passed to the VM 3468 // via the sun.java.launcher.pid property. 3469 // Use this property instead of getpid() if it was correctly passed. 3470 // See bug 6351349. 3471 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); 3472 3473 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); 3474 3475 clock_tics_per_sec = CLK_TCK; 3476 3477 init_random(1234567); 3478 3479 ThreadCritical::initialize(); 3480 3481 Bsd::set_page_size(getpagesize()); 3482 if (Bsd::page_size() == -1) { 3483 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)", 3484 strerror(errno))); 3485 } 3486 init_page_sizes((size_t) Bsd::page_size()); 3487 3488 Bsd::initialize_system_info(); 3489 3490 // main_thread points to the aboriginal thread 3491 Bsd::_main_thread = pthread_self(); 3492 3493 Bsd::clock_init(); 3494 initial_time_count = javaTimeNanos(); 3495 3496 #ifdef __APPLE__ 3497 // XXXDARWIN 3498 // Work around the unaligned VM callbacks in hotspot's 3499 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on 3500 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces 3501 // alignment when doing symbol lookup. To work around this, we force early 3502 // binding of all symbols now, thus binding when alignment is known-good. 3503 _dyld_bind_fully_image_containing_address((const void *) &os::init); 3504 #endif 3505 } 3506 3507 // To install functions for atexit system call 3508 extern "C" { 3509 static void perfMemory_exit_helper() { 3510 perfMemory_exit(); 3511 } 3512 } 3513 3514 // this is called _after_ the global arguments have been parsed 3515 jint os::init_2(void) { 3516 // Allocate a single page and mark it as readable for safepoint polling 3517 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3518 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page"); 3519 3520 os::set_polling_page(polling_page); 3521 3522 #ifndef PRODUCT 3523 if (Verbose && PrintMiscellaneous) { 3524 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", 3525 (intptr_t)polling_page); 3526 } 3527 #endif 3528 3529 if (!UseMembar) { 3530 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3531 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 3532 os::set_memory_serialize_page(mem_serialize_page); 3533 3534 #ifndef PRODUCT 3535 if (Verbose && PrintMiscellaneous) { 3536 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", 3537 (intptr_t)mem_serialize_page); 3538 } 3539 #endif 3540 } 3541 3542 // initialize suspend/resume support - must do this before signal_sets_init() 3543 if (SR_initialize() != 0) { 3544 perror("SR_initialize failed"); 3545 return JNI_ERR; 3546 } 3547 3548 Bsd::signal_sets_init(); 3549 Bsd::install_signal_handlers(); 3550 3551 // Check minimum allowable stack size for thread creation and to initialize 3552 // the java system classes, including StackOverflowError - depends on page 3553 // size. Add a page for compiler2 recursion in main thread. 3554 // Add in 2*BytesPerWord times page size to account for VM stack during 3555 // class initialization depending on 32 or 64 bit VM. 3556 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, 3557 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ 3558 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); 3559 3560 size_t threadStackSizeInBytes = ThreadStackSize * K; 3561 if (threadStackSizeInBytes != 0 && 3562 threadStackSizeInBytes < os::Bsd::min_stack_allowed) { 3563 tty->print_cr("\nThe stack size specified is too small, " 3564 "Specify at least %dk", 3565 os::Bsd::min_stack_allowed/ K); 3566 return JNI_ERR; 3567 } 3568 3569 // Make the stack size a multiple of the page size so that 3570 // the yellow/red zones can be guarded. 3571 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 3572 vm_page_size())); 3573 3574 if (MaxFDLimit) { 3575 // set the number of file descriptors to max. print out error 3576 // if getrlimit/setrlimit fails but continue regardless. 3577 struct rlimit nbr_files; 3578 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 3579 if (status != 0) { 3580 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3581 perror("os::init_2 getrlimit failed"); 3582 } 3583 } else { 3584 nbr_files.rlim_cur = nbr_files.rlim_max; 3585 3586 #ifdef __APPLE__ 3587 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if 3588 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must 3589 // be used instead 3590 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); 3591 #endif 3592 3593 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 3594 if (status != 0) { 3595 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3596 perror("os::init_2 setrlimit failed"); 3597 } 3598 } 3599 } 3600 } 3601 3602 // at-exit methods are called in the reverse order of their registration. 3603 // atexit functions are called on return from main or as a result of a 3604 // call to exit(3C). There can be only 32 of these functions registered 3605 // and atexit() does not set errno. 3606 3607 if (PerfAllowAtExitRegistration) { 3608 // only register atexit functions if PerfAllowAtExitRegistration is set. 3609 // atexit functions can be delayed until process exit time, which 3610 // can be problematic for embedded VM situations. Embedded VMs should 3611 // call DestroyJavaVM() to assure that VM resources are released. 3612 3613 // note: perfMemory_exit_helper atexit function may be removed in 3614 // the future if the appropriate cleanup code can be added to the 3615 // VM_Exit VMOperation's doit method. 3616 if (atexit(perfMemory_exit_helper) != 0) { 3617 warning("os::init2 atexit(perfMemory_exit_helper) failed"); 3618 } 3619 } 3620 3621 // initialize thread priority policy 3622 prio_init(); 3623 3624 #ifdef __APPLE__ 3625 // dynamically link to objective c gc registration 3626 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY); 3627 if (handleLibObjc != NULL) { 3628 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER); 3629 } 3630 #endif 3631 3632 return JNI_OK; 3633 } 3634 3635 // Mark the polling page as unreadable 3636 void os::make_polling_page_unreadable(void) { 3637 if (!guard_memory((char*)_polling_page, Bsd::page_size())) { 3638 fatal("Could not disable polling page"); 3639 } 3640 } 3641 3642 // Mark the polling page as readable 3643 void os::make_polling_page_readable(void) { 3644 if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { 3645 fatal("Could not enable polling page"); 3646 } 3647 } 3648 3649 int os::active_processor_count() { 3650 return _processor_count; 3651 } 3652 3653 void os::set_native_thread_name(const char *name) { 3654 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5 3655 // This is only supported in Snow Leopard and beyond 3656 if (name != NULL) { 3657 // Add a "Java: " prefix to the name 3658 char buf[MAXTHREADNAMESIZE]; 3659 snprintf(buf, sizeof(buf), "Java: %s", name); 3660 pthread_setname_np(buf); 3661 } 3662 #endif 3663 } 3664 3665 bool os::distribute_processes(uint length, uint* distribution) { 3666 // Not yet implemented. 3667 return false; 3668 } 3669 3670 bool os::bind_to_processor(uint processor_id) { 3671 // Not yet implemented. 3672 return false; 3673 } 3674 3675 void os::SuspendedThreadTask::internal_do_task() { 3676 if (do_suspend(_thread->osthread())) { 3677 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 3678 do_task(context); 3679 do_resume(_thread->osthread()); 3680 } 3681 } 3682 3683 /// 3684 class PcFetcher : public os::SuspendedThreadTask { 3685 public: 3686 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 3687 ExtendedPC result(); 3688 protected: 3689 void do_task(const os::SuspendedThreadTaskContext& context); 3690 private: 3691 ExtendedPC _epc; 3692 }; 3693 3694 ExtendedPC PcFetcher::result() { 3695 guarantee(is_done(), "task is not done yet."); 3696 return _epc; 3697 } 3698 3699 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 3700 Thread* thread = context.thread(); 3701 OSThread* osthread = thread->osthread(); 3702 if (osthread->ucontext() != NULL) { 3703 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext()); 3704 } else { 3705 // NULL context is unexpected, double-check this is the VMThread 3706 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 3707 } 3708 } 3709 3710 // Suspends the target using the signal mechanism and then grabs the PC before 3711 // resuming the target. Used by the flat-profiler only 3712 ExtendedPC os::get_thread_pc(Thread* thread) { 3713 // Make sure that it is called by the watcher for the VMThread 3714 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 3715 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 3716 3717 PcFetcher fetcher(thread); 3718 fetcher.run(); 3719 return fetcher.result(); 3720 } 3721 3722 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, 3723 pthread_mutex_t *_mutex, 3724 const struct timespec *_abstime) { 3725 return pthread_cond_timedwait(_cond, _mutex, _abstime); 3726 } 3727 3728 //////////////////////////////////////////////////////////////////////////////// 3729 // debug support 3730 3731 bool os::find(address addr, outputStream* st) { 3732 Dl_info dlinfo; 3733 memset(&dlinfo, 0, sizeof(dlinfo)); 3734 if (dladdr(addr, &dlinfo) != 0) { 3735 st->print(PTR_FORMAT ": ", addr); 3736 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 3737 st->print("%s+%#x", dlinfo.dli_sname, 3738 addr - (intptr_t)dlinfo.dli_saddr); 3739 } else if (dlinfo.dli_fbase != NULL) { 3740 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); 3741 } else { 3742 st->print("<absolute address>"); 3743 } 3744 if (dlinfo.dli_fname != NULL) { 3745 st->print(" in %s", dlinfo.dli_fname); 3746 } 3747 if (dlinfo.dli_fbase != NULL) { 3748 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); 3749 } 3750 st->cr(); 3751 3752 if (Verbose) { 3753 // decode some bytes around the PC 3754 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 3755 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 3756 address lowest = (address) dlinfo.dli_sname; 3757 if (!lowest) lowest = (address) dlinfo.dli_fbase; 3758 if (begin < lowest) begin = lowest; 3759 Dl_info dlinfo2; 3760 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 3761 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 3762 end = (address) dlinfo2.dli_saddr; 3763 } 3764 Disassembler::decode(begin, end, st); 3765 } 3766 return true; 3767 } 3768 return false; 3769 } 3770 3771 //////////////////////////////////////////////////////////////////////////////// 3772 // misc 3773 3774 // This does not do anything on Bsd. This is basically a hook for being 3775 // able to use structured exception handling (thread-local exception filters) 3776 // on, e.g., Win32. 3777 void os::os_exception_wrapper(java_call_t f, JavaValue* value, 3778 methodHandle* method, JavaCallArguments* args, 3779 Thread* thread) { 3780 f(value, method, args, thread); 3781 } 3782 3783 void os::print_statistics() { 3784 } 3785 3786 int os::message_box(const char* title, const char* message) { 3787 int i; 3788 fdStream err(defaultStream::error_fd()); 3789 for (i = 0; i < 78; i++) err.print_raw("="); 3790 err.cr(); 3791 err.print_raw_cr(title); 3792 for (i = 0; i < 78; i++) err.print_raw("-"); 3793 err.cr(); 3794 err.print_raw_cr(message); 3795 for (i = 0; i < 78; i++) err.print_raw("="); 3796 err.cr(); 3797 3798 char buf[16]; 3799 // Prevent process from exiting upon "read error" without consuming all CPU 3800 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 3801 3802 return buf[0] == 'y' || buf[0] == 'Y'; 3803 } 3804 3805 int os::stat(const char *path, struct stat *sbuf) { 3806 char pathbuf[MAX_PATH]; 3807 if (strlen(path) > MAX_PATH - 1) { 3808 errno = ENAMETOOLONG; 3809 return -1; 3810 } 3811 os::native_path(strcpy(pathbuf, path)); 3812 return ::stat(pathbuf, sbuf); 3813 } 3814 3815 bool os::check_heap(bool force) { 3816 return true; 3817 } 3818 3819 // Is a (classpath) directory empty? 3820 bool os::dir_is_empty(const char* path) { 3821 DIR *dir = NULL; 3822 struct dirent *ptr; 3823 3824 dir = opendir(path); 3825 if (dir == NULL) return true; 3826 3827 // Scan the directory 3828 bool result = true; 3829 char buf[sizeof(struct dirent) + MAX_PATH]; 3830 while (result && (ptr = ::readdir(dir)) != NULL) { 3831 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 3832 result = false; 3833 } 3834 } 3835 closedir(dir); 3836 return result; 3837 } 3838 3839 // This code originates from JDK's sysOpen and open64_w 3840 // from src/solaris/hpi/src/system_md.c 3841 3842 int os::open(const char *path, int oflag, int mode) { 3843 if (strlen(path) > MAX_PATH - 1) { 3844 errno = ENAMETOOLONG; 3845 return -1; 3846 } 3847 int fd; 3848 3849 fd = ::open(path, oflag, mode); 3850 if (fd == -1) return -1; 3851 3852 // If the open succeeded, the file might still be a directory 3853 { 3854 struct stat buf; 3855 int ret = ::fstat(fd, &buf); 3856 int st_mode = buf.st_mode; 3857 3858 if (ret != -1) { 3859 if ((st_mode & S_IFMT) == S_IFDIR) { 3860 errno = EISDIR; 3861 ::close(fd); 3862 return -1; 3863 } 3864 } else { 3865 ::close(fd); 3866 return -1; 3867 } 3868 } 3869 3870 // All file descriptors that are opened in the JVM and not 3871 // specifically destined for a subprocess should have the 3872 // close-on-exec flag set. If we don't set it, then careless 3rd 3873 // party native code might fork and exec without closing all 3874 // appropriate file descriptors (e.g. as we do in closeDescriptors in 3875 // UNIXProcess.c), and this in turn might: 3876 // 3877 // - cause end-of-file to fail to be detected on some file 3878 // descriptors, resulting in mysterious hangs, or 3879 // 3880 // - might cause an fopen in the subprocess to fail on a system 3881 // suffering from bug 1085341. 3882 // 3883 // (Yes, the default setting of the close-on-exec flag is a Unix 3884 // design flaw) 3885 // 3886 // See: 3887 // 1085341: 32-bit stdio routines should support file descriptors >255 3888 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 3889 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 3890 // 3891 #ifdef FD_CLOEXEC 3892 { 3893 int flags = ::fcntl(fd, F_GETFD); 3894 if (flags != -1) { 3895 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 3896 } 3897 } 3898 #endif 3899 3900 return fd; 3901 } 3902 3903 3904 // create binary file, rewriting existing file if required 3905 int os::create_binary_file(const char* path, bool rewrite_existing) { 3906 int oflags = O_WRONLY | O_CREAT; 3907 if (!rewrite_existing) { 3908 oflags |= O_EXCL; 3909 } 3910 return ::open(path, oflags, S_IREAD | S_IWRITE); 3911 } 3912 3913 // return current position of file pointer 3914 jlong os::current_file_offset(int fd) { 3915 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); 3916 } 3917 3918 // move file pointer to the specified offset 3919 jlong os::seek_to_file_offset(int fd, jlong offset) { 3920 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); 3921 } 3922 3923 // This code originates from JDK's sysAvailable 3924 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 3925 3926 int os::available(int fd, jlong *bytes) { 3927 jlong cur, end; 3928 int mode; 3929 struct stat buf; 3930 3931 if (::fstat(fd, &buf) >= 0) { 3932 mode = buf.st_mode; 3933 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 3934 // XXX: is the following call interruptible? If so, this might 3935 // need to go through the INTERRUPT_IO() wrapper as for other 3936 // blocking, interruptible calls in this file. 3937 int n; 3938 if (::ioctl(fd, FIONREAD, &n) >= 0) { 3939 *bytes = n; 3940 return 1; 3941 } 3942 } 3943 } 3944 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { 3945 return 0; 3946 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { 3947 return 0; 3948 } else if (::lseek(fd, cur, SEEK_SET) == -1) { 3949 return 0; 3950 } 3951 *bytes = end - cur; 3952 return 1; 3953 } 3954 3955 // Map a block of memory. 3956 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 3957 char *addr, size_t bytes, bool read_only, 3958 bool allow_exec) { 3959 int prot; 3960 int flags; 3961 3962 if (read_only) { 3963 prot = PROT_READ; 3964 flags = MAP_SHARED; 3965 } else { 3966 prot = PROT_READ | PROT_WRITE; 3967 flags = MAP_PRIVATE; 3968 } 3969 3970 if (allow_exec) { 3971 prot |= PROT_EXEC; 3972 } 3973 3974 if (addr != NULL) { 3975 flags |= MAP_FIXED; 3976 } 3977 3978 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 3979 fd, file_offset); 3980 if (mapped_address == MAP_FAILED) { 3981 return NULL; 3982 } 3983 return mapped_address; 3984 } 3985 3986 3987 // Remap a block of memory. 3988 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 3989 char *addr, size_t bytes, bool read_only, 3990 bool allow_exec) { 3991 // same as map_memory() on this OS 3992 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 3993 allow_exec); 3994 } 3995 3996 3997 // Unmap a block of memory. 3998 bool os::pd_unmap_memory(char* addr, size_t bytes) { 3999 return munmap(addr, bytes) == 0; 4000 } 4001 4002 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 4003 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 4004 // of a thread. 4005 // 4006 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 4007 // the fast estimate available on the platform. 4008 4009 jlong os::current_thread_cpu_time() { 4010 #ifdef __APPLE__ 4011 return os::thread_cpu_time(Thread::current(), true /* user + sys */); 4012 #else 4013 Unimplemented(); 4014 return 0; 4015 #endif 4016 } 4017 4018 jlong os::thread_cpu_time(Thread* thread) { 4019 #ifdef __APPLE__ 4020 return os::thread_cpu_time(thread, true /* user + sys */); 4021 #else 4022 Unimplemented(); 4023 return 0; 4024 #endif 4025 } 4026 4027 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 4028 #ifdef __APPLE__ 4029 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); 4030 #else 4031 Unimplemented(); 4032 return 0; 4033 #endif 4034 } 4035 4036 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 4037 #ifdef __APPLE__ 4038 struct thread_basic_info tinfo; 4039 mach_msg_type_number_t tcount = THREAD_INFO_MAX; 4040 kern_return_t kr; 4041 thread_t mach_thread; 4042 4043 mach_thread = thread->osthread()->thread_id(); 4044 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); 4045 if (kr != KERN_SUCCESS) { 4046 return -1; 4047 } 4048 4049 if (user_sys_cpu_time) { 4050 jlong nanos; 4051 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; 4052 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; 4053 return nanos; 4054 } else { 4055 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); 4056 } 4057 #else 4058 Unimplemented(); 4059 return 0; 4060 #endif 4061 } 4062 4063 4064 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4065 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4066 info_ptr->may_skip_backward = false; // elapsed time not wall time 4067 info_ptr->may_skip_forward = false; // elapsed time not wall time 4068 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4069 } 4070 4071 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4072 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4073 info_ptr->may_skip_backward = false; // elapsed time not wall time 4074 info_ptr->may_skip_forward = false; // elapsed time not wall time 4075 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4076 } 4077 4078 bool os::is_thread_cpu_time_supported() { 4079 #ifdef __APPLE__ 4080 return true; 4081 #else 4082 return false; 4083 #endif 4084 } 4085 4086 // System loadavg support. Returns -1 if load average cannot be obtained. 4087 // Bsd doesn't yet have a (official) notion of processor sets, 4088 // so just return the system wide load average. 4089 int os::loadavg(double loadavg[], int nelem) { 4090 return ::getloadavg(loadavg, nelem); 4091 } 4092 4093 void os::pause() { 4094 char filename[MAX_PATH]; 4095 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 4096 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); 4097 } else { 4098 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 4099 } 4100 4101 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 4102 if (fd != -1) { 4103 struct stat buf; 4104 ::close(fd); 4105 while (::stat(filename, &buf) == 0) { 4106 (void)::poll(NULL, 0, 100); 4107 } 4108 } else { 4109 jio_fprintf(stderr, 4110 "Could not open pause file '%s', continuing immediately.\n", filename); 4111 } 4112 } 4113 4114 4115 // Refer to the comments in os_solaris.cpp park-unpark. The next two 4116 // comment paragraphs are worth repeating here: 4117 // 4118 // Assumption: 4119 // Only one parker can exist on an event, which is why we allocate 4120 // them per-thread. Multiple unparkers can coexist. 4121 // 4122 // _Event serves as a restricted-range semaphore. 4123 // -1 : thread is blocked, i.e. there is a waiter 4124 // 0 : neutral: thread is running or ready, 4125 // could have been signaled after a wait started 4126 // 1 : signaled - thread is running or ready 4127 // 4128 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 4129 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 4130 // For specifics regarding the bug see GLIBC BUGID 261237 : 4131 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 4132 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 4133 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 4134 // is used. (The simple C test-case provided in the GLIBC bug report manifests the 4135 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 4136 // and monitorenter when we're using 1-0 locking. All those operations may result in 4137 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 4138 // of libpthread avoids the problem, but isn't practical. 4139 // 4140 // Possible remedies: 4141 // 4142 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 4143 // This is palliative and probabilistic, however. If the thread is preempted 4144 // between the call to compute_abstime() and pthread_cond_timedwait(), more 4145 // than the minimum period may have passed, and the abstime may be stale (in the 4146 // past) resultin in a hang. Using this technique reduces the odds of a hang 4147 // but the JVM is still vulnerable, particularly on heavily loaded systems. 4148 // 4149 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 4150 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set 4151 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 4152 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant 4153 // thread. 4154 // 4155 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 4156 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 4157 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). 4158 // This also works well. In fact it avoids kernel-level scalability impediments 4159 // on certain platforms that don't handle lots of active pthread_cond_timedwait() 4160 // timers in a graceful fashion. 4161 // 4162 // 4. When the abstime value is in the past it appears that control returns 4163 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 4164 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we 4165 // can avoid the problem by reinitializing the condvar -- by cond_destroy() 4166 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). 4167 // It may be possible to avoid reinitialization by checking the return 4168 // value from pthread_cond_timedwait(). In addition to reinitializing the 4169 // condvar we must establish the invariant that cond_signal() is only called 4170 // within critical sections protected by the adjunct mutex. This prevents 4171 // cond_signal() from "seeing" a condvar that's in the midst of being 4172 // reinitialized or that is corrupt. Sadly, this invariant obviates the 4173 // desirable signal-after-unlock optimization that avoids futile context switching. 4174 // 4175 // I'm also concerned that some versions of NTPL might allocate an auxilliary 4176 // structure when a condvar is used or initialized. cond_destroy() would 4177 // release the helper structure. Our reinitialize-after-timedwait fix 4178 // put excessive stress on malloc/free and locks protecting the c-heap. 4179 // 4180 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 4181 // It may be possible to refine (4) by checking the kernel and NTPL verisons 4182 // and only enabling the work-around for vulnerable environments. 4183 4184 // utility to compute the abstime argument to timedwait: 4185 // millis is the relative timeout time 4186 // abstime will be the absolute timeout time 4187 // TODO: replace compute_abstime() with unpackTime() 4188 4189 static struct timespec* compute_abstime(struct timespec* abstime, 4190 jlong millis) { 4191 if (millis < 0) millis = 0; 4192 struct timeval now; 4193 int status = gettimeofday(&now, NULL); 4194 assert(status == 0, "gettimeofday"); 4195 jlong seconds = millis / 1000; 4196 millis %= 1000; 4197 if (seconds > 50000000) { // see man cond_timedwait(3T) 4198 seconds = 50000000; 4199 } 4200 abstime->tv_sec = now.tv_sec + seconds; 4201 long usec = now.tv_usec + millis * 1000; 4202 if (usec >= 1000000) { 4203 abstime->tv_sec += 1; 4204 usec -= 1000000; 4205 } 4206 abstime->tv_nsec = usec * 1000; 4207 return abstime; 4208 } 4209 4210 void os::PlatformEvent::park() { // AKA "down()" 4211 // Transitions for _Event: 4212 // -1 => -1 : illegal 4213 // 1 => 0 : pass - return immediately 4214 // 0 => -1 : block; then set _Event to 0 before returning 4215 4216 // Invariant: Only the thread associated with the Event/PlatformEvent 4217 // may call park(). 4218 // TODO: assert that _Assoc != NULL or _Assoc == Self 4219 assert(_nParked == 0, "invariant"); 4220 4221 int v; 4222 for (;;) { 4223 v = _Event; 4224 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4225 } 4226 guarantee(v >= 0, "invariant"); 4227 if (v == 0) { 4228 // Do this the hard way by blocking ... 4229 int status = pthread_mutex_lock(_mutex); 4230 assert_status(status == 0, status, "mutex_lock"); 4231 guarantee(_nParked == 0, "invariant"); 4232 ++_nParked; 4233 while (_Event < 0) { 4234 status = pthread_cond_wait(_cond, _mutex); 4235 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 4236 // Treat this the same as if the wait was interrupted 4237 if (status == ETIMEDOUT) { status = EINTR; } 4238 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 4239 } 4240 --_nParked; 4241 4242 _Event = 0; 4243 status = pthread_mutex_unlock(_mutex); 4244 assert_status(status == 0, status, "mutex_unlock"); 4245 // Paranoia to ensure our locked and lock-free paths interact 4246 // correctly with each other. 4247 OrderAccess::fence(); 4248 } 4249 guarantee(_Event >= 0, "invariant"); 4250 } 4251 4252 int os::PlatformEvent::park(jlong millis) { 4253 // Transitions for _Event: 4254 // -1 => -1 : illegal 4255 // 1 => 0 : pass - return immediately 4256 // 0 => -1 : block; then set _Event to 0 before returning 4257 4258 guarantee(_nParked == 0, "invariant"); 4259 4260 int v; 4261 for (;;) { 4262 v = _Event; 4263 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4264 } 4265 guarantee(v >= 0, "invariant"); 4266 if (v != 0) return OS_OK; 4267 4268 // We do this the hard way, by blocking the thread. 4269 // Consider enforcing a minimum timeout value. 4270 struct timespec abst; 4271 compute_abstime(&abst, millis); 4272 4273 int ret = OS_TIMEOUT; 4274 int status = pthread_mutex_lock(_mutex); 4275 assert_status(status == 0, status, "mutex_lock"); 4276 guarantee(_nParked == 0, "invariant"); 4277 ++_nParked; 4278 4279 // Object.wait(timo) will return because of 4280 // (a) notification 4281 // (b) timeout 4282 // (c) thread.interrupt 4283 // 4284 // Thread.interrupt and object.notify{All} both call Event::set. 4285 // That is, we treat thread.interrupt as a special case of notification. 4286 // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false. 4287 // We assume all ETIME returns are valid. 4288 // 4289 // TODO: properly differentiate simultaneous notify+interrupt. 4290 // In that case, we should propagate the notify to another waiter. 4291 4292 while (_Event < 0) { 4293 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst); 4294 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4295 pthread_cond_destroy(_cond); 4296 pthread_cond_init(_cond, NULL); 4297 } 4298 assert_status(status == 0 || status == EINTR || 4299 status == ETIMEDOUT, 4300 status, "cond_timedwait"); 4301 if (!FilterSpuriousWakeups) break; // previous semantics 4302 if (status == ETIMEDOUT) break; 4303 // We consume and ignore EINTR and spurious wakeups. 4304 } 4305 --_nParked; 4306 if (_Event >= 0) { 4307 ret = OS_OK; 4308 } 4309 _Event = 0; 4310 status = pthread_mutex_unlock(_mutex); 4311 assert_status(status == 0, status, "mutex_unlock"); 4312 assert(_nParked == 0, "invariant"); 4313 // Paranoia to ensure our locked and lock-free paths interact 4314 // correctly with each other. 4315 OrderAccess::fence(); 4316 return ret; 4317 } 4318 4319 void os::PlatformEvent::unpark() { 4320 // Transitions for _Event: 4321 // 0 => 1 : just return 4322 // 1 => 1 : just return 4323 // -1 => either 0 or 1; must signal target thread 4324 // That is, we can safely transition _Event from -1 to either 4325 // 0 or 1. 4326 // See also: "Semaphores in Plan 9" by Mullender & Cox 4327 // 4328 // Note: Forcing a transition from "-1" to "1" on an unpark() means 4329 // that it will take two back-to-back park() calls for the owning 4330 // thread to block. This has the benefit of forcing a spurious return 4331 // from the first park() call after an unpark() call which will help 4332 // shake out uses of park() and unpark() without condition variables. 4333 4334 if (Atomic::xchg(1, &_Event) >= 0) return; 4335 4336 // Wait for the thread associated with the event to vacate 4337 int status = pthread_mutex_lock(_mutex); 4338 assert_status(status == 0, status, "mutex_lock"); 4339 int AnyWaiters = _nParked; 4340 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 4341 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 4342 AnyWaiters = 0; 4343 pthread_cond_signal(_cond); 4344 } 4345 status = pthread_mutex_unlock(_mutex); 4346 assert_status(status == 0, status, "mutex_unlock"); 4347 if (AnyWaiters != 0) { 4348 // Note that we signal() *after* dropping the lock for "immortal" Events. 4349 // This is safe and avoids a common class of futile wakeups. In rare 4350 // circumstances this can cause a thread to return prematurely from 4351 // cond_{timed}wait() but the spurious wakeup is benign and the victim 4352 // will simply re-test the condition and re-park itself. 4353 // This provides particular benefit if the underlying platform does not 4354 // provide wait morphing. 4355 status = pthread_cond_signal(_cond); 4356 assert_status(status == 0, status, "cond_signal"); 4357 } 4358 } 4359 4360 4361 // JSR166 4362 // ------------------------------------------------------- 4363 4364 // The solaris and bsd implementations of park/unpark are fairly 4365 // conservative for now, but can be improved. They currently use a 4366 // mutex/condvar pair, plus a a count. 4367 // Park decrements count if > 0, else does a condvar wait. Unpark 4368 // sets count to 1 and signals condvar. Only one thread ever waits 4369 // on the condvar. Contention seen when trying to park implies that someone 4370 // is unparking you, so don't wait. And spurious returns are fine, so there 4371 // is no need to track notifications. 4372 4373 #define MAX_SECS 100000000 4374 4375 // This code is common to bsd and solaris and will be moved to a 4376 // common place in dolphin. 4377 // 4378 // The passed in time value is either a relative time in nanoseconds 4379 // or an absolute time in milliseconds. Either way it has to be unpacked 4380 // into suitable seconds and nanoseconds components and stored in the 4381 // given timespec structure. 4382 // Given time is a 64-bit value and the time_t used in the timespec is only 4383 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for 4384 // overflow if times way in the future are given. Further on Solaris versions 4385 // prior to 10 there is a restriction (see cond_timedwait) that the specified 4386 // number of seconds, in abstime, is less than current_time + 100,000,000. 4387 // As it will be 28 years before "now + 100000000" will overflow we can 4388 // ignore overflow and just impose a hard-limit on seconds using the value 4389 // of "now + 100,000,000". This places a limit on the timeout of about 3.17 4390 // years from "now". 4391 4392 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { 4393 assert(time > 0, "convertTime"); 4394 4395 struct timeval now; 4396 int status = gettimeofday(&now, NULL); 4397 assert(status == 0, "gettimeofday"); 4398 4399 time_t max_secs = now.tv_sec + MAX_SECS; 4400 4401 if (isAbsolute) { 4402 jlong secs = time / 1000; 4403 if (secs > max_secs) { 4404 absTime->tv_sec = max_secs; 4405 } else { 4406 absTime->tv_sec = secs; 4407 } 4408 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 4409 } else { 4410 jlong secs = time / NANOSECS_PER_SEC; 4411 if (secs >= MAX_SECS) { 4412 absTime->tv_sec = max_secs; 4413 absTime->tv_nsec = 0; 4414 } else { 4415 absTime->tv_sec = now.tv_sec + secs; 4416 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 4417 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 4418 absTime->tv_nsec -= NANOSECS_PER_SEC; 4419 ++absTime->tv_sec; // note: this must be <= max_secs 4420 } 4421 } 4422 } 4423 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 4424 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 4425 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 4426 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 4427 } 4428 4429 void Parker::park(bool isAbsolute, jlong time) { 4430 // Ideally we'd do something useful while spinning, such 4431 // as calling unpackTime(). 4432 4433 // Optional fast-path check: 4434 // Return immediately if a permit is available. 4435 // We depend on Atomic::xchg() having full barrier semantics 4436 // since we are doing a lock-free update to _counter. 4437 if (Atomic::xchg(0, &_counter) > 0) return; 4438 4439 Thread* thread = Thread::current(); 4440 assert(thread->is_Java_thread(), "Must be JavaThread"); 4441 JavaThread *jt = (JavaThread *)thread; 4442 4443 // Optional optimization -- avoid state transitions if there's an interrupt pending. 4444 // Check interrupt before trying to wait 4445 if (Thread::is_interrupted(thread, false)) { 4446 return; 4447 } 4448 4449 // Next, demultiplex/decode time arguments 4450 struct timespec absTime; 4451 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all 4452 return; 4453 } 4454 if (time > 0) { 4455 unpackTime(&absTime, isAbsolute, time); 4456 } 4457 4458 4459 // Enter safepoint region 4460 // Beware of deadlocks such as 6317397. 4461 // The per-thread Parker:: mutex is a classic leaf-lock. 4462 // In particular a thread must never block on the Threads_lock while 4463 // holding the Parker:: mutex. If safepoints are pending both the 4464 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 4465 ThreadBlockInVM tbivm(jt); 4466 4467 // Don't wait if cannot get lock since interference arises from 4468 // unblocking. Also. check interrupt before trying wait 4469 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 4470 return; 4471 } 4472 4473 int status; 4474 if (_counter > 0) { // no wait needed 4475 _counter = 0; 4476 status = pthread_mutex_unlock(_mutex); 4477 assert(status == 0, "invariant"); 4478 // Paranoia to ensure our locked and lock-free paths interact 4479 // correctly with each other and Java-level accesses. 4480 OrderAccess::fence(); 4481 return; 4482 } 4483 4484 #ifdef ASSERT 4485 // Don't catch signals while blocked; let the running threads have the signals. 4486 // (This allows a debugger to break into the running thread.) 4487 sigset_t oldsigs; 4488 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); 4489 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 4490 #endif 4491 4492 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 4493 jt->set_suspend_equivalent(); 4494 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 4495 4496 if (time == 0) { 4497 status = pthread_cond_wait(_cond, _mutex); 4498 } else { 4499 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &absTime); 4500 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4501 pthread_cond_destroy(_cond); 4502 pthread_cond_init(_cond, NULL); 4503 } 4504 } 4505 assert_status(status == 0 || status == EINTR || 4506 status == ETIMEDOUT, 4507 status, "cond_timedwait"); 4508 4509 #ifdef ASSERT 4510 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 4511 #endif 4512 4513 _counter = 0; 4514 status = pthread_mutex_unlock(_mutex); 4515 assert_status(status == 0, status, "invariant"); 4516 // Paranoia to ensure our locked and lock-free paths interact 4517 // correctly with each other and Java-level accesses. 4518 OrderAccess::fence(); 4519 4520 // If externally suspended while waiting, re-suspend 4521 if (jt->handle_special_suspend_equivalent_condition()) { 4522 jt->java_suspend_self(); 4523 } 4524 } 4525 4526 void Parker::unpark() { 4527 int status = pthread_mutex_lock(_mutex); 4528 assert(status == 0, "invariant"); 4529 const int s = _counter; 4530 _counter = 1; 4531 if (s < 1) { 4532 if (WorkAroundNPTLTimedWaitHang) { 4533 status = pthread_cond_signal(_cond); 4534 assert(status == 0, "invariant"); 4535 status = pthread_mutex_unlock(_mutex); 4536 assert(status == 0, "invariant"); 4537 } else { 4538 status = pthread_mutex_unlock(_mutex); 4539 assert(status == 0, "invariant"); 4540 status = pthread_cond_signal(_cond); 4541 assert(status == 0, "invariant"); 4542 } 4543 } else { 4544 pthread_mutex_unlock(_mutex); 4545 assert(status == 0, "invariant"); 4546 } 4547 } 4548 4549 4550 // Darwin has no "environ" in a dynamic library. 4551 #ifdef __APPLE__ 4552 #include <crt_externs.h> 4553 #define environ (*_NSGetEnviron()) 4554 #else 4555 extern char** environ; 4556 #endif 4557 4558 // Run the specified command in a separate process. Return its exit value, 4559 // or -1 on failure (e.g. can't fork a new process). 4560 // Unlike system(), this function can be called from signal handler. It 4561 // doesn't block SIGINT et al. 4562 int os::fork_and_exec(char* cmd) { 4563 const char * argv[4] = {"sh", "-c", cmd, NULL}; 4564 4565 // fork() in BsdThreads/NPTL is not async-safe. It needs to run 4566 // pthread_atfork handlers and reset pthread library. All we need is a 4567 // separate process to execve. Make a direct syscall to fork process. 4568 // On IA64 there's no fork syscall, we have to use fork() and hope for 4569 // the best... 4570 pid_t pid = fork(); 4571 4572 if (pid < 0) { 4573 // fork failed 4574 return -1; 4575 4576 } else if (pid == 0) { 4577 // child process 4578 4579 // execve() in BsdThreads will call pthread_kill_other_threads_np() 4580 // first to kill every thread on the thread list. Because this list is 4581 // not reset by fork() (see notes above), execve() will instead kill 4582 // every thread in the parent process. We know this is the only thread 4583 // in the new process, so make a system call directly. 4584 // IA64 should use normal execve() from glibc to match the glibc fork() 4585 // above. 4586 execve("/bin/sh", (char* const*)argv, environ); 4587 4588 // execve failed 4589 _exit(-1); 4590 4591 } else { 4592 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 4593 // care about the actual exit code, for now. 4594 4595 int status; 4596 4597 // Wait for the child process to exit. This returns immediately if 4598 // the child has already exited. */ 4599 while (waitpid(pid, &status, 0) < 0) { 4600 switch (errno) { 4601 case ECHILD: return 0; 4602 case EINTR: break; 4603 default: return -1; 4604 } 4605 } 4606 4607 if (WIFEXITED(status)) { 4608 // The child exited normally; get its exit code. 4609 return WEXITSTATUS(status); 4610 } else if (WIFSIGNALED(status)) { 4611 // The child exited because of a signal 4612 // The best value to return is 0x80 + signal number, 4613 // because that is what all Unix shells do, and because 4614 // it allows callers to distinguish between process exit and 4615 // process death by signal. 4616 return 0x80 + WTERMSIG(status); 4617 } else { 4618 // Unknown exit code; pass it through 4619 return status; 4620 } 4621 } 4622 } 4623 4624 // is_headless_jre() 4625 // 4626 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 4627 // in order to report if we are running in a headless jre 4628 // 4629 // Since JDK8 xawt/libmawt.so was moved into the same directory 4630 // as libawt.so, and renamed libawt_xawt.so 4631 // 4632 bool os::is_headless_jre() { 4633 #ifdef __APPLE__ 4634 // We no longer build headless-only on Mac OS X 4635 return false; 4636 #else 4637 struct stat statbuf; 4638 char buf[MAXPATHLEN]; 4639 char libmawtpath[MAXPATHLEN]; 4640 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX; 4641 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX; 4642 char *p; 4643 4644 // Get path to libjvm.so 4645 os::jvm_path(buf, sizeof(buf)); 4646 4647 // Get rid of libjvm.so 4648 p = strrchr(buf, '/'); 4649 if (p == NULL) { 4650 return false; 4651 } else { 4652 *p = '\0'; 4653 } 4654 4655 // Get rid of client or server 4656 p = strrchr(buf, '/'); 4657 if (p == NULL) { 4658 return false; 4659 } else { 4660 *p = '\0'; 4661 } 4662 4663 // check xawt/libmawt.so 4664 strcpy(libmawtpath, buf); 4665 strcat(libmawtpath, xawtstr); 4666 if (::stat(libmawtpath, &statbuf) == 0) return false; 4667 4668 // check libawt_xawt.so 4669 strcpy(libmawtpath, buf); 4670 strcat(libmawtpath, new_xawtstr); 4671 if (::stat(libmawtpath, &statbuf) == 0) return false; 4672 4673 return true; 4674 #endif 4675 } 4676 4677 // Get the default path to the core file 4678 // Returns the length of the string 4679 int os::get_core_path(char* buffer, size_t bufferSize) { 4680 int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id()); 4681 4682 // Truncate if theoretical string was longer than bufferSize 4683 n = MIN2(n, (int)bufferSize); 4684 4685 return n; 4686 } 4687 4688 #ifndef PRODUCT 4689 void TestReserveMemorySpecial_test() { 4690 // No tests available for this platform 4691 } 4692 #endif