1 /* 2 * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 // no precompiled headers 26 #include "classfile/classLoader.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "classfile/vmSymbols.hpp" 29 #include "code/icBuffer.hpp" 30 #include "code/vtableStubs.hpp" 31 #include "compiler/compileBroker.hpp" 32 #include "compiler/disassembler.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "jvm_bsd.h" 35 #include "memory/allocation.inline.hpp" 36 #include "memory/filemap.hpp" 37 #include "mutex_bsd.inline.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "os_share_bsd.hpp" 40 #include "prims/jniFastGetField.hpp" 41 #include "prims/jvm.h" 42 #include "prims/jvm_misc.hpp" 43 #include "runtime/arguments.hpp" 44 #include "runtime/extendedPC.hpp" 45 #include "runtime/globals.hpp" 46 #include "runtime/interfaceSupport.hpp" 47 #include "runtime/java.hpp" 48 #include "runtime/javaCalls.hpp" 49 #include "runtime/mutexLocker.hpp" 50 #include "runtime/objectMonitor.hpp" 51 #include "runtime/osThread.hpp" 52 #include "runtime/perfMemory.hpp" 53 #include "runtime/sharedRuntime.hpp" 54 #include "runtime/statSampler.hpp" 55 #include "runtime/stubRoutines.hpp" 56 #include "runtime/thread.inline.hpp" 57 #include "runtime/threadCritical.hpp" 58 #include "runtime/timer.hpp" 59 #include "services/attachListener.hpp" 60 #include "services/memTracker.hpp" 61 #include "services/runtimeService.hpp" 62 #include "utilities/decoder.hpp" 63 #include "utilities/defaultStream.hpp" 64 #include "utilities/events.hpp" 65 #include "utilities/growableArray.hpp" 66 #include "utilities/vmError.hpp" 67 68 // put OS-includes here 69 # include <sys/types.h> 70 # include <sys/mman.h> 71 # include <sys/stat.h> 72 # include <sys/select.h> 73 # include <pthread.h> 74 # include <signal.h> 75 # include <errno.h> 76 # include <dlfcn.h> 77 # include <stdio.h> 78 # include <unistd.h> 79 # include <sys/resource.h> 80 # include <pthread.h> 81 # include <sys/stat.h> 82 # include <sys/time.h> 83 # include <sys/times.h> 84 # include <sys/utsname.h> 85 # include <sys/socket.h> 86 # include <sys/wait.h> 87 # include <time.h> 88 # include <pwd.h> 89 # include <poll.h> 90 # include <semaphore.h> 91 # include <fcntl.h> 92 # include <string.h> 93 # include <sys/param.h> 94 # include <sys/sysctl.h> 95 # include <sys/ipc.h> 96 # include <sys/shm.h> 97 #ifndef __APPLE__ 98 # include <link.h> 99 #endif 100 # include <stdint.h> 101 # include <inttypes.h> 102 # include <sys/ioctl.h> 103 # include <sys/syscall.h> 104 105 #if defined(__FreeBSD__) || defined(__NetBSD__) 106 # include <elf.h> 107 #endif 108 109 #ifdef __APPLE__ 110 # include <mach/mach.h> // semaphore_* API 111 # include <mach-o/dyld.h> 112 # include <sys/proc_info.h> 113 # include <objc/objc-auto.h> 114 #endif 115 116 #ifndef MAP_ANONYMOUS 117 #define MAP_ANONYMOUS MAP_ANON 118 #endif 119 120 #define MAX_PATH (2 * K) 121 122 // for timer info max values which include all bits 123 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 124 125 #define LARGEPAGES_BIT (1 << 6) 126 //////////////////////////////////////////////////////////////////////////////// 127 // global variables 128 julong os::Bsd::_physical_memory = 0; 129 130 131 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; 132 pthread_t os::Bsd::_main_thread; 133 int os::Bsd::_page_size = -1; 134 135 static jlong initial_time_count=0; 136 137 static int clock_tics_per_sec = 100; 138 139 // For diagnostics to print a message once. see run_periodic_checks 140 static sigset_t check_signal_done; 141 static bool check_signals = true; 142 143 static pid_t _initial_pid = 0; 144 145 /* Signal number used to suspend/resume a thread */ 146 147 /* do not use any signal number less than SIGSEGV, see 4355769 */ 148 static int SR_signum = SIGUSR2; 149 sigset_t SR_sigset; 150 151 152 //////////////////////////////////////////////////////////////////////////////// 153 // utility functions 154 155 static int SR_initialize(); 156 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time); 157 158 julong os::available_memory() { 159 return Bsd::available_memory(); 160 } 161 162 // available here means free 163 julong os::Bsd::available_memory() { 164 uint64_t available = physical_memory() >> 2; 165 #ifdef __APPLE__ 166 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT; 167 vm_statistics64_data_t vmstat; 168 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64, 169 (host_info64_t)&vmstat, &count); 170 assert(kerr == KERN_SUCCESS, 171 "host_statistics64 failed - check mach_host_self() and count"); 172 if (kerr == KERN_SUCCESS) { 173 available = vmstat.free_count * os::vm_page_size(); 174 } 175 #endif 176 return available; 177 } 178 179 julong os::physical_memory() { 180 return Bsd::physical_memory(); 181 } 182 183 //////////////////////////////////////////////////////////////////////////////// 184 // environment support 185 186 bool os::getenv(const char* name, char* buf, int len) { 187 const char* val = ::getenv(name); 188 if (val != NULL && strlen(val) < (size_t)len) { 189 strcpy(buf, val); 190 return true; 191 } 192 if (len > 0) buf[0] = 0; // return a null string 193 return false; 194 } 195 196 197 // Return true if user is running as root. 198 199 bool os::have_special_privileges() { 200 static bool init = false; 201 static bool privileges = false; 202 if (!init) { 203 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 204 init = true; 205 } 206 return privileges; 207 } 208 209 210 211 // Cpu architecture string 212 #if defined(ZERO) 213 static char cpu_arch[] = ZERO_LIBARCH; 214 #elif defined(IA64) 215 static char cpu_arch[] = "ia64"; 216 #elif defined(IA32) 217 static char cpu_arch[] = "i386"; 218 #elif defined(AMD64) 219 static char cpu_arch[] = "amd64"; 220 #elif defined(ARM) 221 static char cpu_arch[] = "arm"; 222 #elif defined(PPC32) 223 static char cpu_arch[] = "ppc"; 224 #elif defined(SPARC) 225 # ifdef _LP64 226 static char cpu_arch[] = "sparcv9"; 227 # else 228 static char cpu_arch[] = "sparc"; 229 # endif 230 #else 231 #error Add appropriate cpu_arch setting 232 #endif 233 234 // Compiler variant 235 #ifdef COMPILER2 236 #define COMPILER_VARIANT "server" 237 #else 238 #define COMPILER_VARIANT "client" 239 #endif 240 241 242 void os::Bsd::initialize_system_info() { 243 int mib[2]; 244 size_t len; 245 int cpu_val; 246 julong mem_val; 247 248 /* get processors count via hw.ncpus sysctl */ 249 mib[0] = CTL_HW; 250 mib[1] = HW_NCPU; 251 len = sizeof(cpu_val); 252 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) { 253 assert(len == sizeof(cpu_val), "unexpected data size"); 254 set_processor_count(cpu_val); 255 } 256 else { 257 set_processor_count(1); // fallback 258 } 259 260 /* get physical memory via hw.memsize sysctl (hw.memsize is used 261 * since it returns a 64 bit value) 262 */ 263 mib[0] = CTL_HW; 264 265 #if defined (HW_MEMSIZE) // Apple 266 mib[1] = HW_MEMSIZE; 267 #elif defined(HW_PHYSMEM) // Most of BSD 268 mib[1] = HW_PHYSMEM; 269 #elif defined(HW_REALMEM) // Old FreeBSD 270 mib[1] = HW_REALMEM; 271 #else 272 #error No ways to get physmem 273 #endif 274 275 len = sizeof(mem_val); 276 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) { 277 assert(len == sizeof(mem_val), "unexpected data size"); 278 _physical_memory = mem_val; 279 } else { 280 _physical_memory = 256*1024*1024; // fallback (XXXBSD?) 281 } 282 283 #ifdef __OpenBSD__ 284 { 285 // limit _physical_memory memory view on OpenBSD since 286 // datasize rlimit restricts us anyway. 287 struct rlimit limits; 288 getrlimit(RLIMIT_DATA, &limits); 289 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur); 290 } 291 #endif 292 } 293 294 #ifdef __APPLE__ 295 static const char *get_home() { 296 const char *home_dir = ::getenv("HOME"); 297 if ((home_dir == NULL) || (*home_dir == '\0')) { 298 struct passwd *passwd_info = getpwuid(geteuid()); 299 if (passwd_info != NULL) { 300 home_dir = passwd_info->pw_dir; 301 } 302 } 303 304 return home_dir; 305 } 306 #endif 307 308 void os::init_system_properties_values() { 309 // The next steps are taken in the product version: 310 // 311 // Obtain the JAVA_HOME value from the location of libjvm.so. 312 // This library should be located at: 313 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so. 314 // 315 // If "/jre/lib/" appears at the right place in the path, then we 316 // assume libjvm.so is installed in a JDK and we use this path. 317 // 318 // Otherwise exit with message: "Could not create the Java virtual machine." 319 // 320 // The following extra steps are taken in the debugging version: 321 // 322 // If "/jre/lib/" does NOT appear at the right place in the path 323 // instead of exit check for $JAVA_HOME environment variable. 324 // 325 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 326 // then we append a fake suffix "hotspot/libjvm.so" to this path so 327 // it looks like libjvm.so is installed there 328 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 329 // 330 // Otherwise exit. 331 // 332 // Important note: if the location of libjvm.so changes this 333 // code needs to be changed accordingly. 334 335 // See ld(1): 336 // The linker uses the following search paths to locate required 337 // shared libraries: 338 // 1: ... 339 // ... 340 // 7: The default directories, normally /lib and /usr/lib. 341 #ifndef DEFAULT_LIBPATH 342 #define DEFAULT_LIBPATH "/lib:/usr/lib" 343 #endif 344 345 // Base path of extensions installed on the system. 346 #define SYS_EXT_DIR "/usr/java/packages" 347 #define EXTENSIONS_DIR "/lib/ext" 348 #define ENDORSED_DIR "/lib/endorsed" 349 350 #ifndef __APPLE__ 351 352 // Buffer that fits several sprintfs. 353 // Note that the space for the colon and the trailing null are provided 354 // by the nulls included by the sizeof operator. 355 const size_t bufsize = 356 MAX3((size_t)MAXPATHLEN, // For dll_dir & friends. 357 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR), // extensions dir 358 (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir 359 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 360 361 // sysclasspath, java_home, dll_dir 362 { 363 char *pslash; 364 os::jvm_path(buf, bufsize); 365 366 // Found the full path to libjvm.so. 367 // Now cut the path to <java_home>/jre if we can. 368 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 369 pslash = strrchr(buf, '/'); 370 if (pslash != NULL) { 371 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 372 } 373 Arguments::set_dll_dir(buf); 374 375 if (pslash != NULL) { 376 pslash = strrchr(buf, '/'); 377 if (pslash != NULL) { 378 *pslash = '\0'; // Get rid of /<arch>. 379 pslash = strrchr(buf, '/'); 380 if (pslash != NULL) { 381 *pslash = '\0'; // Get rid of /lib. 382 } 383 } 384 } 385 Arguments::set_java_home(buf); 386 set_boot_path('/', ':'); 387 } 388 389 // Where to look for native libraries. 390 // 391 // Note: Due to a legacy implementation, most of the library path 392 // is set in the launcher. This was to accomodate linking restrictions 393 // on legacy Bsd implementations (which are no longer supported). 394 // Eventually, all the library path setting will be done here. 395 // 396 // However, to prevent the proliferation of improperly built native 397 // libraries, the new path component /usr/java/packages is added here. 398 // Eventually, all the library path setting will be done here. 399 { 400 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 401 // should always exist (until the legacy problem cited above is 402 // addressed). 403 const char *v = ::getenv("LD_LIBRARY_PATH"); 404 const char *v_colon = ":"; 405 if (v == NULL) { v = ""; v_colon = ""; } 406 // That's +1 for the colon and +1 for the trailing '\0'. 407 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 408 strlen(v) + 1 + 409 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1, 410 mtInternal); 411 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch); 412 Arguments::set_library_path(ld_library_path); 413 FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal); 414 } 415 416 // Extensions directories. 417 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 418 Arguments::set_ext_dirs(buf); 419 420 // Endorsed standards default directory. 421 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); 422 Arguments::set_endorsed_dirs(buf); 423 424 FREE_C_HEAP_ARRAY(char, buf, mtInternal); 425 426 #else // __APPLE__ 427 428 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions" 429 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java" 430 431 const char *user_home_dir = get_home(); 432 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir. 433 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) + 434 sizeof(SYS_EXTENSIONS_DIRS); 435 436 // Buffer that fits several sprintfs. 437 // Note that the space for the colon and the trailing null are provided 438 // by the nulls included by the sizeof operator. 439 const size_t bufsize = 440 MAX3((size_t)MAXPATHLEN, // for dll_dir & friends. 441 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size, // extensions dir 442 (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir 443 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 444 445 // sysclasspath, java_home, dll_dir 446 { 447 char *pslash; 448 os::jvm_path(buf, bufsize); 449 450 // Found the full path to libjvm.so. 451 // Now cut the path to <java_home>/jre if we can. 452 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 453 pslash = strrchr(buf, '/'); 454 if (pslash != NULL) { 455 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 456 } 457 Arguments::set_dll_dir(buf); 458 459 if (pslash != NULL) { 460 pslash = strrchr(buf, '/'); 461 if (pslash != NULL) { 462 *pslash = '\0'; // Get rid of /lib. 463 } 464 } 465 Arguments::set_java_home(buf); 466 set_boot_path('/', ':'); 467 } 468 469 // Where to look for native libraries. 470 // 471 // Note: Due to a legacy implementation, most of the library path 472 // is set in the launcher. This was to accomodate linking restrictions 473 // on legacy Bsd implementations (which are no longer supported). 474 // Eventually, all the library path setting will be done here. 475 // 476 // However, to prevent the proliferation of improperly built native 477 // libraries, the new path component /usr/java/packages is added here. 478 // Eventually, all the library path setting will be done here. 479 { 480 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 481 // should always exist (until the legacy problem cited above is 482 // addressed). 483 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code 484 // can specify a directory inside an app wrapper 485 const char *l = ::getenv("JAVA_LIBRARY_PATH"); 486 const char *l_colon = ":"; 487 if (l == NULL) { l = ""; l_colon = ""; } 488 489 const char *v = ::getenv("DYLD_LIBRARY_PATH"); 490 const char *v_colon = ":"; 491 if (v == NULL) { v = ""; v_colon = ""; } 492 493 // Apple's Java6 has "." at the beginning of java.library.path. 494 // OpenJDK on Windows has "." at the end of java.library.path. 495 // OpenJDK on Linux and Solaris don't have "." in java.library.path 496 // at all. To ease the transition from Apple's Java6 to OpenJDK7, 497 // "." is appended to the end of java.library.path. Yes, this 498 // could cause a change in behavior, but Apple's Java6 behavior 499 // can be achieved by putting "." at the beginning of the 500 // JAVA_LIBRARY_PATH environment variable. 501 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 502 strlen(v) + 1 + strlen(l) + 1 + 503 system_ext_size + 3, 504 mtInternal); 505 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.", 506 v, v_colon, l, l_colon, user_home_dir); 507 Arguments::set_library_path(ld_library_path); 508 FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal); 509 } 510 511 // Extensions directories. 512 // 513 // Note that the space for the colon and the trailing null are provided 514 // by the nulls included by the sizeof operator (so actually one byte more 515 // than necessary is allocated). 516 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, 517 user_home_dir, Arguments::get_java_home()); 518 Arguments::set_ext_dirs(buf); 519 520 // Endorsed standards default directory. 521 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); 522 Arguments::set_endorsed_dirs(buf); 523 524 FREE_C_HEAP_ARRAY(char, buf, mtInternal); 525 526 #undef SYS_EXTENSIONS_DIR 527 #undef SYS_EXTENSIONS_DIRS 528 529 #endif // __APPLE__ 530 531 #undef SYS_EXT_DIR 532 #undef EXTENSIONS_DIR 533 #undef ENDORSED_DIR 534 } 535 536 //////////////////////////////////////////////////////////////////////////////// 537 // breakpoint support 538 539 void os::breakpoint() { 540 BREAKPOINT; 541 } 542 543 extern "C" void breakpoint() { 544 // use debugger to set breakpoint here 545 } 546 547 //////////////////////////////////////////////////////////////////////////////// 548 // signal support 549 550 debug_only(static bool signal_sets_initialized = false); 551 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 552 553 bool os::Bsd::is_sig_ignored(int sig) { 554 struct sigaction oact; 555 sigaction(sig, (struct sigaction*)NULL, &oact); 556 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 557 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 558 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) 559 return true; 560 else 561 return false; 562 } 563 564 void os::Bsd::signal_sets_init() { 565 // Should also have an assertion stating we are still single-threaded. 566 assert(!signal_sets_initialized, "Already initialized"); 567 // Fill in signals that are necessarily unblocked for all threads in 568 // the VM. Currently, we unblock the following signals: 569 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 570 // by -Xrs (=ReduceSignalUsage)); 571 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 572 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 573 // the dispositions or masks wrt these signals. 574 // Programs embedding the VM that want to use the above signals for their 575 // own purposes must, at this time, use the "-Xrs" option to prevent 576 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 577 // (See bug 4345157, and other related bugs). 578 // In reality, though, unblocking these signals is really a nop, since 579 // these signals are not blocked by default. 580 sigemptyset(&unblocked_sigs); 581 sigemptyset(&allowdebug_blocked_sigs); 582 sigaddset(&unblocked_sigs, SIGILL); 583 sigaddset(&unblocked_sigs, SIGSEGV); 584 sigaddset(&unblocked_sigs, SIGBUS); 585 sigaddset(&unblocked_sigs, SIGFPE); 586 sigaddset(&unblocked_sigs, SR_signum); 587 588 if (!ReduceSignalUsage) { 589 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 590 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 591 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); 592 } 593 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 594 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 595 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); 596 } 597 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 598 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 599 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); 600 } 601 } 602 // Fill in signals that are blocked by all but the VM thread. 603 sigemptyset(&vm_sigs); 604 if (!ReduceSignalUsage) 605 sigaddset(&vm_sigs, BREAK_SIGNAL); 606 debug_only(signal_sets_initialized = true); 607 608 } 609 610 // These are signals that are unblocked while a thread is running Java. 611 // (For some reason, they get blocked by default.) 612 sigset_t* os::Bsd::unblocked_signals() { 613 assert(signal_sets_initialized, "Not initialized"); 614 return &unblocked_sigs; 615 } 616 617 // These are the signals that are blocked while a (non-VM) thread is 618 // running Java. Only the VM thread handles these signals. 619 sigset_t* os::Bsd::vm_signals() { 620 assert(signal_sets_initialized, "Not initialized"); 621 return &vm_sigs; 622 } 623 624 // These are signals that are blocked during cond_wait to allow debugger in 625 sigset_t* os::Bsd::allowdebug_blocked_signals() { 626 assert(signal_sets_initialized, "Not initialized"); 627 return &allowdebug_blocked_sigs; 628 } 629 630 void os::Bsd::hotspot_sigmask(Thread* thread) { 631 632 //Save caller's signal mask before setting VM signal mask 633 sigset_t caller_sigmask; 634 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 635 636 OSThread* osthread = thread->osthread(); 637 osthread->set_caller_sigmask(caller_sigmask); 638 639 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); 640 641 if (!ReduceSignalUsage) { 642 if (thread->is_VM_thread()) { 643 // Only the VM thread handles BREAK_SIGNAL ... 644 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 645 } else { 646 // ... all other threads block BREAK_SIGNAL 647 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 648 } 649 } 650 } 651 652 653 ////////////////////////////////////////////////////////////////////////////// 654 // create new thread 655 656 // check if it's safe to start a new thread 657 static bool _thread_safety_check(Thread* thread) { 658 return true; 659 } 660 661 #ifdef __APPLE__ 662 // library handle for calling objc_registerThreadWithCollector() 663 // without static linking to the libobjc library 664 #define OBJC_LIB "/usr/lib/libobjc.dylib" 665 #define OBJC_GCREGISTER "objc_registerThreadWithCollector" 666 typedef void (*objc_registerThreadWithCollector_t)(); 667 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction; 668 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL; 669 #endif 670 671 #ifdef __APPLE__ 672 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) { 673 // Additional thread_id used to correlate threads in SA 674 thread_identifier_info_data_t m_ident_info; 675 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT; 676 677 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO, 678 (thread_info_t) &m_ident_info, &count); 679 680 return m_ident_info.thread_id; 681 } 682 #endif 683 684 // Thread start routine for all newly created threads 685 static void *java_start(Thread *thread) { 686 // Try to randomize the cache line index of hot stack frames. 687 // This helps when threads of the same stack traces evict each other's 688 // cache lines. The threads can be either from the same JVM instance, or 689 // from different JVM instances. The benefit is especially true for 690 // processors with hyperthreading technology. 691 static int counter = 0; 692 int pid = os::current_process_id(); 693 alloca(((pid ^ counter++) & 7) * 128); 694 695 ThreadLocalStorage::set_thread(thread); 696 697 OSThread* osthread = thread->osthread(); 698 Monitor* sync = osthread->startThread_lock(); 699 700 // non floating stack BsdThreads needs extra check, see above 701 if (!_thread_safety_check(thread)) { 702 // notify parent thread 703 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 704 osthread->set_state(ZOMBIE); 705 sync->notify_all(); 706 return NULL; 707 } 708 709 osthread->set_thread_id(os::Bsd::gettid()); 710 711 #ifdef __APPLE__ 712 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 713 guarantee(unique_thread_id != 0, "unique thread id was not found"); 714 osthread->set_unique_thread_id(unique_thread_id); 715 #endif 716 // initialize signal mask for this thread 717 os::Bsd::hotspot_sigmask(thread); 718 719 // initialize floating point control register 720 os::Bsd::init_thread_fpu_state(); 721 722 #ifdef __APPLE__ 723 // register thread with objc gc 724 if (objc_registerThreadWithCollectorFunction != NULL) { 725 objc_registerThreadWithCollectorFunction(); 726 } 727 #endif 728 729 // handshaking with parent thread 730 { 731 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 732 733 // notify parent thread 734 osthread->set_state(INITIALIZED); 735 sync->notify_all(); 736 737 // wait until os::start_thread() 738 while (osthread->get_state() == INITIALIZED) { 739 sync->wait(Mutex::_no_safepoint_check_flag); 740 } 741 } 742 743 // call one more level start routine 744 thread->run(); 745 746 return 0; 747 } 748 749 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { 750 assert(thread->osthread() == NULL, "caller responsible"); 751 752 // Allocate the OSThread object 753 OSThread* osthread = new OSThread(NULL, NULL); 754 if (osthread == NULL) { 755 return false; 756 } 757 758 // set the correct thread state 759 osthread->set_thread_type(thr_type); 760 761 // Initial state is ALLOCATED but not INITIALIZED 762 osthread->set_state(ALLOCATED); 763 764 thread->set_osthread(osthread); 765 766 // init thread attributes 767 pthread_attr_t attr; 768 pthread_attr_init(&attr); 769 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 770 771 // stack size 772 if (os::Bsd::supports_variable_stack_size()) { 773 // calculate stack size if it's not specified by caller 774 if (stack_size == 0) { 775 stack_size = os::Bsd::default_stack_size(thr_type); 776 777 switch (thr_type) { 778 case os::java_thread: 779 // Java threads use ThreadStackSize which default value can be 780 // changed with the flag -Xss 781 assert (JavaThread::stack_size_at_create() > 0, "this should be set"); 782 stack_size = JavaThread::stack_size_at_create(); 783 break; 784 case os::compiler_thread: 785 if (CompilerThreadStackSize > 0) { 786 stack_size = (size_t)(CompilerThreadStackSize * K); 787 break; 788 } // else fall through: 789 // use VMThreadStackSize if CompilerThreadStackSize is not defined 790 case os::vm_thread: 791 case os::pgc_thread: 792 case os::cgc_thread: 793 case os::watcher_thread: 794 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 795 break; 796 } 797 } 798 799 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); 800 pthread_attr_setstacksize(&attr, stack_size); 801 } else { 802 // let pthread_create() pick the default value. 803 } 804 805 ThreadState state; 806 807 { 808 pthread_t tid; 809 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 810 811 pthread_attr_destroy(&attr); 812 813 if (ret != 0) { 814 if (PrintMiscellaneous && (Verbose || WizardMode)) { 815 perror("pthread_create()"); 816 } 817 // Need to clean up stuff we've allocated so far 818 thread->set_osthread(NULL); 819 delete osthread; 820 return false; 821 } 822 823 // Store pthread info into the OSThread 824 osthread->set_pthread_id(tid); 825 826 // Wait until child thread is either initialized or aborted 827 { 828 Monitor* sync_with_child = osthread->startThread_lock(); 829 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 830 while ((state = osthread->get_state()) == ALLOCATED) { 831 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 832 } 833 } 834 835 } 836 837 // Aborted due to thread limit being reached 838 if (state == ZOMBIE) { 839 thread->set_osthread(NULL); 840 delete osthread; 841 return false; 842 } 843 844 // The thread is returned suspended (in state INITIALIZED), 845 // and is started higher up in the call chain 846 assert(state == INITIALIZED, "race condition"); 847 return true; 848 } 849 850 ///////////////////////////////////////////////////////////////////////////// 851 // attach existing thread 852 853 // bootstrap the main thread 854 bool os::create_main_thread(JavaThread* thread) { 855 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); 856 return create_attached_thread(thread); 857 } 858 859 bool os::create_attached_thread(JavaThread* thread) { 860 #ifdef ASSERT 861 thread->verify_not_published(); 862 #endif 863 864 // Allocate the OSThread object 865 OSThread* osthread = new OSThread(NULL, NULL); 866 867 if (osthread == NULL) { 868 return false; 869 } 870 871 osthread->set_thread_id(os::Bsd::gettid()); 872 873 // Store pthread info into the OSThread 874 #ifdef __APPLE__ 875 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 876 guarantee(unique_thread_id != 0, "just checking"); 877 osthread->set_unique_thread_id(unique_thread_id); 878 #endif 879 osthread->set_pthread_id(::pthread_self()); 880 881 // initialize floating point control register 882 os::Bsd::init_thread_fpu_state(); 883 884 // Initial thread state is RUNNABLE 885 osthread->set_state(RUNNABLE); 886 887 thread->set_osthread(osthread); 888 889 // initialize signal mask for this thread 890 // and save the caller's signal mask 891 os::Bsd::hotspot_sigmask(thread); 892 893 return true; 894 } 895 896 void os::pd_start_thread(Thread* thread) { 897 OSThread * osthread = thread->osthread(); 898 assert(osthread->get_state() != INITIALIZED, "just checking"); 899 Monitor* sync_with_child = osthread->startThread_lock(); 900 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 901 sync_with_child->notify(); 902 } 903 904 // Free Bsd resources related to the OSThread 905 void os::free_thread(OSThread* osthread) { 906 assert(osthread != NULL, "osthread not set"); 907 908 if (Thread::current()->osthread() == osthread) { 909 // Restore caller's signal mask 910 sigset_t sigmask = osthread->caller_sigmask(); 911 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 912 } 913 914 delete osthread; 915 } 916 917 ////////////////////////////////////////////////////////////////////////////// 918 // thread local storage 919 920 // Restore the thread pointer if the destructor is called. This is in case 921 // someone from JNI code sets up a destructor with pthread_key_create to run 922 // detachCurrentThread on thread death. Unless we restore the thread pointer we 923 // will hang or crash. When detachCurrentThread is called the key will be set 924 // to null and we will not be called again. If detachCurrentThread is never 925 // called we could loop forever depending on the pthread implementation. 926 static void restore_thread_pointer(void* p) { 927 Thread* thread = (Thread*) p; 928 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread); 929 } 930 931 int os::allocate_thread_local_storage() { 932 pthread_key_t key; 933 int rslt = pthread_key_create(&key, restore_thread_pointer); 934 assert(rslt == 0, "cannot allocate thread local storage"); 935 return (int)key; 936 } 937 938 // Note: This is currently not used by VM, as we don't destroy TLS key 939 // on VM exit. 940 void os::free_thread_local_storage(int index) { 941 int rslt = pthread_key_delete((pthread_key_t)index); 942 assert(rslt == 0, "invalid index"); 943 } 944 945 void os::thread_local_storage_at_put(int index, void* value) { 946 int rslt = pthread_setspecific((pthread_key_t)index, value); 947 assert(rslt == 0, "pthread_setspecific failed"); 948 } 949 950 extern "C" Thread* get_thread() { 951 return ThreadLocalStorage::thread(); 952 } 953 954 955 //////////////////////////////////////////////////////////////////////////////// 956 // time support 957 958 // Time since start-up in seconds to a fine granularity. 959 // Used by VMSelfDestructTimer and the MemProfiler. 960 double os::elapsedTime() { 961 962 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); 963 } 964 965 jlong os::elapsed_counter() { 966 return javaTimeNanos() - initial_time_count; 967 } 968 969 jlong os::elapsed_frequency() { 970 return NANOSECS_PER_SEC; // nanosecond resolution 971 } 972 973 bool os::supports_vtime() { return true; } 974 bool os::enable_vtime() { return false; } 975 bool os::vtime_enabled() { return false; } 976 977 double os::elapsedVTime() { 978 // better than nothing, but not much 979 return elapsedTime(); 980 } 981 982 jlong os::javaTimeMillis() { 983 timeval time; 984 int status = gettimeofday(&time, NULL); 985 assert(status != -1, "bsd error"); 986 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 987 } 988 989 #ifndef CLOCK_MONOTONIC 990 #define CLOCK_MONOTONIC (1) 991 #endif 992 993 #ifdef __APPLE__ 994 void os::Bsd::clock_init() { 995 // XXXDARWIN: Investigate replacement monotonic clock 996 } 997 #else 998 void os::Bsd::clock_init() { 999 struct timespec res; 1000 struct timespec tp; 1001 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && 1002 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { 1003 // yes, monotonic clock is supported 1004 _clock_gettime = ::clock_gettime; 1005 } 1006 } 1007 #endif 1008 1009 1010 jlong os::javaTimeNanos() { 1011 if (os::supports_monotonic_clock()) { 1012 struct timespec tp; 1013 int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp); 1014 assert(status == 0, "gettime error"); 1015 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1016 return result; 1017 } else { 1018 timeval time; 1019 int status = gettimeofday(&time, NULL); 1020 assert(status != -1, "bsd error"); 1021 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1022 return 1000 * usecs; 1023 } 1024 } 1025 1026 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1027 if (os::supports_monotonic_clock()) { 1028 info_ptr->max_value = ALL_64_BITS; 1029 1030 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1031 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1032 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1033 } else { 1034 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1035 info_ptr->max_value = ALL_64_BITS; 1036 1037 // gettimeofday is a real time clock so it skips 1038 info_ptr->may_skip_backward = true; 1039 info_ptr->may_skip_forward = true; 1040 } 1041 1042 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1043 } 1044 1045 // Return the real, user, and system times in seconds from an 1046 // arbitrary fixed point in the past. 1047 bool os::getTimesSecs(double* process_real_time, 1048 double* process_user_time, 1049 double* process_system_time) { 1050 struct tms ticks; 1051 clock_t real_ticks = times(&ticks); 1052 1053 if (real_ticks == (clock_t) (-1)) { 1054 return false; 1055 } else { 1056 double ticks_per_second = (double) clock_tics_per_sec; 1057 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1058 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1059 *process_real_time = ((double) real_ticks) / ticks_per_second; 1060 1061 return true; 1062 } 1063 } 1064 1065 1066 char * os::local_time_string(char *buf, size_t buflen) { 1067 struct tm t; 1068 time_t long_time; 1069 time(&long_time); 1070 localtime_r(&long_time, &t); 1071 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1072 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1073 t.tm_hour, t.tm_min, t.tm_sec); 1074 return buf; 1075 } 1076 1077 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1078 return localtime_r(clock, res); 1079 } 1080 1081 //////////////////////////////////////////////////////////////////////////////// 1082 // runtime exit support 1083 1084 // Note: os::shutdown() might be called very early during initialization, or 1085 // called from signal handler. Before adding something to os::shutdown(), make 1086 // sure it is async-safe and can handle partially initialized VM. 1087 void os::shutdown() { 1088 1089 // allow PerfMemory to attempt cleanup of any persistent resources 1090 perfMemory_exit(); 1091 1092 // needs to remove object in file system 1093 AttachListener::abort(); 1094 1095 // flush buffered output, finish log files 1096 ostream_abort(); 1097 1098 // Check for abort hook 1099 abort_hook_t abort_hook = Arguments::abort_hook(); 1100 if (abort_hook != NULL) { 1101 abort_hook(); 1102 } 1103 1104 } 1105 1106 // Note: os::abort() might be called very early during initialization, or 1107 // called from signal handler. Before adding something to os::abort(), make 1108 // sure it is async-safe and can handle partially initialized VM. 1109 void os::abort(bool dump_core) { 1110 os::shutdown(); 1111 if (dump_core) { 1112 #ifndef PRODUCT 1113 fdStream out(defaultStream::output_fd()); 1114 out.print_raw("Current thread is "); 1115 char buf[16]; 1116 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1117 out.print_raw_cr(buf); 1118 out.print_raw_cr("Dumping core ..."); 1119 #endif 1120 ::abort(); // dump core 1121 } 1122 1123 ::exit(1); 1124 } 1125 1126 // Die immediately, no exit hook, no abort hook, no cleanup. 1127 void os::die() { 1128 // _exit() on BsdThreads only kills current thread 1129 ::abort(); 1130 } 1131 1132 // unused on bsd for now. 1133 void os::set_error_file(const char *logfile) {} 1134 1135 1136 // This method is a copy of JDK's sysGetLastErrorString 1137 // from src/solaris/hpi/src/system_md.c 1138 1139 size_t os::lasterror(char *buf, size_t len) { 1140 1141 if (errno == 0) return 0; 1142 1143 const char *s = ::strerror(errno); 1144 size_t n = ::strlen(s); 1145 if (n >= len) { 1146 n = len - 1; 1147 } 1148 ::strncpy(buf, s, n); 1149 buf[n] = '\0'; 1150 return n; 1151 } 1152 1153 // Information of current thread in variety of formats 1154 pid_t os::Bsd::gettid() { 1155 int retval = -1; 1156 1157 #ifdef __APPLE__ //XNU kernel 1158 // despite the fact mach port is actually not a thread id use it 1159 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4 1160 retval = ::pthread_mach_thread_np(::pthread_self()); 1161 guarantee(retval != 0, "just checking"); 1162 return retval; 1163 1164 #elif __FreeBSD__ 1165 retval = syscall(SYS_thr_self); 1166 #elif __OpenBSD__ 1167 retval = syscall(SYS_getthrid); 1168 #elif __NetBSD__ 1169 retval = (pid_t) syscall(SYS__lwp_self); 1170 #endif 1171 1172 if (retval == -1) { 1173 return getpid(); 1174 } 1175 } 1176 1177 intx os::current_thread_id() { 1178 #ifdef __APPLE__ 1179 return (intx)::pthread_mach_thread_np(::pthread_self()); 1180 #else 1181 return (intx)::pthread_self(); 1182 #endif 1183 } 1184 1185 int os::current_process_id() { 1186 1187 // Under the old bsd thread library, bsd gives each thread 1188 // its own process id. Because of this each thread will return 1189 // a different pid if this method were to return the result 1190 // of getpid(2). Bsd provides no api that returns the pid 1191 // of the launcher thread for the vm. This implementation 1192 // returns a unique pid, the pid of the launcher thread 1193 // that starts the vm 'process'. 1194 1195 // Under the NPTL, getpid() returns the same pid as the 1196 // launcher thread rather than a unique pid per thread. 1197 // Use gettid() if you want the old pre NPTL behaviour. 1198 1199 // if you are looking for the result of a call to getpid() that 1200 // returns a unique pid for the calling thread, then look at the 1201 // OSThread::thread_id() method in osThread_bsd.hpp file 1202 1203 return (int)(_initial_pid ? _initial_pid : getpid()); 1204 } 1205 1206 // DLL functions 1207 1208 #define JNI_LIB_PREFIX "lib" 1209 #ifdef __APPLE__ 1210 #define JNI_LIB_SUFFIX ".dylib" 1211 #else 1212 #define JNI_LIB_SUFFIX ".so" 1213 #endif 1214 1215 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } 1216 1217 // This must be hard coded because it's the system's temporary 1218 // directory not the java application's temp directory, ala java.io.tmpdir. 1219 #ifdef __APPLE__ 1220 // macosx has a secure per-user temporary directory 1221 char temp_path_storage[PATH_MAX]; 1222 const char* os::get_temp_directory() { 1223 static char *temp_path = NULL; 1224 if (temp_path == NULL) { 1225 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX); 1226 if (pathSize == 0 || pathSize > PATH_MAX) { 1227 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage)); 1228 } 1229 temp_path = temp_path_storage; 1230 } 1231 return temp_path; 1232 } 1233 #else /* __APPLE__ */ 1234 const char* os::get_temp_directory() { return "/tmp"; } 1235 #endif /* __APPLE__ */ 1236 1237 static bool file_exists(const char* filename) { 1238 struct stat statbuf; 1239 if (filename == NULL || strlen(filename) == 0) { 1240 return false; 1241 } 1242 return os::stat(filename, &statbuf) == 0; 1243 } 1244 1245 bool os::dll_build_name(char* buffer, size_t buflen, 1246 const char* pname, const char* fname) { 1247 bool retval = false; 1248 // Copied from libhpi 1249 const size_t pnamelen = pname ? strlen(pname) : 0; 1250 1251 // Return error on buffer overflow. 1252 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { 1253 return retval; 1254 } 1255 1256 if (pnamelen == 0) { 1257 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); 1258 retval = true; 1259 } else if (strchr(pname, *os::path_separator()) != NULL) { 1260 int n; 1261 char** pelements = split_path(pname, &n); 1262 if (pelements == NULL) { 1263 return false; 1264 } 1265 for (int i = 0 ; i < n ; i++) { 1266 // Really shouldn't be NULL, but check can't hurt 1267 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1268 continue; // skip the empty path values 1269 } 1270 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, 1271 pelements[i], fname); 1272 if (file_exists(buffer)) { 1273 retval = true; 1274 break; 1275 } 1276 } 1277 // release the storage 1278 for (int i = 0 ; i < n ; i++) { 1279 if (pelements[i] != NULL) { 1280 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal); 1281 } 1282 } 1283 if (pelements != NULL) { 1284 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal); 1285 } 1286 } else { 1287 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); 1288 retval = true; 1289 } 1290 return retval; 1291 } 1292 1293 // check if addr is inside libjvm.so 1294 bool os::address_is_in_vm(address addr) { 1295 static address libjvm_base_addr; 1296 Dl_info dlinfo; 1297 1298 if (libjvm_base_addr == NULL) { 1299 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1300 libjvm_base_addr = (address)dlinfo.dli_fbase; 1301 } 1302 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1303 } 1304 1305 if (dladdr((void *)addr, &dlinfo) != 0) { 1306 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1307 } 1308 1309 return false; 1310 } 1311 1312 1313 #define MACH_MAXSYMLEN 256 1314 1315 bool os::dll_address_to_function_name(address addr, char *buf, 1316 int buflen, int *offset) { 1317 // buf is not optional, but offset is optional 1318 assert(buf != NULL, "sanity check"); 1319 1320 Dl_info dlinfo; 1321 char localbuf[MACH_MAXSYMLEN]; 1322 1323 if (dladdr((void*)addr, &dlinfo) != 0) { 1324 // see if we have a matching symbol 1325 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1326 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { 1327 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1328 } 1329 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1330 return true; 1331 } 1332 // no matching symbol so try for just file info 1333 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1334 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1335 buf, buflen, offset, dlinfo.dli_fname)) { 1336 return true; 1337 } 1338 } 1339 1340 // Handle non-dynamic manually: 1341 if (dlinfo.dli_fbase != NULL && 1342 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, 1343 dlinfo.dli_fbase)) { 1344 if (!Decoder::demangle(localbuf, buf, buflen)) { 1345 jio_snprintf(buf, buflen, "%s", localbuf); 1346 } 1347 return true; 1348 } 1349 } 1350 buf[0] = '\0'; 1351 if (offset != NULL) *offset = -1; 1352 return false; 1353 } 1354 1355 // ported from solaris version 1356 bool os::dll_address_to_library_name(address addr, char* buf, 1357 int buflen, int* offset) { 1358 // buf is not optional, but offset is optional 1359 assert(buf != NULL, "sanity check"); 1360 1361 Dl_info dlinfo; 1362 1363 if (dladdr((void*)addr, &dlinfo) != 0) { 1364 if (dlinfo.dli_fname != NULL) { 1365 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1366 } 1367 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1368 *offset = addr - (address)dlinfo.dli_fbase; 1369 } 1370 return true; 1371 } 1372 1373 buf[0] = '\0'; 1374 if (offset) *offset = -1; 1375 return false; 1376 } 1377 1378 // Loads .dll/.so and 1379 // in case of error it checks if .dll/.so was built for the 1380 // same architecture as Hotspot is running on 1381 1382 #ifdef __APPLE__ 1383 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1384 void * result= ::dlopen(filename, RTLD_LAZY); 1385 if (result != NULL) { 1386 // Successful loading 1387 return result; 1388 } 1389 1390 // Read system error message into ebuf 1391 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1392 ebuf[ebuflen-1]='\0'; 1393 1394 return NULL; 1395 } 1396 #else 1397 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) 1398 { 1399 void * result= ::dlopen(filename, RTLD_LAZY); 1400 if (result != NULL) { 1401 // Successful loading 1402 return result; 1403 } 1404 1405 Elf32_Ehdr elf_head; 1406 1407 // Read system error message into ebuf 1408 // It may or may not be overwritten below 1409 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1410 ebuf[ebuflen-1]='\0'; 1411 int diag_msg_max_length=ebuflen-strlen(ebuf); 1412 char* diag_msg_buf=ebuf+strlen(ebuf); 1413 1414 if (diag_msg_max_length==0) { 1415 // No more space in ebuf for additional diagnostics message 1416 return NULL; 1417 } 1418 1419 1420 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1421 1422 if (file_descriptor < 0) { 1423 // Can't open library, report dlerror() message 1424 return NULL; 1425 } 1426 1427 bool failed_to_read_elf_head= 1428 (sizeof(elf_head)!= 1429 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ; 1430 1431 ::close(file_descriptor); 1432 if (failed_to_read_elf_head) { 1433 // file i/o error - report dlerror() msg 1434 return NULL; 1435 } 1436 1437 typedef struct { 1438 Elf32_Half code; // Actual value as defined in elf.h 1439 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1440 char elf_class; // 32 or 64 bit 1441 char endianess; // MSB or LSB 1442 char* name; // String representation 1443 } arch_t; 1444 1445 #ifndef EM_486 1446 #define EM_486 6 /* Intel 80486 */ 1447 #endif 1448 1449 #ifndef EM_MIPS_RS3_LE 1450 #define EM_MIPS_RS3_LE 10 /* MIPS */ 1451 #endif 1452 1453 #ifndef EM_PPC64 1454 #define EM_PPC64 21 /* PowerPC64 */ 1455 #endif 1456 1457 #ifndef EM_S390 1458 #define EM_S390 22 /* IBM System/390 */ 1459 #endif 1460 1461 #ifndef EM_IA_64 1462 #define EM_IA_64 50 /* HP/Intel IA-64 */ 1463 #endif 1464 1465 #ifndef EM_X86_64 1466 #define EM_X86_64 62 /* AMD x86-64 */ 1467 #endif 1468 1469 static const arch_t arch_array[]={ 1470 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1471 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1472 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1473 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1474 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1475 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1476 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1477 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1478 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1479 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1480 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1481 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1482 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1483 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1484 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1485 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} 1486 }; 1487 1488 #if (defined IA32) 1489 static Elf32_Half running_arch_code=EM_386; 1490 #elif (defined AMD64) 1491 static Elf32_Half running_arch_code=EM_X86_64; 1492 #elif (defined IA64) 1493 static Elf32_Half running_arch_code=EM_IA_64; 1494 #elif (defined __sparc) && (defined _LP64) 1495 static Elf32_Half running_arch_code=EM_SPARCV9; 1496 #elif (defined __sparc) && (!defined _LP64) 1497 static Elf32_Half running_arch_code=EM_SPARC; 1498 #elif (defined __powerpc64__) 1499 static Elf32_Half running_arch_code=EM_PPC64; 1500 #elif (defined __powerpc__) 1501 static Elf32_Half running_arch_code=EM_PPC; 1502 #elif (defined ARM) 1503 static Elf32_Half running_arch_code=EM_ARM; 1504 #elif (defined S390) 1505 static Elf32_Half running_arch_code=EM_S390; 1506 #elif (defined ALPHA) 1507 static Elf32_Half running_arch_code=EM_ALPHA; 1508 #elif (defined MIPSEL) 1509 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1510 #elif (defined PARISC) 1511 static Elf32_Half running_arch_code=EM_PARISC; 1512 #elif (defined MIPS) 1513 static Elf32_Half running_arch_code=EM_MIPS; 1514 #elif (defined M68K) 1515 static Elf32_Half running_arch_code=EM_68K; 1516 #else 1517 #error Method os::dll_load requires that one of following is defined:\ 1518 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K 1519 #endif 1520 1521 // Identify compatability class for VM's architecture and library's architecture 1522 // Obtain string descriptions for architectures 1523 1524 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1525 int running_arch_index=-1; 1526 1527 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) { 1528 if (running_arch_code == arch_array[i].code) { 1529 running_arch_index = i; 1530 } 1531 if (lib_arch.code == arch_array[i].code) { 1532 lib_arch.compat_class = arch_array[i].compat_class; 1533 lib_arch.name = arch_array[i].name; 1534 } 1535 } 1536 1537 assert(running_arch_index != -1, 1538 "Didn't find running architecture code (running_arch_code) in arch_array"); 1539 if (running_arch_index == -1) { 1540 // Even though running architecture detection failed 1541 // we may still continue with reporting dlerror() message 1542 return NULL; 1543 } 1544 1545 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1546 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1547 return NULL; 1548 } 1549 1550 #ifndef S390 1551 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1552 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1553 return NULL; 1554 } 1555 #endif // !S390 1556 1557 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1558 if ( lib_arch.name!=NULL ) { 1559 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1560 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1561 lib_arch.name, arch_array[running_arch_index].name); 1562 } else { 1563 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1564 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1565 lib_arch.code, 1566 arch_array[running_arch_index].name); 1567 } 1568 } 1569 1570 return NULL; 1571 } 1572 #endif /* !__APPLE__ */ 1573 1574 void* os::get_default_process_handle() { 1575 #ifdef __APPLE__ 1576 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY 1577 // to avoid finding unexpected symbols on second (or later) 1578 // loads of a library. 1579 return (void*)::dlopen(NULL, RTLD_FIRST); 1580 #else 1581 return (void*)::dlopen(NULL, RTLD_LAZY); 1582 #endif 1583 } 1584 1585 // XXX: Do we need a lock around this as per Linux? 1586 void* os::dll_lookup(void* handle, const char* name) { 1587 return dlsym(handle, name); 1588 } 1589 1590 1591 static bool _print_ascii_file(const char* filename, outputStream* st) { 1592 int fd = ::open(filename, O_RDONLY); 1593 if (fd == -1) { 1594 return false; 1595 } 1596 1597 char buf[32]; 1598 int bytes; 1599 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { 1600 st->print_raw(buf, bytes); 1601 } 1602 1603 ::close(fd); 1604 1605 return true; 1606 } 1607 1608 void os::print_dll_info(outputStream *st) { 1609 st->print_cr("Dynamic libraries:"); 1610 #ifdef RTLD_DI_LINKMAP 1611 Dl_info dli; 1612 void *handle; 1613 Link_map *map; 1614 Link_map *p; 1615 1616 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 || 1617 dli.dli_fname == NULL) { 1618 st->print_cr("Error: Cannot print dynamic libraries."); 1619 return; 1620 } 1621 handle = dlopen(dli.dli_fname, RTLD_LAZY); 1622 if (handle == NULL) { 1623 st->print_cr("Error: Cannot print dynamic libraries."); 1624 return; 1625 } 1626 dlinfo(handle, RTLD_DI_LINKMAP, &map); 1627 if (map == NULL) { 1628 st->print_cr("Error: Cannot print dynamic libraries."); 1629 return; 1630 } 1631 1632 while (map->l_prev != NULL) 1633 map = map->l_prev; 1634 1635 while (map != NULL) { 1636 st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name); 1637 map = map->l_next; 1638 } 1639 1640 dlclose(handle); 1641 #elif defined(__APPLE__) 1642 uint32_t count; 1643 uint32_t i; 1644 1645 count = _dyld_image_count(); 1646 for (i = 1; i < count; i++) { 1647 const char *name = _dyld_get_image_name(i); 1648 intptr_t slide = _dyld_get_image_vmaddr_slide(i); 1649 st->print_cr(PTR_FORMAT " \t%s", slide, name); 1650 } 1651 #else 1652 st->print_cr("Error: Cannot print dynamic libraries."); 1653 #endif 1654 } 1655 1656 void os::print_os_info_brief(outputStream* st) { 1657 st->print("Bsd"); 1658 1659 os::Posix::print_uname_info(st); 1660 } 1661 1662 void os::print_os_info(outputStream* st) { 1663 st->print("OS:"); 1664 st->print("Bsd"); 1665 1666 os::Posix::print_uname_info(st); 1667 1668 os::Posix::print_rlimit_info(st); 1669 1670 os::Posix::print_load_average(st); 1671 } 1672 1673 void os::pd_print_cpu_info(outputStream* st) { 1674 // Nothing to do for now. 1675 } 1676 1677 void os::print_memory_info(outputStream* st) { 1678 1679 st->print("Memory:"); 1680 st->print(" %dk page", os::vm_page_size()>>10); 1681 1682 st->print(", physical " UINT64_FORMAT "k", 1683 os::physical_memory() >> 10); 1684 st->print("(" UINT64_FORMAT "k free)", 1685 os::available_memory() >> 10); 1686 st->cr(); 1687 1688 // meminfo 1689 st->print("\n/proc/meminfo:\n"); 1690 _print_ascii_file("/proc/meminfo", st); 1691 st->cr(); 1692 } 1693 1694 void os::print_siginfo(outputStream* st, void* siginfo) { 1695 const siginfo_t* si = (const siginfo_t*)siginfo; 1696 1697 os::Posix::print_siginfo_brief(st, si); 1698 1699 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && 1700 UseSharedSpaces) { 1701 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1702 if (mapinfo->is_in_shared_space(si->si_addr)) { 1703 st->print("\n\nError accessing class data sharing archive." \ 1704 " Mapped file inaccessible during execution, " \ 1705 " possible disk/network problem."); 1706 } 1707 } 1708 st->cr(); 1709 } 1710 1711 1712 static void print_signal_handler(outputStream* st, int sig, 1713 char* buf, size_t buflen); 1714 1715 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 1716 st->print_cr("Signal Handlers:"); 1717 print_signal_handler(st, SIGSEGV, buf, buflen); 1718 print_signal_handler(st, SIGBUS , buf, buflen); 1719 print_signal_handler(st, SIGFPE , buf, buflen); 1720 print_signal_handler(st, SIGPIPE, buf, buflen); 1721 print_signal_handler(st, SIGXFSZ, buf, buflen); 1722 print_signal_handler(st, SIGILL , buf, buflen); 1723 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); 1724 print_signal_handler(st, SR_signum, buf, buflen); 1725 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 1726 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 1727 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 1728 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 1729 } 1730 1731 static char saved_jvm_path[MAXPATHLEN] = {0}; 1732 1733 // Find the full path to the current module, libjvm 1734 void os::jvm_path(char *buf, jint buflen) { 1735 // Error checking. 1736 if (buflen < MAXPATHLEN) { 1737 assert(false, "must use a large-enough buffer"); 1738 buf[0] = '\0'; 1739 return; 1740 } 1741 // Lazy resolve the path to current module. 1742 if (saved_jvm_path[0] != 0) { 1743 strcpy(buf, saved_jvm_path); 1744 return; 1745 } 1746 1747 char dli_fname[MAXPATHLEN]; 1748 bool ret = dll_address_to_library_name( 1749 CAST_FROM_FN_PTR(address, os::jvm_path), 1750 dli_fname, sizeof(dli_fname), NULL); 1751 assert(ret, "cannot locate libjvm"); 1752 char *rp = NULL; 1753 if (ret && dli_fname[0] != '\0') { 1754 rp = realpath(dli_fname, buf); 1755 } 1756 if (rp == NULL) 1757 return; 1758 1759 if (Arguments::sun_java_launcher_is_altjvm()) { 1760 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 1761 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so" 1762 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/" 1763 // appears at the right place in the string, then assume we are 1764 // installed in a JDK and we're done. Otherwise, check for a 1765 // JAVA_HOME environment variable and construct a path to the JVM 1766 // being overridden. 1767 1768 const char *p = buf + strlen(buf) - 1; 1769 for (int count = 0; p > buf && count < 5; ++count) { 1770 for (--p; p > buf && *p != '/'; --p) 1771 /* empty */ ; 1772 } 1773 1774 if (strncmp(p, "/jre/lib/", 9) != 0) { 1775 // Look for JAVA_HOME in the environment. 1776 char* java_home_var = ::getenv("JAVA_HOME"); 1777 if (java_home_var != NULL && java_home_var[0] != 0) { 1778 char* jrelib_p; 1779 int len; 1780 1781 // Check the current module name "libjvm" 1782 p = strrchr(buf, '/'); 1783 assert(strstr(p, "/libjvm") == p, "invalid library name"); 1784 1785 rp = realpath(java_home_var, buf); 1786 if (rp == NULL) 1787 return; 1788 1789 // determine if this is a legacy image or modules image 1790 // modules image doesn't have "jre" subdirectory 1791 len = strlen(buf); 1792 jrelib_p = buf + len; 1793 1794 // Add the appropriate library subdir 1795 snprintf(jrelib_p, buflen-len, "/jre/lib"); 1796 if (0 != access(buf, F_OK)) { 1797 snprintf(jrelib_p, buflen-len, "/lib"); 1798 } 1799 1800 // Add the appropriate client or server subdir 1801 len = strlen(buf); 1802 jrelib_p = buf + len; 1803 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT); 1804 if (0 != access(buf, F_OK)) { 1805 snprintf(jrelib_p, buflen-len, "%s", ""); 1806 } 1807 1808 // If the path exists within JAVA_HOME, add the JVM library name 1809 // to complete the path to JVM being overridden. Otherwise fallback 1810 // to the path to the current library. 1811 if (0 == access(buf, F_OK)) { 1812 // Use current module name "libjvm" 1813 len = strlen(buf); 1814 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX); 1815 } else { 1816 // Fall back to path of current library 1817 rp = realpath(dli_fname, buf); 1818 if (rp == NULL) 1819 return; 1820 } 1821 } 1822 } 1823 } 1824 1825 strcpy(saved_jvm_path, buf); 1826 } 1827 1828 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 1829 // no prefix required, not even "_" 1830 } 1831 1832 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 1833 // no suffix required 1834 } 1835 1836 //////////////////////////////////////////////////////////////////////////////// 1837 // sun.misc.Signal support 1838 1839 static volatile jint sigint_count = 0; 1840 1841 static void 1842 UserHandler(int sig, void *siginfo, void *context) { 1843 // 4511530 - sem_post is serialized and handled by the manager thread. When 1844 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 1845 // don't want to flood the manager thread with sem_post requests. 1846 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) 1847 return; 1848 1849 // Ctrl-C is pressed during error reporting, likely because the error 1850 // handler fails to abort. Let VM die immediately. 1851 if (sig == SIGINT && is_error_reported()) { 1852 os::die(); 1853 } 1854 1855 os::signal_notify(sig); 1856 } 1857 1858 void* os::user_handler() { 1859 return CAST_FROM_FN_PTR(void*, UserHandler); 1860 } 1861 1862 extern "C" { 1863 typedef void (*sa_handler_t)(int); 1864 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1865 } 1866 1867 void* os::signal(int signal_number, void* handler) { 1868 struct sigaction sigAct, oldSigAct; 1869 1870 sigfillset(&(sigAct.sa_mask)); 1871 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 1872 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 1873 1874 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 1875 // -1 means registration failed 1876 return (void *)-1; 1877 } 1878 1879 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 1880 } 1881 1882 void os::signal_raise(int signal_number) { 1883 ::raise(signal_number); 1884 } 1885 1886 /* 1887 * The following code is moved from os.cpp for making this 1888 * code platform specific, which it is by its very nature. 1889 */ 1890 1891 // Will be modified when max signal is changed to be dynamic 1892 int os::sigexitnum_pd() { 1893 return NSIG; 1894 } 1895 1896 // a counter for each possible signal value 1897 static volatile jint pending_signals[NSIG+1] = { 0 }; 1898 1899 // Bsd(POSIX) specific hand shaking semaphore. 1900 #ifdef __APPLE__ 1901 typedef semaphore_t os_semaphore_t; 1902 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) 1903 #define SEM_WAIT(sem) semaphore_wait(sem) 1904 #define SEM_POST(sem) semaphore_signal(sem) 1905 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem) 1906 #else 1907 typedef sem_t os_semaphore_t; 1908 #define SEM_INIT(sem, value) sem_init(&sem, 0, value) 1909 #define SEM_WAIT(sem) sem_wait(&sem) 1910 #define SEM_POST(sem) sem_post(&sem) 1911 #define SEM_DESTROY(sem) sem_destroy(&sem) 1912 #endif 1913 1914 class Semaphore : public StackObj { 1915 public: 1916 Semaphore(); 1917 ~Semaphore(); 1918 void signal(); 1919 void wait(); 1920 bool trywait(); 1921 bool timedwait(unsigned int sec, int nsec); 1922 private: 1923 jlong currenttime() const; 1924 os_semaphore_t _semaphore; 1925 }; 1926 1927 Semaphore::Semaphore() : _semaphore(0) { 1928 SEM_INIT(_semaphore, 0); 1929 } 1930 1931 Semaphore::~Semaphore() { 1932 SEM_DESTROY(_semaphore); 1933 } 1934 1935 void Semaphore::signal() { 1936 SEM_POST(_semaphore); 1937 } 1938 1939 void Semaphore::wait() { 1940 SEM_WAIT(_semaphore); 1941 } 1942 1943 jlong Semaphore::currenttime() const { 1944 struct timeval tv; 1945 gettimeofday(&tv, NULL); 1946 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000); 1947 } 1948 1949 #ifdef __APPLE__ 1950 bool Semaphore::trywait() { 1951 return timedwait(0, 0); 1952 } 1953 1954 bool Semaphore::timedwait(unsigned int sec, int nsec) { 1955 kern_return_t kr = KERN_ABORTED; 1956 mach_timespec_t waitspec; 1957 waitspec.tv_sec = sec; 1958 waitspec.tv_nsec = nsec; 1959 1960 jlong starttime = currenttime(); 1961 1962 kr = semaphore_timedwait(_semaphore, waitspec); 1963 while (kr == KERN_ABORTED) { 1964 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec; 1965 1966 jlong current = currenttime(); 1967 jlong passedtime = current - starttime; 1968 1969 if (passedtime >= totalwait) { 1970 waitspec.tv_sec = 0; 1971 waitspec.tv_nsec = 0; 1972 } else { 1973 jlong waittime = totalwait - (current - starttime); 1974 waitspec.tv_sec = waittime / NANOSECS_PER_SEC; 1975 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC; 1976 } 1977 1978 kr = semaphore_timedwait(_semaphore, waitspec); 1979 } 1980 1981 return kr == KERN_SUCCESS; 1982 } 1983 1984 #else 1985 1986 bool Semaphore::trywait() { 1987 return sem_trywait(&_semaphore) == 0; 1988 } 1989 1990 bool Semaphore::timedwait(unsigned int sec, int nsec) { 1991 struct timespec ts; 1992 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec); 1993 1994 while (1) { 1995 int result = sem_timedwait(&_semaphore, &ts); 1996 if (result == 0) { 1997 return true; 1998 } else if (errno == EINTR) { 1999 continue; 2000 } else if (errno == ETIMEDOUT) { 2001 return false; 2002 } else { 2003 return false; 2004 } 2005 } 2006 } 2007 2008 #endif // __APPLE__ 2009 2010 static os_semaphore_t sig_sem; 2011 static Semaphore sr_semaphore; 2012 2013 void os::signal_init_pd() { 2014 // Initialize signal structures 2015 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2016 2017 // Initialize signal semaphore 2018 ::SEM_INIT(sig_sem, 0); 2019 } 2020 2021 void os::signal_notify(int sig) { 2022 Atomic::inc(&pending_signals[sig]); 2023 ::SEM_POST(sig_sem); 2024 } 2025 2026 static int check_pending_signals(bool wait) { 2027 Atomic::store(0, &sigint_count); 2028 for (;;) { 2029 for (int i = 0; i < NSIG + 1; i++) { 2030 jint n = pending_signals[i]; 2031 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2032 return i; 2033 } 2034 } 2035 if (!wait) { 2036 return -1; 2037 } 2038 JavaThread *thread = JavaThread::current(); 2039 ThreadBlockInVM tbivm(thread); 2040 2041 bool threadIsSuspended; 2042 do { 2043 thread->set_suspend_equivalent(); 2044 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2045 ::SEM_WAIT(sig_sem); 2046 2047 // were we externally suspended while we were waiting? 2048 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2049 if (threadIsSuspended) { 2050 // 2051 // The semaphore has been incremented, but while we were waiting 2052 // another thread suspended us. We don't want to continue running 2053 // while suspended because that would surprise the thread that 2054 // suspended us. 2055 // 2056 ::SEM_POST(sig_sem); 2057 2058 thread->java_suspend_self(); 2059 } 2060 } while (threadIsSuspended); 2061 } 2062 } 2063 2064 int os::signal_lookup() { 2065 return check_pending_signals(false); 2066 } 2067 2068 int os::signal_wait() { 2069 return check_pending_signals(true); 2070 } 2071 2072 //////////////////////////////////////////////////////////////////////////////// 2073 // Virtual Memory 2074 2075 int os::vm_page_size() { 2076 // Seems redundant as all get out 2077 assert(os::Bsd::page_size() != -1, "must call os::init"); 2078 return os::Bsd::page_size(); 2079 } 2080 2081 // Solaris allocates memory by pages. 2082 int os::vm_allocation_granularity() { 2083 assert(os::Bsd::page_size() != -1, "must call os::init"); 2084 return os::Bsd::page_size(); 2085 } 2086 2087 // Rationale behind this function: 2088 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2089 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2090 // samples for JITted code. Here we create private executable mapping over the code cache 2091 // and then we can use standard (well, almost, as mapping can change) way to provide 2092 // info for the reporting script by storing timestamp and location of symbol 2093 void bsd_wrap_code(char* base, size_t size) { 2094 static volatile jint cnt = 0; 2095 2096 if (!UseOprofile) { 2097 return; 2098 } 2099 2100 char buf[PATH_MAX + 1]; 2101 int num = Atomic::add(1, &cnt); 2102 2103 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", 2104 os::get_temp_directory(), os::current_process_id(), num); 2105 unlink(buf); 2106 2107 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2108 2109 if (fd != -1) { 2110 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2111 if (rv != (off_t)-1) { 2112 if (::write(fd, "", 1) == 1) { 2113 mmap(base, size, 2114 PROT_READ|PROT_WRITE|PROT_EXEC, 2115 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2116 } 2117 } 2118 ::close(fd); 2119 unlink(buf); 2120 } 2121 } 2122 2123 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2124 int err) { 2125 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2126 ", %d) failed; error='%s' (errno=%d)", addr, size, exec, 2127 strerror(err), err); 2128 } 2129 2130 // NOTE: Bsd kernel does not really reserve the pages for us. 2131 // All it does is to check if there are enough free pages 2132 // left at the time of mmap(). This could be a potential 2133 // problem. 2134 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2135 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2136 #ifdef __OpenBSD__ 2137 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2138 if (::mprotect(addr, size, prot) == 0) { 2139 return true; 2140 } 2141 #else 2142 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2143 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2144 if (res != (uintptr_t) MAP_FAILED) { 2145 return true; 2146 } 2147 #endif 2148 2149 // Warn about any commit errors we see in non-product builds just 2150 // in case mmap() doesn't work as described on the man page. 2151 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);) 2152 2153 return false; 2154 } 2155 2156 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2157 bool exec) { 2158 // alignment_hint is ignored on this OS 2159 return pd_commit_memory(addr, size, exec); 2160 } 2161 2162 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2163 const char* mesg) { 2164 assert(mesg != NULL, "mesg must be specified"); 2165 if (!pd_commit_memory(addr, size, exec)) { 2166 // add extra info in product mode for vm_exit_out_of_memory(): 2167 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);) 2168 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg); 2169 } 2170 } 2171 2172 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2173 size_t alignment_hint, bool exec, 2174 const char* mesg) { 2175 // alignment_hint is ignored on this OS 2176 pd_commit_memory_or_exit(addr, size, exec, mesg); 2177 } 2178 2179 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2180 } 2181 2182 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2183 ::madvise(addr, bytes, MADV_DONTNEED); 2184 } 2185 2186 void os::numa_make_global(char *addr, size_t bytes) { 2187 } 2188 2189 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2190 } 2191 2192 bool os::numa_topology_changed() { return false; } 2193 2194 size_t os::numa_get_groups_num() { 2195 return 1; 2196 } 2197 2198 int os::numa_get_group_id() { 2199 return 0; 2200 } 2201 2202 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2203 if (size > 0) { 2204 ids[0] = 0; 2205 return 1; 2206 } 2207 return 0; 2208 } 2209 2210 bool os::get_page_info(char *start, page_info* info) { 2211 return false; 2212 } 2213 2214 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { 2215 return end; 2216 } 2217 2218 2219 bool os::pd_uncommit_memory(char* addr, size_t size) { 2220 #ifdef __OpenBSD__ 2221 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2222 return ::mprotect(addr, size, PROT_NONE) == 0; 2223 #else 2224 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2225 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2226 return res != (uintptr_t) MAP_FAILED; 2227 #endif 2228 } 2229 2230 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2231 return os::commit_memory(addr, size, !ExecMem); 2232 } 2233 2234 // If this is a growable mapping, remove the guard pages entirely by 2235 // munmap()ping them. If not, just call uncommit_memory(). 2236 bool os::remove_stack_guard_pages(char* addr, size_t size) { 2237 return os::uncommit_memory(addr, size); 2238 } 2239 2240 static address _highest_vm_reserved_address = NULL; 2241 2242 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 2243 // at 'requested_addr'. If there are existing memory mappings at the same 2244 // location, however, they will be overwritten. If 'fixed' is false, 2245 // 'requested_addr' is only treated as a hint, the return value may or 2246 // may not start from the requested address. Unlike Bsd mmap(), this 2247 // function returns NULL to indicate failure. 2248 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 2249 char * addr; 2250 int flags; 2251 2252 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 2253 if (fixed) { 2254 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); 2255 flags |= MAP_FIXED; 2256 } 2257 2258 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 2259 // touch an uncommitted page. Otherwise, the read/write might 2260 // succeed if we have enough swap space to back the physical page. 2261 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 2262 flags, -1, 0); 2263 2264 if (addr != MAP_FAILED) { 2265 // anon_mmap() should only get called during VM initialization, 2266 // don't need lock (actually we can skip locking even it can be called 2267 // from multiple threads, because _highest_vm_reserved_address is just a 2268 // hint about the upper limit of non-stack memory regions.) 2269 if ((address)addr + bytes > _highest_vm_reserved_address) { 2270 _highest_vm_reserved_address = (address)addr + bytes; 2271 } 2272 } 2273 2274 return addr == MAP_FAILED ? NULL : addr; 2275 } 2276 2277 // Don't update _highest_vm_reserved_address, because there might be memory 2278 // regions above addr + size. If so, releasing a memory region only creates 2279 // a hole in the address space, it doesn't help prevent heap-stack collision. 2280 // 2281 static int anon_munmap(char * addr, size_t size) { 2282 return ::munmap(addr, size) == 0; 2283 } 2284 2285 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 2286 size_t alignment_hint) { 2287 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 2288 } 2289 2290 bool os::pd_release_memory(char* addr, size_t size) { 2291 return anon_munmap(addr, size); 2292 } 2293 2294 static bool bsd_mprotect(char* addr, size_t size, int prot) { 2295 // Bsd wants the mprotect address argument to be page aligned. 2296 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); 2297 2298 // According to SUSv3, mprotect() should only be used with mappings 2299 // established by mmap(), and mmap() always maps whole pages. Unaligned 2300 // 'addr' likely indicates problem in the VM (e.g. trying to change 2301 // protection of malloc'ed or statically allocated memory). Check the 2302 // caller if you hit this assert. 2303 assert(addr == bottom, "sanity check"); 2304 2305 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); 2306 return ::mprotect(bottom, size, prot) == 0; 2307 } 2308 2309 // Set protections specified 2310 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 2311 bool is_committed) { 2312 unsigned int p = 0; 2313 switch (prot) { 2314 case MEM_PROT_NONE: p = PROT_NONE; break; 2315 case MEM_PROT_READ: p = PROT_READ; break; 2316 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 2317 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 2318 default: 2319 ShouldNotReachHere(); 2320 } 2321 // is_committed is unused. 2322 return bsd_mprotect(addr, bytes, p); 2323 } 2324 2325 bool os::guard_memory(char* addr, size_t size) { 2326 return bsd_mprotect(addr, size, PROT_NONE); 2327 } 2328 2329 bool os::unguard_memory(char* addr, size_t size) { 2330 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); 2331 } 2332 2333 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { 2334 return false; 2335 } 2336 2337 // Large page support 2338 2339 static size_t _large_page_size = 0; 2340 2341 void os::large_page_init() { 2342 } 2343 2344 2345 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) { 2346 fatal("This code is not used or maintained."); 2347 2348 // "exec" is passed in but not used. Creating the shared image for 2349 // the code cache doesn't have an SHM_X executable permission to check. 2350 assert(UseLargePages && UseSHM, "only for SHM large pages"); 2351 2352 key_t key = IPC_PRIVATE; 2353 char *addr; 2354 2355 bool warn_on_failure = UseLargePages && 2356 (!FLAG_IS_DEFAULT(UseLargePages) || 2357 !FLAG_IS_DEFAULT(LargePageSizeInBytes) 2358 ); 2359 char msg[128]; 2360 2361 // Create a large shared memory region to attach to based on size. 2362 // Currently, size is the total size of the heap 2363 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); 2364 if (shmid == -1) { 2365 // Possible reasons for shmget failure: 2366 // 1. shmmax is too small for Java heap. 2367 // > check shmmax value: cat /proc/sys/kernel/shmmax 2368 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 2369 // 2. not enough large page memory. 2370 // > check available large pages: cat /proc/meminfo 2371 // > increase amount of large pages: 2372 // echo new_value > /proc/sys/vm/nr_hugepages 2373 // Note 1: different Bsd may use different name for this property, 2374 // e.g. on Redhat AS-3 it is "hugetlb_pool". 2375 // Note 2: it's possible there's enough physical memory available but 2376 // they are so fragmented after a long run that they can't 2377 // coalesce into large pages. Try to reserve large pages when 2378 // the system is still "fresh". 2379 if (warn_on_failure) { 2380 jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno); 2381 warning(msg); 2382 } 2383 return NULL; 2384 } 2385 2386 // attach to the region 2387 addr = (char*)shmat(shmid, req_addr, 0); 2388 int err = errno; 2389 2390 // Remove shmid. If shmat() is successful, the actual shared memory segment 2391 // will be deleted when it's detached by shmdt() or when the process 2392 // terminates. If shmat() is not successful this will remove the shared 2393 // segment immediately. 2394 shmctl(shmid, IPC_RMID, NULL); 2395 2396 if ((intptr_t)addr == -1) { 2397 if (warn_on_failure) { 2398 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err); 2399 warning(msg); 2400 } 2401 return NULL; 2402 } 2403 2404 // The memory is committed 2405 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, mtNone, CALLER_PC); 2406 2407 return addr; 2408 } 2409 2410 bool os::release_memory_special(char* base, size_t bytes) { 2411 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 2412 // detaching the SHM segment will also delete it, see reserve_memory_special() 2413 int rslt = shmdt(base); 2414 if (rslt == 0) { 2415 tkr.record((address)base, bytes); 2416 return true; 2417 } else { 2418 tkr.discard(); 2419 return false; 2420 } 2421 2422 } 2423 2424 size_t os::large_page_size() { 2425 return _large_page_size; 2426 } 2427 2428 // HugeTLBFS allows application to commit large page memory on demand; 2429 // with SysV SHM the entire memory region must be allocated as shared 2430 // memory. 2431 bool os::can_commit_large_page_memory() { 2432 return UseHugeTLBFS; 2433 } 2434 2435 bool os::can_execute_large_page_memory() { 2436 return UseHugeTLBFS; 2437 } 2438 2439 // Reserve memory at an arbitrary address, only if that area is 2440 // available (and not reserved for something else). 2441 2442 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 2443 const int max_tries = 10; 2444 char* base[max_tries]; 2445 size_t size[max_tries]; 2446 const size_t gap = 0x000000; 2447 2448 // Assert only that the size is a multiple of the page size, since 2449 // that's all that mmap requires, and since that's all we really know 2450 // about at this low abstraction level. If we need higher alignment, 2451 // we can either pass an alignment to this method or verify alignment 2452 // in one of the methods further up the call chain. See bug 5044738. 2453 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 2454 2455 // Repeatedly allocate blocks until the block is allocated at the 2456 // right spot. Give up after max_tries. Note that reserve_memory() will 2457 // automatically update _highest_vm_reserved_address if the call is 2458 // successful. The variable tracks the highest memory address every reserved 2459 // by JVM. It is used to detect heap-stack collision if running with 2460 // fixed-stack BsdThreads. Because here we may attempt to reserve more 2461 // space than needed, it could confuse the collision detecting code. To 2462 // solve the problem, save current _highest_vm_reserved_address and 2463 // calculate the correct value before return. 2464 address old_highest = _highest_vm_reserved_address; 2465 2466 // Bsd mmap allows caller to pass an address as hint; give it a try first, 2467 // if kernel honors the hint then we can return immediately. 2468 char * addr = anon_mmap(requested_addr, bytes, false); 2469 if (addr == requested_addr) { 2470 return requested_addr; 2471 } 2472 2473 if (addr != NULL) { 2474 // mmap() is successful but it fails to reserve at the requested address 2475 anon_munmap(addr, bytes); 2476 } 2477 2478 int i; 2479 for (i = 0; i < max_tries; ++i) { 2480 base[i] = reserve_memory(bytes); 2481 2482 if (base[i] != NULL) { 2483 // Is this the block we wanted? 2484 if (base[i] == requested_addr) { 2485 size[i] = bytes; 2486 break; 2487 } 2488 2489 // Does this overlap the block we wanted? Give back the overlapped 2490 // parts and try again. 2491 2492 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; 2493 if (top_overlap >= 0 && top_overlap < bytes) { 2494 unmap_memory(base[i], top_overlap); 2495 base[i] += top_overlap; 2496 size[i] = bytes - top_overlap; 2497 } else { 2498 size_t bottom_overlap = base[i] + bytes - requested_addr; 2499 if (bottom_overlap >= 0 && bottom_overlap < bytes) { 2500 unmap_memory(requested_addr, bottom_overlap); 2501 size[i] = bytes - bottom_overlap; 2502 } else { 2503 size[i] = bytes; 2504 } 2505 } 2506 } 2507 } 2508 2509 // Give back the unused reserved pieces. 2510 2511 for (int j = 0; j < i; ++j) { 2512 if (base[j] != NULL) { 2513 unmap_memory(base[j], size[j]); 2514 } 2515 } 2516 2517 if (i < max_tries) { 2518 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); 2519 return requested_addr; 2520 } else { 2521 _highest_vm_reserved_address = old_highest; 2522 return NULL; 2523 } 2524 } 2525 2526 size_t os::read(int fd, void *buf, unsigned int nBytes) { 2527 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); 2528 } 2529 2530 void os::naked_short_sleep(jlong ms) { 2531 struct timespec req; 2532 2533 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 2534 req.tv_sec = 0; 2535 if (ms > 0) { 2536 req.tv_nsec = (ms % 1000) * 1000000; 2537 } 2538 else { 2539 req.tv_nsec = 1; 2540 } 2541 2542 nanosleep(&req, NULL); 2543 2544 return; 2545 } 2546 2547 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 2548 void os::infinite_sleep() { 2549 while (true) { // sleep forever ... 2550 ::sleep(100); // ... 100 seconds at a time 2551 } 2552 } 2553 2554 // Used to convert frequent JVM_Yield() to nops 2555 bool os::dont_yield() { 2556 return DontYieldALot; 2557 } 2558 2559 void os::yield() { 2560 sched_yield(); 2561 } 2562 2563 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;} 2564 2565 void os::yield_all() { 2566 // Yields to all threads, including threads with lower priorities 2567 // Threads on Bsd are all with same priority. The Solaris style 2568 // os::yield_all() with nanosleep(1ms) is not necessary. 2569 sched_yield(); 2570 } 2571 2572 //////////////////////////////////////////////////////////////////////////////// 2573 // thread priority support 2574 2575 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER 2576 // only supports dynamic priority, static priority must be zero. For real-time 2577 // applications, Bsd supports SCHED_RR which allows static priority (1-99). 2578 // However, for large multi-threaded applications, SCHED_RR is not only slower 2579 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 2580 // of 5 runs - Sep 2005). 2581 // 2582 // The following code actually changes the niceness of kernel-thread/LWP. It 2583 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 2584 // not the entire user process, and user level threads are 1:1 mapped to kernel 2585 // threads. It has always been the case, but could change in the future. For 2586 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 2587 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 2588 2589 #if !defined(__APPLE__) 2590 int os::java_to_os_priority[CriticalPriority + 1] = { 2591 19, // 0 Entry should never be used 2592 2593 0, // 1 MinPriority 2594 3, // 2 2595 6, // 3 2596 2597 10, // 4 2598 15, // 5 NormPriority 2599 18, // 6 2600 2601 21, // 7 2602 25, // 8 2603 28, // 9 NearMaxPriority 2604 2605 31, // 10 MaxPriority 2606 2607 31 // 11 CriticalPriority 2608 }; 2609 #else 2610 /* Using Mach high-level priority assignments */ 2611 int os::java_to_os_priority[CriticalPriority + 1] = { 2612 0, // 0 Entry should never be used (MINPRI_USER) 2613 2614 27, // 1 MinPriority 2615 28, // 2 2616 29, // 3 2617 2618 30, // 4 2619 31, // 5 NormPriority (BASEPRI_DEFAULT) 2620 32, // 6 2621 2622 33, // 7 2623 34, // 8 2624 35, // 9 NearMaxPriority 2625 2626 36, // 10 MaxPriority 2627 2628 36 // 11 CriticalPriority 2629 }; 2630 #endif 2631 2632 static int prio_init() { 2633 if (ThreadPriorityPolicy == 1) { 2634 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 2635 // if effective uid is not root. Perhaps, a more elegant way of doing 2636 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 2637 if (geteuid() != 0) { 2638 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 2639 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); 2640 } 2641 ThreadPriorityPolicy = 0; 2642 } 2643 } 2644 if (UseCriticalJavaThreadPriority) { 2645 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 2646 } 2647 return 0; 2648 } 2649 2650 OSReturn os::set_native_priority(Thread* thread, int newpri) { 2651 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK; 2652 2653 #ifdef __OpenBSD__ 2654 // OpenBSD pthread_setprio starves low priority threads 2655 return OS_OK; 2656 #elif defined(__FreeBSD__) 2657 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); 2658 #elif defined(__APPLE__) || defined(__NetBSD__) 2659 struct sched_param sp; 2660 int policy; 2661 pthread_t self = pthread_self(); 2662 2663 if (pthread_getschedparam(self, &policy, &sp) != 0) 2664 return OS_ERR; 2665 2666 sp.sched_priority = newpri; 2667 if (pthread_setschedparam(self, policy, &sp) != 0) 2668 return OS_ERR; 2669 2670 return OS_OK; 2671 #else 2672 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 2673 return (ret == 0) ? OS_OK : OS_ERR; 2674 #endif 2675 } 2676 2677 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { 2678 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) { 2679 *priority_ptr = java_to_os_priority[NormPriority]; 2680 return OS_OK; 2681 } 2682 2683 errno = 0; 2684 #if defined(__OpenBSD__) || defined(__FreeBSD__) 2685 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); 2686 #elif defined(__APPLE__) || defined(__NetBSD__) 2687 int policy; 2688 struct sched_param sp; 2689 2690 pthread_getschedparam(pthread_self(), &policy, &sp); 2691 *priority_ptr = sp.sched_priority; 2692 #else 2693 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 2694 #endif 2695 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 2696 } 2697 2698 // Hint to the underlying OS that a task switch would not be good. 2699 // Void return because it's a hint and can fail. 2700 void os::hint_no_preempt() {} 2701 2702 //////////////////////////////////////////////////////////////////////////////// 2703 // suspend/resume support 2704 2705 // the low-level signal-based suspend/resume support is a remnant from the 2706 // old VM-suspension that used to be for java-suspension, safepoints etc, 2707 // within hotspot. Now there is a single use-case for this: 2708 // - calling get_thread_pc() on the VMThread by the flat-profiler task 2709 // that runs in the watcher thread. 2710 // The remaining code is greatly simplified from the more general suspension 2711 // code that used to be used. 2712 // 2713 // The protocol is quite simple: 2714 // - suspend: 2715 // - sends a signal to the target thread 2716 // - polls the suspend state of the osthread using a yield loop 2717 // - target thread signal handler (SR_handler) sets suspend state 2718 // and blocks in sigsuspend until continued 2719 // - resume: 2720 // - sets target osthread state to continue 2721 // - sends signal to end the sigsuspend loop in the SR_handler 2722 // 2723 // Note that the SR_lock plays no role in this suspend/resume protocol. 2724 // 2725 2726 static void resume_clear_context(OSThread *osthread) { 2727 osthread->set_ucontext(NULL); 2728 osthread->set_siginfo(NULL); 2729 } 2730 2731 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { 2732 osthread->set_ucontext(context); 2733 osthread->set_siginfo(siginfo); 2734 } 2735 2736 // 2737 // Handler function invoked when a thread's execution is suspended or 2738 // resumed. We have to be careful that only async-safe functions are 2739 // called here (Note: most pthread functions are not async safe and 2740 // should be avoided.) 2741 // 2742 // Note: sigwait() is a more natural fit than sigsuspend() from an 2743 // interface point of view, but sigwait() prevents the signal hander 2744 // from being run. libpthread would get very confused by not having 2745 // its signal handlers run and prevents sigwait()'s use with the 2746 // mutex granting granting signal. 2747 // 2748 // Currently only ever called on the VMThread or JavaThread 2749 // 2750 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 2751 // Save and restore errno to avoid confusing native code with EINTR 2752 // after sigsuspend. 2753 int old_errno = errno; 2754 2755 Thread* thread = Thread::current(); 2756 OSThread* osthread = thread->osthread(); 2757 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 2758 2759 os::SuspendResume::State current = osthread->sr.state(); 2760 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 2761 suspend_save_context(osthread, siginfo, context); 2762 2763 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 2764 os::SuspendResume::State state = osthread->sr.suspended(); 2765 if (state == os::SuspendResume::SR_SUSPENDED) { 2766 sigset_t suspend_set; // signals for sigsuspend() 2767 2768 // get current set of blocked signals and unblock resume signal 2769 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 2770 sigdelset(&suspend_set, SR_signum); 2771 2772 sr_semaphore.signal(); 2773 // wait here until we are resumed 2774 while (1) { 2775 sigsuspend(&suspend_set); 2776 2777 os::SuspendResume::State result = osthread->sr.running(); 2778 if (result == os::SuspendResume::SR_RUNNING) { 2779 sr_semaphore.signal(); 2780 break; 2781 } else if (result != os::SuspendResume::SR_SUSPENDED) { 2782 ShouldNotReachHere(); 2783 } 2784 } 2785 2786 } else if (state == os::SuspendResume::SR_RUNNING) { 2787 // request was cancelled, continue 2788 } else { 2789 ShouldNotReachHere(); 2790 } 2791 2792 resume_clear_context(osthread); 2793 } else if (current == os::SuspendResume::SR_RUNNING) { 2794 // request was cancelled, continue 2795 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 2796 // ignore 2797 } else { 2798 // ignore 2799 } 2800 2801 errno = old_errno; 2802 } 2803 2804 2805 static int SR_initialize() { 2806 struct sigaction act; 2807 char *s; 2808 /* Get signal number to use for suspend/resume */ 2809 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 2810 int sig = ::strtol(s, 0, 10); 2811 if (sig > 0 || sig < NSIG) { 2812 SR_signum = sig; 2813 } 2814 } 2815 2816 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 2817 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 2818 2819 sigemptyset(&SR_sigset); 2820 sigaddset(&SR_sigset, SR_signum); 2821 2822 /* Set up signal handler for suspend/resume */ 2823 act.sa_flags = SA_RESTART|SA_SIGINFO; 2824 act.sa_handler = (void (*)(int)) SR_handler; 2825 2826 // SR_signum is blocked by default. 2827 // 4528190 - We also need to block pthread restart signal (32 on all 2828 // supported Bsd platforms). Note that BsdThreads need to block 2829 // this signal for all threads to work properly. So we don't have 2830 // to use hard-coded signal number when setting up the mask. 2831 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 2832 2833 if (sigaction(SR_signum, &act, 0) == -1) { 2834 return -1; 2835 } 2836 2837 // Save signal flag 2838 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); 2839 return 0; 2840 } 2841 2842 static int sr_notify(OSThread* osthread) { 2843 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2844 assert_status(status == 0, status, "pthread_kill"); 2845 return status; 2846 } 2847 2848 // "Randomly" selected value for how long we want to spin 2849 // before bailing out on suspending a thread, also how often 2850 // we send a signal to a thread we want to resume 2851 static const int RANDOMLY_LARGE_INTEGER = 1000000; 2852 static const int RANDOMLY_LARGE_INTEGER2 = 100; 2853 2854 // returns true on success and false on error - really an error is fatal 2855 // but this seems the normal response to library errors 2856 static bool do_suspend(OSThread* osthread) { 2857 assert(osthread->sr.is_running(), "thread should be running"); 2858 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 2859 2860 // mark as suspended and send signal 2861 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 2862 // failed to switch, state wasn't running? 2863 ShouldNotReachHere(); 2864 return false; 2865 } 2866 2867 if (sr_notify(osthread) != 0) { 2868 ShouldNotReachHere(); 2869 } 2870 2871 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 2872 while (true) { 2873 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2874 break; 2875 } else { 2876 // timeout 2877 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 2878 if (cancelled == os::SuspendResume::SR_RUNNING) { 2879 return false; 2880 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 2881 // make sure that we consume the signal on the semaphore as well 2882 sr_semaphore.wait(); 2883 break; 2884 } else { 2885 ShouldNotReachHere(); 2886 return false; 2887 } 2888 } 2889 } 2890 2891 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 2892 return true; 2893 } 2894 2895 static void do_resume(OSThread* osthread) { 2896 assert(osthread->sr.is_suspended(), "thread should be suspended"); 2897 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 2898 2899 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 2900 // failed to switch to WAKEUP_REQUEST 2901 ShouldNotReachHere(); 2902 return; 2903 } 2904 2905 while (true) { 2906 if (sr_notify(osthread) == 0) { 2907 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2908 if (osthread->sr.is_running()) { 2909 return; 2910 } 2911 } 2912 } else { 2913 ShouldNotReachHere(); 2914 } 2915 } 2916 2917 guarantee(osthread->sr.is_running(), "Must be running!"); 2918 } 2919 2920 /////////////////////////////////////////////////////////////////////////////////// 2921 // signal handling (except suspend/resume) 2922 2923 // This routine may be used by user applications as a "hook" to catch signals. 2924 // The user-defined signal handler must pass unrecognized signals to this 2925 // routine, and if it returns true (non-zero), then the signal handler must 2926 // return immediately. If the flag "abort_if_unrecognized" is true, then this 2927 // routine will never retun false (zero), but instead will execute a VM panic 2928 // routine kill the process. 2929 // 2930 // If this routine returns false, it is OK to call it again. This allows 2931 // the user-defined signal handler to perform checks either before or after 2932 // the VM performs its own checks. Naturally, the user code would be making 2933 // a serious error if it tried to handle an exception (such as a null check 2934 // or breakpoint) that the VM was generating for its own correct operation. 2935 // 2936 // This routine may recognize any of the following kinds of signals: 2937 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 2938 // It should be consulted by handlers for any of those signals. 2939 // 2940 // The caller of this routine must pass in the three arguments supplied 2941 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 2942 // field of the structure passed to sigaction(). This routine assumes that 2943 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 2944 // 2945 // Note that the VM will print warnings if it detects conflicting signal 2946 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 2947 // 2948 extern "C" JNIEXPORT int 2949 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, 2950 void* ucontext, int abort_if_unrecognized); 2951 2952 void signalHandler(int sig, siginfo_t* info, void* uc) { 2953 assert(info != NULL && uc != NULL, "it must be old kernel"); 2954 int orig_errno = errno; // Preserve errno value over signal handler. 2955 JVM_handle_bsd_signal(sig, info, uc, true); 2956 errno = orig_errno; 2957 } 2958 2959 2960 // This boolean allows users to forward their own non-matching signals 2961 // to JVM_handle_bsd_signal, harmlessly. 2962 bool os::Bsd::signal_handlers_are_installed = false; 2963 2964 // For signal-chaining 2965 struct sigaction os::Bsd::sigact[MAXSIGNUM]; 2966 unsigned int os::Bsd::sigs = 0; 2967 bool os::Bsd::libjsig_is_loaded = false; 2968 typedef struct sigaction *(*get_signal_t)(int); 2969 get_signal_t os::Bsd::get_signal_action = NULL; 2970 2971 struct sigaction* os::Bsd::get_chained_signal_action(int sig) { 2972 struct sigaction *actp = NULL; 2973 2974 if (libjsig_is_loaded) { 2975 // Retrieve the old signal handler from libjsig 2976 actp = (*get_signal_action)(sig); 2977 } 2978 if (actp == NULL) { 2979 // Retrieve the preinstalled signal handler from jvm 2980 actp = get_preinstalled_handler(sig); 2981 } 2982 2983 return actp; 2984 } 2985 2986 static bool call_chained_handler(struct sigaction *actp, int sig, 2987 siginfo_t *siginfo, void *context) { 2988 // Call the old signal handler 2989 if (actp->sa_handler == SIG_DFL) { 2990 // It's more reasonable to let jvm treat it as an unexpected exception 2991 // instead of taking the default action. 2992 return false; 2993 } else if (actp->sa_handler != SIG_IGN) { 2994 if ((actp->sa_flags & SA_NODEFER) == 0) { 2995 // automaticlly block the signal 2996 sigaddset(&(actp->sa_mask), sig); 2997 } 2998 2999 sa_handler_t hand; 3000 sa_sigaction_t sa; 3001 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 3002 // retrieve the chained handler 3003 if (siginfo_flag_set) { 3004 sa = actp->sa_sigaction; 3005 } else { 3006 hand = actp->sa_handler; 3007 } 3008 3009 if ((actp->sa_flags & SA_RESETHAND) != 0) { 3010 actp->sa_handler = SIG_DFL; 3011 } 3012 3013 // try to honor the signal mask 3014 sigset_t oset; 3015 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 3016 3017 // call into the chained handler 3018 if (siginfo_flag_set) { 3019 (*sa)(sig, siginfo, context); 3020 } else { 3021 (*hand)(sig); 3022 } 3023 3024 // restore the signal mask 3025 pthread_sigmask(SIG_SETMASK, &oset, 0); 3026 } 3027 // Tell jvm's signal handler the signal is taken care of. 3028 return true; 3029 } 3030 3031 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { 3032 bool chained = false; 3033 // signal-chaining 3034 if (UseSignalChaining) { 3035 struct sigaction *actp = get_chained_signal_action(sig); 3036 if (actp != NULL) { 3037 chained = call_chained_handler(actp, sig, siginfo, context); 3038 } 3039 } 3040 return chained; 3041 } 3042 3043 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { 3044 if ((( (unsigned int)1 << sig ) & sigs) != 0) { 3045 return &sigact[sig]; 3046 } 3047 return NULL; 3048 } 3049 3050 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 3051 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3052 sigact[sig] = oldAct; 3053 sigs |= (unsigned int)1 << sig; 3054 } 3055 3056 // for diagnostic 3057 int os::Bsd::sigflags[MAXSIGNUM]; 3058 3059 int os::Bsd::get_our_sigflags(int sig) { 3060 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3061 return sigflags[sig]; 3062 } 3063 3064 void os::Bsd::set_our_sigflags(int sig, int flags) { 3065 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3066 sigflags[sig] = flags; 3067 } 3068 3069 void os::Bsd::set_signal_handler(int sig, bool set_installed) { 3070 // Check for overwrite. 3071 struct sigaction oldAct; 3072 sigaction(sig, (struct sigaction*)NULL, &oldAct); 3073 3074 void* oldhand = oldAct.sa_sigaction 3075 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3076 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3077 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 3078 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 3079 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 3080 if (AllowUserSignalHandlers || !set_installed) { 3081 // Do not overwrite; user takes responsibility to forward to us. 3082 return; 3083 } else if (UseSignalChaining) { 3084 // save the old handler in jvm 3085 save_preinstalled_handler(sig, oldAct); 3086 // libjsig also interposes the sigaction() call below and saves the 3087 // old sigaction on it own. 3088 } else { 3089 fatal(err_msg("Encountered unexpected pre-existing sigaction handler " 3090 "%#lx for signal %d.", (long)oldhand, sig)); 3091 } 3092 } 3093 3094 struct sigaction sigAct; 3095 sigfillset(&(sigAct.sa_mask)); 3096 sigAct.sa_handler = SIG_DFL; 3097 if (!set_installed) { 3098 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3099 } else { 3100 sigAct.sa_sigaction = signalHandler; 3101 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3102 } 3103 #ifdef __APPLE__ 3104 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV 3105 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages" 3106 // if the signal handler declares it will handle it on alternate stack. 3107 // Notice we only declare we will handle it on alt stack, but we are not 3108 // actually going to use real alt stack - this is just a workaround. 3109 // Please see ux_exception.c, method catch_mach_exception_raise for details 3110 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c 3111 if (sig == SIGSEGV) { 3112 sigAct.sa_flags |= SA_ONSTACK; 3113 } 3114 #endif 3115 3116 // Save flags, which are set by ours 3117 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3118 sigflags[sig] = sigAct.sa_flags; 3119 3120 int ret = sigaction(sig, &sigAct, &oldAct); 3121 assert(ret == 0, "check"); 3122 3123 void* oldhand2 = oldAct.sa_sigaction 3124 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3125 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3126 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 3127 } 3128 3129 // install signal handlers for signals that HotSpot needs to 3130 // handle in order to support Java-level exception handling. 3131 3132 void os::Bsd::install_signal_handlers() { 3133 if (!signal_handlers_are_installed) { 3134 signal_handlers_are_installed = true; 3135 3136 // signal-chaining 3137 typedef void (*signal_setting_t)(); 3138 signal_setting_t begin_signal_setting = NULL; 3139 signal_setting_t end_signal_setting = NULL; 3140 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3141 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 3142 if (begin_signal_setting != NULL) { 3143 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3144 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 3145 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 3146 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 3147 libjsig_is_loaded = true; 3148 assert(UseSignalChaining, "should enable signal-chaining"); 3149 } 3150 if (libjsig_is_loaded) { 3151 // Tell libjsig jvm is setting signal handlers 3152 (*begin_signal_setting)(); 3153 } 3154 3155 set_signal_handler(SIGSEGV, true); 3156 set_signal_handler(SIGPIPE, true); 3157 set_signal_handler(SIGBUS, true); 3158 set_signal_handler(SIGILL, true); 3159 set_signal_handler(SIGFPE, true); 3160 set_signal_handler(SIGXFSZ, true); 3161 3162 #if defined(__APPLE__) 3163 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including 3164 // signals caught and handled by the JVM. To work around this, we reset the mach task 3165 // signal handler that's placed on our process by CrashReporter. This disables 3166 // CrashReporter-based reporting. 3167 // 3168 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes 3169 // on caught fatal signals. 3170 // 3171 // Additionally, gdb installs both standard BSD signal handlers, and mach exception 3172 // handlers. By replacing the existing task exception handler, we disable gdb's mach 3173 // exception handling, while leaving the standard BSD signal handlers functional. 3174 kern_return_t kr; 3175 kr = task_set_exception_ports(mach_task_self(), 3176 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, 3177 MACH_PORT_NULL, 3178 EXCEPTION_STATE_IDENTITY, 3179 MACHINE_THREAD_STATE); 3180 3181 assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); 3182 #endif 3183 3184 if (libjsig_is_loaded) { 3185 // Tell libjsig jvm finishes setting signal handlers 3186 (*end_signal_setting)(); 3187 } 3188 3189 // We don't activate signal checker if libjsig is in place, we trust ourselves 3190 // and if UserSignalHandler is installed all bets are off 3191 if (CheckJNICalls) { 3192 if (libjsig_is_loaded) { 3193 if (PrintJNIResolving) { 3194 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 3195 } 3196 check_signals = false; 3197 } 3198 if (AllowUserSignalHandlers) { 3199 if (PrintJNIResolving) { 3200 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 3201 } 3202 check_signals = false; 3203 } 3204 } 3205 } 3206 } 3207 3208 3209 ///// 3210 // glibc on Bsd platform uses non-documented flag 3211 // to indicate, that some special sort of signal 3212 // trampoline is used. 3213 // We will never set this flag, and we should 3214 // ignore this flag in our diagnostic 3215 #ifdef SIGNIFICANT_SIGNAL_MASK 3216 #undef SIGNIFICANT_SIGNAL_MASK 3217 #endif 3218 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 3219 3220 static const char* get_signal_handler_name(address handler, 3221 char* buf, int buflen) { 3222 int offset; 3223 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 3224 if (found) { 3225 // skip directory names 3226 const char *p1, *p2; 3227 p1 = buf; 3228 size_t len = strlen(os::file_separator()); 3229 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 3230 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 3231 } else { 3232 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 3233 } 3234 return buf; 3235 } 3236 3237 static void print_signal_handler(outputStream* st, int sig, 3238 char* buf, size_t buflen) { 3239 struct sigaction sa; 3240 3241 sigaction(sig, NULL, &sa); 3242 3243 // See comment for SIGNIFICANT_SIGNAL_MASK define 3244 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3245 3246 st->print("%s: ", os::exception_name(sig, buf, buflen)); 3247 3248 address handler = (sa.sa_flags & SA_SIGINFO) 3249 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 3250 : CAST_FROM_FN_PTR(address, sa.sa_handler); 3251 3252 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 3253 st->print("SIG_DFL"); 3254 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 3255 st->print("SIG_IGN"); 3256 } else { 3257 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 3258 } 3259 3260 st->print(", sa_mask[0]="); 3261 os::Posix::print_signal_set_short(st, &sa.sa_mask); 3262 3263 address rh = VMError::get_resetted_sighandler(sig); 3264 // May be, handler was resetted by VMError? 3265 if(rh != NULL) { 3266 handler = rh; 3267 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 3268 } 3269 3270 st->print(", sa_flags="); 3271 os::Posix::print_sa_flags(st, sa.sa_flags); 3272 3273 // Check: is it our handler? 3274 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 3275 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 3276 // It is our signal handler 3277 // check for flags, reset system-used one! 3278 if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3279 st->print( 3280 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 3281 os::Bsd::get_our_sigflags(sig)); 3282 } 3283 } 3284 st->cr(); 3285 } 3286 3287 3288 #define DO_SIGNAL_CHECK(sig) \ 3289 if (!sigismember(&check_signal_done, sig)) \ 3290 os::Bsd::check_signal_handler(sig) 3291 3292 // This method is a periodic task to check for misbehaving JNI applications 3293 // under CheckJNI, we can add any periodic checks here 3294 3295 void os::run_periodic_checks() { 3296 3297 if (check_signals == false) return; 3298 3299 // SEGV and BUS if overridden could potentially prevent 3300 // generation of hs*.log in the event of a crash, debugging 3301 // such a case can be very challenging, so we absolutely 3302 // check the following for a good measure: 3303 DO_SIGNAL_CHECK(SIGSEGV); 3304 DO_SIGNAL_CHECK(SIGILL); 3305 DO_SIGNAL_CHECK(SIGFPE); 3306 DO_SIGNAL_CHECK(SIGBUS); 3307 DO_SIGNAL_CHECK(SIGPIPE); 3308 DO_SIGNAL_CHECK(SIGXFSZ); 3309 3310 3311 // ReduceSignalUsage allows the user to override these handlers 3312 // see comments at the very top and jvm_solaris.h 3313 if (!ReduceSignalUsage) { 3314 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 3315 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 3316 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 3317 DO_SIGNAL_CHECK(BREAK_SIGNAL); 3318 } 3319 3320 DO_SIGNAL_CHECK(SR_signum); 3321 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); 3322 } 3323 3324 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 3325 3326 static os_sigaction_t os_sigaction = NULL; 3327 3328 void os::Bsd::check_signal_handler(int sig) { 3329 char buf[O_BUFLEN]; 3330 address jvmHandler = NULL; 3331 3332 3333 struct sigaction act; 3334 if (os_sigaction == NULL) { 3335 // only trust the default sigaction, in case it has been interposed 3336 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 3337 if (os_sigaction == NULL) return; 3338 } 3339 3340 os_sigaction(sig, (struct sigaction*)NULL, &act); 3341 3342 3343 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3344 3345 address thisHandler = (act.sa_flags & SA_SIGINFO) 3346 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 3347 : CAST_FROM_FN_PTR(address, act.sa_handler) ; 3348 3349 3350 switch(sig) { 3351 case SIGSEGV: 3352 case SIGBUS: 3353 case SIGFPE: 3354 case SIGPIPE: 3355 case SIGILL: 3356 case SIGXFSZ: 3357 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 3358 break; 3359 3360 case SHUTDOWN1_SIGNAL: 3361 case SHUTDOWN2_SIGNAL: 3362 case SHUTDOWN3_SIGNAL: 3363 case BREAK_SIGNAL: 3364 jvmHandler = (address)user_handler(); 3365 break; 3366 3367 case INTERRUPT_SIGNAL: 3368 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); 3369 break; 3370 3371 default: 3372 if (sig == SR_signum) { 3373 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 3374 } else { 3375 return; 3376 } 3377 break; 3378 } 3379 3380 if (thisHandler != jvmHandler) { 3381 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 3382 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 3383 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 3384 // No need to check this sig any longer 3385 sigaddset(&check_signal_done, sig); 3386 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 3387 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 3388 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 3389 exception_name(sig, buf, O_BUFLEN)); 3390 } 3391 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3392 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 3393 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); 3394 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); 3395 // No need to check this sig any longer 3396 sigaddset(&check_signal_done, sig); 3397 } 3398 3399 // Dump all the signal 3400 if (sigismember(&check_signal_done, sig)) { 3401 print_signal_handlers(tty, buf, O_BUFLEN); 3402 } 3403 } 3404 3405 extern void report_error(char* file_name, int line_no, char* title, char* format, ...); 3406 3407 extern bool signal_name(int signo, char* buf, size_t len); 3408 3409 const char* os::exception_name(int exception_code, char* buf, size_t size) { 3410 if (0 < exception_code && exception_code <= SIGRTMAX) { 3411 // signal 3412 if (!signal_name(exception_code, buf, size)) { 3413 jio_snprintf(buf, size, "SIG%d", exception_code); 3414 } 3415 return buf; 3416 } else { 3417 return NULL; 3418 } 3419 } 3420 3421 // this is called _before_ the most of global arguments have been parsed 3422 void os::init(void) { 3423 char dummy; /* used to get a guess on initial stack address */ 3424 // first_hrtime = gethrtime(); 3425 3426 // With BsdThreads the JavaMain thread pid (primordial thread) 3427 // is different than the pid of the java launcher thread. 3428 // So, on Bsd, the launcher thread pid is passed to the VM 3429 // via the sun.java.launcher.pid property. 3430 // Use this property instead of getpid() if it was correctly passed. 3431 // See bug 6351349. 3432 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); 3433 3434 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); 3435 3436 clock_tics_per_sec = CLK_TCK; 3437 3438 init_random(1234567); 3439 3440 ThreadCritical::initialize(); 3441 3442 Bsd::set_page_size(getpagesize()); 3443 if (Bsd::page_size() == -1) { 3444 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)", 3445 strerror(errno))); 3446 } 3447 init_page_sizes((size_t) Bsd::page_size()); 3448 3449 Bsd::initialize_system_info(); 3450 3451 // main_thread points to the aboriginal thread 3452 Bsd::_main_thread = pthread_self(); 3453 3454 Bsd::clock_init(); 3455 initial_time_count = javaTimeNanos(); 3456 3457 #ifdef __APPLE__ 3458 // XXXDARWIN 3459 // Work around the unaligned VM callbacks in hotspot's 3460 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on 3461 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces 3462 // alignment when doing symbol lookup. To work around this, we force early 3463 // binding of all symbols now, thus binding when alignment is known-good. 3464 _dyld_bind_fully_image_containing_address((const void *) &os::init); 3465 #endif 3466 } 3467 3468 // To install functions for atexit system call 3469 extern "C" { 3470 static void perfMemory_exit_helper() { 3471 perfMemory_exit(); 3472 } 3473 } 3474 3475 // this is called _after_ the global arguments have been parsed 3476 jint os::init_2(void) 3477 { 3478 // Allocate a single page and mark it as readable for safepoint polling 3479 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3480 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" ); 3481 3482 os::set_polling_page( polling_page ); 3483 3484 #ifndef PRODUCT 3485 if(Verbose && PrintMiscellaneous) 3486 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page); 3487 #endif 3488 3489 if (!UseMembar) { 3490 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3491 guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 3492 os::set_memory_serialize_page( mem_serialize_page ); 3493 3494 #ifndef PRODUCT 3495 if(Verbose && PrintMiscellaneous) 3496 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page); 3497 #endif 3498 } 3499 3500 // initialize suspend/resume support - must do this before signal_sets_init() 3501 if (SR_initialize() != 0) { 3502 perror("SR_initialize failed"); 3503 return JNI_ERR; 3504 } 3505 3506 Bsd::signal_sets_init(); 3507 Bsd::install_signal_handlers(); 3508 3509 // Check minimum allowable stack size for thread creation and to initialize 3510 // the java system classes, including StackOverflowError - depends on page 3511 // size. Add a page for compiler2 recursion in main thread. 3512 // Add in 2*BytesPerWord times page size to account for VM stack during 3513 // class initialization depending on 32 or 64 bit VM. 3514 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, 3515 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ 3516 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); 3517 3518 size_t threadStackSizeInBytes = ThreadStackSize * K; 3519 if (threadStackSizeInBytes != 0 && 3520 threadStackSizeInBytes < os::Bsd::min_stack_allowed) { 3521 tty->print_cr("\nThe stack size specified is too small, " 3522 "Specify at least %dk", 3523 os::Bsd::min_stack_allowed/ K); 3524 return JNI_ERR; 3525 } 3526 3527 // Make the stack size a multiple of the page size so that 3528 // the yellow/red zones can be guarded. 3529 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 3530 vm_page_size())); 3531 3532 if (MaxFDLimit) { 3533 // set the number of file descriptors to max. print out error 3534 // if getrlimit/setrlimit fails but continue regardless. 3535 struct rlimit nbr_files; 3536 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 3537 if (status != 0) { 3538 if (PrintMiscellaneous && (Verbose || WizardMode)) 3539 perror("os::init_2 getrlimit failed"); 3540 } else { 3541 nbr_files.rlim_cur = nbr_files.rlim_max; 3542 3543 #ifdef __APPLE__ 3544 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if 3545 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must 3546 // be used instead 3547 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); 3548 #endif 3549 3550 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 3551 if (status != 0) { 3552 if (PrintMiscellaneous && (Verbose || WizardMode)) 3553 perror("os::init_2 setrlimit failed"); 3554 } 3555 } 3556 } 3557 3558 // at-exit methods are called in the reverse order of their registration. 3559 // atexit functions are called on return from main or as a result of a 3560 // call to exit(3C). There can be only 32 of these functions registered 3561 // and atexit() does not set errno. 3562 3563 if (PerfAllowAtExitRegistration) { 3564 // only register atexit functions if PerfAllowAtExitRegistration is set. 3565 // atexit functions can be delayed until process exit time, which 3566 // can be problematic for embedded VM situations. Embedded VMs should 3567 // call DestroyJavaVM() to assure that VM resources are released. 3568 3569 // note: perfMemory_exit_helper atexit function may be removed in 3570 // the future if the appropriate cleanup code can be added to the 3571 // VM_Exit VMOperation's doit method. 3572 if (atexit(perfMemory_exit_helper) != 0) { 3573 warning("os::init2 atexit(perfMemory_exit_helper) failed"); 3574 } 3575 } 3576 3577 // initialize thread priority policy 3578 prio_init(); 3579 3580 #ifdef __APPLE__ 3581 // dynamically link to objective c gc registration 3582 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY); 3583 if (handleLibObjc != NULL) { 3584 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER); 3585 } 3586 #endif 3587 3588 return JNI_OK; 3589 } 3590 3591 // this is called at the end of vm_initialization 3592 void os::init_3(void) { } 3593 3594 // Mark the polling page as unreadable 3595 void os::make_polling_page_unreadable(void) { 3596 if( !guard_memory((char*)_polling_page, Bsd::page_size()) ) 3597 fatal("Could not disable polling page"); 3598 }; 3599 3600 // Mark the polling page as readable 3601 void os::make_polling_page_readable(void) { 3602 if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { 3603 fatal("Could not enable polling page"); 3604 } 3605 }; 3606 3607 int os::active_processor_count() { 3608 return _processor_count; 3609 } 3610 3611 void os::set_native_thread_name(const char *name) { 3612 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5 3613 // This is only supported in Snow Leopard and beyond 3614 if (name != NULL) { 3615 // Add a "Java: " prefix to the name 3616 char buf[MAXTHREADNAMESIZE]; 3617 snprintf(buf, sizeof(buf), "Java: %s", name); 3618 pthread_setname_np(buf); 3619 } 3620 #endif 3621 } 3622 3623 bool os::distribute_processes(uint length, uint* distribution) { 3624 // Not yet implemented. 3625 return false; 3626 } 3627 3628 bool os::bind_to_processor(uint processor_id) { 3629 // Not yet implemented. 3630 return false; 3631 } 3632 3633 void os::SuspendedThreadTask::internal_do_task() { 3634 if (do_suspend(_thread->osthread())) { 3635 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 3636 do_task(context); 3637 do_resume(_thread->osthread()); 3638 } 3639 } 3640 3641 /// 3642 class PcFetcher : public os::SuspendedThreadTask { 3643 public: 3644 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 3645 ExtendedPC result(); 3646 protected: 3647 void do_task(const os::SuspendedThreadTaskContext& context); 3648 private: 3649 ExtendedPC _epc; 3650 }; 3651 3652 ExtendedPC PcFetcher::result() { 3653 guarantee(is_done(), "task is not done yet."); 3654 return _epc; 3655 } 3656 3657 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 3658 Thread* thread = context.thread(); 3659 OSThread* osthread = thread->osthread(); 3660 if (osthread->ucontext() != NULL) { 3661 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext()); 3662 } else { 3663 // NULL context is unexpected, double-check this is the VMThread 3664 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 3665 } 3666 } 3667 3668 // Suspends the target using the signal mechanism and then grabs the PC before 3669 // resuming the target. Used by the flat-profiler only 3670 ExtendedPC os::get_thread_pc(Thread* thread) { 3671 // Make sure that it is called by the watcher for the VMThread 3672 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 3673 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 3674 3675 PcFetcher fetcher(thread); 3676 fetcher.run(); 3677 return fetcher.result(); 3678 } 3679 3680 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime) 3681 { 3682 return pthread_cond_timedwait(_cond, _mutex, _abstime); 3683 } 3684 3685 //////////////////////////////////////////////////////////////////////////////// 3686 // debug support 3687 3688 bool os::find(address addr, outputStream* st) { 3689 Dl_info dlinfo; 3690 memset(&dlinfo, 0, sizeof(dlinfo)); 3691 if (dladdr(addr, &dlinfo) != 0) { 3692 st->print(PTR_FORMAT ": ", addr); 3693 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 3694 st->print("%s+%#x", dlinfo.dli_sname, 3695 addr - (intptr_t)dlinfo.dli_saddr); 3696 } else if (dlinfo.dli_fbase != NULL) { 3697 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); 3698 } else { 3699 st->print("<absolute address>"); 3700 } 3701 if (dlinfo.dli_fname != NULL) { 3702 st->print(" in %s", dlinfo.dli_fname); 3703 } 3704 if (dlinfo.dli_fbase != NULL) { 3705 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); 3706 } 3707 st->cr(); 3708 3709 if (Verbose) { 3710 // decode some bytes around the PC 3711 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 3712 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 3713 address lowest = (address) dlinfo.dli_sname; 3714 if (!lowest) lowest = (address) dlinfo.dli_fbase; 3715 if (begin < lowest) begin = lowest; 3716 Dl_info dlinfo2; 3717 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 3718 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) 3719 end = (address) dlinfo2.dli_saddr; 3720 Disassembler::decode(begin, end, st); 3721 } 3722 return true; 3723 } 3724 return false; 3725 } 3726 3727 //////////////////////////////////////////////////////////////////////////////// 3728 // misc 3729 3730 // This does not do anything on Bsd. This is basically a hook for being 3731 // able to use structured exception handling (thread-local exception filters) 3732 // on, e.g., Win32. 3733 void 3734 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, 3735 JavaCallArguments* args, Thread* thread) { 3736 f(value, method, args, thread); 3737 } 3738 3739 void os::print_statistics() { 3740 } 3741 3742 int os::message_box(const char* title, const char* message) { 3743 int i; 3744 fdStream err(defaultStream::error_fd()); 3745 for (i = 0; i < 78; i++) err.print_raw("="); 3746 err.cr(); 3747 err.print_raw_cr(title); 3748 for (i = 0; i < 78; i++) err.print_raw("-"); 3749 err.cr(); 3750 err.print_raw_cr(message); 3751 for (i = 0; i < 78; i++) err.print_raw("="); 3752 err.cr(); 3753 3754 char buf[16]; 3755 // Prevent process from exiting upon "read error" without consuming all CPU 3756 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 3757 3758 return buf[0] == 'y' || buf[0] == 'Y'; 3759 } 3760 3761 int os::stat(const char *path, struct stat *sbuf) { 3762 char pathbuf[MAX_PATH]; 3763 if (strlen(path) > MAX_PATH - 1) { 3764 errno = ENAMETOOLONG; 3765 return -1; 3766 } 3767 os::native_path(strcpy(pathbuf, path)); 3768 return ::stat(pathbuf, sbuf); 3769 } 3770 3771 bool os::check_heap(bool force) { 3772 return true; 3773 } 3774 3775 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) { 3776 return ::vsnprintf(buf, count, format, args); 3777 } 3778 3779 // Is a (classpath) directory empty? 3780 bool os::dir_is_empty(const char* path) { 3781 DIR *dir = NULL; 3782 struct dirent *ptr; 3783 3784 dir = opendir(path); 3785 if (dir == NULL) return true; 3786 3787 /* Scan the directory */ 3788 bool result = true; 3789 char buf[sizeof(struct dirent) + MAX_PATH]; 3790 while (result && (ptr = ::readdir(dir)) != NULL) { 3791 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 3792 result = false; 3793 } 3794 } 3795 closedir(dir); 3796 return result; 3797 } 3798 3799 // This code originates from JDK's sysOpen and open64_w 3800 // from src/solaris/hpi/src/system_md.c 3801 3802 #ifndef O_DELETE 3803 #define O_DELETE 0x10000 3804 #endif 3805 3806 // Open a file. Unlink the file immediately after open returns 3807 // if the specified oflag has the O_DELETE flag set. 3808 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c 3809 3810 int os::open(const char *path, int oflag, int mode) { 3811 3812 if (strlen(path) > MAX_PATH - 1) { 3813 errno = ENAMETOOLONG; 3814 return -1; 3815 } 3816 int fd; 3817 int o_delete = (oflag & O_DELETE); 3818 oflag = oflag & ~O_DELETE; 3819 3820 fd = ::open(path, oflag, mode); 3821 if (fd == -1) return -1; 3822 3823 //If the open succeeded, the file might still be a directory 3824 { 3825 struct stat buf; 3826 int ret = ::fstat(fd, &buf); 3827 int st_mode = buf.st_mode; 3828 3829 if (ret != -1) { 3830 if ((st_mode & S_IFMT) == S_IFDIR) { 3831 errno = EISDIR; 3832 ::close(fd); 3833 return -1; 3834 } 3835 } else { 3836 ::close(fd); 3837 return -1; 3838 } 3839 } 3840 3841 /* 3842 * All file descriptors that are opened in the JVM and not 3843 * specifically destined for a subprocess should have the 3844 * close-on-exec flag set. If we don't set it, then careless 3rd 3845 * party native code might fork and exec without closing all 3846 * appropriate file descriptors (e.g. as we do in closeDescriptors in 3847 * UNIXProcess.c), and this in turn might: 3848 * 3849 * - cause end-of-file to fail to be detected on some file 3850 * descriptors, resulting in mysterious hangs, or 3851 * 3852 * - might cause an fopen in the subprocess to fail on a system 3853 * suffering from bug 1085341. 3854 * 3855 * (Yes, the default setting of the close-on-exec flag is a Unix 3856 * design flaw) 3857 * 3858 * See: 3859 * 1085341: 32-bit stdio routines should support file descriptors >255 3860 * 4843136: (process) pipe file descriptor from Runtime.exec not being closed 3861 * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 3862 */ 3863 #ifdef FD_CLOEXEC 3864 { 3865 int flags = ::fcntl(fd, F_GETFD); 3866 if (flags != -1) 3867 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 3868 } 3869 #endif 3870 3871 if (o_delete != 0) { 3872 ::unlink(path); 3873 } 3874 return fd; 3875 } 3876 3877 3878 // create binary file, rewriting existing file if required 3879 int os::create_binary_file(const char* path, bool rewrite_existing) { 3880 int oflags = O_WRONLY | O_CREAT; 3881 if (!rewrite_existing) { 3882 oflags |= O_EXCL; 3883 } 3884 return ::open(path, oflags, S_IREAD | S_IWRITE); 3885 } 3886 3887 // return current position of file pointer 3888 jlong os::current_file_offset(int fd) { 3889 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); 3890 } 3891 3892 // move file pointer to the specified offset 3893 jlong os::seek_to_file_offset(int fd, jlong offset) { 3894 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); 3895 } 3896 3897 // This code originates from JDK's sysAvailable 3898 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 3899 3900 int os::available(int fd, jlong *bytes) { 3901 jlong cur, end; 3902 int mode; 3903 struct stat buf; 3904 3905 if (::fstat(fd, &buf) >= 0) { 3906 mode = buf.st_mode; 3907 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 3908 /* 3909 * XXX: is the following call interruptible? If so, this might 3910 * need to go through the INTERRUPT_IO() wrapper as for other 3911 * blocking, interruptible calls in this file. 3912 */ 3913 int n; 3914 if (::ioctl(fd, FIONREAD, &n) >= 0) { 3915 *bytes = n; 3916 return 1; 3917 } 3918 } 3919 } 3920 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { 3921 return 0; 3922 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { 3923 return 0; 3924 } else if (::lseek(fd, cur, SEEK_SET) == -1) { 3925 return 0; 3926 } 3927 *bytes = end - cur; 3928 return 1; 3929 } 3930 3931 int os::socket_available(int fd, jint *pbytes) { 3932 if (fd < 0) 3933 return OS_OK; 3934 3935 int ret; 3936 3937 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret); 3938 3939 //%% note ioctl can return 0 when successful, JVM_SocketAvailable 3940 // is expected to return 0 on failure and 1 on success to the jdk. 3941 3942 return (ret == OS_ERR) ? 0 : 1; 3943 } 3944 3945 // Map a block of memory. 3946 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 3947 char *addr, size_t bytes, bool read_only, 3948 bool allow_exec) { 3949 int prot; 3950 int flags; 3951 3952 if (read_only) { 3953 prot = PROT_READ; 3954 flags = MAP_SHARED; 3955 } else { 3956 prot = PROT_READ | PROT_WRITE; 3957 flags = MAP_PRIVATE; 3958 } 3959 3960 if (allow_exec) { 3961 prot |= PROT_EXEC; 3962 } 3963 3964 if (addr != NULL) { 3965 flags |= MAP_FIXED; 3966 } 3967 3968 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 3969 fd, file_offset); 3970 if (mapped_address == MAP_FAILED) { 3971 return NULL; 3972 } 3973 return mapped_address; 3974 } 3975 3976 3977 // Remap a block of memory. 3978 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 3979 char *addr, size_t bytes, bool read_only, 3980 bool allow_exec) { 3981 // same as map_memory() on this OS 3982 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 3983 allow_exec); 3984 } 3985 3986 3987 // Unmap a block of memory. 3988 bool os::pd_unmap_memory(char* addr, size_t bytes) { 3989 return munmap(addr, bytes) == 0; 3990 } 3991 3992 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 3993 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 3994 // of a thread. 3995 // 3996 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 3997 // the fast estimate available on the platform. 3998 3999 jlong os::current_thread_cpu_time() { 4000 #ifdef __APPLE__ 4001 return os::thread_cpu_time(Thread::current(), true /* user + sys */); 4002 #else 4003 Unimplemented(); 4004 return 0; 4005 #endif 4006 } 4007 4008 jlong os::thread_cpu_time(Thread* thread) { 4009 #ifdef __APPLE__ 4010 return os::thread_cpu_time(thread, true /* user + sys */); 4011 #else 4012 Unimplemented(); 4013 return 0; 4014 #endif 4015 } 4016 4017 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 4018 #ifdef __APPLE__ 4019 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); 4020 #else 4021 Unimplemented(); 4022 return 0; 4023 #endif 4024 } 4025 4026 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 4027 #ifdef __APPLE__ 4028 struct thread_basic_info tinfo; 4029 mach_msg_type_number_t tcount = THREAD_INFO_MAX; 4030 kern_return_t kr; 4031 thread_t mach_thread; 4032 4033 mach_thread = thread->osthread()->thread_id(); 4034 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); 4035 if (kr != KERN_SUCCESS) 4036 return -1; 4037 4038 if (user_sys_cpu_time) { 4039 jlong nanos; 4040 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; 4041 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; 4042 return nanos; 4043 } else { 4044 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); 4045 } 4046 #else 4047 Unimplemented(); 4048 return 0; 4049 #endif 4050 } 4051 4052 4053 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4054 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4055 info_ptr->may_skip_backward = false; // elapsed time not wall time 4056 info_ptr->may_skip_forward = false; // elapsed time not wall time 4057 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4058 } 4059 4060 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4061 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4062 info_ptr->may_skip_backward = false; // elapsed time not wall time 4063 info_ptr->may_skip_forward = false; // elapsed time not wall time 4064 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4065 } 4066 4067 bool os::is_thread_cpu_time_supported() { 4068 #ifdef __APPLE__ 4069 return true; 4070 #else 4071 return false; 4072 #endif 4073 } 4074 4075 // System loadavg support. Returns -1 if load average cannot be obtained. 4076 // Bsd doesn't yet have a (official) notion of processor sets, 4077 // so just return the system wide load average. 4078 int os::loadavg(double loadavg[], int nelem) { 4079 return ::getloadavg(loadavg, nelem); 4080 } 4081 4082 void os::pause() { 4083 char filename[MAX_PATH]; 4084 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 4085 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); 4086 } else { 4087 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 4088 } 4089 4090 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 4091 if (fd != -1) { 4092 struct stat buf; 4093 ::close(fd); 4094 while (::stat(filename, &buf) == 0) { 4095 (void)::poll(NULL, 0, 100); 4096 } 4097 } else { 4098 jio_fprintf(stderr, 4099 "Could not open pause file '%s', continuing immediately.\n", filename); 4100 } 4101 } 4102 4103 4104 // Refer to the comments in os_solaris.cpp park-unpark. 4105 // 4106 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 4107 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 4108 // For specifics regarding the bug see GLIBC BUGID 261237 : 4109 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 4110 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 4111 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 4112 // is used. (The simple C test-case provided in the GLIBC bug report manifests the 4113 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 4114 // and monitorenter when we're using 1-0 locking. All those operations may result in 4115 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 4116 // of libpthread avoids the problem, but isn't practical. 4117 // 4118 // Possible remedies: 4119 // 4120 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 4121 // This is palliative and probabilistic, however. If the thread is preempted 4122 // between the call to compute_abstime() and pthread_cond_timedwait(), more 4123 // than the minimum period may have passed, and the abstime may be stale (in the 4124 // past) resultin in a hang. Using this technique reduces the odds of a hang 4125 // but the JVM is still vulnerable, particularly on heavily loaded systems. 4126 // 4127 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 4128 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set 4129 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 4130 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant 4131 // thread. 4132 // 4133 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 4134 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 4135 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). 4136 // This also works well. In fact it avoids kernel-level scalability impediments 4137 // on certain platforms that don't handle lots of active pthread_cond_timedwait() 4138 // timers in a graceful fashion. 4139 // 4140 // 4. When the abstime value is in the past it appears that control returns 4141 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 4142 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we 4143 // can avoid the problem by reinitializing the condvar -- by cond_destroy() 4144 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). 4145 // It may be possible to avoid reinitialization by checking the return 4146 // value from pthread_cond_timedwait(). In addition to reinitializing the 4147 // condvar we must establish the invariant that cond_signal() is only called 4148 // within critical sections protected by the adjunct mutex. This prevents 4149 // cond_signal() from "seeing" a condvar that's in the midst of being 4150 // reinitialized or that is corrupt. Sadly, this invariant obviates the 4151 // desirable signal-after-unlock optimization that avoids futile context switching. 4152 // 4153 // I'm also concerned that some versions of NTPL might allocate an auxilliary 4154 // structure when a condvar is used or initialized. cond_destroy() would 4155 // release the helper structure. Our reinitialize-after-timedwait fix 4156 // put excessive stress on malloc/free and locks protecting the c-heap. 4157 // 4158 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 4159 // It may be possible to refine (4) by checking the kernel and NTPL verisons 4160 // and only enabling the work-around for vulnerable environments. 4161 4162 // utility to compute the abstime argument to timedwait: 4163 // millis is the relative timeout time 4164 // abstime will be the absolute timeout time 4165 // TODO: replace compute_abstime() with unpackTime() 4166 4167 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) { 4168 if (millis < 0) millis = 0; 4169 struct timeval now; 4170 int status = gettimeofday(&now, NULL); 4171 assert(status == 0, "gettimeofday"); 4172 jlong seconds = millis / 1000; 4173 millis %= 1000; 4174 if (seconds > 50000000) { // see man cond_timedwait(3T) 4175 seconds = 50000000; 4176 } 4177 abstime->tv_sec = now.tv_sec + seconds; 4178 long usec = now.tv_usec + millis * 1000; 4179 if (usec >= 1000000) { 4180 abstime->tv_sec += 1; 4181 usec -= 1000000; 4182 } 4183 abstime->tv_nsec = usec * 1000; 4184 return abstime; 4185 } 4186 4187 4188 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately. 4189 // Conceptually TryPark() should be equivalent to park(0). 4190 4191 int os::PlatformEvent::TryPark() { 4192 for (;;) { 4193 const int v = _Event ; 4194 guarantee ((v == 0) || (v == 1), "invariant") ; 4195 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ; 4196 } 4197 } 4198 4199 void os::PlatformEvent::park() { // AKA "down()" 4200 // Invariant: Only the thread associated with the Event/PlatformEvent 4201 // may call park(). 4202 // TODO: assert that _Assoc != NULL or _Assoc == Self 4203 int v ; 4204 for (;;) { 4205 v = _Event ; 4206 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; 4207 } 4208 guarantee (v >= 0, "invariant") ; 4209 if (v == 0) { 4210 // Do this the hard way by blocking ... 4211 int status = pthread_mutex_lock(_mutex); 4212 assert_status(status == 0, status, "mutex_lock"); 4213 guarantee (_nParked == 0, "invariant") ; 4214 ++ _nParked ; 4215 while (_Event < 0) { 4216 status = pthread_cond_wait(_cond, _mutex); 4217 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 4218 // Treat this the same as if the wait was interrupted 4219 if (status == ETIMEDOUT) { status = EINTR; } 4220 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 4221 } 4222 -- _nParked ; 4223 4224 _Event = 0 ; 4225 status = pthread_mutex_unlock(_mutex); 4226 assert_status(status == 0, status, "mutex_unlock"); 4227 // Paranoia to ensure our locked and lock-free paths interact 4228 // correctly with each other. 4229 OrderAccess::fence(); 4230 } 4231 guarantee (_Event >= 0, "invariant") ; 4232 } 4233 4234 int os::PlatformEvent::park(jlong millis) { 4235 guarantee (_nParked == 0, "invariant") ; 4236 4237 int v ; 4238 for (;;) { 4239 v = _Event ; 4240 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; 4241 } 4242 guarantee (v >= 0, "invariant") ; 4243 if (v != 0) return OS_OK ; 4244 4245 // We do this the hard way, by blocking the thread. 4246 // Consider enforcing a minimum timeout value. 4247 struct timespec abst; 4248 compute_abstime(&abst, millis); 4249 4250 int ret = OS_TIMEOUT; 4251 int status = pthread_mutex_lock(_mutex); 4252 assert_status(status == 0, status, "mutex_lock"); 4253 guarantee (_nParked == 0, "invariant") ; 4254 ++_nParked ; 4255 4256 // Object.wait(timo) will return because of 4257 // (a) notification 4258 // (b) timeout 4259 // (c) thread.interrupt 4260 // 4261 // Thread.interrupt and object.notify{All} both call Event::set. 4262 // That is, we treat thread.interrupt as a special case of notification. 4263 // The underlying Solaris implementation, cond_timedwait, admits 4264 // spurious/premature wakeups, but the JLS/JVM spec prevents the 4265 // JVM from making those visible to Java code. As such, we must 4266 // filter out spurious wakeups. We assume all ETIME returns are valid. 4267 // 4268 // TODO: properly differentiate simultaneous notify+interrupt. 4269 // In that case, we should propagate the notify to another waiter. 4270 4271 while (_Event < 0) { 4272 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst); 4273 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4274 pthread_cond_destroy (_cond); 4275 pthread_cond_init (_cond, NULL) ; 4276 } 4277 assert_status(status == 0 || status == EINTR || 4278 status == ETIMEDOUT, 4279 status, "cond_timedwait"); 4280 if (!FilterSpuriousWakeups) break ; // previous semantics 4281 if (status == ETIMEDOUT) break ; 4282 // We consume and ignore EINTR and spurious wakeups. 4283 } 4284 --_nParked ; 4285 if (_Event >= 0) { 4286 ret = OS_OK; 4287 } 4288 _Event = 0 ; 4289 status = pthread_mutex_unlock(_mutex); 4290 assert_status(status == 0, status, "mutex_unlock"); 4291 assert (_nParked == 0, "invariant") ; 4292 // Paranoia to ensure our locked and lock-free paths interact 4293 // correctly with each other. 4294 OrderAccess::fence(); 4295 return ret; 4296 } 4297 4298 void os::PlatformEvent::unpark() { 4299 // Transitions for _Event: 4300 // 0 :=> 1 4301 // 1 :=> 1 4302 // -1 :=> either 0 or 1; must signal target thread 4303 // That is, we can safely transition _Event from -1 to either 4304 // 0 or 1. Forcing 1 is slightly more efficient for back-to-back 4305 // unpark() calls. 4306 // See also: "Semaphores in Plan 9" by Mullender & Cox 4307 // 4308 // Note: Forcing a transition from "-1" to "1" on an unpark() means 4309 // that it will take two back-to-back park() calls for the owning 4310 // thread to block. This has the benefit of forcing a spurious return 4311 // from the first park() call after an unpark() call which will help 4312 // shake out uses of park() and unpark() without condition variables. 4313 4314 if (Atomic::xchg(1, &_Event) >= 0) return; 4315 4316 // Wait for the thread associated with the event to vacate 4317 int status = pthread_mutex_lock(_mutex); 4318 assert_status(status == 0, status, "mutex_lock"); 4319 int AnyWaiters = _nParked; 4320 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 4321 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 4322 AnyWaiters = 0; 4323 pthread_cond_signal(_cond); 4324 } 4325 status = pthread_mutex_unlock(_mutex); 4326 assert_status(status == 0, status, "mutex_unlock"); 4327 if (AnyWaiters != 0) { 4328 status = pthread_cond_signal(_cond); 4329 assert_status(status == 0, status, "cond_signal"); 4330 } 4331 4332 // Note that we signal() _after dropping the lock for "immortal" Events. 4333 // This is safe and avoids a common class of futile wakeups. In rare 4334 // circumstances this can cause a thread to return prematurely from 4335 // cond_{timed}wait() but the spurious wakeup is benign and the victim will 4336 // simply re-test the condition and re-park itself. 4337 } 4338 4339 4340 // JSR166 4341 // ------------------------------------------------------- 4342 4343 /* 4344 * The solaris and bsd implementations of park/unpark are fairly 4345 * conservative for now, but can be improved. They currently use a 4346 * mutex/condvar pair, plus a a count. 4347 * Park decrements count if > 0, else does a condvar wait. Unpark 4348 * sets count to 1 and signals condvar. Only one thread ever waits 4349 * on the condvar. Contention seen when trying to park implies that someone 4350 * is unparking you, so don't wait. And spurious returns are fine, so there 4351 * is no need to track notifications. 4352 */ 4353 4354 #define MAX_SECS 100000000 4355 /* 4356 * This code is common to bsd and solaris and will be moved to a 4357 * common place in dolphin. 4358 * 4359 * The passed in time value is either a relative time in nanoseconds 4360 * or an absolute time in milliseconds. Either way it has to be unpacked 4361 * into suitable seconds and nanoseconds components and stored in the 4362 * given timespec structure. 4363 * Given time is a 64-bit value and the time_t used in the timespec is only 4364 * a signed-32-bit value (except on 64-bit Bsd) we have to watch for 4365 * overflow if times way in the future are given. Further on Solaris versions 4366 * prior to 10 there is a restriction (see cond_timedwait) that the specified 4367 * number of seconds, in abstime, is less than current_time + 100,000,000. 4368 * As it will be 28 years before "now + 100000000" will overflow we can 4369 * ignore overflow and just impose a hard-limit on seconds using the value 4370 * of "now + 100,000,000". This places a limit on the timeout of about 3.17 4371 * years from "now". 4372 */ 4373 4374 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { 4375 assert (time > 0, "convertTime"); 4376 4377 struct timeval now; 4378 int status = gettimeofday(&now, NULL); 4379 assert(status == 0, "gettimeofday"); 4380 4381 time_t max_secs = now.tv_sec + MAX_SECS; 4382 4383 if (isAbsolute) { 4384 jlong secs = time / 1000; 4385 if (secs > max_secs) { 4386 absTime->tv_sec = max_secs; 4387 } 4388 else { 4389 absTime->tv_sec = secs; 4390 } 4391 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 4392 } 4393 else { 4394 jlong secs = time / NANOSECS_PER_SEC; 4395 if (secs >= MAX_SECS) { 4396 absTime->tv_sec = max_secs; 4397 absTime->tv_nsec = 0; 4398 } 4399 else { 4400 absTime->tv_sec = now.tv_sec + secs; 4401 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 4402 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 4403 absTime->tv_nsec -= NANOSECS_PER_SEC; 4404 ++absTime->tv_sec; // note: this must be <= max_secs 4405 } 4406 } 4407 } 4408 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 4409 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 4410 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 4411 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 4412 } 4413 4414 void Parker::park(bool isAbsolute, jlong time) { 4415 // Ideally we'd do something useful while spinning, such 4416 // as calling unpackTime(). 4417 4418 // Optional fast-path check: 4419 // Return immediately if a permit is available. 4420 // We depend on Atomic::xchg() having full barrier semantics 4421 // since we are doing a lock-free update to _counter. 4422 if (Atomic::xchg(0, &_counter) > 0) return; 4423 4424 Thread* thread = Thread::current(); 4425 assert(thread->is_Java_thread(), "Must be JavaThread"); 4426 JavaThread *jt = (JavaThread *)thread; 4427 4428 // Optional optimization -- avoid state transitions if there's an interrupt pending. 4429 // Check interrupt before trying to wait 4430 if (Thread::is_interrupted(thread, false)) { 4431 return; 4432 } 4433 4434 // Next, demultiplex/decode time arguments 4435 struct timespec absTime; 4436 if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all 4437 return; 4438 } 4439 if (time > 0) { 4440 unpackTime(&absTime, isAbsolute, time); 4441 } 4442 4443 4444 // Enter safepoint region 4445 // Beware of deadlocks such as 6317397. 4446 // The per-thread Parker:: mutex is a classic leaf-lock. 4447 // In particular a thread must never block on the Threads_lock while 4448 // holding the Parker:: mutex. If safepoints are pending both the 4449 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 4450 ThreadBlockInVM tbivm(jt); 4451 4452 // Don't wait if cannot get lock since interference arises from 4453 // unblocking. Also. check interrupt before trying wait 4454 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 4455 return; 4456 } 4457 4458 int status ; 4459 if (_counter > 0) { // no wait needed 4460 _counter = 0; 4461 status = pthread_mutex_unlock(_mutex); 4462 assert (status == 0, "invariant") ; 4463 // Paranoia to ensure our locked and lock-free paths interact 4464 // correctly with each other and Java-level accesses. 4465 OrderAccess::fence(); 4466 return; 4467 } 4468 4469 #ifdef ASSERT 4470 // Don't catch signals while blocked; let the running threads have the signals. 4471 // (This allows a debugger to break into the running thread.) 4472 sigset_t oldsigs; 4473 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); 4474 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 4475 #endif 4476 4477 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 4478 jt->set_suspend_equivalent(); 4479 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 4480 4481 if (time == 0) { 4482 status = pthread_cond_wait (_cond, _mutex) ; 4483 } else { 4484 status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ; 4485 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4486 pthread_cond_destroy (_cond) ; 4487 pthread_cond_init (_cond, NULL); 4488 } 4489 } 4490 assert_status(status == 0 || status == EINTR || 4491 status == ETIMEDOUT, 4492 status, "cond_timedwait"); 4493 4494 #ifdef ASSERT 4495 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 4496 #endif 4497 4498 _counter = 0 ; 4499 status = pthread_mutex_unlock(_mutex) ; 4500 assert_status(status == 0, status, "invariant") ; 4501 // Paranoia to ensure our locked and lock-free paths interact 4502 // correctly with each other and Java-level accesses. 4503 OrderAccess::fence(); 4504 4505 // If externally suspended while waiting, re-suspend 4506 if (jt->handle_special_suspend_equivalent_condition()) { 4507 jt->java_suspend_self(); 4508 } 4509 } 4510 4511 void Parker::unpark() { 4512 int s, status ; 4513 status = pthread_mutex_lock(_mutex); 4514 assert (status == 0, "invariant") ; 4515 s = _counter; 4516 _counter = 1; 4517 if (s < 1) { 4518 if (WorkAroundNPTLTimedWaitHang) { 4519 status = pthread_cond_signal (_cond) ; 4520 assert (status == 0, "invariant") ; 4521 status = pthread_mutex_unlock(_mutex); 4522 assert (status == 0, "invariant") ; 4523 } else { 4524 status = pthread_mutex_unlock(_mutex); 4525 assert (status == 0, "invariant") ; 4526 status = pthread_cond_signal (_cond) ; 4527 assert (status == 0, "invariant") ; 4528 } 4529 } else { 4530 pthread_mutex_unlock(_mutex); 4531 assert (status == 0, "invariant") ; 4532 } 4533 } 4534 4535 4536 /* Darwin has no "environ" in a dynamic library. */ 4537 #ifdef __APPLE__ 4538 #include <crt_externs.h> 4539 #define environ (*_NSGetEnviron()) 4540 #else 4541 extern char** environ; 4542 #endif 4543 4544 // Run the specified command in a separate process. Return its exit value, 4545 // or -1 on failure (e.g. can't fork a new process). 4546 // Unlike system(), this function can be called from signal handler. It 4547 // doesn't block SIGINT et al. 4548 int os::fork_and_exec(char* cmd) { 4549 const char * argv[4] = {"sh", "-c", cmd, NULL}; 4550 4551 // fork() in BsdThreads/NPTL is not async-safe. It needs to run 4552 // pthread_atfork handlers and reset pthread library. All we need is a 4553 // separate process to execve. Make a direct syscall to fork process. 4554 // On IA64 there's no fork syscall, we have to use fork() and hope for 4555 // the best... 4556 pid_t pid = fork(); 4557 4558 if (pid < 0) { 4559 // fork failed 4560 return -1; 4561 4562 } else if (pid == 0) { 4563 // child process 4564 4565 // execve() in BsdThreads will call pthread_kill_other_threads_np() 4566 // first to kill every thread on the thread list. Because this list is 4567 // not reset by fork() (see notes above), execve() will instead kill 4568 // every thread in the parent process. We know this is the only thread 4569 // in the new process, so make a system call directly. 4570 // IA64 should use normal execve() from glibc to match the glibc fork() 4571 // above. 4572 execve("/bin/sh", (char* const*)argv, environ); 4573 4574 // execve failed 4575 _exit(-1); 4576 4577 } else { 4578 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 4579 // care about the actual exit code, for now. 4580 4581 int status; 4582 4583 // Wait for the child process to exit. This returns immediately if 4584 // the child has already exited. */ 4585 while (waitpid(pid, &status, 0) < 0) { 4586 switch (errno) { 4587 case ECHILD: return 0; 4588 case EINTR: break; 4589 default: return -1; 4590 } 4591 } 4592 4593 if (WIFEXITED(status)) { 4594 // The child exited normally; get its exit code. 4595 return WEXITSTATUS(status); 4596 } else if (WIFSIGNALED(status)) { 4597 // The child exited because of a signal 4598 // The best value to return is 0x80 + signal number, 4599 // because that is what all Unix shells do, and because 4600 // it allows callers to distinguish between process exit and 4601 // process death by signal. 4602 return 0x80 + WTERMSIG(status); 4603 } else { 4604 // Unknown exit code; pass it through 4605 return status; 4606 } 4607 } 4608 } 4609 4610 // is_headless_jre() 4611 // 4612 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 4613 // in order to report if we are running in a headless jre 4614 // 4615 // Since JDK8 xawt/libmawt.so was moved into the same directory 4616 // as libawt.so, and renamed libawt_xawt.so 4617 // 4618 bool os::is_headless_jre() { 4619 #ifdef __APPLE__ 4620 // We no longer build headless-only on Mac OS X 4621 return false; 4622 #else 4623 struct stat statbuf; 4624 char buf[MAXPATHLEN]; 4625 char libmawtpath[MAXPATHLEN]; 4626 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX; 4627 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX; 4628 char *p; 4629 4630 // Get path to libjvm.so 4631 os::jvm_path(buf, sizeof(buf)); 4632 4633 // Get rid of libjvm.so 4634 p = strrchr(buf, '/'); 4635 if (p == NULL) return false; 4636 else *p = '\0'; 4637 4638 // Get rid of client or server 4639 p = strrchr(buf, '/'); 4640 if (p == NULL) return false; 4641 else *p = '\0'; 4642 4643 // check xawt/libmawt.so 4644 strcpy(libmawtpath, buf); 4645 strcat(libmawtpath, xawtstr); 4646 if (::stat(libmawtpath, &statbuf) == 0) return false; 4647 4648 // check libawt_xawt.so 4649 strcpy(libmawtpath, buf); 4650 strcat(libmawtpath, new_xawtstr); 4651 if (::stat(libmawtpath, &statbuf) == 0) return false; 4652 4653 return true; 4654 #endif 4655 } 4656 4657 // Get the default path to the core file 4658 // Returns the length of the string 4659 int os::get_core_path(char* buffer, size_t bufferSize) { 4660 int n = jio_snprintf(buffer, bufferSize, "/cores"); 4661 4662 // Truncate if theoretical string was longer than bufferSize 4663 n = MIN2(n, (int)bufferSize); 4664 4665 return n; 4666 } 4667 4668 #ifndef PRODUCT 4669 void TestReserveMemorySpecial_test() { 4670 // No tests available for this platform 4671 } 4672 #endif