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_bsd.inline.hpp" 40 #include "os_share_bsd.hpp" 41 #include "prims/jniFastGetField.hpp" 42 #include "prims/jvm.h" 43 #include "prims/jvm_misc.hpp" 44 #include "runtime/arguments.hpp" 45 #include "runtime/atomic.inline.hpp" 46 #include "runtime/extendedPC.hpp" 47 #include "runtime/globals.hpp" 48 #include "runtime/interfaceSupport.hpp" 49 #include "runtime/java.hpp" 50 #include "runtime/javaCalls.hpp" 51 #include "runtime/mutexLocker.hpp" 52 #include "runtime/objectMonitor.hpp" 53 #include "runtime/orderAccess.inline.hpp" 54 #include "runtime/osThread.hpp" 55 #include "runtime/perfMemory.hpp" 56 #include "runtime/sharedRuntime.hpp" 57 #include "runtime/statSampler.hpp" 58 #include "runtime/stubRoutines.hpp" 59 #include "runtime/thread.inline.hpp" 60 #include "runtime/threadCritical.hpp" 61 #include "runtime/timer.hpp" 62 #include "services/attachListener.hpp" 63 #include "services/memTracker.hpp" 64 #include "services/runtimeService.hpp" 65 #include "utilities/decoder.hpp" 66 #include "utilities/defaultStream.hpp" 67 #include "utilities/events.hpp" 68 #include "utilities/growableArray.hpp" 69 #include "utilities/vmError.hpp" 70 71 // put OS-includes here 72 # include <sys/types.h> 73 # include <sys/mman.h> 74 # include <sys/stat.h> 75 # include <sys/select.h> 76 # include <pthread.h> 77 # include <signal.h> 78 # include <errno.h> 79 # include <dlfcn.h> 80 # include <stdio.h> 81 # include <unistd.h> 82 # include <sys/resource.h> 83 # include <pthread.h> 84 # include <sys/stat.h> 85 # include <sys/time.h> 86 # include <sys/times.h> 87 # include <sys/utsname.h> 88 # include <sys/socket.h> 89 # include <sys/wait.h> 90 # include <time.h> 91 # include <pwd.h> 92 # include <poll.h> 93 # include <semaphore.h> 94 # include <fcntl.h> 95 # include <string.h> 96 # include <sys/param.h> 97 # include <sys/sysctl.h> 98 # include <sys/ipc.h> 99 # include <sys/shm.h> 100 #ifndef __APPLE__ 101 # include <link.h> 102 #endif 103 # include <stdint.h> 104 # include <inttypes.h> 105 # include <sys/ioctl.h> 106 # include <sys/syscall.h> 107 108 #if defined(__FreeBSD__) || defined(__NetBSD__) 109 #include <elf.h> 110 #endif 111 112 #ifdef __APPLE__ 113 #include <mach/mach.h> // semaphore_* API 114 #include <mach-o/dyld.h> 115 #include <sys/proc_info.h> 116 #include <objc/objc-auto.h> 117 #endif 118 119 #ifndef MAP_ANONYMOUS 120 #define MAP_ANONYMOUS MAP_ANON 121 #endif 122 123 #define MAX_PATH (2 * K) 124 125 // for timer info max values which include all bits 126 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 127 128 #define LARGEPAGES_BIT (1 << 6) 129 130 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 131 132 //////////////////////////////////////////////////////////////////////////////// 133 // global variables 134 julong os::Bsd::_physical_memory = 0; 135 136 #ifdef __APPLE__ 137 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0}; 138 volatile uint64_t os::Bsd::_max_abstime = 0; 139 #else 140 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; 141 #endif 142 pthread_t os::Bsd::_main_thread; 143 int os::Bsd::_page_size = -1; 144 145 static jlong initial_time_count=0; 146 147 static int clock_tics_per_sec = 100; 148 149 // For diagnostics to print a message once. see run_periodic_checks 150 static sigset_t check_signal_done; 151 static bool check_signals = true; 152 153 static pid_t _initial_pid = 0; 154 155 // Signal number used to suspend/resume a thread 156 157 // do not use any signal number less than SIGSEGV, see 4355769 158 static int SR_signum = SIGUSR2; 159 sigset_t SR_sigset; 160 161 162 //////////////////////////////////////////////////////////////////////////////// 163 // utility functions 164 165 static int SR_initialize(); 166 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time); 167 168 julong os::available_memory() { 169 return Bsd::available_memory(); 170 } 171 172 // available here means free 173 julong os::Bsd::available_memory() { 174 uint64_t available = physical_memory() >> 2; 175 #ifdef __APPLE__ 176 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT; 177 vm_statistics64_data_t vmstat; 178 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64, 179 (host_info64_t)&vmstat, &count); 180 assert(kerr == KERN_SUCCESS, 181 "host_statistics64 failed - check mach_host_self() and count"); 182 if (kerr == KERN_SUCCESS) { 183 available = vmstat.free_count * os::vm_page_size(); 184 } 185 #endif 186 return available; 187 } 188 189 julong os::physical_memory() { 190 return Bsd::physical_memory(); 191 } 192 193 //////////////////////////////////////////////////////////////////////////////// 194 // environment support 195 196 bool os::getenv(const char* name, char* buf, int len) { 197 const char* val = ::getenv(name); 198 if (val != NULL && strlen(val) < (size_t)len) { 199 strcpy(buf, val); 200 return true; 201 } 202 if (len > 0) buf[0] = 0; // return a null string 203 return false; 204 } 205 206 207 // Return true if user is running as root. 208 209 bool os::have_special_privileges() { 210 static bool init = false; 211 static bool privileges = false; 212 if (!init) { 213 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 214 init = true; 215 } 216 return privileges; 217 } 218 219 220 221 // Cpu architecture string 222 #if defined(ZERO) 223 static char cpu_arch[] = ZERO_LIBARCH; 224 #elif defined(IA64) 225 static char cpu_arch[] = "ia64"; 226 #elif defined(IA32) 227 static char cpu_arch[] = "i386"; 228 #elif defined(AMD64) 229 static char cpu_arch[] = "amd64"; 230 #elif defined(ARM) 231 static char cpu_arch[] = "arm"; 232 #elif defined(PPC32) 233 static char cpu_arch[] = "ppc"; 234 #elif defined(SPARC) 235 #ifdef _LP64 236 static char cpu_arch[] = "sparcv9"; 237 #else 238 static char cpu_arch[] = "sparc"; 239 #endif 240 #else 241 #error Add appropriate cpu_arch setting 242 #endif 243 244 // Compiler variant 245 #ifdef COMPILER2 246 #define COMPILER_VARIANT "server" 247 #else 248 #define COMPILER_VARIANT "client" 249 #endif 250 251 252 void os::Bsd::initialize_system_info() { 253 int mib[2]; 254 size_t len; 255 int cpu_val; 256 julong mem_val; 257 258 // get processors count via hw.ncpus sysctl 259 mib[0] = CTL_HW; 260 mib[1] = HW_NCPU; 261 len = sizeof(cpu_val); 262 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) { 263 assert(len == sizeof(cpu_val), "unexpected data size"); 264 set_processor_count(cpu_val); 265 } else { 266 set_processor_count(1); // fallback 267 } 268 269 // get physical memory via hw.memsize sysctl (hw.memsize is used 270 // since it returns a 64 bit value) 271 mib[0] = CTL_HW; 272 273 #if defined (HW_MEMSIZE) // Apple 274 mib[1] = HW_MEMSIZE; 275 #elif defined(HW_PHYSMEM) // Most of BSD 276 mib[1] = HW_PHYSMEM; 277 #elif defined(HW_REALMEM) // Old FreeBSD 278 mib[1] = HW_REALMEM; 279 #else 280 #error No ways to get physmem 281 #endif 282 283 len = sizeof(mem_val); 284 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) { 285 assert(len == sizeof(mem_val), "unexpected data size"); 286 _physical_memory = mem_val; 287 } else { 288 _physical_memory = 256 * 1024 * 1024; // fallback (XXXBSD?) 289 } 290 291 #ifdef __OpenBSD__ 292 { 293 // limit _physical_memory memory view on OpenBSD since 294 // datasize rlimit restricts us anyway. 295 struct rlimit limits; 296 getrlimit(RLIMIT_DATA, &limits); 297 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur); 298 } 299 #endif 300 } 301 302 #ifdef __APPLE__ 303 static const char *get_home() { 304 const char *home_dir = ::getenv("HOME"); 305 if ((home_dir == NULL) || (*home_dir == '\0')) { 306 struct passwd *passwd_info = getpwuid(geteuid()); 307 if (passwd_info != NULL) { 308 home_dir = passwd_info->pw_dir; 309 } 310 } 311 312 return home_dir; 313 } 314 #endif 315 316 void os::init_system_properties_values() { 317 // The next steps are taken in the product version: 318 // 319 // Obtain the JAVA_HOME value from the location of libjvm.so. 320 // This library should be located at: 321 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so. 322 // 323 // If "/jre/lib/" appears at the right place in the path, then we 324 // assume libjvm.so is installed in a JDK and we use this path. 325 // 326 // Otherwise exit with message: "Could not create the Java virtual machine." 327 // 328 // The following extra steps are taken in the debugging version: 329 // 330 // If "/jre/lib/" does NOT appear at the right place in the path 331 // instead of exit check for $JAVA_HOME environment variable. 332 // 333 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 334 // then we append a fake suffix "hotspot/libjvm.so" to this path so 335 // it looks like libjvm.so is installed there 336 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 337 // 338 // Otherwise exit. 339 // 340 // Important note: if the location of libjvm.so changes this 341 // code needs to be changed accordingly. 342 343 // See ld(1): 344 // The linker uses the following search paths to locate required 345 // shared libraries: 346 // 1: ... 347 // ... 348 // 7: The default directories, normally /lib and /usr/lib. 349 #ifndef DEFAULT_LIBPATH 350 #define DEFAULT_LIBPATH "/lib:/usr/lib" 351 #endif 352 353 // Base path of extensions installed on the system. 354 #define SYS_EXT_DIR "/usr/java/packages" 355 #define EXTENSIONS_DIR "/lib/ext" 356 #define ENDORSED_DIR "/lib/endorsed" 357 358 #ifndef __APPLE__ 359 360 // Buffer that fits several sprintfs. 361 // Note that the space for the colon and the trailing null are provided 362 // by the nulls included by the sizeof operator. 363 const size_t bufsize = 364 MAX3((size_t)MAXPATHLEN, // For dll_dir & friends. 365 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR), // extensions dir 366 (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir 367 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 368 369 // sysclasspath, java_home, dll_dir 370 { 371 char *pslash; 372 os::jvm_path(buf, bufsize); 373 374 // Found the full path to libjvm.so. 375 // Now cut the path to <java_home>/jre if we can. 376 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 377 pslash = strrchr(buf, '/'); 378 if (pslash != NULL) { 379 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 380 } 381 Arguments::set_dll_dir(buf); 382 383 if (pslash != NULL) { 384 pslash = strrchr(buf, '/'); 385 if (pslash != NULL) { 386 *pslash = '\0'; // Get rid of /<arch>. 387 pslash = strrchr(buf, '/'); 388 if (pslash != NULL) { 389 *pslash = '\0'; // Get rid of /lib. 390 } 391 } 392 } 393 Arguments::set_java_home(buf); 394 set_boot_path('/', ':'); 395 } 396 397 // Where to look for native libraries. 398 // 399 // Note: Due to a legacy implementation, most of the library path 400 // is set in the launcher. This was to accomodate linking restrictions 401 // on legacy Bsd implementations (which are no longer supported). 402 // Eventually, all the library path setting will be done here. 403 // 404 // However, to prevent the proliferation of improperly built native 405 // libraries, the new path component /usr/java/packages is added here. 406 // Eventually, all the library path setting will be done here. 407 { 408 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 409 // should always exist (until the legacy problem cited above is 410 // addressed). 411 const char *v = ::getenv("LD_LIBRARY_PATH"); 412 const char *v_colon = ":"; 413 if (v == NULL) { v = ""; v_colon = ""; } 414 // That's +1 for the colon and +1 for the trailing '\0'. 415 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 416 strlen(v) + 1 + 417 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1, 418 mtInternal); 419 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch); 420 Arguments::set_library_path(ld_library_path); 421 FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal); 422 } 423 424 // Extensions directories. 425 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 426 Arguments::set_ext_dirs(buf); 427 428 // Endorsed standards default directory. 429 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); 430 Arguments::set_endorsed_dirs(buf); 431 432 FREE_C_HEAP_ARRAY(char, buf, mtInternal); 433 434 #else // __APPLE__ 435 436 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions" 437 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java" 438 439 const char *user_home_dir = get_home(); 440 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir. 441 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) + 442 sizeof(SYS_EXTENSIONS_DIRS); 443 444 // Buffer that fits several sprintfs. 445 // Note that the space for the colon and the trailing null are provided 446 // by the nulls included by the sizeof operator. 447 const size_t bufsize = 448 MAX3((size_t)MAXPATHLEN, // for dll_dir & friends. 449 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size, // extensions dir 450 (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir 451 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 452 453 // sysclasspath, java_home, dll_dir 454 { 455 char *pslash; 456 os::jvm_path(buf, bufsize); 457 458 // Found the full path to libjvm.so. 459 // Now cut the path to <java_home>/jre if we can. 460 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 461 pslash = strrchr(buf, '/'); 462 if (pslash != NULL) { 463 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 464 } 465 Arguments::set_dll_dir(buf); 466 467 if (pslash != NULL) { 468 pslash = strrchr(buf, '/'); 469 if (pslash != NULL) { 470 *pslash = '\0'; // Get rid of /lib. 471 } 472 } 473 Arguments::set_java_home(buf); 474 set_boot_path('/', ':'); 475 } 476 477 // Where to look for native libraries. 478 // 479 // Note: Due to a legacy implementation, most of the library path 480 // is set in the launcher. This was to accomodate linking restrictions 481 // on legacy Bsd implementations (which are no longer supported). 482 // Eventually, all the library path setting will be done here. 483 // 484 // However, to prevent the proliferation of improperly built native 485 // libraries, the new path component /usr/java/packages is added here. 486 // Eventually, all the library path setting will be done here. 487 { 488 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 489 // should always exist (until the legacy problem cited above is 490 // addressed). 491 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code 492 // can specify a directory inside an app wrapper 493 const char *l = ::getenv("JAVA_LIBRARY_PATH"); 494 const char *l_colon = ":"; 495 if (l == NULL) { l = ""; l_colon = ""; } 496 497 const char *v = ::getenv("DYLD_LIBRARY_PATH"); 498 const char *v_colon = ":"; 499 if (v == NULL) { v = ""; v_colon = ""; } 500 501 // Apple's Java6 has "." at the beginning of java.library.path. 502 // OpenJDK on Windows has "." at the end of java.library.path. 503 // OpenJDK on Linux and Solaris don't have "." in java.library.path 504 // at all. To ease the transition from Apple's Java6 to OpenJDK7, 505 // "." is appended to the end of java.library.path. Yes, this 506 // could cause a change in behavior, but Apple's Java6 behavior 507 // can be achieved by putting "." at the beginning of the 508 // JAVA_LIBRARY_PATH environment variable. 509 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 510 strlen(v) + 1 + strlen(l) + 1 + 511 system_ext_size + 3, 512 mtInternal); 513 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.", 514 v, v_colon, l, l_colon, user_home_dir); 515 Arguments::set_library_path(ld_library_path); 516 FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal); 517 } 518 519 // Extensions directories. 520 // 521 // Note that the space for the colon and the trailing null are provided 522 // by the nulls included by the sizeof operator (so actually one byte more 523 // than necessary is allocated). 524 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, 525 user_home_dir, Arguments::get_java_home()); 526 Arguments::set_ext_dirs(buf); 527 528 // Endorsed standards default directory. 529 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); 530 Arguments::set_endorsed_dirs(buf); 531 532 FREE_C_HEAP_ARRAY(char, buf, mtInternal); 533 534 #undef SYS_EXTENSIONS_DIR 535 #undef SYS_EXTENSIONS_DIRS 536 537 #endif // __APPLE__ 538 539 #undef SYS_EXT_DIR 540 #undef EXTENSIONS_DIR 541 #undef ENDORSED_DIR 542 } 543 544 //////////////////////////////////////////////////////////////////////////////// 545 // breakpoint support 546 547 void os::breakpoint() { 548 BREAKPOINT; 549 } 550 551 extern "C" void breakpoint() { 552 // use debugger to set breakpoint here 553 } 554 555 //////////////////////////////////////////////////////////////////////////////// 556 // signal support 557 558 debug_only(static bool signal_sets_initialized = false); 559 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 560 561 bool os::Bsd::is_sig_ignored(int sig) { 562 struct sigaction oact; 563 sigaction(sig, (struct sigaction*)NULL, &oact); 564 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 565 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 566 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) { 567 return true; 568 } else { 569 return false; 570 } 571 } 572 573 void os::Bsd::signal_sets_init() { 574 // Should also have an assertion stating we are still single-threaded. 575 assert(!signal_sets_initialized, "Already initialized"); 576 // Fill in signals that are necessarily unblocked for all threads in 577 // the VM. Currently, we unblock the following signals: 578 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 579 // by -Xrs (=ReduceSignalUsage)); 580 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 581 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 582 // the dispositions or masks wrt these signals. 583 // Programs embedding the VM that want to use the above signals for their 584 // own purposes must, at this time, use the "-Xrs" option to prevent 585 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 586 // (See bug 4345157, and other related bugs). 587 // In reality, though, unblocking these signals is really a nop, since 588 // these signals are not blocked by default. 589 sigemptyset(&unblocked_sigs); 590 sigemptyset(&allowdebug_blocked_sigs); 591 sigaddset(&unblocked_sigs, SIGILL); 592 sigaddset(&unblocked_sigs, SIGSEGV); 593 sigaddset(&unblocked_sigs, SIGBUS); 594 sigaddset(&unblocked_sigs, SIGFPE); 595 sigaddset(&unblocked_sigs, SR_signum); 596 597 if (!ReduceSignalUsage) { 598 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 599 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 600 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); 601 } 602 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 603 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 604 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); 605 } 606 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 607 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 608 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); 609 } 610 } 611 // Fill in signals that are blocked by all but the VM thread. 612 sigemptyset(&vm_sigs); 613 if (!ReduceSignalUsage) { 614 sigaddset(&vm_sigs, BREAK_SIGNAL); 615 } 616 debug_only(signal_sets_initialized = true); 617 618 } 619 620 // These are signals that are unblocked while a thread is running Java. 621 // (For some reason, they get blocked by default.) 622 sigset_t* os::Bsd::unblocked_signals() { 623 assert(signal_sets_initialized, "Not initialized"); 624 return &unblocked_sigs; 625 } 626 627 // These are the signals that are blocked while a (non-VM) thread is 628 // running Java. Only the VM thread handles these signals. 629 sigset_t* os::Bsd::vm_signals() { 630 assert(signal_sets_initialized, "Not initialized"); 631 return &vm_sigs; 632 } 633 634 // These are signals that are blocked during cond_wait to allow debugger in 635 sigset_t* os::Bsd::allowdebug_blocked_signals() { 636 assert(signal_sets_initialized, "Not initialized"); 637 return &allowdebug_blocked_sigs; 638 } 639 640 void os::Bsd::hotspot_sigmask(Thread* thread) { 641 642 //Save caller's signal mask before setting VM signal mask 643 sigset_t caller_sigmask; 644 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 645 646 OSThread* osthread = thread->osthread(); 647 osthread->set_caller_sigmask(caller_sigmask); 648 649 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); 650 651 if (!ReduceSignalUsage) { 652 if (thread->is_VM_thread()) { 653 // Only the VM thread handles BREAK_SIGNAL ... 654 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 655 } else { 656 // ... all other threads block BREAK_SIGNAL 657 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 658 } 659 } 660 } 661 662 663 ////////////////////////////////////////////////////////////////////////////// 664 // create new thread 665 666 // check if it's safe to start a new thread 667 static bool _thread_safety_check(Thread* thread) { 668 return true; 669 } 670 671 #ifdef __APPLE__ 672 // library handle for calling objc_registerThreadWithCollector() 673 // without static linking to the libobjc library 674 #define OBJC_LIB "/usr/lib/libobjc.dylib" 675 #define OBJC_GCREGISTER "objc_registerThreadWithCollector" 676 typedef void (*objc_registerThreadWithCollector_t)(); 677 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction; 678 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL; 679 #endif 680 681 #ifdef __APPLE__ 682 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) { 683 // Additional thread_id used to correlate threads in SA 684 thread_identifier_info_data_t m_ident_info; 685 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT; 686 687 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO, 688 (thread_info_t) &m_ident_info, &count); 689 690 return m_ident_info.thread_id; 691 } 692 #endif 693 694 // Thread start routine for all newly created threads 695 static void *java_start(Thread *thread) { 696 // Try to randomize the cache line index of hot stack frames. 697 // This helps when threads of the same stack traces evict each other's 698 // cache lines. The threads can be either from the same JVM instance, or 699 // from different JVM instances. The benefit is especially true for 700 // processors with hyperthreading technology. 701 static int counter = 0; 702 int pid = os::current_process_id(); 703 alloca(((pid ^ counter++) & 7) * 128); 704 705 ThreadLocalStorage::set_thread(thread); 706 707 OSThread* osthread = thread->osthread(); 708 Monitor* sync = osthread->startThread_lock(); 709 710 // non floating stack BsdThreads needs extra check, see above 711 if (!_thread_safety_check(thread)) { 712 // notify parent thread 713 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 714 osthread->set_state(ZOMBIE); 715 sync->notify_all(); 716 return NULL; 717 } 718 719 osthread->set_thread_id(os::Bsd::gettid()); 720 721 #ifdef __APPLE__ 722 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 723 guarantee(unique_thread_id != 0, "unique thread id was not found"); 724 osthread->set_unique_thread_id(unique_thread_id); 725 #endif 726 // initialize signal mask for this thread 727 os::Bsd::hotspot_sigmask(thread); 728 729 // initialize floating point control register 730 os::Bsd::init_thread_fpu_state(); 731 732 #ifdef __APPLE__ 733 // register thread with objc gc 734 if (objc_registerThreadWithCollectorFunction != NULL) { 735 objc_registerThreadWithCollectorFunction(); 736 } 737 #endif 738 739 // handshaking with parent thread 740 { 741 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 742 743 // notify parent thread 744 osthread->set_state(INITIALIZED); 745 sync->notify_all(); 746 747 // wait until os::start_thread() 748 while (osthread->get_state() == INITIALIZED) { 749 sync->wait(Mutex::_no_safepoint_check_flag); 750 } 751 } 752 753 // call one more level start routine 754 thread->run(); 755 756 return 0; 757 } 758 759 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { 760 assert(thread->osthread() == NULL, "caller responsible"); 761 762 // Allocate the OSThread object 763 OSThread* osthread = new OSThread(NULL, NULL); 764 if (osthread == NULL) { 765 return false; 766 } 767 768 // set the correct thread state 769 osthread->set_thread_type(thr_type); 770 771 // Initial state is ALLOCATED but not INITIALIZED 772 osthread->set_state(ALLOCATED); 773 774 thread->set_osthread(osthread); 775 776 // init thread attributes 777 pthread_attr_t attr; 778 pthread_attr_init(&attr); 779 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 780 781 // stack size 782 if (os::Bsd::supports_variable_stack_size()) { 783 // calculate stack size if it's not specified by caller 784 if (stack_size == 0) { 785 stack_size = os::Bsd::default_stack_size(thr_type); 786 787 switch (thr_type) { 788 case os::java_thread: 789 // Java threads use ThreadStackSize which default value can be 790 // changed with the flag -Xss 791 assert(JavaThread::stack_size_at_create() > 0, "this should be set"); 792 stack_size = JavaThread::stack_size_at_create(); 793 break; 794 case os::compiler_thread: 795 if (CompilerThreadStackSize > 0) { 796 stack_size = (size_t)(CompilerThreadStackSize * K); 797 break; 798 } // else fall through: 799 // use VMThreadStackSize if CompilerThreadStackSize is not defined 800 case os::vm_thread: 801 case os::pgc_thread: 802 case os::cgc_thread: 803 case os::watcher_thread: 804 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 805 break; 806 } 807 } 808 809 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); 810 pthread_attr_setstacksize(&attr, stack_size); 811 } else { 812 // let pthread_create() pick the default value. 813 } 814 815 ThreadState state; 816 817 { 818 pthread_t tid; 819 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 820 821 pthread_attr_destroy(&attr); 822 823 if (ret != 0) { 824 if (PrintMiscellaneous && (Verbose || WizardMode)) { 825 perror("pthread_create()"); 826 } 827 // Need to clean up stuff we've allocated so far 828 thread->set_osthread(NULL); 829 delete osthread; 830 return false; 831 } 832 833 // Store pthread info into the OSThread 834 osthread->set_pthread_id(tid); 835 836 // Wait until child thread is either initialized or aborted 837 { 838 Monitor* sync_with_child = osthread->startThread_lock(); 839 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 840 while ((state = osthread->get_state()) == ALLOCATED) { 841 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 842 } 843 } 844 845 } 846 847 // Aborted due to thread limit being reached 848 if (state == ZOMBIE) { 849 thread->set_osthread(NULL); 850 delete osthread; 851 return false; 852 } 853 854 // The thread is returned suspended (in state INITIALIZED), 855 // and is started higher up in the call chain 856 assert(state == INITIALIZED, "race condition"); 857 return true; 858 } 859 860 ///////////////////////////////////////////////////////////////////////////// 861 // attach existing thread 862 863 // bootstrap the main thread 864 bool os::create_main_thread(JavaThread* thread) { 865 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); 866 return create_attached_thread(thread); 867 } 868 869 bool os::create_attached_thread(JavaThread* thread) { 870 #ifdef ASSERT 871 thread->verify_not_published(); 872 #endif 873 874 // Allocate the OSThread object 875 OSThread* osthread = new OSThread(NULL, NULL); 876 877 if (osthread == NULL) { 878 return false; 879 } 880 881 osthread->set_thread_id(os::Bsd::gettid()); 882 883 // Store pthread info into the OSThread 884 #ifdef __APPLE__ 885 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 886 guarantee(unique_thread_id != 0, "just checking"); 887 osthread->set_unique_thread_id(unique_thread_id); 888 #endif 889 osthread->set_pthread_id(::pthread_self()); 890 891 // initialize floating point control register 892 os::Bsd::init_thread_fpu_state(); 893 894 // Initial thread state is RUNNABLE 895 osthread->set_state(RUNNABLE); 896 897 thread->set_osthread(osthread); 898 899 // initialize signal mask for this thread 900 // and save the caller's signal mask 901 os::Bsd::hotspot_sigmask(thread); 902 903 return true; 904 } 905 906 void os::pd_start_thread(Thread* thread) { 907 OSThread * osthread = thread->osthread(); 908 assert(osthread->get_state() != INITIALIZED, "just checking"); 909 Monitor* sync_with_child = osthread->startThread_lock(); 910 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 911 sync_with_child->notify(); 912 } 913 914 // Free Bsd resources related to the OSThread 915 void os::free_thread(OSThread* osthread) { 916 assert(osthread != NULL, "osthread not set"); 917 918 if (Thread::current()->osthread() == osthread) { 919 // Restore caller's signal mask 920 sigset_t sigmask = osthread->caller_sigmask(); 921 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 922 } 923 924 delete osthread; 925 } 926 927 ////////////////////////////////////////////////////////////////////////////// 928 // thread local storage 929 930 // Restore the thread pointer if the destructor is called. This is in case 931 // someone from JNI code sets up a destructor with pthread_key_create to run 932 // detachCurrentThread on thread death. Unless we restore the thread pointer we 933 // will hang or crash. When detachCurrentThread is called the key will be set 934 // to null and we will not be called again. If detachCurrentThread is never 935 // called we could loop forever depending on the pthread implementation. 936 static void restore_thread_pointer(void* p) { 937 Thread* thread = (Thread*) p; 938 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread); 939 } 940 941 int os::allocate_thread_local_storage() { 942 pthread_key_t key; 943 int rslt = pthread_key_create(&key, restore_thread_pointer); 944 assert(rslt == 0, "cannot allocate thread local storage"); 945 return (int)key; 946 } 947 948 // Note: This is currently not used by VM, as we don't destroy TLS key 949 // on VM exit. 950 void os::free_thread_local_storage(int index) { 951 int rslt = pthread_key_delete((pthread_key_t)index); 952 assert(rslt == 0, "invalid index"); 953 } 954 955 void os::thread_local_storage_at_put(int index, void* value) { 956 int rslt = pthread_setspecific((pthread_key_t)index, value); 957 assert(rslt == 0, "pthread_setspecific failed"); 958 } 959 960 extern "C" Thread* get_thread() { 961 return ThreadLocalStorage::thread(); 962 } 963 964 965 //////////////////////////////////////////////////////////////////////////////// 966 // time support 967 968 // Time since start-up in seconds to a fine granularity. 969 // Used by VMSelfDestructTimer and the MemProfiler. 970 double os::elapsedTime() { 971 972 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); 973 } 974 975 jlong os::elapsed_counter() { 976 return javaTimeNanos() - initial_time_count; 977 } 978 979 jlong os::elapsed_frequency() { 980 return NANOSECS_PER_SEC; // nanosecond resolution 981 } 982 983 bool os::supports_vtime() { return true; } 984 bool os::enable_vtime() { return false; } 985 bool os::vtime_enabled() { return false; } 986 987 double os::elapsedVTime() { 988 // better than nothing, but not much 989 return elapsedTime(); 990 } 991 992 jlong os::javaTimeMillis() { 993 timeval time; 994 int status = gettimeofday(&time, NULL); 995 assert(status != -1, "bsd error"); 996 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 997 } 998 999 #ifndef __APPLE__ 1000 #ifndef CLOCK_MONOTONIC 1001 #define CLOCK_MONOTONIC (1) 1002 #endif 1003 #endif 1004 1005 #ifdef __APPLE__ 1006 void os::Bsd::clock_init() { 1007 mach_timebase_info(&_timebase_info); 1008 } 1009 #else 1010 void os::Bsd::clock_init() { 1011 struct timespec res; 1012 struct timespec tp; 1013 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && 1014 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { 1015 // yes, monotonic clock is supported 1016 _clock_gettime = ::clock_gettime; 1017 } 1018 } 1019 #endif 1020 1021 1022 1023 #ifdef __APPLE__ 1024 1025 jlong os::javaTimeNanos() { 1026 const uint64_t tm = mach_absolute_time(); 1027 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom; 1028 const uint64_t prev = Bsd::_max_abstime; 1029 if (now <= prev) { 1030 return prev; // same or retrograde time; 1031 } 1032 const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev); 1033 assert(obsv >= prev, "invariant"); // Monotonicity 1034 // If the CAS succeeded then we're done and return "now". 1035 // If the CAS failed and the observed value "obsv" is >= now then 1036 // we should return "obsv". If the CAS failed and now > obsv > prv then 1037 // some other thread raced this thread and installed a new value, in which case 1038 // we could either (a) retry the entire operation, (b) retry trying to install now 1039 // or (c) just return obsv. We use (c). No loop is required although in some cases 1040 // we might discard a higher "now" value in deference to a slightly lower but freshly 1041 // installed obsv value. That's entirely benign -- it admits no new orderings compared 1042 // to (a) or (b) -- and greatly reduces coherence traffic. 1043 // We might also condition (c) on the magnitude of the delta between obsv and now. 1044 // Avoiding excessive CAS operations to hot RW locations is critical. 1045 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate 1046 return (prev == obsv) ? now : obsv; 1047 } 1048 1049 #else // __APPLE__ 1050 1051 jlong os::javaTimeNanos() { 1052 if (os::supports_monotonic_clock()) { 1053 struct timespec tp; 1054 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp); 1055 assert(status == 0, "gettime error"); 1056 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1057 return result; 1058 } else { 1059 timeval time; 1060 int status = gettimeofday(&time, NULL); 1061 assert(status != -1, "bsd error"); 1062 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1063 return 1000 * usecs; 1064 } 1065 } 1066 1067 #endif // __APPLE__ 1068 1069 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1070 if (os::supports_monotonic_clock()) { 1071 info_ptr->max_value = ALL_64_BITS; 1072 1073 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1074 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1075 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1076 } else { 1077 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1078 info_ptr->max_value = ALL_64_BITS; 1079 1080 // gettimeofday is a real time clock so it skips 1081 info_ptr->may_skip_backward = true; 1082 info_ptr->may_skip_forward = true; 1083 } 1084 1085 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1086 } 1087 1088 // Return the real, user, and system times in seconds from an 1089 // arbitrary fixed point in the past. 1090 bool os::getTimesSecs(double* process_real_time, 1091 double* process_user_time, 1092 double* process_system_time) { 1093 struct tms ticks; 1094 clock_t real_ticks = times(&ticks); 1095 1096 if (real_ticks == (clock_t) (-1)) { 1097 return false; 1098 } else { 1099 double ticks_per_second = (double) clock_tics_per_sec; 1100 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1101 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1102 *process_real_time = ((double) real_ticks) / ticks_per_second; 1103 1104 return true; 1105 } 1106 } 1107 1108 1109 char * os::local_time_string(char *buf, size_t buflen) { 1110 struct tm t; 1111 time_t long_time; 1112 time(&long_time); 1113 localtime_r(&long_time, &t); 1114 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1115 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1116 t.tm_hour, t.tm_min, t.tm_sec); 1117 return buf; 1118 } 1119 1120 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1121 return localtime_r(clock, res); 1122 } 1123 1124 //////////////////////////////////////////////////////////////////////////////// 1125 // runtime exit support 1126 1127 // Note: os::shutdown() might be called very early during initialization, or 1128 // called from signal handler. Before adding something to os::shutdown(), make 1129 // sure it is async-safe and can handle partially initialized VM. 1130 void os::shutdown() { 1131 1132 // allow PerfMemory to attempt cleanup of any persistent resources 1133 perfMemory_exit(); 1134 1135 // needs to remove object in file system 1136 AttachListener::abort(); 1137 1138 // flush buffered output, finish log files 1139 ostream_abort(); 1140 1141 // Check for abort hook 1142 abort_hook_t abort_hook = Arguments::abort_hook(); 1143 if (abort_hook != NULL) { 1144 abort_hook(); 1145 } 1146 1147 } 1148 1149 // Note: os::abort() might be called very early during initialization, or 1150 // called from signal handler. Before adding something to os::abort(), make 1151 // sure it is async-safe and can handle partially initialized VM. 1152 void os::abort(bool dump_core) { 1153 os::shutdown(); 1154 if (dump_core) { 1155 #ifndef PRODUCT 1156 fdStream out(defaultStream::output_fd()); 1157 out.print_raw("Current thread is "); 1158 char buf[16]; 1159 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1160 out.print_raw_cr(buf); 1161 out.print_raw_cr("Dumping core ..."); 1162 #endif 1163 ::abort(); // dump core 1164 } 1165 1166 ::exit(1); 1167 } 1168 1169 // Die immediately, no exit hook, no abort hook, no cleanup. 1170 void os::die() { 1171 // _exit() on BsdThreads only kills current thread 1172 ::abort(); 1173 } 1174 1175 // This method is a copy of JDK's sysGetLastErrorString 1176 // from src/solaris/hpi/src/system_md.c 1177 1178 size_t os::lasterror(char *buf, size_t len) { 1179 if (errno == 0) return 0; 1180 1181 const char *s = ::strerror(errno); 1182 size_t n = ::strlen(s); 1183 if (n >= len) { 1184 n = len - 1; 1185 } 1186 ::strncpy(buf, s, n); 1187 buf[n] = '\0'; 1188 return n; 1189 } 1190 1191 // Information of current thread in variety of formats 1192 pid_t os::Bsd::gettid() { 1193 int retval = -1; 1194 1195 #ifdef __APPLE__ //XNU kernel 1196 // despite the fact mach port is actually not a thread id use it 1197 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4 1198 retval = ::pthread_mach_thread_np(::pthread_self()); 1199 guarantee(retval != 0, "just checking"); 1200 return retval; 1201 1202 #elif __FreeBSD__ 1203 retval = syscall(SYS_thr_self); 1204 #elif __OpenBSD__ 1205 retval = syscall(SYS_getthrid); 1206 #elif __NetBSD__ 1207 retval = (pid_t) syscall(SYS__lwp_self); 1208 #endif 1209 1210 if (retval == -1) { 1211 return getpid(); 1212 } 1213 } 1214 1215 intx os::current_thread_id() { 1216 #ifdef __APPLE__ 1217 return (intx)::pthread_mach_thread_np(::pthread_self()); 1218 #else 1219 return (intx)::pthread_self(); 1220 #endif 1221 } 1222 1223 int os::current_process_id() { 1224 1225 // Under the old bsd thread library, bsd gives each thread 1226 // its own process id. Because of this each thread will return 1227 // a different pid if this method were to return the result 1228 // of getpid(2). Bsd provides no api that returns the pid 1229 // of the launcher thread for the vm. This implementation 1230 // returns a unique pid, the pid of the launcher thread 1231 // that starts the vm 'process'. 1232 1233 // Under the NPTL, getpid() returns the same pid as the 1234 // launcher thread rather than a unique pid per thread. 1235 // Use gettid() if you want the old pre NPTL behaviour. 1236 1237 // if you are looking for the result of a call to getpid() that 1238 // returns a unique pid for the calling thread, then look at the 1239 // OSThread::thread_id() method in osThread_bsd.hpp file 1240 1241 return (int)(_initial_pid ? _initial_pid : getpid()); 1242 } 1243 1244 // DLL functions 1245 1246 #define JNI_LIB_PREFIX "lib" 1247 #ifdef __APPLE__ 1248 #define JNI_LIB_SUFFIX ".dylib" 1249 #else 1250 #define JNI_LIB_SUFFIX ".so" 1251 #endif 1252 1253 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } 1254 1255 // This must be hard coded because it's the system's temporary 1256 // directory not the java application's temp directory, ala java.io.tmpdir. 1257 #ifdef __APPLE__ 1258 // macosx has a secure per-user temporary directory 1259 char temp_path_storage[PATH_MAX]; 1260 const char* os::get_temp_directory() { 1261 static char *temp_path = NULL; 1262 if (temp_path == NULL) { 1263 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX); 1264 if (pathSize == 0 || pathSize > PATH_MAX) { 1265 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage)); 1266 } 1267 temp_path = temp_path_storage; 1268 } 1269 return temp_path; 1270 } 1271 #else // __APPLE__ 1272 const char* os::get_temp_directory() { return "/tmp"; } 1273 #endif // __APPLE__ 1274 1275 static bool file_exists(const char* filename) { 1276 struct stat statbuf; 1277 if (filename == NULL || strlen(filename) == 0) { 1278 return false; 1279 } 1280 return os::stat(filename, &statbuf) == 0; 1281 } 1282 1283 bool os::dll_build_name(char* buffer, size_t buflen, 1284 const char* pname, const char* fname) { 1285 bool retval = false; 1286 // Copied from libhpi 1287 const size_t pnamelen = pname ? strlen(pname) : 0; 1288 1289 // Return error on buffer overflow. 1290 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { 1291 return retval; 1292 } 1293 1294 if (pnamelen == 0) { 1295 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); 1296 retval = true; 1297 } else if (strchr(pname, *os::path_separator()) != NULL) { 1298 int n; 1299 char** pelements = split_path(pname, &n); 1300 if (pelements == NULL) { 1301 return false; 1302 } 1303 for (int i = 0; i < n; i++) { 1304 // Really shouldn't be NULL, but check can't hurt 1305 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1306 continue; // skip the empty path values 1307 } 1308 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, 1309 pelements[i], fname); 1310 if (file_exists(buffer)) { 1311 retval = true; 1312 break; 1313 } 1314 } 1315 // release the storage 1316 for (int i = 0; i < n; i++) { 1317 if (pelements[i] != NULL) { 1318 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal); 1319 } 1320 } 1321 if (pelements != NULL) { 1322 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal); 1323 } 1324 } else { 1325 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); 1326 retval = true; 1327 } 1328 return retval; 1329 } 1330 1331 // check if addr is inside libjvm.so 1332 bool os::address_is_in_vm(address addr) { 1333 static address libjvm_base_addr; 1334 Dl_info dlinfo; 1335 1336 if (libjvm_base_addr == NULL) { 1337 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1338 libjvm_base_addr = (address)dlinfo.dli_fbase; 1339 } 1340 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1341 } 1342 1343 if (dladdr((void *)addr, &dlinfo) != 0) { 1344 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1345 } 1346 1347 return false; 1348 } 1349 1350 1351 #define MACH_MAXSYMLEN 256 1352 1353 bool os::dll_address_to_function_name(address addr, char *buf, 1354 int buflen, int *offset) { 1355 // buf is not optional, but offset is optional 1356 assert(buf != NULL, "sanity check"); 1357 1358 Dl_info dlinfo; 1359 char localbuf[MACH_MAXSYMLEN]; 1360 1361 if (dladdr((void*)addr, &dlinfo) != 0) { 1362 // see if we have a matching symbol 1363 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1364 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { 1365 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1366 } 1367 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1368 return true; 1369 } 1370 // no matching symbol so try for just file info 1371 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1372 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1373 buf, buflen, offset, dlinfo.dli_fname)) { 1374 return true; 1375 } 1376 } 1377 1378 // Handle non-dynamic manually: 1379 if (dlinfo.dli_fbase != NULL && 1380 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) { 1381 if (!Decoder::demangle(localbuf, buf, buflen)) { 1382 jio_snprintf(buf, buflen, "%s", localbuf); 1383 } 1384 return true; 1385 } 1386 } 1387 buf[0] = '\0'; 1388 if (offset != NULL) *offset = -1; 1389 return false; 1390 } 1391 1392 // ported from solaris version 1393 bool os::dll_address_to_library_name(address addr, char* buf, 1394 int buflen, int* offset) { 1395 // buf is not optional, but offset is optional 1396 assert(buf != NULL, "sanity check"); 1397 1398 Dl_info dlinfo; 1399 1400 if (dladdr((void*)addr, &dlinfo) != 0) { 1401 if (dlinfo.dli_fname != NULL) { 1402 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1403 } 1404 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1405 *offset = addr - (address)dlinfo.dli_fbase; 1406 } 1407 return true; 1408 } 1409 1410 buf[0] = '\0'; 1411 if (offset) *offset = -1; 1412 return false; 1413 } 1414 1415 // Loads .dll/.so and 1416 // in case of error it checks if .dll/.so was built for the 1417 // same architecture as Hotspot is running on 1418 1419 #ifdef __APPLE__ 1420 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1421 void * result= ::dlopen(filename, RTLD_LAZY); 1422 if (result != NULL) { 1423 // Successful loading 1424 return result; 1425 } 1426 1427 // Read system error message into ebuf 1428 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1429 ebuf[ebuflen-1]='\0'; 1430 1431 return NULL; 1432 } 1433 #else 1434 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1435 void * result= ::dlopen(filename, RTLD_LAZY); 1436 if (result != NULL) { 1437 // Successful loading 1438 return result; 1439 } 1440 1441 Elf32_Ehdr elf_head; 1442 1443 // Read system error message into ebuf 1444 // It may or may not be overwritten below 1445 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1446 ebuf[ebuflen-1]='\0'; 1447 int diag_msg_max_length=ebuflen-strlen(ebuf); 1448 char* diag_msg_buf=ebuf+strlen(ebuf); 1449 1450 if (diag_msg_max_length==0) { 1451 // No more space in ebuf for additional diagnostics message 1452 return NULL; 1453 } 1454 1455 1456 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1457 1458 if (file_descriptor < 0) { 1459 // Can't open library, report dlerror() message 1460 return NULL; 1461 } 1462 1463 bool failed_to_read_elf_head= 1464 (sizeof(elf_head)!= 1465 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1466 1467 ::close(file_descriptor); 1468 if (failed_to_read_elf_head) { 1469 // file i/o error - report dlerror() msg 1470 return NULL; 1471 } 1472 1473 typedef struct { 1474 Elf32_Half code; // Actual value as defined in elf.h 1475 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1476 char elf_class; // 32 or 64 bit 1477 char endianess; // MSB or LSB 1478 char* name; // String representation 1479 } arch_t; 1480 1481 #ifndef EM_486 1482 #define EM_486 6 /* Intel 80486 */ 1483 #endif 1484 1485 #ifndef EM_MIPS_RS3_LE 1486 #define EM_MIPS_RS3_LE 10 /* MIPS */ 1487 #endif 1488 1489 #ifndef EM_PPC64 1490 #define EM_PPC64 21 /* PowerPC64 */ 1491 #endif 1492 1493 #ifndef EM_S390 1494 #define EM_S390 22 /* IBM System/390 */ 1495 #endif 1496 1497 #ifndef EM_IA_64 1498 #define EM_IA_64 50 /* HP/Intel IA-64 */ 1499 #endif 1500 1501 #ifndef EM_X86_64 1502 #define EM_X86_64 62 /* AMD x86-64 */ 1503 #endif 1504 1505 static const arch_t arch_array[]={ 1506 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1507 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1508 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1509 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1510 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1511 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1512 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1513 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1514 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1515 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1516 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1517 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1518 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1519 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1520 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1521 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} 1522 }; 1523 1524 #if (defined IA32) 1525 static Elf32_Half running_arch_code=EM_386; 1526 #elif (defined AMD64) 1527 static Elf32_Half running_arch_code=EM_X86_64; 1528 #elif (defined IA64) 1529 static Elf32_Half running_arch_code=EM_IA_64; 1530 #elif (defined __sparc) && (defined _LP64) 1531 static Elf32_Half running_arch_code=EM_SPARCV9; 1532 #elif (defined __sparc) && (!defined _LP64) 1533 static Elf32_Half running_arch_code=EM_SPARC; 1534 #elif (defined __powerpc64__) 1535 static Elf32_Half running_arch_code=EM_PPC64; 1536 #elif (defined __powerpc__) 1537 static Elf32_Half running_arch_code=EM_PPC; 1538 #elif (defined ARM) 1539 static Elf32_Half running_arch_code=EM_ARM; 1540 #elif (defined S390) 1541 static Elf32_Half running_arch_code=EM_S390; 1542 #elif (defined ALPHA) 1543 static Elf32_Half running_arch_code=EM_ALPHA; 1544 #elif (defined MIPSEL) 1545 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1546 #elif (defined PARISC) 1547 static Elf32_Half running_arch_code=EM_PARISC; 1548 #elif (defined MIPS) 1549 static Elf32_Half running_arch_code=EM_MIPS; 1550 #elif (defined M68K) 1551 static Elf32_Half running_arch_code=EM_68K; 1552 #else 1553 #error Method os::dll_load requires that one of following is defined:\ 1554 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K 1555 #endif 1556 1557 // Identify compatability class for VM's architecture and library's architecture 1558 // Obtain string descriptions for architectures 1559 1560 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1561 int running_arch_index=-1; 1562 1563 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1564 if (running_arch_code == arch_array[i].code) { 1565 running_arch_index = i; 1566 } 1567 if (lib_arch.code == arch_array[i].code) { 1568 lib_arch.compat_class = arch_array[i].compat_class; 1569 lib_arch.name = arch_array[i].name; 1570 } 1571 } 1572 1573 assert(running_arch_index != -1, 1574 "Didn't find running architecture code (running_arch_code) in arch_array"); 1575 if (running_arch_index == -1) { 1576 // Even though running architecture detection failed 1577 // we may still continue with reporting dlerror() message 1578 return NULL; 1579 } 1580 1581 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1582 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1583 return NULL; 1584 } 1585 1586 #ifndef S390 1587 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1588 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1589 return NULL; 1590 } 1591 #endif // !S390 1592 1593 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1594 if (lib_arch.name!=NULL) { 1595 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1596 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1597 lib_arch.name, arch_array[running_arch_index].name); 1598 } else { 1599 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1600 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1601 lib_arch.code, 1602 arch_array[running_arch_index].name); 1603 } 1604 } 1605 1606 return NULL; 1607 } 1608 #endif // !__APPLE__ 1609 1610 void* os::get_default_process_handle() { 1611 #ifdef __APPLE__ 1612 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY 1613 // to avoid finding unexpected symbols on second (or later) 1614 // loads of a library. 1615 return (void*)::dlopen(NULL, RTLD_FIRST); 1616 #else 1617 return (void*)::dlopen(NULL, RTLD_LAZY); 1618 #endif 1619 } 1620 1621 // XXX: Do we need a lock around this as per Linux? 1622 void* os::dll_lookup(void* handle, const char* name) { 1623 return dlsym(handle, name); 1624 } 1625 1626 1627 static bool _print_ascii_file(const char* filename, outputStream* st) { 1628 int fd = ::open(filename, O_RDONLY); 1629 if (fd == -1) { 1630 return false; 1631 } 1632 1633 char buf[32]; 1634 int bytes; 1635 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { 1636 st->print_raw(buf, bytes); 1637 } 1638 1639 ::close(fd); 1640 1641 return true; 1642 } 1643 1644 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) { 1645 outputStream * out = (outputStream *) param; 1646 out->print_cr(PTR_FORMAT " \t%s", base_address, name); 1647 return 0; 1648 } 1649 1650 void os::print_dll_info(outputStream *st) { 1651 st->print_cr("Dynamic libraries:"); 1652 if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) { 1653 st->print_cr("Error: Cannot print dynamic libraries."); 1654 } 1655 } 1656 1657 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1658 #ifdef RTLD_DI_LINKMAP 1659 Dl_info dli; 1660 void *handle; 1661 Link_map *map; 1662 Link_map *p; 1663 1664 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 || 1665 dli.dli_fname == NULL) { 1666 return 1; 1667 } 1668 handle = dlopen(dli.dli_fname, RTLD_LAZY); 1669 if (handle == NULL) { 1670 return 1; 1671 } 1672 dlinfo(handle, RTLD_DI_LINKMAP, &map); 1673 if (map == NULL) { 1674 dlclose(handle); 1675 return 1; 1676 } 1677 1678 while (map->l_prev != NULL) 1679 map = map->l_prev; 1680 1681 while (map != NULL) { 1682 // Value for top_address is returned as 0 since we don't have any information about module size 1683 if (callback(map->l_name, (address)map->l_addr, (address)0, param)) { 1684 dlclose(handle); 1685 return 1; 1686 } 1687 map = map->l_next; 1688 } 1689 1690 dlclose(handle); 1691 #elif defined(__APPLE__) 1692 for (uint32_t i = 1; i < _dyld_image_count(); i++) { 1693 // Value for top_address is returned as 0 since we don't have any information about module size 1694 if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) { 1695 return 1; 1696 } 1697 } 1698 return 0; 1699 #else 1700 return 1; 1701 #endif 1702 } 1703 1704 void os::print_os_info_brief(outputStream* st) { 1705 st->print("Bsd"); 1706 1707 os::Posix::print_uname_info(st); 1708 } 1709 1710 void os::print_os_info(outputStream* st) { 1711 st->print("OS:"); 1712 st->print("Bsd"); 1713 1714 os::Posix::print_uname_info(st); 1715 1716 os::Posix::print_rlimit_info(st); 1717 1718 os::Posix::print_load_average(st); 1719 } 1720 1721 void os::pd_print_cpu_info(outputStream* st) { 1722 // Nothing to do for now. 1723 } 1724 1725 void os::print_memory_info(outputStream* st) { 1726 1727 st->print("Memory:"); 1728 st->print(" %dk page", os::vm_page_size()>>10); 1729 1730 st->print(", physical " UINT64_FORMAT "k", 1731 os::physical_memory() >> 10); 1732 st->print("(" UINT64_FORMAT "k free)", 1733 os::available_memory() >> 10); 1734 st->cr(); 1735 1736 // meminfo 1737 st->print("\n/proc/meminfo:\n"); 1738 _print_ascii_file("/proc/meminfo", st); 1739 st->cr(); 1740 } 1741 1742 void os::print_siginfo(outputStream* st, void* siginfo) { 1743 const siginfo_t* si = (const siginfo_t*)siginfo; 1744 1745 os::Posix::print_siginfo_brief(st, si); 1746 1747 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && 1748 UseSharedSpaces) { 1749 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1750 if (mapinfo->is_in_shared_space(si->si_addr)) { 1751 st->print("\n\nError accessing class data sharing archive." \ 1752 " Mapped file inaccessible during execution, " \ 1753 " possible disk/network problem."); 1754 } 1755 } 1756 st->cr(); 1757 } 1758 1759 1760 static void print_signal_handler(outputStream* st, int sig, 1761 char* buf, size_t buflen); 1762 1763 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 1764 st->print_cr("Signal Handlers:"); 1765 print_signal_handler(st, SIGSEGV, buf, buflen); 1766 print_signal_handler(st, SIGBUS , buf, buflen); 1767 print_signal_handler(st, SIGFPE , buf, buflen); 1768 print_signal_handler(st, SIGPIPE, buf, buflen); 1769 print_signal_handler(st, SIGXFSZ, buf, buflen); 1770 print_signal_handler(st, SIGILL , buf, buflen); 1771 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); 1772 print_signal_handler(st, SR_signum, buf, buflen); 1773 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 1774 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 1775 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 1776 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 1777 } 1778 1779 static char saved_jvm_path[MAXPATHLEN] = {0}; 1780 1781 // Find the full path to the current module, libjvm 1782 void os::jvm_path(char *buf, jint buflen) { 1783 // Error checking. 1784 if (buflen < MAXPATHLEN) { 1785 assert(false, "must use a large-enough buffer"); 1786 buf[0] = '\0'; 1787 return; 1788 } 1789 // Lazy resolve the path to current module. 1790 if (saved_jvm_path[0] != 0) { 1791 strcpy(buf, saved_jvm_path); 1792 return; 1793 } 1794 1795 char dli_fname[MAXPATHLEN]; 1796 bool ret = dll_address_to_library_name( 1797 CAST_FROM_FN_PTR(address, os::jvm_path), 1798 dli_fname, sizeof(dli_fname), NULL); 1799 assert(ret, "cannot locate libjvm"); 1800 char *rp = NULL; 1801 if (ret && dli_fname[0] != '\0') { 1802 rp = realpath(dli_fname, buf); 1803 } 1804 if (rp == NULL) { 1805 return; 1806 } 1807 1808 if (Arguments::sun_java_launcher_is_altjvm()) { 1809 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 1810 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so" 1811 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/" 1812 // appears at the right place in the string, then assume we are 1813 // installed in a JDK and we're done. Otherwise, check for a 1814 // JAVA_HOME environment variable and construct a path to the JVM 1815 // being overridden. 1816 1817 const char *p = buf + strlen(buf) - 1; 1818 for (int count = 0; p > buf && count < 5; ++count) { 1819 for (--p; p > buf && *p != '/'; --p) 1820 /* empty */ ; 1821 } 1822 1823 if (strncmp(p, "/jre/lib/", 9) != 0) { 1824 // Look for JAVA_HOME in the environment. 1825 char* java_home_var = ::getenv("JAVA_HOME"); 1826 if (java_home_var != NULL && java_home_var[0] != 0) { 1827 char* jrelib_p; 1828 int len; 1829 1830 // Check the current module name "libjvm" 1831 p = strrchr(buf, '/'); 1832 assert(strstr(p, "/libjvm") == p, "invalid library name"); 1833 1834 rp = realpath(java_home_var, buf); 1835 if (rp == NULL) { 1836 return; 1837 } 1838 1839 // determine if this is a legacy image or modules image 1840 // modules image doesn't have "jre" subdirectory 1841 len = strlen(buf); 1842 assert(len < buflen, "Ran out of buffer space"); 1843 jrelib_p = buf + len; 1844 1845 // Add the appropriate library subdir 1846 snprintf(jrelib_p, buflen-len, "/jre/lib"); 1847 if (0 != access(buf, F_OK)) { 1848 snprintf(jrelib_p, buflen-len, "/lib"); 1849 } 1850 1851 // Add the appropriate client or server subdir 1852 len = strlen(buf); 1853 jrelib_p = buf + len; 1854 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT); 1855 if (0 != access(buf, F_OK)) { 1856 snprintf(jrelib_p, buflen-len, "%s", ""); 1857 } 1858 1859 // If the path exists within JAVA_HOME, add the JVM library name 1860 // to complete the path to JVM being overridden. Otherwise fallback 1861 // to the path to the current library. 1862 if (0 == access(buf, F_OK)) { 1863 // Use current module name "libjvm" 1864 len = strlen(buf); 1865 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX); 1866 } else { 1867 // Fall back to path of current library 1868 rp = realpath(dli_fname, buf); 1869 if (rp == NULL) { 1870 return; 1871 } 1872 } 1873 } 1874 } 1875 } 1876 1877 strncpy(saved_jvm_path, buf, MAXPATHLEN); 1878 } 1879 1880 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 1881 // no prefix required, not even "_" 1882 } 1883 1884 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 1885 // no suffix required 1886 } 1887 1888 //////////////////////////////////////////////////////////////////////////////// 1889 // sun.misc.Signal support 1890 1891 static volatile jint sigint_count = 0; 1892 1893 static void UserHandler(int sig, void *siginfo, void *context) { 1894 // 4511530 - sem_post is serialized and handled by the manager thread. When 1895 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 1896 // don't want to flood the manager thread with sem_post requests. 1897 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 1898 return; 1899 } 1900 1901 // Ctrl-C is pressed during error reporting, likely because the error 1902 // handler fails to abort. Let VM die immediately. 1903 if (sig == SIGINT && is_error_reported()) { 1904 os::die(); 1905 } 1906 1907 os::signal_notify(sig); 1908 } 1909 1910 void* os::user_handler() { 1911 return CAST_FROM_FN_PTR(void*, UserHandler); 1912 } 1913 1914 extern "C" { 1915 typedef void (*sa_handler_t)(int); 1916 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1917 } 1918 1919 void* os::signal(int signal_number, void* handler) { 1920 struct sigaction sigAct, oldSigAct; 1921 1922 sigfillset(&(sigAct.sa_mask)); 1923 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 1924 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 1925 1926 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 1927 // -1 means registration failed 1928 return (void *)-1; 1929 } 1930 1931 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 1932 } 1933 1934 void os::signal_raise(int signal_number) { 1935 ::raise(signal_number); 1936 } 1937 1938 // The following code is moved from os.cpp for making this 1939 // code platform specific, which it is by its very nature. 1940 1941 // Will be modified when max signal is changed to be dynamic 1942 int os::sigexitnum_pd() { 1943 return NSIG; 1944 } 1945 1946 // a counter for each possible signal value 1947 static volatile jint pending_signals[NSIG+1] = { 0 }; 1948 1949 // Bsd(POSIX) specific hand shaking semaphore. 1950 #ifdef __APPLE__ 1951 typedef semaphore_t os_semaphore_t; 1952 1953 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) 1954 #define SEM_WAIT(sem) semaphore_wait(sem) 1955 #define SEM_POST(sem) semaphore_signal(sem) 1956 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem) 1957 #else 1958 typedef sem_t os_semaphore_t; 1959 1960 #define SEM_INIT(sem, value) sem_init(&sem, 0, value) 1961 #define SEM_WAIT(sem) sem_wait(&sem) 1962 #define SEM_POST(sem) sem_post(&sem) 1963 #define SEM_DESTROY(sem) sem_destroy(&sem) 1964 #endif 1965 1966 class Semaphore : public StackObj { 1967 public: 1968 Semaphore(); 1969 ~Semaphore(); 1970 void signal(); 1971 void wait(); 1972 bool trywait(); 1973 bool timedwait(unsigned int sec, int nsec); 1974 private: 1975 jlong currenttime() const; 1976 os_semaphore_t _semaphore; 1977 }; 1978 1979 Semaphore::Semaphore() : _semaphore(0) { 1980 SEM_INIT(_semaphore, 0); 1981 } 1982 1983 Semaphore::~Semaphore() { 1984 SEM_DESTROY(_semaphore); 1985 } 1986 1987 void Semaphore::signal() { 1988 SEM_POST(_semaphore); 1989 } 1990 1991 void Semaphore::wait() { 1992 SEM_WAIT(_semaphore); 1993 } 1994 1995 jlong Semaphore::currenttime() const { 1996 struct timeval tv; 1997 gettimeofday(&tv, NULL); 1998 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000); 1999 } 2000 2001 #ifdef __APPLE__ 2002 bool Semaphore::trywait() { 2003 return timedwait(0, 0); 2004 } 2005 2006 bool Semaphore::timedwait(unsigned int sec, int nsec) { 2007 kern_return_t kr = KERN_ABORTED; 2008 mach_timespec_t waitspec; 2009 waitspec.tv_sec = sec; 2010 waitspec.tv_nsec = nsec; 2011 2012 jlong starttime = currenttime(); 2013 2014 kr = semaphore_timedwait(_semaphore, waitspec); 2015 while (kr == KERN_ABORTED) { 2016 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec; 2017 2018 jlong current = currenttime(); 2019 jlong passedtime = current - starttime; 2020 2021 if (passedtime >= totalwait) { 2022 waitspec.tv_sec = 0; 2023 waitspec.tv_nsec = 0; 2024 } else { 2025 jlong waittime = totalwait - (current - starttime); 2026 waitspec.tv_sec = waittime / NANOSECS_PER_SEC; 2027 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC; 2028 } 2029 2030 kr = semaphore_timedwait(_semaphore, waitspec); 2031 } 2032 2033 return kr == KERN_SUCCESS; 2034 } 2035 2036 #else 2037 2038 bool Semaphore::trywait() { 2039 return sem_trywait(&_semaphore) == 0; 2040 } 2041 2042 bool Semaphore::timedwait(unsigned int sec, int nsec) { 2043 struct timespec ts; 2044 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec); 2045 2046 while (1) { 2047 int result = sem_timedwait(&_semaphore, &ts); 2048 if (result == 0) { 2049 return true; 2050 } else if (errno == EINTR) { 2051 continue; 2052 } else if (errno == ETIMEDOUT) { 2053 return false; 2054 } else { 2055 return false; 2056 } 2057 } 2058 } 2059 2060 #endif // __APPLE__ 2061 2062 static os_semaphore_t sig_sem; 2063 static Semaphore sr_semaphore; 2064 2065 void os::signal_init_pd() { 2066 // Initialize signal structures 2067 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2068 2069 // Initialize signal semaphore 2070 ::SEM_INIT(sig_sem, 0); 2071 } 2072 2073 void os::signal_notify(int sig) { 2074 Atomic::inc(&pending_signals[sig]); 2075 ::SEM_POST(sig_sem); 2076 } 2077 2078 static int check_pending_signals(bool wait) { 2079 Atomic::store(0, &sigint_count); 2080 for (;;) { 2081 for (int i = 0; i < NSIG + 1; i++) { 2082 jint n = pending_signals[i]; 2083 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2084 return i; 2085 } 2086 } 2087 if (!wait) { 2088 return -1; 2089 } 2090 JavaThread *thread = JavaThread::current(); 2091 ThreadBlockInVM tbivm(thread); 2092 2093 bool threadIsSuspended; 2094 do { 2095 thread->set_suspend_equivalent(); 2096 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2097 ::SEM_WAIT(sig_sem); 2098 2099 // were we externally suspended while we were waiting? 2100 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2101 if (threadIsSuspended) { 2102 // The semaphore has been incremented, but while we were waiting 2103 // another thread suspended us. We don't want to continue running 2104 // while suspended because that would surprise the thread that 2105 // suspended us. 2106 ::SEM_POST(sig_sem); 2107 2108 thread->java_suspend_self(); 2109 } 2110 } while (threadIsSuspended); 2111 } 2112 } 2113 2114 int os::signal_lookup() { 2115 return check_pending_signals(false); 2116 } 2117 2118 int os::signal_wait() { 2119 return check_pending_signals(true); 2120 } 2121 2122 //////////////////////////////////////////////////////////////////////////////// 2123 // Virtual Memory 2124 2125 int os::vm_page_size() { 2126 // Seems redundant as all get out 2127 assert(os::Bsd::page_size() != -1, "must call os::init"); 2128 return os::Bsd::page_size(); 2129 } 2130 2131 // Solaris allocates memory by pages. 2132 int os::vm_allocation_granularity() { 2133 assert(os::Bsd::page_size() != -1, "must call os::init"); 2134 return os::Bsd::page_size(); 2135 } 2136 2137 // Rationale behind this function: 2138 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2139 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2140 // samples for JITted code. Here we create private executable mapping over the code cache 2141 // and then we can use standard (well, almost, as mapping can change) way to provide 2142 // info for the reporting script by storing timestamp and location of symbol 2143 void bsd_wrap_code(char* base, size_t size) { 2144 static volatile jint cnt = 0; 2145 2146 if (!UseOprofile) { 2147 return; 2148 } 2149 2150 char buf[PATH_MAX + 1]; 2151 int num = Atomic::add(1, &cnt); 2152 2153 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", 2154 os::get_temp_directory(), os::current_process_id(), num); 2155 unlink(buf); 2156 2157 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2158 2159 if (fd != -1) { 2160 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2161 if (rv != (off_t)-1) { 2162 if (::write(fd, "", 1) == 1) { 2163 mmap(base, size, 2164 PROT_READ|PROT_WRITE|PROT_EXEC, 2165 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2166 } 2167 } 2168 ::close(fd); 2169 unlink(buf); 2170 } 2171 } 2172 2173 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2174 int err) { 2175 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2176 ", %d) failed; error='%s' (errno=%d)", addr, size, exec, 2177 strerror(err), err); 2178 } 2179 2180 // NOTE: Bsd kernel does not really reserve the pages for us. 2181 // All it does is to check if there are enough free pages 2182 // left at the time of mmap(). This could be a potential 2183 // problem. 2184 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2185 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2186 #ifdef __OpenBSD__ 2187 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2188 if (::mprotect(addr, size, prot) == 0) { 2189 return true; 2190 } 2191 #else 2192 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2193 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2194 if (res != (uintptr_t) MAP_FAILED) { 2195 return true; 2196 } 2197 #endif 2198 2199 // Warn about any commit errors we see in non-product builds just 2200 // in case mmap() doesn't work as described on the man page. 2201 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);) 2202 2203 return false; 2204 } 2205 2206 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2207 bool exec) { 2208 // alignment_hint is ignored on this OS 2209 return pd_commit_memory(addr, size, exec); 2210 } 2211 2212 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2213 const char* mesg) { 2214 assert(mesg != NULL, "mesg must be specified"); 2215 if (!pd_commit_memory(addr, size, exec)) { 2216 // add extra info in product mode for vm_exit_out_of_memory(): 2217 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);) 2218 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg); 2219 } 2220 } 2221 2222 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2223 size_t alignment_hint, bool exec, 2224 const char* mesg) { 2225 // alignment_hint is ignored on this OS 2226 pd_commit_memory_or_exit(addr, size, exec, mesg); 2227 } 2228 2229 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2230 } 2231 2232 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2233 ::madvise(addr, bytes, MADV_DONTNEED); 2234 } 2235 2236 void os::numa_make_global(char *addr, size_t bytes) { 2237 } 2238 2239 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2240 } 2241 2242 bool os::numa_topology_changed() { return false; } 2243 2244 size_t os::numa_get_groups_num() { 2245 return 1; 2246 } 2247 2248 int os::numa_get_group_id() { 2249 return 0; 2250 } 2251 2252 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2253 if (size > 0) { 2254 ids[0] = 0; 2255 return 1; 2256 } 2257 return 0; 2258 } 2259 2260 bool os::get_page_info(char *start, page_info* info) { 2261 return false; 2262 } 2263 2264 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { 2265 return end; 2266 } 2267 2268 2269 bool os::pd_uncommit_memory(char* addr, size_t size) { 2270 #ifdef __OpenBSD__ 2271 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2272 return ::mprotect(addr, size, PROT_NONE) == 0; 2273 #else 2274 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2275 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2276 return res != (uintptr_t) MAP_FAILED; 2277 #endif 2278 } 2279 2280 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2281 return os::commit_memory(addr, size, !ExecMem); 2282 } 2283 2284 // If this is a growable mapping, remove the guard pages entirely by 2285 // munmap()ping them. If not, just call uncommit_memory(). 2286 bool os::remove_stack_guard_pages(char* addr, size_t size) { 2287 return os::uncommit_memory(addr, size); 2288 } 2289 2290 static address _highest_vm_reserved_address = NULL; 2291 2292 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 2293 // at 'requested_addr'. If there are existing memory mappings at the same 2294 // location, however, they will be overwritten. If 'fixed' is false, 2295 // 'requested_addr' is only treated as a hint, the return value may or 2296 // may not start from the requested address. Unlike Bsd mmap(), this 2297 // function returns NULL to indicate failure. 2298 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 2299 char * addr; 2300 int flags; 2301 2302 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 2303 if (fixed) { 2304 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); 2305 flags |= MAP_FIXED; 2306 } 2307 2308 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 2309 // touch an uncommitted page. Otherwise, the read/write might 2310 // succeed if we have enough swap space to back the physical page. 2311 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 2312 flags, -1, 0); 2313 2314 if (addr != MAP_FAILED) { 2315 // anon_mmap() should only get called during VM initialization, 2316 // don't need lock (actually we can skip locking even it can be called 2317 // from multiple threads, because _highest_vm_reserved_address is just a 2318 // hint about the upper limit of non-stack memory regions.) 2319 if ((address)addr + bytes > _highest_vm_reserved_address) { 2320 _highest_vm_reserved_address = (address)addr + bytes; 2321 } 2322 } 2323 2324 return addr == MAP_FAILED ? NULL : addr; 2325 } 2326 2327 // Don't update _highest_vm_reserved_address, because there might be memory 2328 // regions above addr + size. If so, releasing a memory region only creates 2329 // a hole in the address space, it doesn't help prevent heap-stack collision. 2330 // 2331 static int anon_munmap(char * addr, size_t size) { 2332 return ::munmap(addr, size) == 0; 2333 } 2334 2335 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 2336 size_t alignment_hint) { 2337 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 2338 } 2339 2340 bool os::pd_release_memory(char* addr, size_t size) { 2341 return anon_munmap(addr, size); 2342 } 2343 2344 static bool bsd_mprotect(char* addr, size_t size, int prot) { 2345 // Bsd wants the mprotect address argument to be page aligned. 2346 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); 2347 2348 // According to SUSv3, mprotect() should only be used with mappings 2349 // established by mmap(), and mmap() always maps whole pages. Unaligned 2350 // 'addr' likely indicates problem in the VM (e.g. trying to change 2351 // protection of malloc'ed or statically allocated memory). Check the 2352 // caller if you hit this assert. 2353 assert(addr == bottom, "sanity check"); 2354 2355 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); 2356 return ::mprotect(bottom, size, prot) == 0; 2357 } 2358 2359 // Set protections specified 2360 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 2361 bool is_committed) { 2362 unsigned int p = 0; 2363 switch (prot) { 2364 case MEM_PROT_NONE: p = PROT_NONE; break; 2365 case MEM_PROT_READ: p = PROT_READ; break; 2366 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 2367 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 2368 default: 2369 ShouldNotReachHere(); 2370 } 2371 // is_committed is unused. 2372 return bsd_mprotect(addr, bytes, p); 2373 } 2374 2375 bool os::guard_memory(char* addr, size_t size) { 2376 return bsd_mprotect(addr, size, PROT_NONE); 2377 } 2378 2379 bool os::unguard_memory(char* addr, size_t size) { 2380 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); 2381 } 2382 2383 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { 2384 return false; 2385 } 2386 2387 // Large page support 2388 2389 static size_t _large_page_size = 0; 2390 2391 void os::large_page_init() { 2392 } 2393 2394 2395 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) { 2396 fatal("This code is not used or maintained."); 2397 2398 // "exec" is passed in but not used. Creating the shared image for 2399 // the code cache doesn't have an SHM_X executable permission to check. 2400 assert(UseLargePages && UseSHM, "only for SHM large pages"); 2401 2402 key_t key = IPC_PRIVATE; 2403 char *addr; 2404 2405 bool warn_on_failure = UseLargePages && 2406 (!FLAG_IS_DEFAULT(UseLargePages) || 2407 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 2408 2409 // Create a large shared memory region to attach to based on size. 2410 // Currently, size is the total size of the heap 2411 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); 2412 if (shmid == -1) { 2413 // Possible reasons for shmget failure: 2414 // 1. shmmax is too small for Java heap. 2415 // > check shmmax value: cat /proc/sys/kernel/shmmax 2416 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 2417 // 2. not enough large page memory. 2418 // > check available large pages: cat /proc/meminfo 2419 // > increase amount of large pages: 2420 // echo new_value > /proc/sys/vm/nr_hugepages 2421 // Note 1: different Bsd may use different name for this property, 2422 // e.g. on Redhat AS-3 it is "hugetlb_pool". 2423 // Note 2: it's possible there's enough physical memory available but 2424 // they are so fragmented after a long run that they can't 2425 // coalesce into large pages. Try to reserve large pages when 2426 // the system is still "fresh". 2427 if (warn_on_failure) { 2428 warning("Failed to reserve shared memory (errno = %d).", errno); 2429 } 2430 return NULL; 2431 } 2432 2433 // attach to the region 2434 addr = (char*)shmat(shmid, req_addr, 0); 2435 int err = errno; 2436 2437 // Remove shmid. If shmat() is successful, the actual shared memory segment 2438 // will be deleted when it's detached by shmdt() or when the process 2439 // terminates. If shmat() is not successful this will remove the shared 2440 // segment immediately. 2441 shmctl(shmid, IPC_RMID, NULL); 2442 2443 if ((intptr_t)addr == -1) { 2444 if (warn_on_failure) { 2445 warning("Failed to attach shared memory (errno = %d).", err); 2446 } 2447 return NULL; 2448 } 2449 2450 // The memory is committed 2451 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 2452 2453 return addr; 2454 } 2455 2456 bool os::release_memory_special(char* base, size_t bytes) { 2457 if (MemTracker::tracking_level() > NMT_minimal) { 2458 Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 2459 // detaching the SHM segment will also delete it, see reserve_memory_special() 2460 int rslt = shmdt(base); 2461 if (rslt == 0) { 2462 tkr.record((address)base, bytes); 2463 return true; 2464 } else { 2465 return false; 2466 } 2467 } else { 2468 return shmdt(base) == 0; 2469 } 2470 } 2471 2472 size_t os::large_page_size() { 2473 return _large_page_size; 2474 } 2475 2476 // HugeTLBFS allows application to commit large page memory on demand; 2477 // with SysV SHM the entire memory region must be allocated as shared 2478 // memory. 2479 bool os::can_commit_large_page_memory() { 2480 return UseHugeTLBFS; 2481 } 2482 2483 bool os::can_execute_large_page_memory() { 2484 return UseHugeTLBFS; 2485 } 2486 2487 // Reserve memory at an arbitrary address, only if that area is 2488 // available (and not reserved for something else). 2489 2490 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 2491 const int max_tries = 10; 2492 char* base[max_tries]; 2493 size_t size[max_tries]; 2494 const size_t gap = 0x000000; 2495 2496 // Assert only that the size is a multiple of the page size, since 2497 // that's all that mmap requires, and since that's all we really know 2498 // about at this low abstraction level. If we need higher alignment, 2499 // we can either pass an alignment to this method or verify alignment 2500 // in one of the methods further up the call chain. See bug 5044738. 2501 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 2502 2503 // Repeatedly allocate blocks until the block is allocated at the 2504 // right spot. Give up after max_tries. Note that reserve_memory() will 2505 // automatically update _highest_vm_reserved_address if the call is 2506 // successful. The variable tracks the highest memory address every reserved 2507 // by JVM. It is used to detect heap-stack collision if running with 2508 // fixed-stack BsdThreads. Because here we may attempt to reserve more 2509 // space than needed, it could confuse the collision detecting code. To 2510 // solve the problem, save current _highest_vm_reserved_address and 2511 // calculate the correct value before return. 2512 address old_highest = _highest_vm_reserved_address; 2513 2514 // Bsd mmap allows caller to pass an address as hint; give it a try first, 2515 // if kernel honors the hint then we can return immediately. 2516 char * addr = anon_mmap(requested_addr, bytes, false); 2517 if (addr == requested_addr) { 2518 return requested_addr; 2519 } 2520 2521 if (addr != NULL) { 2522 // mmap() is successful but it fails to reserve at the requested address 2523 anon_munmap(addr, bytes); 2524 } 2525 2526 int i; 2527 for (i = 0; i < max_tries; ++i) { 2528 base[i] = reserve_memory(bytes); 2529 2530 if (base[i] != NULL) { 2531 // Is this the block we wanted? 2532 if (base[i] == requested_addr) { 2533 size[i] = bytes; 2534 break; 2535 } 2536 2537 // Does this overlap the block we wanted? Give back the overlapped 2538 // parts and try again. 2539 2540 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; 2541 if (top_overlap >= 0 && top_overlap < bytes) { 2542 unmap_memory(base[i], top_overlap); 2543 base[i] += top_overlap; 2544 size[i] = bytes - top_overlap; 2545 } else { 2546 size_t bottom_overlap = base[i] + bytes - requested_addr; 2547 if (bottom_overlap >= 0 && bottom_overlap < bytes) { 2548 unmap_memory(requested_addr, bottom_overlap); 2549 size[i] = bytes - bottom_overlap; 2550 } else { 2551 size[i] = bytes; 2552 } 2553 } 2554 } 2555 } 2556 2557 // Give back the unused reserved pieces. 2558 2559 for (int j = 0; j < i; ++j) { 2560 if (base[j] != NULL) { 2561 unmap_memory(base[j], size[j]); 2562 } 2563 } 2564 2565 if (i < max_tries) { 2566 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); 2567 return requested_addr; 2568 } else { 2569 _highest_vm_reserved_address = old_highest; 2570 return NULL; 2571 } 2572 } 2573 2574 size_t os::read(int fd, void *buf, unsigned int nBytes) { 2575 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); 2576 } 2577 2578 void os::naked_short_sleep(jlong ms) { 2579 struct timespec req; 2580 2581 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 2582 req.tv_sec = 0; 2583 if (ms > 0) { 2584 req.tv_nsec = (ms % 1000) * 1000000; 2585 } else { 2586 req.tv_nsec = 1; 2587 } 2588 2589 nanosleep(&req, NULL); 2590 2591 return; 2592 } 2593 2594 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 2595 void os::infinite_sleep() { 2596 while (true) { // sleep forever ... 2597 ::sleep(100); // ... 100 seconds at a time 2598 } 2599 } 2600 2601 // Used to convert frequent JVM_Yield() to nops 2602 bool os::dont_yield() { 2603 return DontYieldALot; 2604 } 2605 2606 void os::naked_yield() { 2607 sched_yield(); 2608 } 2609 2610 //////////////////////////////////////////////////////////////////////////////// 2611 // thread priority support 2612 2613 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER 2614 // only supports dynamic priority, static priority must be zero. For real-time 2615 // applications, Bsd supports SCHED_RR which allows static priority (1-99). 2616 // However, for large multi-threaded applications, SCHED_RR is not only slower 2617 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 2618 // of 5 runs - Sep 2005). 2619 // 2620 // The following code actually changes the niceness of kernel-thread/LWP. It 2621 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 2622 // not the entire user process, and user level threads are 1:1 mapped to kernel 2623 // threads. It has always been the case, but could change in the future. For 2624 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 2625 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 2626 2627 #if !defined(__APPLE__) 2628 int os::java_to_os_priority[CriticalPriority + 1] = { 2629 19, // 0 Entry should never be used 2630 2631 0, // 1 MinPriority 2632 3, // 2 2633 6, // 3 2634 2635 10, // 4 2636 15, // 5 NormPriority 2637 18, // 6 2638 2639 21, // 7 2640 25, // 8 2641 28, // 9 NearMaxPriority 2642 2643 31, // 10 MaxPriority 2644 2645 31 // 11 CriticalPriority 2646 }; 2647 #else 2648 // Using Mach high-level priority assignments 2649 int os::java_to_os_priority[CriticalPriority + 1] = { 2650 0, // 0 Entry should never be used (MINPRI_USER) 2651 2652 27, // 1 MinPriority 2653 28, // 2 2654 29, // 3 2655 2656 30, // 4 2657 31, // 5 NormPriority (BASEPRI_DEFAULT) 2658 32, // 6 2659 2660 33, // 7 2661 34, // 8 2662 35, // 9 NearMaxPriority 2663 2664 36, // 10 MaxPriority 2665 2666 36 // 11 CriticalPriority 2667 }; 2668 #endif 2669 2670 static int prio_init() { 2671 if (ThreadPriorityPolicy == 1) { 2672 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 2673 // if effective uid is not root. Perhaps, a more elegant way of doing 2674 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 2675 if (geteuid() != 0) { 2676 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 2677 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); 2678 } 2679 ThreadPriorityPolicy = 0; 2680 } 2681 } 2682 if (UseCriticalJavaThreadPriority) { 2683 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 2684 } 2685 return 0; 2686 } 2687 2688 OSReturn os::set_native_priority(Thread* thread, int newpri) { 2689 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 2690 2691 #ifdef __OpenBSD__ 2692 // OpenBSD pthread_setprio starves low priority threads 2693 return OS_OK; 2694 #elif defined(__FreeBSD__) 2695 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); 2696 #elif defined(__APPLE__) || defined(__NetBSD__) 2697 struct sched_param sp; 2698 int policy; 2699 pthread_t self = pthread_self(); 2700 2701 if (pthread_getschedparam(self, &policy, &sp) != 0) { 2702 return OS_ERR; 2703 } 2704 2705 sp.sched_priority = newpri; 2706 if (pthread_setschedparam(self, policy, &sp) != 0) { 2707 return OS_ERR; 2708 } 2709 2710 return OS_OK; 2711 #else 2712 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 2713 return (ret == 0) ? OS_OK : OS_ERR; 2714 #endif 2715 } 2716 2717 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { 2718 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 2719 *priority_ptr = java_to_os_priority[NormPriority]; 2720 return OS_OK; 2721 } 2722 2723 errno = 0; 2724 #if defined(__OpenBSD__) || defined(__FreeBSD__) 2725 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); 2726 #elif defined(__APPLE__) || defined(__NetBSD__) 2727 int policy; 2728 struct sched_param sp; 2729 2730 pthread_getschedparam(pthread_self(), &policy, &sp); 2731 *priority_ptr = sp.sched_priority; 2732 #else 2733 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 2734 #endif 2735 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 2736 } 2737 2738 // Hint to the underlying OS that a task switch would not be good. 2739 // Void return because it's a hint and can fail. 2740 void os::hint_no_preempt() {} 2741 2742 //////////////////////////////////////////////////////////////////////////////// 2743 // suspend/resume support 2744 2745 // the low-level signal-based suspend/resume support is a remnant from the 2746 // old VM-suspension that used to be for java-suspension, safepoints etc, 2747 // within hotspot. Now there is a single use-case for this: 2748 // - calling get_thread_pc() on the VMThread by the flat-profiler task 2749 // that runs in the watcher thread. 2750 // The remaining code is greatly simplified from the more general suspension 2751 // code that used to be used. 2752 // 2753 // The protocol is quite simple: 2754 // - suspend: 2755 // - sends a signal to the target thread 2756 // - polls the suspend state of the osthread using a yield loop 2757 // - target thread signal handler (SR_handler) sets suspend state 2758 // and blocks in sigsuspend until continued 2759 // - resume: 2760 // - sets target osthread state to continue 2761 // - sends signal to end the sigsuspend loop in the SR_handler 2762 // 2763 // Note that the SR_lock plays no role in this suspend/resume protocol. 2764 2765 static void resume_clear_context(OSThread *osthread) { 2766 osthread->set_ucontext(NULL); 2767 osthread->set_siginfo(NULL); 2768 } 2769 2770 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { 2771 osthread->set_ucontext(context); 2772 osthread->set_siginfo(siginfo); 2773 } 2774 2775 // Handler function invoked when a thread's execution is suspended or 2776 // resumed. We have to be careful that only async-safe functions are 2777 // called here (Note: most pthread functions are not async safe and 2778 // should be avoided.) 2779 // 2780 // Note: sigwait() is a more natural fit than sigsuspend() from an 2781 // interface point of view, but sigwait() prevents the signal hander 2782 // from being run. libpthread would get very confused by not having 2783 // its signal handlers run and prevents sigwait()'s use with the 2784 // mutex granting granting signal. 2785 // 2786 // Currently only ever called on the VMThread or JavaThread 2787 // 2788 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 2789 // Save and restore errno to avoid confusing native code with EINTR 2790 // after sigsuspend. 2791 int old_errno = errno; 2792 2793 Thread* thread = Thread::current(); 2794 OSThread* osthread = thread->osthread(); 2795 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 2796 2797 os::SuspendResume::State current = osthread->sr.state(); 2798 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 2799 suspend_save_context(osthread, siginfo, context); 2800 2801 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 2802 os::SuspendResume::State state = osthread->sr.suspended(); 2803 if (state == os::SuspendResume::SR_SUSPENDED) { 2804 sigset_t suspend_set; // signals for sigsuspend() 2805 2806 // get current set of blocked signals and unblock resume signal 2807 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 2808 sigdelset(&suspend_set, SR_signum); 2809 2810 sr_semaphore.signal(); 2811 // wait here until we are resumed 2812 while (1) { 2813 sigsuspend(&suspend_set); 2814 2815 os::SuspendResume::State result = osthread->sr.running(); 2816 if (result == os::SuspendResume::SR_RUNNING) { 2817 sr_semaphore.signal(); 2818 break; 2819 } else if (result != os::SuspendResume::SR_SUSPENDED) { 2820 ShouldNotReachHere(); 2821 } 2822 } 2823 2824 } else if (state == os::SuspendResume::SR_RUNNING) { 2825 // request was cancelled, continue 2826 } else { 2827 ShouldNotReachHere(); 2828 } 2829 2830 resume_clear_context(osthread); 2831 } else if (current == os::SuspendResume::SR_RUNNING) { 2832 // request was cancelled, continue 2833 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 2834 // ignore 2835 } else { 2836 // ignore 2837 } 2838 2839 errno = old_errno; 2840 } 2841 2842 2843 static int SR_initialize() { 2844 struct sigaction act; 2845 char *s; 2846 // Get signal number to use for suspend/resume 2847 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 2848 int sig = ::strtol(s, 0, 10); 2849 if (sig > 0 || sig < NSIG) { 2850 SR_signum = sig; 2851 } 2852 } 2853 2854 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 2855 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 2856 2857 sigemptyset(&SR_sigset); 2858 sigaddset(&SR_sigset, SR_signum); 2859 2860 // Set up signal handler for suspend/resume 2861 act.sa_flags = SA_RESTART|SA_SIGINFO; 2862 act.sa_handler = (void (*)(int)) SR_handler; 2863 2864 // SR_signum is blocked by default. 2865 // 4528190 - We also need to block pthread restart signal (32 on all 2866 // supported Bsd platforms). Note that BsdThreads need to block 2867 // this signal for all threads to work properly. So we don't have 2868 // to use hard-coded signal number when setting up the mask. 2869 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 2870 2871 if (sigaction(SR_signum, &act, 0) == -1) { 2872 return -1; 2873 } 2874 2875 // Save signal flag 2876 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); 2877 return 0; 2878 } 2879 2880 static int sr_notify(OSThread* osthread) { 2881 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2882 assert_status(status == 0, status, "pthread_kill"); 2883 return status; 2884 } 2885 2886 // "Randomly" selected value for how long we want to spin 2887 // before bailing out on suspending a thread, also how often 2888 // we send a signal to a thread we want to resume 2889 static const int RANDOMLY_LARGE_INTEGER = 1000000; 2890 static const int RANDOMLY_LARGE_INTEGER2 = 100; 2891 2892 // returns true on success and false on error - really an error is fatal 2893 // but this seems the normal response to library errors 2894 static bool do_suspend(OSThread* osthread) { 2895 assert(osthread->sr.is_running(), "thread should be running"); 2896 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 2897 2898 // mark as suspended and send signal 2899 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 2900 // failed to switch, state wasn't running? 2901 ShouldNotReachHere(); 2902 return false; 2903 } 2904 2905 if (sr_notify(osthread) != 0) { 2906 ShouldNotReachHere(); 2907 } 2908 2909 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 2910 while (true) { 2911 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2912 break; 2913 } else { 2914 // timeout 2915 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 2916 if (cancelled == os::SuspendResume::SR_RUNNING) { 2917 return false; 2918 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 2919 // make sure that we consume the signal on the semaphore as well 2920 sr_semaphore.wait(); 2921 break; 2922 } else { 2923 ShouldNotReachHere(); 2924 return false; 2925 } 2926 } 2927 } 2928 2929 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 2930 return true; 2931 } 2932 2933 static void do_resume(OSThread* osthread) { 2934 assert(osthread->sr.is_suspended(), "thread should be suspended"); 2935 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 2936 2937 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 2938 // failed to switch to WAKEUP_REQUEST 2939 ShouldNotReachHere(); 2940 return; 2941 } 2942 2943 while (true) { 2944 if (sr_notify(osthread) == 0) { 2945 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2946 if (osthread->sr.is_running()) { 2947 return; 2948 } 2949 } 2950 } else { 2951 ShouldNotReachHere(); 2952 } 2953 } 2954 2955 guarantee(osthread->sr.is_running(), "Must be running!"); 2956 } 2957 2958 /////////////////////////////////////////////////////////////////////////////////// 2959 // signal handling (except suspend/resume) 2960 2961 // This routine may be used by user applications as a "hook" to catch signals. 2962 // The user-defined signal handler must pass unrecognized signals to this 2963 // routine, and if it returns true (non-zero), then the signal handler must 2964 // return immediately. If the flag "abort_if_unrecognized" is true, then this 2965 // routine will never retun false (zero), but instead will execute a VM panic 2966 // routine kill the process. 2967 // 2968 // If this routine returns false, it is OK to call it again. This allows 2969 // the user-defined signal handler to perform checks either before or after 2970 // the VM performs its own checks. Naturally, the user code would be making 2971 // a serious error if it tried to handle an exception (such as a null check 2972 // or breakpoint) that the VM was generating for its own correct operation. 2973 // 2974 // This routine may recognize any of the following kinds of signals: 2975 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 2976 // It should be consulted by handlers for any of those signals. 2977 // 2978 // The caller of this routine must pass in the three arguments supplied 2979 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 2980 // field of the structure passed to sigaction(). This routine assumes that 2981 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 2982 // 2983 // Note that the VM will print warnings if it detects conflicting signal 2984 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 2985 // 2986 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, 2987 void* ucontext, 2988 int abort_if_unrecognized); 2989 2990 void signalHandler(int sig, siginfo_t* info, void* uc) { 2991 assert(info != NULL && uc != NULL, "it must be old kernel"); 2992 int orig_errno = errno; // Preserve errno value over signal handler. 2993 JVM_handle_bsd_signal(sig, info, uc, true); 2994 errno = orig_errno; 2995 } 2996 2997 2998 // This boolean allows users to forward their own non-matching signals 2999 // to JVM_handle_bsd_signal, harmlessly. 3000 bool os::Bsd::signal_handlers_are_installed = false; 3001 3002 // For signal-chaining 3003 struct sigaction os::Bsd::sigact[MAXSIGNUM]; 3004 unsigned int os::Bsd::sigs = 0; 3005 bool os::Bsd::libjsig_is_loaded = false; 3006 typedef struct sigaction *(*get_signal_t)(int); 3007 get_signal_t os::Bsd::get_signal_action = NULL; 3008 3009 struct sigaction* os::Bsd::get_chained_signal_action(int sig) { 3010 struct sigaction *actp = NULL; 3011 3012 if (libjsig_is_loaded) { 3013 // Retrieve the old signal handler from libjsig 3014 actp = (*get_signal_action)(sig); 3015 } 3016 if (actp == NULL) { 3017 // Retrieve the preinstalled signal handler from jvm 3018 actp = get_preinstalled_handler(sig); 3019 } 3020 3021 return actp; 3022 } 3023 3024 static bool call_chained_handler(struct sigaction *actp, int sig, 3025 siginfo_t *siginfo, void *context) { 3026 // Call the old signal handler 3027 if (actp->sa_handler == SIG_DFL) { 3028 // It's more reasonable to let jvm treat it as an unexpected exception 3029 // instead of taking the default action. 3030 return false; 3031 } else if (actp->sa_handler != SIG_IGN) { 3032 if ((actp->sa_flags & SA_NODEFER) == 0) { 3033 // automaticlly block the signal 3034 sigaddset(&(actp->sa_mask), sig); 3035 } 3036 3037 sa_handler_t hand; 3038 sa_sigaction_t sa; 3039 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 3040 // retrieve the chained handler 3041 if (siginfo_flag_set) { 3042 sa = actp->sa_sigaction; 3043 } else { 3044 hand = actp->sa_handler; 3045 } 3046 3047 if ((actp->sa_flags & SA_RESETHAND) != 0) { 3048 actp->sa_handler = SIG_DFL; 3049 } 3050 3051 // try to honor the signal mask 3052 sigset_t oset; 3053 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 3054 3055 // call into the chained handler 3056 if (siginfo_flag_set) { 3057 (*sa)(sig, siginfo, context); 3058 } else { 3059 (*hand)(sig); 3060 } 3061 3062 // restore the signal mask 3063 pthread_sigmask(SIG_SETMASK, &oset, 0); 3064 } 3065 // Tell jvm's signal handler the signal is taken care of. 3066 return true; 3067 } 3068 3069 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { 3070 bool chained = false; 3071 // signal-chaining 3072 if (UseSignalChaining) { 3073 struct sigaction *actp = get_chained_signal_action(sig); 3074 if (actp != NULL) { 3075 chained = call_chained_handler(actp, sig, siginfo, context); 3076 } 3077 } 3078 return chained; 3079 } 3080 3081 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { 3082 if ((((unsigned int)1 << sig) & sigs) != 0) { 3083 return &sigact[sig]; 3084 } 3085 return NULL; 3086 } 3087 3088 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 3089 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3090 sigact[sig] = oldAct; 3091 sigs |= (unsigned int)1 << sig; 3092 } 3093 3094 // for diagnostic 3095 int os::Bsd::sigflags[MAXSIGNUM]; 3096 3097 int os::Bsd::get_our_sigflags(int sig) { 3098 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3099 return sigflags[sig]; 3100 } 3101 3102 void os::Bsd::set_our_sigflags(int sig, int flags) { 3103 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3104 sigflags[sig] = flags; 3105 } 3106 3107 void os::Bsd::set_signal_handler(int sig, bool set_installed) { 3108 // Check for overwrite. 3109 struct sigaction oldAct; 3110 sigaction(sig, (struct sigaction*)NULL, &oldAct); 3111 3112 void* oldhand = oldAct.sa_sigaction 3113 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3114 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3115 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 3116 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 3117 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 3118 if (AllowUserSignalHandlers || !set_installed) { 3119 // Do not overwrite; user takes responsibility to forward to us. 3120 return; 3121 } else if (UseSignalChaining) { 3122 // save the old handler in jvm 3123 save_preinstalled_handler(sig, oldAct); 3124 // libjsig also interposes the sigaction() call below and saves the 3125 // old sigaction on it own. 3126 } else { 3127 fatal(err_msg("Encountered unexpected pre-existing sigaction handler " 3128 "%#lx for signal %d.", (long)oldhand, sig)); 3129 } 3130 } 3131 3132 struct sigaction sigAct; 3133 sigfillset(&(sigAct.sa_mask)); 3134 sigAct.sa_handler = SIG_DFL; 3135 if (!set_installed) { 3136 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3137 } else { 3138 sigAct.sa_sigaction = signalHandler; 3139 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3140 } 3141 #ifdef __APPLE__ 3142 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV 3143 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages" 3144 // if the signal handler declares it will handle it on alternate stack. 3145 // Notice we only declare we will handle it on alt stack, but we are not 3146 // actually going to use real alt stack - this is just a workaround. 3147 // Please see ux_exception.c, method catch_mach_exception_raise for details 3148 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c 3149 if (sig == SIGSEGV) { 3150 sigAct.sa_flags |= SA_ONSTACK; 3151 } 3152 #endif 3153 3154 // Save flags, which are set by ours 3155 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3156 sigflags[sig] = sigAct.sa_flags; 3157 3158 int ret = sigaction(sig, &sigAct, &oldAct); 3159 assert(ret == 0, "check"); 3160 3161 void* oldhand2 = oldAct.sa_sigaction 3162 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3163 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3164 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 3165 } 3166 3167 // install signal handlers for signals that HotSpot needs to 3168 // handle in order to support Java-level exception handling. 3169 3170 void os::Bsd::install_signal_handlers() { 3171 if (!signal_handlers_are_installed) { 3172 signal_handlers_are_installed = true; 3173 3174 // signal-chaining 3175 typedef void (*signal_setting_t)(); 3176 signal_setting_t begin_signal_setting = NULL; 3177 signal_setting_t end_signal_setting = NULL; 3178 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3179 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 3180 if (begin_signal_setting != NULL) { 3181 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3182 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 3183 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 3184 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 3185 libjsig_is_loaded = true; 3186 assert(UseSignalChaining, "should enable signal-chaining"); 3187 } 3188 if (libjsig_is_loaded) { 3189 // Tell libjsig jvm is setting signal handlers 3190 (*begin_signal_setting)(); 3191 } 3192 3193 set_signal_handler(SIGSEGV, true); 3194 set_signal_handler(SIGPIPE, true); 3195 set_signal_handler(SIGBUS, true); 3196 set_signal_handler(SIGILL, true); 3197 set_signal_handler(SIGFPE, true); 3198 set_signal_handler(SIGXFSZ, true); 3199 3200 #if defined(__APPLE__) 3201 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including 3202 // signals caught and handled by the JVM. To work around this, we reset the mach task 3203 // signal handler that's placed on our process by CrashReporter. This disables 3204 // CrashReporter-based reporting. 3205 // 3206 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes 3207 // on caught fatal signals. 3208 // 3209 // Additionally, gdb installs both standard BSD signal handlers, and mach exception 3210 // handlers. By replacing the existing task exception handler, we disable gdb's mach 3211 // exception handling, while leaving the standard BSD signal handlers functional. 3212 kern_return_t kr; 3213 kr = task_set_exception_ports(mach_task_self(), 3214 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, 3215 MACH_PORT_NULL, 3216 EXCEPTION_STATE_IDENTITY, 3217 MACHINE_THREAD_STATE); 3218 3219 assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); 3220 #endif 3221 3222 if (libjsig_is_loaded) { 3223 // Tell libjsig jvm finishes setting signal handlers 3224 (*end_signal_setting)(); 3225 } 3226 3227 // We don't activate signal checker if libjsig is in place, we trust ourselves 3228 // and if UserSignalHandler is installed all bets are off 3229 if (CheckJNICalls) { 3230 if (libjsig_is_loaded) { 3231 if (PrintJNIResolving) { 3232 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 3233 } 3234 check_signals = false; 3235 } 3236 if (AllowUserSignalHandlers) { 3237 if (PrintJNIResolving) { 3238 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 3239 } 3240 check_signals = false; 3241 } 3242 } 3243 } 3244 } 3245 3246 3247 ///// 3248 // glibc on Bsd platform uses non-documented flag 3249 // to indicate, that some special sort of signal 3250 // trampoline is used. 3251 // We will never set this flag, and we should 3252 // ignore this flag in our diagnostic 3253 #ifdef SIGNIFICANT_SIGNAL_MASK 3254 #undef SIGNIFICANT_SIGNAL_MASK 3255 #endif 3256 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 3257 3258 static const char* get_signal_handler_name(address handler, 3259 char* buf, int buflen) { 3260 int offset; 3261 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 3262 if (found) { 3263 // skip directory names 3264 const char *p1, *p2; 3265 p1 = buf; 3266 size_t len = strlen(os::file_separator()); 3267 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 3268 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 3269 } else { 3270 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 3271 } 3272 return buf; 3273 } 3274 3275 static void print_signal_handler(outputStream* st, int sig, 3276 char* buf, size_t buflen) { 3277 struct sigaction sa; 3278 3279 sigaction(sig, NULL, &sa); 3280 3281 // See comment for SIGNIFICANT_SIGNAL_MASK define 3282 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3283 3284 st->print("%s: ", os::exception_name(sig, buf, buflen)); 3285 3286 address handler = (sa.sa_flags & SA_SIGINFO) 3287 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 3288 : CAST_FROM_FN_PTR(address, sa.sa_handler); 3289 3290 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 3291 st->print("SIG_DFL"); 3292 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 3293 st->print("SIG_IGN"); 3294 } else { 3295 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 3296 } 3297 3298 st->print(", sa_mask[0]="); 3299 os::Posix::print_signal_set_short(st, &sa.sa_mask); 3300 3301 address rh = VMError::get_resetted_sighandler(sig); 3302 // May be, handler was resetted by VMError? 3303 if (rh != NULL) { 3304 handler = rh; 3305 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 3306 } 3307 3308 st->print(", sa_flags="); 3309 os::Posix::print_sa_flags(st, sa.sa_flags); 3310 3311 // Check: is it our handler? 3312 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 3313 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 3314 // It is our signal handler 3315 // check for flags, reset system-used one! 3316 if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3317 st->print( 3318 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 3319 os::Bsd::get_our_sigflags(sig)); 3320 } 3321 } 3322 st->cr(); 3323 } 3324 3325 3326 #define DO_SIGNAL_CHECK(sig) \ 3327 do { \ 3328 if (!sigismember(&check_signal_done, sig)) { \ 3329 os::Bsd::check_signal_handler(sig); \ 3330 } \ 3331 } while (0) 3332 3333 // This method is a periodic task to check for misbehaving JNI applications 3334 // under CheckJNI, we can add any periodic checks here 3335 3336 void os::run_periodic_checks() { 3337 3338 if (check_signals == false) return; 3339 3340 // SEGV and BUS if overridden could potentially prevent 3341 // generation of hs*.log in the event of a crash, debugging 3342 // such a case can be very challenging, so we absolutely 3343 // check the following for a good measure: 3344 DO_SIGNAL_CHECK(SIGSEGV); 3345 DO_SIGNAL_CHECK(SIGILL); 3346 DO_SIGNAL_CHECK(SIGFPE); 3347 DO_SIGNAL_CHECK(SIGBUS); 3348 DO_SIGNAL_CHECK(SIGPIPE); 3349 DO_SIGNAL_CHECK(SIGXFSZ); 3350 3351 3352 // ReduceSignalUsage allows the user to override these handlers 3353 // see comments at the very top and jvm_solaris.h 3354 if (!ReduceSignalUsage) { 3355 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 3356 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 3357 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 3358 DO_SIGNAL_CHECK(BREAK_SIGNAL); 3359 } 3360 3361 DO_SIGNAL_CHECK(SR_signum); 3362 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); 3363 } 3364 3365 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 3366 3367 static os_sigaction_t os_sigaction = NULL; 3368 3369 void os::Bsd::check_signal_handler(int sig) { 3370 char buf[O_BUFLEN]; 3371 address jvmHandler = NULL; 3372 3373 3374 struct sigaction act; 3375 if (os_sigaction == NULL) { 3376 // only trust the default sigaction, in case it has been interposed 3377 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 3378 if (os_sigaction == NULL) return; 3379 } 3380 3381 os_sigaction(sig, (struct sigaction*)NULL, &act); 3382 3383 3384 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3385 3386 address thisHandler = (act.sa_flags & SA_SIGINFO) 3387 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 3388 : CAST_FROM_FN_PTR(address, act.sa_handler); 3389 3390 3391 switch (sig) { 3392 case SIGSEGV: 3393 case SIGBUS: 3394 case SIGFPE: 3395 case SIGPIPE: 3396 case SIGILL: 3397 case SIGXFSZ: 3398 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 3399 break; 3400 3401 case SHUTDOWN1_SIGNAL: 3402 case SHUTDOWN2_SIGNAL: 3403 case SHUTDOWN3_SIGNAL: 3404 case BREAK_SIGNAL: 3405 jvmHandler = (address)user_handler(); 3406 break; 3407 3408 case INTERRUPT_SIGNAL: 3409 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); 3410 break; 3411 3412 default: 3413 if (sig == SR_signum) { 3414 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 3415 } else { 3416 return; 3417 } 3418 break; 3419 } 3420 3421 if (thisHandler != jvmHandler) { 3422 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 3423 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 3424 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 3425 // No need to check this sig any longer 3426 sigaddset(&check_signal_done, sig); 3427 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 3428 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 3429 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 3430 exception_name(sig, buf, O_BUFLEN)); 3431 } 3432 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3433 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 3434 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); 3435 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); 3436 // No need to check this sig any longer 3437 sigaddset(&check_signal_done, sig); 3438 } 3439 3440 // Dump all the signal 3441 if (sigismember(&check_signal_done, sig)) { 3442 print_signal_handlers(tty, buf, O_BUFLEN); 3443 } 3444 } 3445 3446 extern void report_error(char* file_name, int line_no, char* title, 3447 char* format, ...); 3448 3449 extern bool signal_name(int signo, char* buf, size_t len); 3450 3451 const char* os::exception_name(int exception_code, char* buf, size_t size) { 3452 if (0 < exception_code && exception_code <= SIGRTMAX) { 3453 // signal 3454 if (!signal_name(exception_code, buf, size)) { 3455 jio_snprintf(buf, size, "SIG%d", exception_code); 3456 } 3457 return buf; 3458 } else { 3459 return NULL; 3460 } 3461 } 3462 3463 // this is called _before_ the most of global arguments have been parsed 3464 void os::init(void) { 3465 char dummy; // used to get a guess on initial stack address 3466 // first_hrtime = gethrtime(); 3467 3468 // With BsdThreads the JavaMain thread pid (primordial thread) 3469 // is different than the pid of the java launcher thread. 3470 // So, on Bsd, the launcher thread pid is passed to the VM 3471 // via the sun.java.launcher.pid property. 3472 // Use this property instead of getpid() if it was correctly passed. 3473 // See bug 6351349. 3474 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); 3475 3476 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); 3477 3478 clock_tics_per_sec = CLK_TCK; 3479 3480 init_random(1234567); 3481 3482 ThreadCritical::initialize(); 3483 3484 Bsd::set_page_size(getpagesize()); 3485 if (Bsd::page_size() == -1) { 3486 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)", 3487 strerror(errno))); 3488 } 3489 init_page_sizes((size_t) Bsd::page_size()); 3490 3491 Bsd::initialize_system_info(); 3492 3493 // main_thread points to the aboriginal thread 3494 Bsd::_main_thread = pthread_self(); 3495 3496 Bsd::clock_init(); 3497 initial_time_count = javaTimeNanos(); 3498 3499 #ifdef __APPLE__ 3500 // XXXDARWIN 3501 // Work around the unaligned VM callbacks in hotspot's 3502 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on 3503 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces 3504 // alignment when doing symbol lookup. To work around this, we force early 3505 // binding of all symbols now, thus binding when alignment is known-good. 3506 _dyld_bind_fully_image_containing_address((const void *) &os::init); 3507 #endif 3508 } 3509 3510 // To install functions for atexit system call 3511 extern "C" { 3512 static void perfMemory_exit_helper() { 3513 perfMemory_exit(); 3514 } 3515 } 3516 3517 // this is called _after_ the global arguments have been parsed 3518 jint os::init_2(void) { 3519 // Allocate a single page and mark it as readable for safepoint polling 3520 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3521 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page"); 3522 3523 os::set_polling_page(polling_page); 3524 3525 #ifndef PRODUCT 3526 if (Verbose && PrintMiscellaneous) { 3527 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", 3528 (intptr_t)polling_page); 3529 } 3530 #endif 3531 3532 if (!UseMembar) { 3533 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3534 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 3535 os::set_memory_serialize_page(mem_serialize_page); 3536 3537 #ifndef PRODUCT 3538 if (Verbose && PrintMiscellaneous) { 3539 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", 3540 (intptr_t)mem_serialize_page); 3541 } 3542 #endif 3543 } 3544 3545 // initialize suspend/resume support - must do this before signal_sets_init() 3546 if (SR_initialize() != 0) { 3547 perror("SR_initialize failed"); 3548 return JNI_ERR; 3549 } 3550 3551 Bsd::signal_sets_init(); 3552 Bsd::install_signal_handlers(); 3553 3554 // Check minimum allowable stack size for thread creation and to initialize 3555 // the java system classes, including StackOverflowError - depends on page 3556 // size. Add a page for compiler2 recursion in main thread. 3557 // Add in 2*BytesPerWord times page size to account for VM stack during 3558 // class initialization depending on 32 or 64 bit VM. 3559 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, 3560 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ 3561 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); 3562 3563 size_t threadStackSizeInBytes = ThreadStackSize * K; 3564 if (threadStackSizeInBytes != 0 && 3565 threadStackSizeInBytes < os::Bsd::min_stack_allowed) { 3566 tty->print_cr("\nThe stack size specified is too small, " 3567 "Specify at least %dk", 3568 os::Bsd::min_stack_allowed/ K); 3569 return JNI_ERR; 3570 } 3571 3572 // Make the stack size a multiple of the page size so that 3573 // the yellow/red zones can be guarded. 3574 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 3575 vm_page_size())); 3576 3577 if (MaxFDLimit) { 3578 // set the number of file descriptors to max. print out error 3579 // if getrlimit/setrlimit fails but continue regardless. 3580 struct rlimit nbr_files; 3581 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 3582 if (status != 0) { 3583 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3584 perror("os::init_2 getrlimit failed"); 3585 } 3586 } else { 3587 nbr_files.rlim_cur = nbr_files.rlim_max; 3588 3589 #ifdef __APPLE__ 3590 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if 3591 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must 3592 // be used instead 3593 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); 3594 #endif 3595 3596 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 3597 if (status != 0) { 3598 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3599 perror("os::init_2 setrlimit failed"); 3600 } 3601 } 3602 } 3603 } 3604 3605 // at-exit methods are called in the reverse order of their registration. 3606 // atexit functions are called on return from main or as a result of a 3607 // call to exit(3C). There can be only 32 of these functions registered 3608 // and atexit() does not set errno. 3609 3610 if (PerfAllowAtExitRegistration) { 3611 // only register atexit functions if PerfAllowAtExitRegistration is set. 3612 // atexit functions can be delayed until process exit time, which 3613 // can be problematic for embedded VM situations. Embedded VMs should 3614 // call DestroyJavaVM() to assure that VM resources are released. 3615 3616 // note: perfMemory_exit_helper atexit function may be removed in 3617 // the future if the appropriate cleanup code can be added to the 3618 // VM_Exit VMOperation's doit method. 3619 if (atexit(perfMemory_exit_helper) != 0) { 3620 warning("os::init2 atexit(perfMemory_exit_helper) failed"); 3621 } 3622 } 3623 3624 // initialize thread priority policy 3625 prio_init(); 3626 3627 #ifdef __APPLE__ 3628 // dynamically link to objective c gc registration 3629 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY); 3630 if (handleLibObjc != NULL) { 3631 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER); 3632 } 3633 #endif 3634 3635 return JNI_OK; 3636 } 3637 3638 // this is called at the end of vm_initialization 3639 void os::init_3(void) { } 3640 3641 // Mark the polling page as unreadable 3642 void os::make_polling_page_unreadable(void) { 3643 if (!guard_memory((char*)_polling_page, Bsd::page_size())) { 3644 fatal("Could not disable polling page"); 3645 } 3646 } 3647 3648 // Mark the polling page as readable 3649 void os::make_polling_page_readable(void) { 3650 if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { 3651 fatal("Could not enable polling page"); 3652 } 3653 } 3654 3655 int os::active_processor_count() { 3656 return _processor_count; 3657 } 3658 3659 void os::set_native_thread_name(const char *name) { 3660 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5 3661 // This is only supported in Snow Leopard and beyond 3662 if (name != NULL) { 3663 // Add a "Java: " prefix to the name 3664 char buf[MAXTHREADNAMESIZE]; 3665 snprintf(buf, sizeof(buf), "Java: %s", name); 3666 pthread_setname_np(buf); 3667 } 3668 #endif 3669 } 3670 3671 bool os::distribute_processes(uint length, uint* distribution) { 3672 // Not yet implemented. 3673 return false; 3674 } 3675 3676 bool os::bind_to_processor(uint processor_id) { 3677 // Not yet implemented. 3678 return false; 3679 } 3680 3681 void os::SuspendedThreadTask::internal_do_task() { 3682 if (do_suspend(_thread->osthread())) { 3683 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 3684 do_task(context); 3685 do_resume(_thread->osthread()); 3686 } 3687 } 3688 3689 /// 3690 class PcFetcher : public os::SuspendedThreadTask { 3691 public: 3692 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 3693 ExtendedPC result(); 3694 protected: 3695 void do_task(const os::SuspendedThreadTaskContext& context); 3696 private: 3697 ExtendedPC _epc; 3698 }; 3699 3700 ExtendedPC PcFetcher::result() { 3701 guarantee(is_done(), "task is not done yet."); 3702 return _epc; 3703 } 3704 3705 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 3706 Thread* thread = context.thread(); 3707 OSThread* osthread = thread->osthread(); 3708 if (osthread->ucontext() != NULL) { 3709 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext()); 3710 } else { 3711 // NULL context is unexpected, double-check this is the VMThread 3712 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 3713 } 3714 } 3715 3716 // Suspends the target using the signal mechanism and then grabs the PC before 3717 // resuming the target. Used by the flat-profiler only 3718 ExtendedPC os::get_thread_pc(Thread* thread) { 3719 // Make sure that it is called by the watcher for the VMThread 3720 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 3721 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 3722 3723 PcFetcher fetcher(thread); 3724 fetcher.run(); 3725 return fetcher.result(); 3726 } 3727 3728 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, 3729 pthread_mutex_t *_mutex, 3730 const struct timespec *_abstime) { 3731 return pthread_cond_timedwait(_cond, _mutex, _abstime); 3732 } 3733 3734 //////////////////////////////////////////////////////////////////////////////// 3735 // debug support 3736 3737 bool os::find(address addr, outputStream* st) { 3738 Dl_info dlinfo; 3739 memset(&dlinfo, 0, sizeof(dlinfo)); 3740 if (dladdr(addr, &dlinfo) != 0) { 3741 st->print(PTR_FORMAT ": ", addr); 3742 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 3743 st->print("%s+%#x", dlinfo.dli_sname, 3744 addr - (intptr_t)dlinfo.dli_saddr); 3745 } else if (dlinfo.dli_fbase != NULL) { 3746 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); 3747 } else { 3748 st->print("<absolute address>"); 3749 } 3750 if (dlinfo.dli_fname != NULL) { 3751 st->print(" in %s", dlinfo.dli_fname); 3752 } 3753 if (dlinfo.dli_fbase != NULL) { 3754 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); 3755 } 3756 st->cr(); 3757 3758 if (Verbose) { 3759 // decode some bytes around the PC 3760 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 3761 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 3762 address lowest = (address) dlinfo.dli_sname; 3763 if (!lowest) lowest = (address) dlinfo.dli_fbase; 3764 if (begin < lowest) begin = lowest; 3765 Dl_info dlinfo2; 3766 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 3767 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 3768 end = (address) dlinfo2.dli_saddr; 3769 } 3770 Disassembler::decode(begin, end, st); 3771 } 3772 return true; 3773 } 3774 return false; 3775 } 3776 3777 //////////////////////////////////////////////////////////////////////////////// 3778 // misc 3779 3780 // This does not do anything on Bsd. This is basically a hook for being 3781 // able to use structured exception handling (thread-local exception filters) 3782 // on, e.g., Win32. 3783 void os::os_exception_wrapper(java_call_t f, JavaValue* value, 3784 methodHandle* method, JavaCallArguments* args, 3785 Thread* thread) { 3786 f(value, method, args, thread); 3787 } 3788 3789 void os::print_statistics() { 3790 } 3791 3792 int os::message_box(const char* title, const char* message) { 3793 int i; 3794 fdStream err(defaultStream::error_fd()); 3795 for (i = 0; i < 78; i++) err.print_raw("="); 3796 err.cr(); 3797 err.print_raw_cr(title); 3798 for (i = 0; i < 78; i++) err.print_raw("-"); 3799 err.cr(); 3800 err.print_raw_cr(message); 3801 for (i = 0; i < 78; i++) err.print_raw("="); 3802 err.cr(); 3803 3804 char buf[16]; 3805 // Prevent process from exiting upon "read error" without consuming all CPU 3806 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 3807 3808 return buf[0] == 'y' || buf[0] == 'Y'; 3809 } 3810 3811 int os::stat(const char *path, struct stat *sbuf) { 3812 char pathbuf[MAX_PATH]; 3813 if (strlen(path) > MAX_PATH - 1) { 3814 errno = ENAMETOOLONG; 3815 return -1; 3816 } 3817 os::native_path(strcpy(pathbuf, path)); 3818 return ::stat(pathbuf, sbuf); 3819 } 3820 3821 bool os::check_heap(bool force) { 3822 return true; 3823 } 3824 3825 // Is a (classpath) directory empty? 3826 bool os::dir_is_empty(const char* path) { 3827 DIR *dir = NULL; 3828 struct dirent *ptr; 3829 3830 dir = opendir(path); 3831 if (dir == NULL) return true; 3832 3833 // Scan the directory 3834 bool result = true; 3835 char buf[sizeof(struct dirent) + MAX_PATH]; 3836 while (result && (ptr = ::readdir(dir)) != NULL) { 3837 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 3838 result = false; 3839 } 3840 } 3841 closedir(dir); 3842 return result; 3843 } 3844 3845 // This code originates from JDK's sysOpen and open64_w 3846 // from src/solaris/hpi/src/system_md.c 3847 3848 #ifndef O_DELETE 3849 #define O_DELETE 0x10000 3850 #endif 3851 3852 // Open a file. Unlink the file immediately after open returns 3853 // if the specified oflag has the O_DELETE flag set. 3854 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c 3855 3856 int os::open(const char *path, int oflag, int mode) { 3857 if (strlen(path) > MAX_PATH - 1) { 3858 errno = ENAMETOOLONG; 3859 return -1; 3860 } 3861 int fd; 3862 int o_delete = (oflag & O_DELETE); 3863 oflag = oflag & ~O_DELETE; 3864 3865 fd = ::open(path, oflag, mode); 3866 if (fd == -1) return -1; 3867 3868 // If the open succeeded, the file might still be a directory 3869 { 3870 struct stat buf; 3871 int ret = ::fstat(fd, &buf); 3872 int st_mode = buf.st_mode; 3873 3874 if (ret != -1) { 3875 if ((st_mode & S_IFMT) == S_IFDIR) { 3876 errno = EISDIR; 3877 ::close(fd); 3878 return -1; 3879 } 3880 } else { 3881 ::close(fd); 3882 return -1; 3883 } 3884 } 3885 3886 // All file descriptors that are opened in the JVM and not 3887 // specifically destined for a subprocess should have the 3888 // close-on-exec flag set. If we don't set it, then careless 3rd 3889 // party native code might fork and exec without closing all 3890 // appropriate file descriptors (e.g. as we do in closeDescriptors in 3891 // UNIXProcess.c), and this in turn might: 3892 // 3893 // - cause end-of-file to fail to be detected on some file 3894 // descriptors, resulting in mysterious hangs, or 3895 // 3896 // - might cause an fopen in the subprocess to fail on a system 3897 // suffering from bug 1085341. 3898 // 3899 // (Yes, the default setting of the close-on-exec flag is a Unix 3900 // design flaw) 3901 // 3902 // See: 3903 // 1085341: 32-bit stdio routines should support file descriptors >255 3904 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 3905 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 3906 // 3907 #ifdef FD_CLOEXEC 3908 { 3909 int flags = ::fcntl(fd, F_GETFD); 3910 if (flags != -1) { 3911 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 3912 } 3913 } 3914 #endif 3915 3916 if (o_delete != 0) { 3917 ::unlink(path); 3918 } 3919 return fd; 3920 } 3921 3922 3923 // create binary file, rewriting existing file if required 3924 int os::create_binary_file(const char* path, bool rewrite_existing) { 3925 int oflags = O_WRONLY | O_CREAT; 3926 if (!rewrite_existing) { 3927 oflags |= O_EXCL; 3928 } 3929 return ::open(path, oflags, S_IREAD | S_IWRITE); 3930 } 3931 3932 // return current position of file pointer 3933 jlong os::current_file_offset(int fd) { 3934 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); 3935 } 3936 3937 // move file pointer to the specified offset 3938 jlong os::seek_to_file_offset(int fd, jlong offset) { 3939 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); 3940 } 3941 3942 // This code originates from JDK's sysAvailable 3943 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 3944 3945 int os::available(int fd, jlong *bytes) { 3946 jlong cur, end; 3947 int mode; 3948 struct stat buf; 3949 3950 if (::fstat(fd, &buf) >= 0) { 3951 mode = buf.st_mode; 3952 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 3953 // XXX: is the following call interruptible? If so, this might 3954 // need to go through the INTERRUPT_IO() wrapper as for other 3955 // blocking, interruptible calls in this file. 3956 int n; 3957 if (::ioctl(fd, FIONREAD, &n) >= 0) { 3958 *bytes = n; 3959 return 1; 3960 } 3961 } 3962 } 3963 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { 3964 return 0; 3965 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { 3966 return 0; 3967 } else if (::lseek(fd, cur, SEEK_SET) == -1) { 3968 return 0; 3969 } 3970 *bytes = end - cur; 3971 return 1; 3972 } 3973 3974 int os::socket_available(int fd, jint *pbytes) { 3975 if (fd < 0) { 3976 return OS_OK; 3977 } 3978 3979 int ret; 3980 3981 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret); 3982 3983 //%% note ioctl can return 0 when successful, JVM_SocketAvailable 3984 // is expected to return 0 on failure and 1 on success to the jdk. 3985 3986 return (ret == OS_ERR) ? 0 : 1; 3987 } 3988 3989 // Map a block of memory. 3990 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 3991 char *addr, size_t bytes, bool read_only, 3992 bool allow_exec) { 3993 int prot; 3994 int flags; 3995 3996 if (read_only) { 3997 prot = PROT_READ; 3998 flags = MAP_SHARED; 3999 } else { 4000 prot = PROT_READ | PROT_WRITE; 4001 flags = MAP_PRIVATE; 4002 } 4003 4004 if (allow_exec) { 4005 prot |= PROT_EXEC; 4006 } 4007 4008 if (addr != NULL) { 4009 flags |= MAP_FIXED; 4010 } 4011 4012 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 4013 fd, file_offset); 4014 if (mapped_address == MAP_FAILED) { 4015 return NULL; 4016 } 4017 return mapped_address; 4018 } 4019 4020 4021 // Remap a block of memory. 4022 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 4023 char *addr, size_t bytes, bool read_only, 4024 bool allow_exec) { 4025 // same as map_memory() on this OS 4026 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 4027 allow_exec); 4028 } 4029 4030 4031 // Unmap a block of memory. 4032 bool os::pd_unmap_memory(char* addr, size_t bytes) { 4033 return munmap(addr, bytes) == 0; 4034 } 4035 4036 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 4037 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 4038 // of a thread. 4039 // 4040 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 4041 // the fast estimate available on the platform. 4042 4043 jlong os::current_thread_cpu_time() { 4044 #ifdef __APPLE__ 4045 return os::thread_cpu_time(Thread::current(), true /* user + sys */); 4046 #else 4047 Unimplemented(); 4048 return 0; 4049 #endif 4050 } 4051 4052 jlong os::thread_cpu_time(Thread* thread) { 4053 #ifdef __APPLE__ 4054 return os::thread_cpu_time(thread, true /* user + sys */); 4055 #else 4056 Unimplemented(); 4057 return 0; 4058 #endif 4059 } 4060 4061 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 4062 #ifdef __APPLE__ 4063 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); 4064 #else 4065 Unimplemented(); 4066 return 0; 4067 #endif 4068 } 4069 4070 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 4071 #ifdef __APPLE__ 4072 struct thread_basic_info tinfo; 4073 mach_msg_type_number_t tcount = THREAD_INFO_MAX; 4074 kern_return_t kr; 4075 thread_t mach_thread; 4076 4077 mach_thread = thread->osthread()->thread_id(); 4078 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); 4079 if (kr != KERN_SUCCESS) { 4080 return -1; 4081 } 4082 4083 if (user_sys_cpu_time) { 4084 jlong nanos; 4085 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; 4086 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; 4087 return nanos; 4088 } else { 4089 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); 4090 } 4091 #else 4092 Unimplemented(); 4093 return 0; 4094 #endif 4095 } 4096 4097 4098 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4099 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4100 info_ptr->may_skip_backward = false; // elapsed time not wall time 4101 info_ptr->may_skip_forward = false; // elapsed time not wall time 4102 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4103 } 4104 4105 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4106 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4107 info_ptr->may_skip_backward = false; // elapsed time not wall time 4108 info_ptr->may_skip_forward = false; // elapsed time not wall time 4109 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4110 } 4111 4112 bool os::is_thread_cpu_time_supported() { 4113 #ifdef __APPLE__ 4114 return true; 4115 #else 4116 return false; 4117 #endif 4118 } 4119 4120 // System loadavg support. Returns -1 if load average cannot be obtained. 4121 // Bsd doesn't yet have a (official) notion of processor sets, 4122 // so just return the system wide load average. 4123 int os::loadavg(double loadavg[], int nelem) { 4124 return ::getloadavg(loadavg, nelem); 4125 } 4126 4127 void os::pause() { 4128 char filename[MAX_PATH]; 4129 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 4130 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); 4131 } else { 4132 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 4133 } 4134 4135 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 4136 if (fd != -1) { 4137 struct stat buf; 4138 ::close(fd); 4139 while (::stat(filename, &buf) == 0) { 4140 (void)::poll(NULL, 0, 100); 4141 } 4142 } else { 4143 jio_fprintf(stderr, 4144 "Could not open pause file '%s', continuing immediately.\n", filename); 4145 } 4146 } 4147 4148 4149 // Refer to the comments in os_solaris.cpp park-unpark. 4150 // 4151 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 4152 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 4153 // For specifics regarding the bug see GLIBC BUGID 261237 : 4154 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 4155 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 4156 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 4157 // is used. (The simple C test-case provided in the GLIBC bug report manifests the 4158 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 4159 // and monitorenter when we're using 1-0 locking. All those operations may result in 4160 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 4161 // of libpthread avoids the problem, but isn't practical. 4162 // 4163 // Possible remedies: 4164 // 4165 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 4166 // This is palliative and probabilistic, however. If the thread is preempted 4167 // between the call to compute_abstime() and pthread_cond_timedwait(), more 4168 // than the minimum period may have passed, and the abstime may be stale (in the 4169 // past) resultin in a hang. Using this technique reduces the odds of a hang 4170 // but the JVM is still vulnerable, particularly on heavily loaded systems. 4171 // 4172 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 4173 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set 4174 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 4175 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant 4176 // thread. 4177 // 4178 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 4179 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 4180 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). 4181 // This also works well. In fact it avoids kernel-level scalability impediments 4182 // on certain platforms that don't handle lots of active pthread_cond_timedwait() 4183 // timers in a graceful fashion. 4184 // 4185 // 4. When the abstime value is in the past it appears that control returns 4186 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 4187 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we 4188 // can avoid the problem by reinitializing the condvar -- by cond_destroy() 4189 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). 4190 // It may be possible to avoid reinitialization by checking the return 4191 // value from pthread_cond_timedwait(). In addition to reinitializing the 4192 // condvar we must establish the invariant that cond_signal() is only called 4193 // within critical sections protected by the adjunct mutex. This prevents 4194 // cond_signal() from "seeing" a condvar that's in the midst of being 4195 // reinitialized or that is corrupt. Sadly, this invariant obviates the 4196 // desirable signal-after-unlock optimization that avoids futile context switching. 4197 // 4198 // I'm also concerned that some versions of NTPL might allocate an auxilliary 4199 // structure when a condvar is used or initialized. cond_destroy() would 4200 // release the helper structure. Our reinitialize-after-timedwait fix 4201 // put excessive stress on malloc/free and locks protecting the c-heap. 4202 // 4203 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 4204 // It may be possible to refine (4) by checking the kernel and NTPL verisons 4205 // and only enabling the work-around for vulnerable environments. 4206 4207 // utility to compute the abstime argument to timedwait: 4208 // millis is the relative timeout time 4209 // abstime will be the absolute timeout time 4210 // TODO: replace compute_abstime() with unpackTime() 4211 4212 static struct timespec* compute_abstime(struct timespec* abstime, 4213 jlong millis) { 4214 if (millis < 0) millis = 0; 4215 struct timeval now; 4216 int status = gettimeofday(&now, NULL); 4217 assert(status == 0, "gettimeofday"); 4218 jlong seconds = millis / 1000; 4219 millis %= 1000; 4220 if (seconds > 50000000) { // see man cond_timedwait(3T) 4221 seconds = 50000000; 4222 } 4223 abstime->tv_sec = now.tv_sec + seconds; 4224 long usec = now.tv_usec + millis * 1000; 4225 if (usec >= 1000000) { 4226 abstime->tv_sec += 1; 4227 usec -= 1000000; 4228 } 4229 abstime->tv_nsec = usec * 1000; 4230 return abstime; 4231 } 4232 4233 void os::PlatformEvent::park() { // AKA "down()" 4234 // Invariant: Only the thread associated with the Event/PlatformEvent 4235 // may call park(). 4236 // TODO: assert that _Assoc != NULL or _Assoc == Self 4237 assert(_nParked == 0, "invariant"); 4238 4239 int v; 4240 for (;;) { 4241 v = _Event; 4242 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4243 } 4244 guarantee(v >= 0, "invariant"); 4245 if (v == 0) { 4246 // Do this the hard way by blocking ... 4247 int status = pthread_mutex_lock(_mutex); 4248 assert_status(status == 0, status, "mutex_lock"); 4249 guarantee(_nParked == 0, "invariant"); 4250 ++_nParked; 4251 while (_Event < 0) { 4252 status = pthread_cond_wait(_cond, _mutex); 4253 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 4254 // Treat this the same as if the wait was interrupted 4255 if (status == ETIMEDOUT) { status = EINTR; } 4256 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 4257 } 4258 --_nParked; 4259 4260 _Event = 0; 4261 status = pthread_mutex_unlock(_mutex); 4262 assert_status(status == 0, status, "mutex_unlock"); 4263 // Paranoia to ensure our locked and lock-free paths interact 4264 // correctly with each other. 4265 OrderAccess::fence(); 4266 } 4267 guarantee(_Event >= 0, "invariant"); 4268 } 4269 4270 int os::PlatformEvent::park(jlong millis) { 4271 guarantee(_nParked == 0, "invariant"); 4272 4273 int v; 4274 for (;;) { 4275 v = _Event; 4276 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4277 } 4278 guarantee(v >= 0, "invariant"); 4279 if (v != 0) return OS_OK; 4280 4281 // We do this the hard way, by blocking the thread. 4282 // Consider enforcing a minimum timeout value. 4283 struct timespec abst; 4284 compute_abstime(&abst, millis); 4285 4286 int ret = OS_TIMEOUT; 4287 int status = pthread_mutex_lock(_mutex); 4288 assert_status(status == 0, status, "mutex_lock"); 4289 guarantee(_nParked == 0, "invariant"); 4290 ++_nParked; 4291 4292 // Object.wait(timo) will return because of 4293 // (a) notification 4294 // (b) timeout 4295 // (c) thread.interrupt 4296 // 4297 // Thread.interrupt and object.notify{All} both call Event::set. 4298 // That is, we treat thread.interrupt as a special case of notification. 4299 // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false. 4300 // We assume all ETIME returns are valid. 4301 // 4302 // TODO: properly differentiate simultaneous notify+interrupt. 4303 // In that case, we should propagate the notify to another waiter. 4304 4305 while (_Event < 0) { 4306 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst); 4307 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4308 pthread_cond_destroy(_cond); 4309 pthread_cond_init(_cond, NULL); 4310 } 4311 assert_status(status == 0 || status == EINTR || 4312 status == ETIMEDOUT, 4313 status, "cond_timedwait"); 4314 if (!FilterSpuriousWakeups) break; // previous semantics 4315 if (status == ETIMEDOUT) break; 4316 // We consume and ignore EINTR and spurious wakeups. 4317 } 4318 --_nParked; 4319 if (_Event >= 0) { 4320 ret = OS_OK; 4321 } 4322 _Event = 0; 4323 status = pthread_mutex_unlock(_mutex); 4324 assert_status(status == 0, status, "mutex_unlock"); 4325 assert(_nParked == 0, "invariant"); 4326 // Paranoia to ensure our locked and lock-free paths interact 4327 // correctly with each other. 4328 OrderAccess::fence(); 4329 return ret; 4330 } 4331 4332 void os::PlatformEvent::unpark() { 4333 // Transitions for _Event: 4334 // 0 :=> 1 4335 // 1 :=> 1 4336 // -1 :=> either 0 or 1; must signal target thread 4337 // That is, we can safely transition _Event from -1 to either 4338 // 0 or 1. 4339 // See also: "Semaphores in Plan 9" by Mullender & Cox 4340 // 4341 // Note: Forcing a transition from "-1" to "1" on an unpark() means 4342 // that it will take two back-to-back park() calls for the owning 4343 // thread to block. This has the benefit of forcing a spurious return 4344 // from the first park() call after an unpark() call which will help 4345 // shake out uses of park() and unpark() without condition variables. 4346 4347 if (Atomic::xchg(1, &_Event) >= 0) return; 4348 4349 // Wait for the thread associated with the event to vacate 4350 int status = pthread_mutex_lock(_mutex); 4351 assert_status(status == 0, status, "mutex_lock"); 4352 int AnyWaiters = _nParked; 4353 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 4354 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 4355 AnyWaiters = 0; 4356 pthread_cond_signal(_cond); 4357 } 4358 status = pthread_mutex_unlock(_mutex); 4359 assert_status(status == 0, status, "mutex_unlock"); 4360 if (AnyWaiters != 0) { 4361 status = pthread_cond_signal(_cond); 4362 assert_status(status == 0, status, "cond_signal"); 4363 } 4364 4365 // Note that we signal() _after dropping the lock for "immortal" Events. 4366 // This is safe and avoids a common class of futile wakeups. In rare 4367 // circumstances this can cause a thread to return prematurely from 4368 // cond_{timed}wait() but the spurious wakeup is benign and the victim will 4369 // simply re-test the condition and re-park itself. 4370 } 4371 4372 4373 // JSR166 4374 // ------------------------------------------------------- 4375 4376 // The solaris and bsd implementations of park/unpark are fairly 4377 // conservative for now, but can be improved. They currently use a 4378 // mutex/condvar pair, plus a a count. 4379 // Park decrements count if > 0, else does a condvar wait. Unpark 4380 // sets count to 1 and signals condvar. Only one thread ever waits 4381 // on the condvar. Contention seen when trying to park implies that someone 4382 // is unparking you, so don't wait. And spurious returns are fine, so there 4383 // is no need to track notifications. 4384 4385 #define MAX_SECS 100000000 4386 4387 // This code is common to bsd and solaris and will be moved to a 4388 // common place in dolphin. 4389 // 4390 // The passed in time value is either a relative time in nanoseconds 4391 // or an absolute time in milliseconds. Either way it has to be unpacked 4392 // into suitable seconds and nanoseconds components and stored in the 4393 // given timespec structure. 4394 // Given time is a 64-bit value and the time_t used in the timespec is only 4395 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for 4396 // overflow if times way in the future are given. Further on Solaris versions 4397 // prior to 10 there is a restriction (see cond_timedwait) that the specified 4398 // number of seconds, in abstime, is less than current_time + 100,000,000. 4399 // As it will be 28 years before "now + 100000000" will overflow we can 4400 // ignore overflow and just impose a hard-limit on seconds using the value 4401 // of "now + 100,000,000". This places a limit on the timeout of about 3.17 4402 // years from "now". 4403 4404 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { 4405 assert(time > 0, "convertTime"); 4406 4407 struct timeval now; 4408 int status = gettimeofday(&now, NULL); 4409 assert(status == 0, "gettimeofday"); 4410 4411 time_t max_secs = now.tv_sec + MAX_SECS; 4412 4413 if (isAbsolute) { 4414 jlong secs = time / 1000; 4415 if (secs > max_secs) { 4416 absTime->tv_sec = max_secs; 4417 } else { 4418 absTime->tv_sec = secs; 4419 } 4420 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 4421 } else { 4422 jlong secs = time / NANOSECS_PER_SEC; 4423 if (secs >= MAX_SECS) { 4424 absTime->tv_sec = max_secs; 4425 absTime->tv_nsec = 0; 4426 } else { 4427 absTime->tv_sec = now.tv_sec + secs; 4428 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 4429 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 4430 absTime->tv_nsec -= NANOSECS_PER_SEC; 4431 ++absTime->tv_sec; // note: this must be <= max_secs 4432 } 4433 } 4434 } 4435 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 4436 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 4437 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 4438 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 4439 } 4440 4441 void Parker::park(bool isAbsolute, jlong time) { 4442 // Ideally we'd do something useful while spinning, such 4443 // as calling unpackTime(). 4444 4445 // Optional fast-path check: 4446 // Return immediately if a permit is available. 4447 // We depend on Atomic::xchg() having full barrier semantics 4448 // since we are doing a lock-free update to _counter. 4449 if (Atomic::xchg(0, &_counter) > 0) return; 4450 4451 Thread* thread = Thread::current(); 4452 assert(thread->is_Java_thread(), "Must be JavaThread"); 4453 JavaThread *jt = (JavaThread *)thread; 4454 4455 // Optional optimization -- avoid state transitions if there's an interrupt pending. 4456 // Check interrupt before trying to wait 4457 if (Thread::is_interrupted(thread, false)) { 4458 return; 4459 } 4460 4461 // Next, demultiplex/decode time arguments 4462 struct timespec absTime; 4463 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all 4464 return; 4465 } 4466 if (time > 0) { 4467 unpackTime(&absTime, isAbsolute, time); 4468 } 4469 4470 4471 // Enter safepoint region 4472 // Beware of deadlocks such as 6317397. 4473 // The per-thread Parker:: mutex is a classic leaf-lock. 4474 // In particular a thread must never block on the Threads_lock while 4475 // holding the Parker:: mutex. If safepoints are pending both the 4476 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 4477 ThreadBlockInVM tbivm(jt); 4478 4479 // Don't wait if cannot get lock since interference arises from 4480 // unblocking. Also. check interrupt before trying wait 4481 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 4482 return; 4483 } 4484 4485 int status; 4486 if (_counter > 0) { // no wait needed 4487 _counter = 0; 4488 status = pthread_mutex_unlock(_mutex); 4489 assert(status == 0, "invariant"); 4490 // Paranoia to ensure our locked and lock-free paths interact 4491 // correctly with each other and Java-level accesses. 4492 OrderAccess::fence(); 4493 return; 4494 } 4495 4496 #ifdef ASSERT 4497 // Don't catch signals while blocked; let the running threads have the signals. 4498 // (This allows a debugger to break into the running thread.) 4499 sigset_t oldsigs; 4500 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); 4501 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 4502 #endif 4503 4504 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 4505 jt->set_suspend_equivalent(); 4506 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 4507 4508 if (time == 0) { 4509 status = pthread_cond_wait(_cond, _mutex); 4510 } else { 4511 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &absTime); 4512 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4513 pthread_cond_destroy(_cond); 4514 pthread_cond_init(_cond, NULL); 4515 } 4516 } 4517 assert_status(status == 0 || status == EINTR || 4518 status == ETIMEDOUT, 4519 status, "cond_timedwait"); 4520 4521 #ifdef ASSERT 4522 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 4523 #endif 4524 4525 _counter = 0; 4526 status = pthread_mutex_unlock(_mutex); 4527 assert_status(status == 0, status, "invariant"); 4528 // Paranoia to ensure our locked and lock-free paths interact 4529 // correctly with each other and Java-level accesses. 4530 OrderAccess::fence(); 4531 4532 // If externally suspended while waiting, re-suspend 4533 if (jt->handle_special_suspend_equivalent_condition()) { 4534 jt->java_suspend_self(); 4535 } 4536 } 4537 4538 void Parker::unpark() { 4539 int status = pthread_mutex_lock(_mutex); 4540 assert(status == 0, "invariant"); 4541 const int s = _counter; 4542 _counter = 1; 4543 if (s < 1) { 4544 if (WorkAroundNPTLTimedWaitHang) { 4545 status = pthread_cond_signal(_cond); 4546 assert(status == 0, "invariant"); 4547 status = pthread_mutex_unlock(_mutex); 4548 assert(status == 0, "invariant"); 4549 } else { 4550 status = pthread_mutex_unlock(_mutex); 4551 assert(status == 0, "invariant"); 4552 status = pthread_cond_signal(_cond); 4553 assert(status == 0, "invariant"); 4554 } 4555 } else { 4556 pthread_mutex_unlock(_mutex); 4557 assert(status == 0, "invariant"); 4558 } 4559 } 4560 4561 4562 // Darwin has no "environ" in a dynamic library. 4563 #ifdef __APPLE__ 4564 #include <crt_externs.h> 4565 #define environ (*_NSGetEnviron()) 4566 #else 4567 extern char** environ; 4568 #endif 4569 4570 // Run the specified command in a separate process. Return its exit value, 4571 // or -1 on failure (e.g. can't fork a new process). 4572 // Unlike system(), this function can be called from signal handler. It 4573 // doesn't block SIGINT et al. 4574 int os::fork_and_exec(char* cmd) { 4575 const char * argv[4] = {"sh", "-c", cmd, NULL}; 4576 4577 // fork() in BsdThreads/NPTL is not async-safe. It needs to run 4578 // pthread_atfork handlers and reset pthread library. All we need is a 4579 // separate process to execve. Make a direct syscall to fork process. 4580 // On IA64 there's no fork syscall, we have to use fork() and hope for 4581 // the best... 4582 pid_t pid = fork(); 4583 4584 if (pid < 0) { 4585 // fork failed 4586 return -1; 4587 4588 } else if (pid == 0) { 4589 // child process 4590 4591 // execve() in BsdThreads will call pthread_kill_other_threads_np() 4592 // first to kill every thread on the thread list. Because this list is 4593 // not reset by fork() (see notes above), execve() will instead kill 4594 // every thread in the parent process. We know this is the only thread 4595 // in the new process, so make a system call directly. 4596 // IA64 should use normal execve() from glibc to match the glibc fork() 4597 // above. 4598 execve("/bin/sh", (char* const*)argv, environ); 4599 4600 // execve failed 4601 _exit(-1); 4602 4603 } else { 4604 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 4605 // care about the actual exit code, for now. 4606 4607 int status; 4608 4609 // Wait for the child process to exit. This returns immediately if 4610 // the child has already exited. */ 4611 while (waitpid(pid, &status, 0) < 0) { 4612 switch (errno) { 4613 case ECHILD: return 0; 4614 case EINTR: break; 4615 default: return -1; 4616 } 4617 } 4618 4619 if (WIFEXITED(status)) { 4620 // The child exited normally; get its exit code. 4621 return WEXITSTATUS(status); 4622 } else if (WIFSIGNALED(status)) { 4623 // The child exited because of a signal 4624 // The best value to return is 0x80 + signal number, 4625 // because that is what all Unix shells do, and because 4626 // it allows callers to distinguish between process exit and 4627 // process death by signal. 4628 return 0x80 + WTERMSIG(status); 4629 } else { 4630 // Unknown exit code; pass it through 4631 return status; 4632 } 4633 } 4634 } 4635 4636 // is_headless_jre() 4637 // 4638 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 4639 // in order to report if we are running in a headless jre 4640 // 4641 // Since JDK8 xawt/libmawt.so was moved into the same directory 4642 // as libawt.so, and renamed libawt_xawt.so 4643 // 4644 bool os::is_headless_jre() { 4645 #ifdef __APPLE__ 4646 // We no longer build headless-only on Mac OS X 4647 return false; 4648 #else 4649 struct stat statbuf; 4650 char buf[MAXPATHLEN]; 4651 char libmawtpath[MAXPATHLEN]; 4652 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX; 4653 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX; 4654 char *p; 4655 4656 // Get path to libjvm.so 4657 os::jvm_path(buf, sizeof(buf)); 4658 4659 // Get rid of libjvm.so 4660 p = strrchr(buf, '/'); 4661 if (p == NULL) { 4662 return false; 4663 } else { 4664 *p = '\0'; 4665 } 4666 4667 // Get rid of client or server 4668 p = strrchr(buf, '/'); 4669 if (p == NULL) { 4670 return false; 4671 } else { 4672 *p = '\0'; 4673 } 4674 4675 // check xawt/libmawt.so 4676 strcpy(libmawtpath, buf); 4677 strcat(libmawtpath, xawtstr); 4678 if (::stat(libmawtpath, &statbuf) == 0) return false; 4679 4680 // check libawt_xawt.so 4681 strcpy(libmawtpath, buf); 4682 strcat(libmawtpath, new_xawtstr); 4683 if (::stat(libmawtpath, &statbuf) == 0) return false; 4684 4685 return true; 4686 #endif 4687 } 4688 4689 // Get the default path to the core file 4690 // Returns the length of the string 4691 int os::get_core_path(char* buffer, size_t bufferSize) { 4692 int n = jio_snprintf(buffer, bufferSize, "/cores"); 4693 4694 // Truncate if theoretical string was longer than bufferSize 4695 n = MIN2(n, (int)bufferSize); 4696 4697 return n; 4698 } 4699 4700 #ifndef PRODUCT 4701 void TestReserveMemorySpecial_test() { 4702 // No tests available for this platform 4703 } 4704 #endif