1 /* 2 * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 // no precompiled headers 26 #include "classfile/classLoader.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "classfile/vmSymbols.hpp" 29 #include "code/icBuffer.hpp" 30 #include "code/vtableStubs.hpp" 31 #include "compiler/compileBroker.hpp" 32 #include "compiler/disassembler.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "jvm_bsd.h" 35 #include "memory/allocation.inline.hpp" 36 #include "memory/filemap.hpp" 37 #include "mutex_bsd.inline.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "os_bsd.inline.hpp" 40 #include "os_share_bsd.hpp" 41 #include "prims/jniFastGetField.hpp" 42 #include "prims/jvm.h" 43 #include "prims/jvm_misc.hpp" 44 #include "runtime/arguments.hpp" 45 #include "runtime/atomic.inline.hpp" 46 #include "runtime/extendedPC.hpp" 47 #include "runtime/globals.hpp" 48 #include "runtime/interfaceSupport.hpp" 49 #include "runtime/java.hpp" 50 #include "runtime/javaCalls.hpp" 51 #include "runtime/mutexLocker.hpp" 52 #include "runtime/objectMonitor.hpp" 53 #include "runtime/orderAccess.inline.hpp" 54 #include "runtime/osThread.hpp" 55 #include "runtime/perfMemory.hpp" 56 #include "runtime/sharedRuntime.hpp" 57 #include "runtime/statSampler.hpp" 58 #include "runtime/stubRoutines.hpp" 59 #include "runtime/thread.inline.hpp" 60 #include "runtime/threadCritical.hpp" 61 #include "runtime/timer.hpp" 62 #include "services/attachListener.hpp" 63 #include "services/memTracker.hpp" 64 #include "services/runtimeService.hpp" 65 #include "utilities/decoder.hpp" 66 #include "utilities/defaultStream.hpp" 67 #include "utilities/events.hpp" 68 #include "utilities/growableArray.hpp" 69 #include "utilities/vmError.hpp" 70 71 // put OS-includes here 72 # include <sys/types.h> 73 # include <sys/mman.h> 74 # include <sys/stat.h> 75 # include <sys/select.h> 76 # include <pthread.h> 77 # include <signal.h> 78 # include <errno.h> 79 # include <dlfcn.h> 80 # include <stdio.h> 81 # include <unistd.h> 82 # include <sys/resource.h> 83 # include <pthread.h> 84 # include <sys/stat.h> 85 # include <sys/time.h> 86 # include <sys/times.h> 87 # include <sys/utsname.h> 88 # include <sys/socket.h> 89 # include <sys/wait.h> 90 # include <time.h> 91 # include <pwd.h> 92 # include <poll.h> 93 # include <semaphore.h> 94 # include <fcntl.h> 95 # include <string.h> 96 # include <sys/param.h> 97 # include <sys/sysctl.h> 98 # include <sys/ipc.h> 99 # include <sys/shm.h> 100 #ifndef __APPLE__ 101 # include <link.h> 102 #endif 103 # include <stdint.h> 104 # include <inttypes.h> 105 # include <sys/ioctl.h> 106 # include <sys/syscall.h> 107 108 #if defined(__FreeBSD__) || defined(__NetBSD__) 109 #include <elf.h> 110 #endif 111 112 #ifdef __APPLE__ 113 #include <mach/mach.h> // semaphore_* API 114 #include <mach-o/dyld.h> 115 #include <sys/proc_info.h> 116 #include <objc/objc-auto.h> 117 #endif 118 119 #ifndef MAP_ANONYMOUS 120 #define MAP_ANONYMOUS MAP_ANON 121 #endif 122 123 #define MAX_PATH (2 * K) 124 125 // for timer info max values which include all bits 126 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 127 128 #define LARGEPAGES_BIT (1 << 6) 129 130 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 131 132 //////////////////////////////////////////////////////////////////////////////// 133 // global variables 134 julong os::Bsd::_physical_memory = 0; 135 136 #ifdef __APPLE__ 137 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0}; 138 volatile uint64_t os::Bsd::_max_abstime = 0; 139 #else 140 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; 141 #endif 142 pthread_t os::Bsd::_main_thread; 143 int os::Bsd::_page_size = -1; 144 145 static jlong initial_time_count=0; 146 147 static int clock_tics_per_sec = 100; 148 149 // For diagnostics to print a message once. see run_periodic_checks 150 static sigset_t check_signal_done; 151 static bool check_signals = true; 152 153 static pid_t _initial_pid = 0; 154 155 // Signal number used to suspend/resume a thread 156 157 // do not use any signal number less than SIGSEGV, see 4355769 158 static int SR_signum = SIGUSR2; 159 sigset_t SR_sigset; 160 161 162 //////////////////////////////////////////////////////////////////////////////// 163 // utility functions 164 165 static int SR_initialize(); 166 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time); 167 168 julong os::available_memory() { 169 return Bsd::available_memory(); 170 } 171 172 // available here means free 173 julong os::Bsd::available_memory() { 174 uint64_t available = physical_memory() >> 2; 175 #ifdef __APPLE__ 176 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT; 177 vm_statistics64_data_t vmstat; 178 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64, 179 (host_info64_t)&vmstat, &count); 180 assert(kerr == KERN_SUCCESS, 181 "host_statistics64 failed - check mach_host_self() and count"); 182 if (kerr == KERN_SUCCESS) { 183 available = vmstat.free_count * os::vm_page_size(); 184 } 185 #endif 186 return available; 187 } 188 189 julong os::physical_memory() { 190 return Bsd::physical_memory(); 191 } 192 193 //////////////////////////////////////////////////////////////////////////////// 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" 356 357 #ifndef __APPLE__ 358 359 // Buffer that fits several sprintfs. 360 // Note that the space for the colon and the trailing null are provided 361 // by the nulls included by the sizeof operator. 362 const size_t bufsize = 363 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. 364 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir 365 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 366 367 // sysclasspath, java_home, dll_dir 368 { 369 char *pslash; 370 os::jvm_path(buf, bufsize); 371 372 // Found the full path to libjvm.so. 373 // Now cut the path to <java_home>/jre if we can. 374 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 375 pslash = strrchr(buf, '/'); 376 if (pslash != NULL) { 377 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 378 } 379 Arguments::set_dll_dir(buf); 380 381 if (pslash != NULL) { 382 pslash = strrchr(buf, '/'); 383 if (pslash != NULL) { 384 *pslash = '\0'; // Get rid of /<arch>. 385 pslash = strrchr(buf, '/'); 386 if (pslash != NULL) { 387 *pslash = '\0'; // Get rid of /lib. 388 } 389 } 390 } 391 Arguments::set_java_home(buf); 392 set_boot_path('/', ':'); 393 } 394 395 // Where to look for native libraries. 396 // 397 // Note: Due to a legacy implementation, most of the library path 398 // is set in the launcher. This was to accomodate linking restrictions 399 // on legacy Bsd implementations (which are no longer supported). 400 // Eventually, all the library path setting will be done here. 401 // 402 // However, to prevent the proliferation of improperly built native 403 // libraries, the new path component /usr/java/packages is added here. 404 // Eventually, all the library path setting will be done here. 405 { 406 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 407 // should always exist (until the legacy problem cited above is 408 // addressed). 409 const char *v = ::getenv("LD_LIBRARY_PATH"); 410 const char *v_colon = ":"; 411 if (v == NULL) { v = ""; v_colon = ""; } 412 // That's +1 for the colon and +1 for the trailing '\0'. 413 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 414 strlen(v) + 1 + 415 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1, 416 mtInternal); 417 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch); 418 Arguments::set_library_path(ld_library_path); 419 FREE_C_HEAP_ARRAY(char, ld_library_path); 420 } 421 422 // Extensions directories. 423 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 424 Arguments::set_ext_dirs(buf); 425 426 FREE_C_HEAP_ARRAY(char, buf); 427 428 #else // __APPLE__ 429 430 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions" 431 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java" 432 433 const char *user_home_dir = get_home(); 434 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir. 435 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) + 436 sizeof(SYS_EXTENSIONS_DIRS); 437 438 // Buffer that fits several sprintfs. 439 // Note that the space for the colon and the trailing null are provided 440 // by the nulls included by the sizeof operator. 441 const size_t bufsize = 442 MAX2((size_t)MAXPATHLEN, // for dll_dir & friends. 443 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir 444 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 445 446 // sysclasspath, java_home, dll_dir 447 { 448 char *pslash; 449 os::jvm_path(buf, bufsize); 450 451 // Found the full path to libjvm.so. 452 // Now cut the path to <java_home>/jre if we can. 453 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 454 pslash = strrchr(buf, '/'); 455 if (pslash != NULL) { 456 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 457 } 458 Arguments::set_dll_dir(buf); 459 460 if (pslash != NULL) { 461 pslash = strrchr(buf, '/'); 462 if (pslash != NULL) { 463 *pslash = '\0'; // Get rid of /lib. 464 } 465 } 466 Arguments::set_java_home(buf); 467 set_boot_path('/', ':'); 468 } 469 470 // Where to look for native libraries. 471 // 472 // Note: Due to a legacy implementation, most of the library path 473 // is set in the launcher. This was to accomodate linking restrictions 474 // on legacy Bsd implementations (which are no longer supported). 475 // Eventually, all the library path setting will be done here. 476 // 477 // However, to prevent the proliferation of improperly built native 478 // libraries, the new path component /usr/java/packages is added here. 479 // Eventually, all the library path setting will be done here. 480 { 481 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 482 // should always exist (until the legacy problem cited above is 483 // addressed). 484 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code 485 // can specify a directory inside an app wrapper 486 const char *l = ::getenv("JAVA_LIBRARY_PATH"); 487 const char *l_colon = ":"; 488 if (l == NULL) { l = ""; l_colon = ""; } 489 490 const char *v = ::getenv("DYLD_LIBRARY_PATH"); 491 const char *v_colon = ":"; 492 if (v == NULL) { v = ""; v_colon = ""; } 493 494 // Apple's Java6 has "." at the beginning of java.library.path. 495 // OpenJDK on Windows has "." at the end of java.library.path. 496 // OpenJDK on Linux and Solaris don't have "." in java.library.path 497 // at all. To ease the transition from Apple's Java6 to OpenJDK7, 498 // "." is appended to the end of java.library.path. Yes, this 499 // could cause a change in behavior, but Apple's Java6 behavior 500 // can be achieved by putting "." at the beginning of the 501 // JAVA_LIBRARY_PATH environment variable. 502 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 503 strlen(v) + 1 + strlen(l) + 1 + 504 system_ext_size + 3, 505 mtInternal); 506 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.", 507 v, v_colon, l, l_colon, user_home_dir); 508 Arguments::set_library_path(ld_library_path); 509 FREE_C_HEAP_ARRAY(char, ld_library_path); 510 } 511 512 // Extensions directories. 513 // 514 // Note that the space for the colon and the trailing null are provided 515 // by the nulls included by the sizeof operator (so actually one byte more 516 // than necessary is allocated). 517 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, 518 user_home_dir, Arguments::get_java_home()); 519 Arguments::set_ext_dirs(buf); 520 521 FREE_C_HEAP_ARRAY(char, buf); 522 523 #undef SYS_EXTENSIONS_DIR 524 #undef SYS_EXTENSIONS_DIRS 525 526 #endif // __APPLE__ 527 528 #undef SYS_EXT_DIR 529 #undef EXTENSIONS_DIR 530 } 531 532 //////////////////////////////////////////////////////////////////////////////// 533 // breakpoint support 534 535 void os::breakpoint() { 536 BREAKPOINT; 537 } 538 539 extern "C" void breakpoint() { 540 // use debugger to set breakpoint here 541 } 542 543 //////////////////////////////////////////////////////////////////////////////// 544 // signal support 545 546 debug_only(static bool signal_sets_initialized = false); 547 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 548 549 bool os::Bsd::is_sig_ignored(int sig) { 550 struct sigaction oact; 551 sigaction(sig, (struct sigaction*)NULL, &oact); 552 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 553 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 554 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) { 555 return true; 556 } else { 557 return false; 558 } 559 } 560 561 void os::Bsd::signal_sets_init() { 562 // Should also have an assertion stating we are still single-threaded. 563 assert(!signal_sets_initialized, "Already initialized"); 564 // Fill in signals that are necessarily unblocked for all threads in 565 // the VM. Currently, we unblock the following signals: 566 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 567 // by -Xrs (=ReduceSignalUsage)); 568 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 569 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 570 // the dispositions or masks wrt these signals. 571 // Programs embedding the VM that want to use the above signals for their 572 // own purposes must, at this time, use the "-Xrs" option to prevent 573 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 574 // (See bug 4345157, and other related bugs). 575 // In reality, though, unblocking these signals is really a nop, since 576 // these signals are not blocked by default. 577 sigemptyset(&unblocked_sigs); 578 sigemptyset(&allowdebug_blocked_sigs); 579 sigaddset(&unblocked_sigs, SIGILL); 580 sigaddset(&unblocked_sigs, SIGSEGV); 581 sigaddset(&unblocked_sigs, SIGBUS); 582 sigaddset(&unblocked_sigs, SIGFPE); 583 sigaddset(&unblocked_sigs, SR_signum); 584 585 if (!ReduceSignalUsage) { 586 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 587 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 588 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); 589 } 590 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 591 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 592 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); 593 } 594 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 595 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 596 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); 597 } 598 } 599 // Fill in signals that are blocked by all but the VM thread. 600 sigemptyset(&vm_sigs); 601 if (!ReduceSignalUsage) { 602 sigaddset(&vm_sigs, BREAK_SIGNAL); 603 } 604 debug_only(signal_sets_initialized = true); 605 606 } 607 608 // These are signals that are unblocked while a thread is running Java. 609 // (For some reason, they get blocked by default.) 610 sigset_t* os::Bsd::unblocked_signals() { 611 assert(signal_sets_initialized, "Not initialized"); 612 return &unblocked_sigs; 613 } 614 615 // These are the signals that are blocked while a (non-VM) thread is 616 // running Java. Only the VM thread handles these signals. 617 sigset_t* os::Bsd::vm_signals() { 618 assert(signal_sets_initialized, "Not initialized"); 619 return &vm_sigs; 620 } 621 622 // These are signals that are blocked during cond_wait to allow debugger in 623 sigset_t* os::Bsd::allowdebug_blocked_signals() { 624 assert(signal_sets_initialized, "Not initialized"); 625 return &allowdebug_blocked_sigs; 626 } 627 628 void os::Bsd::hotspot_sigmask(Thread* thread) { 629 630 //Save caller's signal mask before setting VM signal mask 631 sigset_t caller_sigmask; 632 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 633 634 OSThread* osthread = thread->osthread(); 635 osthread->set_caller_sigmask(caller_sigmask); 636 637 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); 638 639 if (!ReduceSignalUsage) { 640 if (thread->is_VM_thread()) { 641 // Only the VM thread handles BREAK_SIGNAL ... 642 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 643 } else { 644 // ... all other threads block BREAK_SIGNAL 645 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 646 } 647 } 648 } 649 650 651 ////////////////////////////////////////////////////////////////////////////// 652 // create new thread 653 654 // check if it's safe to start a new thread 655 static bool _thread_safety_check(Thread* thread) { 656 return true; 657 } 658 659 #ifdef __APPLE__ 660 // library handle for calling objc_registerThreadWithCollector() 661 // without static linking to the libobjc library 662 #define OBJC_LIB "/usr/lib/libobjc.dylib" 663 #define OBJC_GCREGISTER "objc_registerThreadWithCollector" 664 typedef void (*objc_registerThreadWithCollector_t)(); 665 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction; 666 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL; 667 #endif 668 669 #ifdef __APPLE__ 670 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) { 671 // Additional thread_id used to correlate threads in SA 672 thread_identifier_info_data_t m_ident_info; 673 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT; 674 675 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO, 676 (thread_info_t) &m_ident_info, &count); 677 678 return m_ident_info.thread_id; 679 } 680 #endif 681 682 // Thread start routine for all newly created threads 683 static void *java_start(Thread *thread) { 684 // Try to randomize the cache line index of hot stack frames. 685 // This helps when threads of the same stack traces evict each other's 686 // cache lines. The threads can be either from the same JVM instance, or 687 // from different JVM instances. The benefit is especially true for 688 // processors with hyperthreading technology. 689 static int counter = 0; 690 int pid = os::current_process_id(); 691 alloca(((pid ^ counter++) & 7) * 128); 692 693 ThreadLocalStorage::set_thread(thread); 694 695 OSThread* osthread = thread->osthread(); 696 Monitor* sync = osthread->startThread_lock(); 697 698 // non floating stack BsdThreads needs extra check, see above 699 if (!_thread_safety_check(thread)) { 700 // notify parent thread 701 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 702 osthread->set_state(ZOMBIE); 703 sync->notify_all(); 704 return NULL; 705 } 706 707 osthread->set_thread_id(os::Bsd::gettid()); 708 709 #ifdef __APPLE__ 710 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 711 guarantee(unique_thread_id != 0, "unique thread id was not found"); 712 osthread->set_unique_thread_id(unique_thread_id); 713 #endif 714 // initialize signal mask for this thread 715 os::Bsd::hotspot_sigmask(thread); 716 717 // initialize floating point control register 718 os::Bsd::init_thread_fpu_state(); 719 720 #ifdef __APPLE__ 721 // register thread with objc gc 722 if (objc_registerThreadWithCollectorFunction != NULL) { 723 objc_registerThreadWithCollectorFunction(); 724 } 725 #endif 726 727 // handshaking with parent thread 728 { 729 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 730 731 // notify parent thread 732 osthread->set_state(INITIALIZED); 733 sync->notify_all(); 734 735 // wait until os::start_thread() 736 while (osthread->get_state() == INITIALIZED) { 737 sync->wait(Mutex::_no_safepoint_check_flag); 738 } 739 } 740 741 // call one more level start routine 742 thread->run(); 743 744 return 0; 745 } 746 747 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { 748 assert(thread->osthread() == NULL, "caller responsible"); 749 750 // Allocate the OSThread object 751 OSThread* osthread = new OSThread(NULL, NULL); 752 if (osthread == NULL) { 753 return false; 754 } 755 756 // set the correct thread state 757 osthread->set_thread_type(thr_type); 758 759 // Initial state is ALLOCATED but not INITIALIZED 760 osthread->set_state(ALLOCATED); 761 762 thread->set_osthread(osthread); 763 764 // init thread attributes 765 pthread_attr_t attr; 766 pthread_attr_init(&attr); 767 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 768 769 // stack size 770 if (os::Bsd::supports_variable_stack_size()) { 771 // calculate stack size if it's not specified by caller 772 if (stack_size == 0) { 773 stack_size = os::Bsd::default_stack_size(thr_type); 774 775 switch (thr_type) { 776 case os::java_thread: 777 // Java threads use ThreadStackSize which default value can be 778 // changed with the flag -Xss 779 assert(JavaThread::stack_size_at_create() > 0, "this should be set"); 780 stack_size = JavaThread::stack_size_at_create(); 781 break; 782 case os::compiler_thread: 783 if (CompilerThreadStackSize > 0) { 784 stack_size = (size_t)(CompilerThreadStackSize * K); 785 break; 786 } // else fall through: 787 // use VMThreadStackSize if CompilerThreadStackSize is not defined 788 case os::vm_thread: 789 case os::pgc_thread: 790 case os::cgc_thread: 791 case os::watcher_thread: 792 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 793 break; 794 } 795 } 796 797 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); 798 pthread_attr_setstacksize(&attr, stack_size); 799 } else { 800 // let pthread_create() pick the default value. 801 } 802 803 ThreadState state; 804 805 { 806 pthread_t tid; 807 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 808 809 pthread_attr_destroy(&attr); 810 811 if (ret != 0) { 812 if (PrintMiscellaneous && (Verbose || WizardMode)) { 813 perror("pthread_create()"); 814 } 815 // Need to clean up stuff we've allocated so far 816 thread->set_osthread(NULL); 817 delete osthread; 818 return false; 819 } 820 821 // Store pthread info into the OSThread 822 osthread->set_pthread_id(tid); 823 824 // Wait until child thread is either initialized or aborted 825 { 826 Monitor* sync_with_child = osthread->startThread_lock(); 827 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 828 while ((state = osthread->get_state()) == ALLOCATED) { 829 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 830 } 831 } 832 833 } 834 835 // Aborted due to thread limit being reached 836 if (state == ZOMBIE) { 837 thread->set_osthread(NULL); 838 delete osthread; 839 return false; 840 } 841 842 // The thread is returned suspended (in state INITIALIZED), 843 // and is started higher up in the call chain 844 assert(state == INITIALIZED, "race condition"); 845 return true; 846 } 847 848 ///////////////////////////////////////////////////////////////////////////// 849 // attach existing thread 850 851 // bootstrap the main thread 852 bool os::create_main_thread(JavaThread* thread) { 853 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); 854 return create_attached_thread(thread); 855 } 856 857 bool os::create_attached_thread(JavaThread* thread) { 858 #ifdef ASSERT 859 thread->verify_not_published(); 860 #endif 861 862 // Allocate the OSThread object 863 OSThread* osthread = new OSThread(NULL, NULL); 864 865 if (osthread == NULL) { 866 return false; 867 } 868 869 osthread->set_thread_id(os::Bsd::gettid()); 870 871 // Store pthread info into the OSThread 872 #ifdef __APPLE__ 873 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 874 guarantee(unique_thread_id != 0, "just checking"); 875 osthread->set_unique_thread_id(unique_thread_id); 876 #endif 877 osthread->set_pthread_id(::pthread_self()); 878 879 // initialize floating point control register 880 os::Bsd::init_thread_fpu_state(); 881 882 // Initial thread state is RUNNABLE 883 osthread->set_state(RUNNABLE); 884 885 thread->set_osthread(osthread); 886 887 // initialize signal mask for this thread 888 // and save the caller's signal mask 889 os::Bsd::hotspot_sigmask(thread); 890 891 return true; 892 } 893 894 void os::pd_start_thread(Thread* thread) { 895 OSThread * osthread = thread->osthread(); 896 assert(osthread->get_state() != INITIALIZED, "just checking"); 897 Monitor* sync_with_child = osthread->startThread_lock(); 898 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 899 sync_with_child->notify(); 900 } 901 902 // Free Bsd resources related to the OSThread 903 void os::free_thread(OSThread* osthread) { 904 assert(osthread != NULL, "osthread not set"); 905 906 if (Thread::current()->osthread() == osthread) { 907 // Restore caller's signal mask 908 sigset_t sigmask = osthread->caller_sigmask(); 909 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 910 } 911 912 delete osthread; 913 } 914 915 ////////////////////////////////////////////////////////////////////////////// 916 // thread local storage 917 918 // Restore the thread pointer if the destructor is called. This is in case 919 // someone from JNI code sets up a destructor with pthread_key_create to run 920 // detachCurrentThread on thread death. Unless we restore the thread pointer we 921 // will hang or crash. When detachCurrentThread is called the key will be set 922 // to null and we will not be called again. If detachCurrentThread is never 923 // called we could loop forever depending on the pthread implementation. 924 static void restore_thread_pointer(void* p) { 925 Thread* thread = (Thread*) p; 926 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread); 927 } 928 929 int os::allocate_thread_local_storage() { 930 pthread_key_t key; 931 int rslt = pthread_key_create(&key, restore_thread_pointer); 932 assert(rslt == 0, "cannot allocate thread local storage"); 933 return (int)key; 934 } 935 936 // Note: This is currently not used by VM, as we don't destroy TLS key 937 // on VM exit. 938 void os::free_thread_local_storage(int index) { 939 int rslt = pthread_key_delete((pthread_key_t)index); 940 assert(rslt == 0, "invalid index"); 941 } 942 943 void os::thread_local_storage_at_put(int index, void* value) { 944 int rslt = pthread_setspecific((pthread_key_t)index, value); 945 assert(rslt == 0, "pthread_setspecific failed"); 946 } 947 948 extern "C" Thread* get_thread() { 949 return ThreadLocalStorage::thread(); 950 } 951 952 953 //////////////////////////////////////////////////////////////////////////////// 954 // time support 955 956 // Time since start-up in seconds to a fine granularity. 957 // Used by VMSelfDestructTimer and the MemProfiler. 958 double os::elapsedTime() { 959 960 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); 961 } 962 963 jlong os::elapsed_counter() { 964 return javaTimeNanos() - initial_time_count; 965 } 966 967 jlong os::elapsed_frequency() { 968 return NANOSECS_PER_SEC; // nanosecond resolution 969 } 970 971 bool os::supports_vtime() { return true; } 972 bool os::enable_vtime() { return false; } 973 bool os::vtime_enabled() { return false; } 974 975 double os::elapsedVTime() { 976 // better than nothing, but not much 977 return elapsedTime(); 978 } 979 980 jlong os::javaTimeMillis() { 981 timeval time; 982 int status = gettimeofday(&time, NULL); 983 assert(status != -1, "bsd error"); 984 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 985 } 986 987 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) { 988 timeval time; 989 int status = gettimeofday(&time, NULL); 990 assert(status != -1, "bsd error"); 991 seconds = jlong(time.tv_sec); 992 nanos = jlong(time.tv_usec) * 1000; 993 } 994 995 #ifndef __APPLE__ 996 #ifndef CLOCK_MONOTONIC 997 #define CLOCK_MONOTONIC (1) 998 #endif 999 #endif 1000 1001 #ifdef __APPLE__ 1002 void os::Bsd::clock_init() { 1003 mach_timebase_info(&_timebase_info); 1004 } 1005 #else 1006 void os::Bsd::clock_init() { 1007 struct timespec res; 1008 struct timespec tp; 1009 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && 1010 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { 1011 // yes, monotonic clock is supported 1012 _clock_gettime = ::clock_gettime; 1013 } 1014 } 1015 #endif 1016 1017 1018 1019 #ifdef __APPLE__ 1020 1021 jlong os::javaTimeNanos() { 1022 const uint64_t tm = mach_absolute_time(); 1023 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom; 1024 const uint64_t prev = Bsd::_max_abstime; 1025 if (now <= prev) { 1026 return prev; // same or retrograde time; 1027 } 1028 const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev); 1029 assert(obsv >= prev, "invariant"); // Monotonicity 1030 // If the CAS succeeded then we're done and return "now". 1031 // If the CAS failed and the observed value "obsv" is >= now then 1032 // we should return "obsv". If the CAS failed and now > obsv > prv then 1033 // some other thread raced this thread and installed a new value, in which case 1034 // we could either (a) retry the entire operation, (b) retry trying to install now 1035 // or (c) just return obsv. We use (c). No loop is required although in some cases 1036 // we might discard a higher "now" value in deference to a slightly lower but freshly 1037 // installed obsv value. That's entirely benign -- it admits no new orderings compared 1038 // to (a) or (b) -- and greatly reduces coherence traffic. 1039 // We might also condition (c) on the magnitude of the delta between obsv and now. 1040 // Avoiding excessive CAS operations to hot RW locations is critical. 1041 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate 1042 return (prev == obsv) ? now : obsv; 1043 } 1044 1045 #else // __APPLE__ 1046 1047 jlong os::javaTimeNanos() { 1048 if (os::supports_monotonic_clock()) { 1049 struct timespec tp; 1050 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp); 1051 assert(status == 0, "gettime error"); 1052 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1053 return result; 1054 } else { 1055 timeval time; 1056 int status = gettimeofday(&time, NULL); 1057 assert(status != -1, "bsd error"); 1058 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1059 return 1000 * usecs; 1060 } 1061 } 1062 1063 #endif // __APPLE__ 1064 1065 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1066 if (os::supports_monotonic_clock()) { 1067 info_ptr->max_value = ALL_64_BITS; 1068 1069 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1070 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1071 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1072 } else { 1073 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1074 info_ptr->max_value = ALL_64_BITS; 1075 1076 // gettimeofday is a real time clock so it skips 1077 info_ptr->may_skip_backward = true; 1078 info_ptr->may_skip_forward = true; 1079 } 1080 1081 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1082 } 1083 1084 // Return the real, user, and system times in seconds from an 1085 // arbitrary fixed point in the past. 1086 bool os::getTimesSecs(double* process_real_time, 1087 double* process_user_time, 1088 double* process_system_time) { 1089 struct tms ticks; 1090 clock_t real_ticks = times(&ticks); 1091 1092 if (real_ticks == (clock_t) (-1)) { 1093 return false; 1094 } else { 1095 double ticks_per_second = (double) clock_tics_per_sec; 1096 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1097 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1098 *process_real_time = ((double) real_ticks) / ticks_per_second; 1099 1100 return true; 1101 } 1102 } 1103 1104 1105 char * os::local_time_string(char *buf, size_t buflen) { 1106 struct tm t; 1107 time_t long_time; 1108 time(&long_time); 1109 localtime_r(&long_time, &t); 1110 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1111 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1112 t.tm_hour, t.tm_min, t.tm_sec); 1113 return buf; 1114 } 1115 1116 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1117 return localtime_r(clock, res); 1118 } 1119 1120 //////////////////////////////////////////////////////////////////////////////// 1121 // runtime exit support 1122 1123 // Note: os::shutdown() might be called very early during initialization, or 1124 // called from signal handler. Before adding something to os::shutdown(), make 1125 // sure it is async-safe and can handle partially initialized VM. 1126 void os::shutdown() { 1127 1128 // allow PerfMemory to attempt cleanup of any persistent resources 1129 perfMemory_exit(); 1130 1131 // needs to remove object in file system 1132 AttachListener::abort(); 1133 1134 // flush buffered output, finish log files 1135 ostream_abort(); 1136 1137 // Check for abort hook 1138 abort_hook_t abort_hook = Arguments::abort_hook(); 1139 if (abort_hook != NULL) { 1140 abort_hook(); 1141 } 1142 1143 } 1144 1145 // Note: os::abort() might be called very early during initialization, or 1146 // called from signal handler. Before adding something to os::abort(), make 1147 // sure it is async-safe and can handle partially initialized VM. 1148 void os::abort(bool dump_core, void* exceptionRecord, void* contextRecord) { 1149 os::shutdown(); 1150 if (dump_core) { 1151 #ifndef PRODUCT 1152 fdStream out(defaultStream::output_fd()); 1153 out.print_raw("Current thread is "); 1154 char buf[16]; 1155 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1156 out.print_raw_cr(buf); 1157 out.print_raw_cr("Dumping core ..."); 1158 #endif 1159 ::abort(); // dump core 1160 } 1161 1162 ::exit(1); 1163 } 1164 1165 // Die immediately, no exit hook, no abort hook, no cleanup. 1166 void os::die() { 1167 // _exit() on BsdThreads only kills current thread 1168 ::abort(); 1169 } 1170 1171 // This method is a copy of JDK's sysGetLastErrorString 1172 // from src/solaris/hpi/src/system_md.c 1173 1174 size_t os::lasterror(char *buf, size_t len) { 1175 if (errno == 0) return 0; 1176 1177 const char *s = ::strerror(errno); 1178 size_t n = ::strlen(s); 1179 if (n >= len) { 1180 n = len - 1; 1181 } 1182 ::strncpy(buf, s, n); 1183 buf[n] = '\0'; 1184 return n; 1185 } 1186 1187 // Information of current thread in variety of formats 1188 pid_t os::Bsd::gettid() { 1189 int retval = -1; 1190 1191 #ifdef __APPLE__ //XNU kernel 1192 // despite the fact mach port is actually not a thread id use it 1193 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4 1194 retval = ::pthread_mach_thread_np(::pthread_self()); 1195 guarantee(retval != 0, "just checking"); 1196 return retval; 1197 1198 #elif __FreeBSD__ 1199 retval = syscall(SYS_thr_self); 1200 #elif __OpenBSD__ 1201 retval = syscall(SYS_getthrid); 1202 #elif __NetBSD__ 1203 retval = (pid_t) syscall(SYS__lwp_self); 1204 #endif 1205 1206 if (retval == -1) { 1207 return getpid(); 1208 } 1209 } 1210 1211 intx os::current_thread_id() { 1212 #ifdef __APPLE__ 1213 return (intx)::pthread_mach_thread_np(::pthread_self()); 1214 #else 1215 return (intx)::pthread_self(); 1216 #endif 1217 } 1218 1219 int os::current_process_id() { 1220 1221 // Under the old bsd thread library, bsd gives each thread 1222 // its own process id. Because of this each thread will return 1223 // a different pid if this method were to return the result 1224 // of getpid(2). Bsd provides no api that returns the pid 1225 // of the launcher thread for the vm. This implementation 1226 // returns a unique pid, the pid of the launcher thread 1227 // that starts the vm 'process'. 1228 1229 // Under the NPTL, getpid() returns the same pid as the 1230 // launcher thread rather than a unique pid per thread. 1231 // Use gettid() if you want the old pre NPTL behaviour. 1232 1233 // if you are looking for the result of a call to getpid() that 1234 // returns a unique pid for the calling thread, then look at the 1235 // OSThread::thread_id() method in osThread_bsd.hpp file 1236 1237 return (int)(_initial_pid ? _initial_pid : getpid()); 1238 } 1239 1240 // DLL functions 1241 1242 #define JNI_LIB_PREFIX "lib" 1243 #ifdef __APPLE__ 1244 #define JNI_LIB_SUFFIX ".dylib" 1245 #else 1246 #define JNI_LIB_SUFFIX ".so" 1247 #endif 1248 1249 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } 1250 1251 // This must be hard coded because it's the system's temporary 1252 // directory not the java application's temp directory, ala java.io.tmpdir. 1253 #ifdef __APPLE__ 1254 // macosx has a secure per-user temporary directory 1255 char temp_path_storage[PATH_MAX]; 1256 const char* os::get_temp_directory() { 1257 static char *temp_path = NULL; 1258 if (temp_path == NULL) { 1259 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX); 1260 if (pathSize == 0 || pathSize > PATH_MAX) { 1261 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage)); 1262 } 1263 temp_path = temp_path_storage; 1264 } 1265 return temp_path; 1266 } 1267 #else // __APPLE__ 1268 const char* os::get_temp_directory() { return "/tmp"; } 1269 #endif // __APPLE__ 1270 1271 static bool file_exists(const char* filename) { 1272 struct stat statbuf; 1273 if (filename == NULL || strlen(filename) == 0) { 1274 return false; 1275 } 1276 return os::stat(filename, &statbuf) == 0; 1277 } 1278 1279 bool os::dll_build_name(char* buffer, size_t buflen, 1280 const char* pname, const char* fname) { 1281 bool retval = false; 1282 // Copied from libhpi 1283 const size_t pnamelen = pname ? strlen(pname) : 0; 1284 1285 // Return error on buffer overflow. 1286 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { 1287 return retval; 1288 } 1289 1290 if (pnamelen == 0) { 1291 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); 1292 retval = true; 1293 } else if (strchr(pname, *os::path_separator()) != NULL) { 1294 int n; 1295 char** pelements = split_path(pname, &n); 1296 if (pelements == NULL) { 1297 return false; 1298 } 1299 for (int i = 0; i < n; i++) { 1300 // Really shouldn't be NULL, but check can't hurt 1301 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1302 continue; // skip the empty path values 1303 } 1304 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, 1305 pelements[i], fname); 1306 if (file_exists(buffer)) { 1307 retval = true; 1308 break; 1309 } 1310 } 1311 // release the storage 1312 for (int i = 0; i < n; i++) { 1313 if (pelements[i] != NULL) { 1314 FREE_C_HEAP_ARRAY(char, pelements[i]); 1315 } 1316 } 1317 if (pelements != NULL) { 1318 FREE_C_HEAP_ARRAY(char*, pelements); 1319 } 1320 } else { 1321 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); 1322 retval = true; 1323 } 1324 return retval; 1325 } 1326 1327 // check if addr is inside libjvm.so 1328 bool os::address_is_in_vm(address addr) { 1329 static address libjvm_base_addr; 1330 Dl_info dlinfo; 1331 1332 if (libjvm_base_addr == NULL) { 1333 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1334 libjvm_base_addr = (address)dlinfo.dli_fbase; 1335 } 1336 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1337 } 1338 1339 if (dladdr((void *)addr, &dlinfo) != 0) { 1340 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1341 } 1342 1343 return false; 1344 } 1345 1346 1347 #define MACH_MAXSYMLEN 256 1348 1349 bool os::dll_address_to_function_name(address addr, char *buf, 1350 int buflen, int *offset) { 1351 // buf is not optional, but offset is optional 1352 assert(buf != NULL, "sanity check"); 1353 1354 Dl_info dlinfo; 1355 char localbuf[MACH_MAXSYMLEN]; 1356 1357 if (dladdr((void*)addr, &dlinfo) != 0) { 1358 // see if we have a matching symbol 1359 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1360 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { 1361 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1362 } 1363 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1364 return true; 1365 } 1366 // no matching symbol so try for just file info 1367 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1368 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1369 buf, buflen, offset, dlinfo.dli_fname)) { 1370 return true; 1371 } 1372 } 1373 1374 // Handle non-dynamic manually: 1375 if (dlinfo.dli_fbase != NULL && 1376 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) { 1377 if (!Decoder::demangle(localbuf, buf, buflen)) { 1378 jio_snprintf(buf, buflen, "%s", localbuf); 1379 } 1380 return true; 1381 } 1382 } 1383 buf[0] = '\0'; 1384 if (offset != NULL) *offset = -1; 1385 return false; 1386 } 1387 1388 // ported from solaris version 1389 bool os::dll_address_to_library_name(address addr, char* buf, 1390 int buflen, int* offset) { 1391 // buf is not optional, but offset is optional 1392 assert(buf != NULL, "sanity check"); 1393 1394 Dl_info dlinfo; 1395 1396 if (dladdr((void*)addr, &dlinfo) != 0) { 1397 if (dlinfo.dli_fname != NULL) { 1398 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1399 } 1400 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1401 *offset = addr - (address)dlinfo.dli_fbase; 1402 } 1403 return true; 1404 } 1405 1406 buf[0] = '\0'; 1407 if (offset) *offset = -1; 1408 return false; 1409 } 1410 1411 // Loads .dll/.so and 1412 // in case of error it checks if .dll/.so was built for the 1413 // same architecture as Hotspot is running on 1414 1415 #ifdef __APPLE__ 1416 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1417 void * result= ::dlopen(filename, RTLD_LAZY); 1418 if (result != NULL) { 1419 // Successful loading 1420 return result; 1421 } 1422 1423 // Read system error message into ebuf 1424 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1425 ebuf[ebuflen-1]='\0'; 1426 1427 return NULL; 1428 } 1429 #else 1430 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1431 void * result= ::dlopen(filename, RTLD_LAZY); 1432 if (result != NULL) { 1433 // Successful loading 1434 return result; 1435 } 1436 1437 Elf32_Ehdr elf_head; 1438 1439 // Read system error message into ebuf 1440 // It may or may not be overwritten below 1441 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1442 ebuf[ebuflen-1]='\0'; 1443 int diag_msg_max_length=ebuflen-strlen(ebuf); 1444 char* diag_msg_buf=ebuf+strlen(ebuf); 1445 1446 if (diag_msg_max_length==0) { 1447 // No more space in ebuf for additional diagnostics message 1448 return NULL; 1449 } 1450 1451 1452 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1453 1454 if (file_descriptor < 0) { 1455 // Can't open library, report dlerror() message 1456 return NULL; 1457 } 1458 1459 bool failed_to_read_elf_head= 1460 (sizeof(elf_head)!= 1461 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1462 1463 ::close(file_descriptor); 1464 if (failed_to_read_elf_head) { 1465 // file i/o error - report dlerror() msg 1466 return NULL; 1467 } 1468 1469 typedef struct { 1470 Elf32_Half code; // Actual value as defined in elf.h 1471 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1472 char elf_class; // 32 or 64 bit 1473 char endianess; // MSB or LSB 1474 char* name; // String representation 1475 } arch_t; 1476 1477 #ifndef EM_486 1478 #define EM_486 6 /* Intel 80486 */ 1479 #endif 1480 1481 #ifndef EM_MIPS_RS3_LE 1482 #define EM_MIPS_RS3_LE 10 /* MIPS */ 1483 #endif 1484 1485 #ifndef EM_PPC64 1486 #define EM_PPC64 21 /* PowerPC64 */ 1487 #endif 1488 1489 #ifndef EM_S390 1490 #define EM_S390 22 /* IBM System/390 */ 1491 #endif 1492 1493 #ifndef EM_IA_64 1494 #define EM_IA_64 50 /* HP/Intel IA-64 */ 1495 #endif 1496 1497 #ifndef EM_X86_64 1498 #define EM_X86_64 62 /* AMD x86-64 */ 1499 #endif 1500 1501 static const arch_t arch_array[]={ 1502 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1503 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1504 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1505 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1506 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1507 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1508 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1509 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1510 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1511 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1512 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1513 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1514 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1515 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1516 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1517 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} 1518 }; 1519 1520 #if (defined IA32) 1521 static Elf32_Half running_arch_code=EM_386; 1522 #elif (defined AMD64) 1523 static Elf32_Half running_arch_code=EM_X86_64; 1524 #elif (defined IA64) 1525 static Elf32_Half running_arch_code=EM_IA_64; 1526 #elif (defined __sparc) && (defined _LP64) 1527 static Elf32_Half running_arch_code=EM_SPARCV9; 1528 #elif (defined __sparc) && (!defined _LP64) 1529 static Elf32_Half running_arch_code=EM_SPARC; 1530 #elif (defined __powerpc64__) 1531 static Elf32_Half running_arch_code=EM_PPC64; 1532 #elif (defined __powerpc__) 1533 static Elf32_Half running_arch_code=EM_PPC; 1534 #elif (defined ARM) 1535 static Elf32_Half running_arch_code=EM_ARM; 1536 #elif (defined S390) 1537 static Elf32_Half running_arch_code=EM_S390; 1538 #elif (defined ALPHA) 1539 static Elf32_Half running_arch_code=EM_ALPHA; 1540 #elif (defined MIPSEL) 1541 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1542 #elif (defined PARISC) 1543 static Elf32_Half running_arch_code=EM_PARISC; 1544 #elif (defined MIPS) 1545 static Elf32_Half running_arch_code=EM_MIPS; 1546 #elif (defined M68K) 1547 static Elf32_Half running_arch_code=EM_68K; 1548 #else 1549 #error Method os::dll_load requires that one of following is defined:\ 1550 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K 1551 #endif 1552 1553 // Identify compatability class for VM's architecture and library's architecture 1554 // Obtain string descriptions for architectures 1555 1556 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1557 int running_arch_index=-1; 1558 1559 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1560 if (running_arch_code == arch_array[i].code) { 1561 running_arch_index = i; 1562 } 1563 if (lib_arch.code == arch_array[i].code) { 1564 lib_arch.compat_class = arch_array[i].compat_class; 1565 lib_arch.name = arch_array[i].name; 1566 } 1567 } 1568 1569 assert(running_arch_index != -1, 1570 "Didn't find running architecture code (running_arch_code) in arch_array"); 1571 if (running_arch_index == -1) { 1572 // Even though running architecture detection failed 1573 // we may still continue with reporting dlerror() message 1574 return NULL; 1575 } 1576 1577 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1578 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1579 return NULL; 1580 } 1581 1582 #ifndef S390 1583 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1584 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1585 return NULL; 1586 } 1587 #endif // !S390 1588 1589 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1590 if (lib_arch.name!=NULL) { 1591 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1592 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1593 lib_arch.name, arch_array[running_arch_index].name); 1594 } else { 1595 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1596 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1597 lib_arch.code, 1598 arch_array[running_arch_index].name); 1599 } 1600 } 1601 1602 return NULL; 1603 } 1604 #endif // !__APPLE__ 1605 1606 void* os::get_default_process_handle() { 1607 #ifdef __APPLE__ 1608 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY 1609 // to avoid finding unexpected symbols on second (or later) 1610 // loads of a library. 1611 return (void*)::dlopen(NULL, RTLD_FIRST); 1612 #else 1613 return (void*)::dlopen(NULL, RTLD_LAZY); 1614 #endif 1615 } 1616 1617 // XXX: Do we need a lock around this as per Linux? 1618 void* os::dll_lookup(void* handle, const char* name) { 1619 return dlsym(handle, name); 1620 } 1621 1622 1623 static bool _print_ascii_file(const char* filename, outputStream* st) { 1624 int fd = ::open(filename, O_RDONLY); 1625 if (fd == -1) { 1626 return false; 1627 } 1628 1629 char buf[32]; 1630 int bytes; 1631 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { 1632 st->print_raw(buf, bytes); 1633 } 1634 1635 ::close(fd); 1636 1637 return true; 1638 } 1639 1640 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) { 1641 outputStream * out = (outputStream *) param; 1642 out->print_cr(PTR_FORMAT " \t%s", base_address, name); 1643 return 0; 1644 } 1645 1646 void os::print_dll_info(outputStream *st) { 1647 st->print_cr("Dynamic libraries:"); 1648 if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) { 1649 st->print_cr("Error: Cannot print dynamic libraries."); 1650 } 1651 } 1652 1653 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1654 #ifdef RTLD_DI_LINKMAP 1655 Dl_info dli; 1656 void *handle; 1657 Link_map *map; 1658 Link_map *p; 1659 1660 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 || 1661 dli.dli_fname == NULL) { 1662 return 1; 1663 } 1664 handle = dlopen(dli.dli_fname, RTLD_LAZY); 1665 if (handle == NULL) { 1666 return 1; 1667 } 1668 dlinfo(handle, RTLD_DI_LINKMAP, &map); 1669 if (map == NULL) { 1670 dlclose(handle); 1671 return 1; 1672 } 1673 1674 while (map->l_prev != NULL) 1675 map = map->l_prev; 1676 1677 while (map != NULL) { 1678 // Value for top_address is returned as 0 since we don't have any information about module size 1679 if (callback(map->l_name, (address)map->l_addr, (address)0, param)) { 1680 dlclose(handle); 1681 return 1; 1682 } 1683 map = map->l_next; 1684 } 1685 1686 dlclose(handle); 1687 #elif defined(__APPLE__) 1688 for (uint32_t i = 1; i < _dyld_image_count(); i++) { 1689 // Value for top_address is returned as 0 since we don't have any information about module size 1690 if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) { 1691 return 1; 1692 } 1693 } 1694 return 0; 1695 #else 1696 return 1; 1697 #endif 1698 } 1699 1700 void os::print_os_info_brief(outputStream* st) { 1701 st->print("Bsd"); 1702 1703 os::Posix::print_uname_info(st); 1704 } 1705 1706 void os::print_os_info(outputStream* st) { 1707 st->print("OS:"); 1708 st->print("Bsd"); 1709 1710 os::Posix::print_uname_info(st); 1711 1712 os::Posix::print_rlimit_info(st); 1713 1714 os::Posix::print_load_average(st); 1715 } 1716 1717 void os::pd_print_cpu_info(outputStream* st) { 1718 // Nothing to do for now. 1719 } 1720 1721 void os::print_memory_info(outputStream* st) { 1722 1723 st->print("Memory:"); 1724 st->print(" %dk page", os::vm_page_size()>>10); 1725 1726 st->print(", physical " UINT64_FORMAT "k", 1727 os::physical_memory() >> 10); 1728 st->print("(" UINT64_FORMAT "k free)", 1729 os::available_memory() >> 10); 1730 st->cr(); 1731 1732 // meminfo 1733 st->print("\n/proc/meminfo:\n"); 1734 _print_ascii_file("/proc/meminfo", st); 1735 st->cr(); 1736 } 1737 1738 void os::print_siginfo(outputStream* st, void* siginfo) { 1739 const siginfo_t* si = (const siginfo_t*)siginfo; 1740 1741 os::Posix::print_siginfo_brief(st, si); 1742 1743 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && 1744 UseSharedSpaces) { 1745 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1746 if (mapinfo->is_in_shared_space(si->si_addr)) { 1747 st->print("\n\nError accessing class data sharing archive." \ 1748 " Mapped file inaccessible during execution, " \ 1749 " possible disk/network problem."); 1750 } 1751 } 1752 st->cr(); 1753 } 1754 1755 1756 static void print_signal_handler(outputStream* st, int sig, 1757 char* buf, size_t buflen); 1758 1759 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 1760 st->print_cr("Signal Handlers:"); 1761 print_signal_handler(st, SIGSEGV, buf, buflen); 1762 print_signal_handler(st, SIGBUS , buf, buflen); 1763 print_signal_handler(st, SIGFPE , buf, buflen); 1764 print_signal_handler(st, SIGPIPE, buf, buflen); 1765 print_signal_handler(st, SIGXFSZ, buf, buflen); 1766 print_signal_handler(st, SIGILL , buf, buflen); 1767 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); 1768 print_signal_handler(st, SR_signum, buf, buflen); 1769 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 1770 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 1771 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 1772 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 1773 } 1774 1775 static char saved_jvm_path[MAXPATHLEN] = {0}; 1776 1777 // Find the full path to the current module, libjvm 1778 void os::jvm_path(char *buf, jint buflen) { 1779 // Error checking. 1780 if (buflen < MAXPATHLEN) { 1781 assert(false, "must use a large-enough buffer"); 1782 buf[0] = '\0'; 1783 return; 1784 } 1785 // Lazy resolve the path to current module. 1786 if (saved_jvm_path[0] != 0) { 1787 strcpy(buf, saved_jvm_path); 1788 return; 1789 } 1790 1791 char dli_fname[MAXPATHLEN]; 1792 bool ret = dll_address_to_library_name( 1793 CAST_FROM_FN_PTR(address, os::jvm_path), 1794 dli_fname, sizeof(dli_fname), NULL); 1795 assert(ret, "cannot locate libjvm"); 1796 char *rp = NULL; 1797 if (ret && dli_fname[0] != '\0') { 1798 rp = realpath(dli_fname, buf); 1799 } 1800 if (rp == NULL) { 1801 return; 1802 } 1803 1804 if (Arguments::sun_java_launcher_is_altjvm()) { 1805 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 1806 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so" 1807 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/" 1808 // appears at the right place in the string, then assume we are 1809 // installed in a JDK and we're done. Otherwise, check for a 1810 // JAVA_HOME environment variable and construct a path to the JVM 1811 // being overridden. 1812 1813 const char *p = buf + strlen(buf) - 1; 1814 for (int count = 0; p > buf && count < 5; ++count) { 1815 for (--p; p > buf && *p != '/'; --p) 1816 /* empty */ ; 1817 } 1818 1819 if (strncmp(p, "/jre/lib/", 9) != 0) { 1820 // Look for JAVA_HOME in the environment. 1821 char* java_home_var = ::getenv("JAVA_HOME"); 1822 if (java_home_var != NULL && java_home_var[0] != 0) { 1823 char* jrelib_p; 1824 int len; 1825 1826 // Check the current module name "libjvm" 1827 p = strrchr(buf, '/'); 1828 assert(strstr(p, "/libjvm") == p, "invalid library name"); 1829 1830 rp = realpath(java_home_var, buf); 1831 if (rp == NULL) { 1832 return; 1833 } 1834 1835 // determine if this is a legacy image or modules image 1836 // modules image doesn't have "jre" subdirectory 1837 len = strlen(buf); 1838 assert(len < buflen, "Ran out of buffer space"); 1839 jrelib_p = buf + len; 1840 1841 // Add the appropriate library subdir 1842 snprintf(jrelib_p, buflen-len, "/jre/lib"); 1843 if (0 != access(buf, F_OK)) { 1844 snprintf(jrelib_p, buflen-len, "/lib"); 1845 } 1846 1847 // Add the appropriate client or server subdir 1848 len = strlen(buf); 1849 jrelib_p = buf + len; 1850 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT); 1851 if (0 != access(buf, F_OK)) { 1852 snprintf(jrelib_p, buflen-len, "%s", ""); 1853 } 1854 1855 // If the path exists within JAVA_HOME, add the JVM library name 1856 // to complete the path to JVM being overridden. Otherwise fallback 1857 // to the path to the current library. 1858 if (0 == access(buf, F_OK)) { 1859 // Use current module name "libjvm" 1860 len = strlen(buf); 1861 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX); 1862 } else { 1863 // Fall back to path of current library 1864 rp = realpath(dli_fname, buf); 1865 if (rp == NULL) { 1866 return; 1867 } 1868 } 1869 } 1870 } 1871 } 1872 1873 strncpy(saved_jvm_path, buf, MAXPATHLEN); 1874 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 1875 } 1876 1877 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 1878 // no prefix required, not even "_" 1879 } 1880 1881 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 1882 // no suffix required 1883 } 1884 1885 //////////////////////////////////////////////////////////////////////////////// 1886 // sun.misc.Signal support 1887 1888 static volatile jint sigint_count = 0; 1889 1890 static void UserHandler(int sig, void *siginfo, void *context) { 1891 // 4511530 - sem_post is serialized and handled by the manager thread. When 1892 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 1893 // don't want to flood the manager thread with sem_post requests. 1894 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 1895 return; 1896 } 1897 1898 // Ctrl-C is pressed during error reporting, likely because the error 1899 // handler fails to abort. Let VM die immediately. 1900 if (sig == SIGINT && is_error_reported()) { 1901 os::die(); 1902 } 1903 1904 os::signal_notify(sig); 1905 } 1906 1907 void* os::user_handler() { 1908 return CAST_FROM_FN_PTR(void*, UserHandler); 1909 } 1910 1911 extern "C" { 1912 typedef void (*sa_handler_t)(int); 1913 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1914 } 1915 1916 void* os::signal(int signal_number, void* handler) { 1917 struct sigaction sigAct, oldSigAct; 1918 1919 sigfillset(&(sigAct.sa_mask)); 1920 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 1921 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 1922 1923 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 1924 // -1 means registration failed 1925 return (void *)-1; 1926 } 1927 1928 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 1929 } 1930 1931 void os::signal_raise(int signal_number) { 1932 ::raise(signal_number); 1933 } 1934 1935 // The following code is moved from os.cpp for making this 1936 // code platform specific, which it is by its very nature. 1937 1938 // Will be modified when max signal is changed to be dynamic 1939 int os::sigexitnum_pd() { 1940 return NSIG; 1941 } 1942 1943 // a counter for each possible signal value 1944 static volatile jint pending_signals[NSIG+1] = { 0 }; 1945 1946 // Bsd(POSIX) specific hand shaking semaphore. 1947 #ifdef __APPLE__ 1948 typedef semaphore_t os_semaphore_t; 1949 1950 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) 1951 #define SEM_WAIT(sem) semaphore_wait(sem) 1952 #define SEM_POST(sem) semaphore_signal(sem) 1953 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem) 1954 #else 1955 typedef sem_t os_semaphore_t; 1956 1957 #define SEM_INIT(sem, value) sem_init(&sem, 0, value) 1958 #define SEM_WAIT(sem) sem_wait(&sem) 1959 #define SEM_POST(sem) sem_post(&sem) 1960 #define SEM_DESTROY(sem) sem_destroy(&sem) 1961 #endif 1962 1963 class Semaphore : public StackObj { 1964 public: 1965 Semaphore(); 1966 ~Semaphore(); 1967 void signal(); 1968 void wait(); 1969 bool trywait(); 1970 bool timedwait(unsigned int sec, int nsec); 1971 private: 1972 jlong currenttime() const; 1973 os_semaphore_t _semaphore; 1974 }; 1975 1976 Semaphore::Semaphore() : _semaphore(0) { 1977 SEM_INIT(_semaphore, 0); 1978 } 1979 1980 Semaphore::~Semaphore() { 1981 SEM_DESTROY(_semaphore); 1982 } 1983 1984 void Semaphore::signal() { 1985 SEM_POST(_semaphore); 1986 } 1987 1988 void Semaphore::wait() { 1989 SEM_WAIT(_semaphore); 1990 } 1991 1992 jlong Semaphore::currenttime() const { 1993 struct timeval tv; 1994 gettimeofday(&tv, NULL); 1995 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000); 1996 } 1997 1998 #ifdef __APPLE__ 1999 bool Semaphore::trywait() { 2000 return timedwait(0, 0); 2001 } 2002 2003 bool Semaphore::timedwait(unsigned int sec, int nsec) { 2004 kern_return_t kr = KERN_ABORTED; 2005 mach_timespec_t waitspec; 2006 waitspec.tv_sec = sec; 2007 waitspec.tv_nsec = nsec; 2008 2009 jlong starttime = currenttime(); 2010 2011 kr = semaphore_timedwait(_semaphore, waitspec); 2012 while (kr == KERN_ABORTED) { 2013 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec; 2014 2015 jlong current = currenttime(); 2016 jlong passedtime = current - starttime; 2017 2018 if (passedtime >= totalwait) { 2019 waitspec.tv_sec = 0; 2020 waitspec.tv_nsec = 0; 2021 } else { 2022 jlong waittime = totalwait - (current - starttime); 2023 waitspec.tv_sec = waittime / NANOSECS_PER_SEC; 2024 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC; 2025 } 2026 2027 kr = semaphore_timedwait(_semaphore, waitspec); 2028 } 2029 2030 return kr == KERN_SUCCESS; 2031 } 2032 2033 #else 2034 2035 bool Semaphore::trywait() { 2036 return sem_trywait(&_semaphore) == 0; 2037 } 2038 2039 bool Semaphore::timedwait(unsigned int sec, int nsec) { 2040 struct timespec ts; 2041 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec); 2042 2043 while (1) { 2044 int result = sem_timedwait(&_semaphore, &ts); 2045 if (result == 0) { 2046 return true; 2047 } else if (errno == EINTR) { 2048 continue; 2049 } else if (errno == ETIMEDOUT) { 2050 return false; 2051 } else { 2052 return false; 2053 } 2054 } 2055 } 2056 2057 #endif // __APPLE__ 2058 2059 static os_semaphore_t sig_sem; 2060 static Semaphore sr_semaphore; 2061 2062 void os::signal_init_pd() { 2063 // Initialize signal structures 2064 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2065 2066 // Initialize signal semaphore 2067 ::SEM_INIT(sig_sem, 0); 2068 } 2069 2070 void os::signal_notify(int sig) { 2071 Atomic::inc(&pending_signals[sig]); 2072 ::SEM_POST(sig_sem); 2073 } 2074 2075 static int check_pending_signals(bool wait) { 2076 Atomic::store(0, &sigint_count); 2077 for (;;) { 2078 for (int i = 0; i < NSIG + 1; i++) { 2079 jint n = pending_signals[i]; 2080 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2081 return i; 2082 } 2083 } 2084 if (!wait) { 2085 return -1; 2086 } 2087 JavaThread *thread = JavaThread::current(); 2088 ThreadBlockInVM tbivm(thread); 2089 2090 bool threadIsSuspended; 2091 do { 2092 thread->set_suspend_equivalent(); 2093 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2094 ::SEM_WAIT(sig_sem); 2095 2096 // were we externally suspended while we were waiting? 2097 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2098 if (threadIsSuspended) { 2099 // The semaphore has been incremented, but while we were waiting 2100 // another thread suspended us. We don't want to continue running 2101 // while suspended because that would surprise the thread that 2102 // suspended us. 2103 ::SEM_POST(sig_sem); 2104 2105 thread->java_suspend_self(); 2106 } 2107 } while (threadIsSuspended); 2108 } 2109 } 2110 2111 int os::signal_lookup() { 2112 return check_pending_signals(false); 2113 } 2114 2115 int os::signal_wait() { 2116 return check_pending_signals(true); 2117 } 2118 2119 //////////////////////////////////////////////////////////////////////////////// 2120 // Virtual Memory 2121 2122 int os::vm_page_size() { 2123 // Seems redundant as all get out 2124 assert(os::Bsd::page_size() != -1, "must call os::init"); 2125 return os::Bsd::page_size(); 2126 } 2127 2128 // Solaris allocates memory by pages. 2129 int os::vm_allocation_granularity() { 2130 assert(os::Bsd::page_size() != -1, "must call os::init"); 2131 return os::Bsd::page_size(); 2132 } 2133 2134 // Rationale behind this function: 2135 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2136 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2137 // samples for JITted code. Here we create private executable mapping over the code cache 2138 // and then we can use standard (well, almost, as mapping can change) way to provide 2139 // info for the reporting script by storing timestamp and location of symbol 2140 void bsd_wrap_code(char* base, size_t size) { 2141 static volatile jint cnt = 0; 2142 2143 if (!UseOprofile) { 2144 return; 2145 } 2146 2147 char buf[PATH_MAX + 1]; 2148 int num = Atomic::add(1, &cnt); 2149 2150 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", 2151 os::get_temp_directory(), os::current_process_id(), num); 2152 unlink(buf); 2153 2154 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2155 2156 if (fd != -1) { 2157 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2158 if (rv != (off_t)-1) { 2159 if (::write(fd, "", 1) == 1) { 2160 mmap(base, size, 2161 PROT_READ|PROT_WRITE|PROT_EXEC, 2162 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2163 } 2164 } 2165 ::close(fd); 2166 unlink(buf); 2167 } 2168 } 2169 2170 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2171 int err) { 2172 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2173 ", %d) failed; error='%s' (errno=%d)", addr, size, exec, 2174 strerror(err), err); 2175 } 2176 2177 // NOTE: Bsd kernel does not really reserve the pages for us. 2178 // All it does is to check if there are enough free pages 2179 // left at the time of mmap(). This could be a potential 2180 // problem. 2181 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2182 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2183 #ifdef __OpenBSD__ 2184 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2185 if (::mprotect(addr, size, prot) == 0) { 2186 return true; 2187 } 2188 #else 2189 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2190 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2191 if (res != (uintptr_t) MAP_FAILED) { 2192 return true; 2193 } 2194 #endif 2195 2196 // Warn about any commit errors we see in non-product builds just 2197 // in case mmap() doesn't work as described on the man page. 2198 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);) 2199 2200 return false; 2201 } 2202 2203 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2204 bool exec) { 2205 // alignment_hint is ignored on this OS 2206 return pd_commit_memory(addr, size, exec); 2207 } 2208 2209 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2210 const char* mesg) { 2211 assert(mesg != NULL, "mesg must be specified"); 2212 if (!pd_commit_memory(addr, size, exec)) { 2213 // add extra info in product mode for vm_exit_out_of_memory(): 2214 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);) 2215 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg); 2216 } 2217 } 2218 2219 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2220 size_t alignment_hint, bool exec, 2221 const char* mesg) { 2222 // alignment_hint is ignored on this OS 2223 pd_commit_memory_or_exit(addr, size, exec, mesg); 2224 } 2225 2226 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2227 } 2228 2229 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2230 ::madvise(addr, bytes, MADV_DONTNEED); 2231 } 2232 2233 void os::numa_make_global(char *addr, size_t bytes) { 2234 } 2235 2236 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2237 } 2238 2239 bool os::numa_topology_changed() { return false; } 2240 2241 size_t os::numa_get_groups_num() { 2242 return 1; 2243 } 2244 2245 int os::numa_get_group_id() { 2246 return 0; 2247 } 2248 2249 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2250 if (size > 0) { 2251 ids[0] = 0; 2252 return 1; 2253 } 2254 return 0; 2255 } 2256 2257 bool os::get_page_info(char *start, page_info* info) { 2258 return false; 2259 } 2260 2261 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { 2262 return end; 2263 } 2264 2265 2266 bool os::pd_uncommit_memory(char* addr, size_t size) { 2267 #ifdef __OpenBSD__ 2268 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2269 return ::mprotect(addr, size, PROT_NONE) == 0; 2270 #else 2271 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2272 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2273 return res != (uintptr_t) MAP_FAILED; 2274 #endif 2275 } 2276 2277 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2278 return os::commit_memory(addr, size, !ExecMem); 2279 } 2280 2281 // If this is a growable mapping, remove the guard pages entirely by 2282 // munmap()ping them. If not, just call uncommit_memory(). 2283 bool os::remove_stack_guard_pages(char* addr, size_t size) { 2284 return os::uncommit_memory(addr, size); 2285 } 2286 2287 static address _highest_vm_reserved_address = NULL; 2288 2289 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 2290 // at 'requested_addr'. If there are existing memory mappings at the same 2291 // location, however, they will be overwritten. If 'fixed' is false, 2292 // 'requested_addr' is only treated as a hint, the return value may or 2293 // may not start from the requested address. Unlike Bsd mmap(), this 2294 // function returns NULL to indicate failure. 2295 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 2296 char * addr; 2297 int flags; 2298 2299 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 2300 if (fixed) { 2301 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); 2302 flags |= MAP_FIXED; 2303 } 2304 2305 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 2306 // touch an uncommitted page. Otherwise, the read/write might 2307 // succeed if we have enough swap space to back the physical page. 2308 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 2309 flags, -1, 0); 2310 2311 if (addr != MAP_FAILED) { 2312 // anon_mmap() should only get called during VM initialization, 2313 // don't need lock (actually we can skip locking even it can be called 2314 // from multiple threads, because _highest_vm_reserved_address is just a 2315 // hint about the upper limit of non-stack memory regions.) 2316 if ((address)addr + bytes > _highest_vm_reserved_address) { 2317 _highest_vm_reserved_address = (address)addr + bytes; 2318 } 2319 } 2320 2321 return addr == MAP_FAILED ? NULL : addr; 2322 } 2323 2324 // Don't update _highest_vm_reserved_address, because there might be memory 2325 // regions above addr + size. If so, releasing a memory region only creates 2326 // a hole in the address space, it doesn't help prevent heap-stack collision. 2327 // 2328 static int anon_munmap(char * addr, size_t size) { 2329 return ::munmap(addr, size) == 0; 2330 } 2331 2332 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 2333 size_t alignment_hint) { 2334 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 2335 } 2336 2337 bool os::pd_release_memory(char* addr, size_t size) { 2338 return anon_munmap(addr, size); 2339 } 2340 2341 static bool bsd_mprotect(char* addr, size_t size, int prot) { 2342 // Bsd wants the mprotect address argument to be page aligned. 2343 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); 2344 2345 // According to SUSv3, mprotect() should only be used with mappings 2346 // established by mmap(), and mmap() always maps whole pages. Unaligned 2347 // 'addr' likely indicates problem in the VM (e.g. trying to change 2348 // protection of malloc'ed or statically allocated memory). Check the 2349 // caller if you hit this assert. 2350 assert(addr == bottom, "sanity check"); 2351 2352 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); 2353 return ::mprotect(bottom, size, prot) == 0; 2354 } 2355 2356 // Set protections specified 2357 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 2358 bool is_committed) { 2359 unsigned int p = 0; 2360 switch (prot) { 2361 case MEM_PROT_NONE: p = PROT_NONE; break; 2362 case MEM_PROT_READ: p = PROT_READ; break; 2363 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 2364 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 2365 default: 2366 ShouldNotReachHere(); 2367 } 2368 // is_committed is unused. 2369 return bsd_mprotect(addr, bytes, p); 2370 } 2371 2372 bool os::guard_memory(char* addr, size_t size) { 2373 return bsd_mprotect(addr, size, PROT_NONE); 2374 } 2375 2376 bool os::unguard_memory(char* addr, size_t size) { 2377 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); 2378 } 2379 2380 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { 2381 return false; 2382 } 2383 2384 // Large page support 2385 2386 static size_t _large_page_size = 0; 2387 2388 void os::large_page_init() { 2389 } 2390 2391 2392 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) { 2393 fatal("This code is not used or maintained."); 2394 2395 // "exec" is passed in but not used. Creating the shared image for 2396 // the code cache doesn't have an SHM_X executable permission to check. 2397 assert(UseLargePages && UseSHM, "only for SHM large pages"); 2398 2399 key_t key = IPC_PRIVATE; 2400 char *addr; 2401 2402 bool warn_on_failure = UseLargePages && 2403 (!FLAG_IS_DEFAULT(UseLargePages) || 2404 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 2405 2406 // Create a large shared memory region to attach to based on size. 2407 // Currently, size is the total size of the heap 2408 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); 2409 if (shmid == -1) { 2410 // Possible reasons for shmget failure: 2411 // 1. shmmax is too small for Java heap. 2412 // > check shmmax value: cat /proc/sys/kernel/shmmax 2413 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 2414 // 2. not enough large page memory. 2415 // > check available large pages: cat /proc/meminfo 2416 // > increase amount of large pages: 2417 // echo new_value > /proc/sys/vm/nr_hugepages 2418 // Note 1: different Bsd may use different name for this property, 2419 // e.g. on Redhat AS-3 it is "hugetlb_pool". 2420 // Note 2: it's possible there's enough physical memory available but 2421 // they are so fragmented after a long run that they can't 2422 // coalesce into large pages. Try to reserve large pages when 2423 // the system is still "fresh". 2424 if (warn_on_failure) { 2425 warning("Failed to reserve shared memory (errno = %d).", errno); 2426 } 2427 return NULL; 2428 } 2429 2430 // attach to the region 2431 addr = (char*)shmat(shmid, req_addr, 0); 2432 int err = errno; 2433 2434 // Remove shmid. If shmat() is successful, the actual shared memory segment 2435 // will be deleted when it's detached by shmdt() or when the process 2436 // terminates. If shmat() is not successful this will remove the shared 2437 // segment immediately. 2438 shmctl(shmid, IPC_RMID, NULL); 2439 2440 if ((intptr_t)addr == -1) { 2441 if (warn_on_failure) { 2442 warning("Failed to attach shared memory (errno = %d).", err); 2443 } 2444 return NULL; 2445 } 2446 2447 // The memory is committed 2448 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 2449 2450 return addr; 2451 } 2452 2453 bool os::release_memory_special(char* base, size_t bytes) { 2454 if (MemTracker::tracking_level() > NMT_minimal) { 2455 Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 2456 // detaching the SHM segment will also delete it, see reserve_memory_special() 2457 int rslt = shmdt(base); 2458 if (rslt == 0) { 2459 tkr.record((address)base, bytes); 2460 return true; 2461 } else { 2462 return false; 2463 } 2464 } else { 2465 return shmdt(base) == 0; 2466 } 2467 } 2468 2469 size_t os::large_page_size() { 2470 return _large_page_size; 2471 } 2472 2473 // HugeTLBFS allows application to commit large page memory on demand; 2474 // with SysV SHM the entire memory region must be allocated as shared 2475 // memory. 2476 bool os::can_commit_large_page_memory() { 2477 return UseHugeTLBFS; 2478 } 2479 2480 bool os::can_execute_large_page_memory() { 2481 return UseHugeTLBFS; 2482 } 2483 2484 // Reserve memory at an arbitrary address, only if that area is 2485 // available (and not reserved for something else). 2486 2487 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 2488 const int max_tries = 10; 2489 char* base[max_tries]; 2490 size_t size[max_tries]; 2491 const size_t gap = 0x000000; 2492 2493 // Assert only that the size is a multiple of the page size, since 2494 // that's all that mmap requires, and since that's all we really know 2495 // about at this low abstraction level. If we need higher alignment, 2496 // we can either pass an alignment to this method or verify alignment 2497 // in one of the methods further up the call chain. See bug 5044738. 2498 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 2499 2500 // Repeatedly allocate blocks until the block is allocated at the 2501 // right spot. Give up after max_tries. Note that reserve_memory() will 2502 // automatically update _highest_vm_reserved_address if the call is 2503 // successful. The variable tracks the highest memory address every reserved 2504 // by JVM. It is used to detect heap-stack collision if running with 2505 // fixed-stack BsdThreads. Because here we may attempt to reserve more 2506 // space than needed, it could confuse the collision detecting code. To 2507 // solve the problem, save current _highest_vm_reserved_address and 2508 // calculate the correct value before return. 2509 address old_highest = _highest_vm_reserved_address; 2510 2511 // Bsd mmap allows caller to pass an address as hint; give it a try first, 2512 // if kernel honors the hint then we can return immediately. 2513 char * addr = anon_mmap(requested_addr, bytes, false); 2514 if (addr == requested_addr) { 2515 return requested_addr; 2516 } 2517 2518 if (addr != NULL) { 2519 // mmap() is successful but it fails to reserve at the requested address 2520 anon_munmap(addr, bytes); 2521 } 2522 2523 int i; 2524 for (i = 0; i < max_tries; ++i) { 2525 base[i] = reserve_memory(bytes); 2526 2527 if (base[i] != NULL) { 2528 // Is this the block we wanted? 2529 if (base[i] == requested_addr) { 2530 size[i] = bytes; 2531 break; 2532 } 2533 2534 // Does this overlap the block we wanted? Give back the overlapped 2535 // parts and try again. 2536 2537 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; 2538 if (top_overlap >= 0 && top_overlap < bytes) { 2539 unmap_memory(base[i], top_overlap); 2540 base[i] += top_overlap; 2541 size[i] = bytes - top_overlap; 2542 } else { 2543 size_t bottom_overlap = base[i] + bytes - requested_addr; 2544 if (bottom_overlap >= 0 && bottom_overlap < bytes) { 2545 unmap_memory(requested_addr, bottom_overlap); 2546 size[i] = bytes - bottom_overlap; 2547 } else { 2548 size[i] = bytes; 2549 } 2550 } 2551 } 2552 } 2553 2554 // Give back the unused reserved pieces. 2555 2556 for (int j = 0; j < i; ++j) { 2557 if (base[j] != NULL) { 2558 unmap_memory(base[j], size[j]); 2559 } 2560 } 2561 2562 if (i < max_tries) { 2563 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); 2564 return requested_addr; 2565 } else { 2566 _highest_vm_reserved_address = old_highest; 2567 return NULL; 2568 } 2569 } 2570 2571 size_t os::read(int fd, void *buf, unsigned int nBytes) { 2572 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); 2573 } 2574 2575 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 2576 RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset)); 2577 } 2578 2579 void os::naked_short_sleep(jlong ms) { 2580 struct timespec req; 2581 2582 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 2583 req.tv_sec = 0; 2584 if (ms > 0) { 2585 req.tv_nsec = (ms % 1000) * 1000000; 2586 } else { 2587 req.tv_nsec = 1; 2588 } 2589 2590 nanosleep(&req, NULL); 2591 2592 return; 2593 } 2594 2595 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 2596 void os::infinite_sleep() { 2597 while (true) { // sleep forever ... 2598 ::sleep(100); // ... 100 seconds at a time 2599 } 2600 } 2601 2602 // Used to convert frequent JVM_Yield() to nops 2603 bool os::dont_yield() { 2604 return DontYieldALot; 2605 } 2606 2607 void os::naked_yield() { 2608 sched_yield(); 2609 } 2610 2611 //////////////////////////////////////////////////////////////////////////////// 2612 // thread priority support 2613 2614 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER 2615 // only supports dynamic priority, static priority must be zero. For real-time 2616 // applications, Bsd supports SCHED_RR which allows static priority (1-99). 2617 // However, for large multi-threaded applications, SCHED_RR is not only slower 2618 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 2619 // of 5 runs - Sep 2005). 2620 // 2621 // The following code actually changes the niceness of kernel-thread/LWP. It 2622 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 2623 // not the entire user process, and user level threads are 1:1 mapped to kernel 2624 // threads. It has always been the case, but could change in the future. For 2625 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 2626 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 2627 2628 #if !defined(__APPLE__) 2629 int os::java_to_os_priority[CriticalPriority + 1] = { 2630 19, // 0 Entry should never be used 2631 2632 0, // 1 MinPriority 2633 3, // 2 2634 6, // 3 2635 2636 10, // 4 2637 15, // 5 NormPriority 2638 18, // 6 2639 2640 21, // 7 2641 25, // 8 2642 28, // 9 NearMaxPriority 2643 2644 31, // 10 MaxPriority 2645 2646 31 // 11 CriticalPriority 2647 }; 2648 #else 2649 // Using Mach high-level priority assignments 2650 int os::java_to_os_priority[CriticalPriority + 1] = { 2651 0, // 0 Entry should never be used (MINPRI_USER) 2652 2653 27, // 1 MinPriority 2654 28, // 2 2655 29, // 3 2656 2657 30, // 4 2658 31, // 5 NormPriority (BASEPRI_DEFAULT) 2659 32, // 6 2660 2661 33, // 7 2662 34, // 8 2663 35, // 9 NearMaxPriority 2664 2665 36, // 10 MaxPriority 2666 2667 36 // 11 CriticalPriority 2668 }; 2669 #endif 2670 2671 static int prio_init() { 2672 if (ThreadPriorityPolicy == 1) { 2673 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 2674 // if effective uid is not root. Perhaps, a more elegant way of doing 2675 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 2676 if (geteuid() != 0) { 2677 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 2678 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); 2679 } 2680 ThreadPriorityPolicy = 0; 2681 } 2682 } 2683 if (UseCriticalJavaThreadPriority) { 2684 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 2685 } 2686 return 0; 2687 } 2688 2689 OSReturn os::set_native_priority(Thread* thread, int newpri) { 2690 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 2691 2692 #ifdef __OpenBSD__ 2693 // OpenBSD pthread_setprio starves low priority threads 2694 return OS_OK; 2695 #elif defined(__FreeBSD__) 2696 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); 2697 #elif defined(__APPLE__) || defined(__NetBSD__) 2698 struct sched_param sp; 2699 int policy; 2700 pthread_t self = pthread_self(); 2701 2702 if (pthread_getschedparam(self, &policy, &sp) != 0) { 2703 return OS_ERR; 2704 } 2705 2706 sp.sched_priority = newpri; 2707 if (pthread_setschedparam(self, policy, &sp) != 0) { 2708 return OS_ERR; 2709 } 2710 2711 return OS_OK; 2712 #else 2713 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 2714 return (ret == 0) ? OS_OK : OS_ERR; 2715 #endif 2716 } 2717 2718 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { 2719 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 2720 *priority_ptr = java_to_os_priority[NormPriority]; 2721 return OS_OK; 2722 } 2723 2724 errno = 0; 2725 #if defined(__OpenBSD__) || defined(__FreeBSD__) 2726 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); 2727 #elif defined(__APPLE__) || defined(__NetBSD__) 2728 int policy; 2729 struct sched_param sp; 2730 2731 pthread_getschedparam(pthread_self(), &policy, &sp); 2732 *priority_ptr = sp.sched_priority; 2733 #else 2734 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 2735 #endif 2736 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 2737 } 2738 2739 // Hint to the underlying OS that a task switch would not be good. 2740 // Void return because it's a hint and can fail. 2741 void os::hint_no_preempt() {} 2742 2743 //////////////////////////////////////////////////////////////////////////////// 2744 // suspend/resume support 2745 2746 // the low-level signal-based suspend/resume support is a remnant from the 2747 // old VM-suspension that used to be for java-suspension, safepoints etc, 2748 // within hotspot. Now there is a single use-case for this: 2749 // - calling get_thread_pc() on the VMThread by the flat-profiler task 2750 // that runs in the watcher thread. 2751 // The remaining code is greatly simplified from the more general suspension 2752 // code that used to be used. 2753 // 2754 // The protocol is quite simple: 2755 // - suspend: 2756 // - sends a signal to the target thread 2757 // - polls the suspend state of the osthread using a yield loop 2758 // - target thread signal handler (SR_handler) sets suspend state 2759 // and blocks in sigsuspend until continued 2760 // - resume: 2761 // - sets target osthread state to continue 2762 // - sends signal to end the sigsuspend loop in the SR_handler 2763 // 2764 // Note that the SR_lock plays no role in this suspend/resume protocol. 2765 2766 static void resume_clear_context(OSThread *osthread) { 2767 osthread->set_ucontext(NULL); 2768 osthread->set_siginfo(NULL); 2769 } 2770 2771 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { 2772 osthread->set_ucontext(context); 2773 osthread->set_siginfo(siginfo); 2774 } 2775 2776 // Handler function invoked when a thread's execution is suspended or 2777 // resumed. We have to be careful that only async-safe functions are 2778 // called here (Note: most pthread functions are not async safe and 2779 // should be avoided.) 2780 // 2781 // Note: sigwait() is a more natural fit than sigsuspend() from an 2782 // interface point of view, but sigwait() prevents the signal hander 2783 // from being run. libpthread would get very confused by not having 2784 // its signal handlers run and prevents sigwait()'s use with the 2785 // mutex granting granting signal. 2786 // 2787 // Currently only ever called on the VMThread or JavaThread 2788 // 2789 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 2790 // Save and restore errno to avoid confusing native code with EINTR 2791 // after sigsuspend. 2792 int old_errno = errno; 2793 2794 Thread* thread = Thread::current(); 2795 OSThread* osthread = thread->osthread(); 2796 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 2797 2798 os::SuspendResume::State current = osthread->sr.state(); 2799 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 2800 suspend_save_context(osthread, siginfo, context); 2801 2802 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 2803 os::SuspendResume::State state = osthread->sr.suspended(); 2804 if (state == os::SuspendResume::SR_SUSPENDED) { 2805 sigset_t suspend_set; // signals for sigsuspend() 2806 2807 // get current set of blocked signals and unblock resume signal 2808 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 2809 sigdelset(&suspend_set, SR_signum); 2810 2811 sr_semaphore.signal(); 2812 // wait here until we are resumed 2813 while (1) { 2814 sigsuspend(&suspend_set); 2815 2816 os::SuspendResume::State result = osthread->sr.running(); 2817 if (result == os::SuspendResume::SR_RUNNING) { 2818 sr_semaphore.signal(); 2819 break; 2820 } else if (result != os::SuspendResume::SR_SUSPENDED) { 2821 ShouldNotReachHere(); 2822 } 2823 } 2824 2825 } else if (state == os::SuspendResume::SR_RUNNING) { 2826 // request was cancelled, continue 2827 } else { 2828 ShouldNotReachHere(); 2829 } 2830 2831 resume_clear_context(osthread); 2832 } else if (current == os::SuspendResume::SR_RUNNING) { 2833 // request was cancelled, continue 2834 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 2835 // ignore 2836 } else { 2837 // ignore 2838 } 2839 2840 errno = old_errno; 2841 } 2842 2843 2844 static int SR_initialize() { 2845 struct sigaction act; 2846 char *s; 2847 // Get signal number to use for suspend/resume 2848 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 2849 int sig = ::strtol(s, 0, 10); 2850 if (sig > 0 || sig < NSIG) { 2851 SR_signum = sig; 2852 } 2853 } 2854 2855 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 2856 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 2857 2858 sigemptyset(&SR_sigset); 2859 sigaddset(&SR_sigset, SR_signum); 2860 2861 // Set up signal handler for suspend/resume 2862 act.sa_flags = SA_RESTART|SA_SIGINFO; 2863 act.sa_handler = (void (*)(int)) SR_handler; 2864 2865 // SR_signum is blocked by default. 2866 // 4528190 - We also need to block pthread restart signal (32 on all 2867 // supported Bsd platforms). Note that BsdThreads need to block 2868 // this signal for all threads to work properly. So we don't have 2869 // to use hard-coded signal number when setting up the mask. 2870 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 2871 2872 if (sigaction(SR_signum, &act, 0) == -1) { 2873 return -1; 2874 } 2875 2876 // Save signal flag 2877 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); 2878 return 0; 2879 } 2880 2881 static int sr_notify(OSThread* osthread) { 2882 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2883 assert_status(status == 0, status, "pthread_kill"); 2884 return status; 2885 } 2886 2887 // "Randomly" selected value for how long we want to spin 2888 // before bailing out on suspending a thread, also how often 2889 // we send a signal to a thread we want to resume 2890 static const int RANDOMLY_LARGE_INTEGER = 1000000; 2891 static const int RANDOMLY_LARGE_INTEGER2 = 100; 2892 2893 // returns true on success and false on error - really an error is fatal 2894 // but this seems the normal response to library errors 2895 static bool do_suspend(OSThread* osthread) { 2896 assert(osthread->sr.is_running(), "thread should be running"); 2897 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 2898 2899 // mark as suspended and send signal 2900 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 2901 // failed to switch, state wasn't running? 2902 ShouldNotReachHere(); 2903 return false; 2904 } 2905 2906 if (sr_notify(osthread) != 0) { 2907 ShouldNotReachHere(); 2908 } 2909 2910 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 2911 while (true) { 2912 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2913 break; 2914 } else { 2915 // timeout 2916 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 2917 if (cancelled == os::SuspendResume::SR_RUNNING) { 2918 return false; 2919 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 2920 // make sure that we consume the signal on the semaphore as well 2921 sr_semaphore.wait(); 2922 break; 2923 } else { 2924 ShouldNotReachHere(); 2925 return false; 2926 } 2927 } 2928 } 2929 2930 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 2931 return true; 2932 } 2933 2934 static void do_resume(OSThread* osthread) { 2935 assert(osthread->sr.is_suspended(), "thread should be suspended"); 2936 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 2937 2938 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 2939 // failed to switch to WAKEUP_REQUEST 2940 ShouldNotReachHere(); 2941 return; 2942 } 2943 2944 while (true) { 2945 if (sr_notify(osthread) == 0) { 2946 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2947 if (osthread->sr.is_running()) { 2948 return; 2949 } 2950 } 2951 } else { 2952 ShouldNotReachHere(); 2953 } 2954 } 2955 2956 guarantee(osthread->sr.is_running(), "Must be running!"); 2957 } 2958 2959 /////////////////////////////////////////////////////////////////////////////////// 2960 // signal handling (except suspend/resume) 2961 2962 // This routine may be used by user applications as a "hook" to catch signals. 2963 // The user-defined signal handler must pass unrecognized signals to this 2964 // routine, and if it returns true (non-zero), then the signal handler must 2965 // return immediately. If the flag "abort_if_unrecognized" is true, then this 2966 // routine will never retun false (zero), but instead will execute a VM panic 2967 // routine kill the process. 2968 // 2969 // If this routine returns false, it is OK to call it again. This allows 2970 // the user-defined signal handler to perform checks either before or after 2971 // the VM performs its own checks. Naturally, the user code would be making 2972 // a serious error if it tried to handle an exception (such as a null check 2973 // or breakpoint) that the VM was generating for its own correct operation. 2974 // 2975 // This routine may recognize any of the following kinds of signals: 2976 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 2977 // It should be consulted by handlers for any of those signals. 2978 // 2979 // The caller of this routine must pass in the three arguments supplied 2980 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 2981 // field of the structure passed to sigaction(). This routine assumes that 2982 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 2983 // 2984 // Note that the VM will print warnings if it detects conflicting signal 2985 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 2986 // 2987 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, 2988 void* ucontext, 2989 int abort_if_unrecognized); 2990 2991 void signalHandler(int sig, siginfo_t* info, void* uc) { 2992 assert(info != NULL && uc != NULL, "it must be old kernel"); 2993 int orig_errno = errno; // Preserve errno value over signal handler. 2994 JVM_handle_bsd_signal(sig, info, uc, true); 2995 errno = orig_errno; 2996 } 2997 2998 2999 // This boolean allows users to forward their own non-matching signals 3000 // to JVM_handle_bsd_signal, harmlessly. 3001 bool os::Bsd::signal_handlers_are_installed = false; 3002 3003 // For signal-chaining 3004 struct sigaction os::Bsd::sigact[MAXSIGNUM]; 3005 unsigned int os::Bsd::sigs = 0; 3006 bool os::Bsd::libjsig_is_loaded = false; 3007 typedef struct sigaction *(*get_signal_t)(int); 3008 get_signal_t os::Bsd::get_signal_action = NULL; 3009 3010 struct sigaction* os::Bsd::get_chained_signal_action(int sig) { 3011 struct sigaction *actp = NULL; 3012 3013 if (libjsig_is_loaded) { 3014 // Retrieve the old signal handler from libjsig 3015 actp = (*get_signal_action)(sig); 3016 } 3017 if (actp == NULL) { 3018 // Retrieve the preinstalled signal handler from jvm 3019 actp = get_preinstalled_handler(sig); 3020 } 3021 3022 return actp; 3023 } 3024 3025 static bool call_chained_handler(struct sigaction *actp, int sig, 3026 siginfo_t *siginfo, void *context) { 3027 // Call the old signal handler 3028 if (actp->sa_handler == SIG_DFL) { 3029 // It's more reasonable to let jvm treat it as an unexpected exception 3030 // instead of taking the default action. 3031 return false; 3032 } else if (actp->sa_handler != SIG_IGN) { 3033 if ((actp->sa_flags & SA_NODEFER) == 0) { 3034 // automaticlly block the signal 3035 sigaddset(&(actp->sa_mask), sig); 3036 } 3037 3038 sa_handler_t hand; 3039 sa_sigaction_t sa; 3040 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 3041 // retrieve the chained handler 3042 if (siginfo_flag_set) { 3043 sa = actp->sa_sigaction; 3044 } else { 3045 hand = actp->sa_handler; 3046 } 3047 3048 if ((actp->sa_flags & SA_RESETHAND) != 0) { 3049 actp->sa_handler = SIG_DFL; 3050 } 3051 3052 // try to honor the signal mask 3053 sigset_t oset; 3054 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 3055 3056 // call into the chained handler 3057 if (siginfo_flag_set) { 3058 (*sa)(sig, siginfo, context); 3059 } else { 3060 (*hand)(sig); 3061 } 3062 3063 // restore the signal mask 3064 pthread_sigmask(SIG_SETMASK, &oset, 0); 3065 } 3066 // Tell jvm's signal handler the signal is taken care of. 3067 return true; 3068 } 3069 3070 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { 3071 bool chained = false; 3072 // signal-chaining 3073 if (UseSignalChaining) { 3074 struct sigaction *actp = get_chained_signal_action(sig); 3075 if (actp != NULL) { 3076 chained = call_chained_handler(actp, sig, siginfo, context); 3077 } 3078 } 3079 return chained; 3080 } 3081 3082 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { 3083 if ((((unsigned int)1 << sig) & sigs) != 0) { 3084 return &sigact[sig]; 3085 } 3086 return NULL; 3087 } 3088 3089 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 3090 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3091 sigact[sig] = oldAct; 3092 sigs |= (unsigned int)1 << sig; 3093 } 3094 3095 // for diagnostic 3096 int os::Bsd::sigflags[MAXSIGNUM]; 3097 3098 int os::Bsd::get_our_sigflags(int sig) { 3099 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3100 return sigflags[sig]; 3101 } 3102 3103 void os::Bsd::set_our_sigflags(int sig, int flags) { 3104 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3105 sigflags[sig] = flags; 3106 } 3107 3108 void os::Bsd::set_signal_handler(int sig, bool set_installed) { 3109 // Check for overwrite. 3110 struct sigaction oldAct; 3111 sigaction(sig, (struct sigaction*)NULL, &oldAct); 3112 3113 void* oldhand = oldAct.sa_sigaction 3114 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3115 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3116 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 3117 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 3118 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 3119 if (AllowUserSignalHandlers || !set_installed) { 3120 // Do not overwrite; user takes responsibility to forward to us. 3121 return; 3122 } else if (UseSignalChaining) { 3123 // save the old handler in jvm 3124 save_preinstalled_handler(sig, oldAct); 3125 // libjsig also interposes the sigaction() call below and saves the 3126 // old sigaction on it own. 3127 } else { 3128 fatal(err_msg("Encountered unexpected pre-existing sigaction handler " 3129 "%#lx for signal %d.", (long)oldhand, sig)); 3130 } 3131 } 3132 3133 struct sigaction sigAct; 3134 sigfillset(&(sigAct.sa_mask)); 3135 sigAct.sa_handler = SIG_DFL; 3136 if (!set_installed) { 3137 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3138 } else { 3139 sigAct.sa_sigaction = signalHandler; 3140 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3141 } 3142 #ifdef __APPLE__ 3143 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV 3144 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages" 3145 // if the signal handler declares it will handle it on alternate stack. 3146 // Notice we only declare we will handle it on alt stack, but we are not 3147 // actually going to use real alt stack - this is just a workaround. 3148 // Please see ux_exception.c, method catch_mach_exception_raise for details 3149 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c 3150 if (sig == SIGSEGV) { 3151 sigAct.sa_flags |= SA_ONSTACK; 3152 } 3153 #endif 3154 3155 // Save flags, which are set by ours 3156 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3157 sigflags[sig] = sigAct.sa_flags; 3158 3159 int ret = sigaction(sig, &sigAct, &oldAct); 3160 assert(ret == 0, "check"); 3161 3162 void* oldhand2 = oldAct.sa_sigaction 3163 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3164 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3165 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 3166 } 3167 3168 // install signal handlers for signals that HotSpot needs to 3169 // handle in order to support Java-level exception handling. 3170 3171 void os::Bsd::install_signal_handlers() { 3172 if (!signal_handlers_are_installed) { 3173 signal_handlers_are_installed = true; 3174 3175 // signal-chaining 3176 typedef void (*signal_setting_t)(); 3177 signal_setting_t begin_signal_setting = NULL; 3178 signal_setting_t end_signal_setting = NULL; 3179 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3180 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 3181 if (begin_signal_setting != NULL) { 3182 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3183 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 3184 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 3185 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 3186 libjsig_is_loaded = true; 3187 assert(UseSignalChaining, "should enable signal-chaining"); 3188 } 3189 if (libjsig_is_loaded) { 3190 // Tell libjsig jvm is setting signal handlers 3191 (*begin_signal_setting)(); 3192 } 3193 3194 set_signal_handler(SIGSEGV, true); 3195 set_signal_handler(SIGPIPE, true); 3196 set_signal_handler(SIGBUS, true); 3197 set_signal_handler(SIGILL, true); 3198 set_signal_handler(SIGFPE, true); 3199 set_signal_handler(SIGXFSZ, true); 3200 3201 #if defined(__APPLE__) 3202 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including 3203 // signals caught and handled by the JVM. To work around this, we reset the mach task 3204 // signal handler that's placed on our process by CrashReporter. This disables 3205 // CrashReporter-based reporting. 3206 // 3207 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes 3208 // on caught fatal signals. 3209 // 3210 // Additionally, gdb installs both standard BSD signal handlers, and mach exception 3211 // handlers. By replacing the existing task exception handler, we disable gdb's mach 3212 // exception handling, while leaving the standard BSD signal handlers functional. 3213 kern_return_t kr; 3214 kr = task_set_exception_ports(mach_task_self(), 3215 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, 3216 MACH_PORT_NULL, 3217 EXCEPTION_STATE_IDENTITY, 3218 MACHINE_THREAD_STATE); 3219 3220 assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); 3221 #endif 3222 3223 if (libjsig_is_loaded) { 3224 // Tell libjsig jvm finishes setting signal handlers 3225 (*end_signal_setting)(); 3226 } 3227 3228 // We don't activate signal checker if libjsig is in place, we trust ourselves 3229 // and if UserSignalHandler is installed all bets are off 3230 if (CheckJNICalls) { 3231 if (libjsig_is_loaded) { 3232 if (PrintJNIResolving) { 3233 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 3234 } 3235 check_signals = false; 3236 } 3237 if (AllowUserSignalHandlers) { 3238 if (PrintJNIResolving) { 3239 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 3240 } 3241 check_signals = false; 3242 } 3243 } 3244 } 3245 } 3246 3247 3248 ///// 3249 // glibc on Bsd platform uses non-documented flag 3250 // to indicate, that some special sort of signal 3251 // trampoline is used. 3252 // We will never set this flag, and we should 3253 // ignore this flag in our diagnostic 3254 #ifdef SIGNIFICANT_SIGNAL_MASK 3255 #undef SIGNIFICANT_SIGNAL_MASK 3256 #endif 3257 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 3258 3259 static const char* get_signal_handler_name(address handler, 3260 char* buf, int buflen) { 3261 int offset; 3262 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 3263 if (found) { 3264 // skip directory names 3265 const char *p1, *p2; 3266 p1 = buf; 3267 size_t len = strlen(os::file_separator()); 3268 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 3269 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 3270 } else { 3271 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 3272 } 3273 return buf; 3274 } 3275 3276 static void print_signal_handler(outputStream* st, int sig, 3277 char* buf, size_t buflen) { 3278 struct sigaction sa; 3279 3280 sigaction(sig, NULL, &sa); 3281 3282 // See comment for SIGNIFICANT_SIGNAL_MASK define 3283 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3284 3285 st->print("%s: ", os::exception_name(sig, buf, buflen)); 3286 3287 address handler = (sa.sa_flags & SA_SIGINFO) 3288 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 3289 : CAST_FROM_FN_PTR(address, sa.sa_handler); 3290 3291 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 3292 st->print("SIG_DFL"); 3293 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 3294 st->print("SIG_IGN"); 3295 } else { 3296 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 3297 } 3298 3299 st->print(", sa_mask[0]="); 3300 os::Posix::print_signal_set_short(st, &sa.sa_mask); 3301 3302 address rh = VMError::get_resetted_sighandler(sig); 3303 // May be, handler was resetted by VMError? 3304 if (rh != NULL) { 3305 handler = rh; 3306 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 3307 } 3308 3309 st->print(", sa_flags="); 3310 os::Posix::print_sa_flags(st, sa.sa_flags); 3311 3312 // Check: is it our handler? 3313 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 3314 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 3315 // It is our signal handler 3316 // check for flags, reset system-used one! 3317 if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3318 st->print( 3319 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 3320 os::Bsd::get_our_sigflags(sig)); 3321 } 3322 } 3323 st->cr(); 3324 } 3325 3326 3327 #define DO_SIGNAL_CHECK(sig) \ 3328 do { \ 3329 if (!sigismember(&check_signal_done, sig)) { \ 3330 os::Bsd::check_signal_handler(sig); \ 3331 } \ 3332 } while (0) 3333 3334 // This method is a periodic task to check for misbehaving JNI applications 3335 // under CheckJNI, we can add any periodic checks here 3336 3337 void os::run_periodic_checks() { 3338 3339 if (check_signals == false) return; 3340 3341 // SEGV and BUS if overridden could potentially prevent 3342 // generation of hs*.log in the event of a crash, debugging 3343 // such a case can be very challenging, so we absolutely 3344 // check the following for a good measure: 3345 DO_SIGNAL_CHECK(SIGSEGV); 3346 DO_SIGNAL_CHECK(SIGILL); 3347 DO_SIGNAL_CHECK(SIGFPE); 3348 DO_SIGNAL_CHECK(SIGBUS); 3349 DO_SIGNAL_CHECK(SIGPIPE); 3350 DO_SIGNAL_CHECK(SIGXFSZ); 3351 3352 3353 // ReduceSignalUsage allows the user to override these handlers 3354 // see comments at the very top and jvm_solaris.h 3355 if (!ReduceSignalUsage) { 3356 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 3357 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 3358 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 3359 DO_SIGNAL_CHECK(BREAK_SIGNAL); 3360 } 3361 3362 DO_SIGNAL_CHECK(SR_signum); 3363 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); 3364 } 3365 3366 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 3367 3368 static os_sigaction_t os_sigaction = NULL; 3369 3370 void os::Bsd::check_signal_handler(int sig) { 3371 char buf[O_BUFLEN]; 3372 address jvmHandler = NULL; 3373 3374 3375 struct sigaction act; 3376 if (os_sigaction == NULL) { 3377 // only trust the default sigaction, in case it has been interposed 3378 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 3379 if (os_sigaction == NULL) return; 3380 } 3381 3382 os_sigaction(sig, (struct sigaction*)NULL, &act); 3383 3384 3385 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3386 3387 address thisHandler = (act.sa_flags & SA_SIGINFO) 3388 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 3389 : CAST_FROM_FN_PTR(address, act.sa_handler); 3390 3391 3392 switch (sig) { 3393 case SIGSEGV: 3394 case SIGBUS: 3395 case SIGFPE: 3396 case SIGPIPE: 3397 case SIGILL: 3398 case SIGXFSZ: 3399 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 3400 break; 3401 3402 case SHUTDOWN1_SIGNAL: 3403 case SHUTDOWN2_SIGNAL: 3404 case SHUTDOWN3_SIGNAL: 3405 case BREAK_SIGNAL: 3406 jvmHandler = (address)user_handler(); 3407 break; 3408 3409 case INTERRUPT_SIGNAL: 3410 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); 3411 break; 3412 3413 default: 3414 if (sig == SR_signum) { 3415 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 3416 } else { 3417 return; 3418 } 3419 break; 3420 } 3421 3422 if (thisHandler != jvmHandler) { 3423 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 3424 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 3425 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 3426 // No need to check this sig any longer 3427 sigaddset(&check_signal_done, sig); 3428 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 3429 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 3430 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 3431 exception_name(sig, buf, O_BUFLEN)); 3432 } 3433 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3434 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 3435 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); 3436 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); 3437 // No need to check this sig any longer 3438 sigaddset(&check_signal_done, sig); 3439 } 3440 3441 // Dump all the signal 3442 if (sigismember(&check_signal_done, sig)) { 3443 print_signal_handlers(tty, buf, O_BUFLEN); 3444 } 3445 } 3446 3447 extern void report_error(char* file_name, int line_no, char* title, 3448 char* format, ...); 3449 3450 extern bool signal_name(int signo, char* buf, size_t len); 3451 3452 const char* os::exception_name(int exception_code, char* buf, size_t size) { 3453 if (0 < exception_code && exception_code <= SIGRTMAX) { 3454 // signal 3455 if (!signal_name(exception_code, buf, size)) { 3456 jio_snprintf(buf, size, "SIG%d", exception_code); 3457 } 3458 return buf; 3459 } else { 3460 return NULL; 3461 } 3462 } 3463 3464 // this is called _before_ the most of global arguments have been parsed 3465 void os::init(void) { 3466 char dummy; // used to get a guess on initial stack address 3467 // first_hrtime = gethrtime(); 3468 3469 // With BsdThreads the JavaMain thread pid (primordial thread) 3470 // is different than the pid of the java launcher thread. 3471 // So, on Bsd, the launcher thread pid is passed to the VM 3472 // via the sun.java.launcher.pid property. 3473 // Use this property instead of getpid() if it was correctly passed. 3474 // See bug 6351349. 3475 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); 3476 3477 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); 3478 3479 clock_tics_per_sec = CLK_TCK; 3480 3481 init_random(1234567); 3482 3483 ThreadCritical::initialize(); 3484 3485 Bsd::set_page_size(getpagesize()); 3486 if (Bsd::page_size() == -1) { 3487 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)", 3488 strerror(errno))); 3489 } 3490 init_page_sizes((size_t) Bsd::page_size()); 3491 3492 Bsd::initialize_system_info(); 3493 3494 // main_thread points to the aboriginal thread 3495 Bsd::_main_thread = pthread_self(); 3496 3497 Bsd::clock_init(); 3498 initial_time_count = javaTimeNanos(); 3499 3500 #ifdef __APPLE__ 3501 // XXXDARWIN 3502 // Work around the unaligned VM callbacks in hotspot's 3503 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on 3504 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces 3505 // alignment when doing symbol lookup. To work around this, we force early 3506 // binding of all symbols now, thus binding when alignment is known-good. 3507 _dyld_bind_fully_image_containing_address((const void *) &os::init); 3508 #endif 3509 } 3510 3511 // To install functions for atexit system call 3512 extern "C" { 3513 static void perfMemory_exit_helper() { 3514 perfMemory_exit(); 3515 } 3516 } 3517 3518 // this is called _after_ the global arguments have been parsed 3519 jint os::init_2(void) { 3520 // Allocate a single page and mark it as readable for safepoint polling 3521 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3522 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page"); 3523 3524 os::set_polling_page(polling_page); 3525 3526 #ifndef PRODUCT 3527 if (Verbose && PrintMiscellaneous) { 3528 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", 3529 (intptr_t)polling_page); 3530 } 3531 #endif 3532 3533 if (!UseMembar) { 3534 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3535 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 3536 os::set_memory_serialize_page(mem_serialize_page); 3537 3538 #ifndef PRODUCT 3539 if (Verbose && PrintMiscellaneous) { 3540 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", 3541 (intptr_t)mem_serialize_page); 3542 } 3543 #endif 3544 } 3545 3546 // initialize suspend/resume support - must do this before signal_sets_init() 3547 if (SR_initialize() != 0) { 3548 perror("SR_initialize failed"); 3549 return JNI_ERR; 3550 } 3551 3552 Bsd::signal_sets_init(); 3553 Bsd::install_signal_handlers(); 3554 3555 // Check minimum allowable stack size for thread creation and to initialize 3556 // the java system classes, including StackOverflowError - depends on page 3557 // size. Add a page for compiler2 recursion in main thread. 3558 // Add in 2*BytesPerWord times page size to account for VM stack during 3559 // class initialization depending on 32 or 64 bit VM. 3560 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, 3561 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ 3562 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); 3563 3564 size_t threadStackSizeInBytes = ThreadStackSize * K; 3565 if (threadStackSizeInBytes != 0 && 3566 threadStackSizeInBytes < os::Bsd::min_stack_allowed) { 3567 tty->print_cr("\nThe stack size specified is too small, " 3568 "Specify at least %dk", 3569 os::Bsd::min_stack_allowed/ K); 3570 return JNI_ERR; 3571 } 3572 3573 // Make the stack size a multiple of the page size so that 3574 // the yellow/red zones can be guarded. 3575 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 3576 vm_page_size())); 3577 3578 if (MaxFDLimit) { 3579 // set the number of file descriptors to max. print out error 3580 // if getrlimit/setrlimit fails but continue regardless. 3581 struct rlimit nbr_files; 3582 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 3583 if (status != 0) { 3584 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3585 perror("os::init_2 getrlimit failed"); 3586 } 3587 } else { 3588 nbr_files.rlim_cur = nbr_files.rlim_max; 3589 3590 #ifdef __APPLE__ 3591 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if 3592 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must 3593 // be used instead 3594 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); 3595 #endif 3596 3597 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 3598 if (status != 0) { 3599 if (PrintMiscellaneous && (Verbose || WizardMode)) { 3600 perror("os::init_2 setrlimit failed"); 3601 } 3602 } 3603 } 3604 } 3605 3606 // at-exit methods are called in the reverse order of their registration. 3607 // atexit functions are called on return from main or as a result of a 3608 // call to exit(3C). There can be only 32 of these functions registered 3609 // and atexit() does not set errno. 3610 3611 if (PerfAllowAtExitRegistration) { 3612 // only register atexit functions if PerfAllowAtExitRegistration is set. 3613 // atexit functions can be delayed until process exit time, which 3614 // can be problematic for embedded VM situations. Embedded VMs should 3615 // call DestroyJavaVM() to assure that VM resources are released. 3616 3617 // note: perfMemory_exit_helper atexit function may be removed in 3618 // the future if the appropriate cleanup code can be added to the 3619 // VM_Exit VMOperation's doit method. 3620 if (atexit(perfMemory_exit_helper) != 0) { 3621 warning("os::init2 atexit(perfMemory_exit_helper) failed"); 3622 } 3623 } 3624 3625 // initialize thread priority policy 3626 prio_init(); 3627 3628 #ifdef __APPLE__ 3629 // dynamically link to objective c gc registration 3630 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY); 3631 if (handleLibObjc != NULL) { 3632 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER); 3633 } 3634 #endif 3635 3636 return JNI_OK; 3637 } 3638 3639 // Mark the polling page as unreadable 3640 void os::make_polling_page_unreadable(void) { 3641 if (!guard_memory((char*)_polling_page, Bsd::page_size())) { 3642 fatal("Could not disable polling page"); 3643 } 3644 } 3645 3646 // Mark the polling page as readable 3647 void os::make_polling_page_readable(void) { 3648 if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { 3649 fatal("Could not enable polling page"); 3650 } 3651 } 3652 3653 int os::active_processor_count() { 3654 return _processor_count; 3655 } 3656 3657 void os::set_native_thread_name(const char *name) { 3658 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5 3659 // This is only supported in Snow Leopard and beyond 3660 if (name != NULL) { 3661 // Add a "Java: " prefix to the name 3662 char buf[MAXTHREADNAMESIZE]; 3663 snprintf(buf, sizeof(buf), "Java: %s", name); 3664 pthread_setname_np(buf); 3665 } 3666 #endif 3667 } 3668 3669 bool os::distribute_processes(uint length, uint* distribution) { 3670 // Not yet implemented. 3671 return false; 3672 } 3673 3674 bool os::bind_to_processor(uint processor_id) { 3675 // Not yet implemented. 3676 return false; 3677 } 3678 3679 void os::SuspendedThreadTask::internal_do_task() { 3680 if (do_suspend(_thread->osthread())) { 3681 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 3682 do_task(context); 3683 do_resume(_thread->osthread()); 3684 } 3685 } 3686 3687 /// 3688 class PcFetcher : public os::SuspendedThreadTask { 3689 public: 3690 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 3691 ExtendedPC result(); 3692 protected: 3693 void do_task(const os::SuspendedThreadTaskContext& context); 3694 private: 3695 ExtendedPC _epc; 3696 }; 3697 3698 ExtendedPC PcFetcher::result() { 3699 guarantee(is_done(), "task is not done yet."); 3700 return _epc; 3701 } 3702 3703 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 3704 Thread* thread = context.thread(); 3705 OSThread* osthread = thread->osthread(); 3706 if (osthread->ucontext() != NULL) { 3707 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext()); 3708 } else { 3709 // NULL context is unexpected, double-check this is the VMThread 3710 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 3711 } 3712 } 3713 3714 // Suspends the target using the signal mechanism and then grabs the PC before 3715 // resuming the target. Used by the flat-profiler only 3716 ExtendedPC os::get_thread_pc(Thread* thread) { 3717 // Make sure that it is called by the watcher for the VMThread 3718 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 3719 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 3720 3721 PcFetcher fetcher(thread); 3722 fetcher.run(); 3723 return fetcher.result(); 3724 } 3725 3726 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, 3727 pthread_mutex_t *_mutex, 3728 const struct timespec *_abstime) { 3729 return pthread_cond_timedwait(_cond, _mutex, _abstime); 3730 } 3731 3732 //////////////////////////////////////////////////////////////////////////////// 3733 // debug support 3734 3735 bool os::find(address addr, outputStream* st) { 3736 Dl_info dlinfo; 3737 memset(&dlinfo, 0, sizeof(dlinfo)); 3738 if (dladdr(addr, &dlinfo) != 0) { 3739 st->print(PTR_FORMAT ": ", addr); 3740 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 3741 st->print("%s+%#x", dlinfo.dli_sname, 3742 addr - (intptr_t)dlinfo.dli_saddr); 3743 } else if (dlinfo.dli_fbase != NULL) { 3744 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); 3745 } else { 3746 st->print("<absolute address>"); 3747 } 3748 if (dlinfo.dli_fname != NULL) { 3749 st->print(" in %s", dlinfo.dli_fname); 3750 } 3751 if (dlinfo.dli_fbase != NULL) { 3752 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); 3753 } 3754 st->cr(); 3755 3756 if (Verbose) { 3757 // decode some bytes around the PC 3758 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 3759 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 3760 address lowest = (address) dlinfo.dli_sname; 3761 if (!lowest) lowest = (address) dlinfo.dli_fbase; 3762 if (begin < lowest) begin = lowest; 3763 Dl_info dlinfo2; 3764 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 3765 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 3766 end = (address) dlinfo2.dli_saddr; 3767 } 3768 Disassembler::decode(begin, end, st); 3769 } 3770 return true; 3771 } 3772 return false; 3773 } 3774 3775 //////////////////////////////////////////////////////////////////////////////// 3776 // misc 3777 3778 // This does not do anything on Bsd. This is basically a hook for being 3779 // able to use structured exception handling (thread-local exception filters) 3780 // on, e.g., Win32. 3781 void os::os_exception_wrapper(java_call_t f, JavaValue* value, 3782 methodHandle* method, JavaCallArguments* args, 3783 Thread* thread) { 3784 f(value, method, args, thread); 3785 } 3786 3787 void os::print_statistics() { 3788 } 3789 3790 int os::message_box(const char* title, const char* message) { 3791 int i; 3792 fdStream err(defaultStream::error_fd()); 3793 for (i = 0; i < 78; i++) err.print_raw("="); 3794 err.cr(); 3795 err.print_raw_cr(title); 3796 for (i = 0; i < 78; i++) err.print_raw("-"); 3797 err.cr(); 3798 err.print_raw_cr(message); 3799 for (i = 0; i < 78; i++) err.print_raw("="); 3800 err.cr(); 3801 3802 char buf[16]; 3803 // Prevent process from exiting upon "read error" without consuming all CPU 3804 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 3805 3806 return buf[0] == 'y' || buf[0] == 'Y'; 3807 } 3808 3809 int os::stat(const char *path, struct stat *sbuf) { 3810 char pathbuf[MAX_PATH]; 3811 if (strlen(path) > MAX_PATH - 1) { 3812 errno = ENAMETOOLONG; 3813 return -1; 3814 } 3815 os::native_path(strcpy(pathbuf, path)); 3816 return ::stat(pathbuf, sbuf); 3817 } 3818 3819 bool os::check_heap(bool force) { 3820 return true; 3821 } 3822 3823 // Is a (classpath) directory empty? 3824 bool os::dir_is_empty(const char* path) { 3825 DIR *dir = NULL; 3826 struct dirent *ptr; 3827 3828 dir = opendir(path); 3829 if (dir == NULL) return true; 3830 3831 // Scan the directory 3832 bool result = true; 3833 char buf[sizeof(struct dirent) + MAX_PATH]; 3834 while (result && (ptr = ::readdir(dir)) != NULL) { 3835 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 3836 result = false; 3837 } 3838 } 3839 closedir(dir); 3840 return result; 3841 } 3842 3843 // This code originates from JDK's sysOpen and open64_w 3844 // from src/solaris/hpi/src/system_md.c 3845 3846 int os::open(const char *path, int oflag, int mode) { 3847 if (strlen(path) > MAX_PATH - 1) { 3848 errno = ENAMETOOLONG; 3849 return -1; 3850 } 3851 int fd; 3852 3853 fd = ::open(path, oflag, mode); 3854 if (fd == -1) return -1; 3855 3856 // If the open succeeded, the file might still be a directory 3857 { 3858 struct stat buf; 3859 int ret = ::fstat(fd, &buf); 3860 int st_mode = buf.st_mode; 3861 3862 if (ret != -1) { 3863 if ((st_mode & S_IFMT) == S_IFDIR) { 3864 errno = EISDIR; 3865 ::close(fd); 3866 return -1; 3867 } 3868 } else { 3869 ::close(fd); 3870 return -1; 3871 } 3872 } 3873 3874 // All file descriptors that are opened in the JVM and not 3875 // specifically destined for a subprocess should have the 3876 // close-on-exec flag set. If we don't set it, then careless 3rd 3877 // party native code might fork and exec without closing all 3878 // appropriate file descriptors (e.g. as we do in closeDescriptors in 3879 // UNIXProcess.c), and this in turn might: 3880 // 3881 // - cause end-of-file to fail to be detected on some file 3882 // descriptors, resulting in mysterious hangs, or 3883 // 3884 // - might cause an fopen in the subprocess to fail on a system 3885 // suffering from bug 1085341. 3886 // 3887 // (Yes, the default setting of the close-on-exec flag is a Unix 3888 // design flaw) 3889 // 3890 // See: 3891 // 1085341: 32-bit stdio routines should support file descriptors >255 3892 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 3893 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 3894 // 3895 #ifdef FD_CLOEXEC 3896 { 3897 int flags = ::fcntl(fd, F_GETFD); 3898 if (flags != -1) { 3899 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 3900 } 3901 } 3902 #endif 3903 3904 return fd; 3905 } 3906 3907 3908 // create binary file, rewriting existing file if required 3909 int os::create_binary_file(const char* path, bool rewrite_existing) { 3910 int oflags = O_WRONLY | O_CREAT; 3911 if (!rewrite_existing) { 3912 oflags |= O_EXCL; 3913 } 3914 return ::open(path, oflags, S_IREAD | S_IWRITE); 3915 } 3916 3917 // return current position of file pointer 3918 jlong os::current_file_offset(int fd) { 3919 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); 3920 } 3921 3922 // move file pointer to the specified offset 3923 jlong os::seek_to_file_offset(int fd, jlong offset) { 3924 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); 3925 } 3926 3927 // This code originates from JDK's sysAvailable 3928 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 3929 3930 int os::available(int fd, jlong *bytes) { 3931 jlong cur, end; 3932 int mode; 3933 struct stat buf; 3934 3935 if (::fstat(fd, &buf) >= 0) { 3936 mode = buf.st_mode; 3937 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 3938 // XXX: is the following call interruptible? If so, this might 3939 // need to go through the INTERRUPT_IO() wrapper as for other 3940 // blocking, interruptible calls in this file. 3941 int n; 3942 if (::ioctl(fd, FIONREAD, &n) >= 0) { 3943 *bytes = n; 3944 return 1; 3945 } 3946 } 3947 } 3948 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { 3949 return 0; 3950 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { 3951 return 0; 3952 } else if (::lseek(fd, cur, SEEK_SET) == -1) { 3953 return 0; 3954 } 3955 *bytes = end - cur; 3956 return 1; 3957 } 3958 3959 // Map a block of memory. 3960 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 3961 char *addr, size_t bytes, bool read_only, 3962 bool allow_exec) { 3963 int prot; 3964 int flags; 3965 3966 if (read_only) { 3967 prot = PROT_READ; 3968 flags = MAP_SHARED; 3969 } else { 3970 prot = PROT_READ | PROT_WRITE; 3971 flags = MAP_PRIVATE; 3972 } 3973 3974 if (allow_exec) { 3975 prot |= PROT_EXEC; 3976 } 3977 3978 if (addr != NULL) { 3979 flags |= MAP_FIXED; 3980 } 3981 3982 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 3983 fd, file_offset); 3984 if (mapped_address == MAP_FAILED) { 3985 return NULL; 3986 } 3987 return mapped_address; 3988 } 3989 3990 3991 // Remap a block of memory. 3992 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 3993 char *addr, size_t bytes, bool read_only, 3994 bool allow_exec) { 3995 // same as map_memory() on this OS 3996 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 3997 allow_exec); 3998 } 3999 4000 4001 // Unmap a block of memory. 4002 bool os::pd_unmap_memory(char* addr, size_t bytes) { 4003 return munmap(addr, bytes) == 0; 4004 } 4005 4006 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 4007 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 4008 // of a thread. 4009 // 4010 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 4011 // the fast estimate available on the platform. 4012 4013 jlong os::current_thread_cpu_time() { 4014 #ifdef __APPLE__ 4015 return os::thread_cpu_time(Thread::current(), true /* user + sys */); 4016 #else 4017 Unimplemented(); 4018 return 0; 4019 #endif 4020 } 4021 4022 jlong os::thread_cpu_time(Thread* thread) { 4023 #ifdef __APPLE__ 4024 return os::thread_cpu_time(thread, true /* user + sys */); 4025 #else 4026 Unimplemented(); 4027 return 0; 4028 #endif 4029 } 4030 4031 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 4032 #ifdef __APPLE__ 4033 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); 4034 #else 4035 Unimplemented(); 4036 return 0; 4037 #endif 4038 } 4039 4040 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 4041 #ifdef __APPLE__ 4042 struct thread_basic_info tinfo; 4043 mach_msg_type_number_t tcount = THREAD_INFO_MAX; 4044 kern_return_t kr; 4045 thread_t mach_thread; 4046 4047 mach_thread = thread->osthread()->thread_id(); 4048 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); 4049 if (kr != KERN_SUCCESS) { 4050 return -1; 4051 } 4052 4053 if (user_sys_cpu_time) { 4054 jlong nanos; 4055 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; 4056 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; 4057 return nanos; 4058 } else { 4059 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); 4060 } 4061 #else 4062 Unimplemented(); 4063 return 0; 4064 #endif 4065 } 4066 4067 4068 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4069 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4070 info_ptr->may_skip_backward = false; // elapsed time not wall time 4071 info_ptr->may_skip_forward = false; // elapsed time not wall time 4072 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4073 } 4074 4075 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4076 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4077 info_ptr->may_skip_backward = false; // elapsed time not wall time 4078 info_ptr->may_skip_forward = false; // elapsed time not wall time 4079 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4080 } 4081 4082 bool os::is_thread_cpu_time_supported() { 4083 #ifdef __APPLE__ 4084 return true; 4085 #else 4086 return false; 4087 #endif 4088 } 4089 4090 // System loadavg support. Returns -1 if load average cannot be obtained. 4091 // Bsd doesn't yet have a (official) notion of processor sets, 4092 // so just return the system wide load average. 4093 int os::loadavg(double loadavg[], int nelem) { 4094 return ::getloadavg(loadavg, nelem); 4095 } 4096 4097 void os::pause() { 4098 char filename[MAX_PATH]; 4099 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 4100 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); 4101 } else { 4102 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 4103 } 4104 4105 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 4106 if (fd != -1) { 4107 struct stat buf; 4108 ::close(fd); 4109 while (::stat(filename, &buf) == 0) { 4110 (void)::poll(NULL, 0, 100); 4111 } 4112 } else { 4113 jio_fprintf(stderr, 4114 "Could not open pause file '%s', continuing immediately.\n", filename); 4115 } 4116 } 4117 4118 4119 // Refer to the comments in os_solaris.cpp park-unpark. The next two 4120 // comment paragraphs are worth repeating here: 4121 // 4122 // Assumption: 4123 // Only one parker can exist on an event, which is why we allocate 4124 // them per-thread. Multiple unparkers can coexist. 4125 // 4126 // _Event serves as a restricted-range semaphore. 4127 // -1 : thread is blocked, i.e. there is a waiter 4128 // 0 : neutral: thread is running or ready, 4129 // could have been signaled after a wait started 4130 // 1 : signaled - thread is running or ready 4131 // 4132 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 4133 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 4134 // For specifics regarding the bug see GLIBC BUGID 261237 : 4135 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 4136 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 4137 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 4138 // is used. (The simple C test-case provided in the GLIBC bug report manifests the 4139 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 4140 // and monitorenter when we're using 1-0 locking. All those operations may result in 4141 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 4142 // of libpthread avoids the problem, but isn't practical. 4143 // 4144 // Possible remedies: 4145 // 4146 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 4147 // This is palliative and probabilistic, however. If the thread is preempted 4148 // between the call to compute_abstime() and pthread_cond_timedwait(), more 4149 // than the minimum period may have passed, and the abstime may be stale (in the 4150 // past) resultin in a hang. Using this technique reduces the odds of a hang 4151 // but the JVM is still vulnerable, particularly on heavily loaded systems. 4152 // 4153 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 4154 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set 4155 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 4156 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant 4157 // thread. 4158 // 4159 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 4160 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 4161 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). 4162 // This also works well. In fact it avoids kernel-level scalability impediments 4163 // on certain platforms that don't handle lots of active pthread_cond_timedwait() 4164 // timers in a graceful fashion. 4165 // 4166 // 4. When the abstime value is in the past it appears that control returns 4167 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 4168 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we 4169 // can avoid the problem by reinitializing the condvar -- by cond_destroy() 4170 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). 4171 // It may be possible to avoid reinitialization by checking the return 4172 // value from pthread_cond_timedwait(). In addition to reinitializing the 4173 // condvar we must establish the invariant that cond_signal() is only called 4174 // within critical sections protected by the adjunct mutex. This prevents 4175 // cond_signal() from "seeing" a condvar that's in the midst of being 4176 // reinitialized or that is corrupt. Sadly, this invariant obviates the 4177 // desirable signal-after-unlock optimization that avoids futile context switching. 4178 // 4179 // I'm also concerned that some versions of NTPL might allocate an auxilliary 4180 // structure when a condvar is used or initialized. cond_destroy() would 4181 // release the helper structure. Our reinitialize-after-timedwait fix 4182 // put excessive stress on malloc/free and locks protecting the c-heap. 4183 // 4184 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 4185 // It may be possible to refine (4) by checking the kernel and NTPL verisons 4186 // and only enabling the work-around for vulnerable environments. 4187 4188 // utility to compute the abstime argument to timedwait: 4189 // millis is the relative timeout time 4190 // abstime will be the absolute timeout time 4191 // TODO: replace compute_abstime() with unpackTime() 4192 4193 static struct timespec* compute_abstime(struct timespec* abstime, 4194 jlong millis) { 4195 if (millis < 0) millis = 0; 4196 struct timeval now; 4197 int status = gettimeofday(&now, NULL); 4198 assert(status == 0, "gettimeofday"); 4199 jlong seconds = millis / 1000; 4200 millis %= 1000; 4201 if (seconds > 50000000) { // see man cond_timedwait(3T) 4202 seconds = 50000000; 4203 } 4204 abstime->tv_sec = now.tv_sec + seconds; 4205 long usec = now.tv_usec + millis * 1000; 4206 if (usec >= 1000000) { 4207 abstime->tv_sec += 1; 4208 usec -= 1000000; 4209 } 4210 abstime->tv_nsec = usec * 1000; 4211 return abstime; 4212 } 4213 4214 void os::PlatformEvent::park() { // AKA "down()" 4215 // Transitions for _Event: 4216 // -1 => -1 : illegal 4217 // 1 => 0 : pass - return immediately 4218 // 0 => -1 : block; then set _Event to 0 before returning 4219 4220 // Invariant: Only the thread associated with the Event/PlatformEvent 4221 // may call park(). 4222 // TODO: assert that _Assoc != NULL or _Assoc == Self 4223 assert(_nParked == 0, "invariant"); 4224 4225 int v; 4226 for (;;) { 4227 v = _Event; 4228 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4229 } 4230 guarantee(v >= 0, "invariant"); 4231 if (v == 0) { 4232 // Do this the hard way by blocking ... 4233 int status = pthread_mutex_lock(_mutex); 4234 assert_status(status == 0, status, "mutex_lock"); 4235 guarantee(_nParked == 0, "invariant"); 4236 ++_nParked; 4237 while (_Event < 0) { 4238 status = pthread_cond_wait(_cond, _mutex); 4239 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 4240 // Treat this the same as if the wait was interrupted 4241 if (status == ETIMEDOUT) { status = EINTR; } 4242 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 4243 } 4244 --_nParked; 4245 4246 _Event = 0; 4247 status = pthread_mutex_unlock(_mutex); 4248 assert_status(status == 0, status, "mutex_unlock"); 4249 // Paranoia to ensure our locked and lock-free paths interact 4250 // correctly with each other. 4251 OrderAccess::fence(); 4252 } 4253 guarantee(_Event >= 0, "invariant"); 4254 } 4255 4256 int os::PlatformEvent::park(jlong millis) { 4257 // Transitions for _Event: 4258 // -1 => -1 : illegal 4259 // 1 => 0 : pass - return immediately 4260 // 0 => -1 : block; then set _Event to 0 before returning 4261 4262 guarantee(_nParked == 0, "invariant"); 4263 4264 int v; 4265 for (;;) { 4266 v = _Event; 4267 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break; 4268 } 4269 guarantee(v >= 0, "invariant"); 4270 if (v != 0) return OS_OK; 4271 4272 // We do this the hard way, by blocking the thread. 4273 // Consider enforcing a minimum timeout value. 4274 struct timespec abst; 4275 compute_abstime(&abst, millis); 4276 4277 int ret = OS_TIMEOUT; 4278 int status = pthread_mutex_lock(_mutex); 4279 assert_status(status == 0, status, "mutex_lock"); 4280 guarantee(_nParked == 0, "invariant"); 4281 ++_nParked; 4282 4283 // Object.wait(timo) will return because of 4284 // (a) notification 4285 // (b) timeout 4286 // (c) thread.interrupt 4287 // 4288 // Thread.interrupt and object.notify{All} both call Event::set. 4289 // That is, we treat thread.interrupt as a special case of notification. 4290 // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false. 4291 // We assume all ETIME returns are valid. 4292 // 4293 // TODO: properly differentiate simultaneous notify+interrupt. 4294 // In that case, we should propagate the notify to another waiter. 4295 4296 while (_Event < 0) { 4297 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst); 4298 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4299 pthread_cond_destroy(_cond); 4300 pthread_cond_init(_cond, NULL); 4301 } 4302 assert_status(status == 0 || status == EINTR || 4303 status == ETIMEDOUT, 4304 status, "cond_timedwait"); 4305 if (!FilterSpuriousWakeups) break; // previous semantics 4306 if (status == ETIMEDOUT) break; 4307 // We consume and ignore EINTR and spurious wakeups. 4308 } 4309 --_nParked; 4310 if (_Event >= 0) { 4311 ret = OS_OK; 4312 } 4313 _Event = 0; 4314 status = pthread_mutex_unlock(_mutex); 4315 assert_status(status == 0, status, "mutex_unlock"); 4316 assert(_nParked == 0, "invariant"); 4317 // Paranoia to ensure our locked and lock-free paths interact 4318 // correctly with each other. 4319 OrderAccess::fence(); 4320 return ret; 4321 } 4322 4323 void os::PlatformEvent::unpark() { 4324 // Transitions for _Event: 4325 // 0 => 1 : just return 4326 // 1 => 1 : just return 4327 // -1 => either 0 or 1; must signal target thread 4328 // That is, we can safely transition _Event from -1 to either 4329 // 0 or 1. 4330 // See also: "Semaphores in Plan 9" by Mullender & Cox 4331 // 4332 // Note: Forcing a transition from "-1" to "1" on an unpark() means 4333 // that it will take two back-to-back park() calls for the owning 4334 // thread to block. This has the benefit of forcing a spurious return 4335 // from the first park() call after an unpark() call which will help 4336 // shake out uses of park() and unpark() without condition variables. 4337 4338 if (Atomic::xchg(1, &_Event) >= 0) return; 4339 4340 // Wait for the thread associated with the event to vacate 4341 int status = pthread_mutex_lock(_mutex); 4342 assert_status(status == 0, status, "mutex_lock"); 4343 int AnyWaiters = _nParked; 4344 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 4345 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 4346 AnyWaiters = 0; 4347 pthread_cond_signal(_cond); 4348 } 4349 status = pthread_mutex_unlock(_mutex); 4350 assert_status(status == 0, status, "mutex_unlock"); 4351 if (AnyWaiters != 0) { 4352 // Note that we signal() *after* dropping the lock for "immortal" Events. 4353 // This is safe and avoids a common class of futile wakeups. In rare 4354 // circumstances this can cause a thread to return prematurely from 4355 // cond_{timed}wait() but the spurious wakeup is benign and the victim 4356 // will simply re-test the condition and re-park itself. 4357 // This provides particular benefit if the underlying platform does not 4358 // provide wait morphing. 4359 status = pthread_cond_signal(_cond); 4360 assert_status(status == 0, status, "cond_signal"); 4361 } 4362 } 4363 4364 4365 // JSR166 4366 // ------------------------------------------------------- 4367 4368 // The solaris and bsd implementations of park/unpark are fairly 4369 // conservative for now, but can be improved. They currently use a 4370 // mutex/condvar pair, plus a a count. 4371 // Park decrements count if > 0, else does a condvar wait. Unpark 4372 // sets count to 1 and signals condvar. Only one thread ever waits 4373 // on the condvar. Contention seen when trying to park implies that someone 4374 // is unparking you, so don't wait. And spurious returns are fine, so there 4375 // is no need to track notifications. 4376 4377 #define MAX_SECS 100000000 4378 4379 // This code is common to bsd and solaris and will be moved to a 4380 // common place in dolphin. 4381 // 4382 // The passed in time value is either a relative time in nanoseconds 4383 // or an absolute time in milliseconds. Either way it has to be unpacked 4384 // into suitable seconds and nanoseconds components and stored in the 4385 // given timespec structure. 4386 // Given time is a 64-bit value and the time_t used in the timespec is only 4387 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for 4388 // overflow if times way in the future are given. Further on Solaris versions 4389 // prior to 10 there is a restriction (see cond_timedwait) that the specified 4390 // number of seconds, in abstime, is less than current_time + 100,000,000. 4391 // As it will be 28 years before "now + 100000000" will overflow we can 4392 // ignore overflow and just impose a hard-limit on seconds using the value 4393 // of "now + 100,000,000". This places a limit on the timeout of about 3.17 4394 // years from "now". 4395 4396 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { 4397 assert(time > 0, "convertTime"); 4398 4399 struct timeval now; 4400 int status = gettimeofday(&now, NULL); 4401 assert(status == 0, "gettimeofday"); 4402 4403 time_t max_secs = now.tv_sec + MAX_SECS; 4404 4405 if (isAbsolute) { 4406 jlong secs = time / 1000; 4407 if (secs > max_secs) { 4408 absTime->tv_sec = max_secs; 4409 } else { 4410 absTime->tv_sec = secs; 4411 } 4412 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 4413 } else { 4414 jlong secs = time / NANOSECS_PER_SEC; 4415 if (secs >= MAX_SECS) { 4416 absTime->tv_sec = max_secs; 4417 absTime->tv_nsec = 0; 4418 } else { 4419 absTime->tv_sec = now.tv_sec + secs; 4420 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 4421 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 4422 absTime->tv_nsec -= NANOSECS_PER_SEC; 4423 ++absTime->tv_sec; // note: this must be <= max_secs 4424 } 4425 } 4426 } 4427 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 4428 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 4429 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 4430 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 4431 } 4432 4433 void Parker::park(bool isAbsolute, jlong time) { 4434 // Ideally we'd do something useful while spinning, such 4435 // as calling unpackTime(). 4436 4437 // Optional fast-path check: 4438 // Return immediately if a permit is available. 4439 // We depend on Atomic::xchg() having full barrier semantics 4440 // since we are doing a lock-free update to _counter. 4441 if (Atomic::xchg(0, &_counter) > 0) return; 4442 4443 Thread* thread = Thread::current(); 4444 assert(thread->is_Java_thread(), "Must be JavaThread"); 4445 JavaThread *jt = (JavaThread *)thread; 4446 4447 // Optional optimization -- avoid state transitions if there's an interrupt pending. 4448 // Check interrupt before trying to wait 4449 if (Thread::is_interrupted(thread, false)) { 4450 return; 4451 } 4452 4453 // Next, demultiplex/decode time arguments 4454 struct timespec absTime; 4455 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all 4456 return; 4457 } 4458 if (time > 0) { 4459 unpackTime(&absTime, isAbsolute, time); 4460 } 4461 4462 4463 // Enter safepoint region 4464 // Beware of deadlocks such as 6317397. 4465 // The per-thread Parker:: mutex is a classic leaf-lock. 4466 // In particular a thread must never block on the Threads_lock while 4467 // holding the Parker:: mutex. If safepoints are pending both the 4468 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 4469 ThreadBlockInVM tbivm(jt); 4470 4471 // Don't wait if cannot get lock since interference arises from 4472 // unblocking. Also. check interrupt before trying wait 4473 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 4474 return; 4475 } 4476 4477 int status; 4478 if (_counter > 0) { // no wait needed 4479 _counter = 0; 4480 status = pthread_mutex_unlock(_mutex); 4481 assert(status == 0, "invariant"); 4482 // Paranoia to ensure our locked and lock-free paths interact 4483 // correctly with each other and Java-level accesses. 4484 OrderAccess::fence(); 4485 return; 4486 } 4487 4488 #ifdef ASSERT 4489 // Don't catch signals while blocked; let the running threads have the signals. 4490 // (This allows a debugger to break into the running thread.) 4491 sigset_t oldsigs; 4492 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); 4493 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 4494 #endif 4495 4496 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 4497 jt->set_suspend_equivalent(); 4498 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 4499 4500 if (time == 0) { 4501 status = pthread_cond_wait(_cond, _mutex); 4502 } else { 4503 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &absTime); 4504 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4505 pthread_cond_destroy(_cond); 4506 pthread_cond_init(_cond, NULL); 4507 } 4508 } 4509 assert_status(status == 0 || status == EINTR || 4510 status == ETIMEDOUT, 4511 status, "cond_timedwait"); 4512 4513 #ifdef ASSERT 4514 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 4515 #endif 4516 4517 _counter = 0; 4518 status = pthread_mutex_unlock(_mutex); 4519 assert_status(status == 0, status, "invariant"); 4520 // Paranoia to ensure our locked and lock-free paths interact 4521 // correctly with each other and Java-level accesses. 4522 OrderAccess::fence(); 4523 4524 // If externally suspended while waiting, re-suspend 4525 if (jt->handle_special_suspend_equivalent_condition()) { 4526 jt->java_suspend_self(); 4527 } 4528 } 4529 4530 void Parker::unpark() { 4531 int status = pthread_mutex_lock(_mutex); 4532 assert(status == 0, "invariant"); 4533 const int s = _counter; 4534 _counter = 1; 4535 if (s < 1) { 4536 if (WorkAroundNPTLTimedWaitHang) { 4537 status = pthread_cond_signal(_cond); 4538 assert(status == 0, "invariant"); 4539 status = pthread_mutex_unlock(_mutex); 4540 assert(status == 0, "invariant"); 4541 } else { 4542 status = pthread_mutex_unlock(_mutex); 4543 assert(status == 0, "invariant"); 4544 status = pthread_cond_signal(_cond); 4545 assert(status == 0, "invariant"); 4546 } 4547 } else { 4548 pthread_mutex_unlock(_mutex); 4549 assert(status == 0, "invariant"); 4550 } 4551 } 4552 4553 4554 // Darwin has no "environ" in a dynamic library. 4555 #ifdef __APPLE__ 4556 #include <crt_externs.h> 4557 #define environ (*_NSGetEnviron()) 4558 #else 4559 extern char** environ; 4560 #endif 4561 4562 // Run the specified command in a separate process. Return its exit value, 4563 // or -1 on failure (e.g. can't fork a new process). 4564 // Unlike system(), this function can be called from signal handler. It 4565 // doesn't block SIGINT et al. 4566 int os::fork_and_exec(char* cmd) { 4567 const char * argv[4] = {"sh", "-c", cmd, NULL}; 4568 4569 // fork() in BsdThreads/NPTL is not async-safe. It needs to run 4570 // pthread_atfork handlers and reset pthread library. All we need is a 4571 // separate process to execve. Make a direct syscall to fork process. 4572 // On IA64 there's no fork syscall, we have to use fork() and hope for 4573 // the best... 4574 pid_t pid = fork(); 4575 4576 if (pid < 0) { 4577 // fork failed 4578 return -1; 4579 4580 } else if (pid == 0) { 4581 // child process 4582 4583 // execve() in BsdThreads will call pthread_kill_other_threads_np() 4584 // first to kill every thread on the thread list. Because this list is 4585 // not reset by fork() (see notes above), execve() will instead kill 4586 // every thread in the parent process. We know this is the only thread 4587 // in the new process, so make a system call directly. 4588 // IA64 should use normal execve() from glibc to match the glibc fork() 4589 // above. 4590 execve("/bin/sh", (char* const*)argv, environ); 4591 4592 // execve failed 4593 _exit(-1); 4594 4595 } else { 4596 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 4597 // care about the actual exit code, for now. 4598 4599 int status; 4600 4601 // Wait for the child process to exit. This returns immediately if 4602 // the child has already exited. */ 4603 while (waitpid(pid, &status, 0) < 0) { 4604 switch (errno) { 4605 case ECHILD: return 0; 4606 case EINTR: break; 4607 default: return -1; 4608 } 4609 } 4610 4611 if (WIFEXITED(status)) { 4612 // The child exited normally; get its exit code. 4613 return WEXITSTATUS(status); 4614 } else if (WIFSIGNALED(status)) { 4615 // The child exited because of a signal 4616 // The best value to return is 0x80 + signal number, 4617 // because that is what all Unix shells do, and because 4618 // it allows callers to distinguish between process exit and 4619 // process death by signal. 4620 return 0x80 + WTERMSIG(status); 4621 } else { 4622 // Unknown exit code; pass it through 4623 return status; 4624 } 4625 } 4626 } 4627 4628 // is_headless_jre() 4629 // 4630 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 4631 // in order to report if we are running in a headless jre 4632 // 4633 // Since JDK8 xawt/libmawt.so was moved into the same directory 4634 // as libawt.so, and renamed libawt_xawt.so 4635 // 4636 bool os::is_headless_jre() { 4637 #ifdef __APPLE__ 4638 // We no longer build headless-only on Mac OS X 4639 return false; 4640 #else 4641 struct stat statbuf; 4642 char buf[MAXPATHLEN]; 4643 char libmawtpath[MAXPATHLEN]; 4644 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX; 4645 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX; 4646 char *p; 4647 4648 // Get path to libjvm.so 4649 os::jvm_path(buf, sizeof(buf)); 4650 4651 // Get rid of libjvm.so 4652 p = strrchr(buf, '/'); 4653 if (p == NULL) { 4654 return false; 4655 } else { 4656 *p = '\0'; 4657 } 4658 4659 // Get rid of client or server 4660 p = strrchr(buf, '/'); 4661 if (p == NULL) { 4662 return false; 4663 } else { 4664 *p = '\0'; 4665 } 4666 4667 // check xawt/libmawt.so 4668 strcpy(libmawtpath, buf); 4669 strcat(libmawtpath, xawtstr); 4670 if (::stat(libmawtpath, &statbuf) == 0) return false; 4671 4672 // check libawt_xawt.so 4673 strcpy(libmawtpath, buf); 4674 strcat(libmawtpath, new_xawtstr); 4675 if (::stat(libmawtpath, &statbuf) == 0) return false; 4676 4677 return true; 4678 #endif 4679 } 4680 4681 // Get the default path to the core file 4682 // Returns the length of the string 4683 int os::get_core_path(char* buffer, size_t bufferSize) { 4684 int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id()); 4685 4686 // Truncate if theoretical string was longer than bufferSize 4687 n = MIN2(n, (int)bufferSize); 4688 4689 return n; 4690 } 4691 4692 #ifndef PRODUCT 4693 void TestReserveMemorySpecial_test() { 4694 // No tests available for this platform 4695 } 4696 #endif