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_share_bsd.hpp" 40 #include "prims/jniFastGetField.hpp" 41 #include "prims/jvm.h" 42 #include "prims/jvm_misc.hpp" 43 #include "runtime/arguments.hpp" 44 #include "runtime/extendedPC.hpp" 45 #include "runtime/globals.hpp" 46 #include "runtime/interfaceSupport.hpp" 47 #include "runtime/java.hpp" 48 #include "runtime/javaCalls.hpp" 49 #include "runtime/mutexLocker.hpp" 50 #include "runtime/objectMonitor.hpp" 51 #include "runtime/orderAccess.inline.hpp" 52 #include "runtime/osThread.hpp" 53 #include "runtime/perfMemory.hpp" 54 #include "runtime/sharedRuntime.hpp" 55 #include "runtime/statSampler.hpp" 56 #include "runtime/stubRoutines.hpp" 57 #include "runtime/thread.inline.hpp" 58 #include "runtime/threadCritical.hpp" 59 #include "runtime/timer.hpp" 60 #include "services/attachListener.hpp" 61 #include "services/memTracker.hpp" 62 #include "services/runtimeService.hpp" 63 #include "utilities/decoder.hpp" 64 #include "utilities/defaultStream.hpp" 65 #include "utilities/events.hpp" 66 #include "utilities/growableArray.hpp" 67 #include "utilities/vmError.hpp" 68 69 // put OS-includes here 70 # include <sys/types.h> 71 # include <sys/mman.h> 72 # include <sys/stat.h> 73 # include <sys/select.h> 74 # include <pthread.h> 75 # include <signal.h> 76 # include <errno.h> 77 # include <dlfcn.h> 78 # include <stdio.h> 79 # include <unistd.h> 80 # include <sys/resource.h> 81 # include <pthread.h> 82 # include <sys/stat.h> 83 # include <sys/time.h> 84 # include <sys/times.h> 85 # include <sys/utsname.h> 86 # include <sys/socket.h> 87 # include <sys/wait.h> 88 # include <time.h> 89 # include <pwd.h> 90 # include <poll.h> 91 # include <semaphore.h> 92 # include <fcntl.h> 93 # include <string.h> 94 # include <sys/param.h> 95 # include <sys/sysctl.h> 96 # include <sys/ipc.h> 97 # include <sys/shm.h> 98 #ifndef __APPLE__ 99 # include <link.h> 100 #endif 101 # include <stdint.h> 102 # include <inttypes.h> 103 # include <sys/ioctl.h> 104 # include <sys/syscall.h> 105 106 #if defined(__FreeBSD__) || defined(__NetBSD__) 107 # include <elf.h> 108 #endif 109 110 #ifdef __APPLE__ 111 # include <mach/mach.h> // semaphore_* API 112 # include <mach-o/dyld.h> 113 # include <sys/proc_info.h> 114 # include <objc/objc-auto.h> 115 #endif 116 117 #ifndef MAP_ANONYMOUS 118 #define MAP_ANONYMOUS MAP_ANON 119 #endif 120 121 #define MAX_PATH (2 * K) 122 123 // for timer info max values which include all bits 124 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 125 126 #define LARGEPAGES_BIT (1 << 6) 127 128 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 129 130 //////////////////////////////////////////////////////////////////////////////// 131 // global variables 132 julong os::Bsd::_physical_memory = 0; 133 134 #ifdef __APPLE__ 135 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0}; 136 volatile uint64_t os::Bsd::_max_abstime = 0; 137 #else 138 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; 139 #endif 140 pthread_t os::Bsd::_main_thread; 141 int os::Bsd::_page_size = -1; 142 143 static jlong initial_time_count=0; 144 145 static int clock_tics_per_sec = 100; 146 147 // For diagnostics to print a message once. see run_periodic_checks 148 static sigset_t check_signal_done; 149 static bool check_signals = true; 150 151 static pid_t _initial_pid = 0; 152 153 /* Signal number used to suspend/resume a thread */ 154 155 /* do not use any signal number less than SIGSEGV, see 4355769 */ 156 static int SR_signum = SIGUSR2; 157 sigset_t SR_sigset; 158 159 160 //////////////////////////////////////////////////////////////////////////////// 161 // utility functions 162 163 static int SR_initialize(); 164 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time); 165 166 julong os::available_memory() { 167 return Bsd::available_memory(); 168 } 169 170 // available here means free 171 julong os::Bsd::available_memory() { 172 uint64_t available = physical_memory() >> 2; 173 #ifdef __APPLE__ 174 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT; 175 vm_statistics64_data_t vmstat; 176 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64, 177 (host_info64_t)&vmstat, &count); 178 assert(kerr == KERN_SUCCESS, 179 "host_statistics64 failed - check mach_host_self() and count"); 180 if (kerr == KERN_SUCCESS) { 181 available = vmstat.free_count * os::vm_page_size(); 182 } 183 #endif 184 return available; 185 } 186 187 julong os::physical_memory() { 188 return Bsd::physical_memory(); 189 } 190 191 //////////////////////////////////////////////////////////////////////////////// 192 // environment support 193 194 bool os::getenv(const char* name, char* buf, int len) { 195 const char* val = ::getenv(name); 196 if (val != NULL && strlen(val) < (size_t)len) { 197 strcpy(buf, val); 198 return true; 199 } 200 if (len > 0) buf[0] = 0; // return a null string 201 return false; 202 } 203 204 205 // Return true if user is running as root. 206 207 bool os::have_special_privileges() { 208 static bool init = false; 209 static bool privileges = false; 210 if (!init) { 211 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 212 init = true; 213 } 214 return privileges; 215 } 216 217 218 219 // Cpu architecture string 220 #if defined(ZERO) 221 static char cpu_arch[] = ZERO_LIBARCH; 222 #elif defined(IA64) 223 static char cpu_arch[] = "ia64"; 224 #elif defined(IA32) 225 static char cpu_arch[] = "i386"; 226 #elif defined(AMD64) 227 static char cpu_arch[] = "amd64"; 228 #elif defined(ARM) 229 static char cpu_arch[] = "arm"; 230 #elif defined(PPC32) 231 static char cpu_arch[] = "ppc"; 232 #elif defined(SPARC) 233 # ifdef _LP64 234 static char cpu_arch[] = "sparcv9"; 235 # else 236 static char cpu_arch[] = "sparc"; 237 # endif 238 #else 239 #error Add appropriate cpu_arch setting 240 #endif 241 242 // Compiler variant 243 #ifdef COMPILER2 244 #define COMPILER_VARIANT "server" 245 #else 246 #define COMPILER_VARIANT "client" 247 #endif 248 249 250 void os::Bsd::initialize_system_info() { 251 int mib[2]; 252 size_t len; 253 int cpu_val; 254 julong mem_val; 255 256 /* get processors count via hw.ncpus sysctl */ 257 mib[0] = CTL_HW; 258 mib[1] = HW_NCPU; 259 len = sizeof(cpu_val); 260 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) { 261 assert(len == sizeof(cpu_val), "unexpected data size"); 262 set_processor_count(cpu_val); 263 } 264 else { 265 set_processor_count(1); // fallback 266 } 267 268 /* get physical memory via hw.memsize sysctl (hw.memsize is used 269 * since it returns a 64 bit value) 270 */ 271 mib[0] = CTL_HW; 272 273 #if defined (HW_MEMSIZE) // Apple 274 mib[1] = HW_MEMSIZE; 275 #elif defined(HW_PHYSMEM) // Most of BSD 276 mib[1] = HW_PHYSMEM; 277 #elif defined(HW_REALMEM) // Old FreeBSD 278 mib[1] = HW_REALMEM; 279 #else 280 #error No ways to get physmem 281 #endif 282 283 len = sizeof(mem_val); 284 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) { 285 assert(len == sizeof(mem_val), "unexpected data size"); 286 _physical_memory = mem_val; 287 } else { 288 _physical_memory = 256*1024*1024; // fallback (XXXBSD?) 289 } 290 291 #ifdef __OpenBSD__ 292 { 293 // limit _physical_memory memory view on OpenBSD since 294 // datasize rlimit restricts us anyway. 295 struct rlimit limits; 296 getrlimit(RLIMIT_DATA, &limits); 297 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur); 298 } 299 #endif 300 } 301 302 #ifdef __APPLE__ 303 static const char *get_home() { 304 const char *home_dir = ::getenv("HOME"); 305 if ((home_dir == NULL) || (*home_dir == '\0')) { 306 struct passwd *passwd_info = getpwuid(geteuid()); 307 if (passwd_info != NULL) { 308 home_dir = passwd_info->pw_dir; 309 } 310 } 311 312 return home_dir; 313 } 314 #endif 315 316 void os::init_system_properties_values() { 317 // The next steps are taken in the product version: 318 // 319 // Obtain the JAVA_HOME value from the location of libjvm.so. 320 // This library should be located at: 321 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so. 322 // 323 // If "/jre/lib/" appears at the right place in the path, then we 324 // assume libjvm.so is installed in a JDK and we use this path. 325 // 326 // Otherwise exit with message: "Could not create the Java virtual machine." 327 // 328 // The following extra steps are taken in the debugging version: 329 // 330 // If "/jre/lib/" does NOT appear at the right place in the path 331 // instead of exit check for $JAVA_HOME environment variable. 332 // 333 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 334 // then we append a fake suffix "hotspot/libjvm.so" to this path so 335 // it looks like libjvm.so is installed there 336 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 337 // 338 // Otherwise exit. 339 // 340 // Important note: if the location of libjvm.so changes this 341 // code needs to be changed accordingly. 342 343 // See ld(1): 344 // The linker uses the following search paths to locate required 345 // shared libraries: 346 // 1: ... 347 // ... 348 // 7: The default directories, normally /lib and /usr/lib. 349 #ifndef DEFAULT_LIBPATH 350 #define DEFAULT_LIBPATH "/lib:/usr/lib" 351 #endif 352 353 // Base path of extensions installed on the system. 354 #define SYS_EXT_DIR "/usr/java/packages" 355 #define EXTENSIONS_DIR "/lib/ext" 356 #define ENDORSED_DIR "/lib/endorsed" 357 358 #ifndef __APPLE__ 359 360 // Buffer that fits several sprintfs. 361 // Note that the space for the colon and the trailing null are provided 362 // by the nulls included by the sizeof operator. 363 const size_t bufsize = 364 MAX3((size_t)MAXPATHLEN, // For dll_dir & friends. 365 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR), // extensions dir 366 (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir 367 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 368 369 // sysclasspath, java_home, dll_dir 370 { 371 char *pslash; 372 os::jvm_path(buf, bufsize); 373 374 // Found the full path to libjvm.so. 375 // Now cut the path to <java_home>/jre if we can. 376 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 377 pslash = strrchr(buf, '/'); 378 if (pslash != NULL) { 379 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 380 } 381 Arguments::set_dll_dir(buf); 382 383 if (pslash != NULL) { 384 pslash = strrchr(buf, '/'); 385 if (pslash != NULL) { 386 *pslash = '\0'; // Get rid of /<arch>. 387 pslash = strrchr(buf, '/'); 388 if (pslash != NULL) { 389 *pslash = '\0'; // Get rid of /lib. 390 } 391 } 392 } 393 Arguments::set_java_home(buf); 394 set_boot_path('/', ':'); 395 } 396 397 // Where to look for native libraries. 398 // 399 // Note: Due to a legacy implementation, most of the library path 400 // is set in the launcher. This was to accomodate linking restrictions 401 // on legacy Bsd implementations (which are no longer supported). 402 // Eventually, all the library path setting will be done here. 403 // 404 // However, to prevent the proliferation of improperly built native 405 // libraries, the new path component /usr/java/packages is added here. 406 // Eventually, all the library path setting will be done here. 407 { 408 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 409 // should always exist (until the legacy problem cited above is 410 // addressed). 411 const char *v = ::getenv("LD_LIBRARY_PATH"); 412 const char *v_colon = ":"; 413 if (v == NULL) { v = ""; v_colon = ""; } 414 // That's +1 for the colon and +1 for the trailing '\0'. 415 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 416 strlen(v) + 1 + 417 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1, 418 mtInternal); 419 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch); 420 Arguments::set_library_path(ld_library_path); 421 FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal); 422 } 423 424 // Extensions directories. 425 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 426 Arguments::set_ext_dirs(buf); 427 428 // Endorsed standards default directory. 429 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); 430 Arguments::set_endorsed_dirs(buf); 431 432 FREE_C_HEAP_ARRAY(char, buf, mtInternal); 433 434 #else // __APPLE__ 435 436 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions" 437 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java" 438 439 const char *user_home_dir = get_home(); 440 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir. 441 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) + 442 sizeof(SYS_EXTENSIONS_DIRS); 443 444 // Buffer that fits several sprintfs. 445 // Note that the space for the colon and the trailing null are provided 446 // by the nulls included by the sizeof operator. 447 const size_t bufsize = 448 MAX3((size_t)MAXPATHLEN, // for dll_dir & friends. 449 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size, // extensions dir 450 (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir 451 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 452 453 // sysclasspath, java_home, dll_dir 454 { 455 char *pslash; 456 os::jvm_path(buf, bufsize); 457 458 // Found the full path to libjvm.so. 459 // Now cut the path to <java_home>/jre if we can. 460 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so. 461 pslash = strrchr(buf, '/'); 462 if (pslash != NULL) { 463 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 464 } 465 Arguments::set_dll_dir(buf); 466 467 if (pslash != NULL) { 468 pslash = strrchr(buf, '/'); 469 if (pslash != NULL) { 470 *pslash = '\0'; // Get rid of /lib. 471 } 472 } 473 Arguments::set_java_home(buf); 474 set_boot_path('/', ':'); 475 } 476 477 // Where to look for native libraries. 478 // 479 // Note: Due to a legacy implementation, most of the library path 480 // is set in the launcher. This was to accomodate linking restrictions 481 // on legacy Bsd implementations (which are no longer supported). 482 // Eventually, all the library path setting will be done here. 483 // 484 // However, to prevent the proliferation of improperly built native 485 // libraries, the new path component /usr/java/packages is added here. 486 // Eventually, all the library path setting will be done here. 487 { 488 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 489 // should always exist (until the legacy problem cited above is 490 // addressed). 491 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code 492 // can specify a directory inside an app wrapper 493 const char *l = ::getenv("JAVA_LIBRARY_PATH"); 494 const char *l_colon = ":"; 495 if (l == NULL) { l = ""; l_colon = ""; } 496 497 const char *v = ::getenv("DYLD_LIBRARY_PATH"); 498 const char *v_colon = ":"; 499 if (v == NULL) { v = ""; v_colon = ""; } 500 501 // Apple's Java6 has "." at the beginning of java.library.path. 502 // OpenJDK on Windows has "." at the end of java.library.path. 503 // OpenJDK on Linux and Solaris don't have "." in java.library.path 504 // at all. To ease the transition from Apple's Java6 to OpenJDK7, 505 // "." is appended to the end of java.library.path. Yes, this 506 // could cause a change in behavior, but Apple's Java6 behavior 507 // can be achieved by putting "." at the beginning of the 508 // JAVA_LIBRARY_PATH environment variable. 509 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 510 strlen(v) + 1 + strlen(l) + 1 + 511 system_ext_size + 3, 512 mtInternal); 513 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.", 514 v, v_colon, l, l_colon, user_home_dir); 515 Arguments::set_library_path(ld_library_path); 516 FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal); 517 } 518 519 // Extensions directories. 520 // 521 // Note that the space for the colon and the trailing null are provided 522 // by the nulls included by the sizeof operator (so actually one byte more 523 // than necessary is allocated). 524 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, 525 user_home_dir, Arguments::get_java_home()); 526 Arguments::set_ext_dirs(buf); 527 528 // Endorsed standards default directory. 529 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); 530 Arguments::set_endorsed_dirs(buf); 531 532 FREE_C_HEAP_ARRAY(char, buf, mtInternal); 533 534 #undef SYS_EXTENSIONS_DIR 535 #undef SYS_EXTENSIONS_DIRS 536 537 #endif // __APPLE__ 538 539 #undef SYS_EXT_DIR 540 #undef EXTENSIONS_DIR 541 #undef ENDORSED_DIR 542 } 543 544 //////////////////////////////////////////////////////////////////////////////// 545 // breakpoint support 546 547 void os::breakpoint() { 548 BREAKPOINT; 549 } 550 551 extern "C" void breakpoint() { 552 // use debugger to set breakpoint here 553 } 554 555 //////////////////////////////////////////////////////////////////////////////// 556 // signal support 557 558 debug_only(static bool signal_sets_initialized = false); 559 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; 560 561 bool os::Bsd::is_sig_ignored(int sig) { 562 struct sigaction oact; 563 sigaction(sig, (struct sigaction*)NULL, &oact); 564 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 565 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 566 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) 567 return true; 568 else 569 return false; 570 } 571 572 void os::Bsd::signal_sets_init() { 573 // Should also have an assertion stating we are still single-threaded. 574 assert(!signal_sets_initialized, "Already initialized"); 575 // Fill in signals that are necessarily unblocked for all threads in 576 // the VM. Currently, we unblock the following signals: 577 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 578 // by -Xrs (=ReduceSignalUsage)); 579 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 580 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 581 // the dispositions or masks wrt these signals. 582 // Programs embedding the VM that want to use the above signals for their 583 // own purposes must, at this time, use the "-Xrs" option to prevent 584 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 585 // (See bug 4345157, and other related bugs). 586 // In reality, though, unblocking these signals is really a nop, since 587 // these signals are not blocked by default. 588 sigemptyset(&unblocked_sigs); 589 sigemptyset(&allowdebug_blocked_sigs); 590 sigaddset(&unblocked_sigs, SIGILL); 591 sigaddset(&unblocked_sigs, SIGSEGV); 592 sigaddset(&unblocked_sigs, SIGBUS); 593 sigaddset(&unblocked_sigs, SIGFPE); 594 sigaddset(&unblocked_sigs, SR_signum); 595 596 if (!ReduceSignalUsage) { 597 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 598 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 599 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); 600 } 601 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 602 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 603 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); 604 } 605 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 606 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 607 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); 608 } 609 } 610 // Fill in signals that are blocked by all but the VM thread. 611 sigemptyset(&vm_sigs); 612 if (!ReduceSignalUsage) 613 sigaddset(&vm_sigs, BREAK_SIGNAL); 614 debug_only(signal_sets_initialized = true); 615 616 } 617 618 // These are signals that are unblocked while a thread is running Java. 619 // (For some reason, they get blocked by default.) 620 sigset_t* os::Bsd::unblocked_signals() { 621 assert(signal_sets_initialized, "Not initialized"); 622 return &unblocked_sigs; 623 } 624 625 // These are the signals that are blocked while a (non-VM) thread is 626 // running Java. Only the VM thread handles these signals. 627 sigset_t* os::Bsd::vm_signals() { 628 assert(signal_sets_initialized, "Not initialized"); 629 return &vm_sigs; 630 } 631 632 // These are signals that are blocked during cond_wait to allow debugger in 633 sigset_t* os::Bsd::allowdebug_blocked_signals() { 634 assert(signal_sets_initialized, "Not initialized"); 635 return &allowdebug_blocked_sigs; 636 } 637 638 void os::Bsd::hotspot_sigmask(Thread* thread) { 639 640 //Save caller's signal mask before setting VM signal mask 641 sigset_t caller_sigmask; 642 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 643 644 OSThread* osthread = thread->osthread(); 645 osthread->set_caller_sigmask(caller_sigmask); 646 647 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); 648 649 if (!ReduceSignalUsage) { 650 if (thread->is_VM_thread()) { 651 // Only the VM thread handles BREAK_SIGNAL ... 652 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 653 } else { 654 // ... all other threads block BREAK_SIGNAL 655 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 656 } 657 } 658 } 659 660 661 ////////////////////////////////////////////////////////////////////////////// 662 // create new thread 663 664 // check if it's safe to start a new thread 665 static bool _thread_safety_check(Thread* thread) { 666 return true; 667 } 668 669 #ifdef __APPLE__ 670 // library handle for calling objc_registerThreadWithCollector() 671 // without static linking to the libobjc library 672 #define OBJC_LIB "/usr/lib/libobjc.dylib" 673 #define OBJC_GCREGISTER "objc_registerThreadWithCollector" 674 typedef void (*objc_registerThreadWithCollector_t)(); 675 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction; 676 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL; 677 #endif 678 679 #ifdef __APPLE__ 680 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) { 681 // Additional thread_id used to correlate threads in SA 682 thread_identifier_info_data_t m_ident_info; 683 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT; 684 685 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO, 686 (thread_info_t) &m_ident_info, &count); 687 688 return m_ident_info.thread_id; 689 } 690 #endif 691 692 // Thread start routine for all newly created threads 693 static void *java_start(Thread *thread) { 694 // Try to randomize the cache line index of hot stack frames. 695 // This helps when threads of the same stack traces evict each other's 696 // cache lines. The threads can be either from the same JVM instance, or 697 // from different JVM instances. The benefit is especially true for 698 // processors with hyperthreading technology. 699 static int counter = 0; 700 int pid = os::current_process_id(); 701 alloca(((pid ^ counter++) & 7) * 128); 702 703 ThreadLocalStorage::set_thread(thread); 704 705 OSThread* osthread = thread->osthread(); 706 Monitor* sync = osthread->startThread_lock(); 707 708 // non floating stack BsdThreads needs extra check, see above 709 if (!_thread_safety_check(thread)) { 710 // notify parent thread 711 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 712 osthread->set_state(ZOMBIE); 713 sync->notify_all(); 714 return NULL; 715 } 716 717 osthread->set_thread_id(os::Bsd::gettid()); 718 719 #ifdef __APPLE__ 720 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 721 guarantee(unique_thread_id != 0, "unique thread id was not found"); 722 osthread->set_unique_thread_id(unique_thread_id); 723 #endif 724 // initialize signal mask for this thread 725 os::Bsd::hotspot_sigmask(thread); 726 727 // initialize floating point control register 728 os::Bsd::init_thread_fpu_state(); 729 730 #ifdef __APPLE__ 731 // register thread with objc gc 732 if (objc_registerThreadWithCollectorFunction != NULL) { 733 objc_registerThreadWithCollectorFunction(); 734 } 735 #endif 736 737 // handshaking with parent thread 738 { 739 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 740 741 // notify parent thread 742 osthread->set_state(INITIALIZED); 743 sync->notify_all(); 744 745 // wait until os::start_thread() 746 while (osthread->get_state() == INITIALIZED) { 747 sync->wait(Mutex::_no_safepoint_check_flag); 748 } 749 } 750 751 // call one more level start routine 752 thread->run(); 753 754 return 0; 755 } 756 757 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { 758 assert(thread->osthread() == NULL, "caller responsible"); 759 760 // Allocate the OSThread object 761 OSThread* osthread = new OSThread(NULL, NULL); 762 if (osthread == NULL) { 763 return false; 764 } 765 766 // set the correct thread state 767 osthread->set_thread_type(thr_type); 768 769 // Initial state is ALLOCATED but not INITIALIZED 770 osthread->set_state(ALLOCATED); 771 772 thread->set_osthread(osthread); 773 774 // init thread attributes 775 pthread_attr_t attr; 776 pthread_attr_init(&attr); 777 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 778 779 // stack size 780 if (os::Bsd::supports_variable_stack_size()) { 781 // calculate stack size if it's not specified by caller 782 if (stack_size == 0) { 783 stack_size = os::Bsd::default_stack_size(thr_type); 784 785 switch (thr_type) { 786 case os::java_thread: 787 // Java threads use ThreadStackSize which default value can be 788 // changed with the flag -Xss 789 assert (JavaThread::stack_size_at_create() > 0, "this should be set"); 790 stack_size = JavaThread::stack_size_at_create(); 791 break; 792 case os::compiler_thread: 793 if (CompilerThreadStackSize > 0) { 794 stack_size = (size_t)(CompilerThreadStackSize * K); 795 break; 796 } // else fall through: 797 // use VMThreadStackSize if CompilerThreadStackSize is not defined 798 case os::vm_thread: 799 case os::pgc_thread: 800 case os::cgc_thread: 801 case os::watcher_thread: 802 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); 803 break; 804 } 805 } 806 807 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); 808 pthread_attr_setstacksize(&attr, stack_size); 809 } else { 810 // let pthread_create() pick the default value. 811 } 812 813 ThreadState state; 814 815 { 816 pthread_t tid; 817 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); 818 819 pthread_attr_destroy(&attr); 820 821 if (ret != 0) { 822 if (PrintMiscellaneous && (Verbose || WizardMode)) { 823 perror("pthread_create()"); 824 } 825 // Need to clean up stuff we've allocated so far 826 thread->set_osthread(NULL); 827 delete osthread; 828 return false; 829 } 830 831 // Store pthread info into the OSThread 832 osthread->set_pthread_id(tid); 833 834 // Wait until child thread is either initialized or aborted 835 { 836 Monitor* sync_with_child = osthread->startThread_lock(); 837 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 838 while ((state = osthread->get_state()) == ALLOCATED) { 839 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 840 } 841 } 842 843 } 844 845 // Aborted due to thread limit being reached 846 if (state == ZOMBIE) { 847 thread->set_osthread(NULL); 848 delete osthread; 849 return false; 850 } 851 852 // The thread is returned suspended (in state INITIALIZED), 853 // and is started higher up in the call chain 854 assert(state == INITIALIZED, "race condition"); 855 return true; 856 } 857 858 ///////////////////////////////////////////////////////////////////////////// 859 // attach existing thread 860 861 // bootstrap the main thread 862 bool os::create_main_thread(JavaThread* thread) { 863 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); 864 return create_attached_thread(thread); 865 } 866 867 bool os::create_attached_thread(JavaThread* thread) { 868 #ifdef ASSERT 869 thread->verify_not_published(); 870 #endif 871 872 // Allocate the OSThread object 873 OSThread* osthread = new OSThread(NULL, NULL); 874 875 if (osthread == NULL) { 876 return false; 877 } 878 879 osthread->set_thread_id(os::Bsd::gettid()); 880 881 // Store pthread info into the OSThread 882 #ifdef __APPLE__ 883 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id()); 884 guarantee(unique_thread_id != 0, "just checking"); 885 osthread->set_unique_thread_id(unique_thread_id); 886 #endif 887 osthread->set_pthread_id(::pthread_self()); 888 889 // initialize floating point control register 890 os::Bsd::init_thread_fpu_state(); 891 892 // Initial thread state is RUNNABLE 893 osthread->set_state(RUNNABLE); 894 895 thread->set_osthread(osthread); 896 897 // initialize signal mask for this thread 898 // and save the caller's signal mask 899 os::Bsd::hotspot_sigmask(thread); 900 901 return true; 902 } 903 904 void os::pd_start_thread(Thread* thread) { 905 OSThread * osthread = thread->osthread(); 906 assert(osthread->get_state() != INITIALIZED, "just checking"); 907 Monitor* sync_with_child = osthread->startThread_lock(); 908 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 909 sync_with_child->notify(); 910 } 911 912 // Free Bsd resources related to the OSThread 913 void os::free_thread(OSThread* osthread) { 914 assert(osthread != NULL, "osthread not set"); 915 916 if (Thread::current()->osthread() == osthread) { 917 // Restore caller's signal mask 918 sigset_t sigmask = osthread->caller_sigmask(); 919 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 920 } 921 922 delete osthread; 923 } 924 925 ////////////////////////////////////////////////////////////////////////////// 926 // thread local storage 927 928 // Restore the thread pointer if the destructor is called. This is in case 929 // someone from JNI code sets up a destructor with pthread_key_create to run 930 // detachCurrentThread on thread death. Unless we restore the thread pointer we 931 // will hang or crash. When detachCurrentThread is called the key will be set 932 // to null and we will not be called again. If detachCurrentThread is never 933 // called we could loop forever depending on the pthread implementation. 934 static void restore_thread_pointer(void* p) { 935 Thread* thread = (Thread*) p; 936 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread); 937 } 938 939 int os::allocate_thread_local_storage() { 940 pthread_key_t key; 941 int rslt = pthread_key_create(&key, restore_thread_pointer); 942 assert(rslt == 0, "cannot allocate thread local storage"); 943 return (int)key; 944 } 945 946 // Note: This is currently not used by VM, as we don't destroy TLS key 947 // on VM exit. 948 void os::free_thread_local_storage(int index) { 949 int rslt = pthread_key_delete((pthread_key_t)index); 950 assert(rslt == 0, "invalid index"); 951 } 952 953 void os::thread_local_storage_at_put(int index, void* value) { 954 int rslt = pthread_setspecific((pthread_key_t)index, value); 955 assert(rslt == 0, "pthread_setspecific failed"); 956 } 957 958 extern "C" Thread* get_thread() { 959 return ThreadLocalStorage::thread(); 960 } 961 962 963 //////////////////////////////////////////////////////////////////////////////// 964 // time support 965 966 // Time since start-up in seconds to a fine granularity. 967 // Used by VMSelfDestructTimer and the MemProfiler. 968 double os::elapsedTime() { 969 970 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); 971 } 972 973 jlong os::elapsed_counter() { 974 return javaTimeNanos() - initial_time_count; 975 } 976 977 jlong os::elapsed_frequency() { 978 return NANOSECS_PER_SEC; // nanosecond resolution 979 } 980 981 bool os::supports_vtime() { return true; } 982 bool os::enable_vtime() { return false; } 983 bool os::vtime_enabled() { return false; } 984 985 double os::elapsedVTime() { 986 // better than nothing, but not much 987 return elapsedTime(); 988 } 989 990 jlong os::javaTimeMillis() { 991 timeval time; 992 int status = gettimeofday(&time, NULL); 993 assert(status != -1, "bsd error"); 994 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 995 } 996 997 #ifndef __APPLE__ 998 #ifndef CLOCK_MONOTONIC 999 #define CLOCK_MONOTONIC (1) 1000 #endif 1001 #endif 1002 1003 #ifdef __APPLE__ 1004 void os::Bsd::clock_init() { 1005 mach_timebase_info(&_timebase_info); 1006 } 1007 #else 1008 void os::Bsd::clock_init() { 1009 struct timespec res; 1010 struct timespec tp; 1011 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && 1012 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { 1013 // yes, monotonic clock is supported 1014 _clock_gettime = ::clock_gettime; 1015 } 1016 } 1017 #endif 1018 1019 1020 #ifdef __APPLE__ 1021 1022 jlong os::javaTimeNanos() { 1023 const uint64_t tm = mach_absolute_time(); 1024 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom; 1025 const uint64_t prev = Bsd::_max_abstime; 1026 if (now <= prev) { 1027 return prev; // same or retrograde time; 1028 } 1029 const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev); 1030 assert(obsv >= prev, "invariant"); // Monotonicity 1031 // If the CAS succeeded then we're done and return "now". 1032 // If the CAS failed and the observed value "obsv" is >= now then 1033 // we should return "obsv". If the CAS failed and now > obsv > prv then 1034 // some other thread raced this thread and installed a new value, in which case 1035 // we could either (a) retry the entire operation, (b) retry trying to install now 1036 // or (c) just return obsv. We use (c). No loop is required although in some cases 1037 // we might discard a higher "now" value in deference to a slightly lower but freshly 1038 // installed obsv value. That's entirely benign -- it admits no new orderings compared 1039 // to (a) or (b) -- and greatly reduces coherence traffic. 1040 // We might also condition (c) on the magnitude of the delta between obsv and now. 1041 // Avoiding excessive CAS operations to hot RW locations is critical. 1042 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate 1043 return (prev == obsv) ? now : obsv; 1044 } 1045 1046 #else // __APPLE__ 1047 1048 jlong os::javaTimeNanos() { 1049 if (Bsd::supports_monotonic_clock()) { 1050 struct timespec tp; 1051 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp); 1052 assert(status == 0, "gettime error"); 1053 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1054 return result; 1055 } else { 1056 timeval time; 1057 int status = gettimeofday(&time, NULL); 1058 assert(status != -1, "bsd error"); 1059 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1060 return 1000 * usecs; 1061 } 1062 } 1063 1064 #endif // __APPLE__ 1065 1066 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1067 if (Bsd::supports_monotonic_clock()) { 1068 info_ptr->max_value = ALL_64_BITS; 1069 1070 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1071 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1072 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1073 } else { 1074 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1075 info_ptr->max_value = ALL_64_BITS; 1076 1077 // gettimeofday is a real time clock so it skips 1078 info_ptr->may_skip_backward = true; 1079 info_ptr->may_skip_forward = true; 1080 } 1081 1082 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1083 } 1084 1085 // Return the real, user, and system times in seconds from an 1086 // arbitrary fixed point in the past. 1087 bool os::getTimesSecs(double* process_real_time, 1088 double* process_user_time, 1089 double* process_system_time) { 1090 struct tms ticks; 1091 clock_t real_ticks = times(&ticks); 1092 1093 if (real_ticks == (clock_t) (-1)) { 1094 return false; 1095 } else { 1096 double ticks_per_second = (double) clock_tics_per_sec; 1097 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1098 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1099 *process_real_time = ((double) real_ticks) / ticks_per_second; 1100 1101 return true; 1102 } 1103 } 1104 1105 1106 char * os::local_time_string(char *buf, size_t buflen) { 1107 struct tm t; 1108 time_t long_time; 1109 time(&long_time); 1110 localtime_r(&long_time, &t); 1111 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1112 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1113 t.tm_hour, t.tm_min, t.tm_sec); 1114 return buf; 1115 } 1116 1117 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1118 return localtime_r(clock, res); 1119 } 1120 1121 //////////////////////////////////////////////////////////////////////////////// 1122 // runtime exit support 1123 1124 // Note: os::shutdown() might be called very early during initialization, or 1125 // called from signal handler. Before adding something to os::shutdown(), make 1126 // sure it is async-safe and can handle partially initialized VM. 1127 void os::shutdown() { 1128 1129 // allow PerfMemory to attempt cleanup of any persistent resources 1130 perfMemory_exit(); 1131 1132 // needs to remove object in file system 1133 AttachListener::abort(); 1134 1135 // flush buffered output, finish log files 1136 ostream_abort(); 1137 1138 // Check for abort hook 1139 abort_hook_t abort_hook = Arguments::abort_hook(); 1140 if (abort_hook != NULL) { 1141 abort_hook(); 1142 } 1143 1144 } 1145 1146 // Note: os::abort() might be called very early during initialization, or 1147 // called from signal handler. Before adding something to os::abort(), make 1148 // sure it is async-safe and can handle partially initialized VM. 1149 void os::abort(bool dump_core) { 1150 os::shutdown(); 1151 if (dump_core) { 1152 #ifndef PRODUCT 1153 fdStream out(defaultStream::output_fd()); 1154 out.print_raw("Current thread is "); 1155 char buf[16]; 1156 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1157 out.print_raw_cr(buf); 1158 out.print_raw_cr("Dumping core ..."); 1159 #endif 1160 ::abort(); // dump core 1161 } 1162 1163 ::exit(1); 1164 } 1165 1166 // Die immediately, no exit hook, no abort hook, no cleanup. 1167 void os::die() { 1168 // _exit() on BsdThreads only kills current thread 1169 ::abort(); 1170 } 1171 1172 // This method is a copy of JDK's sysGetLastErrorString 1173 // from src/solaris/hpi/src/system_md.c 1174 1175 size_t os::lasterror(char *buf, size_t len) { 1176 1177 if (errno == 0) return 0; 1178 1179 const char *s = ::strerror(errno); 1180 size_t n = ::strlen(s); 1181 if (n >= len) { 1182 n = len - 1; 1183 } 1184 ::strncpy(buf, s, n); 1185 buf[n] = '\0'; 1186 return n; 1187 } 1188 1189 // Information of current thread in variety of formats 1190 pid_t os::Bsd::gettid() { 1191 int retval = -1; 1192 1193 #ifdef __APPLE__ //XNU kernel 1194 // despite the fact mach port is actually not a thread id use it 1195 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4 1196 retval = ::pthread_mach_thread_np(::pthread_self()); 1197 guarantee(retval != 0, "just checking"); 1198 return retval; 1199 1200 #else 1201 #ifdef __FreeBSD__ 1202 retval = syscall(SYS_thr_self); 1203 #else 1204 #ifdef __OpenBSD__ 1205 retval = syscall(SYS_getthrid); 1206 #else 1207 #ifdef __NetBSD__ 1208 retval = (pid_t) syscall(SYS__lwp_self); 1209 #endif 1210 #endif 1211 #endif 1212 #endif 1213 1214 if (retval == -1) { 1215 return getpid(); 1216 } 1217 } 1218 1219 intx os::current_thread_id() { 1220 #ifdef __APPLE__ 1221 return (intx)::pthread_mach_thread_np(::pthread_self()); 1222 #else 1223 return (intx)::pthread_self(); 1224 #endif 1225 } 1226 1227 int os::current_process_id() { 1228 1229 // Under the old bsd thread library, bsd gives each thread 1230 // its own process id. Because of this each thread will return 1231 // a different pid if this method were to return the result 1232 // of getpid(2). Bsd provides no api that returns the pid 1233 // of the launcher thread for the vm. This implementation 1234 // returns a unique pid, the pid of the launcher thread 1235 // that starts the vm 'process'. 1236 1237 // Under the NPTL, getpid() returns the same pid as the 1238 // launcher thread rather than a unique pid per thread. 1239 // Use gettid() if you want the old pre NPTL behaviour. 1240 1241 // if you are looking for the result of a call to getpid() that 1242 // returns a unique pid for the calling thread, then look at the 1243 // OSThread::thread_id() method in osThread_bsd.hpp file 1244 1245 return (int)(_initial_pid ? _initial_pid : getpid()); 1246 } 1247 1248 // DLL functions 1249 1250 #define JNI_LIB_PREFIX "lib" 1251 #ifdef __APPLE__ 1252 #define JNI_LIB_SUFFIX ".dylib" 1253 #else 1254 #define JNI_LIB_SUFFIX ".so" 1255 #endif 1256 1257 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } 1258 1259 // This must be hard coded because it's the system's temporary 1260 // directory not the java application's temp directory, ala java.io.tmpdir. 1261 #ifdef __APPLE__ 1262 // macosx has a secure per-user temporary directory 1263 char temp_path_storage[PATH_MAX]; 1264 const char* os::get_temp_directory() { 1265 static char *temp_path = NULL; 1266 if (temp_path == NULL) { 1267 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX); 1268 if (pathSize == 0 || pathSize > PATH_MAX) { 1269 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage)); 1270 } 1271 temp_path = temp_path_storage; 1272 } 1273 return temp_path; 1274 } 1275 #else /* __APPLE__ */ 1276 const char* os::get_temp_directory() { return "/tmp"; } 1277 #endif /* __APPLE__ */ 1278 1279 static bool file_exists(const char* filename) { 1280 struct stat statbuf; 1281 if (filename == NULL || strlen(filename) == 0) { 1282 return false; 1283 } 1284 return os::stat(filename, &statbuf) == 0; 1285 } 1286 1287 bool os::dll_build_name(char* buffer, size_t buflen, 1288 const char* pname, const char* fname) { 1289 bool retval = false; 1290 // Copied from libhpi 1291 const size_t pnamelen = pname ? strlen(pname) : 0; 1292 1293 // Return error on buffer overflow. 1294 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { 1295 return retval; 1296 } 1297 1298 if (pnamelen == 0) { 1299 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); 1300 retval = true; 1301 } else if (strchr(pname, *os::path_separator()) != NULL) { 1302 int n; 1303 char** pelements = split_path(pname, &n); 1304 if (pelements == NULL) { 1305 return false; 1306 } 1307 for (int i = 0 ; i < n ; i++) { 1308 // Really shouldn't be NULL, but check can't hurt 1309 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1310 continue; // skip the empty path values 1311 } 1312 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, 1313 pelements[i], fname); 1314 if (file_exists(buffer)) { 1315 retval = true; 1316 break; 1317 } 1318 } 1319 // release the storage 1320 for (int i = 0 ; i < n ; i++) { 1321 if (pelements[i] != NULL) { 1322 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal); 1323 } 1324 } 1325 if (pelements != NULL) { 1326 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal); 1327 } 1328 } else { 1329 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); 1330 retval = true; 1331 } 1332 return retval; 1333 } 1334 1335 // check if addr is inside libjvm.so 1336 bool os::address_is_in_vm(address addr) { 1337 static address libjvm_base_addr; 1338 Dl_info dlinfo; 1339 1340 if (libjvm_base_addr == NULL) { 1341 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1342 libjvm_base_addr = (address)dlinfo.dli_fbase; 1343 } 1344 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1345 } 1346 1347 if (dladdr((void *)addr, &dlinfo) != 0) { 1348 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1349 } 1350 1351 return false; 1352 } 1353 1354 1355 #define MACH_MAXSYMLEN 256 1356 1357 bool os::dll_address_to_function_name(address addr, char *buf, 1358 int buflen, int *offset) { 1359 // buf is not optional, but offset is optional 1360 assert(buf != NULL, "sanity check"); 1361 1362 Dl_info dlinfo; 1363 char localbuf[MACH_MAXSYMLEN]; 1364 1365 if (dladdr((void*)addr, &dlinfo) != 0) { 1366 // see if we have a matching symbol 1367 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1368 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { 1369 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1370 } 1371 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1372 return true; 1373 } 1374 // no matching symbol so try for just file info 1375 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1376 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1377 buf, buflen, offset, dlinfo.dli_fname)) { 1378 return true; 1379 } 1380 } 1381 1382 // Handle non-dynamic manually: 1383 if (dlinfo.dli_fbase != NULL && 1384 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, 1385 dlinfo.dli_fbase)) { 1386 if (!Decoder::demangle(localbuf, buf, buflen)) { 1387 jio_snprintf(buf, buflen, "%s", localbuf); 1388 } 1389 return true; 1390 } 1391 } 1392 buf[0] = '\0'; 1393 if (offset != NULL) *offset = -1; 1394 return false; 1395 } 1396 1397 // ported from solaris version 1398 bool os::dll_address_to_library_name(address addr, char* buf, 1399 int buflen, int* offset) { 1400 // buf is not optional, but offset is optional 1401 assert(buf != NULL, "sanity check"); 1402 1403 Dl_info dlinfo; 1404 1405 if (dladdr((void*)addr, &dlinfo) != 0) { 1406 if (dlinfo.dli_fname != NULL) { 1407 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1408 } 1409 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1410 *offset = addr - (address)dlinfo.dli_fbase; 1411 } 1412 return true; 1413 } 1414 1415 buf[0] = '\0'; 1416 if (offset) *offset = -1; 1417 return false; 1418 } 1419 1420 // Loads .dll/.so and 1421 // in case of error it checks if .dll/.so was built for the 1422 // same architecture as Hotspot is running on 1423 1424 #ifdef __APPLE__ 1425 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1426 void * result= ::dlopen(filename, RTLD_LAZY); 1427 if (result != NULL) { 1428 // Successful loading 1429 return result; 1430 } 1431 1432 // Read system error message into ebuf 1433 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1434 ebuf[ebuflen-1]='\0'; 1435 1436 return NULL; 1437 } 1438 #else 1439 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) 1440 { 1441 void * result= ::dlopen(filename, RTLD_LAZY); 1442 if (result != NULL) { 1443 // Successful loading 1444 return result; 1445 } 1446 1447 Elf32_Ehdr elf_head; 1448 1449 // Read system error message into ebuf 1450 // It may or may not be overwritten below 1451 ::strncpy(ebuf, ::dlerror(), ebuflen-1); 1452 ebuf[ebuflen-1]='\0'; 1453 int diag_msg_max_length=ebuflen-strlen(ebuf); 1454 char* diag_msg_buf=ebuf+strlen(ebuf); 1455 1456 if (diag_msg_max_length==0) { 1457 // No more space in ebuf for additional diagnostics message 1458 return NULL; 1459 } 1460 1461 1462 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1463 1464 if (file_descriptor < 0) { 1465 // Can't open library, report dlerror() message 1466 return NULL; 1467 } 1468 1469 bool failed_to_read_elf_head= 1470 (sizeof(elf_head)!= 1471 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ; 1472 1473 ::close(file_descriptor); 1474 if (failed_to_read_elf_head) { 1475 // file i/o error - report dlerror() msg 1476 return NULL; 1477 } 1478 1479 typedef struct { 1480 Elf32_Half code; // Actual value as defined in elf.h 1481 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1482 char elf_class; // 32 or 64 bit 1483 char endianess; // MSB or LSB 1484 char* name; // String representation 1485 } arch_t; 1486 1487 #ifndef EM_486 1488 #define EM_486 6 /* Intel 80486 */ 1489 #endif 1490 1491 #ifndef EM_MIPS_RS3_LE 1492 #define EM_MIPS_RS3_LE 10 /* MIPS */ 1493 #endif 1494 1495 #ifndef EM_PPC64 1496 #define EM_PPC64 21 /* PowerPC64 */ 1497 #endif 1498 1499 #ifndef EM_S390 1500 #define EM_S390 22 /* IBM System/390 */ 1501 #endif 1502 1503 #ifndef EM_IA_64 1504 #define EM_IA_64 50 /* HP/Intel IA-64 */ 1505 #endif 1506 1507 #ifndef EM_X86_64 1508 #define EM_X86_64 62 /* AMD x86-64 */ 1509 #endif 1510 1511 static const arch_t arch_array[]={ 1512 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1513 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1514 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1515 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1516 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1517 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1518 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1519 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1520 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, 1521 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1522 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1523 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1524 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1525 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1526 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1527 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} 1528 }; 1529 1530 #if (defined IA32) 1531 static Elf32_Half running_arch_code=EM_386; 1532 #elif (defined AMD64) 1533 static Elf32_Half running_arch_code=EM_X86_64; 1534 #elif (defined IA64) 1535 static Elf32_Half running_arch_code=EM_IA_64; 1536 #elif (defined __sparc) && (defined _LP64) 1537 static Elf32_Half running_arch_code=EM_SPARCV9; 1538 #elif (defined __sparc) && (!defined _LP64) 1539 static Elf32_Half running_arch_code=EM_SPARC; 1540 #elif (defined __powerpc64__) 1541 static Elf32_Half running_arch_code=EM_PPC64; 1542 #elif (defined __powerpc__) 1543 static Elf32_Half running_arch_code=EM_PPC; 1544 #elif (defined ARM) 1545 static Elf32_Half running_arch_code=EM_ARM; 1546 #elif (defined S390) 1547 static Elf32_Half running_arch_code=EM_S390; 1548 #elif (defined ALPHA) 1549 static Elf32_Half running_arch_code=EM_ALPHA; 1550 #elif (defined MIPSEL) 1551 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1552 #elif (defined PARISC) 1553 static Elf32_Half running_arch_code=EM_PARISC; 1554 #elif (defined MIPS) 1555 static Elf32_Half running_arch_code=EM_MIPS; 1556 #elif (defined M68K) 1557 static Elf32_Half running_arch_code=EM_68K; 1558 #else 1559 #error Method os::dll_load requires that one of following is defined:\ 1560 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K 1561 #endif 1562 1563 // Identify compatability class for VM's architecture and library's architecture 1564 // Obtain string descriptions for architectures 1565 1566 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1567 int running_arch_index=-1; 1568 1569 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) { 1570 if (running_arch_code == arch_array[i].code) { 1571 running_arch_index = i; 1572 } 1573 if (lib_arch.code == arch_array[i].code) { 1574 lib_arch.compat_class = arch_array[i].compat_class; 1575 lib_arch.name = arch_array[i].name; 1576 } 1577 } 1578 1579 assert(running_arch_index != -1, 1580 "Didn't find running architecture code (running_arch_code) in arch_array"); 1581 if (running_arch_index == -1) { 1582 // Even though running architecture detection failed 1583 // we may still continue with reporting dlerror() message 1584 return NULL; 1585 } 1586 1587 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1588 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1589 return NULL; 1590 } 1591 1592 #ifndef S390 1593 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1594 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1595 return NULL; 1596 } 1597 #endif // !S390 1598 1599 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1600 if ( lib_arch.name!=NULL ) { 1601 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1602 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1603 lib_arch.name, arch_array[running_arch_index].name); 1604 } else { 1605 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1606 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1607 lib_arch.code, 1608 arch_array[running_arch_index].name); 1609 } 1610 } 1611 1612 return NULL; 1613 } 1614 #endif /* !__APPLE__ */ 1615 1616 void* os::get_default_process_handle() { 1617 #ifdef __APPLE__ 1618 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY 1619 // to avoid finding unexpected symbols on second (or later) 1620 // loads of a library. 1621 return (void*)::dlopen(NULL, RTLD_FIRST); 1622 #else 1623 return (void*)::dlopen(NULL, RTLD_LAZY); 1624 #endif 1625 } 1626 1627 // XXX: Do we need a lock around this as per Linux? 1628 void* os::dll_lookup(void* handle, const char* name) { 1629 return dlsym(handle, name); 1630 } 1631 1632 1633 static bool _print_ascii_file(const char* filename, outputStream* st) { 1634 int fd = ::open(filename, O_RDONLY); 1635 if (fd == -1) { 1636 return false; 1637 } 1638 1639 char buf[32]; 1640 int bytes; 1641 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { 1642 st->print_raw(buf, bytes); 1643 } 1644 1645 ::close(fd); 1646 1647 return true; 1648 } 1649 1650 void os::print_dll_info(outputStream *st) { 1651 st->print_cr("Dynamic libraries:"); 1652 #ifdef RTLD_DI_LINKMAP 1653 Dl_info dli; 1654 void *handle; 1655 Link_map *map; 1656 Link_map *p; 1657 1658 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 || 1659 dli.dli_fname == NULL) { 1660 st->print_cr("Error: Cannot print dynamic libraries."); 1661 return; 1662 } 1663 handle = dlopen(dli.dli_fname, RTLD_LAZY); 1664 if (handle == NULL) { 1665 st->print_cr("Error: Cannot print dynamic libraries."); 1666 return; 1667 } 1668 dlinfo(handle, RTLD_DI_LINKMAP, &map); 1669 if (map == NULL) { 1670 st->print_cr("Error: Cannot print dynamic libraries."); 1671 return; 1672 } 1673 1674 while (map->l_prev != NULL) 1675 map = map->l_prev; 1676 1677 while (map != NULL) { 1678 st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name); 1679 map = map->l_next; 1680 } 1681 1682 dlclose(handle); 1683 #elif defined(__APPLE__) 1684 for (uint32_t i = 1; i < _dyld_image_count(); i++) { 1685 st->print_cr(PTR_FORMAT " \t%s", _dyld_get_image_header(i), 1686 _dyld_get_image_name(i)); 1687 } 1688 #else 1689 st->print_cr("Error: Cannot print dynamic libraries."); 1690 #endif 1691 } 1692 1693 void os::print_os_info_brief(outputStream* st) { 1694 st->print("Bsd"); 1695 1696 os::Posix::print_uname_info(st); 1697 } 1698 1699 void os::print_os_info(outputStream* st) { 1700 st->print("OS:"); 1701 st->print("Bsd"); 1702 1703 os::Posix::print_uname_info(st); 1704 1705 os::Posix::print_rlimit_info(st); 1706 1707 os::Posix::print_load_average(st); 1708 } 1709 1710 void os::pd_print_cpu_info(outputStream* st) { 1711 // Nothing to do for now. 1712 } 1713 1714 void os::print_memory_info(outputStream* st) { 1715 1716 st->print("Memory:"); 1717 st->print(" %dk page", os::vm_page_size()>>10); 1718 1719 st->print(", physical " UINT64_FORMAT "k", 1720 os::physical_memory() >> 10); 1721 st->print("(" UINT64_FORMAT "k free)", 1722 os::available_memory() >> 10); 1723 st->cr(); 1724 1725 // meminfo 1726 st->print("\n/proc/meminfo:\n"); 1727 _print_ascii_file("/proc/meminfo", st); 1728 st->cr(); 1729 } 1730 1731 void os::print_siginfo(outputStream* st, void* siginfo) { 1732 const siginfo_t* si = (const siginfo_t*)siginfo; 1733 1734 os::Posix::print_siginfo_brief(st, si); 1735 1736 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && 1737 UseSharedSpaces) { 1738 FileMapInfo* mapinfo = FileMapInfo::current_info(); 1739 if (mapinfo->is_in_shared_space(si->si_addr)) { 1740 st->print("\n\nError accessing class data sharing archive." \ 1741 " Mapped file inaccessible during execution, " \ 1742 " possible disk/network problem."); 1743 } 1744 } 1745 st->cr(); 1746 } 1747 1748 1749 static void print_signal_handler(outputStream* st, int sig, 1750 char* buf, size_t buflen); 1751 1752 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 1753 st->print_cr("Signal Handlers:"); 1754 print_signal_handler(st, SIGSEGV, buf, buflen); 1755 print_signal_handler(st, SIGBUS , buf, buflen); 1756 print_signal_handler(st, SIGFPE , buf, buflen); 1757 print_signal_handler(st, SIGPIPE, buf, buflen); 1758 print_signal_handler(st, SIGXFSZ, buf, buflen); 1759 print_signal_handler(st, SIGILL , buf, buflen); 1760 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); 1761 print_signal_handler(st, SR_signum, buf, buflen); 1762 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 1763 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 1764 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 1765 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 1766 } 1767 1768 static char saved_jvm_path[MAXPATHLEN] = {0}; 1769 1770 // Find the full path to the current module, libjvm 1771 void os::jvm_path(char *buf, jint buflen) { 1772 // Error checking. 1773 if (buflen < MAXPATHLEN) { 1774 assert(false, "must use a large-enough buffer"); 1775 buf[0] = '\0'; 1776 return; 1777 } 1778 // Lazy resolve the path to current module. 1779 if (saved_jvm_path[0] != 0) { 1780 strcpy(buf, saved_jvm_path); 1781 return; 1782 } 1783 1784 char dli_fname[MAXPATHLEN]; 1785 bool ret = dll_address_to_library_name( 1786 CAST_FROM_FN_PTR(address, os::jvm_path), 1787 dli_fname, sizeof(dli_fname), NULL); 1788 assert(ret, "cannot locate libjvm"); 1789 char *rp = NULL; 1790 if (ret && dli_fname[0] != '\0') { 1791 rp = realpath(dli_fname, buf); 1792 } 1793 if (rp == NULL) 1794 return; 1795 1796 if (Arguments::created_by_gamma_launcher()) { 1797 // Support for the gamma launcher. Typical value for buf is 1798 // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm". If "/jre/lib/" appears at 1799 // the right place in the string, then assume we are installed in a JDK and 1800 // we're done. Otherwise, check for a JAVA_HOME environment variable and 1801 // construct a path to the JVM being overridden. 1802 1803 const char *p = buf + strlen(buf) - 1; 1804 for (int count = 0; p > buf && count < 5; ++count) { 1805 for (--p; p > buf && *p != '/'; --p) 1806 /* empty */ ; 1807 } 1808 1809 if (strncmp(p, "/jre/lib/", 9) != 0) { 1810 // Look for JAVA_HOME in the environment. 1811 char* java_home_var = ::getenv("JAVA_HOME"); 1812 if (java_home_var != NULL && java_home_var[0] != 0) { 1813 char* jrelib_p; 1814 int len; 1815 1816 // Check the current module name "libjvm" 1817 p = strrchr(buf, '/'); 1818 assert(strstr(p, "/libjvm") == p, "invalid library name"); 1819 1820 rp = realpath(java_home_var, buf); 1821 if (rp == NULL) 1822 return; 1823 1824 // determine if this is a legacy image or modules image 1825 // modules image doesn't have "jre" subdirectory 1826 len = strlen(buf); 1827 assert(len < buflen, "Ran out of buffer space"); 1828 jrelib_p = buf + len; 1829 1830 // Add the appropriate library subdir 1831 snprintf(jrelib_p, buflen-len, "/jre/lib"); 1832 if (0 != access(buf, F_OK)) { 1833 snprintf(jrelib_p, buflen-len, "/lib"); 1834 } 1835 1836 // Add the appropriate client or server subdir 1837 len = strlen(buf); 1838 jrelib_p = buf + len; 1839 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT); 1840 if (0 != access(buf, F_OK)) { 1841 snprintf(jrelib_p, buflen-len, ""); 1842 } 1843 1844 // If the path exists within JAVA_HOME, add the JVM library name 1845 // to complete the path to JVM being overridden. Otherwise fallback 1846 // to the path to the current library. 1847 if (0 == access(buf, F_OK)) { 1848 // Use current module name "libjvm" 1849 len = strlen(buf); 1850 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX); 1851 } else { 1852 // Fall back to path of current library 1853 rp = realpath(dli_fname, buf); 1854 if (rp == NULL) 1855 return; 1856 } 1857 } 1858 } 1859 } 1860 1861 strncpy(saved_jvm_path, buf, MAXPATHLEN); 1862 } 1863 1864 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 1865 // no prefix required, not even "_" 1866 } 1867 1868 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 1869 // no suffix required 1870 } 1871 1872 //////////////////////////////////////////////////////////////////////////////// 1873 // sun.misc.Signal support 1874 1875 static volatile jint sigint_count = 0; 1876 1877 static void 1878 UserHandler(int sig, void *siginfo, void *context) { 1879 // 4511530 - sem_post is serialized and handled by the manager thread. When 1880 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 1881 // don't want to flood the manager thread with sem_post requests. 1882 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) 1883 return; 1884 1885 // Ctrl-C is pressed during error reporting, likely because the error 1886 // handler fails to abort. Let VM die immediately. 1887 if (sig == SIGINT && is_error_reported()) { 1888 os::die(); 1889 } 1890 1891 os::signal_notify(sig); 1892 } 1893 1894 void* os::user_handler() { 1895 return CAST_FROM_FN_PTR(void*, UserHandler); 1896 } 1897 1898 extern "C" { 1899 typedef void (*sa_handler_t)(int); 1900 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1901 } 1902 1903 void* os::signal(int signal_number, void* handler) { 1904 struct sigaction sigAct, oldSigAct; 1905 1906 sigfillset(&(sigAct.sa_mask)); 1907 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 1908 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 1909 1910 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 1911 // -1 means registration failed 1912 return (void *)-1; 1913 } 1914 1915 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 1916 } 1917 1918 void os::signal_raise(int signal_number) { 1919 ::raise(signal_number); 1920 } 1921 1922 /* 1923 * The following code is moved from os.cpp for making this 1924 * code platform specific, which it is by its very nature. 1925 */ 1926 1927 // Will be modified when max signal is changed to be dynamic 1928 int os::sigexitnum_pd() { 1929 return NSIG; 1930 } 1931 1932 // a counter for each possible signal value 1933 static volatile jint pending_signals[NSIG+1] = { 0 }; 1934 1935 // Bsd(POSIX) specific hand shaking semaphore. 1936 #ifdef __APPLE__ 1937 typedef semaphore_t os_semaphore_t; 1938 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) 1939 #define SEM_WAIT(sem) semaphore_wait(sem) 1940 #define SEM_POST(sem) semaphore_signal(sem) 1941 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem) 1942 #else 1943 typedef sem_t os_semaphore_t; 1944 #define SEM_INIT(sem, value) sem_init(&sem, 0, value) 1945 #define SEM_WAIT(sem) sem_wait(&sem) 1946 #define SEM_POST(sem) sem_post(&sem) 1947 #define SEM_DESTROY(sem) sem_destroy(&sem) 1948 #endif 1949 1950 class Semaphore : public StackObj { 1951 public: 1952 Semaphore(); 1953 ~Semaphore(); 1954 void signal(); 1955 void wait(); 1956 bool trywait(); 1957 bool timedwait(unsigned int sec, int nsec); 1958 private: 1959 jlong currenttime() const; 1960 os_semaphore_t _semaphore; 1961 }; 1962 1963 Semaphore::Semaphore() : _semaphore(0) { 1964 SEM_INIT(_semaphore, 0); 1965 } 1966 1967 Semaphore::~Semaphore() { 1968 SEM_DESTROY(_semaphore); 1969 } 1970 1971 void Semaphore::signal() { 1972 SEM_POST(_semaphore); 1973 } 1974 1975 void Semaphore::wait() { 1976 SEM_WAIT(_semaphore); 1977 } 1978 1979 jlong Semaphore::currenttime() const { 1980 struct timeval tv; 1981 gettimeofday(&tv, NULL); 1982 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000); 1983 } 1984 1985 #ifdef __APPLE__ 1986 bool Semaphore::trywait() { 1987 return timedwait(0, 0); 1988 } 1989 1990 bool Semaphore::timedwait(unsigned int sec, int nsec) { 1991 kern_return_t kr = KERN_ABORTED; 1992 mach_timespec_t waitspec; 1993 waitspec.tv_sec = sec; 1994 waitspec.tv_nsec = nsec; 1995 1996 jlong starttime = currenttime(); 1997 1998 kr = semaphore_timedwait(_semaphore, waitspec); 1999 while (kr == KERN_ABORTED) { 2000 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec; 2001 2002 jlong current = currenttime(); 2003 jlong passedtime = current - starttime; 2004 2005 if (passedtime >= totalwait) { 2006 waitspec.tv_sec = 0; 2007 waitspec.tv_nsec = 0; 2008 } else { 2009 jlong waittime = totalwait - (current - starttime); 2010 waitspec.tv_sec = waittime / NANOSECS_PER_SEC; 2011 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC; 2012 } 2013 2014 kr = semaphore_timedwait(_semaphore, waitspec); 2015 } 2016 2017 return kr == KERN_SUCCESS; 2018 } 2019 2020 #else 2021 2022 bool Semaphore::trywait() { 2023 return sem_trywait(&_semaphore) == 0; 2024 } 2025 2026 bool Semaphore::timedwait(unsigned int sec, int nsec) { 2027 struct timespec ts; 2028 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec); 2029 2030 while (1) { 2031 int result = sem_timedwait(&_semaphore, &ts); 2032 if (result == 0) { 2033 return true; 2034 } else if (errno == EINTR) { 2035 continue; 2036 } else if (errno == ETIMEDOUT) { 2037 return false; 2038 } else { 2039 return false; 2040 } 2041 } 2042 } 2043 2044 #endif // __APPLE__ 2045 2046 static os_semaphore_t sig_sem; 2047 static Semaphore sr_semaphore; 2048 2049 void os::signal_init_pd() { 2050 // Initialize signal structures 2051 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2052 2053 // Initialize signal semaphore 2054 ::SEM_INIT(sig_sem, 0); 2055 } 2056 2057 void os::signal_notify(int sig) { 2058 Atomic::inc(&pending_signals[sig]); 2059 ::SEM_POST(sig_sem); 2060 } 2061 2062 static int check_pending_signals(bool wait) { 2063 Atomic::store(0, &sigint_count); 2064 for (;;) { 2065 for (int i = 0; i < NSIG + 1; i++) { 2066 jint n = pending_signals[i]; 2067 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2068 return i; 2069 } 2070 } 2071 if (!wait) { 2072 return -1; 2073 } 2074 JavaThread *thread = JavaThread::current(); 2075 ThreadBlockInVM tbivm(thread); 2076 2077 bool threadIsSuspended; 2078 do { 2079 thread->set_suspend_equivalent(); 2080 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2081 ::SEM_WAIT(sig_sem); 2082 2083 // were we externally suspended while we were waiting? 2084 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2085 if (threadIsSuspended) { 2086 // 2087 // The semaphore has been incremented, but while we were waiting 2088 // another thread suspended us. We don't want to continue running 2089 // while suspended because that would surprise the thread that 2090 // suspended us. 2091 // 2092 ::SEM_POST(sig_sem); 2093 2094 thread->java_suspend_self(); 2095 } 2096 } while (threadIsSuspended); 2097 } 2098 } 2099 2100 int os::signal_lookup() { 2101 return check_pending_signals(false); 2102 } 2103 2104 int os::signal_wait() { 2105 return check_pending_signals(true); 2106 } 2107 2108 //////////////////////////////////////////////////////////////////////////////// 2109 // Virtual Memory 2110 2111 int os::vm_page_size() { 2112 // Seems redundant as all get out 2113 assert(os::Bsd::page_size() != -1, "must call os::init"); 2114 return os::Bsd::page_size(); 2115 } 2116 2117 // Solaris allocates memory by pages. 2118 int os::vm_allocation_granularity() { 2119 assert(os::Bsd::page_size() != -1, "must call os::init"); 2120 return os::Bsd::page_size(); 2121 } 2122 2123 // Rationale behind this function: 2124 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2125 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2126 // samples for JITted code. Here we create private executable mapping over the code cache 2127 // and then we can use standard (well, almost, as mapping can change) way to provide 2128 // info for the reporting script by storing timestamp and location of symbol 2129 void bsd_wrap_code(char* base, size_t size) { 2130 static volatile jint cnt = 0; 2131 2132 if (!UseOprofile) { 2133 return; 2134 } 2135 2136 char buf[PATH_MAX + 1]; 2137 int num = Atomic::add(1, &cnt); 2138 2139 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", 2140 os::get_temp_directory(), os::current_process_id(), num); 2141 unlink(buf); 2142 2143 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2144 2145 if (fd != -1) { 2146 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2147 if (rv != (off_t)-1) { 2148 if (::write(fd, "", 1) == 1) { 2149 mmap(base, size, 2150 PROT_READ|PROT_WRITE|PROT_EXEC, 2151 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2152 } 2153 } 2154 ::close(fd); 2155 unlink(buf); 2156 } 2157 } 2158 2159 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2160 int err) { 2161 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2162 ", %d) failed; error='%s' (errno=%d)", addr, size, exec, 2163 strerror(err), err); 2164 } 2165 2166 // NOTE: Bsd kernel does not really reserve the pages for us. 2167 // All it does is to check if there are enough free pages 2168 // left at the time of mmap(). This could be a potential 2169 // problem. 2170 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2171 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2172 #ifdef __OpenBSD__ 2173 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2174 if (::mprotect(addr, size, prot) == 0) { 2175 return true; 2176 } 2177 #else 2178 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2179 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2180 if (res != (uintptr_t) MAP_FAILED) { 2181 return true; 2182 } 2183 #endif 2184 2185 // Warn about any commit errors we see in non-product builds just 2186 // in case mmap() doesn't work as described on the man page. 2187 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);) 2188 2189 return false; 2190 } 2191 2192 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2193 bool exec) { 2194 // alignment_hint is ignored on this OS 2195 return pd_commit_memory(addr, size, exec); 2196 } 2197 2198 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2199 const char* mesg) { 2200 assert(mesg != NULL, "mesg must be specified"); 2201 if (!pd_commit_memory(addr, size, exec)) { 2202 // add extra info in product mode for vm_exit_out_of_memory(): 2203 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);) 2204 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg); 2205 } 2206 } 2207 2208 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2209 size_t alignment_hint, bool exec, 2210 const char* mesg) { 2211 // alignment_hint is ignored on this OS 2212 pd_commit_memory_or_exit(addr, size, exec, mesg); 2213 } 2214 2215 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2216 } 2217 2218 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2219 ::madvise(addr, bytes, MADV_DONTNEED); 2220 } 2221 2222 void os::numa_make_global(char *addr, size_t bytes) { 2223 } 2224 2225 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2226 } 2227 2228 bool os::numa_topology_changed() { return false; } 2229 2230 size_t os::numa_get_groups_num() { 2231 return 1; 2232 } 2233 2234 int os::numa_get_group_id() { 2235 return 0; 2236 } 2237 2238 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2239 if (size > 0) { 2240 ids[0] = 0; 2241 return 1; 2242 } 2243 return 0; 2244 } 2245 2246 bool os::get_page_info(char *start, page_info* info) { 2247 return false; 2248 } 2249 2250 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { 2251 return end; 2252 } 2253 2254 2255 bool os::pd_uncommit_memory(char* addr, size_t size) { 2256 #ifdef __OpenBSD__ 2257 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD 2258 return ::mprotect(addr, size, PROT_NONE) == 0; 2259 #else 2260 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 2261 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 2262 return res != (uintptr_t) MAP_FAILED; 2263 #endif 2264 } 2265 2266 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 2267 return os::commit_memory(addr, size, !ExecMem); 2268 } 2269 2270 // If this is a growable mapping, remove the guard pages entirely by 2271 // munmap()ping them. If not, just call uncommit_memory(). 2272 bool os::remove_stack_guard_pages(char* addr, size_t size) { 2273 return os::uncommit_memory(addr, size); 2274 } 2275 2276 static address _highest_vm_reserved_address = NULL; 2277 2278 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 2279 // at 'requested_addr'. If there are existing memory mappings at the same 2280 // location, however, they will be overwritten. If 'fixed' is false, 2281 // 'requested_addr' is only treated as a hint, the return value may or 2282 // may not start from the requested address. Unlike Bsd mmap(), this 2283 // function returns NULL to indicate failure. 2284 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 2285 char * addr; 2286 int flags; 2287 2288 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 2289 if (fixed) { 2290 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); 2291 flags |= MAP_FIXED; 2292 } 2293 2294 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 2295 // touch an uncommitted page. Otherwise, the read/write might 2296 // succeed if we have enough swap space to back the physical page. 2297 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 2298 flags, -1, 0); 2299 2300 if (addr != MAP_FAILED) { 2301 // anon_mmap() should only get called during VM initialization, 2302 // don't need lock (actually we can skip locking even it can be called 2303 // from multiple threads, because _highest_vm_reserved_address is just a 2304 // hint about the upper limit of non-stack memory regions.) 2305 if ((address)addr + bytes > _highest_vm_reserved_address) { 2306 _highest_vm_reserved_address = (address)addr + bytes; 2307 } 2308 } 2309 2310 return addr == MAP_FAILED ? NULL : addr; 2311 } 2312 2313 // Don't update _highest_vm_reserved_address, because there might be memory 2314 // regions above addr + size. If so, releasing a memory region only creates 2315 // a hole in the address space, it doesn't help prevent heap-stack collision. 2316 // 2317 static int anon_munmap(char * addr, size_t size) { 2318 return ::munmap(addr, size) == 0; 2319 } 2320 2321 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 2322 size_t alignment_hint) { 2323 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 2324 } 2325 2326 bool os::pd_release_memory(char* addr, size_t size) { 2327 return anon_munmap(addr, size); 2328 } 2329 2330 static bool bsd_mprotect(char* addr, size_t size, int prot) { 2331 // Bsd wants the mprotect address argument to be page aligned. 2332 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); 2333 2334 // According to SUSv3, mprotect() should only be used with mappings 2335 // established by mmap(), and mmap() always maps whole pages. Unaligned 2336 // 'addr' likely indicates problem in the VM (e.g. trying to change 2337 // protection of malloc'ed or statically allocated memory). Check the 2338 // caller if you hit this assert. 2339 assert(addr == bottom, "sanity check"); 2340 2341 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); 2342 return ::mprotect(bottom, size, prot) == 0; 2343 } 2344 2345 // Set protections specified 2346 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 2347 bool is_committed) { 2348 unsigned int p = 0; 2349 switch (prot) { 2350 case MEM_PROT_NONE: p = PROT_NONE; break; 2351 case MEM_PROT_READ: p = PROT_READ; break; 2352 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 2353 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 2354 default: 2355 ShouldNotReachHere(); 2356 } 2357 // is_committed is unused. 2358 return bsd_mprotect(addr, bytes, p); 2359 } 2360 2361 bool os::guard_memory(char* addr, size_t size) { 2362 return bsd_mprotect(addr, size, PROT_NONE); 2363 } 2364 2365 bool os::unguard_memory(char* addr, size_t size) { 2366 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); 2367 } 2368 2369 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { 2370 return false; 2371 } 2372 2373 // Large page support 2374 2375 static size_t _large_page_size = 0; 2376 2377 void os::large_page_init() { 2378 } 2379 2380 2381 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) { 2382 fatal("This code is not used or maintained."); 2383 2384 // "exec" is passed in but not used. Creating the shared image for 2385 // the code cache doesn't have an SHM_X executable permission to check. 2386 assert(UseLargePages && UseSHM, "only for SHM large pages"); 2387 2388 key_t key = IPC_PRIVATE; 2389 char *addr; 2390 2391 bool warn_on_failure = UseLargePages && 2392 (!FLAG_IS_DEFAULT(UseLargePages) || 2393 !FLAG_IS_DEFAULT(LargePageSizeInBytes) 2394 ); 2395 2396 // Create a large shared memory region to attach to based on size. 2397 // Currently, size is the total size of the heap 2398 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); 2399 if (shmid == -1) { 2400 // Possible reasons for shmget failure: 2401 // 1. shmmax is too small for Java heap. 2402 // > check shmmax value: cat /proc/sys/kernel/shmmax 2403 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 2404 // 2. not enough large page memory. 2405 // > check available large pages: cat /proc/meminfo 2406 // > increase amount of large pages: 2407 // echo new_value > /proc/sys/vm/nr_hugepages 2408 // Note 1: different Bsd may use different name for this property, 2409 // e.g. on Redhat AS-3 it is "hugetlb_pool". 2410 // Note 2: it's possible there's enough physical memory available but 2411 // they are so fragmented after a long run that they can't 2412 // coalesce into large pages. Try to reserve large pages when 2413 // the system is still "fresh". 2414 if (warn_on_failure) { 2415 warning("Failed to reserve shared memory (errno = %d).", errno); 2416 } 2417 return NULL; 2418 } 2419 2420 // attach to the region 2421 addr = (char*)shmat(shmid, req_addr, 0); 2422 int err = errno; 2423 2424 // Remove shmid. If shmat() is successful, the actual shared memory segment 2425 // will be deleted when it's detached by shmdt() or when the process 2426 // terminates. If shmat() is not successful this will remove the shared 2427 // segment immediately. 2428 shmctl(shmid, IPC_RMID, NULL); 2429 2430 if ((intptr_t)addr == -1) { 2431 if (warn_on_failure) { 2432 warning("Failed to attach shared memory (errno = %d).", err); 2433 } 2434 return NULL; 2435 } 2436 2437 // The memory is committed 2438 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 2439 2440 return addr; 2441 } 2442 2443 bool os::release_memory_special(char* base, size_t bytes) { 2444 if (MemTracker::tracking_level() > NMT_minimal) { 2445 Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 2446 // detaching the SHM segment will also delete it, see reserve_memory_special() 2447 int rslt = shmdt(base); 2448 if (rslt == 0) { 2449 tkr.record((address)base, bytes); 2450 return true; 2451 } else { 2452 return false; 2453 } 2454 } else { 2455 return shmdt(base) == 0; 2456 } 2457 } 2458 2459 size_t os::large_page_size() { 2460 return _large_page_size; 2461 } 2462 2463 // HugeTLBFS allows application to commit large page memory on demand; 2464 // with SysV SHM the entire memory region must be allocated as shared 2465 // memory. 2466 bool os::can_commit_large_page_memory() { 2467 return UseHugeTLBFS; 2468 } 2469 2470 bool os::can_execute_large_page_memory() { 2471 return UseHugeTLBFS; 2472 } 2473 2474 // Reserve memory at an arbitrary address, only if that area is 2475 // available (and not reserved for something else). 2476 2477 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 2478 const int max_tries = 10; 2479 char* base[max_tries]; 2480 size_t size[max_tries]; 2481 const size_t gap = 0x000000; 2482 2483 // Assert only that the size is a multiple of the page size, since 2484 // that's all that mmap requires, and since that's all we really know 2485 // about at this low abstraction level. If we need higher alignment, 2486 // we can either pass an alignment to this method or verify alignment 2487 // in one of the methods further up the call chain. See bug 5044738. 2488 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 2489 2490 // Repeatedly allocate blocks until the block is allocated at the 2491 // right spot. Give up after max_tries. Note that reserve_memory() will 2492 // automatically update _highest_vm_reserved_address if the call is 2493 // successful. The variable tracks the highest memory address every reserved 2494 // by JVM. It is used to detect heap-stack collision if running with 2495 // fixed-stack BsdThreads. Because here we may attempt to reserve more 2496 // space than needed, it could confuse the collision detecting code. To 2497 // solve the problem, save current _highest_vm_reserved_address and 2498 // calculate the correct value before return. 2499 address old_highest = _highest_vm_reserved_address; 2500 2501 // Bsd mmap allows caller to pass an address as hint; give it a try first, 2502 // if kernel honors the hint then we can return immediately. 2503 char * addr = anon_mmap(requested_addr, bytes, false); 2504 if (addr == requested_addr) { 2505 return requested_addr; 2506 } 2507 2508 if (addr != NULL) { 2509 // mmap() is successful but it fails to reserve at the requested address 2510 anon_munmap(addr, bytes); 2511 } 2512 2513 int i; 2514 for (i = 0; i < max_tries; ++i) { 2515 base[i] = reserve_memory(bytes); 2516 2517 if (base[i] != NULL) { 2518 // Is this the block we wanted? 2519 if (base[i] == requested_addr) { 2520 size[i] = bytes; 2521 break; 2522 } 2523 2524 // Does this overlap the block we wanted? Give back the overlapped 2525 // parts and try again. 2526 2527 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; 2528 if (top_overlap >= 0 && top_overlap < bytes) { 2529 unmap_memory(base[i], top_overlap); 2530 base[i] += top_overlap; 2531 size[i] = bytes - top_overlap; 2532 } else { 2533 size_t bottom_overlap = base[i] + bytes - requested_addr; 2534 if (bottom_overlap >= 0 && bottom_overlap < bytes) { 2535 unmap_memory(requested_addr, bottom_overlap); 2536 size[i] = bytes - bottom_overlap; 2537 } else { 2538 size[i] = bytes; 2539 } 2540 } 2541 } 2542 } 2543 2544 // Give back the unused reserved pieces. 2545 2546 for (int j = 0; j < i; ++j) { 2547 if (base[j] != NULL) { 2548 unmap_memory(base[j], size[j]); 2549 } 2550 } 2551 2552 if (i < max_tries) { 2553 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); 2554 return requested_addr; 2555 } else { 2556 _highest_vm_reserved_address = old_highest; 2557 return NULL; 2558 } 2559 } 2560 2561 size_t os::read(int fd, void *buf, unsigned int nBytes) { 2562 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); 2563 } 2564 2565 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation. 2566 // Solaris uses poll(), bsd uses park(). 2567 // Poll() is likely a better choice, assuming that Thread.interrupt() 2568 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with 2569 // SIGSEGV, see 4355769. 2570 2571 int os::sleep(Thread* thread, jlong millis, bool interruptible) { 2572 assert(thread == Thread::current(), "thread consistency check"); 2573 2574 ParkEvent * const slp = thread->_SleepEvent ; 2575 slp->reset() ; 2576 OrderAccess::fence() ; 2577 2578 if (interruptible) { 2579 jlong prevtime = javaTimeNanos(); 2580 2581 for (;;) { 2582 if (os::is_interrupted(thread, true)) { 2583 return OS_INTRPT; 2584 } 2585 2586 jlong newtime = javaTimeNanos(); 2587 2588 if (newtime - prevtime < 0) { 2589 // time moving backwards, should only happen if no monotonic clock 2590 // not a guarantee() because JVM should not abort on kernel/glibc bugs 2591 assert(!Bsd::supports_monotonic_clock(), "time moving backwards"); 2592 } else { 2593 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC; 2594 } 2595 2596 if(millis <= 0) { 2597 return OS_OK; 2598 } 2599 2600 prevtime = newtime; 2601 2602 { 2603 assert(thread->is_Java_thread(), "sanity check"); 2604 JavaThread *jt = (JavaThread *) thread; 2605 ThreadBlockInVM tbivm(jt); 2606 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */); 2607 2608 jt->set_suspend_equivalent(); 2609 // cleared by handle_special_suspend_equivalent_condition() or 2610 // java_suspend_self() via check_and_wait_while_suspended() 2611 2612 slp->park(millis); 2613 2614 // were we externally suspended while we were waiting? 2615 jt->check_and_wait_while_suspended(); 2616 } 2617 } 2618 } else { 2619 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 2620 jlong prevtime = javaTimeNanos(); 2621 2622 for (;;) { 2623 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on 2624 // the 1st iteration ... 2625 jlong newtime = javaTimeNanos(); 2626 2627 if (newtime - prevtime < 0) { 2628 // time moving backwards, should only happen if no monotonic clock 2629 // not a guarantee() because JVM should not abort on kernel/glibc bugs 2630 assert(!Bsd::supports_monotonic_clock(), "time moving backwards"); 2631 } else { 2632 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC; 2633 } 2634 2635 if(millis <= 0) break ; 2636 2637 prevtime = newtime; 2638 slp->park(millis); 2639 } 2640 return OS_OK ; 2641 } 2642 } 2643 2644 void os::naked_short_sleep(jlong ms) { 2645 struct timespec req; 2646 2647 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 2648 req.tv_sec = 0; 2649 if (ms > 0) { 2650 req.tv_nsec = (ms % 1000) * 1000000; 2651 } 2652 else { 2653 req.tv_nsec = 1; 2654 } 2655 2656 nanosleep(&req, NULL); 2657 2658 return; 2659 } 2660 2661 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 2662 void os::infinite_sleep() { 2663 while (true) { // sleep forever ... 2664 ::sleep(100); // ... 100 seconds at a time 2665 } 2666 } 2667 2668 // Used to convert frequent JVM_Yield() to nops 2669 bool os::dont_yield() { 2670 return DontYieldALot; 2671 } 2672 2673 void os::yield() { 2674 sched_yield(); 2675 } 2676 2677 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;} 2678 2679 void os::yield_all(int attempts) { 2680 // Yields to all threads, including threads with lower priorities 2681 // Threads on Bsd are all with same priority. The Solaris style 2682 // os::yield_all() with nanosleep(1ms) is not necessary. 2683 sched_yield(); 2684 } 2685 2686 // Called from the tight loops to possibly influence time-sharing heuristics 2687 void os::loop_breaker(int attempts) { 2688 os::yield_all(attempts); 2689 } 2690 2691 //////////////////////////////////////////////////////////////////////////////// 2692 // thread priority support 2693 2694 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER 2695 // only supports dynamic priority, static priority must be zero. For real-time 2696 // applications, Bsd supports SCHED_RR which allows static priority (1-99). 2697 // However, for large multi-threaded applications, SCHED_RR is not only slower 2698 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 2699 // of 5 runs - Sep 2005). 2700 // 2701 // The following code actually changes the niceness of kernel-thread/LWP. It 2702 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 2703 // not the entire user process, and user level threads are 1:1 mapped to kernel 2704 // threads. It has always been the case, but could change in the future. For 2705 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 2706 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 2707 2708 #if !defined(__APPLE__) 2709 int os::java_to_os_priority[CriticalPriority + 1] = { 2710 19, // 0 Entry should never be used 2711 2712 0, // 1 MinPriority 2713 3, // 2 2714 6, // 3 2715 2716 10, // 4 2717 15, // 5 NormPriority 2718 18, // 6 2719 2720 21, // 7 2721 25, // 8 2722 28, // 9 NearMaxPriority 2723 2724 31, // 10 MaxPriority 2725 2726 31 // 11 CriticalPriority 2727 }; 2728 #else 2729 /* Using Mach high-level priority assignments */ 2730 int os::java_to_os_priority[CriticalPriority + 1] = { 2731 0, // 0 Entry should never be used (MINPRI_USER) 2732 2733 27, // 1 MinPriority 2734 28, // 2 2735 29, // 3 2736 2737 30, // 4 2738 31, // 5 NormPriority (BASEPRI_DEFAULT) 2739 32, // 6 2740 2741 33, // 7 2742 34, // 8 2743 35, // 9 NearMaxPriority 2744 2745 36, // 10 MaxPriority 2746 2747 36 // 11 CriticalPriority 2748 }; 2749 #endif 2750 2751 static int prio_init() { 2752 if (ThreadPriorityPolicy == 1) { 2753 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 2754 // if effective uid is not root. Perhaps, a more elegant way of doing 2755 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 2756 if (geteuid() != 0) { 2757 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 2758 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); 2759 } 2760 ThreadPriorityPolicy = 0; 2761 } 2762 } 2763 if (UseCriticalJavaThreadPriority) { 2764 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 2765 } 2766 return 0; 2767 } 2768 2769 OSReturn os::set_native_priority(Thread* thread, int newpri) { 2770 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK; 2771 2772 #ifdef __OpenBSD__ 2773 // OpenBSD pthread_setprio starves low priority threads 2774 return OS_OK; 2775 #elif defined(__FreeBSD__) 2776 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); 2777 #elif defined(__APPLE__) || defined(__NetBSD__) 2778 struct sched_param sp; 2779 int policy; 2780 pthread_t self = pthread_self(); 2781 2782 if (pthread_getschedparam(self, &policy, &sp) != 0) 2783 return OS_ERR; 2784 2785 sp.sched_priority = newpri; 2786 if (pthread_setschedparam(self, policy, &sp) != 0) 2787 return OS_ERR; 2788 2789 return OS_OK; 2790 #else 2791 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 2792 return (ret == 0) ? OS_OK : OS_ERR; 2793 #endif 2794 } 2795 2796 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { 2797 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) { 2798 *priority_ptr = java_to_os_priority[NormPriority]; 2799 return OS_OK; 2800 } 2801 2802 errno = 0; 2803 #if defined(__OpenBSD__) || defined(__FreeBSD__) 2804 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); 2805 #elif defined(__APPLE__) || defined(__NetBSD__) 2806 int policy; 2807 struct sched_param sp; 2808 2809 pthread_getschedparam(pthread_self(), &policy, &sp); 2810 *priority_ptr = sp.sched_priority; 2811 #else 2812 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 2813 #endif 2814 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 2815 } 2816 2817 // Hint to the underlying OS that a task switch would not be good. 2818 // Void return because it's a hint and can fail. 2819 void os::hint_no_preempt() {} 2820 2821 //////////////////////////////////////////////////////////////////////////////// 2822 // suspend/resume support 2823 2824 // the low-level signal-based suspend/resume support is a remnant from the 2825 // old VM-suspension that used to be for java-suspension, safepoints etc, 2826 // within hotspot. Now there is a single use-case for this: 2827 // - calling get_thread_pc() on the VMThread by the flat-profiler task 2828 // that runs in the watcher thread. 2829 // The remaining code is greatly simplified from the more general suspension 2830 // code that used to be used. 2831 // 2832 // The protocol is quite simple: 2833 // - suspend: 2834 // - sends a signal to the target thread 2835 // - polls the suspend state of the osthread using a yield loop 2836 // - target thread signal handler (SR_handler) sets suspend state 2837 // and blocks in sigsuspend until continued 2838 // - resume: 2839 // - sets target osthread state to continue 2840 // - sends signal to end the sigsuspend loop in the SR_handler 2841 // 2842 // Note that the SR_lock plays no role in this suspend/resume protocol. 2843 // 2844 2845 static void resume_clear_context(OSThread *osthread) { 2846 osthread->set_ucontext(NULL); 2847 osthread->set_siginfo(NULL); 2848 } 2849 2850 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { 2851 osthread->set_ucontext(context); 2852 osthread->set_siginfo(siginfo); 2853 } 2854 2855 // 2856 // Handler function invoked when a thread's execution is suspended or 2857 // resumed. We have to be careful that only async-safe functions are 2858 // called here (Note: most pthread functions are not async safe and 2859 // should be avoided.) 2860 // 2861 // Note: sigwait() is a more natural fit than sigsuspend() from an 2862 // interface point of view, but sigwait() prevents the signal hander 2863 // from being run. libpthread would get very confused by not having 2864 // its signal handlers run and prevents sigwait()'s use with the 2865 // mutex granting granting signal. 2866 // 2867 // Currently only ever called on the VMThread or JavaThread 2868 // 2869 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 2870 // Save and restore errno to avoid confusing native code with EINTR 2871 // after sigsuspend. 2872 int old_errno = errno; 2873 2874 Thread* thread = Thread::current(); 2875 OSThread* osthread = thread->osthread(); 2876 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 2877 2878 os::SuspendResume::State current = osthread->sr.state(); 2879 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 2880 suspend_save_context(osthread, siginfo, context); 2881 2882 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 2883 os::SuspendResume::State state = osthread->sr.suspended(); 2884 if (state == os::SuspendResume::SR_SUSPENDED) { 2885 sigset_t suspend_set; // signals for sigsuspend() 2886 2887 // get current set of blocked signals and unblock resume signal 2888 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 2889 sigdelset(&suspend_set, SR_signum); 2890 2891 sr_semaphore.signal(); 2892 // wait here until we are resumed 2893 while (1) { 2894 sigsuspend(&suspend_set); 2895 2896 os::SuspendResume::State result = osthread->sr.running(); 2897 if (result == os::SuspendResume::SR_RUNNING) { 2898 sr_semaphore.signal(); 2899 break; 2900 } else if (result != os::SuspendResume::SR_SUSPENDED) { 2901 ShouldNotReachHere(); 2902 } 2903 } 2904 2905 } else if (state == os::SuspendResume::SR_RUNNING) { 2906 // request was cancelled, continue 2907 } else { 2908 ShouldNotReachHere(); 2909 } 2910 2911 resume_clear_context(osthread); 2912 } else if (current == os::SuspendResume::SR_RUNNING) { 2913 // request was cancelled, continue 2914 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 2915 // ignore 2916 } else { 2917 // ignore 2918 } 2919 2920 errno = old_errno; 2921 } 2922 2923 2924 static int SR_initialize() { 2925 struct sigaction act; 2926 char *s; 2927 /* Get signal number to use for suspend/resume */ 2928 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 2929 int sig = ::strtol(s, 0, 10); 2930 if (sig > 0 || sig < NSIG) { 2931 SR_signum = sig; 2932 } 2933 } 2934 2935 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 2936 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 2937 2938 sigemptyset(&SR_sigset); 2939 sigaddset(&SR_sigset, SR_signum); 2940 2941 /* Set up signal handler for suspend/resume */ 2942 act.sa_flags = SA_RESTART|SA_SIGINFO; 2943 act.sa_handler = (void (*)(int)) SR_handler; 2944 2945 // SR_signum is blocked by default. 2946 // 4528190 - We also need to block pthread restart signal (32 on all 2947 // supported Bsd platforms). Note that BsdThreads need to block 2948 // this signal for all threads to work properly. So we don't have 2949 // to use hard-coded signal number when setting up the mask. 2950 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 2951 2952 if (sigaction(SR_signum, &act, 0) == -1) { 2953 return -1; 2954 } 2955 2956 // Save signal flag 2957 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); 2958 return 0; 2959 } 2960 2961 static int sr_notify(OSThread* osthread) { 2962 int status = pthread_kill(osthread->pthread_id(), SR_signum); 2963 assert_status(status == 0, status, "pthread_kill"); 2964 return status; 2965 } 2966 2967 // "Randomly" selected value for how long we want to spin 2968 // before bailing out on suspending a thread, also how often 2969 // we send a signal to a thread we want to resume 2970 static const int RANDOMLY_LARGE_INTEGER = 1000000; 2971 static const int RANDOMLY_LARGE_INTEGER2 = 100; 2972 2973 // returns true on success and false on error - really an error is fatal 2974 // but this seems the normal response to library errors 2975 static bool do_suspend(OSThread* osthread) { 2976 assert(osthread->sr.is_running(), "thread should be running"); 2977 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 2978 2979 // mark as suspended and send signal 2980 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 2981 // failed to switch, state wasn't running? 2982 ShouldNotReachHere(); 2983 return false; 2984 } 2985 2986 if (sr_notify(osthread) != 0) { 2987 ShouldNotReachHere(); 2988 } 2989 2990 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 2991 while (true) { 2992 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 2993 break; 2994 } else { 2995 // timeout 2996 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 2997 if (cancelled == os::SuspendResume::SR_RUNNING) { 2998 return false; 2999 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 3000 // make sure that we consume the signal on the semaphore as well 3001 sr_semaphore.wait(); 3002 break; 3003 } else { 3004 ShouldNotReachHere(); 3005 return false; 3006 } 3007 } 3008 } 3009 3010 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 3011 return true; 3012 } 3013 3014 static void do_resume(OSThread* osthread) { 3015 assert(osthread->sr.is_suspended(), "thread should be suspended"); 3016 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 3017 3018 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 3019 // failed to switch to WAKEUP_REQUEST 3020 ShouldNotReachHere(); 3021 return; 3022 } 3023 3024 while (true) { 3025 if (sr_notify(osthread) == 0) { 3026 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 3027 if (osthread->sr.is_running()) { 3028 return; 3029 } 3030 } 3031 } else { 3032 ShouldNotReachHere(); 3033 } 3034 } 3035 3036 guarantee(osthread->sr.is_running(), "Must be running!"); 3037 } 3038 3039 //////////////////////////////////////////////////////////////////////////////// 3040 // interrupt support 3041 3042 void os::interrupt(Thread* thread) { 3043 assert(Thread::current() == thread || Threads_lock->owned_by_self(), 3044 "possibility of dangling Thread pointer"); 3045 3046 OSThread* osthread = thread->osthread(); 3047 3048 if (!osthread->interrupted()) { 3049 osthread->set_interrupted(true); 3050 // More than one thread can get here with the same value of osthread, 3051 // resulting in multiple notifications. We do, however, want the store 3052 // to interrupted() to be visible to other threads before we execute unpark(). 3053 OrderAccess::fence(); 3054 ParkEvent * const slp = thread->_SleepEvent ; 3055 if (slp != NULL) slp->unpark() ; 3056 } 3057 3058 // For JSR166. Unpark even if interrupt status already was set 3059 if (thread->is_Java_thread()) 3060 ((JavaThread*)thread)->parker()->unpark(); 3061 3062 ParkEvent * ev = thread->_ParkEvent ; 3063 if (ev != NULL) ev->unpark() ; 3064 3065 } 3066 3067 bool os::is_interrupted(Thread* thread, bool clear_interrupted) { 3068 assert(Thread::current() == thread || Threads_lock->owned_by_self(), 3069 "possibility of dangling Thread pointer"); 3070 3071 OSThread* osthread = thread->osthread(); 3072 3073 bool interrupted = osthread->interrupted(); 3074 3075 if (interrupted && clear_interrupted) { 3076 osthread->set_interrupted(false); 3077 // consider thread->_SleepEvent->reset() ... optional optimization 3078 } 3079 3080 return interrupted; 3081 } 3082 3083 /////////////////////////////////////////////////////////////////////////////////// 3084 // signal handling (except suspend/resume) 3085 3086 // This routine may be used by user applications as a "hook" to catch signals. 3087 // The user-defined signal handler must pass unrecognized signals to this 3088 // routine, and if it returns true (non-zero), then the signal handler must 3089 // return immediately. If the flag "abort_if_unrecognized" is true, then this 3090 // routine will never retun false (zero), but instead will execute a VM panic 3091 // routine kill the process. 3092 // 3093 // If this routine returns false, it is OK to call it again. This allows 3094 // the user-defined signal handler to perform checks either before or after 3095 // the VM performs its own checks. Naturally, the user code would be making 3096 // a serious error if it tried to handle an exception (such as a null check 3097 // or breakpoint) that the VM was generating for its own correct operation. 3098 // 3099 // This routine may recognize any of the following kinds of signals: 3100 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 3101 // It should be consulted by handlers for any of those signals. 3102 // 3103 // The caller of this routine must pass in the three arguments supplied 3104 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 3105 // field of the structure passed to sigaction(). This routine assumes that 3106 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 3107 // 3108 // Note that the VM will print warnings if it detects conflicting signal 3109 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 3110 // 3111 extern "C" JNIEXPORT int 3112 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, 3113 void* ucontext, int abort_if_unrecognized); 3114 3115 void signalHandler(int sig, siginfo_t* info, void* uc) { 3116 assert(info != NULL && uc != NULL, "it must be old kernel"); 3117 int orig_errno = errno; // Preserve errno value over signal handler. 3118 JVM_handle_bsd_signal(sig, info, uc, true); 3119 errno = orig_errno; 3120 } 3121 3122 3123 // This boolean allows users to forward their own non-matching signals 3124 // to JVM_handle_bsd_signal, harmlessly. 3125 bool os::Bsd::signal_handlers_are_installed = false; 3126 3127 // For signal-chaining 3128 struct sigaction os::Bsd::sigact[MAXSIGNUM]; 3129 unsigned int os::Bsd::sigs = 0; 3130 bool os::Bsd::libjsig_is_loaded = false; 3131 typedef struct sigaction *(*get_signal_t)(int); 3132 get_signal_t os::Bsd::get_signal_action = NULL; 3133 3134 struct sigaction* os::Bsd::get_chained_signal_action(int sig) { 3135 struct sigaction *actp = NULL; 3136 3137 if (libjsig_is_loaded) { 3138 // Retrieve the old signal handler from libjsig 3139 actp = (*get_signal_action)(sig); 3140 } 3141 if (actp == NULL) { 3142 // Retrieve the preinstalled signal handler from jvm 3143 actp = get_preinstalled_handler(sig); 3144 } 3145 3146 return actp; 3147 } 3148 3149 static bool call_chained_handler(struct sigaction *actp, int sig, 3150 siginfo_t *siginfo, void *context) { 3151 // Call the old signal handler 3152 if (actp->sa_handler == SIG_DFL) { 3153 // It's more reasonable to let jvm treat it as an unexpected exception 3154 // instead of taking the default action. 3155 return false; 3156 } else if (actp->sa_handler != SIG_IGN) { 3157 if ((actp->sa_flags & SA_NODEFER) == 0) { 3158 // automaticlly block the signal 3159 sigaddset(&(actp->sa_mask), sig); 3160 } 3161 3162 sa_handler_t hand; 3163 sa_sigaction_t sa; 3164 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 3165 // retrieve the chained handler 3166 if (siginfo_flag_set) { 3167 sa = actp->sa_sigaction; 3168 } else { 3169 hand = actp->sa_handler; 3170 } 3171 3172 if ((actp->sa_flags & SA_RESETHAND) != 0) { 3173 actp->sa_handler = SIG_DFL; 3174 } 3175 3176 // try to honor the signal mask 3177 sigset_t oset; 3178 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 3179 3180 // call into the chained handler 3181 if (siginfo_flag_set) { 3182 (*sa)(sig, siginfo, context); 3183 } else { 3184 (*hand)(sig); 3185 } 3186 3187 // restore the signal mask 3188 pthread_sigmask(SIG_SETMASK, &oset, 0); 3189 } 3190 // Tell jvm's signal handler the signal is taken care of. 3191 return true; 3192 } 3193 3194 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { 3195 bool chained = false; 3196 // signal-chaining 3197 if (UseSignalChaining) { 3198 struct sigaction *actp = get_chained_signal_action(sig); 3199 if (actp != NULL) { 3200 chained = call_chained_handler(actp, sig, siginfo, context); 3201 } 3202 } 3203 return chained; 3204 } 3205 3206 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { 3207 if ((( (unsigned int)1 << sig ) & sigs) != 0) { 3208 return &sigact[sig]; 3209 } 3210 return NULL; 3211 } 3212 3213 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 3214 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3215 sigact[sig] = oldAct; 3216 sigs |= (unsigned int)1 << sig; 3217 } 3218 3219 // for diagnostic 3220 int os::Bsd::sigflags[MAXSIGNUM]; 3221 3222 int os::Bsd::get_our_sigflags(int sig) { 3223 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3224 return sigflags[sig]; 3225 } 3226 3227 void os::Bsd::set_our_sigflags(int sig, int flags) { 3228 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3229 sigflags[sig] = flags; 3230 } 3231 3232 void os::Bsd::set_signal_handler(int sig, bool set_installed) { 3233 // Check for overwrite. 3234 struct sigaction oldAct; 3235 sigaction(sig, (struct sigaction*)NULL, &oldAct); 3236 3237 void* oldhand = oldAct.sa_sigaction 3238 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3239 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3240 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 3241 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 3242 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 3243 if (AllowUserSignalHandlers || !set_installed) { 3244 // Do not overwrite; user takes responsibility to forward to us. 3245 return; 3246 } else if (UseSignalChaining) { 3247 // save the old handler in jvm 3248 save_preinstalled_handler(sig, oldAct); 3249 // libjsig also interposes the sigaction() call below and saves the 3250 // old sigaction on it own. 3251 } else { 3252 fatal(err_msg("Encountered unexpected pre-existing sigaction handler " 3253 "%#lx for signal %d.", (long)oldhand, sig)); 3254 } 3255 } 3256 3257 struct sigaction sigAct; 3258 sigfillset(&(sigAct.sa_mask)); 3259 sigAct.sa_handler = SIG_DFL; 3260 if (!set_installed) { 3261 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3262 } else { 3263 sigAct.sa_sigaction = signalHandler; 3264 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 3265 } 3266 #ifdef __APPLE__ 3267 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV 3268 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages" 3269 // if the signal handler declares it will handle it on alternate stack. 3270 // Notice we only declare we will handle it on alt stack, but we are not 3271 // actually going to use real alt stack - this is just a workaround. 3272 // Please see ux_exception.c, method catch_mach_exception_raise for details 3273 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c 3274 if (sig == SIGSEGV) { 3275 sigAct.sa_flags |= SA_ONSTACK; 3276 } 3277 #endif 3278 3279 // Save flags, which are set by ours 3280 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); 3281 sigflags[sig] = sigAct.sa_flags; 3282 3283 int ret = sigaction(sig, &sigAct, &oldAct); 3284 assert(ret == 0, "check"); 3285 3286 void* oldhand2 = oldAct.sa_sigaction 3287 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 3288 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 3289 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 3290 } 3291 3292 // install signal handlers for signals that HotSpot needs to 3293 // handle in order to support Java-level exception handling. 3294 3295 void os::Bsd::install_signal_handlers() { 3296 if (!signal_handlers_are_installed) { 3297 signal_handlers_are_installed = true; 3298 3299 // signal-chaining 3300 typedef void (*signal_setting_t)(); 3301 signal_setting_t begin_signal_setting = NULL; 3302 signal_setting_t end_signal_setting = NULL; 3303 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3304 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 3305 if (begin_signal_setting != NULL) { 3306 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 3307 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 3308 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 3309 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 3310 libjsig_is_loaded = true; 3311 assert(UseSignalChaining, "should enable signal-chaining"); 3312 } 3313 if (libjsig_is_loaded) { 3314 // Tell libjsig jvm is setting signal handlers 3315 (*begin_signal_setting)(); 3316 } 3317 3318 set_signal_handler(SIGSEGV, true); 3319 set_signal_handler(SIGPIPE, true); 3320 set_signal_handler(SIGBUS, true); 3321 set_signal_handler(SIGILL, true); 3322 set_signal_handler(SIGFPE, true); 3323 set_signal_handler(SIGXFSZ, true); 3324 3325 #if defined(__APPLE__) 3326 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including 3327 // signals caught and handled by the JVM. To work around this, we reset the mach task 3328 // signal handler that's placed on our process by CrashReporter. This disables 3329 // CrashReporter-based reporting. 3330 // 3331 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes 3332 // on caught fatal signals. 3333 // 3334 // Additionally, gdb installs both standard BSD signal handlers, and mach exception 3335 // handlers. By replacing the existing task exception handler, we disable gdb's mach 3336 // exception handling, while leaving the standard BSD signal handlers functional. 3337 kern_return_t kr; 3338 kr = task_set_exception_ports(mach_task_self(), 3339 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, 3340 MACH_PORT_NULL, 3341 EXCEPTION_STATE_IDENTITY, 3342 MACHINE_THREAD_STATE); 3343 3344 assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); 3345 #endif 3346 3347 if (libjsig_is_loaded) { 3348 // Tell libjsig jvm finishes setting signal handlers 3349 (*end_signal_setting)(); 3350 } 3351 3352 // We don't activate signal checker if libjsig is in place, we trust ourselves 3353 // and if UserSignalHandler is installed all bets are off 3354 if (CheckJNICalls) { 3355 if (libjsig_is_loaded) { 3356 if (PrintJNIResolving) { 3357 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 3358 } 3359 check_signals = false; 3360 } 3361 if (AllowUserSignalHandlers) { 3362 if (PrintJNIResolving) { 3363 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 3364 } 3365 check_signals = false; 3366 } 3367 } 3368 } 3369 } 3370 3371 3372 ///// 3373 // glibc on Bsd platform uses non-documented flag 3374 // to indicate, that some special sort of signal 3375 // trampoline is used. 3376 // We will never set this flag, and we should 3377 // ignore this flag in our diagnostic 3378 #ifdef SIGNIFICANT_SIGNAL_MASK 3379 #undef SIGNIFICANT_SIGNAL_MASK 3380 #endif 3381 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 3382 3383 static const char* get_signal_handler_name(address handler, 3384 char* buf, int buflen) { 3385 int offset; 3386 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 3387 if (found) { 3388 // skip directory names 3389 const char *p1, *p2; 3390 p1 = buf; 3391 size_t len = strlen(os::file_separator()); 3392 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 3393 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 3394 } else { 3395 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 3396 } 3397 return buf; 3398 } 3399 3400 static void print_signal_handler(outputStream* st, int sig, 3401 char* buf, size_t buflen) { 3402 struct sigaction sa; 3403 3404 sigaction(sig, NULL, &sa); 3405 3406 // See comment for SIGNIFICANT_SIGNAL_MASK define 3407 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3408 3409 st->print("%s: ", os::exception_name(sig, buf, buflen)); 3410 3411 address handler = (sa.sa_flags & SA_SIGINFO) 3412 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 3413 : CAST_FROM_FN_PTR(address, sa.sa_handler); 3414 3415 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 3416 st->print("SIG_DFL"); 3417 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 3418 st->print("SIG_IGN"); 3419 } else { 3420 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 3421 } 3422 3423 st->print(", sa_mask[0]="); 3424 os::Posix::print_signal_set_short(st, &sa.sa_mask); 3425 3426 address rh = VMError::get_resetted_sighandler(sig); 3427 // May be, handler was resetted by VMError? 3428 if(rh != NULL) { 3429 handler = rh; 3430 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 3431 } 3432 3433 st->print(", sa_flags="); 3434 os::Posix::print_sa_flags(st, sa.sa_flags); 3435 3436 // Check: is it our handler? 3437 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 3438 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 3439 // It is our signal handler 3440 // check for flags, reset system-used one! 3441 if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3442 st->print( 3443 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 3444 os::Bsd::get_our_sigflags(sig)); 3445 } 3446 } 3447 st->cr(); 3448 } 3449 3450 3451 #define DO_SIGNAL_CHECK(sig) \ 3452 if (!sigismember(&check_signal_done, sig)) \ 3453 os::Bsd::check_signal_handler(sig) 3454 3455 // This method is a periodic task to check for misbehaving JNI applications 3456 // under CheckJNI, we can add any periodic checks here 3457 3458 void os::run_periodic_checks() { 3459 3460 if (check_signals == false) return; 3461 3462 // SEGV and BUS if overridden could potentially prevent 3463 // generation of hs*.log in the event of a crash, debugging 3464 // such a case can be very challenging, so we absolutely 3465 // check the following for a good measure: 3466 DO_SIGNAL_CHECK(SIGSEGV); 3467 DO_SIGNAL_CHECK(SIGILL); 3468 DO_SIGNAL_CHECK(SIGFPE); 3469 DO_SIGNAL_CHECK(SIGBUS); 3470 DO_SIGNAL_CHECK(SIGPIPE); 3471 DO_SIGNAL_CHECK(SIGXFSZ); 3472 3473 3474 // ReduceSignalUsage allows the user to override these handlers 3475 // see comments at the very top and jvm_solaris.h 3476 if (!ReduceSignalUsage) { 3477 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 3478 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 3479 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 3480 DO_SIGNAL_CHECK(BREAK_SIGNAL); 3481 } 3482 3483 DO_SIGNAL_CHECK(SR_signum); 3484 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); 3485 } 3486 3487 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 3488 3489 static os_sigaction_t os_sigaction = NULL; 3490 3491 void os::Bsd::check_signal_handler(int sig) { 3492 char buf[O_BUFLEN]; 3493 address jvmHandler = NULL; 3494 3495 3496 struct sigaction act; 3497 if (os_sigaction == NULL) { 3498 // only trust the default sigaction, in case it has been interposed 3499 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 3500 if (os_sigaction == NULL) return; 3501 } 3502 3503 os_sigaction(sig, (struct sigaction*)NULL, &act); 3504 3505 3506 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 3507 3508 address thisHandler = (act.sa_flags & SA_SIGINFO) 3509 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 3510 : CAST_FROM_FN_PTR(address, act.sa_handler) ; 3511 3512 3513 switch(sig) { 3514 case SIGSEGV: 3515 case SIGBUS: 3516 case SIGFPE: 3517 case SIGPIPE: 3518 case SIGILL: 3519 case SIGXFSZ: 3520 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 3521 break; 3522 3523 case SHUTDOWN1_SIGNAL: 3524 case SHUTDOWN2_SIGNAL: 3525 case SHUTDOWN3_SIGNAL: 3526 case BREAK_SIGNAL: 3527 jvmHandler = (address)user_handler(); 3528 break; 3529 3530 case INTERRUPT_SIGNAL: 3531 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); 3532 break; 3533 3534 default: 3535 if (sig == SR_signum) { 3536 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 3537 } else { 3538 return; 3539 } 3540 break; 3541 } 3542 3543 if (thisHandler != jvmHandler) { 3544 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 3545 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 3546 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 3547 // No need to check this sig any longer 3548 sigaddset(&check_signal_done, sig); 3549 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 3550 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 3551 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 3552 exception_name(sig, buf, O_BUFLEN)); 3553 } 3554 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { 3555 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 3556 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); 3557 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); 3558 // No need to check this sig any longer 3559 sigaddset(&check_signal_done, sig); 3560 } 3561 3562 // Dump all the signal 3563 if (sigismember(&check_signal_done, sig)) { 3564 print_signal_handlers(tty, buf, O_BUFLEN); 3565 } 3566 } 3567 3568 extern void report_error(char* file_name, int line_no, char* title, char* format, ...); 3569 3570 extern bool signal_name(int signo, char* buf, size_t len); 3571 3572 const char* os::exception_name(int exception_code, char* buf, size_t size) { 3573 if (0 < exception_code && exception_code <= SIGRTMAX) { 3574 // signal 3575 if (!signal_name(exception_code, buf, size)) { 3576 jio_snprintf(buf, size, "SIG%d", exception_code); 3577 } 3578 return buf; 3579 } else { 3580 return NULL; 3581 } 3582 } 3583 3584 // this is called _before_ the most of global arguments have been parsed 3585 void os::init(void) { 3586 char dummy; /* used to get a guess on initial stack address */ 3587 // first_hrtime = gethrtime(); 3588 3589 // With BsdThreads the JavaMain thread pid (primordial thread) 3590 // is different than the pid of the java launcher thread. 3591 // So, on Bsd, the launcher thread pid is passed to the VM 3592 // via the sun.java.launcher.pid property. 3593 // Use this property instead of getpid() if it was correctly passed. 3594 // See bug 6351349. 3595 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); 3596 3597 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); 3598 3599 clock_tics_per_sec = CLK_TCK; 3600 3601 init_random(1234567); 3602 3603 ThreadCritical::initialize(); 3604 3605 Bsd::set_page_size(getpagesize()); 3606 if (Bsd::page_size() == -1) { 3607 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)", 3608 strerror(errno))); 3609 } 3610 init_page_sizes((size_t) Bsd::page_size()); 3611 3612 Bsd::initialize_system_info(); 3613 3614 // main_thread points to the aboriginal thread 3615 Bsd::_main_thread = pthread_self(); 3616 3617 Bsd::clock_init(); 3618 initial_time_count = javaTimeNanos(); 3619 3620 #ifdef __APPLE__ 3621 // XXXDARWIN 3622 // Work around the unaligned VM callbacks in hotspot's 3623 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on 3624 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces 3625 // alignment when doing symbol lookup. To work around this, we force early 3626 // binding of all symbols now, thus binding when alignment is known-good. 3627 _dyld_bind_fully_image_containing_address((const void *) &os::init); 3628 #endif 3629 } 3630 3631 // To install functions for atexit system call 3632 extern "C" { 3633 static void perfMemory_exit_helper() { 3634 perfMemory_exit(); 3635 } 3636 } 3637 3638 // this is called _after_ the global arguments have been parsed 3639 jint os::init_2(void) 3640 { 3641 // Allocate a single page and mark it as readable for safepoint polling 3642 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3643 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" ); 3644 3645 os::set_polling_page( polling_page ); 3646 3647 #ifndef PRODUCT 3648 if(Verbose && PrintMiscellaneous) 3649 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page); 3650 #endif 3651 3652 if (!UseMembar) { 3653 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 3654 guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 3655 os::set_memory_serialize_page( mem_serialize_page ); 3656 3657 #ifndef PRODUCT 3658 if(Verbose && PrintMiscellaneous) 3659 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page); 3660 #endif 3661 } 3662 3663 // initialize suspend/resume support - must do this before signal_sets_init() 3664 if (SR_initialize() != 0) { 3665 perror("SR_initialize failed"); 3666 return JNI_ERR; 3667 } 3668 3669 Bsd::signal_sets_init(); 3670 Bsd::install_signal_handlers(); 3671 3672 // Check minimum allowable stack size for thread creation and to initialize 3673 // the java system classes, including StackOverflowError - depends on page 3674 // size. Add a page for compiler2 recursion in main thread. 3675 // Add in 2*BytesPerWord times page size to account for VM stack during 3676 // class initialization depending on 32 or 64 bit VM. 3677 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, 3678 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ 3679 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); 3680 3681 size_t threadStackSizeInBytes = ThreadStackSize * K; 3682 if (threadStackSizeInBytes != 0 && 3683 threadStackSizeInBytes < os::Bsd::min_stack_allowed) { 3684 tty->print_cr("\nThe stack size specified is too small, " 3685 "Specify at least %dk", 3686 os::Bsd::min_stack_allowed/ K); 3687 return JNI_ERR; 3688 } 3689 3690 // Make the stack size a multiple of the page size so that 3691 // the yellow/red zones can be guarded. 3692 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, 3693 vm_page_size())); 3694 3695 if (MaxFDLimit) { 3696 // set the number of file descriptors to max. print out error 3697 // if getrlimit/setrlimit fails but continue regardless. 3698 struct rlimit nbr_files; 3699 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 3700 if (status != 0) { 3701 if (PrintMiscellaneous && (Verbose || WizardMode)) 3702 perror("os::init_2 getrlimit failed"); 3703 } else { 3704 nbr_files.rlim_cur = nbr_files.rlim_max; 3705 3706 #ifdef __APPLE__ 3707 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if 3708 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must 3709 // be used instead 3710 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); 3711 #endif 3712 3713 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 3714 if (status != 0) { 3715 if (PrintMiscellaneous && (Verbose || WizardMode)) 3716 perror("os::init_2 setrlimit failed"); 3717 } 3718 } 3719 } 3720 3721 // at-exit methods are called in the reverse order of their registration. 3722 // atexit functions are called on return from main or as a result of a 3723 // call to exit(3C). There can be only 32 of these functions registered 3724 // and atexit() does not set errno. 3725 3726 if (PerfAllowAtExitRegistration) { 3727 // only register atexit functions if PerfAllowAtExitRegistration is set. 3728 // atexit functions can be delayed until process exit time, which 3729 // can be problematic for embedded VM situations. Embedded VMs should 3730 // call DestroyJavaVM() to assure that VM resources are released. 3731 3732 // note: perfMemory_exit_helper atexit function may be removed in 3733 // the future if the appropriate cleanup code can be added to the 3734 // VM_Exit VMOperation's doit method. 3735 if (atexit(perfMemory_exit_helper) != 0) { 3736 warning("os::init2 atexit(perfMemory_exit_helper) failed"); 3737 } 3738 } 3739 3740 // initialize thread priority policy 3741 prio_init(); 3742 3743 #ifdef __APPLE__ 3744 // dynamically link to objective c gc registration 3745 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY); 3746 if (handleLibObjc != NULL) { 3747 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER); 3748 } 3749 #endif 3750 3751 return JNI_OK; 3752 } 3753 3754 // Mark the polling page as unreadable 3755 void os::make_polling_page_unreadable(void) { 3756 if( !guard_memory((char*)_polling_page, Bsd::page_size()) ) 3757 fatal("Could not disable polling page"); 3758 }; 3759 3760 // Mark the polling page as readable 3761 void os::make_polling_page_readable(void) { 3762 if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { 3763 fatal("Could not enable polling page"); 3764 } 3765 }; 3766 3767 int os::active_processor_count() { 3768 return _processor_count; 3769 } 3770 3771 void os::set_native_thread_name(const char *name) { 3772 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5 3773 // This is only supported in Snow Leopard and beyond 3774 if (name != NULL) { 3775 // Add a "Java: " prefix to the name 3776 char buf[MAXTHREADNAMESIZE]; 3777 snprintf(buf, sizeof(buf), "Java: %s", name); 3778 pthread_setname_np(buf); 3779 } 3780 #endif 3781 } 3782 3783 bool os::distribute_processes(uint length, uint* distribution) { 3784 // Not yet implemented. 3785 return false; 3786 } 3787 3788 bool os::bind_to_processor(uint processor_id) { 3789 // Not yet implemented. 3790 return false; 3791 } 3792 3793 void os::SuspendedThreadTask::internal_do_task() { 3794 if (do_suspend(_thread->osthread())) { 3795 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 3796 do_task(context); 3797 do_resume(_thread->osthread()); 3798 } 3799 } 3800 3801 /// 3802 class PcFetcher : public os::SuspendedThreadTask { 3803 public: 3804 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 3805 ExtendedPC result(); 3806 protected: 3807 void do_task(const os::SuspendedThreadTaskContext& context); 3808 private: 3809 ExtendedPC _epc; 3810 }; 3811 3812 ExtendedPC PcFetcher::result() { 3813 guarantee(is_done(), "task is not done yet."); 3814 return _epc; 3815 } 3816 3817 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 3818 Thread* thread = context.thread(); 3819 OSThread* osthread = thread->osthread(); 3820 if (osthread->ucontext() != NULL) { 3821 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext()); 3822 } else { 3823 // NULL context is unexpected, double-check this is the VMThread 3824 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 3825 } 3826 } 3827 3828 // Suspends the target using the signal mechanism and then grabs the PC before 3829 // resuming the target. Used by the flat-profiler only 3830 ExtendedPC os::get_thread_pc(Thread* thread) { 3831 // Make sure that it is called by the watcher for the VMThread 3832 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 3833 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 3834 3835 PcFetcher fetcher(thread); 3836 fetcher.run(); 3837 return fetcher.result(); 3838 } 3839 3840 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime) 3841 { 3842 return pthread_cond_timedwait(_cond, _mutex, _abstime); 3843 } 3844 3845 //////////////////////////////////////////////////////////////////////////////// 3846 // debug support 3847 3848 bool os::find(address addr, outputStream* st) { 3849 Dl_info dlinfo; 3850 memset(&dlinfo, 0, sizeof(dlinfo)); 3851 if (dladdr(addr, &dlinfo) != 0) { 3852 st->print(PTR_FORMAT ": ", addr); 3853 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 3854 st->print("%s+%#x", dlinfo.dli_sname, 3855 addr - (intptr_t)dlinfo.dli_saddr); 3856 } else if (dlinfo.dli_fbase != NULL) { 3857 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); 3858 } else { 3859 st->print("<absolute address>"); 3860 } 3861 if (dlinfo.dli_fname != NULL) { 3862 st->print(" in %s", dlinfo.dli_fname); 3863 } 3864 if (dlinfo.dli_fbase != NULL) { 3865 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); 3866 } 3867 st->cr(); 3868 3869 if (Verbose) { 3870 // decode some bytes around the PC 3871 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 3872 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 3873 address lowest = (address) dlinfo.dli_sname; 3874 if (!lowest) lowest = (address) dlinfo.dli_fbase; 3875 if (begin < lowest) begin = lowest; 3876 Dl_info dlinfo2; 3877 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 3878 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) 3879 end = (address) dlinfo2.dli_saddr; 3880 Disassembler::decode(begin, end, st); 3881 } 3882 return true; 3883 } 3884 return false; 3885 } 3886 3887 //////////////////////////////////////////////////////////////////////////////// 3888 // misc 3889 3890 // This does not do anything on Bsd. This is basically a hook for being 3891 // able to use structured exception handling (thread-local exception filters) 3892 // on, e.g., Win32. 3893 void 3894 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, 3895 JavaCallArguments* args, Thread* thread) { 3896 f(value, method, args, thread); 3897 } 3898 3899 void os::print_statistics() { 3900 } 3901 3902 int os::message_box(const char* title, const char* message) { 3903 int i; 3904 fdStream err(defaultStream::error_fd()); 3905 for (i = 0; i < 78; i++) err.print_raw("="); 3906 err.cr(); 3907 err.print_raw_cr(title); 3908 for (i = 0; i < 78; i++) err.print_raw("-"); 3909 err.cr(); 3910 err.print_raw_cr(message); 3911 for (i = 0; i < 78; i++) err.print_raw("="); 3912 err.cr(); 3913 3914 char buf[16]; 3915 // Prevent process from exiting upon "read error" without consuming all CPU 3916 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 3917 3918 return buf[0] == 'y' || buf[0] == 'Y'; 3919 } 3920 3921 int os::stat(const char *path, struct stat *sbuf) { 3922 char pathbuf[MAX_PATH]; 3923 if (strlen(path) > MAX_PATH - 1) { 3924 errno = ENAMETOOLONG; 3925 return -1; 3926 } 3927 os::native_path(strcpy(pathbuf, path)); 3928 return ::stat(pathbuf, sbuf); 3929 } 3930 3931 bool os::check_heap(bool force) { 3932 return true; 3933 } 3934 3935 ATTRIBUTE_PRINTF(3, 0) 3936 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) { 3937 return ::vsnprintf(buf, count, format, args); 3938 } 3939 3940 // Is a (classpath) directory empty? 3941 bool os::dir_is_empty(const char* path) { 3942 DIR *dir = NULL; 3943 struct dirent *ptr; 3944 3945 dir = opendir(path); 3946 if (dir == NULL) return true; 3947 3948 /* Scan the directory */ 3949 bool result = true; 3950 char buf[sizeof(struct dirent) + MAX_PATH]; 3951 while (result && (ptr = ::readdir(dir)) != NULL) { 3952 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 3953 result = false; 3954 } 3955 } 3956 closedir(dir); 3957 return result; 3958 } 3959 3960 // This code originates from JDK's sysOpen and open64_w 3961 // from src/solaris/hpi/src/system_md.c 3962 3963 #ifndef O_DELETE 3964 #define O_DELETE 0x10000 3965 #endif 3966 3967 // Open a file. Unlink the file immediately after open returns 3968 // if the specified oflag has the O_DELETE flag set. 3969 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c 3970 3971 int os::open(const char *path, int oflag, int mode) { 3972 3973 if (strlen(path) > MAX_PATH - 1) { 3974 errno = ENAMETOOLONG; 3975 return -1; 3976 } 3977 int fd; 3978 int o_delete = (oflag & O_DELETE); 3979 oflag = oflag & ~O_DELETE; 3980 3981 fd = ::open(path, oflag, mode); 3982 if (fd == -1) return -1; 3983 3984 //If the open succeeded, the file might still be a directory 3985 { 3986 struct stat buf; 3987 int ret = ::fstat(fd, &buf); 3988 int st_mode = buf.st_mode; 3989 3990 if (ret != -1) { 3991 if ((st_mode & S_IFMT) == S_IFDIR) { 3992 errno = EISDIR; 3993 ::close(fd); 3994 return -1; 3995 } 3996 } else { 3997 ::close(fd); 3998 return -1; 3999 } 4000 } 4001 4002 /* 4003 * All file descriptors that are opened in the JVM and not 4004 * specifically destined for a subprocess should have the 4005 * close-on-exec flag set. If we don't set it, then careless 3rd 4006 * party native code might fork and exec without closing all 4007 * appropriate file descriptors (e.g. as we do in closeDescriptors in 4008 * UNIXProcess.c), and this in turn might: 4009 * 4010 * - cause end-of-file to fail to be detected on some file 4011 * descriptors, resulting in mysterious hangs, or 4012 * 4013 * - might cause an fopen in the subprocess to fail on a system 4014 * suffering from bug 1085341. 4015 * 4016 * (Yes, the default setting of the close-on-exec flag is a Unix 4017 * design flaw) 4018 * 4019 * See: 4020 * 1085341: 32-bit stdio routines should support file descriptors >255 4021 * 4843136: (process) pipe file descriptor from Runtime.exec not being closed 4022 * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 4023 */ 4024 #ifdef FD_CLOEXEC 4025 { 4026 int flags = ::fcntl(fd, F_GETFD); 4027 if (flags != -1) 4028 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 4029 } 4030 #endif 4031 4032 if (o_delete != 0) { 4033 ::unlink(path); 4034 } 4035 return fd; 4036 } 4037 4038 4039 // create binary file, rewriting existing file if required 4040 int os::create_binary_file(const char* path, bool rewrite_existing) { 4041 int oflags = O_WRONLY | O_CREAT; 4042 if (!rewrite_existing) { 4043 oflags |= O_EXCL; 4044 } 4045 return ::open(path, oflags, S_IREAD | S_IWRITE); 4046 } 4047 4048 // return current position of file pointer 4049 jlong os::current_file_offset(int fd) { 4050 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); 4051 } 4052 4053 // move file pointer to the specified offset 4054 jlong os::seek_to_file_offset(int fd, jlong offset) { 4055 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); 4056 } 4057 4058 // This code originates from JDK's sysAvailable 4059 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 4060 4061 int os::available(int fd, jlong *bytes) { 4062 jlong cur, end; 4063 int mode; 4064 struct stat buf; 4065 4066 if (::fstat(fd, &buf) >= 0) { 4067 mode = buf.st_mode; 4068 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 4069 /* 4070 * XXX: is the following call interruptible? If so, this might 4071 * need to go through the INTERRUPT_IO() wrapper as for other 4072 * blocking, interruptible calls in this file. 4073 */ 4074 int n; 4075 if (::ioctl(fd, FIONREAD, &n) >= 0) { 4076 *bytes = n; 4077 return 1; 4078 } 4079 } 4080 } 4081 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { 4082 return 0; 4083 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { 4084 return 0; 4085 } else if (::lseek(fd, cur, SEEK_SET) == -1) { 4086 return 0; 4087 } 4088 *bytes = end - cur; 4089 return 1; 4090 } 4091 4092 int os::socket_available(int fd, jint *pbytes) { 4093 if (fd < 0) 4094 return OS_OK; 4095 4096 int ret; 4097 4098 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret); 4099 4100 //%% note ioctl can return 0 when successful, JVM_SocketAvailable 4101 // is expected to return 0 on failure and 1 on success to the jdk. 4102 4103 return (ret == OS_ERR) ? 0 : 1; 4104 } 4105 4106 // Map a block of memory. 4107 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 4108 char *addr, size_t bytes, bool read_only, 4109 bool allow_exec) { 4110 int prot; 4111 int flags; 4112 4113 if (read_only) { 4114 prot = PROT_READ; 4115 flags = MAP_SHARED; 4116 } else { 4117 prot = PROT_READ | PROT_WRITE; 4118 flags = MAP_PRIVATE; 4119 } 4120 4121 if (allow_exec) { 4122 prot |= PROT_EXEC; 4123 } 4124 4125 if (addr != NULL) { 4126 flags |= MAP_FIXED; 4127 } 4128 4129 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 4130 fd, file_offset); 4131 if (mapped_address == MAP_FAILED) { 4132 return NULL; 4133 } 4134 return mapped_address; 4135 } 4136 4137 4138 // Remap a block of memory. 4139 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 4140 char *addr, size_t bytes, bool read_only, 4141 bool allow_exec) { 4142 // same as map_memory() on this OS 4143 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 4144 allow_exec); 4145 } 4146 4147 4148 // Unmap a block of memory. 4149 bool os::pd_unmap_memory(char* addr, size_t bytes) { 4150 return munmap(addr, bytes) == 0; 4151 } 4152 4153 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 4154 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 4155 // of a thread. 4156 // 4157 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 4158 // the fast estimate available on the platform. 4159 4160 jlong os::current_thread_cpu_time() { 4161 #ifdef __APPLE__ 4162 return os::thread_cpu_time(Thread::current(), true /* user + sys */); 4163 #else 4164 Unimplemented(); 4165 return 0; 4166 #endif 4167 } 4168 4169 jlong os::thread_cpu_time(Thread* thread) { 4170 #ifdef __APPLE__ 4171 return os::thread_cpu_time(thread, true /* user + sys */); 4172 #else 4173 Unimplemented(); 4174 return 0; 4175 #endif 4176 } 4177 4178 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 4179 #ifdef __APPLE__ 4180 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); 4181 #else 4182 Unimplemented(); 4183 return 0; 4184 #endif 4185 } 4186 4187 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 4188 #ifdef __APPLE__ 4189 struct thread_basic_info tinfo; 4190 mach_msg_type_number_t tcount = THREAD_INFO_MAX; 4191 kern_return_t kr; 4192 thread_t mach_thread; 4193 4194 mach_thread = thread->osthread()->thread_id(); 4195 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); 4196 if (kr != KERN_SUCCESS) 4197 return -1; 4198 4199 if (user_sys_cpu_time) { 4200 jlong nanos; 4201 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; 4202 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; 4203 return nanos; 4204 } else { 4205 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); 4206 } 4207 #else 4208 Unimplemented(); 4209 return 0; 4210 #endif 4211 } 4212 4213 4214 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4215 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4216 info_ptr->may_skip_backward = false; // elapsed time not wall time 4217 info_ptr->may_skip_forward = false; // elapsed time not wall time 4218 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4219 } 4220 4221 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 4222 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 4223 info_ptr->may_skip_backward = false; // elapsed time not wall time 4224 info_ptr->may_skip_forward = false; // elapsed time not wall time 4225 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 4226 } 4227 4228 bool os::is_thread_cpu_time_supported() { 4229 #ifdef __APPLE__ 4230 return true; 4231 #else 4232 return false; 4233 #endif 4234 } 4235 4236 // System loadavg support. Returns -1 if load average cannot be obtained. 4237 // Bsd doesn't yet have a (official) notion of processor sets, 4238 // so just return the system wide load average. 4239 int os::loadavg(double loadavg[], int nelem) { 4240 return ::getloadavg(loadavg, nelem); 4241 } 4242 4243 void os::pause() { 4244 char filename[MAX_PATH]; 4245 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 4246 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); 4247 } else { 4248 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 4249 } 4250 4251 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 4252 if (fd != -1) { 4253 struct stat buf; 4254 ::close(fd); 4255 while (::stat(filename, &buf) == 0) { 4256 (void)::poll(NULL, 0, 100); 4257 } 4258 } else { 4259 jio_fprintf(stderr, 4260 "Could not open pause file '%s', continuing immediately.\n", filename); 4261 } 4262 } 4263 4264 4265 // Refer to the comments in os_solaris.cpp park-unpark. 4266 // 4267 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can 4268 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. 4269 // For specifics regarding the bug see GLIBC BUGID 261237 : 4270 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. 4271 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future 4272 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar 4273 // is used. (The simple C test-case provided in the GLIBC bug report manifests the 4274 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() 4275 // and monitorenter when we're using 1-0 locking. All those operations may result in 4276 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version 4277 // of libpthread avoids the problem, but isn't practical. 4278 // 4279 // Possible remedies: 4280 // 4281 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. 4282 // This is palliative and probabilistic, however. If the thread is preempted 4283 // between the call to compute_abstime() and pthread_cond_timedwait(), more 4284 // than the minimum period may have passed, and the abstime may be stale (in the 4285 // past) resultin in a hang. Using this technique reduces the odds of a hang 4286 // but the JVM is still vulnerable, particularly on heavily loaded systems. 4287 // 4288 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead 4289 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set 4290 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) 4291 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant 4292 // thread. 4293 // 4294 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread 4295 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing 4296 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). 4297 // This also works well. In fact it avoids kernel-level scalability impediments 4298 // on certain platforms that don't handle lots of active pthread_cond_timedwait() 4299 // timers in a graceful fashion. 4300 // 4301 // 4. When the abstime value is in the past it appears that control returns 4302 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. 4303 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we 4304 // can avoid the problem by reinitializing the condvar -- by cond_destroy() 4305 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). 4306 // It may be possible to avoid reinitialization by checking the return 4307 // value from pthread_cond_timedwait(). In addition to reinitializing the 4308 // condvar we must establish the invariant that cond_signal() is only called 4309 // within critical sections protected by the adjunct mutex. This prevents 4310 // cond_signal() from "seeing" a condvar that's in the midst of being 4311 // reinitialized or that is corrupt. Sadly, this invariant obviates the 4312 // desirable signal-after-unlock optimization that avoids futile context switching. 4313 // 4314 // I'm also concerned that some versions of NTPL might allocate an auxilliary 4315 // structure when a condvar is used or initialized. cond_destroy() would 4316 // release the helper structure. Our reinitialize-after-timedwait fix 4317 // put excessive stress on malloc/free and locks protecting the c-heap. 4318 // 4319 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. 4320 // It may be possible to refine (4) by checking the kernel and NTPL verisons 4321 // and only enabling the work-around for vulnerable environments. 4322 4323 // utility to compute the abstime argument to timedwait: 4324 // millis is the relative timeout time 4325 // abstime will be the absolute timeout time 4326 // TODO: replace compute_abstime() with unpackTime() 4327 4328 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) { 4329 if (millis < 0) millis = 0; 4330 struct timeval now; 4331 int status = gettimeofday(&now, NULL); 4332 assert(status == 0, "gettimeofday"); 4333 jlong seconds = millis / 1000; 4334 millis %= 1000; 4335 if (seconds > 50000000) { // see man cond_timedwait(3T) 4336 seconds = 50000000; 4337 } 4338 abstime->tv_sec = now.tv_sec + seconds; 4339 long usec = now.tv_usec + millis * 1000; 4340 if (usec >= 1000000) { 4341 abstime->tv_sec += 1; 4342 usec -= 1000000; 4343 } 4344 abstime->tv_nsec = usec * 1000; 4345 return abstime; 4346 } 4347 4348 4349 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately. 4350 // Conceptually TryPark() should be equivalent to park(0). 4351 4352 int os::PlatformEvent::TryPark() { 4353 for (;;) { 4354 const int v = _Event ; 4355 guarantee ((v == 0) || (v == 1), "invariant") ; 4356 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ; 4357 } 4358 } 4359 4360 void os::PlatformEvent::park() { // AKA "down()" 4361 // Invariant: Only the thread associated with the Event/PlatformEvent 4362 // may call park(). 4363 // TODO: assert that _Assoc != NULL or _Assoc == Self 4364 int v ; 4365 for (;;) { 4366 v = _Event ; 4367 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; 4368 } 4369 guarantee (v >= 0, "invariant") ; 4370 if (v == 0) { 4371 // Do this the hard way by blocking ... 4372 int status = pthread_mutex_lock(_mutex); 4373 assert_status(status == 0, status, "mutex_lock"); 4374 guarantee (_nParked == 0, "invariant") ; 4375 ++ _nParked ; 4376 while (_Event < 0) { 4377 status = pthread_cond_wait(_cond, _mutex); 4378 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... 4379 // Treat this the same as if the wait was interrupted 4380 if (status == ETIMEDOUT) { status = EINTR; } 4381 assert_status(status == 0 || status == EINTR, status, "cond_wait"); 4382 } 4383 -- _nParked ; 4384 4385 _Event = 0 ; 4386 status = pthread_mutex_unlock(_mutex); 4387 assert_status(status == 0, status, "mutex_unlock"); 4388 // Paranoia to ensure our locked and lock-free paths interact 4389 // correctly with each other. 4390 OrderAccess::fence(); 4391 } 4392 guarantee (_Event >= 0, "invariant") ; 4393 } 4394 4395 int os::PlatformEvent::park(jlong millis) { 4396 guarantee (_nParked == 0, "invariant") ; 4397 4398 int v ; 4399 for (;;) { 4400 v = _Event ; 4401 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; 4402 } 4403 guarantee (v >= 0, "invariant") ; 4404 if (v != 0) return OS_OK ; 4405 4406 // We do this the hard way, by blocking the thread. 4407 // Consider enforcing a minimum timeout value. 4408 struct timespec abst; 4409 compute_abstime(&abst, millis); 4410 4411 int ret = OS_TIMEOUT; 4412 int status = pthread_mutex_lock(_mutex); 4413 assert_status(status == 0, status, "mutex_lock"); 4414 guarantee (_nParked == 0, "invariant") ; 4415 ++_nParked ; 4416 4417 // Object.wait(timo) will return because of 4418 // (a) notification 4419 // (b) timeout 4420 // (c) thread.interrupt 4421 // 4422 // Thread.interrupt and object.notify{All} both call Event::set. 4423 // That is, we treat thread.interrupt as a special case of notification. 4424 // The underlying Solaris implementation, cond_timedwait, admits 4425 // spurious/premature wakeups, but the JLS/JVM spec prevents the 4426 // JVM from making those visible to Java code. As such, we must 4427 // filter out spurious wakeups. We assume all ETIME returns are valid. 4428 // 4429 // TODO: properly differentiate simultaneous notify+interrupt. 4430 // In that case, we should propagate the notify to another waiter. 4431 4432 while (_Event < 0) { 4433 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst); 4434 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4435 pthread_cond_destroy (_cond); 4436 pthread_cond_init (_cond, NULL) ; 4437 } 4438 assert_status(status == 0 || status == EINTR || 4439 status == ETIMEDOUT, 4440 status, "cond_timedwait"); 4441 if (!FilterSpuriousWakeups) break ; // previous semantics 4442 if (status == ETIMEDOUT) break ; 4443 // We consume and ignore EINTR and spurious wakeups. 4444 } 4445 --_nParked ; 4446 if (_Event >= 0) { 4447 ret = OS_OK; 4448 } 4449 _Event = 0 ; 4450 status = pthread_mutex_unlock(_mutex); 4451 assert_status(status == 0, status, "mutex_unlock"); 4452 assert (_nParked == 0, "invariant") ; 4453 // Paranoia to ensure our locked and lock-free paths interact 4454 // correctly with each other. 4455 OrderAccess::fence(); 4456 return ret; 4457 } 4458 4459 void os::PlatformEvent::unpark() { 4460 // Transitions for _Event: 4461 // 0 :=> 1 4462 // 1 :=> 1 4463 // -1 :=> either 0 or 1; must signal target thread 4464 // That is, we can safely transition _Event from -1 to either 4465 // 0 or 1. Forcing 1 is slightly more efficient for back-to-back 4466 // unpark() calls. 4467 // See also: "Semaphores in Plan 9" by Mullender & Cox 4468 // 4469 // Note: Forcing a transition from "-1" to "1" on an unpark() means 4470 // that it will take two back-to-back park() calls for the owning 4471 // thread to block. This has the benefit of forcing a spurious return 4472 // from the first park() call after an unpark() call which will help 4473 // shake out uses of park() and unpark() without condition variables. 4474 4475 if (Atomic::xchg(1, &_Event) >= 0) return; 4476 4477 // Wait for the thread associated with the event to vacate 4478 int status = pthread_mutex_lock(_mutex); 4479 assert_status(status == 0, status, "mutex_lock"); 4480 int AnyWaiters = _nParked; 4481 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant"); 4482 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { 4483 AnyWaiters = 0; 4484 pthread_cond_signal(_cond); 4485 } 4486 status = pthread_mutex_unlock(_mutex); 4487 assert_status(status == 0, status, "mutex_unlock"); 4488 if (AnyWaiters != 0) { 4489 status = pthread_cond_signal(_cond); 4490 assert_status(status == 0, status, "cond_signal"); 4491 } 4492 4493 // Note that we signal() _after dropping the lock for "immortal" Events. 4494 // This is safe and avoids a common class of futile wakeups. In rare 4495 // circumstances this can cause a thread to return prematurely from 4496 // cond_{timed}wait() but the spurious wakeup is benign and the victim will 4497 // simply re-test the condition and re-park itself. 4498 } 4499 4500 4501 // JSR166 4502 // ------------------------------------------------------- 4503 4504 /* 4505 * The solaris and bsd implementations of park/unpark are fairly 4506 * conservative for now, but can be improved. They currently use a 4507 * mutex/condvar pair, plus a a count. 4508 * Park decrements count if > 0, else does a condvar wait. Unpark 4509 * sets count to 1 and signals condvar. Only one thread ever waits 4510 * on the condvar. Contention seen when trying to park implies that someone 4511 * is unparking you, so don't wait. And spurious returns are fine, so there 4512 * is no need to track notifications. 4513 */ 4514 4515 #define MAX_SECS 100000000 4516 /* 4517 * This code is common to bsd and solaris and will be moved to a 4518 * common place in dolphin. 4519 * 4520 * The passed in time value is either a relative time in nanoseconds 4521 * or an absolute time in milliseconds. Either way it has to be unpacked 4522 * into suitable seconds and nanoseconds components and stored in the 4523 * given timespec structure. 4524 * Given time is a 64-bit value and the time_t used in the timespec is only 4525 * a signed-32-bit value (except on 64-bit Bsd) we have to watch for 4526 * overflow if times way in the future are given. Further on Solaris versions 4527 * prior to 10 there is a restriction (see cond_timedwait) that the specified 4528 * number of seconds, in abstime, is less than current_time + 100,000,000. 4529 * As it will be 28 years before "now + 100000000" will overflow we can 4530 * ignore overflow and just impose a hard-limit on seconds using the value 4531 * of "now + 100,000,000". This places a limit on the timeout of about 3.17 4532 * years from "now". 4533 */ 4534 4535 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { 4536 assert (time > 0, "convertTime"); 4537 4538 struct timeval now; 4539 int status = gettimeofday(&now, NULL); 4540 assert(status == 0, "gettimeofday"); 4541 4542 time_t max_secs = now.tv_sec + MAX_SECS; 4543 4544 if (isAbsolute) { 4545 jlong secs = time / 1000; 4546 if (secs > max_secs) { 4547 absTime->tv_sec = max_secs; 4548 } 4549 else { 4550 absTime->tv_sec = secs; 4551 } 4552 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; 4553 } 4554 else { 4555 jlong secs = time / NANOSECS_PER_SEC; 4556 if (secs >= MAX_SECS) { 4557 absTime->tv_sec = max_secs; 4558 absTime->tv_nsec = 0; 4559 } 4560 else { 4561 absTime->tv_sec = now.tv_sec + secs; 4562 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; 4563 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { 4564 absTime->tv_nsec -= NANOSECS_PER_SEC; 4565 ++absTime->tv_sec; // note: this must be <= max_secs 4566 } 4567 } 4568 } 4569 assert(absTime->tv_sec >= 0, "tv_sec < 0"); 4570 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); 4571 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); 4572 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); 4573 } 4574 4575 void Parker::park(bool isAbsolute, jlong time) { 4576 // Ideally we'd do something useful while spinning, such 4577 // as calling unpackTime(). 4578 4579 // Optional fast-path check: 4580 // Return immediately if a permit is available. 4581 // We depend on Atomic::xchg() having full barrier semantics 4582 // since we are doing a lock-free update to _counter. 4583 if (Atomic::xchg(0, &_counter) > 0) return; 4584 4585 Thread* thread = Thread::current(); 4586 assert(thread->is_Java_thread(), "Must be JavaThread"); 4587 JavaThread *jt = (JavaThread *)thread; 4588 4589 // Optional optimization -- avoid state transitions if there's an interrupt pending. 4590 // Check interrupt before trying to wait 4591 if (Thread::is_interrupted(thread, false)) { 4592 return; 4593 } 4594 4595 // Next, demultiplex/decode time arguments 4596 struct timespec absTime; 4597 if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all 4598 return; 4599 } 4600 if (time > 0) { 4601 unpackTime(&absTime, isAbsolute, time); 4602 } 4603 4604 4605 // Enter safepoint region 4606 // Beware of deadlocks such as 6317397. 4607 // The per-thread Parker:: mutex is a classic leaf-lock. 4608 // In particular a thread must never block on the Threads_lock while 4609 // holding the Parker:: mutex. If safepoints are pending both the 4610 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. 4611 ThreadBlockInVM tbivm(jt); 4612 4613 // Don't wait if cannot get lock since interference arises from 4614 // unblocking. Also. check interrupt before trying wait 4615 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { 4616 return; 4617 } 4618 4619 int status ; 4620 if (_counter > 0) { // no wait needed 4621 _counter = 0; 4622 status = pthread_mutex_unlock(_mutex); 4623 assert (status == 0, "invariant") ; 4624 // Paranoia to ensure our locked and lock-free paths interact 4625 // correctly with each other and Java-level accesses. 4626 OrderAccess::fence(); 4627 return; 4628 } 4629 4630 #ifdef ASSERT 4631 // Don't catch signals while blocked; let the running threads have the signals. 4632 // (This allows a debugger to break into the running thread.) 4633 sigset_t oldsigs; 4634 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); 4635 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); 4636 #endif 4637 4638 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); 4639 jt->set_suspend_equivalent(); 4640 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 4641 4642 if (time == 0) { 4643 status = pthread_cond_wait (_cond, _mutex) ; 4644 } else { 4645 status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ; 4646 if (status != 0 && WorkAroundNPTLTimedWaitHang) { 4647 pthread_cond_destroy (_cond) ; 4648 pthread_cond_init (_cond, NULL); 4649 } 4650 } 4651 assert_status(status == 0 || status == EINTR || 4652 status == ETIMEDOUT, 4653 status, "cond_timedwait"); 4654 4655 #ifdef ASSERT 4656 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); 4657 #endif 4658 4659 _counter = 0 ; 4660 status = pthread_mutex_unlock(_mutex) ; 4661 assert_status(status == 0, status, "invariant") ; 4662 // Paranoia to ensure our locked and lock-free paths interact 4663 // correctly with each other and Java-level accesses. 4664 OrderAccess::fence(); 4665 4666 // If externally suspended while waiting, re-suspend 4667 if (jt->handle_special_suspend_equivalent_condition()) { 4668 jt->java_suspend_self(); 4669 } 4670 } 4671 4672 void Parker::unpark() { 4673 int s, status ; 4674 status = pthread_mutex_lock(_mutex); 4675 assert (status == 0, "invariant") ; 4676 s = _counter; 4677 _counter = 1; 4678 if (s < 1) { 4679 if (WorkAroundNPTLTimedWaitHang) { 4680 status = pthread_cond_signal (_cond) ; 4681 assert (status == 0, "invariant") ; 4682 status = pthread_mutex_unlock(_mutex); 4683 assert (status == 0, "invariant") ; 4684 } else { 4685 status = pthread_mutex_unlock(_mutex); 4686 assert (status == 0, "invariant") ; 4687 status = pthread_cond_signal (_cond) ; 4688 assert (status == 0, "invariant") ; 4689 } 4690 } else { 4691 pthread_mutex_unlock(_mutex); 4692 assert (status == 0, "invariant") ; 4693 } 4694 } 4695 4696 4697 /* Darwin has no "environ" in a dynamic library. */ 4698 #ifdef __APPLE__ 4699 #include <crt_externs.h> 4700 #define environ (*_NSGetEnviron()) 4701 #else 4702 extern char** environ; 4703 #endif 4704 4705 // Run the specified command in a separate process. Return its exit value, 4706 // or -1 on failure (e.g. can't fork a new process). 4707 // Unlike system(), this function can be called from signal handler. It 4708 // doesn't block SIGINT et al. 4709 int os::fork_and_exec(char* cmd) { 4710 const char * argv[4] = {"sh", "-c", cmd, NULL}; 4711 4712 // fork() in BsdThreads/NPTL is not async-safe. It needs to run 4713 // pthread_atfork handlers and reset pthread library. All we need is a 4714 // separate process to execve. Make a direct syscall to fork process. 4715 // On IA64 there's no fork syscall, we have to use fork() and hope for 4716 // the best... 4717 pid_t pid = fork(); 4718 4719 if (pid < 0) { 4720 // fork failed 4721 return -1; 4722 4723 } else if (pid == 0) { 4724 // child process 4725 4726 // execve() in BsdThreads will call pthread_kill_other_threads_np() 4727 // first to kill every thread on the thread list. Because this list is 4728 // not reset by fork() (see notes above), execve() will instead kill 4729 // every thread in the parent process. We know this is the only thread 4730 // in the new process, so make a system call directly. 4731 // IA64 should use normal execve() from glibc to match the glibc fork() 4732 // above. 4733 execve("/bin/sh", (char* const*)argv, environ); 4734 4735 // execve failed 4736 _exit(-1); 4737 4738 } else { 4739 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 4740 // care about the actual exit code, for now. 4741 4742 int status; 4743 4744 // Wait for the child process to exit. This returns immediately if 4745 // the child has already exited. */ 4746 while (waitpid(pid, &status, 0) < 0) { 4747 switch (errno) { 4748 case ECHILD: return 0; 4749 case EINTR: break; 4750 default: return -1; 4751 } 4752 } 4753 4754 if (WIFEXITED(status)) { 4755 // The child exited normally; get its exit code. 4756 return WEXITSTATUS(status); 4757 } else if (WIFSIGNALED(status)) { 4758 // The child exited because of a signal 4759 // The best value to return is 0x80 + signal number, 4760 // because that is what all Unix shells do, and because 4761 // it allows callers to distinguish between process exit and 4762 // process death by signal. 4763 return 0x80 + WTERMSIG(status); 4764 } else { 4765 // Unknown exit code; pass it through 4766 return status; 4767 } 4768 } 4769 } 4770 4771 // is_headless_jre() 4772 // 4773 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 4774 // in order to report if we are running in a headless jre 4775 // 4776 // Since JDK8 xawt/libmawt.so was moved into the same directory 4777 // as libawt.so, and renamed libawt_xawt.so 4778 // 4779 bool os::is_headless_jre() { 4780 #ifdef __APPLE__ 4781 // We no longer build headless-only on Mac OS X 4782 return false; 4783 #else 4784 struct stat statbuf; 4785 char buf[MAXPATHLEN]; 4786 char libmawtpath[MAXPATHLEN]; 4787 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX; 4788 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX; 4789 char *p; 4790 4791 // Get path to libjvm.so 4792 os::jvm_path(buf, sizeof(buf)); 4793 4794 // Get rid of libjvm.so 4795 p = strrchr(buf, '/'); 4796 if (p == NULL) return false; 4797 else *p = '\0'; 4798 4799 // Get rid of client or server 4800 p = strrchr(buf, '/'); 4801 if (p == NULL) return false; 4802 else *p = '\0'; 4803 4804 // check xawt/libmawt.so 4805 strcpy(libmawtpath, buf); 4806 strcat(libmawtpath, xawtstr); 4807 if (::stat(libmawtpath, &statbuf) == 0) return false; 4808 4809 // check libawt_xawt.so 4810 strcpy(libmawtpath, buf); 4811 strcat(libmawtpath, new_xawtstr); 4812 if (::stat(libmawtpath, &statbuf) == 0) return false; 4813 4814 return true; 4815 #endif 4816 } 4817 4818 // Get the default path to the core file 4819 // Returns the length of the string 4820 int os::get_core_path(char* buffer, size_t bufferSize) { 4821 int n = jio_snprintf(buffer, bufferSize, "/cores"); 4822 4823 // Truncate if theoretical string was longer than bufferSize 4824 n = MIN2(n, (int)bufferSize); 4825 4826 return n; 4827 } 4828 4829 #ifndef PRODUCT 4830 void TestReserveMemorySpecial_test() { 4831 // No tests available for this platform 4832 } 4833 #endif