1 /*
   2  * Copyright (c) 1999, 2019, 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 "jvm.h"
  27 #include "classfile/classLoader.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "classfile/vmSymbols.hpp"
  30 #include "code/icBuffer.hpp"
  31 #include "code/vtableStubs.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "compiler/disassembler.hpp"
  34 #include "interpreter/interpreter.hpp"
  35 #include "logging/log.hpp"
  36 #include "logging/logStream.hpp"
  37 #include "memory/allocation.inline.hpp"
  38 #include "memory/filemap.hpp"
  39 #include "oops/oop.inline.hpp"
  40 #include "os_bsd.inline.hpp"
  41 #include "os_posix.inline.hpp"
  42 #include "os_share_bsd.hpp"
  43 #include "prims/jniFastGetField.hpp"
  44 #include "prims/jvm_misc.hpp"
  45 #include "runtime/arguments.hpp"
  46 #include "runtime/atomic.hpp"
  47 #include "runtime/extendedPC.hpp"
  48 #include "runtime/globals.hpp"
  49 #include "runtime/interfaceSupport.inline.hpp"
  50 #include "runtime/java.hpp"
  51 #include "runtime/javaCalls.hpp"
  52 #include "runtime/mutexLocker.hpp"
  53 #include "runtime/objectMonitor.hpp"
  54 #include "runtime/orderAccess.hpp"
  55 #include "runtime/osThread.hpp"
  56 #include "runtime/perfMemory.hpp"
  57 #include "runtime/semaphore.hpp"
  58 #include "runtime/sharedRuntime.hpp"
  59 #include "runtime/statSampler.hpp"
  60 #include "runtime/stubRoutines.hpp"
  61 #include "runtime/thread.inline.hpp"
  62 #include "runtime/threadCritical.hpp"
  63 #include "runtime/timer.hpp"
  64 #include "services/attachListener.hpp"
  65 #include "services/memTracker.hpp"
  66 #include "services/runtimeService.hpp"
  67 #include "utilities/align.hpp"
  68 #include "utilities/decoder.hpp"
  69 #include "utilities/defaultStream.hpp"
  70 #include "utilities/events.hpp"
  71 #include "utilities/growableArray.hpp"
  72 #include "utilities/vmError.hpp"
  73 
  74 // put OS-includes here
  75 # include <dlfcn.h>
  76 # include <errno.h>
  77 # include <fcntl.h>
  78 # include <inttypes.h>
  79 # include <poll.h>
  80 # include <pthread.h>
  81 # include <pwd.h>
  82 # include <signal.h>
  83 # include <stdint.h>
  84 # include <stdio.h>
  85 # include <string.h>
  86 # include <sys/ioctl.h>
  87 # include <sys/mman.h>
  88 # include <sys/param.h>
  89 # include <sys/resource.h>
  90 # include <sys/socket.h>
  91 # include <sys/stat.h>
  92 # include <sys/syscall.h>
  93 # include <sys/sysctl.h>
  94 # include <sys/time.h>
  95 # include <sys/times.h>
  96 # include <sys/types.h>
  97 # include <sys/wait.h>
  98 # include <time.h>
  99 # include <unistd.h>
 100 
 101 #if defined(__FreeBSD__) || defined(__NetBSD__)
 102   #include <elf.h>
 103 #endif
 104 
 105 #ifdef __APPLE__
 106   #include <mach-o/dyld.h>
 107 #endif
 108 
 109 #ifndef MAP_ANONYMOUS
 110   #define MAP_ANONYMOUS MAP_ANON
 111 #endif
 112 
 113 #define MAX_PATH    (2 * K)
 114 
 115 // for timer info max values which include all bits
 116 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 117 
 118 ////////////////////////////////////////////////////////////////////////////////
 119 // global variables
 120 julong os::Bsd::_physical_memory = 0;
 121 
 122 #ifdef __APPLE__
 123 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
 124 volatile uint64_t         os::Bsd::_max_abstime   = 0;
 125 #else
 126 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 127 #endif
 128 pthread_t os::Bsd::_main_thread;
 129 int os::Bsd::_page_size = -1;
 130 
 131 static jlong initial_time_count=0;
 132 
 133 static int clock_tics_per_sec = 100;
 134 
 135 // For diagnostics to print a message once. see run_periodic_checks
 136 static sigset_t check_signal_done;
 137 static bool check_signals = true;
 138 
 139 // Signal number used to suspend/resume a thread
 140 
 141 // do not use any signal number less than SIGSEGV, see 4355769
 142 static int SR_signum = SIGUSR2;
 143 sigset_t SR_sigset;
 144 
 145 
 146 ////////////////////////////////////////////////////////////////////////////////
 147 // utility functions
 148 
 149 static int SR_initialize();
 150 
 151 julong os::available_memory() {
 152   return Bsd::available_memory();
 153 }
 154 
 155 // available here means free
 156 julong os::Bsd::available_memory() {
 157   uint64_t available = physical_memory() >> 2;
 158 #ifdef __APPLE__
 159   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
 160   vm_statistics64_data_t vmstat;
 161   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
 162                                          (host_info64_t)&vmstat, &count);
 163   assert(kerr == KERN_SUCCESS,
 164          "host_statistics64 failed - check mach_host_self() and count");
 165   if (kerr == KERN_SUCCESS) {
 166     available = vmstat.free_count * os::vm_page_size();
 167   }
 168 #endif
 169   return available;
 170 }
 171 
 172 julong os::physical_memory() {
 173   return Bsd::physical_memory();
 174 }
 175 
 176 // Return true if user is running as root.
 177 
 178 bool os::have_special_privileges() {
 179   static bool init = false;
 180   static bool privileges = false;
 181   if (!init) {
 182     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 183     init = true;
 184   }
 185   return privileges;
 186 }
 187 
 188 
 189 
 190 // Cpu architecture string
 191 #if   defined(ZERO)
 192 static char cpu_arch[] = ZERO_LIBARCH;
 193 #elif defined(IA64)
 194 static char cpu_arch[] = "ia64";
 195 #elif defined(IA32)
 196 static char cpu_arch[] = "i386";
 197 #elif defined(AMD64)
 198 static char cpu_arch[] = "amd64";
 199 #elif defined(ARM)
 200 static char cpu_arch[] = "arm";
 201 #elif defined(PPC32)
 202 static char cpu_arch[] = "ppc";
 203 #elif defined(SPARC)
 204   #ifdef _LP64
 205 static char cpu_arch[] = "sparcv9";
 206   #else
 207 static char cpu_arch[] = "sparc";
 208   #endif
 209 #else
 210   #error Add appropriate cpu_arch setting
 211 #endif
 212 
 213 // Compiler variant
 214 #ifdef COMPILER2
 215   #define COMPILER_VARIANT "server"
 216 #else
 217   #define COMPILER_VARIANT "client"
 218 #endif
 219 
 220 
 221 void os::Bsd::initialize_system_info() {
 222   int mib[2];
 223   size_t len;
 224   int cpu_val;
 225   julong mem_val;
 226 
 227   // get processors count via hw.ncpus sysctl
 228   mib[0] = CTL_HW;
 229   mib[1] = HW_NCPU;
 230   len = sizeof(cpu_val);
 231   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 232     assert(len == sizeof(cpu_val), "unexpected data size");
 233     set_processor_count(cpu_val);
 234   } else {
 235     set_processor_count(1);   // fallback
 236   }
 237 
 238   // get physical memory via hw.memsize sysctl (hw.memsize is used
 239   // since it returns a 64 bit value)
 240   mib[0] = CTL_HW;
 241 
 242 #if defined (HW_MEMSIZE) // Apple
 243   mib[1] = HW_MEMSIZE;
 244 #elif defined(HW_PHYSMEM) // Most of BSD
 245   mib[1] = HW_PHYSMEM;
 246 #elif defined(HW_REALMEM) // Old FreeBSD
 247   mib[1] = HW_REALMEM;
 248 #else
 249   #error No ways to get physmem
 250 #endif
 251 
 252   len = sizeof(mem_val);
 253   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 254     assert(len == sizeof(mem_val), "unexpected data size");
 255     _physical_memory = mem_val;
 256   } else {
 257     _physical_memory = 256 * 1024 * 1024;       // fallback (XXXBSD?)
 258   }
 259 
 260 #ifdef __OpenBSD__
 261   {
 262     // limit _physical_memory memory view on OpenBSD since
 263     // datasize rlimit restricts us anyway.
 264     struct rlimit limits;
 265     getrlimit(RLIMIT_DATA, &limits);
 266     _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 267   }
 268 #endif
 269 }
 270 
 271 #ifdef __APPLE__
 272 static const char *get_home() {
 273   const char *home_dir = ::getenv("HOME");
 274   if ((home_dir == NULL) || (*home_dir == '\0')) {
 275     struct passwd *passwd_info = getpwuid(geteuid());
 276     if (passwd_info != NULL) {
 277       home_dir = passwd_info->pw_dir;
 278     }
 279   }
 280 
 281   return home_dir;
 282 }
 283 #endif
 284 
 285 void os::init_system_properties_values() {
 286   // The next steps are taken in the product version:
 287   //
 288   // Obtain the JAVA_HOME value from the location of libjvm.so.
 289   // This library should be located at:
 290   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 291   //
 292   // If "/jre/lib/" appears at the right place in the path, then we
 293   // assume libjvm.so is installed in a JDK and we use this path.
 294   //
 295   // Otherwise exit with message: "Could not create the Java virtual machine."
 296   //
 297   // The following extra steps are taken in the debugging version:
 298   //
 299   // If "/jre/lib/" does NOT appear at the right place in the path
 300   // instead of exit check for $JAVA_HOME environment variable.
 301   //
 302   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 303   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 304   // it looks like libjvm.so is installed there
 305   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 306   //
 307   // Otherwise exit.
 308   //
 309   // Important note: if the location of libjvm.so changes this
 310   // code needs to be changed accordingly.
 311 
 312   // See ld(1):
 313   //      The linker uses the following search paths to locate required
 314   //      shared libraries:
 315   //        1: ...
 316   //        ...
 317   //        7: The default directories, normally /lib and /usr/lib.
 318 #ifndef DEFAULT_LIBPATH
 319   #ifndef OVERRIDE_LIBPATH
 320     #define DEFAULT_LIBPATH "/lib:/usr/lib"
 321   #else
 322     #define DEFAULT_LIBPATH OVERRIDE_LIBPATH
 323   #endif
 324 #endif
 325 
 326 // Base path of extensions installed on the system.
 327 #define SYS_EXT_DIR     "/usr/java/packages"
 328 #define EXTENSIONS_DIR  "/lib/ext"
 329 
 330 #ifndef __APPLE__
 331 
 332   // Buffer that fits several sprintfs.
 333   // Note that the space for the colon and the trailing null are provided
 334   // by the nulls included by the sizeof operator.
 335   const size_t bufsize =
 336     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 337          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
 338   char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 339 
 340   // sysclasspath, java_home, dll_dir
 341   {
 342     char *pslash;
 343     os::jvm_path(buf, bufsize);
 344 
 345     // Found the full path to libjvm.so.
 346     // Now cut the path to <java_home>/jre if we can.
 347     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 348     pslash = strrchr(buf, '/');
 349     if (pslash != NULL) {
 350       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 351     }
 352     Arguments::set_dll_dir(buf);
 353 
 354     if (pslash != NULL) {
 355       pslash = strrchr(buf, '/');
 356       if (pslash != NULL) {
 357         *pslash = '\0';          // Get rid of /<arch>.
 358         pslash = strrchr(buf, '/');
 359         if (pslash != NULL) {
 360           *pslash = '\0';        // Get rid of /lib.
 361         }
 362       }
 363     }
 364     Arguments::set_java_home(buf);
 365     if (!set_boot_path('/', ':')) {
 366       vm_exit_during_initialization("Failed setting boot class path.", NULL);
 367     }
 368   }
 369 
 370   // Where to look for native libraries.
 371   //
 372   // Note: Due to a legacy implementation, most of the library path
 373   // is set in the launcher. This was to accomodate linking restrictions
 374   // on legacy Bsd implementations (which are no longer supported).
 375   // Eventually, all the library path setting will be done here.
 376   //
 377   // However, to prevent the proliferation of improperly built native
 378   // libraries, the new path component /usr/java/packages is added here.
 379   // Eventually, all the library path setting will be done here.
 380   {
 381     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 382     // should always exist (until the legacy problem cited above is
 383     // addressed).
 384     const char *v = ::getenv("LD_LIBRARY_PATH");
 385     const char *v_colon = ":";
 386     if (v == NULL) { v = ""; v_colon = ""; }
 387     // That's +1 for the colon and +1 for the trailing '\0'.
 388     char *ld_library_path = NEW_C_HEAP_ARRAY(char,
 389                                              strlen(v) + 1 +
 390                                              sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
 391                                              mtInternal);
 392     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
 393     Arguments::set_library_path(ld_library_path);
 394     FREE_C_HEAP_ARRAY(char, ld_library_path);
 395   }
 396 
 397   // Extensions directories.
 398   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
 399   Arguments::set_ext_dirs(buf);
 400 
 401   FREE_C_HEAP_ARRAY(char, buf);
 402 
 403 #else // __APPLE__
 404 
 405   #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 406   #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 407 
 408   const char *user_home_dir = get_home();
 409   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
 410   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 411     sizeof(SYS_EXTENSIONS_DIRS);
 412 
 413   // Buffer that fits several sprintfs.
 414   // Note that the space for the colon and the trailing null are provided
 415   // by the nulls included by the sizeof operator.
 416   const size_t bufsize =
 417     MAX2((size_t)MAXPATHLEN,  // for dll_dir & friends.
 418          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
 419   char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 420 
 421   // sysclasspath, java_home, dll_dir
 422   {
 423     char *pslash;
 424     os::jvm_path(buf, bufsize);
 425 
 426     // Found the full path to libjvm.so.
 427     // Now cut the path to <java_home>/jre if we can.
 428     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 429     pslash = strrchr(buf, '/');
 430     if (pslash != NULL) {
 431       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 432     }
 433 #ifdef STATIC_BUILD
 434     strcat(buf, "/lib");
 435 #endif
 436 
 437     Arguments::set_dll_dir(buf);
 438 
 439     if (pslash != NULL) {
 440       pslash = strrchr(buf, '/');
 441       if (pslash != NULL) {
 442         *pslash = '\0';          // Get rid of /lib.
 443       }
 444     }
 445     Arguments::set_java_home(buf);
 446     set_boot_path('/', ':');
 447   }
 448 
 449   // Where to look for native libraries.
 450   //
 451   // Note: Due to a legacy implementation, most of the library path
 452   // is set in the launcher. This was to accomodate linking restrictions
 453   // on legacy Bsd implementations (which are no longer supported).
 454   // Eventually, all the library path setting will be done here.
 455   //
 456   // However, to prevent the proliferation of improperly built native
 457   // libraries, the new path component /usr/java/packages is added here.
 458   // Eventually, all the library path setting will be done here.
 459   {
 460     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 461     // should always exist (until the legacy problem cited above is
 462     // addressed).
 463     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
 464     // can specify a directory inside an app wrapper
 465     const char *l = ::getenv("JAVA_LIBRARY_PATH");
 466     const char *l_colon = ":";
 467     if (l == NULL) { l = ""; l_colon = ""; }
 468 
 469     const char *v = ::getenv("DYLD_LIBRARY_PATH");
 470     const char *v_colon = ":";
 471     if (v == NULL) { v = ""; v_colon = ""; }
 472 
 473     // Apple's Java6 has "." at the beginning of java.library.path.
 474     // OpenJDK on Windows has "." at the end of java.library.path.
 475     // OpenJDK on Linux and Solaris don't have "." in java.library.path
 476     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 477     // "." is appended to the end of java.library.path. Yes, this
 478     // could cause a change in behavior, but Apple's Java6 behavior
 479     // can be achieved by putting "." at the beginning of the
 480     // JAVA_LIBRARY_PATH environment variable.
 481     char *ld_library_path = NEW_C_HEAP_ARRAY(char,
 482                                              strlen(v) + 1 + strlen(l) + 1 +
 483                                              system_ext_size + 3,
 484                                              mtInternal);
 485     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
 486             v, v_colon, l, l_colon, user_home_dir);
 487     Arguments::set_library_path(ld_library_path);
 488     FREE_C_HEAP_ARRAY(char, ld_library_path);
 489   }
 490 
 491   // Extensions directories.
 492   //
 493   // Note that the space for the colon and the trailing null are provided
 494   // by the nulls included by the sizeof operator (so actually one byte more
 495   // than necessary is allocated).
 496   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
 497           user_home_dir, Arguments::get_java_home());
 498   Arguments::set_ext_dirs(buf);
 499 
 500   FREE_C_HEAP_ARRAY(char, buf);
 501 
 502 #undef SYS_EXTENSIONS_DIR
 503 #undef SYS_EXTENSIONS_DIRS
 504 
 505 #endif // __APPLE__
 506 
 507 #undef SYS_EXT_DIR
 508 #undef EXTENSIONS_DIR
 509 }
 510 
 511 ////////////////////////////////////////////////////////////////////////////////
 512 // breakpoint support
 513 
 514 void os::breakpoint() {
 515   BREAKPOINT;
 516 }
 517 
 518 extern "C" void breakpoint() {
 519   // use debugger to set breakpoint here
 520 }
 521 
 522 ////////////////////////////////////////////////////////////////////////////////
 523 // signal support
 524 
 525 debug_only(static bool signal_sets_initialized = false);
 526 static sigset_t unblocked_sigs, vm_sigs;
 527 
 528 void os::Bsd::signal_sets_init() {
 529   // Should also have an assertion stating we are still single-threaded.
 530   assert(!signal_sets_initialized, "Already initialized");
 531   // Fill in signals that are necessarily unblocked for all threads in
 532   // the VM. Currently, we unblock the following signals:
 533   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 534   //                         by -Xrs (=ReduceSignalUsage));
 535   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 536   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 537   // the dispositions or masks wrt these signals.
 538   // Programs embedding the VM that want to use the above signals for their
 539   // own purposes must, at this time, use the "-Xrs" option to prevent
 540   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 541   // (See bug 4345157, and other related bugs).
 542   // In reality, though, unblocking these signals is really a nop, since
 543   // these signals are not blocked by default.
 544   sigemptyset(&unblocked_sigs);
 545   sigaddset(&unblocked_sigs, SIGILL);
 546   sigaddset(&unblocked_sigs, SIGSEGV);
 547   sigaddset(&unblocked_sigs, SIGBUS);
 548   sigaddset(&unblocked_sigs, SIGFPE);
 549   sigaddset(&unblocked_sigs, SR_signum);
 550 
 551   if (!ReduceSignalUsage) {
 552     if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 553       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 554 
 555     }
 556     if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 557       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 558     }
 559     if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 560       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 561     }
 562   }
 563   // Fill in signals that are blocked by all but the VM thread.
 564   sigemptyset(&vm_sigs);
 565   if (!ReduceSignalUsage) {
 566     sigaddset(&vm_sigs, BREAK_SIGNAL);
 567   }
 568   debug_only(signal_sets_initialized = true);
 569 
 570 }
 571 
 572 // These are signals that are unblocked while a thread is running Java.
 573 // (For some reason, they get blocked by default.)
 574 sigset_t* os::Bsd::unblocked_signals() {
 575   assert(signal_sets_initialized, "Not initialized");
 576   return &unblocked_sigs;
 577 }
 578 
 579 // These are the signals that are blocked while a (non-VM) thread is
 580 // running Java. Only the VM thread handles these signals.
 581 sigset_t* os::Bsd::vm_signals() {
 582   assert(signal_sets_initialized, "Not initialized");
 583   return &vm_sigs;
 584 }
 585 
 586 void os::Bsd::hotspot_sigmask(Thread* thread) {
 587 
 588   //Save caller's signal mask before setting VM signal mask
 589   sigset_t caller_sigmask;
 590   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 591 
 592   OSThread* osthread = thread->osthread();
 593   osthread->set_caller_sigmask(caller_sigmask);
 594 
 595   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 596 
 597   if (!ReduceSignalUsage) {
 598     if (thread->is_VM_thread()) {
 599       // Only the VM thread handles BREAK_SIGNAL ...
 600       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 601     } else {
 602       // ... all other threads block BREAK_SIGNAL
 603       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 604     }
 605   }
 606 }
 607 
 608 
 609 //////////////////////////////////////////////////////////////////////////////
 610 // create new thread
 611 
 612 #ifdef __APPLE__
 613 // library handle for calling objc_registerThreadWithCollector()
 614 // without static linking to the libobjc library
 615   #define OBJC_LIB "/usr/lib/libobjc.dylib"
 616   #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 617 typedef void (*objc_registerThreadWithCollector_t)();
 618 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 619 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 620 #endif
 621 
 622 #ifdef __APPLE__
 623 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 624   // Additional thread_id used to correlate threads in SA
 625   thread_identifier_info_data_t     m_ident_info;
 626   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 627 
 628   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 629               (thread_info_t) &m_ident_info, &count);
 630 
 631   return m_ident_info.thread_id;
 632 }
 633 #endif
 634 
 635 // Thread start routine for all newly created threads
 636 static void *thread_native_entry(Thread *thread) {
 637 
 638   thread->record_stack_base_and_size();
 639 
 640   // Try to randomize the cache line index of hot stack frames.
 641   // This helps when threads of the same stack traces evict each other's
 642   // cache lines. The threads can be either from the same JVM instance, or
 643   // from different JVM instances. The benefit is especially true for
 644   // processors with hyperthreading technology.
 645   static int counter = 0;
 646   int pid = os::current_process_id();
 647   alloca(((pid ^ counter++) & 7) * 128);
 648 
 649   thread->initialize_thread_current();
 650 
 651   OSThread* osthread = thread->osthread();
 652   Monitor* sync = osthread->startThread_lock();
 653 
 654   osthread->set_thread_id(os::Bsd::gettid());
 655 
 656   log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 657     os::current_thread_id(), (uintx) pthread_self());
 658 
 659 #ifdef __APPLE__
 660   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 661   guarantee(unique_thread_id != 0, "unique thread id was not found");
 662   osthread->set_unique_thread_id(unique_thread_id);
 663 #endif
 664   // initialize signal mask for this thread
 665   os::Bsd::hotspot_sigmask(thread);
 666 
 667   // initialize floating point control register
 668   os::Bsd::init_thread_fpu_state();
 669 
 670 #ifdef __APPLE__
 671   // register thread with objc gc
 672   if (objc_registerThreadWithCollectorFunction != NULL) {
 673     objc_registerThreadWithCollectorFunction();
 674   }
 675 #endif
 676 
 677   // handshaking with parent thread
 678   {
 679     MutexLocker ml(sync, Mutex::_no_safepoint_check_flag);
 680 
 681     // notify parent thread
 682     osthread->set_state(INITIALIZED);
 683     sync->notify_all();
 684 
 685     // wait until os::start_thread()
 686     while (osthread->get_state() == INITIALIZED) {
 687       sync->wait_without_safepoint_check();
 688     }
 689   }
 690 
 691   // call one more level start routine
 692   thread->call_run();
 693 
 694   // Note: at this point the thread object may already have deleted itself.
 695   // Prevent dereferencing it from here on out.
 696   thread = NULL;
 697 
 698   log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 699     os::current_thread_id(), (uintx) pthread_self());
 700 
 701   return 0;
 702 }
 703 
 704 bool os::create_thread(Thread* thread, ThreadType thr_type,
 705                        size_t req_stack_size) {
 706   assert(thread->osthread() == NULL, "caller responsible");
 707 
 708   // Allocate the OSThread object
 709   OSThread* osthread = new OSThread(NULL, NULL);
 710   if (osthread == NULL) {
 711     return false;
 712   }
 713 
 714   // set the correct thread state
 715   osthread->set_thread_type(thr_type);
 716 
 717   // Initial state is ALLOCATED but not INITIALIZED
 718   osthread->set_state(ALLOCATED);
 719 
 720   thread->set_osthread(osthread);
 721 
 722   // init thread attributes
 723   pthread_attr_t attr;
 724   pthread_attr_init(&attr);
 725   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 726 
 727   // calculate stack size if it's not specified by caller
 728   size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
 729   int status = pthread_attr_setstacksize(&attr, stack_size);
 730   assert_status(status == 0, status, "pthread_attr_setstacksize");
 731 
 732   ThreadState state;
 733 
 734   {
 735     pthread_t tid;
 736     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
 737 
 738     char buf[64];
 739     if (ret == 0) {
 740       log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
 741         (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 742     } else {
 743       log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
 744         os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 745       // Log some OS information which might explain why creating the thread failed.
 746       log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
 747       LogStream st(Log(os, thread)::info());
 748       os::Posix::print_rlimit_info(&st);
 749       os::print_memory_info(&st);
 750     }
 751 
 752     pthread_attr_destroy(&attr);
 753 
 754     if (ret != 0) {
 755       // Need to clean up stuff we've allocated so far
 756       thread->set_osthread(NULL);
 757       delete osthread;
 758       return false;
 759     }
 760 
 761     // Store pthread info into the OSThread
 762     osthread->set_pthread_id(tid);
 763 
 764     // Wait until child thread is either initialized or aborted
 765     {
 766       Monitor* sync_with_child = osthread->startThread_lock();
 767       MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 768       while ((state = osthread->get_state()) == ALLOCATED) {
 769         sync_with_child->wait_without_safepoint_check();
 770       }
 771     }
 772 
 773   }
 774 
 775   // Aborted due to thread limit being reached
 776   if (state == ZOMBIE) {
 777     thread->set_osthread(NULL);
 778     delete osthread;
 779     return false;
 780   }
 781 
 782   // The thread is returned suspended (in state INITIALIZED),
 783   // and is started higher up in the call chain
 784   assert(state == INITIALIZED, "race condition");
 785   return true;
 786 }
 787 
 788 /////////////////////////////////////////////////////////////////////////////
 789 // attach existing thread
 790 
 791 // bootstrap the main thread
 792 bool os::create_main_thread(JavaThread* thread) {
 793   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 794   return create_attached_thread(thread);
 795 }
 796 
 797 bool os::create_attached_thread(JavaThread* thread) {
 798 #ifdef ASSERT
 799   thread->verify_not_published();
 800 #endif
 801 
 802   // Allocate the OSThread object
 803   OSThread* osthread = new OSThread(NULL, NULL);
 804 
 805   if (osthread == NULL) {
 806     return false;
 807   }
 808 
 809   osthread->set_thread_id(os::Bsd::gettid());
 810 
 811   // Store pthread info into the OSThread
 812 #ifdef __APPLE__
 813   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 814   guarantee(unique_thread_id != 0, "just checking");
 815   osthread->set_unique_thread_id(unique_thread_id);
 816 #endif
 817   osthread->set_pthread_id(::pthread_self());
 818 
 819   // initialize floating point control register
 820   os::Bsd::init_thread_fpu_state();
 821 
 822   // Initial thread state is RUNNABLE
 823   osthread->set_state(RUNNABLE);
 824 
 825   thread->set_osthread(osthread);
 826 
 827   // initialize signal mask for this thread
 828   // and save the caller's signal mask
 829   os::Bsd::hotspot_sigmask(thread);
 830 
 831   log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 832     os::current_thread_id(), (uintx) pthread_self());
 833 
 834   return true;
 835 }
 836 
 837 void os::pd_start_thread(Thread* thread) {
 838   OSThread * osthread = thread->osthread();
 839   assert(osthread->get_state() != INITIALIZED, "just checking");
 840   Monitor* sync_with_child = osthread->startThread_lock();
 841   MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 842   sync_with_child->notify();
 843 }
 844 
 845 // Free Bsd resources related to the OSThread
 846 void os::free_thread(OSThread* osthread) {
 847   assert(osthread != NULL, "osthread not set");
 848 
 849   // We are told to free resources of the argument thread,
 850   // but we can only really operate on the current thread.
 851   assert(Thread::current()->osthread() == osthread,
 852          "os::free_thread but not current thread");
 853 
 854   // Restore caller's signal mask
 855   sigset_t sigmask = osthread->caller_sigmask();
 856   pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 857 
 858   delete osthread;
 859 }
 860 
 861 ////////////////////////////////////////////////////////////////////////////////
 862 // time support
 863 
 864 // Time since start-up in seconds to a fine granularity.
 865 // Used by VMSelfDestructTimer and the MemProfiler.
 866 double os::elapsedTime() {
 867 
 868   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 869 }
 870 
 871 jlong os::elapsed_counter() {
 872   return javaTimeNanos() - initial_time_count;
 873 }
 874 
 875 jlong os::elapsed_frequency() {
 876   return NANOSECS_PER_SEC; // nanosecond resolution
 877 }
 878 
 879 bool os::supports_vtime() { return true; }
 880 
 881 double os::elapsedVTime() {
 882   // better than nothing, but not much
 883   return elapsedTime();
 884 }
 885 
 886 jlong os::javaTimeMillis() {
 887   timeval time;
 888   int status = gettimeofday(&time, NULL);
 889   assert(status != -1, "bsd error");
 890   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 891 }
 892 
 893 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
 894   timeval time;
 895   int status = gettimeofday(&time, NULL);
 896   assert(status != -1, "bsd error");
 897   seconds = jlong(time.tv_sec);
 898   nanos = jlong(time.tv_usec) * 1000;
 899 }
 900 
 901 #ifndef __APPLE__
 902   #ifndef CLOCK_MONOTONIC
 903     #define CLOCK_MONOTONIC (1)
 904   #endif
 905 #endif
 906 
 907 #ifdef __APPLE__
 908 void os::Bsd::clock_init() {
 909   mach_timebase_info(&_timebase_info);
 910 }
 911 #else
 912 void os::Bsd::clock_init() {
 913   struct timespec res;
 914   struct timespec tp;
 915   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
 916       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
 917     // yes, monotonic clock is supported
 918     _clock_gettime = ::clock_gettime;
 919   }
 920 }
 921 #endif
 922 
 923 
 924 
 925 #ifdef __APPLE__
 926 
 927 jlong os::javaTimeNanos() {
 928   const uint64_t tm = mach_absolute_time();
 929   const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
 930   const uint64_t prev = Bsd::_max_abstime;
 931   if (now <= prev) {
 932     return prev;   // same or retrograde time;
 933   }
 934   const uint64_t obsv = Atomic::cmpxchg(now, &Bsd::_max_abstime, prev);
 935   assert(obsv >= prev, "invariant");   // Monotonicity
 936   // If the CAS succeeded then we're done and return "now".
 937   // If the CAS failed and the observed value "obsv" is >= now then
 938   // we should return "obsv".  If the CAS failed and now > obsv > prv then
 939   // some other thread raced this thread and installed a new value, in which case
 940   // we could either (a) retry the entire operation, (b) retry trying to install now
 941   // or (c) just return obsv.  We use (c).   No loop is required although in some cases
 942   // we might discard a higher "now" value in deference to a slightly lower but freshly
 943   // installed obsv value.   That's entirely benign -- it admits no new orderings compared
 944   // to (a) or (b) -- and greatly reduces coherence traffic.
 945   // We might also condition (c) on the magnitude of the delta between obsv and now.
 946   // Avoiding excessive CAS operations to hot RW locations is critical.
 947   // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
 948   return (prev == obsv) ? now : obsv;
 949 }
 950 
 951 #else // __APPLE__
 952 
 953 jlong os::javaTimeNanos() {
 954   if (os::supports_monotonic_clock()) {
 955     struct timespec tp;
 956     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
 957     assert(status == 0, "gettime error");
 958     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
 959     return result;
 960   } else {
 961     timeval time;
 962     int status = gettimeofday(&time, NULL);
 963     assert(status != -1, "bsd error");
 964     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
 965     return 1000 * usecs;
 966   }
 967 }
 968 
 969 #endif // __APPLE__
 970 
 971 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
 972   if (os::supports_monotonic_clock()) {
 973     info_ptr->max_value = ALL_64_BITS;
 974 
 975     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
 976     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
 977     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
 978   } else {
 979     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
 980     info_ptr->max_value = ALL_64_BITS;
 981 
 982     // gettimeofday is a real time clock so it skips
 983     info_ptr->may_skip_backward = true;
 984     info_ptr->may_skip_forward = true;
 985   }
 986 
 987   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
 988 }
 989 
 990 // Return the real, user, and system times in seconds from an
 991 // arbitrary fixed point in the past.
 992 bool os::getTimesSecs(double* process_real_time,
 993                       double* process_user_time,
 994                       double* process_system_time) {
 995   struct tms ticks;
 996   clock_t real_ticks = times(&ticks);
 997 
 998   if (real_ticks == (clock_t) (-1)) {
 999     return false;
1000   } else {
1001     double ticks_per_second = (double) clock_tics_per_sec;
1002     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1003     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1004     *process_real_time = ((double) real_ticks) / ticks_per_second;
1005 
1006     return true;
1007   }
1008 }
1009 
1010 
1011 char * os::local_time_string(char *buf, size_t buflen) {
1012   struct tm t;
1013   time_t long_time;
1014   time(&long_time);
1015   localtime_r(&long_time, &t);
1016   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1017                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1018                t.tm_hour, t.tm_min, t.tm_sec);
1019   return buf;
1020 }
1021 
1022 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1023   return localtime_r(clock, res);
1024 }
1025 
1026 ////////////////////////////////////////////////////////////////////////////////
1027 // runtime exit support
1028 
1029 // Note: os::shutdown() might be called very early during initialization, or
1030 // called from signal handler. Before adding something to os::shutdown(), make
1031 // sure it is async-safe and can handle partially initialized VM.
1032 void os::shutdown() {
1033 
1034   // allow PerfMemory to attempt cleanup of any persistent resources
1035   perfMemory_exit();
1036 
1037   // needs to remove object in file system
1038   AttachListener::abort();
1039 
1040   // flush buffered output, finish log files
1041   ostream_abort();
1042 
1043   // Check for abort hook
1044   abort_hook_t abort_hook = Arguments::abort_hook();
1045   if (abort_hook != NULL) {
1046     abort_hook();
1047   }
1048 
1049 }
1050 
1051 // Note: os::abort() might be called very early during initialization, or
1052 // called from signal handler. Before adding something to os::abort(), make
1053 // sure it is async-safe and can handle partially initialized VM.
1054 void os::abort(bool dump_core, void* siginfo, const void* context) {
1055   os::shutdown();
1056   if (dump_core) {
1057 #ifndef PRODUCT
1058     fdStream out(defaultStream::output_fd());
1059     out.print_raw("Current thread is ");
1060     char buf[16];
1061     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1062     out.print_raw_cr(buf);
1063     out.print_raw_cr("Dumping core ...");
1064 #endif
1065     ::abort(); // dump core
1066   }
1067 
1068   ::exit(1);
1069 }
1070 
1071 // Die immediately, no exit hook, no abort hook, no cleanup.
1072 // Dump a core file, if possible, for debugging.
1073 void os::die() {
1074   if (TestUnresponsiveErrorHandler && !CreateCoredumpOnCrash) {
1075     // For TimeoutInErrorHandlingTest.java, we just kill the VM
1076     // and don't take the time to generate a core file.
1077     os::signal_raise(SIGKILL);
1078   } else {
1079     // _exit() on BsdThreads only kills current thread
1080     ::abort();
1081   }
1082 }
1083 
1084 // Information of current thread in variety of formats
1085 pid_t os::Bsd::gettid() {
1086   int retval = -1;
1087 
1088 #ifdef __APPLE__ //XNU kernel
1089   // despite the fact mach port is actually not a thread id use it
1090   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1091   retval = ::pthread_mach_thread_np(::pthread_self());
1092   guarantee(retval != 0, "just checking");
1093   return retval;
1094 
1095 #else
1096   #ifdef __FreeBSD__
1097   retval = syscall(SYS_thr_self);
1098   #else
1099     #ifdef __OpenBSD__
1100   retval = syscall(SYS_getthrid);
1101     #else
1102       #ifdef __NetBSD__
1103   retval = (pid_t) syscall(SYS__lwp_self);
1104       #endif
1105     #endif
1106   #endif
1107 #endif
1108 
1109   if (retval == -1) {
1110     return getpid();
1111   }
1112 }
1113 
1114 intx os::current_thread_id() {
1115 #ifdef __APPLE__
1116   return (intx)::pthread_mach_thread_np(::pthread_self());
1117 #else
1118   return (intx)::pthread_self();
1119 #endif
1120 }
1121 
1122 int os::current_process_id() {
1123   return (int)(getpid());
1124 }
1125 
1126 // DLL functions
1127 
1128 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1129 
1130 // This must be hard coded because it's the system's temporary
1131 // directory not the java application's temp directory, ala java.io.tmpdir.
1132 #ifdef __APPLE__
1133 // macosx has a secure per-user temporary directory
1134 char temp_path_storage[PATH_MAX];
1135 const char* os::get_temp_directory() {
1136   static char *temp_path = NULL;
1137   if (temp_path == NULL) {
1138     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1139     if (pathSize == 0 || pathSize > PATH_MAX) {
1140       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1141     }
1142     temp_path = temp_path_storage;
1143   }
1144   return temp_path;
1145 }
1146 #else // __APPLE__
1147 const char* os::get_temp_directory() { return "/tmp"; }
1148 #endif // __APPLE__
1149 
1150 // check if addr is inside libjvm.so
1151 bool os::address_is_in_vm(address addr) {
1152   static address libjvm_base_addr;
1153   Dl_info dlinfo;
1154 
1155   if (libjvm_base_addr == NULL) {
1156     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1157       libjvm_base_addr = (address)dlinfo.dli_fbase;
1158     }
1159     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1160   }
1161 
1162   if (dladdr((void *)addr, &dlinfo) != 0) {
1163     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1164   }
1165 
1166   return false;
1167 }
1168 
1169 
1170 #define MACH_MAXSYMLEN 256
1171 
1172 bool os::dll_address_to_function_name(address addr, char *buf,
1173                                       int buflen, int *offset,
1174                                       bool demangle) {
1175   // buf is not optional, but offset is optional
1176   assert(buf != NULL, "sanity check");
1177 
1178   Dl_info dlinfo;
1179   char localbuf[MACH_MAXSYMLEN];
1180 
1181   if (dladdr((void*)addr, &dlinfo) != 0) {
1182     // see if we have a matching symbol
1183     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1184       if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1185         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1186       }
1187       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1188       return true;
1189     }
1190     // no matching symbol so try for just file info
1191     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1192       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1193                           buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1194         return true;
1195       }
1196     }
1197 
1198     // Handle non-dynamic manually:
1199     if (dlinfo.dli_fbase != NULL &&
1200         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1201                         dlinfo.dli_fbase)) {
1202       if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) {
1203         jio_snprintf(buf, buflen, "%s", localbuf);
1204       }
1205       return true;
1206     }
1207   }
1208   buf[0] = '\0';
1209   if (offset != NULL) *offset = -1;
1210   return false;
1211 }
1212 
1213 // ported from solaris version
1214 bool os::dll_address_to_library_name(address addr, char* buf,
1215                                      int buflen, int* offset) {
1216   // buf is not optional, but offset is optional
1217   assert(buf != NULL, "sanity check");
1218 
1219   Dl_info dlinfo;
1220 
1221   if (dladdr((void*)addr, &dlinfo) != 0) {
1222     if (dlinfo.dli_fname != NULL) {
1223       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1224     }
1225     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1226       *offset = addr - (address)dlinfo.dli_fbase;
1227     }
1228     return true;
1229   }
1230 
1231   buf[0] = '\0';
1232   if (offset) *offset = -1;
1233   return false;
1234 }
1235 
1236 // Loads .dll/.so and
1237 // in case of error it checks if .dll/.so was built for the
1238 // same architecture as Hotspot is running on
1239 
1240 #ifdef __APPLE__
1241 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1242 #ifdef STATIC_BUILD
1243   return os::get_default_process_handle();
1244 #else
1245   log_info(os)("attempting shared library load of %s", filename);
1246 
1247   void * result= ::dlopen(filename, RTLD_LAZY);
1248   if (result != NULL) {
1249     Events::log(NULL, "Loaded shared library %s", filename);
1250     // Successful loading
1251     log_info(os)("shared library load of %s was successful", filename);
1252     return result;
1253   }
1254 
1255   const char* error_report = ::dlerror();
1256   if (error_report == NULL) {
1257     error_report = "dlerror returned no error description";
1258   }
1259   if (ebuf != NULL && ebuflen > 0) {
1260     // Read system error message into ebuf
1261     ::strncpy(ebuf, error_report, ebuflen-1);
1262     ebuf[ebuflen-1]='\0';
1263   }
1264   Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
1265   log_info(os)("shared library load of %s failed, %s", filename, error_report);
1266 
1267   return NULL;
1268 #endif // STATIC_BUILD
1269 }
1270 #else
1271 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1272 #ifdef STATIC_BUILD
1273   return os::get_default_process_handle();
1274 #else
1275   log_info(os)("attempting shared library load of %s", filename);
1276   void * result= ::dlopen(filename, RTLD_LAZY);
1277   if (result != NULL) {
1278     Events::log(NULL, "Loaded shared library %s", filename);
1279     // Successful loading
1280     log_info(os)("shared library load of %s was successful", filename);
1281     return result;
1282   }
1283 
1284   Elf32_Ehdr elf_head;
1285 
1286   const char* const error_report = ::dlerror();
1287   if (error_report == NULL) {
1288     error_report = "dlerror returned no error description";
1289   }
1290   if (ebuf != NULL && ebuflen > 0) {
1291     // Read system error message into ebuf
1292     ::strncpy(ebuf, error_report, ebuflen-1);
1293     ebuf[ebuflen-1]='\0';
1294   }
1295   Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
1296   log_info(os)("shared library load of %s failed, %s", filename, error_report);
1297 
1298   int diag_msg_max_length=ebuflen-strlen(ebuf);
1299   char* diag_msg_buf=ebuf+strlen(ebuf);
1300 
1301   if (diag_msg_max_length==0) {
1302     // No more space in ebuf for additional diagnostics message
1303     return NULL;
1304   }
1305 
1306 
1307   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1308 
1309   if (file_descriptor < 0) {
1310     // Can't open library, report dlerror() message
1311     return NULL;
1312   }
1313 
1314   bool failed_to_read_elf_head=
1315     (sizeof(elf_head)!=
1316      (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1317 
1318   ::close(file_descriptor);
1319   if (failed_to_read_elf_head) {
1320     // file i/o error - report dlerror() msg
1321     return NULL;
1322   }
1323 
1324   typedef struct {
1325     Elf32_Half  code;         // Actual value as defined in elf.h
1326     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1327     char        elf_class;    // 32 or 64 bit
1328     char        endianess;    // MSB or LSB
1329     char*       name;         // String representation
1330   } arch_t;
1331 
1332   #ifndef EM_486
1333     #define EM_486          6               /* Intel 80486 */
1334   #endif
1335 
1336   #ifndef EM_MIPS_RS3_LE
1337     #define EM_MIPS_RS3_LE  10              /* MIPS */
1338   #endif
1339 
1340   #ifndef EM_PPC64
1341     #define EM_PPC64        21              /* PowerPC64 */
1342   #endif
1343 
1344   #ifndef EM_S390
1345     #define EM_S390         22              /* IBM System/390 */
1346   #endif
1347 
1348   #ifndef EM_IA_64
1349     #define EM_IA_64        50              /* HP/Intel IA-64 */
1350   #endif
1351 
1352   #ifndef EM_X86_64
1353     #define EM_X86_64       62              /* AMD x86-64 */
1354   #endif
1355 
1356   static const arch_t arch_array[]={
1357     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1358     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1359     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1360     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1361     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1362     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1363     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1364     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1365     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1366     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1367     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1368     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1369     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1370     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1371     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1372     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1373   };
1374 
1375   #if  (defined IA32)
1376   static  Elf32_Half running_arch_code=EM_386;
1377   #elif   (defined AMD64)
1378   static  Elf32_Half running_arch_code=EM_X86_64;
1379   #elif  (defined IA64)
1380   static  Elf32_Half running_arch_code=EM_IA_64;
1381   #elif  (defined __sparc) && (defined _LP64)
1382   static  Elf32_Half running_arch_code=EM_SPARCV9;
1383   #elif  (defined __sparc) && (!defined _LP64)
1384   static  Elf32_Half running_arch_code=EM_SPARC;
1385   #elif  (defined __powerpc64__)
1386   static  Elf32_Half running_arch_code=EM_PPC64;
1387   #elif  (defined __powerpc__)
1388   static  Elf32_Half running_arch_code=EM_PPC;
1389   #elif  (defined ARM)
1390   static  Elf32_Half running_arch_code=EM_ARM;
1391   #elif  (defined S390)
1392   static  Elf32_Half running_arch_code=EM_S390;
1393   #elif  (defined ALPHA)
1394   static  Elf32_Half running_arch_code=EM_ALPHA;
1395   #elif  (defined MIPSEL)
1396   static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1397   #elif  (defined PARISC)
1398   static  Elf32_Half running_arch_code=EM_PARISC;
1399   #elif  (defined MIPS)
1400   static  Elf32_Half running_arch_code=EM_MIPS;
1401   #elif  (defined M68K)
1402   static  Elf32_Half running_arch_code=EM_68K;
1403   #else
1404     #error Method os::dll_load requires that one of following is defined:\
1405          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1406   #endif
1407 
1408   // Identify compatability class for VM's architecture and library's architecture
1409   // Obtain string descriptions for architectures
1410 
1411   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1412   int running_arch_index=-1;
1413 
1414   for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1415     if (running_arch_code == arch_array[i].code) {
1416       running_arch_index    = i;
1417     }
1418     if (lib_arch.code == arch_array[i].code) {
1419       lib_arch.compat_class = arch_array[i].compat_class;
1420       lib_arch.name         = arch_array[i].name;
1421     }
1422   }
1423 
1424   assert(running_arch_index != -1,
1425          "Didn't find running architecture code (running_arch_code) in arch_array");
1426   if (running_arch_index == -1) {
1427     // Even though running architecture detection failed
1428     // we may still continue with reporting dlerror() message
1429     return NULL;
1430   }
1431 
1432   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1433     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1434     return NULL;
1435   }
1436 
1437 #ifndef S390
1438   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1439     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1440     return NULL;
1441   }
1442 #endif // !S390
1443 
1444   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1445     if (lib_arch.name!=NULL) {
1446       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1447                  " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1448                  lib_arch.name, arch_array[running_arch_index].name);
1449     } else {
1450       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1451                  " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1452                  lib_arch.code,
1453                  arch_array[running_arch_index].name);
1454     }
1455   }
1456 
1457   return NULL;
1458 #endif // STATIC_BUILD
1459 }
1460 #endif // !__APPLE__
1461 
1462 void* os::get_default_process_handle() {
1463 #ifdef __APPLE__
1464   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1465   // to avoid finding unexpected symbols on second (or later)
1466   // loads of a library.
1467   return (void*)::dlopen(NULL, RTLD_FIRST);
1468 #else
1469   return (void*)::dlopen(NULL, RTLD_LAZY);
1470 #endif
1471 }
1472 
1473 // XXX: Do we need a lock around this as per Linux?
1474 void* os::dll_lookup(void* handle, const char* name) {
1475   return dlsym(handle, name);
1476 }
1477 
1478 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1479   outputStream * out = (outputStream *) param;
1480   out->print_cr(INTPTR_FORMAT " \t%s", (intptr_t)base_address, name);
1481   return 0;
1482 }
1483 
1484 void os::print_dll_info(outputStream *st) {
1485   st->print_cr("Dynamic libraries:");
1486   if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1487     st->print_cr("Error: Cannot print dynamic libraries.");
1488   }
1489 }
1490 
1491 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1492 #ifdef RTLD_DI_LINKMAP
1493   Dl_info dli;
1494   void *handle;
1495   Link_map *map;
1496   Link_map *p;
1497 
1498   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1499       dli.dli_fname == NULL) {
1500     return 1;
1501   }
1502   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1503   if (handle == NULL) {
1504     return 1;
1505   }
1506   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1507   if (map == NULL) {
1508     dlclose(handle);
1509     return 1;
1510   }
1511 
1512   while (map->l_prev != NULL)
1513     map = map->l_prev;
1514 
1515   while (map != NULL) {
1516     // Value for top_address is returned as 0 since we don't have any information about module size
1517     if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1518       dlclose(handle);
1519       return 1;
1520     }
1521     map = map->l_next;
1522   }
1523 
1524   dlclose(handle);
1525 #elif defined(__APPLE__)
1526   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1527     // Value for top_address is returned as 0 since we don't have any information about module size
1528     if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1529       return 1;
1530     }
1531   }
1532   return 0;
1533 #else
1534   return 1;
1535 #endif
1536 }
1537 
1538 void os::get_summary_os_info(char* buf, size_t buflen) {
1539   // These buffers are small because we want this to be brief
1540   // and not use a lot of stack while generating the hs_err file.
1541   char os[100];
1542   size_t size = sizeof(os);
1543   int mib_kern[] = { CTL_KERN, KERN_OSTYPE };
1544   if (sysctl(mib_kern, 2, os, &size, NULL, 0) < 0) {
1545 #ifdef __APPLE__
1546       strncpy(os, "Darwin", sizeof(os));
1547 #elif __OpenBSD__
1548       strncpy(os, "OpenBSD", sizeof(os));
1549 #else
1550       strncpy(os, "BSD", sizeof(os));
1551 #endif
1552   }
1553 
1554   char release[100];
1555   size = sizeof(release);
1556   int mib_release[] = { CTL_KERN, KERN_OSRELEASE };
1557   if (sysctl(mib_release, 2, release, &size, NULL, 0) < 0) {
1558       // if error, leave blank
1559       strncpy(release, "", sizeof(release));
1560   }
1561   snprintf(buf, buflen, "%s %s", os, release);
1562 }
1563 
1564 void os::print_os_info_brief(outputStream* st) {
1565   os::Posix::print_uname_info(st);
1566 }
1567 
1568 void os::print_os_info(outputStream* st) {
1569   st->print("OS:");
1570 
1571   os::Posix::print_uname_info(st);
1572 
1573   os::Posix::print_rlimit_info(st);
1574 
1575   os::Posix::print_load_average(st);
1576 }
1577 
1578 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1579   // Nothing to do for now.
1580 }
1581 
1582 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1583   unsigned int mhz;
1584   size_t size = sizeof(mhz);
1585   int mib[] = { CTL_HW, HW_CPU_FREQ };
1586   if (sysctl(mib, 2, &mhz, &size, NULL, 0) < 0) {
1587     mhz = 1;  // looks like an error but can be divided by
1588   } else {
1589     mhz /= 1000000;  // reported in millions
1590   }
1591 
1592   char model[100];
1593   size = sizeof(model);
1594   int mib_model[] = { CTL_HW, HW_MODEL };
1595   if (sysctl(mib_model, 2, model, &size, NULL, 0) < 0) {
1596     strncpy(model, cpu_arch, sizeof(model));
1597   }
1598 
1599   char machine[100];
1600   size = sizeof(machine);
1601   int mib_machine[] = { CTL_HW, HW_MACHINE };
1602   if (sysctl(mib_machine, 2, machine, &size, NULL, 0) < 0) {
1603       strncpy(machine, "", sizeof(machine));
1604   }
1605 
1606   snprintf(buf, buflen, "%s %s %d MHz", model, machine, mhz);
1607 }
1608 
1609 void os::print_memory_info(outputStream* st) {
1610   xsw_usage swap_usage;
1611   size_t size = sizeof(swap_usage);
1612 
1613   st->print("Memory:");
1614   st->print(" %dk page", os::vm_page_size()>>10);
1615 
1616   st->print(", physical " UINT64_FORMAT "k",
1617             os::physical_memory() >> 10);
1618   st->print("(" UINT64_FORMAT "k free)",
1619             os::available_memory() >> 10);
1620 
1621   if((sysctlbyname("vm.swapusage", &swap_usage, &size, NULL, 0) == 0) || (errno == ENOMEM)) {
1622     if (size >= offset_of(xsw_usage, xsu_used)) {
1623       st->print(", swap " UINT64_FORMAT "k",
1624                 ((julong) swap_usage.xsu_total) >> 10);
1625       st->print("(" UINT64_FORMAT "k free)",
1626                 ((julong) swap_usage.xsu_avail) >> 10);
1627     }
1628   }
1629 
1630   st->cr();
1631 }
1632 
1633 static void print_signal_handler(outputStream* st, int sig,
1634                                  char* buf, size_t buflen);
1635 
1636 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1637   st->print_cr("Signal Handlers:");
1638   print_signal_handler(st, SIGSEGV, buf, buflen);
1639   print_signal_handler(st, SIGBUS , buf, buflen);
1640   print_signal_handler(st, SIGFPE , buf, buflen);
1641   print_signal_handler(st, SIGPIPE, buf, buflen);
1642   print_signal_handler(st, SIGXFSZ, buf, buflen);
1643   print_signal_handler(st, SIGILL , buf, buflen);
1644   print_signal_handler(st, SR_signum, buf, buflen);
1645   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1646   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1647   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1648   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1649 }
1650 
1651 static char saved_jvm_path[MAXPATHLEN] = {0};
1652 
1653 // Find the full path to the current module, libjvm
1654 void os::jvm_path(char *buf, jint buflen) {
1655   // Error checking.
1656   if (buflen < MAXPATHLEN) {
1657     assert(false, "must use a large-enough buffer");
1658     buf[0] = '\0';
1659     return;
1660   }
1661   // Lazy resolve the path to current module.
1662   if (saved_jvm_path[0] != 0) {
1663     strcpy(buf, saved_jvm_path);
1664     return;
1665   }
1666 
1667   char dli_fname[MAXPATHLEN];
1668   bool ret = dll_address_to_library_name(
1669                                          CAST_FROM_FN_PTR(address, os::jvm_path),
1670                                          dli_fname, sizeof(dli_fname), NULL);
1671   assert(ret, "cannot locate libjvm");
1672   char *rp = NULL;
1673   if (ret && dli_fname[0] != '\0') {
1674     rp = os::Posix::realpath(dli_fname, buf, buflen);
1675   }
1676   if (rp == NULL) {
1677     return;
1678   }
1679 
1680   if (Arguments::sun_java_launcher_is_altjvm()) {
1681     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1682     // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1683     // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1684     // appears at the right place in the string, then assume we are
1685     // installed in a JDK and we're done. Otherwise, check for a
1686     // JAVA_HOME environment variable and construct a path to the JVM
1687     // being overridden.
1688 
1689     const char *p = buf + strlen(buf) - 1;
1690     for (int count = 0; p > buf && count < 5; ++count) {
1691       for (--p; p > buf && *p != '/'; --p)
1692         /* empty */ ;
1693     }
1694 
1695     if (strncmp(p, "/jre/lib/", 9) != 0) {
1696       // Look for JAVA_HOME in the environment.
1697       char* java_home_var = ::getenv("JAVA_HOME");
1698       if (java_home_var != NULL && java_home_var[0] != 0) {
1699         char* jrelib_p;
1700         int len;
1701 
1702         // Check the current module name "libjvm"
1703         p = strrchr(buf, '/');
1704         assert(strstr(p, "/libjvm") == p, "invalid library name");
1705 
1706         rp = os::Posix::realpath(java_home_var, buf, buflen);
1707         if (rp == NULL) {
1708           return;
1709         }
1710 
1711         // determine if this is a legacy image or modules image
1712         // modules image doesn't have "jre" subdirectory
1713         len = strlen(buf);
1714         assert(len < buflen, "Ran out of buffer space");
1715         jrelib_p = buf + len;
1716 
1717         // Add the appropriate library subdir
1718         snprintf(jrelib_p, buflen-len, "/jre/lib");
1719         if (0 != access(buf, F_OK)) {
1720           snprintf(jrelib_p, buflen-len, "/lib");
1721         }
1722 
1723         // Add the appropriate client or server subdir
1724         len = strlen(buf);
1725         jrelib_p = buf + len;
1726         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1727         if (0 != access(buf, F_OK)) {
1728           snprintf(jrelib_p, buflen-len, "%s", "");
1729         }
1730 
1731         // If the path exists within JAVA_HOME, add the JVM library name
1732         // to complete the path to JVM being overridden.  Otherwise fallback
1733         // to the path to the current library.
1734         if (0 == access(buf, F_OK)) {
1735           // Use current module name "libjvm"
1736           len = strlen(buf);
1737           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1738         } else {
1739           // Fall back to path of current library
1740           rp = os::Posix::realpath(dli_fname, buf, buflen);
1741           if (rp == NULL) {
1742             return;
1743           }
1744         }
1745       }
1746     }
1747   }
1748 
1749   strncpy(saved_jvm_path, buf, MAXPATHLEN);
1750   saved_jvm_path[MAXPATHLEN - 1] = '\0';
1751 }
1752 
1753 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1754   // no prefix required, not even "_"
1755 }
1756 
1757 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1758   // no suffix required
1759 }
1760 
1761 ////////////////////////////////////////////////////////////////////////////////
1762 // sun.misc.Signal support
1763 
1764 static void UserHandler(int sig, void *siginfo, void *context) {
1765   // Ctrl-C is pressed during error reporting, likely because the error
1766   // handler fails to abort. Let VM die immediately.
1767   if (sig == SIGINT && VMError::is_error_reported()) {
1768     os::die();
1769   }
1770 
1771   os::signal_notify(sig);
1772 }
1773 
1774 void* os::user_handler() {
1775   return CAST_FROM_FN_PTR(void*, UserHandler);
1776 }
1777 
1778 extern "C" {
1779   typedef void (*sa_handler_t)(int);
1780   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1781 }
1782 
1783 void* os::signal(int signal_number, void* handler) {
1784   struct sigaction sigAct, oldSigAct;
1785 
1786   sigfillset(&(sigAct.sa_mask));
1787   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1788   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1789 
1790   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1791     // -1 means registration failed
1792     return (void *)-1;
1793   }
1794 
1795   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1796 }
1797 
1798 void os::signal_raise(int signal_number) {
1799   ::raise(signal_number);
1800 }
1801 
1802 // The following code is moved from os.cpp for making this
1803 // code platform specific, which it is by its very nature.
1804 
1805 // Will be modified when max signal is changed to be dynamic
1806 int os::sigexitnum_pd() {
1807   return NSIG;
1808 }
1809 
1810 // a counter for each possible signal value
1811 static volatile jint pending_signals[NSIG+1] = { 0 };
1812 static Semaphore* sig_sem = NULL;
1813 
1814 static void jdk_misc_signal_init() {
1815   // Initialize signal structures
1816   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1817 
1818   // Initialize signal semaphore
1819   sig_sem = new Semaphore();
1820 }
1821 
1822 void os::signal_notify(int sig) {
1823   if (sig_sem != NULL) {
1824     Atomic::inc(&pending_signals[sig]);
1825     sig_sem->signal();
1826   } else {
1827     // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
1828     // initialization isn't called.
1829     assert(ReduceSignalUsage, "signal semaphore should be created");
1830   }
1831 }
1832 
1833 static int check_pending_signals() {
1834   for (;;) {
1835     for (int i = 0; i < NSIG + 1; i++) {
1836       jint n = pending_signals[i];
1837       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1838         return i;
1839       }
1840     }
1841     JavaThread *thread = JavaThread::current();
1842     ThreadBlockInVM tbivm(thread);
1843 
1844     bool threadIsSuspended;
1845     do {
1846       thread->set_suspend_equivalent();
1847       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1848       sig_sem->wait();
1849 
1850       // were we externally suspended while we were waiting?
1851       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1852       if (threadIsSuspended) {
1853         // The semaphore has been incremented, but while we were waiting
1854         // another thread suspended us. We don't want to continue running
1855         // while suspended because that would surprise the thread that
1856         // suspended us.
1857         sig_sem->signal();
1858 
1859         thread->java_suspend_self();
1860       }
1861     } while (threadIsSuspended);
1862   }
1863 }
1864 
1865 int os::signal_wait() {
1866   return check_pending_signals();
1867 }
1868 
1869 ////////////////////////////////////////////////////////////////////////////////
1870 // Virtual Memory
1871 
1872 int os::vm_page_size() {
1873   // Seems redundant as all get out
1874   assert(os::Bsd::page_size() != -1, "must call os::init");
1875   return os::Bsd::page_size();
1876 }
1877 
1878 // Solaris allocates memory by pages.
1879 int os::vm_allocation_granularity() {
1880   assert(os::Bsd::page_size() != -1, "must call os::init");
1881   return os::Bsd::page_size();
1882 }
1883 
1884 // Rationale behind this function:
1885 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
1886 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
1887 //  samples for JITted code. Here we create private executable mapping over the code cache
1888 //  and then we can use standard (well, almost, as mapping can change) way to provide
1889 //  info for the reporting script by storing timestamp and location of symbol
1890 void bsd_wrap_code(char* base, size_t size) {
1891   static volatile jint cnt = 0;
1892 
1893   if (!UseOprofile) {
1894     return;
1895   }
1896 
1897   char buf[PATH_MAX + 1];
1898   int num = Atomic::add(1, &cnt);
1899 
1900   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
1901            os::get_temp_directory(), os::current_process_id(), num);
1902   unlink(buf);
1903 
1904   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
1905 
1906   if (fd != -1) {
1907     off_t rv = ::lseek(fd, size-2, SEEK_SET);
1908     if (rv != (off_t)-1) {
1909       if (::write(fd, "", 1) == 1) {
1910         mmap(base, size,
1911              PROT_READ|PROT_WRITE|PROT_EXEC,
1912              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
1913       }
1914     }
1915     ::close(fd);
1916     unlink(buf);
1917   }
1918 }
1919 
1920 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
1921                                     int err) {
1922   warning("INFO: os::commit_memory(" INTPTR_FORMAT ", " SIZE_FORMAT
1923           ", %d) failed; error='%s' (errno=%d)", (intptr_t)addr, size, exec,
1924            os::errno_name(err), err);
1925 }
1926 
1927 // NOTE: Bsd kernel does not really reserve the pages for us.
1928 //       All it does is to check if there are enough free pages
1929 //       left at the time of mmap(). This could be a potential
1930 //       problem.
1931 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
1932   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
1933 #ifdef __OpenBSD__
1934   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
1935   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
1936   if (::mprotect(addr, size, prot) == 0) {
1937     return true;
1938   }
1939 #else
1940   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
1941                                      MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
1942   if (res != (uintptr_t) MAP_FAILED) {
1943     return true;
1944   }
1945 #endif
1946 
1947   // Warn about any commit errors we see in non-product builds just
1948   // in case mmap() doesn't work as described on the man page.
1949   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
1950 
1951   return false;
1952 }
1953 
1954 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
1955                           bool exec) {
1956   // alignment_hint is ignored on this OS
1957   return pd_commit_memory(addr, size, exec);
1958 }
1959 
1960 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
1961                                   const char* mesg) {
1962   assert(mesg != NULL, "mesg must be specified");
1963   if (!pd_commit_memory(addr, size, exec)) {
1964     // add extra info in product mode for vm_exit_out_of_memory():
1965     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
1966     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
1967   }
1968 }
1969 
1970 void os::pd_commit_memory_or_exit(char* addr, size_t size,
1971                                   size_t alignment_hint, bool exec,
1972                                   const char* mesg) {
1973   // alignment_hint is ignored on this OS
1974   pd_commit_memory_or_exit(addr, size, exec, mesg);
1975 }
1976 
1977 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1978 }
1979 
1980 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1981   ::madvise(addr, bytes, MADV_DONTNEED);
1982 }
1983 
1984 void os::numa_make_global(char *addr, size_t bytes) {
1985 }
1986 
1987 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
1988 }
1989 
1990 bool os::numa_topology_changed()   { return false; }
1991 
1992 size_t os::numa_get_groups_num() {
1993   return 1;
1994 }
1995 
1996 int os::numa_get_group_id() {
1997   return 0;
1998 }
1999 
2000 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2001   if (size > 0) {
2002     ids[0] = 0;
2003     return 1;
2004   }
2005   return 0;
2006 }
2007 
2008 bool os::get_page_info(char *start, page_info* info) {
2009   return false;
2010 }
2011 
2012 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2013   return end;
2014 }
2015 
2016 
2017 bool os::pd_uncommit_memory(char* addr, size_t size) {
2018 #ifdef __OpenBSD__
2019   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2020   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with PROT_NONE", p2i(addr), p2i(addr+size));
2021   return ::mprotect(addr, size, PROT_NONE) == 0;
2022 #else
2023   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2024                                      MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2025   return res  != (uintptr_t) MAP_FAILED;
2026 #endif
2027 }
2028 
2029 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2030   return os::commit_memory(addr, size, !ExecMem);
2031 }
2032 
2033 // If this is a growable mapping, remove the guard pages entirely by
2034 // munmap()ping them.  If not, just call uncommit_memory().
2035 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2036   return os::uncommit_memory(addr, size);
2037 }
2038 
2039 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2040 // at 'requested_addr'. If there are existing memory mappings at the same
2041 // location, however, they will be overwritten. If 'fixed' is false,
2042 // 'requested_addr' is only treated as a hint, the return value may or
2043 // may not start from the requested address. Unlike Bsd mmap(), this
2044 // function returns NULL to indicate failure.
2045 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2046   char * addr;
2047   int flags;
2048 
2049   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2050   if (fixed) {
2051     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2052     flags |= MAP_FIXED;
2053   }
2054 
2055   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2056   // touch an uncommitted page. Otherwise, the read/write might
2057   // succeed if we have enough swap space to back the physical page.
2058   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2059                        flags, -1, 0);
2060 
2061   return addr == MAP_FAILED ? NULL : addr;
2062 }
2063 
2064 static int anon_munmap(char * addr, size_t size) {
2065   return ::munmap(addr, size) == 0;
2066 }
2067 
2068 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2069                             size_t alignment_hint) {
2070   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2071 }
2072 
2073 bool os::pd_release_memory(char* addr, size_t size) {
2074   return anon_munmap(addr, size);
2075 }
2076 
2077 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2078   // Bsd wants the mprotect address argument to be page aligned.
2079   char* bottom = (char*)align_down((intptr_t)addr, os::Bsd::page_size());
2080 
2081   // According to SUSv3, mprotect() should only be used with mappings
2082   // established by mmap(), and mmap() always maps whole pages. Unaligned
2083   // 'addr' likely indicates problem in the VM (e.g. trying to change
2084   // protection of malloc'ed or statically allocated memory). Check the
2085   // caller if you hit this assert.
2086   assert(addr == bottom, "sanity check");
2087 
2088   size = align_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2089   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(bottom), p2i(bottom+size), prot);
2090   return ::mprotect(bottom, size, prot) == 0;
2091 }
2092 
2093 // Set protections specified
2094 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2095                         bool is_committed) {
2096   unsigned int p = 0;
2097   switch (prot) {
2098   case MEM_PROT_NONE: p = PROT_NONE; break;
2099   case MEM_PROT_READ: p = PROT_READ; break;
2100   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2101   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2102   default:
2103     ShouldNotReachHere();
2104   }
2105   // is_committed is unused.
2106   return bsd_mprotect(addr, bytes, p);
2107 }
2108 
2109 bool os::guard_memory(char* addr, size_t size) {
2110   return bsd_mprotect(addr, size, PROT_NONE);
2111 }
2112 
2113 bool os::unguard_memory(char* addr, size_t size) {
2114   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2115 }
2116 
2117 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2118   return false;
2119 }
2120 
2121 // Large page support
2122 
2123 static size_t _large_page_size = 0;
2124 
2125 void os::large_page_init() {
2126 }
2127 
2128 
2129 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2130   fatal("os::reserve_memory_special should not be called on BSD.");
2131   return NULL;
2132 }
2133 
2134 bool os::release_memory_special(char* base, size_t bytes) {
2135   fatal("os::release_memory_special should not be called on BSD.");
2136   return false;
2137 }
2138 
2139 size_t os::large_page_size() {
2140   return _large_page_size;
2141 }
2142 
2143 bool os::can_commit_large_page_memory() {
2144   // Does not matter, we do not support huge pages.
2145   return false;
2146 }
2147 
2148 bool os::can_execute_large_page_memory() {
2149   // Does not matter, we do not support huge pages.
2150   return false;
2151 }
2152 
2153 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2154   assert(file_desc >= 0, "file_desc is not valid");
2155   char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
2156   if (result != NULL) {
2157     if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2158       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2159     }
2160   }
2161   return result;
2162 }
2163 
2164 // Reserve memory at an arbitrary address, only if that area is
2165 // available (and not reserved for something else).
2166 
2167 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2168   // Assert only that the size is a multiple of the page size, since
2169   // that's all that mmap requires, and since that's all we really know
2170   // about at this low abstraction level.  If we need higher alignment,
2171   // we can either pass an alignment to this method or verify alignment
2172   // in one of the methods further up the call chain.  See bug 5044738.
2173   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2174 
2175   // Repeatedly allocate blocks until the block is allocated at the
2176   // right spot.
2177 
2178   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2179   // if kernel honors the hint then we can return immediately.
2180   char * addr = anon_mmap(requested_addr, bytes, false);
2181   if (addr == requested_addr) {
2182     return requested_addr;
2183   }
2184 
2185   if (addr != NULL) {
2186     // mmap() is successful but it fails to reserve at the requested address
2187     anon_munmap(addr, bytes);
2188   }
2189 
2190   return NULL;
2191 }
2192 
2193 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2194 void os::infinite_sleep() {
2195   while (true) {    // sleep forever ...
2196     ::sleep(100);   // ... 100 seconds at a time
2197   }
2198 }
2199 
2200 // Used to convert frequent JVM_Yield() to nops
2201 bool os::dont_yield() {
2202   return DontYieldALot;
2203 }
2204 
2205 void os::naked_yield() {
2206   sched_yield();
2207 }
2208 
2209 ////////////////////////////////////////////////////////////////////////////////
2210 // thread priority support
2211 
2212 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2213 // only supports dynamic priority, static priority must be zero. For real-time
2214 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2215 // However, for large multi-threaded applications, SCHED_RR is not only slower
2216 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2217 // of 5 runs - Sep 2005).
2218 //
2219 // The following code actually changes the niceness of kernel-thread/LWP. It
2220 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2221 // not the entire user process, and user level threads are 1:1 mapped to kernel
2222 // threads. It has always been the case, but could change in the future. For
2223 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2224 // It is only used when ThreadPriorityPolicy=1 and may require system level permission
2225 // (e.g., root privilege or CAP_SYS_NICE capability).
2226 
2227 #if !defined(__APPLE__)
2228 int os::java_to_os_priority[CriticalPriority + 1] = {
2229   19,              // 0 Entry should never be used
2230 
2231    0,              // 1 MinPriority
2232    3,              // 2
2233    6,              // 3
2234 
2235   10,              // 4
2236   15,              // 5 NormPriority
2237   18,              // 6
2238 
2239   21,              // 7
2240   25,              // 8
2241   28,              // 9 NearMaxPriority
2242 
2243   31,              // 10 MaxPriority
2244 
2245   31               // 11 CriticalPriority
2246 };
2247 #else
2248 // Using Mach high-level priority assignments
2249 int os::java_to_os_priority[CriticalPriority + 1] = {
2250    0,              // 0 Entry should never be used (MINPRI_USER)
2251 
2252   27,              // 1 MinPriority
2253   28,              // 2
2254   29,              // 3
2255 
2256   30,              // 4
2257   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2258   32,              // 6
2259 
2260   33,              // 7
2261   34,              // 8
2262   35,              // 9 NearMaxPriority
2263 
2264   36,              // 10 MaxPriority
2265 
2266   36               // 11 CriticalPriority
2267 };
2268 #endif
2269 
2270 static int prio_init() {
2271   if (ThreadPriorityPolicy == 1) {
2272     if (geteuid() != 0) {
2273       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2274         warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
2275                 "e.g., being the root user. If the necessary permission is not " \
2276                 "possessed, changes to priority will be silently ignored.");
2277       }
2278     }
2279   }
2280   if (UseCriticalJavaThreadPriority) {
2281     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2282   }
2283   return 0;
2284 }
2285 
2286 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2287   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2288 
2289 #ifdef __OpenBSD__
2290   // OpenBSD pthread_setprio starves low priority threads
2291   return OS_OK;
2292 #elif defined(__FreeBSD__)
2293   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2294   return (ret == 0) ? OS_OK : OS_ERR;
2295 #elif defined(__APPLE__) || defined(__NetBSD__)
2296   struct sched_param sp;
2297   int policy;
2298 
2299   if (pthread_getschedparam(thread->osthread()->pthread_id(), &policy, &sp) != 0) {
2300     return OS_ERR;
2301   }
2302 
2303   sp.sched_priority = newpri;
2304   if (pthread_setschedparam(thread->osthread()->pthread_id(), policy, &sp) != 0) {
2305     return OS_ERR;
2306   }
2307 
2308   return OS_OK;
2309 #else
2310   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2311   return (ret == 0) ? OS_OK : OS_ERR;
2312 #endif
2313 }
2314 
2315 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2316   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2317     *priority_ptr = java_to_os_priority[NormPriority];
2318     return OS_OK;
2319   }
2320 
2321   errno = 0;
2322 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2323   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2324 #elif defined(__APPLE__) || defined(__NetBSD__)
2325   int policy;
2326   struct sched_param sp;
2327 
2328   int res = pthread_getschedparam(thread->osthread()->pthread_id(), &policy, &sp);
2329   if (res != 0) {
2330     *priority_ptr = -1;
2331     return OS_ERR;
2332   } else {
2333     *priority_ptr = sp.sched_priority;
2334     return OS_OK;
2335   }
2336 #else
2337   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2338 #endif
2339   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2340 }
2341 
2342 ////////////////////////////////////////////////////////////////////////////////
2343 // suspend/resume support
2344 
2345 //  The low-level signal-based suspend/resume support is a remnant from the
2346 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2347 //  within hotspot. Currently used by JFR's OSThreadSampler
2348 //
2349 //  The remaining code is greatly simplified from the more general suspension
2350 //  code that used to be used.
2351 //
2352 //  The protocol is quite simple:
2353 //  - suspend:
2354 //      - sends a signal to the target thread
2355 //      - polls the suspend state of the osthread using a yield loop
2356 //      - target thread signal handler (SR_handler) sets suspend state
2357 //        and blocks in sigsuspend until continued
2358 //  - resume:
2359 //      - sets target osthread state to continue
2360 //      - sends signal to end the sigsuspend loop in the SR_handler
2361 //
2362 //  Note that the SR_lock plays no role in this suspend/resume protocol,
2363 //  but is checked for NULL in SR_handler as a thread termination indicator.
2364 //  The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
2365 //
2366 //  Note that resume_clear_context() and suspend_save_context() are needed
2367 //  by SR_handler(), so that fetch_frame_from_ucontext() works,
2368 //  which in part is used by:
2369 //    - Forte Analyzer: AsyncGetCallTrace()
2370 //    - StackBanging: get_frame_at_stack_banging_point()
2371 
2372 static void resume_clear_context(OSThread *osthread) {
2373   osthread->set_ucontext(NULL);
2374   osthread->set_siginfo(NULL);
2375 }
2376 
2377 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2378   osthread->set_ucontext(context);
2379   osthread->set_siginfo(siginfo);
2380 }
2381 
2382 // Handler function invoked when a thread's execution is suspended or
2383 // resumed. We have to be careful that only async-safe functions are
2384 // called here (Note: most pthread functions are not async safe and
2385 // should be avoided.)
2386 //
2387 // Note: sigwait() is a more natural fit than sigsuspend() from an
2388 // interface point of view, but sigwait() prevents the signal hander
2389 // from being run. libpthread would get very confused by not having
2390 // its signal handlers run and prevents sigwait()'s use with the
2391 // mutex granting granting signal.
2392 //
2393 // Currently only ever called on the VMThread or JavaThread
2394 //
2395 #ifdef __APPLE__
2396 static OSXSemaphore sr_semaphore;
2397 #else
2398 static PosixSemaphore sr_semaphore;
2399 #endif
2400 
2401 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2402   // Save and restore errno to avoid confusing native code with EINTR
2403   // after sigsuspend.
2404   int old_errno = errno;
2405 
2406   Thread* thread = Thread::current_or_null_safe();
2407   assert(thread != NULL, "Missing current thread in SR_handler");
2408 
2409   // On some systems we have seen signal delivery get "stuck" until the signal
2410   // mask is changed as part of thread termination. Check that the current thread
2411   // has not already terminated (via SR_lock()) - else the following assertion
2412   // will fail because the thread is no longer a JavaThread as the ~JavaThread
2413   // destructor has completed.
2414 
2415   if (thread->SR_lock() == NULL) {
2416     return;
2417   }
2418 
2419   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2420 
2421   OSThread* osthread = thread->osthread();
2422 
2423   os::SuspendResume::State current = osthread->sr.state();
2424   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2425     suspend_save_context(osthread, siginfo, context);
2426 
2427     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2428     os::SuspendResume::State state = osthread->sr.suspended();
2429     if (state == os::SuspendResume::SR_SUSPENDED) {
2430       sigset_t suspend_set;  // signals for sigsuspend()
2431 
2432       // get current set of blocked signals and unblock resume signal
2433       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2434       sigdelset(&suspend_set, SR_signum);
2435 
2436       sr_semaphore.signal();
2437       // wait here until we are resumed
2438       while (1) {
2439         sigsuspend(&suspend_set);
2440 
2441         os::SuspendResume::State result = osthread->sr.running();
2442         if (result == os::SuspendResume::SR_RUNNING) {
2443           sr_semaphore.signal();
2444           break;
2445         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2446           ShouldNotReachHere();
2447         }
2448       }
2449 
2450     } else if (state == os::SuspendResume::SR_RUNNING) {
2451       // request was cancelled, continue
2452     } else {
2453       ShouldNotReachHere();
2454     }
2455 
2456     resume_clear_context(osthread);
2457   } else if (current == os::SuspendResume::SR_RUNNING) {
2458     // request was cancelled, continue
2459   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2460     // ignore
2461   } else {
2462     // ignore
2463   }
2464 
2465   errno = old_errno;
2466 }
2467 
2468 
2469 static int SR_initialize() {
2470   struct sigaction act;
2471   char *s;
2472   // Get signal number to use for suspend/resume
2473   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2474     int sig = ::strtol(s, 0, 10);
2475     if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
2476         sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
2477       SR_signum = sig;
2478     } else {
2479       warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2480               sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2481     }
2482   }
2483 
2484   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2485          "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2486 
2487   sigemptyset(&SR_sigset);
2488   sigaddset(&SR_sigset, SR_signum);
2489 
2490   // Set up signal handler for suspend/resume
2491   act.sa_flags = SA_RESTART|SA_SIGINFO;
2492   act.sa_handler = (void (*)(int)) SR_handler;
2493 
2494   // SR_signum is blocked by default.
2495   // 4528190 - We also need to block pthread restart signal (32 on all
2496   // supported Bsd platforms). Note that BsdThreads need to block
2497   // this signal for all threads to work properly. So we don't have
2498   // to use hard-coded signal number when setting up the mask.
2499   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2500 
2501   if (sigaction(SR_signum, &act, 0) == -1) {
2502     return -1;
2503   }
2504 
2505   // Save signal flag
2506   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2507   return 0;
2508 }
2509 
2510 static int sr_notify(OSThread* osthread) {
2511   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2512   assert_status(status == 0, status, "pthread_kill");
2513   return status;
2514 }
2515 
2516 // "Randomly" selected value for how long we want to spin
2517 // before bailing out on suspending a thread, also how often
2518 // we send a signal to a thread we want to resume
2519 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2520 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2521 
2522 // returns true on success and false on error - really an error is fatal
2523 // but this seems the normal response to library errors
2524 static bool do_suspend(OSThread* osthread) {
2525   assert(osthread->sr.is_running(), "thread should be running");
2526   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2527 
2528   // mark as suspended and send signal
2529   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2530     // failed to switch, state wasn't running?
2531     ShouldNotReachHere();
2532     return false;
2533   }
2534 
2535   if (sr_notify(osthread) != 0) {
2536     ShouldNotReachHere();
2537   }
2538 
2539   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2540   while (true) {
2541     if (sr_semaphore.timedwait(2)) {
2542       break;
2543     } else {
2544       // timeout
2545       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2546       if (cancelled == os::SuspendResume::SR_RUNNING) {
2547         return false;
2548       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2549         // make sure that we consume the signal on the semaphore as well
2550         sr_semaphore.wait();
2551         break;
2552       } else {
2553         ShouldNotReachHere();
2554         return false;
2555       }
2556     }
2557   }
2558 
2559   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2560   return true;
2561 }
2562 
2563 static void do_resume(OSThread* osthread) {
2564   assert(osthread->sr.is_suspended(), "thread should be suspended");
2565   assert(!sr_semaphore.trywait(), "invalid semaphore state");
2566 
2567   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2568     // failed to switch to WAKEUP_REQUEST
2569     ShouldNotReachHere();
2570     return;
2571   }
2572 
2573   while (true) {
2574     if (sr_notify(osthread) == 0) {
2575       if (sr_semaphore.timedwait(2)) {
2576         if (osthread->sr.is_running()) {
2577           return;
2578         }
2579       }
2580     } else {
2581       ShouldNotReachHere();
2582     }
2583   }
2584 
2585   guarantee(osthread->sr.is_running(), "Must be running!");
2586 }
2587 
2588 ///////////////////////////////////////////////////////////////////////////////////
2589 // signal handling (except suspend/resume)
2590 
2591 // This routine may be used by user applications as a "hook" to catch signals.
2592 // The user-defined signal handler must pass unrecognized signals to this
2593 // routine, and if it returns true (non-zero), then the signal handler must
2594 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
2595 // routine will never retun false (zero), but instead will execute a VM panic
2596 // routine kill the process.
2597 //
2598 // If this routine returns false, it is OK to call it again.  This allows
2599 // the user-defined signal handler to perform checks either before or after
2600 // the VM performs its own checks.  Naturally, the user code would be making
2601 // a serious error if it tried to handle an exception (such as a null check
2602 // or breakpoint) that the VM was generating for its own correct operation.
2603 //
2604 // This routine may recognize any of the following kinds of signals:
2605 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2606 // It should be consulted by handlers for any of those signals.
2607 //
2608 // The caller of this routine must pass in the three arguments supplied
2609 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2610 // field of the structure passed to sigaction().  This routine assumes that
2611 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2612 //
2613 // Note that the VM will print warnings if it detects conflicting signal
2614 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2615 //
2616 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2617                                                void* ucontext,
2618                                                int abort_if_unrecognized);
2619 
2620 static void signalHandler(int sig, siginfo_t* info, void* uc) {
2621   assert(info != NULL && uc != NULL, "it must be old kernel");
2622   int orig_errno = errno;  // Preserve errno value over signal handler.
2623   JVM_handle_bsd_signal(sig, info, uc, true);
2624   errno = orig_errno;
2625 }
2626 
2627 
2628 // This boolean allows users to forward their own non-matching signals
2629 // to JVM_handle_bsd_signal, harmlessly.
2630 bool os::Bsd::signal_handlers_are_installed = false;
2631 
2632 // For signal-chaining
2633 bool os::Bsd::libjsig_is_loaded = false;
2634 typedef struct sigaction *(*get_signal_t)(int);
2635 get_signal_t os::Bsd::get_signal_action = NULL;
2636 
2637 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2638   struct sigaction *actp = NULL;
2639 
2640   if (libjsig_is_loaded) {
2641     // Retrieve the old signal handler from libjsig
2642     actp = (*get_signal_action)(sig);
2643   }
2644   if (actp == NULL) {
2645     // Retrieve the preinstalled signal handler from jvm
2646     actp = os::Posix::get_preinstalled_handler(sig);
2647   }
2648 
2649   return actp;
2650 }
2651 
2652 static bool call_chained_handler(struct sigaction *actp, int sig,
2653                                  siginfo_t *siginfo, void *context) {
2654   // Call the old signal handler
2655   if (actp->sa_handler == SIG_DFL) {
2656     // It's more reasonable to let jvm treat it as an unexpected exception
2657     // instead of taking the default action.
2658     return false;
2659   } else if (actp->sa_handler != SIG_IGN) {
2660     if ((actp->sa_flags & SA_NODEFER) == 0) {
2661       // automaticlly block the signal
2662       sigaddset(&(actp->sa_mask), sig);
2663     }
2664 
2665     sa_handler_t hand;
2666     sa_sigaction_t sa;
2667     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
2668     // retrieve the chained handler
2669     if (siginfo_flag_set) {
2670       sa = actp->sa_sigaction;
2671     } else {
2672       hand = actp->sa_handler;
2673     }
2674 
2675     if ((actp->sa_flags & SA_RESETHAND) != 0) {
2676       actp->sa_handler = SIG_DFL;
2677     }
2678 
2679     // try to honor the signal mask
2680     sigset_t oset;
2681     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
2682 
2683     // call into the chained handler
2684     if (siginfo_flag_set) {
2685       (*sa)(sig, siginfo, context);
2686     } else {
2687       (*hand)(sig);
2688     }
2689 
2690     // restore the signal mask
2691     pthread_sigmask(SIG_SETMASK, &oset, 0);
2692   }
2693   // Tell jvm's signal handler the signal is taken care of.
2694   return true;
2695 }
2696 
2697 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
2698   bool chained = false;
2699   // signal-chaining
2700   if (UseSignalChaining) {
2701     struct sigaction *actp = get_chained_signal_action(sig);
2702     if (actp != NULL) {
2703       chained = call_chained_handler(actp, sig, siginfo, context);
2704     }
2705   }
2706   return chained;
2707 }
2708 
2709 // for diagnostic
2710 int sigflags[NSIG];
2711 
2712 int os::Bsd::get_our_sigflags(int sig) {
2713   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2714   return sigflags[sig];
2715 }
2716 
2717 void os::Bsd::set_our_sigflags(int sig, int flags) {
2718   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2719   if (sig > 0 && sig < NSIG) {
2720     sigflags[sig] = flags;
2721   }
2722 }
2723 
2724 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
2725   // Check for overwrite.
2726   struct sigaction oldAct;
2727   sigaction(sig, (struct sigaction*)NULL, &oldAct);
2728 
2729   void* oldhand = oldAct.sa_sigaction
2730                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
2731                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
2732   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
2733       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
2734       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
2735     if (AllowUserSignalHandlers || !set_installed) {
2736       // Do not overwrite; user takes responsibility to forward to us.
2737       return;
2738     } else if (UseSignalChaining) {
2739       // save the old handler in jvm
2740       os::Posix::save_preinstalled_handler(sig, oldAct);
2741       // libjsig also interposes the sigaction() call below and saves the
2742       // old sigaction on it own.
2743     } else {
2744       fatal("Encountered unexpected pre-existing sigaction handler "
2745             "%#lx for signal %d.", (long)oldhand, sig);
2746     }
2747   }
2748 
2749   struct sigaction sigAct;
2750   sigfillset(&(sigAct.sa_mask));
2751   sigAct.sa_handler = SIG_DFL;
2752   if (!set_installed) {
2753     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
2754   } else {
2755     sigAct.sa_sigaction = signalHandler;
2756     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
2757   }
2758 #ifdef __APPLE__
2759   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
2760   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
2761   // if the signal handler declares it will handle it on alternate stack.
2762   // Notice we only declare we will handle it on alt stack, but we are not
2763   // actually going to use real alt stack - this is just a workaround.
2764   // Please see ux_exception.c, method catch_mach_exception_raise for details
2765   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
2766   if (sig == SIGSEGV) {
2767     sigAct.sa_flags |= SA_ONSTACK;
2768   }
2769 #endif
2770 
2771   // Save flags, which are set by ours
2772   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2773   sigflags[sig] = sigAct.sa_flags;
2774 
2775   int ret = sigaction(sig, &sigAct, &oldAct);
2776   assert(ret == 0, "check");
2777 
2778   void* oldhand2  = oldAct.sa_sigaction
2779                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
2780                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
2781   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
2782 }
2783 
2784 // install signal handlers for signals that HotSpot needs to
2785 // handle in order to support Java-level exception handling.
2786 
2787 void os::Bsd::install_signal_handlers() {
2788   if (!signal_handlers_are_installed) {
2789     signal_handlers_are_installed = true;
2790 
2791     // signal-chaining
2792     typedef void (*signal_setting_t)();
2793     signal_setting_t begin_signal_setting = NULL;
2794     signal_setting_t end_signal_setting = NULL;
2795     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
2796                                           dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
2797     if (begin_signal_setting != NULL) {
2798       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
2799                                           dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
2800       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
2801                                          dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
2802       libjsig_is_loaded = true;
2803       assert(UseSignalChaining, "should enable signal-chaining");
2804     }
2805     if (libjsig_is_loaded) {
2806       // Tell libjsig jvm is setting signal handlers
2807       (*begin_signal_setting)();
2808     }
2809 
2810     set_signal_handler(SIGSEGV, true);
2811     set_signal_handler(SIGPIPE, true);
2812     set_signal_handler(SIGBUS, true);
2813     set_signal_handler(SIGILL, true);
2814     set_signal_handler(SIGFPE, true);
2815     set_signal_handler(SIGXFSZ, true);
2816 
2817 #if defined(__APPLE__)
2818     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
2819     // signals caught and handled by the JVM. To work around this, we reset the mach task
2820     // signal handler that's placed on our process by CrashReporter. This disables
2821     // CrashReporter-based reporting.
2822     //
2823     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
2824     // on caught fatal signals.
2825     //
2826     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
2827     // handlers. By replacing the existing task exception handler, we disable gdb's mach
2828     // exception handling, while leaving the standard BSD signal handlers functional.
2829     kern_return_t kr;
2830     kr = task_set_exception_ports(mach_task_self(),
2831                                   EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
2832                                   MACH_PORT_NULL,
2833                                   EXCEPTION_STATE_IDENTITY,
2834                                   MACHINE_THREAD_STATE);
2835 
2836     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
2837 #endif
2838 
2839     if (libjsig_is_loaded) {
2840       // Tell libjsig jvm finishes setting signal handlers
2841       (*end_signal_setting)();
2842     }
2843 
2844     // We don't activate signal checker if libjsig is in place, we trust ourselves
2845     // and if UserSignalHandler is installed all bets are off
2846     if (CheckJNICalls) {
2847       if (libjsig_is_loaded) {
2848         if (PrintJNIResolving) {
2849           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
2850         }
2851         check_signals = false;
2852       }
2853       if (AllowUserSignalHandlers) {
2854         if (PrintJNIResolving) {
2855           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
2856         }
2857         check_signals = false;
2858       }
2859     }
2860   }
2861 }
2862 
2863 
2864 /////
2865 // glibc on Bsd platform uses non-documented flag
2866 // to indicate, that some special sort of signal
2867 // trampoline is used.
2868 // We will never set this flag, and we should
2869 // ignore this flag in our diagnostic
2870 #ifdef SIGNIFICANT_SIGNAL_MASK
2871   #undef SIGNIFICANT_SIGNAL_MASK
2872 #endif
2873 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
2874 
2875 static const char* get_signal_handler_name(address handler,
2876                                            char* buf, int buflen) {
2877   int offset;
2878   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
2879   if (found) {
2880     // skip directory names
2881     const char *p1, *p2;
2882     p1 = buf;
2883     size_t len = strlen(os::file_separator());
2884     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
2885     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
2886   } else {
2887     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
2888   }
2889   return buf;
2890 }
2891 
2892 static void print_signal_handler(outputStream* st, int sig,
2893                                  char* buf, size_t buflen) {
2894   struct sigaction sa;
2895 
2896   sigaction(sig, NULL, &sa);
2897 
2898   // See comment for SIGNIFICANT_SIGNAL_MASK define
2899   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
2900 
2901   st->print("%s: ", os::exception_name(sig, buf, buflen));
2902 
2903   address handler = (sa.sa_flags & SA_SIGINFO)
2904     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
2905     : CAST_FROM_FN_PTR(address, sa.sa_handler);
2906 
2907   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
2908     st->print("SIG_DFL");
2909   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
2910     st->print("SIG_IGN");
2911   } else {
2912     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
2913   }
2914 
2915   st->print(", sa_mask[0]=");
2916   os::Posix::print_signal_set_short(st, &sa.sa_mask);
2917 
2918   address rh = VMError::get_resetted_sighandler(sig);
2919   // May be, handler was resetted by VMError?
2920   if (rh != NULL) {
2921     handler = rh;
2922     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
2923   }
2924 
2925   st->print(", sa_flags=");
2926   os::Posix::print_sa_flags(st, sa.sa_flags);
2927 
2928   // Check: is it our handler?
2929   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
2930       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
2931     // It is our signal handler
2932     // check for flags, reset system-used one!
2933     if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
2934       st->print(
2935                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
2936                 os::Bsd::get_our_sigflags(sig));
2937     }
2938   }
2939   st->cr();
2940 }
2941 
2942 
2943 #define DO_SIGNAL_CHECK(sig)                      \
2944   do {                                            \
2945     if (!sigismember(&check_signal_done, sig)) {  \
2946       os::Bsd::check_signal_handler(sig);         \
2947     }                                             \
2948   } while (0)
2949 
2950 // This method is a periodic task to check for misbehaving JNI applications
2951 // under CheckJNI, we can add any periodic checks here
2952 
2953 void os::run_periodic_checks() {
2954 
2955   if (check_signals == false) return;
2956 
2957   // SEGV and BUS if overridden could potentially prevent
2958   // generation of hs*.log in the event of a crash, debugging
2959   // such a case can be very challenging, so we absolutely
2960   // check the following for a good measure:
2961   DO_SIGNAL_CHECK(SIGSEGV);
2962   DO_SIGNAL_CHECK(SIGILL);
2963   DO_SIGNAL_CHECK(SIGFPE);
2964   DO_SIGNAL_CHECK(SIGBUS);
2965   DO_SIGNAL_CHECK(SIGPIPE);
2966   DO_SIGNAL_CHECK(SIGXFSZ);
2967 
2968 
2969   // ReduceSignalUsage allows the user to override these handlers
2970   // see comments at the very top and jvm_md.h
2971   if (!ReduceSignalUsage) {
2972     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
2973     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
2974     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
2975     DO_SIGNAL_CHECK(BREAK_SIGNAL);
2976   }
2977 
2978   DO_SIGNAL_CHECK(SR_signum);
2979 }
2980 
2981 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
2982 
2983 static os_sigaction_t os_sigaction = NULL;
2984 
2985 void os::Bsd::check_signal_handler(int sig) {
2986   char buf[O_BUFLEN];
2987   address jvmHandler = NULL;
2988 
2989 
2990   struct sigaction act;
2991   if (os_sigaction == NULL) {
2992     // only trust the default sigaction, in case it has been interposed
2993     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
2994     if (os_sigaction == NULL) return;
2995   }
2996 
2997   os_sigaction(sig, (struct sigaction*)NULL, &act);
2998 
2999 
3000   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3001 
3002   address thisHandler = (act.sa_flags & SA_SIGINFO)
3003     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3004     : CAST_FROM_FN_PTR(address, act.sa_handler);
3005 
3006 
3007   switch (sig) {
3008   case SIGSEGV:
3009   case SIGBUS:
3010   case SIGFPE:
3011   case SIGPIPE:
3012   case SIGILL:
3013   case SIGXFSZ:
3014     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3015     break;
3016 
3017   case SHUTDOWN1_SIGNAL:
3018   case SHUTDOWN2_SIGNAL:
3019   case SHUTDOWN3_SIGNAL:
3020   case BREAK_SIGNAL:
3021     jvmHandler = (address)user_handler();
3022     break;
3023 
3024   default:
3025     if (sig == SR_signum) {
3026       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3027     } else {
3028       return;
3029     }
3030     break;
3031   }
3032 
3033   if (thisHandler != jvmHandler) {
3034     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3035     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3036     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3037     // No need to check this sig any longer
3038     sigaddset(&check_signal_done, sig);
3039     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3040     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3041       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3042                     exception_name(sig, buf, O_BUFLEN));
3043     }
3044   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3045     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3046     tty->print("expected:");
3047     os::Posix::print_sa_flags(tty, os::Bsd::get_our_sigflags(sig));
3048     tty->cr();
3049     tty->print("  found:");
3050     os::Posix::print_sa_flags(tty, act.sa_flags);
3051     tty->cr();
3052     // No need to check this sig any longer
3053     sigaddset(&check_signal_done, sig);
3054   }
3055 
3056   // Dump all the signal
3057   if (sigismember(&check_signal_done, sig)) {
3058     print_signal_handlers(tty, buf, O_BUFLEN);
3059   }
3060 }
3061 
3062 extern void report_error(char* file_name, int line_no, char* title,
3063                          char* format, ...);
3064 
3065 // this is called _before_ the most of global arguments have been parsed
3066 void os::init(void) {
3067   char dummy;   // used to get a guess on initial stack address
3068 
3069   clock_tics_per_sec = CLK_TCK;
3070 
3071   init_random(1234567);
3072 
3073   Bsd::set_page_size(getpagesize());
3074   if (Bsd::page_size() == -1) {
3075     fatal("os_bsd.cpp: os::init: sysconf failed (%s)", os::strerror(errno));
3076   }
3077   init_page_sizes((size_t) Bsd::page_size());
3078 
3079   Bsd::initialize_system_info();
3080 
3081   // _main_thread points to the thread that created/loaded the JVM.
3082   Bsd::_main_thread = pthread_self();
3083 
3084   Bsd::clock_init();
3085   initial_time_count = javaTimeNanos();
3086 
3087   os::Posix::init();
3088 }
3089 
3090 // To install functions for atexit system call
3091 extern "C" {
3092   static void perfMemory_exit_helper() {
3093     perfMemory_exit();
3094   }
3095 }
3096 
3097 // this is called _after_ the global arguments have been parsed
3098 jint os::init_2(void) {
3099 
3100   // This could be set after os::Posix::init() but all platforms
3101   // have to set it the same so we have to mirror Solaris.
3102   DEBUG_ONLY(os::set_mutex_init_done();)
3103 
3104   os::Posix::init_2();
3105 
3106   // initialize suspend/resume support - must do this before signal_sets_init()
3107   if (SR_initialize() != 0) {
3108     perror("SR_initialize failed");
3109     return JNI_ERR;
3110   }
3111 
3112   Bsd::signal_sets_init();
3113   Bsd::install_signal_handlers();
3114   // Initialize data for jdk.internal.misc.Signal
3115   if (!ReduceSignalUsage) {
3116     jdk_misc_signal_init();
3117   }
3118 
3119   // Check and sets minimum stack sizes against command line options
3120   if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
3121     return JNI_ERR;
3122   }
3123 
3124   if (MaxFDLimit) {
3125     // set the number of file descriptors to max. print out error
3126     // if getrlimit/setrlimit fails but continue regardless.
3127     struct rlimit nbr_files;
3128     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3129     if (status != 0) {
3130       log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3131     } else {
3132       nbr_files.rlim_cur = nbr_files.rlim_max;
3133 
3134 #ifdef __APPLE__
3135       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3136       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3137       // be used instead
3138       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3139 #endif
3140 
3141       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3142       if (status != 0) {
3143         log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3144       }
3145     }
3146   }
3147 
3148   // at-exit methods are called in the reverse order of their registration.
3149   // atexit functions are called on return from main or as a result of a
3150   // call to exit(3C). There can be only 32 of these functions registered
3151   // and atexit() does not set errno.
3152 
3153   if (PerfAllowAtExitRegistration) {
3154     // only register atexit functions if PerfAllowAtExitRegistration is set.
3155     // atexit functions can be delayed until process exit time, which
3156     // can be problematic for embedded VM situations. Embedded VMs should
3157     // call DestroyJavaVM() to assure that VM resources are released.
3158 
3159     // note: perfMemory_exit_helper atexit function may be removed in
3160     // the future if the appropriate cleanup code can be added to the
3161     // VM_Exit VMOperation's doit method.
3162     if (atexit(perfMemory_exit_helper) != 0) {
3163       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
3164     }
3165   }
3166 
3167   // initialize thread priority policy
3168   prio_init();
3169 
3170 #ifdef __APPLE__
3171   // dynamically link to objective c gc registration
3172   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3173   if (handleLibObjc != NULL) {
3174     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3175   }
3176 #endif
3177 
3178   return JNI_OK;
3179 }
3180 
3181 // Mark the polling page as unreadable
3182 void os::make_polling_page_unreadable(void) {
3183   if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3184     fatal("Could not disable polling page");
3185   }
3186 }
3187 
3188 // Mark the polling page as readable
3189 void os::make_polling_page_readable(void) {
3190   if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3191     fatal("Could not enable polling page");
3192   }
3193 }
3194 
3195 int os::active_processor_count() {
3196   // User has overridden the number of active processors
3197   if (ActiveProcessorCount > 0) {
3198     log_trace(os)("active_processor_count: "
3199                   "active processor count set by user : %d",
3200                   ActiveProcessorCount);
3201     return ActiveProcessorCount;
3202   }
3203 
3204   return _processor_count;
3205 }
3206 
3207 #ifdef __APPLE__
3208 uint os::processor_id() {
3209   static volatile int* volatile apic_to_cpu_mapping = NULL;
3210   static volatile int next_cpu_id = 0;
3211 
3212   volatile int* mapping = OrderAccess::load_acquire(&apic_to_cpu_mapping);
3213   if (mapping == NULL) {
3214     // Calculate possible number space for APIC ids. This space is not necessarily
3215     // in the range [0, number_of_cpus).
3216     uint total_bits = 0;
3217     for (uint i = 0;; ++i) {
3218       uint eax = 0xb; // Query topology leaf
3219       uint ebx;
3220       uint ecx = i;
3221       uint edx;
3222 
3223       __asm__ ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
3224 
3225       uint level_type = (ecx >> 8) & 0xFF;
3226       if (level_type == 0) {
3227         // Invalid level; end of topology
3228         break;
3229       }
3230       uint level_apic_id_shift = eax & ((1u << 5) - 1);
3231       total_bits += level_apic_id_shift;
3232     }
3233 
3234     uint max_apic_ids = 1u << total_bits;
3235     mapping = NEW_C_HEAP_ARRAY(int, max_apic_ids, mtInternal);
3236 
3237     for (uint i = 0; i < max_apic_ids; ++i) {
3238       mapping[i] = -1;
3239     }
3240 
3241     if (!Atomic::replace_if_null(mapping, &apic_to_cpu_mapping)) {
3242       FREE_C_HEAP_ARRAY(int, mapping);
3243       mapping = OrderAccess::load_acquire(&apic_to_cpu_mapping);
3244     }
3245   }
3246 
3247   uint eax = 0xb;
3248   uint ebx;
3249   uint ecx = 0;
3250   uint edx;
3251 
3252   asm ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
3253 
3254   // Map from APIC id to a unique logical processor ID in the expected
3255   // [0, num_processors) range.
3256 
3257   uint apic_id = edx;
3258   int cpu_id = Atomic::load(&mapping[apic_id]);
3259 
3260   while (cpu_id < 0) {
3261     if (Atomic::cmpxchg(-2, &mapping[apic_id], -1)) {
3262       Atomic::store(Atomic::add(1, &next_cpu_id) - 1, &mapping[apic_id]);
3263     }
3264     cpu_id = Atomic::load(&mapping[apic_id]);
3265   }
3266 
3267   return (uint)cpu_id;
3268 }
3269 #endif
3270 
3271 void os::set_native_thread_name(const char *name) {
3272 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3273   // This is only supported in Snow Leopard and beyond
3274   if (name != NULL) {
3275     // Add a "Java: " prefix to the name
3276     char buf[MAXTHREADNAMESIZE];
3277     snprintf(buf, sizeof(buf), "Java: %s", name);
3278     pthread_setname_np(buf);
3279   }
3280 #endif
3281 }
3282 
3283 bool os::bind_to_processor(uint processor_id) {
3284   // Not yet implemented.
3285   return false;
3286 }
3287 
3288 void os::SuspendedThreadTask::internal_do_task() {
3289   if (do_suspend(_thread->osthread())) {
3290     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3291     do_task(context);
3292     do_resume(_thread->osthread());
3293   }
3294 }
3295 
3296 ////////////////////////////////////////////////////////////////////////////////
3297 // debug support
3298 
3299 bool os::find(address addr, outputStream* st) {
3300   Dl_info dlinfo;
3301   memset(&dlinfo, 0, sizeof(dlinfo));
3302   if (dladdr(addr, &dlinfo) != 0) {
3303     st->print(INTPTR_FORMAT ": ", (intptr_t)addr);
3304     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3305       st->print("%s+%#x", dlinfo.dli_sname,
3306                 (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_saddr));
3307     } else if (dlinfo.dli_fbase != NULL) {
3308       st->print("<offset %#x>", (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_fbase));
3309     } else {
3310       st->print("<absolute address>");
3311     }
3312     if (dlinfo.dli_fname != NULL) {
3313       st->print(" in %s", dlinfo.dli_fname);
3314     }
3315     if (dlinfo.dli_fbase != NULL) {
3316       st->print(" at " INTPTR_FORMAT, (intptr_t)dlinfo.dli_fbase);
3317     }
3318     st->cr();
3319 
3320     if (Verbose) {
3321       // decode some bytes around the PC
3322       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3323       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3324       address       lowest = (address) dlinfo.dli_sname;
3325       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3326       if (begin < lowest)  begin = lowest;
3327       Dl_info dlinfo2;
3328       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3329           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3330         end = (address) dlinfo2.dli_saddr;
3331       }
3332       Disassembler::decode(begin, end, st);
3333     }
3334     return true;
3335   }
3336   return false;
3337 }
3338 
3339 ////////////////////////////////////////////////////////////////////////////////
3340 // misc
3341 
3342 // This does not do anything on Bsd. This is basically a hook for being
3343 // able to use structured exception handling (thread-local exception filters)
3344 // on, e.g., Win32.
3345 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3346                               const methodHandle& method, JavaCallArguments* args,
3347                               Thread* thread) {
3348   f(value, method, args, thread);
3349 }
3350 
3351 void os::print_statistics() {
3352 }
3353 
3354 bool os::message_box(const char* title, const char* message) {
3355   int i;
3356   fdStream err(defaultStream::error_fd());
3357   for (i = 0; i < 78; i++) err.print_raw("=");
3358   err.cr();
3359   err.print_raw_cr(title);
3360   for (i = 0; i < 78; i++) err.print_raw("-");
3361   err.cr();
3362   err.print_raw_cr(message);
3363   for (i = 0; i < 78; i++) err.print_raw("=");
3364   err.cr();
3365 
3366   char buf[16];
3367   // Prevent process from exiting upon "read error" without consuming all CPU
3368   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3369 
3370   return buf[0] == 'y' || buf[0] == 'Y';
3371 }
3372 
3373 static inline struct timespec get_mtime(const char* filename) {
3374   struct stat st;
3375   int ret = os::stat(filename, &st);
3376   assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
3377 #ifdef __APPLE__
3378   return st.st_mtimespec;
3379 #else
3380   return st.st_mtim;
3381 #endif
3382 }
3383 
3384 int os::compare_file_modified_times(const char* file1, const char* file2) {
3385   struct timespec filetime1 = get_mtime(file1);
3386   struct timespec filetime2 = get_mtime(file2);
3387   int diff = filetime1.tv_sec - filetime2.tv_sec;
3388   if (diff == 0) {
3389     return filetime1.tv_nsec - filetime2.tv_nsec;
3390   }
3391   return diff;
3392 }
3393 
3394 // Is a (classpath) directory empty?
3395 bool os::dir_is_empty(const char* path) {
3396   DIR *dir = NULL;
3397   struct dirent *ptr;
3398 
3399   dir = opendir(path);
3400   if (dir == NULL) return true;
3401 
3402   // Scan the directory
3403   bool result = true;
3404   while (result && (ptr = readdir(dir)) != NULL) {
3405     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3406       result = false;
3407     }
3408   }
3409   closedir(dir);
3410   return result;
3411 }
3412 
3413 // This code originates from JDK's sysOpen and open64_w
3414 // from src/solaris/hpi/src/system_md.c
3415 
3416 int os::open(const char *path, int oflag, int mode) {
3417   if (strlen(path) > MAX_PATH - 1) {
3418     errno = ENAMETOOLONG;
3419     return -1;
3420   }
3421   int fd;
3422 
3423   fd = ::open(path, oflag, mode);
3424   if (fd == -1) return -1;
3425 
3426   // If the open succeeded, the file might still be a directory
3427   {
3428     struct stat buf;
3429     int ret = ::fstat(fd, &buf);
3430     int st_mode = buf.st_mode;
3431 
3432     if (ret != -1) {
3433       if ((st_mode & S_IFMT) == S_IFDIR) {
3434         errno = EISDIR;
3435         ::close(fd);
3436         return -1;
3437       }
3438     } else {
3439       ::close(fd);
3440       return -1;
3441     }
3442   }
3443 
3444   // All file descriptors that are opened in the JVM and not
3445   // specifically destined for a subprocess should have the
3446   // close-on-exec flag set.  If we don't set it, then careless 3rd
3447   // party native code might fork and exec without closing all
3448   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3449   // UNIXProcess.c), and this in turn might:
3450   //
3451   // - cause end-of-file to fail to be detected on some file
3452   //   descriptors, resulting in mysterious hangs, or
3453   //
3454   // - might cause an fopen in the subprocess to fail on a system
3455   //   suffering from bug 1085341.
3456   //
3457   // (Yes, the default setting of the close-on-exec flag is a Unix
3458   // design flaw)
3459   //
3460   // See:
3461   // 1085341: 32-bit stdio routines should support file descriptors >255
3462   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3463   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3464   //
3465 #ifdef FD_CLOEXEC
3466   {
3467     int flags = ::fcntl(fd, F_GETFD);
3468     if (flags != -1) {
3469       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3470     }
3471   }
3472 #endif
3473 
3474   return fd;
3475 }
3476 
3477 
3478 // create binary file, rewriting existing file if required
3479 int os::create_binary_file(const char* path, bool rewrite_existing) {
3480   int oflags = O_WRONLY | O_CREAT;
3481   if (!rewrite_existing) {
3482     oflags |= O_EXCL;
3483   }
3484   return ::open(path, oflags, S_IREAD | S_IWRITE);
3485 }
3486 
3487 // return current position of file pointer
3488 jlong os::current_file_offset(int fd) {
3489   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3490 }
3491 
3492 // move file pointer to the specified offset
3493 jlong os::seek_to_file_offset(int fd, jlong offset) {
3494   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3495 }
3496 
3497 // This code originates from JDK's sysAvailable
3498 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3499 
3500 int os::available(int fd, jlong *bytes) {
3501   jlong cur, end;
3502   int mode;
3503   struct stat buf;
3504 
3505   if (::fstat(fd, &buf) >= 0) {
3506     mode = buf.st_mode;
3507     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3508       int n;
3509       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3510         *bytes = n;
3511         return 1;
3512       }
3513     }
3514   }
3515   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3516     return 0;
3517   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3518     return 0;
3519   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3520     return 0;
3521   }
3522   *bytes = end - cur;
3523   return 1;
3524 }
3525 
3526 // Map a block of memory.
3527 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3528                         char *addr, size_t bytes, bool read_only,
3529                         bool allow_exec) {
3530   int prot;
3531   int flags;
3532 
3533   if (read_only) {
3534     prot = PROT_READ;
3535     flags = MAP_SHARED;
3536   } else {
3537     prot = PROT_READ | PROT_WRITE;
3538     flags = MAP_PRIVATE;
3539   }
3540 
3541   if (allow_exec) {
3542     prot |= PROT_EXEC;
3543   }
3544 
3545   if (addr != NULL) {
3546     flags |= MAP_FIXED;
3547   }
3548 
3549   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3550                                      fd, file_offset);
3551   if (mapped_address == MAP_FAILED) {
3552     return NULL;
3553   }
3554   return mapped_address;
3555 }
3556 
3557 
3558 // Remap a block of memory.
3559 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3560                           char *addr, size_t bytes, bool read_only,
3561                           bool allow_exec) {
3562   // same as map_memory() on this OS
3563   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3564                         allow_exec);
3565 }
3566 
3567 
3568 // Unmap a block of memory.
3569 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3570   return munmap(addr, bytes) == 0;
3571 }
3572 
3573 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3574 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3575 // of a thread.
3576 //
3577 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3578 // the fast estimate available on the platform.
3579 
3580 jlong os::current_thread_cpu_time() {
3581 #ifdef __APPLE__
3582   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3583 #else
3584   Unimplemented();
3585   return 0;
3586 #endif
3587 }
3588 
3589 jlong os::thread_cpu_time(Thread* thread) {
3590 #ifdef __APPLE__
3591   return os::thread_cpu_time(thread, true /* user + sys */);
3592 #else
3593   Unimplemented();
3594   return 0;
3595 #endif
3596 }
3597 
3598 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3599 #ifdef __APPLE__
3600   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3601 #else
3602   Unimplemented();
3603   return 0;
3604 #endif
3605 }
3606 
3607 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3608 #ifdef __APPLE__
3609   struct thread_basic_info tinfo;
3610   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
3611   kern_return_t kr;
3612   thread_t mach_thread;
3613 
3614   mach_thread = thread->osthread()->thread_id();
3615   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
3616   if (kr != KERN_SUCCESS) {
3617     return -1;
3618   }
3619 
3620   if (user_sys_cpu_time) {
3621     jlong nanos;
3622     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
3623     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
3624     return nanos;
3625   } else {
3626     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
3627   }
3628 #else
3629   Unimplemented();
3630   return 0;
3631 #endif
3632 }
3633 
3634 
3635 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3636   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3637   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3638   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3639   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3640 }
3641 
3642 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3643   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3644   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3645   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3646   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3647 }
3648 
3649 bool os::is_thread_cpu_time_supported() {
3650 #ifdef __APPLE__
3651   return true;
3652 #else
3653   return false;
3654 #endif
3655 }
3656 
3657 // System loadavg support.  Returns -1 if load average cannot be obtained.
3658 // Bsd doesn't yet have a (official) notion of processor sets,
3659 // so just return the system wide load average.
3660 int os::loadavg(double loadavg[], int nelem) {
3661   return ::getloadavg(loadavg, nelem);
3662 }
3663 
3664 void os::pause() {
3665   char filename[MAX_PATH];
3666   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
3667     jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
3668   } else {
3669     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
3670   }
3671 
3672   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
3673   if (fd != -1) {
3674     struct stat buf;
3675     ::close(fd);
3676     while (::stat(filename, &buf) == 0) {
3677       (void)::poll(NULL, 0, 100);
3678     }
3679   } else {
3680     jio_fprintf(stderr,
3681                 "Could not open pause file '%s', continuing immediately.\n", filename);
3682   }
3683 }
3684 
3685 // Darwin has no "environ" in a dynamic library.
3686 #ifdef __APPLE__
3687   #include <crt_externs.h>
3688   #define environ (*_NSGetEnviron())
3689 #else
3690 extern char** environ;
3691 #endif
3692 
3693 // Run the specified command in a separate process. Return its exit value,
3694 // or -1 on failure (e.g. can't fork a new process).
3695 // Unlike system(), this function can be called from signal handler. It
3696 // doesn't block SIGINT et al.
3697 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
3698   const char * argv[4] = {"sh", "-c", cmd, NULL};
3699 
3700   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
3701   // pthread_atfork handlers and reset pthread library. All we need is a
3702   // separate process to execve. Make a direct syscall to fork process.
3703   // On IA64 there's no fork syscall, we have to use fork() and hope for
3704   // the best...
3705   pid_t pid = fork();
3706 
3707   if (pid < 0) {
3708     // fork failed
3709     return -1;
3710 
3711   } else if (pid == 0) {
3712     // child process
3713 
3714     // execve() in BsdThreads will call pthread_kill_other_threads_np()
3715     // first to kill every thread on the thread list. Because this list is
3716     // not reset by fork() (see notes above), execve() will instead kill
3717     // every thread in the parent process. We know this is the only thread
3718     // in the new process, so make a system call directly.
3719     // IA64 should use normal execve() from glibc to match the glibc fork()
3720     // above.
3721     execve("/bin/sh", (char* const*)argv, environ);
3722 
3723     // execve failed
3724     _exit(-1);
3725 
3726   } else  {
3727     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
3728     // care about the actual exit code, for now.
3729 
3730     int status;
3731 
3732     // Wait for the child process to exit.  This returns immediately if
3733     // the child has already exited. */
3734     while (waitpid(pid, &status, 0) < 0) {
3735       switch (errno) {
3736       case ECHILD: return 0;
3737       case EINTR: break;
3738       default: return -1;
3739       }
3740     }
3741 
3742     if (WIFEXITED(status)) {
3743       // The child exited normally; get its exit code.
3744       return WEXITSTATUS(status);
3745     } else if (WIFSIGNALED(status)) {
3746       // The child exited because of a signal
3747       // The best value to return is 0x80 + signal number,
3748       // because that is what all Unix shells do, and because
3749       // it allows callers to distinguish between process exit and
3750       // process death by signal.
3751       return 0x80 + WTERMSIG(status);
3752     } else {
3753       // Unknown exit code; pass it through
3754       return status;
3755     }
3756   }
3757 }
3758 
3759 // Get the default path to the core file
3760 // Returns the length of the string
3761 int os::get_core_path(char* buffer, size_t bufferSize) {
3762   int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
3763 
3764   // Truncate if theoretical string was longer than bufferSize
3765   n = MIN2(n, (int)bufferSize);
3766 
3767   return n;
3768 }
3769 
3770 bool os::supports_map_sync() {
3771   return false;
3772 }
3773 
3774 #ifndef PRODUCT
3775 void TestReserveMemorySpecial_test() {
3776   // No tests available for this platform
3777 }
3778 #endif
3779 
3780 bool os::start_debugging(char *buf, int buflen) {
3781   int len = (int)strlen(buf);
3782   char *p = &buf[len];
3783 
3784   jio_snprintf(p, buflen-len,
3785              "\n\n"
3786              "Do you want to debug the problem?\n\n"
3787              "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT " (" INTPTR_FORMAT ")\n"
3788              "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
3789              "Otherwise, press RETURN to abort...",
3790              os::current_process_id(), os::current_process_id(),
3791              os::current_thread_id(), os::current_thread_id());
3792 
3793   bool yes = os::message_box("Unexpected Error", buf);
3794 
3795   if (yes) {
3796     // yes, user asked VM to launch debugger
3797     jio_snprintf(buf, sizeof(buf), "gdb /proc/%d/exe %d",
3798                      os::current_process_id(), os::current_process_id());
3799 
3800     os::fork_and_exec(buf);
3801     yes = false;
3802   }
3803   return yes;
3804 }