rev 6280 : [mq]: osx-clock

   1 /*
   2  * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // no precompiled headers
  26 #include "classfile/classLoader.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/icBuffer.hpp"
  30 #include "code/vtableStubs.hpp"
  31 #include "compiler/compileBroker.hpp"
  32 #include "compiler/disassembler.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "jvm_bsd.h"
  35 #include "memory/allocation.inline.hpp"
  36 #include "memory/filemap.hpp"
  37 #include "mutex_bsd.inline.hpp"
  38 #include "oops/oop.inline.hpp"
  39 #include "os_share_bsd.hpp"
  40 #include "prims/jniFastGetField.hpp"
  41 #include "prims/jvm.h"
  42 #include "prims/jvm_misc.hpp"
  43 #include "runtime/arguments.hpp"
  44 #include "runtime/extendedPC.hpp"
  45 #include "runtime/globals.hpp"
  46 #include "runtime/interfaceSupport.hpp"
  47 #include "runtime/java.hpp"
  48 #include "runtime/javaCalls.hpp"
  49 #include "runtime/mutexLocker.hpp"
  50 #include "runtime/objectMonitor.hpp"
  51 #include "runtime/osThread.hpp"
  52 #include "runtime/perfMemory.hpp"
  53 #include "runtime/sharedRuntime.hpp"
  54 #include "runtime/statSampler.hpp"
  55 #include "runtime/stubRoutines.hpp"
  56 #include "runtime/thread.inline.hpp"
  57 #include "runtime/threadCritical.hpp"
  58 #include "runtime/timer.hpp"
  59 #include "services/attachListener.hpp"
  60 #include "services/memTracker.hpp"
  61 #include "services/runtimeService.hpp"
  62 #include "utilities/decoder.hpp"
  63 #include "utilities/defaultStream.hpp"
  64 #include "utilities/events.hpp"
  65 #include "utilities/growableArray.hpp"
  66 #include "utilities/vmError.hpp"
  67 
  68 // put OS-includes here
  69 # include <sys/types.h>
  70 # include <sys/mman.h>
  71 # include <sys/stat.h>
  72 # include <sys/select.h>
  73 # include <pthread.h>
  74 # include <signal.h>
  75 # include <errno.h>
  76 # include <dlfcn.h>
  77 # include <stdio.h>
  78 # include <unistd.h>
  79 # include <sys/resource.h>
  80 # include <pthread.h>
  81 # include <sys/stat.h>
  82 # include <sys/time.h>
  83 # include <sys/times.h>
  84 # include <sys/utsname.h>
  85 # include <sys/socket.h>
  86 # include <sys/wait.h>
  87 # include <time.h>
  88 # include <pwd.h>
  89 # include <poll.h>
  90 # include <semaphore.h>
  91 # include <fcntl.h>
  92 # include <string.h>
  93 # include <sys/param.h>
  94 # include <sys/sysctl.h>
  95 # include <sys/ipc.h>
  96 # include <sys/shm.h>
  97 #ifndef __APPLE__
  98 # include <link.h>
  99 #endif
 100 # include <stdint.h>
 101 # include <inttypes.h>
 102 # include <sys/ioctl.h>
 103 # include <sys/syscall.h>
 104 
 105 #if defined(__FreeBSD__) || defined(__NetBSD__)
 106 # include <elf.h>
 107 #endif
 108 
 109 #ifdef __APPLE__
 110 # include <mach/mach.h> // semaphore_* API
 111 # include <mach-o/dyld.h>
 112 # include <sys/proc_info.h>
 113 # include <objc/objc-auto.h>
 114 #endif
 115 
 116 #ifndef MAP_ANONYMOUS
 117 #define MAP_ANONYMOUS MAP_ANON
 118 #endif
 119 
 120 #define MAX_PATH    (2 * K)
 121 
 122 // for timer info max values which include all bits
 123 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 124 
 125 #define LARGEPAGES_BIT (1 << 6)
 126 ////////////////////////////////////////////////////////////////////////////////
 127 // global variables
 128 julong os::Bsd::_physical_memory = 0;
 129 
 130 #ifdef __APPLE__
 131 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
 132 volatile uint64_t         os::Bsd::_max_abstime   = 0;
 133 #else
 134 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 135 #endif
 136 pthread_t os::Bsd::_main_thread;
 137 int os::Bsd::_page_size = -1;
 138 
 139 static jlong initial_time_count=0;
 140 
 141 static int clock_tics_per_sec = 100;
 142 
 143 // For diagnostics to print a message once. see run_periodic_checks
 144 static sigset_t check_signal_done;
 145 static bool check_signals = true;
 146 
 147 static pid_t _initial_pid = 0;
 148 
 149 /* Signal number used to suspend/resume a thread */
 150 
 151 /* do not use any signal number less than SIGSEGV, see 4355769 */
 152 static int SR_signum = SIGUSR2;
 153 sigset_t SR_sigset;
 154 
 155 
 156 ////////////////////////////////////////////////////////////////////////////////
 157 // utility functions
 158 
 159 static int SR_initialize();
 160 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
 161 
 162 julong os::available_memory() {
 163   return Bsd::available_memory();
 164 }
 165 
 166 // available here means free
 167 julong os::Bsd::available_memory() {
 168   uint64_t available = physical_memory() >> 2;
 169 #ifdef __APPLE__
 170   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
 171   vm_statistics64_data_t vmstat;
 172   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
 173                                          (host_info64_t)&vmstat, &count);
 174   assert(kerr == KERN_SUCCESS,
 175          "host_statistics64 failed - check mach_host_self() and count");
 176   if (kerr == KERN_SUCCESS) {
 177     available = vmstat.free_count * os::vm_page_size();
 178   }
 179 #endif
 180   return available;
 181 }
 182 
 183 julong os::physical_memory() {
 184   return Bsd::physical_memory();
 185 }
 186 
 187 ////////////////////////////////////////////////////////////////////////////////
 188 // environment support
 189 
 190 bool os::getenv(const char* name, char* buf, int len) {
 191   const char* val = ::getenv(name);
 192   if (val != NULL && strlen(val) < (size_t)len) {
 193     strcpy(buf, val);
 194     return true;
 195   }
 196   if (len > 0) buf[0] = 0;  // return a null string
 197   return false;
 198 }
 199 
 200 
 201 // Return true if user is running as root.
 202 
 203 bool os::have_special_privileges() {
 204   static bool init = false;
 205   static bool privileges = false;
 206   if (!init) {
 207     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 208     init = true;
 209   }
 210   return privileges;
 211 }
 212 
 213 
 214 
 215 // Cpu architecture string
 216 #if   defined(ZERO)
 217 static char cpu_arch[] = ZERO_LIBARCH;
 218 #elif defined(IA64)
 219 static char cpu_arch[] = "ia64";
 220 #elif defined(IA32)
 221 static char cpu_arch[] = "i386";
 222 #elif defined(AMD64)
 223 static char cpu_arch[] = "amd64";
 224 #elif defined(ARM)
 225 static char cpu_arch[] = "arm";
 226 #elif defined(PPC32)
 227 static char cpu_arch[] = "ppc";
 228 #elif defined(SPARC)
 229 #  ifdef _LP64
 230 static char cpu_arch[] = "sparcv9";
 231 #  else
 232 static char cpu_arch[] = "sparc";
 233 #  endif
 234 #else
 235 #error Add appropriate cpu_arch setting
 236 #endif
 237 
 238 // Compiler variant
 239 #ifdef COMPILER2
 240 #define COMPILER_VARIANT "server"
 241 #else
 242 #define COMPILER_VARIANT "client"
 243 #endif
 244 
 245 
 246 void os::Bsd::initialize_system_info() {
 247   int mib[2];
 248   size_t len;
 249   int cpu_val;
 250   julong mem_val;
 251 
 252   /* get processors count via hw.ncpus sysctl */
 253   mib[0] = CTL_HW;
 254   mib[1] = HW_NCPU;
 255   len = sizeof(cpu_val);
 256   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 257        assert(len == sizeof(cpu_val), "unexpected data size");
 258        set_processor_count(cpu_val);
 259   }
 260   else {
 261        set_processor_count(1);   // fallback
 262   }
 263 
 264   /* get physical memory via hw.memsize sysctl (hw.memsize is used
 265    * since it returns a 64 bit value)
 266    */
 267   mib[0] = CTL_HW;
 268 
 269 #if defined (HW_MEMSIZE) // Apple
 270   mib[1] = HW_MEMSIZE;
 271 #elif defined(HW_PHYSMEM) // Most of BSD
 272   mib[1] = HW_PHYSMEM;
 273 #elif defined(HW_REALMEM) // Old FreeBSD
 274   mib[1] = HW_REALMEM;
 275 #else
 276   #error No ways to get physmem
 277 #endif
 278 
 279   len = sizeof(mem_val);
 280   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 281        assert(len == sizeof(mem_val), "unexpected data size");
 282        _physical_memory = mem_val;
 283   } else {
 284        _physical_memory = 256*1024*1024;       // fallback (XXXBSD?)
 285   }
 286 
 287 #ifdef __OpenBSD__
 288   {
 289        // limit _physical_memory memory view on OpenBSD since
 290        // datasize rlimit restricts us anyway.
 291        struct rlimit limits;
 292        getrlimit(RLIMIT_DATA, &limits);
 293        _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 294   }
 295 #endif
 296 }
 297 
 298 #ifdef __APPLE__
 299 static const char *get_home() {
 300   const char *home_dir = ::getenv("HOME");
 301   if ((home_dir == NULL) || (*home_dir == '\0')) {
 302     struct passwd *passwd_info = getpwuid(geteuid());
 303     if (passwd_info != NULL) {
 304       home_dir = passwd_info->pw_dir;
 305     }
 306   }
 307 
 308   return home_dir;
 309 }
 310 #endif
 311 
 312 void os::init_system_properties_values() {
 313   // The next steps are taken in the product version:
 314   //
 315   // Obtain the JAVA_HOME value from the location of libjvm.so.
 316   // This library should be located at:
 317   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 318   //
 319   // If "/jre/lib/" appears at the right place in the path, then we
 320   // assume libjvm.so is installed in a JDK and we use this path.
 321   //
 322   // Otherwise exit with message: "Could not create the Java virtual machine."
 323   //
 324   // The following extra steps are taken in the debugging version:
 325   //
 326   // If "/jre/lib/" does NOT appear at the right place in the path
 327   // instead of exit check for $JAVA_HOME environment variable.
 328   //
 329   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 330   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 331   // it looks like libjvm.so is installed there
 332   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 333   //
 334   // Otherwise exit.
 335   //
 336   // Important note: if the location of libjvm.so changes this
 337   // code needs to be changed accordingly.
 338 
 339 // See ld(1):
 340 //      The linker uses the following search paths to locate required
 341 //      shared libraries:
 342 //        1: ...
 343 //        ...
 344 //        7: The default directories, normally /lib and /usr/lib.
 345 #ifndef DEFAULT_LIBPATH
 346 #define DEFAULT_LIBPATH "/lib:/usr/lib"
 347 #endif
 348 
 349 // Base path of extensions installed on the system.
 350 #define SYS_EXT_DIR     "/usr/java/packages"
 351 #define EXTENSIONS_DIR  "/lib/ext"
 352 #define ENDORSED_DIR    "/lib/endorsed"
 353 
 354 #ifndef __APPLE__
 355 
 356   // Buffer that fits several sprintfs.
 357   // Note that the space for the colon and the trailing null are provided
 358   // by the nulls included by the sizeof operator.
 359   const size_t bufsize =
 360     MAX3((size_t)MAXPATHLEN,  // For dll_dir & friends.
 361          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR), // extensions dir
 362          (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir
 363   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 364 
 365   // sysclasspath, java_home, dll_dir
 366   {
 367     char *pslash;
 368     os::jvm_path(buf, bufsize);
 369 
 370     // Found the full path to libjvm.so.
 371     // Now cut the path to <java_home>/jre if we can.
 372     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 373     pslash = strrchr(buf, '/');
 374     if (pslash != NULL) {
 375       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 376     }
 377     Arguments::set_dll_dir(buf);
 378 
 379     if (pslash != NULL) {
 380       pslash = strrchr(buf, '/');
 381       if (pslash != NULL) {
 382         *pslash = '\0';          // Get rid of /<arch>.
 383         pslash = strrchr(buf, '/');
 384         if (pslash != NULL) {
 385           *pslash = '\0';        // Get rid of /lib.
 386         }
 387       }
 388     }
 389     Arguments::set_java_home(buf);
 390     set_boot_path('/', ':');
 391   }
 392 
 393   // Where to look for native libraries.
 394   //
 395   // Note: Due to a legacy implementation, most of the library path
 396   // is set in the launcher. This was to accomodate linking restrictions
 397   // on legacy Bsd implementations (which are no longer supported).
 398   // Eventually, all the library path setting will be done here.
 399   //
 400   // However, to prevent the proliferation of improperly built native
 401   // libraries, the new path component /usr/java/packages is added here.
 402   // Eventually, all the library path setting will be done here.
 403   {
 404     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 405     // should always exist (until the legacy problem cited above is
 406     // addressed).
 407     const char *v = ::getenv("LD_LIBRARY_PATH");
 408     const char *v_colon = ":";
 409     if (v == NULL) { v = ""; v_colon = ""; }
 410     // That's +1 for the colon and +1 for the trailing '\0'.
 411     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 412                                                      strlen(v) + 1 +
 413                                                      sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
 414                                                      mtInternal);
 415     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
 416     Arguments::set_library_path(ld_library_path);
 417     FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal);
 418   }
 419 
 420   // Extensions directories.
 421   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
 422   Arguments::set_ext_dirs(buf);
 423 
 424   // Endorsed standards default directory.
 425   sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
 426   Arguments::set_endorsed_dirs(buf);
 427 
 428   FREE_C_HEAP_ARRAY(char, buf, mtInternal);
 429 
 430 #else // __APPLE__
 431 
 432 #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 433 #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 434 
 435   const char *user_home_dir = get_home();
 436   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
 437   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 438     sizeof(SYS_EXTENSIONS_DIRS);
 439 
 440   // Buffer that fits several sprintfs.
 441   // Note that the space for the colon and the trailing null are provided
 442   // by the nulls included by the sizeof operator.
 443   const size_t bufsize =
 444     MAX3((size_t)MAXPATHLEN,  // for dll_dir & friends.
 445          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size, // extensions dir
 446          (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir
 447   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 448 
 449   // sysclasspath, java_home, dll_dir
 450   {
 451     char *pslash;
 452     os::jvm_path(buf, bufsize);
 453 
 454     // Found the full path to libjvm.so.
 455     // Now cut the path to <java_home>/jre if we can.
 456     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 457     pslash = strrchr(buf, '/');
 458     if (pslash != NULL) {
 459       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 460     }
 461     Arguments::set_dll_dir(buf);
 462 
 463     if (pslash != NULL) {
 464       pslash = strrchr(buf, '/');
 465       if (pslash != NULL) {
 466         *pslash = '\0';          // Get rid of /lib.
 467       }
 468     }
 469     Arguments::set_java_home(buf);
 470     set_boot_path('/', ':');
 471   }
 472 
 473   // Where to look for native libraries.
 474   //
 475   // Note: Due to a legacy implementation, most of the library path
 476   // is set in the launcher. This was to accomodate linking restrictions
 477   // on legacy Bsd implementations (which are no longer supported).
 478   // Eventually, all the library path setting will be done here.
 479   //
 480   // However, to prevent the proliferation of improperly built native
 481   // libraries, the new path component /usr/java/packages is added here.
 482   // Eventually, all the library path setting will be done here.
 483   {
 484     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 485     // should always exist (until the legacy problem cited above is
 486     // addressed).
 487     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
 488     // can specify a directory inside an app wrapper
 489     const char *l = ::getenv("JAVA_LIBRARY_PATH");
 490     const char *l_colon = ":";
 491     if (l == NULL) { l = ""; l_colon = ""; }
 492 
 493     const char *v = ::getenv("DYLD_LIBRARY_PATH");
 494     const char *v_colon = ":";
 495     if (v == NULL) { v = ""; v_colon = ""; }
 496 
 497     // Apple's Java6 has "." at the beginning of java.library.path.
 498     // OpenJDK on Windows has "." at the end of java.library.path.
 499     // OpenJDK on Linux and Solaris don't have "." in java.library.path
 500     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 501     // "." is appended to the end of java.library.path. Yes, this
 502     // could cause a change in behavior, but Apple's Java6 behavior
 503     // can be achieved by putting "." at the beginning of the
 504     // JAVA_LIBRARY_PATH environment variable.
 505     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 506                                                      strlen(v) + 1 + strlen(l) + 1 +
 507                                                      system_ext_size + 3,
 508                                                      mtInternal);
 509     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
 510             v, v_colon, l, l_colon, user_home_dir);
 511     Arguments::set_library_path(ld_library_path);
 512     FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal);
 513   }
 514 
 515   // Extensions directories.
 516   //
 517   // Note that the space for the colon and the trailing null are provided
 518   // by the nulls included by the sizeof operator (so actually one byte more
 519   // than necessary is allocated).
 520   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
 521           user_home_dir, Arguments::get_java_home());
 522   Arguments::set_ext_dirs(buf);
 523 
 524   // Endorsed standards default directory.
 525   sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
 526   Arguments::set_endorsed_dirs(buf);
 527 
 528   FREE_C_HEAP_ARRAY(char, buf, mtInternal);
 529 
 530 #undef SYS_EXTENSIONS_DIR
 531 #undef SYS_EXTENSIONS_DIRS
 532 
 533 #endif // __APPLE__
 534 
 535 #undef SYS_EXT_DIR
 536 #undef EXTENSIONS_DIR
 537 #undef ENDORSED_DIR
 538 }
 539 
 540 ////////////////////////////////////////////////////////////////////////////////
 541 // breakpoint support
 542 
 543 void os::breakpoint() {
 544   BREAKPOINT;
 545 }
 546 
 547 extern "C" void breakpoint() {
 548   // use debugger to set breakpoint here
 549 }
 550 
 551 ////////////////////////////////////////////////////////////////////////////////
 552 // signal support
 553 
 554 debug_only(static bool signal_sets_initialized = false);
 555 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
 556 
 557 bool os::Bsd::is_sig_ignored(int sig) {
 558       struct sigaction oact;
 559       sigaction(sig, (struct sigaction*)NULL, &oact);
 560       void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
 561                                      : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
 562       if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
 563            return true;
 564       else
 565            return false;
 566 }
 567 
 568 void os::Bsd::signal_sets_init() {
 569   // Should also have an assertion stating we are still single-threaded.
 570   assert(!signal_sets_initialized, "Already initialized");
 571   // Fill in signals that are necessarily unblocked for all threads in
 572   // the VM. Currently, we unblock the following signals:
 573   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 574   //                         by -Xrs (=ReduceSignalUsage));
 575   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 576   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 577   // the dispositions or masks wrt these signals.
 578   // Programs embedding the VM that want to use the above signals for their
 579   // own purposes must, at this time, use the "-Xrs" option to prevent
 580   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 581   // (See bug 4345157, and other related bugs).
 582   // In reality, though, unblocking these signals is really a nop, since
 583   // these signals are not blocked by default.
 584   sigemptyset(&unblocked_sigs);
 585   sigemptyset(&allowdebug_blocked_sigs);
 586   sigaddset(&unblocked_sigs, SIGILL);
 587   sigaddset(&unblocked_sigs, SIGSEGV);
 588   sigaddset(&unblocked_sigs, SIGBUS);
 589   sigaddset(&unblocked_sigs, SIGFPE);
 590   sigaddset(&unblocked_sigs, SR_signum);
 591 
 592   if (!ReduceSignalUsage) {
 593    if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 594       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 595       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
 596    }
 597    if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 598       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 599       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
 600    }
 601    if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 602       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 603       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
 604    }
 605   }
 606   // Fill in signals that are blocked by all but the VM thread.
 607   sigemptyset(&vm_sigs);
 608   if (!ReduceSignalUsage)
 609     sigaddset(&vm_sigs, BREAK_SIGNAL);
 610   debug_only(signal_sets_initialized = true);
 611 
 612 }
 613 
 614 // These are signals that are unblocked while a thread is running Java.
 615 // (For some reason, they get blocked by default.)
 616 sigset_t* os::Bsd::unblocked_signals() {
 617   assert(signal_sets_initialized, "Not initialized");
 618   return &unblocked_sigs;
 619 }
 620 
 621 // These are the signals that are blocked while a (non-VM) thread is
 622 // running Java. Only the VM thread handles these signals.
 623 sigset_t* os::Bsd::vm_signals() {
 624   assert(signal_sets_initialized, "Not initialized");
 625   return &vm_sigs;
 626 }
 627 
 628 // These are signals that are blocked during cond_wait to allow debugger in
 629 sigset_t* os::Bsd::allowdebug_blocked_signals() {
 630   assert(signal_sets_initialized, "Not initialized");
 631   return &allowdebug_blocked_sigs;
 632 }
 633 
 634 void os::Bsd::hotspot_sigmask(Thread* thread) {
 635 
 636   //Save caller's signal mask before setting VM signal mask
 637   sigset_t caller_sigmask;
 638   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 639 
 640   OSThread* osthread = thread->osthread();
 641   osthread->set_caller_sigmask(caller_sigmask);
 642 
 643   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 644 
 645   if (!ReduceSignalUsage) {
 646     if (thread->is_VM_thread()) {
 647       // Only the VM thread handles BREAK_SIGNAL ...
 648       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 649     } else {
 650       // ... all other threads block BREAK_SIGNAL
 651       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 652     }
 653   }
 654 }
 655 
 656 
 657 //////////////////////////////////////////////////////////////////////////////
 658 // create new thread
 659 
 660 // check if it's safe to start a new thread
 661 static bool _thread_safety_check(Thread* thread) {
 662   return true;
 663 }
 664 
 665 #ifdef __APPLE__
 666 // library handle for calling objc_registerThreadWithCollector()
 667 // without static linking to the libobjc library
 668 #define OBJC_LIB "/usr/lib/libobjc.dylib"
 669 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 670 typedef void (*objc_registerThreadWithCollector_t)();
 671 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 672 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 673 #endif
 674 
 675 #ifdef __APPLE__
 676 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 677   // Additional thread_id used to correlate threads in SA
 678   thread_identifier_info_data_t     m_ident_info;
 679   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 680 
 681   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 682               (thread_info_t) &m_ident_info, &count);
 683 
 684   return m_ident_info.thread_id;
 685 }
 686 #endif
 687 
 688 // Thread start routine for all newly created threads
 689 static void *java_start(Thread *thread) {
 690   // Try to randomize the cache line index of hot stack frames.
 691   // This helps when threads of the same stack traces evict each other's
 692   // cache lines. The threads can be either from the same JVM instance, or
 693   // from different JVM instances. The benefit is especially true for
 694   // processors with hyperthreading technology.
 695   static int counter = 0;
 696   int pid = os::current_process_id();
 697   alloca(((pid ^ counter++) & 7) * 128);
 698 
 699   ThreadLocalStorage::set_thread(thread);
 700 
 701   OSThread* osthread = thread->osthread();
 702   Monitor* sync = osthread->startThread_lock();
 703 
 704   // non floating stack BsdThreads needs extra check, see above
 705   if (!_thread_safety_check(thread)) {
 706     // notify parent thread
 707     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 708     osthread->set_state(ZOMBIE);
 709     sync->notify_all();
 710     return NULL;
 711   }
 712 
 713   osthread->set_thread_id(os::Bsd::gettid());
 714 
 715 #ifdef __APPLE__
 716   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 717   guarantee(unique_thread_id != 0, "unique thread id was not found");
 718   osthread->set_unique_thread_id(unique_thread_id);
 719 #endif
 720   // initialize signal mask for this thread
 721   os::Bsd::hotspot_sigmask(thread);
 722 
 723   // initialize floating point control register
 724   os::Bsd::init_thread_fpu_state();
 725 
 726 #ifdef __APPLE__
 727   // register thread with objc gc
 728   if (objc_registerThreadWithCollectorFunction != NULL) {
 729     objc_registerThreadWithCollectorFunction();
 730   }
 731 #endif
 732 
 733   // handshaking with parent thread
 734   {
 735     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 736 
 737     // notify parent thread
 738     osthread->set_state(INITIALIZED);
 739     sync->notify_all();
 740 
 741     // wait until os::start_thread()
 742     while (osthread->get_state() == INITIALIZED) {
 743       sync->wait(Mutex::_no_safepoint_check_flag);
 744     }
 745   }
 746 
 747   // call one more level start routine
 748   thread->run();
 749 
 750   return 0;
 751 }
 752 
 753 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
 754   assert(thread->osthread() == NULL, "caller responsible");
 755 
 756   // Allocate the OSThread object
 757   OSThread* osthread = new OSThread(NULL, NULL);
 758   if (osthread == NULL) {
 759     return false;
 760   }
 761 
 762   // set the correct thread state
 763   osthread->set_thread_type(thr_type);
 764 
 765   // Initial state is ALLOCATED but not INITIALIZED
 766   osthread->set_state(ALLOCATED);
 767 
 768   thread->set_osthread(osthread);
 769 
 770   // init thread attributes
 771   pthread_attr_t attr;
 772   pthread_attr_init(&attr);
 773   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 774 
 775   // stack size
 776   if (os::Bsd::supports_variable_stack_size()) {
 777     // calculate stack size if it's not specified by caller
 778     if (stack_size == 0) {
 779       stack_size = os::Bsd::default_stack_size(thr_type);
 780 
 781       switch (thr_type) {
 782       case os::java_thread:
 783         // Java threads use ThreadStackSize which default value can be
 784         // changed with the flag -Xss
 785         assert (JavaThread::stack_size_at_create() > 0, "this should be set");
 786         stack_size = JavaThread::stack_size_at_create();
 787         break;
 788       case os::compiler_thread:
 789         if (CompilerThreadStackSize > 0) {
 790           stack_size = (size_t)(CompilerThreadStackSize * K);
 791           break;
 792         } // else fall through:
 793           // use VMThreadStackSize if CompilerThreadStackSize is not defined
 794       case os::vm_thread:
 795       case os::pgc_thread:
 796       case os::cgc_thread:
 797       case os::watcher_thread:
 798         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 799         break;
 800       }
 801     }
 802 
 803     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
 804     pthread_attr_setstacksize(&attr, stack_size);
 805   } else {
 806     // let pthread_create() pick the default value.
 807   }
 808 
 809   ThreadState state;
 810 
 811   {
 812     pthread_t tid;
 813     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
 814 
 815     pthread_attr_destroy(&attr);
 816 
 817     if (ret != 0) {
 818       if (PrintMiscellaneous && (Verbose || WizardMode)) {
 819         perror("pthread_create()");
 820       }
 821       // Need to clean up stuff we've allocated so far
 822       thread->set_osthread(NULL);
 823       delete osthread;
 824       return false;
 825     }
 826 
 827     // Store pthread info into the OSThread
 828     osthread->set_pthread_id(tid);
 829 
 830     // Wait until child thread is either initialized or aborted
 831     {
 832       Monitor* sync_with_child = osthread->startThread_lock();
 833       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 834       while ((state = osthread->get_state()) == ALLOCATED) {
 835         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 836       }
 837     }
 838 
 839   }
 840 
 841   // Aborted due to thread limit being reached
 842   if (state == ZOMBIE) {
 843       thread->set_osthread(NULL);
 844       delete osthread;
 845       return false;
 846   }
 847 
 848   // The thread is returned suspended (in state INITIALIZED),
 849   // and is started higher up in the call chain
 850   assert(state == INITIALIZED, "race condition");
 851   return true;
 852 }
 853 
 854 /////////////////////////////////////////////////////////////////////////////
 855 // attach existing thread
 856 
 857 // bootstrap the main thread
 858 bool os::create_main_thread(JavaThread* thread) {
 859   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 860   return create_attached_thread(thread);
 861 }
 862 
 863 bool os::create_attached_thread(JavaThread* thread) {
 864 #ifdef ASSERT
 865     thread->verify_not_published();
 866 #endif
 867 
 868   // Allocate the OSThread object
 869   OSThread* osthread = new OSThread(NULL, NULL);
 870 
 871   if (osthread == NULL) {
 872     return false;
 873   }
 874 
 875   osthread->set_thread_id(os::Bsd::gettid());
 876 
 877   // Store pthread info into the OSThread
 878 #ifdef __APPLE__
 879   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 880   guarantee(unique_thread_id != 0, "just checking");
 881   osthread->set_unique_thread_id(unique_thread_id);
 882 #endif
 883   osthread->set_pthread_id(::pthread_self());
 884 
 885   // initialize floating point control register
 886   os::Bsd::init_thread_fpu_state();
 887 
 888   // Initial thread state is RUNNABLE
 889   osthread->set_state(RUNNABLE);
 890 
 891   thread->set_osthread(osthread);
 892 
 893   // initialize signal mask for this thread
 894   // and save the caller's signal mask
 895   os::Bsd::hotspot_sigmask(thread);
 896 
 897   return true;
 898 }
 899 
 900 void os::pd_start_thread(Thread* thread) {
 901   OSThread * osthread = thread->osthread();
 902   assert(osthread->get_state() != INITIALIZED, "just checking");
 903   Monitor* sync_with_child = osthread->startThread_lock();
 904   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 905   sync_with_child->notify();
 906 }
 907 
 908 // Free Bsd resources related to the OSThread
 909 void os::free_thread(OSThread* osthread) {
 910   assert(osthread != NULL, "osthread not set");
 911 
 912   if (Thread::current()->osthread() == osthread) {
 913     // Restore caller's signal mask
 914     sigset_t sigmask = osthread->caller_sigmask();
 915     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 916    }
 917 
 918   delete osthread;
 919 }
 920 
 921 //////////////////////////////////////////////////////////////////////////////
 922 // thread local storage
 923 
 924 // Restore the thread pointer if the destructor is called. This is in case
 925 // someone from JNI code sets up a destructor with pthread_key_create to run
 926 // detachCurrentThread on thread death. Unless we restore the thread pointer we
 927 // will hang or crash. When detachCurrentThread is called the key will be set
 928 // to null and we will not be called again. If detachCurrentThread is never
 929 // called we could loop forever depending on the pthread implementation.
 930 static void restore_thread_pointer(void* p) {
 931   Thread* thread = (Thread*) p;
 932   os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
 933 }
 934 
 935 int os::allocate_thread_local_storage() {
 936   pthread_key_t key;
 937   int rslt = pthread_key_create(&key, restore_thread_pointer);
 938   assert(rslt == 0, "cannot allocate thread local storage");
 939   return (int)key;
 940 }
 941 
 942 // Note: This is currently not used by VM, as we don't destroy TLS key
 943 // on VM exit.
 944 void os::free_thread_local_storage(int index) {
 945   int rslt = pthread_key_delete((pthread_key_t)index);
 946   assert(rslt == 0, "invalid index");
 947 }
 948 
 949 void os::thread_local_storage_at_put(int index, void* value) {
 950   int rslt = pthread_setspecific((pthread_key_t)index, value);
 951   assert(rslt == 0, "pthread_setspecific failed");
 952 }
 953 
 954 extern "C" Thread* get_thread() {
 955   return ThreadLocalStorage::thread();
 956 }
 957 
 958 
 959 ////////////////////////////////////////////////////////////////////////////////
 960 // time support
 961 
 962 // Time since start-up in seconds to a fine granularity.
 963 // Used by VMSelfDestructTimer and the MemProfiler.
 964 double os::elapsedTime() {
 965 
 966   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 967 }
 968 
 969 jlong os::elapsed_counter() {
 970   return javaTimeNanos() - initial_time_count;
 971 }
 972 
 973 jlong os::elapsed_frequency() {
 974   return NANOSECS_PER_SEC; // nanosecond resolution
 975 }
 976 
 977 bool os::supports_vtime() { return true; }
 978 bool os::enable_vtime()   { return false; }
 979 bool os::vtime_enabled()  { return false; }
 980 
 981 double os::elapsedVTime() {
 982   // better than nothing, but not much
 983   return elapsedTime();
 984 }
 985 
 986 jlong os::javaTimeMillis() {
 987   timeval time;
 988   int status = gettimeofday(&time, NULL);
 989   assert(status != -1, "bsd error");
 990   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 991 }
 992 
 993 #ifndef __APPLE__
 994 #ifndef CLOCK_MONOTONIC
 995 #define CLOCK_MONOTONIC (1)
 996 #endif
 997 #endif
 998 
 999 #ifdef __APPLE__
1000 void os::Bsd::clock_init() {
1001   mach_timebase_info(&_timebase_info);
1002 }
1003 #else
1004 void os::Bsd::clock_init() {
1005   struct timespec res;
1006   struct timespec tp;
1007   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
1008       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
1009     // yes, monotonic clock is supported
1010     _clock_gettime = ::clock_gettime;
1011   }
1012 }
1013 #endif
1014 
1015 
1016 
1017 #ifdef __APPLE__
1018 
1019 jlong os::javaTimeNanos() {
1020     const uint64_t tm = mach_absolute_time();
1021     const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
1022     if (AssumeMonotonicOSTimers) {
1023       return now;
1024     }
1025 
1026     const uint64_t prev = Bsd::_max_abstime;
1027     if (now <= prev) {
1028       return prev;   // same or retrograde time;
1029     }
1030     const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
1031     assert(obsv >= prev, "invariant");   // Monotonicity
1032     // If the CAS succeeded then we're done and return "now".
1033     // If the CAS failed and the observed value "obs" is >= now then
1034     // we should return "obs".  If the CAS failed and now > obs > prv then
1035     // some other thread raced this thread and installed a new value, in which case
1036     // we could either (a) retry the entire operation, (b) retry trying to install now
1037     // or (c) just return obs.  We use (c).   No loop is required although in some cases
1038     // we might discard a higher "now" value in deference to a slightly lower but freshly
1039     // installed obs value.   That's entirely benign -- it admits no new orderings compared
1040     // to (a) or (b) -- and greatly reduces coherence traffic.
1041     // We might also condition (c) on the magnitude of the delta between obs and now.
1042     // Avoiding excessive CAS operations to hot RW locations is critical.
1043     // See http://blogs.sun.com/dave/entry/cas_and_cache_trivia_invalidate
1044     return (prev == obsv) ? now : obsv;
1045 }
1046 
1047 #else // __APPLE__
1048 
1049 jlong os::javaTimeNanos() {
1050   if (os::supports_monotonic_clock()) {
1051     struct timespec tp;
1052     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
1053     assert(status == 0, "gettime error");
1054     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1055     return result;
1056   } else {
1057     timeval time;
1058     int status = gettimeofday(&time, NULL);
1059     assert(status != -1, "bsd error");
1060     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1061     return 1000 * usecs;
1062   }
1063 }
1064 
1065 #endif // __APPLE__
1066 
1067 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1068   if (os::supports_monotonic_clock()) {
1069     info_ptr->max_value = ALL_64_BITS;
1070 
1071     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1072     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
1073     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
1074   } else {
1075     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1076     info_ptr->max_value = ALL_64_BITS;
1077 
1078     // gettimeofday is a real time clock so it skips
1079     info_ptr->may_skip_backward = true;
1080     info_ptr->may_skip_forward = true;
1081   }
1082 
1083   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
1084 }
1085 
1086 // Return the real, user, and system times in seconds from an
1087 // arbitrary fixed point in the past.
1088 bool os::getTimesSecs(double* process_real_time,
1089                       double* process_user_time,
1090                       double* process_system_time) {
1091   struct tms ticks;
1092   clock_t real_ticks = times(&ticks);
1093 
1094   if (real_ticks == (clock_t) (-1)) {
1095     return false;
1096   } else {
1097     double ticks_per_second = (double) clock_tics_per_sec;
1098     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1099     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1100     *process_real_time = ((double) real_ticks) / ticks_per_second;
1101 
1102     return true;
1103   }
1104 }
1105 
1106 
1107 char * os::local_time_string(char *buf, size_t buflen) {
1108   struct tm t;
1109   time_t long_time;
1110   time(&long_time);
1111   localtime_r(&long_time, &t);
1112   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1113                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1114                t.tm_hour, t.tm_min, t.tm_sec);
1115   return buf;
1116 }
1117 
1118 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1119   return localtime_r(clock, res);
1120 }
1121 
1122 ////////////////////////////////////////////////////////////////////////////////
1123 // runtime exit support
1124 
1125 // Note: os::shutdown() might be called very early during initialization, or
1126 // called from signal handler. Before adding something to os::shutdown(), make
1127 // sure it is async-safe and can handle partially initialized VM.
1128 void os::shutdown() {
1129 
1130   // allow PerfMemory to attempt cleanup of any persistent resources
1131   perfMemory_exit();
1132 
1133   // needs to remove object in file system
1134   AttachListener::abort();
1135 
1136   // flush buffered output, finish log files
1137   ostream_abort();
1138 
1139   // Check for abort hook
1140   abort_hook_t abort_hook = Arguments::abort_hook();
1141   if (abort_hook != NULL) {
1142     abort_hook();
1143   }
1144 
1145 }
1146 
1147 // Note: os::abort() might be called very early during initialization, or
1148 // called from signal handler. Before adding something to os::abort(), make
1149 // sure it is async-safe and can handle partially initialized VM.
1150 void os::abort(bool dump_core) {
1151   os::shutdown();
1152   if (dump_core) {
1153 #ifndef PRODUCT
1154     fdStream out(defaultStream::output_fd());
1155     out.print_raw("Current thread is ");
1156     char buf[16];
1157     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1158     out.print_raw_cr(buf);
1159     out.print_raw_cr("Dumping core ...");
1160 #endif
1161     ::abort(); // dump core
1162   }
1163 
1164   ::exit(1);
1165 }
1166 
1167 // Die immediately, no exit hook, no abort hook, no cleanup.
1168 void os::die() {
1169   // _exit() on BsdThreads only kills current thread
1170   ::abort();
1171 }
1172 
1173 // unused on bsd for now.
1174 void os::set_error_file(const char *logfile) {}
1175 
1176 
1177 // This method is a copy of JDK's sysGetLastErrorString
1178 // from src/solaris/hpi/src/system_md.c
1179 
1180 size_t os::lasterror(char *buf, size_t len) {
1181 
1182   if (errno == 0)  return 0;
1183 
1184   const char *s = ::strerror(errno);
1185   size_t n = ::strlen(s);
1186   if (n >= len) {
1187     n = len - 1;
1188   }
1189   ::strncpy(buf, s, n);
1190   buf[n] = '\0';
1191   return n;
1192 }
1193 
1194 // Information of current thread in variety of formats
1195 pid_t os::Bsd::gettid() {
1196   int retval = -1;
1197 
1198 #ifdef __APPLE__ //XNU kernel
1199   // despite the fact mach port is actually not a thread id use it
1200   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1201   retval = ::pthread_mach_thread_np(::pthread_self());
1202   guarantee(retval != 0, "just checking");
1203   return retval;
1204 
1205 #elif __FreeBSD__
1206   retval = syscall(SYS_thr_self);
1207 #elif __OpenBSD__
1208   retval = syscall(SYS_getthrid);
1209 #elif __NetBSD__
1210   retval = (pid_t) syscall(SYS__lwp_self);
1211 #endif
1212 
1213   if (retval == -1) {
1214     return getpid();
1215   }
1216 }
1217 
1218 intx os::current_thread_id() {
1219 #ifdef __APPLE__
1220   return (intx)::pthread_mach_thread_np(::pthread_self());
1221 #else
1222   return (intx)::pthread_self();
1223 #endif
1224 }
1225 
1226 int os::current_process_id() {
1227 
1228   // Under the old bsd thread library, bsd gives each thread
1229   // its own process id. Because of this each thread will return
1230   // a different pid if this method were to return the result
1231   // of getpid(2). Bsd provides no api that returns the pid
1232   // of the launcher thread for the vm. This implementation
1233   // returns a unique pid, the pid of the launcher thread
1234   // that starts the vm 'process'.
1235 
1236   // Under the NPTL, getpid() returns the same pid as the
1237   // launcher thread rather than a unique pid per thread.
1238   // Use gettid() if you want the old pre NPTL behaviour.
1239 
1240   // if you are looking for the result of a call to getpid() that
1241   // returns a unique pid for the calling thread, then look at the
1242   // OSThread::thread_id() method in osThread_bsd.hpp file
1243 
1244   return (int)(_initial_pid ? _initial_pid : getpid());
1245 }
1246 
1247 // DLL functions
1248 
1249 #define JNI_LIB_PREFIX "lib"
1250 #ifdef __APPLE__
1251 #define JNI_LIB_SUFFIX ".dylib"
1252 #else
1253 #define JNI_LIB_SUFFIX ".so"
1254 #endif
1255 
1256 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1257 
1258 // This must be hard coded because it's the system's temporary
1259 // directory not the java application's temp directory, ala java.io.tmpdir.
1260 #ifdef __APPLE__
1261 // macosx has a secure per-user temporary directory
1262 char temp_path_storage[PATH_MAX];
1263 const char* os::get_temp_directory() {
1264   static char *temp_path = NULL;
1265   if (temp_path == NULL) {
1266     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1267     if (pathSize == 0 || pathSize > PATH_MAX) {
1268       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1269     }
1270     temp_path = temp_path_storage;
1271   }
1272   return temp_path;
1273 }
1274 #else /* __APPLE__ */
1275 const char* os::get_temp_directory() { return "/tmp"; }
1276 #endif /* __APPLE__ */
1277 
1278 static bool file_exists(const char* filename) {
1279   struct stat statbuf;
1280   if (filename == NULL || strlen(filename) == 0) {
1281     return false;
1282   }
1283   return os::stat(filename, &statbuf) == 0;
1284 }
1285 
1286 bool os::dll_build_name(char* buffer, size_t buflen,
1287                         const char* pname, const char* fname) {
1288   bool retval = false;
1289   // Copied from libhpi
1290   const size_t pnamelen = pname ? strlen(pname) : 0;
1291 
1292   // Return error on buffer overflow.
1293   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1294     return retval;
1295   }
1296 
1297   if (pnamelen == 0) {
1298     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1299     retval = true;
1300   } else if (strchr(pname, *os::path_separator()) != NULL) {
1301     int n;
1302     char** pelements = split_path(pname, &n);
1303     if (pelements == NULL) {
1304       return false;
1305     }
1306     for (int i = 0 ; i < n ; i++) {
1307       // Really shouldn't be NULL, but check can't hurt
1308       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1309         continue; // skip the empty path values
1310       }
1311       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1312           pelements[i], fname);
1313       if (file_exists(buffer)) {
1314         retval = true;
1315         break;
1316       }
1317     }
1318     // release the storage
1319     for (int i = 0 ; i < n ; i++) {
1320       if (pelements[i] != NULL) {
1321         FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
1322       }
1323     }
1324     if (pelements != NULL) {
1325       FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
1326     }
1327   } else {
1328     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1329     retval = true;
1330   }
1331   return retval;
1332 }
1333 
1334 // check if addr is inside libjvm.so
1335 bool os::address_is_in_vm(address addr) {
1336   static address libjvm_base_addr;
1337   Dl_info dlinfo;
1338 
1339   if (libjvm_base_addr == NULL) {
1340     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1341       libjvm_base_addr = (address)dlinfo.dli_fbase;
1342     }
1343     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1344   }
1345 
1346   if (dladdr((void *)addr, &dlinfo) != 0) {
1347     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1348   }
1349 
1350   return false;
1351 }
1352 
1353 
1354 #define MACH_MAXSYMLEN 256
1355 
1356 bool os::dll_address_to_function_name(address addr, char *buf,
1357                                       int buflen, int *offset) {
1358   // buf is not optional, but offset is optional
1359   assert(buf != NULL, "sanity check");
1360 
1361   Dl_info dlinfo;
1362   char localbuf[MACH_MAXSYMLEN];
1363 
1364   if (dladdr((void*)addr, &dlinfo) != 0) {
1365     // see if we have a matching symbol
1366     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1367       if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1368         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1369       }
1370       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1371       return true;
1372     }
1373     // no matching symbol so try for just file info
1374     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1375       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1376                           buf, buflen, offset, dlinfo.dli_fname)) {
1377          return true;
1378       }
1379     }
1380 
1381     // Handle non-dynamic manually:
1382     if (dlinfo.dli_fbase != NULL &&
1383         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1384                         dlinfo.dli_fbase)) {
1385       if (!Decoder::demangle(localbuf, buf, buflen)) {
1386         jio_snprintf(buf, buflen, "%s", localbuf);
1387       }
1388       return true;
1389     }
1390   }
1391   buf[0] = '\0';
1392   if (offset != NULL) *offset = -1;
1393   return false;
1394 }
1395 
1396 // ported from solaris version
1397 bool os::dll_address_to_library_name(address addr, char* buf,
1398                                      int buflen, int* offset) {
1399   // buf is not optional, but offset is optional
1400   assert(buf != NULL, "sanity check");
1401 
1402   Dl_info dlinfo;
1403 
1404   if (dladdr((void*)addr, &dlinfo) != 0) {
1405     if (dlinfo.dli_fname != NULL) {
1406       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1407     }
1408     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1409       *offset = addr - (address)dlinfo.dli_fbase;
1410     }
1411     return true;
1412   }
1413 
1414   buf[0] = '\0';
1415   if (offset) *offset = -1;
1416   return false;
1417 }
1418 
1419 // Loads .dll/.so and
1420 // in case of error it checks if .dll/.so was built for the
1421 // same architecture as Hotspot is running on
1422 
1423 #ifdef __APPLE__
1424 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1425   void * result= ::dlopen(filename, RTLD_LAZY);
1426   if (result != NULL) {
1427     // Successful loading
1428     return result;
1429   }
1430 
1431   // Read system error message into ebuf
1432   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1433   ebuf[ebuflen-1]='\0';
1434 
1435   return NULL;
1436 }
1437 #else
1438 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
1439 {
1440   void * result= ::dlopen(filename, RTLD_LAZY);
1441   if (result != NULL) {
1442     // Successful loading
1443     return result;
1444   }
1445 
1446   Elf32_Ehdr elf_head;
1447 
1448   // Read system error message into ebuf
1449   // It may or may not be overwritten below
1450   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1451   ebuf[ebuflen-1]='\0';
1452   int diag_msg_max_length=ebuflen-strlen(ebuf);
1453   char* diag_msg_buf=ebuf+strlen(ebuf);
1454 
1455   if (diag_msg_max_length==0) {
1456     // No more space in ebuf for additional diagnostics message
1457     return NULL;
1458   }
1459 
1460 
1461   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1462 
1463   if (file_descriptor < 0) {
1464     // Can't open library, report dlerror() message
1465     return NULL;
1466   }
1467 
1468   bool failed_to_read_elf_head=
1469     (sizeof(elf_head)!=
1470         (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
1471 
1472   ::close(file_descriptor);
1473   if (failed_to_read_elf_head) {
1474     // file i/o error - report dlerror() msg
1475     return NULL;
1476   }
1477 
1478   typedef struct {
1479     Elf32_Half  code;         // Actual value as defined in elf.h
1480     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1481     char        elf_class;    // 32 or 64 bit
1482     char        endianess;    // MSB or LSB
1483     char*       name;         // String representation
1484   } arch_t;
1485 
1486   #ifndef EM_486
1487   #define EM_486          6               /* Intel 80486 */
1488   #endif
1489 
1490   #ifndef EM_MIPS_RS3_LE
1491   #define EM_MIPS_RS3_LE  10              /* MIPS */
1492   #endif
1493 
1494   #ifndef EM_PPC64
1495   #define EM_PPC64        21              /* PowerPC64 */
1496   #endif
1497 
1498   #ifndef EM_S390
1499   #define EM_S390         22              /* IBM System/390 */
1500   #endif
1501 
1502   #ifndef EM_IA_64
1503   #define EM_IA_64        50              /* HP/Intel IA-64 */
1504   #endif
1505 
1506   #ifndef EM_X86_64
1507   #define EM_X86_64       62              /* AMD x86-64 */
1508   #endif
1509 
1510   static const arch_t arch_array[]={
1511     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1512     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1513     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1514     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1515     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1516     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1517     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1518     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1519     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1520     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1521     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1522     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1523     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1524     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1525     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1526     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1527   };
1528 
1529   #if  (defined IA32)
1530     static  Elf32_Half running_arch_code=EM_386;
1531   #elif   (defined AMD64)
1532     static  Elf32_Half running_arch_code=EM_X86_64;
1533   #elif  (defined IA64)
1534     static  Elf32_Half running_arch_code=EM_IA_64;
1535   #elif  (defined __sparc) && (defined _LP64)
1536     static  Elf32_Half running_arch_code=EM_SPARCV9;
1537   #elif  (defined __sparc) && (!defined _LP64)
1538     static  Elf32_Half running_arch_code=EM_SPARC;
1539   #elif  (defined __powerpc64__)
1540     static  Elf32_Half running_arch_code=EM_PPC64;
1541   #elif  (defined __powerpc__)
1542     static  Elf32_Half running_arch_code=EM_PPC;
1543   #elif  (defined ARM)
1544     static  Elf32_Half running_arch_code=EM_ARM;
1545   #elif  (defined S390)
1546     static  Elf32_Half running_arch_code=EM_S390;
1547   #elif  (defined ALPHA)
1548     static  Elf32_Half running_arch_code=EM_ALPHA;
1549   #elif  (defined MIPSEL)
1550     static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1551   #elif  (defined PARISC)
1552     static  Elf32_Half running_arch_code=EM_PARISC;
1553   #elif  (defined MIPS)
1554     static  Elf32_Half running_arch_code=EM_MIPS;
1555   #elif  (defined M68K)
1556     static  Elf32_Half running_arch_code=EM_68K;
1557   #else
1558     #error Method os::dll_load requires that one of following is defined:\
1559          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1560   #endif
1561 
1562   // Identify compatability class for VM's architecture and library's architecture
1563   // Obtain string descriptions for architectures
1564 
1565   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1566   int running_arch_index=-1;
1567 
1568   for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
1569     if (running_arch_code == arch_array[i].code) {
1570       running_arch_index    = i;
1571     }
1572     if (lib_arch.code == arch_array[i].code) {
1573       lib_arch.compat_class = arch_array[i].compat_class;
1574       lib_arch.name         = arch_array[i].name;
1575     }
1576   }
1577 
1578   assert(running_arch_index != -1,
1579     "Didn't find running architecture code (running_arch_code) in arch_array");
1580   if (running_arch_index == -1) {
1581     // Even though running architecture detection failed
1582     // we may still continue with reporting dlerror() message
1583     return NULL;
1584   }
1585 
1586   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1587     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1588     return NULL;
1589   }
1590 
1591 #ifndef S390
1592   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1593     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1594     return NULL;
1595   }
1596 #endif // !S390
1597 
1598   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1599     if ( lib_arch.name!=NULL ) {
1600       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1601         " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1602         lib_arch.name, arch_array[running_arch_index].name);
1603     } else {
1604       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1605       " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1606         lib_arch.code,
1607         arch_array[running_arch_index].name);
1608     }
1609   }
1610 
1611   return NULL;
1612 }
1613 #endif /* !__APPLE__ */
1614 
1615 void* os::get_default_process_handle() {
1616 #ifdef __APPLE__
1617   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1618   // to avoid finding unexpected symbols on second (or later)
1619   // loads of a library.
1620   return (void*)::dlopen(NULL, RTLD_FIRST);
1621 #else
1622   return (void*)::dlopen(NULL, RTLD_LAZY);
1623 #endif
1624 }
1625 
1626 // XXX: Do we need a lock around this as per Linux?
1627 void* os::dll_lookup(void* handle, const char* name) {
1628   return dlsym(handle, name);
1629 }
1630 
1631 
1632 static bool _print_ascii_file(const char* filename, outputStream* st) {
1633   int fd = ::open(filename, O_RDONLY);
1634   if (fd == -1) {
1635      return false;
1636   }
1637 
1638   char buf[32];
1639   int bytes;
1640   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1641     st->print_raw(buf, bytes);
1642   }
1643 
1644   ::close(fd);
1645 
1646   return true;
1647 }
1648 
1649 void os::print_dll_info(outputStream *st) {
1650   st->print_cr("Dynamic libraries:");
1651 #ifdef RTLD_DI_LINKMAP
1652   Dl_info dli;
1653   void *handle;
1654   Link_map *map;
1655   Link_map *p;
1656 
1657   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1658       dli.dli_fname == NULL) {
1659     st->print_cr("Error: Cannot print dynamic libraries.");
1660     return;
1661   }
1662   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1663   if (handle == NULL) {
1664     st->print_cr("Error: Cannot print dynamic libraries.");
1665     return;
1666   }
1667   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1668   if (map == NULL) {
1669     st->print_cr("Error: Cannot print dynamic libraries.");
1670     return;
1671   }
1672 
1673   while (map->l_prev != NULL)
1674     map = map->l_prev;
1675 
1676   while (map != NULL) {
1677     st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
1678     map = map->l_next;
1679   }
1680 
1681   dlclose(handle);
1682 #elif defined(__APPLE__)
1683   uint32_t count;
1684   uint32_t i;
1685 
1686   count = _dyld_image_count();
1687   for (i = 1; i < count; i++) {
1688     const char *name = _dyld_get_image_name(i);
1689     intptr_t slide = _dyld_get_image_vmaddr_slide(i);
1690     st->print_cr(PTR_FORMAT " \t%s", slide, name);
1691   }
1692 #else
1693   st->print_cr("Error: Cannot print dynamic libraries.");
1694 #endif
1695 }
1696 
1697 void os::print_os_info_brief(outputStream* st) {
1698   st->print("Bsd");
1699 
1700   os::Posix::print_uname_info(st);
1701 }
1702 
1703 void os::print_os_info(outputStream* st) {
1704   st->print("OS:");
1705   st->print("Bsd");
1706 
1707   os::Posix::print_uname_info(st);
1708 
1709   os::Posix::print_rlimit_info(st);
1710 
1711   os::Posix::print_load_average(st);
1712 }
1713 
1714 void os::pd_print_cpu_info(outputStream* st) {
1715   // Nothing to do for now.
1716 }
1717 
1718 void os::print_memory_info(outputStream* st) {
1719 
1720   st->print("Memory:");
1721   st->print(" %dk page", os::vm_page_size()>>10);
1722 
1723   st->print(", physical " UINT64_FORMAT "k",
1724             os::physical_memory() >> 10);
1725   st->print("(" UINT64_FORMAT "k free)",
1726             os::available_memory() >> 10);
1727   st->cr();
1728 
1729   // meminfo
1730   st->print("\n/proc/meminfo:\n");
1731   _print_ascii_file("/proc/meminfo", st);
1732   st->cr();
1733 }
1734 
1735 void os::print_siginfo(outputStream* st, void* siginfo) {
1736   const siginfo_t* si = (const siginfo_t*)siginfo;
1737 
1738   os::Posix::print_siginfo_brief(st, si);
1739 
1740   if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1741       UseSharedSpaces) {
1742     FileMapInfo* mapinfo = FileMapInfo::current_info();
1743     if (mapinfo->is_in_shared_space(si->si_addr)) {
1744       st->print("\n\nError accessing class data sharing archive."   \
1745                 " Mapped file inaccessible during execution, "      \
1746                 " possible disk/network problem.");
1747     }
1748   }
1749   st->cr();
1750 }
1751 
1752 
1753 static void print_signal_handler(outputStream* st, int sig,
1754                                  char* buf, size_t buflen);
1755 
1756 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1757   st->print_cr("Signal Handlers:");
1758   print_signal_handler(st, SIGSEGV, buf, buflen);
1759   print_signal_handler(st, SIGBUS , buf, buflen);
1760   print_signal_handler(st, SIGFPE , buf, buflen);
1761   print_signal_handler(st, SIGPIPE, buf, buflen);
1762   print_signal_handler(st, SIGXFSZ, buf, buflen);
1763   print_signal_handler(st, SIGILL , buf, buflen);
1764   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1765   print_signal_handler(st, SR_signum, buf, buflen);
1766   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1767   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1768   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1769   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1770 }
1771 
1772 static char saved_jvm_path[MAXPATHLEN] = {0};
1773 
1774 // Find the full path to the current module, libjvm
1775 void os::jvm_path(char *buf, jint buflen) {
1776   // Error checking.
1777   if (buflen < MAXPATHLEN) {
1778     assert(false, "must use a large-enough buffer");
1779     buf[0] = '\0';
1780     return;
1781   }
1782   // Lazy resolve the path to current module.
1783   if (saved_jvm_path[0] != 0) {
1784     strcpy(buf, saved_jvm_path);
1785     return;
1786   }
1787 
1788   char dli_fname[MAXPATHLEN];
1789   bool ret = dll_address_to_library_name(
1790                 CAST_FROM_FN_PTR(address, os::jvm_path),
1791                 dli_fname, sizeof(dli_fname), NULL);
1792   assert(ret, "cannot locate libjvm");
1793   char *rp = NULL;
1794   if (ret && dli_fname[0] != '\0') {
1795     rp = realpath(dli_fname, buf);
1796   }
1797   if (rp == NULL)
1798     return;
1799 
1800   if (Arguments::sun_java_launcher_is_altjvm()) {
1801     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1802     // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1803     // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1804     // appears at the right place in the string, then assume we are
1805     // installed in a JDK and we're done. Otherwise, check for a
1806     // JAVA_HOME environment variable and construct a path to the JVM
1807     // being overridden.
1808 
1809     const char *p = buf + strlen(buf) - 1;
1810     for (int count = 0; p > buf && count < 5; ++count) {
1811       for (--p; p > buf && *p != '/'; --p)
1812         /* empty */ ;
1813     }
1814 
1815     if (strncmp(p, "/jre/lib/", 9) != 0) {
1816       // Look for JAVA_HOME in the environment.
1817       char* java_home_var = ::getenv("JAVA_HOME");
1818       if (java_home_var != NULL && java_home_var[0] != 0) {
1819         char* jrelib_p;
1820         int len;
1821 
1822         // Check the current module name "libjvm"
1823         p = strrchr(buf, '/');
1824         assert(strstr(p, "/libjvm") == p, "invalid library name");
1825 
1826         rp = realpath(java_home_var, buf);
1827         if (rp == NULL)
1828           return;
1829 
1830         // determine if this is a legacy image or modules image
1831         // modules image doesn't have "jre" subdirectory
1832         len = strlen(buf);
1833         jrelib_p = buf + len;
1834 
1835         // Add the appropriate library subdir
1836         snprintf(jrelib_p, buflen-len, "/jre/lib");
1837         if (0 != access(buf, F_OK)) {
1838           snprintf(jrelib_p, buflen-len, "/lib");
1839         }
1840 
1841         // Add the appropriate client or server subdir
1842         len = strlen(buf);
1843         jrelib_p = buf + len;
1844         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1845         if (0 != access(buf, F_OK)) {
1846           snprintf(jrelib_p, buflen-len, "%s", "");
1847         }
1848 
1849         // If the path exists within JAVA_HOME, add the JVM library name
1850         // to complete the path to JVM being overridden.  Otherwise fallback
1851         // to the path to the current library.
1852         if (0 == access(buf, F_OK)) {
1853           // Use current module name "libjvm"
1854           len = strlen(buf);
1855           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1856         } else {
1857           // Fall back to path of current library
1858           rp = realpath(dli_fname, buf);
1859           if (rp == NULL)
1860             return;
1861         }
1862       }
1863     }
1864   }
1865 
1866   strcpy(saved_jvm_path, buf);
1867 }
1868 
1869 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1870   // no prefix required, not even "_"
1871 }
1872 
1873 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1874   // no suffix required
1875 }
1876 
1877 ////////////////////////////////////////////////////////////////////////////////
1878 // sun.misc.Signal support
1879 
1880 static volatile jint sigint_count = 0;
1881 
1882 static void
1883 UserHandler(int sig, void *siginfo, void *context) {
1884   // 4511530 - sem_post is serialized and handled by the manager thread. When
1885   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1886   // don't want to flood the manager thread with sem_post requests.
1887   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
1888       return;
1889 
1890   // Ctrl-C is pressed during error reporting, likely because the error
1891   // handler fails to abort. Let VM die immediately.
1892   if (sig == SIGINT && is_error_reported()) {
1893      os::die();
1894   }
1895 
1896   os::signal_notify(sig);
1897 }
1898 
1899 void* os::user_handler() {
1900   return CAST_FROM_FN_PTR(void*, UserHandler);
1901 }
1902 
1903 extern "C" {
1904   typedef void (*sa_handler_t)(int);
1905   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1906 }
1907 
1908 void* os::signal(int signal_number, void* handler) {
1909   struct sigaction sigAct, oldSigAct;
1910 
1911   sigfillset(&(sigAct.sa_mask));
1912   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1913   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1914 
1915   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1916     // -1 means registration failed
1917     return (void *)-1;
1918   }
1919 
1920   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1921 }
1922 
1923 void os::signal_raise(int signal_number) {
1924   ::raise(signal_number);
1925 }
1926 
1927 /*
1928  * The following code is moved from os.cpp for making this
1929  * code platform specific, which it is by its very nature.
1930  */
1931 
1932 // Will be modified when max signal is changed to be dynamic
1933 int os::sigexitnum_pd() {
1934   return NSIG;
1935 }
1936 
1937 // a counter for each possible signal value
1938 static volatile jint pending_signals[NSIG+1] = { 0 };
1939 
1940 // Bsd(POSIX) specific hand shaking semaphore.
1941 #ifdef __APPLE__
1942 typedef semaphore_t os_semaphore_t;
1943 #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1944 #define SEM_WAIT(sem)           semaphore_wait(sem)
1945 #define SEM_POST(sem)           semaphore_signal(sem)
1946 #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
1947 #else
1948 typedef sem_t os_semaphore_t;
1949 #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
1950 #define SEM_WAIT(sem)           sem_wait(&sem)
1951 #define SEM_POST(sem)           sem_post(&sem)
1952 #define SEM_DESTROY(sem)        sem_destroy(&sem)
1953 #endif
1954 
1955 class Semaphore : public StackObj {
1956   public:
1957     Semaphore();
1958     ~Semaphore();
1959     void signal();
1960     void wait();
1961     bool trywait();
1962     bool timedwait(unsigned int sec, int nsec);
1963   private:
1964     jlong currenttime() const;
1965     os_semaphore_t _semaphore;
1966 };
1967 
1968 Semaphore::Semaphore() : _semaphore(0) {
1969   SEM_INIT(_semaphore, 0);
1970 }
1971 
1972 Semaphore::~Semaphore() {
1973   SEM_DESTROY(_semaphore);
1974 }
1975 
1976 void Semaphore::signal() {
1977   SEM_POST(_semaphore);
1978 }
1979 
1980 void Semaphore::wait() {
1981   SEM_WAIT(_semaphore);
1982 }
1983 
1984 jlong Semaphore::currenttime() const {
1985     struct timeval tv;
1986     gettimeofday(&tv, NULL);
1987     return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
1988 }
1989 
1990 #ifdef __APPLE__
1991 bool Semaphore::trywait() {
1992   return timedwait(0, 0);
1993 }
1994 
1995 bool Semaphore::timedwait(unsigned int sec, int nsec) {
1996   kern_return_t kr = KERN_ABORTED;
1997   mach_timespec_t waitspec;
1998   waitspec.tv_sec = sec;
1999   waitspec.tv_nsec = nsec;
2000 
2001   jlong starttime = currenttime();
2002 
2003   kr = semaphore_timedwait(_semaphore, waitspec);
2004   while (kr == KERN_ABORTED) {
2005     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
2006 
2007     jlong current = currenttime();
2008     jlong passedtime = current - starttime;
2009 
2010     if (passedtime >= totalwait) {
2011       waitspec.tv_sec = 0;
2012       waitspec.tv_nsec = 0;
2013     } else {
2014       jlong waittime = totalwait - (current - starttime);
2015       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
2016       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
2017     }
2018 
2019     kr = semaphore_timedwait(_semaphore, waitspec);
2020   }
2021 
2022   return kr == KERN_SUCCESS;
2023 }
2024 
2025 #else
2026 
2027 bool Semaphore::trywait() {
2028   return sem_trywait(&_semaphore) == 0;
2029 }
2030 
2031 bool Semaphore::timedwait(unsigned int sec, int nsec) {
2032   struct timespec ts;
2033   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2034 
2035   while (1) {
2036     int result = sem_timedwait(&_semaphore, &ts);
2037     if (result == 0) {
2038       return true;
2039     } else if (errno == EINTR) {
2040       continue;
2041     } else if (errno == ETIMEDOUT) {
2042       return false;
2043     } else {
2044       return false;
2045     }
2046   }
2047 }
2048 
2049 #endif // __APPLE__
2050 
2051 static os_semaphore_t sig_sem;
2052 static Semaphore sr_semaphore;
2053 
2054 void os::signal_init_pd() {
2055   // Initialize signal structures
2056   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2057 
2058   // Initialize signal semaphore
2059   ::SEM_INIT(sig_sem, 0);
2060 }
2061 
2062 void os::signal_notify(int sig) {
2063   Atomic::inc(&pending_signals[sig]);
2064   ::SEM_POST(sig_sem);
2065 }
2066 
2067 static int check_pending_signals(bool wait) {
2068   Atomic::store(0, &sigint_count);
2069   for (;;) {
2070     for (int i = 0; i < NSIG + 1; i++) {
2071       jint n = pending_signals[i];
2072       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2073         return i;
2074       }
2075     }
2076     if (!wait) {
2077       return -1;
2078     }
2079     JavaThread *thread = JavaThread::current();
2080     ThreadBlockInVM tbivm(thread);
2081 
2082     bool threadIsSuspended;
2083     do {
2084       thread->set_suspend_equivalent();
2085       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2086       ::SEM_WAIT(sig_sem);
2087 
2088       // were we externally suspended while we were waiting?
2089       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2090       if (threadIsSuspended) {
2091         //
2092         // The semaphore has been incremented, but while we were waiting
2093         // another thread suspended us. We don't want to continue running
2094         // while suspended because that would surprise the thread that
2095         // suspended us.
2096         //
2097         ::SEM_POST(sig_sem);
2098 
2099         thread->java_suspend_self();
2100       }
2101     } while (threadIsSuspended);
2102   }
2103 }
2104 
2105 int os::signal_lookup() {
2106   return check_pending_signals(false);
2107 }
2108 
2109 int os::signal_wait() {
2110   return check_pending_signals(true);
2111 }
2112 
2113 ////////////////////////////////////////////////////////////////////////////////
2114 // Virtual Memory
2115 
2116 int os::vm_page_size() {
2117   // Seems redundant as all get out
2118   assert(os::Bsd::page_size() != -1, "must call os::init");
2119   return os::Bsd::page_size();
2120 }
2121 
2122 // Solaris allocates memory by pages.
2123 int os::vm_allocation_granularity() {
2124   assert(os::Bsd::page_size() != -1, "must call os::init");
2125   return os::Bsd::page_size();
2126 }
2127 
2128 // Rationale behind this function:
2129 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2130 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2131 //  samples for JITted code. Here we create private executable mapping over the code cache
2132 //  and then we can use standard (well, almost, as mapping can change) way to provide
2133 //  info for the reporting script by storing timestamp and location of symbol
2134 void bsd_wrap_code(char* base, size_t size) {
2135   static volatile jint cnt = 0;
2136 
2137   if (!UseOprofile) {
2138     return;
2139   }
2140 
2141   char buf[PATH_MAX + 1];
2142   int num = Atomic::add(1, &cnt);
2143 
2144   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2145            os::get_temp_directory(), os::current_process_id(), num);
2146   unlink(buf);
2147 
2148   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2149 
2150   if (fd != -1) {
2151     off_t rv = ::lseek(fd, size-2, SEEK_SET);
2152     if (rv != (off_t)-1) {
2153       if (::write(fd, "", 1) == 1) {
2154         mmap(base, size,
2155              PROT_READ|PROT_WRITE|PROT_EXEC,
2156              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2157       }
2158     }
2159     ::close(fd);
2160     unlink(buf);
2161   }
2162 }
2163 
2164 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2165                                     int err) {
2166   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2167           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2168           strerror(err), err);
2169 }
2170 
2171 // NOTE: Bsd kernel does not really reserve the pages for us.
2172 //       All it does is to check if there are enough free pages
2173 //       left at the time of mmap(). This could be a potential
2174 //       problem.
2175 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2176   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2177 #ifdef __OpenBSD__
2178   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2179   if (::mprotect(addr, size, prot) == 0) {
2180     return true;
2181   }
2182 #else
2183   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2184                                    MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2185   if (res != (uintptr_t) MAP_FAILED) {
2186     return true;
2187   }
2188 #endif
2189 
2190   // Warn about any commit errors we see in non-product builds just
2191   // in case mmap() doesn't work as described on the man page.
2192   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2193 
2194   return false;
2195 }
2196 
2197 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2198                        bool exec) {
2199   // alignment_hint is ignored on this OS
2200   return pd_commit_memory(addr, size, exec);
2201 }
2202 
2203 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2204                                   const char* mesg) {
2205   assert(mesg != NULL, "mesg must be specified");
2206   if (!pd_commit_memory(addr, size, exec)) {
2207     // add extra info in product mode for vm_exit_out_of_memory():
2208     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2209     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
2210   }
2211 }
2212 
2213 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2214                                   size_t alignment_hint, bool exec,
2215                                   const char* mesg) {
2216   // alignment_hint is ignored on this OS
2217   pd_commit_memory_or_exit(addr, size, exec, mesg);
2218 }
2219 
2220 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2221 }
2222 
2223 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2224   ::madvise(addr, bytes, MADV_DONTNEED);
2225 }
2226 
2227 void os::numa_make_global(char *addr, size_t bytes) {
2228 }
2229 
2230 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2231 }
2232 
2233 bool os::numa_topology_changed()   { return false; }
2234 
2235 size_t os::numa_get_groups_num() {
2236   return 1;
2237 }
2238 
2239 int os::numa_get_group_id() {
2240   return 0;
2241 }
2242 
2243 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2244   if (size > 0) {
2245     ids[0] = 0;
2246     return 1;
2247   }
2248   return 0;
2249 }
2250 
2251 bool os::get_page_info(char *start, page_info* info) {
2252   return false;
2253 }
2254 
2255 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2256   return end;
2257 }
2258 
2259 
2260 bool os::pd_uncommit_memory(char* addr, size_t size) {
2261 #ifdef __OpenBSD__
2262   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2263   return ::mprotect(addr, size, PROT_NONE) == 0;
2264 #else
2265   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2266                 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2267   return res  != (uintptr_t) MAP_FAILED;
2268 #endif
2269 }
2270 
2271 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2272   return os::commit_memory(addr, size, !ExecMem);
2273 }
2274 
2275 // If this is a growable mapping, remove the guard pages entirely by
2276 // munmap()ping them.  If not, just call uncommit_memory().
2277 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2278   return os::uncommit_memory(addr, size);
2279 }
2280 
2281 static address _highest_vm_reserved_address = NULL;
2282 
2283 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2284 // at 'requested_addr'. If there are existing memory mappings at the same
2285 // location, however, they will be overwritten. If 'fixed' is false,
2286 // 'requested_addr' is only treated as a hint, the return value may or
2287 // may not start from the requested address. Unlike Bsd mmap(), this
2288 // function returns NULL to indicate failure.
2289 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2290   char * addr;
2291   int flags;
2292 
2293   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2294   if (fixed) {
2295     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2296     flags |= MAP_FIXED;
2297   }
2298 
2299   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2300   // touch an uncommitted page. Otherwise, the read/write might
2301   // succeed if we have enough swap space to back the physical page.
2302   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2303                        flags, -1, 0);
2304 
2305   if (addr != MAP_FAILED) {
2306     // anon_mmap() should only get called during VM initialization,
2307     // don't need lock (actually we can skip locking even it can be called
2308     // from multiple threads, because _highest_vm_reserved_address is just a
2309     // hint about the upper limit of non-stack memory regions.)
2310     if ((address)addr + bytes > _highest_vm_reserved_address) {
2311       _highest_vm_reserved_address = (address)addr + bytes;
2312     }
2313   }
2314 
2315   return addr == MAP_FAILED ? NULL : addr;
2316 }
2317 
2318 // Don't update _highest_vm_reserved_address, because there might be memory
2319 // regions above addr + size. If so, releasing a memory region only creates
2320 // a hole in the address space, it doesn't help prevent heap-stack collision.
2321 //
2322 static int anon_munmap(char * addr, size_t size) {
2323   return ::munmap(addr, size) == 0;
2324 }
2325 
2326 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2327                          size_t alignment_hint) {
2328   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2329 }
2330 
2331 bool os::pd_release_memory(char* addr, size_t size) {
2332   return anon_munmap(addr, size);
2333 }
2334 
2335 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2336   // Bsd wants the mprotect address argument to be page aligned.
2337   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2338 
2339   // According to SUSv3, mprotect() should only be used with mappings
2340   // established by mmap(), and mmap() always maps whole pages. Unaligned
2341   // 'addr' likely indicates problem in the VM (e.g. trying to change
2342   // protection of malloc'ed or statically allocated memory). Check the
2343   // caller if you hit this assert.
2344   assert(addr == bottom, "sanity check");
2345 
2346   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2347   return ::mprotect(bottom, size, prot) == 0;
2348 }
2349 
2350 // Set protections specified
2351 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2352                         bool is_committed) {
2353   unsigned int p = 0;
2354   switch (prot) {
2355   case MEM_PROT_NONE: p = PROT_NONE; break;
2356   case MEM_PROT_READ: p = PROT_READ; break;
2357   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2358   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2359   default:
2360     ShouldNotReachHere();
2361   }
2362   // is_committed is unused.
2363   return bsd_mprotect(addr, bytes, p);
2364 }
2365 
2366 bool os::guard_memory(char* addr, size_t size) {
2367   return bsd_mprotect(addr, size, PROT_NONE);
2368 }
2369 
2370 bool os::unguard_memory(char* addr, size_t size) {
2371   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2372 }
2373 
2374 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2375   return false;
2376 }
2377 
2378 // Large page support
2379 
2380 static size_t _large_page_size = 0;
2381 
2382 void os::large_page_init() {
2383 }
2384 
2385 
2386 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2387   fatal("This code is not used or maintained.");
2388 
2389   // "exec" is passed in but not used.  Creating the shared image for
2390   // the code cache doesn't have an SHM_X executable permission to check.
2391   assert(UseLargePages && UseSHM, "only for SHM large pages");
2392 
2393   key_t key = IPC_PRIVATE;
2394   char *addr;
2395 
2396   bool warn_on_failure = UseLargePages &&
2397                         (!FLAG_IS_DEFAULT(UseLargePages) ||
2398                          !FLAG_IS_DEFAULT(LargePageSizeInBytes)
2399                         );
2400   char msg[128];
2401 
2402   // Create a large shared memory region to attach to based on size.
2403   // Currently, size is the total size of the heap
2404   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2405   if (shmid == -1) {
2406      // Possible reasons for shmget failure:
2407      // 1. shmmax is too small for Java heap.
2408      //    > check shmmax value: cat /proc/sys/kernel/shmmax
2409      //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2410      // 2. not enough large page memory.
2411      //    > check available large pages: cat /proc/meminfo
2412      //    > increase amount of large pages:
2413      //          echo new_value > /proc/sys/vm/nr_hugepages
2414      //      Note 1: different Bsd may use different name for this property,
2415      //            e.g. on Redhat AS-3 it is "hugetlb_pool".
2416      //      Note 2: it's possible there's enough physical memory available but
2417      //            they are so fragmented after a long run that they can't
2418      //            coalesce into large pages. Try to reserve large pages when
2419      //            the system is still "fresh".
2420      if (warn_on_failure) {
2421        jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
2422        warning(msg);
2423      }
2424      return NULL;
2425   }
2426 
2427   // attach to the region
2428   addr = (char*)shmat(shmid, req_addr, 0);
2429   int err = errno;
2430 
2431   // Remove shmid. If shmat() is successful, the actual shared memory segment
2432   // will be deleted when it's detached by shmdt() or when the process
2433   // terminates. If shmat() is not successful this will remove the shared
2434   // segment immediately.
2435   shmctl(shmid, IPC_RMID, NULL);
2436 
2437   if ((intptr_t)addr == -1) {
2438      if (warn_on_failure) {
2439        jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
2440        warning(msg);
2441      }
2442      return NULL;
2443   }
2444 
2445   // The memory is committed
2446   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, mtNone, CALLER_PC);
2447 
2448   return addr;
2449 }
2450 
2451 bool os::release_memory_special(char* base, size_t bytes) {
2452   MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2453   // detaching the SHM segment will also delete it, see reserve_memory_special()
2454   int rslt = shmdt(base);
2455   if (rslt == 0) {
2456     tkr.record((address)base, bytes);
2457     return true;
2458   } else {
2459     tkr.discard();
2460     return false;
2461   }
2462 
2463 }
2464 
2465 size_t os::large_page_size() {
2466   return _large_page_size;
2467 }
2468 
2469 // HugeTLBFS allows application to commit large page memory on demand;
2470 // with SysV SHM the entire memory region must be allocated as shared
2471 // memory.
2472 bool os::can_commit_large_page_memory() {
2473   return UseHugeTLBFS;
2474 }
2475 
2476 bool os::can_execute_large_page_memory() {
2477   return UseHugeTLBFS;
2478 }
2479 
2480 // Reserve memory at an arbitrary address, only if that area is
2481 // available (and not reserved for something else).
2482 
2483 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2484   const int max_tries = 10;
2485   char* base[max_tries];
2486   size_t size[max_tries];
2487   const size_t gap = 0x000000;
2488 
2489   // Assert only that the size is a multiple of the page size, since
2490   // that's all that mmap requires, and since that's all we really know
2491   // about at this low abstraction level.  If we need higher alignment,
2492   // we can either pass an alignment to this method or verify alignment
2493   // in one of the methods further up the call chain.  See bug 5044738.
2494   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2495 
2496   // Repeatedly allocate blocks until the block is allocated at the
2497   // right spot. Give up after max_tries. Note that reserve_memory() will
2498   // automatically update _highest_vm_reserved_address if the call is
2499   // successful. The variable tracks the highest memory address every reserved
2500   // by JVM. It is used to detect heap-stack collision if running with
2501   // fixed-stack BsdThreads. Because here we may attempt to reserve more
2502   // space than needed, it could confuse the collision detecting code. To
2503   // solve the problem, save current _highest_vm_reserved_address and
2504   // calculate the correct value before return.
2505   address old_highest = _highest_vm_reserved_address;
2506 
2507   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2508   // if kernel honors the hint then we can return immediately.
2509   char * addr = anon_mmap(requested_addr, bytes, false);
2510   if (addr == requested_addr) {
2511      return requested_addr;
2512   }
2513 
2514   if (addr != NULL) {
2515      // mmap() is successful but it fails to reserve at the requested address
2516      anon_munmap(addr, bytes);
2517   }
2518 
2519   int i;
2520   for (i = 0; i < max_tries; ++i) {
2521     base[i] = reserve_memory(bytes);
2522 
2523     if (base[i] != NULL) {
2524       // Is this the block we wanted?
2525       if (base[i] == requested_addr) {
2526         size[i] = bytes;
2527         break;
2528       }
2529 
2530       // Does this overlap the block we wanted? Give back the overlapped
2531       // parts and try again.
2532 
2533       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2534       if (top_overlap >= 0 && top_overlap < bytes) {
2535         unmap_memory(base[i], top_overlap);
2536         base[i] += top_overlap;
2537         size[i] = bytes - top_overlap;
2538       } else {
2539         size_t bottom_overlap = base[i] + bytes - requested_addr;
2540         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2541           unmap_memory(requested_addr, bottom_overlap);
2542           size[i] = bytes - bottom_overlap;
2543         } else {
2544           size[i] = bytes;
2545         }
2546       }
2547     }
2548   }
2549 
2550   // Give back the unused reserved pieces.
2551 
2552   for (int j = 0; j < i; ++j) {
2553     if (base[j] != NULL) {
2554       unmap_memory(base[j], size[j]);
2555     }
2556   }
2557 
2558   if (i < max_tries) {
2559     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2560     return requested_addr;
2561   } else {
2562     _highest_vm_reserved_address = old_highest;
2563     return NULL;
2564   }
2565 }
2566 
2567 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2568   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2569 }
2570 
2571 void os::naked_short_sleep(jlong ms) {
2572   struct timespec req;
2573 
2574   assert(ms < 1000, "Un-interruptable sleep, short time use only");
2575   req.tv_sec = 0;
2576   if (ms > 0) {
2577     req.tv_nsec = (ms % 1000) * 1000000;
2578   }
2579   else {
2580     req.tv_nsec = 1;
2581   }
2582 
2583   nanosleep(&req, NULL);
2584 
2585   return;
2586 }
2587 
2588 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2589 void os::infinite_sleep() {
2590   while (true) {    // sleep forever ...
2591     ::sleep(100);   // ... 100 seconds at a time
2592   }
2593 }
2594 
2595 // Used to convert frequent JVM_Yield() to nops
2596 bool os::dont_yield() {
2597   return DontYieldALot;
2598 }
2599 
2600 void os::yield() {
2601   sched_yield();
2602 }
2603 
2604 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
2605 
2606 void os::yield_all() {
2607   // Yields to all threads, including threads with lower priorities
2608   // Threads on Bsd are all with same priority. The Solaris style
2609   // os::yield_all() with nanosleep(1ms) is not necessary.
2610   sched_yield();
2611 }
2612 
2613 ////////////////////////////////////////////////////////////////////////////////
2614 // thread priority support
2615 
2616 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2617 // only supports dynamic priority, static priority must be zero. For real-time
2618 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2619 // However, for large multi-threaded applications, SCHED_RR is not only slower
2620 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2621 // of 5 runs - Sep 2005).
2622 //
2623 // The following code actually changes the niceness of kernel-thread/LWP. It
2624 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2625 // not the entire user process, and user level threads are 1:1 mapped to kernel
2626 // threads. It has always been the case, but could change in the future. For
2627 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2628 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2629 
2630 #if !defined(__APPLE__)
2631 int os::java_to_os_priority[CriticalPriority + 1] = {
2632   19,              // 0 Entry should never be used
2633 
2634    0,              // 1 MinPriority
2635    3,              // 2
2636    6,              // 3
2637 
2638   10,              // 4
2639   15,              // 5 NormPriority
2640   18,              // 6
2641 
2642   21,              // 7
2643   25,              // 8
2644   28,              // 9 NearMaxPriority
2645 
2646   31,              // 10 MaxPriority
2647 
2648   31               // 11 CriticalPriority
2649 };
2650 #else
2651 /* Using Mach high-level priority assignments */
2652 int os::java_to_os_priority[CriticalPriority + 1] = {
2653    0,              // 0 Entry should never be used (MINPRI_USER)
2654 
2655   27,              // 1 MinPriority
2656   28,              // 2
2657   29,              // 3
2658 
2659   30,              // 4
2660   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2661   32,              // 6
2662 
2663   33,              // 7
2664   34,              // 8
2665   35,              // 9 NearMaxPriority
2666 
2667   36,              // 10 MaxPriority
2668 
2669   36               // 11 CriticalPriority
2670 };
2671 #endif
2672 
2673 static int prio_init() {
2674   if (ThreadPriorityPolicy == 1) {
2675     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2676     // if effective uid is not root. Perhaps, a more elegant way of doing
2677     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2678     if (geteuid() != 0) {
2679       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2680         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2681       }
2682       ThreadPriorityPolicy = 0;
2683     }
2684   }
2685   if (UseCriticalJavaThreadPriority) {
2686     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2687   }
2688   return 0;
2689 }
2690 
2691 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2692   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
2693 
2694 #ifdef __OpenBSD__
2695   // OpenBSD pthread_setprio starves low priority threads
2696   return OS_OK;
2697 #elif defined(__FreeBSD__)
2698   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2699 #elif defined(__APPLE__) || defined(__NetBSD__)
2700   struct sched_param sp;
2701   int policy;
2702   pthread_t self = pthread_self();
2703 
2704   if (pthread_getschedparam(self, &policy, &sp) != 0)
2705     return OS_ERR;
2706 
2707   sp.sched_priority = newpri;
2708   if (pthread_setschedparam(self, policy, &sp) != 0)
2709     return OS_ERR;
2710 
2711   return OS_OK;
2712 #else
2713   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2714   return (ret == 0) ? OS_OK : OS_ERR;
2715 #endif
2716 }
2717 
2718 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2719   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
2720     *priority_ptr = java_to_os_priority[NormPriority];
2721     return OS_OK;
2722   }
2723 
2724   errno = 0;
2725 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2726   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2727 #elif defined(__APPLE__) || defined(__NetBSD__)
2728   int policy;
2729   struct sched_param sp;
2730 
2731   pthread_getschedparam(pthread_self(), &policy, &sp);
2732   *priority_ptr = sp.sched_priority;
2733 #else
2734   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2735 #endif
2736   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2737 }
2738 
2739 // Hint to the underlying OS that a task switch would not be good.
2740 // Void return because it's a hint and can fail.
2741 void os::hint_no_preempt() {}
2742 
2743 ////////////////////////////////////////////////////////////////////////////////
2744 // suspend/resume support
2745 
2746 //  the low-level signal-based suspend/resume support is a remnant from the
2747 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2748 //  within hotspot. Now there is a single use-case for this:
2749 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
2750 //      that runs in the watcher thread.
2751 //  The remaining code is greatly simplified from the more general suspension
2752 //  code that used to be used.
2753 //
2754 //  The protocol is quite simple:
2755 //  - suspend:
2756 //      - sends a signal to the target thread
2757 //      - polls the suspend state of the osthread using a yield loop
2758 //      - target thread signal handler (SR_handler) sets suspend state
2759 //        and blocks in sigsuspend until continued
2760 //  - resume:
2761 //      - sets target osthread state to continue
2762 //      - sends signal to end the sigsuspend loop in the SR_handler
2763 //
2764 //  Note that the SR_lock plays no role in this suspend/resume protocol.
2765 //
2766 
2767 static void resume_clear_context(OSThread *osthread) {
2768   osthread->set_ucontext(NULL);
2769   osthread->set_siginfo(NULL);
2770 }
2771 
2772 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2773   osthread->set_ucontext(context);
2774   osthread->set_siginfo(siginfo);
2775 }
2776 
2777 //
2778 // Handler function invoked when a thread's execution is suspended or
2779 // resumed. We have to be careful that only async-safe functions are
2780 // called here (Note: most pthread functions are not async safe and
2781 // should be avoided.)
2782 //
2783 // Note: sigwait() is a more natural fit than sigsuspend() from an
2784 // interface point of view, but sigwait() prevents the signal hander
2785 // from being run. libpthread would get very confused by not having
2786 // its signal handlers run and prevents sigwait()'s use with the
2787 // mutex granting granting signal.
2788 //
2789 // Currently only ever called on the VMThread or JavaThread
2790 //
2791 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2792   // Save and restore errno to avoid confusing native code with EINTR
2793   // after sigsuspend.
2794   int old_errno = errno;
2795 
2796   Thread* thread = Thread::current();
2797   OSThread* osthread = thread->osthread();
2798   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2799 
2800   os::SuspendResume::State current = osthread->sr.state();
2801   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2802     suspend_save_context(osthread, siginfo, context);
2803 
2804     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2805     os::SuspendResume::State state = osthread->sr.suspended();
2806     if (state == os::SuspendResume::SR_SUSPENDED) {
2807       sigset_t suspend_set;  // signals for sigsuspend()
2808 
2809       // get current set of blocked signals and unblock resume signal
2810       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2811       sigdelset(&suspend_set, SR_signum);
2812 
2813       sr_semaphore.signal();
2814       // wait here until we are resumed
2815       while (1) {
2816         sigsuspend(&suspend_set);
2817 
2818         os::SuspendResume::State result = osthread->sr.running();
2819         if (result == os::SuspendResume::SR_RUNNING) {
2820           sr_semaphore.signal();
2821           break;
2822         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2823           ShouldNotReachHere();
2824         }
2825       }
2826 
2827     } else if (state == os::SuspendResume::SR_RUNNING) {
2828       // request was cancelled, continue
2829     } else {
2830       ShouldNotReachHere();
2831     }
2832 
2833     resume_clear_context(osthread);
2834   } else if (current == os::SuspendResume::SR_RUNNING) {
2835     // request was cancelled, continue
2836   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2837     // ignore
2838   } else {
2839     // ignore
2840   }
2841 
2842   errno = old_errno;
2843 }
2844 
2845 
2846 static int SR_initialize() {
2847   struct sigaction act;
2848   char *s;
2849   /* Get signal number to use for suspend/resume */
2850   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2851     int sig = ::strtol(s, 0, 10);
2852     if (sig > 0 || sig < NSIG) {
2853         SR_signum = sig;
2854     }
2855   }
2856 
2857   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2858         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2859 
2860   sigemptyset(&SR_sigset);
2861   sigaddset(&SR_sigset, SR_signum);
2862 
2863   /* Set up signal handler for suspend/resume */
2864   act.sa_flags = SA_RESTART|SA_SIGINFO;
2865   act.sa_handler = (void (*)(int)) SR_handler;
2866 
2867   // SR_signum is blocked by default.
2868   // 4528190 - We also need to block pthread restart signal (32 on all
2869   // supported Bsd platforms). Note that BsdThreads need to block
2870   // this signal for all threads to work properly. So we don't have
2871   // to use hard-coded signal number when setting up the mask.
2872   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2873 
2874   if (sigaction(SR_signum, &act, 0) == -1) {
2875     return -1;
2876   }
2877 
2878   // Save signal flag
2879   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2880   return 0;
2881 }
2882 
2883 static int sr_notify(OSThread* osthread) {
2884   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2885   assert_status(status == 0, status, "pthread_kill");
2886   return status;
2887 }
2888 
2889 // "Randomly" selected value for how long we want to spin
2890 // before bailing out on suspending a thread, also how often
2891 // we send a signal to a thread we want to resume
2892 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2893 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2894 
2895 // returns true on success and false on error - really an error is fatal
2896 // but this seems the normal response to library errors
2897 static bool do_suspend(OSThread* osthread) {
2898   assert(osthread->sr.is_running(), "thread should be running");
2899   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2900 
2901   // mark as suspended and send signal
2902   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2903     // failed to switch, state wasn't running?
2904     ShouldNotReachHere();
2905     return false;
2906   }
2907 
2908   if (sr_notify(osthread) != 0) {
2909     ShouldNotReachHere();
2910   }
2911 
2912   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2913   while (true) {
2914     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2915       break;
2916     } else {
2917       // timeout
2918       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2919       if (cancelled == os::SuspendResume::SR_RUNNING) {
2920         return false;
2921       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2922         // make sure that we consume the signal on the semaphore as well
2923         sr_semaphore.wait();
2924         break;
2925       } else {
2926         ShouldNotReachHere();
2927         return false;
2928       }
2929     }
2930   }
2931 
2932   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2933   return true;
2934 }
2935 
2936 static void do_resume(OSThread* osthread) {
2937   assert(osthread->sr.is_suspended(), "thread should be suspended");
2938   assert(!sr_semaphore.trywait(), "invalid semaphore state");
2939 
2940   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2941     // failed to switch to WAKEUP_REQUEST
2942     ShouldNotReachHere();
2943     return;
2944   }
2945 
2946   while (true) {
2947     if (sr_notify(osthread) == 0) {
2948       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2949         if (osthread->sr.is_running()) {
2950           return;
2951         }
2952       }
2953     } else {
2954       ShouldNotReachHere();
2955     }
2956   }
2957 
2958   guarantee(osthread->sr.is_running(), "Must be running!");
2959 }
2960 
2961 ///////////////////////////////////////////////////////////////////////////////////
2962 // signal handling (except suspend/resume)
2963 
2964 // This routine may be used by user applications as a "hook" to catch signals.
2965 // The user-defined signal handler must pass unrecognized signals to this
2966 // routine, and if it returns true (non-zero), then the signal handler must
2967 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
2968 // routine will never retun false (zero), but instead will execute a VM panic
2969 // routine kill the process.
2970 //
2971 // If this routine returns false, it is OK to call it again.  This allows
2972 // the user-defined signal handler to perform checks either before or after
2973 // the VM performs its own checks.  Naturally, the user code would be making
2974 // a serious error if it tried to handle an exception (such as a null check
2975 // or breakpoint) that the VM was generating for its own correct operation.
2976 //
2977 // This routine may recognize any of the following kinds of signals:
2978 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2979 // It should be consulted by handlers for any of those signals.
2980 //
2981 // The caller of this routine must pass in the three arguments supplied
2982 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2983 // field of the structure passed to sigaction().  This routine assumes that
2984 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2985 //
2986 // Note that the VM will print warnings if it detects conflicting signal
2987 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2988 //
2989 extern "C" JNIEXPORT int
2990 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2991                         void* ucontext, int abort_if_unrecognized);
2992 
2993 void signalHandler(int sig, siginfo_t* info, void* uc) {
2994   assert(info != NULL && uc != NULL, "it must be old kernel");
2995   int orig_errno = errno;  // Preserve errno value over signal handler.
2996   JVM_handle_bsd_signal(sig, info, uc, true);
2997   errno = orig_errno;
2998 }
2999 
3000 
3001 // This boolean allows users to forward their own non-matching signals
3002 // to JVM_handle_bsd_signal, harmlessly.
3003 bool os::Bsd::signal_handlers_are_installed = false;
3004 
3005 // For signal-chaining
3006 struct sigaction os::Bsd::sigact[MAXSIGNUM];
3007 unsigned int os::Bsd::sigs = 0;
3008 bool os::Bsd::libjsig_is_loaded = false;
3009 typedef struct sigaction *(*get_signal_t)(int);
3010 get_signal_t os::Bsd::get_signal_action = NULL;
3011 
3012 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
3013   struct sigaction *actp = NULL;
3014 
3015   if (libjsig_is_loaded) {
3016     // Retrieve the old signal handler from libjsig
3017     actp = (*get_signal_action)(sig);
3018   }
3019   if (actp == NULL) {
3020     // Retrieve the preinstalled signal handler from jvm
3021     actp = get_preinstalled_handler(sig);
3022   }
3023 
3024   return actp;
3025 }
3026 
3027 static bool call_chained_handler(struct sigaction *actp, int sig,
3028                                  siginfo_t *siginfo, void *context) {
3029   // Call the old signal handler
3030   if (actp->sa_handler == SIG_DFL) {
3031     // It's more reasonable to let jvm treat it as an unexpected exception
3032     // instead of taking the default action.
3033     return false;
3034   } else if (actp->sa_handler != SIG_IGN) {
3035     if ((actp->sa_flags & SA_NODEFER) == 0) {
3036       // automaticlly block the signal
3037       sigaddset(&(actp->sa_mask), sig);
3038     }
3039 
3040     sa_handler_t hand;
3041     sa_sigaction_t sa;
3042     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3043     // retrieve the chained handler
3044     if (siginfo_flag_set) {
3045       sa = actp->sa_sigaction;
3046     } else {
3047       hand = actp->sa_handler;
3048     }
3049 
3050     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3051       actp->sa_handler = SIG_DFL;
3052     }
3053 
3054     // try to honor the signal mask
3055     sigset_t oset;
3056     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3057 
3058     // call into the chained handler
3059     if (siginfo_flag_set) {
3060       (*sa)(sig, siginfo, context);
3061     } else {
3062       (*hand)(sig);
3063     }
3064 
3065     // restore the signal mask
3066     pthread_sigmask(SIG_SETMASK, &oset, 0);
3067   }
3068   // Tell jvm's signal handler the signal is taken care of.
3069   return true;
3070 }
3071 
3072 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3073   bool chained = false;
3074   // signal-chaining
3075   if (UseSignalChaining) {
3076     struct sigaction *actp = get_chained_signal_action(sig);
3077     if (actp != NULL) {
3078       chained = call_chained_handler(actp, sig, siginfo, context);
3079     }
3080   }
3081   return chained;
3082 }
3083 
3084 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3085   if ((( (unsigned int)1 << sig ) & sigs) != 0) {
3086     return &sigact[sig];
3087   }
3088   return NULL;
3089 }
3090 
3091 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3092   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3093   sigact[sig] = oldAct;
3094   sigs |= (unsigned int)1 << sig;
3095 }
3096 
3097 // for diagnostic
3098 int os::Bsd::sigflags[MAXSIGNUM];
3099 
3100 int os::Bsd::get_our_sigflags(int sig) {
3101   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3102   return sigflags[sig];
3103 }
3104 
3105 void os::Bsd::set_our_sigflags(int sig, int flags) {
3106   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3107   sigflags[sig] = flags;
3108 }
3109 
3110 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3111   // Check for overwrite.
3112   struct sigaction oldAct;
3113   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3114 
3115   void* oldhand = oldAct.sa_sigaction
3116                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
3117                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
3118   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3119       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3120       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3121     if (AllowUserSignalHandlers || !set_installed) {
3122       // Do not overwrite; user takes responsibility to forward to us.
3123       return;
3124     } else if (UseSignalChaining) {
3125       // save the old handler in jvm
3126       save_preinstalled_handler(sig, oldAct);
3127       // libjsig also interposes the sigaction() call below and saves the
3128       // old sigaction on it own.
3129     } else {
3130       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3131                     "%#lx for signal %d.", (long)oldhand, sig));
3132     }
3133   }
3134 
3135   struct sigaction sigAct;
3136   sigfillset(&(sigAct.sa_mask));
3137   sigAct.sa_handler = SIG_DFL;
3138   if (!set_installed) {
3139     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3140   } else {
3141     sigAct.sa_sigaction = signalHandler;
3142     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3143   }
3144 #ifdef __APPLE__
3145   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3146   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3147   // if the signal handler declares it will handle it on alternate stack.
3148   // Notice we only declare we will handle it on alt stack, but we are not
3149   // actually going to use real alt stack - this is just a workaround.
3150   // Please see ux_exception.c, method catch_mach_exception_raise for details
3151   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3152   if (sig == SIGSEGV) {
3153     sigAct.sa_flags |= SA_ONSTACK;
3154   }
3155 #endif
3156 
3157   // Save flags, which are set by ours
3158   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3159   sigflags[sig] = sigAct.sa_flags;
3160 
3161   int ret = sigaction(sig, &sigAct, &oldAct);
3162   assert(ret == 0, "check");
3163 
3164   void* oldhand2  = oldAct.sa_sigaction
3165                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3166                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3167   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3168 }
3169 
3170 // install signal handlers for signals that HotSpot needs to
3171 // handle in order to support Java-level exception handling.
3172 
3173 void os::Bsd::install_signal_handlers() {
3174   if (!signal_handlers_are_installed) {
3175     signal_handlers_are_installed = true;
3176 
3177     // signal-chaining
3178     typedef void (*signal_setting_t)();
3179     signal_setting_t begin_signal_setting = NULL;
3180     signal_setting_t end_signal_setting = NULL;
3181     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3182                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3183     if (begin_signal_setting != NULL) {
3184       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3185                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3186       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3187                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3188       libjsig_is_loaded = true;
3189       assert(UseSignalChaining, "should enable signal-chaining");
3190     }
3191     if (libjsig_is_loaded) {
3192       // Tell libjsig jvm is setting signal handlers
3193       (*begin_signal_setting)();
3194     }
3195 
3196     set_signal_handler(SIGSEGV, true);
3197     set_signal_handler(SIGPIPE, true);
3198     set_signal_handler(SIGBUS, true);
3199     set_signal_handler(SIGILL, true);
3200     set_signal_handler(SIGFPE, true);
3201     set_signal_handler(SIGXFSZ, true);
3202 
3203 #if defined(__APPLE__)
3204     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3205     // signals caught and handled by the JVM. To work around this, we reset the mach task
3206     // signal handler that's placed on our process by CrashReporter. This disables
3207     // CrashReporter-based reporting.
3208     //
3209     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3210     // on caught fatal signals.
3211     //
3212     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3213     // handlers. By replacing the existing task exception handler, we disable gdb's mach
3214     // exception handling, while leaving the standard BSD signal handlers functional.
3215     kern_return_t kr;
3216     kr = task_set_exception_ports(mach_task_self(),
3217         EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3218         MACH_PORT_NULL,
3219         EXCEPTION_STATE_IDENTITY,
3220         MACHINE_THREAD_STATE);
3221 
3222     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3223 #endif
3224 
3225     if (libjsig_is_loaded) {
3226       // Tell libjsig jvm finishes setting signal handlers
3227       (*end_signal_setting)();
3228     }
3229 
3230     // We don't activate signal checker if libjsig is in place, we trust ourselves
3231     // and if UserSignalHandler is installed all bets are off
3232     if (CheckJNICalls) {
3233       if (libjsig_is_loaded) {
3234         if (PrintJNIResolving) {
3235           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3236         }
3237         check_signals = false;
3238       }
3239       if (AllowUserSignalHandlers) {
3240         if (PrintJNIResolving) {
3241           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3242         }
3243         check_signals = false;
3244       }
3245     }
3246   }
3247 }
3248 
3249 
3250 /////
3251 // glibc on Bsd platform uses non-documented flag
3252 // to indicate, that some special sort of signal
3253 // trampoline is used.
3254 // We will never set this flag, and we should
3255 // ignore this flag in our diagnostic
3256 #ifdef SIGNIFICANT_SIGNAL_MASK
3257 #undef SIGNIFICANT_SIGNAL_MASK
3258 #endif
3259 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3260 
3261 static const char* get_signal_handler_name(address handler,
3262                                            char* buf, int buflen) {
3263   int offset;
3264   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3265   if (found) {
3266     // skip directory names
3267     const char *p1, *p2;
3268     p1 = buf;
3269     size_t len = strlen(os::file_separator());
3270     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3271     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3272   } else {
3273     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3274   }
3275   return buf;
3276 }
3277 
3278 static void print_signal_handler(outputStream* st, int sig,
3279                                  char* buf, size_t buflen) {
3280   struct sigaction sa;
3281 
3282   sigaction(sig, NULL, &sa);
3283 
3284   // See comment for SIGNIFICANT_SIGNAL_MASK define
3285   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3286 
3287   st->print("%s: ", os::exception_name(sig, buf, buflen));
3288 
3289   address handler = (sa.sa_flags & SA_SIGINFO)
3290     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3291     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3292 
3293   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3294     st->print("SIG_DFL");
3295   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3296     st->print("SIG_IGN");
3297   } else {
3298     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3299   }
3300 
3301   st->print(", sa_mask[0]=");
3302   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3303 
3304   address rh = VMError::get_resetted_sighandler(sig);
3305   // May be, handler was resetted by VMError?
3306   if(rh != NULL) {
3307     handler = rh;
3308     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3309   }
3310 
3311   st->print(", sa_flags=");
3312   os::Posix::print_sa_flags(st, sa.sa_flags);
3313 
3314   // Check: is it our handler?
3315   if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3316      handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3317     // It is our signal handler
3318     // check for flags, reset system-used one!
3319     if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3320       st->print(
3321                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3322                 os::Bsd::get_our_sigflags(sig));
3323     }
3324   }
3325   st->cr();
3326 }
3327 
3328 
3329 #define DO_SIGNAL_CHECK(sig) \
3330   if (!sigismember(&check_signal_done, sig)) \
3331     os::Bsd::check_signal_handler(sig)
3332 
3333 // This method is a periodic task to check for misbehaving JNI applications
3334 // under CheckJNI, we can add any periodic checks here
3335 
3336 void os::run_periodic_checks() {
3337 
3338   if (check_signals == false) return;
3339 
3340   // SEGV and BUS if overridden could potentially prevent
3341   // generation of hs*.log in the event of a crash, debugging
3342   // such a case can be very challenging, so we absolutely
3343   // check the following for a good measure:
3344   DO_SIGNAL_CHECK(SIGSEGV);
3345   DO_SIGNAL_CHECK(SIGILL);
3346   DO_SIGNAL_CHECK(SIGFPE);
3347   DO_SIGNAL_CHECK(SIGBUS);
3348   DO_SIGNAL_CHECK(SIGPIPE);
3349   DO_SIGNAL_CHECK(SIGXFSZ);
3350 
3351 
3352   // ReduceSignalUsage allows the user to override these handlers
3353   // see comments at the very top and jvm_solaris.h
3354   if (!ReduceSignalUsage) {
3355     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3356     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3357     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3358     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3359   }
3360 
3361   DO_SIGNAL_CHECK(SR_signum);
3362   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3363 }
3364 
3365 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3366 
3367 static os_sigaction_t os_sigaction = NULL;
3368 
3369 void os::Bsd::check_signal_handler(int sig) {
3370   char buf[O_BUFLEN];
3371   address jvmHandler = NULL;
3372 
3373 
3374   struct sigaction act;
3375   if (os_sigaction == NULL) {
3376     // only trust the default sigaction, in case it has been interposed
3377     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3378     if (os_sigaction == NULL) return;
3379   }
3380 
3381   os_sigaction(sig, (struct sigaction*)NULL, &act);
3382 
3383 
3384   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3385 
3386   address thisHandler = (act.sa_flags & SA_SIGINFO)
3387     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3388     : CAST_FROM_FN_PTR(address, act.sa_handler) ;
3389 
3390 
3391   switch(sig) {
3392   case SIGSEGV:
3393   case SIGBUS:
3394   case SIGFPE:
3395   case SIGPIPE:
3396   case SIGILL:
3397   case SIGXFSZ:
3398     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3399     break;
3400 
3401   case SHUTDOWN1_SIGNAL:
3402   case SHUTDOWN2_SIGNAL:
3403   case SHUTDOWN3_SIGNAL:
3404   case BREAK_SIGNAL:
3405     jvmHandler = (address)user_handler();
3406     break;
3407 
3408   case INTERRUPT_SIGNAL:
3409     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3410     break;
3411 
3412   default:
3413     if (sig == SR_signum) {
3414       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3415     } else {
3416       return;
3417     }
3418     break;
3419   }
3420 
3421   if (thisHandler != jvmHandler) {
3422     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3423     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3424     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3425     // No need to check this sig any longer
3426     sigaddset(&check_signal_done, sig);
3427     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3428     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3429       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3430                     exception_name(sig, buf, O_BUFLEN));
3431     }
3432   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3433     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3434     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3435     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
3436     // No need to check this sig any longer
3437     sigaddset(&check_signal_done, sig);
3438   }
3439 
3440   // Dump all the signal
3441   if (sigismember(&check_signal_done, sig)) {
3442     print_signal_handlers(tty, buf, O_BUFLEN);
3443   }
3444 }
3445 
3446 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
3447 
3448 extern bool signal_name(int signo, char* buf, size_t len);
3449 
3450 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3451   if (0 < exception_code && exception_code <= SIGRTMAX) {
3452     // signal
3453     if (!signal_name(exception_code, buf, size)) {
3454       jio_snprintf(buf, size, "SIG%d", exception_code);
3455     }
3456     return buf;
3457   } else {
3458     return NULL;
3459   }
3460 }
3461 
3462 // this is called _before_ the most of global arguments have been parsed
3463 void os::init(void) {
3464   char dummy;   /* used to get a guess on initial stack address */
3465 //  first_hrtime = gethrtime();
3466 
3467   // With BsdThreads the JavaMain thread pid (primordial thread)
3468   // is different than the pid of the java launcher thread.
3469   // So, on Bsd, the launcher thread pid is passed to the VM
3470   // via the sun.java.launcher.pid property.
3471   // Use this property instead of getpid() if it was correctly passed.
3472   // See bug 6351349.
3473   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3474 
3475   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3476 
3477   clock_tics_per_sec = CLK_TCK;
3478 
3479   init_random(1234567);
3480 
3481   ThreadCritical::initialize();
3482 
3483   Bsd::set_page_size(getpagesize());
3484   if (Bsd::page_size() == -1) {
3485     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3486                   strerror(errno)));
3487   }
3488   init_page_sizes((size_t) Bsd::page_size());
3489 
3490   Bsd::initialize_system_info();
3491 
3492   // main_thread points to the aboriginal thread
3493   Bsd::_main_thread = pthread_self();
3494 
3495   Bsd::clock_init();
3496   initial_time_count = javaTimeNanos();
3497 
3498 #ifdef __APPLE__
3499   // XXXDARWIN
3500   // Work around the unaligned VM callbacks in hotspot's
3501   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3502   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3503   // alignment when doing symbol lookup. To work around this, we force early
3504   // binding of all symbols now, thus binding when alignment is known-good.
3505   _dyld_bind_fully_image_containing_address((const void *) &os::init);
3506 #endif
3507 }
3508 
3509 // To install functions for atexit system call
3510 extern "C" {
3511   static void perfMemory_exit_helper() {
3512     perfMemory_exit();
3513   }
3514 }
3515 
3516 // this is called _after_ the global arguments have been parsed
3517 jint os::init_2(void)
3518 {
3519   // Allocate a single page and mark it as readable for safepoint polling
3520   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3521   guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
3522 
3523   os::set_polling_page( polling_page );
3524 
3525 #ifndef PRODUCT
3526   if(Verbose && PrintMiscellaneous)
3527     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
3528 #endif
3529 
3530   if (!UseMembar) {
3531     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3532     guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3533     os::set_memory_serialize_page( mem_serialize_page );
3534 
3535 #ifndef PRODUCT
3536     if(Verbose && PrintMiscellaneous)
3537       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
3538 #endif
3539   }
3540 
3541   // initialize suspend/resume support - must do this before signal_sets_init()
3542   if (SR_initialize() != 0) {
3543     perror("SR_initialize failed");
3544     return JNI_ERR;
3545   }
3546 
3547   Bsd::signal_sets_init();
3548   Bsd::install_signal_handlers();
3549 
3550   // Check minimum allowable stack size for thread creation and to initialize
3551   // the java system classes, including StackOverflowError - depends on page
3552   // size.  Add a page for compiler2 recursion in main thread.
3553   // Add in 2*BytesPerWord times page size to account for VM stack during
3554   // class initialization depending on 32 or 64 bit VM.
3555   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3556             (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3557                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3558 
3559   size_t threadStackSizeInBytes = ThreadStackSize * K;
3560   if (threadStackSizeInBytes != 0 &&
3561       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3562         tty->print_cr("\nThe stack size specified is too small, "
3563                       "Specify at least %dk",
3564                       os::Bsd::min_stack_allowed/ K);
3565         return JNI_ERR;
3566   }
3567 
3568   // Make the stack size a multiple of the page size so that
3569   // the yellow/red zones can be guarded.
3570   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3571         vm_page_size()));
3572 
3573   if (MaxFDLimit) {
3574     // set the number of file descriptors to max. print out error
3575     // if getrlimit/setrlimit fails but continue regardless.
3576     struct rlimit nbr_files;
3577     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3578     if (status != 0) {
3579       if (PrintMiscellaneous && (Verbose || WizardMode))
3580         perror("os::init_2 getrlimit failed");
3581     } else {
3582       nbr_files.rlim_cur = nbr_files.rlim_max;
3583 
3584 #ifdef __APPLE__
3585       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3586       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3587       // be used instead
3588       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3589 #endif
3590 
3591       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3592       if (status != 0) {
3593         if (PrintMiscellaneous && (Verbose || WizardMode))
3594           perror("os::init_2 setrlimit failed");
3595       }
3596     }
3597   }
3598 
3599   // at-exit methods are called in the reverse order of their registration.
3600   // atexit functions are called on return from main or as a result of a
3601   // call to exit(3C). There can be only 32 of these functions registered
3602   // and atexit() does not set errno.
3603 
3604   if (PerfAllowAtExitRegistration) {
3605     // only register atexit functions if PerfAllowAtExitRegistration is set.
3606     // atexit functions can be delayed until process exit time, which
3607     // can be problematic for embedded VM situations. Embedded VMs should
3608     // call DestroyJavaVM() to assure that VM resources are released.
3609 
3610     // note: perfMemory_exit_helper atexit function may be removed in
3611     // the future if the appropriate cleanup code can be added to the
3612     // VM_Exit VMOperation's doit method.
3613     if (atexit(perfMemory_exit_helper) != 0) {
3614       warning("os::init2 atexit(perfMemory_exit_helper) failed");
3615     }
3616   }
3617 
3618   // initialize thread priority policy
3619   prio_init();
3620 
3621 #ifdef __APPLE__
3622   // dynamically link to objective c gc registration
3623   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3624   if (handleLibObjc != NULL) {
3625     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3626   }
3627 #endif
3628 
3629   return JNI_OK;
3630 }
3631 
3632 // this is called at the end of vm_initialization
3633 void os::init_3(void) { }
3634 
3635 // Mark the polling page as unreadable
3636 void os::make_polling_page_unreadable(void) {
3637   if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
3638     fatal("Could not disable polling page");
3639 };
3640 
3641 // Mark the polling page as readable
3642 void os::make_polling_page_readable(void) {
3643   if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3644     fatal("Could not enable polling page");
3645   }
3646 };
3647 
3648 int os::active_processor_count() {
3649   return _processor_count;
3650 }
3651 
3652 void os::set_native_thread_name(const char *name) {
3653 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3654   // This is only supported in Snow Leopard and beyond
3655   if (name != NULL) {
3656     // Add a "Java: " prefix to the name
3657     char buf[MAXTHREADNAMESIZE];
3658     snprintf(buf, sizeof(buf), "Java: %s", name);
3659     pthread_setname_np(buf);
3660   }
3661 #endif
3662 }
3663 
3664 bool os::distribute_processes(uint length, uint* distribution) {
3665   // Not yet implemented.
3666   return false;
3667 }
3668 
3669 bool os::bind_to_processor(uint processor_id) {
3670   // Not yet implemented.
3671   return false;
3672 }
3673 
3674 void os::SuspendedThreadTask::internal_do_task() {
3675   if (do_suspend(_thread->osthread())) {
3676     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3677     do_task(context);
3678     do_resume(_thread->osthread());
3679   }
3680 }
3681 
3682 ///
3683 class PcFetcher : public os::SuspendedThreadTask {
3684 public:
3685   PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3686   ExtendedPC result();
3687 protected:
3688   void do_task(const os::SuspendedThreadTaskContext& context);
3689 private:
3690   ExtendedPC _epc;
3691 };
3692 
3693 ExtendedPC PcFetcher::result() {
3694   guarantee(is_done(), "task is not done yet.");
3695   return _epc;
3696 }
3697 
3698 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3699   Thread* thread = context.thread();
3700   OSThread* osthread = thread->osthread();
3701   if (osthread->ucontext() != NULL) {
3702     _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
3703   } else {
3704     // NULL context is unexpected, double-check this is the VMThread
3705     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3706   }
3707 }
3708 
3709 // Suspends the target using the signal mechanism and then grabs the PC before
3710 // resuming the target. Used by the flat-profiler only
3711 ExtendedPC os::get_thread_pc(Thread* thread) {
3712   // Make sure that it is called by the watcher for the VMThread
3713   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3714   assert(thread->is_VM_thread(), "Can only be called for VMThread");
3715 
3716   PcFetcher fetcher(thread);
3717   fetcher.run();
3718   return fetcher.result();
3719 }
3720 
3721 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
3722 {
3723   return pthread_cond_timedwait(_cond, _mutex, _abstime);
3724 }
3725 
3726 ////////////////////////////////////////////////////////////////////////////////
3727 // debug support
3728 
3729 bool os::find(address addr, outputStream* st) {
3730   Dl_info dlinfo;
3731   memset(&dlinfo, 0, sizeof(dlinfo));
3732   if (dladdr(addr, &dlinfo) != 0) {
3733     st->print(PTR_FORMAT ": ", addr);
3734     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3735       st->print("%s+%#x", dlinfo.dli_sname,
3736                  addr - (intptr_t)dlinfo.dli_saddr);
3737     } else if (dlinfo.dli_fbase != NULL) {
3738       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3739     } else {
3740       st->print("<absolute address>");
3741     }
3742     if (dlinfo.dli_fname != NULL) {
3743       st->print(" in %s", dlinfo.dli_fname);
3744     }
3745     if (dlinfo.dli_fbase != NULL) {
3746       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3747     }
3748     st->cr();
3749 
3750     if (Verbose) {
3751       // decode some bytes around the PC
3752       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3753       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3754       address       lowest = (address) dlinfo.dli_sname;
3755       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3756       if (begin < lowest)  begin = lowest;
3757       Dl_info dlinfo2;
3758       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3759           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
3760         end = (address) dlinfo2.dli_saddr;
3761       Disassembler::decode(begin, end, st);
3762     }
3763     return true;
3764   }
3765   return false;
3766 }
3767 
3768 ////////////////////////////////////////////////////////////////////////////////
3769 // misc
3770 
3771 // This does not do anything on Bsd. This is basically a hook for being
3772 // able to use structured exception handling (thread-local exception filters)
3773 // on, e.g., Win32.
3774 void
3775 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
3776                          JavaCallArguments* args, Thread* thread) {
3777   f(value, method, args, thread);
3778 }
3779 
3780 void os::print_statistics() {
3781 }
3782 
3783 int os::message_box(const char* title, const char* message) {
3784   int i;
3785   fdStream err(defaultStream::error_fd());
3786   for (i = 0; i < 78; i++) err.print_raw("=");
3787   err.cr();
3788   err.print_raw_cr(title);
3789   for (i = 0; i < 78; i++) err.print_raw("-");
3790   err.cr();
3791   err.print_raw_cr(message);
3792   for (i = 0; i < 78; i++) err.print_raw("=");
3793   err.cr();
3794 
3795   char buf[16];
3796   // Prevent process from exiting upon "read error" without consuming all CPU
3797   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3798 
3799   return buf[0] == 'y' || buf[0] == 'Y';
3800 }
3801 
3802 int os::stat(const char *path, struct stat *sbuf) {
3803   char pathbuf[MAX_PATH];
3804   if (strlen(path) > MAX_PATH - 1) {
3805     errno = ENAMETOOLONG;
3806     return -1;
3807   }
3808   os::native_path(strcpy(pathbuf, path));
3809   return ::stat(pathbuf, sbuf);
3810 }
3811 
3812 bool os::check_heap(bool force) {
3813   return true;
3814 }
3815 
3816 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
3817   return ::vsnprintf(buf, count, format, args);
3818 }
3819 
3820 // Is a (classpath) directory empty?
3821 bool os::dir_is_empty(const char* path) {
3822   DIR *dir = NULL;
3823   struct dirent *ptr;
3824 
3825   dir = opendir(path);
3826   if (dir == NULL) return true;
3827 
3828   /* Scan the directory */
3829   bool result = true;
3830   char buf[sizeof(struct dirent) + MAX_PATH];
3831   while (result && (ptr = ::readdir(dir)) != NULL) {
3832     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3833       result = false;
3834     }
3835   }
3836   closedir(dir);
3837   return result;
3838 }
3839 
3840 // This code originates from JDK's sysOpen and open64_w
3841 // from src/solaris/hpi/src/system_md.c
3842 
3843 #ifndef O_DELETE
3844 #define O_DELETE 0x10000
3845 #endif
3846 
3847 // Open a file. Unlink the file immediately after open returns
3848 // if the specified oflag has the O_DELETE flag set.
3849 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
3850 
3851 int os::open(const char *path, int oflag, int mode) {
3852 
3853   if (strlen(path) > MAX_PATH - 1) {
3854     errno = ENAMETOOLONG;
3855     return -1;
3856   }
3857   int fd;
3858   int o_delete = (oflag & O_DELETE);
3859   oflag = oflag & ~O_DELETE;
3860 
3861   fd = ::open(path, oflag, mode);
3862   if (fd == -1) return -1;
3863 
3864   //If the open succeeded, the file might still be a directory
3865   {
3866     struct stat buf;
3867     int ret = ::fstat(fd, &buf);
3868     int st_mode = buf.st_mode;
3869 
3870     if (ret != -1) {
3871       if ((st_mode & S_IFMT) == S_IFDIR) {
3872         errno = EISDIR;
3873         ::close(fd);
3874         return -1;
3875       }
3876     } else {
3877       ::close(fd);
3878       return -1;
3879     }
3880   }
3881 
3882     /*
3883      * All file descriptors that are opened in the JVM and not
3884      * specifically destined for a subprocess should have the
3885      * close-on-exec flag set.  If we don't set it, then careless 3rd
3886      * party native code might fork and exec without closing all
3887      * appropriate file descriptors (e.g. as we do in closeDescriptors in
3888      * UNIXProcess.c), and this in turn might:
3889      *
3890      * - cause end-of-file to fail to be detected on some file
3891      *   descriptors, resulting in mysterious hangs, or
3892      *
3893      * - might cause an fopen in the subprocess to fail on a system
3894      *   suffering from bug 1085341.
3895      *
3896      * (Yes, the default setting of the close-on-exec flag is a Unix
3897      * design flaw)
3898      *
3899      * See:
3900      * 1085341: 32-bit stdio routines should support file descriptors >255
3901      * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3902      * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3903      */
3904 #ifdef FD_CLOEXEC
3905     {
3906         int flags = ::fcntl(fd, F_GETFD);
3907         if (flags != -1)
3908             ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3909     }
3910 #endif
3911 
3912   if (o_delete != 0) {
3913     ::unlink(path);
3914   }
3915   return fd;
3916 }
3917 
3918 
3919 // create binary file, rewriting existing file if required
3920 int os::create_binary_file(const char* path, bool rewrite_existing) {
3921   int oflags = O_WRONLY | O_CREAT;
3922   if (!rewrite_existing) {
3923     oflags |= O_EXCL;
3924   }
3925   return ::open(path, oflags, S_IREAD | S_IWRITE);
3926 }
3927 
3928 // return current position of file pointer
3929 jlong os::current_file_offset(int fd) {
3930   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3931 }
3932 
3933 // move file pointer to the specified offset
3934 jlong os::seek_to_file_offset(int fd, jlong offset) {
3935   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3936 }
3937 
3938 // This code originates from JDK's sysAvailable
3939 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3940 
3941 int os::available(int fd, jlong *bytes) {
3942   jlong cur, end;
3943   int mode;
3944   struct stat buf;
3945 
3946   if (::fstat(fd, &buf) >= 0) {
3947     mode = buf.st_mode;
3948     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3949       /*
3950       * XXX: is the following call interruptible? If so, this might
3951       * need to go through the INTERRUPT_IO() wrapper as for other
3952       * blocking, interruptible calls in this file.
3953       */
3954       int n;
3955       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3956         *bytes = n;
3957         return 1;
3958       }
3959     }
3960   }
3961   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3962     return 0;
3963   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3964     return 0;
3965   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3966     return 0;
3967   }
3968   *bytes = end - cur;
3969   return 1;
3970 }
3971 
3972 int os::socket_available(int fd, jint *pbytes) {
3973    if (fd < 0)
3974      return OS_OK;
3975 
3976    int ret;
3977 
3978    RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
3979 
3980    //%% note ioctl can return 0 when successful, JVM_SocketAvailable
3981    // is expected to return 0 on failure and 1 on success to the jdk.
3982 
3983    return (ret == OS_ERR) ? 0 : 1;
3984 }
3985 
3986 // Map a block of memory.
3987 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3988                      char *addr, size_t bytes, bool read_only,
3989                      bool allow_exec) {
3990   int prot;
3991   int flags;
3992 
3993   if (read_only) {
3994     prot = PROT_READ;
3995     flags = MAP_SHARED;
3996   } else {
3997     prot = PROT_READ | PROT_WRITE;
3998     flags = MAP_PRIVATE;
3999   }
4000 
4001   if (allow_exec) {
4002     prot |= PROT_EXEC;
4003   }
4004 
4005   if (addr != NULL) {
4006     flags |= MAP_FIXED;
4007   }
4008 
4009   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
4010                                      fd, file_offset);
4011   if (mapped_address == MAP_FAILED) {
4012     return NULL;
4013   }
4014   return mapped_address;
4015 }
4016 
4017 
4018 // Remap a block of memory.
4019 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
4020                        char *addr, size_t bytes, bool read_only,
4021                        bool allow_exec) {
4022   // same as map_memory() on this OS
4023   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
4024                         allow_exec);
4025 }
4026 
4027 
4028 // Unmap a block of memory.
4029 bool os::pd_unmap_memory(char* addr, size_t bytes) {
4030   return munmap(addr, bytes) == 0;
4031 }
4032 
4033 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
4034 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4035 // of a thread.
4036 //
4037 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4038 // the fast estimate available on the platform.
4039 
4040 jlong os::current_thread_cpu_time() {
4041 #ifdef __APPLE__
4042   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
4043 #else
4044   Unimplemented();
4045   return 0;
4046 #endif
4047 }
4048 
4049 jlong os::thread_cpu_time(Thread* thread) {
4050 #ifdef __APPLE__
4051   return os::thread_cpu_time(thread, true /* user + sys */);
4052 #else
4053   Unimplemented();
4054   return 0;
4055 #endif
4056 }
4057 
4058 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4059 #ifdef __APPLE__
4060   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4061 #else
4062   Unimplemented();
4063   return 0;
4064 #endif
4065 }
4066 
4067 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4068 #ifdef __APPLE__
4069   struct thread_basic_info tinfo;
4070   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
4071   kern_return_t kr;
4072   thread_t mach_thread;
4073 
4074   mach_thread = thread->osthread()->thread_id();
4075   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
4076   if (kr != KERN_SUCCESS)
4077     return -1;
4078 
4079   if (user_sys_cpu_time) {
4080     jlong nanos;
4081     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4082     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4083     return nanos;
4084   } else {
4085     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4086   }
4087 #else
4088   Unimplemented();
4089   return 0;
4090 #endif
4091 }
4092 
4093 
4094 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4095   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4096   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4097   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4098   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4099 }
4100 
4101 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4102   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4103   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4104   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4105   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4106 }
4107 
4108 bool os::is_thread_cpu_time_supported() {
4109 #ifdef __APPLE__
4110   return true;
4111 #else
4112   return false;
4113 #endif
4114 }
4115 
4116 // System loadavg support.  Returns -1 if load average cannot be obtained.
4117 // Bsd doesn't yet have a (official) notion of processor sets,
4118 // so just return the system wide load average.
4119 int os::loadavg(double loadavg[], int nelem) {
4120   return ::getloadavg(loadavg, nelem);
4121 }
4122 
4123 void os::pause() {
4124   char filename[MAX_PATH];
4125   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4126     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4127   } else {
4128     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4129   }
4130 
4131   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4132   if (fd != -1) {
4133     struct stat buf;
4134     ::close(fd);
4135     while (::stat(filename, &buf) == 0) {
4136       (void)::poll(NULL, 0, 100);
4137     }
4138   } else {
4139     jio_fprintf(stderr,
4140       "Could not open pause file '%s', continuing immediately.\n", filename);
4141   }
4142 }
4143 
4144 
4145 // Refer to the comments in os_solaris.cpp park-unpark.
4146 //
4147 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4148 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4149 // For specifics regarding the bug see GLIBC BUGID 261237 :
4150 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4151 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4152 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4153 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
4154 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4155 // and monitorenter when we're using 1-0 locking.  All those operations may result in
4156 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
4157 // of libpthread avoids the problem, but isn't practical.
4158 //
4159 // Possible remedies:
4160 //
4161 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
4162 //      This is palliative and probabilistic, however.  If the thread is preempted
4163 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
4164 //      than the minimum period may have passed, and the abstime may be stale (in the
4165 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
4166 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
4167 //
4168 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4169 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
4170 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4171 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
4172 //      thread.
4173 //
4174 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
4175 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
4176 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
4177 //      This also works well.  In fact it avoids kernel-level scalability impediments
4178 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
4179 //      timers in a graceful fashion.
4180 //
4181 // 4.   When the abstime value is in the past it appears that control returns
4182 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4183 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
4184 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
4185 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
4186 //      It may be possible to avoid reinitialization by checking the return
4187 //      value from pthread_cond_timedwait().  In addition to reinitializing the
4188 //      condvar we must establish the invariant that cond_signal() is only called
4189 //      within critical sections protected by the adjunct mutex.  This prevents
4190 //      cond_signal() from "seeing" a condvar that's in the midst of being
4191 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
4192 //      desirable signal-after-unlock optimization that avoids futile context switching.
4193 //
4194 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
4195 //      structure when a condvar is used or initialized.  cond_destroy()  would
4196 //      release the helper structure.  Our reinitialize-after-timedwait fix
4197 //      put excessive stress on malloc/free and locks protecting the c-heap.
4198 //
4199 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
4200 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4201 // and only enabling the work-around for vulnerable environments.
4202 
4203 // utility to compute the abstime argument to timedwait:
4204 // millis is the relative timeout time
4205 // abstime will be the absolute timeout time
4206 // TODO: replace compute_abstime() with unpackTime()
4207 
4208 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
4209   if (millis < 0)  millis = 0;
4210   struct timeval now;
4211   int status = gettimeofday(&now, NULL);
4212   assert(status == 0, "gettimeofday");
4213   jlong seconds = millis / 1000;
4214   millis %= 1000;
4215   if (seconds > 50000000) { // see man cond_timedwait(3T)
4216     seconds = 50000000;
4217   }
4218   abstime->tv_sec = now.tv_sec  + seconds;
4219   long       usec = now.tv_usec + millis * 1000;
4220   if (usec >= 1000000) {
4221     abstime->tv_sec += 1;
4222     usec -= 1000000;
4223   }
4224   abstime->tv_nsec = usec * 1000;
4225   return abstime;
4226 }
4227 
4228 
4229 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
4230 // Conceptually TryPark() should be equivalent to park(0).
4231 
4232 int os::PlatformEvent::TryPark() {
4233   for (;;) {
4234     const int v = _Event ;
4235     guarantee ((v == 0) || (v == 1), "invariant") ;
4236     if (Atomic::cmpxchg (0, &_Event, v) == v) return v  ;
4237   }
4238 }
4239 
4240 void os::PlatformEvent::park() {       // AKA "down()"
4241   // Invariant: Only the thread associated with the Event/PlatformEvent
4242   // may call park().
4243   // TODO: assert that _Assoc != NULL or _Assoc == Self
4244   int v ;
4245   for (;;) {
4246       v = _Event ;
4247       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4248   }
4249   guarantee (v >= 0, "invariant") ;
4250   if (v == 0) {
4251      // Do this the hard way by blocking ...
4252      int status = pthread_mutex_lock(_mutex);
4253      assert_status(status == 0, status, "mutex_lock");
4254      guarantee (_nParked == 0, "invariant") ;
4255      ++ _nParked ;
4256      while (_Event < 0) {
4257         status = pthread_cond_wait(_cond, _mutex);
4258         // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4259         // Treat this the same as if the wait was interrupted
4260         if (status == ETIMEDOUT) { status = EINTR; }
4261         assert_status(status == 0 || status == EINTR, status, "cond_wait");
4262      }
4263      -- _nParked ;
4264 
4265     _Event = 0 ;
4266      status = pthread_mutex_unlock(_mutex);
4267      assert_status(status == 0, status, "mutex_unlock");
4268     // Paranoia to ensure our locked and lock-free paths interact
4269     // correctly with each other.
4270     OrderAccess::fence();
4271   }
4272   guarantee (_Event >= 0, "invariant") ;
4273 }
4274 
4275 int os::PlatformEvent::park(jlong millis) {
4276   guarantee (_nParked == 0, "invariant") ;
4277 
4278   int v ;
4279   for (;;) {
4280       v = _Event ;
4281       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4282   }
4283   guarantee (v >= 0, "invariant") ;
4284   if (v != 0) return OS_OK ;
4285 
4286   // We do this the hard way, by blocking the thread.
4287   // Consider enforcing a minimum timeout value.
4288   struct timespec abst;
4289   compute_abstime(&abst, millis);
4290 
4291   int ret = OS_TIMEOUT;
4292   int status = pthread_mutex_lock(_mutex);
4293   assert_status(status == 0, status, "mutex_lock");
4294   guarantee (_nParked == 0, "invariant") ;
4295   ++_nParked ;
4296 
4297   // Object.wait(timo) will return because of
4298   // (a) notification
4299   // (b) timeout
4300   // (c) thread.interrupt
4301   //
4302   // Thread.interrupt and object.notify{All} both call Event::set.
4303   // That is, we treat thread.interrupt as a special case of notification.
4304   // The underlying Solaris implementation, cond_timedwait, admits
4305   // spurious/premature wakeups, but the JLS/JVM spec prevents the
4306   // JVM from making those visible to Java code.  As such, we must
4307   // filter out spurious wakeups.  We assume all ETIME returns are valid.
4308   //
4309   // TODO: properly differentiate simultaneous notify+interrupt.
4310   // In that case, we should propagate the notify to another waiter.
4311 
4312   while (_Event < 0) {
4313     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4314     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4315       pthread_cond_destroy (_cond);
4316       pthread_cond_init (_cond, NULL) ;
4317     }
4318     assert_status(status == 0 || status == EINTR ||
4319                   status == ETIMEDOUT,
4320                   status, "cond_timedwait");
4321     if (!FilterSpuriousWakeups) break ;                 // previous semantics
4322     if (status == ETIMEDOUT) break ;
4323     // We consume and ignore EINTR and spurious wakeups.
4324   }
4325   --_nParked ;
4326   if (_Event >= 0) {
4327      ret = OS_OK;
4328   }
4329   _Event = 0 ;
4330   status = pthread_mutex_unlock(_mutex);
4331   assert_status(status == 0, status, "mutex_unlock");
4332   assert (_nParked == 0, "invariant") ;
4333   // Paranoia to ensure our locked and lock-free paths interact
4334   // correctly with each other.
4335   OrderAccess::fence();
4336   return ret;
4337 }
4338 
4339 void os::PlatformEvent::unpark() {
4340   // Transitions for _Event:
4341   //    0 :=> 1
4342   //    1 :=> 1
4343   //   -1 :=> either 0 or 1; must signal target thread
4344   //          That is, we can safely transition _Event from -1 to either
4345   //          0 or 1. Forcing 1 is slightly more efficient for back-to-back
4346   //          unpark() calls.
4347   // See also: "Semaphores in Plan 9" by Mullender & Cox
4348   //
4349   // Note: Forcing a transition from "-1" to "1" on an unpark() means
4350   // that it will take two back-to-back park() calls for the owning
4351   // thread to block. This has the benefit of forcing a spurious return
4352   // from the first park() call after an unpark() call which will help
4353   // shake out uses of park() and unpark() without condition variables.
4354 
4355   if (Atomic::xchg(1, &_Event) >= 0) return;
4356 
4357   // Wait for the thread associated with the event to vacate
4358   int status = pthread_mutex_lock(_mutex);
4359   assert_status(status == 0, status, "mutex_lock");
4360   int AnyWaiters = _nParked;
4361   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4362   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4363     AnyWaiters = 0;
4364     pthread_cond_signal(_cond);
4365   }
4366   status = pthread_mutex_unlock(_mutex);
4367   assert_status(status == 0, status, "mutex_unlock");
4368   if (AnyWaiters != 0) {
4369     status = pthread_cond_signal(_cond);
4370     assert_status(status == 0, status, "cond_signal");
4371   }
4372 
4373   // Note that we signal() _after dropping the lock for "immortal" Events.
4374   // This is safe and avoids a common class of  futile wakeups.  In rare
4375   // circumstances this can cause a thread to return prematurely from
4376   // cond_{timed}wait() but the spurious wakeup is benign and the victim will
4377   // simply re-test the condition and re-park itself.
4378 }
4379 
4380 
4381 // JSR166
4382 // -------------------------------------------------------
4383 
4384 /*
4385  * The solaris and bsd implementations of park/unpark are fairly
4386  * conservative for now, but can be improved. They currently use a
4387  * mutex/condvar pair, plus a a count.
4388  * Park decrements count if > 0, else does a condvar wait.  Unpark
4389  * sets count to 1 and signals condvar.  Only one thread ever waits
4390  * on the condvar. Contention seen when trying to park implies that someone
4391  * is unparking you, so don't wait. And spurious returns are fine, so there
4392  * is no need to track notifications.
4393  */
4394 
4395 #define MAX_SECS 100000000
4396 /*
4397  * This code is common to bsd and solaris and will be moved to a
4398  * common place in dolphin.
4399  *
4400  * The passed in time value is either a relative time in nanoseconds
4401  * or an absolute time in milliseconds. Either way it has to be unpacked
4402  * into suitable seconds and nanoseconds components and stored in the
4403  * given timespec structure.
4404  * Given time is a 64-bit value and the time_t used in the timespec is only
4405  * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4406  * overflow if times way in the future are given. Further on Solaris versions
4407  * prior to 10 there is a restriction (see cond_timedwait) that the specified
4408  * number of seconds, in abstime, is less than current_time  + 100,000,000.
4409  * As it will be 28 years before "now + 100000000" will overflow we can
4410  * ignore overflow and just impose a hard-limit on seconds using the value
4411  * of "now + 100,000,000". This places a limit on the timeout of about 3.17
4412  * years from "now".
4413  */
4414 
4415 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4416   assert (time > 0, "convertTime");
4417 
4418   struct timeval now;
4419   int status = gettimeofday(&now, NULL);
4420   assert(status == 0, "gettimeofday");
4421 
4422   time_t max_secs = now.tv_sec + MAX_SECS;
4423 
4424   if (isAbsolute) {
4425     jlong secs = time / 1000;
4426     if (secs > max_secs) {
4427       absTime->tv_sec = max_secs;
4428     }
4429     else {
4430       absTime->tv_sec = secs;
4431     }
4432     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4433   }
4434   else {
4435     jlong secs = time / NANOSECS_PER_SEC;
4436     if (secs >= MAX_SECS) {
4437       absTime->tv_sec = max_secs;
4438       absTime->tv_nsec = 0;
4439     }
4440     else {
4441       absTime->tv_sec = now.tv_sec + secs;
4442       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4443       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4444         absTime->tv_nsec -= NANOSECS_PER_SEC;
4445         ++absTime->tv_sec; // note: this must be <= max_secs
4446       }
4447     }
4448   }
4449   assert(absTime->tv_sec >= 0, "tv_sec < 0");
4450   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4451   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4452   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4453 }
4454 
4455 void Parker::park(bool isAbsolute, jlong time) {
4456   // Ideally we'd do something useful while spinning, such
4457   // as calling unpackTime().
4458 
4459   // Optional fast-path check:
4460   // Return immediately if a permit is available.
4461   // We depend on Atomic::xchg() having full barrier semantics
4462   // since we are doing a lock-free update to _counter.
4463   if (Atomic::xchg(0, &_counter) > 0) return;
4464 
4465   Thread* thread = Thread::current();
4466   assert(thread->is_Java_thread(), "Must be JavaThread");
4467   JavaThread *jt = (JavaThread *)thread;
4468 
4469   // Optional optimization -- avoid state transitions if there's an interrupt pending.
4470   // Check interrupt before trying to wait
4471   if (Thread::is_interrupted(thread, false)) {
4472     return;
4473   }
4474 
4475   // Next, demultiplex/decode time arguments
4476   struct timespec absTime;
4477   if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
4478     return;
4479   }
4480   if (time > 0) {
4481     unpackTime(&absTime, isAbsolute, time);
4482   }
4483 
4484 
4485   // Enter safepoint region
4486   // Beware of deadlocks such as 6317397.
4487   // The per-thread Parker:: mutex is a classic leaf-lock.
4488   // In particular a thread must never block on the Threads_lock while
4489   // holding the Parker:: mutex.  If safepoints are pending both the
4490   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4491   ThreadBlockInVM tbivm(jt);
4492 
4493   // Don't wait if cannot get lock since interference arises from
4494   // unblocking.  Also. check interrupt before trying wait
4495   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4496     return;
4497   }
4498 
4499   int status ;
4500   if (_counter > 0)  { // no wait needed
4501     _counter = 0;
4502     status = pthread_mutex_unlock(_mutex);
4503     assert (status == 0, "invariant") ;
4504     // Paranoia to ensure our locked and lock-free paths interact
4505     // correctly with each other and Java-level accesses.
4506     OrderAccess::fence();
4507     return;
4508   }
4509 
4510 #ifdef ASSERT
4511   // Don't catch signals while blocked; let the running threads have the signals.
4512   // (This allows a debugger to break into the running thread.)
4513   sigset_t oldsigs;
4514   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4515   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4516 #endif
4517 
4518   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4519   jt->set_suspend_equivalent();
4520   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4521 
4522   if (time == 0) {
4523     status = pthread_cond_wait (_cond, _mutex) ;
4524   } else {
4525     status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
4526     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4527       pthread_cond_destroy (_cond) ;
4528       pthread_cond_init    (_cond, NULL);
4529     }
4530   }
4531   assert_status(status == 0 || status == EINTR ||
4532                 status == ETIMEDOUT,
4533                 status, "cond_timedwait");
4534 
4535 #ifdef ASSERT
4536   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4537 #endif
4538 
4539   _counter = 0 ;
4540   status = pthread_mutex_unlock(_mutex) ;
4541   assert_status(status == 0, status, "invariant") ;
4542   // Paranoia to ensure our locked and lock-free paths interact
4543   // correctly with each other and Java-level accesses.
4544   OrderAccess::fence();
4545 
4546   // If externally suspended while waiting, re-suspend
4547   if (jt->handle_special_suspend_equivalent_condition()) {
4548     jt->java_suspend_self();
4549   }
4550 }
4551 
4552 void Parker::unpark() {
4553   int s, status ;
4554   status = pthread_mutex_lock(_mutex);
4555   assert (status == 0, "invariant") ;
4556   s = _counter;
4557   _counter = 1;
4558   if (s < 1) {
4559      if (WorkAroundNPTLTimedWaitHang) {
4560         status = pthread_cond_signal (_cond) ;
4561         assert (status == 0, "invariant") ;
4562         status = pthread_mutex_unlock(_mutex);
4563         assert (status == 0, "invariant") ;
4564      } else {
4565         status = pthread_mutex_unlock(_mutex);
4566         assert (status == 0, "invariant") ;
4567         status = pthread_cond_signal (_cond) ;
4568         assert (status == 0, "invariant") ;
4569      }
4570   } else {
4571     pthread_mutex_unlock(_mutex);
4572     assert (status == 0, "invariant") ;
4573   }
4574 }
4575 
4576 
4577 /* Darwin has no "environ" in a dynamic library. */
4578 #ifdef __APPLE__
4579 #include <crt_externs.h>
4580 #define environ (*_NSGetEnviron())
4581 #else
4582 extern char** environ;
4583 #endif
4584 
4585 // Run the specified command in a separate process. Return its exit value,
4586 // or -1 on failure (e.g. can't fork a new process).
4587 // Unlike system(), this function can be called from signal handler. It
4588 // doesn't block SIGINT et al.
4589 int os::fork_and_exec(char* cmd) {
4590   const char * argv[4] = {"sh", "-c", cmd, NULL};
4591 
4592   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4593   // pthread_atfork handlers and reset pthread library. All we need is a
4594   // separate process to execve. Make a direct syscall to fork process.
4595   // On IA64 there's no fork syscall, we have to use fork() and hope for
4596   // the best...
4597   pid_t pid = fork();
4598 
4599   if (pid < 0) {
4600     // fork failed
4601     return -1;
4602 
4603   } else if (pid == 0) {
4604     // child process
4605 
4606     // execve() in BsdThreads will call pthread_kill_other_threads_np()
4607     // first to kill every thread on the thread list. Because this list is
4608     // not reset by fork() (see notes above), execve() will instead kill
4609     // every thread in the parent process. We know this is the only thread
4610     // in the new process, so make a system call directly.
4611     // IA64 should use normal execve() from glibc to match the glibc fork()
4612     // above.
4613     execve("/bin/sh", (char* const*)argv, environ);
4614 
4615     // execve failed
4616     _exit(-1);
4617 
4618   } else  {
4619     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4620     // care about the actual exit code, for now.
4621 
4622     int status;
4623 
4624     // Wait for the child process to exit.  This returns immediately if
4625     // the child has already exited. */
4626     while (waitpid(pid, &status, 0) < 0) {
4627         switch (errno) {
4628         case ECHILD: return 0;
4629         case EINTR: break;
4630         default: return -1;
4631         }
4632     }
4633 
4634     if (WIFEXITED(status)) {
4635        // The child exited normally; get its exit code.
4636        return WEXITSTATUS(status);
4637     } else if (WIFSIGNALED(status)) {
4638        // The child exited because of a signal
4639        // The best value to return is 0x80 + signal number,
4640        // because that is what all Unix shells do, and because
4641        // it allows callers to distinguish between process exit and
4642        // process death by signal.
4643        return 0x80 + WTERMSIG(status);
4644     } else {
4645        // Unknown exit code; pass it through
4646        return status;
4647     }
4648   }
4649 }
4650 
4651 // is_headless_jre()
4652 //
4653 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4654 // in order to report if we are running in a headless jre
4655 //
4656 // Since JDK8 xawt/libmawt.so was moved into the same directory
4657 // as libawt.so, and renamed libawt_xawt.so
4658 //
4659 bool os::is_headless_jre() {
4660 #ifdef __APPLE__
4661     // We no longer build headless-only on Mac OS X
4662     return false;
4663 #else
4664     struct stat statbuf;
4665     char buf[MAXPATHLEN];
4666     char libmawtpath[MAXPATHLEN];
4667     const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
4668     const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4669     char *p;
4670 
4671     // Get path to libjvm.so
4672     os::jvm_path(buf, sizeof(buf));
4673 
4674     // Get rid of libjvm.so
4675     p = strrchr(buf, '/');
4676     if (p == NULL) return false;
4677     else *p = '\0';
4678 
4679     // Get rid of client or server
4680     p = strrchr(buf, '/');
4681     if (p == NULL) return false;
4682     else *p = '\0';
4683 
4684     // check xawt/libmawt.so
4685     strcpy(libmawtpath, buf);
4686     strcat(libmawtpath, xawtstr);
4687     if (::stat(libmawtpath, &statbuf) == 0) return false;
4688 
4689     // check libawt_xawt.so
4690     strcpy(libmawtpath, buf);
4691     strcat(libmawtpath, new_xawtstr);
4692     if (::stat(libmawtpath, &statbuf) == 0) return false;
4693 
4694     return true;
4695 #endif
4696 }
4697 
4698 // Get the default path to the core file
4699 // Returns the length of the string
4700 int os::get_core_path(char* buffer, size_t bufferSize) {
4701   int n = jio_snprintf(buffer, bufferSize, "/cores");
4702 
4703   // Truncate if theoretical string was longer than bufferSize
4704   n = MIN2(n, (int)bufferSize);
4705 
4706   return n;
4707 }
4708 
4709 #ifndef PRODUCT
4710 void TestReserveMemorySpecial_test() {
4711   // No tests available for this platform
4712 }
4713 #endif
--- EOF ---