1 /*
   2  * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // no precompiled headers
  26 #include "classfile/classLoader.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/icBuffer.hpp"
  30 #include "code/vtableStubs.hpp"
  31 #include "compiler/compileBroker.hpp"
  32 #include "compiler/disassembler.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "jvm_bsd.h"
  35 #include "memory/allocation.inline.hpp"
  36 #include "memory/filemap.hpp"
  37 #include "mutex_bsd.inline.hpp"
  38 #include "oops/oop.inline.hpp"
  39 #include "os_share_bsd.hpp"
  40 #include "prims/jniFastGetField.hpp"
  41 #include "prims/jvm.h"
  42 #include "prims/jvm_misc.hpp"
  43 #include "runtime/arguments.hpp"
  44 #include "runtime/extendedPC.hpp"
  45 #include "runtime/globals.hpp"
  46 #include "runtime/interfaceSupport.hpp"
  47 #include "runtime/java.hpp"
  48 #include "runtime/javaCalls.hpp"
  49 #include "runtime/mutexLocker.hpp"
  50 #include "runtime/objectMonitor.hpp"
  51 #include "runtime/orderAccess.inline.hpp"
  52 #include "runtime/osThread.hpp"
  53 #include "runtime/perfMemory.hpp"
  54 #include "runtime/sharedRuntime.hpp"
  55 #include "runtime/statSampler.hpp"
  56 #include "runtime/stubRoutines.hpp"
  57 #include "runtime/thread.inline.hpp"
  58 #include "runtime/threadCritical.hpp"
  59 #include "runtime/timer.hpp"
  60 #include "services/attachListener.hpp"
  61 #include "services/memTracker.hpp"
  62 #include "services/runtimeService.hpp"
  63 #include "utilities/decoder.hpp"
  64 #include "utilities/defaultStream.hpp"
  65 #include "utilities/events.hpp"
  66 #include "utilities/growableArray.hpp"
  67 #include "utilities/vmError.hpp"
  68 
  69 // put OS-includes here
  70 # include <sys/types.h>
  71 # include <sys/mman.h>
  72 # include <sys/stat.h>
  73 # include <sys/select.h>
  74 # include <pthread.h>
  75 # include <signal.h>
  76 # include <errno.h>
  77 # include <dlfcn.h>
  78 # include <stdio.h>
  79 # include <unistd.h>
  80 # include <sys/resource.h>
  81 # include <pthread.h>
  82 # include <sys/stat.h>
  83 # include <sys/time.h>
  84 # include <sys/times.h>
  85 # include <sys/utsname.h>
  86 # include <sys/socket.h>
  87 # include <sys/wait.h>
  88 # include <time.h>
  89 # include <pwd.h>
  90 # include <poll.h>
  91 # include <semaphore.h>
  92 # include <fcntl.h>
  93 # include <string.h>
  94 # include <sys/param.h>
  95 # include <sys/sysctl.h>
  96 # include <sys/ipc.h>
  97 # include <sys/shm.h>
  98 #ifndef __APPLE__
  99 # include <link.h>
 100 #endif
 101 # include <stdint.h>
 102 # include <inttypes.h>
 103 # include <sys/ioctl.h>
 104 # include <sys/syscall.h>
 105 
 106 #if defined(__FreeBSD__) || defined(__NetBSD__)
 107 # include <elf.h>
 108 #endif
 109 
 110 #ifdef __APPLE__
 111 # include <mach/mach.h> // semaphore_* API
 112 # include <mach-o/dyld.h>
 113 # include <sys/proc_info.h>
 114 # include <objc/objc-auto.h>
 115 #endif
 116 
 117 #ifndef MAP_ANONYMOUS
 118 #define MAP_ANONYMOUS MAP_ANON
 119 #endif
 120 
 121 #define MAX_PATH    (2 * K)
 122 
 123 // for timer info max values which include all bits
 124 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 125 
 126 #define LARGEPAGES_BIT (1 << 6)
 127 
 128 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 129 
 130 ////////////////////////////////////////////////////////////////////////////////
 131 // global variables
 132 julong os::Bsd::_physical_memory = 0;
 133 
 134 #ifdef __APPLE__
 135 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
 136 volatile uint64_t         os::Bsd::_max_abstime   = 0;
 137 #else
 138 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 139 #endif
 140 pthread_t os::Bsd::_main_thread;
 141 int os::Bsd::_page_size = -1;
 142 
 143 static jlong initial_time_count=0;
 144 
 145 static int clock_tics_per_sec = 100;
 146 
 147 // For diagnostics to print a message once. see run_periodic_checks
 148 static sigset_t check_signal_done;
 149 static bool check_signals = true;
 150 
 151 static pid_t _initial_pid = 0;
 152 
 153 /* Signal number used to suspend/resume a thread */
 154 
 155 /* do not use any signal number less than SIGSEGV, see 4355769 */
 156 static int SR_signum = SIGUSR2;
 157 sigset_t SR_sigset;
 158 
 159 
 160 ////////////////////////////////////////////////////////////////////////////////
 161 // utility functions
 162 
 163 static int SR_initialize();
 164 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
 165 
 166 julong os::available_memory() {
 167   return Bsd::available_memory();
 168 }
 169 
 170 // available here means free
 171 julong os::Bsd::available_memory() {
 172   uint64_t available = physical_memory() >> 2;
 173 #ifdef __APPLE__
 174   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
 175   vm_statistics64_data_t vmstat;
 176   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
 177                                          (host_info64_t)&vmstat, &count);
 178   assert(kerr == KERN_SUCCESS,
 179          "host_statistics64 failed - check mach_host_self() and count");
 180   if (kerr == KERN_SUCCESS) {
 181     available = vmstat.free_count * os::vm_page_size();
 182   }
 183 #endif
 184   return available;
 185 }
 186 
 187 julong os::physical_memory() {
 188   return Bsd::physical_memory();
 189 }
 190 
 191 ////////////////////////////////////////////////////////////////////////////////
 192 // environment support
 193 
 194 bool os::getenv(const char* name, char* buf, int len) {
 195   const char* val = ::getenv(name);
 196   if (val != NULL && strlen(val) < (size_t)len) {
 197     strcpy(buf, val);
 198     return true;
 199   }
 200   if (len > 0) buf[0] = 0;  // return a null string
 201   return false;
 202 }
 203 
 204 
 205 // Return true if user is running as root.
 206 
 207 bool os::have_special_privileges() {
 208   static bool init = false;
 209   static bool privileges = false;
 210   if (!init) {
 211     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 212     init = true;
 213   }
 214   return privileges;
 215 }
 216 
 217 
 218 
 219 // Cpu architecture string
 220 #if   defined(ZERO)
 221 static char cpu_arch[] = ZERO_LIBARCH;
 222 #elif defined(IA64)
 223 static char cpu_arch[] = "ia64";
 224 #elif defined(IA32)
 225 static char cpu_arch[] = "i386";
 226 #elif defined(AMD64)
 227 static char cpu_arch[] = "amd64";
 228 #elif defined(ARM)
 229 static char cpu_arch[] = "arm";
 230 #elif defined(PPC32)
 231 static char cpu_arch[] = "ppc";
 232 #elif defined(SPARC)
 233 #  ifdef _LP64
 234 static char cpu_arch[] = "sparcv9";
 235 #  else
 236 static char cpu_arch[] = "sparc";
 237 #  endif
 238 #else
 239 #error Add appropriate cpu_arch setting
 240 #endif
 241 
 242 // Compiler variant
 243 #ifdef COMPILER2
 244 #define COMPILER_VARIANT "server"
 245 #else
 246 #define COMPILER_VARIANT "client"
 247 #endif
 248 
 249 
 250 void os::Bsd::initialize_system_info() {
 251   int mib[2];
 252   size_t len;
 253   int cpu_val;
 254   julong mem_val;
 255 
 256   /* get processors count via hw.ncpus sysctl */
 257   mib[0] = CTL_HW;
 258   mib[1] = HW_NCPU;
 259   len = sizeof(cpu_val);
 260   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 261        assert(len == sizeof(cpu_val), "unexpected data size");
 262        set_processor_count(cpu_val);
 263   }
 264   else {
 265        set_processor_count(1);   // fallback
 266   }
 267 
 268   /* get physical memory via hw.memsize sysctl (hw.memsize is used
 269    * since it returns a 64 bit value)
 270    */
 271   mib[0] = CTL_HW;
 272 
 273 #if defined (HW_MEMSIZE) // Apple
 274   mib[1] = HW_MEMSIZE;
 275 #elif defined(HW_PHYSMEM) // Most of BSD
 276   mib[1] = HW_PHYSMEM;
 277 #elif defined(HW_REALMEM) // Old FreeBSD
 278   mib[1] = HW_REALMEM;
 279 #else
 280   #error No ways to get physmem
 281 #endif
 282 
 283   len = sizeof(mem_val);
 284   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 285        assert(len == sizeof(mem_val), "unexpected data size");
 286        _physical_memory = mem_val;
 287   } else {
 288        _physical_memory = 256*1024*1024;       // fallback (XXXBSD?)
 289   }
 290 
 291 #ifdef __OpenBSD__
 292   {
 293        // limit _physical_memory memory view on OpenBSD since
 294        // datasize rlimit restricts us anyway.
 295        struct rlimit limits;
 296        getrlimit(RLIMIT_DATA, &limits);
 297        _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 298   }
 299 #endif
 300 }
 301 
 302 #ifdef __APPLE__
 303 static const char *get_home() {
 304   const char *home_dir = ::getenv("HOME");
 305   if ((home_dir == NULL) || (*home_dir == '\0')) {
 306     struct passwd *passwd_info = getpwuid(geteuid());
 307     if (passwd_info != NULL) {
 308       home_dir = passwd_info->pw_dir;
 309     }
 310   }
 311 
 312   return home_dir;
 313 }
 314 #endif
 315 
 316 void os::init_system_properties_values() {
 317   // The next steps are taken in the product version:
 318   //
 319   // Obtain the JAVA_HOME value from the location of libjvm.so.
 320   // This library should be located at:
 321   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 322   //
 323   // If "/jre/lib/" appears at the right place in the path, then we
 324   // assume libjvm.so is installed in a JDK and we use this path.
 325   //
 326   // Otherwise exit with message: "Could not create the Java virtual machine."
 327   //
 328   // The following extra steps are taken in the debugging version:
 329   //
 330   // If "/jre/lib/" does NOT appear at the right place in the path
 331   // instead of exit check for $JAVA_HOME environment variable.
 332   //
 333   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 334   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 335   // it looks like libjvm.so is installed there
 336   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 337   //
 338   // Otherwise exit.
 339   //
 340   // Important note: if the location of libjvm.so changes this
 341   // code needs to be changed accordingly.
 342 
 343 // See ld(1):
 344 //      The linker uses the following search paths to locate required
 345 //      shared libraries:
 346 //        1: ...
 347 //        ...
 348 //        7: The default directories, normally /lib and /usr/lib.
 349 #ifndef DEFAULT_LIBPATH
 350 #define DEFAULT_LIBPATH "/lib:/usr/lib"
 351 #endif
 352 
 353 // Base path of extensions installed on the system.
 354 #define SYS_EXT_DIR     "/usr/java/packages"
 355 #define EXTENSIONS_DIR  "/lib/ext"
 356 #define ENDORSED_DIR    "/lib/endorsed"
 357 
 358 #ifndef __APPLE__
 359 
 360   // Buffer that fits several sprintfs.
 361   // Note that the space for the colon and the trailing null are provided
 362   // by the nulls included by the sizeof operator.
 363   const size_t bufsize =
 364     MAX3((size_t)MAXPATHLEN,  // For dll_dir & friends.
 365          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR), // extensions dir
 366          (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir
 367   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 368 
 369   // sysclasspath, java_home, dll_dir
 370   {
 371     char *pslash;
 372     os::jvm_path(buf, bufsize);
 373 
 374     // Found the full path to libjvm.so.
 375     // Now cut the path to <java_home>/jre if we can.
 376     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 377     pslash = strrchr(buf, '/');
 378     if (pslash != NULL) {
 379       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 380     }
 381     Arguments::set_dll_dir(buf);
 382 
 383     if (pslash != NULL) {
 384       pslash = strrchr(buf, '/');
 385       if (pslash != NULL) {
 386         *pslash = '\0';          // Get rid of /<arch>.
 387         pslash = strrchr(buf, '/');
 388         if (pslash != NULL) {
 389           *pslash = '\0';        // Get rid of /lib.
 390         }
 391       }
 392     }
 393     Arguments::set_java_home(buf);
 394     set_boot_path('/', ':');
 395   }
 396 
 397   // Where to look for native libraries.
 398   //
 399   // Note: Due to a legacy implementation, most of the library path
 400   // is set in the launcher. This was to accomodate linking restrictions
 401   // on legacy Bsd implementations (which are no longer supported).
 402   // Eventually, all the library path setting will be done here.
 403   //
 404   // However, to prevent the proliferation of improperly built native
 405   // libraries, the new path component /usr/java/packages is added here.
 406   // Eventually, all the library path setting will be done here.
 407   {
 408     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 409     // should always exist (until the legacy problem cited above is
 410     // addressed).
 411     const char *v = ::getenv("LD_LIBRARY_PATH");
 412     const char *v_colon = ":";
 413     if (v == NULL) { v = ""; v_colon = ""; }
 414     // That's +1 for the colon and +1 for the trailing '\0'.
 415     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 416                                                      strlen(v) + 1 +
 417                                                      sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
 418                                                      mtInternal);
 419     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
 420     Arguments::set_library_path(ld_library_path);
 421     FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal);
 422   }
 423 
 424   // Extensions directories.
 425   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
 426   Arguments::set_ext_dirs(buf);
 427 
 428   // Endorsed standards default directory.
 429   sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
 430   Arguments::set_endorsed_dirs(buf);
 431 
 432   FREE_C_HEAP_ARRAY(char, buf, mtInternal);
 433 
 434 #else // __APPLE__
 435 
 436 #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 437 #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 438 
 439   const char *user_home_dir = get_home();
 440   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
 441   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 442     sizeof(SYS_EXTENSIONS_DIRS);
 443 
 444   // Buffer that fits several sprintfs.
 445   // Note that the space for the colon and the trailing null are provided
 446   // by the nulls included by the sizeof operator.
 447   const size_t bufsize =
 448     MAX3((size_t)MAXPATHLEN,  // for dll_dir & friends.
 449          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size, // extensions dir
 450          (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir
 451   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 452 
 453   // sysclasspath, java_home, dll_dir
 454   {
 455     char *pslash;
 456     os::jvm_path(buf, bufsize);
 457 
 458     // Found the full path to libjvm.so.
 459     // Now cut the path to <java_home>/jre if we can.
 460     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 461     pslash = strrchr(buf, '/');
 462     if (pslash != NULL) {
 463       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 464     }
 465     Arguments::set_dll_dir(buf);
 466 
 467     if (pslash != NULL) {
 468       pslash = strrchr(buf, '/');
 469       if (pslash != NULL) {
 470         *pslash = '\0';          // Get rid of /lib.
 471       }
 472     }
 473     Arguments::set_java_home(buf);
 474     set_boot_path('/', ':');
 475   }
 476 
 477   // Where to look for native libraries.
 478   //
 479   // Note: Due to a legacy implementation, most of the library path
 480   // is set in the launcher. This was to accomodate linking restrictions
 481   // on legacy Bsd implementations (which are no longer supported).
 482   // Eventually, all the library path setting will be done here.
 483   //
 484   // However, to prevent the proliferation of improperly built native
 485   // libraries, the new path component /usr/java/packages is added here.
 486   // Eventually, all the library path setting will be done here.
 487   {
 488     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 489     // should always exist (until the legacy problem cited above is
 490     // addressed).
 491     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
 492     // can specify a directory inside an app wrapper
 493     const char *l = ::getenv("JAVA_LIBRARY_PATH");
 494     const char *l_colon = ":";
 495     if (l == NULL) { l = ""; l_colon = ""; }
 496 
 497     const char *v = ::getenv("DYLD_LIBRARY_PATH");
 498     const char *v_colon = ":";
 499     if (v == NULL) { v = ""; v_colon = ""; }
 500 
 501     // Apple's Java6 has "." at the beginning of java.library.path.
 502     // OpenJDK on Windows has "." at the end of java.library.path.
 503     // OpenJDK on Linux and Solaris don't have "." in java.library.path
 504     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 505     // "." is appended to the end of java.library.path. Yes, this
 506     // could cause a change in behavior, but Apple's Java6 behavior
 507     // can be achieved by putting "." at the beginning of the
 508     // JAVA_LIBRARY_PATH environment variable.
 509     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 510                                                      strlen(v) + 1 + strlen(l) + 1 +
 511                                                      system_ext_size + 3,
 512                                                      mtInternal);
 513     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
 514             v, v_colon, l, l_colon, user_home_dir);
 515     Arguments::set_library_path(ld_library_path);
 516     FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal);
 517   }
 518 
 519   // Extensions directories.
 520   //
 521   // Note that the space for the colon and the trailing null are provided
 522   // by the nulls included by the sizeof operator (so actually one byte more
 523   // than necessary is allocated).
 524   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
 525           user_home_dir, Arguments::get_java_home());
 526   Arguments::set_ext_dirs(buf);
 527 
 528   // Endorsed standards default directory.
 529   sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
 530   Arguments::set_endorsed_dirs(buf);
 531 
 532   FREE_C_HEAP_ARRAY(char, buf, mtInternal);
 533 
 534 #undef SYS_EXTENSIONS_DIR
 535 #undef SYS_EXTENSIONS_DIRS
 536 
 537 #endif // __APPLE__
 538 
 539 #undef SYS_EXT_DIR
 540 #undef EXTENSIONS_DIR
 541 #undef ENDORSED_DIR
 542 }
 543 
 544 ////////////////////////////////////////////////////////////////////////////////
 545 // breakpoint support
 546 
 547 void os::breakpoint() {
 548   BREAKPOINT;
 549 }
 550 
 551 extern "C" void breakpoint() {
 552   // use debugger to set breakpoint here
 553 }
 554 
 555 ////////////////////////////////////////////////////////////////////////////////
 556 // signal support
 557 
 558 debug_only(static bool signal_sets_initialized = false);
 559 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
 560 
 561 bool os::Bsd::is_sig_ignored(int sig) {
 562       struct sigaction oact;
 563       sigaction(sig, (struct sigaction*)NULL, &oact);
 564       void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
 565                                      : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
 566       if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
 567            return true;
 568       else
 569            return false;
 570 }
 571 
 572 void os::Bsd::signal_sets_init() {
 573   // Should also have an assertion stating we are still single-threaded.
 574   assert(!signal_sets_initialized, "Already initialized");
 575   // Fill in signals that are necessarily unblocked for all threads in
 576   // the VM. Currently, we unblock the following signals:
 577   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 578   //                         by -Xrs (=ReduceSignalUsage));
 579   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 580   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 581   // the dispositions or masks wrt these signals.
 582   // Programs embedding the VM that want to use the above signals for their
 583   // own purposes must, at this time, use the "-Xrs" option to prevent
 584   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 585   // (See bug 4345157, and other related bugs).
 586   // In reality, though, unblocking these signals is really a nop, since
 587   // these signals are not blocked by default.
 588   sigemptyset(&unblocked_sigs);
 589   sigemptyset(&allowdebug_blocked_sigs);
 590   sigaddset(&unblocked_sigs, SIGILL);
 591   sigaddset(&unblocked_sigs, SIGSEGV);
 592   sigaddset(&unblocked_sigs, SIGBUS);
 593   sigaddset(&unblocked_sigs, SIGFPE);
 594   sigaddset(&unblocked_sigs, SR_signum);
 595 
 596   if (!ReduceSignalUsage) {
 597    if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 598       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 599       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
 600    }
 601    if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 602       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 603       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
 604    }
 605    if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 606       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 607       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
 608    }
 609   }
 610   // Fill in signals that are blocked by all but the VM thread.
 611   sigemptyset(&vm_sigs);
 612   if (!ReduceSignalUsage)
 613     sigaddset(&vm_sigs, BREAK_SIGNAL);
 614   debug_only(signal_sets_initialized = true);
 615 
 616 }
 617 
 618 // These are signals that are unblocked while a thread is running Java.
 619 // (For some reason, they get blocked by default.)
 620 sigset_t* os::Bsd::unblocked_signals() {
 621   assert(signal_sets_initialized, "Not initialized");
 622   return &unblocked_sigs;
 623 }
 624 
 625 // These are the signals that are blocked while a (non-VM) thread is
 626 // running Java. Only the VM thread handles these signals.
 627 sigset_t* os::Bsd::vm_signals() {
 628   assert(signal_sets_initialized, "Not initialized");
 629   return &vm_sigs;
 630 }
 631 
 632 // These are signals that are blocked during cond_wait to allow debugger in
 633 sigset_t* os::Bsd::allowdebug_blocked_signals() {
 634   assert(signal_sets_initialized, "Not initialized");
 635   return &allowdebug_blocked_sigs;
 636 }
 637 
 638 void os::Bsd::hotspot_sigmask(Thread* thread) {
 639 
 640   //Save caller's signal mask before setting VM signal mask
 641   sigset_t caller_sigmask;
 642   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 643 
 644   OSThread* osthread = thread->osthread();
 645   osthread->set_caller_sigmask(caller_sigmask);
 646 
 647   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 648 
 649   if (!ReduceSignalUsage) {
 650     if (thread->is_VM_thread()) {
 651       // Only the VM thread handles BREAK_SIGNAL ...
 652       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 653     } else {
 654       // ... all other threads block BREAK_SIGNAL
 655       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 656     }
 657   }
 658 }
 659 
 660 
 661 //////////////////////////////////////////////////////////////////////////////
 662 // create new thread
 663 
 664 // check if it's safe to start a new thread
 665 static bool _thread_safety_check(Thread* thread) {
 666   return true;
 667 }
 668 
 669 #ifdef __APPLE__
 670 // library handle for calling objc_registerThreadWithCollector()
 671 // without static linking to the libobjc library
 672 #define OBJC_LIB "/usr/lib/libobjc.dylib"
 673 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 674 typedef void (*objc_registerThreadWithCollector_t)();
 675 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 676 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 677 #endif
 678 
 679 #ifdef __APPLE__
 680 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 681   // Additional thread_id used to correlate threads in SA
 682   thread_identifier_info_data_t     m_ident_info;
 683   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 684 
 685   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 686               (thread_info_t) &m_ident_info, &count);
 687 
 688   return m_ident_info.thread_id;
 689 }
 690 #endif
 691 
 692 // Thread start routine for all newly created threads
 693 static void *java_start(Thread *thread) {
 694   // Try to randomize the cache line index of hot stack frames.
 695   // This helps when threads of the same stack traces evict each other's
 696   // cache lines. The threads can be either from the same JVM instance, or
 697   // from different JVM instances. The benefit is especially true for
 698   // processors with hyperthreading technology.
 699   static int counter = 0;
 700   int pid = os::current_process_id();
 701   alloca(((pid ^ counter++) & 7) * 128);
 702 
 703   ThreadLocalStorage::set_thread(thread);
 704 
 705   OSThread* osthread = thread->osthread();
 706   Monitor* sync = osthread->startThread_lock();
 707 
 708   // non floating stack BsdThreads needs extra check, see above
 709   if (!_thread_safety_check(thread)) {
 710     // notify parent thread
 711     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 712     osthread->set_state(ZOMBIE);
 713     sync->notify_all();
 714     return NULL;
 715   }
 716 
 717   osthread->set_thread_id(os::Bsd::gettid());
 718 
 719 #ifdef __APPLE__
 720   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 721   guarantee(unique_thread_id != 0, "unique thread id was not found");
 722   osthread->set_unique_thread_id(unique_thread_id);
 723 #endif
 724   // initialize signal mask for this thread
 725   os::Bsd::hotspot_sigmask(thread);
 726 
 727   // initialize floating point control register
 728   os::Bsd::init_thread_fpu_state();
 729 
 730 #ifdef __APPLE__
 731   // register thread with objc gc
 732   if (objc_registerThreadWithCollectorFunction != NULL) {
 733     objc_registerThreadWithCollectorFunction();
 734   }
 735 #endif
 736 
 737   // handshaking with parent thread
 738   {
 739     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 740 
 741     // notify parent thread
 742     osthread->set_state(INITIALIZED);
 743     sync->notify_all();
 744 
 745     // wait until os::start_thread()
 746     while (osthread->get_state() == INITIALIZED) {
 747       sync->wait(Mutex::_no_safepoint_check_flag);
 748     }
 749   }
 750 
 751   // call one more level start routine
 752   thread->run();
 753 
 754   return 0;
 755 }
 756 
 757 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
 758   assert(thread->osthread() == NULL, "caller responsible");
 759 
 760   // Allocate the OSThread object
 761   OSThread* osthread = new OSThread(NULL, NULL);
 762   if (osthread == NULL) {
 763     return false;
 764   }
 765 
 766   // set the correct thread state
 767   osthread->set_thread_type(thr_type);
 768 
 769   // Initial state is ALLOCATED but not INITIALIZED
 770   osthread->set_state(ALLOCATED);
 771 
 772   thread->set_osthread(osthread);
 773 
 774   // init thread attributes
 775   pthread_attr_t attr;
 776   pthread_attr_init(&attr);
 777   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 778 
 779   // stack size
 780   if (os::Bsd::supports_variable_stack_size()) {
 781     // calculate stack size if it's not specified by caller
 782     if (stack_size == 0) {
 783       stack_size = os::Bsd::default_stack_size(thr_type);
 784 
 785       switch (thr_type) {
 786       case os::java_thread:
 787         // Java threads use ThreadStackSize which default value can be
 788         // changed with the flag -Xss
 789         assert (JavaThread::stack_size_at_create() > 0, "this should be set");
 790         stack_size = JavaThread::stack_size_at_create();
 791         break;
 792       case os::compiler_thread:
 793         if (CompilerThreadStackSize > 0) {
 794           stack_size = (size_t)(CompilerThreadStackSize * K);
 795           break;
 796         } // else fall through:
 797           // use VMThreadStackSize if CompilerThreadStackSize is not defined
 798       case os::vm_thread:
 799       case os::pgc_thread:
 800       case os::cgc_thread:
 801       case os::watcher_thread:
 802         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 803         break;
 804       }
 805     }
 806 
 807     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
 808     pthread_attr_setstacksize(&attr, stack_size);
 809   } else {
 810     // let pthread_create() pick the default value.
 811   }
 812 
 813   ThreadState state;
 814 
 815   {
 816     pthread_t tid;
 817     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
 818 
 819     pthread_attr_destroy(&attr);
 820 
 821     if (ret != 0) {
 822       if (PrintMiscellaneous && (Verbose || WizardMode)) {
 823         perror("pthread_create()");
 824       }
 825       // Need to clean up stuff we've allocated so far
 826       thread->set_osthread(NULL);
 827       delete osthread;
 828       return false;
 829     }
 830 
 831     // Store pthread info into the OSThread
 832     osthread->set_pthread_id(tid);
 833 
 834     // Wait until child thread is either initialized or aborted
 835     {
 836       Monitor* sync_with_child = osthread->startThread_lock();
 837       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 838       while ((state = osthread->get_state()) == ALLOCATED) {
 839         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 840       }
 841     }
 842 
 843   }
 844 
 845   // Aborted due to thread limit being reached
 846   if (state == ZOMBIE) {
 847       thread->set_osthread(NULL);
 848       delete osthread;
 849       return false;
 850   }
 851 
 852   // The thread is returned suspended (in state INITIALIZED),
 853   // and is started higher up in the call chain
 854   assert(state == INITIALIZED, "race condition");
 855   return true;
 856 }
 857 
 858 /////////////////////////////////////////////////////////////////////////////
 859 // attach existing thread
 860 
 861 // bootstrap the main thread
 862 bool os::create_main_thread(JavaThread* thread) {
 863   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 864   return create_attached_thread(thread);
 865 }
 866 
 867 bool os::create_attached_thread(JavaThread* thread) {
 868 #ifdef ASSERT
 869     thread->verify_not_published();
 870 #endif
 871 
 872   // Allocate the OSThread object
 873   OSThread* osthread = new OSThread(NULL, NULL);
 874 
 875   if (osthread == NULL) {
 876     return false;
 877   }
 878 
 879   osthread->set_thread_id(os::Bsd::gettid());
 880 
 881   // Store pthread info into the OSThread
 882 #ifdef __APPLE__
 883   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 884   guarantee(unique_thread_id != 0, "just checking");
 885   osthread->set_unique_thread_id(unique_thread_id);
 886 #endif
 887   osthread->set_pthread_id(::pthread_self());
 888 
 889   // initialize floating point control register
 890   os::Bsd::init_thread_fpu_state();
 891 
 892   // Initial thread state is RUNNABLE
 893   osthread->set_state(RUNNABLE);
 894 
 895   thread->set_osthread(osthread);
 896 
 897   // initialize signal mask for this thread
 898   // and save the caller's signal mask
 899   os::Bsd::hotspot_sigmask(thread);
 900 
 901   return true;
 902 }
 903 
 904 void os::pd_start_thread(Thread* thread) {
 905   OSThread * osthread = thread->osthread();
 906   assert(osthread->get_state() != INITIALIZED, "just checking");
 907   Monitor* sync_with_child = osthread->startThread_lock();
 908   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 909   sync_with_child->notify();
 910 }
 911 
 912 // Free Bsd resources related to the OSThread
 913 void os::free_thread(OSThread* osthread) {
 914   assert(osthread != NULL, "osthread not set");
 915 
 916   if (Thread::current()->osthread() == osthread) {
 917     // Restore caller's signal mask
 918     sigset_t sigmask = osthread->caller_sigmask();
 919     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 920    }
 921 
 922   delete osthread;
 923 }
 924 
 925 //////////////////////////////////////////////////////////////////////////////
 926 // thread local storage
 927 
 928 // Restore the thread pointer if the destructor is called. This is in case
 929 // someone from JNI code sets up a destructor with pthread_key_create to run
 930 // detachCurrentThread on thread death. Unless we restore the thread pointer we
 931 // will hang or crash. When detachCurrentThread is called the key will be set
 932 // to null and we will not be called again. If detachCurrentThread is never
 933 // called we could loop forever depending on the pthread implementation.
 934 static void restore_thread_pointer(void* p) {
 935   Thread* thread = (Thread*) p;
 936   os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
 937 }
 938 
 939 int os::allocate_thread_local_storage() {
 940   pthread_key_t key;
 941   int rslt = pthread_key_create(&key, restore_thread_pointer);
 942   assert(rslt == 0, "cannot allocate thread local storage");
 943   return (int)key;
 944 }
 945 
 946 // Note: This is currently not used by VM, as we don't destroy TLS key
 947 // on VM exit.
 948 void os::free_thread_local_storage(int index) {
 949   int rslt = pthread_key_delete((pthread_key_t)index);
 950   assert(rslt == 0, "invalid index");
 951 }
 952 
 953 void os::thread_local_storage_at_put(int index, void* value) {
 954   int rslt = pthread_setspecific((pthread_key_t)index, value);
 955   assert(rslt == 0, "pthread_setspecific failed");
 956 }
 957 
 958 extern "C" Thread* get_thread() {
 959   return ThreadLocalStorage::thread();
 960 }
 961 
 962 
 963 ////////////////////////////////////////////////////////////////////////////////
 964 // time support
 965 
 966 // Time since start-up in seconds to a fine granularity.
 967 // Used by VMSelfDestructTimer and the MemProfiler.
 968 double os::elapsedTime() {
 969 
 970   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 971 }
 972 
 973 jlong os::elapsed_counter() {
 974   return javaTimeNanos() - initial_time_count;
 975 }
 976 
 977 jlong os::elapsed_frequency() {
 978   return NANOSECS_PER_SEC; // nanosecond resolution
 979 }
 980 
 981 bool os::supports_vtime() { return true; }
 982 bool os::enable_vtime()   { return false; }
 983 bool os::vtime_enabled()  { return false; }
 984 
 985 double os::elapsedVTime() {
 986   // better than nothing, but not much
 987   return elapsedTime();
 988 }
 989 
 990 jlong os::javaTimeMillis() {
 991   timeval time;
 992   int status = gettimeofday(&time, NULL);
 993   assert(status != -1, "bsd error");
 994   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 995 }
 996 
 997 #ifndef __APPLE__
 998 #ifndef CLOCK_MONOTONIC
 999 #define CLOCK_MONOTONIC (1)
1000 #endif
1001 #endif
1002 
1003 #ifdef __APPLE__
1004 void os::Bsd::clock_init() {
1005   mach_timebase_info(&_timebase_info);
1006 }
1007 #else
1008 void os::Bsd::clock_init() {
1009   struct timespec res;
1010   struct timespec tp;
1011   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
1012       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
1013     // yes, monotonic clock is supported
1014     _clock_gettime = ::clock_gettime;
1015   }
1016 }
1017 #endif
1018 
1019 
1020 #ifdef __APPLE__
1021 
1022 jlong os::javaTimeNanos() {
1023     const uint64_t tm = mach_absolute_time();
1024     const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
1025     const uint64_t prev = Bsd::_max_abstime;
1026     if (now <= prev) {
1027       return prev;   // same or retrograde time;
1028     }
1029     const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
1030     assert(obsv >= prev, "invariant");   // Monotonicity
1031     // If the CAS succeeded then we're done and return "now".
1032     // If the CAS failed and the observed value "obsv" is >= now then
1033     // we should return "obsv".  If the CAS failed and now > obsv > prv then
1034     // some other thread raced this thread and installed a new value, in which case
1035     // we could either (a) retry the entire operation, (b) retry trying to install now
1036     // or (c) just return obsv.  We use (c).   No loop is required although in some cases
1037     // we might discard a higher "now" value in deference to a slightly lower but freshly
1038     // installed obsv value.   That's entirely benign -- it admits no new orderings compared
1039     // to (a) or (b) -- and greatly reduces coherence traffic.
1040     // We might also condition (c) on the magnitude of the delta between obsv and now.
1041     // Avoiding excessive CAS operations to hot RW locations is critical.
1042     // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1043     return (prev == obsv) ? now : obsv;
1044 }
1045 
1046 #else // __APPLE__
1047 
1048 jlong os::javaTimeNanos() {
1049   if (Bsd::supports_monotonic_clock()) {
1050     struct timespec tp;
1051     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
1052     assert(status == 0, "gettime error");
1053     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1054     return result;
1055   } else {
1056     timeval time;
1057     int status = gettimeofday(&time, NULL);
1058     assert(status != -1, "bsd error");
1059     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1060     return 1000 * usecs;
1061   }
1062 }
1063 
1064 #endif // __APPLE__
1065 
1066 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1067   if (Bsd::supports_monotonic_clock()) {
1068     info_ptr->max_value = ALL_64_BITS;
1069 
1070     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1071     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
1072     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
1073   } else {
1074     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1075     info_ptr->max_value = ALL_64_BITS;
1076 
1077     // gettimeofday is a real time clock so it skips
1078     info_ptr->may_skip_backward = true;
1079     info_ptr->may_skip_forward = true;
1080   }
1081 
1082   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
1083 }
1084 
1085 // Return the real, user, and system times in seconds from an
1086 // arbitrary fixed point in the past.
1087 bool os::getTimesSecs(double* process_real_time,
1088                       double* process_user_time,
1089                       double* process_system_time) {
1090   struct tms ticks;
1091   clock_t real_ticks = times(&ticks);
1092 
1093   if (real_ticks == (clock_t) (-1)) {
1094     return false;
1095   } else {
1096     double ticks_per_second = (double) clock_tics_per_sec;
1097     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1098     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1099     *process_real_time = ((double) real_ticks) / ticks_per_second;
1100 
1101     return true;
1102   }
1103 }
1104 
1105 
1106 char * os::local_time_string(char *buf, size_t buflen) {
1107   struct tm t;
1108   time_t long_time;
1109   time(&long_time);
1110   localtime_r(&long_time, &t);
1111   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1112                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1113                t.tm_hour, t.tm_min, t.tm_sec);
1114   return buf;
1115 }
1116 
1117 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1118   return localtime_r(clock, res);
1119 }
1120 
1121 ////////////////////////////////////////////////////////////////////////////////
1122 // runtime exit support
1123 
1124 // Note: os::shutdown() might be called very early during initialization, or
1125 // called from signal handler. Before adding something to os::shutdown(), make
1126 // sure it is async-safe and can handle partially initialized VM.
1127 void os::shutdown() {
1128 
1129   // allow PerfMemory to attempt cleanup of any persistent resources
1130   perfMemory_exit();
1131 
1132   // needs to remove object in file system
1133   AttachListener::abort();
1134 
1135   // flush buffered output, finish log files
1136   ostream_abort();
1137 
1138   // Check for abort hook
1139   abort_hook_t abort_hook = Arguments::abort_hook();
1140   if (abort_hook != NULL) {
1141     abort_hook();
1142   }
1143 
1144 }
1145 
1146 // Note: os::abort() might be called very early during initialization, or
1147 // called from signal handler. Before adding something to os::abort(), make
1148 // sure it is async-safe and can handle partially initialized VM.
1149 void os::abort(bool dump_core) {
1150   os::shutdown();
1151   if (dump_core) {
1152 #ifndef PRODUCT
1153     fdStream out(defaultStream::output_fd());
1154     out.print_raw("Current thread is ");
1155     char buf[16];
1156     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1157     out.print_raw_cr(buf);
1158     out.print_raw_cr("Dumping core ...");
1159 #endif
1160     ::abort(); // dump core
1161   }
1162 
1163   ::exit(1);
1164 }
1165 
1166 // Die immediately, no exit hook, no abort hook, no cleanup.
1167 void os::die() {
1168   // _exit() on BsdThreads only kills current thread
1169   ::abort();
1170 }
1171 
1172 // This method is a copy of JDK's sysGetLastErrorString
1173 // from src/solaris/hpi/src/system_md.c
1174 
1175 size_t os::lasterror(char *buf, size_t len) {
1176 
1177   if (errno == 0)  return 0;
1178 
1179   const char *s = ::strerror(errno);
1180   size_t n = ::strlen(s);
1181   if (n >= len) {
1182     n = len - 1;
1183   }
1184   ::strncpy(buf, s, n);
1185   buf[n] = '\0';
1186   return n;
1187 }
1188 
1189 // Information of current thread in variety of formats
1190 pid_t os::Bsd::gettid() {
1191   int retval = -1;
1192 
1193 #ifdef __APPLE__ //XNU kernel
1194   // despite the fact mach port is actually not a thread id use it
1195   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1196   retval = ::pthread_mach_thread_np(::pthread_self());
1197   guarantee(retval != 0, "just checking");
1198   return retval;
1199 
1200 #else
1201   #ifdef __FreeBSD__
1202   retval = syscall(SYS_thr_self);
1203   #else
1204     #ifdef __OpenBSD__
1205   retval = syscall(SYS_getthrid);
1206     #else
1207       #ifdef __NetBSD__
1208   retval = (pid_t) syscall(SYS__lwp_self);
1209       #endif
1210     #endif
1211   #endif
1212 #endif
1213 
1214   if (retval == -1) {
1215     return getpid();
1216   }
1217 }
1218 
1219 intx os::current_thread_id() {
1220 #ifdef __APPLE__
1221   return (intx)::pthread_mach_thread_np(::pthread_self());
1222 #else
1223   return (intx)::pthread_self();
1224 #endif
1225 }
1226 
1227 int os::current_process_id() {
1228 
1229   // Under the old bsd thread library, bsd gives each thread
1230   // its own process id. Because of this each thread will return
1231   // a different pid if this method were to return the result
1232   // of getpid(2). Bsd provides no api that returns the pid
1233   // of the launcher thread for the vm. This implementation
1234   // returns a unique pid, the pid of the launcher thread
1235   // that starts the vm 'process'.
1236 
1237   // Under the NPTL, getpid() returns the same pid as the
1238   // launcher thread rather than a unique pid per thread.
1239   // Use gettid() if you want the old pre NPTL behaviour.
1240 
1241   // if you are looking for the result of a call to getpid() that
1242   // returns a unique pid for the calling thread, then look at the
1243   // OSThread::thread_id() method in osThread_bsd.hpp file
1244 
1245   return (int)(_initial_pid ? _initial_pid : getpid());
1246 }
1247 
1248 // DLL functions
1249 
1250 #define JNI_LIB_PREFIX "lib"
1251 #ifdef __APPLE__
1252 #define JNI_LIB_SUFFIX ".dylib"
1253 #else
1254 #define JNI_LIB_SUFFIX ".so"
1255 #endif
1256 
1257 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1258 
1259 // This must be hard coded because it's the system's temporary
1260 // directory not the java application's temp directory, ala java.io.tmpdir.
1261 #ifdef __APPLE__
1262 // macosx has a secure per-user temporary directory
1263 char temp_path_storage[PATH_MAX];
1264 const char* os::get_temp_directory() {
1265   static char *temp_path = NULL;
1266   if (temp_path == NULL) {
1267     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1268     if (pathSize == 0 || pathSize > PATH_MAX) {
1269       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1270     }
1271     temp_path = temp_path_storage;
1272   }
1273   return temp_path;
1274 }
1275 #else /* __APPLE__ */
1276 const char* os::get_temp_directory() { return "/tmp"; }
1277 #endif /* __APPLE__ */
1278 
1279 static bool file_exists(const char* filename) {
1280   struct stat statbuf;
1281   if (filename == NULL || strlen(filename) == 0) {
1282     return false;
1283   }
1284   return os::stat(filename, &statbuf) == 0;
1285 }
1286 
1287 bool os::dll_build_name(char* buffer, size_t buflen,
1288                         const char* pname, const char* fname) {
1289   bool retval = false;
1290   // Copied from libhpi
1291   const size_t pnamelen = pname ? strlen(pname) : 0;
1292 
1293   // Return error on buffer overflow.
1294   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1295     return retval;
1296   }
1297 
1298   if (pnamelen == 0) {
1299     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1300     retval = true;
1301   } else if (strchr(pname, *os::path_separator()) != NULL) {
1302     int n;
1303     char** pelements = split_path(pname, &n);
1304     if (pelements == NULL) {
1305       return false;
1306     }
1307     for (int i = 0 ; i < n ; i++) {
1308       // Really shouldn't be NULL, but check can't hurt
1309       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1310         continue; // skip the empty path values
1311       }
1312       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1313           pelements[i], fname);
1314       if (file_exists(buffer)) {
1315         retval = true;
1316         break;
1317       }
1318     }
1319     // release the storage
1320     for (int i = 0 ; i < n ; i++) {
1321       if (pelements[i] != NULL) {
1322         FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
1323       }
1324     }
1325     if (pelements != NULL) {
1326       FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
1327     }
1328   } else {
1329     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1330     retval = true;
1331   }
1332   return retval;
1333 }
1334 
1335 // check if addr is inside libjvm.so
1336 bool os::address_is_in_vm(address addr) {
1337   static address libjvm_base_addr;
1338   Dl_info dlinfo;
1339 
1340   if (libjvm_base_addr == NULL) {
1341     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1342       libjvm_base_addr = (address)dlinfo.dli_fbase;
1343     }
1344     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1345   }
1346 
1347   if (dladdr((void *)addr, &dlinfo) != 0) {
1348     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1349   }
1350 
1351   return false;
1352 }
1353 
1354 
1355 #define MACH_MAXSYMLEN 256
1356 
1357 bool os::dll_address_to_function_name(address addr, char *buf,
1358                                       int buflen, int *offset) {
1359   // buf is not optional, but offset is optional
1360   assert(buf != NULL, "sanity check");
1361 
1362   Dl_info dlinfo;
1363   char localbuf[MACH_MAXSYMLEN];
1364 
1365   if (dladdr((void*)addr, &dlinfo) != 0) {
1366     // see if we have a matching symbol
1367     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1368       if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1369         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1370       }
1371       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1372       return true;
1373     }
1374     // no matching symbol so try for just file info
1375     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1376       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1377                           buf, buflen, offset, dlinfo.dli_fname)) {
1378          return true;
1379       }
1380     }
1381 
1382     // Handle non-dynamic manually:
1383     if (dlinfo.dli_fbase != NULL &&
1384         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1385                         dlinfo.dli_fbase)) {
1386       if (!Decoder::demangle(localbuf, buf, buflen)) {
1387         jio_snprintf(buf, buflen, "%s", localbuf);
1388       }
1389       return true;
1390     }
1391   }
1392   buf[0] = '\0';
1393   if (offset != NULL) *offset = -1;
1394   return false;
1395 }
1396 
1397 // ported from solaris version
1398 bool os::dll_address_to_library_name(address addr, char* buf,
1399                                      int buflen, int* offset) {
1400   // buf is not optional, but offset is optional
1401   assert(buf != NULL, "sanity check");
1402 
1403   Dl_info dlinfo;
1404 
1405   if (dladdr((void*)addr, &dlinfo) != 0) {
1406     if (dlinfo.dli_fname != NULL) {
1407       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1408     }
1409     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1410       *offset = addr - (address)dlinfo.dli_fbase;
1411     }
1412     return true;
1413   }
1414 
1415   buf[0] = '\0';
1416   if (offset) *offset = -1;
1417   return false;
1418 }
1419 
1420 // Loads .dll/.so and
1421 // in case of error it checks if .dll/.so was built for the
1422 // same architecture as Hotspot is running on
1423 
1424 #ifdef __APPLE__
1425 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1426   void * result= ::dlopen(filename, RTLD_LAZY);
1427   if (result != NULL) {
1428     // Successful loading
1429     return result;
1430   }
1431 
1432   // Read system error message into ebuf
1433   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1434   ebuf[ebuflen-1]='\0';
1435 
1436   return NULL;
1437 }
1438 #else
1439 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
1440 {
1441   void * result= ::dlopen(filename, RTLD_LAZY);
1442   if (result != NULL) {
1443     // Successful loading
1444     return result;
1445   }
1446 
1447   Elf32_Ehdr elf_head;
1448 
1449   // Read system error message into ebuf
1450   // It may or may not be overwritten below
1451   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1452   ebuf[ebuflen-1]='\0';
1453   int diag_msg_max_length=ebuflen-strlen(ebuf);
1454   char* diag_msg_buf=ebuf+strlen(ebuf);
1455 
1456   if (diag_msg_max_length==0) {
1457     // No more space in ebuf for additional diagnostics message
1458     return NULL;
1459   }
1460 
1461 
1462   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1463 
1464   if (file_descriptor < 0) {
1465     // Can't open library, report dlerror() message
1466     return NULL;
1467   }
1468 
1469   bool failed_to_read_elf_head=
1470     (sizeof(elf_head)!=
1471         (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
1472 
1473   ::close(file_descriptor);
1474   if (failed_to_read_elf_head) {
1475     // file i/o error - report dlerror() msg
1476     return NULL;
1477   }
1478 
1479   typedef struct {
1480     Elf32_Half  code;         // Actual value as defined in elf.h
1481     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1482     char        elf_class;    // 32 or 64 bit
1483     char        endianess;    // MSB or LSB
1484     char*       name;         // String representation
1485   } arch_t;
1486 
1487   #ifndef EM_486
1488   #define EM_486          6               /* Intel 80486 */
1489   #endif
1490 
1491   #ifndef EM_MIPS_RS3_LE
1492   #define EM_MIPS_RS3_LE  10              /* MIPS */
1493   #endif
1494 
1495   #ifndef EM_PPC64
1496   #define EM_PPC64        21              /* PowerPC64 */
1497   #endif
1498 
1499   #ifndef EM_S390
1500   #define EM_S390         22              /* IBM System/390 */
1501   #endif
1502 
1503   #ifndef EM_IA_64
1504   #define EM_IA_64        50              /* HP/Intel IA-64 */
1505   #endif
1506 
1507   #ifndef EM_X86_64
1508   #define EM_X86_64       62              /* AMD x86-64 */
1509   #endif
1510 
1511   static const arch_t arch_array[]={
1512     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1513     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1514     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1515     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1516     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1517     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1518     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1519     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1520     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1521     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1522     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1523     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1524     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1525     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1526     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1527     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1528   };
1529 
1530   #if  (defined IA32)
1531     static  Elf32_Half running_arch_code=EM_386;
1532   #elif   (defined AMD64)
1533     static  Elf32_Half running_arch_code=EM_X86_64;
1534   #elif  (defined IA64)
1535     static  Elf32_Half running_arch_code=EM_IA_64;
1536   #elif  (defined __sparc) && (defined _LP64)
1537     static  Elf32_Half running_arch_code=EM_SPARCV9;
1538   #elif  (defined __sparc) && (!defined _LP64)
1539     static  Elf32_Half running_arch_code=EM_SPARC;
1540   #elif  (defined __powerpc64__)
1541     static  Elf32_Half running_arch_code=EM_PPC64;
1542   #elif  (defined __powerpc__)
1543     static  Elf32_Half running_arch_code=EM_PPC;
1544   #elif  (defined ARM)
1545     static  Elf32_Half running_arch_code=EM_ARM;
1546   #elif  (defined S390)
1547     static  Elf32_Half running_arch_code=EM_S390;
1548   #elif  (defined ALPHA)
1549     static  Elf32_Half running_arch_code=EM_ALPHA;
1550   #elif  (defined MIPSEL)
1551     static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1552   #elif  (defined PARISC)
1553     static  Elf32_Half running_arch_code=EM_PARISC;
1554   #elif  (defined MIPS)
1555     static  Elf32_Half running_arch_code=EM_MIPS;
1556   #elif  (defined M68K)
1557     static  Elf32_Half running_arch_code=EM_68K;
1558   #else
1559     #error Method os::dll_load requires that one of following is defined:\
1560          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1561   #endif
1562 
1563   // Identify compatability class for VM's architecture and library's architecture
1564   // Obtain string descriptions for architectures
1565 
1566   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1567   int running_arch_index=-1;
1568 
1569   for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
1570     if (running_arch_code == arch_array[i].code) {
1571       running_arch_index    = i;
1572     }
1573     if (lib_arch.code == arch_array[i].code) {
1574       lib_arch.compat_class = arch_array[i].compat_class;
1575       lib_arch.name         = arch_array[i].name;
1576     }
1577   }
1578 
1579   assert(running_arch_index != -1,
1580     "Didn't find running architecture code (running_arch_code) in arch_array");
1581   if (running_arch_index == -1) {
1582     // Even though running architecture detection failed
1583     // we may still continue with reporting dlerror() message
1584     return NULL;
1585   }
1586 
1587   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1588     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1589     return NULL;
1590   }
1591 
1592 #ifndef S390
1593   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1594     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1595     return NULL;
1596   }
1597 #endif // !S390
1598 
1599   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1600     if ( lib_arch.name!=NULL ) {
1601       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1602         " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1603         lib_arch.name, arch_array[running_arch_index].name);
1604     } else {
1605       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1606       " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1607         lib_arch.code,
1608         arch_array[running_arch_index].name);
1609     }
1610   }
1611 
1612   return NULL;
1613 }
1614 #endif /* !__APPLE__ */
1615 
1616 void* os::get_default_process_handle() {
1617 #ifdef __APPLE__
1618   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1619   // to avoid finding unexpected symbols on second (or later)
1620   // loads of a library.
1621   return (void*)::dlopen(NULL, RTLD_FIRST);
1622 #else
1623   return (void*)::dlopen(NULL, RTLD_LAZY);
1624 #endif
1625 }
1626 
1627 // XXX: Do we need a lock around this as per Linux?
1628 void* os::dll_lookup(void* handle, const char* name) {
1629   return dlsym(handle, name);
1630 }
1631 
1632 
1633 static bool _print_ascii_file(const char* filename, outputStream* st) {
1634   int fd = ::open(filename, O_RDONLY);
1635   if (fd == -1) {
1636      return false;
1637   }
1638 
1639   char buf[32];
1640   int bytes;
1641   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1642     st->print_raw(buf, bytes);
1643   }
1644 
1645   ::close(fd);
1646 
1647   return true;
1648 }
1649 
1650 void os::print_dll_info(outputStream *st) {
1651   st->print_cr("Dynamic libraries:");
1652 #ifdef RTLD_DI_LINKMAP
1653   Dl_info dli;
1654   void *handle;
1655   Link_map *map;
1656   Link_map *p;
1657 
1658   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1659       dli.dli_fname == NULL) {
1660     st->print_cr("Error: Cannot print dynamic libraries.");
1661     return;
1662   }
1663   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1664   if (handle == NULL) {
1665     st->print_cr("Error: Cannot print dynamic libraries.");
1666     return;
1667   }
1668   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1669   if (map == NULL) {
1670     st->print_cr("Error: Cannot print dynamic libraries.");
1671     return;
1672   }
1673 
1674   while (map->l_prev != NULL)
1675     map = map->l_prev;
1676 
1677   while (map != NULL) {
1678     st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
1679     map = map->l_next;
1680   }
1681 
1682   dlclose(handle);
1683 #elif defined(__APPLE__)
1684   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1685     st->print_cr(PTR_FORMAT " \t%s", _dyld_get_image_header(i),
1686         _dyld_get_image_name(i));
1687   }
1688 #else
1689   st->print_cr("Error: Cannot print dynamic libraries.");
1690 #endif
1691 }
1692 
1693 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1694 #ifdef RTLD_DI_LINKMAP
1695   Dl_info dli;
1696   void *handle;
1697   Link_map *map;
1698   Link_map *p;
1699 
1700   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1701       dli.dli_fname == NULL) {
1702     return 1;
1703   }
1704   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1705   if (handle == NULL) {
1706     return 1;
1707   }
1708   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1709   if (map == NULL) {
1710     dlclose(handle);
1711     return 1;
1712   }
1713 
1714   while (map->l_prev != NULL)
1715     map = map->l_prev;
1716 
1717   while (map != NULL) {
1718     // Value for top_address is returned as 0 since we don't have any information about module size
1719     if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1720       dlclose(handle);
1721       return 1;
1722     }
1723     map = map->l_next;
1724   }
1725 
1726   dlclose(handle);
1727 #elif defined(__APPLE__)
1728   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1729     // Value for top_address is returned as 0 since we don't have any information about module size
1730     if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1731       return 1;
1732     }
1733   }
1734   return 0;
1735 #else
1736   return 1;
1737 #endif
1738 }
1739 
1740 void os::print_os_info_brief(outputStream* st) {
1741   st->print("Bsd");
1742 
1743   os::Posix::print_uname_info(st);
1744 }
1745 
1746 void os::print_os_info(outputStream* st) {
1747   st->print("OS:");
1748   st->print("Bsd");
1749 
1750   os::Posix::print_uname_info(st);
1751 
1752   os::Posix::print_rlimit_info(st);
1753 
1754   os::Posix::print_load_average(st);
1755 }
1756 
1757 void os::pd_print_cpu_info(outputStream* st) {
1758   // Nothing to do for now.
1759 }
1760 
1761 void os::print_memory_info(outputStream* st) {
1762 
1763   st->print("Memory:");
1764   st->print(" %dk page", os::vm_page_size()>>10);
1765 
1766   st->print(", physical " UINT64_FORMAT "k",
1767             os::physical_memory() >> 10);
1768   st->print("(" UINT64_FORMAT "k free)",
1769             os::available_memory() >> 10);
1770   st->cr();
1771 
1772   // meminfo
1773   st->print("\n/proc/meminfo:\n");
1774   _print_ascii_file("/proc/meminfo", st);
1775   st->cr();
1776 }
1777 
1778 void os::print_siginfo(outputStream* st, void* siginfo) {
1779   const siginfo_t* si = (const siginfo_t*)siginfo;
1780 
1781   os::Posix::print_siginfo_brief(st, si);
1782 
1783   if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1784       UseSharedSpaces) {
1785     FileMapInfo* mapinfo = FileMapInfo::current_info();
1786     if (mapinfo->is_in_shared_space(si->si_addr)) {
1787       st->print("\n\nError accessing class data sharing archive."   \
1788                 " Mapped file inaccessible during execution, "      \
1789                 " possible disk/network problem.");
1790     }
1791   }
1792   st->cr();
1793 }
1794 
1795 
1796 static void print_signal_handler(outputStream* st, int sig,
1797                                  char* buf, size_t buflen);
1798 
1799 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1800   st->print_cr("Signal Handlers:");
1801   print_signal_handler(st, SIGSEGV, buf, buflen);
1802   print_signal_handler(st, SIGBUS , buf, buflen);
1803   print_signal_handler(st, SIGFPE , buf, buflen);
1804   print_signal_handler(st, SIGPIPE, buf, buflen);
1805   print_signal_handler(st, SIGXFSZ, buf, buflen);
1806   print_signal_handler(st, SIGILL , buf, buflen);
1807   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1808   print_signal_handler(st, SR_signum, buf, buflen);
1809   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1810   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1811   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1812   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1813 }
1814 
1815 static char saved_jvm_path[MAXPATHLEN] = {0};
1816 
1817 // Find the full path to the current module, libjvm
1818 void os::jvm_path(char *buf, jint buflen) {
1819   // Error checking.
1820   if (buflen < MAXPATHLEN) {
1821     assert(false, "must use a large-enough buffer");
1822     buf[0] = '\0';
1823     return;
1824   }
1825   // Lazy resolve the path to current module.
1826   if (saved_jvm_path[0] != 0) {
1827     strcpy(buf, saved_jvm_path);
1828     return;
1829   }
1830 
1831   char dli_fname[MAXPATHLEN];
1832   bool ret = dll_address_to_library_name(
1833                 CAST_FROM_FN_PTR(address, os::jvm_path),
1834                 dli_fname, sizeof(dli_fname), NULL);
1835   assert(ret, "cannot locate libjvm");
1836   char *rp = NULL;
1837   if (ret && dli_fname[0] != '\0') {
1838     rp = realpath(dli_fname, buf);
1839   }
1840   if (rp == NULL)
1841     return;
1842 
1843   if (Arguments::created_by_gamma_launcher()) {
1844     // Support for the gamma launcher.  Typical value for buf is
1845     // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm".  If "/jre/lib/" appears at
1846     // the right place in the string, then assume we are installed in a JDK and
1847     // we're done.  Otherwise, check for a JAVA_HOME environment variable and
1848     // construct a path to the JVM being overridden.
1849 
1850     const char *p = buf + strlen(buf) - 1;
1851     for (int count = 0; p > buf && count < 5; ++count) {
1852       for (--p; p > buf && *p != '/'; --p)
1853         /* empty */ ;
1854     }
1855 
1856     if (strncmp(p, "/jre/lib/", 9) != 0) {
1857       // Look for JAVA_HOME in the environment.
1858       char* java_home_var = ::getenv("JAVA_HOME");
1859       if (java_home_var != NULL && java_home_var[0] != 0) {
1860         char* jrelib_p;
1861         int len;
1862 
1863         // Check the current module name "libjvm"
1864         p = strrchr(buf, '/');
1865         assert(strstr(p, "/libjvm") == p, "invalid library name");
1866 
1867         rp = realpath(java_home_var, buf);
1868         if (rp == NULL)
1869           return;
1870 
1871         // determine if this is a legacy image or modules image
1872         // modules image doesn't have "jre" subdirectory
1873         len = strlen(buf);
1874         assert(len < buflen, "Ran out of buffer space");
1875         jrelib_p = buf + len;
1876 
1877         // Add the appropriate library subdir
1878         snprintf(jrelib_p, buflen-len, "/jre/lib");
1879         if (0 != access(buf, F_OK)) {
1880           snprintf(jrelib_p, buflen-len, "/lib");
1881         }
1882 
1883         // Add the appropriate client or server subdir
1884         len = strlen(buf);
1885         jrelib_p = buf + len;
1886         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1887         if (0 != access(buf, F_OK)) {
1888           snprintf(jrelib_p, buflen-len, "");
1889         }
1890 
1891         // If the path exists within JAVA_HOME, add the JVM library name
1892         // to complete the path to JVM being overridden.  Otherwise fallback
1893         // to the path to the current library.
1894         if (0 == access(buf, F_OK)) {
1895           // Use current module name "libjvm"
1896           len = strlen(buf);
1897           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1898         } else {
1899           // Fall back to path of current library
1900           rp = realpath(dli_fname, buf);
1901           if (rp == NULL)
1902             return;
1903         }
1904       }
1905     }
1906   }
1907 
1908   strncpy(saved_jvm_path, buf, MAXPATHLEN);
1909 }
1910 
1911 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1912   // no prefix required, not even "_"
1913 }
1914 
1915 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1916   // no suffix required
1917 }
1918 
1919 ////////////////////////////////////////////////////////////////////////////////
1920 // sun.misc.Signal support
1921 
1922 static volatile jint sigint_count = 0;
1923 
1924 static void
1925 UserHandler(int sig, void *siginfo, void *context) {
1926   // 4511530 - sem_post is serialized and handled by the manager thread. When
1927   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1928   // don't want to flood the manager thread with sem_post requests.
1929   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
1930       return;
1931 
1932   // Ctrl-C is pressed during error reporting, likely because the error
1933   // handler fails to abort. Let VM die immediately.
1934   if (sig == SIGINT && is_error_reported()) {
1935      os::die();
1936   }
1937 
1938   os::signal_notify(sig);
1939 }
1940 
1941 void* os::user_handler() {
1942   return CAST_FROM_FN_PTR(void*, UserHandler);
1943 }
1944 
1945 extern "C" {
1946   typedef void (*sa_handler_t)(int);
1947   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1948 }
1949 
1950 void* os::signal(int signal_number, void* handler) {
1951   struct sigaction sigAct, oldSigAct;
1952 
1953   sigfillset(&(sigAct.sa_mask));
1954   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1955   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1956 
1957   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1958     // -1 means registration failed
1959     return (void *)-1;
1960   }
1961 
1962   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1963 }
1964 
1965 void os::signal_raise(int signal_number) {
1966   ::raise(signal_number);
1967 }
1968 
1969 /*
1970  * The following code is moved from os.cpp for making this
1971  * code platform specific, which it is by its very nature.
1972  */
1973 
1974 // Will be modified when max signal is changed to be dynamic
1975 int os::sigexitnum_pd() {
1976   return NSIG;
1977 }
1978 
1979 // a counter for each possible signal value
1980 static volatile jint pending_signals[NSIG+1] = { 0 };
1981 
1982 // Bsd(POSIX) specific hand shaking semaphore.
1983 #ifdef __APPLE__
1984 typedef semaphore_t os_semaphore_t;
1985 #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1986 #define SEM_WAIT(sem)           semaphore_wait(sem)
1987 #define SEM_POST(sem)           semaphore_signal(sem)
1988 #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
1989 #else
1990 typedef sem_t os_semaphore_t;
1991 #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
1992 #define SEM_WAIT(sem)           sem_wait(&sem)
1993 #define SEM_POST(sem)           sem_post(&sem)
1994 #define SEM_DESTROY(sem)        sem_destroy(&sem)
1995 #endif
1996 
1997 class Semaphore : public StackObj {
1998   public:
1999     Semaphore();
2000     ~Semaphore();
2001     void signal();
2002     void wait();
2003     bool trywait();
2004     bool timedwait(unsigned int sec, int nsec);
2005   private:
2006     jlong currenttime() const;
2007     os_semaphore_t _semaphore;
2008 };
2009 
2010 Semaphore::Semaphore() : _semaphore(0) {
2011   SEM_INIT(_semaphore, 0);
2012 }
2013 
2014 Semaphore::~Semaphore() {
2015   SEM_DESTROY(_semaphore);
2016 }
2017 
2018 void Semaphore::signal() {
2019   SEM_POST(_semaphore);
2020 }
2021 
2022 void Semaphore::wait() {
2023   SEM_WAIT(_semaphore);
2024 }
2025 
2026 jlong Semaphore::currenttime() const {
2027     struct timeval tv;
2028     gettimeofday(&tv, NULL);
2029     return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
2030 }
2031 
2032 #ifdef __APPLE__
2033 bool Semaphore::trywait() {
2034   return timedwait(0, 0);
2035 }
2036 
2037 bool Semaphore::timedwait(unsigned int sec, int nsec) {
2038   kern_return_t kr = KERN_ABORTED;
2039   mach_timespec_t waitspec;
2040   waitspec.tv_sec = sec;
2041   waitspec.tv_nsec = nsec;
2042 
2043   jlong starttime = currenttime();
2044 
2045   kr = semaphore_timedwait(_semaphore, waitspec);
2046   while (kr == KERN_ABORTED) {
2047     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
2048 
2049     jlong current = currenttime();
2050     jlong passedtime = current - starttime;
2051 
2052     if (passedtime >= totalwait) {
2053       waitspec.tv_sec = 0;
2054       waitspec.tv_nsec = 0;
2055     } else {
2056       jlong waittime = totalwait - (current - starttime);
2057       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
2058       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
2059     }
2060 
2061     kr = semaphore_timedwait(_semaphore, waitspec);
2062   }
2063 
2064   return kr == KERN_SUCCESS;
2065 }
2066 
2067 #else
2068 
2069 bool Semaphore::trywait() {
2070   return sem_trywait(&_semaphore) == 0;
2071 }
2072 
2073 bool Semaphore::timedwait(unsigned int sec, int nsec) {
2074   struct timespec ts;
2075   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2076 
2077   while (1) {
2078     int result = sem_timedwait(&_semaphore, &ts);
2079     if (result == 0) {
2080       return true;
2081     } else if (errno == EINTR) {
2082       continue;
2083     } else if (errno == ETIMEDOUT) {
2084       return false;
2085     } else {
2086       return false;
2087     }
2088   }
2089 }
2090 
2091 #endif // __APPLE__
2092 
2093 static os_semaphore_t sig_sem;
2094 static Semaphore sr_semaphore;
2095 
2096 void os::signal_init_pd() {
2097   // Initialize signal structures
2098   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2099 
2100   // Initialize signal semaphore
2101   ::SEM_INIT(sig_sem, 0);
2102 }
2103 
2104 void os::signal_notify(int sig) {
2105   Atomic::inc(&pending_signals[sig]);
2106   ::SEM_POST(sig_sem);
2107 }
2108 
2109 static int check_pending_signals(bool wait) {
2110   Atomic::store(0, &sigint_count);
2111   for (;;) {
2112     for (int i = 0; i < NSIG + 1; i++) {
2113       jint n = pending_signals[i];
2114       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2115         return i;
2116       }
2117     }
2118     if (!wait) {
2119       return -1;
2120     }
2121     JavaThread *thread = JavaThread::current();
2122     ThreadBlockInVM tbivm(thread);
2123 
2124     bool threadIsSuspended;
2125     do {
2126       thread->set_suspend_equivalent();
2127       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2128       ::SEM_WAIT(sig_sem);
2129 
2130       // were we externally suspended while we were waiting?
2131       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2132       if (threadIsSuspended) {
2133         //
2134         // The semaphore has been incremented, but while we were waiting
2135         // another thread suspended us. We don't want to continue running
2136         // while suspended because that would surprise the thread that
2137         // suspended us.
2138         //
2139         ::SEM_POST(sig_sem);
2140 
2141         thread->java_suspend_self();
2142       }
2143     } while (threadIsSuspended);
2144   }
2145 }
2146 
2147 int os::signal_lookup() {
2148   return check_pending_signals(false);
2149 }
2150 
2151 int os::signal_wait() {
2152   return check_pending_signals(true);
2153 }
2154 
2155 ////////////////////////////////////////////////////////////////////////////////
2156 // Virtual Memory
2157 
2158 int os::vm_page_size() {
2159   // Seems redundant as all get out
2160   assert(os::Bsd::page_size() != -1, "must call os::init");
2161   return os::Bsd::page_size();
2162 }
2163 
2164 // Solaris allocates memory by pages.
2165 int os::vm_allocation_granularity() {
2166   assert(os::Bsd::page_size() != -1, "must call os::init");
2167   return os::Bsd::page_size();
2168 }
2169 
2170 // Rationale behind this function:
2171 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2172 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2173 //  samples for JITted code. Here we create private executable mapping over the code cache
2174 //  and then we can use standard (well, almost, as mapping can change) way to provide
2175 //  info for the reporting script by storing timestamp and location of symbol
2176 void bsd_wrap_code(char* base, size_t size) {
2177   static volatile jint cnt = 0;
2178 
2179   if (!UseOprofile) {
2180     return;
2181   }
2182 
2183   char buf[PATH_MAX + 1];
2184   int num = Atomic::add(1, &cnt);
2185 
2186   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2187            os::get_temp_directory(), os::current_process_id(), num);
2188   unlink(buf);
2189 
2190   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2191 
2192   if (fd != -1) {
2193     off_t rv = ::lseek(fd, size-2, SEEK_SET);
2194     if (rv != (off_t)-1) {
2195       if (::write(fd, "", 1) == 1) {
2196         mmap(base, size,
2197              PROT_READ|PROT_WRITE|PROT_EXEC,
2198              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2199       }
2200     }
2201     ::close(fd);
2202     unlink(buf);
2203   }
2204 }
2205 
2206 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2207                                     int err) {
2208   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2209           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2210           strerror(err), err);
2211 }
2212 
2213 // NOTE: Bsd kernel does not really reserve the pages for us.
2214 //       All it does is to check if there are enough free pages
2215 //       left at the time of mmap(). This could be a potential
2216 //       problem.
2217 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2218   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2219 #ifdef __OpenBSD__
2220   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2221   if (::mprotect(addr, size, prot) == 0) {
2222     return true;
2223   }
2224 #else
2225   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2226                                    MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2227   if (res != (uintptr_t) MAP_FAILED) {
2228     return true;
2229   }
2230 #endif
2231 
2232   // Warn about any commit errors we see in non-product builds just
2233   // in case mmap() doesn't work as described on the man page.
2234   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2235 
2236   return false;
2237 }
2238 
2239 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2240                        bool exec) {
2241   // alignment_hint is ignored on this OS
2242   return pd_commit_memory(addr, size, exec);
2243 }
2244 
2245 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2246                                   const char* mesg) {
2247   assert(mesg != NULL, "mesg must be specified");
2248   if (!pd_commit_memory(addr, size, exec)) {
2249     // add extra info in product mode for vm_exit_out_of_memory():
2250     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2251     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
2252   }
2253 }
2254 
2255 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2256                                   size_t alignment_hint, bool exec,
2257                                   const char* mesg) {
2258   // alignment_hint is ignored on this OS
2259   pd_commit_memory_or_exit(addr, size, exec, mesg);
2260 }
2261 
2262 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2263 }
2264 
2265 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2266   ::madvise(addr, bytes, MADV_DONTNEED);
2267 }
2268 
2269 void os::numa_make_global(char *addr, size_t bytes) {
2270 }
2271 
2272 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2273 }
2274 
2275 bool os::numa_topology_changed()   { return false; }
2276 
2277 size_t os::numa_get_groups_num() {
2278   return 1;
2279 }
2280 
2281 int os::numa_get_group_id() {
2282   return 0;
2283 }
2284 
2285 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2286   if (size > 0) {
2287     ids[0] = 0;
2288     return 1;
2289   }
2290   return 0;
2291 }
2292 
2293 bool os::get_page_info(char *start, page_info* info) {
2294   return false;
2295 }
2296 
2297 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2298   return end;
2299 }
2300 
2301 
2302 bool os::pd_uncommit_memory(char* addr, size_t size) {
2303 #ifdef __OpenBSD__
2304   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2305   return ::mprotect(addr, size, PROT_NONE) == 0;
2306 #else
2307   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2308                 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2309   return res  != (uintptr_t) MAP_FAILED;
2310 #endif
2311 }
2312 
2313 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2314   return os::commit_memory(addr, size, !ExecMem);
2315 }
2316 
2317 // If this is a growable mapping, remove the guard pages entirely by
2318 // munmap()ping them.  If not, just call uncommit_memory().
2319 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2320   return os::uncommit_memory(addr, size);
2321 }
2322 
2323 static address _highest_vm_reserved_address = NULL;
2324 
2325 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2326 // at 'requested_addr'. If there are existing memory mappings at the same
2327 // location, however, they will be overwritten. If 'fixed' is false,
2328 // 'requested_addr' is only treated as a hint, the return value may or
2329 // may not start from the requested address. Unlike Bsd mmap(), this
2330 // function returns NULL to indicate failure.
2331 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2332   char * addr;
2333   int flags;
2334 
2335   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2336   if (fixed) {
2337     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2338     flags |= MAP_FIXED;
2339   }
2340 
2341   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2342   // touch an uncommitted page. Otherwise, the read/write might
2343   // succeed if we have enough swap space to back the physical page.
2344   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2345                        flags, -1, 0);
2346 
2347   if (addr != MAP_FAILED) {
2348     // anon_mmap() should only get called during VM initialization,
2349     // don't need lock (actually we can skip locking even it can be called
2350     // from multiple threads, because _highest_vm_reserved_address is just a
2351     // hint about the upper limit of non-stack memory regions.)
2352     if ((address)addr + bytes > _highest_vm_reserved_address) {
2353       _highest_vm_reserved_address = (address)addr + bytes;
2354     }
2355   }
2356 
2357   return addr == MAP_FAILED ? NULL : addr;
2358 }
2359 
2360 // Don't update _highest_vm_reserved_address, because there might be memory
2361 // regions above addr + size. If so, releasing a memory region only creates
2362 // a hole in the address space, it doesn't help prevent heap-stack collision.
2363 //
2364 static int anon_munmap(char * addr, size_t size) {
2365   return ::munmap(addr, size) == 0;
2366 }
2367 
2368 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2369                          size_t alignment_hint) {
2370   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2371 }
2372 
2373 bool os::pd_release_memory(char* addr, size_t size) {
2374   return anon_munmap(addr, size);
2375 }
2376 
2377 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2378   // Bsd wants the mprotect address argument to be page aligned.
2379   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2380 
2381   // According to SUSv3, mprotect() should only be used with mappings
2382   // established by mmap(), and mmap() always maps whole pages. Unaligned
2383   // 'addr' likely indicates problem in the VM (e.g. trying to change
2384   // protection of malloc'ed or statically allocated memory). Check the
2385   // caller if you hit this assert.
2386   assert(addr == bottom, "sanity check");
2387 
2388   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2389   return ::mprotect(bottom, size, prot) == 0;
2390 }
2391 
2392 // Set protections specified
2393 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2394                         bool is_committed) {
2395   unsigned int p = 0;
2396   switch (prot) {
2397   case MEM_PROT_NONE: p = PROT_NONE; break;
2398   case MEM_PROT_READ: p = PROT_READ; break;
2399   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2400   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2401   default:
2402     ShouldNotReachHere();
2403   }
2404   // is_committed is unused.
2405   return bsd_mprotect(addr, bytes, p);
2406 }
2407 
2408 bool os::guard_memory(char* addr, size_t size) {
2409   return bsd_mprotect(addr, size, PROT_NONE);
2410 }
2411 
2412 bool os::unguard_memory(char* addr, size_t size) {
2413   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2414 }
2415 
2416 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2417   return false;
2418 }
2419 
2420 // Large page support
2421 
2422 static size_t _large_page_size = 0;
2423 
2424 void os::large_page_init() {
2425 }
2426 
2427 
2428 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2429   fatal("This code is not used or maintained.");
2430 
2431   // "exec" is passed in but not used.  Creating the shared image for
2432   // the code cache doesn't have an SHM_X executable permission to check.
2433   assert(UseLargePages && UseSHM, "only for SHM large pages");
2434 
2435   key_t key = IPC_PRIVATE;
2436   char *addr;
2437 
2438   bool warn_on_failure = UseLargePages &&
2439                         (!FLAG_IS_DEFAULT(UseLargePages) ||
2440                          !FLAG_IS_DEFAULT(LargePageSizeInBytes)
2441                         );
2442 
2443   // Create a large shared memory region to attach to based on size.
2444   // Currently, size is the total size of the heap
2445   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2446   if (shmid == -1) {
2447      // Possible reasons for shmget failure:
2448      // 1. shmmax is too small for Java heap.
2449      //    > check shmmax value: cat /proc/sys/kernel/shmmax
2450      //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2451      // 2. not enough large page memory.
2452      //    > check available large pages: cat /proc/meminfo
2453      //    > increase amount of large pages:
2454      //          echo new_value > /proc/sys/vm/nr_hugepages
2455      //      Note 1: different Bsd may use different name for this property,
2456      //            e.g. on Redhat AS-3 it is "hugetlb_pool".
2457      //      Note 2: it's possible there's enough physical memory available but
2458      //            they are so fragmented after a long run that they can't
2459      //            coalesce into large pages. Try to reserve large pages when
2460      //            the system is still "fresh".
2461      if (warn_on_failure) {
2462        warning("Failed to reserve shared memory (errno = %d).", errno);
2463      }
2464      return NULL;
2465   }
2466 
2467   // attach to the region
2468   addr = (char*)shmat(shmid, req_addr, 0);
2469   int err = errno;
2470 
2471   // Remove shmid. If shmat() is successful, the actual shared memory segment
2472   // will be deleted when it's detached by shmdt() or when the process
2473   // terminates. If shmat() is not successful this will remove the shared
2474   // segment immediately.
2475   shmctl(shmid, IPC_RMID, NULL);
2476 
2477   if ((intptr_t)addr == -1) {
2478      if (warn_on_failure) {
2479        warning("Failed to attach shared memory (errno = %d).", err);
2480      }
2481      return NULL;
2482   }
2483 
2484   // The memory is committed
2485   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
2486 
2487   return addr;
2488 }
2489 
2490 bool os::release_memory_special(char* base, size_t bytes) {
2491   if (MemTracker::tracking_level() > NMT_minimal) {
2492     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2493     // detaching the SHM segment will also delete it, see reserve_memory_special()
2494     int rslt = shmdt(base);
2495     if (rslt == 0) {
2496       tkr.record((address)base, bytes);
2497       return true;
2498     } else {
2499       return false;
2500     }
2501   } else {
2502     return shmdt(base) == 0;
2503   }
2504 }
2505 
2506 size_t os::large_page_size() {
2507   return _large_page_size;
2508 }
2509 
2510 // HugeTLBFS allows application to commit large page memory on demand;
2511 // with SysV SHM the entire memory region must be allocated as shared
2512 // memory.
2513 bool os::can_commit_large_page_memory() {
2514   return UseHugeTLBFS;
2515 }
2516 
2517 bool os::can_execute_large_page_memory() {
2518   return UseHugeTLBFS;
2519 }
2520 
2521 // Reserve memory at an arbitrary address, only if that area is
2522 // available (and not reserved for something else).
2523 
2524 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2525   const int max_tries = 10;
2526   char* base[max_tries];
2527   size_t size[max_tries];
2528   const size_t gap = 0x000000;
2529 
2530   // Assert only that the size is a multiple of the page size, since
2531   // that's all that mmap requires, and since that's all we really know
2532   // about at this low abstraction level.  If we need higher alignment,
2533   // we can either pass an alignment to this method or verify alignment
2534   // in one of the methods further up the call chain.  See bug 5044738.
2535   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2536 
2537   // Repeatedly allocate blocks until the block is allocated at the
2538   // right spot. Give up after max_tries. Note that reserve_memory() will
2539   // automatically update _highest_vm_reserved_address if the call is
2540   // successful. The variable tracks the highest memory address every reserved
2541   // by JVM. It is used to detect heap-stack collision if running with
2542   // fixed-stack BsdThreads. Because here we may attempt to reserve more
2543   // space than needed, it could confuse the collision detecting code. To
2544   // solve the problem, save current _highest_vm_reserved_address and
2545   // calculate the correct value before return.
2546   address old_highest = _highest_vm_reserved_address;
2547 
2548   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2549   // if kernel honors the hint then we can return immediately.
2550   char * addr = anon_mmap(requested_addr, bytes, false);
2551   if (addr == requested_addr) {
2552      return requested_addr;
2553   }
2554 
2555   if (addr != NULL) {
2556      // mmap() is successful but it fails to reserve at the requested address
2557      anon_munmap(addr, bytes);
2558   }
2559 
2560   int i;
2561   for (i = 0; i < max_tries; ++i) {
2562     base[i] = reserve_memory(bytes);
2563 
2564     if (base[i] != NULL) {
2565       // Is this the block we wanted?
2566       if (base[i] == requested_addr) {
2567         size[i] = bytes;
2568         break;
2569       }
2570 
2571       // Does this overlap the block we wanted? Give back the overlapped
2572       // parts and try again.
2573 
2574       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2575       if (top_overlap >= 0 && top_overlap < bytes) {
2576         unmap_memory(base[i], top_overlap);
2577         base[i] += top_overlap;
2578         size[i] = bytes - top_overlap;
2579       } else {
2580         size_t bottom_overlap = base[i] + bytes - requested_addr;
2581         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2582           unmap_memory(requested_addr, bottom_overlap);
2583           size[i] = bytes - bottom_overlap;
2584         } else {
2585           size[i] = bytes;
2586         }
2587       }
2588     }
2589   }
2590 
2591   // Give back the unused reserved pieces.
2592 
2593   for (int j = 0; j < i; ++j) {
2594     if (base[j] != NULL) {
2595       unmap_memory(base[j], size[j]);
2596     }
2597   }
2598 
2599   if (i < max_tries) {
2600     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2601     return requested_addr;
2602   } else {
2603     _highest_vm_reserved_address = old_highest;
2604     return NULL;
2605   }
2606 }
2607 
2608 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2609   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2610 }
2611 
2612 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
2613   RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset));
2614 }
2615 
2616 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
2617 // Solaris uses poll(), bsd uses park().
2618 // Poll() is likely a better choice, assuming that Thread.interrupt()
2619 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
2620 // SIGSEGV, see 4355769.
2621 
2622 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
2623   assert(thread == Thread::current(),  "thread consistency check");
2624 
2625   ParkEvent * const slp = thread->_SleepEvent ;
2626   slp->reset() ;
2627   OrderAccess::fence() ;
2628 
2629   if (interruptible) {
2630     jlong prevtime = javaTimeNanos();
2631 
2632     for (;;) {
2633       if (os::is_interrupted(thread, true)) {
2634         return OS_INTRPT;
2635       }
2636 
2637       jlong newtime = javaTimeNanos();
2638 
2639       if (newtime - prevtime < 0) {
2640         // time moving backwards, should only happen if no monotonic clock
2641         // not a guarantee() because JVM should not abort on kernel/glibc bugs
2642         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2643       } else {
2644         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2645       }
2646 
2647       if(millis <= 0) {
2648         return OS_OK;
2649       }
2650 
2651       prevtime = newtime;
2652 
2653       {
2654         assert(thread->is_Java_thread(), "sanity check");
2655         JavaThread *jt = (JavaThread *) thread;
2656         ThreadBlockInVM tbivm(jt);
2657         OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
2658 
2659         jt->set_suspend_equivalent();
2660         // cleared by handle_special_suspend_equivalent_condition() or
2661         // java_suspend_self() via check_and_wait_while_suspended()
2662 
2663         slp->park(millis);
2664 
2665         // were we externally suspended while we were waiting?
2666         jt->check_and_wait_while_suspended();
2667       }
2668     }
2669   } else {
2670     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2671     jlong prevtime = javaTimeNanos();
2672 
2673     for (;;) {
2674       // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
2675       // the 1st iteration ...
2676       jlong newtime = javaTimeNanos();
2677 
2678       if (newtime - prevtime < 0) {
2679         // time moving backwards, should only happen if no monotonic clock
2680         // not a guarantee() because JVM should not abort on kernel/glibc bugs
2681         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2682       } else {
2683         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2684       }
2685 
2686       if(millis <= 0) break ;
2687 
2688       prevtime = newtime;
2689       slp->park(millis);
2690     }
2691     return OS_OK ;
2692   }
2693 }
2694 
2695 void os::naked_short_sleep(jlong ms) {
2696   struct timespec req;
2697 
2698   assert(ms < 1000, "Un-interruptable sleep, short time use only");
2699   req.tv_sec = 0;
2700   if (ms > 0) {
2701     req.tv_nsec = (ms % 1000) * 1000000;
2702   }
2703   else {
2704     req.tv_nsec = 1;
2705   }
2706 
2707   nanosleep(&req, NULL);
2708 
2709   return;
2710 }
2711 
2712 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2713 void os::infinite_sleep() {
2714   while (true) {    // sleep forever ...
2715     ::sleep(100);   // ... 100 seconds at a time
2716   }
2717 }
2718 
2719 // Used to convert frequent JVM_Yield() to nops
2720 bool os::dont_yield() {
2721   return DontYieldALot;
2722 }
2723 
2724 void os::yield() {
2725   sched_yield();
2726 }
2727 
2728 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
2729 
2730 void os::yield_all(int attempts) {
2731   // Yields to all threads, including threads with lower priorities
2732   // Threads on Bsd are all with same priority. The Solaris style
2733   // os::yield_all() with nanosleep(1ms) is not necessary.
2734   sched_yield();
2735 }
2736 
2737 // Called from the tight loops to possibly influence time-sharing heuristics
2738 void os::loop_breaker(int attempts) {
2739   os::yield_all(attempts);
2740 }
2741 
2742 ////////////////////////////////////////////////////////////////////////////////
2743 // thread priority support
2744 
2745 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2746 // only supports dynamic priority, static priority must be zero. For real-time
2747 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2748 // However, for large multi-threaded applications, SCHED_RR is not only slower
2749 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2750 // of 5 runs - Sep 2005).
2751 //
2752 // The following code actually changes the niceness of kernel-thread/LWP. It
2753 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2754 // not the entire user process, and user level threads are 1:1 mapped to kernel
2755 // threads. It has always been the case, but could change in the future. For
2756 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2757 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2758 
2759 #if !defined(__APPLE__)
2760 int os::java_to_os_priority[CriticalPriority + 1] = {
2761   19,              // 0 Entry should never be used
2762 
2763    0,              // 1 MinPriority
2764    3,              // 2
2765    6,              // 3
2766 
2767   10,              // 4
2768   15,              // 5 NormPriority
2769   18,              // 6
2770 
2771   21,              // 7
2772   25,              // 8
2773   28,              // 9 NearMaxPriority
2774 
2775   31,              // 10 MaxPriority
2776 
2777   31               // 11 CriticalPriority
2778 };
2779 #else
2780 /* Using Mach high-level priority assignments */
2781 int os::java_to_os_priority[CriticalPriority + 1] = {
2782    0,              // 0 Entry should never be used (MINPRI_USER)
2783 
2784   27,              // 1 MinPriority
2785   28,              // 2
2786   29,              // 3
2787 
2788   30,              // 4
2789   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2790   32,              // 6
2791 
2792   33,              // 7
2793   34,              // 8
2794   35,              // 9 NearMaxPriority
2795 
2796   36,              // 10 MaxPriority
2797 
2798   36               // 11 CriticalPriority
2799 };
2800 #endif
2801 
2802 static int prio_init() {
2803   if (ThreadPriorityPolicy == 1) {
2804     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2805     // if effective uid is not root. Perhaps, a more elegant way of doing
2806     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2807     if (geteuid() != 0) {
2808       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2809         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2810       }
2811       ThreadPriorityPolicy = 0;
2812     }
2813   }
2814   if (UseCriticalJavaThreadPriority) {
2815     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2816   }
2817   return 0;
2818 }
2819 
2820 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2821   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
2822 
2823 #ifdef __OpenBSD__
2824   // OpenBSD pthread_setprio starves low priority threads
2825   return OS_OK;
2826 #elif defined(__FreeBSD__)
2827   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2828 #elif defined(__APPLE__) || defined(__NetBSD__)
2829   struct sched_param sp;
2830   int policy;
2831   pthread_t self = pthread_self();
2832 
2833   if (pthread_getschedparam(self, &policy, &sp) != 0)
2834     return OS_ERR;
2835 
2836   sp.sched_priority = newpri;
2837   if (pthread_setschedparam(self, policy, &sp) != 0)
2838     return OS_ERR;
2839 
2840   return OS_OK;
2841 #else
2842   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2843   return (ret == 0) ? OS_OK : OS_ERR;
2844 #endif
2845 }
2846 
2847 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2848   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
2849     *priority_ptr = java_to_os_priority[NormPriority];
2850     return OS_OK;
2851   }
2852 
2853   errno = 0;
2854 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2855   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2856 #elif defined(__APPLE__) || defined(__NetBSD__)
2857   int policy;
2858   struct sched_param sp;
2859 
2860   pthread_getschedparam(pthread_self(), &policy, &sp);
2861   *priority_ptr = sp.sched_priority;
2862 #else
2863   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2864 #endif
2865   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2866 }
2867 
2868 // Hint to the underlying OS that a task switch would not be good.
2869 // Void return because it's a hint and can fail.
2870 void os::hint_no_preempt() {}
2871 
2872 ////////////////////////////////////////////////////////////////////////////////
2873 // suspend/resume support
2874 
2875 //  the low-level signal-based suspend/resume support is a remnant from the
2876 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2877 //  within hotspot. Now there is a single use-case for this:
2878 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
2879 //      that runs in the watcher thread.
2880 //  The remaining code is greatly simplified from the more general suspension
2881 //  code that used to be used.
2882 //
2883 //  The protocol is quite simple:
2884 //  - suspend:
2885 //      - sends a signal to the target thread
2886 //      - polls the suspend state of the osthread using a yield loop
2887 //      - target thread signal handler (SR_handler) sets suspend state
2888 //        and blocks in sigsuspend until continued
2889 //  - resume:
2890 //      - sets target osthread state to continue
2891 //      - sends signal to end the sigsuspend loop in the SR_handler
2892 //
2893 //  Note that the SR_lock plays no role in this suspend/resume protocol.
2894 //
2895 
2896 static void resume_clear_context(OSThread *osthread) {
2897   osthread->set_ucontext(NULL);
2898   osthread->set_siginfo(NULL);
2899 }
2900 
2901 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2902   osthread->set_ucontext(context);
2903   osthread->set_siginfo(siginfo);
2904 }
2905 
2906 //
2907 // Handler function invoked when a thread's execution is suspended or
2908 // resumed. We have to be careful that only async-safe functions are
2909 // called here (Note: most pthread functions are not async safe and
2910 // should be avoided.)
2911 //
2912 // Note: sigwait() is a more natural fit than sigsuspend() from an
2913 // interface point of view, but sigwait() prevents the signal hander
2914 // from being run. libpthread would get very confused by not having
2915 // its signal handlers run and prevents sigwait()'s use with the
2916 // mutex granting granting signal.
2917 //
2918 // Currently only ever called on the VMThread or JavaThread
2919 //
2920 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2921   // Save and restore errno to avoid confusing native code with EINTR
2922   // after sigsuspend.
2923   int old_errno = errno;
2924 
2925   Thread* thread = Thread::current();
2926   OSThread* osthread = thread->osthread();
2927   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2928 
2929   os::SuspendResume::State current = osthread->sr.state();
2930   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2931     suspend_save_context(osthread, siginfo, context);
2932 
2933     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2934     os::SuspendResume::State state = osthread->sr.suspended();
2935     if (state == os::SuspendResume::SR_SUSPENDED) {
2936       sigset_t suspend_set;  // signals for sigsuspend()
2937 
2938       // get current set of blocked signals and unblock resume signal
2939       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2940       sigdelset(&suspend_set, SR_signum);
2941 
2942       sr_semaphore.signal();
2943       // wait here until we are resumed
2944       while (1) {
2945         sigsuspend(&suspend_set);
2946 
2947         os::SuspendResume::State result = osthread->sr.running();
2948         if (result == os::SuspendResume::SR_RUNNING) {
2949           sr_semaphore.signal();
2950           break;
2951         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2952           ShouldNotReachHere();
2953         }
2954       }
2955 
2956     } else if (state == os::SuspendResume::SR_RUNNING) {
2957       // request was cancelled, continue
2958     } else {
2959       ShouldNotReachHere();
2960     }
2961 
2962     resume_clear_context(osthread);
2963   } else if (current == os::SuspendResume::SR_RUNNING) {
2964     // request was cancelled, continue
2965   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2966     // ignore
2967   } else {
2968     // ignore
2969   }
2970 
2971   errno = old_errno;
2972 }
2973 
2974 
2975 static int SR_initialize() {
2976   struct sigaction act;
2977   char *s;
2978   /* Get signal number to use for suspend/resume */
2979   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2980     int sig = ::strtol(s, 0, 10);
2981     if (sig > 0 || sig < NSIG) {
2982         SR_signum = sig;
2983     }
2984   }
2985 
2986   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2987         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2988 
2989   sigemptyset(&SR_sigset);
2990   sigaddset(&SR_sigset, SR_signum);
2991 
2992   /* Set up signal handler for suspend/resume */
2993   act.sa_flags = SA_RESTART|SA_SIGINFO;
2994   act.sa_handler = (void (*)(int)) SR_handler;
2995 
2996   // SR_signum is blocked by default.
2997   // 4528190 - We also need to block pthread restart signal (32 on all
2998   // supported Bsd platforms). Note that BsdThreads need to block
2999   // this signal for all threads to work properly. So we don't have
3000   // to use hard-coded signal number when setting up the mask.
3001   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
3002 
3003   if (sigaction(SR_signum, &act, 0) == -1) {
3004     return -1;
3005   }
3006 
3007   // Save signal flag
3008   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
3009   return 0;
3010 }
3011 
3012 static int sr_notify(OSThread* osthread) {
3013   int status = pthread_kill(osthread->pthread_id(), SR_signum);
3014   assert_status(status == 0, status, "pthread_kill");
3015   return status;
3016 }
3017 
3018 // "Randomly" selected value for how long we want to spin
3019 // before bailing out on suspending a thread, also how often
3020 // we send a signal to a thread we want to resume
3021 static const int RANDOMLY_LARGE_INTEGER = 1000000;
3022 static const int RANDOMLY_LARGE_INTEGER2 = 100;
3023 
3024 // returns true on success and false on error - really an error is fatal
3025 // but this seems the normal response to library errors
3026 static bool do_suspend(OSThread* osthread) {
3027   assert(osthread->sr.is_running(), "thread should be running");
3028   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
3029 
3030   // mark as suspended and send signal
3031   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
3032     // failed to switch, state wasn't running?
3033     ShouldNotReachHere();
3034     return false;
3035   }
3036 
3037   if (sr_notify(osthread) != 0) {
3038     ShouldNotReachHere();
3039   }
3040 
3041   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
3042   while (true) {
3043     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
3044       break;
3045     } else {
3046       // timeout
3047       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
3048       if (cancelled == os::SuspendResume::SR_RUNNING) {
3049         return false;
3050       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
3051         // make sure that we consume the signal on the semaphore as well
3052         sr_semaphore.wait();
3053         break;
3054       } else {
3055         ShouldNotReachHere();
3056         return false;
3057       }
3058     }
3059   }
3060 
3061   guarantee(osthread->sr.is_suspended(), "Must be suspended");
3062   return true;
3063 }
3064 
3065 static void do_resume(OSThread* osthread) {
3066   assert(osthread->sr.is_suspended(), "thread should be suspended");
3067   assert(!sr_semaphore.trywait(), "invalid semaphore state");
3068 
3069   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
3070     // failed to switch to WAKEUP_REQUEST
3071     ShouldNotReachHere();
3072     return;
3073   }
3074 
3075   while (true) {
3076     if (sr_notify(osthread) == 0) {
3077       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
3078         if (osthread->sr.is_running()) {
3079           return;
3080         }
3081       }
3082     } else {
3083       ShouldNotReachHere();
3084     }
3085   }
3086 
3087   guarantee(osthread->sr.is_running(), "Must be running!");
3088 }
3089 
3090 ////////////////////////////////////////////////////////////////////////////////
3091 // interrupt support
3092 
3093 void os::interrupt(Thread* thread) {
3094   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
3095     "possibility of dangling Thread pointer");
3096 
3097   OSThread* osthread = thread->osthread();
3098 
3099   if (!osthread->interrupted()) {
3100     osthread->set_interrupted(true);
3101     // More than one thread can get here with the same value of osthread,
3102     // resulting in multiple notifications.  We do, however, want the store
3103     // to interrupted() to be visible to other threads before we execute unpark().
3104     OrderAccess::fence();
3105     ParkEvent * const slp = thread->_SleepEvent ;
3106     if (slp != NULL) slp->unpark() ;
3107   }
3108 
3109   // For JSR166. Unpark even if interrupt status already was set
3110   if (thread->is_Java_thread())
3111     ((JavaThread*)thread)->parker()->unpark();
3112 
3113   ParkEvent * ev = thread->_ParkEvent ;
3114   if (ev != NULL) ev->unpark() ;
3115 
3116 }
3117 
3118 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
3119   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
3120     "possibility of dangling Thread pointer");
3121 
3122   OSThread* osthread = thread->osthread();
3123 
3124   bool interrupted = osthread->interrupted();
3125 
3126   if (interrupted && clear_interrupted) {
3127     osthread->set_interrupted(false);
3128     // consider thread->_SleepEvent->reset() ... optional optimization
3129   }
3130 
3131   return interrupted;
3132 }
3133 
3134 ///////////////////////////////////////////////////////////////////////////////////
3135 // signal handling (except suspend/resume)
3136 
3137 // This routine may be used by user applications as a "hook" to catch signals.
3138 // The user-defined signal handler must pass unrecognized signals to this
3139 // routine, and if it returns true (non-zero), then the signal handler must
3140 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
3141 // routine will never retun false (zero), but instead will execute a VM panic
3142 // routine kill the process.
3143 //
3144 // If this routine returns false, it is OK to call it again.  This allows
3145 // the user-defined signal handler to perform checks either before or after
3146 // the VM performs its own checks.  Naturally, the user code would be making
3147 // a serious error if it tried to handle an exception (such as a null check
3148 // or breakpoint) that the VM was generating for its own correct operation.
3149 //
3150 // This routine may recognize any of the following kinds of signals:
3151 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
3152 // It should be consulted by handlers for any of those signals.
3153 //
3154 // The caller of this routine must pass in the three arguments supplied
3155 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
3156 // field of the structure passed to sigaction().  This routine assumes that
3157 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
3158 //
3159 // Note that the VM will print warnings if it detects conflicting signal
3160 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
3161 //
3162 extern "C" JNIEXPORT int
3163 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
3164                         void* ucontext, int abort_if_unrecognized);
3165 
3166 void signalHandler(int sig, siginfo_t* info, void* uc) {
3167   assert(info != NULL && uc != NULL, "it must be old kernel");
3168   int orig_errno = errno;  // Preserve errno value over signal handler.
3169   JVM_handle_bsd_signal(sig, info, uc, true);
3170   errno = orig_errno;
3171 }
3172 
3173 
3174 // This boolean allows users to forward their own non-matching signals
3175 // to JVM_handle_bsd_signal, harmlessly.
3176 bool os::Bsd::signal_handlers_are_installed = false;
3177 
3178 // For signal-chaining
3179 struct sigaction os::Bsd::sigact[MAXSIGNUM];
3180 unsigned int os::Bsd::sigs = 0;
3181 bool os::Bsd::libjsig_is_loaded = false;
3182 typedef struct sigaction *(*get_signal_t)(int);
3183 get_signal_t os::Bsd::get_signal_action = NULL;
3184 
3185 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
3186   struct sigaction *actp = NULL;
3187 
3188   if (libjsig_is_loaded) {
3189     // Retrieve the old signal handler from libjsig
3190     actp = (*get_signal_action)(sig);
3191   }
3192   if (actp == NULL) {
3193     // Retrieve the preinstalled signal handler from jvm
3194     actp = get_preinstalled_handler(sig);
3195   }
3196 
3197   return actp;
3198 }
3199 
3200 static bool call_chained_handler(struct sigaction *actp, int sig,
3201                                  siginfo_t *siginfo, void *context) {
3202   // Call the old signal handler
3203   if (actp->sa_handler == SIG_DFL) {
3204     // It's more reasonable to let jvm treat it as an unexpected exception
3205     // instead of taking the default action.
3206     return false;
3207   } else if (actp->sa_handler != SIG_IGN) {
3208     if ((actp->sa_flags & SA_NODEFER) == 0) {
3209       // automaticlly block the signal
3210       sigaddset(&(actp->sa_mask), sig);
3211     }
3212 
3213     sa_handler_t hand;
3214     sa_sigaction_t sa;
3215     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3216     // retrieve the chained handler
3217     if (siginfo_flag_set) {
3218       sa = actp->sa_sigaction;
3219     } else {
3220       hand = actp->sa_handler;
3221     }
3222 
3223     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3224       actp->sa_handler = SIG_DFL;
3225     }
3226 
3227     // try to honor the signal mask
3228     sigset_t oset;
3229     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3230 
3231     // call into the chained handler
3232     if (siginfo_flag_set) {
3233       (*sa)(sig, siginfo, context);
3234     } else {
3235       (*hand)(sig);
3236     }
3237 
3238     // restore the signal mask
3239     pthread_sigmask(SIG_SETMASK, &oset, 0);
3240   }
3241   // Tell jvm's signal handler the signal is taken care of.
3242   return true;
3243 }
3244 
3245 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3246   bool chained = false;
3247   // signal-chaining
3248   if (UseSignalChaining) {
3249     struct sigaction *actp = get_chained_signal_action(sig);
3250     if (actp != NULL) {
3251       chained = call_chained_handler(actp, sig, siginfo, context);
3252     }
3253   }
3254   return chained;
3255 }
3256 
3257 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3258   if ((( (unsigned int)1 << sig ) & sigs) != 0) {
3259     return &sigact[sig];
3260   }
3261   return NULL;
3262 }
3263 
3264 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3265   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3266   sigact[sig] = oldAct;
3267   sigs |= (unsigned int)1 << sig;
3268 }
3269 
3270 // for diagnostic
3271 int os::Bsd::sigflags[MAXSIGNUM];
3272 
3273 int os::Bsd::get_our_sigflags(int sig) {
3274   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3275   return sigflags[sig];
3276 }
3277 
3278 void os::Bsd::set_our_sigflags(int sig, int flags) {
3279   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3280   sigflags[sig] = flags;
3281 }
3282 
3283 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3284   // Check for overwrite.
3285   struct sigaction oldAct;
3286   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3287 
3288   void* oldhand = oldAct.sa_sigaction
3289                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
3290                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
3291   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3292       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3293       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3294     if (AllowUserSignalHandlers || !set_installed) {
3295       // Do not overwrite; user takes responsibility to forward to us.
3296       return;
3297     } else if (UseSignalChaining) {
3298       // save the old handler in jvm
3299       save_preinstalled_handler(sig, oldAct);
3300       // libjsig also interposes the sigaction() call below and saves the
3301       // old sigaction on it own.
3302     } else {
3303       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3304                     "%#lx for signal %d.", (long)oldhand, sig));
3305     }
3306   }
3307 
3308   struct sigaction sigAct;
3309   sigfillset(&(sigAct.sa_mask));
3310   sigAct.sa_handler = SIG_DFL;
3311   if (!set_installed) {
3312     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3313   } else {
3314     sigAct.sa_sigaction = signalHandler;
3315     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3316   }
3317 #ifdef __APPLE__
3318   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3319   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3320   // if the signal handler declares it will handle it on alternate stack.
3321   // Notice we only declare we will handle it on alt stack, but we are not
3322   // actually going to use real alt stack - this is just a workaround.
3323   // Please see ux_exception.c, method catch_mach_exception_raise for details
3324   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3325   if (sig == SIGSEGV) {
3326     sigAct.sa_flags |= SA_ONSTACK;
3327   }
3328 #endif
3329 
3330   // Save flags, which are set by ours
3331   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3332   sigflags[sig] = sigAct.sa_flags;
3333 
3334   int ret = sigaction(sig, &sigAct, &oldAct);
3335   assert(ret == 0, "check");
3336 
3337   void* oldhand2  = oldAct.sa_sigaction
3338                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3339                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3340   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3341 }
3342 
3343 // install signal handlers for signals that HotSpot needs to
3344 // handle in order to support Java-level exception handling.
3345 
3346 void os::Bsd::install_signal_handlers() {
3347   if (!signal_handlers_are_installed) {
3348     signal_handlers_are_installed = true;
3349 
3350     // signal-chaining
3351     typedef void (*signal_setting_t)();
3352     signal_setting_t begin_signal_setting = NULL;
3353     signal_setting_t end_signal_setting = NULL;
3354     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3355                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3356     if (begin_signal_setting != NULL) {
3357       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3358                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3359       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3360                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3361       libjsig_is_loaded = true;
3362       assert(UseSignalChaining, "should enable signal-chaining");
3363     }
3364     if (libjsig_is_loaded) {
3365       // Tell libjsig jvm is setting signal handlers
3366       (*begin_signal_setting)();
3367     }
3368 
3369     set_signal_handler(SIGSEGV, true);
3370     set_signal_handler(SIGPIPE, true);
3371     set_signal_handler(SIGBUS, true);
3372     set_signal_handler(SIGILL, true);
3373     set_signal_handler(SIGFPE, true);
3374     set_signal_handler(SIGXFSZ, true);
3375 
3376 #if defined(__APPLE__)
3377     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3378     // signals caught and handled by the JVM. To work around this, we reset the mach task
3379     // signal handler that's placed on our process by CrashReporter. This disables
3380     // CrashReporter-based reporting.
3381     //
3382     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3383     // on caught fatal signals.
3384     //
3385     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3386     // handlers. By replacing the existing task exception handler, we disable gdb's mach
3387     // exception handling, while leaving the standard BSD signal handlers functional.
3388     kern_return_t kr;
3389     kr = task_set_exception_ports(mach_task_self(),
3390         EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3391         MACH_PORT_NULL,
3392         EXCEPTION_STATE_IDENTITY,
3393         MACHINE_THREAD_STATE);
3394 
3395     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3396 #endif
3397 
3398     if (libjsig_is_loaded) {
3399       // Tell libjsig jvm finishes setting signal handlers
3400       (*end_signal_setting)();
3401     }
3402 
3403     // We don't activate signal checker if libjsig is in place, we trust ourselves
3404     // and if UserSignalHandler is installed all bets are off
3405     if (CheckJNICalls) {
3406       if (libjsig_is_loaded) {
3407         if (PrintJNIResolving) {
3408           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3409         }
3410         check_signals = false;
3411       }
3412       if (AllowUserSignalHandlers) {
3413         if (PrintJNIResolving) {
3414           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3415         }
3416         check_signals = false;
3417       }
3418     }
3419   }
3420 }
3421 
3422 
3423 /////
3424 // glibc on Bsd platform uses non-documented flag
3425 // to indicate, that some special sort of signal
3426 // trampoline is used.
3427 // We will never set this flag, and we should
3428 // ignore this flag in our diagnostic
3429 #ifdef SIGNIFICANT_SIGNAL_MASK
3430 #undef SIGNIFICANT_SIGNAL_MASK
3431 #endif
3432 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3433 
3434 static const char* get_signal_handler_name(address handler,
3435                                            char* buf, int buflen) {
3436   int offset;
3437   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3438   if (found) {
3439     // skip directory names
3440     const char *p1, *p2;
3441     p1 = buf;
3442     size_t len = strlen(os::file_separator());
3443     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3444     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3445   } else {
3446     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3447   }
3448   return buf;
3449 }
3450 
3451 static void print_signal_handler(outputStream* st, int sig,
3452                                  char* buf, size_t buflen) {
3453   struct sigaction sa;
3454 
3455   sigaction(sig, NULL, &sa);
3456 
3457   // See comment for SIGNIFICANT_SIGNAL_MASK define
3458   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3459 
3460   st->print("%s: ", os::exception_name(sig, buf, buflen));
3461 
3462   address handler = (sa.sa_flags & SA_SIGINFO)
3463     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3464     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3465 
3466   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3467     st->print("SIG_DFL");
3468   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3469     st->print("SIG_IGN");
3470   } else {
3471     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3472   }
3473 
3474   st->print(", sa_mask[0]=");
3475   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3476 
3477   address rh = VMError::get_resetted_sighandler(sig);
3478   // May be, handler was resetted by VMError?
3479   if(rh != NULL) {
3480     handler = rh;
3481     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3482   }
3483 
3484   st->print(", sa_flags=");
3485   os::Posix::print_sa_flags(st, sa.sa_flags);
3486 
3487   // Check: is it our handler?
3488   if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3489      handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3490     // It is our signal handler
3491     // check for flags, reset system-used one!
3492     if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3493       st->print(
3494                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3495                 os::Bsd::get_our_sigflags(sig));
3496     }
3497   }
3498   st->cr();
3499 }
3500 
3501 
3502 #define DO_SIGNAL_CHECK(sig) \
3503   if (!sigismember(&check_signal_done, sig)) \
3504     os::Bsd::check_signal_handler(sig)
3505 
3506 // This method is a periodic task to check for misbehaving JNI applications
3507 // under CheckJNI, we can add any periodic checks here
3508 
3509 void os::run_periodic_checks() {
3510 
3511   if (check_signals == false) return;
3512 
3513   // SEGV and BUS if overridden could potentially prevent
3514   // generation of hs*.log in the event of a crash, debugging
3515   // such a case can be very challenging, so we absolutely
3516   // check the following for a good measure:
3517   DO_SIGNAL_CHECK(SIGSEGV);
3518   DO_SIGNAL_CHECK(SIGILL);
3519   DO_SIGNAL_CHECK(SIGFPE);
3520   DO_SIGNAL_CHECK(SIGBUS);
3521   DO_SIGNAL_CHECK(SIGPIPE);
3522   DO_SIGNAL_CHECK(SIGXFSZ);
3523 
3524 
3525   // ReduceSignalUsage allows the user to override these handlers
3526   // see comments at the very top and jvm_solaris.h
3527   if (!ReduceSignalUsage) {
3528     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3529     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3530     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3531     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3532   }
3533 
3534   DO_SIGNAL_CHECK(SR_signum);
3535   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3536 }
3537 
3538 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3539 
3540 static os_sigaction_t os_sigaction = NULL;
3541 
3542 void os::Bsd::check_signal_handler(int sig) {
3543   char buf[O_BUFLEN];
3544   address jvmHandler = NULL;
3545 
3546 
3547   struct sigaction act;
3548   if (os_sigaction == NULL) {
3549     // only trust the default sigaction, in case it has been interposed
3550     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3551     if (os_sigaction == NULL) return;
3552   }
3553 
3554   os_sigaction(sig, (struct sigaction*)NULL, &act);
3555 
3556 
3557   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3558 
3559   address thisHandler = (act.sa_flags & SA_SIGINFO)
3560     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3561     : CAST_FROM_FN_PTR(address, act.sa_handler) ;
3562 
3563 
3564   switch(sig) {
3565   case SIGSEGV:
3566   case SIGBUS:
3567   case SIGFPE:
3568   case SIGPIPE:
3569   case SIGILL:
3570   case SIGXFSZ:
3571     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3572     break;
3573 
3574   case SHUTDOWN1_SIGNAL:
3575   case SHUTDOWN2_SIGNAL:
3576   case SHUTDOWN3_SIGNAL:
3577   case BREAK_SIGNAL:
3578     jvmHandler = (address)user_handler();
3579     break;
3580 
3581   case INTERRUPT_SIGNAL:
3582     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3583     break;
3584 
3585   default:
3586     if (sig == SR_signum) {
3587       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3588     } else {
3589       return;
3590     }
3591     break;
3592   }
3593 
3594   if (thisHandler != jvmHandler) {
3595     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3596     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3597     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3598     // No need to check this sig any longer
3599     sigaddset(&check_signal_done, sig);
3600     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3601     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3602       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3603                     exception_name(sig, buf, O_BUFLEN));
3604     }
3605   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3606     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3607     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3608     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
3609     // No need to check this sig any longer
3610     sigaddset(&check_signal_done, sig);
3611   }
3612 
3613   // Dump all the signal
3614   if (sigismember(&check_signal_done, sig)) {
3615     print_signal_handlers(tty, buf, O_BUFLEN);
3616   }
3617 }
3618 
3619 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
3620 
3621 extern bool signal_name(int signo, char* buf, size_t len);
3622 
3623 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3624   if (0 < exception_code && exception_code <= SIGRTMAX) {
3625     // signal
3626     if (!signal_name(exception_code, buf, size)) {
3627       jio_snprintf(buf, size, "SIG%d", exception_code);
3628     }
3629     return buf;
3630   } else {
3631     return NULL;
3632   }
3633 }
3634 
3635 // this is called _before_ the most of global arguments have been parsed
3636 void os::init(void) {
3637   char dummy;   /* used to get a guess on initial stack address */
3638 //  first_hrtime = gethrtime();
3639 
3640   // With BsdThreads the JavaMain thread pid (primordial thread)
3641   // is different than the pid of the java launcher thread.
3642   // So, on Bsd, the launcher thread pid is passed to the VM
3643   // via the sun.java.launcher.pid property.
3644   // Use this property instead of getpid() if it was correctly passed.
3645   // See bug 6351349.
3646   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3647 
3648   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3649 
3650   clock_tics_per_sec = CLK_TCK;
3651 
3652   init_random(1234567);
3653 
3654   ThreadCritical::initialize();
3655 
3656   Bsd::set_page_size(getpagesize());
3657   if (Bsd::page_size() == -1) {
3658     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3659                   strerror(errno)));
3660   }
3661   init_page_sizes((size_t) Bsd::page_size());
3662 
3663   Bsd::initialize_system_info();
3664 
3665   // _main_thread points to the thread that created/loaded the JVM.
3666   Bsd::_main_thread = pthread_self();
3667 
3668   Bsd::clock_init();
3669   initial_time_count = javaTimeNanos();
3670 
3671 #ifdef __APPLE__
3672   // XXXDARWIN
3673   // Work around the unaligned VM callbacks in hotspot's
3674   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3675   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3676   // alignment when doing symbol lookup. To work around this, we force early
3677   // binding of all symbols now, thus binding when alignment is known-good.
3678   _dyld_bind_fully_image_containing_address((const void *) &os::init);
3679 #endif
3680 }
3681 
3682 // To install functions for atexit system call
3683 extern "C" {
3684   static void perfMemory_exit_helper() {
3685     perfMemory_exit();
3686   }
3687 }
3688 
3689 // this is called _after_ the global arguments have been parsed
3690 jint os::init_2(void)
3691 {
3692   // Allocate a single page and mark it as readable for safepoint polling
3693   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3694   guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
3695 
3696   os::set_polling_page( polling_page );
3697 
3698 #ifndef PRODUCT
3699   if(Verbose && PrintMiscellaneous)
3700     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
3701 #endif
3702 
3703   if (!UseMembar) {
3704     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3705     guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3706     os::set_memory_serialize_page( mem_serialize_page );
3707 
3708 #ifndef PRODUCT
3709     if(Verbose && PrintMiscellaneous)
3710       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
3711 #endif
3712   }
3713 
3714   // initialize suspend/resume support - must do this before signal_sets_init()
3715   if (SR_initialize() != 0) {
3716     perror("SR_initialize failed");
3717     return JNI_ERR;
3718   }
3719 
3720   Bsd::signal_sets_init();
3721   Bsd::install_signal_handlers();
3722 
3723   // Check minimum allowable stack size for thread creation and to initialize
3724   // the java system classes, including StackOverflowError - depends on page
3725   // size.  Add a page for compiler2 recursion in main thread.
3726   // Add in 2*BytesPerWord times page size to account for VM stack during
3727   // class initialization depending on 32 or 64 bit VM.
3728   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3729             (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3730                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3731 
3732   size_t threadStackSizeInBytes = ThreadStackSize * K;
3733   if (threadStackSizeInBytes != 0 &&
3734       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3735         tty->print_cr("\nThe stack size specified is too small, "
3736                       "Specify at least %dk",
3737                       os::Bsd::min_stack_allowed/ K);
3738         return JNI_ERR;
3739   }
3740 
3741   // Make the stack size a multiple of the page size so that
3742   // the yellow/red zones can be guarded.
3743   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3744         vm_page_size()));
3745 
3746   if (MaxFDLimit) {
3747     // set the number of file descriptors to max. print out error
3748     // if getrlimit/setrlimit fails but continue regardless.
3749     struct rlimit nbr_files;
3750     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3751     if (status != 0) {
3752       if (PrintMiscellaneous && (Verbose || WizardMode))
3753         perror("os::init_2 getrlimit failed");
3754     } else {
3755       nbr_files.rlim_cur = nbr_files.rlim_max;
3756 
3757 #ifdef __APPLE__
3758       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3759       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3760       // be used instead
3761       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3762 #endif
3763 
3764       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3765       if (status != 0) {
3766         if (PrintMiscellaneous && (Verbose || WizardMode))
3767           perror("os::init_2 setrlimit failed");
3768       }
3769     }
3770   }
3771 
3772   // at-exit methods are called in the reverse order of their registration.
3773   // atexit functions are called on return from main or as a result of a
3774   // call to exit(3C). There can be only 32 of these functions registered
3775   // and atexit() does not set errno.
3776 
3777   if (PerfAllowAtExitRegistration) {
3778     // only register atexit functions if PerfAllowAtExitRegistration is set.
3779     // atexit functions can be delayed until process exit time, which
3780     // can be problematic for embedded VM situations. Embedded VMs should
3781     // call DestroyJavaVM() to assure that VM resources are released.
3782 
3783     // note: perfMemory_exit_helper atexit function may be removed in
3784     // the future if the appropriate cleanup code can be added to the
3785     // VM_Exit VMOperation's doit method.
3786     if (atexit(perfMemory_exit_helper) != 0) {
3787       warning("os::init2 atexit(perfMemory_exit_helper) failed");
3788     }
3789   }
3790 
3791   // initialize thread priority policy
3792   prio_init();
3793 
3794 #ifdef __APPLE__
3795   // dynamically link to objective c gc registration
3796   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3797   if (handleLibObjc != NULL) {
3798     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3799   }
3800 #endif
3801 
3802   return JNI_OK;
3803 }
3804 
3805 // Mark the polling page as unreadable
3806 void os::make_polling_page_unreadable(void) {
3807   if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
3808     fatal("Could not disable polling page");
3809 };
3810 
3811 // Mark the polling page as readable
3812 void os::make_polling_page_readable(void) {
3813   if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3814     fatal("Could not enable polling page");
3815   }
3816 };
3817 
3818 int os::active_processor_count() {
3819   // User has overridden the number of active processors
3820   if (ActiveProcessorCount > 0) {
3821     if (PrintActiveCpus) {
3822       tty->print_cr("active_processor_count: "
3823                     "active processor count set by user : %d",
3824                      ActiveProcessorCount);
3825     }
3826     return ActiveProcessorCount;
3827   }
3828 
3829   return _processor_count;
3830 }
3831 
3832 void os::set_native_thread_name(const char *name) {
3833 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3834   // This is only supported in Snow Leopard and beyond
3835   if (name != NULL) {
3836     // Add a "Java: " prefix to the name
3837     char buf[MAXTHREADNAMESIZE];
3838     snprintf(buf, sizeof(buf), "Java: %s", name);
3839     pthread_setname_np(buf);
3840   }
3841 #endif
3842 }
3843 
3844 bool os::distribute_processes(uint length, uint* distribution) {
3845   // Not yet implemented.
3846   return false;
3847 }
3848 
3849 bool os::bind_to_processor(uint processor_id) {
3850   // Not yet implemented.
3851   return false;
3852 }
3853 
3854 void os::SuspendedThreadTask::internal_do_task() {
3855   if (do_suspend(_thread->osthread())) {
3856     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3857     do_task(context);
3858     do_resume(_thread->osthread());
3859   }
3860 }
3861 
3862 ///
3863 class PcFetcher : public os::SuspendedThreadTask {
3864 public:
3865   PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3866   ExtendedPC result();
3867 protected:
3868   void do_task(const os::SuspendedThreadTaskContext& context);
3869 private:
3870   ExtendedPC _epc;
3871 };
3872 
3873 ExtendedPC PcFetcher::result() {
3874   guarantee(is_done(), "task is not done yet.");
3875   return _epc;
3876 }
3877 
3878 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3879   Thread* thread = context.thread();
3880   OSThread* osthread = thread->osthread();
3881   if (osthread->ucontext() != NULL) {
3882     _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
3883   } else {
3884     // NULL context is unexpected, double-check this is the VMThread
3885     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3886   }
3887 }
3888 
3889 // Suspends the target using the signal mechanism and then grabs the PC before
3890 // resuming the target. Used by the flat-profiler only
3891 ExtendedPC os::get_thread_pc(Thread* thread) {
3892   // Make sure that it is called by the watcher for the VMThread
3893   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3894   assert(thread->is_VM_thread(), "Can only be called for VMThread");
3895 
3896   PcFetcher fetcher(thread);
3897   fetcher.run();
3898   return fetcher.result();
3899 }
3900 
3901 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
3902 {
3903   return pthread_cond_timedwait(_cond, _mutex, _abstime);
3904 }
3905 
3906 ////////////////////////////////////////////////////////////////////////////////
3907 // debug support
3908 
3909 bool os::find(address addr, outputStream* st) {
3910   Dl_info dlinfo;
3911   memset(&dlinfo, 0, sizeof(dlinfo));
3912   if (dladdr(addr, &dlinfo) != 0) {
3913     st->print(PTR_FORMAT ": ", addr);
3914     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3915       st->print("%s+%#x", dlinfo.dli_sname,
3916                  addr - (intptr_t)dlinfo.dli_saddr);
3917     } else if (dlinfo.dli_fbase != NULL) {
3918       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3919     } else {
3920       st->print("<absolute address>");
3921     }
3922     if (dlinfo.dli_fname != NULL) {
3923       st->print(" in %s", dlinfo.dli_fname);
3924     }
3925     if (dlinfo.dli_fbase != NULL) {
3926       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3927     }
3928     st->cr();
3929 
3930     if (Verbose) {
3931       // decode some bytes around the PC
3932       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3933       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3934       address       lowest = (address) dlinfo.dli_sname;
3935       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3936       if (begin < lowest)  begin = lowest;
3937       Dl_info dlinfo2;
3938       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3939           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
3940         end = (address) dlinfo2.dli_saddr;
3941       Disassembler::decode(begin, end, st);
3942     }
3943     return true;
3944   }
3945   return false;
3946 }
3947 
3948 ////////////////////////////////////////////////////////////////////////////////
3949 // misc
3950 
3951 // This does not do anything on Bsd. This is basically a hook for being
3952 // able to use structured exception handling (thread-local exception filters)
3953 // on, e.g., Win32.
3954 void
3955 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
3956                          JavaCallArguments* args, Thread* thread) {
3957   f(value, method, args, thread);
3958 }
3959 
3960 void os::print_statistics() {
3961 }
3962 
3963 int os::message_box(const char* title, const char* message) {
3964   int i;
3965   fdStream err(defaultStream::error_fd());
3966   for (i = 0; i < 78; i++) err.print_raw("=");
3967   err.cr();
3968   err.print_raw_cr(title);
3969   for (i = 0; i < 78; i++) err.print_raw("-");
3970   err.cr();
3971   err.print_raw_cr(message);
3972   for (i = 0; i < 78; i++) err.print_raw("=");
3973   err.cr();
3974 
3975   char buf[16];
3976   // Prevent process from exiting upon "read error" without consuming all CPU
3977   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3978 
3979   return buf[0] == 'y' || buf[0] == 'Y';
3980 }
3981 
3982 int os::stat(const char *path, struct stat *sbuf) {
3983   char pathbuf[MAX_PATH];
3984   if (strlen(path) > MAX_PATH - 1) {
3985     errno = ENAMETOOLONG;
3986     return -1;
3987   }
3988   os::native_path(strcpy(pathbuf, path));
3989   return ::stat(pathbuf, sbuf);
3990 }
3991 
3992 bool os::check_heap(bool force) {
3993   return true;
3994 }
3995 
3996 ATTRIBUTE_PRINTF(3, 0)
3997 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
3998   return ::vsnprintf(buf, count, format, args);
3999 }
4000 
4001 // Is a (classpath) directory empty?
4002 bool os::dir_is_empty(const char* path) {
4003   DIR *dir = NULL;
4004   struct dirent *ptr;
4005 
4006   dir = opendir(path);
4007   if (dir == NULL) return true;
4008 
4009   /* Scan the directory */
4010   bool result = true;
4011   while (result && (ptr = readdir(dir)) != NULL) {
4012     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
4013       result = false;
4014     }
4015   }
4016   closedir(dir);
4017   return result;
4018 }
4019 
4020 // This code originates from JDK's sysOpen and open64_w
4021 // from src/solaris/hpi/src/system_md.c
4022 
4023 #ifndef O_DELETE
4024 #define O_DELETE 0x10000
4025 #endif
4026 
4027 // Open a file. Unlink the file immediately after open returns
4028 // if the specified oflag has the O_DELETE flag set.
4029 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
4030 
4031 int os::open(const char *path, int oflag, int mode) {
4032 
4033   if (strlen(path) > MAX_PATH - 1) {
4034     errno = ENAMETOOLONG;
4035     return -1;
4036   }
4037   int fd;
4038   int o_delete = (oflag & O_DELETE);
4039   oflag = oflag & ~O_DELETE;
4040 
4041   fd = ::open(path, oflag, mode);
4042   if (fd == -1) return -1;
4043 
4044   //If the open succeeded, the file might still be a directory
4045   {
4046     struct stat buf;
4047     int ret = ::fstat(fd, &buf);
4048     int st_mode = buf.st_mode;
4049 
4050     if (ret != -1) {
4051       if ((st_mode & S_IFMT) == S_IFDIR) {
4052         errno = EISDIR;
4053         ::close(fd);
4054         return -1;
4055       }
4056     } else {
4057       ::close(fd);
4058       return -1;
4059     }
4060   }
4061 
4062     /*
4063      * All file descriptors that are opened in the JVM and not
4064      * specifically destined for a subprocess should have the
4065      * close-on-exec flag set.  If we don't set it, then careless 3rd
4066      * party native code might fork and exec without closing all
4067      * appropriate file descriptors (e.g. as we do in closeDescriptors in
4068      * UNIXProcess.c), and this in turn might:
4069      *
4070      * - cause end-of-file to fail to be detected on some file
4071      *   descriptors, resulting in mysterious hangs, or
4072      *
4073      * - might cause an fopen in the subprocess to fail on a system
4074      *   suffering from bug 1085341.
4075      *
4076      * (Yes, the default setting of the close-on-exec flag is a Unix
4077      * design flaw)
4078      *
4079      * See:
4080      * 1085341: 32-bit stdio routines should support file descriptors >255
4081      * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
4082      * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
4083      */
4084 #ifdef FD_CLOEXEC
4085     {
4086         int flags = ::fcntl(fd, F_GETFD);
4087         if (flags != -1)
4088             ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
4089     }
4090 #endif
4091 
4092   if (o_delete != 0) {
4093     ::unlink(path);
4094   }
4095   return fd;
4096 }
4097 
4098 
4099 // create binary file, rewriting existing file if required
4100 int os::create_binary_file(const char* path, bool rewrite_existing) {
4101   int oflags = O_WRONLY | O_CREAT;
4102   if (!rewrite_existing) {
4103     oflags |= O_EXCL;
4104   }
4105   return ::open(path, oflags, S_IREAD | S_IWRITE);
4106 }
4107 
4108 // return current position of file pointer
4109 jlong os::current_file_offset(int fd) {
4110   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
4111 }
4112 
4113 // move file pointer to the specified offset
4114 jlong os::seek_to_file_offset(int fd, jlong offset) {
4115   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
4116 }
4117 
4118 // This code originates from JDK's sysAvailable
4119 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
4120 
4121 int os::available(int fd, jlong *bytes) {
4122   jlong cur, end;
4123   int mode;
4124   struct stat buf;
4125 
4126   if (::fstat(fd, &buf) >= 0) {
4127     mode = buf.st_mode;
4128     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
4129       /*
4130       * XXX: is the following call interruptible? If so, this might
4131       * need to go through the INTERRUPT_IO() wrapper as for other
4132       * blocking, interruptible calls in this file.
4133       */
4134       int n;
4135       if (::ioctl(fd, FIONREAD, &n) >= 0) {
4136         *bytes = n;
4137         return 1;
4138       }
4139     }
4140   }
4141   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
4142     return 0;
4143   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
4144     return 0;
4145   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
4146     return 0;
4147   }
4148   *bytes = end - cur;
4149   return 1;
4150 }
4151 
4152 int os::socket_available(int fd, jint *pbytes) {
4153    if (fd < 0)
4154      return OS_OK;
4155 
4156    int ret;
4157 
4158    RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
4159 
4160    //%% note ioctl can return 0 when successful, JVM_SocketAvailable
4161    // is expected to return 0 on failure and 1 on success to the jdk.
4162 
4163    return (ret == OS_ERR) ? 0 : 1;
4164 }
4165 
4166 // Map a block of memory.
4167 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
4168                      char *addr, size_t bytes, bool read_only,
4169                      bool allow_exec) {
4170   int prot;
4171   int flags;
4172 
4173   if (read_only) {
4174     prot = PROT_READ;
4175     flags = MAP_SHARED;
4176   } else {
4177     prot = PROT_READ | PROT_WRITE;
4178     flags = MAP_PRIVATE;
4179   }
4180 
4181   if (allow_exec) {
4182     prot |= PROT_EXEC;
4183   }
4184 
4185   if (addr != NULL) {
4186     flags |= MAP_FIXED;
4187   }
4188 
4189   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
4190                                      fd, file_offset);
4191   if (mapped_address == MAP_FAILED) {
4192     return NULL;
4193   }
4194   return mapped_address;
4195 }
4196 
4197 
4198 // Remap a block of memory.
4199 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
4200                        char *addr, size_t bytes, bool read_only,
4201                        bool allow_exec) {
4202   // same as map_memory() on this OS
4203   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
4204                         allow_exec);
4205 }
4206 
4207 
4208 // Unmap a block of memory.
4209 bool os::pd_unmap_memory(char* addr, size_t bytes) {
4210   return munmap(addr, bytes) == 0;
4211 }
4212 
4213 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
4214 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4215 // of a thread.
4216 //
4217 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4218 // the fast estimate available on the platform.
4219 
4220 jlong os::current_thread_cpu_time() {
4221 #ifdef __APPLE__
4222   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
4223 #else
4224   Unimplemented();
4225   return 0;
4226 #endif
4227 }
4228 
4229 jlong os::thread_cpu_time(Thread* thread) {
4230 #ifdef __APPLE__
4231   return os::thread_cpu_time(thread, true /* user + sys */);
4232 #else
4233   Unimplemented();
4234   return 0;
4235 #endif
4236 }
4237 
4238 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4239 #ifdef __APPLE__
4240   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4241 #else
4242   Unimplemented();
4243   return 0;
4244 #endif
4245 }
4246 
4247 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4248 #ifdef __APPLE__
4249   struct thread_basic_info tinfo;
4250   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
4251   kern_return_t kr;
4252   thread_t mach_thread;
4253 
4254   mach_thread = thread->osthread()->thread_id();
4255   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
4256   if (kr != KERN_SUCCESS)
4257     return -1;
4258 
4259   if (user_sys_cpu_time) {
4260     jlong nanos;
4261     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4262     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4263     return nanos;
4264   } else {
4265     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4266   }
4267 #else
4268   Unimplemented();
4269   return 0;
4270 #endif
4271 }
4272 
4273 
4274 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4275   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4276   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4277   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4278   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4279 }
4280 
4281 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4282   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4283   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4284   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4285   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4286 }
4287 
4288 bool os::is_thread_cpu_time_supported() {
4289 #ifdef __APPLE__
4290   return true;
4291 #else
4292   return false;
4293 #endif
4294 }
4295 
4296 // System loadavg support.  Returns -1 if load average cannot be obtained.
4297 // Bsd doesn't yet have a (official) notion of processor sets,
4298 // so just return the system wide load average.
4299 int os::loadavg(double loadavg[], int nelem) {
4300   return ::getloadavg(loadavg, nelem);
4301 }
4302 
4303 void os::pause() {
4304   char filename[MAX_PATH];
4305   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4306     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4307   } else {
4308     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4309   }
4310 
4311   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4312   if (fd != -1) {
4313     struct stat buf;
4314     ::close(fd);
4315     while (::stat(filename, &buf) == 0) {
4316       (void)::poll(NULL, 0, 100);
4317     }
4318   } else {
4319     jio_fprintf(stderr,
4320       "Could not open pause file '%s', continuing immediately.\n", filename);
4321   }
4322 }
4323 
4324 
4325 // Refer to the comments in os_solaris.cpp park-unpark.
4326 //
4327 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4328 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4329 // For specifics regarding the bug see GLIBC BUGID 261237 :
4330 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4331 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4332 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4333 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
4334 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4335 // and monitorenter when we're using 1-0 locking.  All those operations may result in
4336 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
4337 // of libpthread avoids the problem, but isn't practical.
4338 //
4339 // Possible remedies:
4340 //
4341 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
4342 //      This is palliative and probabilistic, however.  If the thread is preempted
4343 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
4344 //      than the minimum period may have passed, and the abstime may be stale (in the
4345 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
4346 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
4347 //
4348 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4349 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
4350 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4351 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
4352 //      thread.
4353 //
4354 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
4355 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
4356 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
4357 //      This also works well.  In fact it avoids kernel-level scalability impediments
4358 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
4359 //      timers in a graceful fashion.
4360 //
4361 // 4.   When the abstime value is in the past it appears that control returns
4362 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4363 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
4364 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
4365 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
4366 //      It may be possible to avoid reinitialization by checking the return
4367 //      value from pthread_cond_timedwait().  In addition to reinitializing the
4368 //      condvar we must establish the invariant that cond_signal() is only called
4369 //      within critical sections protected by the adjunct mutex.  This prevents
4370 //      cond_signal() from "seeing" a condvar that's in the midst of being
4371 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
4372 //      desirable signal-after-unlock optimization that avoids futile context switching.
4373 //
4374 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
4375 //      structure when a condvar is used or initialized.  cond_destroy()  would
4376 //      release the helper structure.  Our reinitialize-after-timedwait fix
4377 //      put excessive stress on malloc/free and locks protecting the c-heap.
4378 //
4379 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
4380 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4381 // and only enabling the work-around for vulnerable environments.
4382 
4383 // utility to compute the abstime argument to timedwait:
4384 // millis is the relative timeout time
4385 // abstime will be the absolute timeout time
4386 // TODO: replace compute_abstime() with unpackTime()
4387 
4388 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
4389   if (millis < 0)  millis = 0;
4390   struct timeval now;
4391   int status = gettimeofday(&now, NULL);
4392   assert(status == 0, "gettimeofday");
4393   jlong seconds = millis / 1000;
4394   millis %= 1000;
4395   if (seconds > 50000000) { // see man cond_timedwait(3T)
4396     seconds = 50000000;
4397   }
4398   abstime->tv_sec = now.tv_sec  + seconds;
4399   long       usec = now.tv_usec + millis * 1000;
4400   if (usec >= 1000000) {
4401     abstime->tv_sec += 1;
4402     usec -= 1000000;
4403   }
4404   abstime->tv_nsec = usec * 1000;
4405   return abstime;
4406 }
4407 
4408 
4409 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
4410 // Conceptually TryPark() should be equivalent to park(0).
4411 
4412 int os::PlatformEvent::TryPark() {
4413   for (;;) {
4414     const int v = _Event ;
4415     guarantee ((v == 0) || (v == 1), "invariant") ;
4416     if (Atomic::cmpxchg (0, &_Event, v) == v) return v  ;
4417   }
4418 }
4419 
4420 void os::PlatformEvent::park() {       // AKA "down()"
4421   // Invariant: Only the thread associated with the Event/PlatformEvent
4422   // may call park().
4423   // TODO: assert that _Assoc != NULL or _Assoc == Self
4424   int v ;
4425   for (;;) {
4426       v = _Event ;
4427       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4428   }
4429   guarantee (v >= 0, "invariant") ;
4430   if (v == 0) {
4431      // Do this the hard way by blocking ...
4432      int status = pthread_mutex_lock(_mutex);
4433      assert_status(status == 0, status, "mutex_lock");
4434      guarantee (_nParked == 0, "invariant") ;
4435      ++ _nParked ;
4436      while (_Event < 0) {
4437         status = pthread_cond_wait(_cond, _mutex);
4438         // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4439         // Treat this the same as if the wait was interrupted
4440         if (status == ETIMEDOUT) { status = EINTR; }
4441         assert_status(status == 0 || status == EINTR, status, "cond_wait");
4442      }
4443      -- _nParked ;
4444 
4445     _Event = 0 ;
4446      status = pthread_mutex_unlock(_mutex);
4447      assert_status(status == 0, status, "mutex_unlock");
4448     // Paranoia to ensure our locked and lock-free paths interact
4449     // correctly with each other.
4450     OrderAccess::fence();
4451   }
4452   guarantee (_Event >= 0, "invariant") ;
4453 }
4454 
4455 int os::PlatformEvent::park(jlong millis) {
4456   guarantee (_nParked == 0, "invariant") ;
4457 
4458   int v ;
4459   for (;;) {
4460       v = _Event ;
4461       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4462   }
4463   guarantee (v >= 0, "invariant") ;
4464   if (v != 0) return OS_OK ;
4465 
4466   // We do this the hard way, by blocking the thread.
4467   // Consider enforcing a minimum timeout value.
4468   struct timespec abst;
4469   compute_abstime(&abst, millis);
4470 
4471   int ret = OS_TIMEOUT;
4472   int status = pthread_mutex_lock(_mutex);
4473   assert_status(status == 0, status, "mutex_lock");
4474   guarantee (_nParked == 0, "invariant") ;
4475   ++_nParked ;
4476 
4477   // Object.wait(timo) will return because of
4478   // (a) notification
4479   // (b) timeout
4480   // (c) thread.interrupt
4481   //
4482   // Thread.interrupt and object.notify{All} both call Event::set.
4483   // That is, we treat thread.interrupt as a special case of notification.
4484   // The underlying Solaris implementation, cond_timedwait, admits
4485   // spurious/premature wakeups, but the JLS/JVM spec prevents the
4486   // JVM from making those visible to Java code.  As such, we must
4487   // filter out spurious wakeups.  We assume all ETIME returns are valid.
4488   //
4489   // TODO: properly differentiate simultaneous notify+interrupt.
4490   // In that case, we should propagate the notify to another waiter.
4491 
4492   while (_Event < 0) {
4493     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4494     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4495       pthread_cond_destroy (_cond);
4496       pthread_cond_init (_cond, NULL) ;
4497     }
4498     assert_status(status == 0 || status == EINTR ||
4499                   status == ETIMEDOUT,
4500                   status, "cond_timedwait");
4501     if (!FilterSpuriousWakeups) break ;                 // previous semantics
4502     if (status == ETIMEDOUT) break ;
4503     // We consume and ignore EINTR and spurious wakeups.
4504   }
4505   --_nParked ;
4506   if (_Event >= 0) {
4507      ret = OS_OK;
4508   }
4509   _Event = 0 ;
4510   status = pthread_mutex_unlock(_mutex);
4511   assert_status(status == 0, status, "mutex_unlock");
4512   assert (_nParked == 0, "invariant") ;
4513   // Paranoia to ensure our locked and lock-free paths interact
4514   // correctly with each other.
4515   OrderAccess::fence();
4516   return ret;
4517 }
4518 
4519 void os::PlatformEvent::unpark() {
4520   // Transitions for _Event:
4521   //    0 :=> 1
4522   //    1 :=> 1
4523   //   -1 :=> either 0 or 1; must signal target thread
4524   //          That is, we can safely transition _Event from -1 to either
4525   //          0 or 1. Forcing 1 is slightly more efficient for back-to-back
4526   //          unpark() calls.
4527   // See also: "Semaphores in Plan 9" by Mullender & Cox
4528   //
4529   // Note: Forcing a transition from "-1" to "1" on an unpark() means
4530   // that it will take two back-to-back park() calls for the owning
4531   // thread to block. This has the benefit of forcing a spurious return
4532   // from the first park() call after an unpark() call which will help
4533   // shake out uses of park() and unpark() without condition variables.
4534 
4535   if (Atomic::xchg(1, &_Event) >= 0) return;
4536 
4537   // Wait for the thread associated with the event to vacate
4538   int status = pthread_mutex_lock(_mutex);
4539   assert_status(status == 0, status, "mutex_lock");
4540   int AnyWaiters = _nParked;
4541   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4542   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4543     AnyWaiters = 0;
4544     pthread_cond_signal(_cond);
4545   }
4546   status = pthread_mutex_unlock(_mutex);
4547   assert_status(status == 0, status, "mutex_unlock");
4548   if (AnyWaiters != 0) {
4549     status = pthread_cond_signal(_cond);
4550     assert_status(status == 0, status, "cond_signal");
4551   }
4552 
4553   // Note that we signal() _after dropping the lock for "immortal" Events.
4554   // This is safe and avoids a common class of  futile wakeups.  In rare
4555   // circumstances this can cause a thread to return prematurely from
4556   // cond_{timed}wait() but the spurious wakeup is benign and the victim will
4557   // simply re-test the condition and re-park itself.
4558 }
4559 
4560 
4561 // JSR166
4562 // -------------------------------------------------------
4563 
4564 /*
4565  * The solaris and bsd implementations of park/unpark are fairly
4566  * conservative for now, but can be improved. They currently use a
4567  * mutex/condvar pair, plus a a count.
4568  * Park decrements count if > 0, else does a condvar wait.  Unpark
4569  * sets count to 1 and signals condvar.  Only one thread ever waits
4570  * on the condvar. Contention seen when trying to park implies that someone
4571  * is unparking you, so don't wait. And spurious returns are fine, so there
4572  * is no need to track notifications.
4573  */
4574 
4575 #define MAX_SECS 100000000
4576 /*
4577  * This code is common to bsd and solaris and will be moved to a
4578  * common place in dolphin.
4579  *
4580  * The passed in time value is either a relative time in nanoseconds
4581  * or an absolute time in milliseconds. Either way it has to be unpacked
4582  * into suitable seconds and nanoseconds components and stored in the
4583  * given timespec structure.
4584  * Given time is a 64-bit value and the time_t used in the timespec is only
4585  * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4586  * overflow if times way in the future are given. Further on Solaris versions
4587  * prior to 10 there is a restriction (see cond_timedwait) that the specified
4588  * number of seconds, in abstime, is less than current_time  + 100,000,000.
4589  * As it will be 28 years before "now + 100000000" will overflow we can
4590  * ignore overflow and just impose a hard-limit on seconds using the value
4591  * of "now + 100,000,000". This places a limit on the timeout of about 3.17
4592  * years from "now".
4593  */
4594 
4595 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4596   assert (time > 0, "convertTime");
4597 
4598   struct timeval now;
4599   int status = gettimeofday(&now, NULL);
4600   assert(status == 0, "gettimeofday");
4601 
4602   time_t max_secs = now.tv_sec + MAX_SECS;
4603 
4604   if (isAbsolute) {
4605     jlong secs = time / 1000;
4606     if (secs > max_secs) {
4607       absTime->tv_sec = max_secs;
4608     }
4609     else {
4610       absTime->tv_sec = secs;
4611     }
4612     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4613   }
4614   else {
4615     jlong secs = time / NANOSECS_PER_SEC;
4616     if (secs >= MAX_SECS) {
4617       absTime->tv_sec = max_secs;
4618       absTime->tv_nsec = 0;
4619     }
4620     else {
4621       absTime->tv_sec = now.tv_sec + secs;
4622       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4623       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4624         absTime->tv_nsec -= NANOSECS_PER_SEC;
4625         ++absTime->tv_sec; // note: this must be <= max_secs
4626       }
4627     }
4628   }
4629   assert(absTime->tv_sec >= 0, "tv_sec < 0");
4630   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4631   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4632   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4633 }
4634 
4635 void Parker::park(bool isAbsolute, jlong time) {
4636   // Ideally we'd do something useful while spinning, such
4637   // as calling unpackTime().
4638 
4639   // Optional fast-path check:
4640   // Return immediately if a permit is available.
4641   // We depend on Atomic::xchg() having full barrier semantics
4642   // since we are doing a lock-free update to _counter.
4643   if (Atomic::xchg(0, &_counter) > 0) return;
4644 
4645   Thread* thread = Thread::current();
4646   assert(thread->is_Java_thread(), "Must be JavaThread");
4647   JavaThread *jt = (JavaThread *)thread;
4648 
4649   // Optional optimization -- avoid state transitions if there's an interrupt pending.
4650   // Check interrupt before trying to wait
4651   if (Thread::is_interrupted(thread, false)) {
4652     return;
4653   }
4654 
4655   // Next, demultiplex/decode time arguments
4656   struct timespec absTime;
4657   if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
4658     return;
4659   }
4660   if (time > 0) {
4661     unpackTime(&absTime, isAbsolute, time);
4662   }
4663 
4664 
4665   // Enter safepoint region
4666   // Beware of deadlocks such as 6317397.
4667   // The per-thread Parker:: mutex is a classic leaf-lock.
4668   // In particular a thread must never block on the Threads_lock while
4669   // holding the Parker:: mutex.  If safepoints are pending both the
4670   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4671   ThreadBlockInVM tbivm(jt);
4672 
4673   // Don't wait if cannot get lock since interference arises from
4674   // unblocking.  Also. check interrupt before trying wait
4675   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4676     return;
4677   }
4678 
4679   int status ;
4680   if (_counter > 0)  { // no wait needed
4681     _counter = 0;
4682     status = pthread_mutex_unlock(_mutex);
4683     assert (status == 0, "invariant") ;
4684     // Paranoia to ensure our locked and lock-free paths interact
4685     // correctly with each other and Java-level accesses.
4686     OrderAccess::fence();
4687     return;
4688   }
4689 
4690 #ifdef ASSERT
4691   // Don't catch signals while blocked; let the running threads have the signals.
4692   // (This allows a debugger to break into the running thread.)
4693   sigset_t oldsigs;
4694   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4695   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4696 #endif
4697 
4698   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4699   jt->set_suspend_equivalent();
4700   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4701 
4702   if (time == 0) {
4703     status = pthread_cond_wait (_cond, _mutex) ;
4704   } else {
4705     status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
4706     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4707       pthread_cond_destroy (_cond) ;
4708       pthread_cond_init    (_cond, NULL);
4709     }
4710   }
4711   assert_status(status == 0 || status == EINTR ||
4712                 status == ETIMEDOUT,
4713                 status, "cond_timedwait");
4714 
4715 #ifdef ASSERT
4716   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4717 #endif
4718 
4719   _counter = 0 ;
4720   status = pthread_mutex_unlock(_mutex) ;
4721   assert_status(status == 0, status, "invariant") ;
4722   // Paranoia to ensure our locked and lock-free paths interact
4723   // correctly with each other and Java-level accesses.
4724   OrderAccess::fence();
4725 
4726   // If externally suspended while waiting, re-suspend
4727   if (jt->handle_special_suspend_equivalent_condition()) {
4728     jt->java_suspend_self();
4729   }
4730 }
4731 
4732 void Parker::unpark() {
4733   int s, status ;
4734   status = pthread_mutex_lock(_mutex);
4735   assert (status == 0, "invariant") ;
4736   s = _counter;
4737   _counter = 1;
4738   if (s < 1) {
4739      if (WorkAroundNPTLTimedWaitHang) {
4740         status = pthread_cond_signal (_cond) ;
4741         assert (status == 0, "invariant") ;
4742         status = pthread_mutex_unlock(_mutex);
4743         assert (status == 0, "invariant") ;
4744      } else {
4745         status = pthread_mutex_unlock(_mutex);
4746         assert (status == 0, "invariant") ;
4747         status = pthread_cond_signal (_cond) ;
4748         assert (status == 0, "invariant") ;
4749      }
4750   } else {
4751     pthread_mutex_unlock(_mutex);
4752     assert (status == 0, "invariant") ;
4753   }
4754 }
4755 
4756 
4757 /* Darwin has no "environ" in a dynamic library. */
4758 #ifdef __APPLE__
4759 #include <crt_externs.h>
4760 #define environ (*_NSGetEnviron())
4761 #else
4762 extern char** environ;
4763 #endif
4764 
4765 // Run the specified command in a separate process. Return its exit value,
4766 // or -1 on failure (e.g. can't fork a new process).
4767 // Unlike system(), this function can be called from signal handler. It
4768 // doesn't block SIGINT et al.
4769 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
4770   const char * argv[4] = {"sh", "-c", cmd, NULL};
4771 
4772   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4773   // pthread_atfork handlers and reset pthread library. All we need is a
4774   // separate process to execve. Make a direct syscall to fork process.
4775   // On IA64 there's no fork syscall, we have to use fork() and hope for
4776   // the best...
4777   pid_t pid = fork();
4778 
4779   if (pid < 0) {
4780     // fork failed
4781     return -1;
4782 
4783   } else if (pid == 0) {
4784     // child process
4785 
4786     // execve() in BsdThreads will call pthread_kill_other_threads_np()
4787     // first to kill every thread on the thread list. Because this list is
4788     // not reset by fork() (see notes above), execve() will instead kill
4789     // every thread in the parent process. We know this is the only thread
4790     // in the new process, so make a system call directly.
4791     // IA64 should use normal execve() from glibc to match the glibc fork()
4792     // above.
4793     execve("/bin/sh", (char* const*)argv, environ);
4794 
4795     // execve failed
4796     _exit(-1);
4797 
4798   } else  {
4799     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4800     // care about the actual exit code, for now.
4801 
4802     int status;
4803 
4804     // Wait for the child process to exit.  This returns immediately if
4805     // the child has already exited. */
4806     while (waitpid(pid, &status, 0) < 0) {
4807         switch (errno) {
4808         case ECHILD: return 0;
4809         case EINTR: break;
4810         default: return -1;
4811         }
4812     }
4813 
4814     if (WIFEXITED(status)) {
4815        // The child exited normally; get its exit code.
4816        return WEXITSTATUS(status);
4817     } else if (WIFSIGNALED(status)) {
4818        // The child exited because of a signal
4819        // The best value to return is 0x80 + signal number,
4820        // because that is what all Unix shells do, and because
4821        // it allows callers to distinguish between process exit and
4822        // process death by signal.
4823        return 0x80 + WTERMSIG(status);
4824     } else {
4825        // Unknown exit code; pass it through
4826        return status;
4827     }
4828   }
4829 }
4830 
4831 // is_headless_jre()
4832 //
4833 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4834 // in order to report if we are running in a headless jre
4835 //
4836 // Since JDK8 xawt/libmawt.so was moved into the same directory
4837 // as libawt.so, and renamed libawt_xawt.so
4838 //
4839 bool os::is_headless_jre() {
4840 #ifdef __APPLE__
4841     // We no longer build headless-only on Mac OS X
4842     return false;
4843 #else
4844     struct stat statbuf;
4845     char buf[MAXPATHLEN];
4846     char libmawtpath[MAXPATHLEN];
4847     const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
4848     const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4849     char *p;
4850 
4851     // Get path to libjvm.so
4852     os::jvm_path(buf, sizeof(buf));
4853 
4854     // Get rid of libjvm.so
4855     p = strrchr(buf, '/');
4856     if (p == NULL) return false;
4857     else *p = '\0';
4858 
4859     // Get rid of client or server
4860     p = strrchr(buf, '/');
4861     if (p == NULL) return false;
4862     else *p = '\0';
4863 
4864     // check xawt/libmawt.so
4865     strcpy(libmawtpath, buf);
4866     strcat(libmawtpath, xawtstr);
4867     if (::stat(libmawtpath, &statbuf) == 0) return false;
4868 
4869     // check libawt_xawt.so
4870     strcpy(libmawtpath, buf);
4871     strcat(libmawtpath, new_xawtstr);
4872     if (::stat(libmawtpath, &statbuf) == 0) return false;
4873 
4874     return true;
4875 #endif
4876 }
4877 
4878 // Get the default path to the core file
4879 // Returns the length of the string
4880 int os::get_core_path(char* buffer, size_t bufferSize) {
4881   int n = jio_snprintf(buffer, bufferSize, "/cores");
4882 
4883   // Truncate if theoretical string was longer than bufferSize
4884   n = MIN2(n, (int)bufferSize);
4885 
4886   return n;
4887 }
4888 
4889 #ifndef PRODUCT
4890 void TestReserveMemorySpecial_test() {
4891   // No tests available for this platform
4892 }
4893 #endif