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