rev 6937 : 8055755: Information about loaded dynamic libraries is wrong on MacOSX
Summary: The information about loaded dynamic libraries printed in hs_err_pid files or by running the jcmd VM.dynlib is partly incorrect. The address printed in front of the library file name is wrong.
Reviewed-by: duke
Contributed-by:

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