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