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 "semaphore_bsd.hpp"
  63 #include "services/attachListener.hpp"
  64 #include "services/memTracker.hpp"
  65 #include "services/runtimeService.hpp"
  66 #include "utilities/decoder.hpp"
  67 #include "utilities/defaultStream.hpp"
  68 #include "utilities/events.hpp"
  69 #include "utilities/growableArray.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 #ifdef __APPLE__
 642 // library handle for calling objc_registerThreadWithCollector()
 643 // without static linking to the libobjc library
 644   #define OBJC_LIB "/usr/lib/libobjc.dylib"
 645   #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 646 typedef void (*objc_registerThreadWithCollector_t)();
 647 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 648 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 649 #endif
 650 
 651 #ifdef __APPLE__
 652 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 653   // Additional thread_id used to correlate threads in SA
 654   thread_identifier_info_data_t     m_ident_info;
 655   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 656 
 657   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 658               (thread_info_t) &m_ident_info, &count);
 659 
 660   return m_ident_info.thread_id;
 661 }
 662 #endif
 663 
 664 // Thread start routine for all newly created threads
 665 static void *java_start(Thread *thread) {
 666   // Try to randomize the cache line index of hot stack frames.
 667   // This helps when threads of the same stack traces evict each other's
 668   // cache lines. The threads can be either from the same JVM instance, or
 669   // from different JVM instances. The benefit is especially true for
 670   // processors with hyperthreading technology.
 671   static int counter = 0;
 672   int pid = os::current_process_id();
 673   alloca(((pid ^ counter++) & 7) * 128);
 674 
 675   ThreadLocalStorage::set_thread(thread);
 676 
 677   OSThread* osthread = thread->osthread();
 678   Monitor* sync = osthread->startThread_lock();
 679 
 680   osthread->set_thread_id(os::Bsd::gettid());
 681 
 682 #ifdef __APPLE__
 683   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 684   guarantee(unique_thread_id != 0, "unique thread id was not found");
 685   osthread->set_unique_thread_id(unique_thread_id);
 686 #endif
 687   // initialize signal mask for this thread
 688   os::Bsd::hotspot_sigmask(thread);
 689 
 690   // initialize floating point control register
 691   os::Bsd::init_thread_fpu_state();
 692 
 693 #ifdef __APPLE__
 694   // register thread with objc gc
 695   if (objc_registerThreadWithCollectorFunction != NULL) {
 696     objc_registerThreadWithCollectorFunction();
 697   }
 698 #endif
 699 
 700   // handshaking with parent thread
 701   {
 702     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 703 
 704     // notify parent thread
 705     osthread->set_state(INITIALIZED);
 706     sync->notify_all();
 707 
 708     // wait until os::start_thread()
 709     while (osthread->get_state() == INITIALIZED) {
 710       sync->wait(Mutex::_no_safepoint_check_flag);
 711     }
 712   }
 713 
 714   // call one more level start routine
 715   thread->run();
 716 
 717   return 0;
 718 }
 719 
 720 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
 721   assert(thread->osthread() == NULL, "caller responsible");
 722 
 723   // Allocate the OSThread object
 724   OSThread* osthread = new OSThread(NULL, NULL);
 725   if (osthread == NULL) {
 726     return false;
 727   }
 728 
 729   // set the correct thread state
 730   osthread->set_thread_type(thr_type);
 731 
 732   // Initial state is ALLOCATED but not INITIALIZED
 733   osthread->set_state(ALLOCATED);
 734 
 735   thread->set_osthread(osthread);
 736 
 737   // init thread attributes
 738   pthread_attr_t attr;
 739   pthread_attr_init(&attr);
 740   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 741 
 742   // stack size
 743   if (os::Bsd::supports_variable_stack_size()) {
 744     // calculate stack size if it's not specified by caller
 745     if (stack_size == 0) {
 746       stack_size = os::Bsd::default_stack_size(thr_type);
 747 
 748       switch (thr_type) {
 749       case os::java_thread:
 750         // Java threads use ThreadStackSize which default value can be
 751         // changed with the flag -Xss
 752         assert(JavaThread::stack_size_at_create() > 0, "this should be set");
 753         stack_size = JavaThread::stack_size_at_create();
 754         break;
 755       case os::compiler_thread:
 756         if (CompilerThreadStackSize > 0) {
 757           stack_size = (size_t)(CompilerThreadStackSize * K);
 758           break;
 759         } // else fall through:
 760           // use VMThreadStackSize if CompilerThreadStackSize is not defined
 761       case os::vm_thread:
 762       case os::pgc_thread:
 763       case os::cgc_thread:
 764       case os::watcher_thread:
 765         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 766         break;
 767       }
 768     }
 769 
 770     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
 771     pthread_attr_setstacksize(&attr, stack_size);
 772   } else {
 773     // let pthread_create() pick the default value.
 774   }
 775 
 776   ThreadState state;
 777 
 778   {
 779     pthread_t tid;
 780     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
 781 
 782     pthread_attr_destroy(&attr);
 783 
 784     if (ret != 0) {
 785       if (PrintMiscellaneous && (Verbose || WizardMode)) {
 786         perror("pthread_create()");
 787       }
 788       // Need to clean up stuff we've allocated so far
 789       thread->set_osthread(NULL);
 790       delete osthread;
 791       return false;
 792     }
 793 
 794     // Store pthread info into the OSThread
 795     osthread->set_pthread_id(tid);
 796 
 797     // Wait until child thread is either initialized or aborted
 798     {
 799       Monitor* sync_with_child = osthread->startThread_lock();
 800       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 801       while ((state = osthread->get_state()) == ALLOCATED) {
 802         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 803       }
 804     }
 805 
 806   }
 807 
 808   // Aborted due to thread limit being reached
 809   if (state == ZOMBIE) {
 810     thread->set_osthread(NULL);
 811     delete osthread;
 812     return false;
 813   }
 814 
 815   // The thread is returned suspended (in state INITIALIZED),
 816   // and is started higher up in the call chain
 817   assert(state == INITIALIZED, "race condition");
 818   return true;
 819 }
 820 
 821 /////////////////////////////////////////////////////////////////////////////
 822 // attach existing thread
 823 
 824 // bootstrap the main thread
 825 bool os::create_main_thread(JavaThread* thread) {
 826   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 827   return create_attached_thread(thread);
 828 }
 829 
 830 bool os::create_attached_thread(JavaThread* thread) {
 831 #ifdef ASSERT
 832   thread->verify_not_published();
 833 #endif
 834 
 835   // Allocate the OSThread object
 836   OSThread* osthread = new OSThread(NULL, NULL);
 837 
 838   if (osthread == NULL) {
 839     return false;
 840   }
 841 
 842   osthread->set_thread_id(os::Bsd::gettid());
 843 
 844   // Store pthread info into the OSThread
 845 #ifdef __APPLE__
 846   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 847   guarantee(unique_thread_id != 0, "just checking");
 848   osthread->set_unique_thread_id(unique_thread_id);
 849 #endif
 850   osthread->set_pthread_id(::pthread_self());
 851 
 852   // initialize floating point control register
 853   os::Bsd::init_thread_fpu_state();
 854 
 855   // Initial thread state is RUNNABLE
 856   osthread->set_state(RUNNABLE);
 857 
 858   thread->set_osthread(osthread);
 859 
 860   // initialize signal mask for this thread
 861   // and save the caller's signal mask
 862   os::Bsd::hotspot_sigmask(thread);
 863 
 864   return true;
 865 }
 866 
 867 void os::pd_start_thread(Thread* thread) {
 868   OSThread * osthread = thread->osthread();
 869   assert(osthread->get_state() != INITIALIZED, "just checking");
 870   Monitor* sync_with_child = osthread->startThread_lock();
 871   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 872   sync_with_child->notify();
 873 }
 874 
 875 // Free Bsd resources related to the OSThread
 876 void os::free_thread(OSThread* osthread) {
 877   assert(osthread != NULL, "osthread not set");
 878 
 879   if (Thread::current()->osthread() == osthread) {
 880     // Restore caller's signal mask
 881     sigset_t sigmask = osthread->caller_sigmask();
 882     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 883   }
 884 
 885   delete osthread;
 886 }
 887 
 888 //////////////////////////////////////////////////////////////////////////////
 889 // thread local storage
 890 
 891 // Restore the thread pointer if the destructor is called. This is in case
 892 // someone from JNI code sets up a destructor with pthread_key_create to run
 893 // detachCurrentThread on thread death. Unless we restore the thread pointer we
 894 // will hang or crash. When detachCurrentThread is called the key will be set
 895 // to null and we will not be called again. If detachCurrentThread is never
 896 // called we could loop forever depending on the pthread implementation.
 897 static void restore_thread_pointer(void* p) {
 898   Thread* thread = (Thread*) p;
 899   os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
 900 }
 901 
 902 int os::allocate_thread_local_storage() {
 903   pthread_key_t key;
 904   int rslt = pthread_key_create(&key, restore_thread_pointer);
 905   assert(rslt == 0, "cannot allocate thread local storage");
 906   return (int)key;
 907 }
 908 
 909 // Note: This is currently not used by VM, as we don't destroy TLS key
 910 // on VM exit.
 911 void os::free_thread_local_storage(int index) {
 912   int rslt = pthread_key_delete((pthread_key_t)index);
 913   assert(rslt == 0, "invalid index");
 914 }
 915 
 916 void os::thread_local_storage_at_put(int index, void* value) {
 917   int rslt = pthread_setspecific((pthread_key_t)index, value);
 918   assert(rslt == 0, "pthread_setspecific failed");
 919 }
 920 
 921 extern "C" Thread* get_thread() {
 922   return ThreadLocalStorage::thread();
 923 }
 924 
 925 
 926 ////////////////////////////////////////////////////////////////////////////////
 927 // time support
 928 
 929 // Time since start-up in seconds to a fine granularity.
 930 // Used by VMSelfDestructTimer and the MemProfiler.
 931 double os::elapsedTime() {
 932 
 933   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 934 }
 935 
 936 jlong os::elapsed_counter() {
 937   return javaTimeNanos() - initial_time_count;
 938 }
 939 
 940 jlong os::elapsed_frequency() {
 941   return NANOSECS_PER_SEC; // nanosecond resolution
 942 }
 943 
 944 bool os::supports_vtime() { return true; }
 945 bool os::enable_vtime()   { return false; }
 946 bool os::vtime_enabled()  { return false; }
 947 
 948 double os::elapsedVTime() {
 949   // better than nothing, but not much
 950   return elapsedTime();
 951 }
 952 
 953 jlong os::javaTimeMillis() {
 954   timeval time;
 955   int status = gettimeofday(&time, NULL);
 956   assert(status != -1, "bsd error");
 957   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 958 }
 959 
 960 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
 961   timeval time;
 962   int status = gettimeofday(&time, NULL);
 963   assert(status != -1, "bsd error");
 964   seconds = jlong(time.tv_sec);
 965   nanos = jlong(time.tv_usec) * 1000;
 966 }
 967 
 968 #ifndef __APPLE__
 969   #ifndef CLOCK_MONOTONIC
 970     #define CLOCK_MONOTONIC (1)
 971   #endif
 972 #endif
 973 
 974 #ifdef __APPLE__
 975 void os::Bsd::clock_init() {
 976   mach_timebase_info(&_timebase_info);
 977 }
 978 #else
 979 void os::Bsd::clock_init() {
 980   struct timespec res;
 981   struct timespec tp;
 982   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
 983       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
 984     // yes, monotonic clock is supported
 985     _clock_gettime = ::clock_gettime;
 986   }
 987 }
 988 #endif
 989 
 990 
 991 
 992 #ifdef __APPLE__
 993 
 994 jlong os::javaTimeNanos() {
 995   const uint64_t tm = mach_absolute_time();
 996   const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
 997   const uint64_t prev = Bsd::_max_abstime;
 998   if (now <= prev) {
 999     return prev;   // same or retrograde time;
1000   }
1001   const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
1002   assert(obsv >= prev, "invariant");   // Monotonicity
1003   // If the CAS succeeded then we're done and return "now".
1004   // If the CAS failed and the observed value "obsv" is >= now then
1005   // we should return "obsv".  If the CAS failed and now > obsv > prv then
1006   // some other thread raced this thread and installed a new value, in which case
1007   // we could either (a) retry the entire operation, (b) retry trying to install now
1008   // or (c) just return obsv.  We use (c).   No loop is required although in some cases
1009   // we might discard a higher "now" value in deference to a slightly lower but freshly
1010   // installed obsv value.   That's entirely benign -- it admits no new orderings compared
1011   // to (a) or (b) -- and greatly reduces coherence traffic.
1012   // We might also condition (c) on the magnitude of the delta between obsv and now.
1013   // Avoiding excessive CAS operations to hot RW locations is critical.
1014   // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1015   return (prev == obsv) ? now : obsv;
1016 }
1017 
1018 #else // __APPLE__
1019 
1020 jlong os::javaTimeNanos() {
1021   if (os::supports_monotonic_clock()) {
1022     struct timespec tp;
1023     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
1024     assert(status == 0, "gettime error");
1025     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1026     return result;
1027   } else {
1028     timeval time;
1029     int status = gettimeofday(&time, NULL);
1030     assert(status != -1, "bsd error");
1031     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1032     return 1000 * usecs;
1033   }
1034 }
1035 
1036 #endif // __APPLE__
1037 
1038 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1039   if (os::supports_monotonic_clock()) {
1040     info_ptr->max_value = ALL_64_BITS;
1041 
1042     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1043     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
1044     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
1045   } else {
1046     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1047     info_ptr->max_value = ALL_64_BITS;
1048 
1049     // gettimeofday is a real time clock so it skips
1050     info_ptr->may_skip_backward = true;
1051     info_ptr->may_skip_forward = true;
1052   }
1053 
1054   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
1055 }
1056 
1057 // Return the real, user, and system times in seconds from an
1058 // arbitrary fixed point in the past.
1059 bool os::getTimesSecs(double* process_real_time,
1060                       double* process_user_time,
1061                       double* process_system_time) {
1062   struct tms ticks;
1063   clock_t real_ticks = times(&ticks);
1064 
1065   if (real_ticks == (clock_t) (-1)) {
1066     return false;
1067   } else {
1068     double ticks_per_second = (double) clock_tics_per_sec;
1069     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1070     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1071     *process_real_time = ((double) real_ticks) / ticks_per_second;
1072 
1073     return true;
1074   }
1075 }
1076 
1077 
1078 char * os::local_time_string(char *buf, size_t buflen) {
1079   struct tm t;
1080   time_t long_time;
1081   time(&long_time);
1082   localtime_r(&long_time, &t);
1083   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1084                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1085                t.tm_hour, t.tm_min, t.tm_sec);
1086   return buf;
1087 }
1088 
1089 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1090   return localtime_r(clock, res);
1091 }
1092 
1093 ////////////////////////////////////////////////////////////////////////////////
1094 // runtime exit support
1095 
1096 // Note: os::shutdown() might be called very early during initialization, or
1097 // called from signal handler. Before adding something to os::shutdown(), make
1098 // sure it is async-safe and can handle partially initialized VM.
1099 void os::shutdown() {
1100 
1101   // allow PerfMemory to attempt cleanup of any persistent resources
1102   perfMemory_exit();
1103 
1104   // needs to remove object in file system
1105   AttachListener::abort();
1106 
1107   // flush buffered output, finish log files
1108   ostream_abort();
1109 
1110   // Check for abort hook
1111   abort_hook_t abort_hook = Arguments::abort_hook();
1112   if (abort_hook != NULL) {
1113     abort_hook();
1114   }
1115 
1116 }
1117 
1118 // Note: os::abort() might be called very early during initialization, or
1119 // called from signal handler. Before adding something to os::abort(), make
1120 // sure it is async-safe and can handle partially initialized VM.
1121 void os::abort(bool dump_core, void* siginfo, void* context) {
1122   os::shutdown();
1123   if (dump_core) {
1124 #ifndef PRODUCT
1125     fdStream out(defaultStream::output_fd());
1126     out.print_raw("Current thread is ");
1127     char buf[16];
1128     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1129     out.print_raw_cr(buf);
1130     out.print_raw_cr("Dumping core ...");
1131 #endif
1132     ::abort(); // dump core
1133   }
1134 
1135   ::exit(1);
1136 }
1137 
1138 // Die immediately, no exit hook, no abort hook, no cleanup.
1139 void os::die() {
1140   // _exit() on BsdThreads only kills current thread
1141   ::abort();
1142 }
1143 
1144 // This method is a copy of JDK's sysGetLastErrorString
1145 // from src/solaris/hpi/src/system_md.c
1146 
1147 size_t os::lasterror(char *buf, size_t len) {
1148   if (errno == 0)  return 0;
1149 
1150   const char *s = ::strerror(errno);
1151   size_t n = ::strlen(s);
1152   if (n >= len) {
1153     n = len - 1;
1154   }
1155   ::strncpy(buf, s, n);
1156   buf[n] = '\0';
1157   return n;
1158 }
1159 
1160 // Information of current thread in variety of formats
1161 pid_t os::Bsd::gettid() {
1162   int retval = -1;
1163 
1164 #ifdef __APPLE__ //XNU kernel
1165   // despite the fact mach port is actually not a thread id use it
1166   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1167   retval = ::pthread_mach_thread_np(::pthread_self());
1168   guarantee(retval != 0, "just checking");
1169   return retval;
1170 
1171 #else
1172   #ifdef __FreeBSD__
1173   retval = syscall(SYS_thr_self);
1174   #else
1175     #ifdef __OpenBSD__
1176   retval = syscall(SYS_getthrid);
1177     #else
1178       #ifdef __NetBSD__
1179   retval = (pid_t) syscall(SYS__lwp_self);
1180       #endif
1181     #endif
1182   #endif
1183 #endif
1184 
1185   if (retval == -1) {
1186     return getpid();
1187   }
1188 }
1189 
1190 intx os::current_thread_id() {
1191 #ifdef __APPLE__
1192   return (intx)::pthread_mach_thread_np(::pthread_self());
1193 #else
1194   return (intx)::pthread_self();
1195 #endif
1196 }
1197 
1198 int os::current_process_id() {
1199 
1200   // Under the old bsd thread library, bsd gives each thread
1201   // its own process id. Because of this each thread will return
1202   // a different pid if this method were to return the result
1203   // of getpid(2). Bsd provides no api that returns the pid
1204   // of the launcher thread for the vm. This implementation
1205   // returns a unique pid, the pid of the launcher thread
1206   // that starts the vm 'process'.
1207 
1208   // Under the NPTL, getpid() returns the same pid as the
1209   // launcher thread rather than a unique pid per thread.
1210   // Use gettid() if you want the old pre NPTL behaviour.
1211 
1212   // if you are looking for the result of a call to getpid() that
1213   // returns a unique pid for the calling thread, then look at the
1214   // OSThread::thread_id() method in osThread_bsd.hpp file
1215 
1216   return (int)(_initial_pid ? _initial_pid : getpid());
1217 }
1218 
1219 // DLL functions
1220 
1221 #define JNI_LIB_PREFIX "lib"
1222 #ifdef __APPLE__
1223   #define JNI_LIB_SUFFIX ".dylib"
1224 #else
1225   #define JNI_LIB_SUFFIX ".so"
1226 #endif
1227 
1228 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1229 
1230 // This must be hard coded because it's the system's temporary
1231 // directory not the java application's temp directory, ala java.io.tmpdir.
1232 #ifdef __APPLE__
1233 // macosx has a secure per-user temporary directory
1234 char temp_path_storage[PATH_MAX];
1235 const char* os::get_temp_directory() {
1236   static char *temp_path = NULL;
1237   if (temp_path == NULL) {
1238     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1239     if (pathSize == 0 || pathSize > PATH_MAX) {
1240       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1241     }
1242     temp_path = temp_path_storage;
1243   }
1244   return temp_path;
1245 }
1246 #else // __APPLE__
1247 const char* os::get_temp_directory() { return "/tmp"; }
1248 #endif // __APPLE__
1249 
1250 static bool file_exists(const char* filename) {
1251   struct stat statbuf;
1252   if (filename == NULL || strlen(filename) == 0) {
1253     return false;
1254   }
1255   return os::stat(filename, &statbuf) == 0;
1256 }
1257 
1258 bool os::dll_build_name(char* buffer, size_t buflen,
1259                         const char* pname, const char* fname) {
1260   bool retval = false;
1261   // Copied from libhpi
1262   const size_t pnamelen = pname ? strlen(pname) : 0;
1263 
1264   // Return error on buffer overflow.
1265   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1266     return retval;
1267   }
1268 
1269   if (pnamelen == 0) {
1270     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1271     retval = true;
1272   } else if (strchr(pname, *os::path_separator()) != NULL) {
1273     int n;
1274     char** pelements = split_path(pname, &n);
1275     if (pelements == NULL) {
1276       return false;
1277     }
1278     for (int i = 0; i < n; i++) {
1279       // Really shouldn't be NULL, but check can't hurt
1280       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1281         continue; // skip the empty path values
1282       }
1283       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1284                pelements[i], fname);
1285       if (file_exists(buffer)) {
1286         retval = true;
1287         break;
1288       }
1289     }
1290     // release the storage
1291     for (int i = 0; i < n; i++) {
1292       if (pelements[i] != NULL) {
1293         FREE_C_HEAP_ARRAY(char, pelements[i]);
1294       }
1295     }
1296     if (pelements != NULL) {
1297       FREE_C_HEAP_ARRAY(char*, pelements);
1298     }
1299   } else {
1300     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1301     retval = true;
1302   }
1303   return retval;
1304 }
1305 
1306 // check if addr is inside libjvm.so
1307 bool os::address_is_in_vm(address addr) {
1308   static address libjvm_base_addr;
1309   Dl_info dlinfo;
1310 
1311   if (libjvm_base_addr == NULL) {
1312     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1313       libjvm_base_addr = (address)dlinfo.dli_fbase;
1314     }
1315     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1316   }
1317 
1318   if (dladdr((void *)addr, &dlinfo) != 0) {
1319     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1320   }
1321 
1322   return false;
1323 }
1324 
1325 
1326 #define MACH_MAXSYMLEN 256
1327 
1328 bool os::dll_address_to_function_name(address addr, char *buf,
1329                                       int buflen, int *offset,
1330                                       bool demangle) {
1331   // buf is not optional, but offset is optional
1332   assert(buf != NULL, "sanity check");
1333 
1334   Dl_info dlinfo;
1335   char localbuf[MACH_MAXSYMLEN];
1336 
1337   if (dladdr((void*)addr, &dlinfo) != 0) {
1338     // see if we have a matching symbol
1339     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1340       if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1341         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1342       }
1343       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1344       return true;
1345     }
1346     // no matching symbol so try for just file info
1347     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1348       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1349                           buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1350         return true;
1351       }
1352     }
1353 
1354     // Handle non-dynamic manually:
1355     if (dlinfo.dli_fbase != NULL &&
1356         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1357                         dlinfo.dli_fbase)) {
1358       if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) {
1359         jio_snprintf(buf, buflen, "%s", localbuf);
1360       }
1361       return true;
1362     }
1363   }
1364   buf[0] = '\0';
1365   if (offset != NULL) *offset = -1;
1366   return false;
1367 }
1368 
1369 // ported from solaris version
1370 bool os::dll_address_to_library_name(address addr, char* buf,
1371                                      int buflen, int* offset) {
1372   // buf is not optional, but offset is optional
1373   assert(buf != NULL, "sanity check");
1374 
1375   Dl_info dlinfo;
1376 
1377   if (dladdr((void*)addr, &dlinfo) != 0) {
1378     if (dlinfo.dli_fname != NULL) {
1379       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1380     }
1381     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1382       *offset = addr - (address)dlinfo.dli_fbase;
1383     }
1384     return true;
1385   }
1386 
1387   buf[0] = '\0';
1388   if (offset) *offset = -1;
1389   return false;
1390 }
1391 
1392 // Loads .dll/.so and
1393 // in case of error it checks if .dll/.so was built for the
1394 // same architecture as Hotspot is running on
1395 
1396 #ifdef __APPLE__
1397 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1398   void * result= ::dlopen(filename, RTLD_LAZY);
1399   if (result != NULL) {
1400     // Successful loading
1401     return result;
1402   }
1403 
1404   // Read system error message into ebuf
1405   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1406   ebuf[ebuflen-1]='\0';
1407 
1408   return NULL;
1409 }
1410 #else
1411 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1412   void * result= ::dlopen(filename, RTLD_LAZY);
1413   if (result != NULL) {
1414     // Successful loading
1415     return result;
1416   }
1417 
1418   Elf32_Ehdr elf_head;
1419 
1420   // Read system error message into ebuf
1421   // It may or may not be overwritten below
1422   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1423   ebuf[ebuflen-1]='\0';
1424   int diag_msg_max_length=ebuflen-strlen(ebuf);
1425   char* diag_msg_buf=ebuf+strlen(ebuf);
1426 
1427   if (diag_msg_max_length==0) {
1428     // No more space in ebuf for additional diagnostics message
1429     return NULL;
1430   }
1431 
1432 
1433   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1434 
1435   if (file_descriptor < 0) {
1436     // Can't open library, report dlerror() message
1437     return NULL;
1438   }
1439 
1440   bool failed_to_read_elf_head=
1441     (sizeof(elf_head)!=
1442      (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1443 
1444   ::close(file_descriptor);
1445   if (failed_to_read_elf_head) {
1446     // file i/o error - report dlerror() msg
1447     return NULL;
1448   }
1449 
1450   typedef struct {
1451     Elf32_Half  code;         // Actual value as defined in elf.h
1452     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1453     char        elf_class;    // 32 or 64 bit
1454     char        endianess;    // MSB or LSB
1455     char*       name;         // String representation
1456   } arch_t;
1457 
1458   #ifndef EM_486
1459     #define EM_486          6               /* Intel 80486 */
1460   #endif
1461 
1462   #ifndef EM_MIPS_RS3_LE
1463     #define EM_MIPS_RS3_LE  10              /* MIPS */
1464   #endif
1465 
1466   #ifndef EM_PPC64
1467     #define EM_PPC64        21              /* PowerPC64 */
1468   #endif
1469 
1470   #ifndef EM_S390
1471     #define EM_S390         22              /* IBM System/390 */
1472   #endif
1473 
1474   #ifndef EM_IA_64
1475     #define EM_IA_64        50              /* HP/Intel IA-64 */
1476   #endif
1477 
1478   #ifndef EM_X86_64
1479     #define EM_X86_64       62              /* AMD x86-64 */
1480   #endif
1481 
1482   static const arch_t arch_array[]={
1483     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1484     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1485     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1486     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1487     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1488     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1489     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1490     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1491     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1492     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1493     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1494     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1495     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1496     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1497     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1498     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1499   };
1500 
1501   #if  (defined IA32)
1502   static  Elf32_Half running_arch_code=EM_386;
1503   #elif   (defined AMD64)
1504   static  Elf32_Half running_arch_code=EM_X86_64;
1505   #elif  (defined IA64)
1506   static  Elf32_Half running_arch_code=EM_IA_64;
1507   #elif  (defined __sparc) && (defined _LP64)
1508   static  Elf32_Half running_arch_code=EM_SPARCV9;
1509   #elif  (defined __sparc) && (!defined _LP64)
1510   static  Elf32_Half running_arch_code=EM_SPARC;
1511   #elif  (defined __powerpc64__)
1512   static  Elf32_Half running_arch_code=EM_PPC64;
1513   #elif  (defined __powerpc__)
1514   static  Elf32_Half running_arch_code=EM_PPC;
1515   #elif  (defined ARM)
1516   static  Elf32_Half running_arch_code=EM_ARM;
1517   #elif  (defined S390)
1518   static  Elf32_Half running_arch_code=EM_S390;
1519   #elif  (defined ALPHA)
1520   static  Elf32_Half running_arch_code=EM_ALPHA;
1521   #elif  (defined MIPSEL)
1522   static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1523   #elif  (defined PARISC)
1524   static  Elf32_Half running_arch_code=EM_PARISC;
1525   #elif  (defined MIPS)
1526   static  Elf32_Half running_arch_code=EM_MIPS;
1527   #elif  (defined M68K)
1528   static  Elf32_Half running_arch_code=EM_68K;
1529   #else
1530     #error Method os::dll_load requires that one of following is defined:\
1531          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1532   #endif
1533 
1534   // Identify compatability class for VM's architecture and library's architecture
1535   // Obtain string descriptions for architectures
1536 
1537   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1538   int running_arch_index=-1;
1539 
1540   for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1541     if (running_arch_code == arch_array[i].code) {
1542       running_arch_index    = i;
1543     }
1544     if (lib_arch.code == arch_array[i].code) {
1545       lib_arch.compat_class = arch_array[i].compat_class;
1546       lib_arch.name         = arch_array[i].name;
1547     }
1548   }
1549 
1550   assert(running_arch_index != -1,
1551          "Didn't find running architecture code (running_arch_code) in arch_array");
1552   if (running_arch_index == -1) {
1553     // Even though running architecture detection failed
1554     // we may still continue with reporting dlerror() message
1555     return NULL;
1556   }
1557 
1558   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1559     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1560     return NULL;
1561   }
1562 
1563 #ifndef S390
1564   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1565     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1566     return NULL;
1567   }
1568 #endif // !S390
1569 
1570   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1571     if (lib_arch.name!=NULL) {
1572       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1573                  " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1574                  lib_arch.name, arch_array[running_arch_index].name);
1575     } else {
1576       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1577                  " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1578                  lib_arch.code,
1579                  arch_array[running_arch_index].name);
1580     }
1581   }
1582 
1583   return NULL;
1584 }
1585 #endif // !__APPLE__
1586 
1587 void* os::get_default_process_handle() {
1588 #ifdef __APPLE__
1589   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1590   // to avoid finding unexpected symbols on second (or later)
1591   // loads of a library.
1592   return (void*)::dlopen(NULL, RTLD_FIRST);
1593 #else
1594   return (void*)::dlopen(NULL, RTLD_LAZY);
1595 #endif
1596 }
1597 
1598 // XXX: Do we need a lock around this as per Linux?
1599 void* os::dll_lookup(void* handle, const char* name) {
1600   return dlsym(handle, name);
1601 }
1602 


















1603 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1604   outputStream * out = (outputStream *) param;
1605   out->print_cr(PTR_FORMAT " \t%s", base_address, name);
1606   return 0;
1607 }
1608 
1609 void os::print_dll_info(outputStream *st) {
1610   st->print_cr("Dynamic libraries:");
1611   if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1612     st->print_cr("Error: Cannot print dynamic libraries.");
1613   }
1614 }
1615 
1616 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1617 #ifdef RTLD_DI_LINKMAP
1618   Dl_info dli;
1619   void *handle;
1620   Link_map *map;
1621   Link_map *p;
1622 
1623   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1624       dli.dli_fname == NULL) {
1625     return 1;
1626   }
1627   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1628   if (handle == NULL) {
1629     return 1;
1630   }
1631   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1632   if (map == NULL) {
1633     dlclose(handle);
1634     return 1;
1635   }
1636 
1637   while (map->l_prev != NULL)
1638     map = map->l_prev;
1639 
1640   while (map != NULL) {
1641     // Value for top_address is returned as 0 since we don't have any information about module size
1642     if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1643       dlclose(handle);
1644       return 1;
1645     }
1646     map = map->l_next;
1647   }
1648 
1649   dlclose(handle);
1650 #elif defined(__APPLE__)
1651   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1652     // Value for top_address is returned as 0 since we don't have any information about module size
1653     if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1654       return 1;
1655     }
1656   }
1657   return 0;
1658 #else
1659   return 1;
1660 #endif
1661 }
1662 
1663 void os::get_summary_os_info(char* buf, size_t buflen) {
1664   // These buffers are small because we want this to be brief
1665   // and not use a lot of stack while generating the hs_err file.
1666   char os[100];
1667   size_t size = sizeof(os);
1668   int mib_kern[] = { CTL_KERN, KERN_OSTYPE };
1669   if (sysctl(mib_kern, 2, os, &size, NULL, 0) < 0) {
1670 #ifdef __APPLE__
1671       strncpy(os, "Darwin", sizeof(os));
1672 #elif __OpenBSD__
1673       strncpy(os, "OpenBSD", sizeof(os));
1674 #else
1675       strncpy(os, "BSD", sizeof(os));
1676 #endif
1677   }
1678 
1679   char release[100];
1680   size = sizeof(release);
1681   int mib_release[] = { CTL_KERN, KERN_OSRELEASE };
1682   if (sysctl(mib_release, 2, release, &size, NULL, 0) < 0) {
1683       // if error, leave blank
1684       strncpy(release, "", sizeof(release));
1685   }
1686   snprintf(buf, buflen, "%s %s", os, release);
1687 }
1688 
1689 void os::print_os_info_brief(outputStream* st) {
1690   os::Posix::print_uname_info(st);
1691 }
1692 
1693 void os::print_os_info(outputStream* st) {
1694   st->print("OS:");

1695 
1696   os::Posix::print_uname_info(st);
1697 
1698   os::Posix::print_rlimit_info(st);
1699 
1700   os::Posix::print_load_average(st);
1701 }
1702 
1703 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1704   // Nothing to do for now.
1705 }
1706 
1707 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1708   unsigned int mhz;
1709   size_t size = sizeof(mhz);
1710   int mib[] = { CTL_HW, HW_CPU_FREQ };
1711   size = sizeof(mhz);
1712   if (sysctl(mib, 2, &mhz, &size, NULL, 0) < 0) {
1713       mhz = 0;
1714   }
1715   mhz /= 1000000;  // reported in millions
1716 
1717   char model[100];
1718   size = sizeof(model);
1719   int mib_model[] = { CTL_HW, HW_MODEL };
1720   if (sysctl(mib_model, 2, model, &size, NULL, 0) < 0) {
1721     strncpy(model, cpu_arch, sizeof(model));
1722   }
1723 
1724   char machine[100];
1725   size = sizeof(machine);
1726   int mib_machine[] = { CTL_HW, HW_MACHINE };
1727   if (sysctl(mib_machine, 2, machine, &size, NULL, 0) < 0) {
1728       strncpy(machine, "", sizeof(machine));
1729   }
1730 
1731   snprintf(buf, buflen, "%s %s %d MHz", model, machine, mhz);
1732 }
1733 
1734 void os::print_memory_info(outputStream* st) {
1735 
1736   st->print("Memory:");
1737   st->print(" %dk page", os::vm_page_size()>>10);
1738 
1739   st->print(", physical " UINT64_FORMAT "k",
1740             os::physical_memory() >> 10);
1741   st->print("(" UINT64_FORMAT "k free)",
1742             os::available_memory() >> 10);





1743   st->cr();
1744 }
1745 
1746 void os::print_siginfo(outputStream* st, void* siginfo) {
1747   const siginfo_t* si = (const siginfo_t*)siginfo;
1748 
1749   os::Posix::print_siginfo_brief(st, si);
1750 
1751   if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1752       UseSharedSpaces) {
1753     FileMapInfo* mapinfo = FileMapInfo::current_info();
1754     if (mapinfo->is_in_shared_space(si->si_addr)) {
1755       st->print("\n\nError accessing class data sharing archive."   \
1756                 " Mapped file inaccessible during execution, "      \
1757                 " possible disk/network problem.");
1758     }
1759   }
1760   st->cr();
1761 }
1762 
1763 
1764 static void print_signal_handler(outputStream* st, int sig,
1765                                  char* buf, size_t buflen);
1766 
1767 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1768   st->print_cr("Signal Handlers:");
1769   print_signal_handler(st, SIGSEGV, buf, buflen);
1770   print_signal_handler(st, SIGBUS , buf, buflen);
1771   print_signal_handler(st, SIGFPE , buf, buflen);
1772   print_signal_handler(st, SIGPIPE, buf, buflen);
1773   print_signal_handler(st, SIGXFSZ, buf, buflen);
1774   print_signal_handler(st, SIGILL , buf, buflen);
1775   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1776   print_signal_handler(st, SR_signum, buf, buflen);
1777   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1778   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1779   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1780   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1781 }
1782 
1783 static char saved_jvm_path[MAXPATHLEN] = {0};
1784 
1785 // Find the full path to the current module, libjvm
1786 void os::jvm_path(char *buf, jint buflen) {
1787   // Error checking.
1788   if (buflen < MAXPATHLEN) {
1789     assert(false, "must use a large-enough buffer");
1790     buf[0] = '\0';
1791     return;
1792   }
1793   // Lazy resolve the path to current module.
1794   if (saved_jvm_path[0] != 0) {
1795     strcpy(buf, saved_jvm_path);
1796     return;
1797   }
1798 
1799   char dli_fname[MAXPATHLEN];
1800   bool ret = dll_address_to_library_name(
1801                                          CAST_FROM_FN_PTR(address, os::jvm_path),
1802                                          dli_fname, sizeof(dli_fname), NULL);
1803   assert(ret, "cannot locate libjvm");
1804   char *rp = NULL;
1805   if (ret && dli_fname[0] != '\0') {
1806     rp = realpath(dli_fname, buf);
1807   }
1808   if (rp == NULL) {
1809     return;
1810   }
1811 
1812   if (Arguments::sun_java_launcher_is_altjvm()) {
1813     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1814     // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1815     // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1816     // appears at the right place in the string, then assume we are
1817     // installed in a JDK and we're done. Otherwise, check for a
1818     // JAVA_HOME environment variable and construct a path to the JVM
1819     // being overridden.
1820 
1821     const char *p = buf + strlen(buf) - 1;
1822     for (int count = 0; p > buf && count < 5; ++count) {
1823       for (--p; p > buf && *p != '/'; --p)
1824         /* empty */ ;
1825     }
1826 
1827     if (strncmp(p, "/jre/lib/", 9) != 0) {
1828       // Look for JAVA_HOME in the environment.
1829       char* java_home_var = ::getenv("JAVA_HOME");
1830       if (java_home_var != NULL && java_home_var[0] != 0) {
1831         char* jrelib_p;
1832         int len;
1833 
1834         // Check the current module name "libjvm"
1835         p = strrchr(buf, '/');
1836         assert(strstr(p, "/libjvm") == p, "invalid library name");
1837 
1838         rp = realpath(java_home_var, buf);
1839         if (rp == NULL) {
1840           return;
1841         }
1842 
1843         // determine if this is a legacy image or modules image
1844         // modules image doesn't have "jre" subdirectory
1845         len = strlen(buf);
1846         assert(len < buflen, "Ran out of buffer space");
1847         jrelib_p = buf + len;
1848 
1849         // Add the appropriate library subdir
1850         snprintf(jrelib_p, buflen-len, "/jre/lib");
1851         if (0 != access(buf, F_OK)) {
1852           snprintf(jrelib_p, buflen-len, "/lib");
1853         }
1854 
1855         // Add the appropriate client or server subdir
1856         len = strlen(buf);
1857         jrelib_p = buf + len;
1858         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1859         if (0 != access(buf, F_OK)) {
1860           snprintf(jrelib_p, buflen-len, "%s", "");
1861         }
1862 
1863         // If the path exists within JAVA_HOME, add the JVM library name
1864         // to complete the path to JVM being overridden.  Otherwise fallback
1865         // to the path to the current library.
1866         if (0 == access(buf, F_OK)) {
1867           // Use current module name "libjvm"
1868           len = strlen(buf);
1869           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1870         } else {
1871           // Fall back to path of current library
1872           rp = realpath(dli_fname, buf);
1873           if (rp == NULL) {
1874             return;
1875           }
1876         }
1877       }
1878     }
1879   }
1880 
1881   strncpy(saved_jvm_path, buf, MAXPATHLEN);
1882   saved_jvm_path[MAXPATHLEN - 1] = '\0';
1883 }
1884 
1885 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1886   // no prefix required, not even "_"
1887 }
1888 
1889 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1890   // no suffix required
1891 }
1892 
1893 ////////////////////////////////////////////////////////////////////////////////
1894 // sun.misc.Signal support
1895 
1896 static volatile jint sigint_count = 0;
1897 
1898 static void UserHandler(int sig, void *siginfo, void *context) {
1899   // 4511530 - sem_post is serialized and handled by the manager thread. When
1900   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1901   // don't want to flood the manager thread with sem_post requests.
1902   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
1903     return;
1904   }
1905 
1906   // Ctrl-C is pressed during error reporting, likely because the error
1907   // handler fails to abort. Let VM die immediately.
1908   if (sig == SIGINT && is_error_reported()) {
1909     os::die();
1910   }
1911 
1912   os::signal_notify(sig);
1913 }
1914 
1915 void* os::user_handler() {
1916   return CAST_FROM_FN_PTR(void*, UserHandler);
1917 }
1918 
1919 extern "C" {
1920   typedef void (*sa_handler_t)(int);
1921   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1922 }
1923 
1924 void* os::signal(int signal_number, void* handler) {
1925   struct sigaction sigAct, oldSigAct;
1926 
1927   sigfillset(&(sigAct.sa_mask));
1928   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1929   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1930 
1931   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1932     // -1 means registration failed
1933     return (void *)-1;
1934   }
1935 
1936   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1937 }
1938 
1939 void os::signal_raise(int signal_number) {
1940   ::raise(signal_number);
1941 }
1942 
1943 // The following code is moved from os.cpp for making this
1944 // code platform specific, which it is by its very nature.
1945 
1946 // Will be modified when max signal is changed to be dynamic
1947 int os::sigexitnum_pd() {
1948   return NSIG;
1949 }
1950 
1951 // a counter for each possible signal value
1952 static volatile jint pending_signals[NSIG+1] = { 0 };
1953 
1954 // Bsd(POSIX) specific hand shaking semaphore.
1955 #ifdef __APPLE__
1956 typedef semaphore_t os_semaphore_t;
1957 
1958   #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1959   #define SEM_WAIT(sem)           semaphore_wait(sem)
1960   #define SEM_POST(sem)           semaphore_signal(sem)
1961   #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
1962 #else
1963 typedef sem_t os_semaphore_t;
1964 
1965   #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
1966   #define SEM_WAIT(sem)           sem_wait(&sem)
1967   #define SEM_POST(sem)           sem_post(&sem)
1968   #define SEM_DESTROY(sem)        sem_destroy(&sem)
1969 #endif
1970 
1971 #ifdef __APPLE__
1972 // OS X doesn't support unamed POSIX semaphores, so the implementation in os_posix.cpp can't be used.
1973 
1974 static const char* sem_init_strerror(kern_return_t value) {
1975   switch (value) {
1976     case KERN_INVALID_ARGUMENT:  return "Invalid argument";
1977     case KERN_RESOURCE_SHORTAGE: return "Resource shortage";
1978     default:                     return "Unknown";
1979   }
1980 }
1981 
1982 OSXSemaphore::OSXSemaphore(uint value) {
1983   kern_return_t ret = SEM_INIT(_semaphore, value);
1984 
1985   guarantee(ret == KERN_SUCCESS, err_msg("Failed to create semaphore: %s", sem_init_strerror(ret)));
1986 }
1987 
1988 OSXSemaphore::~OSXSemaphore() {
1989   SEM_DESTROY(_semaphore);
1990 }
1991 
1992 void OSXSemaphore::signal(uint count) {
1993   for (uint i = 0; i < count; i++) {
1994     kern_return_t ret = SEM_POST(_semaphore);
1995 
1996     assert(ret == KERN_SUCCESS, "Failed to signal semaphore");
1997   }
1998 }
1999 
2000 void OSXSemaphore::wait() {
2001   kern_return_t ret;
2002   while ((ret = SEM_WAIT(_semaphore)) == KERN_ABORTED) {
2003     // Semaphore was interrupted. Retry.
2004   }
2005   assert(ret == KERN_SUCCESS, "Failed to wait on semaphore");
2006 }
2007 
2008 jlong OSXSemaphore::currenttime() {
2009   struct timeval tv;
2010   gettimeofday(&tv, NULL);
2011   return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
2012 }
2013 
2014 bool OSXSemaphore::trywait() {
2015   return timedwait(0, 0);
2016 }
2017 
2018 bool OSXSemaphore::timedwait(unsigned int sec, int nsec) {
2019   kern_return_t kr = KERN_ABORTED;
2020   mach_timespec_t waitspec;
2021   waitspec.tv_sec = sec;
2022   waitspec.tv_nsec = nsec;
2023 
2024   jlong starttime = currenttime();
2025 
2026   kr = semaphore_timedwait(_semaphore, waitspec);
2027   while (kr == KERN_ABORTED) {
2028     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
2029 
2030     jlong current = currenttime();
2031     jlong passedtime = current - starttime;
2032 
2033     if (passedtime >= totalwait) {
2034       waitspec.tv_sec = 0;
2035       waitspec.tv_nsec = 0;
2036     } else {
2037       jlong waittime = totalwait - (current - starttime);
2038       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
2039       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
2040     }
2041 
2042     kr = semaphore_timedwait(_semaphore, waitspec);
2043   }
2044 
2045   return kr == KERN_SUCCESS;
2046 }
2047 
2048 #else
2049 // Use POSIX implementation of semaphores.
2050 
2051 struct timespec PosixSemaphore::create_timespec(unsigned int sec, int nsec) {
2052   struct timespec ts;
2053   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2054 
2055   return ts;
2056 }
2057 
2058 #endif // __APPLE__
2059 
2060 static os_semaphore_t sig_sem;
2061 
2062 #ifdef __APPLE__
2063 static OSXSemaphore sr_semaphore;
2064 #else
2065 static PosixSemaphore sr_semaphore;
2066 #endif
2067 
2068 void os::signal_init_pd() {
2069   // Initialize signal structures
2070   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2071 
2072   // Initialize signal semaphore
2073   ::SEM_INIT(sig_sem, 0);
2074 }
2075 
2076 void os::signal_notify(int sig) {
2077   Atomic::inc(&pending_signals[sig]);
2078   ::SEM_POST(sig_sem);
2079 }
2080 
2081 static int check_pending_signals(bool wait) {
2082   Atomic::store(0, &sigint_count);
2083   for (;;) {
2084     for (int i = 0; i < NSIG + 1; i++) {
2085       jint n = pending_signals[i];
2086       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2087         return i;
2088       }
2089     }
2090     if (!wait) {
2091       return -1;
2092     }
2093     JavaThread *thread = JavaThread::current();
2094     ThreadBlockInVM tbivm(thread);
2095 
2096     bool threadIsSuspended;
2097     do {
2098       thread->set_suspend_equivalent();
2099       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2100       ::SEM_WAIT(sig_sem);
2101 
2102       // were we externally suspended while we were waiting?
2103       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2104       if (threadIsSuspended) {
2105         // The semaphore has been incremented, but while we were waiting
2106         // another thread suspended us. We don't want to continue running
2107         // while suspended because that would surprise the thread that
2108         // suspended us.
2109         ::SEM_POST(sig_sem);
2110 
2111         thread->java_suspend_self();
2112       }
2113     } while (threadIsSuspended);
2114   }
2115 }
2116 
2117 int os::signal_lookup() {
2118   return check_pending_signals(false);
2119 }
2120 
2121 int os::signal_wait() {
2122   return check_pending_signals(true);
2123 }
2124 
2125 ////////////////////////////////////////////////////////////////////////////////
2126 // Virtual Memory
2127 
2128 int os::vm_page_size() {
2129   // Seems redundant as all get out
2130   assert(os::Bsd::page_size() != -1, "must call os::init");
2131   return os::Bsd::page_size();
2132 }
2133 
2134 // Solaris allocates memory by pages.
2135 int os::vm_allocation_granularity() {
2136   assert(os::Bsd::page_size() != -1, "must call os::init");
2137   return os::Bsd::page_size();
2138 }
2139 
2140 // Rationale behind this function:
2141 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2142 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2143 //  samples for JITted code. Here we create private executable mapping over the code cache
2144 //  and then we can use standard (well, almost, as mapping can change) way to provide
2145 //  info for the reporting script by storing timestamp and location of symbol
2146 void bsd_wrap_code(char* base, size_t size) {
2147   static volatile jint cnt = 0;
2148 
2149   if (!UseOprofile) {
2150     return;
2151   }
2152 
2153   char buf[PATH_MAX + 1];
2154   int num = Atomic::add(1, &cnt);
2155 
2156   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2157            os::get_temp_directory(), os::current_process_id(), num);
2158   unlink(buf);
2159 
2160   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2161 
2162   if (fd != -1) {
2163     off_t rv = ::lseek(fd, size-2, SEEK_SET);
2164     if (rv != (off_t)-1) {
2165       if (::write(fd, "", 1) == 1) {
2166         mmap(base, size,
2167              PROT_READ|PROT_WRITE|PROT_EXEC,
2168              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2169       }
2170     }
2171     ::close(fd);
2172     unlink(buf);
2173   }
2174 }
2175 
2176 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2177                                     int err) {
2178   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2179           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2180           strerror(err), err);
2181 }
2182 
2183 // NOTE: Bsd kernel does not really reserve the pages for us.
2184 //       All it does is to check if there are enough free pages
2185 //       left at the time of mmap(). This could be a potential
2186 //       problem.
2187 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2188   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2189 #ifdef __OpenBSD__
2190   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2191   if (::mprotect(addr, size, prot) == 0) {
2192     return true;
2193   }
2194 #else
2195   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2196                                      MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2197   if (res != (uintptr_t) MAP_FAILED) {
2198     return true;
2199   }
2200 #endif
2201 
2202   // Warn about any commit errors we see in non-product builds just
2203   // in case mmap() doesn't work as described on the man page.
2204   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2205 
2206   return false;
2207 }
2208 
2209 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2210                           bool exec) {
2211   // alignment_hint is ignored on this OS
2212   return pd_commit_memory(addr, size, exec);
2213 }
2214 
2215 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2216                                   const char* mesg) {
2217   assert(mesg != NULL, "mesg must be specified");
2218   if (!pd_commit_memory(addr, size, exec)) {
2219     // add extra info in product mode for vm_exit_out_of_memory():
2220     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2221     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
2222   }
2223 }
2224 
2225 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2226                                   size_t alignment_hint, bool exec,
2227                                   const char* mesg) {
2228   // alignment_hint is ignored on this OS
2229   pd_commit_memory_or_exit(addr, size, exec, mesg);
2230 }
2231 
2232 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2233 }
2234 
2235 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2236   ::madvise(addr, bytes, MADV_DONTNEED);
2237 }
2238 
2239 void os::numa_make_global(char *addr, size_t bytes) {
2240 }
2241 
2242 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2243 }
2244 
2245 bool os::numa_topology_changed()   { return false; }
2246 
2247 size_t os::numa_get_groups_num() {
2248   return 1;
2249 }
2250 
2251 int os::numa_get_group_id() {
2252   return 0;
2253 }
2254 
2255 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2256   if (size > 0) {
2257     ids[0] = 0;
2258     return 1;
2259   }
2260   return 0;
2261 }
2262 
2263 bool os::get_page_info(char *start, page_info* info) {
2264   return false;
2265 }
2266 
2267 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2268   return end;
2269 }
2270 
2271 
2272 bool os::pd_uncommit_memory(char* addr, size_t size) {
2273 #ifdef __OpenBSD__
2274   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2275   return ::mprotect(addr, size, PROT_NONE) == 0;
2276 #else
2277   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2278                                      MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2279   return res  != (uintptr_t) MAP_FAILED;
2280 #endif
2281 }
2282 
2283 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2284   return os::commit_memory(addr, size, !ExecMem);
2285 }
2286 
2287 // If this is a growable mapping, remove the guard pages entirely by
2288 // munmap()ping them.  If not, just call uncommit_memory().
2289 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2290   return os::uncommit_memory(addr, size);
2291 }
2292 
2293 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2294 // at 'requested_addr'. If there are existing memory mappings at the same
2295 // location, however, they will be overwritten. If 'fixed' is false,
2296 // 'requested_addr' is only treated as a hint, the return value may or
2297 // may not start from the requested address. Unlike Bsd mmap(), this
2298 // function returns NULL to indicate failure.
2299 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2300   char * addr;
2301   int flags;
2302 
2303   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2304   if (fixed) {
2305     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2306     flags |= MAP_FIXED;
2307   }
2308 
2309   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2310   // touch an uncommitted page. Otherwise, the read/write might
2311   // succeed if we have enough swap space to back the physical page.
2312   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2313                        flags, -1, 0);
2314 
2315   return addr == MAP_FAILED ? NULL : addr;
2316 }
2317 
2318 static int anon_munmap(char * addr, size_t size) {
2319   return ::munmap(addr, size) == 0;
2320 }
2321 
2322 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2323                             size_t alignment_hint) {
2324   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2325 }
2326 
2327 bool os::pd_release_memory(char* addr, size_t size) {
2328   return anon_munmap(addr, size);
2329 }
2330 
2331 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2332   // Bsd wants the mprotect address argument to be page aligned.
2333   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2334 
2335   // According to SUSv3, mprotect() should only be used with mappings
2336   // established by mmap(), and mmap() always maps whole pages. Unaligned
2337   // 'addr' likely indicates problem in the VM (e.g. trying to change
2338   // protection of malloc'ed or statically allocated memory). Check the
2339   // caller if you hit this assert.
2340   assert(addr == bottom, "sanity check");
2341 
2342   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2343   return ::mprotect(bottom, size, prot) == 0;
2344 }
2345 
2346 // Set protections specified
2347 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2348                         bool is_committed) {
2349   unsigned int p = 0;
2350   switch (prot) {
2351   case MEM_PROT_NONE: p = PROT_NONE; break;
2352   case MEM_PROT_READ: p = PROT_READ; break;
2353   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2354   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2355   default:
2356     ShouldNotReachHere();
2357   }
2358   // is_committed is unused.
2359   return bsd_mprotect(addr, bytes, p);
2360 }
2361 
2362 bool os::guard_memory(char* addr, size_t size) {
2363   return bsd_mprotect(addr, size, PROT_NONE);
2364 }
2365 
2366 bool os::unguard_memory(char* addr, size_t size) {
2367   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2368 }
2369 
2370 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2371   return false;
2372 }
2373 
2374 // Large page support
2375 
2376 static size_t _large_page_size = 0;
2377 
2378 void os::large_page_init() {
2379 }
2380 
2381 
2382 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2383   fatal("This code is not used or maintained.");
2384 
2385   // "exec" is passed in but not used.  Creating the shared image for
2386   // the code cache doesn't have an SHM_X executable permission to check.
2387   assert(UseLargePages && UseSHM, "only for SHM large pages");
2388 
2389   key_t key = IPC_PRIVATE;
2390   char *addr;
2391 
2392   bool warn_on_failure = UseLargePages &&
2393                          (!FLAG_IS_DEFAULT(UseLargePages) ||
2394                           !FLAG_IS_DEFAULT(LargePageSizeInBytes));
2395 
2396   // Create a large shared memory region to attach to based on size.
2397   // Currently, size is the total size of the heap
2398   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2399   if (shmid == -1) {
2400     // Possible reasons for shmget failure:
2401     // 1. shmmax is too small for Java heap.
2402     //    > check shmmax value: cat /proc/sys/kernel/shmmax
2403     //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2404     // 2. not enough large page memory.
2405     //    > check available large pages: cat /proc/meminfo
2406     //    > increase amount of large pages:
2407     //          echo new_value > /proc/sys/vm/nr_hugepages
2408     //      Note 1: different Bsd may use different name for this property,
2409     //            e.g. on Redhat AS-3 it is "hugetlb_pool".
2410     //      Note 2: it's possible there's enough physical memory available but
2411     //            they are so fragmented after a long run that they can't
2412     //            coalesce into large pages. Try to reserve large pages when
2413     //            the system is still "fresh".
2414     if (warn_on_failure) {
2415       warning("Failed to reserve shared memory (errno = %d).", errno);
2416     }
2417     return NULL;
2418   }
2419 
2420   // attach to the region
2421   addr = (char*)shmat(shmid, req_addr, 0);
2422   int err = errno;
2423 
2424   // Remove shmid. If shmat() is successful, the actual shared memory segment
2425   // will be deleted when it's detached by shmdt() or when the process
2426   // terminates. If shmat() is not successful this will remove the shared
2427   // segment immediately.
2428   shmctl(shmid, IPC_RMID, NULL);
2429 
2430   if ((intptr_t)addr == -1) {
2431     if (warn_on_failure) {
2432       warning("Failed to attach shared memory (errno = %d).", err);
2433     }
2434     return NULL;
2435   }
2436 
2437   // The memory is committed
2438   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
2439 
2440   return addr;
2441 }
2442 
2443 bool os::release_memory_special(char* base, size_t bytes) {
2444   if (MemTracker::tracking_level() > NMT_minimal) {
2445     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2446     // detaching the SHM segment will also delete it, see reserve_memory_special()
2447     int rslt = shmdt(base);
2448     if (rslt == 0) {
2449       tkr.record((address)base, bytes);
2450       return true;
2451     } else {
2452       return false;
2453     }
2454   } else {
2455     return shmdt(base) == 0;
2456   }
2457 }
2458 
2459 size_t os::large_page_size() {
2460   return _large_page_size;
2461 }
2462 
2463 // HugeTLBFS allows application to commit large page memory on demand;
2464 // with SysV SHM the entire memory region must be allocated as shared
2465 // memory.
2466 bool os::can_commit_large_page_memory() {
2467   return UseHugeTLBFS;
2468 }
2469 
2470 bool os::can_execute_large_page_memory() {
2471   return UseHugeTLBFS;
2472 }
2473 
2474 // Reserve memory at an arbitrary address, only if that area is
2475 // available (and not reserved for something else).
2476 
2477 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2478   const int max_tries = 10;
2479   char* base[max_tries];
2480   size_t size[max_tries];
2481   const size_t gap = 0x000000;
2482 
2483   // Assert only that the size is a multiple of the page size, since
2484   // that's all that mmap requires, and since that's all we really know
2485   // about at this low abstraction level.  If we need higher alignment,
2486   // we can either pass an alignment to this method or verify alignment
2487   // in one of the methods further up the call chain.  See bug 5044738.
2488   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2489 
2490   // Repeatedly allocate blocks until the block is allocated at the
2491   // right spot.
2492 
2493   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2494   // if kernel honors the hint then we can return immediately.
2495   char * addr = anon_mmap(requested_addr, bytes, false);
2496   if (addr == requested_addr) {
2497     return requested_addr;
2498   }
2499 
2500   if (addr != NULL) {
2501     // mmap() is successful but it fails to reserve at the requested address
2502     anon_munmap(addr, bytes);
2503   }
2504 
2505   int i;
2506   for (i = 0; i < max_tries; ++i) {
2507     base[i] = reserve_memory(bytes);
2508 
2509     if (base[i] != NULL) {
2510       // Is this the block we wanted?
2511       if (base[i] == requested_addr) {
2512         size[i] = bytes;
2513         break;
2514       }
2515 
2516       // Does this overlap the block we wanted? Give back the overlapped
2517       // parts and try again.
2518 
2519       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2520       if (top_overlap >= 0 && top_overlap < bytes) {
2521         unmap_memory(base[i], top_overlap);
2522         base[i] += top_overlap;
2523         size[i] = bytes - top_overlap;
2524       } else {
2525         size_t bottom_overlap = base[i] + bytes - requested_addr;
2526         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2527           unmap_memory(requested_addr, bottom_overlap);
2528           size[i] = bytes - bottom_overlap;
2529         } else {
2530           size[i] = bytes;
2531         }
2532       }
2533     }
2534   }
2535 
2536   // Give back the unused reserved pieces.
2537 
2538   for (int j = 0; j < i; ++j) {
2539     if (base[j] != NULL) {
2540       unmap_memory(base[j], size[j]);
2541     }
2542   }
2543 
2544   if (i < max_tries) {
2545     return requested_addr;
2546   } else {
2547     return NULL;
2548   }
2549 }
2550 
2551 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2552   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2553 }
2554 
2555 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
2556   RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset));
2557 }
2558 
2559 void os::naked_short_sleep(jlong ms) {
2560   struct timespec req;
2561 
2562   assert(ms < 1000, "Un-interruptable sleep, short time use only");
2563   req.tv_sec = 0;
2564   if (ms > 0) {
2565     req.tv_nsec = (ms % 1000) * 1000000;
2566   } else {
2567     req.tv_nsec = 1;
2568   }
2569 
2570   nanosleep(&req, NULL);
2571 
2572   return;
2573 }
2574 
2575 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2576 void os::infinite_sleep() {
2577   while (true) {    // sleep forever ...
2578     ::sleep(100);   // ... 100 seconds at a time
2579   }
2580 }
2581 
2582 // Used to convert frequent JVM_Yield() to nops
2583 bool os::dont_yield() {
2584   return DontYieldALot;
2585 }
2586 
2587 void os::naked_yield() {
2588   sched_yield();
2589 }
2590 
2591 ////////////////////////////////////////////////////////////////////////////////
2592 // thread priority support
2593 
2594 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2595 // only supports dynamic priority, static priority must be zero. For real-time
2596 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2597 // However, for large multi-threaded applications, SCHED_RR is not only slower
2598 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2599 // of 5 runs - Sep 2005).
2600 //
2601 // The following code actually changes the niceness of kernel-thread/LWP. It
2602 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2603 // not the entire user process, and user level threads are 1:1 mapped to kernel
2604 // threads. It has always been the case, but could change in the future. For
2605 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2606 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2607 
2608 #if !defined(__APPLE__)
2609 int os::java_to_os_priority[CriticalPriority + 1] = {
2610   19,              // 0 Entry should never be used
2611 
2612    0,              // 1 MinPriority
2613    3,              // 2
2614    6,              // 3
2615 
2616   10,              // 4
2617   15,              // 5 NormPriority
2618   18,              // 6
2619 
2620   21,              // 7
2621   25,              // 8
2622   28,              // 9 NearMaxPriority
2623 
2624   31,              // 10 MaxPriority
2625 
2626   31               // 11 CriticalPriority
2627 };
2628 #else
2629 // Using Mach high-level priority assignments
2630 int os::java_to_os_priority[CriticalPriority + 1] = {
2631    0,              // 0 Entry should never be used (MINPRI_USER)
2632 
2633   27,              // 1 MinPriority
2634   28,              // 2
2635   29,              // 3
2636 
2637   30,              // 4
2638   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2639   32,              // 6
2640 
2641   33,              // 7
2642   34,              // 8
2643   35,              // 9 NearMaxPriority
2644 
2645   36,              // 10 MaxPriority
2646 
2647   36               // 11 CriticalPriority
2648 };
2649 #endif
2650 
2651 static int prio_init() {
2652   if (ThreadPriorityPolicy == 1) {
2653     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2654     // if effective uid is not root. Perhaps, a more elegant way of doing
2655     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2656     if (geteuid() != 0) {
2657       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2658         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2659       }
2660       ThreadPriorityPolicy = 0;
2661     }
2662   }
2663   if (UseCriticalJavaThreadPriority) {
2664     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2665   }
2666   return 0;
2667 }
2668 
2669 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2670   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2671 
2672 #ifdef __OpenBSD__
2673   // OpenBSD pthread_setprio starves low priority threads
2674   return OS_OK;
2675 #elif defined(__FreeBSD__)
2676   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2677 #elif defined(__APPLE__) || defined(__NetBSD__)
2678   struct sched_param sp;
2679   int policy;
2680   pthread_t self = pthread_self();
2681 
2682   if (pthread_getschedparam(self, &policy, &sp) != 0) {
2683     return OS_ERR;
2684   }
2685 
2686   sp.sched_priority = newpri;
2687   if (pthread_setschedparam(self, policy, &sp) != 0) {
2688     return OS_ERR;
2689   }
2690 
2691   return OS_OK;
2692 #else
2693   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2694   return (ret == 0) ? OS_OK : OS_ERR;
2695 #endif
2696 }
2697 
2698 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2699   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2700     *priority_ptr = java_to_os_priority[NormPriority];
2701     return OS_OK;
2702   }
2703 
2704   errno = 0;
2705 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2706   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2707 #elif defined(__APPLE__) || defined(__NetBSD__)
2708   int policy;
2709   struct sched_param sp;
2710 
2711   pthread_getschedparam(pthread_self(), &policy, &sp);
2712   *priority_ptr = sp.sched_priority;
2713 #else
2714   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2715 #endif
2716   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2717 }
2718 
2719 // Hint to the underlying OS that a task switch would not be good.
2720 // Void return because it's a hint and can fail.
2721 void os::hint_no_preempt() {}
2722 
2723 ////////////////////////////////////////////////////////////////////////////////
2724 // suspend/resume support
2725 
2726 //  the low-level signal-based suspend/resume support is a remnant from the
2727 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2728 //  within hotspot. Now there is a single use-case for this:
2729 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
2730 //      that runs in the watcher thread.
2731 //  The remaining code is greatly simplified from the more general suspension
2732 //  code that used to be used.
2733 //
2734 //  The protocol is quite simple:
2735 //  - suspend:
2736 //      - sends a signal to the target thread
2737 //      - polls the suspend state of the osthread using a yield loop
2738 //      - target thread signal handler (SR_handler) sets suspend state
2739 //        and blocks in sigsuspend until continued
2740 //  - resume:
2741 //      - sets target osthread state to continue
2742 //      - sends signal to end the sigsuspend loop in the SR_handler
2743 //
2744 //  Note that the SR_lock plays no role in this suspend/resume protocol.
2745 
2746 static void resume_clear_context(OSThread *osthread) {
2747   osthread->set_ucontext(NULL);
2748   osthread->set_siginfo(NULL);
2749 }
2750 
2751 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2752   osthread->set_ucontext(context);
2753   osthread->set_siginfo(siginfo);
2754 }
2755 
2756 // Handler function invoked when a thread's execution is suspended or
2757 // resumed. We have to be careful that only async-safe functions are
2758 // called here (Note: most pthread functions are not async safe and
2759 // should be avoided.)
2760 //
2761 // Note: sigwait() is a more natural fit than sigsuspend() from an
2762 // interface point of view, but sigwait() prevents the signal hander
2763 // from being run. libpthread would get very confused by not having
2764 // its signal handlers run and prevents sigwait()'s use with the
2765 // mutex granting granting signal.
2766 //
2767 // Currently only ever called on the VMThread or JavaThread
2768 //
2769 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2770   // Save and restore errno to avoid confusing native code with EINTR
2771   // after sigsuspend.
2772   int old_errno = errno;
2773 
2774   Thread* thread = Thread::current();
2775   OSThread* osthread = thread->osthread();
2776   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2777 
2778   os::SuspendResume::State current = osthread->sr.state();
2779   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2780     suspend_save_context(osthread, siginfo, context);
2781 
2782     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2783     os::SuspendResume::State state = osthread->sr.suspended();
2784     if (state == os::SuspendResume::SR_SUSPENDED) {
2785       sigset_t suspend_set;  // signals for sigsuspend()
2786 
2787       // get current set of blocked signals and unblock resume signal
2788       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2789       sigdelset(&suspend_set, SR_signum);
2790 
2791       sr_semaphore.signal();
2792       // wait here until we are resumed
2793       while (1) {
2794         sigsuspend(&suspend_set);
2795 
2796         os::SuspendResume::State result = osthread->sr.running();
2797         if (result == os::SuspendResume::SR_RUNNING) {
2798           sr_semaphore.signal();
2799           break;
2800         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2801           ShouldNotReachHere();
2802         }
2803       }
2804 
2805     } else if (state == os::SuspendResume::SR_RUNNING) {
2806       // request was cancelled, continue
2807     } else {
2808       ShouldNotReachHere();
2809     }
2810 
2811     resume_clear_context(osthread);
2812   } else if (current == os::SuspendResume::SR_RUNNING) {
2813     // request was cancelled, continue
2814   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2815     // ignore
2816   } else {
2817     // ignore
2818   }
2819 
2820   errno = old_errno;
2821 }
2822 
2823 
2824 static int SR_initialize() {
2825   struct sigaction act;
2826   char *s;
2827   // Get signal number to use for suspend/resume
2828   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2829     int sig = ::strtol(s, 0, 10);
2830     if (sig > 0 || sig < NSIG) {
2831       SR_signum = sig;
2832     }
2833   }
2834 
2835   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2836          "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2837 
2838   sigemptyset(&SR_sigset);
2839   sigaddset(&SR_sigset, SR_signum);
2840 
2841   // Set up signal handler for suspend/resume
2842   act.sa_flags = SA_RESTART|SA_SIGINFO;
2843   act.sa_handler = (void (*)(int)) SR_handler;
2844 
2845   // SR_signum is blocked by default.
2846   // 4528190 - We also need to block pthread restart signal (32 on all
2847   // supported Bsd platforms). Note that BsdThreads need to block
2848   // this signal for all threads to work properly. So we don't have
2849   // to use hard-coded signal number when setting up the mask.
2850   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2851 
2852   if (sigaction(SR_signum, &act, 0) == -1) {
2853     return -1;
2854   }
2855 
2856   // Save signal flag
2857   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2858   return 0;
2859 }
2860 
2861 static int sr_notify(OSThread* osthread) {
2862   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2863   assert_status(status == 0, status, "pthread_kill");
2864   return status;
2865 }
2866 
2867 // "Randomly" selected value for how long we want to spin
2868 // before bailing out on suspending a thread, also how often
2869 // we send a signal to a thread we want to resume
2870 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2871 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2872 
2873 // returns true on success and false on error - really an error is fatal
2874 // but this seems the normal response to library errors
2875 static bool do_suspend(OSThread* osthread) {
2876   assert(osthread->sr.is_running(), "thread should be running");
2877   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2878 
2879   // mark as suspended and send signal
2880   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2881     // failed to switch, state wasn't running?
2882     ShouldNotReachHere();
2883     return false;
2884   }
2885 
2886   if (sr_notify(osthread) != 0) {
2887     ShouldNotReachHere();
2888   }
2889 
2890   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2891   while (true) {
2892     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2893       break;
2894     } else {
2895       // timeout
2896       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2897       if (cancelled == os::SuspendResume::SR_RUNNING) {
2898         return false;
2899       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2900         // make sure that we consume the signal on the semaphore as well
2901         sr_semaphore.wait();
2902         break;
2903       } else {
2904         ShouldNotReachHere();
2905         return false;
2906       }
2907     }
2908   }
2909 
2910   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2911   return true;
2912 }
2913 
2914 static void do_resume(OSThread* osthread) {
2915   assert(osthread->sr.is_suspended(), "thread should be suspended");
2916   assert(!sr_semaphore.trywait(), "invalid semaphore state");
2917 
2918   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2919     // failed to switch to WAKEUP_REQUEST
2920     ShouldNotReachHere();
2921     return;
2922   }
2923 
2924   while (true) {
2925     if (sr_notify(osthread) == 0) {
2926       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2927         if (osthread->sr.is_running()) {
2928           return;
2929         }
2930       }
2931     } else {
2932       ShouldNotReachHere();
2933     }
2934   }
2935 
2936   guarantee(osthread->sr.is_running(), "Must be running!");
2937 }
2938 
2939 ///////////////////////////////////////////////////////////////////////////////////
2940 // signal handling (except suspend/resume)
2941 
2942 // This routine may be used by user applications as a "hook" to catch signals.
2943 // The user-defined signal handler must pass unrecognized signals to this
2944 // routine, and if it returns true (non-zero), then the signal handler must
2945 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
2946 // routine will never retun false (zero), but instead will execute a VM panic
2947 // routine kill the process.
2948 //
2949 // If this routine returns false, it is OK to call it again.  This allows
2950 // the user-defined signal handler to perform checks either before or after
2951 // the VM performs its own checks.  Naturally, the user code would be making
2952 // a serious error if it tried to handle an exception (such as a null check
2953 // or breakpoint) that the VM was generating for its own correct operation.
2954 //
2955 // This routine may recognize any of the following kinds of signals:
2956 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2957 // It should be consulted by handlers for any of those signals.
2958 //
2959 // The caller of this routine must pass in the three arguments supplied
2960 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2961 // field of the structure passed to sigaction().  This routine assumes that
2962 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2963 //
2964 // Note that the VM will print warnings if it detects conflicting signal
2965 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2966 //
2967 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2968                                                void* ucontext,
2969                                                int abort_if_unrecognized);
2970 
2971 void signalHandler(int sig, siginfo_t* info, void* uc) {
2972   assert(info != NULL && uc != NULL, "it must be old kernel");
2973   int orig_errno = errno;  // Preserve errno value over signal handler.
2974   JVM_handle_bsd_signal(sig, info, uc, true);
2975   errno = orig_errno;
2976 }
2977 
2978 
2979 // This boolean allows users to forward their own non-matching signals
2980 // to JVM_handle_bsd_signal, harmlessly.
2981 bool os::Bsd::signal_handlers_are_installed = false;
2982 
2983 // For signal-chaining
2984 struct sigaction os::Bsd::sigact[MAXSIGNUM];
2985 unsigned int os::Bsd::sigs = 0;
2986 bool os::Bsd::libjsig_is_loaded = false;
2987 typedef struct sigaction *(*get_signal_t)(int);
2988 get_signal_t os::Bsd::get_signal_action = NULL;
2989 
2990 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2991   struct sigaction *actp = NULL;
2992 
2993   if (libjsig_is_loaded) {
2994     // Retrieve the old signal handler from libjsig
2995     actp = (*get_signal_action)(sig);
2996   }
2997   if (actp == NULL) {
2998     // Retrieve the preinstalled signal handler from jvm
2999     actp = get_preinstalled_handler(sig);
3000   }
3001 
3002   return actp;
3003 }
3004 
3005 static bool call_chained_handler(struct sigaction *actp, int sig,
3006                                  siginfo_t *siginfo, void *context) {
3007   // Call the old signal handler
3008   if (actp->sa_handler == SIG_DFL) {
3009     // It's more reasonable to let jvm treat it as an unexpected exception
3010     // instead of taking the default action.
3011     return false;
3012   } else if (actp->sa_handler != SIG_IGN) {
3013     if ((actp->sa_flags & SA_NODEFER) == 0) {
3014       // automaticlly block the signal
3015       sigaddset(&(actp->sa_mask), sig);
3016     }
3017 
3018     sa_handler_t hand;
3019     sa_sigaction_t sa;
3020     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3021     // retrieve the chained handler
3022     if (siginfo_flag_set) {
3023       sa = actp->sa_sigaction;
3024     } else {
3025       hand = actp->sa_handler;
3026     }
3027 
3028     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3029       actp->sa_handler = SIG_DFL;
3030     }
3031 
3032     // try to honor the signal mask
3033     sigset_t oset;
3034     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3035 
3036     // call into the chained handler
3037     if (siginfo_flag_set) {
3038       (*sa)(sig, siginfo, context);
3039     } else {
3040       (*hand)(sig);
3041     }
3042 
3043     // restore the signal mask
3044     pthread_sigmask(SIG_SETMASK, &oset, 0);
3045   }
3046   // Tell jvm's signal handler the signal is taken care of.
3047   return true;
3048 }
3049 
3050 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3051   bool chained = false;
3052   // signal-chaining
3053   if (UseSignalChaining) {
3054     struct sigaction *actp = get_chained_signal_action(sig);
3055     if (actp != NULL) {
3056       chained = call_chained_handler(actp, sig, siginfo, context);
3057     }
3058   }
3059   return chained;
3060 }
3061 
3062 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3063   if ((((unsigned int)1 << sig) & sigs) != 0) {
3064     return &sigact[sig];
3065   }
3066   return NULL;
3067 }
3068 
3069 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3070   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3071   sigact[sig] = oldAct;
3072   sigs |= (unsigned int)1 << sig;
3073 }
3074 
3075 // for diagnostic
3076 int os::Bsd::sigflags[MAXSIGNUM];
3077 
3078 int os::Bsd::get_our_sigflags(int sig) {
3079   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3080   return sigflags[sig];
3081 }
3082 
3083 void os::Bsd::set_our_sigflags(int sig, int flags) {
3084   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3085   sigflags[sig] = flags;
3086 }
3087 
3088 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3089   // Check for overwrite.
3090   struct sigaction oldAct;
3091   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3092 
3093   void* oldhand = oldAct.sa_sigaction
3094                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
3095                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
3096   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3097       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3098       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3099     if (AllowUserSignalHandlers || !set_installed) {
3100       // Do not overwrite; user takes responsibility to forward to us.
3101       return;
3102     } else if (UseSignalChaining) {
3103       // save the old handler in jvm
3104       save_preinstalled_handler(sig, oldAct);
3105       // libjsig also interposes the sigaction() call below and saves the
3106       // old sigaction on it own.
3107     } else {
3108       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3109                     "%#lx for signal %d.", (long)oldhand, sig));
3110     }
3111   }
3112 
3113   struct sigaction sigAct;
3114   sigfillset(&(sigAct.sa_mask));
3115   sigAct.sa_handler = SIG_DFL;
3116   if (!set_installed) {
3117     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3118   } else {
3119     sigAct.sa_sigaction = signalHandler;
3120     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3121   }
3122 #ifdef __APPLE__
3123   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3124   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3125   // if the signal handler declares it will handle it on alternate stack.
3126   // Notice we only declare we will handle it on alt stack, but we are not
3127   // actually going to use real alt stack - this is just a workaround.
3128   // Please see ux_exception.c, method catch_mach_exception_raise for details
3129   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3130   if (sig == SIGSEGV) {
3131     sigAct.sa_flags |= SA_ONSTACK;
3132   }
3133 #endif
3134 
3135   // Save flags, which are set by ours
3136   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3137   sigflags[sig] = sigAct.sa_flags;
3138 
3139   int ret = sigaction(sig, &sigAct, &oldAct);
3140   assert(ret == 0, "check");
3141 
3142   void* oldhand2  = oldAct.sa_sigaction
3143                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3144                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3145   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3146 }
3147 
3148 // install signal handlers for signals that HotSpot needs to
3149 // handle in order to support Java-level exception handling.
3150 
3151 void os::Bsd::install_signal_handlers() {
3152   if (!signal_handlers_are_installed) {
3153     signal_handlers_are_installed = true;
3154 
3155     // signal-chaining
3156     typedef void (*signal_setting_t)();
3157     signal_setting_t begin_signal_setting = NULL;
3158     signal_setting_t end_signal_setting = NULL;
3159     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3160                                           dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3161     if (begin_signal_setting != NULL) {
3162       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3163                                           dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3164       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3165                                          dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3166       libjsig_is_loaded = true;
3167       assert(UseSignalChaining, "should enable signal-chaining");
3168     }
3169     if (libjsig_is_loaded) {
3170       // Tell libjsig jvm is setting signal handlers
3171       (*begin_signal_setting)();
3172     }
3173 
3174     set_signal_handler(SIGSEGV, true);
3175     set_signal_handler(SIGPIPE, true);
3176     set_signal_handler(SIGBUS, true);
3177     set_signal_handler(SIGILL, true);
3178     set_signal_handler(SIGFPE, true);
3179     set_signal_handler(SIGXFSZ, true);
3180 
3181 #if defined(__APPLE__)
3182     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3183     // signals caught and handled by the JVM. To work around this, we reset the mach task
3184     // signal handler that's placed on our process by CrashReporter. This disables
3185     // CrashReporter-based reporting.
3186     //
3187     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3188     // on caught fatal signals.
3189     //
3190     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3191     // handlers. By replacing the existing task exception handler, we disable gdb's mach
3192     // exception handling, while leaving the standard BSD signal handlers functional.
3193     kern_return_t kr;
3194     kr = task_set_exception_ports(mach_task_self(),
3195                                   EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3196                                   MACH_PORT_NULL,
3197                                   EXCEPTION_STATE_IDENTITY,
3198                                   MACHINE_THREAD_STATE);
3199 
3200     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3201 #endif
3202 
3203     if (libjsig_is_loaded) {
3204       // Tell libjsig jvm finishes setting signal handlers
3205       (*end_signal_setting)();
3206     }
3207 
3208     // We don't activate signal checker if libjsig is in place, we trust ourselves
3209     // and if UserSignalHandler is installed all bets are off
3210     if (CheckJNICalls) {
3211       if (libjsig_is_loaded) {
3212         if (PrintJNIResolving) {
3213           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3214         }
3215         check_signals = false;
3216       }
3217       if (AllowUserSignalHandlers) {
3218         if (PrintJNIResolving) {
3219           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3220         }
3221         check_signals = false;
3222       }
3223     }
3224   }
3225 }
3226 
3227 
3228 /////
3229 // glibc on Bsd platform uses non-documented flag
3230 // to indicate, that some special sort of signal
3231 // trampoline is used.
3232 // We will never set this flag, and we should
3233 // ignore this flag in our diagnostic
3234 #ifdef SIGNIFICANT_SIGNAL_MASK
3235   #undef SIGNIFICANT_SIGNAL_MASK
3236 #endif
3237 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3238 
3239 static const char* get_signal_handler_name(address handler,
3240                                            char* buf, int buflen) {
3241   int offset;
3242   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3243   if (found) {
3244     // skip directory names
3245     const char *p1, *p2;
3246     p1 = buf;
3247     size_t len = strlen(os::file_separator());
3248     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3249     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3250   } else {
3251     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3252   }
3253   return buf;
3254 }
3255 
3256 static void print_signal_handler(outputStream* st, int sig,
3257                                  char* buf, size_t buflen) {
3258   struct sigaction sa;
3259 
3260   sigaction(sig, NULL, &sa);
3261 
3262   // See comment for SIGNIFICANT_SIGNAL_MASK define
3263   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3264 
3265   st->print("%s: ", os::exception_name(sig, buf, buflen));
3266 
3267   address handler = (sa.sa_flags & SA_SIGINFO)
3268     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3269     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3270 
3271   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3272     st->print("SIG_DFL");
3273   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3274     st->print("SIG_IGN");
3275   } else {
3276     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3277   }
3278 
3279   st->print(", sa_mask[0]=");
3280   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3281 
3282   address rh = VMError::get_resetted_sighandler(sig);
3283   // May be, handler was resetted by VMError?
3284   if (rh != NULL) {
3285     handler = rh;
3286     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3287   }
3288 
3289   st->print(", sa_flags=");
3290   os::Posix::print_sa_flags(st, sa.sa_flags);
3291 
3292   // Check: is it our handler?
3293   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3294       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3295     // It is our signal handler
3296     // check for flags, reset system-used one!
3297     if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3298       st->print(
3299                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3300                 os::Bsd::get_our_sigflags(sig));
3301     }
3302   }
3303   st->cr();
3304 }
3305 
3306 
3307 #define DO_SIGNAL_CHECK(sig)                      \
3308   do {                                            \
3309     if (!sigismember(&check_signal_done, sig)) {  \
3310       os::Bsd::check_signal_handler(sig);         \
3311     }                                             \
3312   } while (0)
3313 
3314 // This method is a periodic task to check for misbehaving JNI applications
3315 // under CheckJNI, we can add any periodic checks here
3316 
3317 void os::run_periodic_checks() {
3318 
3319   if (check_signals == false) return;
3320 
3321   // SEGV and BUS if overridden could potentially prevent
3322   // generation of hs*.log in the event of a crash, debugging
3323   // such a case can be very challenging, so we absolutely
3324   // check the following for a good measure:
3325   DO_SIGNAL_CHECK(SIGSEGV);
3326   DO_SIGNAL_CHECK(SIGILL);
3327   DO_SIGNAL_CHECK(SIGFPE);
3328   DO_SIGNAL_CHECK(SIGBUS);
3329   DO_SIGNAL_CHECK(SIGPIPE);
3330   DO_SIGNAL_CHECK(SIGXFSZ);
3331 
3332 
3333   // ReduceSignalUsage allows the user to override these handlers
3334   // see comments at the very top and jvm_solaris.h
3335   if (!ReduceSignalUsage) {
3336     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3337     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3338     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3339     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3340   }
3341 
3342   DO_SIGNAL_CHECK(SR_signum);
3343   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3344 }
3345 
3346 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3347 
3348 static os_sigaction_t os_sigaction = NULL;
3349 
3350 void os::Bsd::check_signal_handler(int sig) {
3351   char buf[O_BUFLEN];
3352   address jvmHandler = NULL;
3353 
3354 
3355   struct sigaction act;
3356   if (os_sigaction == NULL) {
3357     // only trust the default sigaction, in case it has been interposed
3358     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3359     if (os_sigaction == NULL) return;
3360   }
3361 
3362   os_sigaction(sig, (struct sigaction*)NULL, &act);
3363 
3364 
3365   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3366 
3367   address thisHandler = (act.sa_flags & SA_SIGINFO)
3368     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3369     : CAST_FROM_FN_PTR(address, act.sa_handler);
3370 
3371 
3372   switch (sig) {
3373   case SIGSEGV:
3374   case SIGBUS:
3375   case SIGFPE:
3376   case SIGPIPE:
3377   case SIGILL:
3378   case SIGXFSZ:
3379     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3380     break;
3381 
3382   case SHUTDOWN1_SIGNAL:
3383   case SHUTDOWN2_SIGNAL:
3384   case SHUTDOWN3_SIGNAL:
3385   case BREAK_SIGNAL:
3386     jvmHandler = (address)user_handler();
3387     break;
3388 
3389   case INTERRUPT_SIGNAL:
3390     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3391     break;
3392 
3393   default:
3394     if (sig == SR_signum) {
3395       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3396     } else {
3397       return;
3398     }
3399     break;
3400   }
3401 
3402   if (thisHandler != jvmHandler) {
3403     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3404     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3405     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3406     // No need to check this sig any longer
3407     sigaddset(&check_signal_done, sig);
3408     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3409     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3410       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3411                     exception_name(sig, buf, O_BUFLEN));
3412     }
3413   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3414     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3415     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3416     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
3417     // No need to check this sig any longer
3418     sigaddset(&check_signal_done, sig);
3419   }
3420 
3421   // Dump all the signal
3422   if (sigismember(&check_signal_done, sig)) {
3423     print_signal_handlers(tty, buf, O_BUFLEN);
3424   }
3425 }
3426 
3427 extern void report_error(char* file_name, int line_no, char* title,
3428                          char* format, ...);
3429 
3430 extern bool signal_name(int signo, char* buf, size_t len);
3431 
3432 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3433   if (0 < exception_code && exception_code <= SIGRTMAX) {
3434     // signal
3435     if (!signal_name(exception_code, buf, size)) {
3436       jio_snprintf(buf, size, "SIG%d", exception_code);
3437     }
3438     return buf;
3439   } else {
3440     return NULL;
3441   }
3442 }
3443 
3444 // this is called _before_ the most of global arguments have been parsed
3445 void os::init(void) {
3446   char dummy;   // used to get a guess on initial stack address
3447 //  first_hrtime = gethrtime();
3448 
3449   // With BsdThreads the JavaMain thread pid (primordial thread)
3450   // is different than the pid of the java launcher thread.
3451   // So, on Bsd, the launcher thread pid is passed to the VM
3452   // via the sun.java.launcher.pid property.
3453   // Use this property instead of getpid() if it was correctly passed.
3454   // See bug 6351349.
3455   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3456 
3457   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3458 
3459   clock_tics_per_sec = CLK_TCK;
3460 
3461   init_random(1234567);
3462 
3463   ThreadCritical::initialize();
3464 
3465   Bsd::set_page_size(getpagesize());
3466   if (Bsd::page_size() == -1) {
3467     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3468                   strerror(errno)));
3469   }
3470   init_page_sizes((size_t) Bsd::page_size());
3471 
3472   Bsd::initialize_system_info();
3473 
3474   // main_thread points to the aboriginal thread
3475   Bsd::_main_thread = pthread_self();
3476 
3477   Bsd::clock_init();
3478   initial_time_count = javaTimeNanos();
3479 
3480 #ifdef __APPLE__
3481   // XXXDARWIN
3482   // Work around the unaligned VM callbacks in hotspot's
3483   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3484   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3485   // alignment when doing symbol lookup. To work around this, we force early
3486   // binding of all symbols now, thus binding when alignment is known-good.
3487   _dyld_bind_fully_image_containing_address((const void *) &os::init);
3488 #endif
3489 }
3490 
3491 // To install functions for atexit system call
3492 extern "C" {
3493   static void perfMemory_exit_helper() {
3494     perfMemory_exit();
3495   }
3496 }
3497 
3498 // this is called _after_ the global arguments have been parsed
3499 jint os::init_2(void) {
3500   // Allocate a single page and mark it as readable for safepoint polling
3501   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3502   guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page");
3503 
3504   os::set_polling_page(polling_page);
3505 
3506 #ifndef PRODUCT
3507   if (Verbose && PrintMiscellaneous) {
3508     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n",
3509                (intptr_t)polling_page);
3510   }
3511 #endif
3512 
3513   if (!UseMembar) {
3514     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3515     guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3516     os::set_memory_serialize_page(mem_serialize_page);
3517 
3518 #ifndef PRODUCT
3519     if (Verbose && PrintMiscellaneous) {
3520       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n",
3521                  (intptr_t)mem_serialize_page);
3522     }
3523 #endif
3524   }
3525 
3526   // initialize suspend/resume support - must do this before signal_sets_init()
3527   if (SR_initialize() != 0) {
3528     perror("SR_initialize failed");
3529     return JNI_ERR;
3530   }
3531 
3532   Bsd::signal_sets_init();
3533   Bsd::install_signal_handlers();
3534 
3535   // Check minimum allowable stack size for thread creation and to initialize
3536   // the java system classes, including StackOverflowError - depends on page
3537   // size.  Add a page for compiler2 recursion in main thread.
3538   // Add in 2*BytesPerWord times page size to account for VM stack during
3539   // class initialization depending on 32 or 64 bit VM.
3540   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3541                                     (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3542                                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3543 
3544   size_t threadStackSizeInBytes = ThreadStackSize * K;
3545   if (threadStackSizeInBytes != 0 &&
3546       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3547     tty->print_cr("\nThe stack size specified is too small, "
3548                   "Specify at least %dk",
3549                   os::Bsd::min_stack_allowed/ K);
3550     return JNI_ERR;
3551   }
3552 
3553   // Make the stack size a multiple of the page size so that
3554   // the yellow/red zones can be guarded.
3555   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3556                                                 vm_page_size()));
3557 
3558   if (MaxFDLimit) {
3559     // set the number of file descriptors to max. print out error
3560     // if getrlimit/setrlimit fails but continue regardless.
3561     struct rlimit nbr_files;
3562     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3563     if (status != 0) {
3564       if (PrintMiscellaneous && (Verbose || WizardMode)) {
3565         perror("os::init_2 getrlimit failed");
3566       }
3567     } else {
3568       nbr_files.rlim_cur = nbr_files.rlim_max;
3569 
3570 #ifdef __APPLE__
3571       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3572       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3573       // be used instead
3574       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3575 #endif
3576 
3577       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3578       if (status != 0) {
3579         if (PrintMiscellaneous && (Verbose || WizardMode)) {
3580           perror("os::init_2 setrlimit failed");
3581         }
3582       }
3583     }
3584   }
3585 
3586   // at-exit methods are called in the reverse order of their registration.
3587   // atexit functions are called on return from main or as a result of a
3588   // call to exit(3C). There can be only 32 of these functions registered
3589   // and atexit() does not set errno.
3590 
3591   if (PerfAllowAtExitRegistration) {
3592     // only register atexit functions if PerfAllowAtExitRegistration is set.
3593     // atexit functions can be delayed until process exit time, which
3594     // can be problematic for embedded VM situations. Embedded VMs should
3595     // call DestroyJavaVM() to assure that VM resources are released.
3596 
3597     // note: perfMemory_exit_helper atexit function may be removed in
3598     // the future if the appropriate cleanup code can be added to the
3599     // VM_Exit VMOperation's doit method.
3600     if (atexit(perfMemory_exit_helper) != 0) {
3601       warning("os::init2 atexit(perfMemory_exit_helper) failed");
3602     }
3603   }
3604 
3605   // initialize thread priority policy
3606   prio_init();
3607 
3608 #ifdef __APPLE__
3609   // dynamically link to objective c gc registration
3610   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3611   if (handleLibObjc != NULL) {
3612     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3613   }
3614 #endif
3615 
3616   return JNI_OK;
3617 }
3618 
3619 // Mark the polling page as unreadable
3620 void os::make_polling_page_unreadable(void) {
3621   if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3622     fatal("Could not disable polling page");
3623   }
3624 }
3625 
3626 // Mark the polling page as readable
3627 void os::make_polling_page_readable(void) {
3628   if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3629     fatal("Could not enable polling page");
3630   }
3631 }
3632 
3633 int os::active_processor_count() {
3634   return _processor_count;
3635 }
3636 
3637 void os::set_native_thread_name(const char *name) {
3638 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3639   // This is only supported in Snow Leopard and beyond
3640   if (name != NULL) {
3641     // Add a "Java: " prefix to the name
3642     char buf[MAXTHREADNAMESIZE];
3643     snprintf(buf, sizeof(buf), "Java: %s", name);
3644     pthread_setname_np(buf);
3645   }
3646 #endif
3647 }
3648 
3649 bool os::distribute_processes(uint length, uint* distribution) {
3650   // Not yet implemented.
3651   return false;
3652 }
3653 
3654 bool os::bind_to_processor(uint processor_id) {
3655   // Not yet implemented.
3656   return false;
3657 }
3658 
3659 void os::SuspendedThreadTask::internal_do_task() {
3660   if (do_suspend(_thread->osthread())) {
3661     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3662     do_task(context);
3663     do_resume(_thread->osthread());
3664   }
3665 }
3666 
3667 ///
3668 class PcFetcher : public os::SuspendedThreadTask {
3669  public:
3670   PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3671   ExtendedPC result();
3672  protected:
3673   void do_task(const os::SuspendedThreadTaskContext& context);
3674  private:
3675   ExtendedPC _epc;
3676 };
3677 
3678 ExtendedPC PcFetcher::result() {
3679   guarantee(is_done(), "task is not done yet.");
3680   return _epc;
3681 }
3682 
3683 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3684   Thread* thread = context.thread();
3685   OSThread* osthread = thread->osthread();
3686   if (osthread->ucontext() != NULL) {
3687     _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
3688   } else {
3689     // NULL context is unexpected, double-check this is the VMThread
3690     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3691   }
3692 }
3693 
3694 // Suspends the target using the signal mechanism and then grabs the PC before
3695 // resuming the target. Used by the flat-profiler only
3696 ExtendedPC os::get_thread_pc(Thread* thread) {
3697   // Make sure that it is called by the watcher for the VMThread
3698   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3699   assert(thread->is_VM_thread(), "Can only be called for VMThread");
3700 
3701   PcFetcher fetcher(thread);
3702   fetcher.run();
3703   return fetcher.result();
3704 }
3705 
3706 ////////////////////////////////////////////////////////////////////////////////
3707 // debug support
3708 
3709 bool os::find(address addr, outputStream* st) {
3710   Dl_info dlinfo;
3711   memset(&dlinfo, 0, sizeof(dlinfo));
3712   if (dladdr(addr, &dlinfo) != 0) {
3713     st->print(PTR_FORMAT ": ", addr);
3714     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3715       st->print("%s+%#x", dlinfo.dli_sname,
3716                 addr - (intptr_t)dlinfo.dli_saddr);
3717     } else if (dlinfo.dli_fbase != NULL) {
3718       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3719     } else {
3720       st->print("<absolute address>");
3721     }
3722     if (dlinfo.dli_fname != NULL) {
3723       st->print(" in %s", dlinfo.dli_fname);
3724     }
3725     if (dlinfo.dli_fbase != NULL) {
3726       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3727     }
3728     st->cr();
3729 
3730     if (Verbose) {
3731       // decode some bytes around the PC
3732       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3733       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3734       address       lowest = (address) dlinfo.dli_sname;
3735       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3736       if (begin < lowest)  begin = lowest;
3737       Dl_info dlinfo2;
3738       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3739           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3740         end = (address) dlinfo2.dli_saddr;
3741       }
3742       Disassembler::decode(begin, end, st);
3743     }
3744     return true;
3745   }
3746   return false;
3747 }
3748 
3749 ////////////////////////////////////////////////////////////////////////////////
3750 // misc
3751 
3752 // This does not do anything on Bsd. This is basically a hook for being
3753 // able to use structured exception handling (thread-local exception filters)
3754 // on, e.g., Win32.
3755 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3756                               methodHandle* method, JavaCallArguments* args,
3757                               Thread* thread) {
3758   f(value, method, args, thread);
3759 }
3760 
3761 void os::print_statistics() {
3762 }
3763 
3764 int os::message_box(const char* title, const char* message) {
3765   int i;
3766   fdStream err(defaultStream::error_fd());
3767   for (i = 0; i < 78; i++) err.print_raw("=");
3768   err.cr();
3769   err.print_raw_cr(title);
3770   for (i = 0; i < 78; i++) err.print_raw("-");
3771   err.cr();
3772   err.print_raw_cr(message);
3773   for (i = 0; i < 78; i++) err.print_raw("=");
3774   err.cr();
3775 
3776   char buf[16];
3777   // Prevent process from exiting upon "read error" without consuming all CPU
3778   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3779 
3780   return buf[0] == 'y' || buf[0] == 'Y';
3781 }
3782 
3783 int os::stat(const char *path, struct stat *sbuf) {
3784   char pathbuf[MAX_PATH];
3785   if (strlen(path) > MAX_PATH - 1) {
3786     errno = ENAMETOOLONG;
3787     return -1;
3788   }
3789   os::native_path(strcpy(pathbuf, path));
3790   return ::stat(pathbuf, sbuf);
3791 }
3792 
3793 bool os::check_heap(bool force) {
3794   return true;
3795 }
3796 
3797 // Is a (classpath) directory empty?
3798 bool os::dir_is_empty(const char* path) {
3799   DIR *dir = NULL;
3800   struct dirent *ptr;
3801 
3802   dir = opendir(path);
3803   if (dir == NULL) return true;
3804 
3805   // Scan the directory
3806   bool result = true;
3807   char buf[sizeof(struct dirent) + MAX_PATH];
3808   while (result && (ptr = ::readdir(dir)) != NULL) {
3809     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3810       result = false;
3811     }
3812   }
3813   closedir(dir);
3814   return result;
3815 }
3816 
3817 // This code originates from JDK's sysOpen and open64_w
3818 // from src/solaris/hpi/src/system_md.c
3819 
3820 int os::open(const char *path, int oflag, int mode) {
3821   if (strlen(path) > MAX_PATH - 1) {
3822     errno = ENAMETOOLONG;
3823     return -1;
3824   }
3825   int fd;
3826 
3827   fd = ::open(path, oflag, mode);
3828   if (fd == -1) return -1;
3829 
3830   // If the open succeeded, the file might still be a directory
3831   {
3832     struct stat buf;
3833     int ret = ::fstat(fd, &buf);
3834     int st_mode = buf.st_mode;
3835 
3836     if (ret != -1) {
3837       if ((st_mode & S_IFMT) == S_IFDIR) {
3838         errno = EISDIR;
3839         ::close(fd);
3840         return -1;
3841       }
3842     } else {
3843       ::close(fd);
3844       return -1;
3845     }
3846   }
3847 
3848   // All file descriptors that are opened in the JVM and not
3849   // specifically destined for a subprocess should have the
3850   // close-on-exec flag set.  If we don't set it, then careless 3rd
3851   // party native code might fork and exec without closing all
3852   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3853   // UNIXProcess.c), and this in turn might:
3854   //
3855   // - cause end-of-file to fail to be detected on some file
3856   //   descriptors, resulting in mysterious hangs, or
3857   //
3858   // - might cause an fopen in the subprocess to fail on a system
3859   //   suffering from bug 1085341.
3860   //
3861   // (Yes, the default setting of the close-on-exec flag is a Unix
3862   // design flaw)
3863   //
3864   // See:
3865   // 1085341: 32-bit stdio routines should support file descriptors >255
3866   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3867   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3868   //
3869 #ifdef FD_CLOEXEC
3870   {
3871     int flags = ::fcntl(fd, F_GETFD);
3872     if (flags != -1) {
3873       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3874     }
3875   }
3876 #endif
3877 
3878   return fd;
3879 }
3880 
3881 
3882 // create binary file, rewriting existing file if required
3883 int os::create_binary_file(const char* path, bool rewrite_existing) {
3884   int oflags = O_WRONLY | O_CREAT;
3885   if (!rewrite_existing) {
3886     oflags |= O_EXCL;
3887   }
3888   return ::open(path, oflags, S_IREAD | S_IWRITE);
3889 }
3890 
3891 // return current position of file pointer
3892 jlong os::current_file_offset(int fd) {
3893   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3894 }
3895 
3896 // move file pointer to the specified offset
3897 jlong os::seek_to_file_offset(int fd, jlong offset) {
3898   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3899 }
3900 
3901 // This code originates from JDK's sysAvailable
3902 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3903 
3904 int os::available(int fd, jlong *bytes) {
3905   jlong cur, end;
3906   int mode;
3907   struct stat buf;
3908 
3909   if (::fstat(fd, &buf) >= 0) {
3910     mode = buf.st_mode;
3911     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3912       // XXX: is the following call interruptible? If so, this might
3913       // need to go through the INTERRUPT_IO() wrapper as for other
3914       // blocking, interruptible calls in this file.
3915       int n;
3916       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3917         *bytes = n;
3918         return 1;
3919       }
3920     }
3921   }
3922   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3923     return 0;
3924   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3925     return 0;
3926   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3927     return 0;
3928   }
3929   *bytes = end - cur;
3930   return 1;
3931 }
3932 
3933 // Map a block of memory.
3934 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3935                         char *addr, size_t bytes, bool read_only,
3936                         bool allow_exec) {
3937   int prot;
3938   int flags;
3939 
3940   if (read_only) {
3941     prot = PROT_READ;
3942     flags = MAP_SHARED;
3943   } else {
3944     prot = PROT_READ | PROT_WRITE;
3945     flags = MAP_PRIVATE;
3946   }
3947 
3948   if (allow_exec) {
3949     prot |= PROT_EXEC;
3950   }
3951 
3952   if (addr != NULL) {
3953     flags |= MAP_FIXED;
3954   }
3955 
3956   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3957                                      fd, file_offset);
3958   if (mapped_address == MAP_FAILED) {
3959     return NULL;
3960   }
3961   return mapped_address;
3962 }
3963 
3964 
3965 // Remap a block of memory.
3966 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3967                           char *addr, size_t bytes, bool read_only,
3968                           bool allow_exec) {
3969   // same as map_memory() on this OS
3970   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3971                         allow_exec);
3972 }
3973 
3974 
3975 // Unmap a block of memory.
3976 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3977   return munmap(addr, bytes) == 0;
3978 }
3979 
3980 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3981 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3982 // of a thread.
3983 //
3984 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3985 // the fast estimate available on the platform.
3986 
3987 jlong os::current_thread_cpu_time() {
3988 #ifdef __APPLE__
3989   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3990 #else
3991   Unimplemented();
3992   return 0;
3993 #endif
3994 }
3995 
3996 jlong os::thread_cpu_time(Thread* thread) {
3997 #ifdef __APPLE__
3998   return os::thread_cpu_time(thread, true /* user + sys */);
3999 #else
4000   Unimplemented();
4001   return 0;
4002 #endif
4003 }
4004 
4005 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4006 #ifdef __APPLE__
4007   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4008 #else
4009   Unimplemented();
4010   return 0;
4011 #endif
4012 }
4013 
4014 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4015 #ifdef __APPLE__
4016   struct thread_basic_info tinfo;
4017   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
4018   kern_return_t kr;
4019   thread_t mach_thread;
4020 
4021   mach_thread = thread->osthread()->thread_id();
4022   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
4023   if (kr != KERN_SUCCESS) {
4024     return -1;
4025   }
4026 
4027   if (user_sys_cpu_time) {
4028     jlong nanos;
4029     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4030     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4031     return nanos;
4032   } else {
4033     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4034   }
4035 #else
4036   Unimplemented();
4037   return 0;
4038 #endif
4039 }
4040 
4041 
4042 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4043   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4044   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4045   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4046   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4047 }
4048 
4049 void os::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 bool os::is_thread_cpu_time_supported() {
4057 #ifdef __APPLE__
4058   return true;
4059 #else
4060   return false;
4061 #endif
4062 }
4063 
4064 // System loadavg support.  Returns -1 if load average cannot be obtained.
4065 // Bsd doesn't yet have a (official) notion of processor sets,
4066 // so just return the system wide load average.
4067 int os::loadavg(double loadavg[], int nelem) {
4068   return ::getloadavg(loadavg, nelem);
4069 }
4070 
4071 void os::pause() {
4072   char filename[MAX_PATH];
4073   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4074     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4075   } else {
4076     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4077   }
4078 
4079   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4080   if (fd != -1) {
4081     struct stat buf;
4082     ::close(fd);
4083     while (::stat(filename, &buf) == 0) {
4084       (void)::poll(NULL, 0, 100);
4085     }
4086   } else {
4087     jio_fprintf(stderr,
4088                 "Could not open pause file '%s', continuing immediately.\n", filename);
4089   }
4090 }
4091 
4092 
4093 // Refer to the comments in os_solaris.cpp park-unpark. The next two
4094 // comment paragraphs are worth repeating here:
4095 //
4096 // Assumption:
4097 //    Only one parker can exist on an event, which is why we allocate
4098 //    them per-thread. Multiple unparkers can coexist.
4099 //
4100 // _Event serves as a restricted-range semaphore.
4101 //   -1 : thread is blocked, i.e. there is a waiter
4102 //    0 : neutral: thread is running or ready,
4103 //        could have been signaled after a wait started
4104 //    1 : signaled - thread is running or ready
4105 //
4106 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4107 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4108 // For specifics regarding the bug see GLIBC BUGID 261237 :
4109 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4110 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4111 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4112 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
4113 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4114 // and monitorenter when we're using 1-0 locking.  All those operations may result in
4115 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
4116 // of libpthread avoids the problem, but isn't practical.
4117 //
4118 // Possible remedies:
4119 //
4120 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
4121 //      This is palliative and probabilistic, however.  If the thread is preempted
4122 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
4123 //      than the minimum period may have passed, and the abstime may be stale (in the
4124 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
4125 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
4126 //
4127 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4128 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
4129 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4130 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
4131 //      thread.
4132 //
4133 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
4134 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
4135 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
4136 //      This also works well.  In fact it avoids kernel-level scalability impediments
4137 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
4138 //      timers in a graceful fashion.
4139 //
4140 // 4.   When the abstime value is in the past it appears that control returns
4141 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4142 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
4143 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
4144 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
4145 //      It may be possible to avoid reinitialization by checking the return
4146 //      value from pthread_cond_timedwait().  In addition to reinitializing the
4147 //      condvar we must establish the invariant that cond_signal() is only called
4148 //      within critical sections protected by the adjunct mutex.  This prevents
4149 //      cond_signal() from "seeing" a condvar that's in the midst of being
4150 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
4151 //      desirable signal-after-unlock optimization that avoids futile context switching.
4152 //
4153 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
4154 //      structure when a condvar is used or initialized.  cond_destroy()  would
4155 //      release the helper structure.  Our reinitialize-after-timedwait fix
4156 //      put excessive stress on malloc/free and locks protecting the c-heap.
4157 //
4158 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
4159 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4160 // and only enabling the work-around for vulnerable environments.
4161 
4162 // utility to compute the abstime argument to timedwait:
4163 // millis is the relative timeout time
4164 // abstime will be the absolute timeout time
4165 // TODO: replace compute_abstime() with unpackTime()
4166 
4167 static struct timespec* compute_abstime(struct timespec* abstime,
4168                                         jlong millis) {
4169   if (millis < 0)  millis = 0;
4170   struct timeval now;
4171   int status = gettimeofday(&now, NULL);
4172   assert(status == 0, "gettimeofday");
4173   jlong seconds = millis / 1000;
4174   millis %= 1000;
4175   if (seconds > 50000000) { // see man cond_timedwait(3T)
4176     seconds = 50000000;
4177   }
4178   abstime->tv_sec = now.tv_sec  + seconds;
4179   long       usec = now.tv_usec + millis * 1000;
4180   if (usec >= 1000000) {
4181     abstime->tv_sec += 1;
4182     usec -= 1000000;
4183   }
4184   abstime->tv_nsec = usec * 1000;
4185   return abstime;
4186 }
4187 
4188 void os::PlatformEvent::park() {       // AKA "down()"
4189   // Transitions for _Event:
4190   //   -1 => -1 : illegal
4191   //    1 =>  0 : pass - return immediately
4192   //    0 => -1 : block; then set _Event to 0 before returning
4193 
4194   // Invariant: Only the thread associated with the Event/PlatformEvent
4195   // may call park().
4196   // TODO: assert that _Assoc != NULL or _Assoc == Self
4197   assert(_nParked == 0, "invariant");
4198 
4199   int v;
4200   for (;;) {
4201     v = _Event;
4202     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4203   }
4204   guarantee(v >= 0, "invariant");
4205   if (v == 0) {
4206     // Do this the hard way by blocking ...
4207     int status = pthread_mutex_lock(_mutex);
4208     assert_status(status == 0, status, "mutex_lock");
4209     guarantee(_nParked == 0, "invariant");
4210     ++_nParked;
4211     while (_Event < 0) {
4212       status = pthread_cond_wait(_cond, _mutex);
4213       // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4214       // Treat this the same as if the wait was interrupted
4215       if (status == ETIMEDOUT) { status = EINTR; }
4216       assert_status(status == 0 || status == EINTR, status, "cond_wait");
4217     }
4218     --_nParked;
4219 
4220     _Event = 0;
4221     status = pthread_mutex_unlock(_mutex);
4222     assert_status(status == 0, status, "mutex_unlock");
4223     // Paranoia to ensure our locked and lock-free paths interact
4224     // correctly with each other.
4225     OrderAccess::fence();
4226   }
4227   guarantee(_Event >= 0, "invariant");
4228 }
4229 
4230 int os::PlatformEvent::park(jlong millis) {
4231   // Transitions for _Event:
4232   //   -1 => -1 : illegal
4233   //    1 =>  0 : pass - return immediately
4234   //    0 => -1 : block; then set _Event to 0 before returning
4235 
4236   guarantee(_nParked == 0, "invariant");
4237 
4238   int v;
4239   for (;;) {
4240     v = _Event;
4241     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4242   }
4243   guarantee(v >= 0, "invariant");
4244   if (v != 0) return OS_OK;
4245 
4246   // We do this the hard way, by blocking the thread.
4247   // Consider enforcing a minimum timeout value.
4248   struct timespec abst;
4249   compute_abstime(&abst, millis);
4250 
4251   int ret = OS_TIMEOUT;
4252   int status = pthread_mutex_lock(_mutex);
4253   assert_status(status == 0, status, "mutex_lock");
4254   guarantee(_nParked == 0, "invariant");
4255   ++_nParked;
4256 
4257   // Object.wait(timo) will return because of
4258   // (a) notification
4259   // (b) timeout
4260   // (c) thread.interrupt
4261   //
4262   // Thread.interrupt and object.notify{All} both call Event::set.
4263   // That is, we treat thread.interrupt as a special case of notification.
4264   // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false.
4265   // We assume all ETIME returns are valid.
4266   //
4267   // TODO: properly differentiate simultaneous notify+interrupt.
4268   // In that case, we should propagate the notify to another waiter.
4269 
4270   while (_Event < 0) {
4271     status = pthread_cond_timedwait(_cond, _mutex, &abst);
4272     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4273       pthread_cond_destroy(_cond);
4274       pthread_cond_init(_cond, NULL);
4275     }
4276     assert_status(status == 0 || status == EINTR ||
4277                   status == ETIMEDOUT,
4278                   status, "cond_timedwait");
4279     if (!FilterSpuriousWakeups) break;                 // previous semantics
4280     if (status == ETIMEDOUT) break;
4281     // We consume and ignore EINTR and spurious wakeups.
4282   }
4283   --_nParked;
4284   if (_Event >= 0) {
4285     ret = OS_OK;
4286   }
4287   _Event = 0;
4288   status = pthread_mutex_unlock(_mutex);
4289   assert_status(status == 0, status, "mutex_unlock");
4290   assert(_nParked == 0, "invariant");
4291   // Paranoia to ensure our locked and lock-free paths interact
4292   // correctly with each other.
4293   OrderAccess::fence();
4294   return ret;
4295 }
4296 
4297 void os::PlatformEvent::unpark() {
4298   // Transitions for _Event:
4299   //    0 => 1 : just return
4300   //    1 => 1 : just return
4301   //   -1 => either 0 or 1; must signal target thread
4302   //         That is, we can safely transition _Event from -1 to either
4303   //         0 or 1.
4304   // See also: "Semaphores in Plan 9" by Mullender & Cox
4305   //
4306   // Note: Forcing a transition from "-1" to "1" on an unpark() means
4307   // that it will take two back-to-back park() calls for the owning
4308   // thread to block. This has the benefit of forcing a spurious return
4309   // from the first park() call after an unpark() call which will help
4310   // shake out uses of park() and unpark() without condition variables.
4311 
4312   if (Atomic::xchg(1, &_Event) >= 0) return;
4313 
4314   // Wait for the thread associated with the event to vacate
4315   int status = pthread_mutex_lock(_mutex);
4316   assert_status(status == 0, status, "mutex_lock");
4317   int AnyWaiters = _nParked;
4318   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4319   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4320     AnyWaiters = 0;
4321     pthread_cond_signal(_cond);
4322   }
4323   status = pthread_mutex_unlock(_mutex);
4324   assert_status(status == 0, status, "mutex_unlock");
4325   if (AnyWaiters != 0) {
4326     // Note that we signal() *after* dropping the lock for "immortal" Events.
4327     // This is safe and avoids a common class of  futile wakeups.  In rare
4328     // circumstances this can cause a thread to return prematurely from
4329     // cond_{timed}wait() but the spurious wakeup is benign and the victim
4330     // will simply re-test the condition and re-park itself.
4331     // This provides particular benefit if the underlying platform does not
4332     // provide wait morphing.
4333     status = pthread_cond_signal(_cond);
4334     assert_status(status == 0, status, "cond_signal");
4335   }
4336 }
4337 
4338 
4339 // JSR166
4340 // -------------------------------------------------------
4341 
4342 // The solaris and bsd implementations of park/unpark are fairly
4343 // conservative for now, but can be improved. They currently use a
4344 // mutex/condvar pair, plus a a count.
4345 // Park decrements count if > 0, else does a condvar wait.  Unpark
4346 // sets count to 1 and signals condvar.  Only one thread ever waits
4347 // on the condvar. Contention seen when trying to park implies that someone
4348 // is unparking you, so don't wait. And spurious returns are fine, so there
4349 // is no need to track notifications.
4350 
4351 #define MAX_SECS 100000000
4352 
4353 // This code is common to bsd and solaris and will be moved to a
4354 // common place in dolphin.
4355 //
4356 // The passed in time value is either a relative time in nanoseconds
4357 // or an absolute time in milliseconds. Either way it has to be unpacked
4358 // into suitable seconds and nanoseconds components and stored in the
4359 // given timespec structure.
4360 // Given time is a 64-bit value and the time_t used in the timespec is only
4361 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4362 // overflow if times way in the future are given. Further on Solaris versions
4363 // prior to 10 there is a restriction (see cond_timedwait) that the specified
4364 // number of seconds, in abstime, is less than current_time  + 100,000,000.
4365 // As it will be 28 years before "now + 100000000" will overflow we can
4366 // ignore overflow and just impose a hard-limit on seconds using the value
4367 // of "now + 100,000,000". This places a limit on the timeout of about 3.17
4368 // years from "now".
4369 
4370 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4371   assert(time > 0, "convertTime");
4372 
4373   struct timeval now;
4374   int status = gettimeofday(&now, NULL);
4375   assert(status == 0, "gettimeofday");
4376 
4377   time_t max_secs = now.tv_sec + MAX_SECS;
4378 
4379   if (isAbsolute) {
4380     jlong secs = time / 1000;
4381     if (secs > max_secs) {
4382       absTime->tv_sec = max_secs;
4383     } else {
4384       absTime->tv_sec = secs;
4385     }
4386     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4387   } else {
4388     jlong secs = time / NANOSECS_PER_SEC;
4389     if (secs >= MAX_SECS) {
4390       absTime->tv_sec = max_secs;
4391       absTime->tv_nsec = 0;
4392     } else {
4393       absTime->tv_sec = now.tv_sec + secs;
4394       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4395       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4396         absTime->tv_nsec -= NANOSECS_PER_SEC;
4397         ++absTime->tv_sec; // note: this must be <= max_secs
4398       }
4399     }
4400   }
4401   assert(absTime->tv_sec >= 0, "tv_sec < 0");
4402   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4403   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4404   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4405 }
4406 
4407 void Parker::park(bool isAbsolute, jlong time) {
4408   // Ideally we'd do something useful while spinning, such
4409   // as calling unpackTime().
4410 
4411   // Optional fast-path check:
4412   // Return immediately if a permit is available.
4413   // We depend on Atomic::xchg() having full barrier semantics
4414   // since we are doing a lock-free update to _counter.
4415   if (Atomic::xchg(0, &_counter) > 0) return;
4416 
4417   Thread* thread = Thread::current();
4418   assert(thread->is_Java_thread(), "Must be JavaThread");
4419   JavaThread *jt = (JavaThread *)thread;
4420 
4421   // Optional optimization -- avoid state transitions if there's an interrupt pending.
4422   // Check interrupt before trying to wait
4423   if (Thread::is_interrupted(thread, false)) {
4424     return;
4425   }
4426 
4427   // Next, demultiplex/decode time arguments
4428   struct timespec absTime;
4429   if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
4430     return;
4431   }
4432   if (time > 0) {
4433     unpackTime(&absTime, isAbsolute, time);
4434   }
4435 
4436 
4437   // Enter safepoint region
4438   // Beware of deadlocks such as 6317397.
4439   // The per-thread Parker:: mutex is a classic leaf-lock.
4440   // In particular a thread must never block on the Threads_lock while
4441   // holding the Parker:: mutex.  If safepoints are pending both the
4442   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4443   ThreadBlockInVM tbivm(jt);
4444 
4445   // Don't wait if cannot get lock since interference arises from
4446   // unblocking.  Also. check interrupt before trying wait
4447   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4448     return;
4449   }
4450 
4451   int status;
4452   if (_counter > 0)  { // no wait needed
4453     _counter = 0;
4454     status = pthread_mutex_unlock(_mutex);
4455     assert(status == 0, "invariant");
4456     // Paranoia to ensure our locked and lock-free paths interact
4457     // correctly with each other and Java-level accesses.
4458     OrderAccess::fence();
4459     return;
4460   }
4461 
4462 #ifdef ASSERT
4463   // Don't catch signals while blocked; let the running threads have the signals.
4464   // (This allows a debugger to break into the running thread.)
4465   sigset_t oldsigs;
4466   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4467   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4468 #endif
4469 
4470   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4471   jt->set_suspend_equivalent();
4472   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4473 
4474   if (time == 0) {
4475     status = pthread_cond_wait(_cond, _mutex);
4476   } else {
4477     status = pthread_cond_timedwait(_cond, _mutex, &absTime);
4478     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4479       pthread_cond_destroy(_cond);
4480       pthread_cond_init(_cond, NULL);
4481     }
4482   }
4483   assert_status(status == 0 || status == EINTR ||
4484                 status == ETIMEDOUT,
4485                 status, "cond_timedwait");
4486 
4487 #ifdef ASSERT
4488   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4489 #endif
4490 
4491   _counter = 0;
4492   status = pthread_mutex_unlock(_mutex);
4493   assert_status(status == 0, status, "invariant");
4494   // Paranoia to ensure our locked and lock-free paths interact
4495   // correctly with each other and Java-level accesses.
4496   OrderAccess::fence();
4497 
4498   // If externally suspended while waiting, re-suspend
4499   if (jt->handle_special_suspend_equivalent_condition()) {
4500     jt->java_suspend_self();
4501   }
4502 }
4503 
4504 void Parker::unpark() {
4505   int status = pthread_mutex_lock(_mutex);
4506   assert(status == 0, "invariant");
4507   const int s = _counter;
4508   _counter = 1;
4509   if (s < 1) {
4510     if (WorkAroundNPTLTimedWaitHang) {
4511       status = pthread_cond_signal(_cond);
4512       assert(status == 0, "invariant");
4513       status = pthread_mutex_unlock(_mutex);
4514       assert(status == 0, "invariant");
4515     } else {
4516       status = pthread_mutex_unlock(_mutex);
4517       assert(status == 0, "invariant");
4518       status = pthread_cond_signal(_cond);
4519       assert(status == 0, "invariant");
4520     }
4521   } else {
4522     pthread_mutex_unlock(_mutex);
4523     assert(status == 0, "invariant");
4524   }
4525 }
4526 
4527 
4528 // Darwin has no "environ" in a dynamic library.
4529 #ifdef __APPLE__
4530   #include <crt_externs.h>
4531   #define environ (*_NSGetEnviron())
4532 #else
4533 extern char** environ;
4534 #endif
4535 
4536 // Run the specified command in a separate process. Return its exit value,
4537 // or -1 on failure (e.g. can't fork a new process).
4538 // Unlike system(), this function can be called from signal handler. It
4539 // doesn't block SIGINT et al.
4540 int os::fork_and_exec(char* cmd) {
4541   const char * argv[4] = {"sh", "-c", cmd, NULL};
4542 
4543   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4544   // pthread_atfork handlers and reset pthread library. All we need is a
4545   // separate process to execve. Make a direct syscall to fork process.
4546   // On IA64 there's no fork syscall, we have to use fork() and hope for
4547   // the best...
4548   pid_t pid = fork();
4549 
4550   if (pid < 0) {
4551     // fork failed
4552     return -1;
4553 
4554   } else if (pid == 0) {
4555     // child process
4556 
4557     // execve() in BsdThreads will call pthread_kill_other_threads_np()
4558     // first to kill every thread on the thread list. Because this list is
4559     // not reset by fork() (see notes above), execve() will instead kill
4560     // every thread in the parent process. We know this is the only thread
4561     // in the new process, so make a system call directly.
4562     // IA64 should use normal execve() from glibc to match the glibc fork()
4563     // above.
4564     execve("/bin/sh", (char* const*)argv, environ);
4565 
4566     // execve failed
4567     _exit(-1);
4568 
4569   } else  {
4570     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4571     // care about the actual exit code, for now.
4572 
4573     int status;
4574 
4575     // Wait for the child process to exit.  This returns immediately if
4576     // the child has already exited. */
4577     while (waitpid(pid, &status, 0) < 0) {
4578       switch (errno) {
4579       case ECHILD: return 0;
4580       case EINTR: break;
4581       default: return -1;
4582       }
4583     }
4584 
4585     if (WIFEXITED(status)) {
4586       // The child exited normally; get its exit code.
4587       return WEXITSTATUS(status);
4588     } else if (WIFSIGNALED(status)) {
4589       // The child exited because of a signal
4590       // The best value to return is 0x80 + signal number,
4591       // because that is what all Unix shells do, and because
4592       // it allows callers to distinguish between process exit and
4593       // process death by signal.
4594       return 0x80 + WTERMSIG(status);
4595     } else {
4596       // Unknown exit code; pass it through
4597       return status;
4598     }
4599   }
4600 }
4601 
4602 // is_headless_jre()
4603 //
4604 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4605 // in order to report if we are running in a headless jre
4606 //
4607 // Since JDK8 xawt/libmawt.so was moved into the same directory
4608 // as libawt.so, and renamed libawt_xawt.so
4609 //
4610 bool os::is_headless_jre() {
4611 #ifdef __APPLE__
4612   // We no longer build headless-only on Mac OS X
4613   return false;
4614 #else
4615   struct stat statbuf;
4616   char buf[MAXPATHLEN];
4617   char libmawtpath[MAXPATHLEN];
4618   const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
4619   const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4620   char *p;
4621 
4622   // Get path to libjvm.so
4623   os::jvm_path(buf, sizeof(buf));
4624 
4625   // Get rid of libjvm.so
4626   p = strrchr(buf, '/');
4627   if (p == NULL) {
4628     return false;
4629   } else {
4630     *p = '\0';
4631   }
4632 
4633   // Get rid of client or server
4634   p = strrchr(buf, '/');
4635   if (p == NULL) {
4636     return false;
4637   } else {
4638     *p = '\0';
4639   }
4640 
4641   // check xawt/libmawt.so
4642   strcpy(libmawtpath, buf);
4643   strcat(libmawtpath, xawtstr);
4644   if (::stat(libmawtpath, &statbuf) == 0) return false;
4645 
4646   // check libawt_xawt.so
4647   strcpy(libmawtpath, buf);
4648   strcat(libmawtpath, new_xawtstr);
4649   if (::stat(libmawtpath, &statbuf) == 0) return false;
4650 
4651   return true;
4652 #endif
4653 }
4654 
4655 // Get the default path to the core file
4656 // Returns the length of the string
4657 int os::get_core_path(char* buffer, size_t bufferSize) {
4658   int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
4659 
4660   // Truncate if theoretical string was longer than bufferSize
4661   n = MIN2(n, (int)bufferSize);
4662 
4663   return n;
4664 }
4665 
4666 #ifndef PRODUCT
4667 void TestReserveMemorySpecial_test() {
4668   // No tests available for this platform
4669 }
4670 #endif
--- EOF ---