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