1 /*
   2  * Copyright (c) 1999, 2013, 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_share_bsd.hpp"
  40 #include "prims/jniFastGetField.hpp"
  41 #include "prims/jvm.h"
  42 #include "prims/jvm_misc.hpp"
  43 #include "runtime/arguments.hpp"
  44 #include "runtime/extendedPC.hpp"
  45 #include "runtime/globals.hpp"
  46 #include "runtime/interfaceSupport.hpp"
  47 #include "runtime/java.hpp"
  48 #include "runtime/javaCalls.hpp"
  49 #include "runtime/mutexLocker.hpp"
  50 #include "runtime/objectMonitor.hpp"
  51 #include "runtime/osThread.hpp"
  52 #include "runtime/perfMemory.hpp"
  53 #include "runtime/sharedRuntime.hpp"
  54 #include "runtime/statSampler.hpp"
  55 #include "runtime/stubRoutines.hpp"
  56 #include "runtime/thread.inline.hpp"
  57 #include "runtime/threadCritical.hpp"
  58 #include "runtime/timer.hpp"
  59 #include "services/attachListener.hpp"
  60 #include "services/memTracker.hpp"
  61 #include "services/runtimeService.hpp"
  62 #include "utilities/decoder.hpp"
  63 #include "utilities/defaultStream.hpp"
  64 #include "utilities/events.hpp"
  65 #include "utilities/growableArray.hpp"
  66 #include "utilities/vmError.hpp"
  67 
  68 // put OS-includes here
  69 # include <sys/types.h>
  70 # include <sys/mman.h>
  71 # include <sys/stat.h>
  72 # include <sys/select.h>
  73 # include <pthread.h>
  74 # include <signal.h>
  75 # include <errno.h>
  76 # include <dlfcn.h>
  77 # include <stdio.h>
  78 # include <unistd.h>
  79 # include <sys/resource.h>
  80 # include <pthread.h>
  81 # include <sys/stat.h>
  82 # include <sys/time.h>
  83 # include <sys/times.h>
  84 # include <sys/utsname.h>
  85 # include <sys/socket.h>
  86 # include <sys/wait.h>
  87 # include <time.h>
  88 # include <pwd.h>
  89 # include <poll.h>
  90 # include <semaphore.h>
  91 # include <fcntl.h>
  92 # include <string.h>
  93 # include <sys/param.h>
  94 # include <sys/sysctl.h>
  95 # include <sys/ipc.h>
  96 # include <sys/shm.h>
  97 #ifndef __APPLE__
  98 # include <link.h>
  99 #endif
 100 # include <stdint.h>
 101 # include <inttypes.h>
 102 # include <sys/ioctl.h>
 103 
 104 #if defined(__FreeBSD__) || defined(__NetBSD__)
 105 # include <elf.h>
 106 #endif
 107 
 108 #ifdef __APPLE__
 109 # include <mach/mach.h> // semaphore_* API
 110 # include <mach-o/dyld.h>
 111 # include <sys/proc_info.h>
 112 # include <objc/objc-auto.h>
 113 #endif
 114 
 115 #ifndef MAP_ANONYMOUS
 116 #define MAP_ANONYMOUS MAP_ANON
 117 #endif
 118 
 119 #define MAX_PATH    (2 * K)
 120 
 121 // for timer info max values which include all bits
 122 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 123 
 124 #define LARGEPAGES_BIT (1 << 6)
 125 ////////////////////////////////////////////////////////////////////////////////
 126 // global variables
 127 julong os::Bsd::_physical_memory = 0;
 128 
 129 
 130 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 131 pthread_t os::Bsd::_main_thread;
 132 int os::Bsd::_page_size = -1;
 133 
 134 static jlong initial_time_count=0;
 135 
 136 static int clock_tics_per_sec = 100;
 137 
 138 // For diagnostics to print a message once. see run_periodic_checks
 139 static sigset_t check_signal_done;
 140 static bool check_signals = true;
 141 
 142 static pid_t _initial_pid = 0;
 143 
 144 /* Signal number used to suspend/resume a thread */
 145 
 146 /* do not use any signal number less than SIGSEGV, see 4355769 */
 147 static int SR_signum = SIGUSR2;
 148 sigset_t SR_sigset;
 149 
 150 
 151 ////////////////////////////////////////////////////////////////////////////////
 152 // utility functions
 153 
 154 static int SR_initialize();
 155 
 156 julong os::available_memory() {
 157   return Bsd::available_memory();
 158 }
 159 
 160 julong os::Bsd::available_memory() {
 161   // XXXBSD: this is just a stopgap implementation
 162   return physical_memory() >> 2;
 163 }
 164 
 165 julong os::physical_memory() {
 166   return Bsd::physical_memory();
 167 }
 168 
 169 ////////////////////////////////////////////////////////////////////////////////
 170 // environment support
 171 
 172 bool os::getenv(const char* name, char* buf, int len) {
 173   const char* val = ::getenv(name);
 174   if (val != NULL && strlen(val) < (size_t)len) {
 175     strcpy(buf, val);
 176     return true;
 177   }
 178   if (len > 0) buf[0] = 0;  // return a null string
 179   return false;
 180 }
 181 
 182 
 183 // Return true if user is running as root.
 184 
 185 bool os::have_special_privileges() {
 186   static bool init = false;
 187   static bool privileges = false;
 188   if (!init) {
 189     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 190     init = true;
 191   }
 192   return privileges;
 193 }
 194 
 195 
 196 
 197 // Cpu architecture string
 198 #if   defined(ZERO)
 199 static char cpu_arch[] = ZERO_LIBARCH;
 200 #elif defined(IA64)
 201 static char cpu_arch[] = "ia64";
 202 #elif defined(IA32)
 203 static char cpu_arch[] = "i386";
 204 #elif defined(AMD64)
 205 static char cpu_arch[] = "amd64";
 206 #elif defined(ARM)
 207 static char cpu_arch[] = "arm";
 208 #elif defined(PPC)
 209 static char cpu_arch[] = "ppc";
 210 #elif defined(SPARC)
 211 #  ifdef _LP64
 212 static char cpu_arch[] = "sparcv9";
 213 #  else
 214 static char cpu_arch[] = "sparc";
 215 #  endif
 216 #else
 217 #error Add appropriate cpu_arch setting
 218 #endif
 219 
 220 // Compiler variant
 221 #ifdef COMPILER2
 222 #define COMPILER_VARIANT "server"
 223 #else
 224 #define COMPILER_VARIANT "client"
 225 #endif
 226 
 227 
 228 void os::Bsd::initialize_system_info() {
 229   int mib[2];
 230   size_t len;
 231   int cpu_val;
 232   julong mem_val;
 233 
 234   /* get processors count via hw.ncpus sysctl */
 235   mib[0] = CTL_HW;
 236   mib[1] = HW_NCPU;
 237   len = sizeof(cpu_val);
 238   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 239        assert(len == sizeof(cpu_val), "unexpected data size");
 240        set_processor_count(cpu_val);
 241   }
 242   else {
 243        set_processor_count(1);   // fallback
 244   }
 245 
 246   /* get physical memory via hw.memsize sysctl (hw.memsize is used
 247    * since it returns a 64 bit value)
 248    */
 249   mib[0] = CTL_HW;
 250   mib[1] = HW_MEMSIZE;
 251   len = sizeof(mem_val);
 252   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 253        assert(len == sizeof(mem_val), "unexpected data size");
 254        _physical_memory = mem_val;
 255   } else {
 256        _physical_memory = 256*1024*1024;       // fallback (XXXBSD?)
 257   }
 258 
 259 #ifdef __OpenBSD__
 260   {
 261        // limit _physical_memory memory view on OpenBSD since
 262        // datasize rlimit restricts us anyway.
 263        struct rlimit limits;
 264        getrlimit(RLIMIT_DATA, &limits);
 265        _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 266   }
 267 #endif
 268 }
 269 
 270 #ifdef __APPLE__
 271 static const char *get_home() {
 272   const char *home_dir = ::getenv("HOME");
 273   if ((home_dir == NULL) || (*home_dir == '\0')) {
 274     struct passwd *passwd_info = getpwuid(geteuid());
 275     if (passwd_info != NULL) {
 276       home_dir = passwd_info->pw_dir;
 277     }
 278   }
 279 
 280   return home_dir;
 281 }
 282 #endif
 283 
 284 void os::init_system_properties_values() {
 285 //  char arch[12];
 286 //  sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
 287 
 288   // The next steps are taken in the product version:
 289   //
 290   // Obtain the JAVA_HOME value from the location of libjvm.so.
 291   // This library should be located at:
 292   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 293   //
 294   // If "/jre/lib/" appears at the right place in the path, then we
 295   // assume libjvm.so is installed in a JDK and we use this path.
 296   //
 297   // Otherwise exit with message: "Could not create the Java virtual machine."
 298   //
 299   // The following extra steps are taken in the debugging version:
 300   //
 301   // If "/jre/lib/" does NOT appear at the right place in the path
 302   // instead of exit check for $JAVA_HOME environment variable.
 303   //
 304   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 305   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 306   // it looks like libjvm.so is installed there
 307   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 308   //
 309   // Otherwise exit.
 310   //
 311   // Important note: if the location of libjvm.so changes this
 312   // code needs to be changed accordingly.
 313 
 314   // The next few definitions allow the code to be verbatim:
 315 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal)
 316 #define getenv(n) ::getenv(n)
 317 
 318 /*
 319  * See ld(1):
 320  *      The linker uses the following search paths to locate required
 321  *      shared libraries:
 322  *        1: ...
 323  *        ...
 324  *        7: The default directories, normally /lib and /usr/lib.
 325  */
 326 #ifndef DEFAULT_LIBPATH
 327 #define DEFAULT_LIBPATH "/lib:/usr/lib"
 328 #endif
 329 
 330 #define EXTENSIONS_DIR  "/lib/ext"
 331 #define ENDORSED_DIR    "/lib/endorsed"
 332 #define REG_DIR         "/usr/java/packages"
 333 
 334 #ifdef __APPLE__
 335 #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 336 #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 337         const char *user_home_dir = get_home();
 338         // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir
 339         int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 340             sizeof(SYS_EXTENSIONS_DIRS);
 341 #endif
 342 
 343   {
 344     /* sysclasspath, java_home, dll_dir */
 345     {
 346         char *home_path;
 347         char *dll_path;
 348         char *pslash;
 349         char buf[MAXPATHLEN];
 350         os::jvm_path(buf, sizeof(buf));
 351 
 352         // Found the full path to libjvm.so.
 353         // Now cut the path to <java_home>/jre if we can.
 354         *(strrchr(buf, '/')) = '\0';  /* get rid of /libjvm.so */
 355         pslash = strrchr(buf, '/');
 356         if (pslash != NULL)
 357             *pslash = '\0';           /* get rid of /{client|server|hotspot} */
 358         dll_path = malloc(strlen(buf) + 1);
 359         if (dll_path == NULL)
 360             return;
 361         strcpy(dll_path, buf);
 362         Arguments::set_dll_dir(dll_path);
 363 
 364         if (pslash != NULL) {
 365             pslash = strrchr(buf, '/');
 366             if (pslash != NULL) {
 367                 *pslash = '\0';       /* get rid of /<arch> (/lib on macosx) */
 368 #ifndef __APPLE__
 369                 pslash = strrchr(buf, '/');
 370                 if (pslash != NULL)
 371                     *pslash = '\0';   /* get rid of /lib */
 372 #endif
 373             }
 374         }
 375 
 376         home_path = malloc(strlen(buf) + 1);
 377         if (home_path == NULL)
 378             return;
 379         strcpy(home_path, buf);
 380         Arguments::set_java_home(home_path);
 381 
 382         if (!set_boot_path('/', ':'))
 383             return;
 384     }
 385 
 386     /*
 387      * Where to look for native libraries
 388      *
 389      * Note: Due to a legacy implementation, most of the library path
 390      * is set in the launcher.  This was to accomodate linking restrictions
 391      * on legacy Bsd implementations (which are no longer supported).
 392      * Eventually, all the library path setting will be done here.
 393      *
 394      * However, to prevent the proliferation of improperly built native
 395      * libraries, the new path component /usr/java/packages is added here.
 396      * Eventually, all the library path setting will be done here.
 397      */
 398     {
 399         char *ld_library_path;
 400 
 401         /*
 402          * Construct the invariant part of ld_library_path. Note that the
 403          * space for the colon and the trailing null are provided by the
 404          * nulls included by the sizeof operator (so actually we allocate
 405          * a byte more than necessary).
 406          */
 407 #ifdef __APPLE__
 408         ld_library_path = (char *) malloc(system_ext_size);
 409         sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir);
 410 #else
 411         ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
 412             strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
 413         sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
 414 #endif
 415 
 416         /*
 417          * Get the user setting of LD_LIBRARY_PATH, and prepended it.  It
 418          * should always exist (until the legacy problem cited above is
 419          * addressed).
 420          */
 421 #ifdef __APPLE__
 422         // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper
 423         char *l = getenv("JAVA_LIBRARY_PATH");
 424         if (l != NULL) {
 425             char *t = ld_library_path;
 426             /* That's +1 for the colon and +1 for the trailing '\0' */
 427             ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1);
 428             sprintf(ld_library_path, "%s:%s", l, t);
 429             free(t);
 430         }
 431 
 432         char *v = getenv("DYLD_LIBRARY_PATH");
 433 #else
 434         char *v = getenv("LD_LIBRARY_PATH");
 435 #endif
 436         if (v != NULL) {
 437             char *t = ld_library_path;
 438             /* That's +1 for the colon and +1 for the trailing '\0' */
 439             ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
 440             sprintf(ld_library_path, "%s:%s", v, t);
 441             free(t);
 442         }
 443 
 444 #ifdef __APPLE__
 445         // Apple's Java6 has "." at the beginning of java.library.path.
 446         // OpenJDK on Windows has "." at the end of java.library.path.
 447         // OpenJDK on Linux and Solaris don't have "." in java.library.path
 448         // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 449         // "." is appended to the end of java.library.path. Yes, this
 450         // could cause a change in behavior, but Apple's Java6 behavior
 451         // can be achieved by putting "." at the beginning of the
 452         // JAVA_LIBRARY_PATH environment variable.
 453         {
 454             char *t = ld_library_path;
 455             // that's +3 for appending ":." and the trailing '\0'
 456             ld_library_path = (char *) malloc(strlen(t) + 3);
 457             sprintf(ld_library_path, "%s:%s", t, ".");
 458             free(t);
 459         }
 460 #endif
 461 
 462         Arguments::set_library_path(ld_library_path);
 463     }
 464 
 465     /*
 466      * Extensions directories.
 467      *
 468      * Note that the space for the colon and the trailing null are provided
 469      * by the nulls included by the sizeof operator (so actually one byte more
 470      * than necessary is allocated).
 471      */
 472     {
 473 #ifdef __APPLE__
 474         char *buf = malloc(strlen(Arguments::get_java_home()) +
 475             sizeof(EXTENSIONS_DIR) + system_ext_size);
 476         sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":"
 477             SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home());
 478 #else
 479         char *buf = malloc(strlen(Arguments::get_java_home()) +
 480             sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
 481         sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
 482             Arguments::get_java_home());
 483 #endif
 484 
 485         Arguments::set_ext_dirs(buf);
 486     }
 487 
 488     /* Endorsed standards default directory. */
 489     {
 490         char * buf;
 491         buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
 492         sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
 493         Arguments::set_endorsed_dirs(buf);
 494     }
 495   }
 496 
 497 #ifdef __APPLE__
 498 #undef SYS_EXTENSIONS_DIR
 499 #endif
 500 #undef malloc
 501 #undef getenv
 502 #undef EXTENSIONS_DIR
 503 #undef ENDORSED_DIR
 504 
 505   // Done
 506   return;
 507 }
 508 
 509 ////////////////////////////////////////////////////////////////////////////////
 510 // breakpoint support
 511 
 512 void os::breakpoint() {
 513   BREAKPOINT;
 514 }
 515 
 516 extern "C" void breakpoint() {
 517   // use debugger to set breakpoint here
 518 }
 519 
 520 ////////////////////////////////////////////////////////////////////////////////
 521 // signal support
 522 
 523 debug_only(static bool signal_sets_initialized = false);
 524 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
 525 
 526 bool os::Bsd::is_sig_ignored(int sig) {
 527       struct sigaction oact;
 528       sigaction(sig, (struct sigaction*)NULL, &oact);
 529       void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
 530                                      : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
 531       if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
 532            return true;
 533       else
 534            return false;
 535 }
 536 
 537 void os::Bsd::signal_sets_init() {
 538   // Should also have an assertion stating we are still single-threaded.
 539   assert(!signal_sets_initialized, "Already initialized");
 540   // Fill in signals that are necessarily unblocked for all threads in
 541   // the VM. Currently, we unblock the following signals:
 542   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 543   //                         by -Xrs (=ReduceSignalUsage));
 544   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 545   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 546   // the dispositions or masks wrt these signals.
 547   // Programs embedding the VM that want to use the above signals for their
 548   // own purposes must, at this time, use the "-Xrs" option to prevent
 549   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 550   // (See bug 4345157, and other related bugs).
 551   // In reality, though, unblocking these signals is really a nop, since
 552   // these signals are not blocked by default.
 553   sigemptyset(&unblocked_sigs);
 554   sigemptyset(&allowdebug_blocked_sigs);
 555   sigaddset(&unblocked_sigs, SIGILL);
 556   sigaddset(&unblocked_sigs, SIGSEGV);
 557   sigaddset(&unblocked_sigs, SIGBUS);
 558   sigaddset(&unblocked_sigs, SIGFPE);
 559   sigaddset(&unblocked_sigs, SR_signum);
 560 
 561   if (!ReduceSignalUsage) {
 562    if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 563       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 564       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
 565    }
 566    if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 567       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 568       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
 569    }
 570    if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 571       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 572       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
 573    }
 574   }
 575   // Fill in signals that are blocked by all but the VM thread.
 576   sigemptyset(&vm_sigs);
 577   if (!ReduceSignalUsage)
 578     sigaddset(&vm_sigs, BREAK_SIGNAL);
 579   debug_only(signal_sets_initialized = true);
 580 
 581 }
 582 
 583 // These are signals that are unblocked while a thread is running Java.
 584 // (For some reason, they get blocked by default.)
 585 sigset_t* os::Bsd::unblocked_signals() {
 586   assert(signal_sets_initialized, "Not initialized");
 587   return &unblocked_sigs;
 588 }
 589 
 590 // These are the signals that are blocked while a (non-VM) thread is
 591 // running Java. Only the VM thread handles these signals.
 592 sigset_t* os::Bsd::vm_signals() {
 593   assert(signal_sets_initialized, "Not initialized");
 594   return &vm_sigs;
 595 }
 596 
 597 // These are signals that are blocked during cond_wait to allow debugger in
 598 sigset_t* os::Bsd::allowdebug_blocked_signals() {
 599   assert(signal_sets_initialized, "Not initialized");
 600   return &allowdebug_blocked_sigs;
 601 }
 602 
 603 void os::Bsd::hotspot_sigmask(Thread* thread) {
 604 
 605   //Save caller's signal mask before setting VM signal mask
 606   sigset_t caller_sigmask;
 607   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 608 
 609   OSThread* osthread = thread->osthread();
 610   osthread->set_caller_sigmask(caller_sigmask);
 611 
 612   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 613 
 614   if (!ReduceSignalUsage) {
 615     if (thread->is_VM_thread()) {
 616       // Only the VM thread handles BREAK_SIGNAL ...
 617       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 618     } else {
 619       // ... all other threads block BREAK_SIGNAL
 620       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 621     }
 622   }
 623 }
 624 
 625 
 626 //////////////////////////////////////////////////////////////////////////////
 627 // create new thread
 628 
 629 // check if it's safe to start a new thread
 630 static bool _thread_safety_check(Thread* thread) {
 631   return true;
 632 }
 633 
 634 #ifdef __APPLE__
 635 // library handle for calling objc_registerThreadWithCollector()
 636 // without static linking to the libobjc library
 637 #define OBJC_LIB "/usr/lib/libobjc.dylib"
 638 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 639 typedef void (*objc_registerThreadWithCollector_t)();
 640 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 641 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 642 #endif
 643 
 644 #ifdef __APPLE__
 645 static uint64_t locate_unique_thread_id() {
 646   // Additional thread_id used to correlate threads in SA
 647   thread_identifier_info_data_t     m_ident_info;
 648   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 649 
 650   thread_info(::mach_thread_self(), THREAD_IDENTIFIER_INFO,
 651               (thread_info_t) &m_ident_info, &count);
 652   return m_ident_info.thread_id;
 653 }
 654 #endif
 655 
 656 // Thread start routine for all newly created threads
 657 static void *java_start(Thread *thread) {
 658   // Try to randomize the cache line index of hot stack frames.
 659   // This helps when threads of the same stack traces evict each other's
 660   // cache lines. The threads can be either from the same JVM instance, or
 661   // from different JVM instances. The benefit is especially true for
 662   // processors with hyperthreading technology.
 663   static int counter = 0;
 664   int pid = os::current_process_id();
 665   alloca(((pid ^ counter++) & 7) * 128);
 666 
 667   ThreadLocalStorage::set_thread(thread);
 668 
 669   OSThread* osthread = thread->osthread();
 670   Monitor* sync = osthread->startThread_lock();
 671 
 672   // non floating stack BsdThreads needs extra check, see above
 673   if (!_thread_safety_check(thread)) {
 674     // notify parent thread
 675     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 676     osthread->set_state(ZOMBIE);
 677     sync->notify_all();
 678     return NULL;
 679   }
 680 
 681 #ifdef __APPLE__
 682   // thread_id is mach thread on macos
 683   osthread->set_thread_id(::mach_thread_self());
 684   osthread->set_unique_thread_id(locate_unique_thread_id());
 685 #else
 686   // thread_id is pthread_id on BSD
 687   osthread->set_thread_id(::pthread_self());
 688 #endif
 689   // initialize signal mask for this thread
 690   os::Bsd::hotspot_sigmask(thread);
 691 
 692   // initialize floating point control register
 693   os::Bsd::init_thread_fpu_state();
 694 
 695 #ifdef __APPLE__
 696   // register thread with objc gc
 697   if (objc_registerThreadWithCollectorFunction != NULL) {
 698     objc_registerThreadWithCollectorFunction();
 699   }
 700 #endif
 701 
 702   // handshaking with parent thread
 703   {
 704     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 705 
 706     // notify parent thread
 707     osthread->set_state(INITIALIZED);
 708     sync->notify_all();
 709 
 710     // wait until os::start_thread()
 711     while (osthread->get_state() == INITIALIZED) {
 712       sync->wait(Mutex::_no_safepoint_check_flag);
 713     }
 714   }
 715 
 716   // call one more level start routine
 717   thread->run();
 718 
 719   return 0;
 720 }
 721 
 722 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
 723   assert(thread->osthread() == NULL, "caller responsible");
 724 
 725   // Allocate the OSThread object
 726   OSThread* osthread = new OSThread(NULL, NULL);
 727   if (osthread == NULL) {
 728     return false;
 729   }
 730 
 731   // set the correct thread state
 732   osthread->set_thread_type(thr_type);
 733 
 734   // Initial state is ALLOCATED but not INITIALIZED
 735   osthread->set_state(ALLOCATED);
 736 
 737   thread->set_osthread(osthread);
 738 
 739   // init thread attributes
 740   pthread_attr_t attr;
 741   pthread_attr_init(&attr);
 742   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 743 
 744   // stack size
 745   if (os::Bsd::supports_variable_stack_size()) {
 746     // calculate stack size if it's not specified by caller
 747     if (stack_size == 0) {
 748       stack_size = os::Bsd::default_stack_size(thr_type);
 749 
 750       switch (thr_type) {
 751       case os::java_thread:
 752         // Java threads use ThreadStackSize which default value can be
 753         // changed with the flag -Xss
 754         assert (JavaThread::stack_size_at_create() > 0, "this should be set");
 755         stack_size = JavaThread::stack_size_at_create();
 756         break;
 757       case os::compiler_thread:
 758         if (CompilerThreadStackSize > 0) {
 759           stack_size = (size_t)(CompilerThreadStackSize * K);
 760           break;
 761         } // else fall through:
 762           // use VMThreadStackSize if CompilerThreadStackSize is not defined
 763       case os::vm_thread:
 764       case os::pgc_thread:
 765       case os::cgc_thread:
 766       case os::watcher_thread:
 767         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 768         break;
 769       }
 770     }
 771 
 772     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
 773     pthread_attr_setstacksize(&attr, stack_size);
 774   } else {
 775     // let pthread_create() pick the default value.
 776   }
 777 
 778   ThreadState state;
 779 
 780   {
 781     pthread_t tid;
 782     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
 783 
 784     pthread_attr_destroy(&attr);
 785 
 786     if (ret != 0) {
 787       if (PrintMiscellaneous && (Verbose || WizardMode)) {
 788         perror("pthread_create()");
 789       }
 790       // Need to clean up stuff we've allocated so far
 791       thread->set_osthread(NULL);
 792       delete osthread;
 793       return false;
 794     }
 795 
 796     // Store pthread info into the OSThread
 797     osthread->set_pthread_id(tid);
 798 
 799     // Wait until child thread is either initialized or aborted
 800     {
 801       Monitor* sync_with_child = osthread->startThread_lock();
 802       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 803       while ((state = osthread->get_state()) == ALLOCATED) {
 804         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 805       }
 806     }
 807 
 808   }
 809 
 810   // Aborted due to thread limit being reached
 811   if (state == ZOMBIE) {
 812       thread->set_osthread(NULL);
 813       delete osthread;
 814       return false;
 815   }
 816 
 817   // The thread is returned suspended (in state INITIALIZED),
 818   // and is started higher up in the call chain
 819   assert(state == INITIALIZED, "race condition");
 820   return true;
 821 }
 822 
 823 /////////////////////////////////////////////////////////////////////////////
 824 // attach existing thread
 825 
 826 // bootstrap the main thread
 827 bool os::create_main_thread(JavaThread* thread) {
 828   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 829   return create_attached_thread(thread);
 830 }
 831 
 832 bool os::create_attached_thread(JavaThread* thread) {
 833 #ifdef ASSERT
 834     thread->verify_not_published();
 835 #endif
 836 
 837   // Allocate the OSThread object
 838   OSThread* osthread = new OSThread(NULL, NULL);
 839 
 840   if (osthread == NULL) {
 841     return false;
 842   }
 843 
 844   // Store pthread info into the OSThread
 845 #ifdef __APPLE__
 846   osthread->set_thread_id(::mach_thread_self());
 847   osthread->set_unique_thread_id(locate_unique_thread_id());
 848 #else
 849   osthread->set_thread_id(::pthread_self());
 850 #endif
 851   osthread->set_pthread_id(::pthread_self());
 852 
 853   // initialize floating point control register
 854   os::Bsd::init_thread_fpu_state();
 855 
 856   // Initial thread state is RUNNABLE
 857   osthread->set_state(RUNNABLE);
 858 
 859   thread->set_osthread(osthread);
 860 
 861   // initialize signal mask for this thread
 862   // and save the caller's signal mask
 863   os::Bsd::hotspot_sigmask(thread);
 864 
 865   return true;
 866 }
 867 
 868 void os::pd_start_thread(Thread* thread) {
 869   OSThread * osthread = thread->osthread();
 870   assert(osthread->get_state() != INITIALIZED, "just checking");
 871   Monitor* sync_with_child = osthread->startThread_lock();
 872   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 873   sync_with_child->notify();
 874 }
 875 
 876 // Free Bsd resources related to the OSThread
 877 void os::free_thread(OSThread* osthread) {
 878   assert(osthread != NULL, "osthread not set");
 879 
 880   if (Thread::current()->osthread() == osthread) {
 881     // Restore caller's signal mask
 882     sigset_t sigmask = osthread->caller_sigmask();
 883     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 884    }
 885 
 886   delete osthread;
 887 }
 888 
 889 //////////////////////////////////////////////////////////////////////////////
 890 // thread local storage
 891 
 892 int os::allocate_thread_local_storage() {
 893   pthread_key_t key;
 894   int rslt = pthread_key_create(&key, NULL);
 895   assert(rslt == 0, "cannot allocate thread local storage");
 896   return (int)key;
 897 }
 898 
 899 // Note: This is currently not used by VM, as we don't destroy TLS key
 900 // on VM exit.
 901 void os::free_thread_local_storage(int index) {
 902   int rslt = pthread_key_delete((pthread_key_t)index);
 903   assert(rslt == 0, "invalid index");
 904 }
 905 
 906 void os::thread_local_storage_at_put(int index, void* value) {
 907   int rslt = pthread_setspecific((pthread_key_t)index, value);
 908   assert(rslt == 0, "pthread_setspecific failed");
 909 }
 910 
 911 extern "C" Thread* get_thread() {
 912   return ThreadLocalStorage::thread();
 913 }
 914 
 915 
 916 ////////////////////////////////////////////////////////////////////////////////
 917 // time support
 918 
 919 // Time since start-up in seconds to a fine granularity.
 920 // Used by VMSelfDestructTimer and the MemProfiler.
 921 double os::elapsedTime() {
 922 
 923   return (double)(os::elapsed_counter()) * 0.000001;
 924 }
 925 
 926 jlong os::elapsed_counter() {
 927   timeval time;
 928   int status = gettimeofday(&time, NULL);
 929   return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count;
 930 }
 931 
 932 jlong os::elapsed_frequency() {
 933   return (1000 * 1000);
 934 }
 935 
 936 // XXX: For now, code this as if BSD does not support vtime.
 937 bool os::supports_vtime() { return false; }
 938 bool os::enable_vtime()   { return false; }
 939 bool os::vtime_enabled()  { return false; }
 940 double os::elapsedVTime() {
 941   // better than nothing, but not much
 942   return elapsedTime();
 943 }
 944 
 945 jlong os::javaTimeMillis() {
 946   timeval time;
 947   int status = gettimeofday(&time, NULL);
 948   assert(status != -1, "bsd error");
 949   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 950 }
 951 
 952 #ifndef CLOCK_MONOTONIC
 953 #define CLOCK_MONOTONIC (1)
 954 #endif
 955 
 956 #ifdef __APPLE__
 957 void os::Bsd::clock_init() {
 958         // XXXDARWIN: Investigate replacement monotonic clock
 959 }
 960 #else
 961 void os::Bsd::clock_init() {
 962   struct timespec res;
 963   struct timespec tp;
 964   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
 965       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
 966     // yes, monotonic clock is supported
 967     _clock_gettime = ::clock_gettime;
 968   }
 969 }
 970 #endif
 971 
 972 
 973 jlong os::javaTimeNanos() {
 974   if (Bsd::supports_monotonic_clock()) {
 975     struct timespec tp;
 976     int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp);
 977     assert(status == 0, "gettime error");
 978     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
 979     return result;
 980   } else {
 981     timeval time;
 982     int status = gettimeofday(&time, NULL);
 983     assert(status != -1, "bsd error");
 984     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
 985     return 1000 * usecs;
 986   }
 987 }
 988 
 989 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
 990   if (Bsd::supports_monotonic_clock()) {
 991     info_ptr->max_value = ALL_64_BITS;
 992 
 993     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
 994     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
 995     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
 996   } else {
 997     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
 998     info_ptr->max_value = ALL_64_BITS;
 999 
1000     // gettimeofday is a real time clock so it skips
1001     info_ptr->may_skip_backward = true;
1002     info_ptr->may_skip_forward = true;
1003   }
1004 
1005   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
1006 }
1007 
1008 // Return the real, user, and system times in seconds from an
1009 // arbitrary fixed point in the past.
1010 bool os::getTimesSecs(double* process_real_time,
1011                       double* process_user_time,
1012                       double* process_system_time) {
1013   struct tms ticks;
1014   clock_t real_ticks = times(&ticks);
1015 
1016   if (real_ticks == (clock_t) (-1)) {
1017     return false;
1018   } else {
1019     double ticks_per_second = (double) clock_tics_per_sec;
1020     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1021     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1022     *process_real_time = ((double) real_ticks) / ticks_per_second;
1023 
1024     return true;
1025   }
1026 }
1027 
1028 
1029 char * os::local_time_string(char *buf, size_t buflen) {
1030   struct tm t;
1031   time_t long_time;
1032   time(&long_time);
1033   localtime_r(&long_time, &t);
1034   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1035                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1036                t.tm_hour, t.tm_min, t.tm_sec);
1037   return buf;
1038 }
1039 
1040 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1041   return localtime_r(clock, res);
1042 }
1043 
1044 ////////////////////////////////////////////////////////////////////////////////
1045 // runtime exit support
1046 
1047 // Note: os::shutdown() might be called very early during initialization, or
1048 // called from signal handler. Before adding something to os::shutdown(), make
1049 // sure it is async-safe and can handle partially initialized VM.
1050 void os::shutdown() {
1051 
1052   // allow PerfMemory to attempt cleanup of any persistent resources
1053   perfMemory_exit();
1054 
1055   // needs to remove object in file system
1056   AttachListener::abort();
1057 
1058   // flush buffered output, finish log files
1059   ostream_abort();
1060 
1061   // Check for abort hook
1062   abort_hook_t abort_hook = Arguments::abort_hook();
1063   if (abort_hook != NULL) {
1064     abort_hook();
1065   }
1066 
1067 }
1068 
1069 // Note: os::abort() might be called very early during initialization, or
1070 // called from signal handler. Before adding something to os::abort(), make
1071 // sure it is async-safe and can handle partially initialized VM.
1072 void os::abort(bool dump_core) {
1073   os::shutdown();
1074   if (dump_core) {
1075 #ifndef PRODUCT
1076     fdStream out(defaultStream::output_fd());
1077     out.print_raw("Current thread is ");
1078     char buf[16];
1079     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1080     out.print_raw_cr(buf);
1081     out.print_raw_cr("Dumping core ...");
1082 #endif
1083     ::abort(); // dump core
1084   }
1085 
1086   ::exit(1);
1087 }
1088 
1089 // Die immediately, no exit hook, no abort hook, no cleanup.
1090 void os::die() {
1091   // _exit() on BsdThreads only kills current thread
1092   ::abort();
1093 }
1094 
1095 // unused on bsd for now.
1096 void os::set_error_file(const char *logfile) {}
1097 
1098 
1099 // This method is a copy of JDK's sysGetLastErrorString
1100 // from src/solaris/hpi/src/system_md.c
1101 
1102 size_t os::lasterror(char *buf, size_t len) {
1103 
1104   if (errno == 0)  return 0;
1105 
1106   const char *s = ::strerror(errno);
1107   size_t n = ::strlen(s);
1108   if (n >= len) {
1109     n = len - 1;
1110   }
1111   ::strncpy(buf, s, n);
1112   buf[n] = '\0';
1113   return n;
1114 }
1115 
1116 intx os::current_thread_id() {
1117 #ifdef __APPLE__
1118   return (intx)::mach_thread_self();
1119 #else
1120   return (intx)::pthread_self();
1121 #endif
1122 }
1123 int os::current_process_id() {
1124 
1125   // Under the old bsd thread library, bsd gives each thread
1126   // its own process id. Because of this each thread will return
1127   // a different pid if this method were to return the result
1128   // of getpid(2). Bsd provides no api that returns the pid
1129   // of the launcher thread for the vm. This implementation
1130   // returns a unique pid, the pid of the launcher thread
1131   // that starts the vm 'process'.
1132 
1133   // Under the NPTL, getpid() returns the same pid as the
1134   // launcher thread rather than a unique pid per thread.
1135   // Use gettid() if you want the old pre NPTL behaviour.
1136 
1137   // if you are looking for the result of a call to getpid() that
1138   // returns a unique pid for the calling thread, then look at the
1139   // OSThread::thread_id() method in osThread_bsd.hpp file
1140 
1141   return (int)(_initial_pid ? _initial_pid : getpid());
1142 }
1143 
1144 // DLL functions
1145 
1146 #define JNI_LIB_PREFIX "lib"
1147 #ifdef __APPLE__
1148 #define JNI_LIB_SUFFIX ".dylib"
1149 #else
1150 #define JNI_LIB_SUFFIX ".so"
1151 #endif
1152 
1153 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1154 
1155 // This must be hard coded because it's the system's temporary
1156 // directory not the java application's temp directory, ala java.io.tmpdir.
1157 #ifdef __APPLE__
1158 // macosx has a secure per-user temporary directory
1159 char temp_path_storage[PATH_MAX];
1160 const char* os::get_temp_directory() {
1161   static char *temp_path = NULL;
1162   if (temp_path == NULL) {
1163     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1164     if (pathSize == 0 || pathSize > PATH_MAX) {
1165       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1166     }
1167     temp_path = temp_path_storage;
1168   }
1169   return temp_path;
1170 }
1171 #else /* __APPLE__ */
1172 const char* os::get_temp_directory() { return "/tmp"; }
1173 #endif /* __APPLE__ */
1174 
1175 static bool file_exists(const char* filename) {
1176   struct stat statbuf;
1177   if (filename == NULL || strlen(filename) == 0) {
1178     return false;
1179   }
1180   return os::stat(filename, &statbuf) == 0;
1181 }
1182 
1183 bool os::dll_build_name(char* buffer, size_t buflen,
1184                         const char* pname, const char* fname) {
1185   bool retval = false;
1186   // Copied from libhpi
1187   const size_t pnamelen = pname ? strlen(pname) : 0;
1188 
1189   // Return error on buffer overflow.
1190   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1191     return retval;
1192   }
1193 
1194   if (pnamelen == 0) {
1195     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1196     retval = true;
1197   } else if (strchr(pname, *os::path_separator()) != NULL) {
1198     int n;
1199     char** pelements = split_path(pname, &n);
1200     if (pelements == NULL) {
1201       return false;
1202     }
1203     for (int i = 0 ; i < n ; i++) {
1204       // Really shouldn't be NULL, but check can't hurt
1205       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1206         continue; // skip the empty path values
1207       }
1208       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1209           pelements[i], fname);
1210       if (file_exists(buffer)) {
1211         retval = true;
1212         break;
1213       }
1214     }
1215     // release the storage
1216     for (int i = 0 ; i < n ; i++) {
1217       if (pelements[i] != NULL) {
1218         FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
1219       }
1220     }
1221     if (pelements != NULL) {
1222       FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
1223     }
1224   } else {
1225     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1226     retval = true;
1227   }
1228   return retval;
1229 }
1230 
1231 // check if addr is inside libjvm.so
1232 bool os::address_is_in_vm(address addr) {
1233   static address libjvm_base_addr;
1234   Dl_info dlinfo;
1235 
1236   if (libjvm_base_addr == NULL) {
1237     dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo);
1238     libjvm_base_addr = (address)dlinfo.dli_fbase;
1239     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1240   }
1241 
1242   if (dladdr((void *)addr, &dlinfo)) {
1243     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1244   }
1245 
1246   return false;
1247 }
1248 
1249 
1250 #define MACH_MAXSYMLEN 256
1251 
1252 bool os::dll_address_to_function_name(address addr, char *buf,
1253                                       int buflen, int *offset) {
1254   Dl_info dlinfo;
1255   char localbuf[MACH_MAXSYMLEN];
1256 
1257   // dladdr will find names of dynamic functions only, but does
1258   // it set dli_fbase with mach_header address when it "fails" ?
1259   if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) {
1260     if (buf != NULL) {
1261       if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1262         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1263       }
1264     }
1265     if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1266     return true;
1267   } else if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != 0) {
1268     if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1269        buf, buflen, offset, dlinfo.dli_fname)) {
1270        return true;
1271     }
1272   }
1273 
1274   // Handle non-dymanic manually:
1275   if (dlinfo.dli_fbase != NULL &&
1276       Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
1277     if(!Decoder::demangle(localbuf, buf, buflen)) {
1278       jio_snprintf(buf, buflen, "%s", localbuf);
1279     }
1280     return true;
1281   }
1282   if (buf != NULL) buf[0] = '\0';
1283   if (offset != NULL) *offset = -1;
1284   return false;
1285 }
1286 
1287 // ported from solaris version
1288 bool os::dll_address_to_library_name(address addr, char* buf,
1289                                      int buflen, int* offset) {
1290   Dl_info dlinfo;
1291 
1292   if (dladdr((void*)addr, &dlinfo)){
1293      if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1294      if (offset) *offset = addr - (address)dlinfo.dli_fbase;
1295      return true;
1296   } else {
1297      if (buf) buf[0] = '\0';
1298      if (offset) *offset = -1;
1299      return false;
1300   }
1301 }
1302 
1303 // Loads .dll/.so and
1304 // in case of error it checks if .dll/.so was built for the
1305 // same architecture as Hotspot is running on
1306 
1307 #ifdef __APPLE__
1308 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1309   void * result= ::dlopen(filename, RTLD_LAZY);
1310   if (result != NULL) {
1311     // Successful loading
1312     return result;
1313   }
1314 
1315   // Read system error message into ebuf
1316   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1317   ebuf[ebuflen-1]='\0';
1318 
1319   return NULL;
1320 }
1321 #else
1322 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
1323 {
1324   void * result= ::dlopen(filename, RTLD_LAZY);
1325   if (result != NULL) {
1326     // Successful loading
1327     return result;
1328   }
1329 
1330   Elf32_Ehdr elf_head;
1331 
1332   // Read system error message into ebuf
1333   // It may or may not be overwritten below
1334   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1335   ebuf[ebuflen-1]='\0';
1336   int diag_msg_max_length=ebuflen-strlen(ebuf);
1337   char* diag_msg_buf=ebuf+strlen(ebuf);
1338 
1339   if (diag_msg_max_length==0) {
1340     // No more space in ebuf for additional diagnostics message
1341     return NULL;
1342   }
1343 
1344 
1345   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1346 
1347   if (file_descriptor < 0) {
1348     // Can't open library, report dlerror() message
1349     return NULL;
1350   }
1351 
1352   bool failed_to_read_elf_head=
1353     (sizeof(elf_head)!=
1354         (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
1355 
1356   ::close(file_descriptor);
1357   if (failed_to_read_elf_head) {
1358     // file i/o error - report dlerror() msg
1359     return NULL;
1360   }
1361 
1362   typedef struct {
1363     Elf32_Half  code;         // Actual value as defined in elf.h
1364     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1365     char        elf_class;    // 32 or 64 bit
1366     char        endianess;    // MSB or LSB
1367     char*       name;         // String representation
1368   } arch_t;
1369 
1370   #ifndef EM_486
1371   #define EM_486          6               /* Intel 80486 */
1372   #endif
1373 
1374   #ifndef EM_MIPS_RS3_LE
1375   #define EM_MIPS_RS3_LE  10              /* MIPS */
1376   #endif
1377 
1378   #ifndef EM_PPC64
1379   #define EM_PPC64        21              /* PowerPC64 */
1380   #endif
1381 
1382   #ifndef EM_S390
1383   #define EM_S390         22              /* IBM System/390 */
1384   #endif
1385 
1386   #ifndef EM_IA_64
1387   #define EM_IA_64        50              /* HP/Intel IA-64 */
1388   #endif
1389 
1390   #ifndef EM_X86_64
1391   #define EM_X86_64       62              /* AMD x86-64 */
1392   #endif
1393 
1394   static const arch_t arch_array[]={
1395     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1396     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1397     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1398     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1399     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1400     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1401     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1402     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1403     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1404     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1405     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1406     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1407     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1408     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1409     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1410     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1411   };
1412 
1413   #if  (defined IA32)
1414     static  Elf32_Half running_arch_code=EM_386;
1415   #elif   (defined AMD64)
1416     static  Elf32_Half running_arch_code=EM_X86_64;
1417   #elif  (defined IA64)
1418     static  Elf32_Half running_arch_code=EM_IA_64;
1419   #elif  (defined __sparc) && (defined _LP64)
1420     static  Elf32_Half running_arch_code=EM_SPARCV9;
1421   #elif  (defined __sparc) && (!defined _LP64)
1422     static  Elf32_Half running_arch_code=EM_SPARC;
1423   #elif  (defined __powerpc64__)
1424     static  Elf32_Half running_arch_code=EM_PPC64;
1425   #elif  (defined __powerpc__)
1426     static  Elf32_Half running_arch_code=EM_PPC;
1427   #elif  (defined ARM)
1428     static  Elf32_Half running_arch_code=EM_ARM;
1429   #elif  (defined S390)
1430     static  Elf32_Half running_arch_code=EM_S390;
1431   #elif  (defined ALPHA)
1432     static  Elf32_Half running_arch_code=EM_ALPHA;
1433   #elif  (defined MIPSEL)
1434     static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1435   #elif  (defined PARISC)
1436     static  Elf32_Half running_arch_code=EM_PARISC;
1437   #elif  (defined MIPS)
1438     static  Elf32_Half running_arch_code=EM_MIPS;
1439   #elif  (defined M68K)
1440     static  Elf32_Half running_arch_code=EM_68K;
1441   #else
1442     #error Method os::dll_load requires that one of following is defined:\
1443          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1444   #endif
1445 
1446   // Identify compatability class for VM's architecture and library's architecture
1447   // Obtain string descriptions for architectures
1448 
1449   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1450   int running_arch_index=-1;
1451 
1452   for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
1453     if (running_arch_code == arch_array[i].code) {
1454       running_arch_index    = i;
1455     }
1456     if (lib_arch.code == arch_array[i].code) {
1457       lib_arch.compat_class = arch_array[i].compat_class;
1458       lib_arch.name         = arch_array[i].name;
1459     }
1460   }
1461 
1462   assert(running_arch_index != -1,
1463     "Didn't find running architecture code (running_arch_code) in arch_array");
1464   if (running_arch_index == -1) {
1465     // Even though running architecture detection failed
1466     // we may still continue with reporting dlerror() message
1467     return NULL;
1468   }
1469 
1470   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1471     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1472     return NULL;
1473   }
1474 
1475 #ifndef S390
1476   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1477     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1478     return NULL;
1479   }
1480 #endif // !S390
1481 
1482   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1483     if ( lib_arch.name!=NULL ) {
1484       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1485         " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1486         lib_arch.name, arch_array[running_arch_index].name);
1487     } else {
1488       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1489       " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1490         lib_arch.code,
1491         arch_array[running_arch_index].name);
1492     }
1493   }
1494 
1495   return NULL;
1496 }
1497 #endif /* !__APPLE__ */
1498 
1499 // XXX: Do we need a lock around this as per Linux?
1500 void* os::dll_lookup(void* handle, const char* name) {
1501   return dlsym(handle, name);
1502 }
1503 
1504 
1505 static bool _print_ascii_file(const char* filename, outputStream* st) {
1506   int fd = ::open(filename, O_RDONLY);
1507   if (fd == -1) {
1508      return false;
1509   }
1510 
1511   char buf[32];
1512   int bytes;
1513   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1514     st->print_raw(buf, bytes);
1515   }
1516 
1517   ::close(fd);
1518 
1519   return true;
1520 }
1521 
1522 void os::print_dll_info(outputStream *st) {
1523    st->print_cr("Dynamic libraries:");
1524 #ifdef RTLD_DI_LINKMAP
1525     Dl_info dli;
1526     void *handle;
1527     Link_map *map;
1528     Link_map *p;
1529 
1530     if (!dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli)) {
1531         st->print_cr("Error: Cannot print dynamic libraries.");
1532         return;
1533     }
1534     handle = dlopen(dli.dli_fname, RTLD_LAZY);
1535     if (handle == NULL) {
1536         st->print_cr("Error: Cannot print dynamic libraries.");
1537         return;
1538     }
1539     dlinfo(handle, RTLD_DI_LINKMAP, &map);
1540     if (map == NULL) {
1541         st->print_cr("Error: Cannot print dynamic libraries.");
1542         return;
1543     }
1544 
1545     while (map->l_prev != NULL)
1546         map = map->l_prev;
1547 
1548     while (map != NULL) {
1549         st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
1550         map = map->l_next;
1551     }
1552 
1553     dlclose(handle);
1554 #elif defined(__APPLE__)
1555     uint32_t count;
1556     uint32_t i;
1557 
1558     count = _dyld_image_count();
1559     for (i = 1; i < count; i++) {
1560         const char *name = _dyld_get_image_name(i);
1561         intptr_t slide = _dyld_get_image_vmaddr_slide(i);
1562         st->print_cr(PTR_FORMAT " \t%s", slide, name);
1563     }
1564 #else
1565    st->print_cr("Error: Cannot print dynamic libraries.");
1566 #endif
1567 }
1568 
1569 void os::print_os_info_brief(outputStream* st) {
1570   st->print("Bsd");
1571 
1572   os::Posix::print_uname_info(st);
1573 }
1574 
1575 void os::print_os_info(outputStream* st) {
1576   st->print("OS:");
1577   st->print("Bsd");
1578 
1579   os::Posix::print_uname_info(st);
1580 
1581   os::Posix::print_rlimit_info(st);
1582 
1583   os::Posix::print_load_average(st);
1584 }
1585 
1586 void os::pd_print_cpu_info(outputStream* st) {
1587   // Nothing to do for now.
1588 }
1589 
1590 void os::print_memory_info(outputStream* st) {
1591 
1592   st->print("Memory:");
1593   st->print(" %dk page", os::vm_page_size()>>10);
1594 
1595   st->print(", physical " UINT64_FORMAT "k",
1596             os::physical_memory() >> 10);
1597   st->print("(" UINT64_FORMAT "k free)",
1598             os::available_memory() >> 10);
1599   st->cr();
1600 
1601   // meminfo
1602   st->print("\n/proc/meminfo:\n");
1603   _print_ascii_file("/proc/meminfo", st);
1604   st->cr();
1605 }
1606 
1607 // Taken from /usr/include/bits/siginfo.h  Supposed to be architecture specific
1608 // but they're the same for all the bsd arch that we support
1609 // and they're the same for solaris but there's no common place to put this.
1610 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
1611                           "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
1612                           "ILL_COPROC", "ILL_BADSTK" };
1613 
1614 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
1615                           "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
1616                           "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
1617 
1618 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
1619 
1620 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
1621 
1622 void os::print_siginfo(outputStream* st, void* siginfo) {
1623   st->print("siginfo:");
1624 
1625   const int buflen = 100;
1626   char buf[buflen];
1627   siginfo_t *si = (siginfo_t*)siginfo;
1628   st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
1629   if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
1630     st->print("si_errno=%s", buf);
1631   } else {
1632     st->print("si_errno=%d", si->si_errno);
1633   }
1634   const int c = si->si_code;
1635   assert(c > 0, "unexpected si_code");
1636   switch (si->si_signo) {
1637   case SIGILL:
1638     st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
1639     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1640     break;
1641   case SIGFPE:
1642     st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
1643     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1644     break;
1645   case SIGSEGV:
1646     st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
1647     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1648     break;
1649   case SIGBUS:
1650     st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
1651     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1652     break;
1653   default:
1654     st->print(", si_code=%d", si->si_code);
1655     // no si_addr
1656   }
1657 
1658   if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1659       UseSharedSpaces) {
1660     FileMapInfo* mapinfo = FileMapInfo::current_info();
1661     if (mapinfo->is_in_shared_space(si->si_addr)) {
1662       st->print("\n\nError accessing class data sharing archive."   \
1663                 " Mapped file inaccessible during execution, "      \
1664                 " possible disk/network problem.");
1665     }
1666   }
1667   st->cr();
1668 }
1669 
1670 
1671 static void print_signal_handler(outputStream* st, int sig,
1672                                  char* buf, size_t buflen);
1673 
1674 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1675   st->print_cr("Signal Handlers:");
1676   print_signal_handler(st, SIGSEGV, buf, buflen);
1677   print_signal_handler(st, SIGBUS , buf, buflen);
1678   print_signal_handler(st, SIGFPE , buf, buflen);
1679   print_signal_handler(st, SIGPIPE, buf, buflen);
1680   print_signal_handler(st, SIGXFSZ, buf, buflen);
1681   print_signal_handler(st, SIGILL , buf, buflen);
1682   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1683   print_signal_handler(st, SR_signum, buf, buflen);
1684   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1685   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1686   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1687   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1688 }
1689 
1690 static char saved_jvm_path[MAXPATHLEN] = {0};
1691 
1692 // Find the full path to the current module, libjvm
1693 void os::jvm_path(char *buf, jint buflen) {
1694   // Error checking.
1695   if (buflen < MAXPATHLEN) {
1696     assert(false, "must use a large-enough buffer");
1697     buf[0] = '\0';
1698     return;
1699   }
1700   // Lazy resolve the path to current module.
1701   if (saved_jvm_path[0] != 0) {
1702     strcpy(buf, saved_jvm_path);
1703     return;
1704   }
1705 
1706   char dli_fname[MAXPATHLEN];
1707   bool ret = dll_address_to_library_name(
1708                 CAST_FROM_FN_PTR(address, os::jvm_path),
1709                 dli_fname, sizeof(dli_fname), NULL);
1710   assert(ret != 0, "cannot locate libjvm");
1711   char *rp = realpath(dli_fname, buf);
1712   if (rp == NULL)
1713     return;
1714 
1715   if (Arguments::created_by_gamma_launcher()) {
1716     // Support for the gamma launcher.  Typical value for buf is
1717     // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm".  If "/jre/lib/" appears at
1718     // the right place in the string, then assume we are installed in a JDK and
1719     // we're done.  Otherwise, check for a JAVA_HOME environment variable and
1720     // construct a path to the JVM being overridden.
1721 
1722     const char *p = buf + strlen(buf) - 1;
1723     for (int count = 0; p > buf && count < 5; ++count) {
1724       for (--p; p > buf && *p != '/'; --p)
1725         /* empty */ ;
1726     }
1727 
1728     if (strncmp(p, "/jre/lib/", 9) != 0) {
1729       // Look for JAVA_HOME in the environment.
1730       char* java_home_var = ::getenv("JAVA_HOME");
1731       if (java_home_var != NULL && java_home_var[0] != 0) {
1732         char* jrelib_p;
1733         int len;
1734 
1735         // Check the current module name "libjvm"
1736         p = strrchr(buf, '/');
1737         assert(strstr(p, "/libjvm") == p, "invalid library name");
1738 
1739         rp = realpath(java_home_var, buf);
1740         if (rp == NULL)
1741           return;
1742 
1743         // determine if this is a legacy image or modules image
1744         // modules image doesn't have "jre" subdirectory
1745         len = strlen(buf);
1746         jrelib_p = buf + len;
1747 
1748         // Add the appropriate library subdir
1749         snprintf(jrelib_p, buflen-len, "/jre/lib");
1750         if (0 != access(buf, F_OK)) {
1751           snprintf(jrelib_p, buflen-len, "/lib");
1752         }
1753 
1754         // Add the appropriate client or server subdir
1755         len = strlen(buf);
1756         jrelib_p = buf + len;
1757         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1758         if (0 != access(buf, F_OK)) {
1759           snprintf(jrelib_p, buflen-len, "");
1760         }
1761 
1762         // If the path exists within JAVA_HOME, add the JVM library name
1763         // to complete the path to JVM being overridden.  Otherwise fallback
1764         // to the path to the current library.
1765         if (0 == access(buf, F_OK)) {
1766           // Use current module name "libjvm"
1767           len = strlen(buf);
1768           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1769         } else {
1770           // Fall back to path of current library
1771           rp = realpath(dli_fname, buf);
1772           if (rp == NULL)
1773             return;
1774         }
1775       }
1776     }
1777   }
1778 
1779   strcpy(saved_jvm_path, buf);
1780 }
1781 
1782 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1783   // no prefix required, not even "_"
1784 }
1785 
1786 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1787   // no suffix required
1788 }
1789 
1790 ////////////////////////////////////////////////////////////////////////////////
1791 // sun.misc.Signal support
1792 
1793 static volatile jint sigint_count = 0;
1794 
1795 static void
1796 UserHandler(int sig, void *siginfo, void *context) {
1797   // 4511530 - sem_post is serialized and handled by the manager thread. When
1798   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1799   // don't want to flood the manager thread with sem_post requests.
1800   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
1801       return;
1802 
1803   // Ctrl-C is pressed during error reporting, likely because the error
1804   // handler fails to abort. Let VM die immediately.
1805   if (sig == SIGINT && is_error_reported()) {
1806      os::die();
1807   }
1808 
1809   os::signal_notify(sig);
1810 }
1811 
1812 void* os::user_handler() {
1813   return CAST_FROM_FN_PTR(void*, UserHandler);
1814 }
1815 
1816 extern "C" {
1817   typedef void (*sa_handler_t)(int);
1818   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1819 }
1820 
1821 void* os::signal(int signal_number, void* handler) {
1822   struct sigaction sigAct, oldSigAct;
1823 
1824   sigfillset(&(sigAct.sa_mask));
1825   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1826   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1827 
1828   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1829     // -1 means registration failed
1830     return (void *)-1;
1831   }
1832 
1833   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1834 }
1835 
1836 void os::signal_raise(int signal_number) {
1837   ::raise(signal_number);
1838 }
1839 
1840 /*
1841  * The following code is moved from os.cpp for making this
1842  * code platform specific, which it is by its very nature.
1843  */
1844 
1845 // Will be modified when max signal is changed to be dynamic
1846 int os::sigexitnum_pd() {
1847   return NSIG;
1848 }
1849 
1850 // a counter for each possible signal value
1851 static volatile jint pending_signals[NSIG+1] = { 0 };
1852 
1853 // Bsd(POSIX) specific hand shaking semaphore.
1854 #ifdef __APPLE__
1855 static semaphore_t sig_sem;
1856 #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1857 #define SEM_WAIT(sem)           semaphore_wait(sem);
1858 #define SEM_POST(sem)           semaphore_signal(sem);
1859 #else
1860 static sem_t sig_sem;
1861 #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
1862 #define SEM_WAIT(sem)           sem_wait(&sem);
1863 #define SEM_POST(sem)           sem_post(&sem);
1864 #endif
1865 
1866 void os::signal_init_pd() {
1867   // Initialize signal structures
1868   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1869 
1870   // Initialize signal semaphore
1871   ::SEM_INIT(sig_sem, 0);
1872 }
1873 
1874 void os::signal_notify(int sig) {
1875   Atomic::inc(&pending_signals[sig]);
1876   ::SEM_POST(sig_sem);
1877 }
1878 
1879 static int check_pending_signals(bool wait) {
1880   Atomic::store(0, &sigint_count);
1881   for (;;) {
1882     for (int i = 0; i < NSIG + 1; i++) {
1883       jint n = pending_signals[i];
1884       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1885         return i;
1886       }
1887     }
1888     if (!wait) {
1889       return -1;
1890     }
1891     JavaThread *thread = JavaThread::current();
1892     ThreadBlockInVM tbivm(thread);
1893 
1894     bool threadIsSuspended;
1895     do {
1896       thread->set_suspend_equivalent();
1897       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1898       ::SEM_WAIT(sig_sem);
1899 
1900       // were we externally suspended while we were waiting?
1901       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1902       if (threadIsSuspended) {
1903         //
1904         // The semaphore has been incremented, but while we were waiting
1905         // another thread suspended us. We don't want to continue running
1906         // while suspended because that would surprise the thread that
1907         // suspended us.
1908         //
1909         ::SEM_POST(sig_sem);
1910 
1911         thread->java_suspend_self();
1912       }
1913     } while (threadIsSuspended);
1914   }
1915 }
1916 
1917 int os::signal_lookup() {
1918   return check_pending_signals(false);
1919 }
1920 
1921 int os::signal_wait() {
1922   return check_pending_signals(true);
1923 }
1924 
1925 ////////////////////////////////////////////////////////////////////////////////
1926 // Virtual Memory
1927 
1928 int os::vm_page_size() {
1929   // Seems redundant as all get out
1930   assert(os::Bsd::page_size() != -1, "must call os::init");
1931   return os::Bsd::page_size();
1932 }
1933 
1934 // Solaris allocates memory by pages.
1935 int os::vm_allocation_granularity() {
1936   assert(os::Bsd::page_size() != -1, "must call os::init");
1937   return os::Bsd::page_size();
1938 }
1939 
1940 // Rationale behind this function:
1941 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
1942 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
1943 //  samples for JITted code. Here we create private executable mapping over the code cache
1944 //  and then we can use standard (well, almost, as mapping can change) way to provide
1945 //  info for the reporting script by storing timestamp and location of symbol
1946 void bsd_wrap_code(char* base, size_t size) {
1947   static volatile jint cnt = 0;
1948 
1949   if (!UseOprofile) {
1950     return;
1951   }
1952 
1953   char buf[PATH_MAX + 1];
1954   int num = Atomic::add(1, &cnt);
1955 
1956   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
1957            os::get_temp_directory(), os::current_process_id(), num);
1958   unlink(buf);
1959 
1960   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
1961 
1962   if (fd != -1) {
1963     off_t rv = ::lseek(fd, size-2, SEEK_SET);
1964     if (rv != (off_t)-1) {
1965       if (::write(fd, "", 1) == 1) {
1966         mmap(base, size,
1967              PROT_READ|PROT_WRITE|PROT_EXEC,
1968              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
1969       }
1970     }
1971     ::close(fd);
1972     unlink(buf);
1973   }
1974 }
1975 
1976 // NOTE: Bsd kernel does not really reserve the pages for us.
1977 //       All it does is to check if there are enough free pages
1978 //       left at the time of mmap(). This could be a potential
1979 //       problem.
1980 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
1981   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
1982 #ifdef __OpenBSD__
1983   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
1984   return ::mprotect(addr, size, prot) == 0;
1985 #else
1986   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
1987                                    MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
1988   return res != (uintptr_t) MAP_FAILED;
1989 #endif
1990 }
1991 
1992 
1993 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
1994                        bool exec) {
1995   return commit_memory(addr, size, exec);
1996 }
1997 
1998 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1999 }
2000 
2001 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2002   ::madvise(addr, bytes, MADV_DONTNEED);
2003 }
2004 
2005 void os::numa_make_global(char *addr, size_t bytes) {
2006 }
2007 
2008 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2009 }
2010 
2011 bool os::numa_topology_changed()   { return false; }
2012 
2013 size_t os::numa_get_groups_num() {
2014   return 1;
2015 }
2016 
2017 int os::numa_get_group_id() {
2018   return 0;
2019 }
2020 
2021 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2022   if (size > 0) {
2023     ids[0] = 0;
2024     return 1;
2025   }
2026   return 0;
2027 }
2028 
2029 bool os::get_page_info(char *start, page_info* info) {
2030   return false;
2031 }
2032 
2033 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2034   return end;
2035 }
2036 
2037 
2038 bool os::pd_uncommit_memory(char* addr, size_t size) {
2039 #ifdef __OpenBSD__
2040   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2041   return ::mprotect(addr, size, PROT_NONE) == 0;
2042 #else
2043   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2044                 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2045   return res  != (uintptr_t) MAP_FAILED;
2046 #endif
2047 }
2048 
2049 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2050   return os::commit_memory(addr, size);
2051 }
2052 
2053 // If this is a growable mapping, remove the guard pages entirely by
2054 // munmap()ping them.  If not, just call uncommit_memory().
2055 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2056   return os::uncommit_memory(addr, size);
2057 }
2058 
2059 static address _highest_vm_reserved_address = NULL;
2060 
2061 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2062 // at 'requested_addr'. If there are existing memory mappings at the same
2063 // location, however, they will be overwritten. If 'fixed' is false,
2064 // 'requested_addr' is only treated as a hint, the return value may or
2065 // may not start from the requested address. Unlike Bsd mmap(), this
2066 // function returns NULL to indicate failure.
2067 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2068   char * addr;
2069   int flags;
2070 
2071   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2072   if (fixed) {
2073     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2074     flags |= MAP_FIXED;
2075   }
2076 
2077   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2078   // touch an uncommitted page. Otherwise, the read/write might
2079   // succeed if we have enough swap space to back the physical page.
2080   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2081                        flags, -1, 0);
2082 
2083   if (addr != MAP_FAILED) {
2084     // anon_mmap() should only get called during VM initialization,
2085     // don't need lock (actually we can skip locking even it can be called
2086     // from multiple threads, because _highest_vm_reserved_address is just a
2087     // hint about the upper limit of non-stack memory regions.)
2088     if ((address)addr + bytes > _highest_vm_reserved_address) {
2089       _highest_vm_reserved_address = (address)addr + bytes;
2090     }
2091   }
2092 
2093   return addr == MAP_FAILED ? NULL : addr;
2094 }
2095 
2096 // Don't update _highest_vm_reserved_address, because there might be memory
2097 // regions above addr + size. If so, releasing a memory region only creates
2098 // a hole in the address space, it doesn't help prevent heap-stack collision.
2099 //
2100 static int anon_munmap(char * addr, size_t size) {
2101   return ::munmap(addr, size) == 0;
2102 }
2103 
2104 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2105                          size_t alignment_hint) {
2106   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2107 }
2108 
2109 bool os::pd_release_memory(char* addr, size_t size) {
2110   return anon_munmap(addr, size);
2111 }
2112 
2113 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2114   // Bsd wants the mprotect address argument to be page aligned.
2115   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2116 
2117   // According to SUSv3, mprotect() should only be used with mappings
2118   // established by mmap(), and mmap() always maps whole pages. Unaligned
2119   // 'addr' likely indicates problem in the VM (e.g. trying to change
2120   // protection of malloc'ed or statically allocated memory). Check the
2121   // caller if you hit this assert.
2122   assert(addr == bottom, "sanity check");
2123 
2124   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2125   return ::mprotect(bottom, size, prot) == 0;
2126 }
2127 
2128 // Set protections specified
2129 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2130                         bool is_committed) {
2131   unsigned int p = 0;
2132   switch (prot) {
2133   case MEM_PROT_NONE: p = PROT_NONE; break;
2134   case MEM_PROT_READ: p = PROT_READ; break;
2135   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2136   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2137   default:
2138     ShouldNotReachHere();
2139   }
2140   // is_committed is unused.
2141   return bsd_mprotect(addr, bytes, p);
2142 }
2143 
2144 bool os::guard_memory(char* addr, size_t size) {
2145   return bsd_mprotect(addr, size, PROT_NONE);
2146 }
2147 
2148 bool os::unguard_memory(char* addr, size_t size) {
2149   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2150 }
2151 
2152 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2153   return false;
2154 }
2155 
2156 // Large page support
2157 
2158 static size_t _large_page_size = 0;
2159 
2160 void os::large_page_init() {
2161 }
2162 
2163 
2164 char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) {
2165   // "exec" is passed in but not used.  Creating the shared image for
2166   // the code cache doesn't have an SHM_X executable permission to check.
2167   assert(UseLargePages && UseSHM, "only for SHM large pages");
2168 
2169   key_t key = IPC_PRIVATE;
2170   char *addr;
2171 
2172   bool warn_on_failure = UseLargePages &&
2173                         (!FLAG_IS_DEFAULT(UseLargePages) ||
2174                          !FLAG_IS_DEFAULT(LargePageSizeInBytes)
2175                         );
2176   char msg[128];
2177 
2178   // Create a large shared memory region to attach to based on size.
2179   // Currently, size is the total size of the heap
2180   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2181   if (shmid == -1) {
2182      // Possible reasons for shmget failure:
2183      // 1. shmmax is too small for Java heap.
2184      //    > check shmmax value: cat /proc/sys/kernel/shmmax
2185      //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2186      // 2. not enough large page memory.
2187      //    > check available large pages: cat /proc/meminfo
2188      //    > increase amount of large pages:
2189      //          echo new_value > /proc/sys/vm/nr_hugepages
2190      //      Note 1: different Bsd may use different name for this property,
2191      //            e.g. on Redhat AS-3 it is "hugetlb_pool".
2192      //      Note 2: it's possible there's enough physical memory available but
2193      //            they are so fragmented after a long run that they can't
2194      //            coalesce into large pages. Try to reserve large pages when
2195      //            the system is still "fresh".
2196      if (warn_on_failure) {
2197        jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
2198        warning(msg);
2199      }
2200      return NULL;
2201   }
2202 
2203   // attach to the region
2204   addr = (char*)shmat(shmid, req_addr, 0);
2205   int err = errno;
2206 
2207   // Remove shmid. If shmat() is successful, the actual shared memory segment
2208   // will be deleted when it's detached by shmdt() or when the process
2209   // terminates. If shmat() is not successful this will remove the shared
2210   // segment immediately.
2211   shmctl(shmid, IPC_RMID, NULL);
2212 
2213   if ((intptr_t)addr == -1) {
2214      if (warn_on_failure) {
2215        jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
2216        warning(msg);
2217      }
2218      return NULL;
2219   }
2220 
2221   // The memory is committed
2222   address pc = CALLER_PC;
2223   MemTracker::record_virtual_memory_reserve((address)addr, bytes, pc);
2224   MemTracker::record_virtual_memory_commit((address)addr, bytes, pc);
2225 
2226   return addr;
2227 }
2228 
2229 bool os::release_memory_special(char* base, size_t bytes) {
2230   // detaching the SHM segment will also delete it, see reserve_memory_special()
2231   int rslt = shmdt(base);
2232   if (rslt == 0) {
2233     MemTracker::record_virtual_memory_uncommit((address)base, bytes);
2234     MemTracker::record_virtual_memory_release((address)base, bytes);
2235     return true;
2236   } else {
2237     return false;
2238   }
2239 
2240 }
2241 
2242 size_t os::large_page_size() {
2243   return _large_page_size;
2244 }
2245 
2246 // HugeTLBFS allows application to commit large page memory on demand;
2247 // with SysV SHM the entire memory region must be allocated as shared
2248 // memory.
2249 bool os::can_commit_large_page_memory() {
2250   return UseHugeTLBFS;
2251 }
2252 
2253 bool os::can_execute_large_page_memory() {
2254   return UseHugeTLBFS;
2255 }
2256 
2257 // Reserve memory at an arbitrary address, only if that area is
2258 // available (and not reserved for something else).
2259 
2260 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2261   const int max_tries = 10;
2262   char* base[max_tries];
2263   size_t size[max_tries];
2264   const size_t gap = 0x000000;
2265 
2266   // Assert only that the size is a multiple of the page size, since
2267   // that's all that mmap requires, and since that's all we really know
2268   // about at this low abstraction level.  If we need higher alignment,
2269   // we can either pass an alignment to this method or verify alignment
2270   // in one of the methods further up the call chain.  See bug 5044738.
2271   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2272 
2273   // Repeatedly allocate blocks until the block is allocated at the
2274   // right spot. Give up after max_tries. Note that reserve_memory() will
2275   // automatically update _highest_vm_reserved_address if the call is
2276   // successful. The variable tracks the highest memory address every reserved
2277   // by JVM. It is used to detect heap-stack collision if running with
2278   // fixed-stack BsdThreads. Because here we may attempt to reserve more
2279   // space than needed, it could confuse the collision detecting code. To
2280   // solve the problem, save current _highest_vm_reserved_address and
2281   // calculate the correct value before return.
2282   address old_highest = _highest_vm_reserved_address;
2283 
2284   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2285   // if kernel honors the hint then we can return immediately.
2286   char * addr = anon_mmap(requested_addr, bytes, false);
2287   if (addr == requested_addr) {
2288      return requested_addr;
2289   }
2290 
2291   if (addr != NULL) {
2292      // mmap() is successful but it fails to reserve at the requested address
2293      anon_munmap(addr, bytes);
2294   }
2295 
2296   int i;
2297   for (i = 0; i < max_tries; ++i) {
2298     base[i] = reserve_memory(bytes);
2299 
2300     if (base[i] != NULL) {
2301       // Is this the block we wanted?
2302       if (base[i] == requested_addr) {
2303         size[i] = bytes;
2304         break;
2305       }
2306 
2307       // Does this overlap the block we wanted? Give back the overlapped
2308       // parts and try again.
2309 
2310       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2311       if (top_overlap >= 0 && top_overlap < bytes) {
2312         unmap_memory(base[i], top_overlap);
2313         base[i] += top_overlap;
2314         size[i] = bytes - top_overlap;
2315       } else {
2316         size_t bottom_overlap = base[i] + bytes - requested_addr;
2317         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2318           unmap_memory(requested_addr, bottom_overlap);
2319           size[i] = bytes - bottom_overlap;
2320         } else {
2321           size[i] = bytes;
2322         }
2323       }
2324     }
2325   }
2326 
2327   // Give back the unused reserved pieces.
2328 
2329   for (int j = 0; j < i; ++j) {
2330     if (base[j] != NULL) {
2331       unmap_memory(base[j], size[j]);
2332     }
2333   }
2334 
2335   if (i < max_tries) {
2336     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2337     return requested_addr;
2338   } else {
2339     _highest_vm_reserved_address = old_highest;
2340     return NULL;
2341   }
2342 }
2343 
2344 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2345   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2346 }
2347 
2348 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
2349 // Solaris uses poll(), bsd uses park().
2350 // Poll() is likely a better choice, assuming that Thread.interrupt()
2351 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
2352 // SIGSEGV, see 4355769.
2353 
2354 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
2355   assert(thread == Thread::current(),  "thread consistency check");
2356 
2357   ParkEvent * const slp = thread->_SleepEvent ;
2358   slp->reset() ;
2359   OrderAccess::fence() ;
2360 
2361   if (interruptible) {
2362     jlong prevtime = javaTimeNanos();
2363 
2364     for (;;) {
2365       if (os::is_interrupted(thread, true)) {
2366         return OS_INTRPT;
2367       }
2368 
2369       jlong newtime = javaTimeNanos();
2370 
2371       if (newtime - prevtime < 0) {
2372         // time moving backwards, should only happen if no monotonic clock
2373         // not a guarantee() because JVM should not abort on kernel/glibc bugs
2374         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2375       } else {
2376         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2377       }
2378 
2379       if(millis <= 0) {
2380         return OS_OK;
2381       }
2382 
2383       prevtime = newtime;
2384 
2385       {
2386         assert(thread->is_Java_thread(), "sanity check");
2387         JavaThread *jt = (JavaThread *) thread;
2388         ThreadBlockInVM tbivm(jt);
2389         OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
2390 
2391         jt->set_suspend_equivalent();
2392         // cleared by handle_special_suspend_equivalent_condition() or
2393         // java_suspend_self() via check_and_wait_while_suspended()
2394 
2395         slp->park(millis);
2396 
2397         // were we externally suspended while we were waiting?
2398         jt->check_and_wait_while_suspended();
2399       }
2400     }
2401   } else {
2402     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2403     jlong prevtime = javaTimeNanos();
2404 
2405     for (;;) {
2406       // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
2407       // the 1st iteration ...
2408       jlong newtime = javaTimeNanos();
2409 
2410       if (newtime - prevtime < 0) {
2411         // time moving backwards, should only happen if no monotonic clock
2412         // not a guarantee() because JVM should not abort on kernel/glibc bugs
2413         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2414       } else {
2415         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2416       }
2417 
2418       if(millis <= 0) break ;
2419 
2420       prevtime = newtime;
2421       slp->park(millis);
2422     }
2423     return OS_OK ;
2424   }
2425 }
2426 
2427 int os::naked_sleep() {
2428   // %% make the sleep time an integer flag. for now use 1 millisec.
2429   return os::sleep(Thread::current(), 1, false);
2430 }
2431 
2432 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2433 void os::infinite_sleep() {
2434   while (true) {    // sleep forever ...
2435     ::sleep(100);   // ... 100 seconds at a time
2436   }
2437 }
2438 
2439 // Used to convert frequent JVM_Yield() to nops
2440 bool os::dont_yield() {
2441   return DontYieldALot;
2442 }
2443 
2444 void os::yield() {
2445   sched_yield();
2446 }
2447 
2448 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
2449 
2450 void os::yield_all(int attempts) {
2451   // Yields to all threads, including threads with lower priorities
2452   // Threads on Bsd are all with same priority. The Solaris style
2453   // os::yield_all() with nanosleep(1ms) is not necessary.
2454   sched_yield();
2455 }
2456 
2457 // Called from the tight loops to possibly influence time-sharing heuristics
2458 void os::loop_breaker(int attempts) {
2459   os::yield_all(attempts);
2460 }
2461 
2462 ////////////////////////////////////////////////////////////////////////////////
2463 // thread priority support
2464 
2465 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2466 // only supports dynamic priority, static priority must be zero. For real-time
2467 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2468 // However, for large multi-threaded applications, SCHED_RR is not only slower
2469 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2470 // of 5 runs - Sep 2005).
2471 //
2472 // The following code actually changes the niceness of kernel-thread/LWP. It
2473 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2474 // not the entire user process, and user level threads are 1:1 mapped to kernel
2475 // threads. It has always been the case, but could change in the future. For
2476 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2477 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2478 
2479 #if !defined(__APPLE__)
2480 int os::java_to_os_priority[CriticalPriority + 1] = {
2481   19,              // 0 Entry should never be used
2482 
2483    0,              // 1 MinPriority
2484    3,              // 2
2485    6,              // 3
2486 
2487   10,              // 4
2488   15,              // 5 NormPriority
2489   18,              // 6
2490 
2491   21,              // 7
2492   25,              // 8
2493   28,              // 9 NearMaxPriority
2494 
2495   31,              // 10 MaxPriority
2496 
2497   31               // 11 CriticalPriority
2498 };
2499 #else
2500 /* Using Mach high-level priority assignments */
2501 int os::java_to_os_priority[CriticalPriority + 1] = {
2502    0,              // 0 Entry should never be used (MINPRI_USER)
2503 
2504   27,              // 1 MinPriority
2505   28,              // 2
2506   29,              // 3
2507 
2508   30,              // 4
2509   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2510   32,              // 6
2511 
2512   33,              // 7
2513   34,              // 8
2514   35,              // 9 NearMaxPriority
2515 
2516   36,              // 10 MaxPriority
2517 
2518   36               // 11 CriticalPriority
2519 };
2520 #endif
2521 
2522 static int prio_init() {
2523   if (ThreadPriorityPolicy == 1) {
2524     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2525     // if effective uid is not root. Perhaps, a more elegant way of doing
2526     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2527     if (geteuid() != 0) {
2528       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2529         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2530       }
2531       ThreadPriorityPolicy = 0;
2532     }
2533   }
2534   if (UseCriticalJavaThreadPriority) {
2535     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2536   }
2537   return 0;
2538 }
2539 
2540 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2541   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
2542 
2543 #ifdef __OpenBSD__
2544   // OpenBSD pthread_setprio starves low priority threads
2545   return OS_OK;
2546 #elif defined(__FreeBSD__)
2547   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2548 #elif defined(__APPLE__) || defined(__NetBSD__)
2549   struct sched_param sp;
2550   int policy;
2551   pthread_t self = pthread_self();
2552 
2553   if (pthread_getschedparam(self, &policy, &sp) != 0)
2554     return OS_ERR;
2555 
2556   sp.sched_priority = newpri;
2557   if (pthread_setschedparam(self, policy, &sp) != 0)
2558     return OS_ERR;
2559 
2560   return OS_OK;
2561 #else
2562   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2563   return (ret == 0) ? OS_OK : OS_ERR;
2564 #endif
2565 }
2566 
2567 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2568   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
2569     *priority_ptr = java_to_os_priority[NormPriority];
2570     return OS_OK;
2571   }
2572 
2573   errno = 0;
2574 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2575   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2576 #elif defined(__APPLE__) || defined(__NetBSD__)
2577   int policy;
2578   struct sched_param sp;
2579 
2580   pthread_getschedparam(pthread_self(), &policy, &sp);
2581   *priority_ptr = sp.sched_priority;
2582 #else
2583   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2584 #endif
2585   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2586 }
2587 
2588 // Hint to the underlying OS that a task switch would not be good.
2589 // Void return because it's a hint and can fail.
2590 void os::hint_no_preempt() {}
2591 
2592 ////////////////////////////////////////////////////////////////////////////////
2593 // suspend/resume support
2594 
2595 //  the low-level signal-based suspend/resume support is a remnant from the
2596 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2597 //  within hotspot. Now there is a single use-case for this:
2598 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
2599 //      that runs in the watcher thread.
2600 //  The remaining code is greatly simplified from the more general suspension
2601 //  code that used to be used.
2602 //
2603 //  The protocol is quite simple:
2604 //  - suspend:
2605 //      - sends a signal to the target thread
2606 //      - polls the suspend state of the osthread using a yield loop
2607 //      - target thread signal handler (SR_handler) sets suspend state
2608 //        and blocks in sigsuspend until continued
2609 //  - resume:
2610 //      - sets target osthread state to continue
2611 //      - sends signal to end the sigsuspend loop in the SR_handler
2612 //
2613 //  Note that the SR_lock plays no role in this suspend/resume protocol.
2614 //
2615 
2616 static void resume_clear_context(OSThread *osthread) {
2617   osthread->set_ucontext(NULL);
2618   osthread->set_siginfo(NULL);
2619 
2620   // notify the suspend action is completed, we have now resumed
2621   osthread->sr.clear_suspended();
2622 }
2623 
2624 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2625   osthread->set_ucontext(context);
2626   osthread->set_siginfo(siginfo);
2627 }
2628 
2629 //
2630 // Handler function invoked when a thread's execution is suspended or
2631 // resumed. We have to be careful that only async-safe functions are
2632 // called here (Note: most pthread functions are not async safe and
2633 // should be avoided.)
2634 //
2635 // Note: sigwait() is a more natural fit than sigsuspend() from an
2636 // interface point of view, but sigwait() prevents the signal hander
2637 // from being run. libpthread would get very confused by not having
2638 // its signal handlers run and prevents sigwait()'s use with the
2639 // mutex granting granting signal.
2640 //
2641 // Currently only ever called on the VMThread
2642 //
2643 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2644   // Save and restore errno to avoid confusing native code with EINTR
2645   // after sigsuspend.
2646   int old_errno = errno;
2647 
2648   Thread* thread = Thread::current();
2649   OSThread* osthread = thread->osthread();
2650   assert(thread->is_VM_thread(), "Must be VMThread");
2651   // read current suspend action
2652   int action = osthread->sr.suspend_action();
2653   if (action == os::Bsd::SuspendResume::SR_SUSPEND) {
2654     suspend_save_context(osthread, siginfo, context);
2655 
2656     // Notify the suspend action is about to be completed. do_suspend()
2657     // waits until SR_SUSPENDED is set and then returns. We will wait
2658     // here for a resume signal and that completes the suspend-other
2659     // action. do_suspend/do_resume is always called as a pair from
2660     // the same thread - so there are no races
2661 
2662     // notify the caller
2663     osthread->sr.set_suspended();
2664 
2665     sigset_t suspend_set;  // signals for sigsuspend()
2666 
2667     // get current set of blocked signals and unblock resume signal
2668     pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2669     sigdelset(&suspend_set, SR_signum);
2670 
2671     // wait here until we are resumed
2672     do {
2673       sigsuspend(&suspend_set);
2674       // ignore all returns until we get a resume signal
2675     } while (osthread->sr.suspend_action() != os::Bsd::SuspendResume::SR_CONTINUE);
2676 
2677     resume_clear_context(osthread);
2678 
2679   } else {
2680     assert(action == os::Bsd::SuspendResume::SR_CONTINUE, "unexpected sr action");
2681     // nothing special to do - just leave the handler
2682   }
2683 
2684   errno = old_errno;
2685 }
2686 
2687 
2688 static int SR_initialize() {
2689   struct sigaction act;
2690   char *s;
2691   /* Get signal number to use for suspend/resume */
2692   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2693     int sig = ::strtol(s, 0, 10);
2694     if (sig > 0 || sig < NSIG) {
2695         SR_signum = sig;
2696     }
2697   }
2698 
2699   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2700         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2701 
2702   sigemptyset(&SR_sigset);
2703   sigaddset(&SR_sigset, SR_signum);
2704 
2705   /* Set up signal handler for suspend/resume */
2706   act.sa_flags = SA_RESTART|SA_SIGINFO;
2707   act.sa_handler = (void (*)(int)) SR_handler;
2708 
2709   // SR_signum is blocked by default.
2710   // 4528190 - We also need to block pthread restart signal (32 on all
2711   // supported Bsd platforms). Note that BsdThreads need to block
2712   // this signal for all threads to work properly. So we don't have
2713   // to use hard-coded signal number when setting up the mask.
2714   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2715 
2716   if (sigaction(SR_signum, &act, 0) == -1) {
2717     return -1;
2718   }
2719 
2720   // Save signal flag
2721   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2722   return 0;
2723 }
2724 
2725 
2726 // returns true on success and false on error - really an error is fatal
2727 // but this seems the normal response to library errors
2728 static bool do_suspend(OSThread* osthread) {
2729   // mark as suspended and send signal
2730   osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_SUSPEND);
2731   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2732   assert_status(status == 0, status, "pthread_kill");
2733 
2734   // check status and wait until notified of suspension
2735   if (status == 0) {
2736     for (int i = 0; !osthread->sr.is_suspended(); i++) {
2737       os::yield_all(i);
2738     }
2739     osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
2740     return true;
2741   }
2742   else {
2743     osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
2744     return false;
2745   }
2746 }
2747 
2748 static void do_resume(OSThread* osthread) {
2749   assert(osthread->sr.is_suspended(), "thread should be suspended");
2750   osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_CONTINUE);
2751 
2752   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2753   assert_status(status == 0, status, "pthread_kill");
2754   // check status and wait unit notified of resumption
2755   if (status == 0) {
2756     for (int i = 0; osthread->sr.is_suspended(); i++) {
2757       os::yield_all(i);
2758     }
2759   }
2760   osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
2761 }
2762 
2763 ////////////////////////////////////////////////////////////////////////////////
2764 // interrupt support
2765 
2766 void os::interrupt(Thread* thread) {
2767   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
2768     "possibility of dangling Thread pointer");
2769 
2770   OSThread* osthread = thread->osthread();
2771 
2772   if (!osthread->interrupted()) {
2773     osthread->set_interrupted(true);
2774     // More than one thread can get here with the same value of osthread,
2775     // resulting in multiple notifications.  We do, however, want the store
2776     // to interrupted() to be visible to other threads before we execute unpark().
2777     OrderAccess::fence();
2778     ParkEvent * const slp = thread->_SleepEvent ;
2779     if (slp != NULL) slp->unpark() ;
2780   }
2781 
2782   // For JSR166. Unpark even if interrupt status already was set
2783   if (thread->is_Java_thread())
2784     ((JavaThread*)thread)->parker()->unpark();
2785 
2786   ParkEvent * ev = thread->_ParkEvent ;
2787   if (ev != NULL) ev->unpark() ;
2788 
2789 }
2790 
2791 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
2792   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
2793     "possibility of dangling Thread pointer");
2794 
2795   OSThread* osthread = thread->osthread();
2796 
2797   bool interrupted = osthread->interrupted();
2798 
2799   if (interrupted && clear_interrupted) {
2800     osthread->set_interrupted(false);
2801     // consider thread->_SleepEvent->reset() ... optional optimization
2802   }
2803 
2804   return interrupted;
2805 }
2806 
2807 ///////////////////////////////////////////////////////////////////////////////////
2808 // signal handling (except suspend/resume)
2809 
2810 // This routine may be used by user applications as a "hook" to catch signals.
2811 // The user-defined signal handler must pass unrecognized signals to this
2812 // routine, and if it returns true (non-zero), then the signal handler must
2813 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
2814 // routine will never retun false (zero), but instead will execute a VM panic
2815 // routine kill the process.
2816 //
2817 // If this routine returns false, it is OK to call it again.  This allows
2818 // the user-defined signal handler to perform checks either before or after
2819 // the VM performs its own checks.  Naturally, the user code would be making
2820 // a serious error if it tried to handle an exception (such as a null check
2821 // or breakpoint) that the VM was generating for its own correct operation.
2822 //
2823 // This routine may recognize any of the following kinds of signals:
2824 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2825 // It should be consulted by handlers for any of those signals.
2826 //
2827 // The caller of this routine must pass in the three arguments supplied
2828 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2829 // field of the structure passed to sigaction().  This routine assumes that
2830 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2831 //
2832 // Note that the VM will print warnings if it detects conflicting signal
2833 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2834 //
2835 extern "C" JNIEXPORT int
2836 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2837                         void* ucontext, int abort_if_unrecognized);
2838 
2839 void signalHandler(int sig, siginfo_t* info, void* uc) {
2840   assert(info != NULL && uc != NULL, "it must be old kernel");
2841   int orig_errno = errno;  // Preserve errno value over signal handler.
2842   JVM_handle_bsd_signal(sig, info, uc, true);
2843   errno = orig_errno;
2844 }
2845 
2846 
2847 // This boolean allows users to forward their own non-matching signals
2848 // to JVM_handle_bsd_signal, harmlessly.
2849 bool os::Bsd::signal_handlers_are_installed = false;
2850 
2851 // For signal-chaining
2852 struct sigaction os::Bsd::sigact[MAXSIGNUM];
2853 unsigned int os::Bsd::sigs = 0;
2854 bool os::Bsd::libjsig_is_loaded = false;
2855 typedef struct sigaction *(*get_signal_t)(int);
2856 get_signal_t os::Bsd::get_signal_action = NULL;
2857 
2858 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2859   struct sigaction *actp = NULL;
2860 
2861   if (libjsig_is_loaded) {
2862     // Retrieve the old signal handler from libjsig
2863     actp = (*get_signal_action)(sig);
2864   }
2865   if (actp == NULL) {
2866     // Retrieve the preinstalled signal handler from jvm
2867     actp = get_preinstalled_handler(sig);
2868   }
2869 
2870   return actp;
2871 }
2872 
2873 static bool call_chained_handler(struct sigaction *actp, int sig,
2874                                  siginfo_t *siginfo, void *context) {
2875   // Call the old signal handler
2876   if (actp->sa_handler == SIG_DFL) {
2877     // It's more reasonable to let jvm treat it as an unexpected exception
2878     // instead of taking the default action.
2879     return false;
2880   } else if (actp->sa_handler != SIG_IGN) {
2881     if ((actp->sa_flags & SA_NODEFER) == 0) {
2882       // automaticlly block the signal
2883       sigaddset(&(actp->sa_mask), sig);
2884     }
2885 
2886     sa_handler_t hand;
2887     sa_sigaction_t sa;
2888     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
2889     // retrieve the chained handler
2890     if (siginfo_flag_set) {
2891       sa = actp->sa_sigaction;
2892     } else {
2893       hand = actp->sa_handler;
2894     }
2895 
2896     if ((actp->sa_flags & SA_RESETHAND) != 0) {
2897       actp->sa_handler = SIG_DFL;
2898     }
2899 
2900     // try to honor the signal mask
2901     sigset_t oset;
2902     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
2903 
2904     // call into the chained handler
2905     if (siginfo_flag_set) {
2906       (*sa)(sig, siginfo, context);
2907     } else {
2908       (*hand)(sig);
2909     }
2910 
2911     // restore the signal mask
2912     pthread_sigmask(SIG_SETMASK, &oset, 0);
2913   }
2914   // Tell jvm's signal handler the signal is taken care of.
2915   return true;
2916 }
2917 
2918 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
2919   bool chained = false;
2920   // signal-chaining
2921   if (UseSignalChaining) {
2922     struct sigaction *actp = get_chained_signal_action(sig);
2923     if (actp != NULL) {
2924       chained = call_chained_handler(actp, sig, siginfo, context);
2925     }
2926   }
2927   return chained;
2928 }
2929 
2930 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
2931   if ((( (unsigned int)1 << sig ) & sigs) != 0) {
2932     return &sigact[sig];
2933   }
2934   return NULL;
2935 }
2936 
2937 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
2938   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2939   sigact[sig] = oldAct;
2940   sigs |= (unsigned int)1 << sig;
2941 }
2942 
2943 // for diagnostic
2944 int os::Bsd::sigflags[MAXSIGNUM];
2945 
2946 int os::Bsd::get_our_sigflags(int sig) {
2947   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2948   return sigflags[sig];
2949 }
2950 
2951 void os::Bsd::set_our_sigflags(int sig, int flags) {
2952   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2953   sigflags[sig] = flags;
2954 }
2955 
2956 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
2957   // Check for overwrite.
2958   struct sigaction oldAct;
2959   sigaction(sig, (struct sigaction*)NULL, &oldAct);
2960 
2961   void* oldhand = oldAct.sa_sigaction
2962                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
2963                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
2964   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
2965       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
2966       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
2967     if (AllowUserSignalHandlers || !set_installed) {
2968       // Do not overwrite; user takes responsibility to forward to us.
2969       return;
2970     } else if (UseSignalChaining) {
2971       // save the old handler in jvm
2972       save_preinstalled_handler(sig, oldAct);
2973       // libjsig also interposes the sigaction() call below and saves the
2974       // old sigaction on it own.
2975     } else {
2976       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
2977                     "%#lx for signal %d.", (long)oldhand, sig));
2978     }
2979   }
2980 
2981   struct sigaction sigAct;
2982   sigfillset(&(sigAct.sa_mask));
2983   sigAct.sa_handler = SIG_DFL;
2984   if (!set_installed) {
2985     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
2986   } else {
2987     sigAct.sa_sigaction = signalHandler;
2988     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
2989   }
2990   // Save flags, which are set by ours
2991   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2992   sigflags[sig] = sigAct.sa_flags;
2993 
2994   int ret = sigaction(sig, &sigAct, &oldAct);
2995   assert(ret == 0, "check");
2996 
2997   void* oldhand2  = oldAct.sa_sigaction
2998                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
2999                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3000   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3001 }
3002 
3003 // install signal handlers for signals that HotSpot needs to
3004 // handle in order to support Java-level exception handling.
3005 
3006 void os::Bsd::install_signal_handlers() {
3007   if (!signal_handlers_are_installed) {
3008     signal_handlers_are_installed = true;
3009 
3010     // signal-chaining
3011     typedef void (*signal_setting_t)();
3012     signal_setting_t begin_signal_setting = NULL;
3013     signal_setting_t end_signal_setting = NULL;
3014     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3015                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3016     if (begin_signal_setting != NULL) {
3017       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3018                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3019       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3020                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3021       libjsig_is_loaded = true;
3022       assert(UseSignalChaining, "should enable signal-chaining");
3023     }
3024     if (libjsig_is_loaded) {
3025       // Tell libjsig jvm is setting signal handlers
3026       (*begin_signal_setting)();
3027     }
3028 
3029     set_signal_handler(SIGSEGV, true);
3030     set_signal_handler(SIGPIPE, true);
3031     set_signal_handler(SIGBUS, true);
3032     set_signal_handler(SIGILL, true);
3033     set_signal_handler(SIGFPE, true);
3034     set_signal_handler(SIGXFSZ, true);
3035 
3036 #if defined(__APPLE__)
3037     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3038     // signals caught and handled by the JVM. To work around this, we reset the mach task
3039     // signal handler that's placed on our process by CrashReporter. This disables
3040     // CrashReporter-based reporting.
3041     //
3042     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3043     // on caught fatal signals.
3044     //
3045     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3046     // handlers. By replacing the existing task exception handler, we disable gdb's mach
3047     // exception handling, while leaving the standard BSD signal handlers functional.
3048     kern_return_t kr;
3049     kr = task_set_exception_ports(mach_task_self(),
3050         EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3051         MACH_PORT_NULL,
3052         EXCEPTION_STATE_IDENTITY,
3053         MACHINE_THREAD_STATE);
3054 
3055     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3056 #endif
3057 
3058     if (libjsig_is_loaded) {
3059       // Tell libjsig jvm finishes setting signal handlers
3060       (*end_signal_setting)();
3061     }
3062 
3063     // We don't activate signal checker if libjsig is in place, we trust ourselves
3064     // and if UserSignalHandler is installed all bets are off
3065     if (CheckJNICalls) {
3066       if (libjsig_is_loaded) {
3067         tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3068         check_signals = false;
3069       }
3070       if (AllowUserSignalHandlers) {
3071         tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3072         check_signals = false;
3073       }
3074     }
3075   }
3076 }
3077 
3078 
3079 /////
3080 // glibc on Bsd platform uses non-documented flag
3081 // to indicate, that some special sort of signal
3082 // trampoline is used.
3083 // We will never set this flag, and we should
3084 // ignore this flag in our diagnostic
3085 #ifdef SIGNIFICANT_SIGNAL_MASK
3086 #undef SIGNIFICANT_SIGNAL_MASK
3087 #endif
3088 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3089 
3090 static const char* get_signal_handler_name(address handler,
3091                                            char* buf, int buflen) {
3092   int offset;
3093   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3094   if (found) {
3095     // skip directory names
3096     const char *p1, *p2;
3097     p1 = buf;
3098     size_t len = strlen(os::file_separator());
3099     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3100     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3101   } else {
3102     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3103   }
3104   return buf;
3105 }
3106 
3107 static void print_signal_handler(outputStream* st, int sig,
3108                                  char* buf, size_t buflen) {
3109   struct sigaction sa;
3110 
3111   sigaction(sig, NULL, &sa);
3112 
3113   // See comment for SIGNIFICANT_SIGNAL_MASK define
3114   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3115 
3116   st->print("%s: ", os::exception_name(sig, buf, buflen));
3117 
3118   address handler = (sa.sa_flags & SA_SIGINFO)
3119     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3120     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3121 
3122   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3123     st->print("SIG_DFL");
3124   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3125     st->print("SIG_IGN");
3126   } else {
3127     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3128   }
3129 
3130   st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask);
3131 
3132   address rh = VMError::get_resetted_sighandler(sig);
3133   // May be, handler was resetted by VMError?
3134   if(rh != NULL) {
3135     handler = rh;
3136     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3137   }
3138 
3139   st->print(", sa_flags="   PTR32_FORMAT, sa.sa_flags);
3140 
3141   // Check: is it our handler?
3142   if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3143      handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3144     // It is our signal handler
3145     // check for flags, reset system-used one!
3146     if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3147       st->print(
3148                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3149                 os::Bsd::get_our_sigflags(sig));
3150     }
3151   }
3152   st->cr();
3153 }
3154 
3155 
3156 #define DO_SIGNAL_CHECK(sig) \
3157   if (!sigismember(&check_signal_done, sig)) \
3158     os::Bsd::check_signal_handler(sig)
3159 
3160 // This method is a periodic task to check for misbehaving JNI applications
3161 // under CheckJNI, we can add any periodic checks here
3162 
3163 void os::run_periodic_checks() {
3164 
3165   if (check_signals == false) return;
3166 
3167   // SEGV and BUS if overridden could potentially prevent
3168   // generation of hs*.log in the event of a crash, debugging
3169   // such a case can be very challenging, so we absolutely
3170   // check the following for a good measure:
3171   DO_SIGNAL_CHECK(SIGSEGV);
3172   DO_SIGNAL_CHECK(SIGILL);
3173   DO_SIGNAL_CHECK(SIGFPE);
3174   DO_SIGNAL_CHECK(SIGBUS);
3175   DO_SIGNAL_CHECK(SIGPIPE);
3176   DO_SIGNAL_CHECK(SIGXFSZ);
3177 
3178 
3179   // ReduceSignalUsage allows the user to override these handlers
3180   // see comments at the very top and jvm_solaris.h
3181   if (!ReduceSignalUsage) {
3182     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3183     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3184     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3185     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3186   }
3187 
3188   DO_SIGNAL_CHECK(SR_signum);
3189   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3190 }
3191 
3192 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3193 
3194 static os_sigaction_t os_sigaction = NULL;
3195 
3196 void os::Bsd::check_signal_handler(int sig) {
3197   char buf[O_BUFLEN];
3198   address jvmHandler = NULL;
3199 
3200 
3201   struct sigaction act;
3202   if (os_sigaction == NULL) {
3203     // only trust the default sigaction, in case it has been interposed
3204     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3205     if (os_sigaction == NULL) return;
3206   }
3207 
3208   os_sigaction(sig, (struct sigaction*)NULL, &act);
3209 
3210 
3211   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3212 
3213   address thisHandler = (act.sa_flags & SA_SIGINFO)
3214     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3215     : CAST_FROM_FN_PTR(address, act.sa_handler) ;
3216 
3217 
3218   switch(sig) {
3219   case SIGSEGV:
3220   case SIGBUS:
3221   case SIGFPE:
3222   case SIGPIPE:
3223   case SIGILL:
3224   case SIGXFSZ:
3225     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3226     break;
3227 
3228   case SHUTDOWN1_SIGNAL:
3229   case SHUTDOWN2_SIGNAL:
3230   case SHUTDOWN3_SIGNAL:
3231   case BREAK_SIGNAL:
3232     jvmHandler = (address)user_handler();
3233     break;
3234 
3235   case INTERRUPT_SIGNAL:
3236     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3237     break;
3238 
3239   default:
3240     if (sig == SR_signum) {
3241       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3242     } else {
3243       return;
3244     }
3245     break;
3246   }
3247 
3248   if (thisHandler != jvmHandler) {
3249     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3250     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3251     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3252     // No need to check this sig any longer
3253     sigaddset(&check_signal_done, sig);
3254   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3255     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3256     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3257     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
3258     // No need to check this sig any longer
3259     sigaddset(&check_signal_done, sig);
3260   }
3261 
3262   // Dump all the signal
3263   if (sigismember(&check_signal_done, sig)) {
3264     print_signal_handlers(tty, buf, O_BUFLEN);
3265   }
3266 }
3267 
3268 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
3269 
3270 extern bool signal_name(int signo, char* buf, size_t len);
3271 
3272 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3273   if (0 < exception_code && exception_code <= SIGRTMAX) {
3274     // signal
3275     if (!signal_name(exception_code, buf, size)) {
3276       jio_snprintf(buf, size, "SIG%d", exception_code);
3277     }
3278     return buf;
3279   } else {
3280     return NULL;
3281   }
3282 }
3283 
3284 // this is called _before_ the most of global arguments have been parsed
3285 void os::init(void) {
3286   char dummy;   /* used to get a guess on initial stack address */
3287 //  first_hrtime = gethrtime();
3288 
3289   // With BsdThreads the JavaMain thread pid (primordial thread)
3290   // is different than the pid of the java launcher thread.
3291   // So, on Bsd, the launcher thread pid is passed to the VM
3292   // via the sun.java.launcher.pid property.
3293   // Use this property instead of getpid() if it was correctly passed.
3294   // See bug 6351349.
3295   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3296 
3297   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3298 
3299   clock_tics_per_sec = CLK_TCK;
3300 
3301   init_random(1234567);
3302 
3303   ThreadCritical::initialize();
3304 
3305   Bsd::set_page_size(getpagesize());
3306   if (Bsd::page_size() == -1) {
3307     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3308                   strerror(errno)));
3309   }
3310   init_page_sizes((size_t) Bsd::page_size());
3311 
3312   Bsd::initialize_system_info();
3313 
3314   // main_thread points to the aboriginal thread
3315   Bsd::_main_thread = pthread_self();
3316 
3317   Bsd::clock_init();
3318   initial_time_count = os::elapsed_counter();
3319 
3320 #ifdef __APPLE__
3321   // XXXDARWIN
3322   // Work around the unaligned VM callbacks in hotspot's
3323   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3324   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3325   // alignment when doing symbol lookup. To work around this, we force early
3326   // binding of all symbols now, thus binding when alignment is known-good.
3327   _dyld_bind_fully_image_containing_address((const void *) &os::init);
3328 #endif
3329 }
3330 
3331 // To install functions for atexit system call
3332 extern "C" {
3333   static void perfMemory_exit_helper() {
3334     perfMemory_exit();
3335   }
3336 }
3337 
3338 // this is called _after_ the global arguments have been parsed
3339 jint os::init_2(void)
3340 {
3341   // Allocate a single page and mark it as readable for safepoint polling
3342   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3343   guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
3344 
3345   os::set_polling_page( polling_page );
3346 
3347 #ifndef PRODUCT
3348   if(Verbose && PrintMiscellaneous)
3349     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
3350 #endif
3351 
3352   if (!UseMembar) {
3353     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3354     guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page");
3355     os::set_memory_serialize_page( mem_serialize_page );
3356 
3357 #ifndef PRODUCT
3358     if(Verbose && PrintMiscellaneous)
3359       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
3360 #endif
3361   }
3362 
3363   os::large_page_init();
3364 
3365   // initialize suspend/resume support - must do this before signal_sets_init()
3366   if (SR_initialize() != 0) {
3367     perror("SR_initialize failed");
3368     return JNI_ERR;
3369   }
3370 
3371   Bsd::signal_sets_init();
3372   Bsd::install_signal_handlers();
3373 
3374   // Check minimum allowable stack size for thread creation and to initialize
3375   // the java system classes, including StackOverflowError - depends on page
3376   // size.  Add a page for compiler2 recursion in main thread.
3377   // Add in 2*BytesPerWord times page size to account for VM stack during
3378   // class initialization depending on 32 or 64 bit VM.
3379   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3380             (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3381                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3382 
3383   size_t threadStackSizeInBytes = ThreadStackSize * K;
3384   if (threadStackSizeInBytes != 0 &&
3385       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3386         tty->print_cr("\nThe stack size specified is too small, "
3387                       "Specify at least %dk",
3388                       os::Bsd::min_stack_allowed/ K);
3389         return JNI_ERR;
3390   }
3391 
3392   // Make the stack size a multiple of the page size so that
3393   // the yellow/red zones can be guarded.
3394   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3395         vm_page_size()));
3396 
3397   if (MaxFDLimit) {
3398     // set the number of file descriptors to max. print out error
3399     // if getrlimit/setrlimit fails but continue regardless.
3400     struct rlimit nbr_files;
3401     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3402     if (status != 0) {
3403       if (PrintMiscellaneous && (Verbose || WizardMode))
3404         perror("os::init_2 getrlimit failed");
3405     } else {
3406       nbr_files.rlim_cur = nbr_files.rlim_max;
3407 
3408 #ifdef __APPLE__
3409       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3410       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3411       // be used instead
3412       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3413 #endif
3414 
3415       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3416       if (status != 0) {
3417         if (PrintMiscellaneous && (Verbose || WizardMode))
3418           perror("os::init_2 setrlimit failed");
3419       }
3420     }
3421   }
3422 
3423   // at-exit methods are called in the reverse order of their registration.
3424   // atexit functions are called on return from main or as a result of a
3425   // call to exit(3C). There can be only 32 of these functions registered
3426   // and atexit() does not set errno.
3427 
3428   if (PerfAllowAtExitRegistration) {
3429     // only register atexit functions if PerfAllowAtExitRegistration is set.
3430     // atexit functions can be delayed until process exit time, which
3431     // can be problematic for embedded VM situations. Embedded VMs should
3432     // call DestroyJavaVM() to assure that VM resources are released.
3433 
3434     // note: perfMemory_exit_helper atexit function may be removed in
3435     // the future if the appropriate cleanup code can be added to the
3436     // VM_Exit VMOperation's doit method.
3437     if (atexit(perfMemory_exit_helper) != 0) {
3438       warning("os::init2 atexit(perfMemory_exit_helper) failed");
3439     }
3440   }
3441 
3442   // initialize thread priority policy
3443   prio_init();
3444 
3445 #ifdef __APPLE__
3446   // dynamically link to objective c gc registration
3447   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3448   if (handleLibObjc != NULL) {
3449     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3450   }
3451 #endif
3452 
3453   return JNI_OK;
3454 }
3455 
3456 // this is called at the end of vm_initialization
3457 void os::init_3(void) { }
3458 
3459 // Mark the polling page as unreadable
3460 void os::make_polling_page_unreadable(void) {
3461   if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
3462     fatal("Could not disable polling page");
3463 };
3464 
3465 // Mark the polling page as readable
3466 void os::make_polling_page_readable(void) {
3467   if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3468     fatal("Could not enable polling page");
3469   }
3470 };
3471 
3472 int os::active_processor_count() {
3473   return _processor_count;
3474 }
3475 
3476 void os::set_native_thread_name(const char *name) {
3477 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3478   // This is only supported in Snow Leopard and beyond
3479   if (name != NULL) {
3480     // Add a "Java: " prefix to the name
3481     char buf[MAXTHREADNAMESIZE];
3482     snprintf(buf, sizeof(buf), "Java: %s", name);
3483     pthread_setname_np(buf);
3484   }
3485 #endif
3486 }
3487 
3488 bool os::distribute_processes(uint length, uint* distribution) {
3489   // Not yet implemented.
3490   return false;
3491 }
3492 
3493 bool os::bind_to_processor(uint processor_id) {
3494   // Not yet implemented.
3495   return false;
3496 }
3497 
3498 ///
3499 
3500 // Suspends the target using the signal mechanism and then grabs the PC before
3501 // resuming the target. Used by the flat-profiler only
3502 ExtendedPC os::get_thread_pc(Thread* thread) {
3503   // Make sure that it is called by the watcher for the VMThread
3504   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3505   assert(thread->is_VM_thread(), "Can only be called for VMThread");
3506 
3507   ExtendedPC epc;
3508 
3509   OSThread* osthread = thread->osthread();
3510   if (do_suspend(osthread)) {
3511     if (osthread->ucontext() != NULL) {
3512       epc = os::Bsd::ucontext_get_pc(osthread->ucontext());
3513     } else {
3514       // NULL context is unexpected, double-check this is the VMThread
3515       guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3516     }
3517     do_resume(osthread);
3518   }
3519   // failure means pthread_kill failed for some reason - arguably this is
3520   // a fatal problem, but such problems are ignored elsewhere
3521 
3522   return epc;
3523 }
3524 
3525 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
3526 {
3527   return pthread_cond_timedwait(_cond, _mutex, _abstime);
3528 }
3529 
3530 ////////////////////////////////////////////////////////////////////////////////
3531 // debug support
3532 
3533 bool os::find(address addr, outputStream* st) {
3534   Dl_info dlinfo;
3535   memset(&dlinfo, 0, sizeof(dlinfo));
3536   if (dladdr(addr, &dlinfo)) {
3537     st->print(PTR_FORMAT ": ", addr);
3538     if (dlinfo.dli_sname != NULL) {
3539       st->print("%s+%#x", dlinfo.dli_sname,
3540                  addr - (intptr_t)dlinfo.dli_saddr);
3541     } else if (dlinfo.dli_fname) {
3542       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3543     } else {
3544       st->print("<absolute address>");
3545     }
3546     if (dlinfo.dli_fname) {
3547       st->print(" in %s", dlinfo.dli_fname);
3548     }
3549     if (dlinfo.dli_fbase) {
3550       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3551     }
3552     st->cr();
3553 
3554     if (Verbose) {
3555       // decode some bytes around the PC
3556       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3557       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3558       address       lowest = (address) dlinfo.dli_sname;
3559       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3560       if (begin < lowest)  begin = lowest;
3561       Dl_info dlinfo2;
3562       if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr
3563           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
3564         end = (address) dlinfo2.dli_saddr;
3565       Disassembler::decode(begin, end, st);
3566     }
3567     return true;
3568   }
3569   return false;
3570 }
3571 
3572 ////////////////////////////////////////////////////////////////////////////////
3573 // misc
3574 
3575 // This does not do anything on Bsd. This is basically a hook for being
3576 // able to use structured exception handling (thread-local exception filters)
3577 // on, e.g., Win32.
3578 void
3579 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
3580                          JavaCallArguments* args, Thread* thread) {
3581   f(value, method, args, thread);
3582 }
3583 
3584 void os::print_statistics() {
3585 }
3586 
3587 int os::message_box(const char* title, const char* message) {
3588   int i;
3589   fdStream err(defaultStream::error_fd());
3590   for (i = 0; i < 78; i++) err.print_raw("=");
3591   err.cr();
3592   err.print_raw_cr(title);
3593   for (i = 0; i < 78; i++) err.print_raw("-");
3594   err.cr();
3595   err.print_raw_cr(message);
3596   for (i = 0; i < 78; i++) err.print_raw("=");
3597   err.cr();
3598 
3599   char buf[16];
3600   // Prevent process from exiting upon "read error" without consuming all CPU
3601   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3602 
3603   return buf[0] == 'y' || buf[0] == 'Y';
3604 }
3605 
3606 int os::stat(const char *path, struct stat *sbuf) {
3607   char pathbuf[MAX_PATH];
3608   if (strlen(path) > MAX_PATH - 1) {
3609     errno = ENAMETOOLONG;
3610     return -1;
3611   }
3612   os::native_path(strcpy(pathbuf, path));
3613   return ::stat(pathbuf, sbuf);
3614 }
3615 
3616 bool os::check_heap(bool force) {
3617   return true;
3618 }
3619 
3620 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
3621   return ::vsnprintf(buf, count, format, args);
3622 }
3623 
3624 // Is a (classpath) directory empty?
3625 bool os::dir_is_empty(const char* path) {
3626   DIR *dir = NULL;
3627   struct dirent *ptr;
3628 
3629   dir = opendir(path);
3630   if (dir == NULL) return true;
3631 
3632   /* Scan the directory */
3633   bool result = true;
3634   char buf[sizeof(struct dirent) + MAX_PATH];
3635   while (result && (ptr = ::readdir(dir)) != NULL) {
3636     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3637       result = false;
3638     }
3639   }
3640   closedir(dir);
3641   return result;
3642 }
3643 
3644 // This code originates from JDK's sysOpen and open64_w
3645 // from src/solaris/hpi/src/system_md.c
3646 
3647 #ifndef O_DELETE
3648 #define O_DELETE 0x10000
3649 #endif
3650 
3651 // Open a file. Unlink the file immediately after open returns
3652 // if the specified oflag has the O_DELETE flag set.
3653 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
3654 
3655 int os::open(const char *path, int oflag, int mode) {
3656 
3657   if (strlen(path) > MAX_PATH - 1) {
3658     errno = ENAMETOOLONG;
3659     return -1;
3660   }
3661   int fd;
3662   int o_delete = (oflag & O_DELETE);
3663   oflag = oflag & ~O_DELETE;
3664 
3665   fd = ::open(path, oflag, mode);
3666   if (fd == -1) return -1;
3667 
3668   //If the open succeeded, the file might still be a directory
3669   {
3670     struct stat buf;
3671     int ret = ::fstat(fd, &buf);
3672     int st_mode = buf.st_mode;
3673 
3674     if (ret != -1) {
3675       if ((st_mode & S_IFMT) == S_IFDIR) {
3676         errno = EISDIR;
3677         ::close(fd);
3678         return -1;
3679       }
3680     } else {
3681       ::close(fd);
3682       return -1;
3683     }
3684   }
3685 
3686     /*
3687      * All file descriptors that are opened in the JVM and not
3688      * specifically destined for a subprocess should have the
3689      * close-on-exec flag set.  If we don't set it, then careless 3rd
3690      * party native code might fork and exec without closing all
3691      * appropriate file descriptors (e.g. as we do in closeDescriptors in
3692      * UNIXProcess.c), and this in turn might:
3693      *
3694      * - cause end-of-file to fail to be detected on some file
3695      *   descriptors, resulting in mysterious hangs, or
3696      *
3697      * - might cause an fopen in the subprocess to fail on a system
3698      *   suffering from bug 1085341.
3699      *
3700      * (Yes, the default setting of the close-on-exec flag is a Unix
3701      * design flaw)
3702      *
3703      * See:
3704      * 1085341: 32-bit stdio routines should support file descriptors >255
3705      * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3706      * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3707      */
3708 #ifdef FD_CLOEXEC
3709     {
3710         int flags = ::fcntl(fd, F_GETFD);
3711         if (flags != -1)
3712             ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3713     }
3714 #endif
3715 
3716   if (o_delete != 0) {
3717     ::unlink(path);
3718   }
3719   return fd;
3720 }
3721 
3722 
3723 // create binary file, rewriting existing file if required
3724 int os::create_binary_file(const char* path, bool rewrite_existing) {
3725   int oflags = O_WRONLY | O_CREAT;
3726   if (!rewrite_existing) {
3727     oflags |= O_EXCL;
3728   }
3729   return ::open(path, oflags, S_IREAD | S_IWRITE);
3730 }
3731 
3732 // return current position of file pointer
3733 jlong os::current_file_offset(int fd) {
3734   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3735 }
3736 
3737 // move file pointer to the specified offset
3738 jlong os::seek_to_file_offset(int fd, jlong offset) {
3739   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3740 }
3741 
3742 // This code originates from JDK's sysAvailable
3743 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3744 
3745 int os::available(int fd, jlong *bytes) {
3746   jlong cur, end;
3747   int mode;
3748   struct stat buf;
3749 
3750   if (::fstat(fd, &buf) >= 0) {
3751     mode = buf.st_mode;
3752     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3753       /*
3754       * XXX: is the following call interruptible? If so, this might
3755       * need to go through the INTERRUPT_IO() wrapper as for other
3756       * blocking, interruptible calls in this file.
3757       */
3758       int n;
3759       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3760         *bytes = n;
3761         return 1;
3762       }
3763     }
3764   }
3765   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3766     return 0;
3767   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3768     return 0;
3769   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3770     return 0;
3771   }
3772   *bytes = end - cur;
3773   return 1;
3774 }
3775 
3776 int os::socket_available(int fd, jint *pbytes) {
3777    if (fd < 0)
3778      return OS_OK;
3779 
3780    int ret;
3781 
3782    RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
3783 
3784    //%% note ioctl can return 0 when successful, JVM_SocketAvailable
3785    // is expected to return 0 on failure and 1 on success to the jdk.
3786 
3787    return (ret == OS_ERR) ? 0 : 1;
3788 }
3789 
3790 // Map a block of memory.
3791 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3792                      char *addr, size_t bytes, bool read_only,
3793                      bool allow_exec) {
3794   int prot;
3795   int flags;
3796 
3797   if (read_only) {
3798     prot = PROT_READ;
3799     flags = MAP_SHARED;
3800   } else {
3801     prot = PROT_READ | PROT_WRITE;
3802     flags = MAP_PRIVATE;
3803   }
3804 
3805   if (allow_exec) {
3806     prot |= PROT_EXEC;
3807   }
3808 
3809   if (addr != NULL) {
3810     flags |= MAP_FIXED;
3811   }
3812 
3813   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3814                                      fd, file_offset);
3815   if (mapped_address == MAP_FAILED) {
3816     return NULL;
3817   }
3818   return mapped_address;
3819 }
3820 
3821 
3822 // Remap a block of memory.
3823 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3824                        char *addr, size_t bytes, bool read_only,
3825                        bool allow_exec) {
3826   // same as map_memory() on this OS
3827   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3828                         allow_exec);
3829 }
3830 
3831 
3832 // Unmap a block of memory.
3833 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3834   return munmap(addr, bytes) == 0;
3835 }
3836 
3837 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3838 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3839 // of a thread.
3840 //
3841 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3842 // the fast estimate available on the platform.
3843 
3844 jlong os::current_thread_cpu_time() {
3845 #ifdef __APPLE__
3846   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3847 #else
3848   Unimplemented();
3849   return 0;
3850 #endif
3851 }
3852 
3853 jlong os::thread_cpu_time(Thread* thread) {
3854 #ifdef __APPLE__
3855   return os::thread_cpu_time(thread, true /* user + sys */);
3856 #else
3857   Unimplemented();
3858   return 0;
3859 #endif
3860 }
3861 
3862 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3863 #ifdef __APPLE__
3864   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3865 #else
3866   Unimplemented();
3867   return 0;
3868 #endif
3869 }
3870 
3871 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3872 #ifdef __APPLE__
3873   struct thread_basic_info tinfo;
3874   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
3875   kern_return_t kr;
3876   thread_t mach_thread;
3877 
3878   mach_thread = thread->osthread()->thread_id();
3879   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
3880   if (kr != KERN_SUCCESS)
3881     return -1;
3882 
3883   if (user_sys_cpu_time) {
3884     jlong nanos;
3885     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
3886     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
3887     return nanos;
3888   } else {
3889     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
3890   }
3891 #else
3892   Unimplemented();
3893   return 0;
3894 #endif
3895 }
3896 
3897 
3898 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3899   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3900   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3901   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3902   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3903 }
3904 
3905 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3906   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3907   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3908   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3909   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3910 }
3911 
3912 bool os::is_thread_cpu_time_supported() {
3913 #ifdef __APPLE__
3914   return true;
3915 #else
3916   return false;
3917 #endif
3918 }
3919 
3920 // System loadavg support.  Returns -1 if load average cannot be obtained.
3921 // Bsd doesn't yet have a (official) notion of processor sets,
3922 // so just return the system wide load average.
3923 int os::loadavg(double loadavg[], int nelem) {
3924   return ::getloadavg(loadavg, nelem);
3925 }
3926 
3927 void os::pause() {
3928   char filename[MAX_PATH];
3929   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
3930     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
3931   } else {
3932     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
3933   }
3934 
3935   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
3936   if (fd != -1) {
3937     struct stat buf;
3938     ::close(fd);
3939     while (::stat(filename, &buf) == 0) {
3940       (void)::poll(NULL, 0, 100);
3941     }
3942   } else {
3943     jio_fprintf(stderr,
3944       "Could not open pause file '%s', continuing immediately.\n", filename);
3945   }
3946 }
3947 
3948 
3949 // Refer to the comments in os_solaris.cpp park-unpark.
3950 //
3951 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
3952 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
3953 // For specifics regarding the bug see GLIBC BUGID 261237 :
3954 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
3955 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
3956 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
3957 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
3958 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
3959 // and monitorenter when we're using 1-0 locking.  All those operations may result in
3960 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
3961 // of libpthread avoids the problem, but isn't practical.
3962 //
3963 // Possible remedies:
3964 //
3965 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
3966 //      This is palliative and probabilistic, however.  If the thread is preempted
3967 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
3968 //      than the minimum period may have passed, and the abstime may be stale (in the
3969 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
3970 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
3971 //
3972 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
3973 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
3974 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
3975 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
3976 //      thread.
3977 //
3978 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
3979 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
3980 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
3981 //      This also works well.  In fact it avoids kernel-level scalability impediments
3982 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
3983 //      timers in a graceful fashion.
3984 //
3985 // 4.   When the abstime value is in the past it appears that control returns
3986 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
3987 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
3988 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
3989 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
3990 //      It may be possible to avoid reinitialization by checking the return
3991 //      value from pthread_cond_timedwait().  In addition to reinitializing the
3992 //      condvar we must establish the invariant that cond_signal() is only called
3993 //      within critical sections protected by the adjunct mutex.  This prevents
3994 //      cond_signal() from "seeing" a condvar that's in the midst of being
3995 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
3996 //      desirable signal-after-unlock optimization that avoids futile context switching.
3997 //
3998 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
3999 //      structure when a condvar is used or initialized.  cond_destroy()  would
4000 //      release the helper structure.  Our reinitialize-after-timedwait fix
4001 //      put excessive stress on malloc/free and locks protecting the c-heap.
4002 //
4003 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
4004 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4005 // and only enabling the work-around for vulnerable environments.
4006 
4007 // utility to compute the abstime argument to timedwait:
4008 // millis is the relative timeout time
4009 // abstime will be the absolute timeout time
4010 // TODO: replace compute_abstime() with unpackTime()
4011 
4012 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
4013   if (millis < 0)  millis = 0;
4014   struct timeval now;
4015   int status = gettimeofday(&now, NULL);
4016   assert(status == 0, "gettimeofday");
4017   jlong seconds = millis / 1000;
4018   millis %= 1000;
4019   if (seconds > 50000000) { // see man cond_timedwait(3T)
4020     seconds = 50000000;
4021   }
4022   abstime->tv_sec = now.tv_sec  + seconds;
4023   long       usec = now.tv_usec + millis * 1000;
4024   if (usec >= 1000000) {
4025     abstime->tv_sec += 1;
4026     usec -= 1000000;
4027   }
4028   abstime->tv_nsec = usec * 1000;
4029   return abstime;
4030 }
4031 
4032 
4033 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
4034 // Conceptually TryPark() should be equivalent to park(0).
4035 
4036 int os::PlatformEvent::TryPark() {
4037   for (;;) {
4038     const int v = _Event ;
4039     guarantee ((v == 0) || (v == 1), "invariant") ;
4040     if (Atomic::cmpxchg (0, &_Event, v) == v) return v  ;
4041   }
4042 }
4043 
4044 void os::PlatformEvent::park() {       // AKA "down()"
4045   // Invariant: Only the thread associated with the Event/PlatformEvent
4046   // may call park().
4047   // TODO: assert that _Assoc != NULL or _Assoc == Self
4048   int v ;
4049   for (;;) {
4050       v = _Event ;
4051       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4052   }
4053   guarantee (v >= 0, "invariant") ;
4054   if (v == 0) {
4055      // Do this the hard way by blocking ...
4056      int status = pthread_mutex_lock(_mutex);
4057      assert_status(status == 0, status, "mutex_lock");
4058      guarantee (_nParked == 0, "invariant") ;
4059      ++ _nParked ;
4060      while (_Event < 0) {
4061         status = pthread_cond_wait(_cond, _mutex);
4062         // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4063         // Treat this the same as if the wait was interrupted
4064         if (status == ETIMEDOUT) { status = EINTR; }
4065         assert_status(status == 0 || status == EINTR, status, "cond_wait");
4066      }
4067      -- _nParked ;
4068 
4069     _Event = 0 ;
4070      status = pthread_mutex_unlock(_mutex);
4071      assert_status(status == 0, status, "mutex_unlock");
4072     // Paranoia to ensure our locked and lock-free paths interact
4073     // correctly with each other.
4074     OrderAccess::fence();
4075   }
4076   guarantee (_Event >= 0, "invariant") ;
4077 }
4078 
4079 int os::PlatformEvent::park(jlong millis) {
4080   guarantee (_nParked == 0, "invariant") ;
4081 
4082   int v ;
4083   for (;;) {
4084       v = _Event ;
4085       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4086   }
4087   guarantee (v >= 0, "invariant") ;
4088   if (v != 0) return OS_OK ;
4089 
4090   // We do this the hard way, by blocking the thread.
4091   // Consider enforcing a minimum timeout value.
4092   struct timespec abst;
4093   compute_abstime(&abst, millis);
4094 
4095   int ret = OS_TIMEOUT;
4096   int status = pthread_mutex_lock(_mutex);
4097   assert_status(status == 0, status, "mutex_lock");
4098   guarantee (_nParked == 0, "invariant") ;
4099   ++_nParked ;
4100 
4101   // Object.wait(timo) will return because of
4102   // (a) notification
4103   // (b) timeout
4104   // (c) thread.interrupt
4105   //
4106   // Thread.interrupt and object.notify{All} both call Event::set.
4107   // That is, we treat thread.interrupt as a special case of notification.
4108   // The underlying Solaris implementation, cond_timedwait, admits
4109   // spurious/premature wakeups, but the JLS/JVM spec prevents the
4110   // JVM from making those visible to Java code.  As such, we must
4111   // filter out spurious wakeups.  We assume all ETIME returns are valid.
4112   //
4113   // TODO: properly differentiate simultaneous notify+interrupt.
4114   // In that case, we should propagate the notify to another waiter.
4115 
4116   while (_Event < 0) {
4117     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4118     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4119       pthread_cond_destroy (_cond);
4120       pthread_cond_init (_cond, NULL) ;
4121     }
4122     assert_status(status == 0 || status == EINTR ||
4123                   status == ETIMEDOUT,
4124                   status, "cond_timedwait");
4125     if (!FilterSpuriousWakeups) break ;                 // previous semantics
4126     if (status == ETIMEDOUT) break ;
4127     // We consume and ignore EINTR and spurious wakeups.
4128   }
4129   --_nParked ;
4130   if (_Event >= 0) {
4131      ret = OS_OK;
4132   }
4133   _Event = 0 ;
4134   status = pthread_mutex_unlock(_mutex);
4135   assert_status(status == 0, status, "mutex_unlock");
4136   assert (_nParked == 0, "invariant") ;
4137   // Paranoia to ensure our locked and lock-free paths interact
4138   // correctly with each other.
4139   OrderAccess::fence();
4140   return ret;
4141 }
4142 
4143 void os::PlatformEvent::unpark() {
4144   // Transitions for _Event:
4145   //    0 :=> 1
4146   //    1 :=> 1
4147   //   -1 :=> either 0 or 1; must signal target thread
4148   //          That is, we can safely transition _Event from -1 to either
4149   //          0 or 1. Forcing 1 is slightly more efficient for back-to-back
4150   //          unpark() calls.
4151   // See also: "Semaphores in Plan 9" by Mullender & Cox
4152   //
4153   // Note: Forcing a transition from "-1" to "1" on an unpark() means
4154   // that it will take two back-to-back park() calls for the owning
4155   // thread to block. This has the benefit of forcing a spurious return
4156   // from the first park() call after an unpark() call which will help
4157   // shake out uses of park() and unpark() without condition variables.
4158 
4159   if (Atomic::xchg(1, &_Event) >= 0) return;
4160 
4161   // Wait for the thread associated with the event to vacate
4162   int status = pthread_mutex_lock(_mutex);
4163   assert_status(status == 0, status, "mutex_lock");
4164   int AnyWaiters = _nParked;
4165   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4166   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4167     AnyWaiters = 0;
4168     pthread_cond_signal(_cond);
4169   }
4170   status = pthread_mutex_unlock(_mutex);
4171   assert_status(status == 0, status, "mutex_unlock");
4172   if (AnyWaiters != 0) {
4173     status = pthread_cond_signal(_cond);
4174     assert_status(status == 0, status, "cond_signal");
4175   }
4176 
4177   // Note that we signal() _after dropping the lock for "immortal" Events.
4178   // This is safe and avoids a common class of  futile wakeups.  In rare
4179   // circumstances this can cause a thread to return prematurely from
4180   // cond_{timed}wait() but the spurious wakeup is benign and the victim will
4181   // simply re-test the condition and re-park itself.
4182 }
4183 
4184 
4185 // JSR166
4186 // -------------------------------------------------------
4187 
4188 /*
4189  * The solaris and bsd implementations of park/unpark are fairly
4190  * conservative for now, but can be improved. They currently use a
4191  * mutex/condvar pair, plus a a count.
4192  * Park decrements count if > 0, else does a condvar wait.  Unpark
4193  * sets count to 1 and signals condvar.  Only one thread ever waits
4194  * on the condvar. Contention seen when trying to park implies that someone
4195  * is unparking you, so don't wait. And spurious returns are fine, so there
4196  * is no need to track notifications.
4197  */
4198 
4199 #define MAX_SECS 100000000
4200 /*
4201  * This code is common to bsd and solaris and will be moved to a
4202  * common place in dolphin.
4203  *
4204  * The passed in time value is either a relative time in nanoseconds
4205  * or an absolute time in milliseconds. Either way it has to be unpacked
4206  * into suitable seconds and nanoseconds components and stored in the
4207  * given timespec structure.
4208  * Given time is a 64-bit value and the time_t used in the timespec is only
4209  * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4210  * overflow if times way in the future are given. Further on Solaris versions
4211  * prior to 10 there is a restriction (see cond_timedwait) that the specified
4212  * number of seconds, in abstime, is less than current_time  + 100,000,000.
4213  * As it will be 28 years before "now + 100000000" will overflow we can
4214  * ignore overflow and just impose a hard-limit on seconds using the value
4215  * of "now + 100,000,000". This places a limit on the timeout of about 3.17
4216  * years from "now".
4217  */
4218 
4219 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4220   assert (time > 0, "convertTime");
4221 
4222   struct timeval now;
4223   int status = gettimeofday(&now, NULL);
4224   assert(status == 0, "gettimeofday");
4225 
4226   time_t max_secs = now.tv_sec + MAX_SECS;
4227 
4228   if (isAbsolute) {
4229     jlong secs = time / 1000;
4230     if (secs > max_secs) {
4231       absTime->tv_sec = max_secs;
4232     }
4233     else {
4234       absTime->tv_sec = secs;
4235     }
4236     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4237   }
4238   else {
4239     jlong secs = time / NANOSECS_PER_SEC;
4240     if (secs >= MAX_SECS) {
4241       absTime->tv_sec = max_secs;
4242       absTime->tv_nsec = 0;
4243     }
4244     else {
4245       absTime->tv_sec = now.tv_sec + secs;
4246       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4247       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4248         absTime->tv_nsec -= NANOSECS_PER_SEC;
4249         ++absTime->tv_sec; // note: this must be <= max_secs
4250       }
4251     }
4252   }
4253   assert(absTime->tv_sec >= 0, "tv_sec < 0");
4254   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4255   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4256   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4257 }
4258 
4259 void Parker::park(bool isAbsolute, jlong time) {
4260   // Ideally we'd do something useful while spinning, such
4261   // as calling unpackTime().
4262 
4263   // Optional fast-path check:
4264   // Return immediately if a permit is available.
4265   // We depend on Atomic::xchg() having full barrier semantics
4266   // since we are doing a lock-free update to _counter.
4267   if (Atomic::xchg(0, &_counter) > 0) return;
4268 
4269   Thread* thread = Thread::current();
4270   assert(thread->is_Java_thread(), "Must be JavaThread");
4271   JavaThread *jt = (JavaThread *)thread;
4272 
4273   // Optional optimization -- avoid state transitions if there's an interrupt pending.
4274   // Check interrupt before trying to wait
4275   if (Thread::is_interrupted(thread, false)) {
4276     return;
4277   }
4278 
4279   // Next, demultiplex/decode time arguments
4280   struct timespec absTime;
4281   if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
4282     return;
4283   }
4284   if (time > 0) {
4285     unpackTime(&absTime, isAbsolute, time);
4286   }
4287 
4288 
4289   // Enter safepoint region
4290   // Beware of deadlocks such as 6317397.
4291   // The per-thread Parker:: mutex is a classic leaf-lock.
4292   // In particular a thread must never block on the Threads_lock while
4293   // holding the Parker:: mutex.  If safepoints are pending both the
4294   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4295   ThreadBlockInVM tbivm(jt);
4296 
4297   // Don't wait if cannot get lock since interference arises from
4298   // unblocking.  Also. check interrupt before trying wait
4299   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4300     return;
4301   }
4302 
4303   int status ;
4304   if (_counter > 0)  { // no wait needed
4305     _counter = 0;
4306     status = pthread_mutex_unlock(_mutex);
4307     assert (status == 0, "invariant") ;
4308     // Paranoia to ensure our locked and lock-free paths interact
4309     // correctly with each other and Java-level accesses.
4310     OrderAccess::fence();
4311     return;
4312   }
4313 
4314 #ifdef ASSERT
4315   // Don't catch signals while blocked; let the running threads have the signals.
4316   // (This allows a debugger to break into the running thread.)
4317   sigset_t oldsigs;
4318   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4319   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4320 #endif
4321 
4322   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4323   jt->set_suspend_equivalent();
4324   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4325 
4326   if (time == 0) {
4327     status = pthread_cond_wait (_cond, _mutex) ;
4328   } else {
4329     status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
4330     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4331       pthread_cond_destroy (_cond) ;
4332       pthread_cond_init    (_cond, NULL);
4333     }
4334   }
4335   assert_status(status == 0 || status == EINTR ||
4336                 status == ETIMEDOUT,
4337                 status, "cond_timedwait");
4338 
4339 #ifdef ASSERT
4340   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4341 #endif
4342 
4343   _counter = 0 ;
4344   status = pthread_mutex_unlock(_mutex) ;
4345   assert_status(status == 0, status, "invariant") ;
4346   // Paranoia to ensure our locked and lock-free paths interact
4347   // correctly with each other and Java-level accesses.
4348   OrderAccess::fence();
4349 
4350   // If externally suspended while waiting, re-suspend
4351   if (jt->handle_special_suspend_equivalent_condition()) {
4352     jt->java_suspend_self();
4353   }
4354 }
4355 
4356 void Parker::unpark() {
4357   int s, status ;
4358   status = pthread_mutex_lock(_mutex);
4359   assert (status == 0, "invariant") ;
4360   s = _counter;
4361   _counter = 1;
4362   if (s < 1) {
4363      if (WorkAroundNPTLTimedWaitHang) {
4364         status = pthread_cond_signal (_cond) ;
4365         assert (status == 0, "invariant") ;
4366         status = pthread_mutex_unlock(_mutex);
4367         assert (status == 0, "invariant") ;
4368      } else {
4369         status = pthread_mutex_unlock(_mutex);
4370         assert (status == 0, "invariant") ;
4371         status = pthread_cond_signal (_cond) ;
4372         assert (status == 0, "invariant") ;
4373      }
4374   } else {
4375     pthread_mutex_unlock(_mutex);
4376     assert (status == 0, "invariant") ;
4377   }
4378 }
4379 
4380 
4381 /* Darwin has no "environ" in a dynamic library. */
4382 #ifdef __APPLE__
4383 #include <crt_externs.h>
4384 #define environ (*_NSGetEnviron())
4385 #else
4386 extern char** environ;
4387 #endif
4388 
4389 // Run the specified command in a separate process. Return its exit value,
4390 // or -1 on failure (e.g. can't fork a new process).
4391 // Unlike system(), this function can be called from signal handler. It
4392 // doesn't block SIGINT et al.
4393 int os::fork_and_exec(char* cmd) {
4394   const char * argv[4] = {"sh", "-c", cmd, NULL};
4395 
4396   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4397   // pthread_atfork handlers and reset pthread library. All we need is a
4398   // separate process to execve. Make a direct syscall to fork process.
4399   // On IA64 there's no fork syscall, we have to use fork() and hope for
4400   // the best...
4401   pid_t pid = fork();
4402 
4403   if (pid < 0) {
4404     // fork failed
4405     return -1;
4406 
4407   } else if (pid == 0) {
4408     // child process
4409 
4410     // execve() in BsdThreads will call pthread_kill_other_threads_np()
4411     // first to kill every thread on the thread list. Because this list is
4412     // not reset by fork() (see notes above), execve() will instead kill
4413     // every thread in the parent process. We know this is the only thread
4414     // in the new process, so make a system call directly.
4415     // IA64 should use normal execve() from glibc to match the glibc fork()
4416     // above.
4417     execve("/bin/sh", (char* const*)argv, environ);
4418 
4419     // execve failed
4420     _exit(-1);
4421 
4422   } else  {
4423     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4424     // care about the actual exit code, for now.
4425 
4426     int status;
4427 
4428     // Wait for the child process to exit.  This returns immediately if
4429     // the child has already exited. */
4430     while (waitpid(pid, &status, 0) < 0) {
4431         switch (errno) {
4432         case ECHILD: return 0;
4433         case EINTR: break;
4434         default: return -1;
4435         }
4436     }
4437 
4438     if (WIFEXITED(status)) {
4439        // The child exited normally; get its exit code.
4440        return WEXITSTATUS(status);
4441     } else if (WIFSIGNALED(status)) {
4442        // The child exited because of a signal
4443        // The best value to return is 0x80 + signal number,
4444        // because that is what all Unix shells do, and because
4445        // it allows callers to distinguish between process exit and
4446        // process death by signal.
4447        return 0x80 + WTERMSIG(status);
4448     } else {
4449        // Unknown exit code; pass it through
4450        return status;
4451     }
4452   }
4453 }
4454 
4455 // is_headless_jre()
4456 //
4457 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4458 // in order to report if we are running in a headless jre
4459 //
4460 // Since JDK8 xawt/libmawt.so was moved into the same directory
4461 // as libawt.so, and renamed libawt_xawt.so
4462 //
4463 bool os::is_headless_jre() {
4464     struct stat statbuf;
4465     char buf[MAXPATHLEN];
4466     char libmawtpath[MAXPATHLEN];
4467     const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
4468     const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4469     char *p;
4470 
4471     // Get path to libjvm.so
4472     os::jvm_path(buf, sizeof(buf));
4473 
4474     // Get rid of libjvm.so
4475     p = strrchr(buf, '/');
4476     if (p == NULL) return false;
4477     else *p = '\0';
4478 
4479     // Get rid of client or server
4480     p = strrchr(buf, '/');
4481     if (p == NULL) return false;
4482     else *p = '\0';
4483 
4484     // check xawt/libmawt.so
4485     strcpy(libmawtpath, buf);
4486     strcat(libmawtpath, xawtstr);
4487     if (::stat(libmawtpath, &statbuf) == 0) return false;
4488 
4489     // check libawt_xawt.so
4490     strcpy(libmawtpath, buf);
4491     strcat(libmawtpath, new_xawtstr);
4492     if (::stat(libmawtpath, &statbuf) == 0) return false;
4493 
4494     return true;
4495 }
4496 
4497 // Get the default path to the core file
4498 // Returns the length of the string
4499 int os::get_core_path(char* buffer, size_t bufferSize) {
4500   int n = jio_snprintf(buffer, bufferSize, "/cores");
4501 
4502   // Truncate if theoretical string was longer than bufferSize
4503   n = MIN2(n, (int)bufferSize);
4504 
4505   return n;
4506 }