src/os/bsd/vm/os_bsd.cpp

Wed, 05 Jun 2013 14:12:49 -0400

author
hseigel
date
Wed, 05 Jun 2013 14:12:49 -0400
changeset 5218
6bf8b8bb7c19
parent 5040
9ce110b1d14a
child 5219
f8c8cace25ad
permissions
-rw-r--r--

8009302: Mac OS X: JVM crash on infinite recursion on Appkit Thread
Summary: Use SA_ONSTACK flag to ensure signal gets delivered properly.
Reviewed-by: dholmes, coleenp
Contributed-by: gerard.ziemski@oracle.com

     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  */
    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"
    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>
   104 #if defined(__FreeBSD__) || defined(__NetBSD__)
   105 # include <elf.h>
   106 #endif
   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
   115 #ifndef MAP_ANONYMOUS
   116 #define MAP_ANONYMOUS MAP_ANON
   117 #endif
   119 #define MAX_PATH    (2 * K)
   121 // for timer info max values which include all bits
   122 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
   124 #define LARGEPAGES_BIT (1 << 6)
   125 ////////////////////////////////////////////////////////////////////////////////
   126 // global variables
   127 julong os::Bsd::_physical_memory = 0;
   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;
   134 static jlong initial_time_count=0;
   136 static int clock_tics_per_sec = 100;
   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;
   142 static pid_t _initial_pid = 0;
   144 /* Signal number used to suspend/resume a thread */
   146 /* do not use any signal number less than SIGSEGV, see 4355769 */
   147 static int SR_signum = SIGUSR2;
   148 sigset_t SR_sigset;
   151 ////////////////////////////////////////////////////////////////////////////////
   152 // utility functions
   154 static int SR_initialize();
   156 julong os::available_memory() {
   157   return Bsd::available_memory();
   158 }
   160 julong os::Bsd::available_memory() {
   161   // XXXBSD: this is just a stopgap implementation
   162   return physical_memory() >> 2;
   163 }
   165 julong os::physical_memory() {
   166   return Bsd::physical_memory();
   167 }
   169 ////////////////////////////////////////////////////////////////////////////////
   170 // environment support
   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 }
   183 // Return true if user is running as root.
   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 }
   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
   220 // Compiler variant
   221 #ifdef COMPILER2
   222 #define COMPILER_VARIANT "server"
   223 #else
   224 #define COMPILER_VARIANT "client"
   225 #endif
   228 void os::Bsd::initialize_system_info() {
   229   int mib[2];
   230   size_t len;
   231   int cpu_val;
   232   julong mem_val;
   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   }
   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   }
   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 }
   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   }
   280   return home_dir;
   281 }
   282 #endif
   284 void os::init_system_properties_values() {
   285 //  char arch[12];
   286 //  sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
   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.
   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)
   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
   330 #define EXTENSIONS_DIR  "/lib/ext"
   331 #define ENDORSED_DIR    "/lib/endorsed"
   332 #define REG_DIR         "/usr/java/packages"
   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
   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));
   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);
   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         }
   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);
   382         if (!set_boot_path('/', ':'))
   383             return;
   384     }
   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;
   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
   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         }
   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         }
   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
   462         Arguments::set_library_path(ld_library_path);
   463     }
   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
   485         Arguments::set_ext_dirs(buf);
   486     }
   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   }
   497 #ifdef __APPLE__
   498 #undef SYS_EXTENSIONS_DIR
   499 #endif
   500 #undef malloc
   501 #undef getenv
   502 #undef EXTENSIONS_DIR
   503 #undef ENDORSED_DIR
   505   // Done
   506   return;
   507 }
   509 ////////////////////////////////////////////////////////////////////////////////
   510 // breakpoint support
   512 void os::breakpoint() {
   513   BREAKPOINT;
   514 }
   516 extern "C" void breakpoint() {
   517   // use debugger to set breakpoint here
   518 }
   520 ////////////////////////////////////////////////////////////////////////////////
   521 // signal support
   523 debug_only(static bool signal_sets_initialized = false);
   524 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
   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 }
   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);
   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);
   581 }
   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 }
   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 }
   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 }
   603 void os::Bsd::hotspot_sigmask(Thread* thread) {
   605   //Save caller's signal mask before setting VM signal mask
   606   sigset_t caller_sigmask;
   607   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
   609   OSThread* osthread = thread->osthread();
   610   osthread->set_caller_sigmask(caller_sigmask);
   612   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
   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 }
   626 //////////////////////////////////////////////////////////////////////////////
   627 // create new thread
   629 static address highest_vm_reserved_address();
   631 // check if it's safe to start a new thread
   632 static bool _thread_safety_check(Thread* thread) {
   633   return true;
   634 }
   636 #ifdef __APPLE__
   637 // library handle for calling objc_registerThreadWithCollector()
   638 // without static linking to the libobjc library
   639 #define OBJC_LIB "/usr/lib/libobjc.dylib"
   640 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
   641 typedef void (*objc_registerThreadWithCollector_t)();
   642 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
   643 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
   644 #endif
   646 #ifdef __APPLE__
   647 static uint64_t locate_unique_thread_id() {
   648   // Additional thread_id used to correlate threads in SA
   649   thread_identifier_info_data_t     m_ident_info;
   650   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
   652   thread_info(::mach_thread_self(), THREAD_IDENTIFIER_INFO,
   653               (thread_info_t) &m_ident_info, &count);
   654   return m_ident_info.thread_id;
   655 }
   656 #endif
   658 // Thread start routine for all newly created threads
   659 static void *java_start(Thread *thread) {
   660   // Try to randomize the cache line index of hot stack frames.
   661   // This helps when threads of the same stack traces evict each other's
   662   // cache lines. The threads can be either from the same JVM instance, or
   663   // from different JVM instances. The benefit is especially true for
   664   // processors with hyperthreading technology.
   665   static int counter = 0;
   666   int pid = os::current_process_id();
   667   alloca(((pid ^ counter++) & 7) * 128);
   669   ThreadLocalStorage::set_thread(thread);
   671   OSThread* osthread = thread->osthread();
   672   Monitor* sync = osthread->startThread_lock();
   674   // non floating stack BsdThreads needs extra check, see above
   675   if (!_thread_safety_check(thread)) {
   676     // notify parent thread
   677     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
   678     osthread->set_state(ZOMBIE);
   679     sync->notify_all();
   680     return NULL;
   681   }
   683 #ifdef __APPLE__
   684   // thread_id is mach thread on macos
   685   osthread->set_thread_id(::mach_thread_self());
   686   osthread->set_unique_thread_id(locate_unique_thread_id());
   687 #else
   688   // thread_id is pthread_id on BSD
   689   osthread->set_thread_id(::pthread_self());
   690 #endif
   691   // initialize signal mask for this thread
   692   os::Bsd::hotspot_sigmask(thread);
   694   // initialize floating point control register
   695   os::Bsd::init_thread_fpu_state();
   697 #ifdef __APPLE__
   698   // register thread with objc gc
   699   if (objc_registerThreadWithCollectorFunction != NULL) {
   700     objc_registerThreadWithCollectorFunction();
   701   }
   702 #endif
   704   // handshaking with parent thread
   705   {
   706     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
   708     // notify parent thread
   709     osthread->set_state(INITIALIZED);
   710     sync->notify_all();
   712     // wait until os::start_thread()
   713     while (osthread->get_state() == INITIALIZED) {
   714       sync->wait(Mutex::_no_safepoint_check_flag);
   715     }
   716   }
   718   // call one more level start routine
   719   thread->run();
   721   return 0;
   722 }
   724 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
   725   assert(thread->osthread() == NULL, "caller responsible");
   727   // Allocate the OSThread object
   728   OSThread* osthread = new OSThread(NULL, NULL);
   729   if (osthread == NULL) {
   730     return false;
   731   }
   733   // set the correct thread state
   734   osthread->set_thread_type(thr_type);
   736   // Initial state is ALLOCATED but not INITIALIZED
   737   osthread->set_state(ALLOCATED);
   739   thread->set_osthread(osthread);
   741   // init thread attributes
   742   pthread_attr_t attr;
   743   pthread_attr_init(&attr);
   744   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
   746   // stack size
   747   if (os::Bsd::supports_variable_stack_size()) {
   748     // calculate stack size if it's not specified by caller
   749     if (stack_size == 0) {
   750       stack_size = os::Bsd::default_stack_size(thr_type);
   752       switch (thr_type) {
   753       case os::java_thread:
   754         // Java threads use ThreadStackSize which default value can be
   755         // changed with the flag -Xss
   756         assert (JavaThread::stack_size_at_create() > 0, "this should be set");
   757         stack_size = JavaThread::stack_size_at_create();
   758         break;
   759       case os::compiler_thread:
   760         if (CompilerThreadStackSize > 0) {
   761           stack_size = (size_t)(CompilerThreadStackSize * K);
   762           break;
   763         } // else fall through:
   764           // use VMThreadStackSize if CompilerThreadStackSize is not defined
   765       case os::vm_thread:
   766       case os::pgc_thread:
   767       case os::cgc_thread:
   768       case os::watcher_thread:
   769         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
   770         break;
   771       }
   772     }
   774     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
   775     pthread_attr_setstacksize(&attr, stack_size);
   776   } else {
   777     // let pthread_create() pick the default value.
   778   }
   780   ThreadState state;
   782   {
   783     pthread_t tid;
   784     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
   786     pthread_attr_destroy(&attr);
   788     if (ret != 0) {
   789       if (PrintMiscellaneous && (Verbose || WizardMode)) {
   790         perror("pthread_create()");
   791       }
   792       // Need to clean up stuff we've allocated so far
   793       thread->set_osthread(NULL);
   794       delete osthread;
   795       return false;
   796     }
   798     // Store pthread info into the OSThread
   799     osthread->set_pthread_id(tid);
   801     // Wait until child thread is either initialized or aborted
   802     {
   803       Monitor* sync_with_child = osthread->startThread_lock();
   804       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
   805       while ((state = osthread->get_state()) == ALLOCATED) {
   806         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
   807       }
   808     }
   810   }
   812   // Aborted due to thread limit being reached
   813   if (state == ZOMBIE) {
   814       thread->set_osthread(NULL);
   815       delete osthread;
   816       return false;
   817   }
   819   // The thread is returned suspended (in state INITIALIZED),
   820   // and is started higher up in the call chain
   821   assert(state == INITIALIZED, "race condition");
   822   return true;
   823 }
   825 /////////////////////////////////////////////////////////////////////////////
   826 // attach existing thread
   828 // bootstrap the main thread
   829 bool os::create_main_thread(JavaThread* thread) {
   830   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
   831   return create_attached_thread(thread);
   832 }
   834 bool os::create_attached_thread(JavaThread* thread) {
   835 #ifdef ASSERT
   836     thread->verify_not_published();
   837 #endif
   839   // Allocate the OSThread object
   840   OSThread* osthread = new OSThread(NULL, NULL);
   842   if (osthread == NULL) {
   843     return false;
   844   }
   846   // Store pthread info into the OSThread
   847 #ifdef __APPLE__
   848   osthread->set_thread_id(::mach_thread_self());
   849   osthread->set_unique_thread_id(locate_unique_thread_id());
   850 #else
   851   osthread->set_thread_id(::pthread_self());
   852 #endif
   853   osthread->set_pthread_id(::pthread_self());
   855   // initialize floating point control register
   856   os::Bsd::init_thread_fpu_state();
   858   // Initial thread state is RUNNABLE
   859   osthread->set_state(RUNNABLE);
   861   thread->set_osthread(osthread);
   863   // initialize signal mask for this thread
   864   // and save the caller's signal mask
   865   os::Bsd::hotspot_sigmask(thread);
   867   return true;
   868 }
   870 void os::pd_start_thread(Thread* thread) {
   871   OSThread * osthread = thread->osthread();
   872   assert(osthread->get_state() != INITIALIZED, "just checking");
   873   Monitor* sync_with_child = osthread->startThread_lock();
   874   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
   875   sync_with_child->notify();
   876 }
   878 // Free Bsd resources related to the OSThread
   879 void os::free_thread(OSThread* osthread) {
   880   assert(osthread != NULL, "osthread not set");
   882   if (Thread::current()->osthread() == osthread) {
   883     // Restore caller's signal mask
   884     sigset_t sigmask = osthread->caller_sigmask();
   885     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
   886    }
   888   delete osthread;
   889 }
   891 //////////////////////////////////////////////////////////////////////////////
   892 // thread local storage
   894 int os::allocate_thread_local_storage() {
   895   pthread_key_t key;
   896   int rslt = pthread_key_create(&key, NULL);
   897   assert(rslt == 0, "cannot allocate thread local storage");
   898   return (int)key;
   899 }
   901 // Note: This is currently not used by VM, as we don't destroy TLS key
   902 // on VM exit.
   903 void os::free_thread_local_storage(int index) {
   904   int rslt = pthread_key_delete((pthread_key_t)index);
   905   assert(rslt == 0, "invalid index");
   906 }
   908 void os::thread_local_storage_at_put(int index, void* value) {
   909   int rslt = pthread_setspecific((pthread_key_t)index, value);
   910   assert(rslt == 0, "pthread_setspecific failed");
   911 }
   913 extern "C" Thread* get_thread() {
   914   return ThreadLocalStorage::thread();
   915 }
   918 ////////////////////////////////////////////////////////////////////////////////
   919 // time support
   921 // Time since start-up in seconds to a fine granularity.
   922 // Used by VMSelfDestructTimer and the MemProfiler.
   923 double os::elapsedTime() {
   925   return (double)(os::elapsed_counter()) * 0.000001;
   926 }
   928 jlong os::elapsed_counter() {
   929   timeval time;
   930   int status = gettimeofday(&time, NULL);
   931   return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count;
   932 }
   934 jlong os::elapsed_frequency() {
   935   return (1000 * 1000);
   936 }
   938 // XXX: For now, code this as if BSD does not support vtime.
   939 bool os::supports_vtime() { return false; }
   940 bool os::enable_vtime()   { return false; }
   941 bool os::vtime_enabled()  { return false; }
   942 double os::elapsedVTime() {
   943   // better than nothing, but not much
   944   return elapsedTime();
   945 }
   947 jlong os::javaTimeMillis() {
   948   timeval time;
   949   int status = gettimeofday(&time, NULL);
   950   assert(status != -1, "bsd error");
   951   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
   952 }
   954 #ifndef CLOCK_MONOTONIC
   955 #define CLOCK_MONOTONIC (1)
   956 #endif
   958 #ifdef __APPLE__
   959 void os::Bsd::clock_init() {
   960         // XXXDARWIN: Investigate replacement monotonic clock
   961 }
   962 #else
   963 void os::Bsd::clock_init() {
   964   struct timespec res;
   965   struct timespec tp;
   966   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
   967       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
   968     // yes, monotonic clock is supported
   969     _clock_gettime = ::clock_gettime;
   970   }
   971 }
   972 #endif
   975 jlong os::javaTimeNanos() {
   976   if (Bsd::supports_monotonic_clock()) {
   977     struct timespec tp;
   978     int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp);
   979     assert(status == 0, "gettime error");
   980     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
   981     return result;
   982   } else {
   983     timeval time;
   984     int status = gettimeofday(&time, NULL);
   985     assert(status != -1, "bsd error");
   986     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
   987     return 1000 * usecs;
   988   }
   989 }
   991 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
   992   if (Bsd::supports_monotonic_clock()) {
   993     info_ptr->max_value = ALL_64_BITS;
   995     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
   996     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
   997     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
   998   } else {
   999     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
  1000     info_ptr->max_value = ALL_64_BITS;
  1002     // gettimeofday is a real time clock so it skips
  1003     info_ptr->may_skip_backward = true;
  1004     info_ptr->may_skip_forward = true;
  1007   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
  1010 // Return the real, user, and system times in seconds from an
  1011 // arbitrary fixed point in the past.
  1012 bool os::getTimesSecs(double* process_real_time,
  1013                       double* process_user_time,
  1014                       double* process_system_time) {
  1015   struct tms ticks;
  1016   clock_t real_ticks = times(&ticks);
  1018   if (real_ticks == (clock_t) (-1)) {
  1019     return false;
  1020   } else {
  1021     double ticks_per_second = (double) clock_tics_per_sec;
  1022     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
  1023     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
  1024     *process_real_time = ((double) real_ticks) / ticks_per_second;
  1026     return true;
  1031 char * os::local_time_string(char *buf, size_t buflen) {
  1032   struct tm t;
  1033   time_t long_time;
  1034   time(&long_time);
  1035   localtime_r(&long_time, &t);
  1036   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
  1037                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
  1038                t.tm_hour, t.tm_min, t.tm_sec);
  1039   return buf;
  1042 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
  1043   return localtime_r(clock, res);
  1046 ////////////////////////////////////////////////////////////////////////////////
  1047 // runtime exit support
  1049 // Note: os::shutdown() might be called very early during initialization, or
  1050 // called from signal handler. Before adding something to os::shutdown(), make
  1051 // sure it is async-safe and can handle partially initialized VM.
  1052 void os::shutdown() {
  1054   // allow PerfMemory to attempt cleanup of any persistent resources
  1055   perfMemory_exit();
  1057   // needs to remove object in file system
  1058   AttachListener::abort();
  1060   // flush buffered output, finish log files
  1061   ostream_abort();
  1063   // Check for abort hook
  1064   abort_hook_t abort_hook = Arguments::abort_hook();
  1065   if (abort_hook != NULL) {
  1066     abort_hook();
  1071 // Note: os::abort() might be called very early during initialization, or
  1072 // called from signal handler. Before adding something to os::abort(), make
  1073 // sure it is async-safe and can handle partially initialized VM.
  1074 void os::abort(bool dump_core) {
  1075   os::shutdown();
  1076   if (dump_core) {
  1077 #ifndef PRODUCT
  1078     fdStream out(defaultStream::output_fd());
  1079     out.print_raw("Current thread is ");
  1080     char buf[16];
  1081     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
  1082     out.print_raw_cr(buf);
  1083     out.print_raw_cr("Dumping core ...");
  1084 #endif
  1085     ::abort(); // dump core
  1088   ::exit(1);
  1091 // Die immediately, no exit hook, no abort hook, no cleanup.
  1092 void os::die() {
  1093   // _exit() on BsdThreads only kills current thread
  1094   ::abort();
  1097 // unused on bsd for now.
  1098 void os::set_error_file(const char *logfile) {}
  1101 // This method is a copy of JDK's sysGetLastErrorString
  1102 // from src/solaris/hpi/src/system_md.c
  1104 size_t os::lasterror(char *buf, size_t len) {
  1106   if (errno == 0)  return 0;
  1108   const char *s = ::strerror(errno);
  1109   size_t n = ::strlen(s);
  1110   if (n >= len) {
  1111     n = len - 1;
  1113   ::strncpy(buf, s, n);
  1114   buf[n] = '\0';
  1115   return n;
  1118 intx os::current_thread_id() {
  1119 #ifdef __APPLE__
  1120   return (intx)::mach_thread_self();
  1121 #else
  1122   return (intx)::pthread_self();
  1123 #endif
  1125 int os::current_process_id() {
  1127   // Under the old bsd thread library, bsd gives each thread
  1128   // its own process id. Because of this each thread will return
  1129   // a different pid if this method were to return the result
  1130   // of getpid(2). Bsd provides no api that returns the pid
  1131   // of the launcher thread for the vm. This implementation
  1132   // returns a unique pid, the pid of the launcher thread
  1133   // that starts the vm 'process'.
  1135   // Under the NPTL, getpid() returns the same pid as the
  1136   // launcher thread rather than a unique pid per thread.
  1137   // Use gettid() if you want the old pre NPTL behaviour.
  1139   // if you are looking for the result of a call to getpid() that
  1140   // returns a unique pid for the calling thread, then look at the
  1141   // OSThread::thread_id() method in osThread_bsd.hpp file
  1143   return (int)(_initial_pid ? _initial_pid : getpid());
  1146 // DLL functions
  1148 #define JNI_LIB_PREFIX "lib"
  1149 #ifdef __APPLE__
  1150 #define JNI_LIB_SUFFIX ".dylib"
  1151 #else
  1152 #define JNI_LIB_SUFFIX ".so"
  1153 #endif
  1155 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
  1157 // This must be hard coded because it's the system's temporary
  1158 // directory not the java application's temp directory, ala java.io.tmpdir.
  1159 #ifdef __APPLE__
  1160 // macosx has a secure per-user temporary directory
  1161 char temp_path_storage[PATH_MAX];
  1162 const char* os::get_temp_directory() {
  1163   static char *temp_path = NULL;
  1164   if (temp_path == NULL) {
  1165     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
  1166     if (pathSize == 0 || pathSize > PATH_MAX) {
  1167       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
  1169     temp_path = temp_path_storage;
  1171   return temp_path;
  1173 #else /* __APPLE__ */
  1174 const char* os::get_temp_directory() { return "/tmp"; }
  1175 #endif /* __APPLE__ */
  1177 static bool file_exists(const char* filename) {
  1178   struct stat statbuf;
  1179   if (filename == NULL || strlen(filename) == 0) {
  1180     return false;
  1182   return os::stat(filename, &statbuf) == 0;
  1185 bool os::dll_build_name(char* buffer, size_t buflen,
  1186                         const char* pname, const char* fname) {
  1187   bool retval = false;
  1188   // Copied from libhpi
  1189   const size_t pnamelen = pname ? strlen(pname) : 0;
  1191   // Return error on buffer overflow.
  1192   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
  1193     return retval;
  1196   if (pnamelen == 0) {
  1197     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
  1198     retval = true;
  1199   } else if (strchr(pname, *os::path_separator()) != NULL) {
  1200     int n;
  1201     char** pelements = split_path(pname, &n);
  1202     if (pelements == NULL) {
  1203       return false;
  1205     for (int i = 0 ; i < n ; i++) {
  1206       // Really shouldn't be NULL, but check can't hurt
  1207       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
  1208         continue; // skip the empty path values
  1210       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
  1211           pelements[i], fname);
  1212       if (file_exists(buffer)) {
  1213         retval = true;
  1214         break;
  1217     // release the storage
  1218     for (int i = 0 ; i < n ; i++) {
  1219       if (pelements[i] != NULL) {
  1220         FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
  1223     if (pelements != NULL) {
  1224       FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
  1226   } else {
  1227     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
  1228     retval = true;
  1230   return retval;
  1233 // check if addr is inside libjvm.so
  1234 bool os::address_is_in_vm(address addr) {
  1235   static address libjvm_base_addr;
  1236   Dl_info dlinfo;
  1238   if (libjvm_base_addr == NULL) {
  1239     dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo);
  1240     libjvm_base_addr = (address)dlinfo.dli_fbase;
  1241     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
  1244   if (dladdr((void *)addr, &dlinfo)) {
  1245     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
  1248   return false;
  1252 #define MACH_MAXSYMLEN 256
  1254 bool os::dll_address_to_function_name(address addr, char *buf,
  1255                                       int buflen, int *offset) {
  1256   Dl_info dlinfo;
  1257   char localbuf[MACH_MAXSYMLEN];
  1259   // dladdr will find names of dynamic functions only, but does
  1260   // it set dli_fbase with mach_header address when it "fails" ?
  1261   if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) {
  1262     if (buf != NULL) {
  1263       if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
  1264         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
  1267     if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
  1268     return true;
  1269   } else if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != 0) {
  1270     if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
  1271        buf, buflen, offset, dlinfo.dli_fname)) {
  1272        return true;
  1276   // Handle non-dymanic manually:
  1277   if (dlinfo.dli_fbase != NULL &&
  1278       Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
  1279     if(!Decoder::demangle(localbuf, buf, buflen)) {
  1280       jio_snprintf(buf, buflen, "%s", localbuf);
  1282     return true;
  1284   if (buf != NULL) buf[0] = '\0';
  1285   if (offset != NULL) *offset = -1;
  1286   return false;
  1289 // ported from solaris version
  1290 bool os::dll_address_to_library_name(address addr, char* buf,
  1291                                      int buflen, int* offset) {
  1292   Dl_info dlinfo;
  1294   if (dladdr((void*)addr, &dlinfo)){
  1295      if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
  1296      if (offset) *offset = addr - (address)dlinfo.dli_fbase;
  1297      return true;
  1298   } else {
  1299      if (buf) buf[0] = '\0';
  1300      if (offset) *offset = -1;
  1301      return false;
  1305 // Loads .dll/.so and
  1306 // in case of error it checks if .dll/.so was built for the
  1307 // same architecture as Hotspot is running on
  1309 #ifdef __APPLE__
  1310 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
  1311   void * result= ::dlopen(filename, RTLD_LAZY);
  1312   if (result != NULL) {
  1313     // Successful loading
  1314     return result;
  1317   // Read system error message into ebuf
  1318   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
  1319   ebuf[ebuflen-1]='\0';
  1321   return NULL;
  1323 #else
  1324 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
  1326   void * result= ::dlopen(filename, RTLD_LAZY);
  1327   if (result != NULL) {
  1328     // Successful loading
  1329     return result;
  1332   Elf32_Ehdr elf_head;
  1334   // Read system error message into ebuf
  1335   // It may or may not be overwritten below
  1336   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
  1337   ebuf[ebuflen-1]='\0';
  1338   int diag_msg_max_length=ebuflen-strlen(ebuf);
  1339   char* diag_msg_buf=ebuf+strlen(ebuf);
  1341   if (diag_msg_max_length==0) {
  1342     // No more space in ebuf for additional diagnostics message
  1343     return NULL;
  1347   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
  1349   if (file_descriptor < 0) {
  1350     // Can't open library, report dlerror() message
  1351     return NULL;
  1354   bool failed_to_read_elf_head=
  1355     (sizeof(elf_head)!=
  1356         (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
  1358   ::close(file_descriptor);
  1359   if (failed_to_read_elf_head) {
  1360     // file i/o error - report dlerror() msg
  1361     return NULL;
  1364   typedef struct {
  1365     Elf32_Half  code;         // Actual value as defined in elf.h
  1366     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
  1367     char        elf_class;    // 32 or 64 bit
  1368     char        endianess;    // MSB or LSB
  1369     char*       name;         // String representation
  1370   } arch_t;
  1372   #ifndef EM_486
  1373   #define EM_486          6               /* Intel 80486 */
  1374   #endif
  1376   #ifndef EM_MIPS_RS3_LE
  1377   #define EM_MIPS_RS3_LE  10              /* MIPS */
  1378   #endif
  1380   #ifndef EM_PPC64
  1381   #define EM_PPC64        21              /* PowerPC64 */
  1382   #endif
  1384   #ifndef EM_S390
  1385   #define EM_S390         22              /* IBM System/390 */
  1386   #endif
  1388   #ifndef EM_IA_64
  1389   #define EM_IA_64        50              /* HP/Intel IA-64 */
  1390   #endif
  1392   #ifndef EM_X86_64
  1393   #define EM_X86_64       62              /* AMD x86-64 */
  1394   #endif
  1396   static const arch_t arch_array[]={
  1397     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
  1398     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
  1399     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
  1400     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
  1401     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
  1402     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
  1403     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
  1404     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
  1405     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
  1406     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
  1407     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
  1408     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
  1409     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
  1410     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
  1411     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
  1412     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
  1413   };
  1415   #if  (defined IA32)
  1416     static  Elf32_Half running_arch_code=EM_386;
  1417   #elif   (defined AMD64)
  1418     static  Elf32_Half running_arch_code=EM_X86_64;
  1419   #elif  (defined IA64)
  1420     static  Elf32_Half running_arch_code=EM_IA_64;
  1421   #elif  (defined __sparc) && (defined _LP64)
  1422     static  Elf32_Half running_arch_code=EM_SPARCV9;
  1423   #elif  (defined __sparc) && (!defined _LP64)
  1424     static  Elf32_Half running_arch_code=EM_SPARC;
  1425   #elif  (defined __powerpc64__)
  1426     static  Elf32_Half running_arch_code=EM_PPC64;
  1427   #elif  (defined __powerpc__)
  1428     static  Elf32_Half running_arch_code=EM_PPC;
  1429   #elif  (defined ARM)
  1430     static  Elf32_Half running_arch_code=EM_ARM;
  1431   #elif  (defined S390)
  1432     static  Elf32_Half running_arch_code=EM_S390;
  1433   #elif  (defined ALPHA)
  1434     static  Elf32_Half running_arch_code=EM_ALPHA;
  1435   #elif  (defined MIPSEL)
  1436     static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
  1437   #elif  (defined PARISC)
  1438     static  Elf32_Half running_arch_code=EM_PARISC;
  1439   #elif  (defined MIPS)
  1440     static  Elf32_Half running_arch_code=EM_MIPS;
  1441   #elif  (defined M68K)
  1442     static  Elf32_Half running_arch_code=EM_68K;
  1443   #else
  1444     #error Method os::dll_load requires that one of following is defined:\
  1445          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
  1446   #endif
  1448   // Identify compatability class for VM's architecture and library's architecture
  1449   // Obtain string descriptions for architectures
  1451   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
  1452   int running_arch_index=-1;
  1454   for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
  1455     if (running_arch_code == arch_array[i].code) {
  1456       running_arch_index    = i;
  1458     if (lib_arch.code == arch_array[i].code) {
  1459       lib_arch.compat_class = arch_array[i].compat_class;
  1460       lib_arch.name         = arch_array[i].name;
  1464   assert(running_arch_index != -1,
  1465     "Didn't find running architecture code (running_arch_code) in arch_array");
  1466   if (running_arch_index == -1) {
  1467     // Even though running architecture detection failed
  1468     // we may still continue with reporting dlerror() message
  1469     return NULL;
  1472   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
  1473     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
  1474     return NULL;
  1477 #ifndef S390
  1478   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
  1479     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
  1480     return NULL;
  1482 #endif // !S390
  1484   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
  1485     if ( lib_arch.name!=NULL ) {
  1486       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
  1487         " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
  1488         lib_arch.name, arch_array[running_arch_index].name);
  1489     } else {
  1490       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
  1491       " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
  1492         lib_arch.code,
  1493         arch_array[running_arch_index].name);
  1497   return NULL;
  1499 #endif /* !__APPLE__ */
  1501 // XXX: Do we need a lock around this as per Linux?
  1502 void* os::dll_lookup(void* handle, const char* name) {
  1503   return dlsym(handle, name);
  1507 static bool _print_ascii_file(const char* filename, outputStream* st) {
  1508   int fd = ::open(filename, O_RDONLY);
  1509   if (fd == -1) {
  1510      return false;
  1513   char buf[32];
  1514   int bytes;
  1515   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
  1516     st->print_raw(buf, bytes);
  1519   ::close(fd);
  1521   return true;
  1524 void os::print_dll_info(outputStream *st) {
  1525    st->print_cr("Dynamic libraries:");
  1526 #ifdef RTLD_DI_LINKMAP
  1527     Dl_info dli;
  1528     void *handle;
  1529     Link_map *map;
  1530     Link_map *p;
  1532     if (!dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli)) {
  1533         st->print_cr("Error: Cannot print dynamic libraries.");
  1534         return;
  1536     handle = dlopen(dli.dli_fname, RTLD_LAZY);
  1537     if (handle == NULL) {
  1538         st->print_cr("Error: Cannot print dynamic libraries.");
  1539         return;
  1541     dlinfo(handle, RTLD_DI_LINKMAP, &map);
  1542     if (map == NULL) {
  1543         st->print_cr("Error: Cannot print dynamic libraries.");
  1544         return;
  1547     while (map->l_prev != NULL)
  1548         map = map->l_prev;
  1550     while (map != NULL) {
  1551         st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
  1552         map = map->l_next;
  1555     dlclose(handle);
  1556 #elif defined(__APPLE__)
  1557     uint32_t count;
  1558     uint32_t i;
  1560     count = _dyld_image_count();
  1561     for (i = 1; i < count; i++) {
  1562         const char *name = _dyld_get_image_name(i);
  1563         intptr_t slide = _dyld_get_image_vmaddr_slide(i);
  1564         st->print_cr(PTR_FORMAT " \t%s", slide, name);
  1566 #else
  1567    st->print_cr("Error: Cannot print dynamic libraries.");
  1568 #endif
  1571 void os::print_os_info_brief(outputStream* st) {
  1572   st->print("Bsd");
  1574   os::Posix::print_uname_info(st);
  1577 void os::print_os_info(outputStream* st) {
  1578   st->print("OS:");
  1579   st->print("Bsd");
  1581   os::Posix::print_uname_info(st);
  1583   os::Posix::print_rlimit_info(st);
  1585   os::Posix::print_load_average(st);
  1588 void os::pd_print_cpu_info(outputStream* st) {
  1589   // Nothing to do for now.
  1592 void os::print_memory_info(outputStream* st) {
  1594   st->print("Memory:");
  1595   st->print(" %dk page", os::vm_page_size()>>10);
  1597   st->print(", physical " UINT64_FORMAT "k",
  1598             os::physical_memory() >> 10);
  1599   st->print("(" UINT64_FORMAT "k free)",
  1600             os::available_memory() >> 10);
  1601   st->cr();
  1603   // meminfo
  1604   st->print("\n/proc/meminfo:\n");
  1605   _print_ascii_file("/proc/meminfo", st);
  1606   st->cr();
  1609 // Taken from /usr/include/bits/siginfo.h  Supposed to be architecture specific
  1610 // but they're the same for all the bsd arch that we support
  1611 // and they're the same for solaris but there's no common place to put this.
  1612 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
  1613                           "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
  1614                           "ILL_COPROC", "ILL_BADSTK" };
  1616 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
  1617                           "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
  1618                           "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
  1620 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
  1622 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
  1624 void os::print_siginfo(outputStream* st, void* siginfo) {
  1625   st->print("siginfo:");
  1627   const int buflen = 100;
  1628   char buf[buflen];
  1629   siginfo_t *si = (siginfo_t*)siginfo;
  1630   st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
  1631   if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
  1632     st->print("si_errno=%s", buf);
  1633   } else {
  1634     st->print("si_errno=%d", si->si_errno);
  1636   const int c = si->si_code;
  1637   assert(c > 0, "unexpected si_code");
  1638   switch (si->si_signo) {
  1639   case SIGILL:
  1640     st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
  1641     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1642     break;
  1643   case SIGFPE:
  1644     st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
  1645     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1646     break;
  1647   case SIGSEGV:
  1648     st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
  1649     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1650     break;
  1651   case SIGBUS:
  1652     st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
  1653     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1654     break;
  1655   default:
  1656     st->print(", si_code=%d", si->si_code);
  1657     // no si_addr
  1660   if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
  1661       UseSharedSpaces) {
  1662     FileMapInfo* mapinfo = FileMapInfo::current_info();
  1663     if (mapinfo->is_in_shared_space(si->si_addr)) {
  1664       st->print("\n\nError accessing class data sharing archive."   \
  1665                 " Mapped file inaccessible during execution, "      \
  1666                 " possible disk/network problem.");
  1669   st->cr();
  1673 static void print_signal_handler(outputStream* st, int sig,
  1674                                  char* buf, size_t buflen);
  1676 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
  1677   st->print_cr("Signal Handlers:");
  1678   print_signal_handler(st, SIGSEGV, buf, buflen);
  1679   print_signal_handler(st, SIGBUS , buf, buflen);
  1680   print_signal_handler(st, SIGFPE , buf, buflen);
  1681   print_signal_handler(st, SIGPIPE, buf, buflen);
  1682   print_signal_handler(st, SIGXFSZ, buf, buflen);
  1683   print_signal_handler(st, SIGILL , buf, buflen);
  1684   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
  1685   print_signal_handler(st, SR_signum, buf, buflen);
  1686   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
  1687   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
  1688   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
  1689   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
  1692 static char saved_jvm_path[MAXPATHLEN] = {0};
  1694 // Find the full path to the current module, libjvm
  1695 void os::jvm_path(char *buf, jint buflen) {
  1696   // Error checking.
  1697   if (buflen < MAXPATHLEN) {
  1698     assert(false, "must use a large-enough buffer");
  1699     buf[0] = '\0';
  1700     return;
  1702   // Lazy resolve the path to current module.
  1703   if (saved_jvm_path[0] != 0) {
  1704     strcpy(buf, saved_jvm_path);
  1705     return;
  1708   char dli_fname[MAXPATHLEN];
  1709   bool ret = dll_address_to_library_name(
  1710                 CAST_FROM_FN_PTR(address, os::jvm_path),
  1711                 dli_fname, sizeof(dli_fname), NULL);
  1712   assert(ret != 0, "cannot locate libjvm");
  1713   char *rp = realpath(dli_fname, buf);
  1714   if (rp == NULL)
  1715     return;
  1717   if (Arguments::created_by_gamma_launcher()) {
  1718     // Support for the gamma launcher.  Typical value for buf is
  1719     // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm".  If "/jre/lib/" appears at
  1720     // the right place in the string, then assume we are installed in a JDK and
  1721     // we're done.  Otherwise, check for a JAVA_HOME environment variable and
  1722     // construct a path to the JVM being overridden.
  1724     const char *p = buf + strlen(buf) - 1;
  1725     for (int count = 0; p > buf && count < 5; ++count) {
  1726       for (--p; p > buf && *p != '/'; --p)
  1727         /* empty */ ;
  1730     if (strncmp(p, "/jre/lib/", 9) != 0) {
  1731       // Look for JAVA_HOME in the environment.
  1732       char* java_home_var = ::getenv("JAVA_HOME");
  1733       if (java_home_var != NULL && java_home_var[0] != 0) {
  1734         char* jrelib_p;
  1735         int len;
  1737         // Check the current module name "libjvm"
  1738         p = strrchr(buf, '/');
  1739         assert(strstr(p, "/libjvm") == p, "invalid library name");
  1741         rp = realpath(java_home_var, buf);
  1742         if (rp == NULL)
  1743           return;
  1745         // determine if this is a legacy image or modules image
  1746         // modules image doesn't have "jre" subdirectory
  1747         len = strlen(buf);
  1748         jrelib_p = buf + len;
  1750         // Add the appropriate library subdir
  1751         snprintf(jrelib_p, buflen-len, "/jre/lib");
  1752         if (0 != access(buf, F_OK)) {
  1753           snprintf(jrelib_p, buflen-len, "/lib");
  1756         // Add the appropriate client or server subdir
  1757         len = strlen(buf);
  1758         jrelib_p = buf + len;
  1759         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
  1760         if (0 != access(buf, F_OK)) {
  1761           snprintf(jrelib_p, buflen-len, "");
  1764         // If the path exists within JAVA_HOME, add the JVM library name
  1765         // to complete the path to JVM being overridden.  Otherwise fallback
  1766         // to the path to the current library.
  1767         if (0 == access(buf, F_OK)) {
  1768           // Use current module name "libjvm"
  1769           len = strlen(buf);
  1770           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
  1771         } else {
  1772           // Fall back to path of current library
  1773           rp = realpath(dli_fname, buf);
  1774           if (rp == NULL)
  1775             return;
  1781   strcpy(saved_jvm_path, buf);
  1784 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
  1785   // no prefix required, not even "_"
  1788 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
  1789   // no suffix required
  1792 ////////////////////////////////////////////////////////////////////////////////
  1793 // sun.misc.Signal support
  1795 static volatile jint sigint_count = 0;
  1797 static void
  1798 UserHandler(int sig, void *siginfo, void *context) {
  1799   // 4511530 - sem_post is serialized and handled by the manager thread. When
  1800   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
  1801   // don't want to flood the manager thread with sem_post requests.
  1802   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
  1803       return;
  1805   // Ctrl-C is pressed during error reporting, likely because the error
  1806   // handler fails to abort. Let VM die immediately.
  1807   if (sig == SIGINT && is_error_reported()) {
  1808      os::die();
  1811   os::signal_notify(sig);
  1814 void* os::user_handler() {
  1815   return CAST_FROM_FN_PTR(void*, UserHandler);
  1818 extern "C" {
  1819   typedef void (*sa_handler_t)(int);
  1820   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
  1823 void* os::signal(int signal_number, void* handler) {
  1824   struct sigaction sigAct, oldSigAct;
  1826   sigfillset(&(sigAct.sa_mask));
  1827   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
  1828   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
  1830   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
  1831     // -1 means registration failed
  1832     return (void *)-1;
  1835   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
  1838 void os::signal_raise(int signal_number) {
  1839   ::raise(signal_number);
  1842 /*
  1843  * The following code is moved from os.cpp for making this
  1844  * code platform specific, which it is by its very nature.
  1845  */
  1847 // Will be modified when max signal is changed to be dynamic
  1848 int os::sigexitnum_pd() {
  1849   return NSIG;
  1852 // a counter for each possible signal value
  1853 static volatile jint pending_signals[NSIG+1] = { 0 };
  1855 // Bsd(POSIX) specific hand shaking semaphore.
  1856 #ifdef __APPLE__
  1857 static semaphore_t sig_sem;
  1858 #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
  1859 #define SEM_WAIT(sem)           semaphore_wait(sem);
  1860 #define SEM_POST(sem)           semaphore_signal(sem);
  1861 #else
  1862 static sem_t sig_sem;
  1863 #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
  1864 #define SEM_WAIT(sem)           sem_wait(&sem);
  1865 #define SEM_POST(sem)           sem_post(&sem);
  1866 #endif
  1868 void os::signal_init_pd() {
  1869   // Initialize signal structures
  1870   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
  1872   // Initialize signal semaphore
  1873   ::SEM_INIT(sig_sem, 0);
  1876 void os::signal_notify(int sig) {
  1877   Atomic::inc(&pending_signals[sig]);
  1878   ::SEM_POST(sig_sem);
  1881 static int check_pending_signals(bool wait) {
  1882   Atomic::store(0, &sigint_count);
  1883   for (;;) {
  1884     for (int i = 0; i < NSIG + 1; i++) {
  1885       jint n = pending_signals[i];
  1886       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
  1887         return i;
  1890     if (!wait) {
  1891       return -1;
  1893     JavaThread *thread = JavaThread::current();
  1894     ThreadBlockInVM tbivm(thread);
  1896     bool threadIsSuspended;
  1897     do {
  1898       thread->set_suspend_equivalent();
  1899       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
  1900       ::SEM_WAIT(sig_sem);
  1902       // were we externally suspended while we were waiting?
  1903       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
  1904       if (threadIsSuspended) {
  1905         //
  1906         // The semaphore has been incremented, but while we were waiting
  1907         // another thread suspended us. We don't want to continue running
  1908         // while suspended because that would surprise the thread that
  1909         // suspended us.
  1910         //
  1911         ::SEM_POST(sig_sem);
  1913         thread->java_suspend_self();
  1915     } while (threadIsSuspended);
  1919 int os::signal_lookup() {
  1920   return check_pending_signals(false);
  1923 int os::signal_wait() {
  1924   return check_pending_signals(true);
  1927 ////////////////////////////////////////////////////////////////////////////////
  1928 // Virtual Memory
  1930 int os::vm_page_size() {
  1931   // Seems redundant as all get out
  1932   assert(os::Bsd::page_size() != -1, "must call os::init");
  1933   return os::Bsd::page_size();
  1936 // Solaris allocates memory by pages.
  1937 int os::vm_allocation_granularity() {
  1938   assert(os::Bsd::page_size() != -1, "must call os::init");
  1939   return os::Bsd::page_size();
  1942 // Rationale behind this function:
  1943 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
  1944 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
  1945 //  samples for JITted code. Here we create private executable mapping over the code cache
  1946 //  and then we can use standard (well, almost, as mapping can change) way to provide
  1947 //  info for the reporting script by storing timestamp and location of symbol
  1948 void bsd_wrap_code(char* base, size_t size) {
  1949   static volatile jint cnt = 0;
  1951   if (!UseOprofile) {
  1952     return;
  1955   char buf[PATH_MAX + 1];
  1956   int num = Atomic::add(1, &cnt);
  1958   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
  1959            os::get_temp_directory(), os::current_process_id(), num);
  1960   unlink(buf);
  1962   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
  1964   if (fd != -1) {
  1965     off_t rv = ::lseek(fd, size-2, SEEK_SET);
  1966     if (rv != (off_t)-1) {
  1967       if (::write(fd, "", 1) == 1) {
  1968         mmap(base, size,
  1969              PROT_READ|PROT_WRITE|PROT_EXEC,
  1970              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
  1973     ::close(fd);
  1974     unlink(buf);
  1978 // NOTE: Bsd kernel does not really reserve the pages for us.
  1979 //       All it does is to check if there are enough free pages
  1980 //       left at the time of mmap(). This could be a potential
  1981 //       problem.
  1982 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
  1983   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
  1984 #ifdef __OpenBSD__
  1985   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
  1986   return ::mprotect(addr, size, prot) == 0;
  1987 #else
  1988   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
  1989                                    MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
  1990   return res != (uintptr_t) MAP_FAILED;
  1991 #endif
  1995 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
  1996                        bool exec) {
  1997   return commit_memory(addr, size, exec);
  2000 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
  2003 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
  2004   ::madvise(addr, bytes, MADV_DONTNEED);
  2007 void os::numa_make_global(char *addr, size_t bytes) {
  2010 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
  2013 bool os::numa_topology_changed()   { return false; }
  2015 size_t os::numa_get_groups_num() {
  2016   return 1;
  2019 int os::numa_get_group_id() {
  2020   return 0;
  2023 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
  2024   if (size > 0) {
  2025     ids[0] = 0;
  2026     return 1;
  2028   return 0;
  2031 bool os::get_page_info(char *start, page_info* info) {
  2032   return false;
  2035 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
  2036   return end;
  2040 bool os::pd_uncommit_memory(char* addr, size_t size) {
  2041 #ifdef __OpenBSD__
  2042   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
  2043   return ::mprotect(addr, size, PROT_NONE) == 0;
  2044 #else
  2045   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
  2046                 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
  2047   return res  != (uintptr_t) MAP_FAILED;
  2048 #endif
  2051 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
  2052   return os::commit_memory(addr, size);
  2055 // If this is a growable mapping, remove the guard pages entirely by
  2056 // munmap()ping them.  If not, just call uncommit_memory().
  2057 bool os::remove_stack_guard_pages(char* addr, size_t size) {
  2058   return os::uncommit_memory(addr, size);
  2061 static address _highest_vm_reserved_address = NULL;
  2063 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
  2064 // at 'requested_addr'. If there are existing memory mappings at the same
  2065 // location, however, they will be overwritten. If 'fixed' is false,
  2066 // 'requested_addr' is only treated as a hint, the return value may or
  2067 // may not start from the requested address. Unlike Bsd mmap(), this
  2068 // function returns NULL to indicate failure.
  2069 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
  2070   char * addr;
  2071   int flags;
  2073   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
  2074   if (fixed) {
  2075     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
  2076     flags |= MAP_FIXED;
  2079   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
  2080   // touch an uncommitted page. Otherwise, the read/write might
  2081   // succeed if we have enough swap space to back the physical page.
  2082   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
  2083                        flags, -1, 0);
  2085   if (addr != MAP_FAILED) {
  2086     // anon_mmap() should only get called during VM initialization,
  2087     // don't need lock (actually we can skip locking even it can be called
  2088     // from multiple threads, because _highest_vm_reserved_address is just a
  2089     // hint about the upper limit of non-stack memory regions.)
  2090     if ((address)addr + bytes > _highest_vm_reserved_address) {
  2091       _highest_vm_reserved_address = (address)addr + bytes;
  2095   return addr == MAP_FAILED ? NULL : addr;
  2098 // Don't update _highest_vm_reserved_address, because there might be memory
  2099 // regions above addr + size. If so, releasing a memory region only creates
  2100 // a hole in the address space, it doesn't help prevent heap-stack collision.
  2101 //
  2102 static int anon_munmap(char * addr, size_t size) {
  2103   return ::munmap(addr, size) == 0;
  2106 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
  2107                          size_t alignment_hint) {
  2108   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
  2111 bool os::pd_release_memory(char* addr, size_t size) {
  2112   return anon_munmap(addr, size);
  2115 static address highest_vm_reserved_address() {
  2116   return _highest_vm_reserved_address;
  2119 static bool bsd_mprotect(char* addr, size_t size, int prot) {
  2120   // Bsd wants the mprotect address argument to be page aligned.
  2121   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
  2123   // According to SUSv3, mprotect() should only be used with mappings
  2124   // established by mmap(), and mmap() always maps whole pages. Unaligned
  2125   // 'addr' likely indicates problem in the VM (e.g. trying to change
  2126   // protection of malloc'ed or statically allocated memory). Check the
  2127   // caller if you hit this assert.
  2128   assert(addr == bottom, "sanity check");
  2130   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
  2131   return ::mprotect(bottom, size, prot) == 0;
  2134 // Set protections specified
  2135 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
  2136                         bool is_committed) {
  2137   unsigned int p = 0;
  2138   switch (prot) {
  2139   case MEM_PROT_NONE: p = PROT_NONE; break;
  2140   case MEM_PROT_READ: p = PROT_READ; break;
  2141   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
  2142   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
  2143   default:
  2144     ShouldNotReachHere();
  2146   // is_committed is unused.
  2147   return bsd_mprotect(addr, bytes, p);
  2150 bool os::guard_memory(char* addr, size_t size) {
  2151   return bsd_mprotect(addr, size, PROT_NONE);
  2154 bool os::unguard_memory(char* addr, size_t size) {
  2155   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
  2158 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
  2159   return false;
  2162 /*
  2163 * Set the coredump_filter bits to include largepages in core dump (bit 6)
  2165 * From the coredump_filter documentation:
  2167 * - (bit 0) anonymous private memory
  2168 * - (bit 1) anonymous shared memory
  2169 * - (bit 2) file-backed private memory
  2170 * - (bit 3) file-backed shared memory
  2171 * - (bit 4) ELF header pages in file-backed private memory areas (it is
  2172 *           effective only if the bit 2 is cleared)
  2173 * - (bit 5) hugetlb private memory
  2174 * - (bit 6) hugetlb shared memory
  2175 */
  2176 static void set_coredump_filter(void) {
  2177   FILE *f;
  2178   long cdm;
  2180   if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
  2181     return;
  2184   if (fscanf(f, "%lx", &cdm) != 1) {
  2185     fclose(f);
  2186     return;
  2189   rewind(f);
  2191   if ((cdm & LARGEPAGES_BIT) == 0) {
  2192     cdm |= LARGEPAGES_BIT;
  2193     fprintf(f, "%#lx", cdm);
  2196   fclose(f);
  2199 // Large page support
  2201 static size_t _large_page_size = 0;
  2203 void os::large_page_init() {
  2207 char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) {
  2208   // "exec" is passed in but not used.  Creating the shared image for
  2209   // the code cache doesn't have an SHM_X executable permission to check.
  2210   assert(UseLargePages && UseSHM, "only for SHM large pages");
  2212   key_t key = IPC_PRIVATE;
  2213   char *addr;
  2215   bool warn_on_failure = UseLargePages &&
  2216                         (!FLAG_IS_DEFAULT(UseLargePages) ||
  2217                          !FLAG_IS_DEFAULT(LargePageSizeInBytes)
  2218                         );
  2219   char msg[128];
  2221   // Create a large shared memory region to attach to based on size.
  2222   // Currently, size is the total size of the heap
  2223   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
  2224   if (shmid == -1) {
  2225      // Possible reasons for shmget failure:
  2226      // 1. shmmax is too small for Java heap.
  2227      //    > check shmmax value: cat /proc/sys/kernel/shmmax
  2228      //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
  2229      // 2. not enough large page memory.
  2230      //    > check available large pages: cat /proc/meminfo
  2231      //    > increase amount of large pages:
  2232      //          echo new_value > /proc/sys/vm/nr_hugepages
  2233      //      Note 1: different Bsd may use different name for this property,
  2234      //            e.g. on Redhat AS-3 it is "hugetlb_pool".
  2235      //      Note 2: it's possible there's enough physical memory available but
  2236      //            they are so fragmented after a long run that they can't
  2237      //            coalesce into large pages. Try to reserve large pages when
  2238      //            the system is still "fresh".
  2239      if (warn_on_failure) {
  2240        jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
  2241        warning(msg);
  2243      return NULL;
  2246   // attach to the region
  2247   addr = (char*)shmat(shmid, req_addr, 0);
  2248   int err = errno;
  2250   // Remove shmid. If shmat() is successful, the actual shared memory segment
  2251   // will be deleted when it's detached by shmdt() or when the process
  2252   // terminates. If shmat() is not successful this will remove the shared
  2253   // segment immediately.
  2254   shmctl(shmid, IPC_RMID, NULL);
  2256   if ((intptr_t)addr == -1) {
  2257      if (warn_on_failure) {
  2258        jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
  2259        warning(msg);
  2261      return NULL;
  2264   // The memory is committed
  2265   address pc = CALLER_PC;
  2266   MemTracker::record_virtual_memory_reserve((address)addr, bytes, pc);
  2267   MemTracker::record_virtual_memory_commit((address)addr, bytes, pc);
  2269   return addr;
  2272 bool os::release_memory_special(char* base, size_t bytes) {
  2273   // detaching the SHM segment will also delete it, see reserve_memory_special()
  2274   int rslt = shmdt(base);
  2275   if (rslt == 0) {
  2276     MemTracker::record_virtual_memory_uncommit((address)base, bytes);
  2277     MemTracker::record_virtual_memory_release((address)base, bytes);
  2278     return true;
  2279   } else {
  2280     return false;
  2285 size_t os::large_page_size() {
  2286   return _large_page_size;
  2289 // HugeTLBFS allows application to commit large page memory on demand;
  2290 // with SysV SHM the entire memory region must be allocated as shared
  2291 // memory.
  2292 bool os::can_commit_large_page_memory() {
  2293   return UseHugeTLBFS;
  2296 bool os::can_execute_large_page_memory() {
  2297   return UseHugeTLBFS;
  2300 // Reserve memory at an arbitrary address, only if that area is
  2301 // available (and not reserved for something else).
  2303 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
  2304   const int max_tries = 10;
  2305   char* base[max_tries];
  2306   size_t size[max_tries];
  2307   const size_t gap = 0x000000;
  2309   // Assert only that the size is a multiple of the page size, since
  2310   // that's all that mmap requires, and since that's all we really know
  2311   // about at this low abstraction level.  If we need higher alignment,
  2312   // we can either pass an alignment to this method or verify alignment
  2313   // in one of the methods further up the call chain.  See bug 5044738.
  2314   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
  2316   // Repeatedly allocate blocks until the block is allocated at the
  2317   // right spot. Give up after max_tries. Note that reserve_memory() will
  2318   // automatically update _highest_vm_reserved_address if the call is
  2319   // successful. The variable tracks the highest memory address every reserved
  2320   // by JVM. It is used to detect heap-stack collision if running with
  2321   // fixed-stack BsdThreads. Because here we may attempt to reserve more
  2322   // space than needed, it could confuse the collision detecting code. To
  2323   // solve the problem, save current _highest_vm_reserved_address and
  2324   // calculate the correct value before return.
  2325   address old_highest = _highest_vm_reserved_address;
  2327   // Bsd mmap allows caller to pass an address as hint; give it a try first,
  2328   // if kernel honors the hint then we can return immediately.
  2329   char * addr = anon_mmap(requested_addr, bytes, false);
  2330   if (addr == requested_addr) {
  2331      return requested_addr;
  2334   if (addr != NULL) {
  2335      // mmap() is successful but it fails to reserve at the requested address
  2336      anon_munmap(addr, bytes);
  2339   int i;
  2340   for (i = 0; i < max_tries; ++i) {
  2341     base[i] = reserve_memory(bytes);
  2343     if (base[i] != NULL) {
  2344       // Is this the block we wanted?
  2345       if (base[i] == requested_addr) {
  2346         size[i] = bytes;
  2347         break;
  2350       // Does this overlap the block we wanted? Give back the overlapped
  2351       // parts and try again.
  2353       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
  2354       if (top_overlap >= 0 && top_overlap < bytes) {
  2355         unmap_memory(base[i], top_overlap);
  2356         base[i] += top_overlap;
  2357         size[i] = bytes - top_overlap;
  2358       } else {
  2359         size_t bottom_overlap = base[i] + bytes - requested_addr;
  2360         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
  2361           unmap_memory(requested_addr, bottom_overlap);
  2362           size[i] = bytes - bottom_overlap;
  2363         } else {
  2364           size[i] = bytes;
  2370   // Give back the unused reserved pieces.
  2372   for (int j = 0; j < i; ++j) {
  2373     if (base[j] != NULL) {
  2374       unmap_memory(base[j], size[j]);
  2378   if (i < max_tries) {
  2379     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
  2380     return requested_addr;
  2381   } else {
  2382     _highest_vm_reserved_address = old_highest;
  2383     return NULL;
  2387 size_t os::read(int fd, void *buf, unsigned int nBytes) {
  2388   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
  2391 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
  2392 // Solaris uses poll(), bsd uses park().
  2393 // Poll() is likely a better choice, assuming that Thread.interrupt()
  2394 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
  2395 // SIGSEGV, see 4355769.
  2397 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
  2398   assert(thread == Thread::current(),  "thread consistency check");
  2400   ParkEvent * const slp = thread->_SleepEvent ;
  2401   slp->reset() ;
  2402   OrderAccess::fence() ;
  2404   if (interruptible) {
  2405     jlong prevtime = javaTimeNanos();
  2407     for (;;) {
  2408       if (os::is_interrupted(thread, true)) {
  2409         return OS_INTRPT;
  2412       jlong newtime = javaTimeNanos();
  2414       if (newtime - prevtime < 0) {
  2415         // time moving backwards, should only happen if no monotonic clock
  2416         // not a guarantee() because JVM should not abort on kernel/glibc bugs
  2417         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
  2418       } else {
  2419         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
  2422       if(millis <= 0) {
  2423         return OS_OK;
  2426       prevtime = newtime;
  2429         assert(thread->is_Java_thread(), "sanity check");
  2430         JavaThread *jt = (JavaThread *) thread;
  2431         ThreadBlockInVM tbivm(jt);
  2432         OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
  2434         jt->set_suspend_equivalent();
  2435         // cleared by handle_special_suspend_equivalent_condition() or
  2436         // java_suspend_self() via check_and_wait_while_suspended()
  2438         slp->park(millis);
  2440         // were we externally suspended while we were waiting?
  2441         jt->check_and_wait_while_suspended();
  2444   } else {
  2445     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
  2446     jlong prevtime = javaTimeNanos();
  2448     for (;;) {
  2449       // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
  2450       // the 1st iteration ...
  2451       jlong newtime = javaTimeNanos();
  2453       if (newtime - prevtime < 0) {
  2454         // time moving backwards, should only happen if no monotonic clock
  2455         // not a guarantee() because JVM should not abort on kernel/glibc bugs
  2456         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
  2457       } else {
  2458         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
  2461       if(millis <= 0) break ;
  2463       prevtime = newtime;
  2464       slp->park(millis);
  2466     return OS_OK ;
  2470 int os::naked_sleep() {
  2471   // %% make the sleep time an integer flag. for now use 1 millisec.
  2472   return os::sleep(Thread::current(), 1, false);
  2475 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
  2476 void os::infinite_sleep() {
  2477   while (true) {    // sleep forever ...
  2478     ::sleep(100);   // ... 100 seconds at a time
  2482 // Used to convert frequent JVM_Yield() to nops
  2483 bool os::dont_yield() {
  2484   return DontYieldALot;
  2487 void os::yield() {
  2488   sched_yield();
  2491 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
  2493 void os::yield_all(int attempts) {
  2494   // Yields to all threads, including threads with lower priorities
  2495   // Threads on Bsd are all with same priority. The Solaris style
  2496   // os::yield_all() with nanosleep(1ms) is not necessary.
  2497   sched_yield();
  2500 // Called from the tight loops to possibly influence time-sharing heuristics
  2501 void os::loop_breaker(int attempts) {
  2502   os::yield_all(attempts);
  2505 ////////////////////////////////////////////////////////////////////////////////
  2506 // thread priority support
  2508 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
  2509 // only supports dynamic priority, static priority must be zero. For real-time
  2510 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
  2511 // However, for large multi-threaded applications, SCHED_RR is not only slower
  2512 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
  2513 // of 5 runs - Sep 2005).
  2514 //
  2515 // The following code actually changes the niceness of kernel-thread/LWP. It
  2516 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
  2517 // not the entire user process, and user level threads are 1:1 mapped to kernel
  2518 // threads. It has always been the case, but could change in the future. For
  2519 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
  2520 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
  2522 #if !defined(__APPLE__)
  2523 int os::java_to_os_priority[CriticalPriority + 1] = {
  2524   19,              // 0 Entry should never be used
  2526    0,              // 1 MinPriority
  2527    3,              // 2
  2528    6,              // 3
  2530   10,              // 4
  2531   15,              // 5 NormPriority
  2532   18,              // 6
  2534   21,              // 7
  2535   25,              // 8
  2536   28,              // 9 NearMaxPriority
  2538   31,              // 10 MaxPriority
  2540   31               // 11 CriticalPriority
  2541 };
  2542 #else
  2543 /* Using Mach high-level priority assignments */
  2544 int os::java_to_os_priority[CriticalPriority + 1] = {
  2545    0,              // 0 Entry should never be used (MINPRI_USER)
  2547   27,              // 1 MinPriority
  2548   28,              // 2
  2549   29,              // 3
  2551   30,              // 4
  2552   31,              // 5 NormPriority (BASEPRI_DEFAULT)
  2553   32,              // 6
  2555   33,              // 7
  2556   34,              // 8
  2557   35,              // 9 NearMaxPriority
  2559   36,              // 10 MaxPriority
  2561   36               // 11 CriticalPriority
  2562 };
  2563 #endif
  2565 static int prio_init() {
  2566   if (ThreadPriorityPolicy == 1) {
  2567     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
  2568     // if effective uid is not root. Perhaps, a more elegant way of doing
  2569     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
  2570     if (geteuid() != 0) {
  2571       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
  2572         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
  2574       ThreadPriorityPolicy = 0;
  2577   if (UseCriticalJavaThreadPriority) {
  2578     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
  2580   return 0;
  2583 OSReturn os::set_native_priority(Thread* thread, int newpri) {
  2584   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
  2586 #ifdef __OpenBSD__
  2587   // OpenBSD pthread_setprio starves low priority threads
  2588   return OS_OK;
  2589 #elif defined(__FreeBSD__)
  2590   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
  2591 #elif defined(__APPLE__) || defined(__NetBSD__)
  2592   struct sched_param sp;
  2593   int policy;
  2594   pthread_t self = pthread_self();
  2596   if (pthread_getschedparam(self, &policy, &sp) != 0)
  2597     return OS_ERR;
  2599   sp.sched_priority = newpri;
  2600   if (pthread_setschedparam(self, policy, &sp) != 0)
  2601     return OS_ERR;
  2603   return OS_OK;
  2604 #else
  2605   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
  2606   return (ret == 0) ? OS_OK : OS_ERR;
  2607 #endif
  2610 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
  2611   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
  2612     *priority_ptr = java_to_os_priority[NormPriority];
  2613     return OS_OK;
  2616   errno = 0;
  2617 #if defined(__OpenBSD__) || defined(__FreeBSD__)
  2618   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
  2619 #elif defined(__APPLE__) || defined(__NetBSD__)
  2620   int policy;
  2621   struct sched_param sp;
  2623   pthread_getschedparam(pthread_self(), &policy, &sp);
  2624   *priority_ptr = sp.sched_priority;
  2625 #else
  2626   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
  2627 #endif
  2628   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
  2631 // Hint to the underlying OS that a task switch would not be good.
  2632 // Void return because it's a hint and can fail.
  2633 void os::hint_no_preempt() {}
  2635 ////////////////////////////////////////////////////////////////////////////////
  2636 // suspend/resume support
  2638 //  the low-level signal-based suspend/resume support is a remnant from the
  2639 //  old VM-suspension that used to be for java-suspension, safepoints etc,
  2640 //  within hotspot. Now there is a single use-case for this:
  2641 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
  2642 //      that runs in the watcher thread.
  2643 //  The remaining code is greatly simplified from the more general suspension
  2644 //  code that used to be used.
  2645 //
  2646 //  The protocol is quite simple:
  2647 //  - suspend:
  2648 //      - sends a signal to the target thread
  2649 //      - polls the suspend state of the osthread using a yield loop
  2650 //      - target thread signal handler (SR_handler) sets suspend state
  2651 //        and blocks in sigsuspend until continued
  2652 //  - resume:
  2653 //      - sets target osthread state to continue
  2654 //      - sends signal to end the sigsuspend loop in the SR_handler
  2655 //
  2656 //  Note that the SR_lock plays no role in this suspend/resume protocol.
  2657 //
  2659 static void resume_clear_context(OSThread *osthread) {
  2660   osthread->set_ucontext(NULL);
  2661   osthread->set_siginfo(NULL);
  2663   // notify the suspend action is completed, we have now resumed
  2664   osthread->sr.clear_suspended();
  2667 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
  2668   osthread->set_ucontext(context);
  2669   osthread->set_siginfo(siginfo);
  2672 //
  2673 // Handler function invoked when a thread's execution is suspended or
  2674 // resumed. We have to be careful that only async-safe functions are
  2675 // called here (Note: most pthread functions are not async safe and
  2676 // should be avoided.)
  2677 //
  2678 // Note: sigwait() is a more natural fit than sigsuspend() from an
  2679 // interface point of view, but sigwait() prevents the signal hander
  2680 // from being run. libpthread would get very confused by not having
  2681 // its signal handlers run and prevents sigwait()'s use with the
  2682 // mutex granting granting signal.
  2683 //
  2684 // Currently only ever called on the VMThread
  2685 //
  2686 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
  2687   // Save and restore errno to avoid confusing native code with EINTR
  2688   // after sigsuspend.
  2689   int old_errno = errno;
  2691   Thread* thread = Thread::current();
  2692   OSThread* osthread = thread->osthread();
  2693   assert(thread->is_VM_thread(), "Must be VMThread");
  2694   // read current suspend action
  2695   int action = osthread->sr.suspend_action();
  2696   if (action == os::Bsd::SuspendResume::SR_SUSPEND) {
  2697     suspend_save_context(osthread, siginfo, context);
  2699     // Notify the suspend action is about to be completed. do_suspend()
  2700     // waits until SR_SUSPENDED is set and then returns. We will wait
  2701     // here for a resume signal and that completes the suspend-other
  2702     // action. do_suspend/do_resume is always called as a pair from
  2703     // the same thread - so there are no races
  2705     // notify the caller
  2706     osthread->sr.set_suspended();
  2708     sigset_t suspend_set;  // signals for sigsuspend()
  2710     // get current set of blocked signals and unblock resume signal
  2711     pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
  2712     sigdelset(&suspend_set, SR_signum);
  2714     // wait here until we are resumed
  2715     do {
  2716       sigsuspend(&suspend_set);
  2717       // ignore all returns until we get a resume signal
  2718     } while (osthread->sr.suspend_action() != os::Bsd::SuspendResume::SR_CONTINUE);
  2720     resume_clear_context(osthread);
  2722   } else {
  2723     assert(action == os::Bsd::SuspendResume::SR_CONTINUE, "unexpected sr action");
  2724     // nothing special to do - just leave the handler
  2727   errno = old_errno;
  2731 static int SR_initialize() {
  2732   struct sigaction act;
  2733   char *s;
  2734   /* Get signal number to use for suspend/resume */
  2735   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
  2736     int sig = ::strtol(s, 0, 10);
  2737     if (sig > 0 || sig < NSIG) {
  2738         SR_signum = sig;
  2742   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
  2743         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
  2745   sigemptyset(&SR_sigset);
  2746   sigaddset(&SR_sigset, SR_signum);
  2748   /* Set up signal handler for suspend/resume */
  2749   act.sa_flags = SA_RESTART|SA_SIGINFO;
  2750   act.sa_handler = (void (*)(int)) SR_handler;
  2752   // SR_signum is blocked by default.
  2753   // 4528190 - We also need to block pthread restart signal (32 on all
  2754   // supported Bsd platforms). Note that BsdThreads need to block
  2755   // this signal for all threads to work properly. So we don't have
  2756   // to use hard-coded signal number when setting up the mask.
  2757   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
  2759   if (sigaction(SR_signum, &act, 0) == -1) {
  2760     return -1;
  2763   // Save signal flag
  2764   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
  2765   return 0;
  2769 // returns true on success and false on error - really an error is fatal
  2770 // but this seems the normal response to library errors
  2771 static bool do_suspend(OSThread* osthread) {
  2772   // mark as suspended and send signal
  2773   osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_SUSPEND);
  2774   int status = pthread_kill(osthread->pthread_id(), SR_signum);
  2775   assert_status(status == 0, status, "pthread_kill");
  2777   // check status and wait until notified of suspension
  2778   if (status == 0) {
  2779     for (int i = 0; !osthread->sr.is_suspended(); i++) {
  2780       os::yield_all(i);
  2782     osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
  2783     return true;
  2785   else {
  2786     osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
  2787     return false;
  2791 static void do_resume(OSThread* osthread) {
  2792   assert(osthread->sr.is_suspended(), "thread should be suspended");
  2793   osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_CONTINUE);
  2795   int status = pthread_kill(osthread->pthread_id(), SR_signum);
  2796   assert_status(status == 0, status, "pthread_kill");
  2797   // check status and wait unit notified of resumption
  2798   if (status == 0) {
  2799     for (int i = 0; osthread->sr.is_suspended(); i++) {
  2800       os::yield_all(i);
  2803   osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
  2806 ////////////////////////////////////////////////////////////////////////////////
  2807 // interrupt support
  2809 void os::interrupt(Thread* thread) {
  2810   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
  2811     "possibility of dangling Thread pointer");
  2813   OSThread* osthread = thread->osthread();
  2815   if (!osthread->interrupted()) {
  2816     osthread->set_interrupted(true);
  2817     // More than one thread can get here with the same value of osthread,
  2818     // resulting in multiple notifications.  We do, however, want the store
  2819     // to interrupted() to be visible to other threads before we execute unpark().
  2820     OrderAccess::fence();
  2821     ParkEvent * const slp = thread->_SleepEvent ;
  2822     if (slp != NULL) slp->unpark() ;
  2825   // For JSR166. Unpark even if interrupt status already was set
  2826   if (thread->is_Java_thread())
  2827     ((JavaThread*)thread)->parker()->unpark();
  2829   ParkEvent * ev = thread->_ParkEvent ;
  2830   if (ev != NULL) ev->unpark() ;
  2834 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
  2835   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
  2836     "possibility of dangling Thread pointer");
  2838   OSThread* osthread = thread->osthread();
  2840   bool interrupted = osthread->interrupted();
  2842   if (interrupted && clear_interrupted) {
  2843     osthread->set_interrupted(false);
  2844     // consider thread->_SleepEvent->reset() ... optional optimization
  2847   return interrupted;
  2850 ///////////////////////////////////////////////////////////////////////////////////
  2851 // signal handling (except suspend/resume)
  2853 // This routine may be used by user applications as a "hook" to catch signals.
  2854 // The user-defined signal handler must pass unrecognized signals to this
  2855 // routine, and if it returns true (non-zero), then the signal handler must
  2856 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
  2857 // routine will never retun false (zero), but instead will execute a VM panic
  2858 // routine kill the process.
  2859 //
  2860 // If this routine returns false, it is OK to call it again.  This allows
  2861 // the user-defined signal handler to perform checks either before or after
  2862 // the VM performs its own checks.  Naturally, the user code would be making
  2863 // a serious error if it tried to handle an exception (such as a null check
  2864 // or breakpoint) that the VM was generating for its own correct operation.
  2865 //
  2866 // This routine may recognize any of the following kinds of signals:
  2867 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
  2868 // It should be consulted by handlers for any of those signals.
  2869 //
  2870 // The caller of this routine must pass in the three arguments supplied
  2871 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
  2872 // field of the structure passed to sigaction().  This routine assumes that
  2873 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
  2874 //
  2875 // Note that the VM will print warnings if it detects conflicting signal
  2876 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
  2877 //
  2878 extern "C" JNIEXPORT int
  2879 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
  2880                         void* ucontext, int abort_if_unrecognized);
  2882 void signalHandler(int sig, siginfo_t* info, void* uc) {
  2883   assert(info != NULL && uc != NULL, "it must be old kernel");
  2884   int orig_errno = errno;  // Preserve errno value over signal handler.
  2885   JVM_handle_bsd_signal(sig, info, uc, true);
  2886   errno = orig_errno;
  2890 // This boolean allows users to forward their own non-matching signals
  2891 // to JVM_handle_bsd_signal, harmlessly.
  2892 bool os::Bsd::signal_handlers_are_installed = false;
  2894 // For signal-chaining
  2895 struct sigaction os::Bsd::sigact[MAXSIGNUM];
  2896 unsigned int os::Bsd::sigs = 0;
  2897 bool os::Bsd::libjsig_is_loaded = false;
  2898 typedef struct sigaction *(*get_signal_t)(int);
  2899 get_signal_t os::Bsd::get_signal_action = NULL;
  2901 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
  2902   struct sigaction *actp = NULL;
  2904   if (libjsig_is_loaded) {
  2905     // Retrieve the old signal handler from libjsig
  2906     actp = (*get_signal_action)(sig);
  2908   if (actp == NULL) {
  2909     // Retrieve the preinstalled signal handler from jvm
  2910     actp = get_preinstalled_handler(sig);
  2913   return actp;
  2916 static bool call_chained_handler(struct sigaction *actp, int sig,
  2917                                  siginfo_t *siginfo, void *context) {
  2918   // Call the old signal handler
  2919   if (actp->sa_handler == SIG_DFL) {
  2920     // It's more reasonable to let jvm treat it as an unexpected exception
  2921     // instead of taking the default action.
  2922     return false;
  2923   } else if (actp->sa_handler != SIG_IGN) {
  2924     if ((actp->sa_flags & SA_NODEFER) == 0) {
  2925       // automaticlly block the signal
  2926       sigaddset(&(actp->sa_mask), sig);
  2929     sa_handler_t hand;
  2930     sa_sigaction_t sa;
  2931     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
  2932     // retrieve the chained handler
  2933     if (siginfo_flag_set) {
  2934       sa = actp->sa_sigaction;
  2935     } else {
  2936       hand = actp->sa_handler;
  2939     if ((actp->sa_flags & SA_RESETHAND) != 0) {
  2940       actp->sa_handler = SIG_DFL;
  2943     // try to honor the signal mask
  2944     sigset_t oset;
  2945     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
  2947     // call into the chained handler
  2948     if (siginfo_flag_set) {
  2949       (*sa)(sig, siginfo, context);
  2950     } else {
  2951       (*hand)(sig);
  2954     // restore the signal mask
  2955     pthread_sigmask(SIG_SETMASK, &oset, 0);
  2957   // Tell jvm's signal handler the signal is taken care of.
  2958   return true;
  2961 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
  2962   bool chained = false;
  2963   // signal-chaining
  2964   if (UseSignalChaining) {
  2965     struct sigaction *actp = get_chained_signal_action(sig);
  2966     if (actp != NULL) {
  2967       chained = call_chained_handler(actp, sig, siginfo, context);
  2970   return chained;
  2973 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
  2974   if ((( (unsigned int)1 << sig ) & sigs) != 0) {
  2975     return &sigact[sig];
  2977   return NULL;
  2980 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
  2981   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  2982   sigact[sig] = oldAct;
  2983   sigs |= (unsigned int)1 << sig;
  2986 // for diagnostic
  2987 int os::Bsd::sigflags[MAXSIGNUM];
  2989 int os::Bsd::get_our_sigflags(int sig) {
  2990   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  2991   return sigflags[sig];
  2994 void os::Bsd::set_our_sigflags(int sig, int flags) {
  2995   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  2996   sigflags[sig] = flags;
  2999 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
  3000   // Check for overwrite.
  3001   struct sigaction oldAct;
  3002   sigaction(sig, (struct sigaction*)NULL, &oldAct);
  3004   void* oldhand = oldAct.sa_sigaction
  3005                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
  3006                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
  3007   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
  3008       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
  3009       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
  3010     if (AllowUserSignalHandlers || !set_installed) {
  3011       // Do not overwrite; user takes responsibility to forward to us.
  3012       return;
  3013     } else if (UseSignalChaining) {
  3014       // save the old handler in jvm
  3015       save_preinstalled_handler(sig, oldAct);
  3016       // libjsig also interposes the sigaction() call below and saves the
  3017       // old sigaction on it own.
  3018     } else {
  3019       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
  3020                     "%#lx for signal %d.", (long)oldhand, sig));
  3024   struct sigaction sigAct;
  3025   sigfillset(&(sigAct.sa_mask));
  3026   sigAct.sa_handler = SIG_DFL;
  3027   if (!set_installed) {
  3028     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  3029   } else {
  3030     sigAct.sa_sigaction = signalHandler;
  3031     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  3033 #if __APPLE__
  3034   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
  3035   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
  3036   // if the signal handler declares it will handle it on alternate stack.
  3037   // Notice we only declare we will handle it on alt stack, but we are not
  3038   // actually going to use real alt stack - this is just a workaround.
  3039   // Please see ux_exception.c, method catch_mach_exception_raise for details
  3040   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
  3041   if (sig == SIGSEGV) {
  3042     sigAct.sa_flags |= SA_ONSTACK;
  3044 #endif
  3046   // Save flags, which are set by ours
  3047   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3048   sigflags[sig] = sigAct.sa_flags;
  3050   int ret = sigaction(sig, &sigAct, &oldAct);
  3051   assert(ret == 0, "check");
  3053   void* oldhand2  = oldAct.sa_sigaction
  3054                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
  3055                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
  3056   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
  3059 // install signal handlers for signals that HotSpot needs to
  3060 // handle in order to support Java-level exception handling.
  3062 void os::Bsd::install_signal_handlers() {
  3063   if (!signal_handlers_are_installed) {
  3064     signal_handlers_are_installed = true;
  3066     // signal-chaining
  3067     typedef void (*signal_setting_t)();
  3068     signal_setting_t begin_signal_setting = NULL;
  3069     signal_setting_t end_signal_setting = NULL;
  3070     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
  3071                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
  3072     if (begin_signal_setting != NULL) {
  3073       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
  3074                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
  3075       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
  3076                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
  3077       libjsig_is_loaded = true;
  3078       assert(UseSignalChaining, "should enable signal-chaining");
  3080     if (libjsig_is_loaded) {
  3081       // Tell libjsig jvm is setting signal handlers
  3082       (*begin_signal_setting)();
  3085     set_signal_handler(SIGSEGV, true);
  3086     set_signal_handler(SIGPIPE, true);
  3087     set_signal_handler(SIGBUS, true);
  3088     set_signal_handler(SIGILL, true);
  3089     set_signal_handler(SIGFPE, true);
  3090     set_signal_handler(SIGXFSZ, true);
  3092 #if defined(__APPLE__)
  3093     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
  3094     // signals caught and handled by the JVM. To work around this, we reset the mach task
  3095     // signal handler that's placed on our process by CrashReporter. This disables
  3096     // CrashReporter-based reporting.
  3097     //
  3098     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
  3099     // on caught fatal signals.
  3100     //
  3101     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
  3102     // handlers. By replacing the existing task exception handler, we disable gdb's mach
  3103     // exception handling, while leaving the standard BSD signal handlers functional.
  3104     kern_return_t kr;
  3105     kr = task_set_exception_ports(mach_task_self(),
  3106         EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
  3107         MACH_PORT_NULL,
  3108         EXCEPTION_STATE_IDENTITY,
  3109         MACHINE_THREAD_STATE);
  3111     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
  3112 #endif
  3114     if (libjsig_is_loaded) {
  3115       // Tell libjsig jvm finishes setting signal handlers
  3116       (*end_signal_setting)();
  3119     // We don't activate signal checker if libjsig is in place, we trust ourselves
  3120     // and if UserSignalHandler is installed all bets are off
  3121     if (CheckJNICalls) {
  3122       if (libjsig_is_loaded) {
  3123         tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
  3124         check_signals = false;
  3126       if (AllowUserSignalHandlers) {
  3127         tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
  3128         check_signals = false;
  3135 /////
  3136 // glibc on Bsd platform uses non-documented flag
  3137 // to indicate, that some special sort of signal
  3138 // trampoline is used.
  3139 // We will never set this flag, and we should
  3140 // ignore this flag in our diagnostic
  3141 #ifdef SIGNIFICANT_SIGNAL_MASK
  3142 #undef SIGNIFICANT_SIGNAL_MASK
  3143 #endif
  3144 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
  3146 static const char* get_signal_handler_name(address handler,
  3147                                            char* buf, int buflen) {
  3148   int offset;
  3149   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
  3150   if (found) {
  3151     // skip directory names
  3152     const char *p1, *p2;
  3153     p1 = buf;
  3154     size_t len = strlen(os::file_separator());
  3155     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
  3156     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
  3157   } else {
  3158     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
  3160   return buf;
  3163 static void print_signal_handler(outputStream* st, int sig,
  3164                                  char* buf, size_t buflen) {
  3165   struct sigaction sa;
  3167   sigaction(sig, NULL, &sa);
  3169   // See comment for SIGNIFICANT_SIGNAL_MASK define
  3170   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
  3172   st->print("%s: ", os::exception_name(sig, buf, buflen));
  3174   address handler = (sa.sa_flags & SA_SIGINFO)
  3175     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
  3176     : CAST_FROM_FN_PTR(address, sa.sa_handler);
  3178   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
  3179     st->print("SIG_DFL");
  3180   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
  3181     st->print("SIG_IGN");
  3182   } else {
  3183     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
  3186   st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask);
  3188   address rh = VMError::get_resetted_sighandler(sig);
  3189   // May be, handler was resetted by VMError?
  3190   if(rh != NULL) {
  3191     handler = rh;
  3192     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
  3195   st->print(", sa_flags="   PTR32_FORMAT, sa.sa_flags);
  3197   // Check: is it our handler?
  3198   if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
  3199      handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
  3200     // It is our signal handler
  3201     // check for flags, reset system-used one!
  3202     if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
  3203       st->print(
  3204                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
  3205                 os::Bsd::get_our_sigflags(sig));
  3208   st->cr();
  3212 #define DO_SIGNAL_CHECK(sig) \
  3213   if (!sigismember(&check_signal_done, sig)) \
  3214     os::Bsd::check_signal_handler(sig)
  3216 // This method is a periodic task to check for misbehaving JNI applications
  3217 // under CheckJNI, we can add any periodic checks here
  3219 void os::run_periodic_checks() {
  3221   if (check_signals == false) return;
  3223   // SEGV and BUS if overridden could potentially prevent
  3224   // generation of hs*.log in the event of a crash, debugging
  3225   // such a case can be very challenging, so we absolutely
  3226   // check the following for a good measure:
  3227   DO_SIGNAL_CHECK(SIGSEGV);
  3228   DO_SIGNAL_CHECK(SIGILL);
  3229   DO_SIGNAL_CHECK(SIGFPE);
  3230   DO_SIGNAL_CHECK(SIGBUS);
  3231   DO_SIGNAL_CHECK(SIGPIPE);
  3232   DO_SIGNAL_CHECK(SIGXFSZ);
  3235   // ReduceSignalUsage allows the user to override these handlers
  3236   // see comments at the very top and jvm_solaris.h
  3237   if (!ReduceSignalUsage) {
  3238     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
  3239     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
  3240     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
  3241     DO_SIGNAL_CHECK(BREAK_SIGNAL);
  3244   DO_SIGNAL_CHECK(SR_signum);
  3245   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
  3248 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
  3250 static os_sigaction_t os_sigaction = NULL;
  3252 void os::Bsd::check_signal_handler(int sig) {
  3253   char buf[O_BUFLEN];
  3254   address jvmHandler = NULL;
  3257   struct sigaction act;
  3258   if (os_sigaction == NULL) {
  3259     // only trust the default sigaction, in case it has been interposed
  3260     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
  3261     if (os_sigaction == NULL) return;
  3264   os_sigaction(sig, (struct sigaction*)NULL, &act);
  3267   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
  3269   address thisHandler = (act.sa_flags & SA_SIGINFO)
  3270     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
  3271     : CAST_FROM_FN_PTR(address, act.sa_handler) ;
  3274   switch(sig) {
  3275   case SIGSEGV:
  3276   case SIGBUS:
  3277   case SIGFPE:
  3278   case SIGPIPE:
  3279   case SIGILL:
  3280   case SIGXFSZ:
  3281     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
  3282     break;
  3284   case SHUTDOWN1_SIGNAL:
  3285   case SHUTDOWN2_SIGNAL:
  3286   case SHUTDOWN3_SIGNAL:
  3287   case BREAK_SIGNAL:
  3288     jvmHandler = (address)user_handler();
  3289     break;
  3291   case INTERRUPT_SIGNAL:
  3292     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
  3293     break;
  3295   default:
  3296     if (sig == SR_signum) {
  3297       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
  3298     } else {
  3299       return;
  3301     break;
  3304   if (thisHandler != jvmHandler) {
  3305     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
  3306     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
  3307     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
  3308     // No need to check this sig any longer
  3309     sigaddset(&check_signal_done, sig);
  3310   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
  3311     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
  3312     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
  3313     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
  3314     // No need to check this sig any longer
  3315     sigaddset(&check_signal_done, sig);
  3318   // Dump all the signal
  3319   if (sigismember(&check_signal_done, sig)) {
  3320     print_signal_handlers(tty, buf, O_BUFLEN);
  3324 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
  3326 extern bool signal_name(int signo, char* buf, size_t len);
  3328 const char* os::exception_name(int exception_code, char* buf, size_t size) {
  3329   if (0 < exception_code && exception_code <= SIGRTMAX) {
  3330     // signal
  3331     if (!signal_name(exception_code, buf, size)) {
  3332       jio_snprintf(buf, size, "SIG%d", exception_code);
  3334     return buf;
  3335   } else {
  3336     return NULL;
  3340 // this is called _before_ the most of global arguments have been parsed
  3341 void os::init(void) {
  3342   char dummy;   /* used to get a guess on initial stack address */
  3343 //  first_hrtime = gethrtime();
  3345   // With BsdThreads the JavaMain thread pid (primordial thread)
  3346   // is different than the pid of the java launcher thread.
  3347   // So, on Bsd, the launcher thread pid is passed to the VM
  3348   // via the sun.java.launcher.pid property.
  3349   // Use this property instead of getpid() if it was correctly passed.
  3350   // See bug 6351349.
  3351   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
  3353   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
  3355   clock_tics_per_sec = CLK_TCK;
  3357   init_random(1234567);
  3359   ThreadCritical::initialize();
  3361   Bsd::set_page_size(getpagesize());
  3362   if (Bsd::page_size() == -1) {
  3363     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
  3364                   strerror(errno)));
  3366   init_page_sizes((size_t) Bsd::page_size());
  3368   Bsd::initialize_system_info();
  3370   // main_thread points to the aboriginal thread
  3371   Bsd::_main_thread = pthread_self();
  3373   Bsd::clock_init();
  3374   initial_time_count = os::elapsed_counter();
  3376 #ifdef __APPLE__
  3377   // XXXDARWIN
  3378   // Work around the unaligned VM callbacks in hotspot's
  3379   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
  3380   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
  3381   // alignment when doing symbol lookup. To work around this, we force early
  3382   // binding of all symbols now, thus binding when alignment is known-good.
  3383   _dyld_bind_fully_image_containing_address((const void *) &os::init);
  3384 #endif
  3387 // To install functions for atexit system call
  3388 extern "C" {
  3389   static void perfMemory_exit_helper() {
  3390     perfMemory_exit();
  3394 // this is called _after_ the global arguments have been parsed
  3395 jint os::init_2(void)
  3397   // Allocate a single page and mark it as readable for safepoint polling
  3398   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  3399   guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
  3401   os::set_polling_page( polling_page );
  3403 #ifndef PRODUCT
  3404   if(Verbose && PrintMiscellaneous)
  3405     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
  3406 #endif
  3408   if (!UseMembar) {
  3409     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  3410     guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page");
  3411     os::set_memory_serialize_page( mem_serialize_page );
  3413 #ifndef PRODUCT
  3414     if(Verbose && PrintMiscellaneous)
  3415       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
  3416 #endif
  3419   os::large_page_init();
  3421   // initialize suspend/resume support - must do this before signal_sets_init()
  3422   if (SR_initialize() != 0) {
  3423     perror("SR_initialize failed");
  3424     return JNI_ERR;
  3427   Bsd::signal_sets_init();
  3428   Bsd::install_signal_handlers();
  3430   // Check minimum allowable stack size for thread creation and to initialize
  3431   // the java system classes, including StackOverflowError - depends on page
  3432   // size.  Add a page for compiler2 recursion in main thread.
  3433   // Add in 2*BytesPerWord times page size to account for VM stack during
  3434   // class initialization depending on 32 or 64 bit VM.
  3435   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
  3436             (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
  3437                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
  3439   size_t threadStackSizeInBytes = ThreadStackSize * K;
  3440   if (threadStackSizeInBytes != 0 &&
  3441       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
  3442         tty->print_cr("\nThe stack size specified is too small, "
  3443                       "Specify at least %dk",
  3444                       os::Bsd::min_stack_allowed/ K);
  3445         return JNI_ERR;
  3448   // Make the stack size a multiple of the page size so that
  3449   // the yellow/red zones can be guarded.
  3450   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
  3451         vm_page_size()));
  3453   if (MaxFDLimit) {
  3454     // set the number of file descriptors to max. print out error
  3455     // if getrlimit/setrlimit fails but continue regardless.
  3456     struct rlimit nbr_files;
  3457     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
  3458     if (status != 0) {
  3459       if (PrintMiscellaneous && (Verbose || WizardMode))
  3460         perror("os::init_2 getrlimit failed");
  3461     } else {
  3462       nbr_files.rlim_cur = nbr_files.rlim_max;
  3464 #ifdef __APPLE__
  3465       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
  3466       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
  3467       // be used instead
  3468       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
  3469 #endif
  3471       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
  3472       if (status != 0) {
  3473         if (PrintMiscellaneous && (Verbose || WizardMode))
  3474           perror("os::init_2 setrlimit failed");
  3479   // at-exit methods are called in the reverse order of their registration.
  3480   // atexit functions are called on return from main or as a result of a
  3481   // call to exit(3C). There can be only 32 of these functions registered
  3482   // and atexit() does not set errno.
  3484   if (PerfAllowAtExitRegistration) {
  3485     // only register atexit functions if PerfAllowAtExitRegistration is set.
  3486     // atexit functions can be delayed until process exit time, which
  3487     // can be problematic for embedded VM situations. Embedded VMs should
  3488     // call DestroyJavaVM() to assure that VM resources are released.
  3490     // note: perfMemory_exit_helper atexit function may be removed in
  3491     // the future if the appropriate cleanup code can be added to the
  3492     // VM_Exit VMOperation's doit method.
  3493     if (atexit(perfMemory_exit_helper) != 0) {
  3494       warning("os::init2 atexit(perfMemory_exit_helper) failed");
  3498   // initialize thread priority policy
  3499   prio_init();
  3501 #ifdef __APPLE__
  3502   // dynamically link to objective c gc registration
  3503   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
  3504   if (handleLibObjc != NULL) {
  3505     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
  3507 #endif
  3509   return JNI_OK;
  3512 // this is called at the end of vm_initialization
  3513 void os::init_3(void) { }
  3515 // Mark the polling page as unreadable
  3516 void os::make_polling_page_unreadable(void) {
  3517   if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
  3518     fatal("Could not disable polling page");
  3519 };
  3521 // Mark the polling page as readable
  3522 void os::make_polling_page_readable(void) {
  3523   if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
  3524     fatal("Could not enable polling page");
  3526 };
  3528 int os::active_processor_count() {
  3529   return _processor_count;
  3532 void os::set_native_thread_name(const char *name) {
  3533 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
  3534   // This is only supported in Snow Leopard and beyond
  3535   if (name != NULL) {
  3536     // Add a "Java: " prefix to the name
  3537     char buf[MAXTHREADNAMESIZE];
  3538     snprintf(buf, sizeof(buf), "Java: %s", name);
  3539     pthread_setname_np(buf);
  3541 #endif
  3544 bool os::distribute_processes(uint length, uint* distribution) {
  3545   // Not yet implemented.
  3546   return false;
  3549 bool os::bind_to_processor(uint processor_id) {
  3550   // Not yet implemented.
  3551   return false;
  3554 ///
  3556 // Suspends the target using the signal mechanism and then grabs the PC before
  3557 // resuming the target. Used by the flat-profiler only
  3558 ExtendedPC os::get_thread_pc(Thread* thread) {
  3559   // Make sure that it is called by the watcher for the VMThread
  3560   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
  3561   assert(thread->is_VM_thread(), "Can only be called for VMThread");
  3563   ExtendedPC epc;
  3565   OSThread* osthread = thread->osthread();
  3566   if (do_suspend(osthread)) {
  3567     if (osthread->ucontext() != NULL) {
  3568       epc = os::Bsd::ucontext_get_pc(osthread->ucontext());
  3569     } else {
  3570       // NULL context is unexpected, double-check this is the VMThread
  3571       guarantee(thread->is_VM_thread(), "can only be called for VMThread");
  3573     do_resume(osthread);
  3575   // failure means pthread_kill failed for some reason - arguably this is
  3576   // a fatal problem, but such problems are ignored elsewhere
  3578   return epc;
  3581 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
  3583   return pthread_cond_timedwait(_cond, _mutex, _abstime);
  3586 ////////////////////////////////////////////////////////////////////////////////
  3587 // debug support
  3589 bool os::find(address addr, outputStream* st) {
  3590   Dl_info dlinfo;
  3591   memset(&dlinfo, 0, sizeof(dlinfo));
  3592   if (dladdr(addr, &dlinfo)) {
  3593     st->print(PTR_FORMAT ": ", addr);
  3594     if (dlinfo.dli_sname != NULL) {
  3595       st->print("%s+%#x", dlinfo.dli_sname,
  3596                  addr - (intptr_t)dlinfo.dli_saddr);
  3597     } else if (dlinfo.dli_fname) {
  3598       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
  3599     } else {
  3600       st->print("<absolute address>");
  3602     if (dlinfo.dli_fname) {
  3603       st->print(" in %s", dlinfo.dli_fname);
  3605     if (dlinfo.dli_fbase) {
  3606       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
  3608     st->cr();
  3610     if (Verbose) {
  3611       // decode some bytes around the PC
  3612       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
  3613       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
  3614       address       lowest = (address) dlinfo.dli_sname;
  3615       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
  3616       if (begin < lowest)  begin = lowest;
  3617       Dl_info dlinfo2;
  3618       if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr
  3619           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
  3620         end = (address) dlinfo2.dli_saddr;
  3621       Disassembler::decode(begin, end, st);
  3623     return true;
  3625   return false;
  3628 ////////////////////////////////////////////////////////////////////////////////
  3629 // misc
  3631 // This does not do anything on Bsd. This is basically a hook for being
  3632 // able to use structured exception handling (thread-local exception filters)
  3633 // on, e.g., Win32.
  3634 void
  3635 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
  3636                          JavaCallArguments* args, Thread* thread) {
  3637   f(value, method, args, thread);
  3640 void os::print_statistics() {
  3643 int os::message_box(const char* title, const char* message) {
  3644   int i;
  3645   fdStream err(defaultStream::error_fd());
  3646   for (i = 0; i < 78; i++) err.print_raw("=");
  3647   err.cr();
  3648   err.print_raw_cr(title);
  3649   for (i = 0; i < 78; i++) err.print_raw("-");
  3650   err.cr();
  3651   err.print_raw_cr(message);
  3652   for (i = 0; i < 78; i++) err.print_raw("=");
  3653   err.cr();
  3655   char buf[16];
  3656   // Prevent process from exiting upon "read error" without consuming all CPU
  3657   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
  3659   return buf[0] == 'y' || buf[0] == 'Y';
  3662 int os::stat(const char *path, struct stat *sbuf) {
  3663   char pathbuf[MAX_PATH];
  3664   if (strlen(path) > MAX_PATH - 1) {
  3665     errno = ENAMETOOLONG;
  3666     return -1;
  3668   os::native_path(strcpy(pathbuf, path));
  3669   return ::stat(pathbuf, sbuf);
  3672 bool os::check_heap(bool force) {
  3673   return true;
  3676 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
  3677   return ::vsnprintf(buf, count, format, args);
  3680 // Is a (classpath) directory empty?
  3681 bool os::dir_is_empty(const char* path) {
  3682   DIR *dir = NULL;
  3683   struct dirent *ptr;
  3685   dir = opendir(path);
  3686   if (dir == NULL) return true;
  3688   /* Scan the directory */
  3689   bool result = true;
  3690   char buf[sizeof(struct dirent) + MAX_PATH];
  3691   while (result && (ptr = ::readdir(dir)) != NULL) {
  3692     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
  3693       result = false;
  3696   closedir(dir);
  3697   return result;
  3700 // This code originates from JDK's sysOpen and open64_w
  3701 // from src/solaris/hpi/src/system_md.c
  3703 #ifndef O_DELETE
  3704 #define O_DELETE 0x10000
  3705 #endif
  3707 // Open a file. Unlink the file immediately after open returns
  3708 // if the specified oflag has the O_DELETE flag set.
  3709 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
  3711 int os::open(const char *path, int oflag, int mode) {
  3713   if (strlen(path) > MAX_PATH - 1) {
  3714     errno = ENAMETOOLONG;
  3715     return -1;
  3717   int fd;
  3718   int o_delete = (oflag & O_DELETE);
  3719   oflag = oflag & ~O_DELETE;
  3721   fd = ::open(path, oflag, mode);
  3722   if (fd == -1) return -1;
  3724   //If the open succeeded, the file might still be a directory
  3726     struct stat buf;
  3727     int ret = ::fstat(fd, &buf);
  3728     int st_mode = buf.st_mode;
  3730     if (ret != -1) {
  3731       if ((st_mode & S_IFMT) == S_IFDIR) {
  3732         errno = EISDIR;
  3733         ::close(fd);
  3734         return -1;
  3736     } else {
  3737       ::close(fd);
  3738       return -1;
  3742     /*
  3743      * All file descriptors that are opened in the JVM and not
  3744      * specifically destined for a subprocess should have the
  3745      * close-on-exec flag set.  If we don't set it, then careless 3rd
  3746      * party native code might fork and exec without closing all
  3747      * appropriate file descriptors (e.g. as we do in closeDescriptors in
  3748      * UNIXProcess.c), and this in turn might:
  3750      * - cause end-of-file to fail to be detected on some file
  3751      *   descriptors, resulting in mysterious hangs, or
  3753      * - might cause an fopen in the subprocess to fail on a system
  3754      *   suffering from bug 1085341.
  3756      * (Yes, the default setting of the close-on-exec flag is a Unix
  3757      * design flaw)
  3759      * See:
  3760      * 1085341: 32-bit stdio routines should support file descriptors >255
  3761      * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
  3762      * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
  3763      */
  3764 #ifdef FD_CLOEXEC
  3766         int flags = ::fcntl(fd, F_GETFD);
  3767         if (flags != -1)
  3768             ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
  3770 #endif
  3772   if (o_delete != 0) {
  3773     ::unlink(path);
  3775   return fd;
  3779 // create binary file, rewriting existing file if required
  3780 int os::create_binary_file(const char* path, bool rewrite_existing) {
  3781   int oflags = O_WRONLY | O_CREAT;
  3782   if (!rewrite_existing) {
  3783     oflags |= O_EXCL;
  3785   return ::open(path, oflags, S_IREAD | S_IWRITE);
  3788 // return current position of file pointer
  3789 jlong os::current_file_offset(int fd) {
  3790   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
  3793 // move file pointer to the specified offset
  3794 jlong os::seek_to_file_offset(int fd, jlong offset) {
  3795   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
  3798 // This code originates from JDK's sysAvailable
  3799 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
  3801 int os::available(int fd, jlong *bytes) {
  3802   jlong cur, end;
  3803   int mode;
  3804   struct stat buf;
  3806   if (::fstat(fd, &buf) >= 0) {
  3807     mode = buf.st_mode;
  3808     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
  3809       /*
  3810       * XXX: is the following call interruptible? If so, this might
  3811       * need to go through the INTERRUPT_IO() wrapper as for other
  3812       * blocking, interruptible calls in this file.
  3813       */
  3814       int n;
  3815       if (::ioctl(fd, FIONREAD, &n) >= 0) {
  3816         *bytes = n;
  3817         return 1;
  3821   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
  3822     return 0;
  3823   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
  3824     return 0;
  3825   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
  3826     return 0;
  3828   *bytes = end - cur;
  3829   return 1;
  3832 int os::socket_available(int fd, jint *pbytes) {
  3833    if (fd < 0)
  3834      return OS_OK;
  3836    int ret;
  3838    RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
  3840    //%% note ioctl can return 0 when successful, JVM_SocketAvailable
  3841    // is expected to return 0 on failure and 1 on success to the jdk.
  3843    return (ret == OS_ERR) ? 0 : 1;
  3846 // Map a block of memory.
  3847 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
  3848                      char *addr, size_t bytes, bool read_only,
  3849                      bool allow_exec) {
  3850   int prot;
  3851   int flags;
  3853   if (read_only) {
  3854     prot = PROT_READ;
  3855     flags = MAP_SHARED;
  3856   } else {
  3857     prot = PROT_READ | PROT_WRITE;
  3858     flags = MAP_PRIVATE;
  3861   if (allow_exec) {
  3862     prot |= PROT_EXEC;
  3865   if (addr != NULL) {
  3866     flags |= MAP_FIXED;
  3869   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
  3870                                      fd, file_offset);
  3871   if (mapped_address == MAP_FAILED) {
  3872     return NULL;
  3874   return mapped_address;
  3878 // Remap a block of memory.
  3879 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
  3880                        char *addr, size_t bytes, bool read_only,
  3881                        bool allow_exec) {
  3882   // same as map_memory() on this OS
  3883   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
  3884                         allow_exec);
  3888 // Unmap a block of memory.
  3889 bool os::pd_unmap_memory(char* addr, size_t bytes) {
  3890   return munmap(addr, bytes) == 0;
  3893 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
  3894 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
  3895 // of a thread.
  3896 //
  3897 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
  3898 // the fast estimate available on the platform.
  3900 jlong os::current_thread_cpu_time() {
  3901 #ifdef __APPLE__
  3902   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
  3903 #else
  3904   Unimplemented();
  3905   return 0;
  3906 #endif
  3909 jlong os::thread_cpu_time(Thread* thread) {
  3910 #ifdef __APPLE__
  3911   return os::thread_cpu_time(thread, true /* user + sys */);
  3912 #else
  3913   Unimplemented();
  3914   return 0;
  3915 #endif
  3918 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
  3919 #ifdef __APPLE__
  3920   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
  3921 #else
  3922   Unimplemented();
  3923   return 0;
  3924 #endif
  3927 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
  3928 #ifdef __APPLE__
  3929   struct thread_basic_info tinfo;
  3930   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
  3931   kern_return_t kr;
  3932   thread_t mach_thread;
  3934   mach_thread = thread->osthread()->thread_id();
  3935   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
  3936   if (kr != KERN_SUCCESS)
  3937     return -1;
  3939   if (user_sys_cpu_time) {
  3940     jlong nanos;
  3941     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
  3942     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
  3943     return nanos;
  3944   } else {
  3945     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
  3947 #else
  3948   Unimplemented();
  3949   return 0;
  3950 #endif
  3954 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
  3955   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
  3956   info_ptr->may_skip_backward = false;     // elapsed time not wall time
  3957   info_ptr->may_skip_forward = false;      // elapsed time not wall time
  3958   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
  3961 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
  3962   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
  3963   info_ptr->may_skip_backward = false;     // elapsed time not wall time
  3964   info_ptr->may_skip_forward = false;      // elapsed time not wall time
  3965   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
  3968 bool os::is_thread_cpu_time_supported() {
  3969 #ifdef __APPLE__
  3970   return true;
  3971 #else
  3972   return false;
  3973 #endif
  3976 // System loadavg support.  Returns -1 if load average cannot be obtained.
  3977 // Bsd doesn't yet have a (official) notion of processor sets,
  3978 // so just return the system wide load average.
  3979 int os::loadavg(double loadavg[], int nelem) {
  3980   return ::getloadavg(loadavg, nelem);
  3983 void os::pause() {
  3984   char filename[MAX_PATH];
  3985   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
  3986     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
  3987   } else {
  3988     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
  3991   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
  3992   if (fd != -1) {
  3993     struct stat buf;
  3994     ::close(fd);
  3995     while (::stat(filename, &buf) == 0) {
  3996       (void)::poll(NULL, 0, 100);
  3998   } else {
  3999     jio_fprintf(stderr,
  4000       "Could not open pause file '%s', continuing immediately.\n", filename);
  4005 // Refer to the comments in os_solaris.cpp park-unpark.
  4006 //
  4007 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
  4008 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
  4009 // For specifics regarding the bug see GLIBC BUGID 261237 :
  4010 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
  4011 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
  4012 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
  4013 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
  4014 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
  4015 // and monitorenter when we're using 1-0 locking.  All those operations may result in
  4016 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
  4017 // of libpthread avoids the problem, but isn't practical.
  4018 //
  4019 // Possible remedies:
  4020 //
  4021 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
  4022 //      This is palliative and probabilistic, however.  If the thread is preempted
  4023 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
  4024 //      than the minimum period may have passed, and the abstime may be stale (in the
  4025 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
  4026 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
  4027 //
  4028 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
  4029 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
  4030 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
  4031 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
  4032 //      thread.
  4033 //
  4034 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
  4035 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
  4036 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
  4037 //      This also works well.  In fact it avoids kernel-level scalability impediments
  4038 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
  4039 //      timers in a graceful fashion.
  4040 //
  4041 // 4.   When the abstime value is in the past it appears that control returns
  4042 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
  4043 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
  4044 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
  4045 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
  4046 //      It may be possible to avoid reinitialization by checking the return
  4047 //      value from pthread_cond_timedwait().  In addition to reinitializing the
  4048 //      condvar we must establish the invariant that cond_signal() is only called
  4049 //      within critical sections protected by the adjunct mutex.  This prevents
  4050 //      cond_signal() from "seeing" a condvar that's in the midst of being
  4051 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
  4052 //      desirable signal-after-unlock optimization that avoids futile context switching.
  4053 //
  4054 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
  4055 //      structure when a condvar is used or initialized.  cond_destroy()  would
  4056 //      release the helper structure.  Our reinitialize-after-timedwait fix
  4057 //      put excessive stress on malloc/free and locks protecting the c-heap.
  4058 //
  4059 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
  4060 // It may be possible to refine (4) by checking the kernel and NTPL verisons
  4061 // and only enabling the work-around for vulnerable environments.
  4063 // utility to compute the abstime argument to timedwait:
  4064 // millis is the relative timeout time
  4065 // abstime will be the absolute timeout time
  4066 // TODO: replace compute_abstime() with unpackTime()
  4068 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
  4069   if (millis < 0)  millis = 0;
  4070   struct timeval now;
  4071   int status = gettimeofday(&now, NULL);
  4072   assert(status == 0, "gettimeofday");
  4073   jlong seconds = millis / 1000;
  4074   millis %= 1000;
  4075   if (seconds > 50000000) { // see man cond_timedwait(3T)
  4076     seconds = 50000000;
  4078   abstime->tv_sec = now.tv_sec  + seconds;
  4079   long       usec = now.tv_usec + millis * 1000;
  4080   if (usec >= 1000000) {
  4081     abstime->tv_sec += 1;
  4082     usec -= 1000000;
  4084   abstime->tv_nsec = usec * 1000;
  4085   return abstime;
  4089 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
  4090 // Conceptually TryPark() should be equivalent to park(0).
  4092 int os::PlatformEvent::TryPark() {
  4093   for (;;) {
  4094     const int v = _Event ;
  4095     guarantee ((v == 0) || (v == 1), "invariant") ;
  4096     if (Atomic::cmpxchg (0, &_Event, v) == v) return v  ;
  4100 void os::PlatformEvent::park() {       // AKA "down()"
  4101   // Invariant: Only the thread associated with the Event/PlatformEvent
  4102   // may call park().
  4103   // TODO: assert that _Assoc != NULL or _Assoc == Self
  4104   int v ;
  4105   for (;;) {
  4106       v = _Event ;
  4107       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
  4109   guarantee (v >= 0, "invariant") ;
  4110   if (v == 0) {
  4111      // Do this the hard way by blocking ...
  4112      int status = pthread_mutex_lock(_mutex);
  4113      assert_status(status == 0, status, "mutex_lock");
  4114      guarantee (_nParked == 0, "invariant") ;
  4115      ++ _nParked ;
  4116      while (_Event < 0) {
  4117         status = pthread_cond_wait(_cond, _mutex);
  4118         // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
  4119         // Treat this the same as if the wait was interrupted
  4120         if (status == ETIMEDOUT) { status = EINTR; }
  4121         assert_status(status == 0 || status == EINTR, status, "cond_wait");
  4123      -- _nParked ;
  4125     _Event = 0 ;
  4126      status = pthread_mutex_unlock(_mutex);
  4127      assert_status(status == 0, status, "mutex_unlock");
  4128     // Paranoia to ensure our locked and lock-free paths interact
  4129     // correctly with each other.
  4130     OrderAccess::fence();
  4132   guarantee (_Event >= 0, "invariant") ;
  4135 int os::PlatformEvent::park(jlong millis) {
  4136   guarantee (_nParked == 0, "invariant") ;
  4138   int v ;
  4139   for (;;) {
  4140       v = _Event ;
  4141       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
  4143   guarantee (v >= 0, "invariant") ;
  4144   if (v != 0) return OS_OK ;
  4146   // We do this the hard way, by blocking the thread.
  4147   // Consider enforcing a minimum timeout value.
  4148   struct timespec abst;
  4149   compute_abstime(&abst, millis);
  4151   int ret = OS_TIMEOUT;
  4152   int status = pthread_mutex_lock(_mutex);
  4153   assert_status(status == 0, status, "mutex_lock");
  4154   guarantee (_nParked == 0, "invariant") ;
  4155   ++_nParked ;
  4157   // Object.wait(timo) will return because of
  4158   // (a) notification
  4159   // (b) timeout
  4160   // (c) thread.interrupt
  4161   //
  4162   // Thread.interrupt and object.notify{All} both call Event::set.
  4163   // That is, we treat thread.interrupt as a special case of notification.
  4164   // The underlying Solaris implementation, cond_timedwait, admits
  4165   // spurious/premature wakeups, but the JLS/JVM spec prevents the
  4166   // JVM from making those visible to Java code.  As such, we must
  4167   // filter out spurious wakeups.  We assume all ETIME returns are valid.
  4168   //
  4169   // TODO: properly differentiate simultaneous notify+interrupt.
  4170   // In that case, we should propagate the notify to another waiter.
  4172   while (_Event < 0) {
  4173     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
  4174     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
  4175       pthread_cond_destroy (_cond);
  4176       pthread_cond_init (_cond, NULL) ;
  4178     assert_status(status == 0 || status == EINTR ||
  4179                   status == ETIMEDOUT,
  4180                   status, "cond_timedwait");
  4181     if (!FilterSpuriousWakeups) break ;                 // previous semantics
  4182     if (status == ETIMEDOUT) break ;
  4183     // We consume and ignore EINTR and spurious wakeups.
  4185   --_nParked ;
  4186   if (_Event >= 0) {
  4187      ret = OS_OK;
  4189   _Event = 0 ;
  4190   status = pthread_mutex_unlock(_mutex);
  4191   assert_status(status == 0, status, "mutex_unlock");
  4192   assert (_nParked == 0, "invariant") ;
  4193   // Paranoia to ensure our locked and lock-free paths interact
  4194   // correctly with each other.
  4195   OrderAccess::fence();
  4196   return ret;
  4199 void os::PlatformEvent::unpark() {
  4200   // Transitions for _Event:
  4201   //    0 :=> 1
  4202   //    1 :=> 1
  4203   //   -1 :=> either 0 or 1; must signal target thread
  4204   //          That is, we can safely transition _Event from -1 to either
  4205   //          0 or 1. Forcing 1 is slightly more efficient for back-to-back
  4206   //          unpark() calls.
  4207   // See also: "Semaphores in Plan 9" by Mullender & Cox
  4208   //
  4209   // Note: Forcing a transition from "-1" to "1" on an unpark() means
  4210   // that it will take two back-to-back park() calls for the owning
  4211   // thread to block. This has the benefit of forcing a spurious return
  4212   // from the first park() call after an unpark() call which will help
  4213   // shake out uses of park() and unpark() without condition variables.
  4215   if (Atomic::xchg(1, &_Event) >= 0) return;
  4217   // Wait for the thread associated with the event to vacate
  4218   int status = pthread_mutex_lock(_mutex);
  4219   assert_status(status == 0, status, "mutex_lock");
  4220   int AnyWaiters = _nParked;
  4221   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
  4222   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
  4223     AnyWaiters = 0;
  4224     pthread_cond_signal(_cond);
  4226   status = pthread_mutex_unlock(_mutex);
  4227   assert_status(status == 0, status, "mutex_unlock");
  4228   if (AnyWaiters != 0) {
  4229     status = pthread_cond_signal(_cond);
  4230     assert_status(status == 0, status, "cond_signal");
  4233   // Note that we signal() _after dropping the lock for "immortal" Events.
  4234   // This is safe and avoids a common class of  futile wakeups.  In rare
  4235   // circumstances this can cause a thread to return prematurely from
  4236   // cond_{timed}wait() but the spurious wakeup is benign and the victim will
  4237   // simply re-test the condition and re-park itself.
  4241 // JSR166
  4242 // -------------------------------------------------------
  4244 /*
  4245  * The solaris and bsd implementations of park/unpark are fairly
  4246  * conservative for now, but can be improved. They currently use a
  4247  * mutex/condvar pair, plus a a count.
  4248  * Park decrements count if > 0, else does a condvar wait.  Unpark
  4249  * sets count to 1 and signals condvar.  Only one thread ever waits
  4250  * on the condvar. Contention seen when trying to park implies that someone
  4251  * is unparking you, so don't wait. And spurious returns are fine, so there
  4252  * is no need to track notifications.
  4253  */
  4255 #define MAX_SECS 100000000
  4256 /*
  4257  * This code is common to bsd and solaris and will be moved to a
  4258  * common place in dolphin.
  4260  * The passed in time value is either a relative time in nanoseconds
  4261  * or an absolute time in milliseconds. Either way it has to be unpacked
  4262  * into suitable seconds and nanoseconds components and stored in the
  4263  * given timespec structure.
  4264  * Given time is a 64-bit value and the time_t used in the timespec is only
  4265  * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
  4266  * overflow if times way in the future are given. Further on Solaris versions
  4267  * prior to 10 there is a restriction (see cond_timedwait) that the specified
  4268  * number of seconds, in abstime, is less than current_time  + 100,000,000.
  4269  * As it will be 28 years before "now + 100000000" will overflow we can
  4270  * ignore overflow and just impose a hard-limit on seconds using the value
  4271  * of "now + 100,000,000". This places a limit on the timeout of about 3.17
  4272  * years from "now".
  4273  */
  4275 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
  4276   assert (time > 0, "convertTime");
  4278   struct timeval now;
  4279   int status = gettimeofday(&now, NULL);
  4280   assert(status == 0, "gettimeofday");
  4282   time_t max_secs = now.tv_sec + MAX_SECS;
  4284   if (isAbsolute) {
  4285     jlong secs = time / 1000;
  4286     if (secs > max_secs) {
  4287       absTime->tv_sec = max_secs;
  4289     else {
  4290       absTime->tv_sec = secs;
  4292     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
  4294   else {
  4295     jlong secs = time / NANOSECS_PER_SEC;
  4296     if (secs >= MAX_SECS) {
  4297       absTime->tv_sec = max_secs;
  4298       absTime->tv_nsec = 0;
  4300     else {
  4301       absTime->tv_sec = now.tv_sec + secs;
  4302       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
  4303       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
  4304         absTime->tv_nsec -= NANOSECS_PER_SEC;
  4305         ++absTime->tv_sec; // note: this must be <= max_secs
  4309   assert(absTime->tv_sec >= 0, "tv_sec < 0");
  4310   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
  4311   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
  4312   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
  4315 void Parker::park(bool isAbsolute, jlong time) {
  4316   // Ideally we'd do something useful while spinning, such
  4317   // as calling unpackTime().
  4319   // Optional fast-path check:
  4320   // Return immediately if a permit is available.
  4321   // We depend on Atomic::xchg() having full barrier semantics
  4322   // since we are doing a lock-free update to _counter.
  4323   if (Atomic::xchg(0, &_counter) > 0) return;
  4325   Thread* thread = Thread::current();
  4326   assert(thread->is_Java_thread(), "Must be JavaThread");
  4327   JavaThread *jt = (JavaThread *)thread;
  4329   // Optional optimization -- avoid state transitions if there's an interrupt pending.
  4330   // Check interrupt before trying to wait
  4331   if (Thread::is_interrupted(thread, false)) {
  4332     return;
  4335   // Next, demultiplex/decode time arguments
  4336   struct timespec absTime;
  4337   if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
  4338     return;
  4340   if (time > 0) {
  4341     unpackTime(&absTime, isAbsolute, time);
  4345   // Enter safepoint region
  4346   // Beware of deadlocks such as 6317397.
  4347   // The per-thread Parker:: mutex is a classic leaf-lock.
  4348   // In particular a thread must never block on the Threads_lock while
  4349   // holding the Parker:: mutex.  If safepoints are pending both the
  4350   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
  4351   ThreadBlockInVM tbivm(jt);
  4353   // Don't wait if cannot get lock since interference arises from
  4354   // unblocking.  Also. check interrupt before trying wait
  4355   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
  4356     return;
  4359   int status ;
  4360   if (_counter > 0)  { // no wait needed
  4361     _counter = 0;
  4362     status = pthread_mutex_unlock(_mutex);
  4363     assert (status == 0, "invariant") ;
  4364     // Paranoia to ensure our locked and lock-free paths interact
  4365     // correctly with each other and Java-level accesses.
  4366     OrderAccess::fence();
  4367     return;
  4370 #ifdef ASSERT
  4371   // Don't catch signals while blocked; let the running threads have the signals.
  4372   // (This allows a debugger to break into the running thread.)
  4373   sigset_t oldsigs;
  4374   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
  4375   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
  4376 #endif
  4378   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
  4379   jt->set_suspend_equivalent();
  4380   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
  4382   if (time == 0) {
  4383     status = pthread_cond_wait (_cond, _mutex) ;
  4384   } else {
  4385     status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
  4386     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
  4387       pthread_cond_destroy (_cond) ;
  4388       pthread_cond_init    (_cond, NULL);
  4391   assert_status(status == 0 || status == EINTR ||
  4392                 status == ETIMEDOUT,
  4393                 status, "cond_timedwait");
  4395 #ifdef ASSERT
  4396   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
  4397 #endif
  4399   _counter = 0 ;
  4400   status = pthread_mutex_unlock(_mutex) ;
  4401   assert_status(status == 0, status, "invariant") ;
  4402   // Paranoia to ensure our locked and lock-free paths interact
  4403   // correctly with each other and Java-level accesses.
  4404   OrderAccess::fence();
  4406   // If externally suspended while waiting, re-suspend
  4407   if (jt->handle_special_suspend_equivalent_condition()) {
  4408     jt->java_suspend_self();
  4412 void Parker::unpark() {
  4413   int s, status ;
  4414   status = pthread_mutex_lock(_mutex);
  4415   assert (status == 0, "invariant") ;
  4416   s = _counter;
  4417   _counter = 1;
  4418   if (s < 1) {
  4419      if (WorkAroundNPTLTimedWaitHang) {
  4420         status = pthread_cond_signal (_cond) ;
  4421         assert (status == 0, "invariant") ;
  4422         status = pthread_mutex_unlock(_mutex);
  4423         assert (status == 0, "invariant") ;
  4424      } else {
  4425         status = pthread_mutex_unlock(_mutex);
  4426         assert (status == 0, "invariant") ;
  4427         status = pthread_cond_signal (_cond) ;
  4428         assert (status == 0, "invariant") ;
  4430   } else {
  4431     pthread_mutex_unlock(_mutex);
  4432     assert (status == 0, "invariant") ;
  4437 /* Darwin has no "environ" in a dynamic library. */
  4438 #ifdef __APPLE__
  4439 #include <crt_externs.h>
  4440 #define environ (*_NSGetEnviron())
  4441 #else
  4442 extern char** environ;
  4443 #endif
  4445 // Run the specified command in a separate process. Return its exit value,
  4446 // or -1 on failure (e.g. can't fork a new process).
  4447 // Unlike system(), this function can be called from signal handler. It
  4448 // doesn't block SIGINT et al.
  4449 int os::fork_and_exec(char* cmd) {
  4450   const char * argv[4] = {"sh", "-c", cmd, NULL};
  4452   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
  4453   // pthread_atfork handlers and reset pthread library. All we need is a
  4454   // separate process to execve. Make a direct syscall to fork process.
  4455   // On IA64 there's no fork syscall, we have to use fork() and hope for
  4456   // the best...
  4457   pid_t pid = fork();
  4459   if (pid < 0) {
  4460     // fork failed
  4461     return -1;
  4463   } else if (pid == 0) {
  4464     // child process
  4466     // execve() in BsdThreads will call pthread_kill_other_threads_np()
  4467     // first to kill every thread on the thread list. Because this list is
  4468     // not reset by fork() (see notes above), execve() will instead kill
  4469     // every thread in the parent process. We know this is the only thread
  4470     // in the new process, so make a system call directly.
  4471     // IA64 should use normal execve() from glibc to match the glibc fork()
  4472     // above.
  4473     execve("/bin/sh", (char* const*)argv, environ);
  4475     // execve failed
  4476     _exit(-1);
  4478   } else  {
  4479     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
  4480     // care about the actual exit code, for now.
  4482     int status;
  4484     // Wait for the child process to exit.  This returns immediately if
  4485     // the child has already exited. */
  4486     while (waitpid(pid, &status, 0) < 0) {
  4487         switch (errno) {
  4488         case ECHILD: return 0;
  4489         case EINTR: break;
  4490         default: return -1;
  4494     if (WIFEXITED(status)) {
  4495        // The child exited normally; get its exit code.
  4496        return WEXITSTATUS(status);
  4497     } else if (WIFSIGNALED(status)) {
  4498        // The child exited because of a signal
  4499        // The best value to return is 0x80 + signal number,
  4500        // because that is what all Unix shells do, and because
  4501        // it allows callers to distinguish between process exit and
  4502        // process death by signal.
  4503        return 0x80 + WTERMSIG(status);
  4504     } else {
  4505        // Unknown exit code; pass it through
  4506        return status;
  4511 // is_headless_jre()
  4512 //
  4513 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
  4514 // in order to report if we are running in a headless jre
  4515 //
  4516 // Since JDK8 xawt/libmawt.so was moved into the same directory
  4517 // as libawt.so, and renamed libawt_xawt.so
  4518 //
  4519 bool os::is_headless_jre() {
  4520     struct stat statbuf;
  4521     char buf[MAXPATHLEN];
  4522     char libmawtpath[MAXPATHLEN];
  4523     const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
  4524     const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
  4525     char *p;
  4527     // Get path to libjvm.so
  4528     os::jvm_path(buf, sizeof(buf));
  4530     // Get rid of libjvm.so
  4531     p = strrchr(buf, '/');
  4532     if (p == NULL) return false;
  4533     else *p = '\0';
  4535     // Get rid of client or server
  4536     p = strrchr(buf, '/');
  4537     if (p == NULL) return false;
  4538     else *p = '\0';
  4540     // check xawt/libmawt.so
  4541     strcpy(libmawtpath, buf);
  4542     strcat(libmawtpath, xawtstr);
  4543     if (::stat(libmawtpath, &statbuf) == 0) return false;
  4545     // check libawt_xawt.so
  4546     strcpy(libmawtpath, buf);
  4547     strcat(libmawtpath, new_xawtstr);
  4548     if (::stat(libmawtpath, &statbuf) == 0) return false;
  4550     return true;
  4553 // Get the default path to the core file
  4554 // Returns the length of the string
  4555 int os::get_core_path(char* buffer, size_t bufferSize) {
  4556   int n = jio_snprintf(buffer, bufferSize, "/cores");
  4558   // Truncate if theoretical string was longer than bufferSize
  4559   n = MIN2(n, (int)bufferSize);
  4561   return n;

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