src/os/bsd/vm/os_bsd.cpp

Wed, 02 Apr 2014 18:40:52 +0200

author
kevinw
date
Wed, 02 Apr 2014 18:40:52 +0200
changeset 6553
21dd1c827123
parent 6518
62c54fcc0a35
child 6556
6048424d3865
permissions
-rw-r--r--

8033696: "assert(thread != NULL) failed: just checking" due to Thread::current() and JNI pthread interaction
Reviewed-by: dholmes, dsamersoff
Contributed-by: andreas.eriksson@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>
   103 # include <sys/syscall.h>
   105 #if defined(__FreeBSD__) || defined(__NetBSD__)
   106 # include <elf.h>
   107 #endif
   109 #ifdef __APPLE__
   110 # include <mach/mach.h> // semaphore_* API
   111 # include <mach-o/dyld.h>
   112 # include <sys/proc_info.h>
   113 # include <objc/objc-auto.h>
   114 #endif
   116 #ifndef MAP_ANONYMOUS
   117 #define MAP_ANONYMOUS MAP_ANON
   118 #endif
   120 #define MAX_PATH    (2 * K)
   122 // for timer info max values which include all bits
   123 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
   125 #define LARGEPAGES_BIT (1 << 6)
   126 ////////////////////////////////////////////////////////////////////////////////
   127 // global variables
   128 julong os::Bsd::_physical_memory = 0;
   131 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
   132 pthread_t os::Bsd::_main_thread;
   133 int os::Bsd::_page_size = -1;
   135 static jlong initial_time_count=0;
   137 static int clock_tics_per_sec = 100;
   139 // For diagnostics to print a message once. see run_periodic_checks
   140 static sigset_t check_signal_done;
   141 static bool check_signals = true;
   143 static pid_t _initial_pid = 0;
   145 /* Signal number used to suspend/resume a thread */
   147 /* do not use any signal number less than SIGSEGV, see 4355769 */
   148 static int SR_signum = SIGUSR2;
   149 sigset_t SR_sigset;
   152 ////////////////////////////////////////////////////////////////////////////////
   153 // utility functions
   155 static int SR_initialize();
   156 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
   158 julong os::available_memory() {
   159   return Bsd::available_memory();
   160 }
   162 // available here means free
   163 julong os::Bsd::available_memory() {
   164   uint64_t available = physical_memory() >> 2;
   165 #ifdef __APPLE__
   166   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
   167   vm_statistics64_data_t vmstat;
   168   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
   169                                          (host_info64_t)&vmstat, &count);
   170   assert(kerr == KERN_SUCCESS,
   171          "host_statistics64 failed - check mach_host_self() and count");
   172   if (kerr == KERN_SUCCESS) {
   173     available = vmstat.free_count * os::vm_page_size();
   174   }
   175 #endif
   176   return available;
   177 }
   179 julong os::physical_memory() {
   180   return Bsd::physical_memory();
   181 }
   183 ////////////////////////////////////////////////////////////////////////////////
   184 // environment support
   186 bool os::getenv(const char* name, char* buf, int len) {
   187   const char* val = ::getenv(name);
   188   if (val != NULL && strlen(val) < (size_t)len) {
   189     strcpy(buf, val);
   190     return true;
   191   }
   192   if (len > 0) buf[0] = 0;  // return a null string
   193   return false;
   194 }
   197 // Return true if user is running as root.
   199 bool os::have_special_privileges() {
   200   static bool init = false;
   201   static bool privileges = false;
   202   if (!init) {
   203     privileges = (getuid() != geteuid()) || (getgid() != getegid());
   204     init = true;
   205   }
   206   return privileges;
   207 }
   211 // Cpu architecture string
   212 #if   defined(ZERO)
   213 static char cpu_arch[] = ZERO_LIBARCH;
   214 #elif defined(IA64)
   215 static char cpu_arch[] = "ia64";
   216 #elif defined(IA32)
   217 static char cpu_arch[] = "i386";
   218 #elif defined(AMD64)
   219 static char cpu_arch[] = "amd64";
   220 #elif defined(ARM)
   221 static char cpu_arch[] = "arm";
   222 #elif defined(PPC32)
   223 static char cpu_arch[] = "ppc";
   224 #elif defined(SPARC)
   225 #  ifdef _LP64
   226 static char cpu_arch[] = "sparcv9";
   227 #  else
   228 static char cpu_arch[] = "sparc";
   229 #  endif
   230 #else
   231 #error Add appropriate cpu_arch setting
   232 #endif
   234 // Compiler variant
   235 #ifdef COMPILER2
   236 #define COMPILER_VARIANT "server"
   237 #else
   238 #define COMPILER_VARIANT "client"
   239 #endif
   242 void os::Bsd::initialize_system_info() {
   243   int mib[2];
   244   size_t len;
   245   int cpu_val;
   246   julong mem_val;
   248   /* get processors count via hw.ncpus sysctl */
   249   mib[0] = CTL_HW;
   250   mib[1] = HW_NCPU;
   251   len = sizeof(cpu_val);
   252   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
   253        assert(len == sizeof(cpu_val), "unexpected data size");
   254        set_processor_count(cpu_val);
   255   }
   256   else {
   257        set_processor_count(1);   // fallback
   258   }
   260   /* get physical memory via hw.memsize sysctl (hw.memsize is used
   261    * since it returns a 64 bit value)
   262    */
   263   mib[0] = CTL_HW;
   265 #if defined (HW_MEMSIZE) // Apple
   266   mib[1] = HW_MEMSIZE;
   267 #elif defined(HW_PHYSMEM) // Most of BSD
   268   mib[1] = HW_PHYSMEM;
   269 #elif defined(HW_REALMEM) // Old FreeBSD
   270   mib[1] = HW_REALMEM;
   271 #else
   272   #error No ways to get physmem
   273 #endif
   275   len = sizeof(mem_val);
   276   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
   277        assert(len == sizeof(mem_val), "unexpected data size");
   278        _physical_memory = mem_val;
   279   } else {
   280        _physical_memory = 256*1024*1024;       // fallback (XXXBSD?)
   281   }
   283 #ifdef __OpenBSD__
   284   {
   285        // limit _physical_memory memory view on OpenBSD since
   286        // datasize rlimit restricts us anyway.
   287        struct rlimit limits;
   288        getrlimit(RLIMIT_DATA, &limits);
   289        _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
   290   }
   291 #endif
   292 }
   294 #ifdef __APPLE__
   295 static const char *get_home() {
   296   const char *home_dir = ::getenv("HOME");
   297   if ((home_dir == NULL) || (*home_dir == '\0')) {
   298     struct passwd *passwd_info = getpwuid(geteuid());
   299     if (passwd_info != NULL) {
   300       home_dir = passwd_info->pw_dir;
   301     }
   302   }
   304   return home_dir;
   305 }
   306 #endif
   308 void os::init_system_properties_values() {
   309 //  char arch[12];
   310 //  sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
   312   // The next steps are taken in the product version:
   313   //
   314   // Obtain the JAVA_HOME value from the location of libjvm.so.
   315   // This library should be located at:
   316   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
   317   //
   318   // If "/jre/lib/" appears at the right place in the path, then we
   319   // assume libjvm.so is installed in a JDK and we use this path.
   320   //
   321   // Otherwise exit with message: "Could not create the Java virtual machine."
   322   //
   323   // The following extra steps are taken in the debugging version:
   324   //
   325   // If "/jre/lib/" does NOT appear at the right place in the path
   326   // instead of exit check for $JAVA_HOME environment variable.
   327   //
   328   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
   329   // then we append a fake suffix "hotspot/libjvm.so" to this path so
   330   // it looks like libjvm.so is installed there
   331   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
   332   //
   333   // Otherwise exit.
   334   //
   335   // Important note: if the location of libjvm.so changes this
   336   // code needs to be changed accordingly.
   338   // The next few definitions allow the code to be verbatim:
   339 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal)
   340 #define getenv(n) ::getenv(n)
   342 /*
   343  * See ld(1):
   344  *      The linker uses the following search paths to locate required
   345  *      shared libraries:
   346  *        1: ...
   347  *        ...
   348  *        7: The default directories, normally /lib and /usr/lib.
   349  */
   350 #ifndef DEFAULT_LIBPATH
   351 #define DEFAULT_LIBPATH "/lib:/usr/lib"
   352 #endif
   354 #define EXTENSIONS_DIR  "/lib/ext"
   355 #define ENDORSED_DIR    "/lib/endorsed"
   356 #define REG_DIR         "/usr/java/packages"
   358 #ifdef __APPLE__
   359 #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
   360 #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
   361         const char *user_home_dir = get_home();
   362         // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir
   363         int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
   364             sizeof(SYS_EXTENSIONS_DIRS);
   365 #endif
   367   {
   368     /* sysclasspath, java_home, dll_dir */
   369     {
   370         char *home_path;
   371         char *dll_path;
   372         char *pslash;
   373         char buf[MAXPATHLEN];
   374         os::jvm_path(buf, sizeof(buf));
   376         // Found the full path to libjvm.so.
   377         // Now cut the path to <java_home>/jre if we can.
   378         *(strrchr(buf, '/')) = '\0';  /* get rid of /libjvm.so */
   379         pslash = strrchr(buf, '/');
   380         if (pslash != NULL)
   381             *pslash = '\0';           /* get rid of /{client|server|hotspot} */
   382         dll_path = malloc(strlen(buf) + 1);
   383         if (dll_path == NULL)
   384             return;
   385         strcpy(dll_path, buf);
   386         Arguments::set_dll_dir(dll_path);
   388         if (pslash != NULL) {
   389             pslash = strrchr(buf, '/');
   390             if (pslash != NULL) {
   391                 *pslash = '\0';       /* get rid of /<arch> (/lib on macosx) */
   392 #ifndef __APPLE__
   393                 pslash = strrchr(buf, '/');
   394                 if (pslash != NULL)
   395                     *pslash = '\0';   /* get rid of /lib */
   396 #endif
   397             }
   398         }
   400         home_path = malloc(strlen(buf) + 1);
   401         if (home_path == NULL)
   402             return;
   403         strcpy(home_path, buf);
   404         Arguments::set_java_home(home_path);
   406         if (!set_boot_path('/', ':'))
   407             return;
   408     }
   410     /*
   411      * Where to look for native libraries
   412      *
   413      * Note: Due to a legacy implementation, most of the library path
   414      * is set in the launcher.  This was to accomodate linking restrictions
   415      * on legacy Bsd implementations (which are no longer supported).
   416      * Eventually, all the library path setting will be done here.
   417      *
   418      * However, to prevent the proliferation of improperly built native
   419      * libraries, the new path component /usr/java/packages is added here.
   420      * Eventually, all the library path setting will be done here.
   421      */
   422     {
   423         char *ld_library_path;
   425         /*
   426          * Construct the invariant part of ld_library_path. Note that the
   427          * space for the colon and the trailing null are provided by the
   428          * nulls included by the sizeof operator (so actually we allocate
   429          * a byte more than necessary).
   430          */
   431 #ifdef __APPLE__
   432         ld_library_path = (char *) malloc(system_ext_size);
   433         sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir);
   434 #else
   435         ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
   436             strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
   437         sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
   438 #endif
   440         /*
   441          * Get the user setting of LD_LIBRARY_PATH, and prepended it.  It
   442          * should always exist (until the legacy problem cited above is
   443          * addressed).
   444          */
   445 #ifdef __APPLE__
   446         // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper
   447         char *l = getenv("JAVA_LIBRARY_PATH");
   448         if (l != NULL) {
   449             char *t = ld_library_path;
   450             /* That's +1 for the colon and +1 for the trailing '\0' */
   451             ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1);
   452             sprintf(ld_library_path, "%s:%s", l, t);
   453             free(t);
   454         }
   456         char *v = getenv("DYLD_LIBRARY_PATH");
   457 #else
   458         char *v = getenv("LD_LIBRARY_PATH");
   459 #endif
   460         if (v != NULL) {
   461             char *t = ld_library_path;
   462             /* That's +1 for the colon and +1 for the trailing '\0' */
   463             ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
   464             sprintf(ld_library_path, "%s:%s", v, t);
   465             free(t);
   466         }
   468 #ifdef __APPLE__
   469         // Apple's Java6 has "." at the beginning of java.library.path.
   470         // OpenJDK on Windows has "." at the end of java.library.path.
   471         // OpenJDK on Linux and Solaris don't have "." in java.library.path
   472         // at all. To ease the transition from Apple's Java6 to OpenJDK7,
   473         // "." is appended to the end of java.library.path. Yes, this
   474         // could cause a change in behavior, but Apple's Java6 behavior
   475         // can be achieved by putting "." at the beginning of the
   476         // JAVA_LIBRARY_PATH environment variable.
   477         {
   478             char *t = ld_library_path;
   479             // that's +3 for appending ":." and the trailing '\0'
   480             ld_library_path = (char *) malloc(strlen(t) + 3);
   481             sprintf(ld_library_path, "%s:%s", t, ".");
   482             free(t);
   483         }
   484 #endif
   486         Arguments::set_library_path(ld_library_path);
   487     }
   489     /*
   490      * Extensions directories.
   491      *
   492      * Note that the space for the colon and the trailing null are provided
   493      * by the nulls included by the sizeof operator (so actually one byte more
   494      * than necessary is allocated).
   495      */
   496     {
   497 #ifdef __APPLE__
   498         char *buf = malloc(strlen(Arguments::get_java_home()) +
   499             sizeof(EXTENSIONS_DIR) + system_ext_size);
   500         sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":"
   501             SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home());
   502 #else
   503         char *buf = malloc(strlen(Arguments::get_java_home()) +
   504             sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
   505         sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
   506             Arguments::get_java_home());
   507 #endif
   509         Arguments::set_ext_dirs(buf);
   510     }
   512     /* Endorsed standards default directory. */
   513     {
   514         char * buf;
   515         buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
   516         sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
   517         Arguments::set_endorsed_dirs(buf);
   518     }
   519   }
   521 #ifdef __APPLE__
   522 #undef SYS_EXTENSIONS_DIR
   523 #endif
   524 #undef malloc
   525 #undef getenv
   526 #undef EXTENSIONS_DIR
   527 #undef ENDORSED_DIR
   529   // Done
   530   return;
   531 }
   533 ////////////////////////////////////////////////////////////////////////////////
   534 // breakpoint support
   536 void os::breakpoint() {
   537   BREAKPOINT;
   538 }
   540 extern "C" void breakpoint() {
   541   // use debugger to set breakpoint here
   542 }
   544 ////////////////////////////////////////////////////////////////////////////////
   545 // signal support
   547 debug_only(static bool signal_sets_initialized = false);
   548 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
   550 bool os::Bsd::is_sig_ignored(int sig) {
   551       struct sigaction oact;
   552       sigaction(sig, (struct sigaction*)NULL, &oact);
   553       void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
   554                                      : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
   555       if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
   556            return true;
   557       else
   558            return false;
   559 }
   561 void os::Bsd::signal_sets_init() {
   562   // Should also have an assertion stating we are still single-threaded.
   563   assert(!signal_sets_initialized, "Already initialized");
   564   // Fill in signals that are necessarily unblocked for all threads in
   565   // the VM. Currently, we unblock the following signals:
   566   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
   567   //                         by -Xrs (=ReduceSignalUsage));
   568   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
   569   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
   570   // the dispositions or masks wrt these signals.
   571   // Programs embedding the VM that want to use the above signals for their
   572   // own purposes must, at this time, use the "-Xrs" option to prevent
   573   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
   574   // (See bug 4345157, and other related bugs).
   575   // In reality, though, unblocking these signals is really a nop, since
   576   // these signals are not blocked by default.
   577   sigemptyset(&unblocked_sigs);
   578   sigemptyset(&allowdebug_blocked_sigs);
   579   sigaddset(&unblocked_sigs, SIGILL);
   580   sigaddset(&unblocked_sigs, SIGSEGV);
   581   sigaddset(&unblocked_sigs, SIGBUS);
   582   sigaddset(&unblocked_sigs, SIGFPE);
   583   sigaddset(&unblocked_sigs, SR_signum);
   585   if (!ReduceSignalUsage) {
   586    if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
   587       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
   588       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
   589    }
   590    if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
   591       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
   592       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
   593    }
   594    if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
   595       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
   596       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
   597    }
   598   }
   599   // Fill in signals that are blocked by all but the VM thread.
   600   sigemptyset(&vm_sigs);
   601   if (!ReduceSignalUsage)
   602     sigaddset(&vm_sigs, BREAK_SIGNAL);
   603   debug_only(signal_sets_initialized = true);
   605 }
   607 // These are signals that are unblocked while a thread is running Java.
   608 // (For some reason, they get blocked by default.)
   609 sigset_t* os::Bsd::unblocked_signals() {
   610   assert(signal_sets_initialized, "Not initialized");
   611   return &unblocked_sigs;
   612 }
   614 // These are the signals that are blocked while a (non-VM) thread is
   615 // running Java. Only the VM thread handles these signals.
   616 sigset_t* os::Bsd::vm_signals() {
   617   assert(signal_sets_initialized, "Not initialized");
   618   return &vm_sigs;
   619 }
   621 // These are signals that are blocked during cond_wait to allow debugger in
   622 sigset_t* os::Bsd::allowdebug_blocked_signals() {
   623   assert(signal_sets_initialized, "Not initialized");
   624   return &allowdebug_blocked_sigs;
   625 }
   627 void os::Bsd::hotspot_sigmask(Thread* thread) {
   629   //Save caller's signal mask before setting VM signal mask
   630   sigset_t caller_sigmask;
   631   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
   633   OSThread* osthread = thread->osthread();
   634   osthread->set_caller_sigmask(caller_sigmask);
   636   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
   638   if (!ReduceSignalUsage) {
   639     if (thread->is_VM_thread()) {
   640       // Only the VM thread handles BREAK_SIGNAL ...
   641       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
   642     } else {
   643       // ... all other threads block BREAK_SIGNAL
   644       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
   645     }
   646   }
   647 }
   650 //////////////////////////////////////////////////////////////////////////////
   651 // create new thread
   653 // check if it's safe to start a new thread
   654 static bool _thread_safety_check(Thread* thread) {
   655   return true;
   656 }
   658 #ifdef __APPLE__
   659 // library handle for calling objc_registerThreadWithCollector()
   660 // without static linking to the libobjc library
   661 #define OBJC_LIB "/usr/lib/libobjc.dylib"
   662 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
   663 typedef void (*objc_registerThreadWithCollector_t)();
   664 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
   665 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
   666 #endif
   668 #ifdef __APPLE__
   669 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
   670   // Additional thread_id used to correlate threads in SA
   671   thread_identifier_info_data_t     m_ident_info;
   672   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
   674   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
   675               (thread_info_t) &m_ident_info, &count);
   677   return m_ident_info.thread_id;
   678 }
   679 #endif
   681 // Thread start routine for all newly created threads
   682 static void *java_start(Thread *thread) {
   683   // Try to randomize the cache line index of hot stack frames.
   684   // This helps when threads of the same stack traces evict each other's
   685   // cache lines. The threads can be either from the same JVM instance, or
   686   // from different JVM instances. The benefit is especially true for
   687   // processors with hyperthreading technology.
   688   static int counter = 0;
   689   int pid = os::current_process_id();
   690   alloca(((pid ^ counter++) & 7) * 128);
   692   ThreadLocalStorage::set_thread(thread);
   694   OSThread* osthread = thread->osthread();
   695   Monitor* sync = osthread->startThread_lock();
   697   // non floating stack BsdThreads needs extra check, see above
   698   if (!_thread_safety_check(thread)) {
   699     // notify parent thread
   700     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
   701     osthread->set_state(ZOMBIE);
   702     sync->notify_all();
   703     return NULL;
   704   }
   706   osthread->set_thread_id(os::Bsd::gettid());
   708 #ifdef __APPLE__
   709   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
   710   guarantee(unique_thread_id != 0, "unique thread id was not found");
   711   osthread->set_unique_thread_id(unique_thread_id);
   712 #endif
   713   // initialize signal mask for this thread
   714   os::Bsd::hotspot_sigmask(thread);
   716   // initialize floating point control register
   717   os::Bsd::init_thread_fpu_state();
   719 #ifdef __APPLE__
   720   // register thread with objc gc
   721   if (objc_registerThreadWithCollectorFunction != NULL) {
   722     objc_registerThreadWithCollectorFunction();
   723   }
   724 #endif
   726   // handshaking with parent thread
   727   {
   728     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
   730     // notify parent thread
   731     osthread->set_state(INITIALIZED);
   732     sync->notify_all();
   734     // wait until os::start_thread()
   735     while (osthread->get_state() == INITIALIZED) {
   736       sync->wait(Mutex::_no_safepoint_check_flag);
   737     }
   738   }
   740   // call one more level start routine
   741   thread->run();
   743   return 0;
   744 }
   746 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
   747   assert(thread->osthread() == NULL, "caller responsible");
   749   // Allocate the OSThread object
   750   OSThread* osthread = new OSThread(NULL, NULL);
   751   if (osthread == NULL) {
   752     return false;
   753   }
   755   // set the correct thread state
   756   osthread->set_thread_type(thr_type);
   758   // Initial state is ALLOCATED but not INITIALIZED
   759   osthread->set_state(ALLOCATED);
   761   thread->set_osthread(osthread);
   763   // init thread attributes
   764   pthread_attr_t attr;
   765   pthread_attr_init(&attr);
   766   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
   768   // stack size
   769   if (os::Bsd::supports_variable_stack_size()) {
   770     // calculate stack size if it's not specified by caller
   771     if (stack_size == 0) {
   772       stack_size = os::Bsd::default_stack_size(thr_type);
   774       switch (thr_type) {
   775       case os::java_thread:
   776         // Java threads use ThreadStackSize which default value can be
   777         // changed with the flag -Xss
   778         assert (JavaThread::stack_size_at_create() > 0, "this should be set");
   779         stack_size = JavaThread::stack_size_at_create();
   780         break;
   781       case os::compiler_thread:
   782         if (CompilerThreadStackSize > 0) {
   783           stack_size = (size_t)(CompilerThreadStackSize * K);
   784           break;
   785         } // else fall through:
   786           // use VMThreadStackSize if CompilerThreadStackSize is not defined
   787       case os::vm_thread:
   788       case os::pgc_thread:
   789       case os::cgc_thread:
   790       case os::watcher_thread:
   791         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
   792         break;
   793       }
   794     }
   796     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
   797     pthread_attr_setstacksize(&attr, stack_size);
   798   } else {
   799     // let pthread_create() pick the default value.
   800   }
   802   ThreadState state;
   804   {
   805     pthread_t tid;
   806     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
   808     pthread_attr_destroy(&attr);
   810     if (ret != 0) {
   811       if (PrintMiscellaneous && (Verbose || WizardMode)) {
   812         perror("pthread_create()");
   813       }
   814       // Need to clean up stuff we've allocated so far
   815       thread->set_osthread(NULL);
   816       delete osthread;
   817       return false;
   818     }
   820     // Store pthread info into the OSThread
   821     osthread->set_pthread_id(tid);
   823     // Wait until child thread is either initialized or aborted
   824     {
   825       Monitor* sync_with_child = osthread->startThread_lock();
   826       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
   827       while ((state = osthread->get_state()) == ALLOCATED) {
   828         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
   829       }
   830     }
   832   }
   834   // Aborted due to thread limit being reached
   835   if (state == ZOMBIE) {
   836       thread->set_osthread(NULL);
   837       delete osthread;
   838       return false;
   839   }
   841   // The thread is returned suspended (in state INITIALIZED),
   842   // and is started higher up in the call chain
   843   assert(state == INITIALIZED, "race condition");
   844   return true;
   845 }
   847 /////////////////////////////////////////////////////////////////////////////
   848 // attach existing thread
   850 // bootstrap the main thread
   851 bool os::create_main_thread(JavaThread* thread) {
   852   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
   853   return create_attached_thread(thread);
   854 }
   856 bool os::create_attached_thread(JavaThread* thread) {
   857 #ifdef ASSERT
   858     thread->verify_not_published();
   859 #endif
   861   // Allocate the OSThread object
   862   OSThread* osthread = new OSThread(NULL, NULL);
   864   if (osthread == NULL) {
   865     return false;
   866   }
   868   osthread->set_thread_id(os::Bsd::gettid());
   870   // Store pthread info into the OSThread
   871 #ifdef __APPLE__
   872   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
   873   guarantee(unique_thread_id != 0, "just checking");
   874   osthread->set_unique_thread_id(unique_thread_id);
   875 #endif
   876   osthread->set_pthread_id(::pthread_self());
   878   // initialize floating point control register
   879   os::Bsd::init_thread_fpu_state();
   881   // Initial thread state is RUNNABLE
   882   osthread->set_state(RUNNABLE);
   884   thread->set_osthread(osthread);
   886   // initialize signal mask for this thread
   887   // and save the caller's signal mask
   888   os::Bsd::hotspot_sigmask(thread);
   890   return true;
   891 }
   893 void os::pd_start_thread(Thread* thread) {
   894   OSThread * osthread = thread->osthread();
   895   assert(osthread->get_state() != INITIALIZED, "just checking");
   896   Monitor* sync_with_child = osthread->startThread_lock();
   897   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
   898   sync_with_child->notify();
   899 }
   901 // Free Bsd resources related to the OSThread
   902 void os::free_thread(OSThread* osthread) {
   903   assert(osthread != NULL, "osthread not set");
   905   if (Thread::current()->osthread() == osthread) {
   906     // Restore caller's signal mask
   907     sigset_t sigmask = osthread->caller_sigmask();
   908     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
   909    }
   911   delete osthread;
   912 }
   914 //////////////////////////////////////////////////////////////////////////////
   915 // thread local storage
   917 // Restore the thread pointer if the destructor is called. This is in case
   918 // someone from JNI code sets up a destructor with pthread_key_create to run
   919 // detachCurrentThread on thread death. Unless we restore the thread pointer we
   920 // will hang or crash. When detachCurrentThread is called the key will be set
   921 // to null and we will not be called again. If detachCurrentThread is never
   922 // called we could loop forever depending on the pthread implementation.
   923 static void restore_thread_pointer(void* p) {
   924   Thread* thread = (Thread*) p;
   925   os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
   926 }
   928 int os::allocate_thread_local_storage() {
   929   pthread_key_t key;
   930   int rslt = pthread_key_create(&key, restore_thread_pointer);
   931   assert(rslt == 0, "cannot allocate thread local storage");
   932   return (int)key;
   933 }
   935 // Note: This is currently not used by VM, as we don't destroy TLS key
   936 // on VM exit.
   937 void os::free_thread_local_storage(int index) {
   938   int rslt = pthread_key_delete((pthread_key_t)index);
   939   assert(rslt == 0, "invalid index");
   940 }
   942 void os::thread_local_storage_at_put(int index, void* value) {
   943   int rslt = pthread_setspecific((pthread_key_t)index, value);
   944   assert(rslt == 0, "pthread_setspecific failed");
   945 }
   947 extern "C" Thread* get_thread() {
   948   return ThreadLocalStorage::thread();
   949 }
   952 ////////////////////////////////////////////////////////////////////////////////
   953 // time support
   955 // Time since start-up in seconds to a fine granularity.
   956 // Used by VMSelfDestructTimer and the MemProfiler.
   957 double os::elapsedTime() {
   959   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
   960 }
   962 jlong os::elapsed_counter() {
   963   return javaTimeNanos() - initial_time_count;
   964 }
   966 jlong os::elapsed_frequency() {
   967   return NANOSECS_PER_SEC; // nanosecond resolution
   968 }
   970 bool os::supports_vtime() { return true; }
   971 bool os::enable_vtime()   { return false; }
   972 bool os::vtime_enabled()  { return false; }
   974 double os::elapsedVTime() {
   975   // better than nothing, but not much
   976   return elapsedTime();
   977 }
   979 jlong os::javaTimeMillis() {
   980   timeval time;
   981   int status = gettimeofday(&time, NULL);
   982   assert(status != -1, "bsd error");
   983   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
   984 }
   986 #ifndef CLOCK_MONOTONIC
   987 #define CLOCK_MONOTONIC (1)
   988 #endif
   990 #ifdef __APPLE__
   991 void os::Bsd::clock_init() {
   992         // XXXDARWIN: Investigate replacement monotonic clock
   993 }
   994 #else
   995 void os::Bsd::clock_init() {
   996   struct timespec res;
   997   struct timespec tp;
   998   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
   999       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
  1000     // yes, monotonic clock is supported
  1001     _clock_gettime = ::clock_gettime;
  1004 #endif
  1007 jlong os::javaTimeNanos() {
  1008   if (Bsd::supports_monotonic_clock()) {
  1009     struct timespec tp;
  1010     int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp);
  1011     assert(status == 0, "gettime error");
  1012     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
  1013     return result;
  1014   } else {
  1015     timeval time;
  1016     int status = gettimeofday(&time, NULL);
  1017     assert(status != -1, "bsd error");
  1018     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
  1019     return 1000 * usecs;
  1023 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
  1024   if (Bsd::supports_monotonic_clock()) {
  1025     info_ptr->max_value = ALL_64_BITS;
  1027     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
  1028     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
  1029     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
  1030   } else {
  1031     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
  1032     info_ptr->max_value = ALL_64_BITS;
  1034     // gettimeofday is a real time clock so it skips
  1035     info_ptr->may_skip_backward = true;
  1036     info_ptr->may_skip_forward = true;
  1039   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
  1042 // Return the real, user, and system times in seconds from an
  1043 // arbitrary fixed point in the past.
  1044 bool os::getTimesSecs(double* process_real_time,
  1045                       double* process_user_time,
  1046                       double* process_system_time) {
  1047   struct tms ticks;
  1048   clock_t real_ticks = times(&ticks);
  1050   if (real_ticks == (clock_t) (-1)) {
  1051     return false;
  1052   } else {
  1053     double ticks_per_second = (double) clock_tics_per_sec;
  1054     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
  1055     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
  1056     *process_real_time = ((double) real_ticks) / ticks_per_second;
  1058     return true;
  1063 char * os::local_time_string(char *buf, size_t buflen) {
  1064   struct tm t;
  1065   time_t long_time;
  1066   time(&long_time);
  1067   localtime_r(&long_time, &t);
  1068   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
  1069                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
  1070                t.tm_hour, t.tm_min, t.tm_sec);
  1071   return buf;
  1074 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
  1075   return localtime_r(clock, res);
  1078 ////////////////////////////////////////////////////////////////////////////////
  1079 // runtime exit support
  1081 // Note: os::shutdown() might be called very early during initialization, or
  1082 // called from signal handler. Before adding something to os::shutdown(), make
  1083 // sure it is async-safe and can handle partially initialized VM.
  1084 void os::shutdown() {
  1086   // allow PerfMemory to attempt cleanup of any persistent resources
  1087   perfMemory_exit();
  1089   // needs to remove object in file system
  1090   AttachListener::abort();
  1092   // flush buffered output, finish log files
  1093   ostream_abort();
  1095   // Check for abort hook
  1096   abort_hook_t abort_hook = Arguments::abort_hook();
  1097   if (abort_hook != NULL) {
  1098     abort_hook();
  1103 // Note: os::abort() might be called very early during initialization, or
  1104 // called from signal handler. Before adding something to os::abort(), make
  1105 // sure it is async-safe and can handle partially initialized VM.
  1106 void os::abort(bool dump_core) {
  1107   os::shutdown();
  1108   if (dump_core) {
  1109 #ifndef PRODUCT
  1110     fdStream out(defaultStream::output_fd());
  1111     out.print_raw("Current thread is ");
  1112     char buf[16];
  1113     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
  1114     out.print_raw_cr(buf);
  1115     out.print_raw_cr("Dumping core ...");
  1116 #endif
  1117     ::abort(); // dump core
  1120   ::exit(1);
  1123 // Die immediately, no exit hook, no abort hook, no cleanup.
  1124 void os::die() {
  1125   // _exit() on BsdThreads only kills current thread
  1126   ::abort();
  1129 // unused on bsd for now.
  1130 void os::set_error_file(const char *logfile) {}
  1133 // This method is a copy of JDK's sysGetLastErrorString
  1134 // from src/solaris/hpi/src/system_md.c
  1136 size_t os::lasterror(char *buf, size_t len) {
  1138   if (errno == 0)  return 0;
  1140   const char *s = ::strerror(errno);
  1141   size_t n = ::strlen(s);
  1142   if (n >= len) {
  1143     n = len - 1;
  1145   ::strncpy(buf, s, n);
  1146   buf[n] = '\0';
  1147   return n;
  1150 // Information of current thread in variety of formats
  1151 pid_t os::Bsd::gettid() {
  1152   int retval = -1;
  1154 #ifdef __APPLE__ //XNU kernel
  1155   // despite the fact mach port is actually not a thread id use it
  1156   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
  1157   retval = ::pthread_mach_thread_np(::pthread_self());
  1158   guarantee(retval != 0, "just checking");
  1159   return retval;
  1161 #elif __FreeBSD__
  1162   retval = syscall(SYS_thr_self);
  1163 #elif __OpenBSD__
  1164   retval = syscall(SYS_getthrid);
  1165 #elif __NetBSD__
  1166   retval = (pid_t) syscall(SYS__lwp_self);
  1167 #endif
  1169   if (retval == -1) {
  1170     return getpid();
  1174 intx os::current_thread_id() {
  1175 #ifdef __APPLE__
  1176   return (intx)::pthread_mach_thread_np(::pthread_self());
  1177 #else
  1178   return (intx)::pthread_self();
  1179 #endif
  1182 int os::current_process_id() {
  1184   // Under the old bsd thread library, bsd gives each thread
  1185   // its own process id. Because of this each thread will return
  1186   // a different pid if this method were to return the result
  1187   // of getpid(2). Bsd provides no api that returns the pid
  1188   // of the launcher thread for the vm. This implementation
  1189   // returns a unique pid, the pid of the launcher thread
  1190   // that starts the vm 'process'.
  1192   // Under the NPTL, getpid() returns the same pid as the
  1193   // launcher thread rather than a unique pid per thread.
  1194   // Use gettid() if you want the old pre NPTL behaviour.
  1196   // if you are looking for the result of a call to getpid() that
  1197   // returns a unique pid for the calling thread, then look at the
  1198   // OSThread::thread_id() method in osThread_bsd.hpp file
  1200   return (int)(_initial_pid ? _initial_pid : getpid());
  1203 // DLL functions
  1205 #define JNI_LIB_PREFIX "lib"
  1206 #ifdef __APPLE__
  1207 #define JNI_LIB_SUFFIX ".dylib"
  1208 #else
  1209 #define JNI_LIB_SUFFIX ".so"
  1210 #endif
  1212 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
  1214 // This must be hard coded because it's the system's temporary
  1215 // directory not the java application's temp directory, ala java.io.tmpdir.
  1216 #ifdef __APPLE__
  1217 // macosx has a secure per-user temporary directory
  1218 char temp_path_storage[PATH_MAX];
  1219 const char* os::get_temp_directory() {
  1220   static char *temp_path = NULL;
  1221   if (temp_path == NULL) {
  1222     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
  1223     if (pathSize == 0 || pathSize > PATH_MAX) {
  1224       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
  1226     temp_path = temp_path_storage;
  1228   return temp_path;
  1230 #else /* __APPLE__ */
  1231 const char* os::get_temp_directory() { return "/tmp"; }
  1232 #endif /* __APPLE__ */
  1234 static bool file_exists(const char* filename) {
  1235   struct stat statbuf;
  1236   if (filename == NULL || strlen(filename) == 0) {
  1237     return false;
  1239   return os::stat(filename, &statbuf) == 0;
  1242 bool os::dll_build_name(char* buffer, size_t buflen,
  1243                         const char* pname, const char* fname) {
  1244   bool retval = false;
  1245   // Copied from libhpi
  1246   const size_t pnamelen = pname ? strlen(pname) : 0;
  1248   // Return error on buffer overflow.
  1249   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
  1250     return retval;
  1253   if (pnamelen == 0) {
  1254     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
  1255     retval = true;
  1256   } else if (strchr(pname, *os::path_separator()) != NULL) {
  1257     int n;
  1258     char** pelements = split_path(pname, &n);
  1259     if (pelements == NULL) {
  1260       return false;
  1262     for (int i = 0 ; i < n ; i++) {
  1263       // Really shouldn't be NULL, but check can't hurt
  1264       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
  1265         continue; // skip the empty path values
  1267       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
  1268           pelements[i], fname);
  1269       if (file_exists(buffer)) {
  1270         retval = true;
  1271         break;
  1274     // release the storage
  1275     for (int i = 0 ; i < n ; i++) {
  1276       if (pelements[i] != NULL) {
  1277         FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
  1280     if (pelements != NULL) {
  1281       FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
  1283   } else {
  1284     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
  1285     retval = true;
  1287   return retval;
  1290 // check if addr is inside libjvm.so
  1291 bool os::address_is_in_vm(address addr) {
  1292   static address libjvm_base_addr;
  1293   Dl_info dlinfo;
  1295   if (libjvm_base_addr == NULL) {
  1296     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
  1297       libjvm_base_addr = (address)dlinfo.dli_fbase;
  1299     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
  1302   if (dladdr((void *)addr, &dlinfo) != 0) {
  1303     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
  1306   return false;
  1310 #define MACH_MAXSYMLEN 256
  1312 bool os::dll_address_to_function_name(address addr, char *buf,
  1313                                       int buflen, int *offset) {
  1314   // buf is not optional, but offset is optional
  1315   assert(buf != NULL, "sanity check");
  1317   Dl_info dlinfo;
  1318   char localbuf[MACH_MAXSYMLEN];
  1320   if (dladdr((void*)addr, &dlinfo) != 0) {
  1321     // see if we have a matching symbol
  1322     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
  1323       if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
  1324         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
  1326       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
  1327       return true;
  1329     // no matching symbol so try for just file info
  1330     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
  1331       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
  1332                           buf, buflen, offset, dlinfo.dli_fname)) {
  1333          return true;
  1337     // Handle non-dynamic manually:
  1338     if (dlinfo.dli_fbase != NULL &&
  1339         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
  1340                         dlinfo.dli_fbase)) {
  1341       if (!Decoder::demangle(localbuf, buf, buflen)) {
  1342         jio_snprintf(buf, buflen, "%s", localbuf);
  1344       return true;
  1347   buf[0] = '\0';
  1348   if (offset != NULL) *offset = -1;
  1349   return false;
  1352 // ported from solaris version
  1353 bool os::dll_address_to_library_name(address addr, char* buf,
  1354                                      int buflen, int* offset) {
  1355   // buf is not optional, but offset is optional
  1356   assert(buf != NULL, "sanity check");
  1358   Dl_info dlinfo;
  1360   if (dladdr((void*)addr, &dlinfo) != 0) {
  1361     if (dlinfo.dli_fname != NULL) {
  1362       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
  1364     if (dlinfo.dli_fbase != NULL && offset != NULL) {
  1365       *offset = addr - (address)dlinfo.dli_fbase;
  1367     return true;
  1370   buf[0] = '\0';
  1371   if (offset) *offset = -1;
  1372   return false;
  1375 // Loads .dll/.so and
  1376 // in case of error it checks if .dll/.so was built for the
  1377 // same architecture as Hotspot is running on
  1379 #ifdef __APPLE__
  1380 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
  1381   void * result= ::dlopen(filename, RTLD_LAZY);
  1382   if (result != NULL) {
  1383     // Successful loading
  1384     return result;
  1387   // Read system error message into ebuf
  1388   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
  1389   ebuf[ebuflen-1]='\0';
  1391   return NULL;
  1393 #else
  1394 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
  1396   void * result= ::dlopen(filename, RTLD_LAZY);
  1397   if (result != NULL) {
  1398     // Successful loading
  1399     return result;
  1402   Elf32_Ehdr elf_head;
  1404   // Read system error message into ebuf
  1405   // It may or may not be overwritten below
  1406   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
  1407   ebuf[ebuflen-1]='\0';
  1408   int diag_msg_max_length=ebuflen-strlen(ebuf);
  1409   char* diag_msg_buf=ebuf+strlen(ebuf);
  1411   if (diag_msg_max_length==0) {
  1412     // No more space in ebuf for additional diagnostics message
  1413     return NULL;
  1417   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
  1419   if (file_descriptor < 0) {
  1420     // Can't open library, report dlerror() message
  1421     return NULL;
  1424   bool failed_to_read_elf_head=
  1425     (sizeof(elf_head)!=
  1426         (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
  1428   ::close(file_descriptor);
  1429   if (failed_to_read_elf_head) {
  1430     // file i/o error - report dlerror() msg
  1431     return NULL;
  1434   typedef struct {
  1435     Elf32_Half  code;         // Actual value as defined in elf.h
  1436     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
  1437     char        elf_class;    // 32 or 64 bit
  1438     char        endianess;    // MSB or LSB
  1439     char*       name;         // String representation
  1440   } arch_t;
  1442   #ifndef EM_486
  1443   #define EM_486          6               /* Intel 80486 */
  1444   #endif
  1446   #ifndef EM_MIPS_RS3_LE
  1447   #define EM_MIPS_RS3_LE  10              /* MIPS */
  1448   #endif
  1450   #ifndef EM_PPC64
  1451   #define EM_PPC64        21              /* PowerPC64 */
  1452   #endif
  1454   #ifndef EM_S390
  1455   #define EM_S390         22              /* IBM System/390 */
  1456   #endif
  1458   #ifndef EM_IA_64
  1459   #define EM_IA_64        50              /* HP/Intel IA-64 */
  1460   #endif
  1462   #ifndef EM_X86_64
  1463   #define EM_X86_64       62              /* AMD x86-64 */
  1464   #endif
  1466   static const arch_t arch_array[]={
  1467     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
  1468     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
  1469     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
  1470     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
  1471     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
  1472     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
  1473     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
  1474     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
  1475     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
  1476     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
  1477     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
  1478     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
  1479     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
  1480     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
  1481     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
  1482     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
  1483   };
  1485   #if  (defined IA32)
  1486     static  Elf32_Half running_arch_code=EM_386;
  1487   #elif   (defined AMD64)
  1488     static  Elf32_Half running_arch_code=EM_X86_64;
  1489   #elif  (defined IA64)
  1490     static  Elf32_Half running_arch_code=EM_IA_64;
  1491   #elif  (defined __sparc) && (defined _LP64)
  1492     static  Elf32_Half running_arch_code=EM_SPARCV9;
  1493   #elif  (defined __sparc) && (!defined _LP64)
  1494     static  Elf32_Half running_arch_code=EM_SPARC;
  1495   #elif  (defined __powerpc64__)
  1496     static  Elf32_Half running_arch_code=EM_PPC64;
  1497   #elif  (defined __powerpc__)
  1498     static  Elf32_Half running_arch_code=EM_PPC;
  1499   #elif  (defined ARM)
  1500     static  Elf32_Half running_arch_code=EM_ARM;
  1501   #elif  (defined S390)
  1502     static  Elf32_Half running_arch_code=EM_S390;
  1503   #elif  (defined ALPHA)
  1504     static  Elf32_Half running_arch_code=EM_ALPHA;
  1505   #elif  (defined MIPSEL)
  1506     static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
  1507   #elif  (defined PARISC)
  1508     static  Elf32_Half running_arch_code=EM_PARISC;
  1509   #elif  (defined MIPS)
  1510     static  Elf32_Half running_arch_code=EM_MIPS;
  1511   #elif  (defined M68K)
  1512     static  Elf32_Half running_arch_code=EM_68K;
  1513   #else
  1514     #error Method os::dll_load requires that one of following is defined:\
  1515          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
  1516   #endif
  1518   // Identify compatability class for VM's architecture and library's architecture
  1519   // Obtain string descriptions for architectures
  1521   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
  1522   int running_arch_index=-1;
  1524   for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
  1525     if (running_arch_code == arch_array[i].code) {
  1526       running_arch_index    = i;
  1528     if (lib_arch.code == arch_array[i].code) {
  1529       lib_arch.compat_class = arch_array[i].compat_class;
  1530       lib_arch.name         = arch_array[i].name;
  1534   assert(running_arch_index != -1,
  1535     "Didn't find running architecture code (running_arch_code) in arch_array");
  1536   if (running_arch_index == -1) {
  1537     // Even though running architecture detection failed
  1538     // we may still continue with reporting dlerror() message
  1539     return NULL;
  1542   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
  1543     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
  1544     return NULL;
  1547 #ifndef S390
  1548   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
  1549     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
  1550     return NULL;
  1552 #endif // !S390
  1554   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
  1555     if ( lib_arch.name!=NULL ) {
  1556       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
  1557         " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
  1558         lib_arch.name, arch_array[running_arch_index].name);
  1559     } else {
  1560       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
  1561       " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
  1562         lib_arch.code,
  1563         arch_array[running_arch_index].name);
  1567   return NULL;
  1569 #endif /* !__APPLE__ */
  1571 void* os::get_default_process_handle() {
  1572 #ifdef __APPLE__
  1573   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
  1574   // to avoid finding unexpected symbols on second (or later)
  1575   // loads of a library.
  1576   return (void*)::dlopen(NULL, RTLD_FIRST);
  1577 #else
  1578   return (void*)::dlopen(NULL, RTLD_LAZY);
  1579 #endif
  1582 // XXX: Do we need a lock around this as per Linux?
  1583 void* os::dll_lookup(void* handle, const char* name) {
  1584   return dlsym(handle, name);
  1588 static bool _print_ascii_file(const char* filename, outputStream* st) {
  1589   int fd = ::open(filename, O_RDONLY);
  1590   if (fd == -1) {
  1591      return false;
  1594   char buf[32];
  1595   int bytes;
  1596   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
  1597     st->print_raw(buf, bytes);
  1600   ::close(fd);
  1602   return true;
  1605 void os::print_dll_info(outputStream *st) {
  1606   st->print_cr("Dynamic libraries:");
  1607 #ifdef RTLD_DI_LINKMAP
  1608   Dl_info dli;
  1609   void *handle;
  1610   Link_map *map;
  1611   Link_map *p;
  1613   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
  1614       dli.dli_fname == NULL) {
  1615     st->print_cr("Error: Cannot print dynamic libraries.");
  1616     return;
  1618   handle = dlopen(dli.dli_fname, RTLD_LAZY);
  1619   if (handle == NULL) {
  1620     st->print_cr("Error: Cannot print dynamic libraries.");
  1621     return;
  1623   dlinfo(handle, RTLD_DI_LINKMAP, &map);
  1624   if (map == NULL) {
  1625     st->print_cr("Error: Cannot print dynamic libraries.");
  1626     return;
  1629   while (map->l_prev != NULL)
  1630     map = map->l_prev;
  1632   while (map != NULL) {
  1633     st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
  1634     map = map->l_next;
  1637   dlclose(handle);
  1638 #elif defined(__APPLE__)
  1639   uint32_t count;
  1640   uint32_t i;
  1642   count = _dyld_image_count();
  1643   for (i = 1; i < count; i++) {
  1644     const char *name = _dyld_get_image_name(i);
  1645     intptr_t slide = _dyld_get_image_vmaddr_slide(i);
  1646     st->print_cr(PTR_FORMAT " \t%s", slide, name);
  1648 #else
  1649   st->print_cr("Error: Cannot print dynamic libraries.");
  1650 #endif
  1653 void os::print_os_info_brief(outputStream* st) {
  1654   st->print("Bsd");
  1656   os::Posix::print_uname_info(st);
  1659 void os::print_os_info(outputStream* st) {
  1660   st->print("OS:");
  1661   st->print("Bsd");
  1663   os::Posix::print_uname_info(st);
  1665   os::Posix::print_rlimit_info(st);
  1667   os::Posix::print_load_average(st);
  1670 void os::pd_print_cpu_info(outputStream* st) {
  1671   // Nothing to do for now.
  1674 void os::print_memory_info(outputStream* st) {
  1676   st->print("Memory:");
  1677   st->print(" %dk page", os::vm_page_size()>>10);
  1679   st->print(", physical " UINT64_FORMAT "k",
  1680             os::physical_memory() >> 10);
  1681   st->print("(" UINT64_FORMAT "k free)",
  1682             os::available_memory() >> 10);
  1683   st->cr();
  1685   // meminfo
  1686   st->print("\n/proc/meminfo:\n");
  1687   _print_ascii_file("/proc/meminfo", st);
  1688   st->cr();
  1691 void os::print_siginfo(outputStream* st, void* siginfo) {
  1692   const siginfo_t* si = (const siginfo_t*)siginfo;
  1694   os::Posix::print_siginfo_brief(st, si);
  1696   if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
  1697       UseSharedSpaces) {
  1698     FileMapInfo* mapinfo = FileMapInfo::current_info();
  1699     if (mapinfo->is_in_shared_space(si->si_addr)) {
  1700       st->print("\n\nError accessing class data sharing archive."   \
  1701                 " Mapped file inaccessible during execution, "      \
  1702                 " possible disk/network problem.");
  1705   st->cr();
  1709 static void print_signal_handler(outputStream* st, int sig,
  1710                                  char* buf, size_t buflen);
  1712 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
  1713   st->print_cr("Signal Handlers:");
  1714   print_signal_handler(st, SIGSEGV, buf, buflen);
  1715   print_signal_handler(st, SIGBUS , buf, buflen);
  1716   print_signal_handler(st, SIGFPE , buf, buflen);
  1717   print_signal_handler(st, SIGPIPE, buf, buflen);
  1718   print_signal_handler(st, SIGXFSZ, buf, buflen);
  1719   print_signal_handler(st, SIGILL , buf, buflen);
  1720   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
  1721   print_signal_handler(st, SR_signum, buf, buflen);
  1722   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
  1723   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
  1724   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
  1725   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
  1728 static char saved_jvm_path[MAXPATHLEN] = {0};
  1730 // Find the full path to the current module, libjvm
  1731 void os::jvm_path(char *buf, jint buflen) {
  1732   // Error checking.
  1733   if (buflen < MAXPATHLEN) {
  1734     assert(false, "must use a large-enough buffer");
  1735     buf[0] = '\0';
  1736     return;
  1738   // Lazy resolve the path to current module.
  1739   if (saved_jvm_path[0] != 0) {
  1740     strcpy(buf, saved_jvm_path);
  1741     return;
  1744   char dli_fname[MAXPATHLEN];
  1745   bool ret = dll_address_to_library_name(
  1746                 CAST_FROM_FN_PTR(address, os::jvm_path),
  1747                 dli_fname, sizeof(dli_fname), NULL);
  1748   assert(ret, "cannot locate libjvm");
  1749   char *rp = NULL;
  1750   if (ret && dli_fname[0] != '\0') {
  1751     rp = realpath(dli_fname, buf);
  1753   if (rp == NULL)
  1754     return;
  1756   if (Arguments::created_by_gamma_launcher()) {
  1757     // Support for the gamma launcher.  Typical value for buf is
  1758     // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm".  If "/jre/lib/" appears at
  1759     // the right place in the string, then assume we are installed in a JDK and
  1760     // we're done.  Otherwise, check for a JAVA_HOME environment variable and
  1761     // construct a path to the JVM being overridden.
  1763     const char *p = buf + strlen(buf) - 1;
  1764     for (int count = 0; p > buf && count < 5; ++count) {
  1765       for (--p; p > buf && *p != '/'; --p)
  1766         /* empty */ ;
  1769     if (strncmp(p, "/jre/lib/", 9) != 0) {
  1770       // Look for JAVA_HOME in the environment.
  1771       char* java_home_var = ::getenv("JAVA_HOME");
  1772       if (java_home_var != NULL && java_home_var[0] != 0) {
  1773         char* jrelib_p;
  1774         int len;
  1776         // Check the current module name "libjvm"
  1777         p = strrchr(buf, '/');
  1778         assert(strstr(p, "/libjvm") == p, "invalid library name");
  1780         rp = realpath(java_home_var, buf);
  1781         if (rp == NULL)
  1782           return;
  1784         // determine if this is a legacy image or modules image
  1785         // modules image doesn't have "jre" subdirectory
  1786         len = strlen(buf);
  1787         jrelib_p = buf + len;
  1789         // Add the appropriate library subdir
  1790         snprintf(jrelib_p, buflen-len, "/jre/lib");
  1791         if (0 != access(buf, F_OK)) {
  1792           snprintf(jrelib_p, buflen-len, "/lib");
  1795         // Add the appropriate client or server subdir
  1796         len = strlen(buf);
  1797         jrelib_p = buf + len;
  1798         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
  1799         if (0 != access(buf, F_OK)) {
  1800           snprintf(jrelib_p, buflen-len, "");
  1803         // If the path exists within JAVA_HOME, add the JVM library name
  1804         // to complete the path to JVM being overridden.  Otherwise fallback
  1805         // to the path to the current library.
  1806         if (0 == access(buf, F_OK)) {
  1807           // Use current module name "libjvm"
  1808           len = strlen(buf);
  1809           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
  1810         } else {
  1811           // Fall back to path of current library
  1812           rp = realpath(dli_fname, buf);
  1813           if (rp == NULL)
  1814             return;
  1820   strcpy(saved_jvm_path, buf);
  1823 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
  1824   // no prefix required, not even "_"
  1827 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
  1828   // no suffix required
  1831 ////////////////////////////////////////////////////////////////////////////////
  1832 // sun.misc.Signal support
  1834 static volatile jint sigint_count = 0;
  1836 static void
  1837 UserHandler(int sig, void *siginfo, void *context) {
  1838   // 4511530 - sem_post is serialized and handled by the manager thread. When
  1839   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
  1840   // don't want to flood the manager thread with sem_post requests.
  1841   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
  1842       return;
  1844   // Ctrl-C is pressed during error reporting, likely because the error
  1845   // handler fails to abort. Let VM die immediately.
  1846   if (sig == SIGINT && is_error_reported()) {
  1847      os::die();
  1850   os::signal_notify(sig);
  1853 void* os::user_handler() {
  1854   return CAST_FROM_FN_PTR(void*, UserHandler);
  1857 extern "C" {
  1858   typedef void (*sa_handler_t)(int);
  1859   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
  1862 void* os::signal(int signal_number, void* handler) {
  1863   struct sigaction sigAct, oldSigAct;
  1865   sigfillset(&(sigAct.sa_mask));
  1866   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
  1867   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
  1869   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
  1870     // -1 means registration failed
  1871     return (void *)-1;
  1874   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
  1877 void os::signal_raise(int signal_number) {
  1878   ::raise(signal_number);
  1881 /*
  1882  * The following code is moved from os.cpp for making this
  1883  * code platform specific, which it is by its very nature.
  1884  */
  1886 // Will be modified when max signal is changed to be dynamic
  1887 int os::sigexitnum_pd() {
  1888   return NSIG;
  1891 // a counter for each possible signal value
  1892 static volatile jint pending_signals[NSIG+1] = { 0 };
  1894 // Bsd(POSIX) specific hand shaking semaphore.
  1895 #ifdef __APPLE__
  1896 typedef semaphore_t os_semaphore_t;
  1897 #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
  1898 #define SEM_WAIT(sem)           semaphore_wait(sem)
  1899 #define SEM_POST(sem)           semaphore_signal(sem)
  1900 #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
  1901 #else
  1902 typedef sem_t os_semaphore_t;
  1903 #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
  1904 #define SEM_WAIT(sem)           sem_wait(&sem)
  1905 #define SEM_POST(sem)           sem_post(&sem)
  1906 #define SEM_DESTROY(sem)        sem_destroy(&sem)
  1907 #endif
  1909 class Semaphore : public StackObj {
  1910   public:
  1911     Semaphore();
  1912     ~Semaphore();
  1913     void signal();
  1914     void wait();
  1915     bool trywait();
  1916     bool timedwait(unsigned int sec, int nsec);
  1917   private:
  1918     jlong currenttime() const;
  1919     os_semaphore_t _semaphore;
  1920 };
  1922 Semaphore::Semaphore() : _semaphore(0) {
  1923   SEM_INIT(_semaphore, 0);
  1926 Semaphore::~Semaphore() {
  1927   SEM_DESTROY(_semaphore);
  1930 void Semaphore::signal() {
  1931   SEM_POST(_semaphore);
  1934 void Semaphore::wait() {
  1935   SEM_WAIT(_semaphore);
  1938 jlong Semaphore::currenttime() const {
  1939     struct timeval tv;
  1940     gettimeofday(&tv, NULL);
  1941     return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
  1944 #ifdef __APPLE__
  1945 bool Semaphore::trywait() {
  1946   return timedwait(0, 0);
  1949 bool Semaphore::timedwait(unsigned int sec, int nsec) {
  1950   kern_return_t kr = KERN_ABORTED;
  1951   mach_timespec_t waitspec;
  1952   waitspec.tv_sec = sec;
  1953   waitspec.tv_nsec = nsec;
  1955   jlong starttime = currenttime();
  1957   kr = semaphore_timedwait(_semaphore, waitspec);
  1958   while (kr == KERN_ABORTED) {
  1959     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
  1961     jlong current = currenttime();
  1962     jlong passedtime = current - starttime;
  1964     if (passedtime >= totalwait) {
  1965       waitspec.tv_sec = 0;
  1966       waitspec.tv_nsec = 0;
  1967     } else {
  1968       jlong waittime = totalwait - (current - starttime);
  1969       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
  1970       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
  1973     kr = semaphore_timedwait(_semaphore, waitspec);
  1976   return kr == KERN_SUCCESS;
  1979 #else
  1981 bool Semaphore::trywait() {
  1982   return sem_trywait(&_semaphore) == 0;
  1985 bool Semaphore::timedwait(unsigned int sec, int nsec) {
  1986   struct timespec ts;
  1987   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
  1989   while (1) {
  1990     int result = sem_timedwait(&_semaphore, &ts);
  1991     if (result == 0) {
  1992       return true;
  1993     } else if (errno == EINTR) {
  1994       continue;
  1995     } else if (errno == ETIMEDOUT) {
  1996       return false;
  1997     } else {
  1998       return false;
  2003 #endif // __APPLE__
  2005 static os_semaphore_t sig_sem;
  2006 static Semaphore sr_semaphore;
  2008 void os::signal_init_pd() {
  2009   // Initialize signal structures
  2010   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
  2012   // Initialize signal semaphore
  2013   ::SEM_INIT(sig_sem, 0);
  2016 void os::signal_notify(int sig) {
  2017   Atomic::inc(&pending_signals[sig]);
  2018   ::SEM_POST(sig_sem);
  2021 static int check_pending_signals(bool wait) {
  2022   Atomic::store(0, &sigint_count);
  2023   for (;;) {
  2024     for (int i = 0; i < NSIG + 1; i++) {
  2025       jint n = pending_signals[i];
  2026       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
  2027         return i;
  2030     if (!wait) {
  2031       return -1;
  2033     JavaThread *thread = JavaThread::current();
  2034     ThreadBlockInVM tbivm(thread);
  2036     bool threadIsSuspended;
  2037     do {
  2038       thread->set_suspend_equivalent();
  2039       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
  2040       ::SEM_WAIT(sig_sem);
  2042       // were we externally suspended while we were waiting?
  2043       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
  2044       if (threadIsSuspended) {
  2045         //
  2046         // The semaphore has been incremented, but while we were waiting
  2047         // another thread suspended us. We don't want to continue running
  2048         // while suspended because that would surprise the thread that
  2049         // suspended us.
  2050         //
  2051         ::SEM_POST(sig_sem);
  2053         thread->java_suspend_self();
  2055     } while (threadIsSuspended);
  2059 int os::signal_lookup() {
  2060   return check_pending_signals(false);
  2063 int os::signal_wait() {
  2064   return check_pending_signals(true);
  2067 ////////////////////////////////////////////////////////////////////////////////
  2068 // Virtual Memory
  2070 int os::vm_page_size() {
  2071   // Seems redundant as all get out
  2072   assert(os::Bsd::page_size() != -1, "must call os::init");
  2073   return os::Bsd::page_size();
  2076 // Solaris allocates memory by pages.
  2077 int os::vm_allocation_granularity() {
  2078   assert(os::Bsd::page_size() != -1, "must call os::init");
  2079   return os::Bsd::page_size();
  2082 // Rationale behind this function:
  2083 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
  2084 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
  2085 //  samples for JITted code. Here we create private executable mapping over the code cache
  2086 //  and then we can use standard (well, almost, as mapping can change) way to provide
  2087 //  info for the reporting script by storing timestamp and location of symbol
  2088 void bsd_wrap_code(char* base, size_t size) {
  2089   static volatile jint cnt = 0;
  2091   if (!UseOprofile) {
  2092     return;
  2095   char buf[PATH_MAX + 1];
  2096   int num = Atomic::add(1, &cnt);
  2098   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
  2099            os::get_temp_directory(), os::current_process_id(), num);
  2100   unlink(buf);
  2102   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
  2104   if (fd != -1) {
  2105     off_t rv = ::lseek(fd, size-2, SEEK_SET);
  2106     if (rv != (off_t)-1) {
  2107       if (::write(fd, "", 1) == 1) {
  2108         mmap(base, size,
  2109              PROT_READ|PROT_WRITE|PROT_EXEC,
  2110              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
  2113     ::close(fd);
  2114     unlink(buf);
  2118 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
  2119                                     int err) {
  2120   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
  2121           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
  2122           strerror(err), err);
  2125 // NOTE: Bsd kernel does not really reserve the pages for us.
  2126 //       All it does is to check if there are enough free pages
  2127 //       left at the time of mmap(). This could be a potential
  2128 //       problem.
  2129 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
  2130   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
  2131 #ifdef __OpenBSD__
  2132   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
  2133   if (::mprotect(addr, size, prot) == 0) {
  2134     return true;
  2136 #else
  2137   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
  2138                                    MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
  2139   if (res != (uintptr_t) MAP_FAILED) {
  2140     return true;
  2142 #endif
  2144   // Warn about any commit errors we see in non-product builds just
  2145   // in case mmap() doesn't work as described on the man page.
  2146   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
  2148   return false;
  2151 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
  2152                        bool exec) {
  2153   // alignment_hint is ignored on this OS
  2154   return pd_commit_memory(addr, size, exec);
  2157 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
  2158                                   const char* mesg) {
  2159   assert(mesg != NULL, "mesg must be specified");
  2160   if (!pd_commit_memory(addr, size, exec)) {
  2161     // add extra info in product mode for vm_exit_out_of_memory():
  2162     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
  2163     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
  2167 void os::pd_commit_memory_or_exit(char* addr, size_t size,
  2168                                   size_t alignment_hint, bool exec,
  2169                                   const char* mesg) {
  2170   // alignment_hint is ignored on this OS
  2171   pd_commit_memory_or_exit(addr, size, exec, mesg);
  2174 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
  2177 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
  2178   ::madvise(addr, bytes, MADV_DONTNEED);
  2181 void os::numa_make_global(char *addr, size_t bytes) {
  2184 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
  2187 bool os::numa_topology_changed()   { return false; }
  2189 size_t os::numa_get_groups_num() {
  2190   return 1;
  2193 int os::numa_get_group_id() {
  2194   return 0;
  2197 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
  2198   if (size > 0) {
  2199     ids[0] = 0;
  2200     return 1;
  2202   return 0;
  2205 bool os::get_page_info(char *start, page_info* info) {
  2206   return false;
  2209 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
  2210   return end;
  2214 bool os::pd_uncommit_memory(char* addr, size_t size) {
  2215 #ifdef __OpenBSD__
  2216   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
  2217   return ::mprotect(addr, size, PROT_NONE) == 0;
  2218 #else
  2219   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
  2220                 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
  2221   return res  != (uintptr_t) MAP_FAILED;
  2222 #endif
  2225 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
  2226   return os::commit_memory(addr, size, !ExecMem);
  2229 // If this is a growable mapping, remove the guard pages entirely by
  2230 // munmap()ping them.  If not, just call uncommit_memory().
  2231 bool os::remove_stack_guard_pages(char* addr, size_t size) {
  2232   return os::uncommit_memory(addr, size);
  2235 static address _highest_vm_reserved_address = NULL;
  2237 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
  2238 // at 'requested_addr'. If there are existing memory mappings at the same
  2239 // location, however, they will be overwritten. If 'fixed' is false,
  2240 // 'requested_addr' is only treated as a hint, the return value may or
  2241 // may not start from the requested address. Unlike Bsd mmap(), this
  2242 // function returns NULL to indicate failure.
  2243 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
  2244   char * addr;
  2245   int flags;
  2247   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
  2248   if (fixed) {
  2249     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
  2250     flags |= MAP_FIXED;
  2253   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
  2254   // touch an uncommitted page. Otherwise, the read/write might
  2255   // succeed if we have enough swap space to back the physical page.
  2256   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
  2257                        flags, -1, 0);
  2259   if (addr != MAP_FAILED) {
  2260     // anon_mmap() should only get called during VM initialization,
  2261     // don't need lock (actually we can skip locking even it can be called
  2262     // from multiple threads, because _highest_vm_reserved_address is just a
  2263     // hint about the upper limit of non-stack memory regions.)
  2264     if ((address)addr + bytes > _highest_vm_reserved_address) {
  2265       _highest_vm_reserved_address = (address)addr + bytes;
  2269   return addr == MAP_FAILED ? NULL : addr;
  2272 // Don't update _highest_vm_reserved_address, because there might be memory
  2273 // regions above addr + size. If so, releasing a memory region only creates
  2274 // a hole in the address space, it doesn't help prevent heap-stack collision.
  2275 //
  2276 static int anon_munmap(char * addr, size_t size) {
  2277   return ::munmap(addr, size) == 0;
  2280 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
  2281                          size_t alignment_hint) {
  2282   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
  2285 bool os::pd_release_memory(char* addr, size_t size) {
  2286   return anon_munmap(addr, size);
  2289 static bool bsd_mprotect(char* addr, size_t size, int prot) {
  2290   // Bsd wants the mprotect address argument to be page aligned.
  2291   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
  2293   // According to SUSv3, mprotect() should only be used with mappings
  2294   // established by mmap(), and mmap() always maps whole pages. Unaligned
  2295   // 'addr' likely indicates problem in the VM (e.g. trying to change
  2296   // protection of malloc'ed or statically allocated memory). Check the
  2297   // caller if you hit this assert.
  2298   assert(addr == bottom, "sanity check");
  2300   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
  2301   return ::mprotect(bottom, size, prot) == 0;
  2304 // Set protections specified
  2305 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
  2306                         bool is_committed) {
  2307   unsigned int p = 0;
  2308   switch (prot) {
  2309   case MEM_PROT_NONE: p = PROT_NONE; break;
  2310   case MEM_PROT_READ: p = PROT_READ; break;
  2311   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
  2312   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
  2313   default:
  2314     ShouldNotReachHere();
  2316   // is_committed is unused.
  2317   return bsd_mprotect(addr, bytes, p);
  2320 bool os::guard_memory(char* addr, size_t size) {
  2321   return bsd_mprotect(addr, size, PROT_NONE);
  2324 bool os::unguard_memory(char* addr, size_t size) {
  2325   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
  2328 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
  2329   return false;
  2332 // Large page support
  2334 static size_t _large_page_size = 0;
  2336 void os::large_page_init() {
  2340 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
  2341   fatal("This code is not used or maintained.");
  2343   // "exec" is passed in but not used.  Creating the shared image for
  2344   // the code cache doesn't have an SHM_X executable permission to check.
  2345   assert(UseLargePages && UseSHM, "only for SHM large pages");
  2347   key_t key = IPC_PRIVATE;
  2348   char *addr;
  2350   bool warn_on_failure = UseLargePages &&
  2351                         (!FLAG_IS_DEFAULT(UseLargePages) ||
  2352                          !FLAG_IS_DEFAULT(LargePageSizeInBytes)
  2353                         );
  2354   char msg[128];
  2356   // Create a large shared memory region to attach to based on size.
  2357   // Currently, size is the total size of the heap
  2358   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
  2359   if (shmid == -1) {
  2360      // Possible reasons for shmget failure:
  2361      // 1. shmmax is too small for Java heap.
  2362      //    > check shmmax value: cat /proc/sys/kernel/shmmax
  2363      //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
  2364      // 2. not enough large page memory.
  2365      //    > check available large pages: cat /proc/meminfo
  2366      //    > increase amount of large pages:
  2367      //          echo new_value > /proc/sys/vm/nr_hugepages
  2368      //      Note 1: different Bsd may use different name for this property,
  2369      //            e.g. on Redhat AS-3 it is "hugetlb_pool".
  2370      //      Note 2: it's possible there's enough physical memory available but
  2371      //            they are so fragmented after a long run that they can't
  2372      //            coalesce into large pages. Try to reserve large pages when
  2373      //            the system is still "fresh".
  2374      if (warn_on_failure) {
  2375        jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
  2376        warning(msg);
  2378      return NULL;
  2381   // attach to the region
  2382   addr = (char*)shmat(shmid, req_addr, 0);
  2383   int err = errno;
  2385   // Remove shmid. If shmat() is successful, the actual shared memory segment
  2386   // will be deleted when it's detached by shmdt() or when the process
  2387   // terminates. If shmat() is not successful this will remove the shared
  2388   // segment immediately.
  2389   shmctl(shmid, IPC_RMID, NULL);
  2391   if ((intptr_t)addr == -1) {
  2392      if (warn_on_failure) {
  2393        jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
  2394        warning(msg);
  2396      return NULL;
  2399   // The memory is committed
  2400   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, mtNone, CALLER_PC);
  2402   return addr;
  2405 bool os::release_memory_special(char* base, size_t bytes) {
  2406   MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
  2407   // detaching the SHM segment will also delete it, see reserve_memory_special()
  2408   int rslt = shmdt(base);
  2409   if (rslt == 0) {
  2410     tkr.record((address)base, bytes);
  2411     return true;
  2412   } else {
  2413     tkr.discard();
  2414     return false;
  2419 size_t os::large_page_size() {
  2420   return _large_page_size;
  2423 // HugeTLBFS allows application to commit large page memory on demand;
  2424 // with SysV SHM the entire memory region must be allocated as shared
  2425 // memory.
  2426 bool os::can_commit_large_page_memory() {
  2427   return UseHugeTLBFS;
  2430 bool os::can_execute_large_page_memory() {
  2431   return UseHugeTLBFS;
  2434 // Reserve memory at an arbitrary address, only if that area is
  2435 // available (and not reserved for something else).
  2437 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
  2438   const int max_tries = 10;
  2439   char* base[max_tries];
  2440   size_t size[max_tries];
  2441   const size_t gap = 0x000000;
  2443   // Assert only that the size is a multiple of the page size, since
  2444   // that's all that mmap requires, and since that's all we really know
  2445   // about at this low abstraction level.  If we need higher alignment,
  2446   // we can either pass an alignment to this method or verify alignment
  2447   // in one of the methods further up the call chain.  See bug 5044738.
  2448   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
  2450   // Repeatedly allocate blocks until the block is allocated at the
  2451   // right spot. Give up after max_tries. Note that reserve_memory() will
  2452   // automatically update _highest_vm_reserved_address if the call is
  2453   // successful. The variable tracks the highest memory address every reserved
  2454   // by JVM. It is used to detect heap-stack collision if running with
  2455   // fixed-stack BsdThreads. Because here we may attempt to reserve more
  2456   // space than needed, it could confuse the collision detecting code. To
  2457   // solve the problem, save current _highest_vm_reserved_address and
  2458   // calculate the correct value before return.
  2459   address old_highest = _highest_vm_reserved_address;
  2461   // Bsd mmap allows caller to pass an address as hint; give it a try first,
  2462   // if kernel honors the hint then we can return immediately.
  2463   char * addr = anon_mmap(requested_addr, bytes, false);
  2464   if (addr == requested_addr) {
  2465      return requested_addr;
  2468   if (addr != NULL) {
  2469      // mmap() is successful but it fails to reserve at the requested address
  2470      anon_munmap(addr, bytes);
  2473   int i;
  2474   for (i = 0; i < max_tries; ++i) {
  2475     base[i] = reserve_memory(bytes);
  2477     if (base[i] != NULL) {
  2478       // Is this the block we wanted?
  2479       if (base[i] == requested_addr) {
  2480         size[i] = bytes;
  2481         break;
  2484       // Does this overlap the block we wanted? Give back the overlapped
  2485       // parts and try again.
  2487       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
  2488       if (top_overlap >= 0 && top_overlap < bytes) {
  2489         unmap_memory(base[i], top_overlap);
  2490         base[i] += top_overlap;
  2491         size[i] = bytes - top_overlap;
  2492       } else {
  2493         size_t bottom_overlap = base[i] + bytes - requested_addr;
  2494         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
  2495           unmap_memory(requested_addr, bottom_overlap);
  2496           size[i] = bytes - bottom_overlap;
  2497         } else {
  2498           size[i] = bytes;
  2504   // Give back the unused reserved pieces.
  2506   for (int j = 0; j < i; ++j) {
  2507     if (base[j] != NULL) {
  2508       unmap_memory(base[j], size[j]);
  2512   if (i < max_tries) {
  2513     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
  2514     return requested_addr;
  2515   } else {
  2516     _highest_vm_reserved_address = old_highest;
  2517     return NULL;
  2521 size_t os::read(int fd, void *buf, unsigned int nBytes) {
  2522   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
  2525 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
  2526 // Solaris uses poll(), bsd uses park().
  2527 // Poll() is likely a better choice, assuming that Thread.interrupt()
  2528 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
  2529 // SIGSEGV, see 4355769.
  2531 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
  2532   assert(thread == Thread::current(),  "thread consistency check");
  2534   ParkEvent * const slp = thread->_SleepEvent ;
  2535   slp->reset() ;
  2536   OrderAccess::fence() ;
  2538   if (interruptible) {
  2539     jlong prevtime = javaTimeNanos();
  2541     for (;;) {
  2542       if (os::is_interrupted(thread, true)) {
  2543         return OS_INTRPT;
  2546       jlong newtime = javaTimeNanos();
  2548       if (newtime - prevtime < 0) {
  2549         // time moving backwards, should only happen if no monotonic clock
  2550         // not a guarantee() because JVM should not abort on kernel/glibc bugs
  2551         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
  2552       } else {
  2553         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
  2556       if(millis <= 0) {
  2557         return OS_OK;
  2560       prevtime = newtime;
  2563         assert(thread->is_Java_thread(), "sanity check");
  2564         JavaThread *jt = (JavaThread *) thread;
  2565         ThreadBlockInVM tbivm(jt);
  2566         OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
  2568         jt->set_suspend_equivalent();
  2569         // cleared by handle_special_suspend_equivalent_condition() or
  2570         // java_suspend_self() via check_and_wait_while_suspended()
  2572         slp->park(millis);
  2574         // were we externally suspended while we were waiting?
  2575         jt->check_and_wait_while_suspended();
  2578   } else {
  2579     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
  2580     jlong prevtime = javaTimeNanos();
  2582     for (;;) {
  2583       // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
  2584       // the 1st iteration ...
  2585       jlong newtime = javaTimeNanos();
  2587       if (newtime - prevtime < 0) {
  2588         // time moving backwards, should only happen if no monotonic clock
  2589         // not a guarantee() because JVM should not abort on kernel/glibc bugs
  2590         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
  2591       } else {
  2592         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
  2595       if(millis <= 0) break ;
  2597       prevtime = newtime;
  2598       slp->park(millis);
  2600     return OS_OK ;
  2604 void os::naked_short_sleep(jlong ms) {
  2605   struct timespec req;
  2607   assert(ms < 1000, "Un-interruptable sleep, short time use only");
  2608   req.tv_sec = 0;
  2609   if (ms > 0) {
  2610     req.tv_nsec = (ms % 1000) * 1000000;
  2612   else {
  2613     req.tv_nsec = 1;
  2616   nanosleep(&req, NULL);
  2618   return;
  2621 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
  2622 void os::infinite_sleep() {
  2623   while (true) {    // sleep forever ...
  2624     ::sleep(100);   // ... 100 seconds at a time
  2628 // Used to convert frequent JVM_Yield() to nops
  2629 bool os::dont_yield() {
  2630   return DontYieldALot;
  2633 void os::yield() {
  2634   sched_yield();
  2637 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
  2639 void os::yield_all(int attempts) {
  2640   // Yields to all threads, including threads with lower priorities
  2641   // Threads on Bsd are all with same priority. The Solaris style
  2642   // os::yield_all() with nanosleep(1ms) is not necessary.
  2643   sched_yield();
  2646 // Called from the tight loops to possibly influence time-sharing heuristics
  2647 void os::loop_breaker(int attempts) {
  2648   os::yield_all(attempts);
  2651 ////////////////////////////////////////////////////////////////////////////////
  2652 // thread priority support
  2654 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
  2655 // only supports dynamic priority, static priority must be zero. For real-time
  2656 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
  2657 // However, for large multi-threaded applications, SCHED_RR is not only slower
  2658 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
  2659 // of 5 runs - Sep 2005).
  2660 //
  2661 // The following code actually changes the niceness of kernel-thread/LWP. It
  2662 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
  2663 // not the entire user process, and user level threads are 1:1 mapped to kernel
  2664 // threads. It has always been the case, but could change in the future. For
  2665 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
  2666 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
  2668 #if !defined(__APPLE__)
  2669 int os::java_to_os_priority[CriticalPriority + 1] = {
  2670   19,              // 0 Entry should never be used
  2672    0,              // 1 MinPriority
  2673    3,              // 2
  2674    6,              // 3
  2676   10,              // 4
  2677   15,              // 5 NormPriority
  2678   18,              // 6
  2680   21,              // 7
  2681   25,              // 8
  2682   28,              // 9 NearMaxPriority
  2684   31,              // 10 MaxPriority
  2686   31               // 11 CriticalPriority
  2687 };
  2688 #else
  2689 /* Using Mach high-level priority assignments */
  2690 int os::java_to_os_priority[CriticalPriority + 1] = {
  2691    0,              // 0 Entry should never be used (MINPRI_USER)
  2693   27,              // 1 MinPriority
  2694   28,              // 2
  2695   29,              // 3
  2697   30,              // 4
  2698   31,              // 5 NormPriority (BASEPRI_DEFAULT)
  2699   32,              // 6
  2701   33,              // 7
  2702   34,              // 8
  2703   35,              // 9 NearMaxPriority
  2705   36,              // 10 MaxPriority
  2707   36               // 11 CriticalPriority
  2708 };
  2709 #endif
  2711 static int prio_init() {
  2712   if (ThreadPriorityPolicy == 1) {
  2713     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
  2714     // if effective uid is not root. Perhaps, a more elegant way of doing
  2715     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
  2716     if (geteuid() != 0) {
  2717       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
  2718         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
  2720       ThreadPriorityPolicy = 0;
  2723   if (UseCriticalJavaThreadPriority) {
  2724     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
  2726   return 0;
  2729 OSReturn os::set_native_priority(Thread* thread, int newpri) {
  2730   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
  2732 #ifdef __OpenBSD__
  2733   // OpenBSD pthread_setprio starves low priority threads
  2734   return OS_OK;
  2735 #elif defined(__FreeBSD__)
  2736   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
  2737 #elif defined(__APPLE__) || defined(__NetBSD__)
  2738   struct sched_param sp;
  2739   int policy;
  2740   pthread_t self = pthread_self();
  2742   if (pthread_getschedparam(self, &policy, &sp) != 0)
  2743     return OS_ERR;
  2745   sp.sched_priority = newpri;
  2746   if (pthread_setschedparam(self, policy, &sp) != 0)
  2747     return OS_ERR;
  2749   return OS_OK;
  2750 #else
  2751   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
  2752   return (ret == 0) ? OS_OK : OS_ERR;
  2753 #endif
  2756 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
  2757   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
  2758     *priority_ptr = java_to_os_priority[NormPriority];
  2759     return OS_OK;
  2762   errno = 0;
  2763 #if defined(__OpenBSD__) || defined(__FreeBSD__)
  2764   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
  2765 #elif defined(__APPLE__) || defined(__NetBSD__)
  2766   int policy;
  2767   struct sched_param sp;
  2769   pthread_getschedparam(pthread_self(), &policy, &sp);
  2770   *priority_ptr = sp.sched_priority;
  2771 #else
  2772   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
  2773 #endif
  2774   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
  2777 // Hint to the underlying OS that a task switch would not be good.
  2778 // Void return because it's a hint and can fail.
  2779 void os::hint_no_preempt() {}
  2781 ////////////////////////////////////////////////////////////////////////////////
  2782 // suspend/resume support
  2784 //  the low-level signal-based suspend/resume support is a remnant from the
  2785 //  old VM-suspension that used to be for java-suspension, safepoints etc,
  2786 //  within hotspot. Now there is a single use-case for this:
  2787 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
  2788 //      that runs in the watcher thread.
  2789 //  The remaining code is greatly simplified from the more general suspension
  2790 //  code that used to be used.
  2791 //
  2792 //  The protocol is quite simple:
  2793 //  - suspend:
  2794 //      - sends a signal to the target thread
  2795 //      - polls the suspend state of the osthread using a yield loop
  2796 //      - target thread signal handler (SR_handler) sets suspend state
  2797 //        and blocks in sigsuspend until continued
  2798 //  - resume:
  2799 //      - sets target osthread state to continue
  2800 //      - sends signal to end the sigsuspend loop in the SR_handler
  2801 //
  2802 //  Note that the SR_lock plays no role in this suspend/resume protocol.
  2803 //
  2805 static void resume_clear_context(OSThread *osthread) {
  2806   osthread->set_ucontext(NULL);
  2807   osthread->set_siginfo(NULL);
  2810 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
  2811   osthread->set_ucontext(context);
  2812   osthread->set_siginfo(siginfo);
  2815 //
  2816 // Handler function invoked when a thread's execution is suspended or
  2817 // resumed. We have to be careful that only async-safe functions are
  2818 // called here (Note: most pthread functions are not async safe and
  2819 // should be avoided.)
  2820 //
  2821 // Note: sigwait() is a more natural fit than sigsuspend() from an
  2822 // interface point of view, but sigwait() prevents the signal hander
  2823 // from being run. libpthread would get very confused by not having
  2824 // its signal handlers run and prevents sigwait()'s use with the
  2825 // mutex granting granting signal.
  2826 //
  2827 // Currently only ever called on the VMThread or JavaThread
  2828 //
  2829 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
  2830   // Save and restore errno to avoid confusing native code with EINTR
  2831   // after sigsuspend.
  2832   int old_errno = errno;
  2834   Thread* thread = Thread::current();
  2835   OSThread* osthread = thread->osthread();
  2836   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
  2838   os::SuspendResume::State current = osthread->sr.state();
  2839   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
  2840     suspend_save_context(osthread, siginfo, context);
  2842     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
  2843     os::SuspendResume::State state = osthread->sr.suspended();
  2844     if (state == os::SuspendResume::SR_SUSPENDED) {
  2845       sigset_t suspend_set;  // signals for sigsuspend()
  2847       // get current set of blocked signals and unblock resume signal
  2848       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
  2849       sigdelset(&suspend_set, SR_signum);
  2851       sr_semaphore.signal();
  2852       // wait here until we are resumed
  2853       while (1) {
  2854         sigsuspend(&suspend_set);
  2856         os::SuspendResume::State result = osthread->sr.running();
  2857         if (result == os::SuspendResume::SR_RUNNING) {
  2858           sr_semaphore.signal();
  2859           break;
  2860         } else if (result != os::SuspendResume::SR_SUSPENDED) {
  2861           ShouldNotReachHere();
  2865     } else if (state == os::SuspendResume::SR_RUNNING) {
  2866       // request was cancelled, continue
  2867     } else {
  2868       ShouldNotReachHere();
  2871     resume_clear_context(osthread);
  2872   } else if (current == os::SuspendResume::SR_RUNNING) {
  2873     // request was cancelled, continue
  2874   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
  2875     // ignore
  2876   } else {
  2877     // ignore
  2880   errno = old_errno;
  2884 static int SR_initialize() {
  2885   struct sigaction act;
  2886   char *s;
  2887   /* Get signal number to use for suspend/resume */
  2888   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
  2889     int sig = ::strtol(s, 0, 10);
  2890     if (sig > 0 || sig < NSIG) {
  2891         SR_signum = sig;
  2895   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
  2896         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
  2898   sigemptyset(&SR_sigset);
  2899   sigaddset(&SR_sigset, SR_signum);
  2901   /* Set up signal handler for suspend/resume */
  2902   act.sa_flags = SA_RESTART|SA_SIGINFO;
  2903   act.sa_handler = (void (*)(int)) SR_handler;
  2905   // SR_signum is blocked by default.
  2906   // 4528190 - We also need to block pthread restart signal (32 on all
  2907   // supported Bsd platforms). Note that BsdThreads need to block
  2908   // this signal for all threads to work properly. So we don't have
  2909   // to use hard-coded signal number when setting up the mask.
  2910   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
  2912   if (sigaction(SR_signum, &act, 0) == -1) {
  2913     return -1;
  2916   // Save signal flag
  2917   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
  2918   return 0;
  2921 static int sr_notify(OSThread* osthread) {
  2922   int status = pthread_kill(osthread->pthread_id(), SR_signum);
  2923   assert_status(status == 0, status, "pthread_kill");
  2924   return status;
  2927 // "Randomly" selected value for how long we want to spin
  2928 // before bailing out on suspending a thread, also how often
  2929 // we send a signal to a thread we want to resume
  2930 static const int RANDOMLY_LARGE_INTEGER = 1000000;
  2931 static const int RANDOMLY_LARGE_INTEGER2 = 100;
  2933 // returns true on success and false on error - really an error is fatal
  2934 // but this seems the normal response to library errors
  2935 static bool do_suspend(OSThread* osthread) {
  2936   assert(osthread->sr.is_running(), "thread should be running");
  2937   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
  2939   // mark as suspended and send signal
  2940   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
  2941     // failed to switch, state wasn't running?
  2942     ShouldNotReachHere();
  2943     return false;
  2946   if (sr_notify(osthread) != 0) {
  2947     ShouldNotReachHere();
  2950   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
  2951   while (true) {
  2952     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
  2953       break;
  2954     } else {
  2955       // timeout
  2956       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
  2957       if (cancelled == os::SuspendResume::SR_RUNNING) {
  2958         return false;
  2959       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
  2960         // make sure that we consume the signal on the semaphore as well
  2961         sr_semaphore.wait();
  2962         break;
  2963       } else {
  2964         ShouldNotReachHere();
  2965         return false;
  2970   guarantee(osthread->sr.is_suspended(), "Must be suspended");
  2971   return true;
  2974 static void do_resume(OSThread* osthread) {
  2975   assert(osthread->sr.is_suspended(), "thread should be suspended");
  2976   assert(!sr_semaphore.trywait(), "invalid semaphore state");
  2978   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
  2979     // failed to switch to WAKEUP_REQUEST
  2980     ShouldNotReachHere();
  2981     return;
  2984   while (true) {
  2985     if (sr_notify(osthread) == 0) {
  2986       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
  2987         if (osthread->sr.is_running()) {
  2988           return;
  2991     } else {
  2992       ShouldNotReachHere();
  2996   guarantee(osthread->sr.is_running(), "Must be running!");
  2999 ////////////////////////////////////////////////////////////////////////////////
  3000 // interrupt support
  3002 void os::interrupt(Thread* thread) {
  3003   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
  3004     "possibility of dangling Thread pointer");
  3006   OSThread* osthread = thread->osthread();
  3008   if (!osthread->interrupted()) {
  3009     osthread->set_interrupted(true);
  3010     // More than one thread can get here with the same value of osthread,
  3011     // resulting in multiple notifications.  We do, however, want the store
  3012     // to interrupted() to be visible to other threads before we execute unpark().
  3013     OrderAccess::fence();
  3014     ParkEvent * const slp = thread->_SleepEvent ;
  3015     if (slp != NULL) slp->unpark() ;
  3018   // For JSR166. Unpark even if interrupt status already was set
  3019   if (thread->is_Java_thread())
  3020     ((JavaThread*)thread)->parker()->unpark();
  3022   ParkEvent * ev = thread->_ParkEvent ;
  3023   if (ev != NULL) ev->unpark() ;
  3027 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
  3028   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
  3029     "possibility of dangling Thread pointer");
  3031   OSThread* osthread = thread->osthread();
  3033   bool interrupted = osthread->interrupted();
  3035   if (interrupted && clear_interrupted) {
  3036     osthread->set_interrupted(false);
  3037     // consider thread->_SleepEvent->reset() ... optional optimization
  3040   return interrupted;
  3043 ///////////////////////////////////////////////////////////////////////////////////
  3044 // signal handling (except suspend/resume)
  3046 // This routine may be used by user applications as a "hook" to catch signals.
  3047 // The user-defined signal handler must pass unrecognized signals to this
  3048 // routine, and if it returns true (non-zero), then the signal handler must
  3049 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
  3050 // routine will never retun false (zero), but instead will execute a VM panic
  3051 // routine kill the process.
  3052 //
  3053 // If this routine returns false, it is OK to call it again.  This allows
  3054 // the user-defined signal handler to perform checks either before or after
  3055 // the VM performs its own checks.  Naturally, the user code would be making
  3056 // a serious error if it tried to handle an exception (such as a null check
  3057 // or breakpoint) that the VM was generating for its own correct operation.
  3058 //
  3059 // This routine may recognize any of the following kinds of signals:
  3060 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
  3061 // It should be consulted by handlers for any of those signals.
  3062 //
  3063 // The caller of this routine must pass in the three arguments supplied
  3064 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
  3065 // field of the structure passed to sigaction().  This routine assumes that
  3066 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
  3067 //
  3068 // Note that the VM will print warnings if it detects conflicting signal
  3069 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
  3070 //
  3071 extern "C" JNIEXPORT int
  3072 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
  3073                         void* ucontext, int abort_if_unrecognized);
  3075 void signalHandler(int sig, siginfo_t* info, void* uc) {
  3076   assert(info != NULL && uc != NULL, "it must be old kernel");
  3077   int orig_errno = errno;  // Preserve errno value over signal handler.
  3078   JVM_handle_bsd_signal(sig, info, uc, true);
  3079   errno = orig_errno;
  3083 // This boolean allows users to forward their own non-matching signals
  3084 // to JVM_handle_bsd_signal, harmlessly.
  3085 bool os::Bsd::signal_handlers_are_installed = false;
  3087 // For signal-chaining
  3088 struct sigaction os::Bsd::sigact[MAXSIGNUM];
  3089 unsigned int os::Bsd::sigs = 0;
  3090 bool os::Bsd::libjsig_is_loaded = false;
  3091 typedef struct sigaction *(*get_signal_t)(int);
  3092 get_signal_t os::Bsd::get_signal_action = NULL;
  3094 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
  3095   struct sigaction *actp = NULL;
  3097   if (libjsig_is_loaded) {
  3098     // Retrieve the old signal handler from libjsig
  3099     actp = (*get_signal_action)(sig);
  3101   if (actp == NULL) {
  3102     // Retrieve the preinstalled signal handler from jvm
  3103     actp = get_preinstalled_handler(sig);
  3106   return actp;
  3109 static bool call_chained_handler(struct sigaction *actp, int sig,
  3110                                  siginfo_t *siginfo, void *context) {
  3111   // Call the old signal handler
  3112   if (actp->sa_handler == SIG_DFL) {
  3113     // It's more reasonable to let jvm treat it as an unexpected exception
  3114     // instead of taking the default action.
  3115     return false;
  3116   } else if (actp->sa_handler != SIG_IGN) {
  3117     if ((actp->sa_flags & SA_NODEFER) == 0) {
  3118       // automaticlly block the signal
  3119       sigaddset(&(actp->sa_mask), sig);
  3122     sa_handler_t hand;
  3123     sa_sigaction_t sa;
  3124     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
  3125     // retrieve the chained handler
  3126     if (siginfo_flag_set) {
  3127       sa = actp->sa_sigaction;
  3128     } else {
  3129       hand = actp->sa_handler;
  3132     if ((actp->sa_flags & SA_RESETHAND) != 0) {
  3133       actp->sa_handler = SIG_DFL;
  3136     // try to honor the signal mask
  3137     sigset_t oset;
  3138     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
  3140     // call into the chained handler
  3141     if (siginfo_flag_set) {
  3142       (*sa)(sig, siginfo, context);
  3143     } else {
  3144       (*hand)(sig);
  3147     // restore the signal mask
  3148     pthread_sigmask(SIG_SETMASK, &oset, 0);
  3150   // Tell jvm's signal handler the signal is taken care of.
  3151   return true;
  3154 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
  3155   bool chained = false;
  3156   // signal-chaining
  3157   if (UseSignalChaining) {
  3158     struct sigaction *actp = get_chained_signal_action(sig);
  3159     if (actp != NULL) {
  3160       chained = call_chained_handler(actp, sig, siginfo, context);
  3163   return chained;
  3166 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
  3167   if ((( (unsigned int)1 << sig ) & sigs) != 0) {
  3168     return &sigact[sig];
  3170   return NULL;
  3173 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
  3174   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3175   sigact[sig] = oldAct;
  3176   sigs |= (unsigned int)1 << sig;
  3179 // for diagnostic
  3180 int os::Bsd::sigflags[MAXSIGNUM];
  3182 int os::Bsd::get_our_sigflags(int sig) {
  3183   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3184   return sigflags[sig];
  3187 void os::Bsd::set_our_sigflags(int sig, int flags) {
  3188   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3189   sigflags[sig] = flags;
  3192 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
  3193   // Check for overwrite.
  3194   struct sigaction oldAct;
  3195   sigaction(sig, (struct sigaction*)NULL, &oldAct);
  3197   void* oldhand = oldAct.sa_sigaction
  3198                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
  3199                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
  3200   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
  3201       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
  3202       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
  3203     if (AllowUserSignalHandlers || !set_installed) {
  3204       // Do not overwrite; user takes responsibility to forward to us.
  3205       return;
  3206     } else if (UseSignalChaining) {
  3207       // save the old handler in jvm
  3208       save_preinstalled_handler(sig, oldAct);
  3209       // libjsig also interposes the sigaction() call below and saves the
  3210       // old sigaction on it own.
  3211     } else {
  3212       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
  3213                     "%#lx for signal %d.", (long)oldhand, sig));
  3217   struct sigaction sigAct;
  3218   sigfillset(&(sigAct.sa_mask));
  3219   sigAct.sa_handler = SIG_DFL;
  3220   if (!set_installed) {
  3221     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  3222   } else {
  3223     sigAct.sa_sigaction = signalHandler;
  3224     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  3226 #if __APPLE__
  3227   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
  3228   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
  3229   // if the signal handler declares it will handle it on alternate stack.
  3230   // Notice we only declare we will handle it on alt stack, but we are not
  3231   // actually going to use real alt stack - this is just a workaround.
  3232   // Please see ux_exception.c, method catch_mach_exception_raise for details
  3233   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
  3234   if (sig == SIGSEGV) {
  3235     sigAct.sa_flags |= SA_ONSTACK;
  3237 #endif
  3239   // Save flags, which are set by ours
  3240   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3241   sigflags[sig] = sigAct.sa_flags;
  3243   int ret = sigaction(sig, &sigAct, &oldAct);
  3244   assert(ret == 0, "check");
  3246   void* oldhand2  = oldAct.sa_sigaction
  3247                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
  3248                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
  3249   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
  3252 // install signal handlers for signals that HotSpot needs to
  3253 // handle in order to support Java-level exception handling.
  3255 void os::Bsd::install_signal_handlers() {
  3256   if (!signal_handlers_are_installed) {
  3257     signal_handlers_are_installed = true;
  3259     // signal-chaining
  3260     typedef void (*signal_setting_t)();
  3261     signal_setting_t begin_signal_setting = NULL;
  3262     signal_setting_t end_signal_setting = NULL;
  3263     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
  3264                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
  3265     if (begin_signal_setting != NULL) {
  3266       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
  3267                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
  3268       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
  3269                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
  3270       libjsig_is_loaded = true;
  3271       assert(UseSignalChaining, "should enable signal-chaining");
  3273     if (libjsig_is_loaded) {
  3274       // Tell libjsig jvm is setting signal handlers
  3275       (*begin_signal_setting)();
  3278     set_signal_handler(SIGSEGV, true);
  3279     set_signal_handler(SIGPIPE, true);
  3280     set_signal_handler(SIGBUS, true);
  3281     set_signal_handler(SIGILL, true);
  3282     set_signal_handler(SIGFPE, true);
  3283     set_signal_handler(SIGXFSZ, true);
  3285 #if defined(__APPLE__)
  3286     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
  3287     // signals caught and handled by the JVM. To work around this, we reset the mach task
  3288     // signal handler that's placed on our process by CrashReporter. This disables
  3289     // CrashReporter-based reporting.
  3290     //
  3291     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
  3292     // on caught fatal signals.
  3293     //
  3294     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
  3295     // handlers. By replacing the existing task exception handler, we disable gdb's mach
  3296     // exception handling, while leaving the standard BSD signal handlers functional.
  3297     kern_return_t kr;
  3298     kr = task_set_exception_ports(mach_task_self(),
  3299         EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
  3300         MACH_PORT_NULL,
  3301         EXCEPTION_STATE_IDENTITY,
  3302         MACHINE_THREAD_STATE);
  3304     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
  3305 #endif
  3307     if (libjsig_is_loaded) {
  3308       // Tell libjsig jvm finishes setting signal handlers
  3309       (*end_signal_setting)();
  3312     // We don't activate signal checker if libjsig is in place, we trust ourselves
  3313     // and if UserSignalHandler is installed all bets are off
  3314     if (CheckJNICalls) {
  3315       if (libjsig_is_loaded) {
  3316         if (PrintJNIResolving) {
  3317           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
  3319         check_signals = false;
  3321       if (AllowUserSignalHandlers) {
  3322         if (PrintJNIResolving) {
  3323           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
  3325         check_signals = false;
  3332 /////
  3333 // glibc on Bsd platform uses non-documented flag
  3334 // to indicate, that some special sort of signal
  3335 // trampoline is used.
  3336 // We will never set this flag, and we should
  3337 // ignore this flag in our diagnostic
  3338 #ifdef SIGNIFICANT_SIGNAL_MASK
  3339 #undef SIGNIFICANT_SIGNAL_MASK
  3340 #endif
  3341 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
  3343 static const char* get_signal_handler_name(address handler,
  3344                                            char* buf, int buflen) {
  3345   int offset;
  3346   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
  3347   if (found) {
  3348     // skip directory names
  3349     const char *p1, *p2;
  3350     p1 = buf;
  3351     size_t len = strlen(os::file_separator());
  3352     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
  3353     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
  3354   } else {
  3355     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
  3357   return buf;
  3360 static void print_signal_handler(outputStream* st, int sig,
  3361                                  char* buf, size_t buflen) {
  3362   struct sigaction sa;
  3364   sigaction(sig, NULL, &sa);
  3366   // See comment for SIGNIFICANT_SIGNAL_MASK define
  3367   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
  3369   st->print("%s: ", os::exception_name(sig, buf, buflen));
  3371   address handler = (sa.sa_flags & SA_SIGINFO)
  3372     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
  3373     : CAST_FROM_FN_PTR(address, sa.sa_handler);
  3375   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
  3376     st->print("SIG_DFL");
  3377   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
  3378     st->print("SIG_IGN");
  3379   } else {
  3380     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
  3383   st->print(", sa_mask[0]=");
  3384   os::Posix::print_signal_set_short(st, &sa.sa_mask);
  3386   address rh = VMError::get_resetted_sighandler(sig);
  3387   // May be, handler was resetted by VMError?
  3388   if(rh != NULL) {
  3389     handler = rh;
  3390     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
  3393   st->print(", sa_flags=");
  3394   os::Posix::print_sa_flags(st, sa.sa_flags);
  3396   // Check: is it our handler?
  3397   if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
  3398      handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
  3399     // It is our signal handler
  3400     // check for flags, reset system-used one!
  3401     if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
  3402       st->print(
  3403                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
  3404                 os::Bsd::get_our_sigflags(sig));
  3407   st->cr();
  3411 #define DO_SIGNAL_CHECK(sig) \
  3412   if (!sigismember(&check_signal_done, sig)) \
  3413     os::Bsd::check_signal_handler(sig)
  3415 // This method is a periodic task to check for misbehaving JNI applications
  3416 // under CheckJNI, we can add any periodic checks here
  3418 void os::run_periodic_checks() {
  3420   if (check_signals == false) return;
  3422   // SEGV and BUS if overridden could potentially prevent
  3423   // generation of hs*.log in the event of a crash, debugging
  3424   // such a case can be very challenging, so we absolutely
  3425   // check the following for a good measure:
  3426   DO_SIGNAL_CHECK(SIGSEGV);
  3427   DO_SIGNAL_CHECK(SIGILL);
  3428   DO_SIGNAL_CHECK(SIGFPE);
  3429   DO_SIGNAL_CHECK(SIGBUS);
  3430   DO_SIGNAL_CHECK(SIGPIPE);
  3431   DO_SIGNAL_CHECK(SIGXFSZ);
  3434   // ReduceSignalUsage allows the user to override these handlers
  3435   // see comments at the very top and jvm_solaris.h
  3436   if (!ReduceSignalUsage) {
  3437     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
  3438     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
  3439     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
  3440     DO_SIGNAL_CHECK(BREAK_SIGNAL);
  3443   DO_SIGNAL_CHECK(SR_signum);
  3444   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
  3447 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
  3449 static os_sigaction_t os_sigaction = NULL;
  3451 void os::Bsd::check_signal_handler(int sig) {
  3452   char buf[O_BUFLEN];
  3453   address jvmHandler = NULL;
  3456   struct sigaction act;
  3457   if (os_sigaction == NULL) {
  3458     // only trust the default sigaction, in case it has been interposed
  3459     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
  3460     if (os_sigaction == NULL) return;
  3463   os_sigaction(sig, (struct sigaction*)NULL, &act);
  3466   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
  3468   address thisHandler = (act.sa_flags & SA_SIGINFO)
  3469     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
  3470     : CAST_FROM_FN_PTR(address, act.sa_handler) ;
  3473   switch(sig) {
  3474   case SIGSEGV:
  3475   case SIGBUS:
  3476   case SIGFPE:
  3477   case SIGPIPE:
  3478   case SIGILL:
  3479   case SIGXFSZ:
  3480     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
  3481     break;
  3483   case SHUTDOWN1_SIGNAL:
  3484   case SHUTDOWN2_SIGNAL:
  3485   case SHUTDOWN3_SIGNAL:
  3486   case BREAK_SIGNAL:
  3487     jvmHandler = (address)user_handler();
  3488     break;
  3490   case INTERRUPT_SIGNAL:
  3491     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
  3492     break;
  3494   default:
  3495     if (sig == SR_signum) {
  3496       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
  3497     } else {
  3498       return;
  3500     break;
  3503   if (thisHandler != jvmHandler) {
  3504     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
  3505     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
  3506     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
  3507     // No need to check this sig any longer
  3508     sigaddset(&check_signal_done, sig);
  3509   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
  3510     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
  3511     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
  3512     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
  3513     // No need to check this sig any longer
  3514     sigaddset(&check_signal_done, sig);
  3517   // Dump all the signal
  3518   if (sigismember(&check_signal_done, sig)) {
  3519     print_signal_handlers(tty, buf, O_BUFLEN);
  3523 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
  3525 extern bool signal_name(int signo, char* buf, size_t len);
  3527 const char* os::exception_name(int exception_code, char* buf, size_t size) {
  3528   if (0 < exception_code && exception_code <= SIGRTMAX) {
  3529     // signal
  3530     if (!signal_name(exception_code, buf, size)) {
  3531       jio_snprintf(buf, size, "SIG%d", exception_code);
  3533     return buf;
  3534   } else {
  3535     return NULL;
  3539 // this is called _before_ the most of global arguments have been parsed
  3540 void os::init(void) {
  3541   char dummy;   /* used to get a guess on initial stack address */
  3542 //  first_hrtime = gethrtime();
  3544   // With BsdThreads the JavaMain thread pid (primordial thread)
  3545   // is different than the pid of the java launcher thread.
  3546   // So, on Bsd, the launcher thread pid is passed to the VM
  3547   // via the sun.java.launcher.pid property.
  3548   // Use this property instead of getpid() if it was correctly passed.
  3549   // See bug 6351349.
  3550   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
  3552   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
  3554   clock_tics_per_sec = CLK_TCK;
  3556   init_random(1234567);
  3558   ThreadCritical::initialize();
  3560   Bsd::set_page_size(getpagesize());
  3561   if (Bsd::page_size() == -1) {
  3562     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
  3563                   strerror(errno)));
  3565   init_page_sizes((size_t) Bsd::page_size());
  3567   Bsd::initialize_system_info();
  3569   // main_thread points to the aboriginal thread
  3570   Bsd::_main_thread = pthread_self();
  3572   Bsd::clock_init();
  3573   initial_time_count = javaTimeNanos();
  3575 #ifdef __APPLE__
  3576   // XXXDARWIN
  3577   // Work around the unaligned VM callbacks in hotspot's
  3578   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
  3579   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
  3580   // alignment when doing symbol lookup. To work around this, we force early
  3581   // binding of all symbols now, thus binding when alignment is known-good.
  3582   _dyld_bind_fully_image_containing_address((const void *) &os::init);
  3583 #endif
  3586 // To install functions for atexit system call
  3587 extern "C" {
  3588   static void perfMemory_exit_helper() {
  3589     perfMemory_exit();
  3593 // this is called _after_ the global arguments have been parsed
  3594 jint os::init_2(void)
  3596   // Allocate a single page and mark it as readable for safepoint polling
  3597   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  3598   guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
  3600   os::set_polling_page( polling_page );
  3602 #ifndef PRODUCT
  3603   if(Verbose && PrintMiscellaneous)
  3604     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
  3605 #endif
  3607   if (!UseMembar) {
  3608     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  3609     guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
  3610     os::set_memory_serialize_page( mem_serialize_page );
  3612 #ifndef PRODUCT
  3613     if(Verbose && PrintMiscellaneous)
  3614       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
  3615 #endif
  3618   // initialize suspend/resume support - must do this before signal_sets_init()
  3619   if (SR_initialize() != 0) {
  3620     perror("SR_initialize failed");
  3621     return JNI_ERR;
  3624   Bsd::signal_sets_init();
  3625   Bsd::install_signal_handlers();
  3627   // Check minimum allowable stack size for thread creation and to initialize
  3628   // the java system classes, including StackOverflowError - depends on page
  3629   // size.  Add a page for compiler2 recursion in main thread.
  3630   // Add in 2*BytesPerWord times page size to account for VM stack during
  3631   // class initialization depending on 32 or 64 bit VM.
  3632   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
  3633             (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
  3634                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
  3636   size_t threadStackSizeInBytes = ThreadStackSize * K;
  3637   if (threadStackSizeInBytes != 0 &&
  3638       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
  3639         tty->print_cr("\nThe stack size specified is too small, "
  3640                       "Specify at least %dk",
  3641                       os::Bsd::min_stack_allowed/ K);
  3642         return JNI_ERR;
  3645   // Make the stack size a multiple of the page size so that
  3646   // the yellow/red zones can be guarded.
  3647   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
  3648         vm_page_size()));
  3650   if (MaxFDLimit) {
  3651     // set the number of file descriptors to max. print out error
  3652     // if getrlimit/setrlimit fails but continue regardless.
  3653     struct rlimit nbr_files;
  3654     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
  3655     if (status != 0) {
  3656       if (PrintMiscellaneous && (Verbose || WizardMode))
  3657         perror("os::init_2 getrlimit failed");
  3658     } else {
  3659       nbr_files.rlim_cur = nbr_files.rlim_max;
  3661 #ifdef __APPLE__
  3662       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
  3663       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
  3664       // be used instead
  3665       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
  3666 #endif
  3668       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
  3669       if (status != 0) {
  3670         if (PrintMiscellaneous && (Verbose || WizardMode))
  3671           perror("os::init_2 setrlimit failed");
  3676   // at-exit methods are called in the reverse order of their registration.
  3677   // atexit functions are called on return from main or as a result of a
  3678   // call to exit(3C). There can be only 32 of these functions registered
  3679   // and atexit() does not set errno.
  3681   if (PerfAllowAtExitRegistration) {
  3682     // only register atexit functions if PerfAllowAtExitRegistration is set.
  3683     // atexit functions can be delayed until process exit time, which
  3684     // can be problematic for embedded VM situations. Embedded VMs should
  3685     // call DestroyJavaVM() to assure that VM resources are released.
  3687     // note: perfMemory_exit_helper atexit function may be removed in
  3688     // the future if the appropriate cleanup code can be added to the
  3689     // VM_Exit VMOperation's doit method.
  3690     if (atexit(perfMemory_exit_helper) != 0) {
  3691       warning("os::init2 atexit(perfMemory_exit_helper) failed");
  3695   // initialize thread priority policy
  3696   prio_init();
  3698 #ifdef __APPLE__
  3699   // dynamically link to objective c gc registration
  3700   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
  3701   if (handleLibObjc != NULL) {
  3702     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
  3704 #endif
  3706   return JNI_OK;
  3709 // this is called at the end of vm_initialization
  3710 void os::init_3(void) { }
  3712 // Mark the polling page as unreadable
  3713 void os::make_polling_page_unreadable(void) {
  3714   if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
  3715     fatal("Could not disable polling page");
  3716 };
  3718 // Mark the polling page as readable
  3719 void os::make_polling_page_readable(void) {
  3720   if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
  3721     fatal("Could not enable polling page");
  3723 };
  3725 int os::active_processor_count() {
  3726   return _processor_count;
  3729 void os::set_native_thread_name(const char *name) {
  3730 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
  3731   // This is only supported in Snow Leopard and beyond
  3732   if (name != NULL) {
  3733     // Add a "Java: " prefix to the name
  3734     char buf[MAXTHREADNAMESIZE];
  3735     snprintf(buf, sizeof(buf), "Java: %s", name);
  3736     pthread_setname_np(buf);
  3738 #endif
  3741 bool os::distribute_processes(uint length, uint* distribution) {
  3742   // Not yet implemented.
  3743   return false;
  3746 bool os::bind_to_processor(uint processor_id) {
  3747   // Not yet implemented.
  3748   return false;
  3751 void os::SuspendedThreadTask::internal_do_task() {
  3752   if (do_suspend(_thread->osthread())) {
  3753     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
  3754     do_task(context);
  3755     do_resume(_thread->osthread());
  3759 ///
  3760 class PcFetcher : public os::SuspendedThreadTask {
  3761 public:
  3762   PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
  3763   ExtendedPC result();
  3764 protected:
  3765   void do_task(const os::SuspendedThreadTaskContext& context);
  3766 private:
  3767   ExtendedPC _epc;
  3768 };
  3770 ExtendedPC PcFetcher::result() {
  3771   guarantee(is_done(), "task is not done yet.");
  3772   return _epc;
  3775 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
  3776   Thread* thread = context.thread();
  3777   OSThread* osthread = thread->osthread();
  3778   if (osthread->ucontext() != NULL) {
  3779     _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
  3780   } else {
  3781     // NULL context is unexpected, double-check this is the VMThread
  3782     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
  3786 // Suspends the target using the signal mechanism and then grabs the PC before
  3787 // resuming the target. Used by the flat-profiler only
  3788 ExtendedPC os::get_thread_pc(Thread* thread) {
  3789   // Make sure that it is called by the watcher for the VMThread
  3790   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
  3791   assert(thread->is_VM_thread(), "Can only be called for VMThread");
  3793   PcFetcher fetcher(thread);
  3794   fetcher.run();
  3795   return fetcher.result();
  3798 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
  3800   return pthread_cond_timedwait(_cond, _mutex, _abstime);
  3803 ////////////////////////////////////////////////////////////////////////////////
  3804 // debug support
  3806 bool os::find(address addr, outputStream* st) {
  3807   Dl_info dlinfo;
  3808   memset(&dlinfo, 0, sizeof(dlinfo));
  3809   if (dladdr(addr, &dlinfo) != 0) {
  3810     st->print(PTR_FORMAT ": ", addr);
  3811     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
  3812       st->print("%s+%#x", dlinfo.dli_sname,
  3813                  addr - (intptr_t)dlinfo.dli_saddr);
  3814     } else if (dlinfo.dli_fbase != NULL) {
  3815       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
  3816     } else {
  3817       st->print("<absolute address>");
  3819     if (dlinfo.dli_fname != NULL) {
  3820       st->print(" in %s", dlinfo.dli_fname);
  3822     if (dlinfo.dli_fbase != NULL) {
  3823       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
  3825     st->cr();
  3827     if (Verbose) {
  3828       // decode some bytes around the PC
  3829       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
  3830       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
  3831       address       lowest = (address) dlinfo.dli_sname;
  3832       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
  3833       if (begin < lowest)  begin = lowest;
  3834       Dl_info dlinfo2;
  3835       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
  3836           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
  3837         end = (address) dlinfo2.dli_saddr;
  3838       Disassembler::decode(begin, end, st);
  3840     return true;
  3842   return false;
  3845 ////////////////////////////////////////////////////////////////////////////////
  3846 // misc
  3848 // This does not do anything on Bsd. This is basically a hook for being
  3849 // able to use structured exception handling (thread-local exception filters)
  3850 // on, e.g., Win32.
  3851 void
  3852 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
  3853                          JavaCallArguments* args, Thread* thread) {
  3854   f(value, method, args, thread);
  3857 void os::print_statistics() {
  3860 int os::message_box(const char* title, const char* message) {
  3861   int i;
  3862   fdStream err(defaultStream::error_fd());
  3863   for (i = 0; i < 78; i++) err.print_raw("=");
  3864   err.cr();
  3865   err.print_raw_cr(title);
  3866   for (i = 0; i < 78; i++) err.print_raw("-");
  3867   err.cr();
  3868   err.print_raw_cr(message);
  3869   for (i = 0; i < 78; i++) err.print_raw("=");
  3870   err.cr();
  3872   char buf[16];
  3873   // Prevent process from exiting upon "read error" without consuming all CPU
  3874   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
  3876   return buf[0] == 'y' || buf[0] == 'Y';
  3879 int os::stat(const char *path, struct stat *sbuf) {
  3880   char pathbuf[MAX_PATH];
  3881   if (strlen(path) > MAX_PATH - 1) {
  3882     errno = ENAMETOOLONG;
  3883     return -1;
  3885   os::native_path(strcpy(pathbuf, path));
  3886   return ::stat(pathbuf, sbuf);
  3889 bool os::check_heap(bool force) {
  3890   return true;
  3893 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
  3894   return ::vsnprintf(buf, count, format, args);
  3897 // Is a (classpath) directory empty?
  3898 bool os::dir_is_empty(const char* path) {
  3899   DIR *dir = NULL;
  3900   struct dirent *ptr;
  3902   dir = opendir(path);
  3903   if (dir == NULL) return true;
  3905   /* Scan the directory */
  3906   bool result = true;
  3907   char buf[sizeof(struct dirent) + MAX_PATH];
  3908   while (result && (ptr = ::readdir(dir)) != NULL) {
  3909     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
  3910       result = false;
  3913   closedir(dir);
  3914   return result;
  3917 // This code originates from JDK's sysOpen and open64_w
  3918 // from src/solaris/hpi/src/system_md.c
  3920 #ifndef O_DELETE
  3921 #define O_DELETE 0x10000
  3922 #endif
  3924 // Open a file. Unlink the file immediately after open returns
  3925 // if the specified oflag has the O_DELETE flag set.
  3926 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
  3928 int os::open(const char *path, int oflag, int mode) {
  3930   if (strlen(path) > MAX_PATH - 1) {
  3931     errno = ENAMETOOLONG;
  3932     return -1;
  3934   int fd;
  3935   int o_delete = (oflag & O_DELETE);
  3936   oflag = oflag & ~O_DELETE;
  3938   fd = ::open(path, oflag, mode);
  3939   if (fd == -1) return -1;
  3941   //If the open succeeded, the file might still be a directory
  3943     struct stat buf;
  3944     int ret = ::fstat(fd, &buf);
  3945     int st_mode = buf.st_mode;
  3947     if (ret != -1) {
  3948       if ((st_mode & S_IFMT) == S_IFDIR) {
  3949         errno = EISDIR;
  3950         ::close(fd);
  3951         return -1;
  3953     } else {
  3954       ::close(fd);
  3955       return -1;
  3959     /*
  3960      * All file descriptors that are opened in the JVM and not
  3961      * specifically destined for a subprocess should have the
  3962      * close-on-exec flag set.  If we don't set it, then careless 3rd
  3963      * party native code might fork and exec without closing all
  3964      * appropriate file descriptors (e.g. as we do in closeDescriptors in
  3965      * UNIXProcess.c), and this in turn might:
  3967      * - cause end-of-file to fail to be detected on some file
  3968      *   descriptors, resulting in mysterious hangs, or
  3970      * - might cause an fopen in the subprocess to fail on a system
  3971      *   suffering from bug 1085341.
  3973      * (Yes, the default setting of the close-on-exec flag is a Unix
  3974      * design flaw)
  3976      * See:
  3977      * 1085341: 32-bit stdio routines should support file descriptors >255
  3978      * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
  3979      * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
  3980      */
  3981 #ifdef FD_CLOEXEC
  3983         int flags = ::fcntl(fd, F_GETFD);
  3984         if (flags != -1)
  3985             ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
  3987 #endif
  3989   if (o_delete != 0) {
  3990     ::unlink(path);
  3992   return fd;
  3996 // create binary file, rewriting existing file if required
  3997 int os::create_binary_file(const char* path, bool rewrite_existing) {
  3998   int oflags = O_WRONLY | O_CREAT;
  3999   if (!rewrite_existing) {
  4000     oflags |= O_EXCL;
  4002   return ::open(path, oflags, S_IREAD | S_IWRITE);
  4005 // return current position of file pointer
  4006 jlong os::current_file_offset(int fd) {
  4007   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
  4010 // move file pointer to the specified offset
  4011 jlong os::seek_to_file_offset(int fd, jlong offset) {
  4012   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
  4015 // This code originates from JDK's sysAvailable
  4016 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
  4018 int os::available(int fd, jlong *bytes) {
  4019   jlong cur, end;
  4020   int mode;
  4021   struct stat buf;
  4023   if (::fstat(fd, &buf) >= 0) {
  4024     mode = buf.st_mode;
  4025     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
  4026       /*
  4027       * XXX: is the following call interruptible? If so, this might
  4028       * need to go through the INTERRUPT_IO() wrapper as for other
  4029       * blocking, interruptible calls in this file.
  4030       */
  4031       int n;
  4032       if (::ioctl(fd, FIONREAD, &n) >= 0) {
  4033         *bytes = n;
  4034         return 1;
  4038   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
  4039     return 0;
  4040   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
  4041     return 0;
  4042   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
  4043     return 0;
  4045   *bytes = end - cur;
  4046   return 1;
  4049 int os::socket_available(int fd, jint *pbytes) {
  4050    if (fd < 0)
  4051      return OS_OK;
  4053    int ret;
  4055    RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
  4057    //%% note ioctl can return 0 when successful, JVM_SocketAvailable
  4058    // is expected to return 0 on failure and 1 on success to the jdk.
  4060    return (ret == OS_ERR) ? 0 : 1;
  4063 // Map a block of memory.
  4064 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
  4065                      char *addr, size_t bytes, bool read_only,
  4066                      bool allow_exec) {
  4067   int prot;
  4068   int flags;
  4070   if (read_only) {
  4071     prot = PROT_READ;
  4072     flags = MAP_SHARED;
  4073   } else {
  4074     prot = PROT_READ | PROT_WRITE;
  4075     flags = MAP_PRIVATE;
  4078   if (allow_exec) {
  4079     prot |= PROT_EXEC;
  4082   if (addr != NULL) {
  4083     flags |= MAP_FIXED;
  4086   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
  4087                                      fd, file_offset);
  4088   if (mapped_address == MAP_FAILED) {
  4089     return NULL;
  4091   return mapped_address;
  4095 // Remap a block of memory.
  4096 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
  4097                        char *addr, size_t bytes, bool read_only,
  4098                        bool allow_exec) {
  4099   // same as map_memory() on this OS
  4100   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
  4101                         allow_exec);
  4105 // Unmap a block of memory.
  4106 bool os::pd_unmap_memory(char* addr, size_t bytes) {
  4107   return munmap(addr, bytes) == 0;
  4110 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
  4111 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
  4112 // of a thread.
  4113 //
  4114 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
  4115 // the fast estimate available on the platform.
  4117 jlong os::current_thread_cpu_time() {
  4118 #ifdef __APPLE__
  4119   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
  4120 #else
  4121   Unimplemented();
  4122   return 0;
  4123 #endif
  4126 jlong os::thread_cpu_time(Thread* thread) {
  4127 #ifdef __APPLE__
  4128   return os::thread_cpu_time(thread, true /* user + sys */);
  4129 #else
  4130   Unimplemented();
  4131   return 0;
  4132 #endif
  4135 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
  4136 #ifdef __APPLE__
  4137   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
  4138 #else
  4139   Unimplemented();
  4140   return 0;
  4141 #endif
  4144 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
  4145 #ifdef __APPLE__
  4146   struct thread_basic_info tinfo;
  4147   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
  4148   kern_return_t kr;
  4149   thread_t mach_thread;
  4151   mach_thread = thread->osthread()->thread_id();
  4152   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
  4153   if (kr != KERN_SUCCESS)
  4154     return -1;
  4156   if (user_sys_cpu_time) {
  4157     jlong nanos;
  4158     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
  4159     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
  4160     return nanos;
  4161   } else {
  4162     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
  4164 #else
  4165   Unimplemented();
  4166   return 0;
  4167 #endif
  4171 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
  4172   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
  4173   info_ptr->may_skip_backward = false;     // elapsed time not wall time
  4174   info_ptr->may_skip_forward = false;      // elapsed time not wall time
  4175   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
  4178 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
  4179   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
  4180   info_ptr->may_skip_backward = false;     // elapsed time not wall time
  4181   info_ptr->may_skip_forward = false;      // elapsed time not wall time
  4182   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
  4185 bool os::is_thread_cpu_time_supported() {
  4186 #ifdef __APPLE__
  4187   return true;
  4188 #else
  4189   return false;
  4190 #endif
  4193 // System loadavg support.  Returns -1 if load average cannot be obtained.
  4194 // Bsd doesn't yet have a (official) notion of processor sets,
  4195 // so just return the system wide load average.
  4196 int os::loadavg(double loadavg[], int nelem) {
  4197   return ::getloadavg(loadavg, nelem);
  4200 void os::pause() {
  4201   char filename[MAX_PATH];
  4202   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
  4203     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
  4204   } else {
  4205     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
  4208   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
  4209   if (fd != -1) {
  4210     struct stat buf;
  4211     ::close(fd);
  4212     while (::stat(filename, &buf) == 0) {
  4213       (void)::poll(NULL, 0, 100);
  4215   } else {
  4216     jio_fprintf(stderr,
  4217       "Could not open pause file '%s', continuing immediately.\n", filename);
  4222 // Refer to the comments in os_solaris.cpp park-unpark.
  4223 //
  4224 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
  4225 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
  4226 // For specifics regarding the bug see GLIBC BUGID 261237 :
  4227 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
  4228 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
  4229 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
  4230 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
  4231 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
  4232 // and monitorenter when we're using 1-0 locking.  All those operations may result in
  4233 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
  4234 // of libpthread avoids the problem, but isn't practical.
  4235 //
  4236 // Possible remedies:
  4237 //
  4238 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
  4239 //      This is palliative and probabilistic, however.  If the thread is preempted
  4240 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
  4241 //      than the minimum period may have passed, and the abstime may be stale (in the
  4242 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
  4243 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
  4244 //
  4245 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
  4246 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
  4247 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
  4248 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
  4249 //      thread.
  4250 //
  4251 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
  4252 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
  4253 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
  4254 //      This also works well.  In fact it avoids kernel-level scalability impediments
  4255 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
  4256 //      timers in a graceful fashion.
  4257 //
  4258 // 4.   When the abstime value is in the past it appears that control returns
  4259 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
  4260 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
  4261 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
  4262 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
  4263 //      It may be possible to avoid reinitialization by checking the return
  4264 //      value from pthread_cond_timedwait().  In addition to reinitializing the
  4265 //      condvar we must establish the invariant that cond_signal() is only called
  4266 //      within critical sections protected by the adjunct mutex.  This prevents
  4267 //      cond_signal() from "seeing" a condvar that's in the midst of being
  4268 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
  4269 //      desirable signal-after-unlock optimization that avoids futile context switching.
  4270 //
  4271 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
  4272 //      structure when a condvar is used or initialized.  cond_destroy()  would
  4273 //      release the helper structure.  Our reinitialize-after-timedwait fix
  4274 //      put excessive stress on malloc/free and locks protecting the c-heap.
  4275 //
  4276 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
  4277 // It may be possible to refine (4) by checking the kernel and NTPL verisons
  4278 // and only enabling the work-around for vulnerable environments.
  4280 // utility to compute the abstime argument to timedwait:
  4281 // millis is the relative timeout time
  4282 // abstime will be the absolute timeout time
  4283 // TODO: replace compute_abstime() with unpackTime()
  4285 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
  4286   if (millis < 0)  millis = 0;
  4287   struct timeval now;
  4288   int status = gettimeofday(&now, NULL);
  4289   assert(status == 0, "gettimeofday");
  4290   jlong seconds = millis / 1000;
  4291   millis %= 1000;
  4292   if (seconds > 50000000) { // see man cond_timedwait(3T)
  4293     seconds = 50000000;
  4295   abstime->tv_sec = now.tv_sec  + seconds;
  4296   long       usec = now.tv_usec + millis * 1000;
  4297   if (usec >= 1000000) {
  4298     abstime->tv_sec += 1;
  4299     usec -= 1000000;
  4301   abstime->tv_nsec = usec * 1000;
  4302   return abstime;
  4306 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
  4307 // Conceptually TryPark() should be equivalent to park(0).
  4309 int os::PlatformEvent::TryPark() {
  4310   for (;;) {
  4311     const int v = _Event ;
  4312     guarantee ((v == 0) || (v == 1), "invariant") ;
  4313     if (Atomic::cmpxchg (0, &_Event, v) == v) return v  ;
  4317 void os::PlatformEvent::park() {       // AKA "down()"
  4318   // Invariant: Only the thread associated with the Event/PlatformEvent
  4319   // may call park().
  4320   // TODO: assert that _Assoc != NULL or _Assoc == Self
  4321   int v ;
  4322   for (;;) {
  4323       v = _Event ;
  4324       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
  4326   guarantee (v >= 0, "invariant") ;
  4327   if (v == 0) {
  4328      // Do this the hard way by blocking ...
  4329      int status = pthread_mutex_lock(_mutex);
  4330      assert_status(status == 0, status, "mutex_lock");
  4331      guarantee (_nParked == 0, "invariant") ;
  4332      ++ _nParked ;
  4333      while (_Event < 0) {
  4334         status = pthread_cond_wait(_cond, _mutex);
  4335         // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
  4336         // Treat this the same as if the wait was interrupted
  4337         if (status == ETIMEDOUT) { status = EINTR; }
  4338         assert_status(status == 0 || status == EINTR, status, "cond_wait");
  4340      -- _nParked ;
  4342     _Event = 0 ;
  4343      status = pthread_mutex_unlock(_mutex);
  4344      assert_status(status == 0, status, "mutex_unlock");
  4345     // Paranoia to ensure our locked and lock-free paths interact
  4346     // correctly with each other.
  4347     OrderAccess::fence();
  4349   guarantee (_Event >= 0, "invariant") ;
  4352 int os::PlatformEvent::park(jlong millis) {
  4353   guarantee (_nParked == 0, "invariant") ;
  4355   int v ;
  4356   for (;;) {
  4357       v = _Event ;
  4358       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
  4360   guarantee (v >= 0, "invariant") ;
  4361   if (v != 0) return OS_OK ;
  4363   // We do this the hard way, by blocking the thread.
  4364   // Consider enforcing a minimum timeout value.
  4365   struct timespec abst;
  4366   compute_abstime(&abst, millis);
  4368   int ret = OS_TIMEOUT;
  4369   int status = pthread_mutex_lock(_mutex);
  4370   assert_status(status == 0, status, "mutex_lock");
  4371   guarantee (_nParked == 0, "invariant") ;
  4372   ++_nParked ;
  4374   // Object.wait(timo) will return because of
  4375   // (a) notification
  4376   // (b) timeout
  4377   // (c) thread.interrupt
  4378   //
  4379   // Thread.interrupt and object.notify{All} both call Event::set.
  4380   // That is, we treat thread.interrupt as a special case of notification.
  4381   // The underlying Solaris implementation, cond_timedwait, admits
  4382   // spurious/premature wakeups, but the JLS/JVM spec prevents the
  4383   // JVM from making those visible to Java code.  As such, we must
  4384   // filter out spurious wakeups.  We assume all ETIME returns are valid.
  4385   //
  4386   // TODO: properly differentiate simultaneous notify+interrupt.
  4387   // In that case, we should propagate the notify to another waiter.
  4389   while (_Event < 0) {
  4390     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
  4391     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
  4392       pthread_cond_destroy (_cond);
  4393       pthread_cond_init (_cond, NULL) ;
  4395     assert_status(status == 0 || status == EINTR ||
  4396                   status == ETIMEDOUT,
  4397                   status, "cond_timedwait");
  4398     if (!FilterSpuriousWakeups) break ;                 // previous semantics
  4399     if (status == ETIMEDOUT) break ;
  4400     // We consume and ignore EINTR and spurious wakeups.
  4402   --_nParked ;
  4403   if (_Event >= 0) {
  4404      ret = OS_OK;
  4406   _Event = 0 ;
  4407   status = pthread_mutex_unlock(_mutex);
  4408   assert_status(status == 0, status, "mutex_unlock");
  4409   assert (_nParked == 0, "invariant") ;
  4410   // Paranoia to ensure our locked and lock-free paths interact
  4411   // correctly with each other.
  4412   OrderAccess::fence();
  4413   return ret;
  4416 void os::PlatformEvent::unpark() {
  4417   // Transitions for _Event:
  4418   //    0 :=> 1
  4419   //    1 :=> 1
  4420   //   -1 :=> either 0 or 1; must signal target thread
  4421   //          That is, we can safely transition _Event from -1 to either
  4422   //          0 or 1. Forcing 1 is slightly more efficient for back-to-back
  4423   //          unpark() calls.
  4424   // See also: "Semaphores in Plan 9" by Mullender & Cox
  4425   //
  4426   // Note: Forcing a transition from "-1" to "1" on an unpark() means
  4427   // that it will take two back-to-back park() calls for the owning
  4428   // thread to block. This has the benefit of forcing a spurious return
  4429   // from the first park() call after an unpark() call which will help
  4430   // shake out uses of park() and unpark() without condition variables.
  4432   if (Atomic::xchg(1, &_Event) >= 0) return;
  4434   // Wait for the thread associated with the event to vacate
  4435   int status = pthread_mutex_lock(_mutex);
  4436   assert_status(status == 0, status, "mutex_lock");
  4437   int AnyWaiters = _nParked;
  4438   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
  4439   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
  4440     AnyWaiters = 0;
  4441     pthread_cond_signal(_cond);
  4443   status = pthread_mutex_unlock(_mutex);
  4444   assert_status(status == 0, status, "mutex_unlock");
  4445   if (AnyWaiters != 0) {
  4446     status = pthread_cond_signal(_cond);
  4447     assert_status(status == 0, status, "cond_signal");
  4450   // Note that we signal() _after dropping the lock for "immortal" Events.
  4451   // This is safe and avoids a common class of  futile wakeups.  In rare
  4452   // circumstances this can cause a thread to return prematurely from
  4453   // cond_{timed}wait() but the spurious wakeup is benign and the victim will
  4454   // simply re-test the condition and re-park itself.
  4458 // JSR166
  4459 // -------------------------------------------------------
  4461 /*
  4462  * The solaris and bsd implementations of park/unpark are fairly
  4463  * conservative for now, but can be improved. They currently use a
  4464  * mutex/condvar pair, plus a a count.
  4465  * Park decrements count if > 0, else does a condvar wait.  Unpark
  4466  * sets count to 1 and signals condvar.  Only one thread ever waits
  4467  * on the condvar. Contention seen when trying to park implies that someone
  4468  * is unparking you, so don't wait. And spurious returns are fine, so there
  4469  * is no need to track notifications.
  4470  */
  4472 #define MAX_SECS 100000000
  4473 /*
  4474  * This code is common to bsd and solaris and will be moved to a
  4475  * common place in dolphin.
  4477  * The passed in time value is either a relative time in nanoseconds
  4478  * or an absolute time in milliseconds. Either way it has to be unpacked
  4479  * into suitable seconds and nanoseconds components and stored in the
  4480  * given timespec structure.
  4481  * Given time is a 64-bit value and the time_t used in the timespec is only
  4482  * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
  4483  * overflow if times way in the future are given. Further on Solaris versions
  4484  * prior to 10 there is a restriction (see cond_timedwait) that the specified
  4485  * number of seconds, in abstime, is less than current_time  + 100,000,000.
  4486  * As it will be 28 years before "now + 100000000" will overflow we can
  4487  * ignore overflow and just impose a hard-limit on seconds using the value
  4488  * of "now + 100,000,000". This places a limit on the timeout of about 3.17
  4489  * years from "now".
  4490  */
  4492 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
  4493   assert (time > 0, "convertTime");
  4495   struct timeval now;
  4496   int status = gettimeofday(&now, NULL);
  4497   assert(status == 0, "gettimeofday");
  4499   time_t max_secs = now.tv_sec + MAX_SECS;
  4501   if (isAbsolute) {
  4502     jlong secs = time / 1000;
  4503     if (secs > max_secs) {
  4504       absTime->tv_sec = max_secs;
  4506     else {
  4507       absTime->tv_sec = secs;
  4509     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
  4511   else {
  4512     jlong secs = time / NANOSECS_PER_SEC;
  4513     if (secs >= MAX_SECS) {
  4514       absTime->tv_sec = max_secs;
  4515       absTime->tv_nsec = 0;
  4517     else {
  4518       absTime->tv_sec = now.tv_sec + secs;
  4519       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
  4520       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
  4521         absTime->tv_nsec -= NANOSECS_PER_SEC;
  4522         ++absTime->tv_sec; // note: this must be <= max_secs
  4526   assert(absTime->tv_sec >= 0, "tv_sec < 0");
  4527   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
  4528   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
  4529   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
  4532 void Parker::park(bool isAbsolute, jlong time) {
  4533   // Ideally we'd do something useful while spinning, such
  4534   // as calling unpackTime().
  4536   // Optional fast-path check:
  4537   // Return immediately if a permit is available.
  4538   // We depend on Atomic::xchg() having full barrier semantics
  4539   // since we are doing a lock-free update to _counter.
  4540   if (Atomic::xchg(0, &_counter) > 0) return;
  4542   Thread* thread = Thread::current();
  4543   assert(thread->is_Java_thread(), "Must be JavaThread");
  4544   JavaThread *jt = (JavaThread *)thread;
  4546   // Optional optimization -- avoid state transitions if there's an interrupt pending.
  4547   // Check interrupt before trying to wait
  4548   if (Thread::is_interrupted(thread, false)) {
  4549     return;
  4552   // Next, demultiplex/decode time arguments
  4553   struct timespec absTime;
  4554   if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
  4555     return;
  4557   if (time > 0) {
  4558     unpackTime(&absTime, isAbsolute, time);
  4562   // Enter safepoint region
  4563   // Beware of deadlocks such as 6317397.
  4564   // The per-thread Parker:: mutex is a classic leaf-lock.
  4565   // In particular a thread must never block on the Threads_lock while
  4566   // holding the Parker:: mutex.  If safepoints are pending both the
  4567   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
  4568   ThreadBlockInVM tbivm(jt);
  4570   // Don't wait if cannot get lock since interference arises from
  4571   // unblocking.  Also. check interrupt before trying wait
  4572   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
  4573     return;
  4576   int status ;
  4577   if (_counter > 0)  { // no wait needed
  4578     _counter = 0;
  4579     status = pthread_mutex_unlock(_mutex);
  4580     assert (status == 0, "invariant") ;
  4581     // Paranoia to ensure our locked and lock-free paths interact
  4582     // correctly with each other and Java-level accesses.
  4583     OrderAccess::fence();
  4584     return;
  4587 #ifdef ASSERT
  4588   // Don't catch signals while blocked; let the running threads have the signals.
  4589   // (This allows a debugger to break into the running thread.)
  4590   sigset_t oldsigs;
  4591   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
  4592   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
  4593 #endif
  4595   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
  4596   jt->set_suspend_equivalent();
  4597   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
  4599   if (time == 0) {
  4600     status = pthread_cond_wait (_cond, _mutex) ;
  4601   } else {
  4602     status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
  4603     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
  4604       pthread_cond_destroy (_cond) ;
  4605       pthread_cond_init    (_cond, NULL);
  4608   assert_status(status == 0 || status == EINTR ||
  4609                 status == ETIMEDOUT,
  4610                 status, "cond_timedwait");
  4612 #ifdef ASSERT
  4613   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
  4614 #endif
  4616   _counter = 0 ;
  4617   status = pthread_mutex_unlock(_mutex) ;
  4618   assert_status(status == 0, status, "invariant") ;
  4619   // Paranoia to ensure our locked and lock-free paths interact
  4620   // correctly with each other and Java-level accesses.
  4621   OrderAccess::fence();
  4623   // If externally suspended while waiting, re-suspend
  4624   if (jt->handle_special_suspend_equivalent_condition()) {
  4625     jt->java_suspend_self();
  4629 void Parker::unpark() {
  4630   int s, status ;
  4631   status = pthread_mutex_lock(_mutex);
  4632   assert (status == 0, "invariant") ;
  4633   s = _counter;
  4634   _counter = 1;
  4635   if (s < 1) {
  4636      if (WorkAroundNPTLTimedWaitHang) {
  4637         status = pthread_cond_signal (_cond) ;
  4638         assert (status == 0, "invariant") ;
  4639         status = pthread_mutex_unlock(_mutex);
  4640         assert (status == 0, "invariant") ;
  4641      } else {
  4642         status = pthread_mutex_unlock(_mutex);
  4643         assert (status == 0, "invariant") ;
  4644         status = pthread_cond_signal (_cond) ;
  4645         assert (status == 0, "invariant") ;
  4647   } else {
  4648     pthread_mutex_unlock(_mutex);
  4649     assert (status == 0, "invariant") ;
  4654 /* Darwin has no "environ" in a dynamic library. */
  4655 #ifdef __APPLE__
  4656 #include <crt_externs.h>
  4657 #define environ (*_NSGetEnviron())
  4658 #else
  4659 extern char** environ;
  4660 #endif
  4662 // Run the specified command in a separate process. Return its exit value,
  4663 // or -1 on failure (e.g. can't fork a new process).
  4664 // Unlike system(), this function can be called from signal handler. It
  4665 // doesn't block SIGINT et al.
  4666 int os::fork_and_exec(char* cmd) {
  4667   const char * argv[4] = {"sh", "-c", cmd, NULL};
  4669   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
  4670   // pthread_atfork handlers and reset pthread library. All we need is a
  4671   // separate process to execve. Make a direct syscall to fork process.
  4672   // On IA64 there's no fork syscall, we have to use fork() and hope for
  4673   // the best...
  4674   pid_t pid = fork();
  4676   if (pid < 0) {
  4677     // fork failed
  4678     return -1;
  4680   } else if (pid == 0) {
  4681     // child process
  4683     // execve() in BsdThreads will call pthread_kill_other_threads_np()
  4684     // first to kill every thread on the thread list. Because this list is
  4685     // not reset by fork() (see notes above), execve() will instead kill
  4686     // every thread in the parent process. We know this is the only thread
  4687     // in the new process, so make a system call directly.
  4688     // IA64 should use normal execve() from glibc to match the glibc fork()
  4689     // above.
  4690     execve("/bin/sh", (char* const*)argv, environ);
  4692     // execve failed
  4693     _exit(-1);
  4695   } else  {
  4696     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
  4697     // care about the actual exit code, for now.
  4699     int status;
  4701     // Wait for the child process to exit.  This returns immediately if
  4702     // the child has already exited. */
  4703     while (waitpid(pid, &status, 0) < 0) {
  4704         switch (errno) {
  4705         case ECHILD: return 0;
  4706         case EINTR: break;
  4707         default: return -1;
  4711     if (WIFEXITED(status)) {
  4712        // The child exited normally; get its exit code.
  4713        return WEXITSTATUS(status);
  4714     } else if (WIFSIGNALED(status)) {
  4715        // The child exited because of a signal
  4716        // The best value to return is 0x80 + signal number,
  4717        // because that is what all Unix shells do, and because
  4718        // it allows callers to distinguish between process exit and
  4719        // process death by signal.
  4720        return 0x80 + WTERMSIG(status);
  4721     } else {
  4722        // Unknown exit code; pass it through
  4723        return status;
  4728 // is_headless_jre()
  4729 //
  4730 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
  4731 // in order to report if we are running in a headless jre
  4732 //
  4733 // Since JDK8 xawt/libmawt.so was moved into the same directory
  4734 // as libawt.so, and renamed libawt_xawt.so
  4735 //
  4736 bool os::is_headless_jre() {
  4737 #ifdef __APPLE__
  4738     // We no longer build headless-only on Mac OS X
  4739     return false;
  4740 #else
  4741     struct stat statbuf;
  4742     char buf[MAXPATHLEN];
  4743     char libmawtpath[MAXPATHLEN];
  4744     const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
  4745     const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
  4746     char *p;
  4748     // Get path to libjvm.so
  4749     os::jvm_path(buf, sizeof(buf));
  4751     // Get rid of libjvm.so
  4752     p = strrchr(buf, '/');
  4753     if (p == NULL) return false;
  4754     else *p = '\0';
  4756     // Get rid of client or server
  4757     p = strrchr(buf, '/');
  4758     if (p == NULL) return false;
  4759     else *p = '\0';
  4761     // check xawt/libmawt.so
  4762     strcpy(libmawtpath, buf);
  4763     strcat(libmawtpath, xawtstr);
  4764     if (::stat(libmawtpath, &statbuf) == 0) return false;
  4766     // check libawt_xawt.so
  4767     strcpy(libmawtpath, buf);
  4768     strcat(libmawtpath, new_xawtstr);
  4769     if (::stat(libmawtpath, &statbuf) == 0) return false;
  4771     return true;
  4772 #endif
  4775 // Get the default path to the core file
  4776 // Returns the length of the string
  4777 int os::get_core_path(char* buffer, size_t bufferSize) {
  4778   int n = jio_snprintf(buffer, bufferSize, "/cores");
  4780   // Truncate if theoretical string was longer than bufferSize
  4781   n = MIN2(n, (int)bufferSize);
  4783   return n;
  4786 #ifndef PRODUCT
  4787 void TestReserveMemorySpecial_test() {
  4788   // No tests available for this platform
  4790 #endif

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