src/os/bsd/vm/os_bsd.cpp

Wed, 03 Apr 2013 16:43:09 -0700

author
ccheung
date
Wed, 03 Apr 2013 16:43:09 -0700
changeset 4888
17bf4d428955
parent 4713
252ad8d5f22b
child 4889
cc32ccaaf47f
permissions
-rw-r--r--

8006103: [parfait] Possible null pointer dereference at hotspot/src/os/linux/vm/os_linux.cpp; os_windows.cpp; os_solaris.cpp; os_bsd.cpp
Reviewed-by: zgu, iklam

     1 /*
     2  * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 // no precompiled headers
    26 #include "classfile/classLoader.hpp"
    27 #include "classfile/systemDictionary.hpp"
    28 #include "classfile/vmSymbols.hpp"
    29 #include "code/icBuffer.hpp"
    30 #include "code/vtableStubs.hpp"
    31 #include "compiler/compileBroker.hpp"
    32 #include "compiler/disassembler.hpp"
    33 #include "interpreter/interpreter.hpp"
    34 #include "jvm_bsd.h"
    35 #include "memory/allocation.inline.hpp"
    36 #include "memory/filemap.hpp"
    37 #include "mutex_bsd.inline.hpp"
    38 #include "oops/oop.inline.hpp"
    39 #include "os_share_bsd.hpp"
    40 #include "prims/jniFastGetField.hpp"
    41 #include "prims/jvm.h"
    42 #include "prims/jvm_misc.hpp"
    43 #include "runtime/arguments.hpp"
    44 #include "runtime/extendedPC.hpp"
    45 #include "runtime/globals.hpp"
    46 #include "runtime/interfaceSupport.hpp"
    47 #include "runtime/java.hpp"
    48 #include "runtime/javaCalls.hpp"
    49 #include "runtime/mutexLocker.hpp"
    50 #include "runtime/objectMonitor.hpp"
    51 #include "runtime/osThread.hpp"
    52 #include "runtime/perfMemory.hpp"
    53 #include "runtime/sharedRuntime.hpp"
    54 #include "runtime/statSampler.hpp"
    55 #include "runtime/stubRoutines.hpp"
    56 #include "runtime/thread.inline.hpp"
    57 #include "runtime/threadCritical.hpp"
    58 #include "runtime/timer.hpp"
    59 #include "services/attachListener.hpp"
    60 #include "services/memTracker.hpp"
    61 #include "services/runtimeService.hpp"
    62 #include "utilities/decoder.hpp"
    63 #include "utilities/defaultStream.hpp"
    64 #include "utilities/events.hpp"
    65 #include "utilities/growableArray.hpp"
    66 #include "utilities/vmError.hpp"
    68 // put OS-includes here
    69 # include <sys/types.h>
    70 # include <sys/mman.h>
    71 # include <sys/stat.h>
    72 # include <sys/select.h>
    73 # include <pthread.h>
    74 # include <signal.h>
    75 # include <errno.h>
    76 # include <dlfcn.h>
    77 # include <stdio.h>
    78 # include <unistd.h>
    79 # include <sys/resource.h>
    80 # include <pthread.h>
    81 # include <sys/stat.h>
    82 # include <sys/time.h>
    83 # include <sys/times.h>
    84 # include <sys/utsname.h>
    85 # include <sys/socket.h>
    86 # include <sys/wait.h>
    87 # include <time.h>
    88 # include <pwd.h>
    89 # include <poll.h>
    90 # include <semaphore.h>
    91 # include <fcntl.h>
    92 # include <string.h>
    93 # include <sys/param.h>
    94 # include <sys/sysctl.h>
    95 # include <sys/ipc.h>
    96 # include <sys/shm.h>
    97 #ifndef __APPLE__
    98 # include <link.h>
    99 #endif
   100 # include <stdint.h>
   101 # include <inttypes.h>
   102 # include <sys/ioctl.h>
   104 #if defined(__FreeBSD__) || defined(__NetBSD__)
   105 # include <elf.h>
   106 #endif
   108 #ifdef __APPLE__
   109 # include <mach/mach.h> // semaphore_* API
   110 # include <mach-o/dyld.h>
   111 # include <sys/proc_info.h>
   112 # include <objc/objc-auto.h>
   113 #endif
   115 #ifndef MAP_ANONYMOUS
   116 #define MAP_ANONYMOUS MAP_ANON
   117 #endif
   119 #define MAX_PATH    (2 * K)
   121 // for timer info max values which include all bits
   122 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
   124 #define LARGEPAGES_BIT (1 << 6)
   125 ////////////////////////////////////////////////////////////////////////////////
   126 // global variables
   127 julong os::Bsd::_physical_memory = 0;
   130 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
   131 pthread_t os::Bsd::_main_thread;
   132 int os::Bsd::_page_size = -1;
   134 static jlong initial_time_count=0;
   136 static int clock_tics_per_sec = 100;
   138 // For diagnostics to print a message once. see run_periodic_checks
   139 static sigset_t check_signal_done;
   140 static bool check_signals = true;
   142 static pid_t _initial_pid = 0;
   144 /* Signal number used to suspend/resume a thread */
   146 /* do not use any signal number less than SIGSEGV, see 4355769 */
   147 static int SR_signum = SIGUSR2;
   148 sigset_t SR_sigset;
   151 ////////////////////////////////////////////////////////////////////////////////
   152 // utility functions
   154 static int SR_initialize();
   155 static int SR_finalize();
   157 julong os::available_memory() {
   158   return Bsd::available_memory();
   159 }
   161 julong os::Bsd::available_memory() {
   162   // XXXBSD: this is just a stopgap implementation
   163   return physical_memory() >> 2;
   164 }
   166 julong os::physical_memory() {
   167   return Bsd::physical_memory();
   168 }
   170 julong os::allocatable_physical_memory(julong size) {
   171 #ifdef _LP64
   172   return size;
   173 #else
   174   julong result = MIN2(size, (julong)3800*M);
   175    if (!is_allocatable(result)) {
   176      // See comments under solaris for alignment considerations
   177      julong reasonable_size = (julong)2*G - 2 * os::vm_page_size();
   178      result =  MIN2(size, reasonable_size);
   179    }
   180    return result;
   181 #endif // _LP64
   182 }
   184 ////////////////////////////////////////////////////////////////////////////////
   185 // environment support
   187 bool os::getenv(const char* name, char* buf, int len) {
   188   const char* val = ::getenv(name);
   189   if (val != NULL && strlen(val) < (size_t)len) {
   190     strcpy(buf, val);
   191     return true;
   192   }
   193   if (len > 0) buf[0] = 0;  // return a null string
   194   return false;
   195 }
   198 // Return true if user is running as root.
   200 bool os::have_special_privileges() {
   201   static bool init = false;
   202   static bool privileges = false;
   203   if (!init) {
   204     privileges = (getuid() != geteuid()) || (getgid() != getegid());
   205     init = true;
   206   }
   207   return privileges;
   208 }
   212 // Cpu architecture string
   213 #if   defined(ZERO)
   214 static char cpu_arch[] = ZERO_LIBARCH;
   215 #elif defined(IA64)
   216 static char cpu_arch[] = "ia64";
   217 #elif defined(IA32)
   218 static char cpu_arch[] = "i386";
   219 #elif defined(AMD64)
   220 static char cpu_arch[] = "amd64";
   221 #elif defined(ARM)
   222 static char cpu_arch[] = "arm";
   223 #elif defined(PPC)
   224 static char cpu_arch[] = "ppc";
   225 #elif defined(SPARC)
   226 #  ifdef _LP64
   227 static char cpu_arch[] = "sparcv9";
   228 #  else
   229 static char cpu_arch[] = "sparc";
   230 #  endif
   231 #else
   232 #error Add appropriate cpu_arch setting
   233 #endif
   235 // Compiler variant
   236 #ifdef COMPILER2
   237 #define COMPILER_VARIANT "server"
   238 #else
   239 #define COMPILER_VARIANT "client"
   240 #endif
   243 void os::Bsd::initialize_system_info() {
   244   int mib[2];
   245   size_t len;
   246   int cpu_val;
   247   julong mem_val;
   249   /* get processors count via hw.ncpus sysctl */
   250   mib[0] = CTL_HW;
   251   mib[1] = HW_NCPU;
   252   len = sizeof(cpu_val);
   253   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
   254        assert(len == sizeof(cpu_val), "unexpected data size");
   255        set_processor_count(cpu_val);
   256   }
   257   else {
   258        set_processor_count(1);   // fallback
   259   }
   261   /* get physical memory via hw.memsize sysctl (hw.memsize is used
   262    * since it returns a 64 bit value)
   263    */
   264   mib[0] = CTL_HW;
   265   mib[1] = HW_MEMSIZE;
   266   len = sizeof(mem_val);
   267   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
   268        assert(len == sizeof(mem_val), "unexpected data size");
   269        _physical_memory = mem_val;
   270   } else {
   271        _physical_memory = 256*1024*1024;       // fallback (XXXBSD?)
   272   }
   274 #ifdef __OpenBSD__
   275   {
   276        // limit _physical_memory memory view on OpenBSD since
   277        // datasize rlimit restricts us anyway.
   278        struct rlimit limits;
   279        getrlimit(RLIMIT_DATA, &limits);
   280        _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
   281   }
   282 #endif
   283 }
   285 #ifdef __APPLE__
   286 static const char *get_home() {
   287   const char *home_dir = ::getenv("HOME");
   288   if ((home_dir == NULL) || (*home_dir == '\0')) {
   289     struct passwd *passwd_info = getpwuid(geteuid());
   290     if (passwd_info != NULL) {
   291       home_dir = passwd_info->pw_dir;
   292     }
   293   }
   295   return home_dir;
   296 }
   297 #endif
   299 void os::init_system_properties_values() {
   300 //  char arch[12];
   301 //  sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
   303   // The next steps are taken in the product version:
   304   //
   305   // Obtain the JAVA_HOME value from the location of libjvm.so.
   306   // This library should be located at:
   307   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
   308   //
   309   // If "/jre/lib/" appears at the right place in the path, then we
   310   // assume libjvm.so is installed in a JDK and we use this path.
   311   //
   312   // Otherwise exit with message: "Could not create the Java virtual machine."
   313   //
   314   // The following extra steps are taken in the debugging version:
   315   //
   316   // If "/jre/lib/" does NOT appear at the right place in the path
   317   // instead of exit check for $JAVA_HOME environment variable.
   318   //
   319   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
   320   // then we append a fake suffix "hotspot/libjvm.so" to this path so
   321   // it looks like libjvm.so is installed there
   322   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
   323   //
   324   // Otherwise exit.
   325   //
   326   // Important note: if the location of libjvm.so changes this
   327   // code needs to be changed accordingly.
   329   // The next few definitions allow the code to be verbatim:
   330 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal)
   331 #define getenv(n) ::getenv(n)
   333 /*
   334  * See ld(1):
   335  *      The linker uses the following search paths to locate required
   336  *      shared libraries:
   337  *        1: ...
   338  *        ...
   339  *        7: The default directories, normally /lib and /usr/lib.
   340  */
   341 #ifndef DEFAULT_LIBPATH
   342 #define DEFAULT_LIBPATH "/lib:/usr/lib"
   343 #endif
   345 #define EXTENSIONS_DIR  "/lib/ext"
   346 #define ENDORSED_DIR    "/lib/endorsed"
   347 #define REG_DIR         "/usr/java/packages"
   349 #ifdef __APPLE__
   350 #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
   351 #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
   352         const char *user_home_dir = get_home();
   353         // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir
   354         int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
   355             sizeof(SYS_EXTENSIONS_DIRS);
   356 #endif
   358   {
   359     /* sysclasspath, java_home, dll_dir */
   360     {
   361         char *home_path;
   362         char *dll_path;
   363         char *pslash;
   364         char buf[MAXPATHLEN];
   365         os::jvm_path(buf, sizeof(buf));
   367         // Found the full path to libjvm.so.
   368         // Now cut the path to <java_home>/jre if we can.
   369         *(strrchr(buf, '/')) = '\0';  /* get rid of /libjvm.so */
   370         pslash = strrchr(buf, '/');
   371         if (pslash != NULL)
   372             *pslash = '\0';           /* get rid of /{client|server|hotspot} */
   373         dll_path = malloc(strlen(buf) + 1);
   374         if (dll_path == NULL)
   375             return;
   376         strcpy(dll_path, buf);
   377         Arguments::set_dll_dir(dll_path);
   379         if (pslash != NULL) {
   380             pslash = strrchr(buf, '/');
   381             if (pslash != NULL) {
   382                 *pslash = '\0';       /* get rid of /<arch> (/lib on macosx) */
   383 #ifndef __APPLE__
   384                 pslash = strrchr(buf, '/');
   385                 if (pslash != NULL)
   386                     *pslash = '\0';   /* get rid of /lib */
   387 #endif
   388             }
   389         }
   391         home_path = malloc(strlen(buf) + 1);
   392         if (home_path == NULL)
   393             return;
   394         strcpy(home_path, buf);
   395         Arguments::set_java_home(home_path);
   397         if (!set_boot_path('/', ':'))
   398             return;
   399     }
   401     /*
   402      * Where to look for native libraries
   403      *
   404      * Note: Due to a legacy implementation, most of the library path
   405      * is set in the launcher.  This was to accomodate linking restrictions
   406      * on legacy Bsd implementations (which are no longer supported).
   407      * Eventually, all the library path setting will be done here.
   408      *
   409      * However, to prevent the proliferation of improperly built native
   410      * libraries, the new path component /usr/java/packages is added here.
   411      * Eventually, all the library path setting will be done here.
   412      */
   413     {
   414         char *ld_library_path;
   416         /*
   417          * Construct the invariant part of ld_library_path. Note that the
   418          * space for the colon and the trailing null are provided by the
   419          * nulls included by the sizeof operator (so actually we allocate
   420          * a byte more than necessary).
   421          */
   422 #ifdef __APPLE__
   423         ld_library_path = (char *) malloc(system_ext_size);
   424         sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir);
   425 #else
   426         ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
   427             strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
   428         sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
   429 #endif
   431         /*
   432          * Get the user setting of LD_LIBRARY_PATH, and prepended it.  It
   433          * should always exist (until the legacy problem cited above is
   434          * addressed).
   435          */
   436 #ifdef __APPLE__
   437         // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper
   438         char *l = getenv("JAVA_LIBRARY_PATH");
   439         if (l != NULL) {
   440             char *t = ld_library_path;
   441             /* That's +1 for the colon and +1 for the trailing '\0' */
   442             ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1);
   443             sprintf(ld_library_path, "%s:%s", l, t);
   444             free(t);
   445         }
   447         char *v = getenv("DYLD_LIBRARY_PATH");
   448 #else
   449         char *v = getenv("LD_LIBRARY_PATH");
   450 #endif
   451         if (v != NULL) {
   452             char *t = ld_library_path;
   453             /* That's +1 for the colon and +1 for the trailing '\0' */
   454             ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
   455             sprintf(ld_library_path, "%s:%s", v, t);
   456             free(t);
   457         }
   459 #ifdef __APPLE__
   460         // Apple's Java6 has "." at the beginning of java.library.path.
   461         // OpenJDK on Windows has "." at the end of java.library.path.
   462         // OpenJDK on Linux and Solaris don't have "." in java.library.path
   463         // at all. To ease the transition from Apple's Java6 to OpenJDK7,
   464         // "." is appended to the end of java.library.path. Yes, this
   465         // could cause a change in behavior, but Apple's Java6 behavior
   466         // can be achieved by putting "." at the beginning of the
   467         // JAVA_LIBRARY_PATH environment variable.
   468         {
   469             char *t = ld_library_path;
   470             // that's +3 for appending ":." and the trailing '\0'
   471             ld_library_path = (char *) malloc(strlen(t) + 3);
   472             sprintf(ld_library_path, "%s:%s", t, ".");
   473             free(t);
   474         }
   475 #endif
   477         Arguments::set_library_path(ld_library_path);
   478     }
   480     /*
   481      * Extensions directories.
   482      *
   483      * Note that the space for the colon and the trailing null are provided
   484      * by the nulls included by the sizeof operator (so actually one byte more
   485      * than necessary is allocated).
   486      */
   487     {
   488 #ifdef __APPLE__
   489         char *buf = malloc(strlen(Arguments::get_java_home()) +
   490             sizeof(EXTENSIONS_DIR) + system_ext_size);
   491         sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":"
   492             SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home());
   493 #else
   494         char *buf = malloc(strlen(Arguments::get_java_home()) +
   495             sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
   496         sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
   497             Arguments::get_java_home());
   498 #endif
   500         Arguments::set_ext_dirs(buf);
   501     }
   503     /* Endorsed standards default directory. */
   504     {
   505         char * buf;
   506         buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
   507         sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
   508         Arguments::set_endorsed_dirs(buf);
   509     }
   510   }
   512 #ifdef __APPLE__
   513 #undef SYS_EXTENSIONS_DIR
   514 #endif
   515 #undef malloc
   516 #undef getenv
   517 #undef EXTENSIONS_DIR
   518 #undef ENDORSED_DIR
   520   // Done
   521   return;
   522 }
   524 ////////////////////////////////////////////////////////////////////////////////
   525 // breakpoint support
   527 void os::breakpoint() {
   528   BREAKPOINT;
   529 }
   531 extern "C" void breakpoint() {
   532   // use debugger to set breakpoint here
   533 }
   535 ////////////////////////////////////////////////////////////////////////////////
   536 // signal support
   538 debug_only(static bool signal_sets_initialized = false);
   539 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
   541 bool os::Bsd::is_sig_ignored(int sig) {
   542       struct sigaction oact;
   543       sigaction(sig, (struct sigaction*)NULL, &oact);
   544       void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
   545                                      : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
   546       if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
   547            return true;
   548       else
   549            return false;
   550 }
   552 void os::Bsd::signal_sets_init() {
   553   // Should also have an assertion stating we are still single-threaded.
   554   assert(!signal_sets_initialized, "Already initialized");
   555   // Fill in signals that are necessarily unblocked for all threads in
   556   // the VM. Currently, we unblock the following signals:
   557   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
   558   //                         by -Xrs (=ReduceSignalUsage));
   559   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
   560   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
   561   // the dispositions or masks wrt these signals.
   562   // Programs embedding the VM that want to use the above signals for their
   563   // own purposes must, at this time, use the "-Xrs" option to prevent
   564   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
   565   // (See bug 4345157, and other related bugs).
   566   // In reality, though, unblocking these signals is really a nop, since
   567   // these signals are not blocked by default.
   568   sigemptyset(&unblocked_sigs);
   569   sigemptyset(&allowdebug_blocked_sigs);
   570   sigaddset(&unblocked_sigs, SIGILL);
   571   sigaddset(&unblocked_sigs, SIGSEGV);
   572   sigaddset(&unblocked_sigs, SIGBUS);
   573   sigaddset(&unblocked_sigs, SIGFPE);
   574   sigaddset(&unblocked_sigs, SR_signum);
   576   if (!ReduceSignalUsage) {
   577    if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
   578       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
   579       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
   580    }
   581    if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
   582       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
   583       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
   584    }
   585    if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
   586       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
   587       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
   588    }
   589   }
   590   // Fill in signals that are blocked by all but the VM thread.
   591   sigemptyset(&vm_sigs);
   592   if (!ReduceSignalUsage)
   593     sigaddset(&vm_sigs, BREAK_SIGNAL);
   594   debug_only(signal_sets_initialized = true);
   596 }
   598 // These are signals that are unblocked while a thread is running Java.
   599 // (For some reason, they get blocked by default.)
   600 sigset_t* os::Bsd::unblocked_signals() {
   601   assert(signal_sets_initialized, "Not initialized");
   602   return &unblocked_sigs;
   603 }
   605 // These are the signals that are blocked while a (non-VM) thread is
   606 // running Java. Only the VM thread handles these signals.
   607 sigset_t* os::Bsd::vm_signals() {
   608   assert(signal_sets_initialized, "Not initialized");
   609   return &vm_sigs;
   610 }
   612 // These are signals that are blocked during cond_wait to allow debugger in
   613 sigset_t* os::Bsd::allowdebug_blocked_signals() {
   614   assert(signal_sets_initialized, "Not initialized");
   615   return &allowdebug_blocked_sigs;
   616 }
   618 void os::Bsd::hotspot_sigmask(Thread* thread) {
   620   //Save caller's signal mask before setting VM signal mask
   621   sigset_t caller_sigmask;
   622   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
   624   OSThread* osthread = thread->osthread();
   625   osthread->set_caller_sigmask(caller_sigmask);
   627   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
   629   if (!ReduceSignalUsage) {
   630     if (thread->is_VM_thread()) {
   631       // Only the VM thread handles BREAK_SIGNAL ...
   632       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
   633     } else {
   634       // ... all other threads block BREAK_SIGNAL
   635       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
   636     }
   637   }
   638 }
   641 //////////////////////////////////////////////////////////////////////////////
   642 // create new thread
   644 static address highest_vm_reserved_address();
   646 // check if it's safe to start a new thread
   647 static bool _thread_safety_check(Thread* thread) {
   648   return true;
   649 }
   651 #ifdef __APPLE__
   652 // library handle for calling objc_registerThreadWithCollector()
   653 // without static linking to the libobjc library
   654 #define OBJC_LIB "/usr/lib/libobjc.dylib"
   655 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
   656 typedef void (*objc_registerThreadWithCollector_t)();
   657 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
   658 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
   659 #endif
   661 #ifdef __APPLE__
   662 static uint64_t locate_unique_thread_id() {
   663   // Additional thread_id used to correlate threads in SA
   664   thread_identifier_info_data_t     m_ident_info;
   665   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
   667   thread_info(::mach_thread_self(), THREAD_IDENTIFIER_INFO,
   668               (thread_info_t) &m_ident_info, &count);
   669   return m_ident_info.thread_id;
   670 }
   671 #endif
   673 // Thread start routine for all newly created threads
   674 static void *java_start(Thread *thread) {
   675   // Try to randomize the cache line index of hot stack frames.
   676   // This helps when threads of the same stack traces evict each other's
   677   // cache lines. The threads can be either from the same JVM instance, or
   678   // from different JVM instances. The benefit is especially true for
   679   // processors with hyperthreading technology.
   680   static int counter = 0;
   681   int pid = os::current_process_id();
   682   alloca(((pid ^ counter++) & 7) * 128);
   684   ThreadLocalStorage::set_thread(thread);
   686   OSThread* osthread = thread->osthread();
   687   Monitor* sync = osthread->startThread_lock();
   689   // non floating stack BsdThreads needs extra check, see above
   690   if (!_thread_safety_check(thread)) {
   691     // notify parent thread
   692     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
   693     osthread->set_state(ZOMBIE);
   694     sync->notify_all();
   695     return NULL;
   696   }
   698 #ifdef __APPLE__
   699   // thread_id is mach thread on macos
   700   osthread->set_thread_id(::mach_thread_self());
   701   osthread->set_unique_thread_id(locate_unique_thread_id());
   702 #else
   703   // thread_id is pthread_id on BSD
   704   osthread->set_thread_id(::pthread_self());
   705 #endif
   706   // initialize signal mask for this thread
   707   os::Bsd::hotspot_sigmask(thread);
   709   // initialize floating point control register
   710   os::Bsd::init_thread_fpu_state();
   712 #ifdef __APPLE__
   713   // register thread with objc gc
   714   if (objc_registerThreadWithCollectorFunction != NULL) {
   715     objc_registerThreadWithCollectorFunction();
   716   }
   717 #endif
   719   // handshaking with parent thread
   720   {
   721     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
   723     // notify parent thread
   724     osthread->set_state(INITIALIZED);
   725     sync->notify_all();
   727     // wait until os::start_thread()
   728     while (osthread->get_state() == INITIALIZED) {
   729       sync->wait(Mutex::_no_safepoint_check_flag);
   730     }
   731   }
   733   // call one more level start routine
   734   thread->run();
   736   return 0;
   737 }
   739 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
   740   assert(thread->osthread() == NULL, "caller responsible");
   742   // Allocate the OSThread object
   743   OSThread* osthread = new OSThread(NULL, NULL);
   744   if (osthread == NULL) {
   745     return false;
   746   }
   748   // set the correct thread state
   749   osthread->set_thread_type(thr_type);
   751   // Initial state is ALLOCATED but not INITIALIZED
   752   osthread->set_state(ALLOCATED);
   754   thread->set_osthread(osthread);
   756   // init thread attributes
   757   pthread_attr_t attr;
   758   pthread_attr_init(&attr);
   759   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
   761   // stack size
   762   if (os::Bsd::supports_variable_stack_size()) {
   763     // calculate stack size if it's not specified by caller
   764     if (stack_size == 0) {
   765       stack_size = os::Bsd::default_stack_size(thr_type);
   767       switch (thr_type) {
   768       case os::java_thread:
   769         // Java threads use ThreadStackSize which default value can be
   770         // changed with the flag -Xss
   771         assert (JavaThread::stack_size_at_create() > 0, "this should be set");
   772         stack_size = JavaThread::stack_size_at_create();
   773         break;
   774       case os::compiler_thread:
   775         if (CompilerThreadStackSize > 0) {
   776           stack_size = (size_t)(CompilerThreadStackSize * K);
   777           break;
   778         } // else fall through:
   779           // use VMThreadStackSize if CompilerThreadStackSize is not defined
   780       case os::vm_thread:
   781       case os::pgc_thread:
   782       case os::cgc_thread:
   783       case os::watcher_thread:
   784         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
   785         break;
   786       }
   787     }
   789     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
   790     pthread_attr_setstacksize(&attr, stack_size);
   791   } else {
   792     // let pthread_create() pick the default value.
   793   }
   795   ThreadState state;
   797   {
   798     pthread_t tid;
   799     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
   801     pthread_attr_destroy(&attr);
   803     if (ret != 0) {
   804       if (PrintMiscellaneous && (Verbose || WizardMode)) {
   805         perror("pthread_create()");
   806       }
   807       // Need to clean up stuff we've allocated so far
   808       thread->set_osthread(NULL);
   809       delete osthread;
   810       return false;
   811     }
   813     // Store pthread info into the OSThread
   814     osthread->set_pthread_id(tid);
   816     // Wait until child thread is either initialized or aborted
   817     {
   818       Monitor* sync_with_child = osthread->startThread_lock();
   819       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
   820       while ((state = osthread->get_state()) == ALLOCATED) {
   821         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
   822       }
   823     }
   825   }
   827   // Aborted due to thread limit being reached
   828   if (state == ZOMBIE) {
   829       thread->set_osthread(NULL);
   830       delete osthread;
   831       return false;
   832   }
   834   // The thread is returned suspended (in state INITIALIZED),
   835   // and is started higher up in the call chain
   836   assert(state == INITIALIZED, "race condition");
   837   return true;
   838 }
   840 /////////////////////////////////////////////////////////////////////////////
   841 // attach existing thread
   843 // bootstrap the main thread
   844 bool os::create_main_thread(JavaThread* thread) {
   845   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
   846   return create_attached_thread(thread);
   847 }
   849 bool os::create_attached_thread(JavaThread* thread) {
   850 #ifdef ASSERT
   851     thread->verify_not_published();
   852 #endif
   854   // Allocate the OSThread object
   855   OSThread* osthread = new OSThread(NULL, NULL);
   857   if (osthread == NULL) {
   858     return false;
   859   }
   861   // Store pthread info into the OSThread
   862 #ifdef __APPLE__
   863   osthread->set_thread_id(::mach_thread_self());
   864   osthread->set_unique_thread_id(locate_unique_thread_id());
   865 #else
   866   osthread->set_thread_id(::pthread_self());
   867 #endif
   868   osthread->set_pthread_id(::pthread_self());
   870   // initialize floating point control register
   871   os::Bsd::init_thread_fpu_state();
   873   // Initial thread state is RUNNABLE
   874   osthread->set_state(RUNNABLE);
   876   thread->set_osthread(osthread);
   878   // initialize signal mask for this thread
   879   // and save the caller's signal mask
   880   os::Bsd::hotspot_sigmask(thread);
   882   return true;
   883 }
   885 void os::pd_start_thread(Thread* thread) {
   886   OSThread * osthread = thread->osthread();
   887   assert(osthread->get_state() != INITIALIZED, "just checking");
   888   Monitor* sync_with_child = osthread->startThread_lock();
   889   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
   890   sync_with_child->notify();
   891 }
   893 // Free Bsd resources related to the OSThread
   894 void os::free_thread(OSThread* osthread) {
   895   assert(osthread != NULL, "osthread not set");
   897   if (Thread::current()->osthread() == osthread) {
   898     // Restore caller's signal mask
   899     sigset_t sigmask = osthread->caller_sigmask();
   900     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
   901    }
   903   delete osthread;
   904 }
   906 //////////////////////////////////////////////////////////////////////////////
   907 // thread local storage
   909 int os::allocate_thread_local_storage() {
   910   pthread_key_t key;
   911   int rslt = pthread_key_create(&key, NULL);
   912   assert(rslt == 0, "cannot allocate thread local storage");
   913   return (int)key;
   914 }
   916 // Note: This is currently not used by VM, as we don't destroy TLS key
   917 // on VM exit.
   918 void os::free_thread_local_storage(int index) {
   919   int rslt = pthread_key_delete((pthread_key_t)index);
   920   assert(rslt == 0, "invalid index");
   921 }
   923 void os::thread_local_storage_at_put(int index, void* value) {
   924   int rslt = pthread_setspecific((pthread_key_t)index, value);
   925   assert(rslt == 0, "pthread_setspecific failed");
   926 }
   928 extern "C" Thread* get_thread() {
   929   return ThreadLocalStorage::thread();
   930 }
   933 ////////////////////////////////////////////////////////////////////////////////
   934 // time support
   936 // Time since start-up in seconds to a fine granularity.
   937 // Used by VMSelfDestructTimer and the MemProfiler.
   938 double os::elapsedTime() {
   940   return (double)(os::elapsed_counter()) * 0.000001;
   941 }
   943 jlong os::elapsed_counter() {
   944   timeval time;
   945   int status = gettimeofday(&time, NULL);
   946   return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count;
   947 }
   949 jlong os::elapsed_frequency() {
   950   return (1000 * 1000);
   951 }
   953 // XXX: For now, code this as if BSD does not support vtime.
   954 bool os::supports_vtime() { return false; }
   955 bool os::enable_vtime()   { return false; }
   956 bool os::vtime_enabled()  { return false; }
   957 double os::elapsedVTime() {
   958   // better than nothing, but not much
   959   return elapsedTime();
   960 }
   962 jlong os::javaTimeMillis() {
   963   timeval time;
   964   int status = gettimeofday(&time, NULL);
   965   assert(status != -1, "bsd error");
   966   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
   967 }
   969 #ifndef CLOCK_MONOTONIC
   970 #define CLOCK_MONOTONIC (1)
   971 #endif
   973 #ifdef __APPLE__
   974 void os::Bsd::clock_init() {
   975         // XXXDARWIN: Investigate replacement monotonic clock
   976 }
   977 #else
   978 void os::Bsd::clock_init() {
   979   struct timespec res;
   980   struct timespec tp;
   981   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
   982       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
   983     // yes, monotonic clock is supported
   984     _clock_gettime = ::clock_gettime;
   985   }
   986 }
   987 #endif
   990 jlong os::javaTimeNanos() {
   991   if (Bsd::supports_monotonic_clock()) {
   992     struct timespec tp;
   993     int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp);
   994     assert(status == 0, "gettime error");
   995     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
   996     return result;
   997   } else {
   998     timeval time;
   999     int status = gettimeofday(&time, NULL);
  1000     assert(status != -1, "bsd error");
  1001     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
  1002     return 1000 * usecs;
  1006 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
  1007   if (Bsd::supports_monotonic_clock()) {
  1008     info_ptr->max_value = ALL_64_BITS;
  1010     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
  1011     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
  1012     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
  1013   } else {
  1014     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
  1015     info_ptr->max_value = ALL_64_BITS;
  1017     // gettimeofday is a real time clock so it skips
  1018     info_ptr->may_skip_backward = true;
  1019     info_ptr->may_skip_forward = true;
  1022   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
  1025 // Return the real, user, and system times in seconds from an
  1026 // arbitrary fixed point in the past.
  1027 bool os::getTimesSecs(double* process_real_time,
  1028                       double* process_user_time,
  1029                       double* process_system_time) {
  1030   struct tms ticks;
  1031   clock_t real_ticks = times(&ticks);
  1033   if (real_ticks == (clock_t) (-1)) {
  1034     return false;
  1035   } else {
  1036     double ticks_per_second = (double) clock_tics_per_sec;
  1037     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
  1038     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
  1039     *process_real_time = ((double) real_ticks) / ticks_per_second;
  1041     return true;
  1046 char * os::local_time_string(char *buf, size_t buflen) {
  1047   struct tm t;
  1048   time_t long_time;
  1049   time(&long_time);
  1050   localtime_r(&long_time, &t);
  1051   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
  1052                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
  1053                t.tm_hour, t.tm_min, t.tm_sec);
  1054   return buf;
  1057 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
  1058   return localtime_r(clock, res);
  1061 ////////////////////////////////////////////////////////////////////////////////
  1062 // runtime exit support
  1064 // Note: os::shutdown() might be called very early during initialization, or
  1065 // called from signal handler. Before adding something to os::shutdown(), make
  1066 // sure it is async-safe and can handle partially initialized VM.
  1067 void os::shutdown() {
  1069   // allow PerfMemory to attempt cleanup of any persistent resources
  1070   perfMemory_exit();
  1072   // needs to remove object in file system
  1073   AttachListener::abort();
  1075   // flush buffered output, finish log files
  1076   ostream_abort();
  1078   // Check for abort hook
  1079   abort_hook_t abort_hook = Arguments::abort_hook();
  1080   if (abort_hook != NULL) {
  1081     abort_hook();
  1086 // Note: os::abort() might be called very early during initialization, or
  1087 // called from signal handler. Before adding something to os::abort(), make
  1088 // sure it is async-safe and can handle partially initialized VM.
  1089 void os::abort(bool dump_core) {
  1090   os::shutdown();
  1091   if (dump_core) {
  1092 #ifndef PRODUCT
  1093     fdStream out(defaultStream::output_fd());
  1094     out.print_raw("Current thread is ");
  1095     char buf[16];
  1096     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
  1097     out.print_raw_cr(buf);
  1098     out.print_raw_cr("Dumping core ...");
  1099 #endif
  1100     ::abort(); // dump core
  1103   ::exit(1);
  1106 // Die immediately, no exit hook, no abort hook, no cleanup.
  1107 void os::die() {
  1108   // _exit() on BsdThreads only kills current thread
  1109   ::abort();
  1112 // unused on bsd for now.
  1113 void os::set_error_file(const char *logfile) {}
  1116 // This method is a copy of JDK's sysGetLastErrorString
  1117 // from src/solaris/hpi/src/system_md.c
  1119 size_t os::lasterror(char *buf, size_t len) {
  1121   if (errno == 0)  return 0;
  1123   const char *s = ::strerror(errno);
  1124   size_t n = ::strlen(s);
  1125   if (n >= len) {
  1126     n = len - 1;
  1128   ::strncpy(buf, s, n);
  1129   buf[n] = '\0';
  1130   return n;
  1133 intx os::current_thread_id() {
  1134 #ifdef __APPLE__
  1135   return (intx)::mach_thread_self();
  1136 #else
  1137   return (intx)::pthread_self();
  1138 #endif
  1140 int os::current_process_id() {
  1142   // Under the old bsd thread library, bsd gives each thread
  1143   // its own process id. Because of this each thread will return
  1144   // a different pid if this method were to return the result
  1145   // of getpid(2). Bsd provides no api that returns the pid
  1146   // of the launcher thread for the vm. This implementation
  1147   // returns a unique pid, the pid of the launcher thread
  1148   // that starts the vm 'process'.
  1150   // Under the NPTL, getpid() returns the same pid as the
  1151   // launcher thread rather than a unique pid per thread.
  1152   // Use gettid() if you want the old pre NPTL behaviour.
  1154   // if you are looking for the result of a call to getpid() that
  1155   // returns a unique pid for the calling thread, then look at the
  1156   // OSThread::thread_id() method in osThread_bsd.hpp file
  1158   return (int)(_initial_pid ? _initial_pid : getpid());
  1161 // DLL functions
  1163 #define JNI_LIB_PREFIX "lib"
  1164 #ifdef __APPLE__
  1165 #define JNI_LIB_SUFFIX ".dylib"
  1166 #else
  1167 #define JNI_LIB_SUFFIX ".so"
  1168 #endif
  1170 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
  1172 // This must be hard coded because it's the system's temporary
  1173 // directory not the java application's temp directory, ala java.io.tmpdir.
  1174 #ifdef __APPLE__
  1175 // macosx has a secure per-user temporary directory
  1176 char temp_path_storage[PATH_MAX];
  1177 const char* os::get_temp_directory() {
  1178   static char *temp_path = NULL;
  1179   if (temp_path == NULL) {
  1180     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
  1181     if (pathSize == 0 || pathSize > PATH_MAX) {
  1182       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
  1184     temp_path = temp_path_storage;
  1186   return temp_path;
  1188 #else /* __APPLE__ */
  1189 const char* os::get_temp_directory() { return "/tmp"; }
  1190 #endif /* __APPLE__ */
  1192 static bool file_exists(const char* filename) {
  1193   struct stat statbuf;
  1194   if (filename == NULL || strlen(filename) == 0) {
  1195     return false;
  1197   return os::stat(filename, &statbuf) == 0;
  1200 bool os::dll_build_name(char* buffer, size_t buflen,
  1201                         const char* pname, const char* fname) {
  1202   bool retval = false;
  1203   // Copied from libhpi
  1204   const size_t pnamelen = pname ? strlen(pname) : 0;
  1206   // Return error on buffer overflow.
  1207   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
  1208     return retval;
  1211   if (pnamelen == 0) {
  1212     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
  1213     retval = true;
  1214   } else if (strchr(pname, *os::path_separator()) != NULL) {
  1215     int n;
  1216     char** pelements = split_path(pname, &n);
  1217     if (pelements == NULL) {
  1218         return false;
  1220     for (int i = 0 ; i < n ; i++) {
  1221       // Really shouldn't be NULL, but check can't hurt
  1222       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
  1223         continue; // skip the empty path values
  1225       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
  1226           pelements[i], fname);
  1227       if (file_exists(buffer)) {
  1228         retval = true;
  1229         break;
  1232     // release the storage
  1233     for (int i = 0 ; i < n ; i++) {
  1234       if (pelements[i] != NULL) {
  1235         FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
  1238     if (pelements != NULL) {
  1239       FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
  1241   } else {
  1242     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
  1243     retval = true;
  1245   return retval;
  1248 const char* os::get_current_directory(char *buf, int buflen) {
  1249   return getcwd(buf, buflen);
  1252 // check if addr is inside libjvm.so
  1253 bool os::address_is_in_vm(address addr) {
  1254   static address libjvm_base_addr;
  1255   Dl_info dlinfo;
  1257   if (libjvm_base_addr == NULL) {
  1258     dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo);
  1259     libjvm_base_addr = (address)dlinfo.dli_fbase;
  1260     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
  1263   if (dladdr((void *)addr, &dlinfo)) {
  1264     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
  1267   return false;
  1271 #define MACH_MAXSYMLEN 256
  1273 bool os::dll_address_to_function_name(address addr, char *buf,
  1274                                       int buflen, int *offset) {
  1275   Dl_info dlinfo;
  1276   char localbuf[MACH_MAXSYMLEN];
  1278   // dladdr will find names of dynamic functions only, but does
  1279   // it set dli_fbase with mach_header address when it "fails" ?
  1280   if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) {
  1281     if (buf != NULL) {
  1282       if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
  1283         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
  1286     if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
  1287     return true;
  1288   } else if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != 0) {
  1289     if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
  1290        buf, buflen, offset, dlinfo.dli_fname)) {
  1291        return true;
  1295   // Handle non-dymanic manually:
  1296   if (dlinfo.dli_fbase != NULL &&
  1297       Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
  1298     if(!Decoder::demangle(localbuf, buf, buflen)) {
  1299       jio_snprintf(buf, buflen, "%s", localbuf);
  1301     return true;
  1303   if (buf != NULL) buf[0] = '\0';
  1304   if (offset != NULL) *offset = -1;
  1305   return false;
  1308 // ported from solaris version
  1309 bool os::dll_address_to_library_name(address addr, char* buf,
  1310                                      int buflen, int* offset) {
  1311   Dl_info dlinfo;
  1313   if (dladdr((void*)addr, &dlinfo)){
  1314      if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
  1315      if (offset) *offset = addr - (address)dlinfo.dli_fbase;
  1316      return true;
  1317   } else {
  1318      if (buf) buf[0] = '\0';
  1319      if (offset) *offset = -1;
  1320      return false;
  1324 // Loads .dll/.so and
  1325 // in case of error it checks if .dll/.so was built for the
  1326 // same architecture as Hotspot is running on
  1328 #ifdef __APPLE__
  1329 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
  1330   void * result= ::dlopen(filename, RTLD_LAZY);
  1331   if (result != NULL) {
  1332     // Successful loading
  1333     return result;
  1336   // Read system error message into ebuf
  1337   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
  1338   ebuf[ebuflen-1]='\0';
  1340   return NULL;
  1342 #else
  1343 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
  1345   void * result= ::dlopen(filename, RTLD_LAZY);
  1346   if (result != NULL) {
  1347     // Successful loading
  1348     return result;
  1351   Elf32_Ehdr elf_head;
  1353   // Read system error message into ebuf
  1354   // It may or may not be overwritten below
  1355   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
  1356   ebuf[ebuflen-1]='\0';
  1357   int diag_msg_max_length=ebuflen-strlen(ebuf);
  1358   char* diag_msg_buf=ebuf+strlen(ebuf);
  1360   if (diag_msg_max_length==0) {
  1361     // No more space in ebuf for additional diagnostics message
  1362     return NULL;
  1366   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
  1368   if (file_descriptor < 0) {
  1369     // Can't open library, report dlerror() message
  1370     return NULL;
  1373   bool failed_to_read_elf_head=
  1374     (sizeof(elf_head)!=
  1375         (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
  1377   ::close(file_descriptor);
  1378   if (failed_to_read_elf_head) {
  1379     // file i/o error - report dlerror() msg
  1380     return NULL;
  1383   typedef struct {
  1384     Elf32_Half  code;         // Actual value as defined in elf.h
  1385     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
  1386     char        elf_class;    // 32 or 64 bit
  1387     char        endianess;    // MSB or LSB
  1388     char*       name;         // String representation
  1389   } arch_t;
  1391   #ifndef EM_486
  1392   #define EM_486          6               /* Intel 80486 */
  1393   #endif
  1395   #ifndef EM_MIPS_RS3_LE
  1396   #define EM_MIPS_RS3_LE  10              /* MIPS */
  1397   #endif
  1399   #ifndef EM_PPC64
  1400   #define EM_PPC64        21              /* PowerPC64 */
  1401   #endif
  1403   #ifndef EM_S390
  1404   #define EM_S390         22              /* IBM System/390 */
  1405   #endif
  1407   #ifndef EM_IA_64
  1408   #define EM_IA_64        50              /* HP/Intel IA-64 */
  1409   #endif
  1411   #ifndef EM_X86_64
  1412   #define EM_X86_64       62              /* AMD x86-64 */
  1413   #endif
  1415   static const arch_t arch_array[]={
  1416     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
  1417     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
  1418     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
  1419     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
  1420     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
  1421     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
  1422     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
  1423     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
  1424     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
  1425     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
  1426     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
  1427     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
  1428     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
  1429     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
  1430     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
  1431     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
  1432   };
  1434   #if  (defined IA32)
  1435     static  Elf32_Half running_arch_code=EM_386;
  1436   #elif   (defined AMD64)
  1437     static  Elf32_Half running_arch_code=EM_X86_64;
  1438   #elif  (defined IA64)
  1439     static  Elf32_Half running_arch_code=EM_IA_64;
  1440   #elif  (defined __sparc) && (defined _LP64)
  1441     static  Elf32_Half running_arch_code=EM_SPARCV9;
  1442   #elif  (defined __sparc) && (!defined _LP64)
  1443     static  Elf32_Half running_arch_code=EM_SPARC;
  1444   #elif  (defined __powerpc64__)
  1445     static  Elf32_Half running_arch_code=EM_PPC64;
  1446   #elif  (defined __powerpc__)
  1447     static  Elf32_Half running_arch_code=EM_PPC;
  1448   #elif  (defined ARM)
  1449     static  Elf32_Half running_arch_code=EM_ARM;
  1450   #elif  (defined S390)
  1451     static  Elf32_Half running_arch_code=EM_S390;
  1452   #elif  (defined ALPHA)
  1453     static  Elf32_Half running_arch_code=EM_ALPHA;
  1454   #elif  (defined MIPSEL)
  1455     static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
  1456   #elif  (defined PARISC)
  1457     static  Elf32_Half running_arch_code=EM_PARISC;
  1458   #elif  (defined MIPS)
  1459     static  Elf32_Half running_arch_code=EM_MIPS;
  1460   #elif  (defined M68K)
  1461     static  Elf32_Half running_arch_code=EM_68K;
  1462   #else
  1463     #error Method os::dll_load requires that one of following is defined:\
  1464          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
  1465   #endif
  1467   // Identify compatability class for VM's architecture and library's architecture
  1468   // Obtain string descriptions for architectures
  1470   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
  1471   int running_arch_index=-1;
  1473   for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
  1474     if (running_arch_code == arch_array[i].code) {
  1475       running_arch_index    = i;
  1477     if (lib_arch.code == arch_array[i].code) {
  1478       lib_arch.compat_class = arch_array[i].compat_class;
  1479       lib_arch.name         = arch_array[i].name;
  1483   assert(running_arch_index != -1,
  1484     "Didn't find running architecture code (running_arch_code) in arch_array");
  1485   if (running_arch_index == -1) {
  1486     // Even though running architecture detection failed
  1487     // we may still continue with reporting dlerror() message
  1488     return NULL;
  1491   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
  1492     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
  1493     return NULL;
  1496 #ifndef S390
  1497   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
  1498     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
  1499     return NULL;
  1501 #endif // !S390
  1503   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
  1504     if ( lib_arch.name!=NULL ) {
  1505       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
  1506         " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
  1507         lib_arch.name, arch_array[running_arch_index].name);
  1508     } else {
  1509       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
  1510       " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
  1511         lib_arch.code,
  1512         arch_array[running_arch_index].name);
  1516   return NULL;
  1518 #endif /* !__APPLE__ */
  1520 // XXX: Do we need a lock around this as per Linux?
  1521 void* os::dll_lookup(void* handle, const char* name) {
  1522   return dlsym(handle, name);
  1526 static bool _print_ascii_file(const char* filename, outputStream* st) {
  1527   int fd = ::open(filename, O_RDONLY);
  1528   if (fd == -1) {
  1529      return false;
  1532   char buf[32];
  1533   int bytes;
  1534   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
  1535     st->print_raw(buf, bytes);
  1538   ::close(fd);
  1540   return true;
  1543 void os::print_dll_info(outputStream *st) {
  1544    st->print_cr("Dynamic libraries:");
  1545 #ifdef RTLD_DI_LINKMAP
  1546     Dl_info dli;
  1547     void *handle;
  1548     Link_map *map;
  1549     Link_map *p;
  1551     if (!dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli)) {
  1552         st->print_cr("Error: Cannot print dynamic libraries.");
  1553         return;
  1555     handle = dlopen(dli.dli_fname, RTLD_LAZY);
  1556     if (handle == NULL) {
  1557         st->print_cr("Error: Cannot print dynamic libraries.");
  1558         return;
  1560     dlinfo(handle, RTLD_DI_LINKMAP, &map);
  1561     if (map == NULL) {
  1562         st->print_cr("Error: Cannot print dynamic libraries.");
  1563         return;
  1566     while (map->l_prev != NULL)
  1567         map = map->l_prev;
  1569     while (map != NULL) {
  1570         st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
  1571         map = map->l_next;
  1574     dlclose(handle);
  1575 #elif defined(__APPLE__)
  1576     uint32_t count;
  1577     uint32_t i;
  1579     count = _dyld_image_count();
  1580     for (i = 1; i < count; i++) {
  1581         const char *name = _dyld_get_image_name(i);
  1582         intptr_t slide = _dyld_get_image_vmaddr_slide(i);
  1583         st->print_cr(PTR_FORMAT " \t%s", slide, name);
  1585 #else
  1586    st->print_cr("Error: Cannot print dynamic libraries.");
  1587 #endif
  1590 void os::print_os_info_brief(outputStream* st) {
  1591   st->print("Bsd");
  1593   os::Posix::print_uname_info(st);
  1596 void os::print_os_info(outputStream* st) {
  1597   st->print("OS:");
  1598   st->print("Bsd");
  1600   os::Posix::print_uname_info(st);
  1602   os::Posix::print_rlimit_info(st);
  1604   os::Posix::print_load_average(st);
  1607 void os::pd_print_cpu_info(outputStream* st) {
  1608   // Nothing to do for now.
  1611 void os::print_memory_info(outputStream* st) {
  1613   st->print("Memory:");
  1614   st->print(" %dk page", os::vm_page_size()>>10);
  1616   st->print(", physical " UINT64_FORMAT "k",
  1617             os::physical_memory() >> 10);
  1618   st->print("(" UINT64_FORMAT "k free)",
  1619             os::available_memory() >> 10);
  1620   st->cr();
  1622   // meminfo
  1623   st->print("\n/proc/meminfo:\n");
  1624   _print_ascii_file("/proc/meminfo", st);
  1625   st->cr();
  1628 // Taken from /usr/include/bits/siginfo.h  Supposed to be architecture specific
  1629 // but they're the same for all the bsd arch that we support
  1630 // and they're the same for solaris but there's no common place to put this.
  1631 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
  1632                           "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
  1633                           "ILL_COPROC", "ILL_BADSTK" };
  1635 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
  1636                           "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
  1637                           "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
  1639 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
  1641 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
  1643 void os::print_siginfo(outputStream* st, void* siginfo) {
  1644   st->print("siginfo:");
  1646   const int buflen = 100;
  1647   char buf[buflen];
  1648   siginfo_t *si = (siginfo_t*)siginfo;
  1649   st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
  1650   if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
  1651     st->print("si_errno=%s", buf);
  1652   } else {
  1653     st->print("si_errno=%d", si->si_errno);
  1655   const int c = si->si_code;
  1656   assert(c > 0, "unexpected si_code");
  1657   switch (si->si_signo) {
  1658   case SIGILL:
  1659     st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
  1660     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1661     break;
  1662   case SIGFPE:
  1663     st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
  1664     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1665     break;
  1666   case SIGSEGV:
  1667     st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
  1668     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1669     break;
  1670   case SIGBUS:
  1671     st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
  1672     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1673     break;
  1674   default:
  1675     st->print(", si_code=%d", si->si_code);
  1676     // no si_addr
  1679   if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
  1680       UseSharedSpaces) {
  1681     FileMapInfo* mapinfo = FileMapInfo::current_info();
  1682     if (mapinfo->is_in_shared_space(si->si_addr)) {
  1683       st->print("\n\nError accessing class data sharing archive."   \
  1684                 " Mapped file inaccessible during execution, "      \
  1685                 " possible disk/network problem.");
  1688   st->cr();
  1692 static void print_signal_handler(outputStream* st, int sig,
  1693                                  char* buf, size_t buflen);
  1695 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
  1696   st->print_cr("Signal Handlers:");
  1697   print_signal_handler(st, SIGSEGV, buf, buflen);
  1698   print_signal_handler(st, SIGBUS , buf, buflen);
  1699   print_signal_handler(st, SIGFPE , buf, buflen);
  1700   print_signal_handler(st, SIGPIPE, buf, buflen);
  1701   print_signal_handler(st, SIGXFSZ, buf, buflen);
  1702   print_signal_handler(st, SIGILL , buf, buflen);
  1703   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
  1704   print_signal_handler(st, SR_signum, buf, buflen);
  1705   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
  1706   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
  1707   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
  1708   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
  1711 static char saved_jvm_path[MAXPATHLEN] = {0};
  1713 // Find the full path to the current module, libjvm
  1714 void os::jvm_path(char *buf, jint buflen) {
  1715   // Error checking.
  1716   if (buflen < MAXPATHLEN) {
  1717     assert(false, "must use a large-enough buffer");
  1718     buf[0] = '\0';
  1719     return;
  1721   // Lazy resolve the path to current module.
  1722   if (saved_jvm_path[0] != 0) {
  1723     strcpy(buf, saved_jvm_path);
  1724     return;
  1727   char dli_fname[MAXPATHLEN];
  1728   bool ret = dll_address_to_library_name(
  1729                 CAST_FROM_FN_PTR(address, os::jvm_path),
  1730                 dli_fname, sizeof(dli_fname), NULL);
  1731   assert(ret != 0, "cannot locate libjvm");
  1732   char *rp = realpath(dli_fname, buf);
  1733   if (rp == NULL)
  1734     return;
  1736   if (Arguments::created_by_gamma_launcher()) {
  1737     // Support for the gamma launcher.  Typical value for buf is
  1738     // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm".  If "/jre/lib/" appears at
  1739     // the right place in the string, then assume we are installed in a JDK and
  1740     // we're done.  Otherwise, check for a JAVA_HOME environment variable and
  1741     // construct a path to the JVM being overridden.
  1743     const char *p = buf + strlen(buf) - 1;
  1744     for (int count = 0; p > buf && count < 5; ++count) {
  1745       for (--p; p > buf && *p != '/'; --p)
  1746         /* empty */ ;
  1749     if (strncmp(p, "/jre/lib/", 9) != 0) {
  1750       // Look for JAVA_HOME in the environment.
  1751       char* java_home_var = ::getenv("JAVA_HOME");
  1752       if (java_home_var != NULL && java_home_var[0] != 0) {
  1753         char* jrelib_p;
  1754         int len;
  1756         // Check the current module name "libjvm"
  1757         p = strrchr(buf, '/');
  1758         assert(strstr(p, "/libjvm") == p, "invalid library name");
  1760         rp = realpath(java_home_var, buf);
  1761         if (rp == NULL)
  1762           return;
  1764         // determine if this is a legacy image or modules image
  1765         // modules image doesn't have "jre" subdirectory
  1766         len = strlen(buf);
  1767         jrelib_p = buf + len;
  1769         // Add the appropriate library subdir
  1770         snprintf(jrelib_p, buflen-len, "/jre/lib");
  1771         if (0 != access(buf, F_OK)) {
  1772           snprintf(jrelib_p, buflen-len, "/lib");
  1775         // Add the appropriate client or server subdir
  1776         len = strlen(buf);
  1777         jrelib_p = buf + len;
  1778         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
  1779         if (0 != access(buf, F_OK)) {
  1780           snprintf(jrelib_p, buflen-len, "");
  1783         // If the path exists within JAVA_HOME, add the JVM library name
  1784         // to complete the path to JVM being overridden.  Otherwise fallback
  1785         // to the path to the current library.
  1786         if (0 == access(buf, F_OK)) {
  1787           // Use current module name "libjvm"
  1788           len = strlen(buf);
  1789           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
  1790         } else {
  1791           // Fall back to path of current library
  1792           rp = realpath(dli_fname, buf);
  1793           if (rp == NULL)
  1794             return;
  1800   strcpy(saved_jvm_path, buf);
  1803 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
  1804   // no prefix required, not even "_"
  1807 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
  1808   // no suffix required
  1811 ////////////////////////////////////////////////////////////////////////////////
  1812 // sun.misc.Signal support
  1814 static volatile jint sigint_count = 0;
  1816 static void
  1817 UserHandler(int sig, void *siginfo, void *context) {
  1818   // 4511530 - sem_post is serialized and handled by the manager thread. When
  1819   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
  1820   // don't want to flood the manager thread with sem_post requests.
  1821   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
  1822       return;
  1824   // Ctrl-C is pressed during error reporting, likely because the error
  1825   // handler fails to abort. Let VM die immediately.
  1826   if (sig == SIGINT && is_error_reported()) {
  1827      os::die();
  1830   os::signal_notify(sig);
  1833 void* os::user_handler() {
  1834   return CAST_FROM_FN_PTR(void*, UserHandler);
  1837 extern "C" {
  1838   typedef void (*sa_handler_t)(int);
  1839   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
  1842 void* os::signal(int signal_number, void* handler) {
  1843   struct sigaction sigAct, oldSigAct;
  1845   sigfillset(&(sigAct.sa_mask));
  1846   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
  1847   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
  1849   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
  1850     // -1 means registration failed
  1851     return (void *)-1;
  1854   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
  1857 void os::signal_raise(int signal_number) {
  1858   ::raise(signal_number);
  1861 /*
  1862  * The following code is moved from os.cpp for making this
  1863  * code platform specific, which it is by its very nature.
  1864  */
  1866 // Will be modified when max signal is changed to be dynamic
  1867 int os::sigexitnum_pd() {
  1868   return NSIG;
  1871 // a counter for each possible signal value
  1872 static volatile jint pending_signals[NSIG+1] = { 0 };
  1874 // Bsd(POSIX) specific hand shaking semaphore.
  1875 #ifdef __APPLE__
  1876 static semaphore_t sig_sem;
  1877 #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
  1878 #define SEM_WAIT(sem)           semaphore_wait(sem);
  1879 #define SEM_POST(sem)           semaphore_signal(sem);
  1880 #else
  1881 static sem_t sig_sem;
  1882 #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
  1883 #define SEM_WAIT(sem)           sem_wait(&sem);
  1884 #define SEM_POST(sem)           sem_post(&sem);
  1885 #endif
  1887 void os::signal_init_pd() {
  1888   // Initialize signal structures
  1889   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
  1891   // Initialize signal semaphore
  1892   ::SEM_INIT(sig_sem, 0);
  1895 void os::signal_notify(int sig) {
  1896   Atomic::inc(&pending_signals[sig]);
  1897   ::SEM_POST(sig_sem);
  1900 static int check_pending_signals(bool wait) {
  1901   Atomic::store(0, &sigint_count);
  1902   for (;;) {
  1903     for (int i = 0; i < NSIG + 1; i++) {
  1904       jint n = pending_signals[i];
  1905       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
  1906         return i;
  1909     if (!wait) {
  1910       return -1;
  1912     JavaThread *thread = JavaThread::current();
  1913     ThreadBlockInVM tbivm(thread);
  1915     bool threadIsSuspended;
  1916     do {
  1917       thread->set_suspend_equivalent();
  1918       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
  1919       ::SEM_WAIT(sig_sem);
  1921       // were we externally suspended while we were waiting?
  1922       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
  1923       if (threadIsSuspended) {
  1924         //
  1925         // The semaphore has been incremented, but while we were waiting
  1926         // another thread suspended us. We don't want to continue running
  1927         // while suspended because that would surprise the thread that
  1928         // suspended us.
  1929         //
  1930         ::SEM_POST(sig_sem);
  1932         thread->java_suspend_self();
  1934     } while (threadIsSuspended);
  1938 int os::signal_lookup() {
  1939   return check_pending_signals(false);
  1942 int os::signal_wait() {
  1943   return check_pending_signals(true);
  1946 ////////////////////////////////////////////////////////////////////////////////
  1947 // Virtual Memory
  1949 int os::vm_page_size() {
  1950   // Seems redundant as all get out
  1951   assert(os::Bsd::page_size() != -1, "must call os::init");
  1952   return os::Bsd::page_size();
  1955 // Solaris allocates memory by pages.
  1956 int os::vm_allocation_granularity() {
  1957   assert(os::Bsd::page_size() != -1, "must call os::init");
  1958   return os::Bsd::page_size();
  1961 // Rationale behind this function:
  1962 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
  1963 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
  1964 //  samples for JITted code. Here we create private executable mapping over the code cache
  1965 //  and then we can use standard (well, almost, as mapping can change) way to provide
  1966 //  info for the reporting script by storing timestamp and location of symbol
  1967 void bsd_wrap_code(char* base, size_t size) {
  1968   static volatile jint cnt = 0;
  1970   if (!UseOprofile) {
  1971     return;
  1974   char buf[PATH_MAX + 1];
  1975   int num = Atomic::add(1, &cnt);
  1977   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
  1978            os::get_temp_directory(), os::current_process_id(), num);
  1979   unlink(buf);
  1981   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
  1983   if (fd != -1) {
  1984     off_t rv = ::lseek(fd, size-2, SEEK_SET);
  1985     if (rv != (off_t)-1) {
  1986       if (::write(fd, "", 1) == 1) {
  1987         mmap(base, size,
  1988              PROT_READ|PROT_WRITE|PROT_EXEC,
  1989              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
  1992     ::close(fd);
  1993     unlink(buf);
  1997 // NOTE: Bsd kernel does not really reserve the pages for us.
  1998 //       All it does is to check if there are enough free pages
  1999 //       left at the time of mmap(). This could be a potential
  2000 //       problem.
  2001 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
  2002   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
  2003 #ifdef __OpenBSD__
  2004   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
  2005   return ::mprotect(addr, size, prot) == 0;
  2006 #else
  2007   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
  2008                                    MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
  2009   return res != (uintptr_t) MAP_FAILED;
  2010 #endif
  2014 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
  2015                        bool exec) {
  2016   return commit_memory(addr, size, exec);
  2019 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
  2022 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
  2023   ::madvise(addr, bytes, MADV_DONTNEED);
  2026 void os::numa_make_global(char *addr, size_t bytes) {
  2029 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
  2032 bool os::numa_topology_changed()   { return false; }
  2034 size_t os::numa_get_groups_num() {
  2035   return 1;
  2038 int os::numa_get_group_id() {
  2039   return 0;
  2042 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
  2043   if (size > 0) {
  2044     ids[0] = 0;
  2045     return 1;
  2047   return 0;
  2050 bool os::get_page_info(char *start, page_info* info) {
  2051   return false;
  2054 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
  2055   return end;
  2059 bool os::pd_uncommit_memory(char* addr, size_t size) {
  2060 #ifdef __OpenBSD__
  2061   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
  2062   return ::mprotect(addr, size, PROT_NONE) == 0;
  2063 #else
  2064   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
  2065                 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
  2066   return res  != (uintptr_t) MAP_FAILED;
  2067 #endif
  2070 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
  2071   return os::commit_memory(addr, size);
  2074 // If this is a growable mapping, remove the guard pages entirely by
  2075 // munmap()ping them.  If not, just call uncommit_memory().
  2076 bool os::remove_stack_guard_pages(char* addr, size_t size) {
  2077   return os::uncommit_memory(addr, size);
  2080 static address _highest_vm_reserved_address = NULL;
  2082 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
  2083 // at 'requested_addr'. If there are existing memory mappings at the same
  2084 // location, however, they will be overwritten. If 'fixed' is false,
  2085 // 'requested_addr' is only treated as a hint, the return value may or
  2086 // may not start from the requested address. Unlike Bsd mmap(), this
  2087 // function returns NULL to indicate failure.
  2088 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
  2089   char * addr;
  2090   int flags;
  2092   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
  2093   if (fixed) {
  2094     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
  2095     flags |= MAP_FIXED;
  2098   // Map uncommitted pages PROT_READ and PROT_WRITE, change access
  2099   // to PROT_EXEC if executable when we commit the page.
  2100   addr = (char*)::mmap(requested_addr, bytes, PROT_READ|PROT_WRITE,
  2101                        flags, -1, 0);
  2103   if (addr != MAP_FAILED) {
  2104     // anon_mmap() should only get called during VM initialization,
  2105     // don't need lock (actually we can skip locking even it can be called
  2106     // from multiple threads, because _highest_vm_reserved_address is just a
  2107     // hint about the upper limit of non-stack memory regions.)
  2108     if ((address)addr + bytes > _highest_vm_reserved_address) {
  2109       _highest_vm_reserved_address = (address)addr + bytes;
  2113   return addr == MAP_FAILED ? NULL : addr;
  2116 // Don't update _highest_vm_reserved_address, because there might be memory
  2117 // regions above addr + size. If so, releasing a memory region only creates
  2118 // a hole in the address space, it doesn't help prevent heap-stack collision.
  2119 //
  2120 static int anon_munmap(char * addr, size_t size) {
  2121   return ::munmap(addr, size) == 0;
  2124 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
  2125                          size_t alignment_hint) {
  2126   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
  2129 bool os::pd_release_memory(char* addr, size_t size) {
  2130   return anon_munmap(addr, size);
  2133 static address highest_vm_reserved_address() {
  2134   return _highest_vm_reserved_address;
  2137 static bool bsd_mprotect(char* addr, size_t size, int prot) {
  2138   // Bsd wants the mprotect address argument to be page aligned.
  2139   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
  2141   // According to SUSv3, mprotect() should only be used with mappings
  2142   // established by mmap(), and mmap() always maps whole pages. Unaligned
  2143   // 'addr' likely indicates problem in the VM (e.g. trying to change
  2144   // protection of malloc'ed or statically allocated memory). Check the
  2145   // caller if you hit this assert.
  2146   assert(addr == bottom, "sanity check");
  2148   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
  2149   return ::mprotect(bottom, size, prot) == 0;
  2152 // Set protections specified
  2153 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
  2154                         bool is_committed) {
  2155   unsigned int p = 0;
  2156   switch (prot) {
  2157   case MEM_PROT_NONE: p = PROT_NONE; break;
  2158   case MEM_PROT_READ: p = PROT_READ; break;
  2159   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
  2160   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
  2161   default:
  2162     ShouldNotReachHere();
  2164   // is_committed is unused.
  2165   return bsd_mprotect(addr, bytes, p);
  2168 bool os::guard_memory(char* addr, size_t size) {
  2169   return bsd_mprotect(addr, size, PROT_NONE);
  2172 bool os::unguard_memory(char* addr, size_t size) {
  2173   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
  2176 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
  2177   return false;
  2180 /*
  2181 * Set the coredump_filter bits to include largepages in core dump (bit 6)
  2183 * From the coredump_filter documentation:
  2185 * - (bit 0) anonymous private memory
  2186 * - (bit 1) anonymous shared memory
  2187 * - (bit 2) file-backed private memory
  2188 * - (bit 3) file-backed shared memory
  2189 * - (bit 4) ELF header pages in file-backed private memory areas (it is
  2190 *           effective only if the bit 2 is cleared)
  2191 * - (bit 5) hugetlb private memory
  2192 * - (bit 6) hugetlb shared memory
  2193 */
  2194 static void set_coredump_filter(void) {
  2195   FILE *f;
  2196   long cdm;
  2198   if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
  2199     return;
  2202   if (fscanf(f, "%lx", &cdm) != 1) {
  2203     fclose(f);
  2204     return;
  2207   rewind(f);
  2209   if ((cdm & LARGEPAGES_BIT) == 0) {
  2210     cdm |= LARGEPAGES_BIT;
  2211     fprintf(f, "%#lx", cdm);
  2214   fclose(f);
  2217 // Large page support
  2219 static size_t _large_page_size = 0;
  2221 void os::large_page_init() {
  2225 char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) {
  2226   // "exec" is passed in but not used.  Creating the shared image for
  2227   // the code cache doesn't have an SHM_X executable permission to check.
  2228   assert(UseLargePages && UseSHM, "only for SHM large pages");
  2230   key_t key = IPC_PRIVATE;
  2231   char *addr;
  2233   bool warn_on_failure = UseLargePages &&
  2234                         (!FLAG_IS_DEFAULT(UseLargePages) ||
  2235                          !FLAG_IS_DEFAULT(LargePageSizeInBytes)
  2236                         );
  2237   char msg[128];
  2239   // Create a large shared memory region to attach to based on size.
  2240   // Currently, size is the total size of the heap
  2241   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
  2242   if (shmid == -1) {
  2243      // Possible reasons for shmget failure:
  2244      // 1. shmmax is too small for Java heap.
  2245      //    > check shmmax value: cat /proc/sys/kernel/shmmax
  2246      //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
  2247      // 2. not enough large page memory.
  2248      //    > check available large pages: cat /proc/meminfo
  2249      //    > increase amount of large pages:
  2250      //          echo new_value > /proc/sys/vm/nr_hugepages
  2251      //      Note 1: different Bsd may use different name for this property,
  2252      //            e.g. on Redhat AS-3 it is "hugetlb_pool".
  2253      //      Note 2: it's possible there's enough physical memory available but
  2254      //            they are so fragmented after a long run that they can't
  2255      //            coalesce into large pages. Try to reserve large pages when
  2256      //            the system is still "fresh".
  2257      if (warn_on_failure) {
  2258        jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
  2259        warning(msg);
  2261      return NULL;
  2264   // attach to the region
  2265   addr = (char*)shmat(shmid, req_addr, 0);
  2266   int err = errno;
  2268   // Remove shmid. If shmat() is successful, the actual shared memory segment
  2269   // will be deleted when it's detached by shmdt() or when the process
  2270   // terminates. If shmat() is not successful this will remove the shared
  2271   // segment immediately.
  2272   shmctl(shmid, IPC_RMID, NULL);
  2274   if ((intptr_t)addr == -1) {
  2275      if (warn_on_failure) {
  2276        jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
  2277        warning(msg);
  2279      return NULL;
  2282   // The memory is committed
  2283   address pc = CALLER_PC;
  2284   MemTracker::record_virtual_memory_reserve((address)addr, bytes, pc);
  2285   MemTracker::record_virtual_memory_commit((address)addr, bytes, pc);
  2287   return addr;
  2290 bool os::release_memory_special(char* base, size_t bytes) {
  2291   // detaching the SHM segment will also delete it, see reserve_memory_special()
  2292   int rslt = shmdt(base);
  2293   if (rslt == 0) {
  2294     MemTracker::record_virtual_memory_uncommit((address)base, bytes);
  2295     MemTracker::record_virtual_memory_release((address)base, bytes);
  2296     return true;
  2297   } else {
  2298     return false;
  2303 size_t os::large_page_size() {
  2304   return _large_page_size;
  2307 // HugeTLBFS allows application to commit large page memory on demand;
  2308 // with SysV SHM the entire memory region must be allocated as shared
  2309 // memory.
  2310 bool os::can_commit_large_page_memory() {
  2311   return UseHugeTLBFS;
  2314 bool os::can_execute_large_page_memory() {
  2315   return UseHugeTLBFS;
  2318 // Reserve memory at an arbitrary address, only if that area is
  2319 // available (and not reserved for something else).
  2321 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
  2322   const int max_tries = 10;
  2323   char* base[max_tries];
  2324   size_t size[max_tries];
  2325   const size_t gap = 0x000000;
  2327   // Assert only that the size is a multiple of the page size, since
  2328   // that's all that mmap requires, and since that's all we really know
  2329   // about at this low abstraction level.  If we need higher alignment,
  2330   // we can either pass an alignment to this method or verify alignment
  2331   // in one of the methods further up the call chain.  See bug 5044738.
  2332   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
  2334   // Repeatedly allocate blocks until the block is allocated at the
  2335   // right spot. Give up after max_tries. Note that reserve_memory() will
  2336   // automatically update _highest_vm_reserved_address if the call is
  2337   // successful. The variable tracks the highest memory address every reserved
  2338   // by JVM. It is used to detect heap-stack collision if running with
  2339   // fixed-stack BsdThreads. Because here we may attempt to reserve more
  2340   // space than needed, it could confuse the collision detecting code. To
  2341   // solve the problem, save current _highest_vm_reserved_address and
  2342   // calculate the correct value before return.
  2343   address old_highest = _highest_vm_reserved_address;
  2345   // Bsd mmap allows caller to pass an address as hint; give it a try first,
  2346   // if kernel honors the hint then we can return immediately.
  2347   char * addr = anon_mmap(requested_addr, bytes, false);
  2348   if (addr == requested_addr) {
  2349      return requested_addr;
  2352   if (addr != NULL) {
  2353      // mmap() is successful but it fails to reserve at the requested address
  2354      anon_munmap(addr, bytes);
  2357   int i;
  2358   for (i = 0; i < max_tries; ++i) {
  2359     base[i] = reserve_memory(bytes);
  2361     if (base[i] != NULL) {
  2362       // Is this the block we wanted?
  2363       if (base[i] == requested_addr) {
  2364         size[i] = bytes;
  2365         break;
  2368       // Does this overlap the block we wanted? Give back the overlapped
  2369       // parts and try again.
  2371       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
  2372       if (top_overlap >= 0 && top_overlap < bytes) {
  2373         unmap_memory(base[i], top_overlap);
  2374         base[i] += top_overlap;
  2375         size[i] = bytes - top_overlap;
  2376       } else {
  2377         size_t bottom_overlap = base[i] + bytes - requested_addr;
  2378         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
  2379           unmap_memory(requested_addr, bottom_overlap);
  2380           size[i] = bytes - bottom_overlap;
  2381         } else {
  2382           size[i] = bytes;
  2388   // Give back the unused reserved pieces.
  2390   for (int j = 0; j < i; ++j) {
  2391     if (base[j] != NULL) {
  2392       unmap_memory(base[j], size[j]);
  2396   if (i < max_tries) {
  2397     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
  2398     return requested_addr;
  2399   } else {
  2400     _highest_vm_reserved_address = old_highest;
  2401     return NULL;
  2405 size_t os::read(int fd, void *buf, unsigned int nBytes) {
  2406   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
  2409 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
  2410 // Solaris uses poll(), bsd uses park().
  2411 // Poll() is likely a better choice, assuming that Thread.interrupt()
  2412 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
  2413 // SIGSEGV, see 4355769.
  2415 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
  2416   assert(thread == Thread::current(),  "thread consistency check");
  2418   ParkEvent * const slp = thread->_SleepEvent ;
  2419   slp->reset() ;
  2420   OrderAccess::fence() ;
  2422   if (interruptible) {
  2423     jlong prevtime = javaTimeNanos();
  2425     for (;;) {
  2426       if (os::is_interrupted(thread, true)) {
  2427         return OS_INTRPT;
  2430       jlong newtime = javaTimeNanos();
  2432       if (newtime - prevtime < 0) {
  2433         // time moving backwards, should only happen if no monotonic clock
  2434         // not a guarantee() because JVM should not abort on kernel/glibc bugs
  2435         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
  2436       } else {
  2437         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
  2440       if(millis <= 0) {
  2441         return OS_OK;
  2444       prevtime = newtime;
  2447         assert(thread->is_Java_thread(), "sanity check");
  2448         JavaThread *jt = (JavaThread *) thread;
  2449         ThreadBlockInVM tbivm(jt);
  2450         OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
  2452         jt->set_suspend_equivalent();
  2453         // cleared by handle_special_suspend_equivalent_condition() or
  2454         // java_suspend_self() via check_and_wait_while_suspended()
  2456         slp->park(millis);
  2458         // were we externally suspended while we were waiting?
  2459         jt->check_and_wait_while_suspended();
  2462   } else {
  2463     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
  2464     jlong prevtime = javaTimeNanos();
  2466     for (;;) {
  2467       // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
  2468       // the 1st iteration ...
  2469       jlong newtime = javaTimeNanos();
  2471       if (newtime - prevtime < 0) {
  2472         // time moving backwards, should only happen if no monotonic clock
  2473         // not a guarantee() because JVM should not abort on kernel/glibc bugs
  2474         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
  2475       } else {
  2476         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
  2479       if(millis <= 0) break ;
  2481       prevtime = newtime;
  2482       slp->park(millis);
  2484     return OS_OK ;
  2488 int os::naked_sleep() {
  2489   // %% make the sleep time an integer flag. for now use 1 millisec.
  2490   return os::sleep(Thread::current(), 1, false);
  2493 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
  2494 void os::infinite_sleep() {
  2495   while (true) {    // sleep forever ...
  2496     ::sleep(100);   // ... 100 seconds at a time
  2500 // Used to convert frequent JVM_Yield() to nops
  2501 bool os::dont_yield() {
  2502   return DontYieldALot;
  2505 void os::yield() {
  2506   sched_yield();
  2509 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
  2511 void os::yield_all(int attempts) {
  2512   // Yields to all threads, including threads with lower priorities
  2513   // Threads on Bsd are all with same priority. The Solaris style
  2514   // os::yield_all() with nanosleep(1ms) is not necessary.
  2515   sched_yield();
  2518 // Called from the tight loops to possibly influence time-sharing heuristics
  2519 void os::loop_breaker(int attempts) {
  2520   os::yield_all(attempts);
  2523 ////////////////////////////////////////////////////////////////////////////////
  2524 // thread priority support
  2526 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
  2527 // only supports dynamic priority, static priority must be zero. For real-time
  2528 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
  2529 // However, for large multi-threaded applications, SCHED_RR is not only slower
  2530 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
  2531 // of 5 runs - Sep 2005).
  2532 //
  2533 // The following code actually changes the niceness of kernel-thread/LWP. It
  2534 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
  2535 // not the entire user process, and user level threads are 1:1 mapped to kernel
  2536 // threads. It has always been the case, but could change in the future. For
  2537 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
  2538 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
  2540 #if !defined(__APPLE__)
  2541 int os::java_to_os_priority[CriticalPriority + 1] = {
  2542   19,              // 0 Entry should never be used
  2544    0,              // 1 MinPriority
  2545    3,              // 2
  2546    6,              // 3
  2548   10,              // 4
  2549   15,              // 5 NormPriority
  2550   18,              // 6
  2552   21,              // 7
  2553   25,              // 8
  2554   28,              // 9 NearMaxPriority
  2556   31,              // 10 MaxPriority
  2558   31               // 11 CriticalPriority
  2559 };
  2560 #else
  2561 /* Using Mach high-level priority assignments */
  2562 int os::java_to_os_priority[CriticalPriority + 1] = {
  2563    0,              // 0 Entry should never be used (MINPRI_USER)
  2565   27,              // 1 MinPriority
  2566   28,              // 2
  2567   29,              // 3
  2569   30,              // 4
  2570   31,              // 5 NormPriority (BASEPRI_DEFAULT)
  2571   32,              // 6
  2573   33,              // 7
  2574   34,              // 8
  2575   35,              // 9 NearMaxPriority
  2577   36,              // 10 MaxPriority
  2579   36               // 11 CriticalPriority
  2580 };
  2581 #endif
  2583 static int prio_init() {
  2584   if (ThreadPriorityPolicy == 1) {
  2585     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
  2586     // if effective uid is not root. Perhaps, a more elegant way of doing
  2587     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
  2588     if (geteuid() != 0) {
  2589       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
  2590         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
  2592       ThreadPriorityPolicy = 0;
  2595   if (UseCriticalJavaThreadPriority) {
  2596     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
  2598   return 0;
  2601 OSReturn os::set_native_priority(Thread* thread, int newpri) {
  2602   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
  2604 #ifdef __OpenBSD__
  2605   // OpenBSD pthread_setprio starves low priority threads
  2606   return OS_OK;
  2607 #elif defined(__FreeBSD__)
  2608   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
  2609 #elif defined(__APPLE__) || defined(__NetBSD__)
  2610   struct sched_param sp;
  2611   int policy;
  2612   pthread_t self = pthread_self();
  2614   if (pthread_getschedparam(self, &policy, &sp) != 0)
  2615     return OS_ERR;
  2617   sp.sched_priority = newpri;
  2618   if (pthread_setschedparam(self, policy, &sp) != 0)
  2619     return OS_ERR;
  2621   return OS_OK;
  2622 #else
  2623   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
  2624   return (ret == 0) ? OS_OK : OS_ERR;
  2625 #endif
  2628 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
  2629   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
  2630     *priority_ptr = java_to_os_priority[NormPriority];
  2631     return OS_OK;
  2634   errno = 0;
  2635 #if defined(__OpenBSD__) || defined(__FreeBSD__)
  2636   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
  2637 #elif defined(__APPLE__) || defined(__NetBSD__)
  2638   int policy;
  2639   struct sched_param sp;
  2641   pthread_getschedparam(pthread_self(), &policy, &sp);
  2642   *priority_ptr = sp.sched_priority;
  2643 #else
  2644   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
  2645 #endif
  2646   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
  2649 // Hint to the underlying OS that a task switch would not be good.
  2650 // Void return because it's a hint and can fail.
  2651 void os::hint_no_preempt() {}
  2653 ////////////////////////////////////////////////////////////////////////////////
  2654 // suspend/resume support
  2656 //  the low-level signal-based suspend/resume support is a remnant from the
  2657 //  old VM-suspension that used to be for java-suspension, safepoints etc,
  2658 //  within hotspot. Now there is a single use-case for this:
  2659 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
  2660 //      that runs in the watcher thread.
  2661 //  The remaining code is greatly simplified from the more general suspension
  2662 //  code that used to be used.
  2663 //
  2664 //  The protocol is quite simple:
  2665 //  - suspend:
  2666 //      - sends a signal to the target thread
  2667 //      - polls the suspend state of the osthread using a yield loop
  2668 //      - target thread signal handler (SR_handler) sets suspend state
  2669 //        and blocks in sigsuspend until continued
  2670 //  - resume:
  2671 //      - sets target osthread state to continue
  2672 //      - sends signal to end the sigsuspend loop in the SR_handler
  2673 //
  2674 //  Note that the SR_lock plays no role in this suspend/resume protocol.
  2675 //
  2677 static void resume_clear_context(OSThread *osthread) {
  2678   osthread->set_ucontext(NULL);
  2679   osthread->set_siginfo(NULL);
  2681   // notify the suspend action is completed, we have now resumed
  2682   osthread->sr.clear_suspended();
  2685 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
  2686   osthread->set_ucontext(context);
  2687   osthread->set_siginfo(siginfo);
  2690 //
  2691 // Handler function invoked when a thread's execution is suspended or
  2692 // resumed. We have to be careful that only async-safe functions are
  2693 // called here (Note: most pthread functions are not async safe and
  2694 // should be avoided.)
  2695 //
  2696 // Note: sigwait() is a more natural fit than sigsuspend() from an
  2697 // interface point of view, but sigwait() prevents the signal hander
  2698 // from being run. libpthread would get very confused by not having
  2699 // its signal handlers run and prevents sigwait()'s use with the
  2700 // mutex granting granting signal.
  2701 //
  2702 // Currently only ever called on the VMThread
  2703 //
  2704 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
  2705   // Save and restore errno to avoid confusing native code with EINTR
  2706   // after sigsuspend.
  2707   int old_errno = errno;
  2709   Thread* thread = Thread::current();
  2710   OSThread* osthread = thread->osthread();
  2711   assert(thread->is_VM_thread(), "Must be VMThread");
  2712   // read current suspend action
  2713   int action = osthread->sr.suspend_action();
  2714   if (action == os::Bsd::SuspendResume::SR_SUSPEND) {
  2715     suspend_save_context(osthread, siginfo, context);
  2717     // Notify the suspend action is about to be completed. do_suspend()
  2718     // waits until SR_SUSPENDED is set and then returns. We will wait
  2719     // here for a resume signal and that completes the suspend-other
  2720     // action. do_suspend/do_resume is always called as a pair from
  2721     // the same thread - so there are no races
  2723     // notify the caller
  2724     osthread->sr.set_suspended();
  2726     sigset_t suspend_set;  // signals for sigsuspend()
  2728     // get current set of blocked signals and unblock resume signal
  2729     pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
  2730     sigdelset(&suspend_set, SR_signum);
  2732     // wait here until we are resumed
  2733     do {
  2734       sigsuspend(&suspend_set);
  2735       // ignore all returns until we get a resume signal
  2736     } while (osthread->sr.suspend_action() != os::Bsd::SuspendResume::SR_CONTINUE);
  2738     resume_clear_context(osthread);
  2740   } else {
  2741     assert(action == os::Bsd::SuspendResume::SR_CONTINUE, "unexpected sr action");
  2742     // nothing special to do - just leave the handler
  2745   errno = old_errno;
  2749 static int SR_initialize() {
  2750   struct sigaction act;
  2751   char *s;
  2752   /* Get signal number to use for suspend/resume */
  2753   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
  2754     int sig = ::strtol(s, 0, 10);
  2755     if (sig > 0 || sig < NSIG) {
  2756         SR_signum = sig;
  2760   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
  2761         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
  2763   sigemptyset(&SR_sigset);
  2764   sigaddset(&SR_sigset, SR_signum);
  2766   /* Set up signal handler for suspend/resume */
  2767   act.sa_flags = SA_RESTART|SA_SIGINFO;
  2768   act.sa_handler = (void (*)(int)) SR_handler;
  2770   // SR_signum is blocked by default.
  2771   // 4528190 - We also need to block pthread restart signal (32 on all
  2772   // supported Bsd platforms). Note that BsdThreads need to block
  2773   // this signal for all threads to work properly. So we don't have
  2774   // to use hard-coded signal number when setting up the mask.
  2775   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
  2777   if (sigaction(SR_signum, &act, 0) == -1) {
  2778     return -1;
  2781   // Save signal flag
  2782   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
  2783   return 0;
  2786 static int SR_finalize() {
  2787   return 0;
  2791 // returns true on success and false on error - really an error is fatal
  2792 // but this seems the normal response to library errors
  2793 static bool do_suspend(OSThread* osthread) {
  2794   // mark as suspended and send signal
  2795   osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_SUSPEND);
  2796   int status = pthread_kill(osthread->pthread_id(), SR_signum);
  2797   assert_status(status == 0, status, "pthread_kill");
  2799   // check status and wait until notified of suspension
  2800   if (status == 0) {
  2801     for (int i = 0; !osthread->sr.is_suspended(); i++) {
  2802       os::yield_all(i);
  2804     osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
  2805     return true;
  2807   else {
  2808     osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
  2809     return false;
  2813 static void do_resume(OSThread* osthread) {
  2814   assert(osthread->sr.is_suspended(), "thread should be suspended");
  2815   osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_CONTINUE);
  2817   int status = pthread_kill(osthread->pthread_id(), SR_signum);
  2818   assert_status(status == 0, status, "pthread_kill");
  2819   // check status and wait unit notified of resumption
  2820   if (status == 0) {
  2821     for (int i = 0; osthread->sr.is_suspended(); i++) {
  2822       os::yield_all(i);
  2825   osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
  2828 ////////////////////////////////////////////////////////////////////////////////
  2829 // interrupt support
  2831 void os::interrupt(Thread* thread) {
  2832   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
  2833     "possibility of dangling Thread pointer");
  2835   OSThread* osthread = thread->osthread();
  2837   if (!osthread->interrupted()) {
  2838     osthread->set_interrupted(true);
  2839     // More than one thread can get here with the same value of osthread,
  2840     // resulting in multiple notifications.  We do, however, want the store
  2841     // to interrupted() to be visible to other threads before we execute unpark().
  2842     OrderAccess::fence();
  2843     ParkEvent * const slp = thread->_SleepEvent ;
  2844     if (slp != NULL) slp->unpark() ;
  2847   // For JSR166. Unpark even if interrupt status already was set
  2848   if (thread->is_Java_thread())
  2849     ((JavaThread*)thread)->parker()->unpark();
  2851   ParkEvent * ev = thread->_ParkEvent ;
  2852   if (ev != NULL) ev->unpark() ;
  2856 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
  2857   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
  2858     "possibility of dangling Thread pointer");
  2860   OSThread* osthread = thread->osthread();
  2862   bool interrupted = osthread->interrupted();
  2864   if (interrupted && clear_interrupted) {
  2865     osthread->set_interrupted(false);
  2866     // consider thread->_SleepEvent->reset() ... optional optimization
  2869   return interrupted;
  2872 ///////////////////////////////////////////////////////////////////////////////////
  2873 // signal handling (except suspend/resume)
  2875 // This routine may be used by user applications as a "hook" to catch signals.
  2876 // The user-defined signal handler must pass unrecognized signals to this
  2877 // routine, and if it returns true (non-zero), then the signal handler must
  2878 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
  2879 // routine will never retun false (zero), but instead will execute a VM panic
  2880 // routine kill the process.
  2881 //
  2882 // If this routine returns false, it is OK to call it again.  This allows
  2883 // the user-defined signal handler to perform checks either before or after
  2884 // the VM performs its own checks.  Naturally, the user code would be making
  2885 // a serious error if it tried to handle an exception (such as a null check
  2886 // or breakpoint) that the VM was generating for its own correct operation.
  2887 //
  2888 // This routine may recognize any of the following kinds of signals:
  2889 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
  2890 // It should be consulted by handlers for any of those signals.
  2891 //
  2892 // The caller of this routine must pass in the three arguments supplied
  2893 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
  2894 // field of the structure passed to sigaction().  This routine assumes that
  2895 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
  2896 //
  2897 // Note that the VM will print warnings if it detects conflicting signal
  2898 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
  2899 //
  2900 extern "C" JNIEXPORT int
  2901 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
  2902                         void* ucontext, int abort_if_unrecognized);
  2904 void signalHandler(int sig, siginfo_t* info, void* uc) {
  2905   assert(info != NULL && uc != NULL, "it must be old kernel");
  2906   int orig_errno = errno;  // Preserve errno value over signal handler.
  2907   JVM_handle_bsd_signal(sig, info, uc, true);
  2908   errno = orig_errno;
  2912 // This boolean allows users to forward their own non-matching signals
  2913 // to JVM_handle_bsd_signal, harmlessly.
  2914 bool os::Bsd::signal_handlers_are_installed = false;
  2916 // For signal-chaining
  2917 struct sigaction os::Bsd::sigact[MAXSIGNUM];
  2918 unsigned int os::Bsd::sigs = 0;
  2919 bool os::Bsd::libjsig_is_loaded = false;
  2920 typedef struct sigaction *(*get_signal_t)(int);
  2921 get_signal_t os::Bsd::get_signal_action = NULL;
  2923 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
  2924   struct sigaction *actp = NULL;
  2926   if (libjsig_is_loaded) {
  2927     // Retrieve the old signal handler from libjsig
  2928     actp = (*get_signal_action)(sig);
  2930   if (actp == NULL) {
  2931     // Retrieve the preinstalled signal handler from jvm
  2932     actp = get_preinstalled_handler(sig);
  2935   return actp;
  2938 static bool call_chained_handler(struct sigaction *actp, int sig,
  2939                                  siginfo_t *siginfo, void *context) {
  2940   // Call the old signal handler
  2941   if (actp->sa_handler == SIG_DFL) {
  2942     // It's more reasonable to let jvm treat it as an unexpected exception
  2943     // instead of taking the default action.
  2944     return false;
  2945   } else if (actp->sa_handler != SIG_IGN) {
  2946     if ((actp->sa_flags & SA_NODEFER) == 0) {
  2947       // automaticlly block the signal
  2948       sigaddset(&(actp->sa_mask), sig);
  2951     sa_handler_t hand;
  2952     sa_sigaction_t sa;
  2953     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
  2954     // retrieve the chained handler
  2955     if (siginfo_flag_set) {
  2956       sa = actp->sa_sigaction;
  2957     } else {
  2958       hand = actp->sa_handler;
  2961     if ((actp->sa_flags & SA_RESETHAND) != 0) {
  2962       actp->sa_handler = SIG_DFL;
  2965     // try to honor the signal mask
  2966     sigset_t oset;
  2967     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
  2969     // call into the chained handler
  2970     if (siginfo_flag_set) {
  2971       (*sa)(sig, siginfo, context);
  2972     } else {
  2973       (*hand)(sig);
  2976     // restore the signal mask
  2977     pthread_sigmask(SIG_SETMASK, &oset, 0);
  2979   // Tell jvm's signal handler the signal is taken care of.
  2980   return true;
  2983 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
  2984   bool chained = false;
  2985   // signal-chaining
  2986   if (UseSignalChaining) {
  2987     struct sigaction *actp = get_chained_signal_action(sig);
  2988     if (actp != NULL) {
  2989       chained = call_chained_handler(actp, sig, siginfo, context);
  2992   return chained;
  2995 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
  2996   if ((( (unsigned int)1 << sig ) & sigs) != 0) {
  2997     return &sigact[sig];
  2999   return NULL;
  3002 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
  3003   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3004   sigact[sig] = oldAct;
  3005   sigs |= (unsigned int)1 << sig;
  3008 // for diagnostic
  3009 int os::Bsd::sigflags[MAXSIGNUM];
  3011 int os::Bsd::get_our_sigflags(int sig) {
  3012   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3013   return sigflags[sig];
  3016 void os::Bsd::set_our_sigflags(int sig, int flags) {
  3017   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3018   sigflags[sig] = flags;
  3021 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
  3022   // Check for overwrite.
  3023   struct sigaction oldAct;
  3024   sigaction(sig, (struct sigaction*)NULL, &oldAct);
  3026   void* oldhand = oldAct.sa_sigaction
  3027                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
  3028                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
  3029   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
  3030       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
  3031       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
  3032     if (AllowUserSignalHandlers || !set_installed) {
  3033       // Do not overwrite; user takes responsibility to forward to us.
  3034       return;
  3035     } else if (UseSignalChaining) {
  3036       // save the old handler in jvm
  3037       save_preinstalled_handler(sig, oldAct);
  3038       // libjsig also interposes the sigaction() call below and saves the
  3039       // old sigaction on it own.
  3040     } else {
  3041       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
  3042                     "%#lx for signal %d.", (long)oldhand, sig));
  3046   struct sigaction sigAct;
  3047   sigfillset(&(sigAct.sa_mask));
  3048   sigAct.sa_handler = SIG_DFL;
  3049   if (!set_installed) {
  3050     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  3051   } else {
  3052     sigAct.sa_sigaction = signalHandler;
  3053     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  3055   // Save flags, which are set by ours
  3056   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3057   sigflags[sig] = sigAct.sa_flags;
  3059   int ret = sigaction(sig, &sigAct, &oldAct);
  3060   assert(ret == 0, "check");
  3062   void* oldhand2  = oldAct.sa_sigaction
  3063                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
  3064                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
  3065   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
  3068 // install signal handlers for signals that HotSpot needs to
  3069 // handle in order to support Java-level exception handling.
  3071 void os::Bsd::install_signal_handlers() {
  3072   if (!signal_handlers_are_installed) {
  3073     signal_handlers_are_installed = true;
  3075     // signal-chaining
  3076     typedef void (*signal_setting_t)();
  3077     signal_setting_t begin_signal_setting = NULL;
  3078     signal_setting_t end_signal_setting = NULL;
  3079     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
  3080                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
  3081     if (begin_signal_setting != NULL) {
  3082       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
  3083                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
  3084       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
  3085                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
  3086       libjsig_is_loaded = true;
  3087       assert(UseSignalChaining, "should enable signal-chaining");
  3089     if (libjsig_is_loaded) {
  3090       // Tell libjsig jvm is setting signal handlers
  3091       (*begin_signal_setting)();
  3094     set_signal_handler(SIGSEGV, true);
  3095     set_signal_handler(SIGPIPE, true);
  3096     set_signal_handler(SIGBUS, true);
  3097     set_signal_handler(SIGILL, true);
  3098     set_signal_handler(SIGFPE, true);
  3099     set_signal_handler(SIGXFSZ, true);
  3101 #if defined(__APPLE__)
  3102     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
  3103     // signals caught and handled by the JVM. To work around this, we reset the mach task
  3104     // signal handler that's placed on our process by CrashReporter. This disables
  3105     // CrashReporter-based reporting.
  3106     //
  3107     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
  3108     // on caught fatal signals.
  3109     //
  3110     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
  3111     // handlers. By replacing the existing task exception handler, we disable gdb's mach
  3112     // exception handling, while leaving the standard BSD signal handlers functional.
  3113     kern_return_t kr;
  3114     kr = task_set_exception_ports(mach_task_self(),
  3115         EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
  3116         MACH_PORT_NULL,
  3117         EXCEPTION_STATE_IDENTITY,
  3118         MACHINE_THREAD_STATE);
  3120     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
  3121 #endif
  3123     if (libjsig_is_loaded) {
  3124       // Tell libjsig jvm finishes setting signal handlers
  3125       (*end_signal_setting)();
  3128     // We don't activate signal checker if libjsig is in place, we trust ourselves
  3129     // and if UserSignalHandler is installed all bets are off
  3130     if (CheckJNICalls) {
  3131       if (libjsig_is_loaded) {
  3132         tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
  3133         check_signals = false;
  3135       if (AllowUserSignalHandlers) {
  3136         tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
  3137         check_signals = false;
  3144 /////
  3145 // glibc on Bsd platform uses non-documented flag
  3146 // to indicate, that some special sort of signal
  3147 // trampoline is used.
  3148 // We will never set this flag, and we should
  3149 // ignore this flag in our diagnostic
  3150 #ifdef SIGNIFICANT_SIGNAL_MASK
  3151 #undef SIGNIFICANT_SIGNAL_MASK
  3152 #endif
  3153 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
  3155 static const char* get_signal_handler_name(address handler,
  3156                                            char* buf, int buflen) {
  3157   int offset;
  3158   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
  3159   if (found) {
  3160     // skip directory names
  3161     const char *p1, *p2;
  3162     p1 = buf;
  3163     size_t len = strlen(os::file_separator());
  3164     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
  3165     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
  3166   } else {
  3167     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
  3169   return buf;
  3172 static void print_signal_handler(outputStream* st, int sig,
  3173                                  char* buf, size_t buflen) {
  3174   struct sigaction sa;
  3176   sigaction(sig, NULL, &sa);
  3178   // See comment for SIGNIFICANT_SIGNAL_MASK define
  3179   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
  3181   st->print("%s: ", os::exception_name(sig, buf, buflen));
  3183   address handler = (sa.sa_flags & SA_SIGINFO)
  3184     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
  3185     : CAST_FROM_FN_PTR(address, sa.sa_handler);
  3187   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
  3188     st->print("SIG_DFL");
  3189   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
  3190     st->print("SIG_IGN");
  3191   } else {
  3192     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
  3195   st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask);
  3197   address rh = VMError::get_resetted_sighandler(sig);
  3198   // May be, handler was resetted by VMError?
  3199   if(rh != NULL) {
  3200     handler = rh;
  3201     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
  3204   st->print(", sa_flags="   PTR32_FORMAT, sa.sa_flags);
  3206   // Check: is it our handler?
  3207   if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
  3208      handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
  3209     // It is our signal handler
  3210     // check for flags, reset system-used one!
  3211     if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
  3212       st->print(
  3213                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
  3214                 os::Bsd::get_our_sigflags(sig));
  3217   st->cr();
  3221 #define DO_SIGNAL_CHECK(sig) \
  3222   if (!sigismember(&check_signal_done, sig)) \
  3223     os::Bsd::check_signal_handler(sig)
  3225 // This method is a periodic task to check for misbehaving JNI applications
  3226 // under CheckJNI, we can add any periodic checks here
  3228 void os::run_periodic_checks() {
  3230   if (check_signals == false) return;
  3232   // SEGV and BUS if overridden could potentially prevent
  3233   // generation of hs*.log in the event of a crash, debugging
  3234   // such a case can be very challenging, so we absolutely
  3235   // check the following for a good measure:
  3236   DO_SIGNAL_CHECK(SIGSEGV);
  3237   DO_SIGNAL_CHECK(SIGILL);
  3238   DO_SIGNAL_CHECK(SIGFPE);
  3239   DO_SIGNAL_CHECK(SIGBUS);
  3240   DO_SIGNAL_CHECK(SIGPIPE);
  3241   DO_SIGNAL_CHECK(SIGXFSZ);
  3244   // ReduceSignalUsage allows the user to override these handlers
  3245   // see comments at the very top and jvm_solaris.h
  3246   if (!ReduceSignalUsage) {
  3247     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
  3248     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
  3249     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
  3250     DO_SIGNAL_CHECK(BREAK_SIGNAL);
  3253   DO_SIGNAL_CHECK(SR_signum);
  3254   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
  3257 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
  3259 static os_sigaction_t os_sigaction = NULL;
  3261 void os::Bsd::check_signal_handler(int sig) {
  3262   char buf[O_BUFLEN];
  3263   address jvmHandler = NULL;
  3266   struct sigaction act;
  3267   if (os_sigaction == NULL) {
  3268     // only trust the default sigaction, in case it has been interposed
  3269     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
  3270     if (os_sigaction == NULL) return;
  3273   os_sigaction(sig, (struct sigaction*)NULL, &act);
  3276   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
  3278   address thisHandler = (act.sa_flags & SA_SIGINFO)
  3279     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
  3280     : CAST_FROM_FN_PTR(address, act.sa_handler) ;
  3283   switch(sig) {
  3284   case SIGSEGV:
  3285   case SIGBUS:
  3286   case SIGFPE:
  3287   case SIGPIPE:
  3288   case SIGILL:
  3289   case SIGXFSZ:
  3290     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
  3291     break;
  3293   case SHUTDOWN1_SIGNAL:
  3294   case SHUTDOWN2_SIGNAL:
  3295   case SHUTDOWN3_SIGNAL:
  3296   case BREAK_SIGNAL:
  3297     jvmHandler = (address)user_handler();
  3298     break;
  3300   case INTERRUPT_SIGNAL:
  3301     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
  3302     break;
  3304   default:
  3305     if (sig == SR_signum) {
  3306       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
  3307     } else {
  3308       return;
  3310     break;
  3313   if (thisHandler != jvmHandler) {
  3314     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
  3315     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
  3316     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
  3317     // No need to check this sig any longer
  3318     sigaddset(&check_signal_done, sig);
  3319   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
  3320     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
  3321     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
  3322     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
  3323     // No need to check this sig any longer
  3324     sigaddset(&check_signal_done, sig);
  3327   // Dump all the signal
  3328   if (sigismember(&check_signal_done, sig)) {
  3329     print_signal_handlers(tty, buf, O_BUFLEN);
  3333 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
  3335 extern bool signal_name(int signo, char* buf, size_t len);
  3337 const char* os::exception_name(int exception_code, char* buf, size_t size) {
  3338   if (0 < exception_code && exception_code <= SIGRTMAX) {
  3339     // signal
  3340     if (!signal_name(exception_code, buf, size)) {
  3341       jio_snprintf(buf, size, "SIG%d", exception_code);
  3343     return buf;
  3344   } else {
  3345     return NULL;
  3349 // this is called _before_ the most of global arguments have been parsed
  3350 void os::init(void) {
  3351   char dummy;   /* used to get a guess on initial stack address */
  3352 //  first_hrtime = gethrtime();
  3354   // With BsdThreads the JavaMain thread pid (primordial thread)
  3355   // is different than the pid of the java launcher thread.
  3356   // So, on Bsd, the launcher thread pid is passed to the VM
  3357   // via the sun.java.launcher.pid property.
  3358   // Use this property instead of getpid() if it was correctly passed.
  3359   // See bug 6351349.
  3360   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
  3362   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
  3364   clock_tics_per_sec = CLK_TCK;
  3366   init_random(1234567);
  3368   ThreadCritical::initialize();
  3370   Bsd::set_page_size(getpagesize());
  3371   if (Bsd::page_size() == -1) {
  3372     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
  3373                   strerror(errno)));
  3375   init_page_sizes((size_t) Bsd::page_size());
  3377   Bsd::initialize_system_info();
  3379   // main_thread points to the aboriginal thread
  3380   Bsd::_main_thread = pthread_self();
  3382   Bsd::clock_init();
  3383   initial_time_count = os::elapsed_counter();
  3385 #ifdef __APPLE__
  3386   // XXXDARWIN
  3387   // Work around the unaligned VM callbacks in hotspot's
  3388   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
  3389   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
  3390   // alignment when doing symbol lookup. To work around this, we force early
  3391   // binding of all symbols now, thus binding when alignment is known-good.
  3392   _dyld_bind_fully_image_containing_address((const void *) &os::init);
  3393 #endif
  3396 // To install functions for atexit system call
  3397 extern "C" {
  3398   static void perfMemory_exit_helper() {
  3399     perfMemory_exit();
  3403 // this is called _after_ the global arguments have been parsed
  3404 jint os::init_2(void)
  3406   // Allocate a single page and mark it as readable for safepoint polling
  3407   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  3408   guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
  3410   os::set_polling_page( polling_page );
  3412 #ifndef PRODUCT
  3413   if(Verbose && PrintMiscellaneous)
  3414     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
  3415 #endif
  3417   if (!UseMembar) {
  3418     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  3419     guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page");
  3420     os::set_memory_serialize_page( mem_serialize_page );
  3422 #ifndef PRODUCT
  3423     if(Verbose && PrintMiscellaneous)
  3424       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
  3425 #endif
  3428   os::large_page_init();
  3430   // initialize suspend/resume support - must do this before signal_sets_init()
  3431   if (SR_initialize() != 0) {
  3432     perror("SR_initialize failed");
  3433     return JNI_ERR;
  3436   Bsd::signal_sets_init();
  3437   Bsd::install_signal_handlers();
  3439   // Check minimum allowable stack size for thread creation and to initialize
  3440   // the java system classes, including StackOverflowError - depends on page
  3441   // size.  Add a page for compiler2 recursion in main thread.
  3442   // Add in 2*BytesPerWord times page size to account for VM stack during
  3443   // class initialization depending on 32 or 64 bit VM.
  3444   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
  3445             (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
  3446                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
  3448   size_t threadStackSizeInBytes = ThreadStackSize * K;
  3449   if (threadStackSizeInBytes != 0 &&
  3450       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
  3451         tty->print_cr("\nThe stack size specified is too small, "
  3452                       "Specify at least %dk",
  3453                       os::Bsd::min_stack_allowed/ K);
  3454         return JNI_ERR;
  3457   // Make the stack size a multiple of the page size so that
  3458   // the yellow/red zones can be guarded.
  3459   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
  3460         vm_page_size()));
  3462   if (MaxFDLimit) {
  3463     // set the number of file descriptors to max. print out error
  3464     // if getrlimit/setrlimit fails but continue regardless.
  3465     struct rlimit nbr_files;
  3466     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
  3467     if (status != 0) {
  3468       if (PrintMiscellaneous && (Verbose || WizardMode))
  3469         perror("os::init_2 getrlimit failed");
  3470     } else {
  3471       nbr_files.rlim_cur = nbr_files.rlim_max;
  3473 #ifdef __APPLE__
  3474       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
  3475       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
  3476       // be used instead
  3477       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
  3478 #endif
  3480       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
  3481       if (status != 0) {
  3482         if (PrintMiscellaneous && (Verbose || WizardMode))
  3483           perror("os::init_2 setrlimit failed");
  3488   // at-exit methods are called in the reverse order of their registration.
  3489   // atexit functions are called on return from main or as a result of a
  3490   // call to exit(3C). There can be only 32 of these functions registered
  3491   // and atexit() does not set errno.
  3493   if (PerfAllowAtExitRegistration) {
  3494     // only register atexit functions if PerfAllowAtExitRegistration is set.
  3495     // atexit functions can be delayed until process exit time, which
  3496     // can be problematic for embedded VM situations. Embedded VMs should
  3497     // call DestroyJavaVM() to assure that VM resources are released.
  3499     // note: perfMemory_exit_helper atexit function may be removed in
  3500     // the future if the appropriate cleanup code can be added to the
  3501     // VM_Exit VMOperation's doit method.
  3502     if (atexit(perfMemory_exit_helper) != 0) {
  3503       warning("os::init2 atexit(perfMemory_exit_helper) failed");
  3507   // initialize thread priority policy
  3508   prio_init();
  3510 #ifdef __APPLE__
  3511   // dynamically link to objective c gc registration
  3512   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
  3513   if (handleLibObjc != NULL) {
  3514     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
  3516 #endif
  3518   return JNI_OK;
  3521 // this is called at the end of vm_initialization
  3522 void os::init_3(void) { }
  3524 // Mark the polling page as unreadable
  3525 void os::make_polling_page_unreadable(void) {
  3526   if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
  3527     fatal("Could not disable polling page");
  3528 };
  3530 // Mark the polling page as readable
  3531 void os::make_polling_page_readable(void) {
  3532   if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
  3533     fatal("Could not enable polling page");
  3535 };
  3537 int os::active_processor_count() {
  3538   return _processor_count;
  3541 void os::set_native_thread_name(const char *name) {
  3542 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
  3543   // This is only supported in Snow Leopard and beyond
  3544   if (name != NULL) {
  3545     // Add a "Java: " prefix to the name
  3546     char buf[MAXTHREADNAMESIZE];
  3547     snprintf(buf, sizeof(buf), "Java: %s", name);
  3548     pthread_setname_np(buf);
  3550 #endif
  3553 bool os::distribute_processes(uint length, uint* distribution) {
  3554   // Not yet implemented.
  3555   return false;
  3558 bool os::bind_to_processor(uint processor_id) {
  3559   // Not yet implemented.
  3560   return false;
  3563 ///
  3565 // Suspends the target using the signal mechanism and then grabs the PC before
  3566 // resuming the target. Used by the flat-profiler only
  3567 ExtendedPC os::get_thread_pc(Thread* thread) {
  3568   // Make sure that it is called by the watcher for the VMThread
  3569   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
  3570   assert(thread->is_VM_thread(), "Can only be called for VMThread");
  3572   ExtendedPC epc;
  3574   OSThread* osthread = thread->osthread();
  3575   if (do_suspend(osthread)) {
  3576     if (osthread->ucontext() != NULL) {
  3577       epc = os::Bsd::ucontext_get_pc(osthread->ucontext());
  3578     } else {
  3579       // NULL context is unexpected, double-check this is the VMThread
  3580       guarantee(thread->is_VM_thread(), "can only be called for VMThread");
  3582     do_resume(osthread);
  3584   // failure means pthread_kill failed for some reason - arguably this is
  3585   // a fatal problem, but such problems are ignored elsewhere
  3587   return epc;
  3590 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
  3592   return pthread_cond_timedwait(_cond, _mutex, _abstime);
  3595 ////////////////////////////////////////////////////////////////////////////////
  3596 // debug support
  3598 static address same_page(address x, address y) {
  3599   int page_bits = -os::vm_page_size();
  3600   if ((intptr_t(x) & page_bits) == (intptr_t(y) & page_bits))
  3601     return x;
  3602   else if (x > y)
  3603     return (address)(intptr_t(y) | ~page_bits) + 1;
  3604   else
  3605     return (address)(intptr_t(y) & page_bits);
  3608 bool os::find(address addr, outputStream* st) {
  3609   Dl_info dlinfo;
  3610   memset(&dlinfo, 0, sizeof(dlinfo));
  3611   if (dladdr(addr, &dlinfo)) {
  3612     st->print(PTR_FORMAT ": ", addr);
  3613     if (dlinfo.dli_sname != NULL) {
  3614       st->print("%s+%#x", dlinfo.dli_sname,
  3615                  addr - (intptr_t)dlinfo.dli_saddr);
  3616     } else if (dlinfo.dli_fname) {
  3617       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
  3618     } else {
  3619       st->print("<absolute address>");
  3621     if (dlinfo.dli_fname) {
  3622       st->print(" in %s", dlinfo.dli_fname);
  3624     if (dlinfo.dli_fbase) {
  3625       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
  3627     st->cr();
  3629     if (Verbose) {
  3630       // decode some bytes around the PC
  3631       address begin = same_page(addr-40, addr);
  3632       address end   = same_page(addr+40, addr);
  3633       address       lowest = (address) dlinfo.dli_sname;
  3634       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
  3635       if (begin < lowest)  begin = lowest;
  3636       Dl_info dlinfo2;
  3637       if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr
  3638           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
  3639         end = (address) dlinfo2.dli_saddr;
  3640       Disassembler::decode(begin, end, st);
  3642     return true;
  3644   return false;
  3647 ////////////////////////////////////////////////////////////////////////////////
  3648 // misc
  3650 // This does not do anything on Bsd. This is basically a hook for being
  3651 // able to use structured exception handling (thread-local exception filters)
  3652 // on, e.g., Win32.
  3653 void
  3654 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
  3655                          JavaCallArguments* args, Thread* thread) {
  3656   f(value, method, args, thread);
  3659 void os::print_statistics() {
  3662 int os::message_box(const char* title, const char* message) {
  3663   int i;
  3664   fdStream err(defaultStream::error_fd());
  3665   for (i = 0; i < 78; i++) err.print_raw("=");
  3666   err.cr();
  3667   err.print_raw_cr(title);
  3668   for (i = 0; i < 78; i++) err.print_raw("-");
  3669   err.cr();
  3670   err.print_raw_cr(message);
  3671   for (i = 0; i < 78; i++) err.print_raw("=");
  3672   err.cr();
  3674   char buf[16];
  3675   // Prevent process from exiting upon "read error" without consuming all CPU
  3676   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
  3678   return buf[0] == 'y' || buf[0] == 'Y';
  3681 int os::stat(const char *path, struct stat *sbuf) {
  3682   char pathbuf[MAX_PATH];
  3683   if (strlen(path) > MAX_PATH - 1) {
  3684     errno = ENAMETOOLONG;
  3685     return -1;
  3687   os::native_path(strcpy(pathbuf, path));
  3688   return ::stat(pathbuf, sbuf);
  3691 bool os::check_heap(bool force) {
  3692   return true;
  3695 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
  3696   return ::vsnprintf(buf, count, format, args);
  3699 // Is a (classpath) directory empty?
  3700 bool os::dir_is_empty(const char* path) {
  3701   DIR *dir = NULL;
  3702   struct dirent *ptr;
  3704   dir = opendir(path);
  3705   if (dir == NULL) return true;
  3707   /* Scan the directory */
  3708   bool result = true;
  3709   char buf[sizeof(struct dirent) + MAX_PATH];
  3710   while (result && (ptr = ::readdir(dir)) != NULL) {
  3711     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
  3712       result = false;
  3715   closedir(dir);
  3716   return result;
  3719 // This code originates from JDK's sysOpen and open64_w
  3720 // from src/solaris/hpi/src/system_md.c
  3722 #ifndef O_DELETE
  3723 #define O_DELETE 0x10000
  3724 #endif
  3726 // Open a file. Unlink the file immediately after open returns
  3727 // if the specified oflag has the O_DELETE flag set.
  3728 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
  3730 int os::open(const char *path, int oflag, int mode) {
  3732   if (strlen(path) > MAX_PATH - 1) {
  3733     errno = ENAMETOOLONG;
  3734     return -1;
  3736   int fd;
  3737   int o_delete = (oflag & O_DELETE);
  3738   oflag = oflag & ~O_DELETE;
  3740   fd = ::open(path, oflag, mode);
  3741   if (fd == -1) return -1;
  3743   //If the open succeeded, the file might still be a directory
  3745     struct stat buf;
  3746     int ret = ::fstat(fd, &buf);
  3747     int st_mode = buf.st_mode;
  3749     if (ret != -1) {
  3750       if ((st_mode & S_IFMT) == S_IFDIR) {
  3751         errno = EISDIR;
  3752         ::close(fd);
  3753         return -1;
  3755     } else {
  3756       ::close(fd);
  3757       return -1;
  3761     /*
  3762      * All file descriptors that are opened in the JVM and not
  3763      * specifically destined for a subprocess should have the
  3764      * close-on-exec flag set.  If we don't set it, then careless 3rd
  3765      * party native code might fork and exec without closing all
  3766      * appropriate file descriptors (e.g. as we do in closeDescriptors in
  3767      * UNIXProcess.c), and this in turn might:
  3769      * - cause end-of-file to fail to be detected on some file
  3770      *   descriptors, resulting in mysterious hangs, or
  3772      * - might cause an fopen in the subprocess to fail on a system
  3773      *   suffering from bug 1085341.
  3775      * (Yes, the default setting of the close-on-exec flag is a Unix
  3776      * design flaw)
  3778      * See:
  3779      * 1085341: 32-bit stdio routines should support file descriptors >255
  3780      * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
  3781      * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
  3782      */
  3783 #ifdef FD_CLOEXEC
  3785         int flags = ::fcntl(fd, F_GETFD);
  3786         if (flags != -1)
  3787             ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
  3789 #endif
  3791   if (o_delete != 0) {
  3792     ::unlink(path);
  3794   return fd;
  3798 // create binary file, rewriting existing file if required
  3799 int os::create_binary_file(const char* path, bool rewrite_existing) {
  3800   int oflags = O_WRONLY | O_CREAT;
  3801   if (!rewrite_existing) {
  3802     oflags |= O_EXCL;
  3804   return ::open(path, oflags, S_IREAD | S_IWRITE);
  3807 // return current position of file pointer
  3808 jlong os::current_file_offset(int fd) {
  3809   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
  3812 // move file pointer to the specified offset
  3813 jlong os::seek_to_file_offset(int fd, jlong offset) {
  3814   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
  3817 // This code originates from JDK's sysAvailable
  3818 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
  3820 int os::available(int fd, jlong *bytes) {
  3821   jlong cur, end;
  3822   int mode;
  3823   struct stat buf;
  3825   if (::fstat(fd, &buf) >= 0) {
  3826     mode = buf.st_mode;
  3827     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
  3828       /*
  3829       * XXX: is the following call interruptible? If so, this might
  3830       * need to go through the INTERRUPT_IO() wrapper as for other
  3831       * blocking, interruptible calls in this file.
  3832       */
  3833       int n;
  3834       if (::ioctl(fd, FIONREAD, &n) >= 0) {
  3835         *bytes = n;
  3836         return 1;
  3840   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
  3841     return 0;
  3842   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
  3843     return 0;
  3844   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
  3845     return 0;
  3847   *bytes = end - cur;
  3848   return 1;
  3851 int os::socket_available(int fd, jint *pbytes) {
  3852    if (fd < 0)
  3853      return OS_OK;
  3855    int ret;
  3857    RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
  3859    //%% note ioctl can return 0 when successful, JVM_SocketAvailable
  3860    // is expected to return 0 on failure and 1 on success to the jdk.
  3862    return (ret == OS_ERR) ? 0 : 1;
  3865 // Map a block of memory.
  3866 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
  3867                      char *addr, size_t bytes, bool read_only,
  3868                      bool allow_exec) {
  3869   int prot;
  3870   int flags;
  3872   if (read_only) {
  3873     prot = PROT_READ;
  3874     flags = MAP_SHARED;
  3875   } else {
  3876     prot = PROT_READ | PROT_WRITE;
  3877     flags = MAP_PRIVATE;
  3880   if (allow_exec) {
  3881     prot |= PROT_EXEC;
  3884   if (addr != NULL) {
  3885     flags |= MAP_FIXED;
  3888   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
  3889                                      fd, file_offset);
  3890   if (mapped_address == MAP_FAILED) {
  3891     return NULL;
  3893   return mapped_address;
  3897 // Remap a block of memory.
  3898 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
  3899                        char *addr, size_t bytes, bool read_only,
  3900                        bool allow_exec) {
  3901   // same as map_memory() on this OS
  3902   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
  3903                         allow_exec);
  3907 // Unmap a block of memory.
  3908 bool os::pd_unmap_memory(char* addr, size_t bytes) {
  3909   return munmap(addr, bytes) == 0;
  3912 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
  3913 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
  3914 // of a thread.
  3915 //
  3916 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
  3917 // the fast estimate available on the platform.
  3919 jlong os::current_thread_cpu_time() {
  3920 #ifdef __APPLE__
  3921   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
  3922 #else
  3923   Unimplemented();
  3924   return 0;
  3925 #endif
  3928 jlong os::thread_cpu_time(Thread* thread) {
  3929 #ifdef __APPLE__
  3930   return os::thread_cpu_time(thread, true /* user + sys */);
  3931 #else
  3932   Unimplemented();
  3933   return 0;
  3934 #endif
  3937 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
  3938 #ifdef __APPLE__
  3939   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
  3940 #else
  3941   Unimplemented();
  3942   return 0;
  3943 #endif
  3946 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
  3947 #ifdef __APPLE__
  3948   struct thread_basic_info tinfo;
  3949   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
  3950   kern_return_t kr;
  3951   thread_t mach_thread;
  3953   mach_thread = thread->osthread()->thread_id();
  3954   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
  3955   if (kr != KERN_SUCCESS)
  3956     return -1;
  3958   if (user_sys_cpu_time) {
  3959     jlong nanos;
  3960     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
  3961     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
  3962     return nanos;
  3963   } else {
  3964     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
  3966 #else
  3967   Unimplemented();
  3968   return 0;
  3969 #endif
  3973 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
  3974   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
  3975   info_ptr->may_skip_backward = false;     // elapsed time not wall time
  3976   info_ptr->may_skip_forward = false;      // elapsed time not wall time
  3977   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
  3980 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
  3981   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
  3982   info_ptr->may_skip_backward = false;     // elapsed time not wall time
  3983   info_ptr->may_skip_forward = false;      // elapsed time not wall time
  3984   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
  3987 bool os::is_thread_cpu_time_supported() {
  3988 #ifdef __APPLE__
  3989   return true;
  3990 #else
  3991   return false;
  3992 #endif
  3995 // System loadavg support.  Returns -1 if load average cannot be obtained.
  3996 // Bsd doesn't yet have a (official) notion of processor sets,
  3997 // so just return the system wide load average.
  3998 int os::loadavg(double loadavg[], int nelem) {
  3999   return ::getloadavg(loadavg, nelem);
  4002 void os::pause() {
  4003   char filename[MAX_PATH];
  4004   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
  4005     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
  4006   } else {
  4007     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
  4010   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
  4011   if (fd != -1) {
  4012     struct stat buf;
  4013     ::close(fd);
  4014     while (::stat(filename, &buf) == 0) {
  4015       (void)::poll(NULL, 0, 100);
  4017   } else {
  4018     jio_fprintf(stderr,
  4019       "Could not open pause file '%s', continuing immediately.\n", filename);
  4024 // Refer to the comments in os_solaris.cpp park-unpark.
  4025 //
  4026 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
  4027 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
  4028 // For specifics regarding the bug see GLIBC BUGID 261237 :
  4029 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
  4030 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
  4031 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
  4032 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
  4033 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
  4034 // and monitorenter when we're using 1-0 locking.  All those operations may result in
  4035 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
  4036 // of libpthread avoids the problem, but isn't practical.
  4037 //
  4038 // Possible remedies:
  4039 //
  4040 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
  4041 //      This is palliative and probabilistic, however.  If the thread is preempted
  4042 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
  4043 //      than the minimum period may have passed, and the abstime may be stale (in the
  4044 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
  4045 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
  4046 //
  4047 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
  4048 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
  4049 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
  4050 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
  4051 //      thread.
  4052 //
  4053 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
  4054 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
  4055 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
  4056 //      This also works well.  In fact it avoids kernel-level scalability impediments
  4057 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
  4058 //      timers in a graceful fashion.
  4059 //
  4060 // 4.   When the abstime value is in the past it appears that control returns
  4061 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
  4062 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
  4063 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
  4064 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
  4065 //      It may be possible to avoid reinitialization by checking the return
  4066 //      value from pthread_cond_timedwait().  In addition to reinitializing the
  4067 //      condvar we must establish the invariant that cond_signal() is only called
  4068 //      within critical sections protected by the adjunct mutex.  This prevents
  4069 //      cond_signal() from "seeing" a condvar that's in the midst of being
  4070 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
  4071 //      desirable signal-after-unlock optimization that avoids futile context switching.
  4072 //
  4073 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
  4074 //      structure when a condvar is used or initialized.  cond_destroy()  would
  4075 //      release the helper structure.  Our reinitialize-after-timedwait fix
  4076 //      put excessive stress on malloc/free and locks protecting the c-heap.
  4077 //
  4078 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
  4079 // It may be possible to refine (4) by checking the kernel and NTPL verisons
  4080 // and only enabling the work-around for vulnerable environments.
  4082 // utility to compute the abstime argument to timedwait:
  4083 // millis is the relative timeout time
  4084 // abstime will be the absolute timeout time
  4085 // TODO: replace compute_abstime() with unpackTime()
  4087 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
  4088   if (millis < 0)  millis = 0;
  4089   struct timeval now;
  4090   int status = gettimeofday(&now, NULL);
  4091   assert(status == 0, "gettimeofday");
  4092   jlong seconds = millis / 1000;
  4093   millis %= 1000;
  4094   if (seconds > 50000000) { // see man cond_timedwait(3T)
  4095     seconds = 50000000;
  4097   abstime->tv_sec = now.tv_sec  + seconds;
  4098   long       usec = now.tv_usec + millis * 1000;
  4099   if (usec >= 1000000) {
  4100     abstime->tv_sec += 1;
  4101     usec -= 1000000;
  4103   abstime->tv_nsec = usec * 1000;
  4104   return abstime;
  4108 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
  4109 // Conceptually TryPark() should be equivalent to park(0).
  4111 int os::PlatformEvent::TryPark() {
  4112   for (;;) {
  4113     const int v = _Event ;
  4114     guarantee ((v == 0) || (v == 1), "invariant") ;
  4115     if (Atomic::cmpxchg (0, &_Event, v) == v) return v  ;
  4119 void os::PlatformEvent::park() {       // AKA "down()"
  4120   // Invariant: Only the thread associated with the Event/PlatformEvent
  4121   // may call park().
  4122   // TODO: assert that _Assoc != NULL or _Assoc == Self
  4123   int v ;
  4124   for (;;) {
  4125       v = _Event ;
  4126       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
  4128   guarantee (v >= 0, "invariant") ;
  4129   if (v == 0) {
  4130      // Do this the hard way by blocking ...
  4131      int status = pthread_mutex_lock(_mutex);
  4132      assert_status(status == 0, status, "mutex_lock");
  4133      guarantee (_nParked == 0, "invariant") ;
  4134      ++ _nParked ;
  4135      while (_Event < 0) {
  4136         status = pthread_cond_wait(_cond, _mutex);
  4137         // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
  4138         // Treat this the same as if the wait was interrupted
  4139         if (status == ETIMEDOUT) { status = EINTR; }
  4140         assert_status(status == 0 || status == EINTR, status, "cond_wait");
  4142      -- _nParked ;
  4144     _Event = 0 ;
  4145      status = pthread_mutex_unlock(_mutex);
  4146      assert_status(status == 0, status, "mutex_unlock");
  4147     // Paranoia to ensure our locked and lock-free paths interact
  4148     // correctly with each other.
  4149     OrderAccess::fence();
  4151   guarantee (_Event >= 0, "invariant") ;
  4154 int os::PlatformEvent::park(jlong millis) {
  4155   guarantee (_nParked == 0, "invariant") ;
  4157   int v ;
  4158   for (;;) {
  4159       v = _Event ;
  4160       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
  4162   guarantee (v >= 0, "invariant") ;
  4163   if (v != 0) return OS_OK ;
  4165   // We do this the hard way, by blocking the thread.
  4166   // Consider enforcing a minimum timeout value.
  4167   struct timespec abst;
  4168   compute_abstime(&abst, millis);
  4170   int ret = OS_TIMEOUT;
  4171   int status = pthread_mutex_lock(_mutex);
  4172   assert_status(status == 0, status, "mutex_lock");
  4173   guarantee (_nParked == 0, "invariant") ;
  4174   ++_nParked ;
  4176   // Object.wait(timo) will return because of
  4177   // (a) notification
  4178   // (b) timeout
  4179   // (c) thread.interrupt
  4180   //
  4181   // Thread.interrupt and object.notify{All} both call Event::set.
  4182   // That is, we treat thread.interrupt as a special case of notification.
  4183   // The underlying Solaris implementation, cond_timedwait, admits
  4184   // spurious/premature wakeups, but the JLS/JVM spec prevents the
  4185   // JVM from making those visible to Java code.  As such, we must
  4186   // filter out spurious wakeups.  We assume all ETIME returns are valid.
  4187   //
  4188   // TODO: properly differentiate simultaneous notify+interrupt.
  4189   // In that case, we should propagate the notify to another waiter.
  4191   while (_Event < 0) {
  4192     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
  4193     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
  4194       pthread_cond_destroy (_cond);
  4195       pthread_cond_init (_cond, NULL) ;
  4197     assert_status(status == 0 || status == EINTR ||
  4198                   status == ETIMEDOUT,
  4199                   status, "cond_timedwait");
  4200     if (!FilterSpuriousWakeups) break ;                 // previous semantics
  4201     if (status == ETIMEDOUT) break ;
  4202     // We consume and ignore EINTR and spurious wakeups.
  4204   --_nParked ;
  4205   if (_Event >= 0) {
  4206      ret = OS_OK;
  4208   _Event = 0 ;
  4209   status = pthread_mutex_unlock(_mutex);
  4210   assert_status(status == 0, status, "mutex_unlock");
  4211   assert (_nParked == 0, "invariant") ;
  4212   // Paranoia to ensure our locked and lock-free paths interact
  4213   // correctly with each other.
  4214   OrderAccess::fence();
  4215   return ret;
  4218 void os::PlatformEvent::unpark() {
  4219   // Transitions for _Event:
  4220   //    0 :=> 1
  4221   //    1 :=> 1
  4222   //   -1 :=> either 0 or 1; must signal target thread
  4223   //          That is, we can safely transition _Event from -1 to either
  4224   //          0 or 1. Forcing 1 is slightly more efficient for back-to-back
  4225   //          unpark() calls.
  4226   // See also: "Semaphores in Plan 9" by Mullender & Cox
  4227   //
  4228   // Note: Forcing a transition from "-1" to "1" on an unpark() means
  4229   // that it will take two back-to-back park() calls for the owning
  4230   // thread to block. This has the benefit of forcing a spurious return
  4231   // from the first park() call after an unpark() call which will help
  4232   // shake out uses of park() and unpark() without condition variables.
  4234   if (Atomic::xchg(1, &_Event) >= 0) return;
  4236   // Wait for the thread associated with the event to vacate
  4237   int status = pthread_mutex_lock(_mutex);
  4238   assert_status(status == 0, status, "mutex_lock");
  4239   int AnyWaiters = _nParked;
  4240   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
  4241   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
  4242     AnyWaiters = 0;
  4243     pthread_cond_signal(_cond);
  4245   status = pthread_mutex_unlock(_mutex);
  4246   assert_status(status == 0, status, "mutex_unlock");
  4247   if (AnyWaiters != 0) {
  4248     status = pthread_cond_signal(_cond);
  4249     assert_status(status == 0, status, "cond_signal");
  4252   // Note that we signal() _after dropping the lock for "immortal" Events.
  4253   // This is safe and avoids a common class of  futile wakeups.  In rare
  4254   // circumstances this can cause a thread to return prematurely from
  4255   // cond_{timed}wait() but the spurious wakeup is benign and the victim will
  4256   // simply re-test the condition and re-park itself.
  4260 // JSR166
  4261 // -------------------------------------------------------
  4263 /*
  4264  * The solaris and bsd implementations of park/unpark are fairly
  4265  * conservative for now, but can be improved. They currently use a
  4266  * mutex/condvar pair, plus a a count.
  4267  * Park decrements count if > 0, else does a condvar wait.  Unpark
  4268  * sets count to 1 and signals condvar.  Only one thread ever waits
  4269  * on the condvar. Contention seen when trying to park implies that someone
  4270  * is unparking you, so don't wait. And spurious returns are fine, so there
  4271  * is no need to track notifications.
  4272  */
  4274 #define MAX_SECS 100000000
  4275 /*
  4276  * This code is common to bsd and solaris and will be moved to a
  4277  * common place in dolphin.
  4279  * The passed in time value is either a relative time in nanoseconds
  4280  * or an absolute time in milliseconds. Either way it has to be unpacked
  4281  * into suitable seconds and nanoseconds components and stored in the
  4282  * given timespec structure.
  4283  * Given time is a 64-bit value and the time_t used in the timespec is only
  4284  * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
  4285  * overflow if times way in the future are given. Further on Solaris versions
  4286  * prior to 10 there is a restriction (see cond_timedwait) that the specified
  4287  * number of seconds, in abstime, is less than current_time  + 100,000,000.
  4288  * As it will be 28 years before "now + 100000000" will overflow we can
  4289  * ignore overflow and just impose a hard-limit on seconds using the value
  4290  * of "now + 100,000,000". This places a limit on the timeout of about 3.17
  4291  * years from "now".
  4292  */
  4294 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
  4295   assert (time > 0, "convertTime");
  4297   struct timeval now;
  4298   int status = gettimeofday(&now, NULL);
  4299   assert(status == 0, "gettimeofday");
  4301   time_t max_secs = now.tv_sec + MAX_SECS;
  4303   if (isAbsolute) {
  4304     jlong secs = time / 1000;
  4305     if (secs > max_secs) {
  4306       absTime->tv_sec = max_secs;
  4308     else {
  4309       absTime->tv_sec = secs;
  4311     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
  4313   else {
  4314     jlong secs = time / NANOSECS_PER_SEC;
  4315     if (secs >= MAX_SECS) {
  4316       absTime->tv_sec = max_secs;
  4317       absTime->tv_nsec = 0;
  4319     else {
  4320       absTime->tv_sec = now.tv_sec + secs;
  4321       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
  4322       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
  4323         absTime->tv_nsec -= NANOSECS_PER_SEC;
  4324         ++absTime->tv_sec; // note: this must be <= max_secs
  4328   assert(absTime->tv_sec >= 0, "tv_sec < 0");
  4329   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
  4330   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
  4331   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
  4334 void Parker::park(bool isAbsolute, jlong time) {
  4335   // Ideally we'd do something useful while spinning, such
  4336   // as calling unpackTime().
  4338   // Optional fast-path check:
  4339   // Return immediately if a permit is available.
  4340   // We depend on Atomic::xchg() having full barrier semantics
  4341   // since we are doing a lock-free update to _counter.
  4342   if (Atomic::xchg(0, &_counter) > 0) return;
  4344   Thread* thread = Thread::current();
  4345   assert(thread->is_Java_thread(), "Must be JavaThread");
  4346   JavaThread *jt = (JavaThread *)thread;
  4348   // Optional optimization -- avoid state transitions if there's an interrupt pending.
  4349   // Check interrupt before trying to wait
  4350   if (Thread::is_interrupted(thread, false)) {
  4351     return;
  4354   // Next, demultiplex/decode time arguments
  4355   struct timespec absTime;
  4356   if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
  4357     return;
  4359   if (time > 0) {
  4360     unpackTime(&absTime, isAbsolute, time);
  4364   // Enter safepoint region
  4365   // Beware of deadlocks such as 6317397.
  4366   // The per-thread Parker:: mutex is a classic leaf-lock.
  4367   // In particular a thread must never block on the Threads_lock while
  4368   // holding the Parker:: mutex.  If safepoints are pending both the
  4369   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
  4370   ThreadBlockInVM tbivm(jt);
  4372   // Don't wait if cannot get lock since interference arises from
  4373   // unblocking.  Also. check interrupt before trying wait
  4374   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
  4375     return;
  4378   int status ;
  4379   if (_counter > 0)  { // no wait needed
  4380     _counter = 0;
  4381     status = pthread_mutex_unlock(_mutex);
  4382     assert (status == 0, "invariant") ;
  4383     // Paranoia to ensure our locked and lock-free paths interact
  4384     // correctly with each other and Java-level accesses.
  4385     OrderAccess::fence();
  4386     return;
  4389 #ifdef ASSERT
  4390   // Don't catch signals while blocked; let the running threads have the signals.
  4391   // (This allows a debugger to break into the running thread.)
  4392   sigset_t oldsigs;
  4393   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
  4394   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
  4395 #endif
  4397   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
  4398   jt->set_suspend_equivalent();
  4399   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
  4401   if (time == 0) {
  4402     status = pthread_cond_wait (_cond, _mutex) ;
  4403   } else {
  4404     status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
  4405     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
  4406       pthread_cond_destroy (_cond) ;
  4407       pthread_cond_init    (_cond, NULL);
  4410   assert_status(status == 0 || status == EINTR ||
  4411                 status == ETIMEDOUT,
  4412                 status, "cond_timedwait");
  4414 #ifdef ASSERT
  4415   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
  4416 #endif
  4418   _counter = 0 ;
  4419   status = pthread_mutex_unlock(_mutex) ;
  4420   assert_status(status == 0, status, "invariant") ;
  4421   // Paranoia to ensure our locked and lock-free paths interact
  4422   // correctly with each other and Java-level accesses.
  4423   OrderAccess::fence();
  4425   // If externally suspended while waiting, re-suspend
  4426   if (jt->handle_special_suspend_equivalent_condition()) {
  4427     jt->java_suspend_self();
  4431 void Parker::unpark() {
  4432   int s, status ;
  4433   status = pthread_mutex_lock(_mutex);
  4434   assert (status == 0, "invariant") ;
  4435   s = _counter;
  4436   _counter = 1;
  4437   if (s < 1) {
  4438      if (WorkAroundNPTLTimedWaitHang) {
  4439         status = pthread_cond_signal (_cond) ;
  4440         assert (status == 0, "invariant") ;
  4441         status = pthread_mutex_unlock(_mutex);
  4442         assert (status == 0, "invariant") ;
  4443      } else {
  4444         status = pthread_mutex_unlock(_mutex);
  4445         assert (status == 0, "invariant") ;
  4446         status = pthread_cond_signal (_cond) ;
  4447         assert (status == 0, "invariant") ;
  4449   } else {
  4450     pthread_mutex_unlock(_mutex);
  4451     assert (status == 0, "invariant") ;
  4456 /* Darwin has no "environ" in a dynamic library. */
  4457 #ifdef __APPLE__
  4458 #include <crt_externs.h>
  4459 #define environ (*_NSGetEnviron())
  4460 #else
  4461 extern char** environ;
  4462 #endif
  4464 // Run the specified command in a separate process. Return its exit value,
  4465 // or -1 on failure (e.g. can't fork a new process).
  4466 // Unlike system(), this function can be called from signal handler. It
  4467 // doesn't block SIGINT et al.
  4468 int os::fork_and_exec(char* cmd) {
  4469   const char * argv[4] = {"sh", "-c", cmd, NULL};
  4471   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
  4472   // pthread_atfork handlers and reset pthread library. All we need is a
  4473   // separate process to execve. Make a direct syscall to fork process.
  4474   // On IA64 there's no fork syscall, we have to use fork() and hope for
  4475   // the best...
  4476   pid_t pid = fork();
  4478   if (pid < 0) {
  4479     // fork failed
  4480     return -1;
  4482   } else if (pid == 0) {
  4483     // child process
  4485     // execve() in BsdThreads will call pthread_kill_other_threads_np()
  4486     // first to kill every thread on the thread list. Because this list is
  4487     // not reset by fork() (see notes above), execve() will instead kill
  4488     // every thread in the parent process. We know this is the only thread
  4489     // in the new process, so make a system call directly.
  4490     // IA64 should use normal execve() from glibc to match the glibc fork()
  4491     // above.
  4492     execve("/bin/sh", (char* const*)argv, environ);
  4494     // execve failed
  4495     _exit(-1);
  4497   } else  {
  4498     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
  4499     // care about the actual exit code, for now.
  4501     int status;
  4503     // Wait for the child process to exit.  This returns immediately if
  4504     // the child has already exited. */
  4505     while (waitpid(pid, &status, 0) < 0) {
  4506         switch (errno) {
  4507         case ECHILD: return 0;
  4508         case EINTR: break;
  4509         default: return -1;
  4513     if (WIFEXITED(status)) {
  4514        // The child exited normally; get its exit code.
  4515        return WEXITSTATUS(status);
  4516     } else if (WIFSIGNALED(status)) {
  4517        // The child exited because of a signal
  4518        // The best value to return is 0x80 + signal number,
  4519        // because that is what all Unix shells do, and because
  4520        // it allows callers to distinguish between process exit and
  4521        // process death by signal.
  4522        return 0x80 + WTERMSIG(status);
  4523     } else {
  4524        // Unknown exit code; pass it through
  4525        return status;
  4530 // is_headless_jre()
  4531 //
  4532 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
  4533 // in order to report if we are running in a headless jre
  4534 //
  4535 // Since JDK8 xawt/libmawt.so was moved into the same directory
  4536 // as libawt.so, and renamed libawt_xawt.so
  4537 //
  4538 bool os::is_headless_jre() {
  4539     struct stat statbuf;
  4540     char buf[MAXPATHLEN];
  4541     char libmawtpath[MAXPATHLEN];
  4542     const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
  4543     const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
  4544     char *p;
  4546     // Get path to libjvm.so
  4547     os::jvm_path(buf, sizeof(buf));
  4549     // Get rid of libjvm.so
  4550     p = strrchr(buf, '/');
  4551     if (p == NULL) return false;
  4552     else *p = '\0';
  4554     // Get rid of client or server
  4555     p = strrchr(buf, '/');
  4556     if (p == NULL) return false;
  4557     else *p = '\0';
  4559     // check xawt/libmawt.so
  4560     strcpy(libmawtpath, buf);
  4561     strcat(libmawtpath, xawtstr);
  4562     if (::stat(libmawtpath, &statbuf) == 0) return false;
  4564     // check libawt_xawt.so
  4565     strcpy(libmawtpath, buf);
  4566     strcat(libmawtpath, new_xawtstr);
  4567     if (::stat(libmawtpath, &statbuf) == 0) return false;
  4569     return true;
  4572 // Get the default path to the core file
  4573 // Returns the length of the string
  4574 int os::get_core_path(char* buffer, size_t bufferSize) {
  4575   int n = jio_snprintf(buffer, bufferSize, "/cores");
  4577   // Truncate if theoretical string was longer than bufferSize
  4578   n = MIN2(n, (int)bufferSize);
  4580   return n;

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