src/os/bsd/vm/os_bsd.cpp

Thu, 23 Jan 2014 09:06:21 +0100

author
sla
date
Thu, 23 Jan 2014 09:06:21 +0100
changeset 6326
d1621038becf
parent 6054
3b32d287da89
child 6348
0e6af9b390af
child 6513
bbfbe9b06038
permissions
-rw-r--r--

8031968: Mac OS X: VM starts the agent by calling both Agent_OnAttach and Agent_OnAttach_L functions if its agent library is dynamically linked.
Summary: Make sure we only look for statically linked agents in the main process image
Reviewed-by: dsamersoff, bpittore, dcubed

     1 /*
     2  * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 // no precompiled headers
    26 #include "classfile/classLoader.hpp"
    27 #include "classfile/systemDictionary.hpp"
    28 #include "classfile/vmSymbols.hpp"
    29 #include "code/icBuffer.hpp"
    30 #include "code/vtableStubs.hpp"
    31 #include "compiler/compileBroker.hpp"
    32 #include "compiler/disassembler.hpp"
    33 #include "interpreter/interpreter.hpp"
    34 #include "jvm_bsd.h"
    35 #include "memory/allocation.inline.hpp"
    36 #include "memory/filemap.hpp"
    37 #include "mutex_bsd.inline.hpp"
    38 #include "oops/oop.inline.hpp"
    39 #include "os_share_bsd.hpp"
    40 #include "prims/jniFastGetField.hpp"
    41 #include "prims/jvm.h"
    42 #include "prims/jvm_misc.hpp"
    43 #include "runtime/arguments.hpp"
    44 #include "runtime/extendedPC.hpp"
    45 #include "runtime/globals.hpp"
    46 #include "runtime/interfaceSupport.hpp"
    47 #include "runtime/java.hpp"
    48 #include "runtime/javaCalls.hpp"
    49 #include "runtime/mutexLocker.hpp"
    50 #include "runtime/objectMonitor.hpp"
    51 #include "runtime/osThread.hpp"
    52 #include "runtime/perfMemory.hpp"
    53 #include "runtime/sharedRuntime.hpp"
    54 #include "runtime/statSampler.hpp"
    55 #include "runtime/stubRoutines.hpp"
    56 #include "runtime/thread.inline.hpp"
    57 #include "runtime/threadCritical.hpp"
    58 #include "runtime/timer.hpp"
    59 #include "services/attachListener.hpp"
    60 #include "services/memTracker.hpp"
    61 #include "services/runtimeService.hpp"
    62 #include "utilities/decoder.hpp"
    63 #include "utilities/defaultStream.hpp"
    64 #include "utilities/events.hpp"
    65 #include "utilities/growableArray.hpp"
    66 #include "utilities/vmError.hpp"
    68 // put OS-includes here
    69 # include <sys/types.h>
    70 # include <sys/mman.h>
    71 # include <sys/stat.h>
    72 # include <sys/select.h>
    73 # include <pthread.h>
    74 # include <signal.h>
    75 # include <errno.h>
    76 # include <dlfcn.h>
    77 # include <stdio.h>
    78 # include <unistd.h>
    79 # include <sys/resource.h>
    80 # include <pthread.h>
    81 # include <sys/stat.h>
    82 # include <sys/time.h>
    83 # include <sys/times.h>
    84 # include <sys/utsname.h>
    85 # include <sys/socket.h>
    86 # include <sys/wait.h>
    87 # include <time.h>
    88 # include <pwd.h>
    89 # include <poll.h>
    90 # include <semaphore.h>
    91 # include <fcntl.h>
    92 # include <string.h>
    93 # include <sys/param.h>
    94 # include <sys/sysctl.h>
    95 # include <sys/ipc.h>
    96 # include <sys/shm.h>
    97 #ifndef __APPLE__
    98 # include <link.h>
    99 #endif
   100 # include <stdint.h>
   101 # include <inttypes.h>
   102 # include <sys/ioctl.h>
   103 # include <sys/syscall.h>
   105 #if defined(__FreeBSD__) || defined(__NetBSD__)
   106 # include <elf.h>
   107 #endif
   109 #ifdef __APPLE__
   110 # include <mach/mach.h> // semaphore_* API
   111 # include <mach-o/dyld.h>
   112 # include <sys/proc_info.h>
   113 # include <objc/objc-auto.h>
   114 #endif
   116 #ifndef MAP_ANONYMOUS
   117 #define MAP_ANONYMOUS MAP_ANON
   118 #endif
   120 #define MAX_PATH    (2 * K)
   122 // for timer info max values which include all bits
   123 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
   125 #define LARGEPAGES_BIT (1 << 6)
   126 ////////////////////////////////////////////////////////////////////////////////
   127 // global variables
   128 julong os::Bsd::_physical_memory = 0;
   131 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
   132 pthread_t os::Bsd::_main_thread;
   133 int os::Bsd::_page_size = -1;
   135 static jlong initial_time_count=0;
   137 static int clock_tics_per_sec = 100;
   139 // For diagnostics to print a message once. see run_periodic_checks
   140 static sigset_t check_signal_done;
   141 static bool check_signals = true;
   143 static pid_t _initial_pid = 0;
   145 /* Signal number used to suspend/resume a thread */
   147 /* do not use any signal number less than SIGSEGV, see 4355769 */
   148 static int SR_signum = SIGUSR2;
   149 sigset_t SR_sigset;
   152 ////////////////////////////////////////////////////////////////////////////////
   153 // utility functions
   155 static int SR_initialize();
   156 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
   158 julong os::available_memory() {
   159   return Bsd::available_memory();
   160 }
   162 // available here means free
   163 julong os::Bsd::available_memory() {
   164   uint64_t available = physical_memory() >> 2;
   165 #ifdef __APPLE__
   166   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
   167   vm_statistics64_data_t vmstat;
   168   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
   169                                          (host_info64_t)&vmstat, &count);
   170   assert(kerr == KERN_SUCCESS,
   171          "host_statistics64 failed - check mach_host_self() and count");
   172   if (kerr == KERN_SUCCESS) {
   173     available = vmstat.free_count * os::vm_page_size();
   174   }
   175 #endif
   176   return available;
   177 }
   179 julong os::physical_memory() {
   180   return Bsd::physical_memory();
   181 }
   183 ////////////////////////////////////////////////////////////////////////////////
   184 // environment support
   186 bool os::getenv(const char* name, char* buf, int len) {
   187   const char* val = ::getenv(name);
   188   if (val != NULL && strlen(val) < (size_t)len) {
   189     strcpy(buf, val);
   190     return true;
   191   }
   192   if (len > 0) buf[0] = 0;  // return a null string
   193   return false;
   194 }
   197 // Return true if user is running as root.
   199 bool os::have_special_privileges() {
   200   static bool init = false;
   201   static bool privileges = false;
   202   if (!init) {
   203     privileges = (getuid() != geteuid()) || (getgid() != getegid());
   204     init = true;
   205   }
   206   return privileges;
   207 }
   211 // Cpu architecture string
   212 #if   defined(ZERO)
   213 static char cpu_arch[] = ZERO_LIBARCH;
   214 #elif defined(IA64)
   215 static char cpu_arch[] = "ia64";
   216 #elif defined(IA32)
   217 static char cpu_arch[] = "i386";
   218 #elif defined(AMD64)
   219 static char cpu_arch[] = "amd64";
   220 #elif defined(ARM)
   221 static char cpu_arch[] = "arm";
   222 #elif defined(PPC)
   223 static char cpu_arch[] = "ppc";
   224 #elif defined(SPARC)
   225 #  ifdef _LP64
   226 static char cpu_arch[] = "sparcv9";
   227 #  else
   228 static char cpu_arch[] = "sparc";
   229 #  endif
   230 #else
   231 #error Add appropriate cpu_arch setting
   232 #endif
   234 // Compiler variant
   235 #ifdef COMPILER2
   236 #define COMPILER_VARIANT "server"
   237 #else
   238 #define COMPILER_VARIANT "client"
   239 #endif
   242 void os::Bsd::initialize_system_info() {
   243   int mib[2];
   244   size_t len;
   245   int cpu_val;
   246   julong mem_val;
   248   /* get processors count via hw.ncpus sysctl */
   249   mib[0] = CTL_HW;
   250   mib[1] = HW_NCPU;
   251   len = sizeof(cpu_val);
   252   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
   253        assert(len == sizeof(cpu_val), "unexpected data size");
   254        set_processor_count(cpu_val);
   255   }
   256   else {
   257        set_processor_count(1);   // fallback
   258   }
   260   /* get physical memory via hw.memsize sysctl (hw.memsize is used
   261    * since it returns a 64 bit value)
   262    */
   263   mib[0] = CTL_HW;
   265 #if defined (HW_MEMSIZE) // Apple
   266   mib[1] = HW_MEMSIZE;
   267 #elif defined(HW_PHYSMEM) // Most of BSD
   268   mib[1] = HW_PHYSMEM;
   269 #elif defined(HW_REALMEM) // Old FreeBSD
   270   mib[1] = HW_REALMEM;
   271 #else
   272   #error No ways to get physmem
   273 #endif
   275   len = sizeof(mem_val);
   276   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
   277        assert(len == sizeof(mem_val), "unexpected data size");
   278        _physical_memory = mem_val;
   279   } else {
   280        _physical_memory = 256*1024*1024;       // fallback (XXXBSD?)
   281   }
   283 #ifdef __OpenBSD__
   284   {
   285        // limit _physical_memory memory view on OpenBSD since
   286        // datasize rlimit restricts us anyway.
   287        struct rlimit limits;
   288        getrlimit(RLIMIT_DATA, &limits);
   289        _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
   290   }
   291 #endif
   292 }
   294 #ifdef __APPLE__
   295 static const char *get_home() {
   296   const char *home_dir = ::getenv("HOME");
   297   if ((home_dir == NULL) || (*home_dir == '\0')) {
   298     struct passwd *passwd_info = getpwuid(geteuid());
   299     if (passwd_info != NULL) {
   300       home_dir = passwd_info->pw_dir;
   301     }
   302   }
   304   return home_dir;
   305 }
   306 #endif
   308 void os::init_system_properties_values() {
   309 //  char arch[12];
   310 //  sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
   312   // The next steps are taken in the product version:
   313   //
   314   // Obtain the JAVA_HOME value from the location of libjvm.so.
   315   // This library should be located at:
   316   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
   317   //
   318   // If "/jre/lib/" appears at the right place in the path, then we
   319   // assume libjvm.so is installed in a JDK and we use this path.
   320   //
   321   // Otherwise exit with message: "Could not create the Java virtual machine."
   322   //
   323   // The following extra steps are taken in the debugging version:
   324   //
   325   // If "/jre/lib/" does NOT appear at the right place in the path
   326   // instead of exit check for $JAVA_HOME environment variable.
   327   //
   328   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
   329   // then we append a fake suffix "hotspot/libjvm.so" to this path so
   330   // it looks like libjvm.so is installed there
   331   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
   332   //
   333   // Otherwise exit.
   334   //
   335   // Important note: if the location of libjvm.so changes this
   336   // code needs to be changed accordingly.
   338   // The next few definitions allow the code to be verbatim:
   339 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal)
   340 #define getenv(n) ::getenv(n)
   342 /*
   343  * See ld(1):
   344  *      The linker uses the following search paths to locate required
   345  *      shared libraries:
   346  *        1: ...
   347  *        ...
   348  *        7: The default directories, normally /lib and /usr/lib.
   349  */
   350 #ifndef DEFAULT_LIBPATH
   351 #define DEFAULT_LIBPATH "/lib:/usr/lib"
   352 #endif
   354 #define EXTENSIONS_DIR  "/lib/ext"
   355 #define ENDORSED_DIR    "/lib/endorsed"
   356 #define REG_DIR         "/usr/java/packages"
   358 #ifdef __APPLE__
   359 #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
   360 #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
   361         const char *user_home_dir = get_home();
   362         // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir
   363         int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
   364             sizeof(SYS_EXTENSIONS_DIRS);
   365 #endif
   367   {
   368     /* sysclasspath, java_home, dll_dir */
   369     {
   370         char *home_path;
   371         char *dll_path;
   372         char *pslash;
   373         char buf[MAXPATHLEN];
   374         os::jvm_path(buf, sizeof(buf));
   376         // Found the full path to libjvm.so.
   377         // Now cut the path to <java_home>/jre if we can.
   378         *(strrchr(buf, '/')) = '\0';  /* get rid of /libjvm.so */
   379         pslash = strrchr(buf, '/');
   380         if (pslash != NULL)
   381             *pslash = '\0';           /* get rid of /{client|server|hotspot} */
   382         dll_path = malloc(strlen(buf) + 1);
   383         if (dll_path == NULL)
   384             return;
   385         strcpy(dll_path, buf);
   386         Arguments::set_dll_dir(dll_path);
   388         if (pslash != NULL) {
   389             pslash = strrchr(buf, '/');
   390             if (pslash != NULL) {
   391                 *pslash = '\0';       /* get rid of /<arch> (/lib on macosx) */
   392 #ifndef __APPLE__
   393                 pslash = strrchr(buf, '/');
   394                 if (pslash != NULL)
   395                     *pslash = '\0';   /* get rid of /lib */
   396 #endif
   397             }
   398         }
   400         home_path = malloc(strlen(buf) + 1);
   401         if (home_path == NULL)
   402             return;
   403         strcpy(home_path, buf);
   404         Arguments::set_java_home(home_path);
   406         if (!set_boot_path('/', ':'))
   407             return;
   408     }
   410     /*
   411      * Where to look for native libraries
   412      *
   413      * Note: Due to a legacy implementation, most of the library path
   414      * is set in the launcher.  This was to accomodate linking restrictions
   415      * on legacy Bsd implementations (which are no longer supported).
   416      * Eventually, all the library path setting will be done here.
   417      *
   418      * However, to prevent the proliferation of improperly built native
   419      * libraries, the new path component /usr/java/packages is added here.
   420      * Eventually, all the library path setting will be done here.
   421      */
   422     {
   423         char *ld_library_path;
   425         /*
   426          * Construct the invariant part of ld_library_path. Note that the
   427          * space for the colon and the trailing null are provided by the
   428          * nulls included by the sizeof operator (so actually we allocate
   429          * a byte more than necessary).
   430          */
   431 #ifdef __APPLE__
   432         ld_library_path = (char *) malloc(system_ext_size);
   433         sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir);
   434 #else
   435         ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
   436             strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
   437         sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
   438 #endif
   440         /*
   441          * Get the user setting of LD_LIBRARY_PATH, and prepended it.  It
   442          * should always exist (until the legacy problem cited above is
   443          * addressed).
   444          */
   445 #ifdef __APPLE__
   446         // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper
   447         char *l = getenv("JAVA_LIBRARY_PATH");
   448         if (l != NULL) {
   449             char *t = ld_library_path;
   450             /* That's +1 for the colon and +1 for the trailing '\0' */
   451             ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1);
   452             sprintf(ld_library_path, "%s:%s", l, t);
   453             free(t);
   454         }
   456         char *v = getenv("DYLD_LIBRARY_PATH");
   457 #else
   458         char *v = getenv("LD_LIBRARY_PATH");
   459 #endif
   460         if (v != NULL) {
   461             char *t = ld_library_path;
   462             /* That's +1 for the colon and +1 for the trailing '\0' */
   463             ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
   464             sprintf(ld_library_path, "%s:%s", v, t);
   465             free(t);
   466         }
   468 #ifdef __APPLE__
   469         // Apple's Java6 has "." at the beginning of java.library.path.
   470         // OpenJDK on Windows has "." at the end of java.library.path.
   471         // OpenJDK on Linux and Solaris don't have "." in java.library.path
   472         // at all. To ease the transition from Apple's Java6 to OpenJDK7,
   473         // "." is appended to the end of java.library.path. Yes, this
   474         // could cause a change in behavior, but Apple's Java6 behavior
   475         // can be achieved by putting "." at the beginning of the
   476         // JAVA_LIBRARY_PATH environment variable.
   477         {
   478             char *t = ld_library_path;
   479             // that's +3 for appending ":." and the trailing '\0'
   480             ld_library_path = (char *) malloc(strlen(t) + 3);
   481             sprintf(ld_library_path, "%s:%s", t, ".");
   482             free(t);
   483         }
   484 #endif
   486         Arguments::set_library_path(ld_library_path);
   487     }
   489     /*
   490      * Extensions directories.
   491      *
   492      * Note that the space for the colon and the trailing null are provided
   493      * by the nulls included by the sizeof operator (so actually one byte more
   494      * than necessary is allocated).
   495      */
   496     {
   497 #ifdef __APPLE__
   498         char *buf = malloc(strlen(Arguments::get_java_home()) +
   499             sizeof(EXTENSIONS_DIR) + system_ext_size);
   500         sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":"
   501             SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home());
   502 #else
   503         char *buf = malloc(strlen(Arguments::get_java_home()) +
   504             sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
   505         sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
   506             Arguments::get_java_home());
   507 #endif
   509         Arguments::set_ext_dirs(buf);
   510     }
   512     /* Endorsed standards default directory. */
   513     {
   514         char * buf;
   515         buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
   516         sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
   517         Arguments::set_endorsed_dirs(buf);
   518     }
   519   }
   521 #ifdef __APPLE__
   522 #undef SYS_EXTENSIONS_DIR
   523 #endif
   524 #undef malloc
   525 #undef getenv
   526 #undef EXTENSIONS_DIR
   527 #undef ENDORSED_DIR
   529   // Done
   530   return;
   531 }
   533 ////////////////////////////////////////////////////////////////////////////////
   534 // breakpoint support
   536 void os::breakpoint() {
   537   BREAKPOINT;
   538 }
   540 extern "C" void breakpoint() {
   541   // use debugger to set breakpoint here
   542 }
   544 ////////////////////////////////////////////////////////////////////////////////
   545 // signal support
   547 debug_only(static bool signal_sets_initialized = false);
   548 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
   550 bool os::Bsd::is_sig_ignored(int sig) {
   551       struct sigaction oact;
   552       sigaction(sig, (struct sigaction*)NULL, &oact);
   553       void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
   554                                      : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
   555       if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
   556            return true;
   557       else
   558            return false;
   559 }
   561 void os::Bsd::signal_sets_init() {
   562   // Should also have an assertion stating we are still single-threaded.
   563   assert(!signal_sets_initialized, "Already initialized");
   564   // Fill in signals that are necessarily unblocked for all threads in
   565   // the VM. Currently, we unblock the following signals:
   566   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
   567   //                         by -Xrs (=ReduceSignalUsage));
   568   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
   569   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
   570   // the dispositions or masks wrt these signals.
   571   // Programs embedding the VM that want to use the above signals for their
   572   // own purposes must, at this time, use the "-Xrs" option to prevent
   573   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
   574   // (See bug 4345157, and other related bugs).
   575   // In reality, though, unblocking these signals is really a nop, since
   576   // these signals are not blocked by default.
   577   sigemptyset(&unblocked_sigs);
   578   sigemptyset(&allowdebug_blocked_sigs);
   579   sigaddset(&unblocked_sigs, SIGILL);
   580   sigaddset(&unblocked_sigs, SIGSEGV);
   581   sigaddset(&unblocked_sigs, SIGBUS);
   582   sigaddset(&unblocked_sigs, SIGFPE);
   583   sigaddset(&unblocked_sigs, SR_signum);
   585   if (!ReduceSignalUsage) {
   586    if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
   587       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
   588       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
   589    }
   590    if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
   591       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
   592       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
   593    }
   594    if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
   595       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
   596       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
   597    }
   598   }
   599   // Fill in signals that are blocked by all but the VM thread.
   600   sigemptyset(&vm_sigs);
   601   if (!ReduceSignalUsage)
   602     sigaddset(&vm_sigs, BREAK_SIGNAL);
   603   debug_only(signal_sets_initialized = true);
   605 }
   607 // These are signals that are unblocked while a thread is running Java.
   608 // (For some reason, they get blocked by default.)
   609 sigset_t* os::Bsd::unblocked_signals() {
   610   assert(signal_sets_initialized, "Not initialized");
   611   return &unblocked_sigs;
   612 }
   614 // These are the signals that are blocked while a (non-VM) thread is
   615 // running Java. Only the VM thread handles these signals.
   616 sigset_t* os::Bsd::vm_signals() {
   617   assert(signal_sets_initialized, "Not initialized");
   618   return &vm_sigs;
   619 }
   621 // These are signals that are blocked during cond_wait to allow debugger in
   622 sigset_t* os::Bsd::allowdebug_blocked_signals() {
   623   assert(signal_sets_initialized, "Not initialized");
   624   return &allowdebug_blocked_sigs;
   625 }
   627 void os::Bsd::hotspot_sigmask(Thread* thread) {
   629   //Save caller's signal mask before setting VM signal mask
   630   sigset_t caller_sigmask;
   631   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
   633   OSThread* osthread = thread->osthread();
   634   osthread->set_caller_sigmask(caller_sigmask);
   636   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
   638   if (!ReduceSignalUsage) {
   639     if (thread->is_VM_thread()) {
   640       // Only the VM thread handles BREAK_SIGNAL ...
   641       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
   642     } else {
   643       // ... all other threads block BREAK_SIGNAL
   644       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
   645     }
   646   }
   647 }
   650 //////////////////////////////////////////////////////////////////////////////
   651 // create new thread
   653 // check if it's safe to start a new thread
   654 static bool _thread_safety_check(Thread* thread) {
   655   return true;
   656 }
   658 #ifdef __APPLE__
   659 // library handle for calling objc_registerThreadWithCollector()
   660 // without static linking to the libobjc library
   661 #define OBJC_LIB "/usr/lib/libobjc.dylib"
   662 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
   663 typedef void (*objc_registerThreadWithCollector_t)();
   664 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
   665 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
   666 #endif
   668 #ifdef __APPLE__
   669 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
   670   // Additional thread_id used to correlate threads in SA
   671   thread_identifier_info_data_t     m_ident_info;
   672   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
   674   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
   675               (thread_info_t) &m_ident_info, &count);
   677   return m_ident_info.thread_id;
   678 }
   679 #endif
   681 // Thread start routine for all newly created threads
   682 static void *java_start(Thread *thread) {
   683   // Try to randomize the cache line index of hot stack frames.
   684   // This helps when threads of the same stack traces evict each other's
   685   // cache lines. The threads can be either from the same JVM instance, or
   686   // from different JVM instances. The benefit is especially true for
   687   // processors with hyperthreading technology.
   688   static int counter = 0;
   689   int pid = os::current_process_id();
   690   alloca(((pid ^ counter++) & 7) * 128);
   692   ThreadLocalStorage::set_thread(thread);
   694   OSThread* osthread = thread->osthread();
   695   Monitor* sync = osthread->startThread_lock();
   697   // non floating stack BsdThreads needs extra check, see above
   698   if (!_thread_safety_check(thread)) {
   699     // notify parent thread
   700     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
   701     osthread->set_state(ZOMBIE);
   702     sync->notify_all();
   703     return NULL;
   704   }
   706   osthread->set_thread_id(os::Bsd::gettid());
   708 #ifdef __APPLE__
   709   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
   710   guarantee(unique_thread_id != 0, "unique thread id was not found");
   711   osthread->set_unique_thread_id(unique_thread_id);
   712 #endif
   713   // initialize signal mask for this thread
   714   os::Bsd::hotspot_sigmask(thread);
   716   // initialize floating point control register
   717   os::Bsd::init_thread_fpu_state();
   719 #ifdef __APPLE__
   720   // register thread with objc gc
   721   if (objc_registerThreadWithCollectorFunction != NULL) {
   722     objc_registerThreadWithCollectorFunction();
   723   }
   724 #endif
   726   // handshaking with parent thread
   727   {
   728     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
   730     // notify parent thread
   731     osthread->set_state(INITIALIZED);
   732     sync->notify_all();
   734     // wait until os::start_thread()
   735     while (osthread->get_state() == INITIALIZED) {
   736       sync->wait(Mutex::_no_safepoint_check_flag);
   737     }
   738   }
   740   // call one more level start routine
   741   thread->run();
   743   return 0;
   744 }
   746 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
   747   assert(thread->osthread() == NULL, "caller responsible");
   749   // Allocate the OSThread object
   750   OSThread* osthread = new OSThread(NULL, NULL);
   751   if (osthread == NULL) {
   752     return false;
   753   }
   755   // set the correct thread state
   756   osthread->set_thread_type(thr_type);
   758   // Initial state is ALLOCATED but not INITIALIZED
   759   osthread->set_state(ALLOCATED);
   761   thread->set_osthread(osthread);
   763   // init thread attributes
   764   pthread_attr_t attr;
   765   pthread_attr_init(&attr);
   766   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
   768   // stack size
   769   if (os::Bsd::supports_variable_stack_size()) {
   770     // calculate stack size if it's not specified by caller
   771     if (stack_size == 0) {
   772       stack_size = os::Bsd::default_stack_size(thr_type);
   774       switch (thr_type) {
   775       case os::java_thread:
   776         // Java threads use ThreadStackSize which default value can be
   777         // changed with the flag -Xss
   778         assert (JavaThread::stack_size_at_create() > 0, "this should be set");
   779         stack_size = JavaThread::stack_size_at_create();
   780         break;
   781       case os::compiler_thread:
   782         if (CompilerThreadStackSize > 0) {
   783           stack_size = (size_t)(CompilerThreadStackSize * K);
   784           break;
   785         } // else fall through:
   786           // use VMThreadStackSize if CompilerThreadStackSize is not defined
   787       case os::vm_thread:
   788       case os::pgc_thread:
   789       case os::cgc_thread:
   790       case os::watcher_thread:
   791         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
   792         break;
   793       }
   794     }
   796     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
   797     pthread_attr_setstacksize(&attr, stack_size);
   798   } else {
   799     // let pthread_create() pick the default value.
   800   }
   802   ThreadState state;
   804   {
   805     pthread_t tid;
   806     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
   808     pthread_attr_destroy(&attr);
   810     if (ret != 0) {
   811       if (PrintMiscellaneous && (Verbose || WizardMode)) {
   812         perror("pthread_create()");
   813       }
   814       // Need to clean up stuff we've allocated so far
   815       thread->set_osthread(NULL);
   816       delete osthread;
   817       return false;
   818     }
   820     // Store pthread info into the OSThread
   821     osthread->set_pthread_id(tid);
   823     // Wait until child thread is either initialized or aborted
   824     {
   825       Monitor* sync_with_child = osthread->startThread_lock();
   826       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
   827       while ((state = osthread->get_state()) == ALLOCATED) {
   828         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
   829       }
   830     }
   832   }
   834   // Aborted due to thread limit being reached
   835   if (state == ZOMBIE) {
   836       thread->set_osthread(NULL);
   837       delete osthread;
   838       return false;
   839   }
   841   // The thread is returned suspended (in state INITIALIZED),
   842   // and is started higher up in the call chain
   843   assert(state == INITIALIZED, "race condition");
   844   return true;
   845 }
   847 /////////////////////////////////////////////////////////////////////////////
   848 // attach existing thread
   850 // bootstrap the main thread
   851 bool os::create_main_thread(JavaThread* thread) {
   852   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
   853   return create_attached_thread(thread);
   854 }
   856 bool os::create_attached_thread(JavaThread* thread) {
   857 #ifdef ASSERT
   858     thread->verify_not_published();
   859 #endif
   861   // Allocate the OSThread object
   862   OSThread* osthread = new OSThread(NULL, NULL);
   864   if (osthread == NULL) {
   865     return false;
   866   }
   868   osthread->set_thread_id(os::Bsd::gettid());
   870   // Store pthread info into the OSThread
   871 #ifdef __APPLE__
   872   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
   873   guarantee(unique_thread_id != 0, "just checking");
   874   osthread->set_unique_thread_id(unique_thread_id);
   875 #endif
   876   osthread->set_pthread_id(::pthread_self());
   878   // initialize floating point control register
   879   os::Bsd::init_thread_fpu_state();
   881   // Initial thread state is RUNNABLE
   882   osthread->set_state(RUNNABLE);
   884   thread->set_osthread(osthread);
   886   // initialize signal mask for this thread
   887   // and save the caller's signal mask
   888   os::Bsd::hotspot_sigmask(thread);
   890   return true;
   891 }
   893 void os::pd_start_thread(Thread* thread) {
   894   OSThread * osthread = thread->osthread();
   895   assert(osthread->get_state() != INITIALIZED, "just checking");
   896   Monitor* sync_with_child = osthread->startThread_lock();
   897   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
   898   sync_with_child->notify();
   899 }
   901 // Free Bsd resources related to the OSThread
   902 void os::free_thread(OSThread* osthread) {
   903   assert(osthread != NULL, "osthread not set");
   905   if (Thread::current()->osthread() == osthread) {
   906     // Restore caller's signal mask
   907     sigset_t sigmask = osthread->caller_sigmask();
   908     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
   909    }
   911   delete osthread;
   912 }
   914 //////////////////////////////////////////////////////////////////////////////
   915 // thread local storage
   917 int os::allocate_thread_local_storage() {
   918   pthread_key_t key;
   919   int rslt = pthread_key_create(&key, NULL);
   920   assert(rslt == 0, "cannot allocate thread local storage");
   921   return (int)key;
   922 }
   924 // Note: This is currently not used by VM, as we don't destroy TLS key
   925 // on VM exit.
   926 void os::free_thread_local_storage(int index) {
   927   int rslt = pthread_key_delete((pthread_key_t)index);
   928   assert(rslt == 0, "invalid index");
   929 }
   931 void os::thread_local_storage_at_put(int index, void* value) {
   932   int rslt = pthread_setspecific((pthread_key_t)index, value);
   933   assert(rslt == 0, "pthread_setspecific failed");
   934 }
   936 extern "C" Thread* get_thread() {
   937   return ThreadLocalStorage::thread();
   938 }
   941 ////////////////////////////////////////////////////////////////////////////////
   942 // time support
   944 // Time since start-up in seconds to a fine granularity.
   945 // Used by VMSelfDestructTimer and the MemProfiler.
   946 double os::elapsedTime() {
   948   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
   949 }
   951 jlong os::elapsed_counter() {
   952   return javaTimeNanos() - initial_time_count;
   953 }
   955 jlong os::elapsed_frequency() {
   956   return NANOSECS_PER_SEC; // nanosecond resolution
   957 }
   959 bool os::supports_vtime() { return true; }
   960 bool os::enable_vtime()   { return false; }
   961 bool os::vtime_enabled()  { return false; }
   963 double os::elapsedVTime() {
   964   // better than nothing, but not much
   965   return elapsedTime();
   966 }
   968 jlong os::javaTimeMillis() {
   969   timeval time;
   970   int status = gettimeofday(&time, NULL);
   971   assert(status != -1, "bsd error");
   972   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
   973 }
   975 #ifndef CLOCK_MONOTONIC
   976 #define CLOCK_MONOTONIC (1)
   977 #endif
   979 #ifdef __APPLE__
   980 void os::Bsd::clock_init() {
   981         // XXXDARWIN: Investigate replacement monotonic clock
   982 }
   983 #else
   984 void os::Bsd::clock_init() {
   985   struct timespec res;
   986   struct timespec tp;
   987   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
   988       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
   989     // yes, monotonic clock is supported
   990     _clock_gettime = ::clock_gettime;
   991   }
   992 }
   993 #endif
   996 jlong os::javaTimeNanos() {
   997   if (Bsd::supports_monotonic_clock()) {
   998     struct timespec tp;
   999     int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp);
  1000     assert(status == 0, "gettime error");
  1001     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
  1002     return result;
  1003   } else {
  1004     timeval time;
  1005     int status = gettimeofday(&time, NULL);
  1006     assert(status != -1, "bsd error");
  1007     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
  1008     return 1000 * usecs;
  1012 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
  1013   if (Bsd::supports_monotonic_clock()) {
  1014     info_ptr->max_value = ALL_64_BITS;
  1016     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
  1017     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
  1018     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
  1019   } else {
  1020     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
  1021     info_ptr->max_value = ALL_64_BITS;
  1023     // gettimeofday is a real time clock so it skips
  1024     info_ptr->may_skip_backward = true;
  1025     info_ptr->may_skip_forward = true;
  1028   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
  1031 // Return the real, user, and system times in seconds from an
  1032 // arbitrary fixed point in the past.
  1033 bool os::getTimesSecs(double* process_real_time,
  1034                       double* process_user_time,
  1035                       double* process_system_time) {
  1036   struct tms ticks;
  1037   clock_t real_ticks = times(&ticks);
  1039   if (real_ticks == (clock_t) (-1)) {
  1040     return false;
  1041   } else {
  1042     double ticks_per_second = (double) clock_tics_per_sec;
  1043     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
  1044     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
  1045     *process_real_time = ((double) real_ticks) / ticks_per_second;
  1047     return true;
  1052 char * os::local_time_string(char *buf, size_t buflen) {
  1053   struct tm t;
  1054   time_t long_time;
  1055   time(&long_time);
  1056   localtime_r(&long_time, &t);
  1057   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
  1058                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
  1059                t.tm_hour, t.tm_min, t.tm_sec);
  1060   return buf;
  1063 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
  1064   return localtime_r(clock, res);
  1067 ////////////////////////////////////////////////////////////////////////////////
  1068 // runtime exit support
  1070 // Note: os::shutdown() might be called very early during initialization, or
  1071 // called from signal handler. Before adding something to os::shutdown(), make
  1072 // sure it is async-safe and can handle partially initialized VM.
  1073 void os::shutdown() {
  1075   // allow PerfMemory to attempt cleanup of any persistent resources
  1076   perfMemory_exit();
  1078   // needs to remove object in file system
  1079   AttachListener::abort();
  1081   // flush buffered output, finish log files
  1082   ostream_abort();
  1084   // Check for abort hook
  1085   abort_hook_t abort_hook = Arguments::abort_hook();
  1086   if (abort_hook != NULL) {
  1087     abort_hook();
  1092 // Note: os::abort() might be called very early during initialization, or
  1093 // called from signal handler. Before adding something to os::abort(), make
  1094 // sure it is async-safe and can handle partially initialized VM.
  1095 void os::abort(bool dump_core) {
  1096   os::shutdown();
  1097   if (dump_core) {
  1098 #ifndef PRODUCT
  1099     fdStream out(defaultStream::output_fd());
  1100     out.print_raw("Current thread is ");
  1101     char buf[16];
  1102     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
  1103     out.print_raw_cr(buf);
  1104     out.print_raw_cr("Dumping core ...");
  1105 #endif
  1106     ::abort(); // dump core
  1109   ::exit(1);
  1112 // Die immediately, no exit hook, no abort hook, no cleanup.
  1113 void os::die() {
  1114   // _exit() on BsdThreads only kills current thread
  1115   ::abort();
  1118 // unused on bsd for now.
  1119 void os::set_error_file(const char *logfile) {}
  1122 // This method is a copy of JDK's sysGetLastErrorString
  1123 // from src/solaris/hpi/src/system_md.c
  1125 size_t os::lasterror(char *buf, size_t len) {
  1127   if (errno == 0)  return 0;
  1129   const char *s = ::strerror(errno);
  1130   size_t n = ::strlen(s);
  1131   if (n >= len) {
  1132     n = len - 1;
  1134   ::strncpy(buf, s, n);
  1135   buf[n] = '\0';
  1136   return n;
  1139 // Information of current thread in variety of formats
  1140 pid_t os::Bsd::gettid() {
  1141   int retval = -1;
  1143 #ifdef __APPLE__ //XNU kernel
  1144   // despite the fact mach port is actually not a thread id use it
  1145   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
  1146   retval = ::pthread_mach_thread_np(::pthread_self());
  1147   guarantee(retval != 0, "just checking");
  1148   return retval;
  1150 #elif __FreeBSD__
  1151   retval = syscall(SYS_thr_self);
  1152 #elif __OpenBSD__
  1153   retval = syscall(SYS_getthrid);
  1154 #elif __NetBSD__
  1155   retval = (pid_t) syscall(SYS__lwp_self);
  1156 #endif
  1158   if (retval == -1) {
  1159     return getpid();
  1163 intx os::current_thread_id() {
  1164 #ifdef __APPLE__
  1165   return (intx)::pthread_mach_thread_np(::pthread_self());
  1166 #else
  1167   return (intx)::pthread_self();
  1168 #endif
  1171 int os::current_process_id() {
  1173   // Under the old bsd thread library, bsd gives each thread
  1174   // its own process id. Because of this each thread will return
  1175   // a different pid if this method were to return the result
  1176   // of getpid(2). Bsd provides no api that returns the pid
  1177   // of the launcher thread for the vm. This implementation
  1178   // returns a unique pid, the pid of the launcher thread
  1179   // that starts the vm 'process'.
  1181   // Under the NPTL, getpid() returns the same pid as the
  1182   // launcher thread rather than a unique pid per thread.
  1183   // Use gettid() if you want the old pre NPTL behaviour.
  1185   // if you are looking for the result of a call to getpid() that
  1186   // returns a unique pid for the calling thread, then look at the
  1187   // OSThread::thread_id() method in osThread_bsd.hpp file
  1189   return (int)(_initial_pid ? _initial_pid : getpid());
  1192 // DLL functions
  1194 #define JNI_LIB_PREFIX "lib"
  1195 #ifdef __APPLE__
  1196 #define JNI_LIB_SUFFIX ".dylib"
  1197 #else
  1198 #define JNI_LIB_SUFFIX ".so"
  1199 #endif
  1201 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
  1203 // This must be hard coded because it's the system's temporary
  1204 // directory not the java application's temp directory, ala java.io.tmpdir.
  1205 #ifdef __APPLE__
  1206 // macosx has a secure per-user temporary directory
  1207 char temp_path_storage[PATH_MAX];
  1208 const char* os::get_temp_directory() {
  1209   static char *temp_path = NULL;
  1210   if (temp_path == NULL) {
  1211     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
  1212     if (pathSize == 0 || pathSize > PATH_MAX) {
  1213       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
  1215     temp_path = temp_path_storage;
  1217   return temp_path;
  1219 #else /* __APPLE__ */
  1220 const char* os::get_temp_directory() { return "/tmp"; }
  1221 #endif /* __APPLE__ */
  1223 static bool file_exists(const char* filename) {
  1224   struct stat statbuf;
  1225   if (filename == NULL || strlen(filename) == 0) {
  1226     return false;
  1228   return os::stat(filename, &statbuf) == 0;
  1231 bool os::dll_build_name(char* buffer, size_t buflen,
  1232                         const char* pname, const char* fname) {
  1233   bool retval = false;
  1234   // Copied from libhpi
  1235   const size_t pnamelen = pname ? strlen(pname) : 0;
  1237   // Return error on buffer overflow.
  1238   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
  1239     return retval;
  1242   if (pnamelen == 0) {
  1243     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
  1244     retval = true;
  1245   } else if (strchr(pname, *os::path_separator()) != NULL) {
  1246     int n;
  1247     char** pelements = split_path(pname, &n);
  1248     if (pelements == NULL) {
  1249       return false;
  1251     for (int i = 0 ; i < n ; i++) {
  1252       // Really shouldn't be NULL, but check can't hurt
  1253       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
  1254         continue; // skip the empty path values
  1256       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
  1257           pelements[i], fname);
  1258       if (file_exists(buffer)) {
  1259         retval = true;
  1260         break;
  1263     // release the storage
  1264     for (int i = 0 ; i < n ; i++) {
  1265       if (pelements[i] != NULL) {
  1266         FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
  1269     if (pelements != NULL) {
  1270       FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
  1272   } else {
  1273     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
  1274     retval = true;
  1276   return retval;
  1279 // check if addr is inside libjvm.so
  1280 bool os::address_is_in_vm(address addr) {
  1281   static address libjvm_base_addr;
  1282   Dl_info dlinfo;
  1284   if (libjvm_base_addr == NULL) {
  1285     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
  1286       libjvm_base_addr = (address)dlinfo.dli_fbase;
  1288     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
  1291   if (dladdr((void *)addr, &dlinfo) != 0) {
  1292     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
  1295   return false;
  1299 #define MACH_MAXSYMLEN 256
  1301 bool os::dll_address_to_function_name(address addr, char *buf,
  1302                                       int buflen, int *offset) {
  1303   // buf is not optional, but offset is optional
  1304   assert(buf != NULL, "sanity check");
  1306   Dl_info dlinfo;
  1307   char localbuf[MACH_MAXSYMLEN];
  1309   if (dladdr((void*)addr, &dlinfo) != 0) {
  1310     // see if we have a matching symbol
  1311     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
  1312       if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
  1313         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
  1315       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
  1316       return true;
  1318     // no matching symbol so try for just file info
  1319     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
  1320       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
  1321                           buf, buflen, offset, dlinfo.dli_fname)) {
  1322          return true;
  1326     // Handle non-dynamic manually:
  1327     if (dlinfo.dli_fbase != NULL &&
  1328         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
  1329                         dlinfo.dli_fbase)) {
  1330       if (!Decoder::demangle(localbuf, buf, buflen)) {
  1331         jio_snprintf(buf, buflen, "%s", localbuf);
  1333       return true;
  1336   buf[0] = '\0';
  1337   if (offset != NULL) *offset = -1;
  1338   return false;
  1341 // ported from solaris version
  1342 bool os::dll_address_to_library_name(address addr, char* buf,
  1343                                      int buflen, int* offset) {
  1344   // buf is not optional, but offset is optional
  1345   assert(buf != NULL, "sanity check");
  1347   Dl_info dlinfo;
  1349   if (dladdr((void*)addr, &dlinfo) != 0) {
  1350     if (dlinfo.dli_fname != NULL) {
  1351       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
  1353     if (dlinfo.dli_fbase != NULL && offset != NULL) {
  1354       *offset = addr - (address)dlinfo.dli_fbase;
  1356     return true;
  1359   buf[0] = '\0';
  1360   if (offset) *offset = -1;
  1361   return false;
  1364 // Loads .dll/.so and
  1365 // in case of error it checks if .dll/.so was built for the
  1366 // same architecture as Hotspot is running on
  1368 #ifdef __APPLE__
  1369 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
  1370   void * result= ::dlopen(filename, RTLD_LAZY);
  1371   if (result != NULL) {
  1372     // Successful loading
  1373     return result;
  1376   // Read system error message into ebuf
  1377   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
  1378   ebuf[ebuflen-1]='\0';
  1380   return NULL;
  1382 #else
  1383 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
  1385   void * result= ::dlopen(filename, RTLD_LAZY);
  1386   if (result != NULL) {
  1387     // Successful loading
  1388     return result;
  1391   Elf32_Ehdr elf_head;
  1393   // Read system error message into ebuf
  1394   // It may or may not be overwritten below
  1395   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
  1396   ebuf[ebuflen-1]='\0';
  1397   int diag_msg_max_length=ebuflen-strlen(ebuf);
  1398   char* diag_msg_buf=ebuf+strlen(ebuf);
  1400   if (diag_msg_max_length==0) {
  1401     // No more space in ebuf for additional diagnostics message
  1402     return NULL;
  1406   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
  1408   if (file_descriptor < 0) {
  1409     // Can't open library, report dlerror() message
  1410     return NULL;
  1413   bool failed_to_read_elf_head=
  1414     (sizeof(elf_head)!=
  1415         (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
  1417   ::close(file_descriptor);
  1418   if (failed_to_read_elf_head) {
  1419     // file i/o error - report dlerror() msg
  1420     return NULL;
  1423   typedef struct {
  1424     Elf32_Half  code;         // Actual value as defined in elf.h
  1425     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
  1426     char        elf_class;    // 32 or 64 bit
  1427     char        endianess;    // MSB or LSB
  1428     char*       name;         // String representation
  1429   } arch_t;
  1431   #ifndef EM_486
  1432   #define EM_486          6               /* Intel 80486 */
  1433   #endif
  1435   #ifndef EM_MIPS_RS3_LE
  1436   #define EM_MIPS_RS3_LE  10              /* MIPS */
  1437   #endif
  1439   #ifndef EM_PPC64
  1440   #define EM_PPC64        21              /* PowerPC64 */
  1441   #endif
  1443   #ifndef EM_S390
  1444   #define EM_S390         22              /* IBM System/390 */
  1445   #endif
  1447   #ifndef EM_IA_64
  1448   #define EM_IA_64        50              /* HP/Intel IA-64 */
  1449   #endif
  1451   #ifndef EM_X86_64
  1452   #define EM_X86_64       62              /* AMD x86-64 */
  1453   #endif
  1455   static const arch_t arch_array[]={
  1456     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
  1457     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
  1458     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
  1459     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
  1460     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
  1461     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
  1462     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
  1463     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
  1464     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
  1465     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
  1466     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
  1467     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
  1468     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
  1469     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
  1470     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
  1471     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
  1472   };
  1474   #if  (defined IA32)
  1475     static  Elf32_Half running_arch_code=EM_386;
  1476   #elif   (defined AMD64)
  1477     static  Elf32_Half running_arch_code=EM_X86_64;
  1478   #elif  (defined IA64)
  1479     static  Elf32_Half running_arch_code=EM_IA_64;
  1480   #elif  (defined __sparc) && (defined _LP64)
  1481     static  Elf32_Half running_arch_code=EM_SPARCV9;
  1482   #elif  (defined __sparc) && (!defined _LP64)
  1483     static  Elf32_Half running_arch_code=EM_SPARC;
  1484   #elif  (defined __powerpc64__)
  1485     static  Elf32_Half running_arch_code=EM_PPC64;
  1486   #elif  (defined __powerpc__)
  1487     static  Elf32_Half running_arch_code=EM_PPC;
  1488   #elif  (defined ARM)
  1489     static  Elf32_Half running_arch_code=EM_ARM;
  1490   #elif  (defined S390)
  1491     static  Elf32_Half running_arch_code=EM_S390;
  1492   #elif  (defined ALPHA)
  1493     static  Elf32_Half running_arch_code=EM_ALPHA;
  1494   #elif  (defined MIPSEL)
  1495     static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
  1496   #elif  (defined PARISC)
  1497     static  Elf32_Half running_arch_code=EM_PARISC;
  1498   #elif  (defined MIPS)
  1499     static  Elf32_Half running_arch_code=EM_MIPS;
  1500   #elif  (defined M68K)
  1501     static  Elf32_Half running_arch_code=EM_68K;
  1502   #else
  1503     #error Method os::dll_load requires that one of following is defined:\
  1504          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
  1505   #endif
  1507   // Identify compatability class for VM's architecture and library's architecture
  1508   // Obtain string descriptions for architectures
  1510   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
  1511   int running_arch_index=-1;
  1513   for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
  1514     if (running_arch_code == arch_array[i].code) {
  1515       running_arch_index    = i;
  1517     if (lib_arch.code == arch_array[i].code) {
  1518       lib_arch.compat_class = arch_array[i].compat_class;
  1519       lib_arch.name         = arch_array[i].name;
  1523   assert(running_arch_index != -1,
  1524     "Didn't find running architecture code (running_arch_code) in arch_array");
  1525   if (running_arch_index == -1) {
  1526     // Even though running architecture detection failed
  1527     // we may still continue with reporting dlerror() message
  1528     return NULL;
  1531   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
  1532     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
  1533     return NULL;
  1536 #ifndef S390
  1537   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
  1538     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
  1539     return NULL;
  1541 #endif // !S390
  1543   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
  1544     if ( lib_arch.name!=NULL ) {
  1545       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
  1546         " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
  1547         lib_arch.name, arch_array[running_arch_index].name);
  1548     } else {
  1549       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
  1550       " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
  1551         lib_arch.code,
  1552         arch_array[running_arch_index].name);
  1556   return NULL;
  1558 #endif /* !__APPLE__ */
  1560 void* os::get_default_process_handle() {
  1561 #ifdef __APPLE__
  1562   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
  1563   // to avoid finding unexpected symbols on second (or later)
  1564   // loads of a library.
  1565   return (void*)::dlopen(NULL, RTLD_FIRST);
  1566 #else
  1567   return (void*)::dlopen(NULL, RTLD_LAZY);
  1568 #endif
  1571 // XXX: Do we need a lock around this as per Linux?
  1572 void* os::dll_lookup(void* handle, const char* name) {
  1573   return dlsym(handle, name);
  1577 static bool _print_ascii_file(const char* filename, outputStream* st) {
  1578   int fd = ::open(filename, O_RDONLY);
  1579   if (fd == -1) {
  1580      return false;
  1583   char buf[32];
  1584   int bytes;
  1585   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
  1586     st->print_raw(buf, bytes);
  1589   ::close(fd);
  1591   return true;
  1594 void os::print_dll_info(outputStream *st) {
  1595   st->print_cr("Dynamic libraries:");
  1596 #ifdef RTLD_DI_LINKMAP
  1597   Dl_info dli;
  1598   void *handle;
  1599   Link_map *map;
  1600   Link_map *p;
  1602   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
  1603       dli.dli_fname == NULL) {
  1604     st->print_cr("Error: Cannot print dynamic libraries.");
  1605     return;
  1607   handle = dlopen(dli.dli_fname, RTLD_LAZY);
  1608   if (handle == NULL) {
  1609     st->print_cr("Error: Cannot print dynamic libraries.");
  1610     return;
  1612   dlinfo(handle, RTLD_DI_LINKMAP, &map);
  1613   if (map == NULL) {
  1614     st->print_cr("Error: Cannot print dynamic libraries.");
  1615     return;
  1618   while (map->l_prev != NULL)
  1619     map = map->l_prev;
  1621   while (map != NULL) {
  1622     st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
  1623     map = map->l_next;
  1626   dlclose(handle);
  1627 #elif defined(__APPLE__)
  1628   uint32_t count;
  1629   uint32_t i;
  1631   count = _dyld_image_count();
  1632   for (i = 1; i < count; i++) {
  1633     const char *name = _dyld_get_image_name(i);
  1634     intptr_t slide = _dyld_get_image_vmaddr_slide(i);
  1635     st->print_cr(PTR_FORMAT " \t%s", slide, name);
  1637 #else
  1638   st->print_cr("Error: Cannot print dynamic libraries.");
  1639 #endif
  1642 void os::print_os_info_brief(outputStream* st) {
  1643   st->print("Bsd");
  1645   os::Posix::print_uname_info(st);
  1648 void os::print_os_info(outputStream* st) {
  1649   st->print("OS:");
  1650   st->print("Bsd");
  1652   os::Posix::print_uname_info(st);
  1654   os::Posix::print_rlimit_info(st);
  1656   os::Posix::print_load_average(st);
  1659 void os::pd_print_cpu_info(outputStream* st) {
  1660   // Nothing to do for now.
  1663 void os::print_memory_info(outputStream* st) {
  1665   st->print("Memory:");
  1666   st->print(" %dk page", os::vm_page_size()>>10);
  1668   st->print(", physical " UINT64_FORMAT "k",
  1669             os::physical_memory() >> 10);
  1670   st->print("(" UINT64_FORMAT "k free)",
  1671             os::available_memory() >> 10);
  1672   st->cr();
  1674   // meminfo
  1675   st->print("\n/proc/meminfo:\n");
  1676   _print_ascii_file("/proc/meminfo", st);
  1677   st->cr();
  1680 // Taken from /usr/include/bits/siginfo.h  Supposed to be architecture specific
  1681 // but they're the same for all the bsd arch that we support
  1682 // and they're the same for solaris but there's no common place to put this.
  1683 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
  1684                           "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
  1685                           "ILL_COPROC", "ILL_BADSTK" };
  1687 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
  1688                           "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
  1689                           "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
  1691 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
  1693 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
  1695 void os::print_siginfo(outputStream* st, void* siginfo) {
  1696   st->print("siginfo:");
  1698   const int buflen = 100;
  1699   char buf[buflen];
  1700   siginfo_t *si = (siginfo_t*)siginfo;
  1701   st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
  1702   if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
  1703     st->print("si_errno=%s", buf);
  1704   } else {
  1705     st->print("si_errno=%d", si->si_errno);
  1707   const int c = si->si_code;
  1708   assert(c > 0, "unexpected si_code");
  1709   switch (si->si_signo) {
  1710   case SIGILL:
  1711     st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
  1712     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1713     break;
  1714   case SIGFPE:
  1715     st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
  1716     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1717     break;
  1718   case SIGSEGV:
  1719     st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
  1720     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1721     break;
  1722   case SIGBUS:
  1723     st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
  1724     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
  1725     break;
  1726   default:
  1727     st->print(", si_code=%d", si->si_code);
  1728     // no si_addr
  1731   if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
  1732       UseSharedSpaces) {
  1733     FileMapInfo* mapinfo = FileMapInfo::current_info();
  1734     if (mapinfo->is_in_shared_space(si->si_addr)) {
  1735       st->print("\n\nError accessing class data sharing archive."   \
  1736                 " Mapped file inaccessible during execution, "      \
  1737                 " possible disk/network problem.");
  1740   st->cr();
  1744 static void print_signal_handler(outputStream* st, int sig,
  1745                                  char* buf, size_t buflen);
  1747 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
  1748   st->print_cr("Signal Handlers:");
  1749   print_signal_handler(st, SIGSEGV, buf, buflen);
  1750   print_signal_handler(st, SIGBUS , buf, buflen);
  1751   print_signal_handler(st, SIGFPE , buf, buflen);
  1752   print_signal_handler(st, SIGPIPE, buf, buflen);
  1753   print_signal_handler(st, SIGXFSZ, buf, buflen);
  1754   print_signal_handler(st, SIGILL , buf, buflen);
  1755   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
  1756   print_signal_handler(st, SR_signum, buf, buflen);
  1757   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
  1758   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
  1759   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
  1760   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
  1763 static char saved_jvm_path[MAXPATHLEN] = {0};
  1765 // Find the full path to the current module, libjvm
  1766 void os::jvm_path(char *buf, jint buflen) {
  1767   // Error checking.
  1768   if (buflen < MAXPATHLEN) {
  1769     assert(false, "must use a large-enough buffer");
  1770     buf[0] = '\0';
  1771     return;
  1773   // Lazy resolve the path to current module.
  1774   if (saved_jvm_path[0] != 0) {
  1775     strcpy(buf, saved_jvm_path);
  1776     return;
  1779   char dli_fname[MAXPATHLEN];
  1780   bool ret = dll_address_to_library_name(
  1781                 CAST_FROM_FN_PTR(address, os::jvm_path),
  1782                 dli_fname, sizeof(dli_fname), NULL);
  1783   assert(ret, "cannot locate libjvm");
  1784   char *rp = NULL;
  1785   if (ret && dli_fname[0] != '\0') {
  1786     rp = realpath(dli_fname, buf);
  1788   if (rp == NULL)
  1789     return;
  1791   if (Arguments::created_by_gamma_launcher()) {
  1792     // Support for the gamma launcher.  Typical value for buf is
  1793     // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm".  If "/jre/lib/" appears at
  1794     // the right place in the string, then assume we are installed in a JDK and
  1795     // we're done.  Otherwise, check for a JAVA_HOME environment variable and
  1796     // construct a path to the JVM being overridden.
  1798     const char *p = buf + strlen(buf) - 1;
  1799     for (int count = 0; p > buf && count < 5; ++count) {
  1800       for (--p; p > buf && *p != '/'; --p)
  1801         /* empty */ ;
  1804     if (strncmp(p, "/jre/lib/", 9) != 0) {
  1805       // Look for JAVA_HOME in the environment.
  1806       char* java_home_var = ::getenv("JAVA_HOME");
  1807       if (java_home_var != NULL && java_home_var[0] != 0) {
  1808         char* jrelib_p;
  1809         int len;
  1811         // Check the current module name "libjvm"
  1812         p = strrchr(buf, '/');
  1813         assert(strstr(p, "/libjvm") == p, "invalid library name");
  1815         rp = realpath(java_home_var, buf);
  1816         if (rp == NULL)
  1817           return;
  1819         // determine if this is a legacy image or modules image
  1820         // modules image doesn't have "jre" subdirectory
  1821         len = strlen(buf);
  1822         jrelib_p = buf + len;
  1824         // Add the appropriate library subdir
  1825         snprintf(jrelib_p, buflen-len, "/jre/lib");
  1826         if (0 != access(buf, F_OK)) {
  1827           snprintf(jrelib_p, buflen-len, "/lib");
  1830         // Add the appropriate client or server subdir
  1831         len = strlen(buf);
  1832         jrelib_p = buf + len;
  1833         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
  1834         if (0 != access(buf, F_OK)) {
  1835           snprintf(jrelib_p, buflen-len, "");
  1838         // If the path exists within JAVA_HOME, add the JVM library name
  1839         // to complete the path to JVM being overridden.  Otherwise fallback
  1840         // to the path to the current library.
  1841         if (0 == access(buf, F_OK)) {
  1842           // Use current module name "libjvm"
  1843           len = strlen(buf);
  1844           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
  1845         } else {
  1846           // Fall back to path of current library
  1847           rp = realpath(dli_fname, buf);
  1848           if (rp == NULL)
  1849             return;
  1855   strcpy(saved_jvm_path, buf);
  1858 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
  1859   // no prefix required, not even "_"
  1862 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
  1863   // no suffix required
  1866 ////////////////////////////////////////////////////////////////////////////////
  1867 // sun.misc.Signal support
  1869 static volatile jint sigint_count = 0;
  1871 static void
  1872 UserHandler(int sig, void *siginfo, void *context) {
  1873   // 4511530 - sem_post is serialized and handled by the manager thread. When
  1874   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
  1875   // don't want to flood the manager thread with sem_post requests.
  1876   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
  1877       return;
  1879   // Ctrl-C is pressed during error reporting, likely because the error
  1880   // handler fails to abort. Let VM die immediately.
  1881   if (sig == SIGINT && is_error_reported()) {
  1882      os::die();
  1885   os::signal_notify(sig);
  1888 void* os::user_handler() {
  1889   return CAST_FROM_FN_PTR(void*, UserHandler);
  1892 extern "C" {
  1893   typedef void (*sa_handler_t)(int);
  1894   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
  1897 void* os::signal(int signal_number, void* handler) {
  1898   struct sigaction sigAct, oldSigAct;
  1900   sigfillset(&(sigAct.sa_mask));
  1901   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
  1902   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
  1904   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
  1905     // -1 means registration failed
  1906     return (void *)-1;
  1909   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
  1912 void os::signal_raise(int signal_number) {
  1913   ::raise(signal_number);
  1916 /*
  1917  * The following code is moved from os.cpp for making this
  1918  * code platform specific, which it is by its very nature.
  1919  */
  1921 // Will be modified when max signal is changed to be dynamic
  1922 int os::sigexitnum_pd() {
  1923   return NSIG;
  1926 // a counter for each possible signal value
  1927 static volatile jint pending_signals[NSIG+1] = { 0 };
  1929 // Bsd(POSIX) specific hand shaking semaphore.
  1930 #ifdef __APPLE__
  1931 typedef semaphore_t os_semaphore_t;
  1932 #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
  1933 #define SEM_WAIT(sem)           semaphore_wait(sem)
  1934 #define SEM_POST(sem)           semaphore_signal(sem)
  1935 #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
  1936 #else
  1937 typedef sem_t os_semaphore_t;
  1938 #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
  1939 #define SEM_WAIT(sem)           sem_wait(&sem)
  1940 #define SEM_POST(sem)           sem_post(&sem)
  1941 #define SEM_DESTROY(sem)        sem_destroy(&sem)
  1942 #endif
  1944 class Semaphore : public StackObj {
  1945   public:
  1946     Semaphore();
  1947     ~Semaphore();
  1948     void signal();
  1949     void wait();
  1950     bool trywait();
  1951     bool timedwait(unsigned int sec, int nsec);
  1952   private:
  1953     jlong currenttime() const;
  1954     os_semaphore_t _semaphore;
  1955 };
  1957 Semaphore::Semaphore() : _semaphore(0) {
  1958   SEM_INIT(_semaphore, 0);
  1961 Semaphore::~Semaphore() {
  1962   SEM_DESTROY(_semaphore);
  1965 void Semaphore::signal() {
  1966   SEM_POST(_semaphore);
  1969 void Semaphore::wait() {
  1970   SEM_WAIT(_semaphore);
  1973 jlong Semaphore::currenttime() const {
  1974     struct timeval tv;
  1975     gettimeofday(&tv, NULL);
  1976     return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
  1979 #ifdef __APPLE__
  1980 bool Semaphore::trywait() {
  1981   return timedwait(0, 0);
  1984 bool Semaphore::timedwait(unsigned int sec, int nsec) {
  1985   kern_return_t kr = KERN_ABORTED;
  1986   mach_timespec_t waitspec;
  1987   waitspec.tv_sec = sec;
  1988   waitspec.tv_nsec = nsec;
  1990   jlong starttime = currenttime();
  1992   kr = semaphore_timedwait(_semaphore, waitspec);
  1993   while (kr == KERN_ABORTED) {
  1994     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
  1996     jlong current = currenttime();
  1997     jlong passedtime = current - starttime;
  1999     if (passedtime >= totalwait) {
  2000       waitspec.tv_sec = 0;
  2001       waitspec.tv_nsec = 0;
  2002     } else {
  2003       jlong waittime = totalwait - (current - starttime);
  2004       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
  2005       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
  2008     kr = semaphore_timedwait(_semaphore, waitspec);
  2011   return kr == KERN_SUCCESS;
  2014 #else
  2016 bool Semaphore::trywait() {
  2017   return sem_trywait(&_semaphore) == 0;
  2020 bool Semaphore::timedwait(unsigned int sec, int nsec) {
  2021   struct timespec ts;
  2022   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
  2024   while (1) {
  2025     int result = sem_timedwait(&_semaphore, &ts);
  2026     if (result == 0) {
  2027       return true;
  2028     } else if (errno == EINTR) {
  2029       continue;
  2030     } else if (errno == ETIMEDOUT) {
  2031       return false;
  2032     } else {
  2033       return false;
  2038 #endif // __APPLE__
  2040 static os_semaphore_t sig_sem;
  2041 static Semaphore sr_semaphore;
  2043 void os::signal_init_pd() {
  2044   // Initialize signal structures
  2045   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
  2047   // Initialize signal semaphore
  2048   ::SEM_INIT(sig_sem, 0);
  2051 void os::signal_notify(int sig) {
  2052   Atomic::inc(&pending_signals[sig]);
  2053   ::SEM_POST(sig_sem);
  2056 static int check_pending_signals(bool wait) {
  2057   Atomic::store(0, &sigint_count);
  2058   for (;;) {
  2059     for (int i = 0; i < NSIG + 1; i++) {
  2060       jint n = pending_signals[i];
  2061       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
  2062         return i;
  2065     if (!wait) {
  2066       return -1;
  2068     JavaThread *thread = JavaThread::current();
  2069     ThreadBlockInVM tbivm(thread);
  2071     bool threadIsSuspended;
  2072     do {
  2073       thread->set_suspend_equivalent();
  2074       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
  2075       ::SEM_WAIT(sig_sem);
  2077       // were we externally suspended while we were waiting?
  2078       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
  2079       if (threadIsSuspended) {
  2080         //
  2081         // The semaphore has been incremented, but while we were waiting
  2082         // another thread suspended us. We don't want to continue running
  2083         // while suspended because that would surprise the thread that
  2084         // suspended us.
  2085         //
  2086         ::SEM_POST(sig_sem);
  2088         thread->java_suspend_self();
  2090     } while (threadIsSuspended);
  2094 int os::signal_lookup() {
  2095   return check_pending_signals(false);
  2098 int os::signal_wait() {
  2099   return check_pending_signals(true);
  2102 ////////////////////////////////////////////////////////////////////////////////
  2103 // Virtual Memory
  2105 int os::vm_page_size() {
  2106   // Seems redundant as all get out
  2107   assert(os::Bsd::page_size() != -1, "must call os::init");
  2108   return os::Bsd::page_size();
  2111 // Solaris allocates memory by pages.
  2112 int os::vm_allocation_granularity() {
  2113   assert(os::Bsd::page_size() != -1, "must call os::init");
  2114   return os::Bsd::page_size();
  2117 // Rationale behind this function:
  2118 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
  2119 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
  2120 //  samples for JITted code. Here we create private executable mapping over the code cache
  2121 //  and then we can use standard (well, almost, as mapping can change) way to provide
  2122 //  info for the reporting script by storing timestamp and location of symbol
  2123 void bsd_wrap_code(char* base, size_t size) {
  2124   static volatile jint cnt = 0;
  2126   if (!UseOprofile) {
  2127     return;
  2130   char buf[PATH_MAX + 1];
  2131   int num = Atomic::add(1, &cnt);
  2133   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
  2134            os::get_temp_directory(), os::current_process_id(), num);
  2135   unlink(buf);
  2137   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
  2139   if (fd != -1) {
  2140     off_t rv = ::lseek(fd, size-2, SEEK_SET);
  2141     if (rv != (off_t)-1) {
  2142       if (::write(fd, "", 1) == 1) {
  2143         mmap(base, size,
  2144              PROT_READ|PROT_WRITE|PROT_EXEC,
  2145              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
  2148     ::close(fd);
  2149     unlink(buf);
  2153 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
  2154                                     int err) {
  2155   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
  2156           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
  2157           strerror(err), err);
  2160 // NOTE: Bsd kernel does not really reserve the pages for us.
  2161 //       All it does is to check if there are enough free pages
  2162 //       left at the time of mmap(). This could be a potential
  2163 //       problem.
  2164 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
  2165   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
  2166 #ifdef __OpenBSD__
  2167   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
  2168   if (::mprotect(addr, size, prot) == 0) {
  2169     return true;
  2171 #else
  2172   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
  2173                                    MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
  2174   if (res != (uintptr_t) MAP_FAILED) {
  2175     return true;
  2177 #endif
  2179   // Warn about any commit errors we see in non-product builds just
  2180   // in case mmap() doesn't work as described on the man page.
  2181   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
  2183   return false;
  2186 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
  2187                        bool exec) {
  2188   // alignment_hint is ignored on this OS
  2189   return pd_commit_memory(addr, size, exec);
  2192 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
  2193                                   const char* mesg) {
  2194   assert(mesg != NULL, "mesg must be specified");
  2195   if (!pd_commit_memory(addr, size, exec)) {
  2196     // add extra info in product mode for vm_exit_out_of_memory():
  2197     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
  2198     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
  2202 void os::pd_commit_memory_or_exit(char* addr, size_t size,
  2203                                   size_t alignment_hint, bool exec,
  2204                                   const char* mesg) {
  2205   // alignment_hint is ignored on this OS
  2206   pd_commit_memory_or_exit(addr, size, exec, mesg);
  2209 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
  2212 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
  2213   ::madvise(addr, bytes, MADV_DONTNEED);
  2216 void os::numa_make_global(char *addr, size_t bytes) {
  2219 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
  2222 bool os::numa_topology_changed()   { return false; }
  2224 size_t os::numa_get_groups_num() {
  2225   return 1;
  2228 int os::numa_get_group_id() {
  2229   return 0;
  2232 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
  2233   if (size > 0) {
  2234     ids[0] = 0;
  2235     return 1;
  2237   return 0;
  2240 bool os::get_page_info(char *start, page_info* info) {
  2241   return false;
  2244 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
  2245   return end;
  2249 bool os::pd_uncommit_memory(char* addr, size_t size) {
  2250 #ifdef __OpenBSD__
  2251   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
  2252   return ::mprotect(addr, size, PROT_NONE) == 0;
  2253 #else
  2254   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
  2255                 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
  2256   return res  != (uintptr_t) MAP_FAILED;
  2257 #endif
  2260 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
  2261   return os::commit_memory(addr, size, !ExecMem);
  2264 // If this is a growable mapping, remove the guard pages entirely by
  2265 // munmap()ping them.  If not, just call uncommit_memory().
  2266 bool os::remove_stack_guard_pages(char* addr, size_t size) {
  2267   return os::uncommit_memory(addr, size);
  2270 static address _highest_vm_reserved_address = NULL;
  2272 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
  2273 // at 'requested_addr'. If there are existing memory mappings at the same
  2274 // location, however, they will be overwritten. If 'fixed' is false,
  2275 // 'requested_addr' is only treated as a hint, the return value may or
  2276 // may not start from the requested address. Unlike Bsd mmap(), this
  2277 // function returns NULL to indicate failure.
  2278 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
  2279   char * addr;
  2280   int flags;
  2282   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
  2283   if (fixed) {
  2284     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
  2285     flags |= MAP_FIXED;
  2288   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
  2289   // touch an uncommitted page. Otherwise, the read/write might
  2290   // succeed if we have enough swap space to back the physical page.
  2291   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
  2292                        flags, -1, 0);
  2294   if (addr != MAP_FAILED) {
  2295     // anon_mmap() should only get called during VM initialization,
  2296     // don't need lock (actually we can skip locking even it can be called
  2297     // from multiple threads, because _highest_vm_reserved_address is just a
  2298     // hint about the upper limit of non-stack memory regions.)
  2299     if ((address)addr + bytes > _highest_vm_reserved_address) {
  2300       _highest_vm_reserved_address = (address)addr + bytes;
  2304   return addr == MAP_FAILED ? NULL : addr;
  2307 // Don't update _highest_vm_reserved_address, because there might be memory
  2308 // regions above addr + size. If so, releasing a memory region only creates
  2309 // a hole in the address space, it doesn't help prevent heap-stack collision.
  2310 //
  2311 static int anon_munmap(char * addr, size_t size) {
  2312   return ::munmap(addr, size) == 0;
  2315 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
  2316                          size_t alignment_hint) {
  2317   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
  2320 bool os::pd_release_memory(char* addr, size_t size) {
  2321   return anon_munmap(addr, size);
  2324 static bool bsd_mprotect(char* addr, size_t size, int prot) {
  2325   // Bsd wants the mprotect address argument to be page aligned.
  2326   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
  2328   // According to SUSv3, mprotect() should only be used with mappings
  2329   // established by mmap(), and mmap() always maps whole pages. Unaligned
  2330   // 'addr' likely indicates problem in the VM (e.g. trying to change
  2331   // protection of malloc'ed or statically allocated memory). Check the
  2332   // caller if you hit this assert.
  2333   assert(addr == bottom, "sanity check");
  2335   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
  2336   return ::mprotect(bottom, size, prot) == 0;
  2339 // Set protections specified
  2340 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
  2341                         bool is_committed) {
  2342   unsigned int p = 0;
  2343   switch (prot) {
  2344   case MEM_PROT_NONE: p = PROT_NONE; break;
  2345   case MEM_PROT_READ: p = PROT_READ; break;
  2346   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
  2347   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
  2348   default:
  2349     ShouldNotReachHere();
  2351   // is_committed is unused.
  2352   return bsd_mprotect(addr, bytes, p);
  2355 bool os::guard_memory(char* addr, size_t size) {
  2356   return bsd_mprotect(addr, size, PROT_NONE);
  2359 bool os::unguard_memory(char* addr, size_t size) {
  2360   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
  2363 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
  2364   return false;
  2367 // Large page support
  2369 static size_t _large_page_size = 0;
  2371 void os::large_page_init() {
  2375 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
  2376   fatal("This code is not used or maintained.");
  2378   // "exec" is passed in but not used.  Creating the shared image for
  2379   // the code cache doesn't have an SHM_X executable permission to check.
  2380   assert(UseLargePages && UseSHM, "only for SHM large pages");
  2382   key_t key = IPC_PRIVATE;
  2383   char *addr;
  2385   bool warn_on_failure = UseLargePages &&
  2386                         (!FLAG_IS_DEFAULT(UseLargePages) ||
  2387                          !FLAG_IS_DEFAULT(LargePageSizeInBytes)
  2388                         );
  2389   char msg[128];
  2391   // Create a large shared memory region to attach to based on size.
  2392   // Currently, size is the total size of the heap
  2393   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
  2394   if (shmid == -1) {
  2395      // Possible reasons for shmget failure:
  2396      // 1. shmmax is too small for Java heap.
  2397      //    > check shmmax value: cat /proc/sys/kernel/shmmax
  2398      //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
  2399      // 2. not enough large page memory.
  2400      //    > check available large pages: cat /proc/meminfo
  2401      //    > increase amount of large pages:
  2402      //          echo new_value > /proc/sys/vm/nr_hugepages
  2403      //      Note 1: different Bsd may use different name for this property,
  2404      //            e.g. on Redhat AS-3 it is "hugetlb_pool".
  2405      //      Note 2: it's possible there's enough physical memory available but
  2406      //            they are so fragmented after a long run that they can't
  2407      //            coalesce into large pages. Try to reserve large pages when
  2408      //            the system is still "fresh".
  2409      if (warn_on_failure) {
  2410        jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
  2411        warning(msg);
  2413      return NULL;
  2416   // attach to the region
  2417   addr = (char*)shmat(shmid, req_addr, 0);
  2418   int err = errno;
  2420   // Remove shmid. If shmat() is successful, the actual shared memory segment
  2421   // will be deleted when it's detached by shmdt() or when the process
  2422   // terminates. If shmat() is not successful this will remove the shared
  2423   // segment immediately.
  2424   shmctl(shmid, IPC_RMID, NULL);
  2426   if ((intptr_t)addr == -1) {
  2427      if (warn_on_failure) {
  2428        jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
  2429        warning(msg);
  2431      return NULL;
  2434   // The memory is committed
  2435   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, mtNone, CALLER_PC);
  2437   return addr;
  2440 bool os::release_memory_special(char* base, size_t bytes) {
  2441   MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
  2442   // detaching the SHM segment will also delete it, see reserve_memory_special()
  2443   int rslt = shmdt(base);
  2444   if (rslt == 0) {
  2445     tkr.record((address)base, bytes);
  2446     return true;
  2447   } else {
  2448     tkr.discard();
  2449     return false;
  2454 size_t os::large_page_size() {
  2455   return _large_page_size;
  2458 // HugeTLBFS allows application to commit large page memory on demand;
  2459 // with SysV SHM the entire memory region must be allocated as shared
  2460 // memory.
  2461 bool os::can_commit_large_page_memory() {
  2462   return UseHugeTLBFS;
  2465 bool os::can_execute_large_page_memory() {
  2466   return UseHugeTLBFS;
  2469 // Reserve memory at an arbitrary address, only if that area is
  2470 // available (and not reserved for something else).
  2472 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
  2473   const int max_tries = 10;
  2474   char* base[max_tries];
  2475   size_t size[max_tries];
  2476   const size_t gap = 0x000000;
  2478   // Assert only that the size is a multiple of the page size, since
  2479   // that's all that mmap requires, and since that's all we really know
  2480   // about at this low abstraction level.  If we need higher alignment,
  2481   // we can either pass an alignment to this method or verify alignment
  2482   // in one of the methods further up the call chain.  See bug 5044738.
  2483   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
  2485   // Repeatedly allocate blocks until the block is allocated at the
  2486   // right spot. Give up after max_tries. Note that reserve_memory() will
  2487   // automatically update _highest_vm_reserved_address if the call is
  2488   // successful. The variable tracks the highest memory address every reserved
  2489   // by JVM. It is used to detect heap-stack collision if running with
  2490   // fixed-stack BsdThreads. Because here we may attempt to reserve more
  2491   // space than needed, it could confuse the collision detecting code. To
  2492   // solve the problem, save current _highest_vm_reserved_address and
  2493   // calculate the correct value before return.
  2494   address old_highest = _highest_vm_reserved_address;
  2496   // Bsd mmap allows caller to pass an address as hint; give it a try first,
  2497   // if kernel honors the hint then we can return immediately.
  2498   char * addr = anon_mmap(requested_addr, bytes, false);
  2499   if (addr == requested_addr) {
  2500      return requested_addr;
  2503   if (addr != NULL) {
  2504      // mmap() is successful but it fails to reserve at the requested address
  2505      anon_munmap(addr, bytes);
  2508   int i;
  2509   for (i = 0; i < max_tries; ++i) {
  2510     base[i] = reserve_memory(bytes);
  2512     if (base[i] != NULL) {
  2513       // Is this the block we wanted?
  2514       if (base[i] == requested_addr) {
  2515         size[i] = bytes;
  2516         break;
  2519       // Does this overlap the block we wanted? Give back the overlapped
  2520       // parts and try again.
  2522       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
  2523       if (top_overlap >= 0 && top_overlap < bytes) {
  2524         unmap_memory(base[i], top_overlap);
  2525         base[i] += top_overlap;
  2526         size[i] = bytes - top_overlap;
  2527       } else {
  2528         size_t bottom_overlap = base[i] + bytes - requested_addr;
  2529         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
  2530           unmap_memory(requested_addr, bottom_overlap);
  2531           size[i] = bytes - bottom_overlap;
  2532         } else {
  2533           size[i] = bytes;
  2539   // Give back the unused reserved pieces.
  2541   for (int j = 0; j < i; ++j) {
  2542     if (base[j] != NULL) {
  2543       unmap_memory(base[j], size[j]);
  2547   if (i < max_tries) {
  2548     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
  2549     return requested_addr;
  2550   } else {
  2551     _highest_vm_reserved_address = old_highest;
  2552     return NULL;
  2556 size_t os::read(int fd, void *buf, unsigned int nBytes) {
  2557   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
  2560 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
  2561 // Solaris uses poll(), bsd uses park().
  2562 // Poll() is likely a better choice, assuming that Thread.interrupt()
  2563 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
  2564 // SIGSEGV, see 4355769.
  2566 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
  2567   assert(thread == Thread::current(),  "thread consistency check");
  2569   ParkEvent * const slp = thread->_SleepEvent ;
  2570   slp->reset() ;
  2571   OrderAccess::fence() ;
  2573   if (interruptible) {
  2574     jlong prevtime = javaTimeNanos();
  2576     for (;;) {
  2577       if (os::is_interrupted(thread, true)) {
  2578         return OS_INTRPT;
  2581       jlong newtime = javaTimeNanos();
  2583       if (newtime - prevtime < 0) {
  2584         // time moving backwards, should only happen if no monotonic clock
  2585         // not a guarantee() because JVM should not abort on kernel/glibc bugs
  2586         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
  2587       } else {
  2588         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
  2591       if(millis <= 0) {
  2592         return OS_OK;
  2595       prevtime = newtime;
  2598         assert(thread->is_Java_thread(), "sanity check");
  2599         JavaThread *jt = (JavaThread *) thread;
  2600         ThreadBlockInVM tbivm(jt);
  2601         OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
  2603         jt->set_suspend_equivalent();
  2604         // cleared by handle_special_suspend_equivalent_condition() or
  2605         // java_suspend_self() via check_and_wait_while_suspended()
  2607         slp->park(millis);
  2609         // were we externally suspended while we were waiting?
  2610         jt->check_and_wait_while_suspended();
  2613   } else {
  2614     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
  2615     jlong prevtime = javaTimeNanos();
  2617     for (;;) {
  2618       // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
  2619       // the 1st iteration ...
  2620       jlong newtime = javaTimeNanos();
  2622       if (newtime - prevtime < 0) {
  2623         // time moving backwards, should only happen if no monotonic clock
  2624         // not a guarantee() because JVM should not abort on kernel/glibc bugs
  2625         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
  2626       } else {
  2627         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
  2630       if(millis <= 0) break ;
  2632       prevtime = newtime;
  2633       slp->park(millis);
  2635     return OS_OK ;
  2639 int os::naked_sleep() {
  2640   // %% make the sleep time an integer flag. for now use 1 millisec.
  2641   return os::sleep(Thread::current(), 1, false);
  2644 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
  2645 void os::infinite_sleep() {
  2646   while (true) {    // sleep forever ...
  2647     ::sleep(100);   // ... 100 seconds at a time
  2651 // Used to convert frequent JVM_Yield() to nops
  2652 bool os::dont_yield() {
  2653   return DontYieldALot;
  2656 void os::yield() {
  2657   sched_yield();
  2660 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
  2662 void os::yield_all(int attempts) {
  2663   // Yields to all threads, including threads with lower priorities
  2664   // Threads on Bsd are all with same priority. The Solaris style
  2665   // os::yield_all() with nanosleep(1ms) is not necessary.
  2666   sched_yield();
  2669 // Called from the tight loops to possibly influence time-sharing heuristics
  2670 void os::loop_breaker(int attempts) {
  2671   os::yield_all(attempts);
  2674 ////////////////////////////////////////////////////////////////////////////////
  2675 // thread priority support
  2677 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
  2678 // only supports dynamic priority, static priority must be zero. For real-time
  2679 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
  2680 // However, for large multi-threaded applications, SCHED_RR is not only slower
  2681 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
  2682 // of 5 runs - Sep 2005).
  2683 //
  2684 // The following code actually changes the niceness of kernel-thread/LWP. It
  2685 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
  2686 // not the entire user process, and user level threads are 1:1 mapped to kernel
  2687 // threads. It has always been the case, but could change in the future. For
  2688 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
  2689 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
  2691 #if !defined(__APPLE__)
  2692 int os::java_to_os_priority[CriticalPriority + 1] = {
  2693   19,              // 0 Entry should never be used
  2695    0,              // 1 MinPriority
  2696    3,              // 2
  2697    6,              // 3
  2699   10,              // 4
  2700   15,              // 5 NormPriority
  2701   18,              // 6
  2703   21,              // 7
  2704   25,              // 8
  2705   28,              // 9 NearMaxPriority
  2707   31,              // 10 MaxPriority
  2709   31               // 11 CriticalPriority
  2710 };
  2711 #else
  2712 /* Using Mach high-level priority assignments */
  2713 int os::java_to_os_priority[CriticalPriority + 1] = {
  2714    0,              // 0 Entry should never be used (MINPRI_USER)
  2716   27,              // 1 MinPriority
  2717   28,              // 2
  2718   29,              // 3
  2720   30,              // 4
  2721   31,              // 5 NormPriority (BASEPRI_DEFAULT)
  2722   32,              // 6
  2724   33,              // 7
  2725   34,              // 8
  2726   35,              // 9 NearMaxPriority
  2728   36,              // 10 MaxPriority
  2730   36               // 11 CriticalPriority
  2731 };
  2732 #endif
  2734 static int prio_init() {
  2735   if (ThreadPriorityPolicy == 1) {
  2736     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
  2737     // if effective uid is not root. Perhaps, a more elegant way of doing
  2738     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
  2739     if (geteuid() != 0) {
  2740       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
  2741         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
  2743       ThreadPriorityPolicy = 0;
  2746   if (UseCriticalJavaThreadPriority) {
  2747     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
  2749   return 0;
  2752 OSReturn os::set_native_priority(Thread* thread, int newpri) {
  2753   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
  2755 #ifdef __OpenBSD__
  2756   // OpenBSD pthread_setprio starves low priority threads
  2757   return OS_OK;
  2758 #elif defined(__FreeBSD__)
  2759   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
  2760 #elif defined(__APPLE__) || defined(__NetBSD__)
  2761   struct sched_param sp;
  2762   int policy;
  2763   pthread_t self = pthread_self();
  2765   if (pthread_getschedparam(self, &policy, &sp) != 0)
  2766     return OS_ERR;
  2768   sp.sched_priority = newpri;
  2769   if (pthread_setschedparam(self, policy, &sp) != 0)
  2770     return OS_ERR;
  2772   return OS_OK;
  2773 #else
  2774   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
  2775   return (ret == 0) ? OS_OK : OS_ERR;
  2776 #endif
  2779 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
  2780   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
  2781     *priority_ptr = java_to_os_priority[NormPriority];
  2782     return OS_OK;
  2785   errno = 0;
  2786 #if defined(__OpenBSD__) || defined(__FreeBSD__)
  2787   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
  2788 #elif defined(__APPLE__) || defined(__NetBSD__)
  2789   int policy;
  2790   struct sched_param sp;
  2792   pthread_getschedparam(pthread_self(), &policy, &sp);
  2793   *priority_ptr = sp.sched_priority;
  2794 #else
  2795   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
  2796 #endif
  2797   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
  2800 // Hint to the underlying OS that a task switch would not be good.
  2801 // Void return because it's a hint and can fail.
  2802 void os::hint_no_preempt() {}
  2804 ////////////////////////////////////////////////////////////////////////////////
  2805 // suspend/resume support
  2807 //  the low-level signal-based suspend/resume support is a remnant from the
  2808 //  old VM-suspension that used to be for java-suspension, safepoints etc,
  2809 //  within hotspot. Now there is a single use-case for this:
  2810 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
  2811 //      that runs in the watcher thread.
  2812 //  The remaining code is greatly simplified from the more general suspension
  2813 //  code that used to be used.
  2814 //
  2815 //  The protocol is quite simple:
  2816 //  - suspend:
  2817 //      - sends a signal to the target thread
  2818 //      - polls the suspend state of the osthread using a yield loop
  2819 //      - target thread signal handler (SR_handler) sets suspend state
  2820 //        and blocks in sigsuspend until continued
  2821 //  - resume:
  2822 //      - sets target osthread state to continue
  2823 //      - sends signal to end the sigsuspend loop in the SR_handler
  2824 //
  2825 //  Note that the SR_lock plays no role in this suspend/resume protocol.
  2826 //
  2828 static void resume_clear_context(OSThread *osthread) {
  2829   osthread->set_ucontext(NULL);
  2830   osthread->set_siginfo(NULL);
  2833 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
  2834   osthread->set_ucontext(context);
  2835   osthread->set_siginfo(siginfo);
  2838 //
  2839 // Handler function invoked when a thread's execution is suspended or
  2840 // resumed. We have to be careful that only async-safe functions are
  2841 // called here (Note: most pthread functions are not async safe and
  2842 // should be avoided.)
  2843 //
  2844 // Note: sigwait() is a more natural fit than sigsuspend() from an
  2845 // interface point of view, but sigwait() prevents the signal hander
  2846 // from being run. libpthread would get very confused by not having
  2847 // its signal handlers run and prevents sigwait()'s use with the
  2848 // mutex granting granting signal.
  2849 //
  2850 // Currently only ever called on the VMThread or JavaThread
  2851 //
  2852 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
  2853   // Save and restore errno to avoid confusing native code with EINTR
  2854   // after sigsuspend.
  2855   int old_errno = errno;
  2857   Thread* thread = Thread::current();
  2858   OSThread* osthread = thread->osthread();
  2859   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
  2861   os::SuspendResume::State current = osthread->sr.state();
  2862   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
  2863     suspend_save_context(osthread, siginfo, context);
  2865     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
  2866     os::SuspendResume::State state = osthread->sr.suspended();
  2867     if (state == os::SuspendResume::SR_SUSPENDED) {
  2868       sigset_t suspend_set;  // signals for sigsuspend()
  2870       // get current set of blocked signals and unblock resume signal
  2871       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
  2872       sigdelset(&suspend_set, SR_signum);
  2874       sr_semaphore.signal();
  2875       // wait here until we are resumed
  2876       while (1) {
  2877         sigsuspend(&suspend_set);
  2879         os::SuspendResume::State result = osthread->sr.running();
  2880         if (result == os::SuspendResume::SR_RUNNING) {
  2881           sr_semaphore.signal();
  2882           break;
  2883         } else if (result != os::SuspendResume::SR_SUSPENDED) {
  2884           ShouldNotReachHere();
  2888     } else if (state == os::SuspendResume::SR_RUNNING) {
  2889       // request was cancelled, continue
  2890     } else {
  2891       ShouldNotReachHere();
  2894     resume_clear_context(osthread);
  2895   } else if (current == os::SuspendResume::SR_RUNNING) {
  2896     // request was cancelled, continue
  2897   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
  2898     // ignore
  2899   } else {
  2900     // ignore
  2903   errno = old_errno;
  2907 static int SR_initialize() {
  2908   struct sigaction act;
  2909   char *s;
  2910   /* Get signal number to use for suspend/resume */
  2911   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
  2912     int sig = ::strtol(s, 0, 10);
  2913     if (sig > 0 || sig < NSIG) {
  2914         SR_signum = sig;
  2918   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
  2919         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
  2921   sigemptyset(&SR_sigset);
  2922   sigaddset(&SR_sigset, SR_signum);
  2924   /* Set up signal handler for suspend/resume */
  2925   act.sa_flags = SA_RESTART|SA_SIGINFO;
  2926   act.sa_handler = (void (*)(int)) SR_handler;
  2928   // SR_signum is blocked by default.
  2929   // 4528190 - We also need to block pthread restart signal (32 on all
  2930   // supported Bsd platforms). Note that BsdThreads need to block
  2931   // this signal for all threads to work properly. So we don't have
  2932   // to use hard-coded signal number when setting up the mask.
  2933   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
  2935   if (sigaction(SR_signum, &act, 0) == -1) {
  2936     return -1;
  2939   // Save signal flag
  2940   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
  2941   return 0;
  2944 static int sr_notify(OSThread* osthread) {
  2945   int status = pthread_kill(osthread->pthread_id(), SR_signum);
  2946   assert_status(status == 0, status, "pthread_kill");
  2947   return status;
  2950 // "Randomly" selected value for how long we want to spin
  2951 // before bailing out on suspending a thread, also how often
  2952 // we send a signal to a thread we want to resume
  2953 static const int RANDOMLY_LARGE_INTEGER = 1000000;
  2954 static const int RANDOMLY_LARGE_INTEGER2 = 100;
  2956 // returns true on success and false on error - really an error is fatal
  2957 // but this seems the normal response to library errors
  2958 static bool do_suspend(OSThread* osthread) {
  2959   assert(osthread->sr.is_running(), "thread should be running");
  2960   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
  2962   // mark as suspended and send signal
  2963   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
  2964     // failed to switch, state wasn't running?
  2965     ShouldNotReachHere();
  2966     return false;
  2969   if (sr_notify(osthread) != 0) {
  2970     ShouldNotReachHere();
  2973   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
  2974   while (true) {
  2975     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
  2976       break;
  2977     } else {
  2978       // timeout
  2979       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
  2980       if (cancelled == os::SuspendResume::SR_RUNNING) {
  2981         return false;
  2982       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
  2983         // make sure that we consume the signal on the semaphore as well
  2984         sr_semaphore.wait();
  2985         break;
  2986       } else {
  2987         ShouldNotReachHere();
  2988         return false;
  2993   guarantee(osthread->sr.is_suspended(), "Must be suspended");
  2994   return true;
  2997 static void do_resume(OSThread* osthread) {
  2998   assert(osthread->sr.is_suspended(), "thread should be suspended");
  2999   assert(!sr_semaphore.trywait(), "invalid semaphore state");
  3001   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
  3002     // failed to switch to WAKEUP_REQUEST
  3003     ShouldNotReachHere();
  3004     return;
  3007   while (true) {
  3008     if (sr_notify(osthread) == 0) {
  3009       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
  3010         if (osthread->sr.is_running()) {
  3011           return;
  3014     } else {
  3015       ShouldNotReachHere();
  3019   guarantee(osthread->sr.is_running(), "Must be running!");
  3022 ////////////////////////////////////////////////////////////////////////////////
  3023 // interrupt support
  3025 void os::interrupt(Thread* thread) {
  3026   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
  3027     "possibility of dangling Thread pointer");
  3029   OSThread* osthread = thread->osthread();
  3031   if (!osthread->interrupted()) {
  3032     osthread->set_interrupted(true);
  3033     // More than one thread can get here with the same value of osthread,
  3034     // resulting in multiple notifications.  We do, however, want the store
  3035     // to interrupted() to be visible to other threads before we execute unpark().
  3036     OrderAccess::fence();
  3037     ParkEvent * const slp = thread->_SleepEvent ;
  3038     if (slp != NULL) slp->unpark() ;
  3041   // For JSR166. Unpark even if interrupt status already was set
  3042   if (thread->is_Java_thread())
  3043     ((JavaThread*)thread)->parker()->unpark();
  3045   ParkEvent * ev = thread->_ParkEvent ;
  3046   if (ev != NULL) ev->unpark() ;
  3050 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
  3051   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
  3052     "possibility of dangling Thread pointer");
  3054   OSThread* osthread = thread->osthread();
  3056   bool interrupted = osthread->interrupted();
  3058   if (interrupted && clear_interrupted) {
  3059     osthread->set_interrupted(false);
  3060     // consider thread->_SleepEvent->reset() ... optional optimization
  3063   return interrupted;
  3066 ///////////////////////////////////////////////////////////////////////////////////
  3067 // signal handling (except suspend/resume)
  3069 // This routine may be used by user applications as a "hook" to catch signals.
  3070 // The user-defined signal handler must pass unrecognized signals to this
  3071 // routine, and if it returns true (non-zero), then the signal handler must
  3072 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
  3073 // routine will never retun false (zero), but instead will execute a VM panic
  3074 // routine kill the process.
  3075 //
  3076 // If this routine returns false, it is OK to call it again.  This allows
  3077 // the user-defined signal handler to perform checks either before or after
  3078 // the VM performs its own checks.  Naturally, the user code would be making
  3079 // a serious error if it tried to handle an exception (such as a null check
  3080 // or breakpoint) that the VM was generating for its own correct operation.
  3081 //
  3082 // This routine may recognize any of the following kinds of signals:
  3083 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
  3084 // It should be consulted by handlers for any of those signals.
  3085 //
  3086 // The caller of this routine must pass in the three arguments supplied
  3087 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
  3088 // field of the structure passed to sigaction().  This routine assumes that
  3089 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
  3090 //
  3091 // Note that the VM will print warnings if it detects conflicting signal
  3092 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
  3093 //
  3094 extern "C" JNIEXPORT int
  3095 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
  3096                         void* ucontext, int abort_if_unrecognized);
  3098 void signalHandler(int sig, siginfo_t* info, void* uc) {
  3099   assert(info != NULL && uc != NULL, "it must be old kernel");
  3100   int orig_errno = errno;  // Preserve errno value over signal handler.
  3101   JVM_handle_bsd_signal(sig, info, uc, true);
  3102   errno = orig_errno;
  3106 // This boolean allows users to forward their own non-matching signals
  3107 // to JVM_handle_bsd_signal, harmlessly.
  3108 bool os::Bsd::signal_handlers_are_installed = false;
  3110 // For signal-chaining
  3111 struct sigaction os::Bsd::sigact[MAXSIGNUM];
  3112 unsigned int os::Bsd::sigs = 0;
  3113 bool os::Bsd::libjsig_is_loaded = false;
  3114 typedef struct sigaction *(*get_signal_t)(int);
  3115 get_signal_t os::Bsd::get_signal_action = NULL;
  3117 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
  3118   struct sigaction *actp = NULL;
  3120   if (libjsig_is_loaded) {
  3121     // Retrieve the old signal handler from libjsig
  3122     actp = (*get_signal_action)(sig);
  3124   if (actp == NULL) {
  3125     // Retrieve the preinstalled signal handler from jvm
  3126     actp = get_preinstalled_handler(sig);
  3129   return actp;
  3132 static bool call_chained_handler(struct sigaction *actp, int sig,
  3133                                  siginfo_t *siginfo, void *context) {
  3134   // Call the old signal handler
  3135   if (actp->sa_handler == SIG_DFL) {
  3136     // It's more reasonable to let jvm treat it as an unexpected exception
  3137     // instead of taking the default action.
  3138     return false;
  3139   } else if (actp->sa_handler != SIG_IGN) {
  3140     if ((actp->sa_flags & SA_NODEFER) == 0) {
  3141       // automaticlly block the signal
  3142       sigaddset(&(actp->sa_mask), sig);
  3145     sa_handler_t hand;
  3146     sa_sigaction_t sa;
  3147     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
  3148     // retrieve the chained handler
  3149     if (siginfo_flag_set) {
  3150       sa = actp->sa_sigaction;
  3151     } else {
  3152       hand = actp->sa_handler;
  3155     if ((actp->sa_flags & SA_RESETHAND) != 0) {
  3156       actp->sa_handler = SIG_DFL;
  3159     // try to honor the signal mask
  3160     sigset_t oset;
  3161     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
  3163     // call into the chained handler
  3164     if (siginfo_flag_set) {
  3165       (*sa)(sig, siginfo, context);
  3166     } else {
  3167       (*hand)(sig);
  3170     // restore the signal mask
  3171     pthread_sigmask(SIG_SETMASK, &oset, 0);
  3173   // Tell jvm's signal handler the signal is taken care of.
  3174   return true;
  3177 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
  3178   bool chained = false;
  3179   // signal-chaining
  3180   if (UseSignalChaining) {
  3181     struct sigaction *actp = get_chained_signal_action(sig);
  3182     if (actp != NULL) {
  3183       chained = call_chained_handler(actp, sig, siginfo, context);
  3186   return chained;
  3189 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
  3190   if ((( (unsigned int)1 << sig ) & sigs) != 0) {
  3191     return &sigact[sig];
  3193   return NULL;
  3196 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
  3197   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3198   sigact[sig] = oldAct;
  3199   sigs |= (unsigned int)1 << sig;
  3202 // for diagnostic
  3203 int os::Bsd::sigflags[MAXSIGNUM];
  3205 int os::Bsd::get_our_sigflags(int sig) {
  3206   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3207   return sigflags[sig];
  3210 void os::Bsd::set_our_sigflags(int sig, int flags) {
  3211   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3212   sigflags[sig] = flags;
  3215 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
  3216   // Check for overwrite.
  3217   struct sigaction oldAct;
  3218   sigaction(sig, (struct sigaction*)NULL, &oldAct);
  3220   void* oldhand = oldAct.sa_sigaction
  3221                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
  3222                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
  3223   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
  3224       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
  3225       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
  3226     if (AllowUserSignalHandlers || !set_installed) {
  3227       // Do not overwrite; user takes responsibility to forward to us.
  3228       return;
  3229     } else if (UseSignalChaining) {
  3230       // save the old handler in jvm
  3231       save_preinstalled_handler(sig, oldAct);
  3232       // libjsig also interposes the sigaction() call below and saves the
  3233       // old sigaction on it own.
  3234     } else {
  3235       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
  3236                     "%#lx for signal %d.", (long)oldhand, sig));
  3240   struct sigaction sigAct;
  3241   sigfillset(&(sigAct.sa_mask));
  3242   sigAct.sa_handler = SIG_DFL;
  3243   if (!set_installed) {
  3244     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  3245   } else {
  3246     sigAct.sa_sigaction = signalHandler;
  3247     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  3249 #if __APPLE__
  3250   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
  3251   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
  3252   // if the signal handler declares it will handle it on alternate stack.
  3253   // Notice we only declare we will handle it on alt stack, but we are not
  3254   // actually going to use real alt stack - this is just a workaround.
  3255   // Please see ux_exception.c, method catch_mach_exception_raise for details
  3256   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
  3257   if (sig == SIGSEGV) {
  3258     sigAct.sa_flags |= SA_ONSTACK;
  3260 #endif
  3262   // Save flags, which are set by ours
  3263   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3264   sigflags[sig] = sigAct.sa_flags;
  3266   int ret = sigaction(sig, &sigAct, &oldAct);
  3267   assert(ret == 0, "check");
  3269   void* oldhand2  = oldAct.sa_sigaction
  3270                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
  3271                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
  3272   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
  3275 // install signal handlers for signals that HotSpot needs to
  3276 // handle in order to support Java-level exception handling.
  3278 void os::Bsd::install_signal_handlers() {
  3279   if (!signal_handlers_are_installed) {
  3280     signal_handlers_are_installed = true;
  3282     // signal-chaining
  3283     typedef void (*signal_setting_t)();
  3284     signal_setting_t begin_signal_setting = NULL;
  3285     signal_setting_t end_signal_setting = NULL;
  3286     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
  3287                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
  3288     if (begin_signal_setting != NULL) {
  3289       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
  3290                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
  3291       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
  3292                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
  3293       libjsig_is_loaded = true;
  3294       assert(UseSignalChaining, "should enable signal-chaining");
  3296     if (libjsig_is_loaded) {
  3297       // Tell libjsig jvm is setting signal handlers
  3298       (*begin_signal_setting)();
  3301     set_signal_handler(SIGSEGV, true);
  3302     set_signal_handler(SIGPIPE, true);
  3303     set_signal_handler(SIGBUS, true);
  3304     set_signal_handler(SIGILL, true);
  3305     set_signal_handler(SIGFPE, true);
  3306     set_signal_handler(SIGXFSZ, true);
  3308 #if defined(__APPLE__)
  3309     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
  3310     // signals caught and handled by the JVM. To work around this, we reset the mach task
  3311     // signal handler that's placed on our process by CrashReporter. This disables
  3312     // CrashReporter-based reporting.
  3313     //
  3314     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
  3315     // on caught fatal signals.
  3316     //
  3317     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
  3318     // handlers. By replacing the existing task exception handler, we disable gdb's mach
  3319     // exception handling, while leaving the standard BSD signal handlers functional.
  3320     kern_return_t kr;
  3321     kr = task_set_exception_ports(mach_task_self(),
  3322         EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
  3323         MACH_PORT_NULL,
  3324         EXCEPTION_STATE_IDENTITY,
  3325         MACHINE_THREAD_STATE);
  3327     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
  3328 #endif
  3330     if (libjsig_is_loaded) {
  3331       // Tell libjsig jvm finishes setting signal handlers
  3332       (*end_signal_setting)();
  3335     // We don't activate signal checker if libjsig is in place, we trust ourselves
  3336     // and if UserSignalHandler is installed all bets are off
  3337     if (CheckJNICalls) {
  3338       if (libjsig_is_loaded) {
  3339         if (PrintJNIResolving) {
  3340           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
  3342         check_signals = false;
  3344       if (AllowUserSignalHandlers) {
  3345         if (PrintJNIResolving) {
  3346           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
  3348         check_signals = false;
  3355 /////
  3356 // glibc on Bsd platform uses non-documented flag
  3357 // to indicate, that some special sort of signal
  3358 // trampoline is used.
  3359 // We will never set this flag, and we should
  3360 // ignore this flag in our diagnostic
  3361 #ifdef SIGNIFICANT_SIGNAL_MASK
  3362 #undef SIGNIFICANT_SIGNAL_MASK
  3363 #endif
  3364 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
  3366 static const char* get_signal_handler_name(address handler,
  3367                                            char* buf, int buflen) {
  3368   int offset;
  3369   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
  3370   if (found) {
  3371     // skip directory names
  3372     const char *p1, *p2;
  3373     p1 = buf;
  3374     size_t len = strlen(os::file_separator());
  3375     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
  3376     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
  3377   } else {
  3378     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
  3380   return buf;
  3383 static void print_signal_handler(outputStream* st, int sig,
  3384                                  char* buf, size_t buflen) {
  3385   struct sigaction sa;
  3387   sigaction(sig, NULL, &sa);
  3389   // See comment for SIGNIFICANT_SIGNAL_MASK define
  3390   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
  3392   st->print("%s: ", os::exception_name(sig, buf, buflen));
  3394   address handler = (sa.sa_flags & SA_SIGINFO)
  3395     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
  3396     : CAST_FROM_FN_PTR(address, sa.sa_handler);
  3398   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
  3399     st->print("SIG_DFL");
  3400   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
  3401     st->print("SIG_IGN");
  3402   } else {
  3403     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
  3406   st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask);
  3408   address rh = VMError::get_resetted_sighandler(sig);
  3409   // May be, handler was resetted by VMError?
  3410   if(rh != NULL) {
  3411     handler = rh;
  3412     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
  3415   st->print(", sa_flags="   PTR32_FORMAT, sa.sa_flags);
  3417   // Check: is it our handler?
  3418   if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
  3419      handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
  3420     // It is our signal handler
  3421     // check for flags, reset system-used one!
  3422     if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
  3423       st->print(
  3424                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
  3425                 os::Bsd::get_our_sigflags(sig));
  3428   st->cr();
  3432 #define DO_SIGNAL_CHECK(sig) \
  3433   if (!sigismember(&check_signal_done, sig)) \
  3434     os::Bsd::check_signal_handler(sig)
  3436 // This method is a periodic task to check for misbehaving JNI applications
  3437 // under CheckJNI, we can add any periodic checks here
  3439 void os::run_periodic_checks() {
  3441   if (check_signals == false) return;
  3443   // SEGV and BUS if overridden could potentially prevent
  3444   // generation of hs*.log in the event of a crash, debugging
  3445   // such a case can be very challenging, so we absolutely
  3446   // check the following for a good measure:
  3447   DO_SIGNAL_CHECK(SIGSEGV);
  3448   DO_SIGNAL_CHECK(SIGILL);
  3449   DO_SIGNAL_CHECK(SIGFPE);
  3450   DO_SIGNAL_CHECK(SIGBUS);
  3451   DO_SIGNAL_CHECK(SIGPIPE);
  3452   DO_SIGNAL_CHECK(SIGXFSZ);
  3455   // ReduceSignalUsage allows the user to override these handlers
  3456   // see comments at the very top and jvm_solaris.h
  3457   if (!ReduceSignalUsage) {
  3458     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
  3459     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
  3460     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
  3461     DO_SIGNAL_CHECK(BREAK_SIGNAL);
  3464   DO_SIGNAL_CHECK(SR_signum);
  3465   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
  3468 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
  3470 static os_sigaction_t os_sigaction = NULL;
  3472 void os::Bsd::check_signal_handler(int sig) {
  3473   char buf[O_BUFLEN];
  3474   address jvmHandler = NULL;
  3477   struct sigaction act;
  3478   if (os_sigaction == NULL) {
  3479     // only trust the default sigaction, in case it has been interposed
  3480     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
  3481     if (os_sigaction == NULL) return;
  3484   os_sigaction(sig, (struct sigaction*)NULL, &act);
  3487   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
  3489   address thisHandler = (act.sa_flags & SA_SIGINFO)
  3490     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
  3491     : CAST_FROM_FN_PTR(address, act.sa_handler) ;
  3494   switch(sig) {
  3495   case SIGSEGV:
  3496   case SIGBUS:
  3497   case SIGFPE:
  3498   case SIGPIPE:
  3499   case SIGILL:
  3500   case SIGXFSZ:
  3501     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
  3502     break;
  3504   case SHUTDOWN1_SIGNAL:
  3505   case SHUTDOWN2_SIGNAL:
  3506   case SHUTDOWN3_SIGNAL:
  3507   case BREAK_SIGNAL:
  3508     jvmHandler = (address)user_handler();
  3509     break;
  3511   case INTERRUPT_SIGNAL:
  3512     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
  3513     break;
  3515   default:
  3516     if (sig == SR_signum) {
  3517       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
  3518     } else {
  3519       return;
  3521     break;
  3524   if (thisHandler != jvmHandler) {
  3525     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
  3526     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
  3527     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
  3528     // No need to check this sig any longer
  3529     sigaddset(&check_signal_done, sig);
  3530   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
  3531     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
  3532     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
  3533     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
  3534     // No need to check this sig any longer
  3535     sigaddset(&check_signal_done, sig);
  3538   // Dump all the signal
  3539   if (sigismember(&check_signal_done, sig)) {
  3540     print_signal_handlers(tty, buf, O_BUFLEN);
  3544 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
  3546 extern bool signal_name(int signo, char* buf, size_t len);
  3548 const char* os::exception_name(int exception_code, char* buf, size_t size) {
  3549   if (0 < exception_code && exception_code <= SIGRTMAX) {
  3550     // signal
  3551     if (!signal_name(exception_code, buf, size)) {
  3552       jio_snprintf(buf, size, "SIG%d", exception_code);
  3554     return buf;
  3555   } else {
  3556     return NULL;
  3560 // this is called _before_ the most of global arguments have been parsed
  3561 void os::init(void) {
  3562   char dummy;   /* used to get a guess on initial stack address */
  3563 //  first_hrtime = gethrtime();
  3565   // With BsdThreads the JavaMain thread pid (primordial thread)
  3566   // is different than the pid of the java launcher thread.
  3567   // So, on Bsd, the launcher thread pid is passed to the VM
  3568   // via the sun.java.launcher.pid property.
  3569   // Use this property instead of getpid() if it was correctly passed.
  3570   // See bug 6351349.
  3571   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
  3573   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
  3575   clock_tics_per_sec = CLK_TCK;
  3577   init_random(1234567);
  3579   ThreadCritical::initialize();
  3581   Bsd::set_page_size(getpagesize());
  3582   if (Bsd::page_size() == -1) {
  3583     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
  3584                   strerror(errno)));
  3586   init_page_sizes((size_t) Bsd::page_size());
  3588   Bsd::initialize_system_info();
  3590   // main_thread points to the aboriginal thread
  3591   Bsd::_main_thread = pthread_self();
  3593   Bsd::clock_init();
  3594   initial_time_count = javaTimeNanos();
  3596 #ifdef __APPLE__
  3597   // XXXDARWIN
  3598   // Work around the unaligned VM callbacks in hotspot's
  3599   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
  3600   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
  3601   // alignment when doing symbol lookup. To work around this, we force early
  3602   // binding of all symbols now, thus binding when alignment is known-good.
  3603   _dyld_bind_fully_image_containing_address((const void *) &os::init);
  3604 #endif
  3607 // To install functions for atexit system call
  3608 extern "C" {
  3609   static void perfMemory_exit_helper() {
  3610     perfMemory_exit();
  3614 // this is called _after_ the global arguments have been parsed
  3615 jint os::init_2(void)
  3617   // Allocate a single page and mark it as readable for safepoint polling
  3618   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  3619   guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
  3621   os::set_polling_page( polling_page );
  3623 #ifndef PRODUCT
  3624   if(Verbose && PrintMiscellaneous)
  3625     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
  3626 #endif
  3628   if (!UseMembar) {
  3629     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  3630     guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
  3631     os::set_memory_serialize_page( mem_serialize_page );
  3633 #ifndef PRODUCT
  3634     if(Verbose && PrintMiscellaneous)
  3635       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
  3636 #endif
  3639   // initialize suspend/resume support - must do this before signal_sets_init()
  3640   if (SR_initialize() != 0) {
  3641     perror("SR_initialize failed");
  3642     return JNI_ERR;
  3645   Bsd::signal_sets_init();
  3646   Bsd::install_signal_handlers();
  3648   // Check minimum allowable stack size for thread creation and to initialize
  3649   // the java system classes, including StackOverflowError - depends on page
  3650   // size.  Add a page for compiler2 recursion in main thread.
  3651   // Add in 2*BytesPerWord times page size to account for VM stack during
  3652   // class initialization depending on 32 or 64 bit VM.
  3653   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
  3654             (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
  3655                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
  3657   size_t threadStackSizeInBytes = ThreadStackSize * K;
  3658   if (threadStackSizeInBytes != 0 &&
  3659       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
  3660         tty->print_cr("\nThe stack size specified is too small, "
  3661                       "Specify at least %dk",
  3662                       os::Bsd::min_stack_allowed/ K);
  3663         return JNI_ERR;
  3666   // Make the stack size a multiple of the page size so that
  3667   // the yellow/red zones can be guarded.
  3668   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
  3669         vm_page_size()));
  3671   if (MaxFDLimit) {
  3672     // set the number of file descriptors to max. print out error
  3673     // if getrlimit/setrlimit fails but continue regardless.
  3674     struct rlimit nbr_files;
  3675     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
  3676     if (status != 0) {
  3677       if (PrintMiscellaneous && (Verbose || WizardMode))
  3678         perror("os::init_2 getrlimit failed");
  3679     } else {
  3680       nbr_files.rlim_cur = nbr_files.rlim_max;
  3682 #ifdef __APPLE__
  3683       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
  3684       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
  3685       // be used instead
  3686       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
  3687 #endif
  3689       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
  3690       if (status != 0) {
  3691         if (PrintMiscellaneous && (Verbose || WizardMode))
  3692           perror("os::init_2 setrlimit failed");
  3697   // at-exit methods are called in the reverse order of their registration.
  3698   // atexit functions are called on return from main or as a result of a
  3699   // call to exit(3C). There can be only 32 of these functions registered
  3700   // and atexit() does not set errno.
  3702   if (PerfAllowAtExitRegistration) {
  3703     // only register atexit functions if PerfAllowAtExitRegistration is set.
  3704     // atexit functions can be delayed until process exit time, which
  3705     // can be problematic for embedded VM situations. Embedded VMs should
  3706     // call DestroyJavaVM() to assure that VM resources are released.
  3708     // note: perfMemory_exit_helper atexit function may be removed in
  3709     // the future if the appropriate cleanup code can be added to the
  3710     // VM_Exit VMOperation's doit method.
  3711     if (atexit(perfMemory_exit_helper) != 0) {
  3712       warning("os::init2 atexit(perfMemory_exit_helper) failed");
  3716   // initialize thread priority policy
  3717   prio_init();
  3719 #ifdef __APPLE__
  3720   // dynamically link to objective c gc registration
  3721   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
  3722   if (handleLibObjc != NULL) {
  3723     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
  3725 #endif
  3727   return JNI_OK;
  3730 // this is called at the end of vm_initialization
  3731 void os::init_3(void) { }
  3733 // Mark the polling page as unreadable
  3734 void os::make_polling_page_unreadable(void) {
  3735   if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
  3736     fatal("Could not disable polling page");
  3737 };
  3739 // Mark the polling page as readable
  3740 void os::make_polling_page_readable(void) {
  3741   if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
  3742     fatal("Could not enable polling page");
  3744 };
  3746 int os::active_processor_count() {
  3747   return _processor_count;
  3750 void os::set_native_thread_name(const char *name) {
  3751 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
  3752   // This is only supported in Snow Leopard and beyond
  3753   if (name != NULL) {
  3754     // Add a "Java: " prefix to the name
  3755     char buf[MAXTHREADNAMESIZE];
  3756     snprintf(buf, sizeof(buf), "Java: %s", name);
  3757     pthread_setname_np(buf);
  3759 #endif
  3762 bool os::distribute_processes(uint length, uint* distribution) {
  3763   // Not yet implemented.
  3764   return false;
  3767 bool os::bind_to_processor(uint processor_id) {
  3768   // Not yet implemented.
  3769   return false;
  3772 void os::SuspendedThreadTask::internal_do_task() {
  3773   if (do_suspend(_thread->osthread())) {
  3774     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
  3775     do_task(context);
  3776     do_resume(_thread->osthread());
  3780 ///
  3781 class PcFetcher : public os::SuspendedThreadTask {
  3782 public:
  3783   PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
  3784   ExtendedPC result();
  3785 protected:
  3786   void do_task(const os::SuspendedThreadTaskContext& context);
  3787 private:
  3788   ExtendedPC _epc;
  3789 };
  3791 ExtendedPC PcFetcher::result() {
  3792   guarantee(is_done(), "task is not done yet.");
  3793   return _epc;
  3796 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
  3797   Thread* thread = context.thread();
  3798   OSThread* osthread = thread->osthread();
  3799   if (osthread->ucontext() != NULL) {
  3800     _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
  3801   } else {
  3802     // NULL context is unexpected, double-check this is the VMThread
  3803     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
  3807 // Suspends the target using the signal mechanism and then grabs the PC before
  3808 // resuming the target. Used by the flat-profiler only
  3809 ExtendedPC os::get_thread_pc(Thread* thread) {
  3810   // Make sure that it is called by the watcher for the VMThread
  3811   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
  3812   assert(thread->is_VM_thread(), "Can only be called for VMThread");
  3814   PcFetcher fetcher(thread);
  3815   fetcher.run();
  3816   return fetcher.result();
  3819 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
  3821   return pthread_cond_timedwait(_cond, _mutex, _abstime);
  3824 ////////////////////////////////////////////////////////////////////////////////
  3825 // debug support
  3827 bool os::find(address addr, outputStream* st) {
  3828   Dl_info dlinfo;
  3829   memset(&dlinfo, 0, sizeof(dlinfo));
  3830   if (dladdr(addr, &dlinfo) != 0) {
  3831     st->print(PTR_FORMAT ": ", addr);
  3832     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
  3833       st->print("%s+%#x", dlinfo.dli_sname,
  3834                  addr - (intptr_t)dlinfo.dli_saddr);
  3835     } else if (dlinfo.dli_fbase != NULL) {
  3836       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
  3837     } else {
  3838       st->print("<absolute address>");
  3840     if (dlinfo.dli_fname != NULL) {
  3841       st->print(" in %s", dlinfo.dli_fname);
  3843     if (dlinfo.dli_fbase != NULL) {
  3844       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
  3846     st->cr();
  3848     if (Verbose) {
  3849       // decode some bytes around the PC
  3850       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
  3851       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
  3852       address       lowest = (address) dlinfo.dli_sname;
  3853       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
  3854       if (begin < lowest)  begin = lowest;
  3855       Dl_info dlinfo2;
  3856       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
  3857           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
  3858         end = (address) dlinfo2.dli_saddr;
  3859       Disassembler::decode(begin, end, st);
  3861     return true;
  3863   return false;
  3866 ////////////////////////////////////////////////////////////////////////////////
  3867 // misc
  3869 // This does not do anything on Bsd. This is basically a hook for being
  3870 // able to use structured exception handling (thread-local exception filters)
  3871 // on, e.g., Win32.
  3872 void
  3873 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
  3874                          JavaCallArguments* args, Thread* thread) {
  3875   f(value, method, args, thread);
  3878 void os::print_statistics() {
  3881 int os::message_box(const char* title, const char* message) {
  3882   int i;
  3883   fdStream err(defaultStream::error_fd());
  3884   for (i = 0; i < 78; i++) err.print_raw("=");
  3885   err.cr();
  3886   err.print_raw_cr(title);
  3887   for (i = 0; i < 78; i++) err.print_raw("-");
  3888   err.cr();
  3889   err.print_raw_cr(message);
  3890   for (i = 0; i < 78; i++) err.print_raw("=");
  3891   err.cr();
  3893   char buf[16];
  3894   // Prevent process from exiting upon "read error" without consuming all CPU
  3895   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
  3897   return buf[0] == 'y' || buf[0] == 'Y';
  3900 int os::stat(const char *path, struct stat *sbuf) {
  3901   char pathbuf[MAX_PATH];
  3902   if (strlen(path) > MAX_PATH - 1) {
  3903     errno = ENAMETOOLONG;
  3904     return -1;
  3906   os::native_path(strcpy(pathbuf, path));
  3907   return ::stat(pathbuf, sbuf);
  3910 bool os::check_heap(bool force) {
  3911   return true;
  3914 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
  3915   return ::vsnprintf(buf, count, format, args);
  3918 // Is a (classpath) directory empty?
  3919 bool os::dir_is_empty(const char* path) {
  3920   DIR *dir = NULL;
  3921   struct dirent *ptr;
  3923   dir = opendir(path);
  3924   if (dir == NULL) return true;
  3926   /* Scan the directory */
  3927   bool result = true;
  3928   char buf[sizeof(struct dirent) + MAX_PATH];
  3929   while (result && (ptr = ::readdir(dir)) != NULL) {
  3930     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
  3931       result = false;
  3934   closedir(dir);
  3935   return result;
  3938 // This code originates from JDK's sysOpen and open64_w
  3939 // from src/solaris/hpi/src/system_md.c
  3941 #ifndef O_DELETE
  3942 #define O_DELETE 0x10000
  3943 #endif
  3945 // Open a file. Unlink the file immediately after open returns
  3946 // if the specified oflag has the O_DELETE flag set.
  3947 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
  3949 int os::open(const char *path, int oflag, int mode) {
  3951   if (strlen(path) > MAX_PATH - 1) {
  3952     errno = ENAMETOOLONG;
  3953     return -1;
  3955   int fd;
  3956   int o_delete = (oflag & O_DELETE);
  3957   oflag = oflag & ~O_DELETE;
  3959   fd = ::open(path, oflag, mode);
  3960   if (fd == -1) return -1;
  3962   //If the open succeeded, the file might still be a directory
  3964     struct stat buf;
  3965     int ret = ::fstat(fd, &buf);
  3966     int st_mode = buf.st_mode;
  3968     if (ret != -1) {
  3969       if ((st_mode & S_IFMT) == S_IFDIR) {
  3970         errno = EISDIR;
  3971         ::close(fd);
  3972         return -1;
  3974     } else {
  3975       ::close(fd);
  3976       return -1;
  3980     /*
  3981      * All file descriptors that are opened in the JVM and not
  3982      * specifically destined for a subprocess should have the
  3983      * close-on-exec flag set.  If we don't set it, then careless 3rd
  3984      * party native code might fork and exec without closing all
  3985      * appropriate file descriptors (e.g. as we do in closeDescriptors in
  3986      * UNIXProcess.c), and this in turn might:
  3988      * - cause end-of-file to fail to be detected on some file
  3989      *   descriptors, resulting in mysterious hangs, or
  3991      * - might cause an fopen in the subprocess to fail on a system
  3992      *   suffering from bug 1085341.
  3994      * (Yes, the default setting of the close-on-exec flag is a Unix
  3995      * design flaw)
  3997      * See:
  3998      * 1085341: 32-bit stdio routines should support file descriptors >255
  3999      * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
  4000      * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
  4001      */
  4002 #ifdef FD_CLOEXEC
  4004         int flags = ::fcntl(fd, F_GETFD);
  4005         if (flags != -1)
  4006             ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
  4008 #endif
  4010   if (o_delete != 0) {
  4011     ::unlink(path);
  4013   return fd;
  4017 // create binary file, rewriting existing file if required
  4018 int os::create_binary_file(const char* path, bool rewrite_existing) {
  4019   int oflags = O_WRONLY | O_CREAT;
  4020   if (!rewrite_existing) {
  4021     oflags |= O_EXCL;
  4023   return ::open(path, oflags, S_IREAD | S_IWRITE);
  4026 // return current position of file pointer
  4027 jlong os::current_file_offset(int fd) {
  4028   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
  4031 // move file pointer to the specified offset
  4032 jlong os::seek_to_file_offset(int fd, jlong offset) {
  4033   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
  4036 // This code originates from JDK's sysAvailable
  4037 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
  4039 int os::available(int fd, jlong *bytes) {
  4040   jlong cur, end;
  4041   int mode;
  4042   struct stat buf;
  4044   if (::fstat(fd, &buf) >= 0) {
  4045     mode = buf.st_mode;
  4046     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
  4047       /*
  4048       * XXX: is the following call interruptible? If so, this might
  4049       * need to go through the INTERRUPT_IO() wrapper as for other
  4050       * blocking, interruptible calls in this file.
  4051       */
  4052       int n;
  4053       if (::ioctl(fd, FIONREAD, &n) >= 0) {
  4054         *bytes = n;
  4055         return 1;
  4059   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
  4060     return 0;
  4061   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
  4062     return 0;
  4063   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
  4064     return 0;
  4066   *bytes = end - cur;
  4067   return 1;
  4070 int os::socket_available(int fd, jint *pbytes) {
  4071    if (fd < 0)
  4072      return OS_OK;
  4074    int ret;
  4076    RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
  4078    //%% note ioctl can return 0 when successful, JVM_SocketAvailable
  4079    // is expected to return 0 on failure and 1 on success to the jdk.
  4081    return (ret == OS_ERR) ? 0 : 1;
  4084 // Map a block of memory.
  4085 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
  4086                      char *addr, size_t bytes, bool read_only,
  4087                      bool allow_exec) {
  4088   int prot;
  4089   int flags;
  4091   if (read_only) {
  4092     prot = PROT_READ;
  4093     flags = MAP_SHARED;
  4094   } else {
  4095     prot = PROT_READ | PROT_WRITE;
  4096     flags = MAP_PRIVATE;
  4099   if (allow_exec) {
  4100     prot |= PROT_EXEC;
  4103   if (addr != NULL) {
  4104     flags |= MAP_FIXED;
  4107   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
  4108                                      fd, file_offset);
  4109   if (mapped_address == MAP_FAILED) {
  4110     return NULL;
  4112   return mapped_address;
  4116 // Remap a block of memory.
  4117 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
  4118                        char *addr, size_t bytes, bool read_only,
  4119                        bool allow_exec) {
  4120   // same as map_memory() on this OS
  4121   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
  4122                         allow_exec);
  4126 // Unmap a block of memory.
  4127 bool os::pd_unmap_memory(char* addr, size_t bytes) {
  4128   return munmap(addr, bytes) == 0;
  4131 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
  4132 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
  4133 // of a thread.
  4134 //
  4135 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
  4136 // the fast estimate available on the platform.
  4138 jlong os::current_thread_cpu_time() {
  4139 #ifdef __APPLE__
  4140   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
  4141 #else
  4142   Unimplemented();
  4143   return 0;
  4144 #endif
  4147 jlong os::thread_cpu_time(Thread* thread) {
  4148 #ifdef __APPLE__
  4149   return os::thread_cpu_time(thread, true /* user + sys */);
  4150 #else
  4151   Unimplemented();
  4152   return 0;
  4153 #endif
  4156 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
  4157 #ifdef __APPLE__
  4158   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
  4159 #else
  4160   Unimplemented();
  4161   return 0;
  4162 #endif
  4165 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
  4166 #ifdef __APPLE__
  4167   struct thread_basic_info tinfo;
  4168   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
  4169   kern_return_t kr;
  4170   thread_t mach_thread;
  4172   mach_thread = thread->osthread()->thread_id();
  4173   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
  4174   if (kr != KERN_SUCCESS)
  4175     return -1;
  4177   if (user_sys_cpu_time) {
  4178     jlong nanos;
  4179     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
  4180     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
  4181     return nanos;
  4182   } else {
  4183     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
  4185 #else
  4186   Unimplemented();
  4187   return 0;
  4188 #endif
  4192 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
  4193   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
  4194   info_ptr->may_skip_backward = false;     // elapsed time not wall time
  4195   info_ptr->may_skip_forward = false;      // elapsed time not wall time
  4196   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
  4199 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
  4200   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
  4201   info_ptr->may_skip_backward = false;     // elapsed time not wall time
  4202   info_ptr->may_skip_forward = false;      // elapsed time not wall time
  4203   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
  4206 bool os::is_thread_cpu_time_supported() {
  4207 #ifdef __APPLE__
  4208   return true;
  4209 #else
  4210   return false;
  4211 #endif
  4214 // System loadavg support.  Returns -1 if load average cannot be obtained.
  4215 // Bsd doesn't yet have a (official) notion of processor sets,
  4216 // so just return the system wide load average.
  4217 int os::loadavg(double loadavg[], int nelem) {
  4218   return ::getloadavg(loadavg, nelem);
  4221 void os::pause() {
  4222   char filename[MAX_PATH];
  4223   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
  4224     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
  4225   } else {
  4226     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
  4229   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
  4230   if (fd != -1) {
  4231     struct stat buf;
  4232     ::close(fd);
  4233     while (::stat(filename, &buf) == 0) {
  4234       (void)::poll(NULL, 0, 100);
  4236   } else {
  4237     jio_fprintf(stderr,
  4238       "Could not open pause file '%s', continuing immediately.\n", filename);
  4243 // Refer to the comments in os_solaris.cpp park-unpark.
  4244 //
  4245 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
  4246 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
  4247 // For specifics regarding the bug see GLIBC BUGID 261237 :
  4248 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
  4249 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
  4250 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
  4251 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
  4252 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
  4253 // and monitorenter when we're using 1-0 locking.  All those operations may result in
  4254 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
  4255 // of libpthread avoids the problem, but isn't practical.
  4256 //
  4257 // Possible remedies:
  4258 //
  4259 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
  4260 //      This is palliative and probabilistic, however.  If the thread is preempted
  4261 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
  4262 //      than the minimum period may have passed, and the abstime may be stale (in the
  4263 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
  4264 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
  4265 //
  4266 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
  4267 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
  4268 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
  4269 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
  4270 //      thread.
  4271 //
  4272 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
  4273 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
  4274 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
  4275 //      This also works well.  In fact it avoids kernel-level scalability impediments
  4276 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
  4277 //      timers in a graceful fashion.
  4278 //
  4279 // 4.   When the abstime value is in the past it appears that control returns
  4280 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
  4281 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
  4282 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
  4283 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
  4284 //      It may be possible to avoid reinitialization by checking the return
  4285 //      value from pthread_cond_timedwait().  In addition to reinitializing the
  4286 //      condvar we must establish the invariant that cond_signal() is only called
  4287 //      within critical sections protected by the adjunct mutex.  This prevents
  4288 //      cond_signal() from "seeing" a condvar that's in the midst of being
  4289 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
  4290 //      desirable signal-after-unlock optimization that avoids futile context switching.
  4291 //
  4292 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
  4293 //      structure when a condvar is used or initialized.  cond_destroy()  would
  4294 //      release the helper structure.  Our reinitialize-after-timedwait fix
  4295 //      put excessive stress on malloc/free and locks protecting the c-heap.
  4296 //
  4297 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
  4298 // It may be possible to refine (4) by checking the kernel and NTPL verisons
  4299 // and only enabling the work-around for vulnerable environments.
  4301 // utility to compute the abstime argument to timedwait:
  4302 // millis is the relative timeout time
  4303 // abstime will be the absolute timeout time
  4304 // TODO: replace compute_abstime() with unpackTime()
  4306 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
  4307   if (millis < 0)  millis = 0;
  4308   struct timeval now;
  4309   int status = gettimeofday(&now, NULL);
  4310   assert(status == 0, "gettimeofday");
  4311   jlong seconds = millis / 1000;
  4312   millis %= 1000;
  4313   if (seconds > 50000000) { // see man cond_timedwait(3T)
  4314     seconds = 50000000;
  4316   abstime->tv_sec = now.tv_sec  + seconds;
  4317   long       usec = now.tv_usec + millis * 1000;
  4318   if (usec >= 1000000) {
  4319     abstime->tv_sec += 1;
  4320     usec -= 1000000;
  4322   abstime->tv_nsec = usec * 1000;
  4323   return abstime;
  4327 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
  4328 // Conceptually TryPark() should be equivalent to park(0).
  4330 int os::PlatformEvent::TryPark() {
  4331   for (;;) {
  4332     const int v = _Event ;
  4333     guarantee ((v == 0) || (v == 1), "invariant") ;
  4334     if (Atomic::cmpxchg (0, &_Event, v) == v) return v  ;
  4338 void os::PlatformEvent::park() {       // AKA "down()"
  4339   // Invariant: Only the thread associated with the Event/PlatformEvent
  4340   // may call park().
  4341   // TODO: assert that _Assoc != NULL or _Assoc == Self
  4342   int v ;
  4343   for (;;) {
  4344       v = _Event ;
  4345       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
  4347   guarantee (v >= 0, "invariant") ;
  4348   if (v == 0) {
  4349      // Do this the hard way by blocking ...
  4350      int status = pthread_mutex_lock(_mutex);
  4351      assert_status(status == 0, status, "mutex_lock");
  4352      guarantee (_nParked == 0, "invariant") ;
  4353      ++ _nParked ;
  4354      while (_Event < 0) {
  4355         status = pthread_cond_wait(_cond, _mutex);
  4356         // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
  4357         // Treat this the same as if the wait was interrupted
  4358         if (status == ETIMEDOUT) { status = EINTR; }
  4359         assert_status(status == 0 || status == EINTR, status, "cond_wait");
  4361      -- _nParked ;
  4363     _Event = 0 ;
  4364      status = pthread_mutex_unlock(_mutex);
  4365      assert_status(status == 0, status, "mutex_unlock");
  4366     // Paranoia to ensure our locked and lock-free paths interact
  4367     // correctly with each other.
  4368     OrderAccess::fence();
  4370   guarantee (_Event >= 0, "invariant") ;
  4373 int os::PlatformEvent::park(jlong millis) {
  4374   guarantee (_nParked == 0, "invariant") ;
  4376   int v ;
  4377   for (;;) {
  4378       v = _Event ;
  4379       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
  4381   guarantee (v >= 0, "invariant") ;
  4382   if (v != 0) return OS_OK ;
  4384   // We do this the hard way, by blocking the thread.
  4385   // Consider enforcing a minimum timeout value.
  4386   struct timespec abst;
  4387   compute_abstime(&abst, millis);
  4389   int ret = OS_TIMEOUT;
  4390   int status = pthread_mutex_lock(_mutex);
  4391   assert_status(status == 0, status, "mutex_lock");
  4392   guarantee (_nParked == 0, "invariant") ;
  4393   ++_nParked ;
  4395   // Object.wait(timo) will return because of
  4396   // (a) notification
  4397   // (b) timeout
  4398   // (c) thread.interrupt
  4399   //
  4400   // Thread.interrupt and object.notify{All} both call Event::set.
  4401   // That is, we treat thread.interrupt as a special case of notification.
  4402   // The underlying Solaris implementation, cond_timedwait, admits
  4403   // spurious/premature wakeups, but the JLS/JVM spec prevents the
  4404   // JVM from making those visible to Java code.  As such, we must
  4405   // filter out spurious wakeups.  We assume all ETIME returns are valid.
  4406   //
  4407   // TODO: properly differentiate simultaneous notify+interrupt.
  4408   // In that case, we should propagate the notify to another waiter.
  4410   while (_Event < 0) {
  4411     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
  4412     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
  4413       pthread_cond_destroy (_cond);
  4414       pthread_cond_init (_cond, NULL) ;
  4416     assert_status(status == 0 || status == EINTR ||
  4417                   status == ETIMEDOUT,
  4418                   status, "cond_timedwait");
  4419     if (!FilterSpuriousWakeups) break ;                 // previous semantics
  4420     if (status == ETIMEDOUT) break ;
  4421     // We consume and ignore EINTR and spurious wakeups.
  4423   --_nParked ;
  4424   if (_Event >= 0) {
  4425      ret = OS_OK;
  4427   _Event = 0 ;
  4428   status = pthread_mutex_unlock(_mutex);
  4429   assert_status(status == 0, status, "mutex_unlock");
  4430   assert (_nParked == 0, "invariant") ;
  4431   // Paranoia to ensure our locked and lock-free paths interact
  4432   // correctly with each other.
  4433   OrderAccess::fence();
  4434   return ret;
  4437 void os::PlatformEvent::unpark() {
  4438   // Transitions for _Event:
  4439   //    0 :=> 1
  4440   //    1 :=> 1
  4441   //   -1 :=> either 0 or 1; must signal target thread
  4442   //          That is, we can safely transition _Event from -1 to either
  4443   //          0 or 1. Forcing 1 is slightly more efficient for back-to-back
  4444   //          unpark() calls.
  4445   // See also: "Semaphores in Plan 9" by Mullender & Cox
  4446   //
  4447   // Note: Forcing a transition from "-1" to "1" on an unpark() means
  4448   // that it will take two back-to-back park() calls for the owning
  4449   // thread to block. This has the benefit of forcing a spurious return
  4450   // from the first park() call after an unpark() call which will help
  4451   // shake out uses of park() and unpark() without condition variables.
  4453   if (Atomic::xchg(1, &_Event) >= 0) return;
  4455   // Wait for the thread associated with the event to vacate
  4456   int status = pthread_mutex_lock(_mutex);
  4457   assert_status(status == 0, status, "mutex_lock");
  4458   int AnyWaiters = _nParked;
  4459   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
  4460   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
  4461     AnyWaiters = 0;
  4462     pthread_cond_signal(_cond);
  4464   status = pthread_mutex_unlock(_mutex);
  4465   assert_status(status == 0, status, "mutex_unlock");
  4466   if (AnyWaiters != 0) {
  4467     status = pthread_cond_signal(_cond);
  4468     assert_status(status == 0, status, "cond_signal");
  4471   // Note that we signal() _after dropping the lock for "immortal" Events.
  4472   // This is safe and avoids a common class of  futile wakeups.  In rare
  4473   // circumstances this can cause a thread to return prematurely from
  4474   // cond_{timed}wait() but the spurious wakeup is benign and the victim will
  4475   // simply re-test the condition and re-park itself.
  4479 // JSR166
  4480 // -------------------------------------------------------
  4482 /*
  4483  * The solaris and bsd implementations of park/unpark are fairly
  4484  * conservative for now, but can be improved. They currently use a
  4485  * mutex/condvar pair, plus a a count.
  4486  * Park decrements count if > 0, else does a condvar wait.  Unpark
  4487  * sets count to 1 and signals condvar.  Only one thread ever waits
  4488  * on the condvar. Contention seen when trying to park implies that someone
  4489  * is unparking you, so don't wait. And spurious returns are fine, so there
  4490  * is no need to track notifications.
  4491  */
  4493 #define MAX_SECS 100000000
  4494 /*
  4495  * This code is common to bsd and solaris and will be moved to a
  4496  * common place in dolphin.
  4498  * The passed in time value is either a relative time in nanoseconds
  4499  * or an absolute time in milliseconds. Either way it has to be unpacked
  4500  * into suitable seconds and nanoseconds components and stored in the
  4501  * given timespec structure.
  4502  * Given time is a 64-bit value and the time_t used in the timespec is only
  4503  * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
  4504  * overflow if times way in the future are given. Further on Solaris versions
  4505  * prior to 10 there is a restriction (see cond_timedwait) that the specified
  4506  * number of seconds, in abstime, is less than current_time  + 100,000,000.
  4507  * As it will be 28 years before "now + 100000000" will overflow we can
  4508  * ignore overflow and just impose a hard-limit on seconds using the value
  4509  * of "now + 100,000,000". This places a limit on the timeout of about 3.17
  4510  * years from "now".
  4511  */
  4513 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
  4514   assert (time > 0, "convertTime");
  4516   struct timeval now;
  4517   int status = gettimeofday(&now, NULL);
  4518   assert(status == 0, "gettimeofday");
  4520   time_t max_secs = now.tv_sec + MAX_SECS;
  4522   if (isAbsolute) {
  4523     jlong secs = time / 1000;
  4524     if (secs > max_secs) {
  4525       absTime->tv_sec = max_secs;
  4527     else {
  4528       absTime->tv_sec = secs;
  4530     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
  4532   else {
  4533     jlong secs = time / NANOSECS_PER_SEC;
  4534     if (secs >= MAX_SECS) {
  4535       absTime->tv_sec = max_secs;
  4536       absTime->tv_nsec = 0;
  4538     else {
  4539       absTime->tv_sec = now.tv_sec + secs;
  4540       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
  4541       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
  4542         absTime->tv_nsec -= NANOSECS_PER_SEC;
  4543         ++absTime->tv_sec; // note: this must be <= max_secs
  4547   assert(absTime->tv_sec >= 0, "tv_sec < 0");
  4548   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
  4549   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
  4550   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
  4553 void Parker::park(bool isAbsolute, jlong time) {
  4554   // Ideally we'd do something useful while spinning, such
  4555   // as calling unpackTime().
  4557   // Optional fast-path check:
  4558   // Return immediately if a permit is available.
  4559   // We depend on Atomic::xchg() having full barrier semantics
  4560   // since we are doing a lock-free update to _counter.
  4561   if (Atomic::xchg(0, &_counter) > 0) return;
  4563   Thread* thread = Thread::current();
  4564   assert(thread->is_Java_thread(), "Must be JavaThread");
  4565   JavaThread *jt = (JavaThread *)thread;
  4567   // Optional optimization -- avoid state transitions if there's an interrupt pending.
  4568   // Check interrupt before trying to wait
  4569   if (Thread::is_interrupted(thread, false)) {
  4570     return;
  4573   // Next, demultiplex/decode time arguments
  4574   struct timespec absTime;
  4575   if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
  4576     return;
  4578   if (time > 0) {
  4579     unpackTime(&absTime, isAbsolute, time);
  4583   // Enter safepoint region
  4584   // Beware of deadlocks such as 6317397.
  4585   // The per-thread Parker:: mutex is a classic leaf-lock.
  4586   // In particular a thread must never block on the Threads_lock while
  4587   // holding the Parker:: mutex.  If safepoints are pending both the
  4588   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
  4589   ThreadBlockInVM tbivm(jt);
  4591   // Don't wait if cannot get lock since interference arises from
  4592   // unblocking.  Also. check interrupt before trying wait
  4593   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
  4594     return;
  4597   int status ;
  4598   if (_counter > 0)  { // no wait needed
  4599     _counter = 0;
  4600     status = pthread_mutex_unlock(_mutex);
  4601     assert (status == 0, "invariant") ;
  4602     // Paranoia to ensure our locked and lock-free paths interact
  4603     // correctly with each other and Java-level accesses.
  4604     OrderAccess::fence();
  4605     return;
  4608 #ifdef ASSERT
  4609   // Don't catch signals while blocked; let the running threads have the signals.
  4610   // (This allows a debugger to break into the running thread.)
  4611   sigset_t oldsigs;
  4612   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
  4613   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
  4614 #endif
  4616   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
  4617   jt->set_suspend_equivalent();
  4618   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
  4620   if (time == 0) {
  4621     status = pthread_cond_wait (_cond, _mutex) ;
  4622   } else {
  4623     status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
  4624     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
  4625       pthread_cond_destroy (_cond) ;
  4626       pthread_cond_init    (_cond, NULL);
  4629   assert_status(status == 0 || status == EINTR ||
  4630                 status == ETIMEDOUT,
  4631                 status, "cond_timedwait");
  4633 #ifdef ASSERT
  4634   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
  4635 #endif
  4637   _counter = 0 ;
  4638   status = pthread_mutex_unlock(_mutex) ;
  4639   assert_status(status == 0, status, "invariant") ;
  4640   // Paranoia to ensure our locked and lock-free paths interact
  4641   // correctly with each other and Java-level accesses.
  4642   OrderAccess::fence();
  4644   // If externally suspended while waiting, re-suspend
  4645   if (jt->handle_special_suspend_equivalent_condition()) {
  4646     jt->java_suspend_self();
  4650 void Parker::unpark() {
  4651   int s, status ;
  4652   status = pthread_mutex_lock(_mutex);
  4653   assert (status == 0, "invariant") ;
  4654   s = _counter;
  4655   _counter = 1;
  4656   if (s < 1) {
  4657      if (WorkAroundNPTLTimedWaitHang) {
  4658         status = pthread_cond_signal (_cond) ;
  4659         assert (status == 0, "invariant") ;
  4660         status = pthread_mutex_unlock(_mutex);
  4661         assert (status == 0, "invariant") ;
  4662      } else {
  4663         status = pthread_mutex_unlock(_mutex);
  4664         assert (status == 0, "invariant") ;
  4665         status = pthread_cond_signal (_cond) ;
  4666         assert (status == 0, "invariant") ;
  4668   } else {
  4669     pthread_mutex_unlock(_mutex);
  4670     assert (status == 0, "invariant") ;
  4675 /* Darwin has no "environ" in a dynamic library. */
  4676 #ifdef __APPLE__
  4677 #include <crt_externs.h>
  4678 #define environ (*_NSGetEnviron())
  4679 #else
  4680 extern char** environ;
  4681 #endif
  4683 // Run the specified command in a separate process. Return its exit value,
  4684 // or -1 on failure (e.g. can't fork a new process).
  4685 // Unlike system(), this function can be called from signal handler. It
  4686 // doesn't block SIGINT et al.
  4687 int os::fork_and_exec(char* cmd) {
  4688   const char * argv[4] = {"sh", "-c", cmd, NULL};
  4690   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
  4691   // pthread_atfork handlers and reset pthread library. All we need is a
  4692   // separate process to execve. Make a direct syscall to fork process.
  4693   // On IA64 there's no fork syscall, we have to use fork() and hope for
  4694   // the best...
  4695   pid_t pid = fork();
  4697   if (pid < 0) {
  4698     // fork failed
  4699     return -1;
  4701   } else if (pid == 0) {
  4702     // child process
  4704     // execve() in BsdThreads will call pthread_kill_other_threads_np()
  4705     // first to kill every thread on the thread list. Because this list is
  4706     // not reset by fork() (see notes above), execve() will instead kill
  4707     // every thread in the parent process. We know this is the only thread
  4708     // in the new process, so make a system call directly.
  4709     // IA64 should use normal execve() from glibc to match the glibc fork()
  4710     // above.
  4711     execve("/bin/sh", (char* const*)argv, environ);
  4713     // execve failed
  4714     _exit(-1);
  4716   } else  {
  4717     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
  4718     // care about the actual exit code, for now.
  4720     int status;
  4722     // Wait for the child process to exit.  This returns immediately if
  4723     // the child has already exited. */
  4724     while (waitpid(pid, &status, 0) < 0) {
  4725         switch (errno) {
  4726         case ECHILD: return 0;
  4727         case EINTR: break;
  4728         default: return -1;
  4732     if (WIFEXITED(status)) {
  4733        // The child exited normally; get its exit code.
  4734        return WEXITSTATUS(status);
  4735     } else if (WIFSIGNALED(status)) {
  4736        // The child exited because of a signal
  4737        // The best value to return is 0x80 + signal number,
  4738        // because that is what all Unix shells do, and because
  4739        // it allows callers to distinguish between process exit and
  4740        // process death by signal.
  4741        return 0x80 + WTERMSIG(status);
  4742     } else {
  4743        // Unknown exit code; pass it through
  4744        return status;
  4749 // is_headless_jre()
  4750 //
  4751 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
  4752 // in order to report if we are running in a headless jre
  4753 //
  4754 // Since JDK8 xawt/libmawt.so was moved into the same directory
  4755 // as libawt.so, and renamed libawt_xawt.so
  4756 //
  4757 bool os::is_headless_jre() {
  4758 #ifdef __APPLE__
  4759     // We no longer build headless-only on Mac OS X
  4760     return false;
  4761 #else
  4762     struct stat statbuf;
  4763     char buf[MAXPATHLEN];
  4764     char libmawtpath[MAXPATHLEN];
  4765     const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
  4766     const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
  4767     char *p;
  4769     // Get path to libjvm.so
  4770     os::jvm_path(buf, sizeof(buf));
  4772     // Get rid of libjvm.so
  4773     p = strrchr(buf, '/');
  4774     if (p == NULL) return false;
  4775     else *p = '\0';
  4777     // Get rid of client or server
  4778     p = strrchr(buf, '/');
  4779     if (p == NULL) return false;
  4780     else *p = '\0';
  4782     // check xawt/libmawt.so
  4783     strcpy(libmawtpath, buf);
  4784     strcat(libmawtpath, xawtstr);
  4785     if (::stat(libmawtpath, &statbuf) == 0) return false;
  4787     // check libawt_xawt.so
  4788     strcpy(libmawtpath, buf);
  4789     strcat(libmawtpath, new_xawtstr);
  4790     if (::stat(libmawtpath, &statbuf) == 0) return false;
  4792     return true;
  4793 #endif
  4796 // Get the default path to the core file
  4797 // Returns the length of the string
  4798 int os::get_core_path(char* buffer, size_t bufferSize) {
  4799   int n = jio_snprintf(buffer, bufferSize, "/cores");
  4801   // Truncate if theoretical string was longer than bufferSize
  4802   n = MIN2(n, (int)bufferSize);
  4804   return n;
  4807 #ifndef PRODUCT
  4808 void TestReserveMemorySpecial_test() {
  4809   // No tests available for this platform
  4811 #endif

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