src/os/bsd/vm/os_bsd.cpp

Wed, 27 Aug 2014 08:19:12 -0400

author
zgu
date
Wed, 27 Aug 2014 08:19:12 -0400
changeset 7074
833b0f92429a
parent 6918
d22136881b85
child 7535
7ae4e26cb1e0
child 7633
8461d0b03127
permissions
-rw-r--r--

8046598: Scalable Native memory tracking development
Summary: Enhance scalability of native memory tracking
Reviewed-by: coleenp, ctornqvi, gtriantafill

     1 /*
     2  * Copyright (c) 1999, 2014, 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/orderAccess.inline.hpp"
    52 #include "runtime/osThread.hpp"
    53 #include "runtime/perfMemory.hpp"
    54 #include "runtime/sharedRuntime.hpp"
    55 #include "runtime/statSampler.hpp"
    56 #include "runtime/stubRoutines.hpp"
    57 #include "runtime/thread.inline.hpp"
    58 #include "runtime/threadCritical.hpp"
    59 #include "runtime/timer.hpp"
    60 #include "services/attachListener.hpp"
    61 #include "services/memTracker.hpp"
    62 #include "services/runtimeService.hpp"
    63 #include "utilities/decoder.hpp"
    64 #include "utilities/defaultStream.hpp"
    65 #include "utilities/events.hpp"
    66 #include "utilities/growableArray.hpp"
    67 #include "utilities/vmError.hpp"
    69 // put OS-includes here
    70 # include <sys/types.h>
    71 # include <sys/mman.h>
    72 # include <sys/stat.h>
    73 # include <sys/select.h>
    74 # include <pthread.h>
    75 # include <signal.h>
    76 # include <errno.h>
    77 # include <dlfcn.h>
    78 # include <stdio.h>
    79 # include <unistd.h>
    80 # include <sys/resource.h>
    81 # include <pthread.h>
    82 # include <sys/stat.h>
    83 # include <sys/time.h>
    84 # include <sys/times.h>
    85 # include <sys/utsname.h>
    86 # include <sys/socket.h>
    87 # include <sys/wait.h>
    88 # include <time.h>
    89 # include <pwd.h>
    90 # include <poll.h>
    91 # include <semaphore.h>
    92 # include <fcntl.h>
    93 # include <string.h>
    94 # include <sys/param.h>
    95 # include <sys/sysctl.h>
    96 # include <sys/ipc.h>
    97 # include <sys/shm.h>
    98 #ifndef __APPLE__
    99 # include <link.h>
   100 #endif
   101 # include <stdint.h>
   102 # include <inttypes.h>
   103 # include <sys/ioctl.h>
   104 # include <sys/syscall.h>
   106 #if defined(__FreeBSD__) || defined(__NetBSD__)
   107 # include <elf.h>
   108 #endif
   110 #ifdef __APPLE__
   111 # include <mach/mach.h> // semaphore_* API
   112 # include <mach-o/dyld.h>
   113 # include <sys/proc_info.h>
   114 # include <objc/objc-auto.h>
   115 #endif
   117 #ifndef MAP_ANONYMOUS
   118 #define MAP_ANONYMOUS MAP_ANON
   119 #endif
   121 #define MAX_PATH    (2 * K)
   123 // for timer info max values which include all bits
   124 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
   126 #define LARGEPAGES_BIT (1 << 6)
   128 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
   130 ////////////////////////////////////////////////////////////////////////////////
   131 // global variables
   132 julong os::Bsd::_physical_memory = 0;
   134 #ifdef __APPLE__
   135 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
   136 volatile uint64_t         os::Bsd::_max_abstime   = 0;
   137 #else
   138 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
   139 #endif
   140 pthread_t os::Bsd::_main_thread;
   141 int os::Bsd::_page_size = -1;
   143 static jlong initial_time_count=0;
   145 static int clock_tics_per_sec = 100;
   147 // For diagnostics to print a message once. see run_periodic_checks
   148 static sigset_t check_signal_done;
   149 static bool check_signals = true;
   151 static pid_t _initial_pid = 0;
   153 /* Signal number used to suspend/resume a thread */
   155 /* do not use any signal number less than SIGSEGV, see 4355769 */
   156 static int SR_signum = SIGUSR2;
   157 sigset_t SR_sigset;
   160 ////////////////////////////////////////////////////////////////////////////////
   161 // utility functions
   163 static int SR_initialize();
   164 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
   166 julong os::available_memory() {
   167   return Bsd::available_memory();
   168 }
   170 // available here means free
   171 julong os::Bsd::available_memory() {
   172   uint64_t available = physical_memory() >> 2;
   173 #ifdef __APPLE__
   174   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
   175   vm_statistics64_data_t vmstat;
   176   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
   177                                          (host_info64_t)&vmstat, &count);
   178   assert(kerr == KERN_SUCCESS,
   179          "host_statistics64 failed - check mach_host_self() and count");
   180   if (kerr == KERN_SUCCESS) {
   181     available = vmstat.free_count * os::vm_page_size();
   182   }
   183 #endif
   184   return available;
   185 }
   187 julong os::physical_memory() {
   188   return Bsd::physical_memory();
   189 }
   191 ////////////////////////////////////////////////////////////////////////////////
   192 // environment support
   194 bool os::getenv(const char* name, char* buf, int len) {
   195   const char* val = ::getenv(name);
   196   if (val != NULL && strlen(val) < (size_t)len) {
   197     strcpy(buf, val);
   198     return true;
   199   }
   200   if (len > 0) buf[0] = 0;  // return a null string
   201   return false;
   202 }
   205 // Return true if user is running as root.
   207 bool os::have_special_privileges() {
   208   static bool init = false;
   209   static bool privileges = false;
   210   if (!init) {
   211     privileges = (getuid() != geteuid()) || (getgid() != getegid());
   212     init = true;
   213   }
   214   return privileges;
   215 }
   219 // Cpu architecture string
   220 #if   defined(ZERO)
   221 static char cpu_arch[] = ZERO_LIBARCH;
   222 #elif defined(IA64)
   223 static char cpu_arch[] = "ia64";
   224 #elif defined(IA32)
   225 static char cpu_arch[] = "i386";
   226 #elif defined(AMD64)
   227 static char cpu_arch[] = "amd64";
   228 #elif defined(ARM)
   229 static char cpu_arch[] = "arm";
   230 #elif defined(PPC32)
   231 static char cpu_arch[] = "ppc";
   232 #elif defined(SPARC)
   233 #  ifdef _LP64
   234 static char cpu_arch[] = "sparcv9";
   235 #  else
   236 static char cpu_arch[] = "sparc";
   237 #  endif
   238 #else
   239 #error Add appropriate cpu_arch setting
   240 #endif
   242 // Compiler variant
   243 #ifdef COMPILER2
   244 #define COMPILER_VARIANT "server"
   245 #else
   246 #define COMPILER_VARIANT "client"
   247 #endif
   250 void os::Bsd::initialize_system_info() {
   251   int mib[2];
   252   size_t len;
   253   int cpu_val;
   254   julong mem_val;
   256   /* get processors count via hw.ncpus sysctl */
   257   mib[0] = CTL_HW;
   258   mib[1] = HW_NCPU;
   259   len = sizeof(cpu_val);
   260   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
   261        assert(len == sizeof(cpu_val), "unexpected data size");
   262        set_processor_count(cpu_val);
   263   }
   264   else {
   265        set_processor_count(1);   // fallback
   266   }
   268   /* get physical memory via hw.memsize sysctl (hw.memsize is used
   269    * since it returns a 64 bit value)
   270    */
   271   mib[0] = CTL_HW;
   273 #if defined (HW_MEMSIZE) // Apple
   274   mib[1] = HW_MEMSIZE;
   275 #elif defined(HW_PHYSMEM) // Most of BSD
   276   mib[1] = HW_PHYSMEM;
   277 #elif defined(HW_REALMEM) // Old FreeBSD
   278   mib[1] = HW_REALMEM;
   279 #else
   280   #error No ways to get physmem
   281 #endif
   283   len = sizeof(mem_val);
   284   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
   285        assert(len == sizeof(mem_val), "unexpected data size");
   286        _physical_memory = mem_val;
   287   } else {
   288        _physical_memory = 256*1024*1024;       // fallback (XXXBSD?)
   289   }
   291 #ifdef __OpenBSD__
   292   {
   293        // limit _physical_memory memory view on OpenBSD since
   294        // datasize rlimit restricts us anyway.
   295        struct rlimit limits;
   296        getrlimit(RLIMIT_DATA, &limits);
   297        _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
   298   }
   299 #endif
   300 }
   302 #ifdef __APPLE__
   303 static const char *get_home() {
   304   const char *home_dir = ::getenv("HOME");
   305   if ((home_dir == NULL) || (*home_dir == '\0')) {
   306     struct passwd *passwd_info = getpwuid(geteuid());
   307     if (passwd_info != NULL) {
   308       home_dir = passwd_info->pw_dir;
   309     }
   310   }
   312   return home_dir;
   313 }
   314 #endif
   316 void os::init_system_properties_values() {
   317   // The next steps are taken in the product version:
   318   //
   319   // Obtain the JAVA_HOME value from the location of libjvm.so.
   320   // This library should be located at:
   321   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
   322   //
   323   // If "/jre/lib/" appears at the right place in the path, then we
   324   // assume libjvm.so is installed in a JDK and we use this path.
   325   //
   326   // Otherwise exit with message: "Could not create the Java virtual machine."
   327   //
   328   // The following extra steps are taken in the debugging version:
   329   //
   330   // If "/jre/lib/" does NOT appear at the right place in the path
   331   // instead of exit check for $JAVA_HOME environment variable.
   332   //
   333   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
   334   // then we append a fake suffix "hotspot/libjvm.so" to this path so
   335   // it looks like libjvm.so is installed there
   336   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
   337   //
   338   // Otherwise exit.
   339   //
   340   // Important note: if the location of libjvm.so changes this
   341   // code needs to be changed accordingly.
   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 #ifndef DEFAULT_LIBPATH
   350 #define DEFAULT_LIBPATH "/lib:/usr/lib"
   351 #endif
   353 // Base path of extensions installed on the system.
   354 #define SYS_EXT_DIR     "/usr/java/packages"
   355 #define EXTENSIONS_DIR  "/lib/ext"
   356 #define ENDORSED_DIR    "/lib/endorsed"
   358 #ifndef __APPLE__
   360   // Buffer that fits several sprintfs.
   361   // Note that the space for the colon and the trailing null are provided
   362   // by the nulls included by the sizeof operator.
   363   const size_t bufsize =
   364     MAX3((size_t)MAXPATHLEN,  // For dll_dir & friends.
   365          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR), // extensions dir
   366          (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir
   367   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
   369   // sysclasspath, java_home, dll_dir
   370   {
   371     char *pslash;
   372     os::jvm_path(buf, bufsize);
   374     // Found the full path to libjvm.so.
   375     // Now cut the path to <java_home>/jre if we can.
   376     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
   377     pslash = strrchr(buf, '/');
   378     if (pslash != NULL) {
   379       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
   380     }
   381     Arguments::set_dll_dir(buf);
   383     if (pslash != NULL) {
   384       pslash = strrchr(buf, '/');
   385       if (pslash != NULL) {
   386         *pslash = '\0';          // Get rid of /<arch>.
   387         pslash = strrchr(buf, '/');
   388         if (pslash != NULL) {
   389           *pslash = '\0';        // Get rid of /lib.
   390         }
   391       }
   392     }
   393     Arguments::set_java_home(buf);
   394     set_boot_path('/', ':');
   395   }
   397   // Where to look for native libraries.
   398   //
   399   // Note: Due to a legacy implementation, most of the library path
   400   // is set in the launcher. This was to accomodate linking restrictions
   401   // on legacy Bsd implementations (which are no longer supported).
   402   // Eventually, all the library path setting will be done here.
   403   //
   404   // However, to prevent the proliferation of improperly built native
   405   // libraries, the new path component /usr/java/packages is added here.
   406   // Eventually, all the library path setting will be done here.
   407   {
   408     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
   409     // should always exist (until the legacy problem cited above is
   410     // addressed).
   411     const char *v = ::getenv("LD_LIBRARY_PATH");
   412     const char *v_colon = ":";
   413     if (v == NULL) { v = ""; v_colon = ""; }
   414     // That's +1 for the colon and +1 for the trailing '\0'.
   415     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
   416                                                      strlen(v) + 1 +
   417                                                      sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
   418                                                      mtInternal);
   419     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
   420     Arguments::set_library_path(ld_library_path);
   421     FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal);
   422   }
   424   // Extensions directories.
   425   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
   426   Arguments::set_ext_dirs(buf);
   428   // Endorsed standards default directory.
   429   sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
   430   Arguments::set_endorsed_dirs(buf);
   432   FREE_C_HEAP_ARRAY(char, buf, mtInternal);
   434 #else // __APPLE__
   436 #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
   437 #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
   439   const char *user_home_dir = get_home();
   440   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
   441   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
   442     sizeof(SYS_EXTENSIONS_DIRS);
   444   // Buffer that fits several sprintfs.
   445   // Note that the space for the colon and the trailing null are provided
   446   // by the nulls included by the sizeof operator.
   447   const size_t bufsize =
   448     MAX3((size_t)MAXPATHLEN,  // for dll_dir & friends.
   449          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size, // extensions dir
   450          (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir
   451   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
   453   // sysclasspath, java_home, dll_dir
   454   {
   455     char *pslash;
   456     os::jvm_path(buf, bufsize);
   458     // Found the full path to libjvm.so.
   459     // Now cut the path to <java_home>/jre if we can.
   460     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
   461     pslash = strrchr(buf, '/');
   462     if (pslash != NULL) {
   463       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
   464     }
   465     Arguments::set_dll_dir(buf);
   467     if (pslash != NULL) {
   468       pslash = strrchr(buf, '/');
   469       if (pslash != NULL) {
   470         *pslash = '\0';          // Get rid of /lib.
   471       }
   472     }
   473     Arguments::set_java_home(buf);
   474     set_boot_path('/', ':');
   475   }
   477   // Where to look for native libraries.
   478   //
   479   // Note: Due to a legacy implementation, most of the library path
   480   // is set in the launcher. This was to accomodate linking restrictions
   481   // on legacy Bsd implementations (which are no longer supported).
   482   // Eventually, all the library path setting will be done here.
   483   //
   484   // However, to prevent the proliferation of improperly built native
   485   // libraries, the new path component /usr/java/packages is added here.
   486   // Eventually, all the library path setting will be done here.
   487   {
   488     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
   489     // should always exist (until the legacy problem cited above is
   490     // addressed).
   491     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
   492     // can specify a directory inside an app wrapper
   493     const char *l = ::getenv("JAVA_LIBRARY_PATH");
   494     const char *l_colon = ":";
   495     if (l == NULL) { l = ""; l_colon = ""; }
   497     const char *v = ::getenv("DYLD_LIBRARY_PATH");
   498     const char *v_colon = ":";
   499     if (v == NULL) { v = ""; v_colon = ""; }
   501     // Apple's Java6 has "." at the beginning of java.library.path.
   502     // OpenJDK on Windows has "." at the end of java.library.path.
   503     // OpenJDK on Linux and Solaris don't have "." in java.library.path
   504     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
   505     // "." is appended to the end of java.library.path. Yes, this
   506     // could cause a change in behavior, but Apple's Java6 behavior
   507     // can be achieved by putting "." at the beginning of the
   508     // JAVA_LIBRARY_PATH environment variable.
   509     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
   510                                                      strlen(v) + 1 + strlen(l) + 1 +
   511                                                      system_ext_size + 3,
   512                                                      mtInternal);
   513     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
   514             v, v_colon, l, l_colon, user_home_dir);
   515     Arguments::set_library_path(ld_library_path);
   516     FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal);
   517   }
   519   // Extensions directories.
   520   //
   521   // Note that the space for the colon and the trailing null are provided
   522   // by the nulls included by the sizeof operator (so actually one byte more
   523   // than necessary is allocated).
   524   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
   525           user_home_dir, Arguments::get_java_home());
   526   Arguments::set_ext_dirs(buf);
   528   // Endorsed standards default directory.
   529   sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
   530   Arguments::set_endorsed_dirs(buf);
   532   FREE_C_HEAP_ARRAY(char, buf, mtInternal);
   534 #undef SYS_EXTENSIONS_DIR
   535 #undef SYS_EXTENSIONS_DIRS
   537 #endif // __APPLE__
   539 #undef SYS_EXT_DIR
   540 #undef EXTENSIONS_DIR
   541 #undef ENDORSED_DIR
   542 }
   544 ////////////////////////////////////////////////////////////////////////////////
   545 // breakpoint support
   547 void os::breakpoint() {
   548   BREAKPOINT;
   549 }
   551 extern "C" void breakpoint() {
   552   // use debugger to set breakpoint here
   553 }
   555 ////////////////////////////////////////////////////////////////////////////////
   556 // signal support
   558 debug_only(static bool signal_sets_initialized = false);
   559 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
   561 bool os::Bsd::is_sig_ignored(int sig) {
   562       struct sigaction oact;
   563       sigaction(sig, (struct sigaction*)NULL, &oact);
   564       void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
   565                                      : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
   566       if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
   567            return true;
   568       else
   569            return false;
   570 }
   572 void os::Bsd::signal_sets_init() {
   573   // Should also have an assertion stating we are still single-threaded.
   574   assert(!signal_sets_initialized, "Already initialized");
   575   // Fill in signals that are necessarily unblocked for all threads in
   576   // the VM. Currently, we unblock the following signals:
   577   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
   578   //                         by -Xrs (=ReduceSignalUsage));
   579   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
   580   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
   581   // the dispositions or masks wrt these signals.
   582   // Programs embedding the VM that want to use the above signals for their
   583   // own purposes must, at this time, use the "-Xrs" option to prevent
   584   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
   585   // (See bug 4345157, and other related bugs).
   586   // In reality, though, unblocking these signals is really a nop, since
   587   // these signals are not blocked by default.
   588   sigemptyset(&unblocked_sigs);
   589   sigemptyset(&allowdebug_blocked_sigs);
   590   sigaddset(&unblocked_sigs, SIGILL);
   591   sigaddset(&unblocked_sigs, SIGSEGV);
   592   sigaddset(&unblocked_sigs, SIGBUS);
   593   sigaddset(&unblocked_sigs, SIGFPE);
   594   sigaddset(&unblocked_sigs, SR_signum);
   596   if (!ReduceSignalUsage) {
   597    if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
   598       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
   599       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
   600    }
   601    if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
   602       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
   603       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
   604    }
   605    if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
   606       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
   607       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
   608    }
   609   }
   610   // Fill in signals that are blocked by all but the VM thread.
   611   sigemptyset(&vm_sigs);
   612   if (!ReduceSignalUsage)
   613     sigaddset(&vm_sigs, BREAK_SIGNAL);
   614   debug_only(signal_sets_initialized = true);
   616 }
   618 // These are signals that are unblocked while a thread is running Java.
   619 // (For some reason, they get blocked by default.)
   620 sigset_t* os::Bsd::unblocked_signals() {
   621   assert(signal_sets_initialized, "Not initialized");
   622   return &unblocked_sigs;
   623 }
   625 // These are the signals that are blocked while a (non-VM) thread is
   626 // running Java. Only the VM thread handles these signals.
   627 sigset_t* os::Bsd::vm_signals() {
   628   assert(signal_sets_initialized, "Not initialized");
   629   return &vm_sigs;
   630 }
   632 // These are signals that are blocked during cond_wait to allow debugger in
   633 sigset_t* os::Bsd::allowdebug_blocked_signals() {
   634   assert(signal_sets_initialized, "Not initialized");
   635   return &allowdebug_blocked_sigs;
   636 }
   638 void os::Bsd::hotspot_sigmask(Thread* thread) {
   640   //Save caller's signal mask before setting VM signal mask
   641   sigset_t caller_sigmask;
   642   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
   644   OSThread* osthread = thread->osthread();
   645   osthread->set_caller_sigmask(caller_sigmask);
   647   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
   649   if (!ReduceSignalUsage) {
   650     if (thread->is_VM_thread()) {
   651       // Only the VM thread handles BREAK_SIGNAL ...
   652       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
   653     } else {
   654       // ... all other threads block BREAK_SIGNAL
   655       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
   656     }
   657   }
   658 }
   661 //////////////////////////////////////////////////////////////////////////////
   662 // create new thread
   664 // check if it's safe to start a new thread
   665 static bool _thread_safety_check(Thread* thread) {
   666   return true;
   667 }
   669 #ifdef __APPLE__
   670 // library handle for calling objc_registerThreadWithCollector()
   671 // without static linking to the libobjc library
   672 #define OBJC_LIB "/usr/lib/libobjc.dylib"
   673 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
   674 typedef void (*objc_registerThreadWithCollector_t)();
   675 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
   676 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
   677 #endif
   679 #ifdef __APPLE__
   680 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
   681   // Additional thread_id used to correlate threads in SA
   682   thread_identifier_info_data_t     m_ident_info;
   683   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
   685   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
   686               (thread_info_t) &m_ident_info, &count);
   688   return m_ident_info.thread_id;
   689 }
   690 #endif
   692 // Thread start routine for all newly created threads
   693 static void *java_start(Thread *thread) {
   694   // Try to randomize the cache line index of hot stack frames.
   695   // This helps when threads of the same stack traces evict each other's
   696   // cache lines. The threads can be either from the same JVM instance, or
   697   // from different JVM instances. The benefit is especially true for
   698   // processors with hyperthreading technology.
   699   static int counter = 0;
   700   int pid = os::current_process_id();
   701   alloca(((pid ^ counter++) & 7) * 128);
   703   ThreadLocalStorage::set_thread(thread);
   705   OSThread* osthread = thread->osthread();
   706   Monitor* sync = osthread->startThread_lock();
   708   // non floating stack BsdThreads needs extra check, see above
   709   if (!_thread_safety_check(thread)) {
   710     // notify parent thread
   711     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
   712     osthread->set_state(ZOMBIE);
   713     sync->notify_all();
   714     return NULL;
   715   }
   717   osthread->set_thread_id(os::Bsd::gettid());
   719 #ifdef __APPLE__
   720   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
   721   guarantee(unique_thread_id != 0, "unique thread id was not found");
   722   osthread->set_unique_thread_id(unique_thread_id);
   723 #endif
   724   // initialize signal mask for this thread
   725   os::Bsd::hotspot_sigmask(thread);
   727   // initialize floating point control register
   728   os::Bsd::init_thread_fpu_state();
   730 #ifdef __APPLE__
   731   // register thread with objc gc
   732   if (objc_registerThreadWithCollectorFunction != NULL) {
   733     objc_registerThreadWithCollectorFunction();
   734   }
   735 #endif
   737   // handshaking with parent thread
   738   {
   739     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
   741     // notify parent thread
   742     osthread->set_state(INITIALIZED);
   743     sync->notify_all();
   745     // wait until os::start_thread()
   746     while (osthread->get_state() == INITIALIZED) {
   747       sync->wait(Mutex::_no_safepoint_check_flag);
   748     }
   749   }
   751   // call one more level start routine
   752   thread->run();
   754   return 0;
   755 }
   757 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
   758   assert(thread->osthread() == NULL, "caller responsible");
   760   // Allocate the OSThread object
   761   OSThread* osthread = new OSThread(NULL, NULL);
   762   if (osthread == NULL) {
   763     return false;
   764   }
   766   // set the correct thread state
   767   osthread->set_thread_type(thr_type);
   769   // Initial state is ALLOCATED but not INITIALIZED
   770   osthread->set_state(ALLOCATED);
   772   thread->set_osthread(osthread);
   774   // init thread attributes
   775   pthread_attr_t attr;
   776   pthread_attr_init(&attr);
   777   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
   779   // stack size
   780   if (os::Bsd::supports_variable_stack_size()) {
   781     // calculate stack size if it's not specified by caller
   782     if (stack_size == 0) {
   783       stack_size = os::Bsd::default_stack_size(thr_type);
   785       switch (thr_type) {
   786       case os::java_thread:
   787         // Java threads use ThreadStackSize which default value can be
   788         // changed with the flag -Xss
   789         assert (JavaThread::stack_size_at_create() > 0, "this should be set");
   790         stack_size = JavaThread::stack_size_at_create();
   791         break;
   792       case os::compiler_thread:
   793         if (CompilerThreadStackSize > 0) {
   794           stack_size = (size_t)(CompilerThreadStackSize * K);
   795           break;
   796         } // else fall through:
   797           // use VMThreadStackSize if CompilerThreadStackSize is not defined
   798       case os::vm_thread:
   799       case os::pgc_thread:
   800       case os::cgc_thread:
   801       case os::watcher_thread:
   802         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
   803         break;
   804       }
   805     }
   807     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
   808     pthread_attr_setstacksize(&attr, stack_size);
   809   } else {
   810     // let pthread_create() pick the default value.
   811   }
   813   ThreadState state;
   815   {
   816     pthread_t tid;
   817     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
   819     pthread_attr_destroy(&attr);
   821     if (ret != 0) {
   822       if (PrintMiscellaneous && (Verbose || WizardMode)) {
   823         perror("pthread_create()");
   824       }
   825       // Need to clean up stuff we've allocated so far
   826       thread->set_osthread(NULL);
   827       delete osthread;
   828       return false;
   829     }
   831     // Store pthread info into the OSThread
   832     osthread->set_pthread_id(tid);
   834     // Wait until child thread is either initialized or aborted
   835     {
   836       Monitor* sync_with_child = osthread->startThread_lock();
   837       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
   838       while ((state = osthread->get_state()) == ALLOCATED) {
   839         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
   840       }
   841     }
   843   }
   845   // Aborted due to thread limit being reached
   846   if (state == ZOMBIE) {
   847       thread->set_osthread(NULL);
   848       delete osthread;
   849       return false;
   850   }
   852   // The thread is returned suspended (in state INITIALIZED),
   853   // and is started higher up in the call chain
   854   assert(state == INITIALIZED, "race condition");
   855   return true;
   856 }
   858 /////////////////////////////////////////////////////////////////////////////
   859 // attach existing thread
   861 // bootstrap the main thread
   862 bool os::create_main_thread(JavaThread* thread) {
   863   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
   864   return create_attached_thread(thread);
   865 }
   867 bool os::create_attached_thread(JavaThread* thread) {
   868 #ifdef ASSERT
   869     thread->verify_not_published();
   870 #endif
   872   // Allocate the OSThread object
   873   OSThread* osthread = new OSThread(NULL, NULL);
   875   if (osthread == NULL) {
   876     return false;
   877   }
   879   osthread->set_thread_id(os::Bsd::gettid());
   881   // Store pthread info into the OSThread
   882 #ifdef __APPLE__
   883   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
   884   guarantee(unique_thread_id != 0, "just checking");
   885   osthread->set_unique_thread_id(unique_thread_id);
   886 #endif
   887   osthread->set_pthread_id(::pthread_self());
   889   // initialize floating point control register
   890   os::Bsd::init_thread_fpu_state();
   892   // Initial thread state is RUNNABLE
   893   osthread->set_state(RUNNABLE);
   895   thread->set_osthread(osthread);
   897   // initialize signal mask for this thread
   898   // and save the caller's signal mask
   899   os::Bsd::hotspot_sigmask(thread);
   901   return true;
   902 }
   904 void os::pd_start_thread(Thread* thread) {
   905   OSThread * osthread = thread->osthread();
   906   assert(osthread->get_state() != INITIALIZED, "just checking");
   907   Monitor* sync_with_child = osthread->startThread_lock();
   908   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
   909   sync_with_child->notify();
   910 }
   912 // Free Bsd resources related to the OSThread
   913 void os::free_thread(OSThread* osthread) {
   914   assert(osthread != NULL, "osthread not set");
   916   if (Thread::current()->osthread() == osthread) {
   917     // Restore caller's signal mask
   918     sigset_t sigmask = osthread->caller_sigmask();
   919     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
   920    }
   922   delete osthread;
   923 }
   925 //////////////////////////////////////////////////////////////////////////////
   926 // thread local storage
   928 // Restore the thread pointer if the destructor is called. This is in case
   929 // someone from JNI code sets up a destructor with pthread_key_create to run
   930 // detachCurrentThread on thread death. Unless we restore the thread pointer we
   931 // will hang or crash. When detachCurrentThread is called the key will be set
   932 // to null and we will not be called again. If detachCurrentThread is never
   933 // called we could loop forever depending on the pthread implementation.
   934 static void restore_thread_pointer(void* p) {
   935   Thread* thread = (Thread*) p;
   936   os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
   937 }
   939 int os::allocate_thread_local_storage() {
   940   pthread_key_t key;
   941   int rslt = pthread_key_create(&key, restore_thread_pointer);
   942   assert(rslt == 0, "cannot allocate thread local storage");
   943   return (int)key;
   944 }
   946 // Note: This is currently not used by VM, as we don't destroy TLS key
   947 // on VM exit.
   948 void os::free_thread_local_storage(int index) {
   949   int rslt = pthread_key_delete((pthread_key_t)index);
   950   assert(rslt == 0, "invalid index");
   951 }
   953 void os::thread_local_storage_at_put(int index, void* value) {
   954   int rslt = pthread_setspecific((pthread_key_t)index, value);
   955   assert(rslt == 0, "pthread_setspecific failed");
   956 }
   958 extern "C" Thread* get_thread() {
   959   return ThreadLocalStorage::thread();
   960 }
   963 ////////////////////////////////////////////////////////////////////////////////
   964 // time support
   966 // Time since start-up in seconds to a fine granularity.
   967 // Used by VMSelfDestructTimer and the MemProfiler.
   968 double os::elapsedTime() {
   970   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
   971 }
   973 jlong os::elapsed_counter() {
   974   return javaTimeNanos() - initial_time_count;
   975 }
   977 jlong os::elapsed_frequency() {
   978   return NANOSECS_PER_SEC; // nanosecond resolution
   979 }
   981 bool os::supports_vtime() { return true; }
   982 bool os::enable_vtime()   { return false; }
   983 bool os::vtime_enabled()  { return false; }
   985 double os::elapsedVTime() {
   986   // better than nothing, but not much
   987   return elapsedTime();
   988 }
   990 jlong os::javaTimeMillis() {
   991   timeval time;
   992   int status = gettimeofday(&time, NULL);
   993   assert(status != -1, "bsd error");
   994   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
   995 }
   997 #ifndef __APPLE__
   998 #ifndef CLOCK_MONOTONIC
   999 #define CLOCK_MONOTONIC (1)
  1000 #endif
  1001 #endif
  1003 #ifdef __APPLE__
  1004 void os::Bsd::clock_init() {
  1005   mach_timebase_info(&_timebase_info);
  1007 #else
  1008 void os::Bsd::clock_init() {
  1009   struct timespec res;
  1010   struct timespec tp;
  1011   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
  1012       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
  1013     // yes, monotonic clock is supported
  1014     _clock_gettime = ::clock_gettime;
  1017 #endif
  1020 #ifdef __APPLE__
  1022 jlong os::javaTimeNanos() {
  1023     const uint64_t tm = mach_absolute_time();
  1024     const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
  1025     const uint64_t prev = Bsd::_max_abstime;
  1026     if (now <= prev) {
  1027       return prev;   // same or retrograde time;
  1029     const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
  1030     assert(obsv >= prev, "invariant");   // Monotonicity
  1031     // If the CAS succeeded then we're done and return "now".
  1032     // If the CAS failed and the observed value "obsv" is >= now then
  1033     // we should return "obsv".  If the CAS failed and now > obsv > prv then
  1034     // some other thread raced this thread and installed a new value, in which case
  1035     // we could either (a) retry the entire operation, (b) retry trying to install now
  1036     // or (c) just return obsv.  We use (c).   No loop is required although in some cases
  1037     // we might discard a higher "now" value in deference to a slightly lower but freshly
  1038     // installed obsv value.   That's entirely benign -- it admits no new orderings compared
  1039     // to (a) or (b) -- and greatly reduces coherence traffic.
  1040     // We might also condition (c) on the magnitude of the delta between obsv and now.
  1041     // Avoiding excessive CAS operations to hot RW locations is critical.
  1042     // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
  1043     return (prev == obsv) ? now : obsv;
  1046 #else // __APPLE__
  1048 jlong os::javaTimeNanos() {
  1049   if (Bsd::supports_monotonic_clock()) {
  1050     struct timespec tp;
  1051     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
  1052     assert(status == 0, "gettime error");
  1053     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
  1054     return result;
  1055   } else {
  1056     timeval time;
  1057     int status = gettimeofday(&time, NULL);
  1058     assert(status != -1, "bsd error");
  1059     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
  1060     return 1000 * usecs;
  1064 #endif // __APPLE__
  1066 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
  1067   if (Bsd::supports_monotonic_clock()) {
  1068     info_ptr->max_value = ALL_64_BITS;
  1070     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
  1071     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
  1072     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
  1073   } else {
  1074     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
  1075     info_ptr->max_value = ALL_64_BITS;
  1077     // gettimeofday is a real time clock so it skips
  1078     info_ptr->may_skip_backward = true;
  1079     info_ptr->may_skip_forward = true;
  1082   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
  1085 // Return the real, user, and system times in seconds from an
  1086 // arbitrary fixed point in the past.
  1087 bool os::getTimesSecs(double* process_real_time,
  1088                       double* process_user_time,
  1089                       double* process_system_time) {
  1090   struct tms ticks;
  1091   clock_t real_ticks = times(&ticks);
  1093   if (real_ticks == (clock_t) (-1)) {
  1094     return false;
  1095   } else {
  1096     double ticks_per_second = (double) clock_tics_per_sec;
  1097     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
  1098     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
  1099     *process_real_time = ((double) real_ticks) / ticks_per_second;
  1101     return true;
  1106 char * os::local_time_string(char *buf, size_t buflen) {
  1107   struct tm t;
  1108   time_t long_time;
  1109   time(&long_time);
  1110   localtime_r(&long_time, &t);
  1111   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
  1112                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
  1113                t.tm_hour, t.tm_min, t.tm_sec);
  1114   return buf;
  1117 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
  1118   return localtime_r(clock, res);
  1121 ////////////////////////////////////////////////////////////////////////////////
  1122 // runtime exit support
  1124 // Note: os::shutdown() might be called very early during initialization, or
  1125 // called from signal handler. Before adding something to os::shutdown(), make
  1126 // sure it is async-safe and can handle partially initialized VM.
  1127 void os::shutdown() {
  1129   // allow PerfMemory to attempt cleanup of any persistent resources
  1130   perfMemory_exit();
  1132   // needs to remove object in file system
  1133   AttachListener::abort();
  1135   // flush buffered output, finish log files
  1136   ostream_abort();
  1138   // Check for abort hook
  1139   abort_hook_t abort_hook = Arguments::abort_hook();
  1140   if (abort_hook != NULL) {
  1141     abort_hook();
  1146 // Note: os::abort() might be called very early during initialization, or
  1147 // called from signal handler. Before adding something to os::abort(), make
  1148 // sure it is async-safe and can handle partially initialized VM.
  1149 void os::abort(bool dump_core) {
  1150   os::shutdown();
  1151   if (dump_core) {
  1152 #ifndef PRODUCT
  1153     fdStream out(defaultStream::output_fd());
  1154     out.print_raw("Current thread is ");
  1155     char buf[16];
  1156     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
  1157     out.print_raw_cr(buf);
  1158     out.print_raw_cr("Dumping core ...");
  1159 #endif
  1160     ::abort(); // dump core
  1163   ::exit(1);
  1166 // Die immediately, no exit hook, no abort hook, no cleanup.
  1167 void os::die() {
  1168   // _exit() on BsdThreads only kills current thread
  1169   ::abort();
  1172 // This method is a copy of JDK's sysGetLastErrorString
  1173 // from src/solaris/hpi/src/system_md.c
  1175 size_t os::lasterror(char *buf, size_t len) {
  1177   if (errno == 0)  return 0;
  1179   const char *s = ::strerror(errno);
  1180   size_t n = ::strlen(s);
  1181   if (n >= len) {
  1182     n = len - 1;
  1184   ::strncpy(buf, s, n);
  1185   buf[n] = '\0';
  1186   return n;
  1189 // Information of current thread in variety of formats
  1190 pid_t os::Bsd::gettid() {
  1191   int retval = -1;
  1193 #ifdef __APPLE__ //XNU kernel
  1194   // despite the fact mach port is actually not a thread id use it
  1195   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
  1196   retval = ::pthread_mach_thread_np(::pthread_self());
  1197   guarantee(retval != 0, "just checking");
  1198   return retval;
  1200 #elif __FreeBSD__
  1201   retval = syscall(SYS_thr_self);
  1202 #elif __OpenBSD__
  1203   retval = syscall(SYS_getthrid);
  1204 #elif __NetBSD__
  1205   retval = (pid_t) syscall(SYS__lwp_self);
  1206 #endif
  1208   if (retval == -1) {
  1209     return getpid();
  1213 intx os::current_thread_id() {
  1214 #ifdef __APPLE__
  1215   return (intx)::pthread_mach_thread_np(::pthread_self());
  1216 #else
  1217   return (intx)::pthread_self();
  1218 #endif
  1221 int os::current_process_id() {
  1223   // Under the old bsd thread library, bsd gives each thread
  1224   // its own process id. Because of this each thread will return
  1225   // a different pid if this method were to return the result
  1226   // of getpid(2). Bsd provides no api that returns the pid
  1227   // of the launcher thread for the vm. This implementation
  1228   // returns a unique pid, the pid of the launcher thread
  1229   // that starts the vm 'process'.
  1231   // Under the NPTL, getpid() returns the same pid as the
  1232   // launcher thread rather than a unique pid per thread.
  1233   // Use gettid() if you want the old pre NPTL behaviour.
  1235   // if you are looking for the result of a call to getpid() that
  1236   // returns a unique pid for the calling thread, then look at the
  1237   // OSThread::thread_id() method in osThread_bsd.hpp file
  1239   return (int)(_initial_pid ? _initial_pid : getpid());
  1242 // DLL functions
  1244 #define JNI_LIB_PREFIX "lib"
  1245 #ifdef __APPLE__
  1246 #define JNI_LIB_SUFFIX ".dylib"
  1247 #else
  1248 #define JNI_LIB_SUFFIX ".so"
  1249 #endif
  1251 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
  1253 // This must be hard coded because it's the system's temporary
  1254 // directory not the java application's temp directory, ala java.io.tmpdir.
  1255 #ifdef __APPLE__
  1256 // macosx has a secure per-user temporary directory
  1257 char temp_path_storage[PATH_MAX];
  1258 const char* os::get_temp_directory() {
  1259   static char *temp_path = NULL;
  1260   if (temp_path == NULL) {
  1261     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
  1262     if (pathSize == 0 || pathSize > PATH_MAX) {
  1263       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
  1265     temp_path = temp_path_storage;
  1267   return temp_path;
  1269 #else /* __APPLE__ */
  1270 const char* os::get_temp_directory() { return "/tmp"; }
  1271 #endif /* __APPLE__ */
  1273 static bool file_exists(const char* filename) {
  1274   struct stat statbuf;
  1275   if (filename == NULL || strlen(filename) == 0) {
  1276     return false;
  1278   return os::stat(filename, &statbuf) == 0;
  1281 bool os::dll_build_name(char* buffer, size_t buflen,
  1282                         const char* pname, const char* fname) {
  1283   bool retval = false;
  1284   // Copied from libhpi
  1285   const size_t pnamelen = pname ? strlen(pname) : 0;
  1287   // Return error on buffer overflow.
  1288   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
  1289     return retval;
  1292   if (pnamelen == 0) {
  1293     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
  1294     retval = true;
  1295   } else if (strchr(pname, *os::path_separator()) != NULL) {
  1296     int n;
  1297     char** pelements = split_path(pname, &n);
  1298     if (pelements == NULL) {
  1299       return false;
  1301     for (int i = 0 ; i < n ; i++) {
  1302       // Really shouldn't be NULL, but check can't hurt
  1303       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
  1304         continue; // skip the empty path values
  1306       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
  1307           pelements[i], fname);
  1308       if (file_exists(buffer)) {
  1309         retval = true;
  1310         break;
  1313     // release the storage
  1314     for (int i = 0 ; i < n ; i++) {
  1315       if (pelements[i] != NULL) {
  1316         FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
  1319     if (pelements != NULL) {
  1320       FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
  1322   } else {
  1323     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
  1324     retval = true;
  1326   return retval;
  1329 // check if addr is inside libjvm.so
  1330 bool os::address_is_in_vm(address addr) {
  1331   static address libjvm_base_addr;
  1332   Dl_info dlinfo;
  1334   if (libjvm_base_addr == NULL) {
  1335     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
  1336       libjvm_base_addr = (address)dlinfo.dli_fbase;
  1338     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
  1341   if (dladdr((void *)addr, &dlinfo) != 0) {
  1342     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
  1345   return false;
  1349 #define MACH_MAXSYMLEN 256
  1351 bool os::dll_address_to_function_name(address addr, char *buf,
  1352                                       int buflen, int *offset) {
  1353   // buf is not optional, but offset is optional
  1354   assert(buf != NULL, "sanity check");
  1356   Dl_info dlinfo;
  1357   char localbuf[MACH_MAXSYMLEN];
  1359   if (dladdr((void*)addr, &dlinfo) != 0) {
  1360     // see if we have a matching symbol
  1361     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
  1362       if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
  1363         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
  1365       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
  1366       return true;
  1368     // no matching symbol so try for just file info
  1369     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
  1370       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
  1371                           buf, buflen, offset, dlinfo.dli_fname)) {
  1372          return true;
  1376     // Handle non-dynamic manually:
  1377     if (dlinfo.dli_fbase != NULL &&
  1378         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
  1379                         dlinfo.dli_fbase)) {
  1380       if (!Decoder::demangle(localbuf, buf, buflen)) {
  1381         jio_snprintf(buf, buflen, "%s", localbuf);
  1383       return true;
  1386   buf[0] = '\0';
  1387   if (offset != NULL) *offset = -1;
  1388   return false;
  1391 // ported from solaris version
  1392 bool os::dll_address_to_library_name(address addr, char* buf,
  1393                                      int buflen, int* offset) {
  1394   // buf is not optional, but offset is optional
  1395   assert(buf != NULL, "sanity check");
  1397   Dl_info dlinfo;
  1399   if (dladdr((void*)addr, &dlinfo) != 0) {
  1400     if (dlinfo.dli_fname != NULL) {
  1401       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
  1403     if (dlinfo.dli_fbase != NULL && offset != NULL) {
  1404       *offset = addr - (address)dlinfo.dli_fbase;
  1406     return true;
  1409   buf[0] = '\0';
  1410   if (offset) *offset = -1;
  1411   return false;
  1414 // Loads .dll/.so and
  1415 // in case of error it checks if .dll/.so was built for the
  1416 // same architecture as Hotspot is running on
  1418 #ifdef __APPLE__
  1419 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
  1420   void * result= ::dlopen(filename, RTLD_LAZY);
  1421   if (result != NULL) {
  1422     // Successful loading
  1423     return result;
  1426   // Read system error message into ebuf
  1427   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
  1428   ebuf[ebuflen-1]='\0';
  1430   return NULL;
  1432 #else
  1433 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
  1435   void * result= ::dlopen(filename, RTLD_LAZY);
  1436   if (result != NULL) {
  1437     // Successful loading
  1438     return result;
  1441   Elf32_Ehdr elf_head;
  1443   // Read system error message into ebuf
  1444   // It may or may not be overwritten below
  1445   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
  1446   ebuf[ebuflen-1]='\0';
  1447   int diag_msg_max_length=ebuflen-strlen(ebuf);
  1448   char* diag_msg_buf=ebuf+strlen(ebuf);
  1450   if (diag_msg_max_length==0) {
  1451     // No more space in ebuf for additional diagnostics message
  1452     return NULL;
  1456   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
  1458   if (file_descriptor < 0) {
  1459     // Can't open library, report dlerror() message
  1460     return NULL;
  1463   bool failed_to_read_elf_head=
  1464     (sizeof(elf_head)!=
  1465         (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
  1467   ::close(file_descriptor);
  1468   if (failed_to_read_elf_head) {
  1469     // file i/o error - report dlerror() msg
  1470     return NULL;
  1473   typedef struct {
  1474     Elf32_Half  code;         // Actual value as defined in elf.h
  1475     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
  1476     char        elf_class;    // 32 or 64 bit
  1477     char        endianess;    // MSB or LSB
  1478     char*       name;         // String representation
  1479   } arch_t;
  1481   #ifndef EM_486
  1482   #define EM_486          6               /* Intel 80486 */
  1483   #endif
  1485   #ifndef EM_MIPS_RS3_LE
  1486   #define EM_MIPS_RS3_LE  10              /* MIPS */
  1487   #endif
  1489   #ifndef EM_PPC64
  1490   #define EM_PPC64        21              /* PowerPC64 */
  1491   #endif
  1493   #ifndef EM_S390
  1494   #define EM_S390         22              /* IBM System/390 */
  1495   #endif
  1497   #ifndef EM_IA_64
  1498   #define EM_IA_64        50              /* HP/Intel IA-64 */
  1499   #endif
  1501   #ifndef EM_X86_64
  1502   #define EM_X86_64       62              /* AMD x86-64 */
  1503   #endif
  1505   static const arch_t arch_array[]={
  1506     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
  1507     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
  1508     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
  1509     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
  1510     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
  1511     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
  1512     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
  1513     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
  1514     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
  1515     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
  1516     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
  1517     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
  1518     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
  1519     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
  1520     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
  1521     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
  1522   };
  1524   #if  (defined IA32)
  1525     static  Elf32_Half running_arch_code=EM_386;
  1526   #elif   (defined AMD64)
  1527     static  Elf32_Half running_arch_code=EM_X86_64;
  1528   #elif  (defined IA64)
  1529     static  Elf32_Half running_arch_code=EM_IA_64;
  1530   #elif  (defined __sparc) && (defined _LP64)
  1531     static  Elf32_Half running_arch_code=EM_SPARCV9;
  1532   #elif  (defined __sparc) && (!defined _LP64)
  1533     static  Elf32_Half running_arch_code=EM_SPARC;
  1534   #elif  (defined __powerpc64__)
  1535     static  Elf32_Half running_arch_code=EM_PPC64;
  1536   #elif  (defined __powerpc__)
  1537     static  Elf32_Half running_arch_code=EM_PPC;
  1538   #elif  (defined ARM)
  1539     static  Elf32_Half running_arch_code=EM_ARM;
  1540   #elif  (defined S390)
  1541     static  Elf32_Half running_arch_code=EM_S390;
  1542   #elif  (defined ALPHA)
  1543     static  Elf32_Half running_arch_code=EM_ALPHA;
  1544   #elif  (defined MIPSEL)
  1545     static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
  1546   #elif  (defined PARISC)
  1547     static  Elf32_Half running_arch_code=EM_PARISC;
  1548   #elif  (defined MIPS)
  1549     static  Elf32_Half running_arch_code=EM_MIPS;
  1550   #elif  (defined M68K)
  1551     static  Elf32_Half running_arch_code=EM_68K;
  1552   #else
  1553     #error Method os::dll_load requires that one of following is defined:\
  1554          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
  1555   #endif
  1557   // Identify compatability class for VM's architecture and library's architecture
  1558   // Obtain string descriptions for architectures
  1560   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
  1561   int running_arch_index=-1;
  1563   for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
  1564     if (running_arch_code == arch_array[i].code) {
  1565       running_arch_index    = i;
  1567     if (lib_arch.code == arch_array[i].code) {
  1568       lib_arch.compat_class = arch_array[i].compat_class;
  1569       lib_arch.name         = arch_array[i].name;
  1573   assert(running_arch_index != -1,
  1574     "Didn't find running architecture code (running_arch_code) in arch_array");
  1575   if (running_arch_index == -1) {
  1576     // Even though running architecture detection failed
  1577     // we may still continue with reporting dlerror() message
  1578     return NULL;
  1581   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
  1582     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
  1583     return NULL;
  1586 #ifndef S390
  1587   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
  1588     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
  1589     return NULL;
  1591 #endif // !S390
  1593   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
  1594     if ( lib_arch.name!=NULL ) {
  1595       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
  1596         " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
  1597         lib_arch.name, arch_array[running_arch_index].name);
  1598     } else {
  1599       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
  1600       " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
  1601         lib_arch.code,
  1602         arch_array[running_arch_index].name);
  1606   return NULL;
  1608 #endif /* !__APPLE__ */
  1610 void* os::get_default_process_handle() {
  1611 #ifdef __APPLE__
  1612   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
  1613   // to avoid finding unexpected symbols on second (or later)
  1614   // loads of a library.
  1615   return (void*)::dlopen(NULL, RTLD_FIRST);
  1616 #else
  1617   return (void*)::dlopen(NULL, RTLD_LAZY);
  1618 #endif
  1621 // XXX: Do we need a lock around this as per Linux?
  1622 void* os::dll_lookup(void* handle, const char* name) {
  1623   return dlsym(handle, name);
  1627 static bool _print_ascii_file(const char* filename, outputStream* st) {
  1628   int fd = ::open(filename, O_RDONLY);
  1629   if (fd == -1) {
  1630      return false;
  1633   char buf[32];
  1634   int bytes;
  1635   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
  1636     st->print_raw(buf, bytes);
  1639   ::close(fd);
  1641   return true;
  1644 void os::print_dll_info(outputStream *st) {
  1645   st->print_cr("Dynamic libraries:");
  1646 #ifdef RTLD_DI_LINKMAP
  1647   Dl_info dli;
  1648   void *handle;
  1649   Link_map *map;
  1650   Link_map *p;
  1652   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
  1653       dli.dli_fname == NULL) {
  1654     st->print_cr("Error: Cannot print dynamic libraries.");
  1655     return;
  1657   handle = dlopen(dli.dli_fname, RTLD_LAZY);
  1658   if (handle == NULL) {
  1659     st->print_cr("Error: Cannot print dynamic libraries.");
  1660     return;
  1662   dlinfo(handle, RTLD_DI_LINKMAP, &map);
  1663   if (map == NULL) {
  1664     st->print_cr("Error: Cannot print dynamic libraries.");
  1665     return;
  1668   while (map->l_prev != NULL)
  1669     map = map->l_prev;
  1671   while (map != NULL) {
  1672     st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
  1673     map = map->l_next;
  1676   dlclose(handle);
  1677 #elif defined(__APPLE__)
  1678   uint32_t count;
  1679   uint32_t i;
  1681   count = _dyld_image_count();
  1682   for (i = 1; i < count; i++) {
  1683     const char *name = _dyld_get_image_name(i);
  1684     intptr_t slide = _dyld_get_image_vmaddr_slide(i);
  1685     st->print_cr(PTR_FORMAT " \t%s", slide, name);
  1687 #else
  1688   st->print_cr("Error: Cannot print dynamic libraries.");
  1689 #endif
  1692 void os::print_os_info_brief(outputStream* st) {
  1693   st->print("Bsd");
  1695   os::Posix::print_uname_info(st);
  1698 void os::print_os_info(outputStream* st) {
  1699   st->print("OS:");
  1700   st->print("Bsd");
  1702   os::Posix::print_uname_info(st);
  1704   os::Posix::print_rlimit_info(st);
  1706   os::Posix::print_load_average(st);
  1709 void os::pd_print_cpu_info(outputStream* st) {
  1710   // Nothing to do for now.
  1713 void os::print_memory_info(outputStream* st) {
  1715   st->print("Memory:");
  1716   st->print(" %dk page", os::vm_page_size()>>10);
  1718   st->print(", physical " UINT64_FORMAT "k",
  1719             os::physical_memory() >> 10);
  1720   st->print("(" UINT64_FORMAT "k free)",
  1721             os::available_memory() >> 10);
  1722   st->cr();
  1724   // meminfo
  1725   st->print("\n/proc/meminfo:\n");
  1726   _print_ascii_file("/proc/meminfo", st);
  1727   st->cr();
  1730 void os::print_siginfo(outputStream* st, void* siginfo) {
  1731   const siginfo_t* si = (const siginfo_t*)siginfo;
  1733   os::Posix::print_siginfo_brief(st, si);
  1735   if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
  1736       UseSharedSpaces) {
  1737     FileMapInfo* mapinfo = FileMapInfo::current_info();
  1738     if (mapinfo->is_in_shared_space(si->si_addr)) {
  1739       st->print("\n\nError accessing class data sharing archive."   \
  1740                 " Mapped file inaccessible during execution, "      \
  1741                 " possible disk/network problem.");
  1744   st->cr();
  1748 static void print_signal_handler(outputStream* st, int sig,
  1749                                  char* buf, size_t buflen);
  1751 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
  1752   st->print_cr("Signal Handlers:");
  1753   print_signal_handler(st, SIGSEGV, buf, buflen);
  1754   print_signal_handler(st, SIGBUS , buf, buflen);
  1755   print_signal_handler(st, SIGFPE , buf, buflen);
  1756   print_signal_handler(st, SIGPIPE, buf, buflen);
  1757   print_signal_handler(st, SIGXFSZ, buf, buflen);
  1758   print_signal_handler(st, SIGILL , buf, buflen);
  1759   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
  1760   print_signal_handler(st, SR_signum, buf, buflen);
  1761   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
  1762   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
  1763   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
  1764   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
  1767 static char saved_jvm_path[MAXPATHLEN] = {0};
  1769 // Find the full path to the current module, libjvm
  1770 void os::jvm_path(char *buf, jint buflen) {
  1771   // Error checking.
  1772   if (buflen < MAXPATHLEN) {
  1773     assert(false, "must use a large-enough buffer");
  1774     buf[0] = '\0';
  1775     return;
  1777   // Lazy resolve the path to current module.
  1778   if (saved_jvm_path[0] != 0) {
  1779     strcpy(buf, saved_jvm_path);
  1780     return;
  1783   char dli_fname[MAXPATHLEN];
  1784   bool ret = dll_address_to_library_name(
  1785                 CAST_FROM_FN_PTR(address, os::jvm_path),
  1786                 dli_fname, sizeof(dli_fname), NULL);
  1787   assert(ret, "cannot locate libjvm");
  1788   char *rp = NULL;
  1789   if (ret && dli_fname[0] != '\0') {
  1790     rp = realpath(dli_fname, buf);
  1792   if (rp == NULL)
  1793     return;
  1795   if (Arguments::created_by_gamma_launcher()) {
  1796     // Support for the gamma launcher.  Typical value for buf is
  1797     // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm".  If "/jre/lib/" appears at
  1798     // the right place in the string, then assume we are installed in a JDK and
  1799     // we're done.  Otherwise, check for a JAVA_HOME environment variable and
  1800     // construct a path to the JVM being overridden.
  1802     const char *p = buf + strlen(buf) - 1;
  1803     for (int count = 0; p > buf && count < 5; ++count) {
  1804       for (--p; p > buf && *p != '/'; --p)
  1805         /* empty */ ;
  1808     if (strncmp(p, "/jre/lib/", 9) != 0) {
  1809       // Look for JAVA_HOME in the environment.
  1810       char* java_home_var = ::getenv("JAVA_HOME");
  1811       if (java_home_var != NULL && java_home_var[0] != 0) {
  1812         char* jrelib_p;
  1813         int len;
  1815         // Check the current module name "libjvm"
  1816         p = strrchr(buf, '/');
  1817         assert(strstr(p, "/libjvm") == p, "invalid library name");
  1819         rp = realpath(java_home_var, buf);
  1820         if (rp == NULL)
  1821           return;
  1823         // determine if this is a legacy image or modules image
  1824         // modules image doesn't have "jre" subdirectory
  1825         len = strlen(buf);
  1826         assert(len < buflen, "Ran out of buffer space");
  1827         jrelib_p = buf + len;
  1829         // Add the appropriate library subdir
  1830         snprintf(jrelib_p, buflen-len, "/jre/lib");
  1831         if (0 != access(buf, F_OK)) {
  1832           snprintf(jrelib_p, buflen-len, "/lib");
  1835         // Add the appropriate client or server subdir
  1836         len = strlen(buf);
  1837         jrelib_p = buf + len;
  1838         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
  1839         if (0 != access(buf, F_OK)) {
  1840           snprintf(jrelib_p, buflen-len, "");
  1843         // If the path exists within JAVA_HOME, add the JVM library name
  1844         // to complete the path to JVM being overridden.  Otherwise fallback
  1845         // to the path to the current library.
  1846         if (0 == access(buf, F_OK)) {
  1847           // Use current module name "libjvm"
  1848           len = strlen(buf);
  1849           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
  1850         } else {
  1851           // Fall back to path of current library
  1852           rp = realpath(dli_fname, buf);
  1853           if (rp == NULL)
  1854             return;
  1860   strncpy(saved_jvm_path, buf, MAXPATHLEN);
  1863 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
  1864   // no prefix required, not even "_"
  1867 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
  1868   // no suffix required
  1871 ////////////////////////////////////////////////////////////////////////////////
  1872 // sun.misc.Signal support
  1874 static volatile jint sigint_count = 0;
  1876 static void
  1877 UserHandler(int sig, void *siginfo, void *context) {
  1878   // 4511530 - sem_post is serialized and handled by the manager thread. When
  1879   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
  1880   // don't want to flood the manager thread with sem_post requests.
  1881   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
  1882       return;
  1884   // Ctrl-C is pressed during error reporting, likely because the error
  1885   // handler fails to abort. Let VM die immediately.
  1886   if (sig == SIGINT && is_error_reported()) {
  1887      os::die();
  1890   os::signal_notify(sig);
  1893 void* os::user_handler() {
  1894   return CAST_FROM_FN_PTR(void*, UserHandler);
  1897 extern "C" {
  1898   typedef void (*sa_handler_t)(int);
  1899   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
  1902 void* os::signal(int signal_number, void* handler) {
  1903   struct sigaction sigAct, oldSigAct;
  1905   sigfillset(&(sigAct.sa_mask));
  1906   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
  1907   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
  1909   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
  1910     // -1 means registration failed
  1911     return (void *)-1;
  1914   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
  1917 void os::signal_raise(int signal_number) {
  1918   ::raise(signal_number);
  1921 /*
  1922  * The following code is moved from os.cpp for making this
  1923  * code platform specific, which it is by its very nature.
  1924  */
  1926 // Will be modified when max signal is changed to be dynamic
  1927 int os::sigexitnum_pd() {
  1928   return NSIG;
  1931 // a counter for each possible signal value
  1932 static volatile jint pending_signals[NSIG+1] = { 0 };
  1934 // Bsd(POSIX) specific hand shaking semaphore.
  1935 #ifdef __APPLE__
  1936 typedef semaphore_t os_semaphore_t;
  1937 #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
  1938 #define SEM_WAIT(sem)           semaphore_wait(sem)
  1939 #define SEM_POST(sem)           semaphore_signal(sem)
  1940 #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
  1941 #else
  1942 typedef sem_t os_semaphore_t;
  1943 #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
  1944 #define SEM_WAIT(sem)           sem_wait(&sem)
  1945 #define SEM_POST(sem)           sem_post(&sem)
  1946 #define SEM_DESTROY(sem)        sem_destroy(&sem)
  1947 #endif
  1949 class Semaphore : public StackObj {
  1950   public:
  1951     Semaphore();
  1952     ~Semaphore();
  1953     void signal();
  1954     void wait();
  1955     bool trywait();
  1956     bool timedwait(unsigned int sec, int nsec);
  1957   private:
  1958     jlong currenttime() const;
  1959     os_semaphore_t _semaphore;
  1960 };
  1962 Semaphore::Semaphore() : _semaphore(0) {
  1963   SEM_INIT(_semaphore, 0);
  1966 Semaphore::~Semaphore() {
  1967   SEM_DESTROY(_semaphore);
  1970 void Semaphore::signal() {
  1971   SEM_POST(_semaphore);
  1974 void Semaphore::wait() {
  1975   SEM_WAIT(_semaphore);
  1978 jlong Semaphore::currenttime() const {
  1979     struct timeval tv;
  1980     gettimeofday(&tv, NULL);
  1981     return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
  1984 #ifdef __APPLE__
  1985 bool Semaphore::trywait() {
  1986   return timedwait(0, 0);
  1989 bool Semaphore::timedwait(unsigned int sec, int nsec) {
  1990   kern_return_t kr = KERN_ABORTED;
  1991   mach_timespec_t waitspec;
  1992   waitspec.tv_sec = sec;
  1993   waitspec.tv_nsec = nsec;
  1995   jlong starttime = currenttime();
  1997   kr = semaphore_timedwait(_semaphore, waitspec);
  1998   while (kr == KERN_ABORTED) {
  1999     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
  2001     jlong current = currenttime();
  2002     jlong passedtime = current - starttime;
  2004     if (passedtime >= totalwait) {
  2005       waitspec.tv_sec = 0;
  2006       waitspec.tv_nsec = 0;
  2007     } else {
  2008       jlong waittime = totalwait - (current - starttime);
  2009       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
  2010       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
  2013     kr = semaphore_timedwait(_semaphore, waitspec);
  2016   return kr == KERN_SUCCESS;
  2019 #else
  2021 bool Semaphore::trywait() {
  2022   return sem_trywait(&_semaphore) == 0;
  2025 bool Semaphore::timedwait(unsigned int sec, int nsec) {
  2026   struct timespec ts;
  2027   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
  2029   while (1) {
  2030     int result = sem_timedwait(&_semaphore, &ts);
  2031     if (result == 0) {
  2032       return true;
  2033     } else if (errno == EINTR) {
  2034       continue;
  2035     } else if (errno == ETIMEDOUT) {
  2036       return false;
  2037     } else {
  2038       return false;
  2043 #endif // __APPLE__
  2045 static os_semaphore_t sig_sem;
  2046 static Semaphore sr_semaphore;
  2048 void os::signal_init_pd() {
  2049   // Initialize signal structures
  2050   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
  2052   // Initialize signal semaphore
  2053   ::SEM_INIT(sig_sem, 0);
  2056 void os::signal_notify(int sig) {
  2057   Atomic::inc(&pending_signals[sig]);
  2058   ::SEM_POST(sig_sem);
  2061 static int check_pending_signals(bool wait) {
  2062   Atomic::store(0, &sigint_count);
  2063   for (;;) {
  2064     for (int i = 0; i < NSIG + 1; i++) {
  2065       jint n = pending_signals[i];
  2066       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
  2067         return i;
  2070     if (!wait) {
  2071       return -1;
  2073     JavaThread *thread = JavaThread::current();
  2074     ThreadBlockInVM tbivm(thread);
  2076     bool threadIsSuspended;
  2077     do {
  2078       thread->set_suspend_equivalent();
  2079       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
  2080       ::SEM_WAIT(sig_sem);
  2082       // were we externally suspended while we were waiting?
  2083       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
  2084       if (threadIsSuspended) {
  2085         //
  2086         // The semaphore has been incremented, but while we were waiting
  2087         // another thread suspended us. We don't want to continue running
  2088         // while suspended because that would surprise the thread that
  2089         // suspended us.
  2090         //
  2091         ::SEM_POST(sig_sem);
  2093         thread->java_suspend_self();
  2095     } while (threadIsSuspended);
  2099 int os::signal_lookup() {
  2100   return check_pending_signals(false);
  2103 int os::signal_wait() {
  2104   return check_pending_signals(true);
  2107 ////////////////////////////////////////////////////////////////////////////////
  2108 // Virtual Memory
  2110 int os::vm_page_size() {
  2111   // Seems redundant as all get out
  2112   assert(os::Bsd::page_size() != -1, "must call os::init");
  2113   return os::Bsd::page_size();
  2116 // Solaris allocates memory by pages.
  2117 int os::vm_allocation_granularity() {
  2118   assert(os::Bsd::page_size() != -1, "must call os::init");
  2119   return os::Bsd::page_size();
  2122 // Rationale behind this function:
  2123 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
  2124 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
  2125 //  samples for JITted code. Here we create private executable mapping over the code cache
  2126 //  and then we can use standard (well, almost, as mapping can change) way to provide
  2127 //  info for the reporting script by storing timestamp and location of symbol
  2128 void bsd_wrap_code(char* base, size_t size) {
  2129   static volatile jint cnt = 0;
  2131   if (!UseOprofile) {
  2132     return;
  2135   char buf[PATH_MAX + 1];
  2136   int num = Atomic::add(1, &cnt);
  2138   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
  2139            os::get_temp_directory(), os::current_process_id(), num);
  2140   unlink(buf);
  2142   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
  2144   if (fd != -1) {
  2145     off_t rv = ::lseek(fd, size-2, SEEK_SET);
  2146     if (rv != (off_t)-1) {
  2147       if (::write(fd, "", 1) == 1) {
  2148         mmap(base, size,
  2149              PROT_READ|PROT_WRITE|PROT_EXEC,
  2150              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
  2153     ::close(fd);
  2154     unlink(buf);
  2158 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
  2159                                     int err) {
  2160   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
  2161           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
  2162           strerror(err), err);
  2165 // NOTE: Bsd kernel does not really reserve the pages for us.
  2166 //       All it does is to check if there are enough free pages
  2167 //       left at the time of mmap(). This could be a potential
  2168 //       problem.
  2169 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
  2170   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
  2171 #ifdef __OpenBSD__
  2172   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
  2173   if (::mprotect(addr, size, prot) == 0) {
  2174     return true;
  2176 #else
  2177   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
  2178                                    MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
  2179   if (res != (uintptr_t) MAP_FAILED) {
  2180     return true;
  2182 #endif
  2184   // Warn about any commit errors we see in non-product builds just
  2185   // in case mmap() doesn't work as described on the man page.
  2186   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
  2188   return false;
  2191 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
  2192                        bool exec) {
  2193   // alignment_hint is ignored on this OS
  2194   return pd_commit_memory(addr, size, exec);
  2197 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
  2198                                   const char* mesg) {
  2199   assert(mesg != NULL, "mesg must be specified");
  2200   if (!pd_commit_memory(addr, size, exec)) {
  2201     // add extra info in product mode for vm_exit_out_of_memory():
  2202     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
  2203     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
  2207 void os::pd_commit_memory_or_exit(char* addr, size_t size,
  2208                                   size_t alignment_hint, bool exec,
  2209                                   const char* mesg) {
  2210   // alignment_hint is ignored on this OS
  2211   pd_commit_memory_or_exit(addr, size, exec, mesg);
  2214 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
  2217 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
  2218   ::madvise(addr, bytes, MADV_DONTNEED);
  2221 void os::numa_make_global(char *addr, size_t bytes) {
  2224 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
  2227 bool os::numa_topology_changed()   { return false; }
  2229 size_t os::numa_get_groups_num() {
  2230   return 1;
  2233 int os::numa_get_group_id() {
  2234   return 0;
  2237 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
  2238   if (size > 0) {
  2239     ids[0] = 0;
  2240     return 1;
  2242   return 0;
  2245 bool os::get_page_info(char *start, page_info* info) {
  2246   return false;
  2249 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
  2250   return end;
  2254 bool os::pd_uncommit_memory(char* addr, size_t size) {
  2255 #ifdef __OpenBSD__
  2256   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
  2257   return ::mprotect(addr, size, PROT_NONE) == 0;
  2258 #else
  2259   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
  2260                 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
  2261   return res  != (uintptr_t) MAP_FAILED;
  2262 #endif
  2265 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
  2266   return os::commit_memory(addr, size, !ExecMem);
  2269 // If this is a growable mapping, remove the guard pages entirely by
  2270 // munmap()ping them.  If not, just call uncommit_memory().
  2271 bool os::remove_stack_guard_pages(char* addr, size_t size) {
  2272   return os::uncommit_memory(addr, size);
  2275 static address _highest_vm_reserved_address = NULL;
  2277 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
  2278 // at 'requested_addr'. If there are existing memory mappings at the same
  2279 // location, however, they will be overwritten. If 'fixed' is false,
  2280 // 'requested_addr' is only treated as a hint, the return value may or
  2281 // may not start from the requested address. Unlike Bsd mmap(), this
  2282 // function returns NULL to indicate failure.
  2283 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
  2284   char * addr;
  2285   int flags;
  2287   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
  2288   if (fixed) {
  2289     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
  2290     flags |= MAP_FIXED;
  2293   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
  2294   // touch an uncommitted page. Otherwise, the read/write might
  2295   // succeed if we have enough swap space to back the physical page.
  2296   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
  2297                        flags, -1, 0);
  2299   if (addr != MAP_FAILED) {
  2300     // anon_mmap() should only get called during VM initialization,
  2301     // don't need lock (actually we can skip locking even it can be called
  2302     // from multiple threads, because _highest_vm_reserved_address is just a
  2303     // hint about the upper limit of non-stack memory regions.)
  2304     if ((address)addr + bytes > _highest_vm_reserved_address) {
  2305       _highest_vm_reserved_address = (address)addr + bytes;
  2309   return addr == MAP_FAILED ? NULL : addr;
  2312 // Don't update _highest_vm_reserved_address, because there might be memory
  2313 // regions above addr + size. If so, releasing a memory region only creates
  2314 // a hole in the address space, it doesn't help prevent heap-stack collision.
  2315 //
  2316 static int anon_munmap(char * addr, size_t size) {
  2317   return ::munmap(addr, size) == 0;
  2320 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
  2321                          size_t alignment_hint) {
  2322   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
  2325 bool os::pd_release_memory(char* addr, size_t size) {
  2326   return anon_munmap(addr, size);
  2329 static bool bsd_mprotect(char* addr, size_t size, int prot) {
  2330   // Bsd wants the mprotect address argument to be page aligned.
  2331   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
  2333   // According to SUSv3, mprotect() should only be used with mappings
  2334   // established by mmap(), and mmap() always maps whole pages. Unaligned
  2335   // 'addr' likely indicates problem in the VM (e.g. trying to change
  2336   // protection of malloc'ed or statically allocated memory). Check the
  2337   // caller if you hit this assert.
  2338   assert(addr == bottom, "sanity check");
  2340   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
  2341   return ::mprotect(bottom, size, prot) == 0;
  2344 // Set protections specified
  2345 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
  2346                         bool is_committed) {
  2347   unsigned int p = 0;
  2348   switch (prot) {
  2349   case MEM_PROT_NONE: p = PROT_NONE; break;
  2350   case MEM_PROT_READ: p = PROT_READ; break;
  2351   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
  2352   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
  2353   default:
  2354     ShouldNotReachHere();
  2356   // is_committed is unused.
  2357   return bsd_mprotect(addr, bytes, p);
  2360 bool os::guard_memory(char* addr, size_t size) {
  2361   return bsd_mprotect(addr, size, PROT_NONE);
  2364 bool os::unguard_memory(char* addr, size_t size) {
  2365   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
  2368 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
  2369   return false;
  2372 // Large page support
  2374 static size_t _large_page_size = 0;
  2376 void os::large_page_init() {
  2380 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
  2381   fatal("This code is not used or maintained.");
  2383   // "exec" is passed in but not used.  Creating the shared image for
  2384   // the code cache doesn't have an SHM_X executable permission to check.
  2385   assert(UseLargePages && UseSHM, "only for SHM large pages");
  2387   key_t key = IPC_PRIVATE;
  2388   char *addr;
  2390   bool warn_on_failure = UseLargePages &&
  2391                         (!FLAG_IS_DEFAULT(UseLargePages) ||
  2392                          !FLAG_IS_DEFAULT(LargePageSizeInBytes)
  2393                         );
  2395   // Create a large shared memory region to attach to based on size.
  2396   // Currently, size is the total size of the heap
  2397   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
  2398   if (shmid == -1) {
  2399      // Possible reasons for shmget failure:
  2400      // 1. shmmax is too small for Java heap.
  2401      //    > check shmmax value: cat /proc/sys/kernel/shmmax
  2402      //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
  2403      // 2. not enough large page memory.
  2404      //    > check available large pages: cat /proc/meminfo
  2405      //    > increase amount of large pages:
  2406      //          echo new_value > /proc/sys/vm/nr_hugepages
  2407      //      Note 1: different Bsd may use different name for this property,
  2408      //            e.g. on Redhat AS-3 it is "hugetlb_pool".
  2409      //      Note 2: it's possible there's enough physical memory available but
  2410      //            they are so fragmented after a long run that they can't
  2411      //            coalesce into large pages. Try to reserve large pages when
  2412      //            the system is still "fresh".
  2413      if (warn_on_failure) {
  2414        warning("Failed to reserve shared memory (errno = %d).", errno);
  2416      return NULL;
  2419   // attach to the region
  2420   addr = (char*)shmat(shmid, req_addr, 0);
  2421   int err = errno;
  2423   // Remove shmid. If shmat() is successful, the actual shared memory segment
  2424   // will be deleted when it's detached by shmdt() or when the process
  2425   // terminates. If shmat() is not successful this will remove the shared
  2426   // segment immediately.
  2427   shmctl(shmid, IPC_RMID, NULL);
  2429   if ((intptr_t)addr == -1) {
  2430      if (warn_on_failure) {
  2431        warning("Failed to attach shared memory (errno = %d).", err);
  2433      return NULL;
  2436   // The memory is committed
  2437   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
  2439   return addr;
  2442 bool os::release_memory_special(char* base, size_t bytes) {
  2443   if (MemTracker::tracking_level() > NMT_minimal) {
  2444     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
  2445     // detaching the SHM segment will also delete it, see reserve_memory_special()
  2446     int rslt = shmdt(base);
  2447     if (rslt == 0) {
  2448       tkr.record((address)base, bytes);
  2449       return true;
  2450     } else {
  2451       return false;
  2453   } else {
  2454     return shmdt(base) == 0;
  2458 size_t os::large_page_size() {
  2459   return _large_page_size;
  2462 // HugeTLBFS allows application to commit large page memory on demand;
  2463 // with SysV SHM the entire memory region must be allocated as shared
  2464 // memory.
  2465 bool os::can_commit_large_page_memory() {
  2466   return UseHugeTLBFS;
  2469 bool os::can_execute_large_page_memory() {
  2470   return UseHugeTLBFS;
  2473 // Reserve memory at an arbitrary address, only if that area is
  2474 // available (and not reserved for something else).
  2476 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
  2477   const int max_tries = 10;
  2478   char* base[max_tries];
  2479   size_t size[max_tries];
  2480   const size_t gap = 0x000000;
  2482   // Assert only that the size is a multiple of the page size, since
  2483   // that's all that mmap requires, and since that's all we really know
  2484   // about at this low abstraction level.  If we need higher alignment,
  2485   // we can either pass an alignment to this method or verify alignment
  2486   // in one of the methods further up the call chain.  See bug 5044738.
  2487   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
  2489   // Repeatedly allocate blocks until the block is allocated at the
  2490   // right spot. Give up after max_tries. Note that reserve_memory() will
  2491   // automatically update _highest_vm_reserved_address if the call is
  2492   // successful. The variable tracks the highest memory address every reserved
  2493   // by JVM. It is used to detect heap-stack collision if running with
  2494   // fixed-stack BsdThreads. Because here we may attempt to reserve more
  2495   // space than needed, it could confuse the collision detecting code. To
  2496   // solve the problem, save current _highest_vm_reserved_address and
  2497   // calculate the correct value before return.
  2498   address old_highest = _highest_vm_reserved_address;
  2500   // Bsd mmap allows caller to pass an address as hint; give it a try first,
  2501   // if kernel honors the hint then we can return immediately.
  2502   char * addr = anon_mmap(requested_addr, bytes, false);
  2503   if (addr == requested_addr) {
  2504      return requested_addr;
  2507   if (addr != NULL) {
  2508      // mmap() is successful but it fails to reserve at the requested address
  2509      anon_munmap(addr, bytes);
  2512   int i;
  2513   for (i = 0; i < max_tries; ++i) {
  2514     base[i] = reserve_memory(bytes);
  2516     if (base[i] != NULL) {
  2517       // Is this the block we wanted?
  2518       if (base[i] == requested_addr) {
  2519         size[i] = bytes;
  2520         break;
  2523       // Does this overlap the block we wanted? Give back the overlapped
  2524       // parts and try again.
  2526       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
  2527       if (top_overlap >= 0 && top_overlap < bytes) {
  2528         unmap_memory(base[i], top_overlap);
  2529         base[i] += top_overlap;
  2530         size[i] = bytes - top_overlap;
  2531       } else {
  2532         size_t bottom_overlap = base[i] + bytes - requested_addr;
  2533         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
  2534           unmap_memory(requested_addr, bottom_overlap);
  2535           size[i] = bytes - bottom_overlap;
  2536         } else {
  2537           size[i] = bytes;
  2543   // Give back the unused reserved pieces.
  2545   for (int j = 0; j < i; ++j) {
  2546     if (base[j] != NULL) {
  2547       unmap_memory(base[j], size[j]);
  2551   if (i < max_tries) {
  2552     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
  2553     return requested_addr;
  2554   } else {
  2555     _highest_vm_reserved_address = old_highest;
  2556     return NULL;
  2560 size_t os::read(int fd, void *buf, unsigned int nBytes) {
  2561   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
  2564 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
  2565 // Solaris uses poll(), bsd uses park().
  2566 // Poll() is likely a better choice, assuming that Thread.interrupt()
  2567 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
  2568 // SIGSEGV, see 4355769.
  2570 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
  2571   assert(thread == Thread::current(),  "thread consistency check");
  2573   ParkEvent * const slp = thread->_SleepEvent ;
  2574   slp->reset() ;
  2575   OrderAccess::fence() ;
  2577   if (interruptible) {
  2578     jlong prevtime = javaTimeNanos();
  2580     for (;;) {
  2581       if (os::is_interrupted(thread, true)) {
  2582         return OS_INTRPT;
  2585       jlong newtime = javaTimeNanos();
  2587       if (newtime - prevtime < 0) {
  2588         // time moving backwards, should only happen if no monotonic clock
  2589         // not a guarantee() because JVM should not abort on kernel/glibc bugs
  2590         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
  2591       } else {
  2592         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
  2595       if(millis <= 0) {
  2596         return OS_OK;
  2599       prevtime = newtime;
  2602         assert(thread->is_Java_thread(), "sanity check");
  2603         JavaThread *jt = (JavaThread *) thread;
  2604         ThreadBlockInVM tbivm(jt);
  2605         OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
  2607         jt->set_suspend_equivalent();
  2608         // cleared by handle_special_suspend_equivalent_condition() or
  2609         // java_suspend_self() via check_and_wait_while_suspended()
  2611         slp->park(millis);
  2613         // were we externally suspended while we were waiting?
  2614         jt->check_and_wait_while_suspended();
  2617   } else {
  2618     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
  2619     jlong prevtime = javaTimeNanos();
  2621     for (;;) {
  2622       // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
  2623       // the 1st iteration ...
  2624       jlong newtime = javaTimeNanos();
  2626       if (newtime - prevtime < 0) {
  2627         // time moving backwards, should only happen if no monotonic clock
  2628         // not a guarantee() because JVM should not abort on kernel/glibc bugs
  2629         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
  2630       } else {
  2631         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
  2634       if(millis <= 0) break ;
  2636       prevtime = newtime;
  2637       slp->park(millis);
  2639     return OS_OK ;
  2643 void os::naked_short_sleep(jlong ms) {
  2644   struct timespec req;
  2646   assert(ms < 1000, "Un-interruptable sleep, short time use only");
  2647   req.tv_sec = 0;
  2648   if (ms > 0) {
  2649     req.tv_nsec = (ms % 1000) * 1000000;
  2651   else {
  2652     req.tv_nsec = 1;
  2655   nanosleep(&req, NULL);
  2657   return;
  2660 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
  2661 void os::infinite_sleep() {
  2662   while (true) {    // sleep forever ...
  2663     ::sleep(100);   // ... 100 seconds at a time
  2667 // Used to convert frequent JVM_Yield() to nops
  2668 bool os::dont_yield() {
  2669   return DontYieldALot;
  2672 void os::yield() {
  2673   sched_yield();
  2676 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
  2678 void os::yield_all(int attempts) {
  2679   // Yields to all threads, including threads with lower priorities
  2680   // Threads on Bsd are all with same priority. The Solaris style
  2681   // os::yield_all() with nanosleep(1ms) is not necessary.
  2682   sched_yield();
  2685 // Called from the tight loops to possibly influence time-sharing heuristics
  2686 void os::loop_breaker(int attempts) {
  2687   os::yield_all(attempts);
  2690 ////////////////////////////////////////////////////////////////////////////////
  2691 // thread priority support
  2693 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
  2694 // only supports dynamic priority, static priority must be zero. For real-time
  2695 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
  2696 // However, for large multi-threaded applications, SCHED_RR is not only slower
  2697 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
  2698 // of 5 runs - Sep 2005).
  2699 //
  2700 // The following code actually changes the niceness of kernel-thread/LWP. It
  2701 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
  2702 // not the entire user process, and user level threads are 1:1 mapped to kernel
  2703 // threads. It has always been the case, but could change in the future. For
  2704 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
  2705 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
  2707 #if !defined(__APPLE__)
  2708 int os::java_to_os_priority[CriticalPriority + 1] = {
  2709   19,              // 0 Entry should never be used
  2711    0,              // 1 MinPriority
  2712    3,              // 2
  2713    6,              // 3
  2715   10,              // 4
  2716   15,              // 5 NormPriority
  2717   18,              // 6
  2719   21,              // 7
  2720   25,              // 8
  2721   28,              // 9 NearMaxPriority
  2723   31,              // 10 MaxPriority
  2725   31               // 11 CriticalPriority
  2726 };
  2727 #else
  2728 /* Using Mach high-level priority assignments */
  2729 int os::java_to_os_priority[CriticalPriority + 1] = {
  2730    0,              // 0 Entry should never be used (MINPRI_USER)
  2732   27,              // 1 MinPriority
  2733   28,              // 2
  2734   29,              // 3
  2736   30,              // 4
  2737   31,              // 5 NormPriority (BASEPRI_DEFAULT)
  2738   32,              // 6
  2740   33,              // 7
  2741   34,              // 8
  2742   35,              // 9 NearMaxPriority
  2744   36,              // 10 MaxPriority
  2746   36               // 11 CriticalPriority
  2747 };
  2748 #endif
  2750 static int prio_init() {
  2751   if (ThreadPriorityPolicy == 1) {
  2752     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
  2753     // if effective uid is not root. Perhaps, a more elegant way of doing
  2754     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
  2755     if (geteuid() != 0) {
  2756       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
  2757         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
  2759       ThreadPriorityPolicy = 0;
  2762   if (UseCriticalJavaThreadPriority) {
  2763     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
  2765   return 0;
  2768 OSReturn os::set_native_priority(Thread* thread, int newpri) {
  2769   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
  2771 #ifdef __OpenBSD__
  2772   // OpenBSD pthread_setprio starves low priority threads
  2773   return OS_OK;
  2774 #elif defined(__FreeBSD__)
  2775   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
  2776 #elif defined(__APPLE__) || defined(__NetBSD__)
  2777   struct sched_param sp;
  2778   int policy;
  2779   pthread_t self = pthread_self();
  2781   if (pthread_getschedparam(self, &policy, &sp) != 0)
  2782     return OS_ERR;
  2784   sp.sched_priority = newpri;
  2785   if (pthread_setschedparam(self, policy, &sp) != 0)
  2786     return OS_ERR;
  2788   return OS_OK;
  2789 #else
  2790   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
  2791   return (ret == 0) ? OS_OK : OS_ERR;
  2792 #endif
  2795 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
  2796   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
  2797     *priority_ptr = java_to_os_priority[NormPriority];
  2798     return OS_OK;
  2801   errno = 0;
  2802 #if defined(__OpenBSD__) || defined(__FreeBSD__)
  2803   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
  2804 #elif defined(__APPLE__) || defined(__NetBSD__)
  2805   int policy;
  2806   struct sched_param sp;
  2808   pthread_getschedparam(pthread_self(), &policy, &sp);
  2809   *priority_ptr = sp.sched_priority;
  2810 #else
  2811   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
  2812 #endif
  2813   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
  2816 // Hint to the underlying OS that a task switch would not be good.
  2817 // Void return because it's a hint and can fail.
  2818 void os::hint_no_preempt() {}
  2820 ////////////////////////////////////////////////////////////////////////////////
  2821 // suspend/resume support
  2823 //  the low-level signal-based suspend/resume support is a remnant from the
  2824 //  old VM-suspension that used to be for java-suspension, safepoints etc,
  2825 //  within hotspot. Now there is a single use-case for this:
  2826 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
  2827 //      that runs in the watcher thread.
  2828 //  The remaining code is greatly simplified from the more general suspension
  2829 //  code that used to be used.
  2830 //
  2831 //  The protocol is quite simple:
  2832 //  - suspend:
  2833 //      - sends a signal to the target thread
  2834 //      - polls the suspend state of the osthread using a yield loop
  2835 //      - target thread signal handler (SR_handler) sets suspend state
  2836 //        and blocks in sigsuspend until continued
  2837 //  - resume:
  2838 //      - sets target osthread state to continue
  2839 //      - sends signal to end the sigsuspend loop in the SR_handler
  2840 //
  2841 //  Note that the SR_lock plays no role in this suspend/resume protocol.
  2842 //
  2844 static void resume_clear_context(OSThread *osthread) {
  2845   osthread->set_ucontext(NULL);
  2846   osthread->set_siginfo(NULL);
  2849 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
  2850   osthread->set_ucontext(context);
  2851   osthread->set_siginfo(siginfo);
  2854 //
  2855 // Handler function invoked when a thread's execution is suspended or
  2856 // resumed. We have to be careful that only async-safe functions are
  2857 // called here (Note: most pthread functions are not async safe and
  2858 // should be avoided.)
  2859 //
  2860 // Note: sigwait() is a more natural fit than sigsuspend() from an
  2861 // interface point of view, but sigwait() prevents the signal hander
  2862 // from being run. libpthread would get very confused by not having
  2863 // its signal handlers run and prevents sigwait()'s use with the
  2864 // mutex granting granting signal.
  2865 //
  2866 // Currently only ever called on the VMThread or JavaThread
  2867 //
  2868 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
  2869   // Save and restore errno to avoid confusing native code with EINTR
  2870   // after sigsuspend.
  2871   int old_errno = errno;
  2873   Thread* thread = Thread::current();
  2874   OSThread* osthread = thread->osthread();
  2875   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
  2877   os::SuspendResume::State current = osthread->sr.state();
  2878   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
  2879     suspend_save_context(osthread, siginfo, context);
  2881     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
  2882     os::SuspendResume::State state = osthread->sr.suspended();
  2883     if (state == os::SuspendResume::SR_SUSPENDED) {
  2884       sigset_t suspend_set;  // signals for sigsuspend()
  2886       // get current set of blocked signals and unblock resume signal
  2887       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
  2888       sigdelset(&suspend_set, SR_signum);
  2890       sr_semaphore.signal();
  2891       // wait here until we are resumed
  2892       while (1) {
  2893         sigsuspend(&suspend_set);
  2895         os::SuspendResume::State result = osthread->sr.running();
  2896         if (result == os::SuspendResume::SR_RUNNING) {
  2897           sr_semaphore.signal();
  2898           break;
  2899         } else if (result != os::SuspendResume::SR_SUSPENDED) {
  2900           ShouldNotReachHere();
  2904     } else if (state == os::SuspendResume::SR_RUNNING) {
  2905       // request was cancelled, continue
  2906     } else {
  2907       ShouldNotReachHere();
  2910     resume_clear_context(osthread);
  2911   } else if (current == os::SuspendResume::SR_RUNNING) {
  2912     // request was cancelled, continue
  2913   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
  2914     // ignore
  2915   } else {
  2916     // ignore
  2919   errno = old_errno;
  2923 static int SR_initialize() {
  2924   struct sigaction act;
  2925   char *s;
  2926   /* Get signal number to use for suspend/resume */
  2927   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
  2928     int sig = ::strtol(s, 0, 10);
  2929     if (sig > 0 || sig < NSIG) {
  2930         SR_signum = sig;
  2934   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
  2935         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
  2937   sigemptyset(&SR_sigset);
  2938   sigaddset(&SR_sigset, SR_signum);
  2940   /* Set up signal handler for suspend/resume */
  2941   act.sa_flags = SA_RESTART|SA_SIGINFO;
  2942   act.sa_handler = (void (*)(int)) SR_handler;
  2944   // SR_signum is blocked by default.
  2945   // 4528190 - We also need to block pthread restart signal (32 on all
  2946   // supported Bsd platforms). Note that BsdThreads need to block
  2947   // this signal for all threads to work properly. So we don't have
  2948   // to use hard-coded signal number when setting up the mask.
  2949   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
  2951   if (sigaction(SR_signum, &act, 0) == -1) {
  2952     return -1;
  2955   // Save signal flag
  2956   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
  2957   return 0;
  2960 static int sr_notify(OSThread* osthread) {
  2961   int status = pthread_kill(osthread->pthread_id(), SR_signum);
  2962   assert_status(status == 0, status, "pthread_kill");
  2963   return status;
  2966 // "Randomly" selected value for how long we want to spin
  2967 // before bailing out on suspending a thread, also how often
  2968 // we send a signal to a thread we want to resume
  2969 static const int RANDOMLY_LARGE_INTEGER = 1000000;
  2970 static const int RANDOMLY_LARGE_INTEGER2 = 100;
  2972 // returns true on success and false on error - really an error is fatal
  2973 // but this seems the normal response to library errors
  2974 static bool do_suspend(OSThread* osthread) {
  2975   assert(osthread->sr.is_running(), "thread should be running");
  2976   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
  2978   // mark as suspended and send signal
  2979   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
  2980     // failed to switch, state wasn't running?
  2981     ShouldNotReachHere();
  2982     return false;
  2985   if (sr_notify(osthread) != 0) {
  2986     ShouldNotReachHere();
  2989   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
  2990   while (true) {
  2991     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
  2992       break;
  2993     } else {
  2994       // timeout
  2995       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
  2996       if (cancelled == os::SuspendResume::SR_RUNNING) {
  2997         return false;
  2998       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
  2999         // make sure that we consume the signal on the semaphore as well
  3000         sr_semaphore.wait();
  3001         break;
  3002       } else {
  3003         ShouldNotReachHere();
  3004         return false;
  3009   guarantee(osthread->sr.is_suspended(), "Must be suspended");
  3010   return true;
  3013 static void do_resume(OSThread* osthread) {
  3014   assert(osthread->sr.is_suspended(), "thread should be suspended");
  3015   assert(!sr_semaphore.trywait(), "invalid semaphore state");
  3017   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
  3018     // failed to switch to WAKEUP_REQUEST
  3019     ShouldNotReachHere();
  3020     return;
  3023   while (true) {
  3024     if (sr_notify(osthread) == 0) {
  3025       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
  3026         if (osthread->sr.is_running()) {
  3027           return;
  3030     } else {
  3031       ShouldNotReachHere();
  3035   guarantee(osthread->sr.is_running(), "Must be running!");
  3038 ////////////////////////////////////////////////////////////////////////////////
  3039 // interrupt support
  3041 void os::interrupt(Thread* thread) {
  3042   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
  3043     "possibility of dangling Thread pointer");
  3045   OSThread* osthread = thread->osthread();
  3047   if (!osthread->interrupted()) {
  3048     osthread->set_interrupted(true);
  3049     // More than one thread can get here with the same value of osthread,
  3050     // resulting in multiple notifications.  We do, however, want the store
  3051     // to interrupted() to be visible to other threads before we execute unpark().
  3052     OrderAccess::fence();
  3053     ParkEvent * const slp = thread->_SleepEvent ;
  3054     if (slp != NULL) slp->unpark() ;
  3057   // For JSR166. Unpark even if interrupt status already was set
  3058   if (thread->is_Java_thread())
  3059     ((JavaThread*)thread)->parker()->unpark();
  3061   ParkEvent * ev = thread->_ParkEvent ;
  3062   if (ev != NULL) ev->unpark() ;
  3066 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
  3067   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
  3068     "possibility of dangling Thread pointer");
  3070   OSThread* osthread = thread->osthread();
  3072   bool interrupted = osthread->interrupted();
  3074   if (interrupted && clear_interrupted) {
  3075     osthread->set_interrupted(false);
  3076     // consider thread->_SleepEvent->reset() ... optional optimization
  3079   return interrupted;
  3082 ///////////////////////////////////////////////////////////////////////////////////
  3083 // signal handling (except suspend/resume)
  3085 // This routine may be used by user applications as a "hook" to catch signals.
  3086 // The user-defined signal handler must pass unrecognized signals to this
  3087 // routine, and if it returns true (non-zero), then the signal handler must
  3088 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
  3089 // routine will never retun false (zero), but instead will execute a VM panic
  3090 // routine kill the process.
  3091 //
  3092 // If this routine returns false, it is OK to call it again.  This allows
  3093 // the user-defined signal handler to perform checks either before or after
  3094 // the VM performs its own checks.  Naturally, the user code would be making
  3095 // a serious error if it tried to handle an exception (such as a null check
  3096 // or breakpoint) that the VM was generating for its own correct operation.
  3097 //
  3098 // This routine may recognize any of the following kinds of signals:
  3099 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
  3100 // It should be consulted by handlers for any of those signals.
  3101 //
  3102 // The caller of this routine must pass in the three arguments supplied
  3103 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
  3104 // field of the structure passed to sigaction().  This routine assumes that
  3105 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
  3106 //
  3107 // Note that the VM will print warnings if it detects conflicting signal
  3108 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
  3109 //
  3110 extern "C" JNIEXPORT int
  3111 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
  3112                         void* ucontext, int abort_if_unrecognized);
  3114 void signalHandler(int sig, siginfo_t* info, void* uc) {
  3115   assert(info != NULL && uc != NULL, "it must be old kernel");
  3116   int orig_errno = errno;  // Preserve errno value over signal handler.
  3117   JVM_handle_bsd_signal(sig, info, uc, true);
  3118   errno = orig_errno;
  3122 // This boolean allows users to forward their own non-matching signals
  3123 // to JVM_handle_bsd_signal, harmlessly.
  3124 bool os::Bsd::signal_handlers_are_installed = false;
  3126 // For signal-chaining
  3127 struct sigaction os::Bsd::sigact[MAXSIGNUM];
  3128 unsigned int os::Bsd::sigs = 0;
  3129 bool os::Bsd::libjsig_is_loaded = false;
  3130 typedef struct sigaction *(*get_signal_t)(int);
  3131 get_signal_t os::Bsd::get_signal_action = NULL;
  3133 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
  3134   struct sigaction *actp = NULL;
  3136   if (libjsig_is_loaded) {
  3137     // Retrieve the old signal handler from libjsig
  3138     actp = (*get_signal_action)(sig);
  3140   if (actp == NULL) {
  3141     // Retrieve the preinstalled signal handler from jvm
  3142     actp = get_preinstalled_handler(sig);
  3145   return actp;
  3148 static bool call_chained_handler(struct sigaction *actp, int sig,
  3149                                  siginfo_t *siginfo, void *context) {
  3150   // Call the old signal handler
  3151   if (actp->sa_handler == SIG_DFL) {
  3152     // It's more reasonable to let jvm treat it as an unexpected exception
  3153     // instead of taking the default action.
  3154     return false;
  3155   } else if (actp->sa_handler != SIG_IGN) {
  3156     if ((actp->sa_flags & SA_NODEFER) == 0) {
  3157       // automaticlly block the signal
  3158       sigaddset(&(actp->sa_mask), sig);
  3161     sa_handler_t hand;
  3162     sa_sigaction_t sa;
  3163     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
  3164     // retrieve the chained handler
  3165     if (siginfo_flag_set) {
  3166       sa = actp->sa_sigaction;
  3167     } else {
  3168       hand = actp->sa_handler;
  3171     if ((actp->sa_flags & SA_RESETHAND) != 0) {
  3172       actp->sa_handler = SIG_DFL;
  3175     // try to honor the signal mask
  3176     sigset_t oset;
  3177     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
  3179     // call into the chained handler
  3180     if (siginfo_flag_set) {
  3181       (*sa)(sig, siginfo, context);
  3182     } else {
  3183       (*hand)(sig);
  3186     // restore the signal mask
  3187     pthread_sigmask(SIG_SETMASK, &oset, 0);
  3189   // Tell jvm's signal handler the signal is taken care of.
  3190   return true;
  3193 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
  3194   bool chained = false;
  3195   // signal-chaining
  3196   if (UseSignalChaining) {
  3197     struct sigaction *actp = get_chained_signal_action(sig);
  3198     if (actp != NULL) {
  3199       chained = call_chained_handler(actp, sig, siginfo, context);
  3202   return chained;
  3205 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
  3206   if ((( (unsigned int)1 << sig ) & sigs) != 0) {
  3207     return &sigact[sig];
  3209   return NULL;
  3212 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
  3213   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3214   sigact[sig] = oldAct;
  3215   sigs |= (unsigned int)1 << sig;
  3218 // for diagnostic
  3219 int os::Bsd::sigflags[MAXSIGNUM];
  3221 int os::Bsd::get_our_sigflags(int sig) {
  3222   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3223   return sigflags[sig];
  3226 void os::Bsd::set_our_sigflags(int sig, int flags) {
  3227   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3228   sigflags[sig] = flags;
  3231 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
  3232   // Check for overwrite.
  3233   struct sigaction oldAct;
  3234   sigaction(sig, (struct sigaction*)NULL, &oldAct);
  3236   void* oldhand = oldAct.sa_sigaction
  3237                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
  3238                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
  3239   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
  3240       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
  3241       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
  3242     if (AllowUserSignalHandlers || !set_installed) {
  3243       // Do not overwrite; user takes responsibility to forward to us.
  3244       return;
  3245     } else if (UseSignalChaining) {
  3246       // save the old handler in jvm
  3247       save_preinstalled_handler(sig, oldAct);
  3248       // libjsig also interposes the sigaction() call below and saves the
  3249       // old sigaction on it own.
  3250     } else {
  3251       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
  3252                     "%#lx for signal %d.", (long)oldhand, sig));
  3256   struct sigaction sigAct;
  3257   sigfillset(&(sigAct.sa_mask));
  3258   sigAct.sa_handler = SIG_DFL;
  3259   if (!set_installed) {
  3260     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  3261   } else {
  3262     sigAct.sa_sigaction = signalHandler;
  3263     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  3265 #ifdef __APPLE__
  3266   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
  3267   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
  3268   // if the signal handler declares it will handle it on alternate stack.
  3269   // Notice we only declare we will handle it on alt stack, but we are not
  3270   // actually going to use real alt stack - this is just a workaround.
  3271   // Please see ux_exception.c, method catch_mach_exception_raise for details
  3272   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
  3273   if (sig == SIGSEGV) {
  3274     sigAct.sa_flags |= SA_ONSTACK;
  3276 #endif
  3278   // Save flags, which are set by ours
  3279   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
  3280   sigflags[sig] = sigAct.sa_flags;
  3282   int ret = sigaction(sig, &sigAct, &oldAct);
  3283   assert(ret == 0, "check");
  3285   void* oldhand2  = oldAct.sa_sigaction
  3286                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
  3287                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
  3288   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
  3291 // install signal handlers for signals that HotSpot needs to
  3292 // handle in order to support Java-level exception handling.
  3294 void os::Bsd::install_signal_handlers() {
  3295   if (!signal_handlers_are_installed) {
  3296     signal_handlers_are_installed = true;
  3298     // signal-chaining
  3299     typedef void (*signal_setting_t)();
  3300     signal_setting_t begin_signal_setting = NULL;
  3301     signal_setting_t end_signal_setting = NULL;
  3302     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
  3303                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
  3304     if (begin_signal_setting != NULL) {
  3305       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
  3306                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
  3307       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
  3308                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
  3309       libjsig_is_loaded = true;
  3310       assert(UseSignalChaining, "should enable signal-chaining");
  3312     if (libjsig_is_loaded) {
  3313       // Tell libjsig jvm is setting signal handlers
  3314       (*begin_signal_setting)();
  3317     set_signal_handler(SIGSEGV, true);
  3318     set_signal_handler(SIGPIPE, true);
  3319     set_signal_handler(SIGBUS, true);
  3320     set_signal_handler(SIGILL, true);
  3321     set_signal_handler(SIGFPE, true);
  3322     set_signal_handler(SIGXFSZ, true);
  3324 #if defined(__APPLE__)
  3325     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
  3326     // signals caught and handled by the JVM. To work around this, we reset the mach task
  3327     // signal handler that's placed on our process by CrashReporter. This disables
  3328     // CrashReporter-based reporting.
  3329     //
  3330     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
  3331     // on caught fatal signals.
  3332     //
  3333     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
  3334     // handlers. By replacing the existing task exception handler, we disable gdb's mach
  3335     // exception handling, while leaving the standard BSD signal handlers functional.
  3336     kern_return_t kr;
  3337     kr = task_set_exception_ports(mach_task_self(),
  3338         EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
  3339         MACH_PORT_NULL,
  3340         EXCEPTION_STATE_IDENTITY,
  3341         MACHINE_THREAD_STATE);
  3343     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
  3344 #endif
  3346     if (libjsig_is_loaded) {
  3347       // Tell libjsig jvm finishes setting signal handlers
  3348       (*end_signal_setting)();
  3351     // We don't activate signal checker if libjsig is in place, we trust ourselves
  3352     // and if UserSignalHandler is installed all bets are off
  3353     if (CheckJNICalls) {
  3354       if (libjsig_is_loaded) {
  3355         if (PrintJNIResolving) {
  3356           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
  3358         check_signals = false;
  3360       if (AllowUserSignalHandlers) {
  3361         if (PrintJNIResolving) {
  3362           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
  3364         check_signals = false;
  3371 /////
  3372 // glibc on Bsd platform uses non-documented flag
  3373 // to indicate, that some special sort of signal
  3374 // trampoline is used.
  3375 // We will never set this flag, and we should
  3376 // ignore this flag in our diagnostic
  3377 #ifdef SIGNIFICANT_SIGNAL_MASK
  3378 #undef SIGNIFICANT_SIGNAL_MASK
  3379 #endif
  3380 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
  3382 static const char* get_signal_handler_name(address handler,
  3383                                            char* buf, int buflen) {
  3384   int offset;
  3385   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
  3386   if (found) {
  3387     // skip directory names
  3388     const char *p1, *p2;
  3389     p1 = buf;
  3390     size_t len = strlen(os::file_separator());
  3391     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
  3392     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
  3393   } else {
  3394     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
  3396   return buf;
  3399 static void print_signal_handler(outputStream* st, int sig,
  3400                                  char* buf, size_t buflen) {
  3401   struct sigaction sa;
  3403   sigaction(sig, NULL, &sa);
  3405   // See comment for SIGNIFICANT_SIGNAL_MASK define
  3406   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
  3408   st->print("%s: ", os::exception_name(sig, buf, buflen));
  3410   address handler = (sa.sa_flags & SA_SIGINFO)
  3411     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
  3412     : CAST_FROM_FN_PTR(address, sa.sa_handler);
  3414   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
  3415     st->print("SIG_DFL");
  3416   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
  3417     st->print("SIG_IGN");
  3418   } else {
  3419     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
  3422   st->print(", sa_mask[0]=");
  3423   os::Posix::print_signal_set_short(st, &sa.sa_mask);
  3425   address rh = VMError::get_resetted_sighandler(sig);
  3426   // May be, handler was resetted by VMError?
  3427   if(rh != NULL) {
  3428     handler = rh;
  3429     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
  3432   st->print(", sa_flags=");
  3433   os::Posix::print_sa_flags(st, sa.sa_flags);
  3435   // Check: is it our handler?
  3436   if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
  3437      handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
  3438     // It is our signal handler
  3439     // check for flags, reset system-used one!
  3440     if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
  3441       st->print(
  3442                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
  3443                 os::Bsd::get_our_sigflags(sig));
  3446   st->cr();
  3450 #define DO_SIGNAL_CHECK(sig) \
  3451   if (!sigismember(&check_signal_done, sig)) \
  3452     os::Bsd::check_signal_handler(sig)
  3454 // This method is a periodic task to check for misbehaving JNI applications
  3455 // under CheckJNI, we can add any periodic checks here
  3457 void os::run_periodic_checks() {
  3459   if (check_signals == false) return;
  3461   // SEGV and BUS if overridden could potentially prevent
  3462   // generation of hs*.log in the event of a crash, debugging
  3463   // such a case can be very challenging, so we absolutely
  3464   // check the following for a good measure:
  3465   DO_SIGNAL_CHECK(SIGSEGV);
  3466   DO_SIGNAL_CHECK(SIGILL);
  3467   DO_SIGNAL_CHECK(SIGFPE);
  3468   DO_SIGNAL_CHECK(SIGBUS);
  3469   DO_SIGNAL_CHECK(SIGPIPE);
  3470   DO_SIGNAL_CHECK(SIGXFSZ);
  3473   // ReduceSignalUsage allows the user to override these handlers
  3474   // see comments at the very top and jvm_solaris.h
  3475   if (!ReduceSignalUsage) {
  3476     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
  3477     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
  3478     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
  3479     DO_SIGNAL_CHECK(BREAK_SIGNAL);
  3482   DO_SIGNAL_CHECK(SR_signum);
  3483   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
  3486 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
  3488 static os_sigaction_t os_sigaction = NULL;
  3490 void os::Bsd::check_signal_handler(int sig) {
  3491   char buf[O_BUFLEN];
  3492   address jvmHandler = NULL;
  3495   struct sigaction act;
  3496   if (os_sigaction == NULL) {
  3497     // only trust the default sigaction, in case it has been interposed
  3498     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
  3499     if (os_sigaction == NULL) return;
  3502   os_sigaction(sig, (struct sigaction*)NULL, &act);
  3505   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
  3507   address thisHandler = (act.sa_flags & SA_SIGINFO)
  3508     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
  3509     : CAST_FROM_FN_PTR(address, act.sa_handler) ;
  3512   switch(sig) {
  3513   case SIGSEGV:
  3514   case SIGBUS:
  3515   case SIGFPE:
  3516   case SIGPIPE:
  3517   case SIGILL:
  3518   case SIGXFSZ:
  3519     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
  3520     break;
  3522   case SHUTDOWN1_SIGNAL:
  3523   case SHUTDOWN2_SIGNAL:
  3524   case SHUTDOWN3_SIGNAL:
  3525   case BREAK_SIGNAL:
  3526     jvmHandler = (address)user_handler();
  3527     break;
  3529   case INTERRUPT_SIGNAL:
  3530     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
  3531     break;
  3533   default:
  3534     if (sig == SR_signum) {
  3535       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
  3536     } else {
  3537       return;
  3539     break;
  3542   if (thisHandler != jvmHandler) {
  3543     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
  3544     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
  3545     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
  3546     // No need to check this sig any longer
  3547     sigaddset(&check_signal_done, sig);
  3548   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
  3549     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
  3550     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
  3551     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
  3552     // No need to check this sig any longer
  3553     sigaddset(&check_signal_done, sig);
  3556   // Dump all the signal
  3557   if (sigismember(&check_signal_done, sig)) {
  3558     print_signal_handlers(tty, buf, O_BUFLEN);
  3562 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
  3564 extern bool signal_name(int signo, char* buf, size_t len);
  3566 const char* os::exception_name(int exception_code, char* buf, size_t size) {
  3567   if (0 < exception_code && exception_code <= SIGRTMAX) {
  3568     // signal
  3569     if (!signal_name(exception_code, buf, size)) {
  3570       jio_snprintf(buf, size, "SIG%d", exception_code);
  3572     return buf;
  3573   } else {
  3574     return NULL;
  3578 // this is called _before_ the most of global arguments have been parsed
  3579 void os::init(void) {
  3580   char dummy;   /* used to get a guess on initial stack address */
  3581 //  first_hrtime = gethrtime();
  3583   // With BsdThreads the JavaMain thread pid (primordial thread)
  3584   // is different than the pid of the java launcher thread.
  3585   // So, on Bsd, the launcher thread pid is passed to the VM
  3586   // via the sun.java.launcher.pid property.
  3587   // Use this property instead of getpid() if it was correctly passed.
  3588   // See bug 6351349.
  3589   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
  3591   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
  3593   clock_tics_per_sec = CLK_TCK;
  3595   init_random(1234567);
  3597   ThreadCritical::initialize();
  3599   Bsd::set_page_size(getpagesize());
  3600   if (Bsd::page_size() == -1) {
  3601     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
  3602                   strerror(errno)));
  3604   init_page_sizes((size_t) Bsd::page_size());
  3606   Bsd::initialize_system_info();
  3608   // main_thread points to the aboriginal thread
  3609   Bsd::_main_thread = pthread_self();
  3611   Bsd::clock_init();
  3612   initial_time_count = javaTimeNanos();
  3614 #ifdef __APPLE__
  3615   // XXXDARWIN
  3616   // Work around the unaligned VM callbacks in hotspot's
  3617   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
  3618   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
  3619   // alignment when doing symbol lookup. To work around this, we force early
  3620   // binding of all symbols now, thus binding when alignment is known-good.
  3621   _dyld_bind_fully_image_containing_address((const void *) &os::init);
  3622 #endif
  3625 // To install functions for atexit system call
  3626 extern "C" {
  3627   static void perfMemory_exit_helper() {
  3628     perfMemory_exit();
  3632 // this is called _after_ the global arguments have been parsed
  3633 jint os::init_2(void)
  3635   // Allocate a single page and mark it as readable for safepoint polling
  3636   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  3637   guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
  3639   os::set_polling_page( polling_page );
  3641 #ifndef PRODUCT
  3642   if(Verbose && PrintMiscellaneous)
  3643     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
  3644 #endif
  3646   if (!UseMembar) {
  3647     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  3648     guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
  3649     os::set_memory_serialize_page( mem_serialize_page );
  3651 #ifndef PRODUCT
  3652     if(Verbose && PrintMiscellaneous)
  3653       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
  3654 #endif
  3657   // initialize suspend/resume support - must do this before signal_sets_init()
  3658   if (SR_initialize() != 0) {
  3659     perror("SR_initialize failed");
  3660     return JNI_ERR;
  3663   Bsd::signal_sets_init();
  3664   Bsd::install_signal_handlers();
  3666   // Check minimum allowable stack size for thread creation and to initialize
  3667   // the java system classes, including StackOverflowError - depends on page
  3668   // size.  Add a page for compiler2 recursion in main thread.
  3669   // Add in 2*BytesPerWord times page size to account for VM stack during
  3670   // class initialization depending on 32 or 64 bit VM.
  3671   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
  3672             (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
  3673                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
  3675   size_t threadStackSizeInBytes = ThreadStackSize * K;
  3676   if (threadStackSizeInBytes != 0 &&
  3677       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
  3678         tty->print_cr("\nThe stack size specified is too small, "
  3679                       "Specify at least %dk",
  3680                       os::Bsd::min_stack_allowed/ K);
  3681         return JNI_ERR;
  3684   // Make the stack size a multiple of the page size so that
  3685   // the yellow/red zones can be guarded.
  3686   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
  3687         vm_page_size()));
  3689   if (MaxFDLimit) {
  3690     // set the number of file descriptors to max. print out error
  3691     // if getrlimit/setrlimit fails but continue regardless.
  3692     struct rlimit nbr_files;
  3693     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
  3694     if (status != 0) {
  3695       if (PrintMiscellaneous && (Verbose || WizardMode))
  3696         perror("os::init_2 getrlimit failed");
  3697     } else {
  3698       nbr_files.rlim_cur = nbr_files.rlim_max;
  3700 #ifdef __APPLE__
  3701       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
  3702       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
  3703       // be used instead
  3704       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
  3705 #endif
  3707       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
  3708       if (status != 0) {
  3709         if (PrintMiscellaneous && (Verbose || WizardMode))
  3710           perror("os::init_2 setrlimit failed");
  3715   // at-exit methods are called in the reverse order of their registration.
  3716   // atexit functions are called on return from main or as a result of a
  3717   // call to exit(3C). There can be only 32 of these functions registered
  3718   // and atexit() does not set errno.
  3720   if (PerfAllowAtExitRegistration) {
  3721     // only register atexit functions if PerfAllowAtExitRegistration is set.
  3722     // atexit functions can be delayed until process exit time, which
  3723     // can be problematic for embedded VM situations. Embedded VMs should
  3724     // call DestroyJavaVM() to assure that VM resources are released.
  3726     // note: perfMemory_exit_helper atexit function may be removed in
  3727     // the future if the appropriate cleanup code can be added to the
  3728     // VM_Exit VMOperation's doit method.
  3729     if (atexit(perfMemory_exit_helper) != 0) {
  3730       warning("os::init2 atexit(perfMemory_exit_helper) failed");
  3734   // initialize thread priority policy
  3735   prio_init();
  3737 #ifdef __APPLE__
  3738   // dynamically link to objective c gc registration
  3739   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
  3740   if (handleLibObjc != NULL) {
  3741     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
  3743 #endif
  3745   return JNI_OK;
  3748 // this is called at the end of vm_initialization
  3749 void os::init_3(void) { }
  3751 // Mark the polling page as unreadable
  3752 void os::make_polling_page_unreadable(void) {
  3753   if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
  3754     fatal("Could not disable polling page");
  3755 };
  3757 // Mark the polling page as readable
  3758 void os::make_polling_page_readable(void) {
  3759   if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
  3760     fatal("Could not enable polling page");
  3762 };
  3764 int os::active_processor_count() {
  3765   return _processor_count;
  3768 void os::set_native_thread_name(const char *name) {
  3769 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
  3770   // This is only supported in Snow Leopard and beyond
  3771   if (name != NULL) {
  3772     // Add a "Java: " prefix to the name
  3773     char buf[MAXTHREADNAMESIZE];
  3774     snprintf(buf, sizeof(buf), "Java: %s", name);
  3775     pthread_setname_np(buf);
  3777 #endif
  3780 bool os::distribute_processes(uint length, uint* distribution) {
  3781   // Not yet implemented.
  3782   return false;
  3785 bool os::bind_to_processor(uint processor_id) {
  3786   // Not yet implemented.
  3787   return false;
  3790 void os::SuspendedThreadTask::internal_do_task() {
  3791   if (do_suspend(_thread->osthread())) {
  3792     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
  3793     do_task(context);
  3794     do_resume(_thread->osthread());
  3798 ///
  3799 class PcFetcher : public os::SuspendedThreadTask {
  3800 public:
  3801   PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
  3802   ExtendedPC result();
  3803 protected:
  3804   void do_task(const os::SuspendedThreadTaskContext& context);
  3805 private:
  3806   ExtendedPC _epc;
  3807 };
  3809 ExtendedPC PcFetcher::result() {
  3810   guarantee(is_done(), "task is not done yet.");
  3811   return _epc;
  3814 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
  3815   Thread* thread = context.thread();
  3816   OSThread* osthread = thread->osthread();
  3817   if (osthread->ucontext() != NULL) {
  3818     _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
  3819   } else {
  3820     // NULL context is unexpected, double-check this is the VMThread
  3821     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
  3825 // Suspends the target using the signal mechanism and then grabs the PC before
  3826 // resuming the target. Used by the flat-profiler only
  3827 ExtendedPC os::get_thread_pc(Thread* thread) {
  3828   // Make sure that it is called by the watcher for the VMThread
  3829   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
  3830   assert(thread->is_VM_thread(), "Can only be called for VMThread");
  3832   PcFetcher fetcher(thread);
  3833   fetcher.run();
  3834   return fetcher.result();
  3837 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
  3839   return pthread_cond_timedwait(_cond, _mutex, _abstime);
  3842 ////////////////////////////////////////////////////////////////////////////////
  3843 // debug support
  3845 bool os::find(address addr, outputStream* st) {
  3846   Dl_info dlinfo;
  3847   memset(&dlinfo, 0, sizeof(dlinfo));
  3848   if (dladdr(addr, &dlinfo) != 0) {
  3849     st->print(PTR_FORMAT ": ", addr);
  3850     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
  3851       st->print("%s+%#x", dlinfo.dli_sname,
  3852                  addr - (intptr_t)dlinfo.dli_saddr);
  3853     } else if (dlinfo.dli_fbase != NULL) {
  3854       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
  3855     } else {
  3856       st->print("<absolute address>");
  3858     if (dlinfo.dli_fname != NULL) {
  3859       st->print(" in %s", dlinfo.dli_fname);
  3861     if (dlinfo.dli_fbase != NULL) {
  3862       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
  3864     st->cr();
  3866     if (Verbose) {
  3867       // decode some bytes around the PC
  3868       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
  3869       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
  3870       address       lowest = (address) dlinfo.dli_sname;
  3871       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
  3872       if (begin < lowest)  begin = lowest;
  3873       Dl_info dlinfo2;
  3874       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
  3875           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
  3876         end = (address) dlinfo2.dli_saddr;
  3877       Disassembler::decode(begin, end, st);
  3879     return true;
  3881   return false;
  3884 ////////////////////////////////////////////////////////////////////////////////
  3885 // misc
  3887 // This does not do anything on Bsd. This is basically a hook for being
  3888 // able to use structured exception handling (thread-local exception filters)
  3889 // on, e.g., Win32.
  3890 void
  3891 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
  3892                          JavaCallArguments* args, Thread* thread) {
  3893   f(value, method, args, thread);
  3896 void os::print_statistics() {
  3899 int os::message_box(const char* title, const char* message) {
  3900   int i;
  3901   fdStream err(defaultStream::error_fd());
  3902   for (i = 0; i < 78; i++) err.print_raw("=");
  3903   err.cr();
  3904   err.print_raw_cr(title);
  3905   for (i = 0; i < 78; i++) err.print_raw("-");
  3906   err.cr();
  3907   err.print_raw_cr(message);
  3908   for (i = 0; i < 78; i++) err.print_raw("=");
  3909   err.cr();
  3911   char buf[16];
  3912   // Prevent process from exiting upon "read error" without consuming all CPU
  3913   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
  3915   return buf[0] == 'y' || buf[0] == 'Y';
  3918 int os::stat(const char *path, struct stat *sbuf) {
  3919   char pathbuf[MAX_PATH];
  3920   if (strlen(path) > MAX_PATH - 1) {
  3921     errno = ENAMETOOLONG;
  3922     return -1;
  3924   os::native_path(strcpy(pathbuf, path));
  3925   return ::stat(pathbuf, sbuf);
  3928 bool os::check_heap(bool force) {
  3929   return true;
  3932 ATTRIBUTE_PRINTF(3, 0)
  3933 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
  3934   return ::vsnprintf(buf, count, format, args);
  3937 // Is a (classpath) directory empty?
  3938 bool os::dir_is_empty(const char* path) {
  3939   DIR *dir = NULL;
  3940   struct dirent *ptr;
  3942   dir = opendir(path);
  3943   if (dir == NULL) return true;
  3945   /* Scan the directory */
  3946   bool result = true;
  3947   char buf[sizeof(struct dirent) + MAX_PATH];
  3948   while (result && (ptr = ::readdir(dir)) != NULL) {
  3949     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
  3950       result = false;
  3953   closedir(dir);
  3954   return result;
  3957 // This code originates from JDK's sysOpen and open64_w
  3958 // from src/solaris/hpi/src/system_md.c
  3960 #ifndef O_DELETE
  3961 #define O_DELETE 0x10000
  3962 #endif
  3964 // Open a file. Unlink the file immediately after open returns
  3965 // if the specified oflag has the O_DELETE flag set.
  3966 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
  3968 int os::open(const char *path, int oflag, int mode) {
  3970   if (strlen(path) > MAX_PATH - 1) {
  3971     errno = ENAMETOOLONG;
  3972     return -1;
  3974   int fd;
  3975   int o_delete = (oflag & O_DELETE);
  3976   oflag = oflag & ~O_DELETE;
  3978   fd = ::open(path, oflag, mode);
  3979   if (fd == -1) return -1;
  3981   //If the open succeeded, the file might still be a directory
  3983     struct stat buf;
  3984     int ret = ::fstat(fd, &buf);
  3985     int st_mode = buf.st_mode;
  3987     if (ret != -1) {
  3988       if ((st_mode & S_IFMT) == S_IFDIR) {
  3989         errno = EISDIR;
  3990         ::close(fd);
  3991         return -1;
  3993     } else {
  3994       ::close(fd);
  3995       return -1;
  3999     /*
  4000      * All file descriptors that are opened in the JVM and not
  4001      * specifically destined for a subprocess should have the
  4002      * close-on-exec flag set.  If we don't set it, then careless 3rd
  4003      * party native code might fork and exec without closing all
  4004      * appropriate file descriptors (e.g. as we do in closeDescriptors in
  4005      * UNIXProcess.c), and this in turn might:
  4007      * - cause end-of-file to fail to be detected on some file
  4008      *   descriptors, resulting in mysterious hangs, or
  4010      * - might cause an fopen in the subprocess to fail on a system
  4011      *   suffering from bug 1085341.
  4013      * (Yes, the default setting of the close-on-exec flag is a Unix
  4014      * design flaw)
  4016      * See:
  4017      * 1085341: 32-bit stdio routines should support file descriptors >255
  4018      * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
  4019      * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
  4020      */
  4021 #ifdef FD_CLOEXEC
  4023         int flags = ::fcntl(fd, F_GETFD);
  4024         if (flags != -1)
  4025             ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
  4027 #endif
  4029   if (o_delete != 0) {
  4030     ::unlink(path);
  4032   return fd;
  4036 // create binary file, rewriting existing file if required
  4037 int os::create_binary_file(const char* path, bool rewrite_existing) {
  4038   int oflags = O_WRONLY | O_CREAT;
  4039   if (!rewrite_existing) {
  4040     oflags |= O_EXCL;
  4042   return ::open(path, oflags, S_IREAD | S_IWRITE);
  4045 // return current position of file pointer
  4046 jlong os::current_file_offset(int fd) {
  4047   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
  4050 // move file pointer to the specified offset
  4051 jlong os::seek_to_file_offset(int fd, jlong offset) {
  4052   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
  4055 // This code originates from JDK's sysAvailable
  4056 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
  4058 int os::available(int fd, jlong *bytes) {
  4059   jlong cur, end;
  4060   int mode;
  4061   struct stat buf;
  4063   if (::fstat(fd, &buf) >= 0) {
  4064     mode = buf.st_mode;
  4065     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
  4066       /*
  4067       * XXX: is the following call interruptible? If so, this might
  4068       * need to go through the INTERRUPT_IO() wrapper as for other
  4069       * blocking, interruptible calls in this file.
  4070       */
  4071       int n;
  4072       if (::ioctl(fd, FIONREAD, &n) >= 0) {
  4073         *bytes = n;
  4074         return 1;
  4078   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
  4079     return 0;
  4080   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
  4081     return 0;
  4082   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
  4083     return 0;
  4085   *bytes = end - cur;
  4086   return 1;
  4089 int os::socket_available(int fd, jint *pbytes) {
  4090    if (fd < 0)
  4091      return OS_OK;
  4093    int ret;
  4095    RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
  4097    //%% note ioctl can return 0 when successful, JVM_SocketAvailable
  4098    // is expected to return 0 on failure and 1 on success to the jdk.
  4100    return (ret == OS_ERR) ? 0 : 1;
  4103 // Map a block of memory.
  4104 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
  4105                      char *addr, size_t bytes, bool read_only,
  4106                      bool allow_exec) {
  4107   int prot;
  4108   int flags;
  4110   if (read_only) {
  4111     prot = PROT_READ;
  4112     flags = MAP_SHARED;
  4113   } else {
  4114     prot = PROT_READ | PROT_WRITE;
  4115     flags = MAP_PRIVATE;
  4118   if (allow_exec) {
  4119     prot |= PROT_EXEC;
  4122   if (addr != NULL) {
  4123     flags |= MAP_FIXED;
  4126   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
  4127                                      fd, file_offset);
  4128   if (mapped_address == MAP_FAILED) {
  4129     return NULL;
  4131   return mapped_address;
  4135 // Remap a block of memory.
  4136 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
  4137                        char *addr, size_t bytes, bool read_only,
  4138                        bool allow_exec) {
  4139   // same as map_memory() on this OS
  4140   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
  4141                         allow_exec);
  4145 // Unmap a block of memory.
  4146 bool os::pd_unmap_memory(char* addr, size_t bytes) {
  4147   return munmap(addr, bytes) == 0;
  4150 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
  4151 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
  4152 // of a thread.
  4153 //
  4154 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
  4155 // the fast estimate available on the platform.
  4157 jlong os::current_thread_cpu_time() {
  4158 #ifdef __APPLE__
  4159   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
  4160 #else
  4161   Unimplemented();
  4162   return 0;
  4163 #endif
  4166 jlong os::thread_cpu_time(Thread* thread) {
  4167 #ifdef __APPLE__
  4168   return os::thread_cpu_time(thread, true /* user + sys */);
  4169 #else
  4170   Unimplemented();
  4171   return 0;
  4172 #endif
  4175 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
  4176 #ifdef __APPLE__
  4177   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
  4178 #else
  4179   Unimplemented();
  4180   return 0;
  4181 #endif
  4184 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
  4185 #ifdef __APPLE__
  4186   struct thread_basic_info tinfo;
  4187   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
  4188   kern_return_t kr;
  4189   thread_t mach_thread;
  4191   mach_thread = thread->osthread()->thread_id();
  4192   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
  4193   if (kr != KERN_SUCCESS)
  4194     return -1;
  4196   if (user_sys_cpu_time) {
  4197     jlong nanos;
  4198     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
  4199     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
  4200     return nanos;
  4201   } else {
  4202     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
  4204 #else
  4205   Unimplemented();
  4206   return 0;
  4207 #endif
  4211 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
  4212   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
  4213   info_ptr->may_skip_backward = false;     // elapsed time not wall time
  4214   info_ptr->may_skip_forward = false;      // elapsed time not wall time
  4215   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
  4218 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
  4219   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
  4220   info_ptr->may_skip_backward = false;     // elapsed time not wall time
  4221   info_ptr->may_skip_forward = false;      // elapsed time not wall time
  4222   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
  4225 bool os::is_thread_cpu_time_supported() {
  4226 #ifdef __APPLE__
  4227   return true;
  4228 #else
  4229   return false;
  4230 #endif
  4233 // System loadavg support.  Returns -1 if load average cannot be obtained.
  4234 // Bsd doesn't yet have a (official) notion of processor sets,
  4235 // so just return the system wide load average.
  4236 int os::loadavg(double loadavg[], int nelem) {
  4237   return ::getloadavg(loadavg, nelem);
  4240 void os::pause() {
  4241   char filename[MAX_PATH];
  4242   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
  4243     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
  4244   } else {
  4245     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
  4248   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
  4249   if (fd != -1) {
  4250     struct stat buf;
  4251     ::close(fd);
  4252     while (::stat(filename, &buf) == 0) {
  4253       (void)::poll(NULL, 0, 100);
  4255   } else {
  4256     jio_fprintf(stderr,
  4257       "Could not open pause file '%s', continuing immediately.\n", filename);
  4262 // Refer to the comments in os_solaris.cpp park-unpark.
  4263 //
  4264 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
  4265 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
  4266 // For specifics regarding the bug see GLIBC BUGID 261237 :
  4267 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
  4268 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
  4269 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
  4270 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
  4271 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
  4272 // and monitorenter when we're using 1-0 locking.  All those operations may result in
  4273 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
  4274 // of libpthread avoids the problem, but isn't practical.
  4275 //
  4276 // Possible remedies:
  4277 //
  4278 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
  4279 //      This is palliative and probabilistic, however.  If the thread is preempted
  4280 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
  4281 //      than the minimum period may have passed, and the abstime may be stale (in the
  4282 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
  4283 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
  4284 //
  4285 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
  4286 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
  4287 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
  4288 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
  4289 //      thread.
  4290 //
  4291 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
  4292 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
  4293 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
  4294 //      This also works well.  In fact it avoids kernel-level scalability impediments
  4295 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
  4296 //      timers in a graceful fashion.
  4297 //
  4298 // 4.   When the abstime value is in the past it appears that control returns
  4299 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
  4300 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
  4301 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
  4302 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
  4303 //      It may be possible to avoid reinitialization by checking the return
  4304 //      value from pthread_cond_timedwait().  In addition to reinitializing the
  4305 //      condvar we must establish the invariant that cond_signal() is only called
  4306 //      within critical sections protected by the adjunct mutex.  This prevents
  4307 //      cond_signal() from "seeing" a condvar that's in the midst of being
  4308 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
  4309 //      desirable signal-after-unlock optimization that avoids futile context switching.
  4310 //
  4311 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
  4312 //      structure when a condvar is used or initialized.  cond_destroy()  would
  4313 //      release the helper structure.  Our reinitialize-after-timedwait fix
  4314 //      put excessive stress on malloc/free and locks protecting the c-heap.
  4315 //
  4316 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
  4317 // It may be possible to refine (4) by checking the kernel and NTPL verisons
  4318 // and only enabling the work-around for vulnerable environments.
  4320 // utility to compute the abstime argument to timedwait:
  4321 // millis is the relative timeout time
  4322 // abstime will be the absolute timeout time
  4323 // TODO: replace compute_abstime() with unpackTime()
  4325 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
  4326   if (millis < 0)  millis = 0;
  4327   struct timeval now;
  4328   int status = gettimeofday(&now, NULL);
  4329   assert(status == 0, "gettimeofday");
  4330   jlong seconds = millis / 1000;
  4331   millis %= 1000;
  4332   if (seconds > 50000000) { // see man cond_timedwait(3T)
  4333     seconds = 50000000;
  4335   abstime->tv_sec = now.tv_sec  + seconds;
  4336   long       usec = now.tv_usec + millis * 1000;
  4337   if (usec >= 1000000) {
  4338     abstime->tv_sec += 1;
  4339     usec -= 1000000;
  4341   abstime->tv_nsec = usec * 1000;
  4342   return abstime;
  4346 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
  4347 // Conceptually TryPark() should be equivalent to park(0).
  4349 int os::PlatformEvent::TryPark() {
  4350   for (;;) {
  4351     const int v = _Event ;
  4352     guarantee ((v == 0) || (v == 1), "invariant") ;
  4353     if (Atomic::cmpxchg (0, &_Event, v) == v) return v  ;
  4357 void os::PlatformEvent::park() {       // AKA "down()"
  4358   // Invariant: Only the thread associated with the Event/PlatformEvent
  4359   // may call park().
  4360   // TODO: assert that _Assoc != NULL or _Assoc == Self
  4361   int v ;
  4362   for (;;) {
  4363       v = _Event ;
  4364       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
  4366   guarantee (v >= 0, "invariant") ;
  4367   if (v == 0) {
  4368      // Do this the hard way by blocking ...
  4369      int status = pthread_mutex_lock(_mutex);
  4370      assert_status(status == 0, status, "mutex_lock");
  4371      guarantee (_nParked == 0, "invariant") ;
  4372      ++ _nParked ;
  4373      while (_Event < 0) {
  4374         status = pthread_cond_wait(_cond, _mutex);
  4375         // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
  4376         // Treat this the same as if the wait was interrupted
  4377         if (status == ETIMEDOUT) { status = EINTR; }
  4378         assert_status(status == 0 || status == EINTR, status, "cond_wait");
  4380      -- _nParked ;
  4382     _Event = 0 ;
  4383      status = pthread_mutex_unlock(_mutex);
  4384      assert_status(status == 0, status, "mutex_unlock");
  4385     // Paranoia to ensure our locked and lock-free paths interact
  4386     // correctly with each other.
  4387     OrderAccess::fence();
  4389   guarantee (_Event >= 0, "invariant") ;
  4392 int os::PlatformEvent::park(jlong millis) {
  4393   guarantee (_nParked == 0, "invariant") ;
  4395   int v ;
  4396   for (;;) {
  4397       v = _Event ;
  4398       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
  4400   guarantee (v >= 0, "invariant") ;
  4401   if (v != 0) return OS_OK ;
  4403   // We do this the hard way, by blocking the thread.
  4404   // Consider enforcing a minimum timeout value.
  4405   struct timespec abst;
  4406   compute_abstime(&abst, millis);
  4408   int ret = OS_TIMEOUT;
  4409   int status = pthread_mutex_lock(_mutex);
  4410   assert_status(status == 0, status, "mutex_lock");
  4411   guarantee (_nParked == 0, "invariant") ;
  4412   ++_nParked ;
  4414   // Object.wait(timo) will return because of
  4415   // (a) notification
  4416   // (b) timeout
  4417   // (c) thread.interrupt
  4418   //
  4419   // Thread.interrupt and object.notify{All} both call Event::set.
  4420   // That is, we treat thread.interrupt as a special case of notification.
  4421   // The underlying Solaris implementation, cond_timedwait, admits
  4422   // spurious/premature wakeups, but the JLS/JVM spec prevents the
  4423   // JVM from making those visible to Java code.  As such, we must
  4424   // filter out spurious wakeups.  We assume all ETIME returns are valid.
  4425   //
  4426   // TODO: properly differentiate simultaneous notify+interrupt.
  4427   // In that case, we should propagate the notify to another waiter.
  4429   while (_Event < 0) {
  4430     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
  4431     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
  4432       pthread_cond_destroy (_cond);
  4433       pthread_cond_init (_cond, NULL) ;
  4435     assert_status(status == 0 || status == EINTR ||
  4436                   status == ETIMEDOUT,
  4437                   status, "cond_timedwait");
  4438     if (!FilterSpuriousWakeups) break ;                 // previous semantics
  4439     if (status == ETIMEDOUT) break ;
  4440     // We consume and ignore EINTR and spurious wakeups.
  4442   --_nParked ;
  4443   if (_Event >= 0) {
  4444      ret = OS_OK;
  4446   _Event = 0 ;
  4447   status = pthread_mutex_unlock(_mutex);
  4448   assert_status(status == 0, status, "mutex_unlock");
  4449   assert (_nParked == 0, "invariant") ;
  4450   // Paranoia to ensure our locked and lock-free paths interact
  4451   // correctly with each other.
  4452   OrderAccess::fence();
  4453   return ret;
  4456 void os::PlatformEvent::unpark() {
  4457   // Transitions for _Event:
  4458   //    0 :=> 1
  4459   //    1 :=> 1
  4460   //   -1 :=> either 0 or 1; must signal target thread
  4461   //          That is, we can safely transition _Event from -1 to either
  4462   //          0 or 1. Forcing 1 is slightly more efficient for back-to-back
  4463   //          unpark() calls.
  4464   // See also: "Semaphores in Plan 9" by Mullender & Cox
  4465   //
  4466   // Note: Forcing a transition from "-1" to "1" on an unpark() means
  4467   // that it will take two back-to-back park() calls for the owning
  4468   // thread to block. This has the benefit of forcing a spurious return
  4469   // from the first park() call after an unpark() call which will help
  4470   // shake out uses of park() and unpark() without condition variables.
  4472   if (Atomic::xchg(1, &_Event) >= 0) return;
  4474   // Wait for the thread associated with the event to vacate
  4475   int status = pthread_mutex_lock(_mutex);
  4476   assert_status(status == 0, status, "mutex_lock");
  4477   int AnyWaiters = _nParked;
  4478   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
  4479   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
  4480     AnyWaiters = 0;
  4481     pthread_cond_signal(_cond);
  4483   status = pthread_mutex_unlock(_mutex);
  4484   assert_status(status == 0, status, "mutex_unlock");
  4485   if (AnyWaiters != 0) {
  4486     status = pthread_cond_signal(_cond);
  4487     assert_status(status == 0, status, "cond_signal");
  4490   // Note that we signal() _after dropping the lock for "immortal" Events.
  4491   // This is safe and avoids a common class of  futile wakeups.  In rare
  4492   // circumstances this can cause a thread to return prematurely from
  4493   // cond_{timed}wait() but the spurious wakeup is benign and the victim will
  4494   // simply re-test the condition and re-park itself.
  4498 // JSR166
  4499 // -------------------------------------------------------
  4501 /*
  4502  * The solaris and bsd implementations of park/unpark are fairly
  4503  * conservative for now, but can be improved. They currently use a
  4504  * mutex/condvar pair, plus a a count.
  4505  * Park decrements count if > 0, else does a condvar wait.  Unpark
  4506  * sets count to 1 and signals condvar.  Only one thread ever waits
  4507  * on the condvar. Contention seen when trying to park implies that someone
  4508  * is unparking you, so don't wait. And spurious returns are fine, so there
  4509  * is no need to track notifications.
  4510  */
  4512 #define MAX_SECS 100000000
  4513 /*
  4514  * This code is common to bsd and solaris and will be moved to a
  4515  * common place in dolphin.
  4517  * The passed in time value is either a relative time in nanoseconds
  4518  * or an absolute time in milliseconds. Either way it has to be unpacked
  4519  * into suitable seconds and nanoseconds components and stored in the
  4520  * given timespec structure.
  4521  * Given time is a 64-bit value and the time_t used in the timespec is only
  4522  * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
  4523  * overflow if times way in the future are given. Further on Solaris versions
  4524  * prior to 10 there is a restriction (see cond_timedwait) that the specified
  4525  * number of seconds, in abstime, is less than current_time  + 100,000,000.
  4526  * As it will be 28 years before "now + 100000000" will overflow we can
  4527  * ignore overflow and just impose a hard-limit on seconds using the value
  4528  * of "now + 100,000,000". This places a limit on the timeout of about 3.17
  4529  * years from "now".
  4530  */
  4532 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
  4533   assert (time > 0, "convertTime");
  4535   struct timeval now;
  4536   int status = gettimeofday(&now, NULL);
  4537   assert(status == 0, "gettimeofday");
  4539   time_t max_secs = now.tv_sec + MAX_SECS;
  4541   if (isAbsolute) {
  4542     jlong secs = time / 1000;
  4543     if (secs > max_secs) {
  4544       absTime->tv_sec = max_secs;
  4546     else {
  4547       absTime->tv_sec = secs;
  4549     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
  4551   else {
  4552     jlong secs = time / NANOSECS_PER_SEC;
  4553     if (secs >= MAX_SECS) {
  4554       absTime->tv_sec = max_secs;
  4555       absTime->tv_nsec = 0;
  4557     else {
  4558       absTime->tv_sec = now.tv_sec + secs;
  4559       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
  4560       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
  4561         absTime->tv_nsec -= NANOSECS_PER_SEC;
  4562         ++absTime->tv_sec; // note: this must be <= max_secs
  4566   assert(absTime->tv_sec >= 0, "tv_sec < 0");
  4567   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
  4568   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
  4569   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
  4572 void Parker::park(bool isAbsolute, jlong time) {
  4573   // Ideally we'd do something useful while spinning, such
  4574   // as calling unpackTime().
  4576   // Optional fast-path check:
  4577   // Return immediately if a permit is available.
  4578   // We depend on Atomic::xchg() having full barrier semantics
  4579   // since we are doing a lock-free update to _counter.
  4580   if (Atomic::xchg(0, &_counter) > 0) return;
  4582   Thread* thread = Thread::current();
  4583   assert(thread->is_Java_thread(), "Must be JavaThread");
  4584   JavaThread *jt = (JavaThread *)thread;
  4586   // Optional optimization -- avoid state transitions if there's an interrupt pending.
  4587   // Check interrupt before trying to wait
  4588   if (Thread::is_interrupted(thread, false)) {
  4589     return;
  4592   // Next, demultiplex/decode time arguments
  4593   struct timespec absTime;
  4594   if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
  4595     return;
  4597   if (time > 0) {
  4598     unpackTime(&absTime, isAbsolute, time);
  4602   // Enter safepoint region
  4603   // Beware of deadlocks such as 6317397.
  4604   // The per-thread Parker:: mutex is a classic leaf-lock.
  4605   // In particular a thread must never block on the Threads_lock while
  4606   // holding the Parker:: mutex.  If safepoints are pending both the
  4607   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
  4608   ThreadBlockInVM tbivm(jt);
  4610   // Don't wait if cannot get lock since interference arises from
  4611   // unblocking.  Also. check interrupt before trying wait
  4612   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
  4613     return;
  4616   int status ;
  4617   if (_counter > 0)  { // no wait needed
  4618     _counter = 0;
  4619     status = pthread_mutex_unlock(_mutex);
  4620     assert (status == 0, "invariant") ;
  4621     // Paranoia to ensure our locked and lock-free paths interact
  4622     // correctly with each other and Java-level accesses.
  4623     OrderAccess::fence();
  4624     return;
  4627 #ifdef ASSERT
  4628   // Don't catch signals while blocked; let the running threads have the signals.
  4629   // (This allows a debugger to break into the running thread.)
  4630   sigset_t oldsigs;
  4631   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
  4632   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
  4633 #endif
  4635   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
  4636   jt->set_suspend_equivalent();
  4637   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
  4639   if (time == 0) {
  4640     status = pthread_cond_wait (_cond, _mutex) ;
  4641   } else {
  4642     status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
  4643     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
  4644       pthread_cond_destroy (_cond) ;
  4645       pthread_cond_init    (_cond, NULL);
  4648   assert_status(status == 0 || status == EINTR ||
  4649                 status == ETIMEDOUT,
  4650                 status, "cond_timedwait");
  4652 #ifdef ASSERT
  4653   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
  4654 #endif
  4656   _counter = 0 ;
  4657   status = pthread_mutex_unlock(_mutex) ;
  4658   assert_status(status == 0, status, "invariant") ;
  4659   // Paranoia to ensure our locked and lock-free paths interact
  4660   // correctly with each other and Java-level accesses.
  4661   OrderAccess::fence();
  4663   // If externally suspended while waiting, re-suspend
  4664   if (jt->handle_special_suspend_equivalent_condition()) {
  4665     jt->java_suspend_self();
  4669 void Parker::unpark() {
  4670   int s, status ;
  4671   status = pthread_mutex_lock(_mutex);
  4672   assert (status == 0, "invariant") ;
  4673   s = _counter;
  4674   _counter = 1;
  4675   if (s < 1) {
  4676      if (WorkAroundNPTLTimedWaitHang) {
  4677         status = pthread_cond_signal (_cond) ;
  4678         assert (status == 0, "invariant") ;
  4679         status = pthread_mutex_unlock(_mutex);
  4680         assert (status == 0, "invariant") ;
  4681      } else {
  4682         status = pthread_mutex_unlock(_mutex);
  4683         assert (status == 0, "invariant") ;
  4684         status = pthread_cond_signal (_cond) ;
  4685         assert (status == 0, "invariant") ;
  4687   } else {
  4688     pthread_mutex_unlock(_mutex);
  4689     assert (status == 0, "invariant") ;
  4694 /* Darwin has no "environ" in a dynamic library. */
  4695 #ifdef __APPLE__
  4696 #include <crt_externs.h>
  4697 #define environ (*_NSGetEnviron())
  4698 #else
  4699 extern char** environ;
  4700 #endif
  4702 // Run the specified command in a separate process. Return its exit value,
  4703 // or -1 on failure (e.g. can't fork a new process).
  4704 // Unlike system(), this function can be called from signal handler. It
  4705 // doesn't block SIGINT et al.
  4706 int os::fork_and_exec(char* cmd) {
  4707   const char * argv[4] = {"sh", "-c", cmd, NULL};
  4709   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
  4710   // pthread_atfork handlers and reset pthread library. All we need is a
  4711   // separate process to execve. Make a direct syscall to fork process.
  4712   // On IA64 there's no fork syscall, we have to use fork() and hope for
  4713   // the best...
  4714   pid_t pid = fork();
  4716   if (pid < 0) {
  4717     // fork failed
  4718     return -1;
  4720   } else if (pid == 0) {
  4721     // child process
  4723     // execve() in BsdThreads will call pthread_kill_other_threads_np()
  4724     // first to kill every thread on the thread list. Because this list is
  4725     // not reset by fork() (see notes above), execve() will instead kill
  4726     // every thread in the parent process. We know this is the only thread
  4727     // in the new process, so make a system call directly.
  4728     // IA64 should use normal execve() from glibc to match the glibc fork()
  4729     // above.
  4730     execve("/bin/sh", (char* const*)argv, environ);
  4732     // execve failed
  4733     _exit(-1);
  4735   } else  {
  4736     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
  4737     // care about the actual exit code, for now.
  4739     int status;
  4741     // Wait for the child process to exit.  This returns immediately if
  4742     // the child has already exited. */
  4743     while (waitpid(pid, &status, 0) < 0) {
  4744         switch (errno) {
  4745         case ECHILD: return 0;
  4746         case EINTR: break;
  4747         default: return -1;
  4751     if (WIFEXITED(status)) {
  4752        // The child exited normally; get its exit code.
  4753        return WEXITSTATUS(status);
  4754     } else if (WIFSIGNALED(status)) {
  4755        // The child exited because of a signal
  4756        // The best value to return is 0x80 + signal number,
  4757        // because that is what all Unix shells do, and because
  4758        // it allows callers to distinguish between process exit and
  4759        // process death by signal.
  4760        return 0x80 + WTERMSIG(status);
  4761     } else {
  4762        // Unknown exit code; pass it through
  4763        return status;
  4768 // is_headless_jre()
  4769 //
  4770 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
  4771 // in order to report if we are running in a headless jre
  4772 //
  4773 // Since JDK8 xawt/libmawt.so was moved into the same directory
  4774 // as libawt.so, and renamed libawt_xawt.so
  4775 //
  4776 bool os::is_headless_jre() {
  4777 #ifdef __APPLE__
  4778     // We no longer build headless-only on Mac OS X
  4779     return false;
  4780 #else
  4781     struct stat statbuf;
  4782     char buf[MAXPATHLEN];
  4783     char libmawtpath[MAXPATHLEN];
  4784     const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
  4785     const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
  4786     char *p;
  4788     // Get path to libjvm.so
  4789     os::jvm_path(buf, sizeof(buf));
  4791     // Get rid of libjvm.so
  4792     p = strrchr(buf, '/');
  4793     if (p == NULL) return false;
  4794     else *p = '\0';
  4796     // Get rid of client or server
  4797     p = strrchr(buf, '/');
  4798     if (p == NULL) return false;
  4799     else *p = '\0';
  4801     // check xawt/libmawt.so
  4802     strcpy(libmawtpath, buf);
  4803     strcat(libmawtpath, xawtstr);
  4804     if (::stat(libmawtpath, &statbuf) == 0) return false;
  4806     // check libawt_xawt.so
  4807     strcpy(libmawtpath, buf);
  4808     strcat(libmawtpath, new_xawtstr);
  4809     if (::stat(libmawtpath, &statbuf) == 0) return false;
  4811     return true;
  4812 #endif
  4815 // Get the default path to the core file
  4816 // Returns the length of the string
  4817 int os::get_core_path(char* buffer, size_t bufferSize) {
  4818   int n = jio_snprintf(buffer, bufferSize, "/cores");
  4820   // Truncate if theoretical string was longer than bufferSize
  4821   n = MIN2(n, (int)bufferSize);
  4823   return n;
  4826 #ifndef PRODUCT
  4827 void TestReserveMemorySpecial_test() {
  4828   // No tests available for this platform
  4830 #endif

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