src/hotspot/os/bsd/os_bsd.cpp
changeset 47216 71c04702a3d5
parent 47106 bed18a111b90
child 47524 97569cf468f4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/os/bsd/os_bsd.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,4098 @@
+/*
+ * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+// no precompiled headers
+#include "classfile/classLoader.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "classfile/vmSymbols.hpp"
+#include "code/icBuffer.hpp"
+#include "code/vtableStubs.hpp"
+#include "compiler/compileBroker.hpp"
+#include "compiler/disassembler.hpp"
+#include "interpreter/interpreter.hpp"
+#include "jvm_bsd.h"
+#include "logging/log.hpp"
+#include "memory/allocation.inline.hpp"
+#include "memory/filemap.hpp"
+#include "oops/oop.inline.hpp"
+#include "os_bsd.inline.hpp"
+#include "os_share_bsd.hpp"
+#include "prims/jniFastGetField.hpp"
+#include "prims/jvm.h"
+#include "prims/jvm_misc.hpp"
+#include "runtime/arguments.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/extendedPC.hpp"
+#include "runtime/globals.hpp"
+#include "runtime/interfaceSupport.hpp"
+#include "runtime/java.hpp"
+#include "runtime/javaCalls.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "runtime/objectMonitor.hpp"
+#include "runtime/orderAccess.inline.hpp"
+#include "runtime/osThread.hpp"
+#include "runtime/perfMemory.hpp"
+#include "runtime/sharedRuntime.hpp"
+#include "runtime/statSampler.hpp"
+#include "runtime/stubRoutines.hpp"
+#include "runtime/thread.inline.hpp"
+#include "runtime/threadCritical.hpp"
+#include "runtime/timer.hpp"
+#include "semaphore_bsd.hpp"
+#include "services/attachListener.hpp"
+#include "services/memTracker.hpp"
+#include "services/runtimeService.hpp"
+#include "utilities/align.hpp"
+#include "utilities/decoder.hpp"
+#include "utilities/defaultStream.hpp"
+#include "utilities/events.hpp"
+#include "utilities/growableArray.hpp"
+#include "utilities/vmError.hpp"
+
+// put OS-includes here
+# include <sys/types.h>
+# include <sys/mman.h>
+# include <sys/stat.h>
+# include <sys/select.h>
+# include <pthread.h>
+# include <signal.h>
+# include <errno.h>
+# include <dlfcn.h>
+# include <stdio.h>
+# include <unistd.h>
+# include <sys/resource.h>
+# include <pthread.h>
+# include <sys/stat.h>
+# include <sys/time.h>
+# include <sys/times.h>
+# include <sys/utsname.h>
+# include <sys/socket.h>
+# include <sys/wait.h>
+# include <time.h>
+# include <pwd.h>
+# include <poll.h>
+# include <semaphore.h>
+# include <fcntl.h>
+# include <string.h>
+# include <sys/param.h>
+# include <sys/sysctl.h>
+# include <sys/ipc.h>
+# include <sys/shm.h>
+#ifndef __APPLE__
+# include <link.h>
+#endif
+# include <stdint.h>
+# include <inttypes.h>
+# include <sys/ioctl.h>
+# include <sys/syscall.h>
+
+#if defined(__FreeBSD__) || defined(__NetBSD__)
+  #include <elf.h>
+#endif
+
+#ifdef __APPLE__
+  #include <mach/mach.h> // semaphore_* API
+  #include <mach-o/dyld.h>
+  #include <sys/proc_info.h>
+  #include <objc/objc-auto.h>
+#endif
+
+#ifndef MAP_ANONYMOUS
+  #define MAP_ANONYMOUS MAP_ANON
+#endif
+
+#define MAX_PATH    (2 * K)
+
+// for timer info max values which include all bits
+#define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
+
+#define LARGEPAGES_BIT (1 << 6)
+
+////////////////////////////////////////////////////////////////////////////////
+// global variables
+julong os::Bsd::_physical_memory = 0;
+
+#ifdef __APPLE__
+mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
+volatile uint64_t         os::Bsd::_max_abstime   = 0;
+#else
+int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
+#endif
+pthread_t os::Bsd::_main_thread;
+int os::Bsd::_page_size = -1;
+
+static jlong initial_time_count=0;
+
+static int clock_tics_per_sec = 100;
+
+// For diagnostics to print a message once. see run_periodic_checks
+static sigset_t check_signal_done;
+static bool check_signals = true;
+
+static pid_t _initial_pid = 0;
+
+// Signal number used to suspend/resume a thread
+
+// do not use any signal number less than SIGSEGV, see 4355769
+static int SR_signum = SIGUSR2;
+sigset_t SR_sigset;
+
+
+////////////////////////////////////////////////////////////////////////////////
+// utility functions
+
+static int SR_initialize();
+
+julong os::available_memory() {
+  return Bsd::available_memory();
+}
+
+// available here means free
+julong os::Bsd::available_memory() {
+  uint64_t available = physical_memory() >> 2;
+#ifdef __APPLE__
+  mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
+  vm_statistics64_data_t vmstat;
+  kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
+                                         (host_info64_t)&vmstat, &count);
+  assert(kerr == KERN_SUCCESS,
+         "host_statistics64 failed - check mach_host_self() and count");
+  if (kerr == KERN_SUCCESS) {
+    available = vmstat.free_count * os::vm_page_size();
+  }
+#endif
+  return available;
+}
+
+julong os::physical_memory() {
+  return Bsd::physical_memory();
+}
+
+// Return true if user is running as root.
+
+bool os::have_special_privileges() {
+  static bool init = false;
+  static bool privileges = false;
+  if (!init) {
+    privileges = (getuid() != geteuid()) || (getgid() != getegid());
+    init = true;
+  }
+  return privileges;
+}
+
+
+
+// Cpu architecture string
+#if   defined(ZERO)
+static char cpu_arch[] = ZERO_LIBARCH;
+#elif defined(IA64)
+static char cpu_arch[] = "ia64";
+#elif defined(IA32)
+static char cpu_arch[] = "i386";
+#elif defined(AMD64)
+static char cpu_arch[] = "amd64";
+#elif defined(ARM)
+static char cpu_arch[] = "arm";
+#elif defined(PPC32)
+static char cpu_arch[] = "ppc";
+#elif defined(SPARC)
+  #ifdef _LP64
+static char cpu_arch[] = "sparcv9";
+  #else
+static char cpu_arch[] = "sparc";
+  #endif
+#else
+  #error Add appropriate cpu_arch setting
+#endif
+
+// Compiler variant
+#ifdef COMPILER2
+  #define COMPILER_VARIANT "server"
+#else
+  #define COMPILER_VARIANT "client"
+#endif
+
+
+void os::Bsd::initialize_system_info() {
+  int mib[2];
+  size_t len;
+  int cpu_val;
+  julong mem_val;
+
+  // get processors count via hw.ncpus sysctl
+  mib[0] = CTL_HW;
+  mib[1] = HW_NCPU;
+  len = sizeof(cpu_val);
+  if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
+    assert(len == sizeof(cpu_val), "unexpected data size");
+    set_processor_count(cpu_val);
+  } else {
+    set_processor_count(1);   // fallback
+  }
+
+  // get physical memory via hw.memsize sysctl (hw.memsize is used
+  // since it returns a 64 bit value)
+  mib[0] = CTL_HW;
+
+#if defined (HW_MEMSIZE) // Apple
+  mib[1] = HW_MEMSIZE;
+#elif defined(HW_PHYSMEM) // Most of BSD
+  mib[1] = HW_PHYSMEM;
+#elif defined(HW_REALMEM) // Old FreeBSD
+  mib[1] = HW_REALMEM;
+#else
+  #error No ways to get physmem
+#endif
+
+  len = sizeof(mem_val);
+  if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
+    assert(len == sizeof(mem_val), "unexpected data size");
+    _physical_memory = mem_val;
+  } else {
+    _physical_memory = 256 * 1024 * 1024;       // fallback (XXXBSD?)
+  }
+
+#ifdef __OpenBSD__
+  {
+    // limit _physical_memory memory view on OpenBSD since
+    // datasize rlimit restricts us anyway.
+    struct rlimit limits;
+    getrlimit(RLIMIT_DATA, &limits);
+    _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
+  }
+#endif
+}
+
+#ifdef __APPLE__
+static const char *get_home() {
+  const char *home_dir = ::getenv("HOME");
+  if ((home_dir == NULL) || (*home_dir == '\0')) {
+    struct passwd *passwd_info = getpwuid(geteuid());
+    if (passwd_info != NULL) {
+      home_dir = passwd_info->pw_dir;
+    }
+  }
+
+  return home_dir;
+}
+#endif
+
+void os::init_system_properties_values() {
+  // The next steps are taken in the product version:
+  //
+  // Obtain the JAVA_HOME value from the location of libjvm.so.
+  // This library should be located at:
+  // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
+  //
+  // If "/jre/lib/" appears at the right place in the path, then we
+  // assume libjvm.so is installed in a JDK and we use this path.
+  //
+  // Otherwise exit with message: "Could not create the Java virtual machine."
+  //
+  // The following extra steps are taken in the debugging version:
+  //
+  // If "/jre/lib/" does NOT appear at the right place in the path
+  // instead of exit check for $JAVA_HOME environment variable.
+  //
+  // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
+  // then we append a fake suffix "hotspot/libjvm.so" to this path so
+  // it looks like libjvm.so is installed there
+  // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
+  //
+  // Otherwise exit.
+  //
+  // Important note: if the location of libjvm.so changes this
+  // code needs to be changed accordingly.
+
+  // See ld(1):
+  //      The linker uses the following search paths to locate required
+  //      shared libraries:
+  //        1: ...
+  //        ...
+  //        7: The default directories, normally /lib and /usr/lib.
+#ifndef DEFAULT_LIBPATH
+  #define DEFAULT_LIBPATH "/lib:/usr/lib"
+#endif
+
+// Base path of extensions installed on the system.
+#define SYS_EXT_DIR     "/usr/java/packages"
+#define EXTENSIONS_DIR  "/lib/ext"
+
+#ifndef __APPLE__
+
+  // Buffer that fits several sprintfs.
+  // Note that the space for the colon and the trailing null are provided
+  // by the nulls included by the sizeof operator.
+  const size_t bufsize =
+    MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
+         (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
+  char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
+
+  // sysclasspath, java_home, dll_dir
+  {
+    char *pslash;
+    os::jvm_path(buf, bufsize);
+
+    // Found the full path to libjvm.so.
+    // Now cut the path to <java_home>/jre if we can.
+    *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
+    pslash = strrchr(buf, '/');
+    if (pslash != NULL) {
+      *pslash = '\0';            // Get rid of /{client|server|hotspot}.
+    }
+    Arguments::set_dll_dir(buf);
+
+    if (pslash != NULL) {
+      pslash = strrchr(buf, '/');
+      if (pslash != NULL) {
+        *pslash = '\0';          // Get rid of /<arch>.
+        pslash = strrchr(buf, '/');
+        if (pslash != NULL) {
+          *pslash = '\0';        // Get rid of /lib.
+        }
+      }
+    }
+    Arguments::set_java_home(buf);
+    set_boot_path('/', ':');
+  }
+
+  // Where to look for native libraries.
+  //
+  // Note: Due to a legacy implementation, most of the library path
+  // is set in the launcher. This was to accomodate linking restrictions
+  // on legacy Bsd implementations (which are no longer supported).
+  // Eventually, all the library path setting will be done here.
+  //
+  // However, to prevent the proliferation of improperly built native
+  // libraries, the new path component /usr/java/packages is added here.
+  // Eventually, all the library path setting will be done here.
+  {
+    // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
+    // should always exist (until the legacy problem cited above is
+    // addressed).
+    const char *v = ::getenv("LD_LIBRARY_PATH");
+    const char *v_colon = ":";
+    if (v == NULL) { v = ""; v_colon = ""; }
+    // That's +1 for the colon and +1 for the trailing '\0'.
+    char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
+                                                     strlen(v) + 1 +
+                                                     sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
+                                                     mtInternal);
+    sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
+    Arguments::set_library_path(ld_library_path);
+    FREE_C_HEAP_ARRAY(char, ld_library_path);
+  }
+
+  // Extensions directories.
+  sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
+  Arguments::set_ext_dirs(buf);
+
+  FREE_C_HEAP_ARRAY(char, buf);
+
+#else // __APPLE__
+
+  #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
+  #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
+
+  const char *user_home_dir = get_home();
+  // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
+  size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
+    sizeof(SYS_EXTENSIONS_DIRS);
+
+  // Buffer that fits several sprintfs.
+  // Note that the space for the colon and the trailing null are provided
+  // by the nulls included by the sizeof operator.
+  const size_t bufsize =
+    MAX2((size_t)MAXPATHLEN,  // for dll_dir & friends.
+         (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
+  char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
+
+  // sysclasspath, java_home, dll_dir
+  {
+    char *pslash;
+    os::jvm_path(buf, bufsize);
+
+    // Found the full path to libjvm.so.
+    // Now cut the path to <java_home>/jre if we can.
+    *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
+    pslash = strrchr(buf, '/');
+    if (pslash != NULL) {
+      *pslash = '\0';            // Get rid of /{client|server|hotspot}.
+    }
+#ifdef STATIC_BUILD
+    strcat(buf, "/lib");
+#endif
+
+    Arguments::set_dll_dir(buf);
+
+    if (pslash != NULL) {
+      pslash = strrchr(buf, '/');
+      if (pslash != NULL) {
+        *pslash = '\0';          // Get rid of /lib.
+      }
+    }
+    Arguments::set_java_home(buf);
+    set_boot_path('/', ':');
+  }
+
+  // Where to look for native libraries.
+  //
+  // Note: Due to a legacy implementation, most of the library path
+  // is set in the launcher. This was to accomodate linking restrictions
+  // on legacy Bsd implementations (which are no longer supported).
+  // Eventually, all the library path setting will be done here.
+  //
+  // However, to prevent the proliferation of improperly built native
+  // libraries, the new path component /usr/java/packages is added here.
+  // Eventually, all the library path setting will be done here.
+  {
+    // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
+    // should always exist (until the legacy problem cited above is
+    // addressed).
+    // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
+    // can specify a directory inside an app wrapper
+    const char *l = ::getenv("JAVA_LIBRARY_PATH");
+    const char *l_colon = ":";
+    if (l == NULL) { l = ""; l_colon = ""; }
+
+    const char *v = ::getenv("DYLD_LIBRARY_PATH");
+    const char *v_colon = ":";
+    if (v == NULL) { v = ""; v_colon = ""; }
+
+    // Apple's Java6 has "." at the beginning of java.library.path.
+    // OpenJDK on Windows has "." at the end of java.library.path.
+    // OpenJDK on Linux and Solaris don't have "." in java.library.path
+    // at all. To ease the transition from Apple's Java6 to OpenJDK7,
+    // "." is appended to the end of java.library.path. Yes, this
+    // could cause a change in behavior, but Apple's Java6 behavior
+    // can be achieved by putting "." at the beginning of the
+    // JAVA_LIBRARY_PATH environment variable.
+    char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
+                                                     strlen(v) + 1 + strlen(l) + 1 +
+                                                     system_ext_size + 3,
+                                                     mtInternal);
+    sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
+            v, v_colon, l, l_colon, user_home_dir);
+    Arguments::set_library_path(ld_library_path);
+    FREE_C_HEAP_ARRAY(char, ld_library_path);
+  }
+
+  // Extensions directories.
+  //
+  // Note that the space for the colon and the trailing null are provided
+  // by the nulls included by the sizeof operator (so actually one byte more
+  // than necessary is allocated).
+  sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
+          user_home_dir, Arguments::get_java_home());
+  Arguments::set_ext_dirs(buf);
+
+  FREE_C_HEAP_ARRAY(char, buf);
+
+#undef SYS_EXTENSIONS_DIR
+#undef SYS_EXTENSIONS_DIRS
+
+#endif // __APPLE__
+
+#undef SYS_EXT_DIR
+#undef EXTENSIONS_DIR
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// breakpoint support
+
+void os::breakpoint() {
+  BREAKPOINT;
+}
+
+extern "C" void breakpoint() {
+  // use debugger to set breakpoint here
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// signal support
+
+debug_only(static bool signal_sets_initialized = false);
+static sigset_t unblocked_sigs, vm_sigs;
+
+bool os::Bsd::is_sig_ignored(int sig) {
+  struct sigaction oact;
+  sigaction(sig, (struct sigaction*)NULL, &oact);
+  void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
+                                 : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
+  if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
+    return true;
+  } else {
+    return false;
+  }
+}
+
+void os::Bsd::signal_sets_init() {
+  // Should also have an assertion stating we are still single-threaded.
+  assert(!signal_sets_initialized, "Already initialized");
+  // Fill in signals that are necessarily unblocked for all threads in
+  // the VM. Currently, we unblock the following signals:
+  // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
+  //                         by -Xrs (=ReduceSignalUsage));
+  // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
+  // other threads. The "ReduceSignalUsage" boolean tells us not to alter
+  // the dispositions or masks wrt these signals.
+  // Programs embedding the VM that want to use the above signals for their
+  // own purposes must, at this time, use the "-Xrs" option to prevent
+  // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
+  // (See bug 4345157, and other related bugs).
+  // In reality, though, unblocking these signals is really a nop, since
+  // these signals are not blocked by default.
+  sigemptyset(&unblocked_sigs);
+  sigaddset(&unblocked_sigs, SIGILL);
+  sigaddset(&unblocked_sigs, SIGSEGV);
+  sigaddset(&unblocked_sigs, SIGBUS);
+  sigaddset(&unblocked_sigs, SIGFPE);
+  sigaddset(&unblocked_sigs, SR_signum);
+
+  if (!ReduceSignalUsage) {
+    if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
+      sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
+
+    }
+    if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
+      sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
+    }
+    if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
+      sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
+    }
+  }
+  // Fill in signals that are blocked by all but the VM thread.
+  sigemptyset(&vm_sigs);
+  if (!ReduceSignalUsage) {
+    sigaddset(&vm_sigs, BREAK_SIGNAL);
+  }
+  debug_only(signal_sets_initialized = true);
+
+}
+
+// These are signals that are unblocked while a thread is running Java.
+// (For some reason, they get blocked by default.)
+sigset_t* os::Bsd::unblocked_signals() {
+  assert(signal_sets_initialized, "Not initialized");
+  return &unblocked_sigs;
+}
+
+// These are the signals that are blocked while a (non-VM) thread is
+// running Java. Only the VM thread handles these signals.
+sigset_t* os::Bsd::vm_signals() {
+  assert(signal_sets_initialized, "Not initialized");
+  return &vm_sigs;
+}
+
+void os::Bsd::hotspot_sigmask(Thread* thread) {
+
+  //Save caller's signal mask before setting VM signal mask
+  sigset_t caller_sigmask;
+  pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
+
+  OSThread* osthread = thread->osthread();
+  osthread->set_caller_sigmask(caller_sigmask);
+
+  pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
+
+  if (!ReduceSignalUsage) {
+    if (thread->is_VM_thread()) {
+      // Only the VM thread handles BREAK_SIGNAL ...
+      pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
+    } else {
+      // ... all other threads block BREAK_SIGNAL
+      pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
+    }
+  }
+}
+
+
+//////////////////////////////////////////////////////////////////////////////
+// create new thread
+
+#ifdef __APPLE__
+// library handle for calling objc_registerThreadWithCollector()
+// without static linking to the libobjc library
+  #define OBJC_LIB "/usr/lib/libobjc.dylib"
+  #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
+typedef void (*objc_registerThreadWithCollector_t)();
+extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
+objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
+#endif
+
+#ifdef __APPLE__
+static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
+  // Additional thread_id used to correlate threads in SA
+  thread_identifier_info_data_t     m_ident_info;
+  mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
+
+  thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
+              (thread_info_t) &m_ident_info, &count);
+
+  return m_ident_info.thread_id;
+}
+#endif
+
+// Thread start routine for all newly created threads
+static void *thread_native_entry(Thread *thread) {
+  // Try to randomize the cache line index of hot stack frames.
+  // This helps when threads of the same stack traces evict each other's
+  // cache lines. The threads can be either from the same JVM instance, or
+  // from different JVM instances. The benefit is especially true for
+  // processors with hyperthreading technology.
+  static int counter = 0;
+  int pid = os::current_process_id();
+  alloca(((pid ^ counter++) & 7) * 128);
+
+  thread->initialize_thread_current();
+
+  OSThread* osthread = thread->osthread();
+  Monitor* sync = osthread->startThread_lock();
+
+  osthread->set_thread_id(os::Bsd::gettid());
+
+  log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
+    os::current_thread_id(), (uintx) pthread_self());
+
+#ifdef __APPLE__
+  uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
+  guarantee(unique_thread_id != 0, "unique thread id was not found");
+  osthread->set_unique_thread_id(unique_thread_id);
+#endif
+  // initialize signal mask for this thread
+  os::Bsd::hotspot_sigmask(thread);
+
+  // initialize floating point control register
+  os::Bsd::init_thread_fpu_state();
+
+#ifdef __APPLE__
+  // register thread with objc gc
+  if (objc_registerThreadWithCollectorFunction != NULL) {
+    objc_registerThreadWithCollectorFunction();
+  }
+#endif
+
+  // handshaking with parent thread
+  {
+    MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
+
+    // notify parent thread
+    osthread->set_state(INITIALIZED);
+    sync->notify_all();
+
+    // wait until os::start_thread()
+    while (osthread->get_state() == INITIALIZED) {
+      sync->wait(Mutex::_no_safepoint_check_flag);
+    }
+  }
+
+  // call one more level start routine
+  thread->run();
+
+  log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
+    os::current_thread_id(), (uintx) pthread_self());
+
+  // If a thread has not deleted itself ("delete this") as part of its
+  // termination sequence, we have to ensure thread-local-storage is
+  // cleared before we actually terminate. No threads should ever be
+  // deleted asynchronously with respect to their termination.
+  if (Thread::current_or_null_safe() != NULL) {
+    assert(Thread::current_or_null_safe() == thread, "current thread is wrong");
+    thread->clear_thread_current();
+  }
+
+  return 0;
+}
+
+bool os::create_thread(Thread* thread, ThreadType thr_type,
+                       size_t req_stack_size) {
+  assert(thread->osthread() == NULL, "caller responsible");
+
+  // Allocate the OSThread object
+  OSThread* osthread = new OSThread(NULL, NULL);
+  if (osthread == NULL) {
+    return false;
+  }
+
+  // set the correct thread state
+  osthread->set_thread_type(thr_type);
+
+  // Initial state is ALLOCATED but not INITIALIZED
+  osthread->set_state(ALLOCATED);
+
+  thread->set_osthread(osthread);
+
+  // init thread attributes
+  pthread_attr_t attr;
+  pthread_attr_init(&attr);
+  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+
+  // calculate stack size if it's not specified by caller
+  size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
+  int status = pthread_attr_setstacksize(&attr, stack_size);
+  assert_status(status == 0, status, "pthread_attr_setstacksize");
+
+  ThreadState state;
+
+  {
+    pthread_t tid;
+    int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
+
+    char buf[64];
+    if (ret == 0) {
+      log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
+        (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
+    } else {
+      log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
+        os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
+    }
+
+    pthread_attr_destroy(&attr);
+
+    if (ret != 0) {
+      // Need to clean up stuff we've allocated so far
+      thread->set_osthread(NULL);
+      delete osthread;
+      return false;
+    }
+
+    // Store pthread info into the OSThread
+    osthread->set_pthread_id(tid);
+
+    // Wait until child thread is either initialized or aborted
+    {
+      Monitor* sync_with_child = osthread->startThread_lock();
+      MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
+      while ((state = osthread->get_state()) == ALLOCATED) {
+        sync_with_child->wait(Mutex::_no_safepoint_check_flag);
+      }
+    }
+
+  }
+
+  // Aborted due to thread limit being reached
+  if (state == ZOMBIE) {
+    thread->set_osthread(NULL);
+    delete osthread;
+    return false;
+  }
+
+  // The thread is returned suspended (in state INITIALIZED),
+  // and is started higher up in the call chain
+  assert(state == INITIALIZED, "race condition");
+  return true;
+}
+
+/////////////////////////////////////////////////////////////////////////////
+// attach existing thread
+
+// bootstrap the main thread
+bool os::create_main_thread(JavaThread* thread) {
+  assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
+  return create_attached_thread(thread);
+}
+
+bool os::create_attached_thread(JavaThread* thread) {
+#ifdef ASSERT
+  thread->verify_not_published();
+#endif
+
+  // Allocate the OSThread object
+  OSThread* osthread = new OSThread(NULL, NULL);
+
+  if (osthread == NULL) {
+    return false;
+  }
+
+  osthread->set_thread_id(os::Bsd::gettid());
+
+  // Store pthread info into the OSThread
+#ifdef __APPLE__
+  uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
+  guarantee(unique_thread_id != 0, "just checking");
+  osthread->set_unique_thread_id(unique_thread_id);
+#endif
+  osthread->set_pthread_id(::pthread_self());
+
+  // initialize floating point control register
+  os::Bsd::init_thread_fpu_state();
+
+  // Initial thread state is RUNNABLE
+  osthread->set_state(RUNNABLE);
+
+  thread->set_osthread(osthread);
+
+  // initialize signal mask for this thread
+  // and save the caller's signal mask
+  os::Bsd::hotspot_sigmask(thread);
+
+  log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
+    os::current_thread_id(), (uintx) pthread_self());
+
+  return true;
+}
+
+void os::pd_start_thread(Thread* thread) {
+  OSThread * osthread = thread->osthread();
+  assert(osthread->get_state() != INITIALIZED, "just checking");
+  Monitor* sync_with_child = osthread->startThread_lock();
+  MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
+  sync_with_child->notify();
+}
+
+// Free Bsd resources related to the OSThread
+void os::free_thread(OSThread* osthread) {
+  assert(osthread != NULL, "osthread not set");
+
+  // We are told to free resources of the argument thread,
+  // but we can only really operate on the current thread.
+  assert(Thread::current()->osthread() == osthread,
+         "os::free_thread but not current thread");
+
+  // Restore caller's signal mask
+  sigset_t sigmask = osthread->caller_sigmask();
+  pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
+
+  delete osthread;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// time support
+
+// Time since start-up in seconds to a fine granularity.
+// Used by VMSelfDestructTimer and the MemProfiler.
+double os::elapsedTime() {
+
+  return ((double)os::elapsed_counter()) / os::elapsed_frequency();
+}
+
+jlong os::elapsed_counter() {
+  return javaTimeNanos() - initial_time_count;
+}
+
+jlong os::elapsed_frequency() {
+  return NANOSECS_PER_SEC; // nanosecond resolution
+}
+
+bool os::supports_vtime() { return true; }
+bool os::enable_vtime()   { return false; }
+bool os::vtime_enabled()  { return false; }
+
+double os::elapsedVTime() {
+  // better than nothing, but not much
+  return elapsedTime();
+}
+
+jlong os::javaTimeMillis() {
+  timeval time;
+  int status = gettimeofday(&time, NULL);
+  assert(status != -1, "bsd error");
+  return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
+}
+
+void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
+  timeval time;
+  int status = gettimeofday(&time, NULL);
+  assert(status != -1, "bsd error");
+  seconds = jlong(time.tv_sec);
+  nanos = jlong(time.tv_usec) * 1000;
+}
+
+#ifndef __APPLE__
+  #ifndef CLOCK_MONOTONIC
+    #define CLOCK_MONOTONIC (1)
+  #endif
+#endif
+
+#ifdef __APPLE__
+void os::Bsd::clock_init() {
+  mach_timebase_info(&_timebase_info);
+}
+#else
+void os::Bsd::clock_init() {
+  struct timespec res;
+  struct timespec tp;
+  if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
+      ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
+    // yes, monotonic clock is supported
+    _clock_gettime = ::clock_gettime;
+  }
+}
+#endif
+
+
+
+#ifdef __APPLE__
+
+jlong os::javaTimeNanos() {
+  const uint64_t tm = mach_absolute_time();
+  const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
+  const uint64_t prev = Bsd::_max_abstime;
+  if (now <= prev) {
+    return prev;   // same or retrograde time;
+  }
+  const uint64_t obsv = Atomic::cmpxchg(now, &Bsd::_max_abstime, prev);
+  assert(obsv >= prev, "invariant");   // Monotonicity
+  // If the CAS succeeded then we're done and return "now".
+  // If the CAS failed and the observed value "obsv" is >= now then
+  // we should return "obsv".  If the CAS failed and now > obsv > prv then
+  // some other thread raced this thread and installed a new value, in which case
+  // we could either (a) retry the entire operation, (b) retry trying to install now
+  // or (c) just return obsv.  We use (c).   No loop is required although in some cases
+  // we might discard a higher "now" value in deference to a slightly lower but freshly
+  // installed obsv value.   That's entirely benign -- it admits no new orderings compared
+  // to (a) or (b) -- and greatly reduces coherence traffic.
+  // We might also condition (c) on the magnitude of the delta between obsv and now.
+  // Avoiding excessive CAS operations to hot RW locations is critical.
+  // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
+  return (prev == obsv) ? now : obsv;
+}
+
+#else // __APPLE__
+
+jlong os::javaTimeNanos() {
+  if (os::supports_monotonic_clock()) {
+    struct timespec tp;
+    int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
+    assert(status == 0, "gettime error");
+    jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
+    return result;
+  } else {
+    timeval time;
+    int status = gettimeofday(&time, NULL);
+    assert(status != -1, "bsd error");
+    jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
+    return 1000 * usecs;
+  }
+}
+
+#endif // __APPLE__
+
+void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
+  if (os::supports_monotonic_clock()) {
+    info_ptr->max_value = ALL_64_BITS;
+
+    // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
+    info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
+    info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
+  } else {
+    // gettimeofday - based on time in seconds since the Epoch thus does not wrap
+    info_ptr->max_value = ALL_64_BITS;
+
+    // gettimeofday is a real time clock so it skips
+    info_ptr->may_skip_backward = true;
+    info_ptr->may_skip_forward = true;
+  }
+
+  info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
+}
+
+// Return the real, user, and system times in seconds from an
+// arbitrary fixed point in the past.
+bool os::getTimesSecs(double* process_real_time,
+                      double* process_user_time,
+                      double* process_system_time) {
+  struct tms ticks;
+  clock_t real_ticks = times(&ticks);
+
+  if (real_ticks == (clock_t) (-1)) {
+    return false;
+  } else {
+    double ticks_per_second = (double) clock_tics_per_sec;
+    *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
+    *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
+    *process_real_time = ((double) real_ticks) / ticks_per_second;
+
+    return true;
+  }
+}
+
+
+char * os::local_time_string(char *buf, size_t buflen) {
+  struct tm t;
+  time_t long_time;
+  time(&long_time);
+  localtime_r(&long_time, &t);
+  jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
+               t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
+               t.tm_hour, t.tm_min, t.tm_sec);
+  return buf;
+}
+
+struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
+  return localtime_r(clock, res);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// runtime exit support
+
+// Note: os::shutdown() might be called very early during initialization, or
+// called from signal handler. Before adding something to os::shutdown(), make
+// sure it is async-safe and can handle partially initialized VM.
+void os::shutdown() {
+
+  // allow PerfMemory to attempt cleanup of any persistent resources
+  perfMemory_exit();
+
+  // needs to remove object in file system
+  AttachListener::abort();
+
+  // flush buffered output, finish log files
+  ostream_abort();
+
+  // Check for abort hook
+  abort_hook_t abort_hook = Arguments::abort_hook();
+  if (abort_hook != NULL) {
+    abort_hook();
+  }
+
+}
+
+// Note: os::abort() might be called very early during initialization, or
+// called from signal handler. Before adding something to os::abort(), make
+// sure it is async-safe and can handle partially initialized VM.
+void os::abort(bool dump_core, void* siginfo, const void* context) {
+  os::shutdown();
+  if (dump_core) {
+#ifndef PRODUCT
+    fdStream out(defaultStream::output_fd());
+    out.print_raw("Current thread is ");
+    char buf[16];
+    jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
+    out.print_raw_cr(buf);
+    out.print_raw_cr("Dumping core ...");
+#endif
+    ::abort(); // dump core
+  }
+
+  ::exit(1);
+}
+
+// Die immediately, no exit hook, no abort hook, no cleanup.
+void os::die() {
+  // _exit() on BsdThreads only kills current thread
+  ::abort();
+}
+
+// This method is a copy of JDK's sysGetLastErrorString
+// from src/solaris/hpi/src/system_md.c
+
+size_t os::lasterror(char *buf, size_t len) {
+  if (errno == 0)  return 0;
+
+  const char *s = os::strerror(errno);
+  size_t n = ::strlen(s);
+  if (n >= len) {
+    n = len - 1;
+  }
+  ::strncpy(buf, s, n);
+  buf[n] = '\0';
+  return n;
+}
+
+// Information of current thread in variety of formats
+pid_t os::Bsd::gettid() {
+  int retval = -1;
+
+#ifdef __APPLE__ //XNU kernel
+  // despite the fact mach port is actually not a thread id use it
+  // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
+  retval = ::pthread_mach_thread_np(::pthread_self());
+  guarantee(retval != 0, "just checking");
+  return retval;
+
+#else
+  #ifdef __FreeBSD__
+  retval = syscall(SYS_thr_self);
+  #else
+    #ifdef __OpenBSD__
+  retval = syscall(SYS_getthrid);
+    #else
+      #ifdef __NetBSD__
+  retval = (pid_t) syscall(SYS__lwp_self);
+      #endif
+    #endif
+  #endif
+#endif
+
+  if (retval == -1) {
+    return getpid();
+  }
+}
+
+intx os::current_thread_id() {
+#ifdef __APPLE__
+  return (intx)::pthread_mach_thread_np(::pthread_self());
+#else
+  return (intx)::pthread_self();
+#endif
+}
+
+int os::current_process_id() {
+
+  // Under the old bsd thread library, bsd gives each thread
+  // its own process id. Because of this each thread will return
+  // a different pid if this method were to return the result
+  // of getpid(2). Bsd provides no api that returns the pid
+  // of the launcher thread for the vm. This implementation
+  // returns a unique pid, the pid of the launcher thread
+  // that starts the vm 'process'.
+
+  // Under the NPTL, getpid() returns the same pid as the
+  // launcher thread rather than a unique pid per thread.
+  // Use gettid() if you want the old pre NPTL behaviour.
+
+  // if you are looking for the result of a call to getpid() that
+  // returns a unique pid for the calling thread, then look at the
+  // OSThread::thread_id() method in osThread_bsd.hpp file
+
+  return (int)(_initial_pid ? _initial_pid : getpid());
+}
+
+// DLL functions
+
+const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
+
+// This must be hard coded because it's the system's temporary
+// directory not the java application's temp directory, ala java.io.tmpdir.
+#ifdef __APPLE__
+// macosx has a secure per-user temporary directory
+char temp_path_storage[PATH_MAX];
+const char* os::get_temp_directory() {
+  static char *temp_path = NULL;
+  if (temp_path == NULL) {
+    int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
+    if (pathSize == 0 || pathSize > PATH_MAX) {
+      strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
+    }
+    temp_path = temp_path_storage;
+  }
+  return temp_path;
+}
+#else // __APPLE__
+const char* os::get_temp_directory() { return "/tmp"; }
+#endif // __APPLE__
+
+// check if addr is inside libjvm.so
+bool os::address_is_in_vm(address addr) {
+  static address libjvm_base_addr;
+  Dl_info dlinfo;
+
+  if (libjvm_base_addr == NULL) {
+    if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
+      libjvm_base_addr = (address)dlinfo.dli_fbase;
+    }
+    assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
+  }
+
+  if (dladdr((void *)addr, &dlinfo) != 0) {
+    if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
+  }
+
+  return false;
+}
+
+
+#define MACH_MAXSYMLEN 256
+
+bool os::dll_address_to_function_name(address addr, char *buf,
+                                      int buflen, int *offset,
+                                      bool demangle) {
+  // buf is not optional, but offset is optional
+  assert(buf != NULL, "sanity check");
+
+  Dl_info dlinfo;
+  char localbuf[MACH_MAXSYMLEN];
+
+  if (dladdr((void*)addr, &dlinfo) != 0) {
+    // see if we have a matching symbol
+    if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
+      if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
+        jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
+      }
+      if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
+      return true;
+    }
+    // no matching symbol so try for just file info
+    if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
+      if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
+                          buf, buflen, offset, dlinfo.dli_fname, demangle)) {
+        return true;
+      }
+    }
+
+    // Handle non-dynamic manually:
+    if (dlinfo.dli_fbase != NULL &&
+        Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
+                        dlinfo.dli_fbase)) {
+      if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) {
+        jio_snprintf(buf, buflen, "%s", localbuf);
+      }
+      return true;
+    }
+  }
+  buf[0] = '\0';
+  if (offset != NULL) *offset = -1;
+  return false;
+}
+
+// ported from solaris version
+bool os::dll_address_to_library_name(address addr, char* buf,
+                                     int buflen, int* offset) {
+  // buf is not optional, but offset is optional
+  assert(buf != NULL, "sanity check");
+
+  Dl_info dlinfo;
+
+  if (dladdr((void*)addr, &dlinfo) != 0) {
+    if (dlinfo.dli_fname != NULL) {
+      jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
+    }
+    if (dlinfo.dli_fbase != NULL && offset != NULL) {
+      *offset = addr - (address)dlinfo.dli_fbase;
+    }
+    return true;
+  }
+
+  buf[0] = '\0';
+  if (offset) *offset = -1;
+  return false;
+}
+
+// Loads .dll/.so and
+// in case of error it checks if .dll/.so was built for the
+// same architecture as Hotspot is running on
+
+#ifdef __APPLE__
+void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
+#ifdef STATIC_BUILD
+  return os::get_default_process_handle();
+#else
+  void * result= ::dlopen(filename, RTLD_LAZY);
+  if (result != NULL) {
+    // Successful loading
+    return result;
+  }
+
+  // Read system error message into ebuf
+  ::strncpy(ebuf, ::dlerror(), ebuflen-1);
+  ebuf[ebuflen-1]='\0';
+
+  return NULL;
+#endif // STATIC_BUILD
+}
+#else
+void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
+#ifdef STATIC_BUILD
+  return os::get_default_process_handle();
+#else
+  void * result= ::dlopen(filename, RTLD_LAZY);
+  if (result != NULL) {
+    // Successful loading
+    return result;
+  }
+
+  Elf32_Ehdr elf_head;
+
+  // Read system error message into ebuf
+  // It may or may not be overwritten below
+  ::strncpy(ebuf, ::dlerror(), ebuflen-1);
+  ebuf[ebuflen-1]='\0';
+  int diag_msg_max_length=ebuflen-strlen(ebuf);
+  char* diag_msg_buf=ebuf+strlen(ebuf);
+
+  if (diag_msg_max_length==0) {
+    // No more space in ebuf for additional diagnostics message
+    return NULL;
+  }
+
+
+  int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
+
+  if (file_descriptor < 0) {
+    // Can't open library, report dlerror() message
+    return NULL;
+  }
+
+  bool failed_to_read_elf_head=
+    (sizeof(elf_head)!=
+     (::read(file_descriptor, &elf_head,sizeof(elf_head))));
+
+  ::close(file_descriptor);
+  if (failed_to_read_elf_head) {
+    // file i/o error - report dlerror() msg
+    return NULL;
+  }
+
+  typedef struct {
+    Elf32_Half  code;         // Actual value as defined in elf.h
+    Elf32_Half  compat_class; // Compatibility of archs at VM's sense
+    char        elf_class;    // 32 or 64 bit
+    char        endianess;    // MSB or LSB
+    char*       name;         // String representation
+  } arch_t;
+
+  #ifndef EM_486
+    #define EM_486          6               /* Intel 80486 */
+  #endif
+
+  #ifndef EM_MIPS_RS3_LE
+    #define EM_MIPS_RS3_LE  10              /* MIPS */
+  #endif
+
+  #ifndef EM_PPC64
+    #define EM_PPC64        21              /* PowerPC64 */
+  #endif
+
+  #ifndef EM_S390
+    #define EM_S390         22              /* IBM System/390 */
+  #endif
+
+  #ifndef EM_IA_64
+    #define EM_IA_64        50              /* HP/Intel IA-64 */
+  #endif
+
+  #ifndef EM_X86_64
+    #define EM_X86_64       62              /* AMD x86-64 */
+  #endif
+
+  static const arch_t arch_array[]={
+    {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
+    {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
+    {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
+    {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
+    {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
+    {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
+    {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
+    {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
+    {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
+    {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
+    {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
+    {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
+    {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
+    {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
+    {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
+    {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
+  };
+
+  #if  (defined IA32)
+  static  Elf32_Half running_arch_code=EM_386;
+  #elif   (defined AMD64)
+  static  Elf32_Half running_arch_code=EM_X86_64;
+  #elif  (defined IA64)
+  static  Elf32_Half running_arch_code=EM_IA_64;
+  #elif  (defined __sparc) && (defined _LP64)
+  static  Elf32_Half running_arch_code=EM_SPARCV9;
+  #elif  (defined __sparc) && (!defined _LP64)
+  static  Elf32_Half running_arch_code=EM_SPARC;
+  #elif  (defined __powerpc64__)
+  static  Elf32_Half running_arch_code=EM_PPC64;
+  #elif  (defined __powerpc__)
+  static  Elf32_Half running_arch_code=EM_PPC;
+  #elif  (defined ARM)
+  static  Elf32_Half running_arch_code=EM_ARM;
+  #elif  (defined S390)
+  static  Elf32_Half running_arch_code=EM_S390;
+  #elif  (defined ALPHA)
+  static  Elf32_Half running_arch_code=EM_ALPHA;
+  #elif  (defined MIPSEL)
+  static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
+  #elif  (defined PARISC)
+  static  Elf32_Half running_arch_code=EM_PARISC;
+  #elif  (defined MIPS)
+  static  Elf32_Half running_arch_code=EM_MIPS;
+  #elif  (defined M68K)
+  static  Elf32_Half running_arch_code=EM_68K;
+  #else
+    #error Method os::dll_load requires that one of following is defined:\
+         IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
+  #endif
+
+  // Identify compatability class for VM's architecture and library's architecture
+  // Obtain string descriptions for architectures
+
+  arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
+  int running_arch_index=-1;
+
+  for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
+    if (running_arch_code == arch_array[i].code) {
+      running_arch_index    = i;
+    }
+    if (lib_arch.code == arch_array[i].code) {
+      lib_arch.compat_class = arch_array[i].compat_class;
+      lib_arch.name         = arch_array[i].name;
+    }
+  }
+
+  assert(running_arch_index != -1,
+         "Didn't find running architecture code (running_arch_code) in arch_array");
+  if (running_arch_index == -1) {
+    // Even though running architecture detection failed
+    // we may still continue with reporting dlerror() message
+    return NULL;
+  }
+
+  if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
+    ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
+    return NULL;
+  }
+
+#ifndef S390
+  if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
+    ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
+    return NULL;
+  }
+#endif // !S390
+
+  if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
+    if (lib_arch.name!=NULL) {
+      ::snprintf(diag_msg_buf, diag_msg_max_length-1,
+                 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
+                 lib_arch.name, arch_array[running_arch_index].name);
+    } else {
+      ::snprintf(diag_msg_buf, diag_msg_max_length-1,
+                 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
+                 lib_arch.code,
+                 arch_array[running_arch_index].name);
+    }
+  }
+
+  return NULL;
+#endif // STATIC_BUILD
+}
+#endif // !__APPLE__
+
+void* os::get_default_process_handle() {
+#ifdef __APPLE__
+  // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
+  // to avoid finding unexpected symbols on second (or later)
+  // loads of a library.
+  return (void*)::dlopen(NULL, RTLD_FIRST);
+#else
+  return (void*)::dlopen(NULL, RTLD_LAZY);
+#endif
+}
+
+// XXX: Do we need a lock around this as per Linux?
+void* os::dll_lookup(void* handle, const char* name) {
+  return dlsym(handle, name);
+}
+
+int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
+  outputStream * out = (outputStream *) param;
+  out->print_cr(INTPTR_FORMAT " \t%s", (intptr_t)base_address, name);
+  return 0;
+}
+
+void os::print_dll_info(outputStream *st) {
+  st->print_cr("Dynamic libraries:");
+  if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
+    st->print_cr("Error: Cannot print dynamic libraries.");
+  }
+}
+
+int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
+#ifdef RTLD_DI_LINKMAP
+  Dl_info dli;
+  void *handle;
+  Link_map *map;
+  Link_map *p;
+
+  if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
+      dli.dli_fname == NULL) {
+    return 1;
+  }
+  handle = dlopen(dli.dli_fname, RTLD_LAZY);
+  if (handle == NULL) {
+    return 1;
+  }
+  dlinfo(handle, RTLD_DI_LINKMAP, &map);
+  if (map == NULL) {
+    dlclose(handle);
+    return 1;
+  }
+
+  while (map->l_prev != NULL)
+    map = map->l_prev;
+
+  while (map != NULL) {
+    // Value for top_address is returned as 0 since we don't have any information about module size
+    if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
+      dlclose(handle);
+      return 1;
+    }
+    map = map->l_next;
+  }
+
+  dlclose(handle);
+#elif defined(__APPLE__)
+  for (uint32_t i = 1; i < _dyld_image_count(); i++) {
+    // Value for top_address is returned as 0 since we don't have any information about module size
+    if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
+      return 1;
+    }
+  }
+  return 0;
+#else
+  return 1;
+#endif
+}
+
+void os::get_summary_os_info(char* buf, size_t buflen) {
+  // These buffers are small because we want this to be brief
+  // and not use a lot of stack while generating the hs_err file.
+  char os[100];
+  size_t size = sizeof(os);
+  int mib_kern[] = { CTL_KERN, KERN_OSTYPE };
+  if (sysctl(mib_kern, 2, os, &size, NULL, 0) < 0) {
+#ifdef __APPLE__
+      strncpy(os, "Darwin", sizeof(os));
+#elif __OpenBSD__
+      strncpy(os, "OpenBSD", sizeof(os));
+#else
+      strncpy(os, "BSD", sizeof(os));
+#endif
+  }
+
+  char release[100];
+  size = sizeof(release);
+  int mib_release[] = { CTL_KERN, KERN_OSRELEASE };
+  if (sysctl(mib_release, 2, release, &size, NULL, 0) < 0) {
+      // if error, leave blank
+      strncpy(release, "", sizeof(release));
+  }
+  snprintf(buf, buflen, "%s %s", os, release);
+}
+
+void os::print_os_info_brief(outputStream* st) {
+  os::Posix::print_uname_info(st);
+}
+
+void os::print_os_info(outputStream* st) {
+  st->print("OS:");
+
+  os::Posix::print_uname_info(st);
+
+  os::Posix::print_rlimit_info(st);
+
+  os::Posix::print_load_average(st);
+}
+
+void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
+  // Nothing to do for now.
+}
+
+void os::get_summary_cpu_info(char* buf, size_t buflen) {
+  unsigned int mhz;
+  size_t size = sizeof(mhz);
+  int mib[] = { CTL_HW, HW_CPU_FREQ };
+  if (sysctl(mib, 2, &mhz, &size, NULL, 0) < 0) {
+    mhz = 1;  // looks like an error but can be divided by
+  } else {
+    mhz /= 1000000;  // reported in millions
+  }
+
+  char model[100];
+  size = sizeof(model);
+  int mib_model[] = { CTL_HW, HW_MODEL };
+  if (sysctl(mib_model, 2, model, &size, NULL, 0) < 0) {
+    strncpy(model, cpu_arch, sizeof(model));
+  }
+
+  char machine[100];
+  size = sizeof(machine);
+  int mib_machine[] = { CTL_HW, HW_MACHINE };
+  if (sysctl(mib_machine, 2, machine, &size, NULL, 0) < 0) {
+      strncpy(machine, "", sizeof(machine));
+  }
+
+  snprintf(buf, buflen, "%s %s %d MHz", model, machine, mhz);
+}
+
+void os::print_memory_info(outputStream* st) {
+
+  st->print("Memory:");
+  st->print(" %dk page", os::vm_page_size()>>10);
+
+  st->print(", physical " UINT64_FORMAT "k",
+            os::physical_memory() >> 10);
+  st->print("(" UINT64_FORMAT "k free)",
+            os::available_memory() >> 10);
+  st->cr();
+}
+
+static void print_signal_handler(outputStream* st, int sig,
+                                 char* buf, size_t buflen);
+
+void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
+  st->print_cr("Signal Handlers:");
+  print_signal_handler(st, SIGSEGV, buf, buflen);
+  print_signal_handler(st, SIGBUS , buf, buflen);
+  print_signal_handler(st, SIGFPE , buf, buflen);
+  print_signal_handler(st, SIGPIPE, buf, buflen);
+  print_signal_handler(st, SIGXFSZ, buf, buflen);
+  print_signal_handler(st, SIGILL , buf, buflen);
+  print_signal_handler(st, SR_signum, buf, buflen);
+  print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
+  print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
+  print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
+  print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
+}
+
+static char saved_jvm_path[MAXPATHLEN] = {0};
+
+// Find the full path to the current module, libjvm
+void os::jvm_path(char *buf, jint buflen) {
+  // Error checking.
+  if (buflen < MAXPATHLEN) {
+    assert(false, "must use a large-enough buffer");
+    buf[0] = '\0';
+    return;
+  }
+  // Lazy resolve the path to current module.
+  if (saved_jvm_path[0] != 0) {
+    strcpy(buf, saved_jvm_path);
+    return;
+  }
+
+  char dli_fname[MAXPATHLEN];
+  bool ret = dll_address_to_library_name(
+                                         CAST_FROM_FN_PTR(address, os::jvm_path),
+                                         dli_fname, sizeof(dli_fname), NULL);
+  assert(ret, "cannot locate libjvm");
+  char *rp = NULL;
+  if (ret && dli_fname[0] != '\0') {
+    rp = os::Posix::realpath(dli_fname, buf, buflen);
+  }
+  if (rp == NULL) {
+    return;
+  }
+
+  if (Arguments::sun_java_launcher_is_altjvm()) {
+    // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
+    // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
+    // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
+    // appears at the right place in the string, then assume we are
+    // installed in a JDK and we're done. Otherwise, check for a
+    // JAVA_HOME environment variable and construct a path to the JVM
+    // being overridden.
+
+    const char *p = buf + strlen(buf) - 1;
+    for (int count = 0; p > buf && count < 5; ++count) {
+      for (--p; p > buf && *p != '/'; --p)
+        /* empty */ ;
+    }
+
+    if (strncmp(p, "/jre/lib/", 9) != 0) {
+      // Look for JAVA_HOME in the environment.
+      char* java_home_var = ::getenv("JAVA_HOME");
+      if (java_home_var != NULL && java_home_var[0] != 0) {
+        char* jrelib_p;
+        int len;
+
+        // Check the current module name "libjvm"
+        p = strrchr(buf, '/');
+        assert(strstr(p, "/libjvm") == p, "invalid library name");
+
+        rp = os::Posix::realpath(java_home_var, buf, buflen);
+        if (rp == NULL) {
+          return;
+        }
+
+        // determine if this is a legacy image or modules image
+        // modules image doesn't have "jre" subdirectory
+        len = strlen(buf);
+        assert(len < buflen, "Ran out of buffer space");
+        jrelib_p = buf + len;
+
+        // Add the appropriate library subdir
+        snprintf(jrelib_p, buflen-len, "/jre/lib");
+        if (0 != access(buf, F_OK)) {
+          snprintf(jrelib_p, buflen-len, "/lib");
+        }
+
+        // Add the appropriate client or server subdir
+        len = strlen(buf);
+        jrelib_p = buf + len;
+        snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
+        if (0 != access(buf, F_OK)) {
+          snprintf(jrelib_p, buflen-len, "%s", "");
+        }
+
+        // If the path exists within JAVA_HOME, add the JVM library name
+        // to complete the path to JVM being overridden.  Otherwise fallback
+        // to the path to the current library.
+        if (0 == access(buf, F_OK)) {
+          // Use current module name "libjvm"
+          len = strlen(buf);
+          snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
+        } else {
+          // Fall back to path of current library
+          rp = os::Posix::realpath(dli_fname, buf, buflen);
+          if (rp == NULL) {
+            return;
+          }
+        }
+      }
+    }
+  }
+
+  strncpy(saved_jvm_path, buf, MAXPATHLEN);
+  saved_jvm_path[MAXPATHLEN - 1] = '\0';
+}
+
+void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
+  // no prefix required, not even "_"
+}
+
+void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
+  // no suffix required
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// sun.misc.Signal support
+
+static volatile jint sigint_count = 0;
+
+static void UserHandler(int sig, void *siginfo, void *context) {
+  // 4511530 - sem_post is serialized and handled by the manager thread. When
+  // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
+  // don't want to flood the manager thread with sem_post requests.
+  if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
+    return;
+  }
+
+  // Ctrl-C is pressed during error reporting, likely because the error
+  // handler fails to abort. Let VM die immediately.
+  if (sig == SIGINT && VMError::is_error_reported()) {
+    os::die();
+  }
+
+  os::signal_notify(sig);
+}
+
+void* os::user_handler() {
+  return CAST_FROM_FN_PTR(void*, UserHandler);
+}
+
+extern "C" {
+  typedef void (*sa_handler_t)(int);
+  typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
+}
+
+void* os::signal(int signal_number, void* handler) {
+  struct sigaction sigAct, oldSigAct;
+
+  sigfillset(&(sigAct.sa_mask));
+  sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
+  sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
+
+  if (sigaction(signal_number, &sigAct, &oldSigAct)) {
+    // -1 means registration failed
+    return (void *)-1;
+  }
+
+  return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
+}
+
+void os::signal_raise(int signal_number) {
+  ::raise(signal_number);
+}
+
+// The following code is moved from os.cpp for making this
+// code platform specific, which it is by its very nature.
+
+// Will be modified when max signal is changed to be dynamic
+int os::sigexitnum_pd() {
+  return NSIG;
+}
+
+// a counter for each possible signal value
+static volatile jint pending_signals[NSIG+1] = { 0 };
+
+// Bsd(POSIX) specific hand shaking semaphore.
+#ifdef __APPLE__
+typedef semaphore_t os_semaphore_t;
+
+  #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
+  #define SEM_WAIT(sem)           semaphore_wait(sem)
+  #define SEM_POST(sem)           semaphore_signal(sem)
+  #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
+#else
+typedef sem_t os_semaphore_t;
+
+  #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
+  #define SEM_WAIT(sem)           sem_wait(&sem)
+  #define SEM_POST(sem)           sem_post(&sem)
+  #define SEM_DESTROY(sem)        sem_destroy(&sem)
+#endif
+
+#ifdef __APPLE__
+// OS X doesn't support unamed POSIX semaphores, so the implementation in os_posix.cpp can't be used.
+
+static const char* sem_init_strerror(kern_return_t value) {
+  switch (value) {
+    case KERN_INVALID_ARGUMENT:  return "Invalid argument";
+    case KERN_RESOURCE_SHORTAGE: return "Resource shortage";
+    default:                     return "Unknown";
+  }
+}
+
+OSXSemaphore::OSXSemaphore(uint value) {
+  kern_return_t ret = SEM_INIT(_semaphore, value);
+
+  guarantee(ret == KERN_SUCCESS, "Failed to create semaphore: %s", sem_init_strerror(ret));
+}
+
+OSXSemaphore::~OSXSemaphore() {
+  SEM_DESTROY(_semaphore);
+}
+
+void OSXSemaphore::signal(uint count) {
+  for (uint i = 0; i < count; i++) {
+    kern_return_t ret = SEM_POST(_semaphore);
+
+    assert(ret == KERN_SUCCESS, "Failed to signal semaphore");
+  }
+}
+
+void OSXSemaphore::wait() {
+  kern_return_t ret;
+  while ((ret = SEM_WAIT(_semaphore)) == KERN_ABORTED) {
+    // Semaphore was interrupted. Retry.
+  }
+  assert(ret == KERN_SUCCESS, "Failed to wait on semaphore");
+}
+
+jlong OSXSemaphore::currenttime() {
+  struct timeval tv;
+  gettimeofday(&tv, NULL);
+  return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
+}
+
+bool OSXSemaphore::trywait() {
+  return timedwait(0, 0);
+}
+
+bool OSXSemaphore::timedwait(unsigned int sec, int nsec) {
+  kern_return_t kr = KERN_ABORTED;
+  mach_timespec_t waitspec;
+  waitspec.tv_sec = sec;
+  waitspec.tv_nsec = nsec;
+
+  jlong starttime = currenttime();
+
+  kr = semaphore_timedwait(_semaphore, waitspec);
+  while (kr == KERN_ABORTED) {
+    jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
+
+    jlong current = currenttime();
+    jlong passedtime = current - starttime;
+
+    if (passedtime >= totalwait) {
+      waitspec.tv_sec = 0;
+      waitspec.tv_nsec = 0;
+    } else {
+      jlong waittime = totalwait - (current - starttime);
+      waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
+      waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
+    }
+
+    kr = semaphore_timedwait(_semaphore, waitspec);
+  }
+
+  return kr == KERN_SUCCESS;
+}
+
+#else
+// Use POSIX implementation of semaphores.
+
+struct timespec PosixSemaphore::create_timespec(unsigned int sec, int nsec) {
+  struct timespec ts;
+  unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
+
+  return ts;
+}
+
+#endif // __APPLE__
+
+static os_semaphore_t sig_sem;
+
+#ifdef __APPLE__
+static OSXSemaphore sr_semaphore;
+#else
+static PosixSemaphore sr_semaphore;
+#endif
+
+void os::signal_init_pd() {
+  // Initialize signal structures
+  ::memset((void*)pending_signals, 0, sizeof(pending_signals));
+
+  // Initialize signal semaphore
+  ::SEM_INIT(sig_sem, 0);
+}
+
+void os::signal_notify(int sig) {
+  Atomic::inc(&pending_signals[sig]);
+  ::SEM_POST(sig_sem);
+}
+
+static int check_pending_signals(bool wait) {
+  Atomic::store(0, &sigint_count);
+  for (;;) {
+    for (int i = 0; i < NSIG + 1; i++) {
+      jint n = pending_signals[i];
+      if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
+        return i;
+      }
+    }
+    if (!wait) {
+      return -1;
+    }
+    JavaThread *thread = JavaThread::current();
+    ThreadBlockInVM tbivm(thread);
+
+    bool threadIsSuspended;
+    do {
+      thread->set_suspend_equivalent();
+      // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
+      ::SEM_WAIT(sig_sem);
+
+      // were we externally suspended while we were waiting?
+      threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
+      if (threadIsSuspended) {
+        // The semaphore has been incremented, but while we were waiting
+        // another thread suspended us. We don't want to continue running
+        // while suspended because that would surprise the thread that
+        // suspended us.
+        ::SEM_POST(sig_sem);
+
+        thread->java_suspend_self();
+      }
+    } while (threadIsSuspended);
+  }
+}
+
+int os::signal_lookup() {
+  return check_pending_signals(false);
+}
+
+int os::signal_wait() {
+  return check_pending_signals(true);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Virtual Memory
+
+int os::vm_page_size() {
+  // Seems redundant as all get out
+  assert(os::Bsd::page_size() != -1, "must call os::init");
+  return os::Bsd::page_size();
+}
+
+// Solaris allocates memory by pages.
+int os::vm_allocation_granularity() {
+  assert(os::Bsd::page_size() != -1, "must call os::init");
+  return os::Bsd::page_size();
+}
+
+// Rationale behind this function:
+//  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
+//  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
+//  samples for JITted code. Here we create private executable mapping over the code cache
+//  and then we can use standard (well, almost, as mapping can change) way to provide
+//  info for the reporting script by storing timestamp and location of symbol
+void bsd_wrap_code(char* base, size_t size) {
+  static volatile jint cnt = 0;
+
+  if (!UseOprofile) {
+    return;
+  }
+
+  char buf[PATH_MAX + 1];
+  int num = Atomic::add(1, &cnt);
+
+  snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
+           os::get_temp_directory(), os::current_process_id(), num);
+  unlink(buf);
+
+  int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
+
+  if (fd != -1) {
+    off_t rv = ::lseek(fd, size-2, SEEK_SET);
+    if (rv != (off_t)-1) {
+      if (::write(fd, "", 1) == 1) {
+        mmap(base, size,
+             PROT_READ|PROT_WRITE|PROT_EXEC,
+             MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
+      }
+    }
+    ::close(fd);
+    unlink(buf);
+  }
+}
+
+static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
+                                    int err) {
+  warning("INFO: os::commit_memory(" INTPTR_FORMAT ", " SIZE_FORMAT
+          ", %d) failed; error='%s' (errno=%d)", (intptr_t)addr, size, exec,
+           os::errno_name(err), err);
+}
+
+// NOTE: Bsd kernel does not really reserve the pages for us.
+//       All it does is to check if there are enough free pages
+//       left at the time of mmap(). This could be a potential
+//       problem.
+bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
+  int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
+#ifdef __OpenBSD__
+  // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
+  if (::mprotect(addr, size, prot) == 0) {
+    return true;
+  }
+#else
+  uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
+                                     MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
+  if (res != (uintptr_t) MAP_FAILED) {
+    return true;
+  }
+#endif
+
+  // Warn about any commit errors we see in non-product builds just
+  // in case mmap() doesn't work as described on the man page.
+  NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
+
+  return false;
+}
+
+bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
+                          bool exec) {
+  // alignment_hint is ignored on this OS
+  return pd_commit_memory(addr, size, exec);
+}
+
+void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
+                                  const char* mesg) {
+  assert(mesg != NULL, "mesg must be specified");
+  if (!pd_commit_memory(addr, size, exec)) {
+    // add extra info in product mode for vm_exit_out_of_memory():
+    PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
+    vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
+  }
+}
+
+void os::pd_commit_memory_or_exit(char* addr, size_t size,
+                                  size_t alignment_hint, bool exec,
+                                  const char* mesg) {
+  // alignment_hint is ignored on this OS
+  pd_commit_memory_or_exit(addr, size, exec, mesg);
+}
+
+void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
+}
+
+void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
+  ::madvise(addr, bytes, MADV_DONTNEED);
+}
+
+void os::numa_make_global(char *addr, size_t bytes) {
+}
+
+void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
+}
+
+bool os::numa_topology_changed()   { return false; }
+
+size_t os::numa_get_groups_num() {
+  return 1;
+}
+
+int os::numa_get_group_id() {
+  return 0;
+}
+
+size_t os::numa_get_leaf_groups(int *ids, size_t size) {
+  if (size > 0) {
+    ids[0] = 0;
+    return 1;
+  }
+  return 0;
+}
+
+bool os::get_page_info(char *start, page_info* info) {
+  return false;
+}
+
+char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
+  return end;
+}
+
+
+bool os::pd_uncommit_memory(char* addr, size_t size) {
+#ifdef __OpenBSD__
+  // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
+  return ::mprotect(addr, size, PROT_NONE) == 0;
+#else
+  uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
+                                     MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
+  return res  != (uintptr_t) MAP_FAILED;
+#endif
+}
+
+bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
+  return os::commit_memory(addr, size, !ExecMem);
+}
+
+// If this is a growable mapping, remove the guard pages entirely by
+// munmap()ping them.  If not, just call uncommit_memory().
+bool os::remove_stack_guard_pages(char* addr, size_t size) {
+  return os::uncommit_memory(addr, size);
+}
+
+// If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
+// at 'requested_addr'. If there are existing memory mappings at the same
+// location, however, they will be overwritten. If 'fixed' is false,
+// 'requested_addr' is only treated as a hint, the return value may or
+// may not start from the requested address. Unlike Bsd mmap(), this
+// function returns NULL to indicate failure.
+static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
+  char * addr;
+  int flags;
+
+  flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
+  if (fixed) {
+    assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
+    flags |= MAP_FIXED;
+  }
+
+  // Map reserved/uncommitted pages PROT_NONE so we fail early if we
+  // touch an uncommitted page. Otherwise, the read/write might
+  // succeed if we have enough swap space to back the physical page.
+  addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
+                       flags, -1, 0);
+
+  return addr == MAP_FAILED ? NULL : addr;
+}
+
+static int anon_munmap(char * addr, size_t size) {
+  return ::munmap(addr, size) == 0;
+}
+
+char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
+                            size_t alignment_hint) {
+  return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
+}
+
+bool os::pd_release_memory(char* addr, size_t size) {
+  return anon_munmap(addr, size);
+}
+
+static bool bsd_mprotect(char* addr, size_t size, int prot) {
+  // Bsd wants the mprotect address argument to be page aligned.
+  char* bottom = (char*)align_down((intptr_t)addr, os::Bsd::page_size());
+
+  // According to SUSv3, mprotect() should only be used with mappings
+  // established by mmap(), and mmap() always maps whole pages. Unaligned
+  // 'addr' likely indicates problem in the VM (e.g. trying to change
+  // protection of malloc'ed or statically allocated memory). Check the
+  // caller if you hit this assert.
+  assert(addr == bottom, "sanity check");
+
+  size = align_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
+  return ::mprotect(bottom, size, prot) == 0;
+}
+
+// Set protections specified
+bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
+                        bool is_committed) {
+  unsigned int p = 0;
+  switch (prot) {
+  case MEM_PROT_NONE: p = PROT_NONE; break;
+  case MEM_PROT_READ: p = PROT_READ; break;
+  case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
+  case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
+  default:
+    ShouldNotReachHere();
+  }
+  // is_committed is unused.
+  return bsd_mprotect(addr, bytes, p);
+}
+
+bool os::guard_memory(char* addr, size_t size) {
+  return bsd_mprotect(addr, size, PROT_NONE);
+}
+
+bool os::unguard_memory(char* addr, size_t size) {
+  return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
+}
+
+bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
+  return false;
+}
+
+// Large page support
+
+static size_t _large_page_size = 0;
+
+void os::large_page_init() {
+}
+
+
+char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
+  fatal("This code is not used or maintained.");
+
+  // "exec" is passed in but not used.  Creating the shared image for
+  // the code cache doesn't have an SHM_X executable permission to check.
+  assert(UseLargePages && UseSHM, "only for SHM large pages");
+
+  key_t key = IPC_PRIVATE;
+  char *addr;
+
+  bool warn_on_failure = UseLargePages &&
+                         (!FLAG_IS_DEFAULT(UseLargePages) ||
+                          !FLAG_IS_DEFAULT(LargePageSizeInBytes));
+
+  // Create a large shared memory region to attach to based on size.
+  // Currently, size is the total size of the heap
+  int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
+  if (shmid == -1) {
+    // Possible reasons for shmget failure:
+    // 1. shmmax is too small for Java heap.
+    //    > check shmmax value: cat /proc/sys/kernel/shmmax
+    //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
+    // 2. not enough large page memory.
+    //    > check available large pages: cat /proc/meminfo
+    //    > increase amount of large pages:
+    //          echo new_value > /proc/sys/vm/nr_hugepages
+    //      Note 1: different Bsd may use different name for this property,
+    //            e.g. on Redhat AS-3 it is "hugetlb_pool".
+    //      Note 2: it's possible there's enough physical memory available but
+    //            they are so fragmented after a long run that they can't
+    //            coalesce into large pages. Try to reserve large pages when
+    //            the system is still "fresh".
+    if (warn_on_failure) {
+      warning("Failed to reserve shared memory (errno = %d).", errno);
+    }
+    return NULL;
+  }
+
+  // attach to the region
+  addr = (char*)shmat(shmid, req_addr, 0);
+  int err = errno;
+
+  // Remove shmid. If shmat() is successful, the actual shared memory segment
+  // will be deleted when it's detached by shmdt() or when the process
+  // terminates. If shmat() is not successful this will remove the shared
+  // segment immediately.
+  shmctl(shmid, IPC_RMID, NULL);
+
+  if ((intptr_t)addr == -1) {
+    if (warn_on_failure) {
+      warning("Failed to attach shared memory (errno = %d).", err);
+    }
+    return NULL;
+  }
+
+  // The memory is committed
+  MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
+
+  return addr;
+}
+
+bool os::release_memory_special(char* base, size_t bytes) {
+  if (MemTracker::tracking_level() > NMT_minimal) {
+    Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
+    // detaching the SHM segment will also delete it, see reserve_memory_special()
+    int rslt = shmdt(base);
+    if (rslt == 0) {
+      tkr.record((address)base, bytes);
+      return true;
+    } else {
+      return false;
+    }
+  } else {
+    return shmdt(base) == 0;
+  }
+}
+
+size_t os::large_page_size() {
+  return _large_page_size;
+}
+
+// HugeTLBFS allows application to commit large page memory on demand;
+// with SysV SHM the entire memory region must be allocated as shared
+// memory.
+bool os::can_commit_large_page_memory() {
+  return UseHugeTLBFS;
+}
+
+bool os::can_execute_large_page_memory() {
+  return UseHugeTLBFS;
+}
+
+// Reserve memory at an arbitrary address, only if that area is
+// available (and not reserved for something else).
+
+char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
+  const int max_tries = 10;
+  char* base[max_tries];
+  size_t size[max_tries];
+  const size_t gap = 0x000000;
+
+  // Assert only that the size is a multiple of the page size, since
+  // that's all that mmap requires, and since that's all we really know
+  // about at this low abstraction level.  If we need higher alignment,
+  // we can either pass an alignment to this method or verify alignment
+  // in one of the methods further up the call chain.  See bug 5044738.
+  assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
+
+  // Repeatedly allocate blocks until the block is allocated at the
+  // right spot.
+
+  // Bsd mmap allows caller to pass an address as hint; give it a try first,
+  // if kernel honors the hint then we can return immediately.
+  char * addr = anon_mmap(requested_addr, bytes, false);
+  if (addr == requested_addr) {
+    return requested_addr;
+  }
+
+  if (addr != NULL) {
+    // mmap() is successful but it fails to reserve at the requested address
+    anon_munmap(addr, bytes);
+  }
+
+  int i;
+  for (i = 0; i < max_tries; ++i) {
+    base[i] = reserve_memory(bytes);
+
+    if (base[i] != NULL) {
+      // Is this the block we wanted?
+      if (base[i] == requested_addr) {
+        size[i] = bytes;
+        break;
+      }
+
+      // Does this overlap the block we wanted? Give back the overlapped
+      // parts and try again.
+
+      size_t top_overlap = requested_addr + (bytes + gap) - base[i];
+      if (top_overlap >= 0 && top_overlap < bytes) {
+        unmap_memory(base[i], top_overlap);
+        base[i] += top_overlap;
+        size[i] = bytes - top_overlap;
+      } else {
+        size_t bottom_overlap = base[i] + bytes - requested_addr;
+        if (bottom_overlap >= 0 && bottom_overlap < bytes) {
+          unmap_memory(requested_addr, bottom_overlap);
+          size[i] = bytes - bottom_overlap;
+        } else {
+          size[i] = bytes;
+        }
+      }
+    }
+  }
+
+  // Give back the unused reserved pieces.
+
+  for (int j = 0; j < i; ++j) {
+    if (base[j] != NULL) {
+      unmap_memory(base[j], size[j]);
+    }
+  }
+
+  if (i < max_tries) {
+    return requested_addr;
+  } else {
+    return NULL;
+  }
+}
+
+size_t os::read(int fd, void *buf, unsigned int nBytes) {
+  RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
+}
+
+size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
+  RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset));
+}
+
+void os::naked_short_sleep(jlong ms) {
+  struct timespec req;
+
+  assert(ms < 1000, "Un-interruptable sleep, short time use only");
+  req.tv_sec = 0;
+  if (ms > 0) {
+    req.tv_nsec = (ms % 1000) * 1000000;
+  } else {
+    req.tv_nsec = 1;
+  }
+
+  nanosleep(&req, NULL);
+
+  return;
+}
+
+// Sleep forever; naked call to OS-specific sleep; use with CAUTION
+void os::infinite_sleep() {
+  while (true) {    // sleep forever ...
+    ::sleep(100);   // ... 100 seconds at a time
+  }
+}
+
+// Used to convert frequent JVM_Yield() to nops
+bool os::dont_yield() {
+  return DontYieldALot;
+}
+
+void os::naked_yield() {
+  sched_yield();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// thread priority support
+
+// Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
+// only supports dynamic priority, static priority must be zero. For real-time
+// applications, Bsd supports SCHED_RR which allows static priority (1-99).
+// However, for large multi-threaded applications, SCHED_RR is not only slower
+// than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
+// of 5 runs - Sep 2005).
+//
+// The following code actually changes the niceness of kernel-thread/LWP. It
+// has an assumption that setpriority() only modifies one kernel-thread/LWP,
+// not the entire user process, and user level threads are 1:1 mapped to kernel
+// threads. It has always been the case, but could change in the future. For
+// this reason, the code should not be used as default (ThreadPriorityPolicy=0).
+// It is only used when ThreadPriorityPolicy=1 and requires root privilege.
+
+#if !defined(__APPLE__)
+int os::java_to_os_priority[CriticalPriority + 1] = {
+  19,              // 0 Entry should never be used
+
+   0,              // 1 MinPriority
+   3,              // 2
+   6,              // 3
+
+  10,              // 4
+  15,              // 5 NormPriority
+  18,              // 6
+
+  21,              // 7
+  25,              // 8
+  28,              // 9 NearMaxPriority
+
+  31,              // 10 MaxPriority
+
+  31               // 11 CriticalPriority
+};
+#else
+// Using Mach high-level priority assignments
+int os::java_to_os_priority[CriticalPriority + 1] = {
+   0,              // 0 Entry should never be used (MINPRI_USER)
+
+  27,              // 1 MinPriority
+  28,              // 2
+  29,              // 3
+
+  30,              // 4
+  31,              // 5 NormPriority (BASEPRI_DEFAULT)
+  32,              // 6
+
+  33,              // 7
+  34,              // 8
+  35,              // 9 NearMaxPriority
+
+  36,              // 10 MaxPriority
+
+  36               // 11 CriticalPriority
+};
+#endif
+
+static int prio_init() {
+  if (ThreadPriorityPolicy == 1) {
+    // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
+    // if effective uid is not root. Perhaps, a more elegant way of doing
+    // this is to test CAP_SYS_NICE capability, but that will require libcap.so
+    if (geteuid() != 0) {
+      if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
+        warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
+      }
+      ThreadPriorityPolicy = 0;
+    }
+  }
+  if (UseCriticalJavaThreadPriority) {
+    os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
+  }
+  return 0;
+}
+
+OSReturn os::set_native_priority(Thread* thread, int newpri) {
+  if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
+
+#ifdef __OpenBSD__
+  // OpenBSD pthread_setprio starves low priority threads
+  return OS_OK;
+#elif defined(__FreeBSD__)
+  int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
+#elif defined(__APPLE__) || defined(__NetBSD__)
+  struct sched_param sp;
+  int policy;
+  pthread_t self = pthread_self();
+
+  if (pthread_getschedparam(self, &policy, &sp) != 0) {
+    return OS_ERR;
+  }
+
+  sp.sched_priority = newpri;
+  if (pthread_setschedparam(self, policy, &sp) != 0) {
+    return OS_ERR;
+  }
+
+  return OS_OK;
+#else
+  int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
+  return (ret == 0) ? OS_OK : OS_ERR;
+#endif
+}
+
+OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
+  if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
+    *priority_ptr = java_to_os_priority[NormPriority];
+    return OS_OK;
+  }
+
+  errno = 0;
+#if defined(__OpenBSD__) || defined(__FreeBSD__)
+  *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
+#elif defined(__APPLE__) || defined(__NetBSD__)
+  int policy;
+  struct sched_param sp;
+
+  pthread_getschedparam(pthread_self(), &policy, &sp);
+  *priority_ptr = sp.sched_priority;
+#else
+  *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
+#endif
+  return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
+}
+
+// Hint to the underlying OS that a task switch would not be good.
+// Void return because it's a hint and can fail.
+void os::hint_no_preempt() {}
+
+////////////////////////////////////////////////////////////////////////////////
+// suspend/resume support
+
+//  The low-level signal-based suspend/resume support is a remnant from the
+//  old VM-suspension that used to be for java-suspension, safepoints etc,
+//  within hotspot. Currently used by JFR's OSThreadSampler
+//
+//  The remaining code is greatly simplified from the more general suspension
+//  code that used to be used.
+//
+//  The protocol is quite simple:
+//  - suspend:
+//      - sends a signal to the target thread
+//      - polls the suspend state of the osthread using a yield loop
+//      - target thread signal handler (SR_handler) sets suspend state
+//        and blocks in sigsuspend until continued
+//  - resume:
+//      - sets target osthread state to continue
+//      - sends signal to end the sigsuspend loop in the SR_handler
+//
+//  Note that the SR_lock plays no role in this suspend/resume protocol,
+//  but is checked for NULL in SR_handler as a thread termination indicator.
+//  The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
+//
+//  Note that resume_clear_context() and suspend_save_context() are needed
+//  by SR_handler(), so that fetch_frame_from_ucontext() works,
+//  which in part is used by:
+//    - Forte Analyzer: AsyncGetCallTrace()
+//    - StackBanging: get_frame_at_stack_banging_point()
+
+static void resume_clear_context(OSThread *osthread) {
+  osthread->set_ucontext(NULL);
+  osthread->set_siginfo(NULL);
+}
+
+static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
+  osthread->set_ucontext(context);
+  osthread->set_siginfo(siginfo);
+}
+
+// Handler function invoked when a thread's execution is suspended or
+// resumed. We have to be careful that only async-safe functions are
+// called here (Note: most pthread functions are not async safe and
+// should be avoided.)
+//
+// Note: sigwait() is a more natural fit than sigsuspend() from an
+// interface point of view, but sigwait() prevents the signal hander
+// from being run. libpthread would get very confused by not having
+// its signal handlers run and prevents sigwait()'s use with the
+// mutex granting granting signal.
+//
+// Currently only ever called on the VMThread or JavaThread
+//
+static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
+  // Save and restore errno to avoid confusing native code with EINTR
+  // after sigsuspend.
+  int old_errno = errno;
+
+  Thread* thread = Thread::current_or_null_safe();
+  assert(thread != NULL, "Missing current thread in SR_handler");
+
+  // On some systems we have seen signal delivery get "stuck" until the signal
+  // mask is changed as part of thread termination. Check that the current thread
+  // has not already terminated (via SR_lock()) - else the following assertion
+  // will fail because the thread is no longer a JavaThread as the ~JavaThread
+  // destructor has completed.
+
+  if (thread->SR_lock() == NULL) {
+    return;
+  }
+
+  assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
+
+  OSThread* osthread = thread->osthread();
+
+  os::SuspendResume::State current = osthread->sr.state();
+  if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
+    suspend_save_context(osthread, siginfo, context);
+
+    // attempt to switch the state, we assume we had a SUSPEND_REQUEST
+    os::SuspendResume::State state = osthread->sr.suspended();
+    if (state == os::SuspendResume::SR_SUSPENDED) {
+      sigset_t suspend_set;  // signals for sigsuspend()
+
+      // get current set of blocked signals and unblock resume signal
+      pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
+      sigdelset(&suspend_set, SR_signum);
+
+      sr_semaphore.signal();
+      // wait here until we are resumed
+      while (1) {
+        sigsuspend(&suspend_set);
+
+        os::SuspendResume::State result = osthread->sr.running();
+        if (result == os::SuspendResume::SR_RUNNING) {
+          sr_semaphore.signal();
+          break;
+        } else if (result != os::SuspendResume::SR_SUSPENDED) {
+          ShouldNotReachHere();
+        }
+      }
+
+    } else if (state == os::SuspendResume::SR_RUNNING) {
+      // request was cancelled, continue
+    } else {
+      ShouldNotReachHere();
+    }
+
+    resume_clear_context(osthread);
+  } else if (current == os::SuspendResume::SR_RUNNING) {
+    // request was cancelled, continue
+  } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
+    // ignore
+  } else {
+    // ignore
+  }
+
+  errno = old_errno;
+}
+
+
+static int SR_initialize() {
+  struct sigaction act;
+  char *s;
+  // Get signal number to use for suspend/resume
+  if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
+    int sig = ::strtol(s, 0, 10);
+    if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
+        sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
+      SR_signum = sig;
+    } else {
+      warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
+              sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
+    }
+  }
+
+  assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
+         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
+
+  sigemptyset(&SR_sigset);
+  sigaddset(&SR_sigset, SR_signum);
+
+  // Set up signal handler for suspend/resume
+  act.sa_flags = SA_RESTART|SA_SIGINFO;
+  act.sa_handler = (void (*)(int)) SR_handler;
+
+  // SR_signum is blocked by default.
+  // 4528190 - We also need to block pthread restart signal (32 on all
+  // supported Bsd platforms). Note that BsdThreads need to block
+  // this signal for all threads to work properly. So we don't have
+  // to use hard-coded signal number when setting up the mask.
+  pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
+
+  if (sigaction(SR_signum, &act, 0) == -1) {
+    return -1;
+  }
+
+  // Save signal flag
+  os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
+  return 0;
+}
+
+static int sr_notify(OSThread* osthread) {
+  int status = pthread_kill(osthread->pthread_id(), SR_signum);
+  assert_status(status == 0, status, "pthread_kill");
+  return status;
+}
+
+// "Randomly" selected value for how long we want to spin
+// before bailing out on suspending a thread, also how often
+// we send a signal to a thread we want to resume
+static const int RANDOMLY_LARGE_INTEGER = 1000000;
+static const int RANDOMLY_LARGE_INTEGER2 = 100;
+
+// returns true on success and false on error - really an error is fatal
+// but this seems the normal response to library errors
+static bool do_suspend(OSThread* osthread) {
+  assert(osthread->sr.is_running(), "thread should be running");
+  assert(!sr_semaphore.trywait(), "semaphore has invalid state");
+
+  // mark as suspended and send signal
+  if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
+    // failed to switch, state wasn't running?
+    ShouldNotReachHere();
+    return false;
+  }
+
+  if (sr_notify(osthread) != 0) {
+    ShouldNotReachHere();
+  }
+
+  // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
+  while (true) {
+    if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
+      break;
+    } else {
+      // timeout
+      os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
+      if (cancelled == os::SuspendResume::SR_RUNNING) {
+        return false;
+      } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
+        // make sure that we consume the signal on the semaphore as well
+        sr_semaphore.wait();
+        break;
+      } else {
+        ShouldNotReachHere();
+        return false;
+      }
+    }
+  }
+
+  guarantee(osthread->sr.is_suspended(), "Must be suspended");
+  return true;
+}
+
+static void do_resume(OSThread* osthread) {
+  assert(osthread->sr.is_suspended(), "thread should be suspended");
+  assert(!sr_semaphore.trywait(), "invalid semaphore state");
+
+  if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
+    // failed to switch to WAKEUP_REQUEST
+    ShouldNotReachHere();
+    return;
+  }
+
+  while (true) {
+    if (sr_notify(osthread) == 0) {
+      if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
+        if (osthread->sr.is_running()) {
+          return;
+        }
+      }
+    } else {
+      ShouldNotReachHere();
+    }
+  }
+
+  guarantee(osthread->sr.is_running(), "Must be running!");
+}
+
+///////////////////////////////////////////////////////////////////////////////////
+// signal handling (except suspend/resume)
+
+// This routine may be used by user applications as a "hook" to catch signals.
+// The user-defined signal handler must pass unrecognized signals to this
+// routine, and if it returns true (non-zero), then the signal handler must
+// return immediately.  If the flag "abort_if_unrecognized" is true, then this
+// routine will never retun false (zero), but instead will execute a VM panic
+// routine kill the process.
+//
+// If this routine returns false, it is OK to call it again.  This allows
+// the user-defined signal handler to perform checks either before or after
+// the VM performs its own checks.  Naturally, the user code would be making
+// a serious error if it tried to handle an exception (such as a null check
+// or breakpoint) that the VM was generating for its own correct operation.
+//
+// This routine may recognize any of the following kinds of signals:
+//    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
+// It should be consulted by handlers for any of those signals.
+//
+// The caller of this routine must pass in the three arguments supplied
+// to the function referred to in the "sa_sigaction" (not the "sa_handler")
+// field of the structure passed to sigaction().  This routine assumes that
+// the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
+//
+// Note that the VM will print warnings if it detects conflicting signal
+// handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
+//
+extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
+                                               void* ucontext,
+                                               int abort_if_unrecognized);
+
+void signalHandler(int sig, siginfo_t* info, void* uc) {
+  assert(info != NULL && uc != NULL, "it must be old kernel");
+  int orig_errno = errno;  // Preserve errno value over signal handler.
+  JVM_handle_bsd_signal(sig, info, uc, true);
+  errno = orig_errno;
+}
+
+
+// This boolean allows users to forward their own non-matching signals
+// to JVM_handle_bsd_signal, harmlessly.
+bool os::Bsd::signal_handlers_are_installed = false;
+
+// For signal-chaining
+struct sigaction sigact[NSIG];
+uint32_t sigs = 0;
+#if (32 < NSIG-1)
+#error "Not all signals can be encoded in sigs. Adapt its type!"
+#endif
+bool os::Bsd::libjsig_is_loaded = false;
+typedef struct sigaction *(*get_signal_t)(int);
+get_signal_t os::Bsd::get_signal_action = NULL;
+
+struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
+  struct sigaction *actp = NULL;
+
+  if (libjsig_is_loaded) {
+    // Retrieve the old signal handler from libjsig
+    actp = (*get_signal_action)(sig);
+  }
+  if (actp == NULL) {
+    // Retrieve the preinstalled signal handler from jvm
+    actp = get_preinstalled_handler(sig);
+  }
+
+  return actp;
+}
+
+static bool call_chained_handler(struct sigaction *actp, int sig,
+                                 siginfo_t *siginfo, void *context) {
+  // Call the old signal handler
+  if (actp->sa_handler == SIG_DFL) {
+    // It's more reasonable to let jvm treat it as an unexpected exception
+    // instead of taking the default action.
+    return false;
+  } else if (actp->sa_handler != SIG_IGN) {
+    if ((actp->sa_flags & SA_NODEFER) == 0) {
+      // automaticlly block the signal
+      sigaddset(&(actp->sa_mask), sig);
+    }
+
+    sa_handler_t hand;
+    sa_sigaction_t sa;
+    bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
+    // retrieve the chained handler
+    if (siginfo_flag_set) {
+      sa = actp->sa_sigaction;
+    } else {
+      hand = actp->sa_handler;
+    }
+
+    if ((actp->sa_flags & SA_RESETHAND) != 0) {
+      actp->sa_handler = SIG_DFL;
+    }
+
+    // try to honor the signal mask
+    sigset_t oset;
+    pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
+
+    // call into the chained handler
+    if (siginfo_flag_set) {
+      (*sa)(sig, siginfo, context);
+    } else {
+      (*hand)(sig);
+    }
+
+    // restore the signal mask
+    pthread_sigmask(SIG_SETMASK, &oset, 0);
+  }
+  // Tell jvm's signal handler the signal is taken care of.
+  return true;
+}
+
+bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
+  bool chained = false;
+  // signal-chaining
+  if (UseSignalChaining) {
+    struct sigaction *actp = get_chained_signal_action(sig);
+    if (actp != NULL) {
+      chained = call_chained_handler(actp, sig, siginfo, context);
+    }
+  }
+  return chained;
+}
+
+struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
+  if ((((uint32_t)1 << (sig-1)) & sigs) != 0) {
+    return &sigact[sig];
+  }
+  return NULL;
+}
+
+void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
+  assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
+  sigact[sig] = oldAct;
+  sigs |= (uint32_t)1 << (sig-1);
+}
+
+// for diagnostic
+int sigflags[NSIG];
+
+int os::Bsd::get_our_sigflags(int sig) {
+  assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
+  return sigflags[sig];
+}
+
+void os::Bsd::set_our_sigflags(int sig, int flags) {
+  assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
+  if (sig > 0 && sig < NSIG) {
+    sigflags[sig] = flags;
+  }
+}
+
+void os::Bsd::set_signal_handler(int sig, bool set_installed) {
+  // Check for overwrite.
+  struct sigaction oldAct;
+  sigaction(sig, (struct sigaction*)NULL, &oldAct);
+
+  void* oldhand = oldAct.sa_sigaction
+                ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
+                : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
+  if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
+      oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
+      oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
+    if (AllowUserSignalHandlers || !set_installed) {
+      // Do not overwrite; user takes responsibility to forward to us.
+      return;
+    } else if (UseSignalChaining) {
+      // save the old handler in jvm
+      save_preinstalled_handler(sig, oldAct);
+      // libjsig also interposes the sigaction() call below and saves the
+      // old sigaction on it own.
+    } else {
+      fatal("Encountered unexpected pre-existing sigaction handler "
+            "%#lx for signal %d.", (long)oldhand, sig);
+    }
+  }
+
+  struct sigaction sigAct;
+  sigfillset(&(sigAct.sa_mask));
+  sigAct.sa_handler = SIG_DFL;
+  if (!set_installed) {
+    sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
+  } else {
+    sigAct.sa_sigaction = signalHandler;
+    sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
+  }
+#ifdef __APPLE__
+  // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
+  // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
+  // if the signal handler declares it will handle it on alternate stack.
+  // Notice we only declare we will handle it on alt stack, but we are not
+  // actually going to use real alt stack - this is just a workaround.
+  // Please see ux_exception.c, method catch_mach_exception_raise for details
+  // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
+  if (sig == SIGSEGV) {
+    sigAct.sa_flags |= SA_ONSTACK;
+  }
+#endif
+
+  // Save flags, which are set by ours
+  assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
+  sigflags[sig] = sigAct.sa_flags;
+
+  int ret = sigaction(sig, &sigAct, &oldAct);
+  assert(ret == 0, "check");
+
+  void* oldhand2  = oldAct.sa_sigaction
+                  ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
+                  : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
+  assert(oldhand2 == oldhand, "no concurrent signal handler installation");
+}
+
+// install signal handlers for signals that HotSpot needs to
+// handle in order to support Java-level exception handling.
+
+void os::Bsd::install_signal_handlers() {
+  if (!signal_handlers_are_installed) {
+    signal_handlers_are_installed = true;
+
+    // signal-chaining
+    typedef void (*signal_setting_t)();
+    signal_setting_t begin_signal_setting = NULL;
+    signal_setting_t end_signal_setting = NULL;
+    begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
+                                          dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
+    if (begin_signal_setting != NULL) {
+      end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
+                                          dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
+      get_signal_action = CAST_TO_FN_PTR(get_signal_t,
+                                         dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
+      libjsig_is_loaded = true;
+      assert(UseSignalChaining, "should enable signal-chaining");
+    }
+    if (libjsig_is_loaded) {
+      // Tell libjsig jvm is setting signal handlers
+      (*begin_signal_setting)();
+    }
+
+    set_signal_handler(SIGSEGV, true);
+    set_signal_handler(SIGPIPE, true);
+    set_signal_handler(SIGBUS, true);
+    set_signal_handler(SIGILL, true);
+    set_signal_handler(SIGFPE, true);
+    set_signal_handler(SIGXFSZ, true);
+
+#if defined(__APPLE__)
+    // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
+    // signals caught and handled by the JVM. To work around this, we reset the mach task
+    // signal handler that's placed on our process by CrashReporter. This disables
+    // CrashReporter-based reporting.
+    //
+    // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
+    // on caught fatal signals.
+    //
+    // Additionally, gdb installs both standard BSD signal handlers, and mach exception
+    // handlers. By replacing the existing task exception handler, we disable gdb's mach
+    // exception handling, while leaving the standard BSD signal handlers functional.
+    kern_return_t kr;
+    kr = task_set_exception_ports(mach_task_self(),
+                                  EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
+                                  MACH_PORT_NULL,
+                                  EXCEPTION_STATE_IDENTITY,
+                                  MACHINE_THREAD_STATE);
+
+    assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
+#endif
+
+    if (libjsig_is_loaded) {
+      // Tell libjsig jvm finishes setting signal handlers
+      (*end_signal_setting)();
+    }
+
+    // We don't activate signal checker if libjsig is in place, we trust ourselves
+    // and if UserSignalHandler is installed all bets are off
+    if (CheckJNICalls) {
+      if (libjsig_is_loaded) {
+        if (PrintJNIResolving) {
+          tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
+        }
+        check_signals = false;
+      }
+      if (AllowUserSignalHandlers) {
+        if (PrintJNIResolving) {
+          tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
+        }
+        check_signals = false;
+      }
+    }
+  }
+}
+
+
+/////
+// glibc on Bsd platform uses non-documented flag
+// to indicate, that some special sort of signal
+// trampoline is used.
+// We will never set this flag, and we should
+// ignore this flag in our diagnostic
+#ifdef SIGNIFICANT_SIGNAL_MASK
+  #undef SIGNIFICANT_SIGNAL_MASK
+#endif
+#define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
+
+static const char* get_signal_handler_name(address handler,
+                                           char* buf, int buflen) {
+  int offset;
+  bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
+  if (found) {
+    // skip directory names
+    const char *p1, *p2;
+    p1 = buf;
+    size_t len = strlen(os::file_separator());
+    while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
+    jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
+  } else {
+    jio_snprintf(buf, buflen, PTR_FORMAT, handler);
+  }
+  return buf;
+}
+
+static void print_signal_handler(outputStream* st, int sig,
+                                 char* buf, size_t buflen) {
+  struct sigaction sa;
+
+  sigaction(sig, NULL, &sa);
+
+  // See comment for SIGNIFICANT_SIGNAL_MASK define
+  sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
+
+  st->print("%s: ", os::exception_name(sig, buf, buflen));
+
+  address handler = (sa.sa_flags & SA_SIGINFO)
+    ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
+    : CAST_FROM_FN_PTR(address, sa.sa_handler);
+
+  if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
+    st->print("SIG_DFL");
+  } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
+    st->print("SIG_IGN");
+  } else {
+    st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
+  }
+
+  st->print(", sa_mask[0]=");
+  os::Posix::print_signal_set_short(st, &sa.sa_mask);
+
+  address rh = VMError::get_resetted_sighandler(sig);
+  // May be, handler was resetted by VMError?
+  if (rh != NULL) {
+    handler = rh;
+    sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
+  }
+
+  st->print(", sa_flags=");
+  os::Posix::print_sa_flags(st, sa.sa_flags);
+
+  // Check: is it our handler?
+  if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
+      handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
+    // It is our signal handler
+    // check for flags, reset system-used one!
+    if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
+      st->print(
+                ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
+                os::Bsd::get_our_sigflags(sig));
+    }
+  }
+  st->cr();
+}
+
+
+#define DO_SIGNAL_CHECK(sig)                      \
+  do {                                            \
+    if (!sigismember(&check_signal_done, sig)) {  \
+      os::Bsd::check_signal_handler(sig);         \
+    }                                             \
+  } while (0)
+
+// This method is a periodic task to check for misbehaving JNI applications
+// under CheckJNI, we can add any periodic checks here
+
+void os::run_periodic_checks() {
+
+  if (check_signals == false) return;
+
+  // SEGV and BUS if overridden could potentially prevent
+  // generation of hs*.log in the event of a crash, debugging
+  // such a case can be very challenging, so we absolutely
+  // check the following for a good measure:
+  DO_SIGNAL_CHECK(SIGSEGV);
+  DO_SIGNAL_CHECK(SIGILL);
+  DO_SIGNAL_CHECK(SIGFPE);
+  DO_SIGNAL_CHECK(SIGBUS);
+  DO_SIGNAL_CHECK(SIGPIPE);
+  DO_SIGNAL_CHECK(SIGXFSZ);
+
+
+  // ReduceSignalUsage allows the user to override these handlers
+  // see comments at the very top and jvm_solaris.h
+  if (!ReduceSignalUsage) {
+    DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
+    DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
+    DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
+    DO_SIGNAL_CHECK(BREAK_SIGNAL);
+  }
+
+  DO_SIGNAL_CHECK(SR_signum);
+}
+
+typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
+
+static os_sigaction_t os_sigaction = NULL;
+
+void os::Bsd::check_signal_handler(int sig) {
+  char buf[O_BUFLEN];
+  address jvmHandler = NULL;
+
+
+  struct sigaction act;
+  if (os_sigaction == NULL) {
+    // only trust the default sigaction, in case it has been interposed
+    os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
+    if (os_sigaction == NULL) return;
+  }
+
+  os_sigaction(sig, (struct sigaction*)NULL, &act);
+
+
+  act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
+
+  address thisHandler = (act.sa_flags & SA_SIGINFO)
+    ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
+    : CAST_FROM_FN_PTR(address, act.sa_handler);
+
+
+  switch (sig) {
+  case SIGSEGV:
+  case SIGBUS:
+  case SIGFPE:
+  case SIGPIPE:
+  case SIGILL:
+  case SIGXFSZ:
+    jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
+    break;
+
+  case SHUTDOWN1_SIGNAL:
+  case SHUTDOWN2_SIGNAL:
+  case SHUTDOWN3_SIGNAL:
+  case BREAK_SIGNAL:
+    jvmHandler = (address)user_handler();
+    break;
+
+  default:
+    if (sig == SR_signum) {
+      jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
+    } else {
+      return;
+    }
+    break;
+  }
+
+  if (thisHandler != jvmHandler) {
+    tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
+    tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
+    tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
+    // No need to check this sig any longer
+    sigaddset(&check_signal_done, sig);
+    // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
+    if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
+      tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
+                    exception_name(sig, buf, O_BUFLEN));
+    }
+  } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
+    tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
+    tty->print("expected:");
+    os::Posix::print_sa_flags(tty, os::Bsd::get_our_sigflags(sig));
+    tty->cr();
+    tty->print("  found:");
+    os::Posix::print_sa_flags(tty, act.sa_flags);
+    tty->cr();
+    // No need to check this sig any longer
+    sigaddset(&check_signal_done, sig);
+  }
+
+  // Dump all the signal
+  if (sigismember(&check_signal_done, sig)) {
+    print_signal_handlers(tty, buf, O_BUFLEN);
+  }
+}
+
+extern void report_error(char* file_name, int line_no, char* title,
+                         char* format, ...);
+
+// this is called _before_ the most of global arguments have been parsed
+void os::init(void) {
+  char dummy;   // used to get a guess on initial stack address
+
+  // With BsdThreads the JavaMain thread pid (primordial thread)
+  // is different than the pid of the java launcher thread.
+  // So, on Bsd, the launcher thread pid is passed to the VM
+  // via the sun.java.launcher.pid property.
+  // Use this property instead of getpid() if it was correctly passed.
+  // See bug 6351349.
+  pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
+
+  _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
+
+  clock_tics_per_sec = CLK_TCK;
+
+  init_random(1234567);
+
+  ThreadCritical::initialize();
+
+  Bsd::set_page_size(getpagesize());
+  if (Bsd::page_size() == -1) {
+    fatal("os_bsd.cpp: os::init: sysconf failed (%s)", os::strerror(errno));
+  }
+  init_page_sizes((size_t) Bsd::page_size());
+
+  Bsd::initialize_system_info();
+
+  // main_thread points to the aboriginal thread
+  Bsd::_main_thread = pthread_self();
+
+  Bsd::clock_init();
+  initial_time_count = javaTimeNanos();
+
+#ifdef __APPLE__
+  // XXXDARWIN
+  // Work around the unaligned VM callbacks in hotspot's
+  // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
+  // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
+  // alignment when doing symbol lookup. To work around this, we force early
+  // binding of all symbols now, thus binding when alignment is known-good.
+  _dyld_bind_fully_image_containing_address((const void *) &os::init);
+#endif
+
+  os::Posix::init();
+}
+
+// To install functions for atexit system call
+extern "C" {
+  static void perfMemory_exit_helper() {
+    perfMemory_exit();
+  }
+}
+
+// this is called _after_ the global arguments have been parsed
+jint os::init_2(void) {
+
+  os::Posix::init_2();
+
+  // Allocate a single page and mark it as readable for safepoint polling
+  address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+  guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page");
+
+  os::set_polling_page(polling_page);
+  log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
+
+  if (!UseMembar) {
+    address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+    guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
+    os::set_memory_serialize_page(mem_serialize_page);
+    log_info(os)("Memory Serialize Page address: " INTPTR_FORMAT, p2i(mem_serialize_page));
+  }
+
+  // initialize suspend/resume support - must do this before signal_sets_init()
+  if (SR_initialize() != 0) {
+    perror("SR_initialize failed");
+    return JNI_ERR;
+  }
+
+  Bsd::signal_sets_init();
+  Bsd::install_signal_handlers();
+
+  // Check and sets minimum stack sizes against command line options
+  if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
+    return JNI_ERR;
+  }
+
+  if (MaxFDLimit) {
+    // set the number of file descriptors to max. print out error
+    // if getrlimit/setrlimit fails but continue regardless.
+    struct rlimit nbr_files;
+    int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
+    if (status != 0) {
+      log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
+    } else {
+      nbr_files.rlim_cur = nbr_files.rlim_max;
+
+#ifdef __APPLE__
+      // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
+      // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
+      // be used instead
+      nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
+#endif
+
+      status = setrlimit(RLIMIT_NOFILE, &nbr_files);
+      if (status != 0) {
+        log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
+      }
+    }
+  }
+
+  // at-exit methods are called in the reverse order of their registration.
+  // atexit functions are called on return from main or as a result of a
+  // call to exit(3C). There can be only 32 of these functions registered
+  // and atexit() does not set errno.
+
+  if (PerfAllowAtExitRegistration) {
+    // only register atexit functions if PerfAllowAtExitRegistration is set.
+    // atexit functions can be delayed until process exit time, which
+    // can be problematic for embedded VM situations. Embedded VMs should
+    // call DestroyJavaVM() to assure that VM resources are released.
+
+    // note: perfMemory_exit_helper atexit function may be removed in
+    // the future if the appropriate cleanup code can be added to the
+    // VM_Exit VMOperation's doit method.
+    if (atexit(perfMemory_exit_helper) != 0) {
+      warning("os::init_2 atexit(perfMemory_exit_helper) failed");
+    }
+  }
+
+  // initialize thread priority policy
+  prio_init();
+
+#ifdef __APPLE__
+  // dynamically link to objective c gc registration
+  void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
+  if (handleLibObjc != NULL) {
+    objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
+  }
+#endif
+
+  return JNI_OK;
+}
+
+// Mark the polling page as unreadable
+void os::make_polling_page_unreadable(void) {
+  if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
+    fatal("Could not disable polling page");
+  }
+}
+
+// Mark the polling page as readable
+void os::make_polling_page_readable(void) {
+  if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
+    fatal("Could not enable polling page");
+  }
+}
+
+int os::active_processor_count() {
+  return _processor_count;
+}
+
+void os::set_native_thread_name(const char *name) {
+#if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
+  // This is only supported in Snow Leopard and beyond
+  if (name != NULL) {
+    // Add a "Java: " prefix to the name
+    char buf[MAXTHREADNAMESIZE];
+    snprintf(buf, sizeof(buf), "Java: %s", name);
+    pthread_setname_np(buf);
+  }
+#endif
+}
+
+bool os::distribute_processes(uint length, uint* distribution) {
+  // Not yet implemented.
+  return false;
+}
+
+bool os::bind_to_processor(uint processor_id) {
+  // Not yet implemented.
+  return false;
+}
+
+void os::SuspendedThreadTask::internal_do_task() {
+  if (do_suspend(_thread->osthread())) {
+    SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
+    do_task(context);
+    do_resume(_thread->osthread());
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// debug support
+
+bool os::find(address addr, outputStream* st) {
+  Dl_info dlinfo;
+  memset(&dlinfo, 0, sizeof(dlinfo));
+  if (dladdr(addr, &dlinfo) != 0) {
+    st->print(INTPTR_FORMAT ": ", (intptr_t)addr);
+    if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
+      st->print("%s+%#x", dlinfo.dli_sname,
+                (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_saddr));
+    } else if (dlinfo.dli_fbase != NULL) {
+      st->print("<offset %#x>", (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_fbase));
+    } else {
+      st->print("<absolute address>");
+    }
+    if (dlinfo.dli_fname != NULL) {
+      st->print(" in %s", dlinfo.dli_fname);
+    }
+    if (dlinfo.dli_fbase != NULL) {
+      st->print(" at " INTPTR_FORMAT, (intptr_t)dlinfo.dli_fbase);
+    }
+    st->cr();
+
+    if (Verbose) {
+      // decode some bytes around the PC
+      address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
+      address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
+      address       lowest = (address) dlinfo.dli_sname;
+      if (!lowest)  lowest = (address) dlinfo.dli_fbase;
+      if (begin < lowest)  begin = lowest;
+      Dl_info dlinfo2;
+      if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
+          && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
+        end = (address) dlinfo2.dli_saddr;
+      }
+      Disassembler::decode(begin, end, st);
+    }
+    return true;
+  }
+  return false;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// misc
+
+// This does not do anything on Bsd. This is basically a hook for being
+// able to use structured exception handling (thread-local exception filters)
+// on, e.g., Win32.
+void os::os_exception_wrapper(java_call_t f, JavaValue* value,
+                              const methodHandle& method, JavaCallArguments* args,
+                              Thread* thread) {
+  f(value, method, args, thread);
+}
+
+void os::print_statistics() {
+}
+
+bool os::message_box(const char* title, const char* message) {
+  int i;
+  fdStream err(defaultStream::error_fd());
+  for (i = 0; i < 78; i++) err.print_raw("=");
+  err.cr();
+  err.print_raw_cr(title);
+  for (i = 0; i < 78; i++) err.print_raw("-");
+  err.cr();
+  err.print_raw_cr(message);
+  for (i = 0; i < 78; i++) err.print_raw("=");
+  err.cr();
+
+  char buf[16];
+  // Prevent process from exiting upon "read error" without consuming all CPU
+  while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
+
+  return buf[0] == 'y' || buf[0] == 'Y';
+}
+
+int os::stat(const char *path, struct stat *sbuf) {
+  char pathbuf[MAX_PATH];
+  if (strlen(path) > MAX_PATH - 1) {
+    errno = ENAMETOOLONG;
+    return -1;
+  }
+  os::native_path(strcpy(pathbuf, path));
+  return ::stat(pathbuf, sbuf);
+}
+
+static inline struct timespec get_mtime(const char* filename) {
+  struct stat st;
+  int ret = os::stat(filename, &st);
+  assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
+#ifdef __APPLE__
+  return st.st_mtimespec;
+#else
+  return st.st_mtim;
+#endif
+}
+
+int os::compare_file_modified_times(const char* file1, const char* file2) {
+  struct timespec filetime1 = get_mtime(file1);
+  struct timespec filetime2 = get_mtime(file2);
+  int diff = filetime1.tv_sec - filetime2.tv_sec;
+  if (diff == 0) {
+    return filetime1.tv_nsec - filetime2.tv_nsec;
+  }
+  return diff;
+}
+
+// Is a (classpath) directory empty?
+bool os::dir_is_empty(const char* path) {
+  DIR *dir = NULL;
+  struct dirent *ptr;
+
+  dir = opendir(path);
+  if (dir == NULL) return true;
+
+  // Scan the directory
+  bool result = true;
+  char buf[sizeof(struct dirent) + MAX_PATH];
+  while (result && (ptr = ::readdir(dir)) != NULL) {
+    if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
+      result = false;
+    }
+  }
+  closedir(dir);
+  return result;
+}
+
+// This code originates from JDK's sysOpen and open64_w
+// from src/solaris/hpi/src/system_md.c
+
+int os::open(const char *path, int oflag, int mode) {
+  if (strlen(path) > MAX_PATH - 1) {
+    errno = ENAMETOOLONG;
+    return -1;
+  }
+  int fd;
+
+  fd = ::open(path, oflag, mode);
+  if (fd == -1) return -1;
+
+  // If the open succeeded, the file might still be a directory
+  {
+    struct stat buf;
+    int ret = ::fstat(fd, &buf);
+    int st_mode = buf.st_mode;
+
+    if (ret != -1) {
+      if ((st_mode & S_IFMT) == S_IFDIR) {
+        errno = EISDIR;
+        ::close(fd);
+        return -1;
+      }
+    } else {
+      ::close(fd);
+      return -1;
+    }
+  }
+
+  // All file descriptors that are opened in the JVM and not
+  // specifically destined for a subprocess should have the
+  // close-on-exec flag set.  If we don't set it, then careless 3rd
+  // party native code might fork and exec without closing all
+  // appropriate file descriptors (e.g. as we do in closeDescriptors in
+  // UNIXProcess.c), and this in turn might:
+  //
+  // - cause end-of-file to fail to be detected on some file
+  //   descriptors, resulting in mysterious hangs, or
+  //
+  // - might cause an fopen in the subprocess to fail on a system
+  //   suffering from bug 1085341.
+  //
+  // (Yes, the default setting of the close-on-exec flag is a Unix
+  // design flaw)
+  //
+  // See:
+  // 1085341: 32-bit stdio routines should support file descriptors >255
+  // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
+  // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
+  //
+#ifdef FD_CLOEXEC
+  {
+    int flags = ::fcntl(fd, F_GETFD);
+    if (flags != -1) {
+      ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+    }
+  }
+#endif
+
+  return fd;
+}
+
+
+// create binary file, rewriting existing file if required
+int os::create_binary_file(const char* path, bool rewrite_existing) {
+  int oflags = O_WRONLY | O_CREAT;
+  if (!rewrite_existing) {
+    oflags |= O_EXCL;
+  }
+  return ::open(path, oflags, S_IREAD | S_IWRITE);
+}
+
+// return current position of file pointer
+jlong os::current_file_offset(int fd) {
+  return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
+}
+
+// move file pointer to the specified offset
+jlong os::seek_to_file_offset(int fd, jlong offset) {
+  return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
+}
+
+// This code originates from JDK's sysAvailable
+// from src/solaris/hpi/src/native_threads/src/sys_api_td.c
+
+int os::available(int fd, jlong *bytes) {
+  jlong cur, end;
+  int mode;
+  struct stat buf;
+
+  if (::fstat(fd, &buf) >= 0) {
+    mode = buf.st_mode;
+    if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
+      int n;
+      if (::ioctl(fd, FIONREAD, &n) >= 0) {
+        *bytes = n;
+        return 1;
+      }
+    }
+  }
+  if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
+    return 0;
+  } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
+    return 0;
+  } else if (::lseek(fd, cur, SEEK_SET) == -1) {
+    return 0;
+  }
+  *bytes = end - cur;
+  return 1;
+}
+
+// Map a block of memory.
+char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
+                        char *addr, size_t bytes, bool read_only,
+                        bool allow_exec) {
+  int prot;
+  int flags;
+
+  if (read_only) {
+    prot = PROT_READ;
+    flags = MAP_SHARED;
+  } else {
+    prot = PROT_READ | PROT_WRITE;
+    flags = MAP_PRIVATE;
+  }
+
+  if (allow_exec) {
+    prot |= PROT_EXEC;
+  }
+
+  if (addr != NULL) {
+    flags |= MAP_FIXED;
+  }
+
+  char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
+                                     fd, file_offset);
+  if (mapped_address == MAP_FAILED) {
+    return NULL;
+  }
+  return mapped_address;
+}
+
+
+// Remap a block of memory.
+char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
+                          char *addr, size_t bytes, bool read_only,
+                          bool allow_exec) {
+  // same as map_memory() on this OS
+  return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
+                        allow_exec);
+}
+
+
+// Unmap a block of memory.
+bool os::pd_unmap_memory(char* addr, size_t bytes) {
+  return munmap(addr, bytes) == 0;
+}
+
+// current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
+// are used by JVM M&M and JVMTI to get user+sys or user CPU time
+// of a thread.
+//
+// current_thread_cpu_time() and thread_cpu_time(Thread*) returns
+// the fast estimate available on the platform.
+
+jlong os::current_thread_cpu_time() {
+#ifdef __APPLE__
+  return os::thread_cpu_time(Thread::current(), true /* user + sys */);
+#else
+  Unimplemented();
+  return 0;
+#endif
+}
+
+jlong os::thread_cpu_time(Thread* thread) {
+#ifdef __APPLE__
+  return os::thread_cpu_time(thread, true /* user + sys */);
+#else
+  Unimplemented();
+  return 0;
+#endif
+}
+
+jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
+#ifdef __APPLE__
+  return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
+#else
+  Unimplemented();
+  return 0;
+#endif
+}
+
+jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
+#ifdef __APPLE__
+  struct thread_basic_info tinfo;
+  mach_msg_type_number_t tcount = THREAD_INFO_MAX;
+  kern_return_t kr;
+  thread_t mach_thread;
+
+  mach_thread = thread->osthread()->thread_id();
+  kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
+  if (kr != KERN_SUCCESS) {
+    return -1;
+  }
+
+  if (user_sys_cpu_time) {
+    jlong nanos;
+    nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
+    nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
+    return nanos;
+  } else {
+    return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
+  }
+#else
+  Unimplemented();
+  return 0;
+#endif
+}
+
+
+void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
+  info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
+  info_ptr->may_skip_backward = false;     // elapsed time not wall time
+  info_ptr->may_skip_forward = false;      // elapsed time not wall time
+  info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
+}
+
+void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
+  info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
+  info_ptr->may_skip_backward = false;     // elapsed time not wall time
+  info_ptr->may_skip_forward = false;      // elapsed time not wall time
+  info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
+}
+
+bool os::is_thread_cpu_time_supported() {
+#ifdef __APPLE__
+  return true;
+#else
+  return false;
+#endif
+}
+
+// System loadavg support.  Returns -1 if load average cannot be obtained.
+// Bsd doesn't yet have a (official) notion of processor sets,
+// so just return the system wide load average.
+int os::loadavg(double loadavg[], int nelem) {
+  return ::getloadavg(loadavg, nelem);
+}
+
+void os::pause() {
+  char filename[MAX_PATH];
+  if (PauseAtStartupFile && PauseAtStartupFile[0]) {
+    jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
+  } else {
+    jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
+  }
+
+  int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+  if (fd != -1) {
+    struct stat buf;
+    ::close(fd);
+    while (::stat(filename, &buf) == 0) {
+      (void)::poll(NULL, 0, 100);
+    }
+  } else {
+    jio_fprintf(stderr,
+                "Could not open pause file '%s', continuing immediately.\n", filename);
+  }
+}
+
+// Darwin has no "environ" in a dynamic library.
+#ifdef __APPLE__
+  #include <crt_externs.h>
+  #define environ (*_NSGetEnviron())
+#else
+extern char** environ;
+#endif
+
+// Run the specified command in a separate process. Return its exit value,
+// or -1 on failure (e.g. can't fork a new process).
+// Unlike system(), this function can be called from signal handler. It
+// doesn't block SIGINT et al.
+int os::fork_and_exec(char* cmd) {
+  const char * argv[4] = {"sh", "-c", cmd, NULL};
+
+  // fork() in BsdThreads/NPTL is not async-safe. It needs to run
+  // pthread_atfork handlers and reset pthread library. All we need is a
+  // separate process to execve. Make a direct syscall to fork process.
+  // On IA64 there's no fork syscall, we have to use fork() and hope for
+  // the best...
+  pid_t pid = fork();
+
+  if (pid < 0) {
+    // fork failed
+    return -1;
+
+  } else if (pid == 0) {
+    // child process
+
+    // execve() in BsdThreads will call pthread_kill_other_threads_np()
+    // first to kill every thread on the thread list. Because this list is
+    // not reset by fork() (see notes above), execve() will instead kill
+    // every thread in the parent process. We know this is the only thread
+    // in the new process, so make a system call directly.
+    // IA64 should use normal execve() from glibc to match the glibc fork()
+    // above.
+    execve("/bin/sh", (char* const*)argv, environ);
+
+    // execve failed
+    _exit(-1);
+
+  } else  {
+    // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
+    // care about the actual exit code, for now.
+
+    int status;
+
+    // Wait for the child process to exit.  This returns immediately if
+    // the child has already exited. */
+    while (waitpid(pid, &status, 0) < 0) {
+      switch (errno) {
+      case ECHILD: return 0;
+      case EINTR: break;
+      default: return -1;
+      }
+    }
+
+    if (WIFEXITED(status)) {
+      // The child exited normally; get its exit code.
+      return WEXITSTATUS(status);
+    } else if (WIFSIGNALED(status)) {
+      // The child exited because of a signal
+      // The best value to return is 0x80 + signal number,
+      // because that is what all Unix shells do, and because
+      // it allows callers to distinguish between process exit and
+      // process death by signal.
+      return 0x80 + WTERMSIG(status);
+    } else {
+      // Unknown exit code; pass it through
+      return status;
+    }
+  }
+}
+
+// is_headless_jre()
+//
+// Test for the existence of xawt/libmawt.so or libawt_xawt.so
+// in order to report if we are running in a headless jre
+//
+// Since JDK8 xawt/libmawt.so was moved into the same directory
+// as libawt.so, and renamed libawt_xawt.so
+//
+bool os::is_headless_jre() {
+#ifdef __APPLE__
+  // We no longer build headless-only on Mac OS X
+  return false;
+#else
+  struct stat statbuf;
+  char buf[MAXPATHLEN];
+  char libmawtpath[MAXPATHLEN];
+  const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
+  const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
+  char *p;
+
+  // Get path to libjvm.so
+  os::jvm_path(buf, sizeof(buf));
+
+  // Get rid of libjvm.so
+  p = strrchr(buf, '/');
+  if (p == NULL) {
+    return false;
+  } else {
+    *p = '\0';
+  }
+
+  // Get rid of client or server
+  p = strrchr(buf, '/');
+  if (p == NULL) {
+    return false;
+  } else {
+    *p = '\0';
+  }
+
+  // check xawt/libmawt.so
+  strcpy(libmawtpath, buf);
+  strcat(libmawtpath, xawtstr);
+  if (::stat(libmawtpath, &statbuf) == 0) return false;
+
+  // check libawt_xawt.so
+  strcpy(libmawtpath, buf);
+  strcat(libmawtpath, new_xawtstr);
+  if (::stat(libmawtpath, &statbuf) == 0) return false;
+
+  return true;
+#endif
+}
+
+// Get the default path to the core file
+// Returns the length of the string
+int os::get_core_path(char* buffer, size_t bufferSize) {
+  int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
+
+  // Truncate if theoretical string was longer than bufferSize
+  n = MIN2(n, (int)bufferSize);
+
+  return n;
+}
+
+#ifndef PRODUCT
+void TestReserveMemorySpecial_test() {
+  // No tests available for this platform
+}
+#endif
+
+bool os::start_debugging(char *buf, int buflen) {
+  int len = (int)strlen(buf);
+  char *p = &buf[len];
+
+  jio_snprintf(p, buflen-len,
+             "\n\n"
+             "Do you want to debug the problem?\n\n"
+             "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT " (" INTPTR_FORMAT ")\n"
+             "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
+             "Otherwise, press RETURN to abort...",
+             os::current_process_id(), os::current_process_id(),
+             os::current_thread_id(), os::current_thread_id());
+
+  bool yes = os::message_box("Unexpected Error", buf);
+
+  if (yes) {
+    // yes, user asked VM to launch debugger
+    jio_snprintf(buf, sizeof(buf), "gdb /proc/%d/exe %d",
+                     os::current_process_id(), os::current_process_id());
+
+    os::fork_and_exec(buf);
+    yes = false;
+  }
+  return yes;
+}