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The os_bsd.cpp Java example source code
/*
* Copyright (c) 1999, 2013, 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 "memory/allocation.inline.hpp"
#include "memory/filemap.hpp"
#include "mutex_bsd.inline.hpp"
#include "oops/oop.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/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/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 "services/attachListener.hpp"
#include "services/memTracker.hpp"
#include "services/runtimeService.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;
int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
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();
static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
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();
}
////////////////////////////////////////////////////////////////////////////////
// environment support
bool os::getenv(const char* name, char* buf, int len) {
const char* val = ::getenv(name);
if (val != NULL && strlen(val) < (size_t)len) {
strcpy(buf, val);
return true;
}
if (len > 0) buf[0] = 0; // return a null string
return false;
}
// 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(PPC)
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() {
// char arch[12];
// sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
// 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//{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//hotspot/libjvm.so.
//
// Otherwise exit.
//
// Important note: if the location of libjvm.so changes this
// code needs to be changed accordingly.
// The next few definitions allow the code to be verbatim:
#define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal)
#define getenv(n) ::getenv(n)
/*
* 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
#define EXTENSIONS_DIR "/lib/ext"
#define ENDORSED_DIR "/lib/endorsed"
#define REG_DIR "/usr/java/packages"
#ifdef __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
int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
sizeof(SYS_EXTENSIONS_DIRS);
#endif
{
/* sysclasspath, java_home, dll_dir */
{
char *home_path;
char *dll_path;
char *pslash;
char buf[MAXPATHLEN];
os::jvm_path(buf, sizeof(buf));
// 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} */
dll_path = malloc(strlen(buf) + 1);
if (dll_path == NULL)
return;
strcpy(dll_path, buf);
Arguments::set_dll_dir(dll_path);
if (pslash != NULL) {
pslash = strrchr(buf, '/');
if (pslash != NULL) {
*pslash = '\0'; /* get rid of /<arch> (/lib on macosx) */
#ifndef __APPLE__
pslash = strrchr(buf, '/');
if (pslash != NULL)
*pslash = '\0'; /* get rid of /lib */
#endif
}
}
home_path = malloc(strlen(buf) + 1);
if (home_path == NULL)
return;
strcpy(home_path, buf);
Arguments::set_java_home(home_path);
if (!set_boot_path('/', ':'))
return;
}
/*
* 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.
*/
{
char *ld_library_path;
/*
* Construct the invariant part of ld_library_path. Note that the
* space for the colon and the trailing null are provided by the
* nulls included by the sizeof operator (so actually we allocate
* a byte more than necessary).
*/
#ifdef __APPLE__
ld_library_path = (char *) malloc(system_ext_size);
sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir);
#else
ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
#endif
/*
* Get the user setting of LD_LIBRARY_PATH, and prepended it. It
* should always exist (until the legacy problem cited above is
* addressed).
*/
#ifdef __APPLE__
// Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper
char *l = getenv("JAVA_LIBRARY_PATH");
if (l != NULL) {
char *t = ld_library_path;
/* That's +1 for the colon and +1 for the trailing '\0' */
ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1);
sprintf(ld_library_path, "%s:%s", l, t);
free(t);
}
char *v = getenv("DYLD_LIBRARY_PATH");
#else
char *v = getenv("LD_LIBRARY_PATH");
#endif
if (v != NULL) {
char *t = ld_library_path;
/* That's +1 for the colon and +1 for the trailing '\0' */
ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
sprintf(ld_library_path, "%s:%s", v, t);
free(t);
}
#ifdef __APPLE__
// 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 *t = ld_library_path;
// that's +3 for appending ":." and the trailing '\0'
ld_library_path = (char *) malloc(strlen(t) + 3);
sprintf(ld_library_path, "%s:%s", t, ".");
free(t);
}
#endif
Arguments::set_library_path(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).
*/
{
#ifdef __APPLE__
char *buf = malloc(strlen(Arguments::get_java_home()) +
sizeof(EXTENSIONS_DIR) + system_ext_size);
sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":"
SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home());
#else
char *buf = malloc(strlen(Arguments::get_java_home()) +
sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
Arguments::get_java_home());
#endif
Arguments::set_ext_dirs(buf);
}
/* Endorsed standards default directory. */
{
char * buf;
buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
Arguments::set_endorsed_dirs(buf);
}
}
#ifdef __APPLE__
#undef SYS_EXTENSIONS_DIR
#endif
#undef malloc
#undef getenv
#undef EXTENSIONS_DIR
#undef ENDORSED_DIR
// Done
return;
}
////////////////////////////////////////////////////////////////////////////////
// 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, allowdebug_blocked_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);
sigemptyset(&allowdebug_blocked_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);
sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
}
if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
}
if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
sigaddset(&allowdebug_blocked_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;
}
// These are signals that are blocked during cond_wait to allow debugger in
sigset_t* os::Bsd::allowdebug_blocked_signals() {
assert(signal_sets_initialized, "Not initialized");
return &allowdebug_blocked_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
// check if it's safe to start a new thread
static bool _thread_safety_check(Thread* thread) {
return true;
}
#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 *java_start(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);
ThreadLocalStorage::set_thread(thread);
OSThread* osthread = thread->osthread();
Monitor* sync = osthread->startThread_lock();
// non floating stack BsdThreads needs extra check, see above
if (!_thread_safety_check(thread)) {
// notify parent thread
MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
osthread->set_state(ZOMBIE);
sync->notify_all();
return NULL;
}
osthread->set_thread_id(os::Bsd::gettid());
#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();
return 0;
}
bool os::create_thread(Thread* thread, ThreadType thr_type, size_t 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);
// stack size
if (os::Bsd::supports_variable_stack_size()) {
// calculate stack size if it's not specified by caller
if (stack_size == 0) {
stack_size = os::Bsd::default_stack_size(thr_type);
switch (thr_type) {
case os::java_thread:
// Java threads use ThreadStackSize which default value can be
// changed with the flag -Xss
assert (JavaThread::stack_size_at_create() > 0, "this should be set");
stack_size = JavaThread::stack_size_at_create();
break;
case os::compiler_thread:
if (CompilerThreadStackSize > 0) {
stack_size = (size_t)(CompilerThreadStackSize * K);
break;
} // else fall through:
// use VMThreadStackSize if CompilerThreadStackSize is not defined
case os::vm_thread:
case os::pgc_thread:
case os::cgc_thread:
case os::watcher_thread:
if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
break;
}
}
stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
pthread_attr_setstacksize(&attr, stack_size);
} else {
// let pthread_create() pick the default value.
}
ThreadState state;
{
pthread_t tid;
int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
pthread_attr_destroy(&attr);
if (ret != 0) {
if (PrintMiscellaneous && (Verbose || WizardMode)) {
perror("pthread_create()");
}
// 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);
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");
if (Thread::current()->osthread() == osthread) {
// Restore caller's signal mask
sigset_t sigmask = osthread->caller_sigmask();
pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
}
delete osthread;
}
//////////////////////////////////////////////////////////////////////////////
// thread local storage
int os::allocate_thread_local_storage() {
pthread_key_t key;
int rslt = pthread_key_create(&key, NULL);
assert(rslt == 0, "cannot allocate thread local storage");
return (int)key;
}
// Note: This is currently not used by VM, as we don't destroy TLS key
// on VM exit.
void os::free_thread_local_storage(int index) {
int rslt = pthread_key_delete((pthread_key_t)index);
assert(rslt == 0, "invalid index");
}
void os::thread_local_storage_at_put(int index, void* value) {
int rslt = pthread_setspecific((pthread_key_t)index, value);
assert(rslt == 0, "pthread_setspecific failed");
}
extern "C" Thread* get_thread() {
return ThreadLocalStorage::thread();
}
////////////////////////////////////////////////////////////////////////////////
// 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);
}
#ifndef CLOCK_MONOTONIC
#define CLOCK_MONOTONIC (1)
#endif
#ifdef __APPLE__
void os::Bsd::clock_init() {
// XXXDARWIN: Investigate replacement monotonic clock
}
#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
jlong os::javaTimeNanos() {
if (Bsd::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;
}
}
void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
if (Bsd::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) {
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();
}
// unused on bsd for now.
void os::set_error_file(const char *logfile) {}
// 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 = ::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;
#elif __FreeBSD__
retval = syscall(SYS_thr_self);
#elif __OpenBSD__
retval = syscall(SYS_getthrid);
#elif __NetBSD__
retval = (pid_t) syscall(SYS__lwp_self);
#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
#define JNI_LIB_PREFIX "lib"
#ifdef __APPLE__
#define JNI_LIB_SUFFIX ".dylib"
#else
#define JNI_LIB_SUFFIX ".so"
#endif
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__ */
static bool file_exists(const char* filename) {
struct stat statbuf;
if (filename == NULL || strlen(filename) == 0) {
return false;
}
return os::stat(filename, &statbuf) == 0;
}
bool os::dll_build_name(char* buffer, size_t buflen,
const char* pname, const char* fname) {
bool retval = false;
// Copied from libhpi
const size_t pnamelen = pname ? strlen(pname) : 0;
// Return error on buffer overflow.
if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
return retval;
}
if (pnamelen == 0) {
snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
retval = true;
} else if (strchr(pname, *os::path_separator()) != NULL) {
int n;
char** pelements = split_path(pname, &n);
if (pelements == NULL) {
return false;
}
for (int i = 0 ; i < n ; i++) {
// Really shouldn't be NULL, but check can't hurt
if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
continue; // skip the empty path values
}
snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
pelements[i], fname);
if (file_exists(buffer)) {
retval = true;
break;
}
}
// release the storage
for (int i = 0 ; i < n ; i++) {
if (pelements[i] != NULL) {
FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
}
}
if (pelements != NULL) {
FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
}
} else {
snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
retval = true;
}
return retval;
}
// 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) {
// 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 (!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)) {
return true;
}
}
// Handle non-dynamic manually:
if (dlinfo.dli_fbase != NULL &&
Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
dlinfo.dli_fbase)) {
if (!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) {
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;
}
#else
void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
{
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 /* !__APPLE__ */
// XXX: Do we need a lock around this as per Linux?
void* os::dll_lookup(void* handle, const char* name) {
return dlsym(handle, name);
}
static bool _print_ascii_file(const char* filename, outputStream* st) {
int fd = ::open(filename, O_RDONLY);
if (fd == -1) {
return false;
}
char buf[32];
int bytes;
while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
st->print_raw(buf, bytes);
}
::close(fd);
return true;
}
void os::print_dll_info(outputStream *st) {
st->print_cr("Dynamic libraries:");
#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) {
st->print_cr("Error: Cannot print dynamic libraries.");
return;
}
handle = dlopen(dli.dli_fname, RTLD_LAZY);
if (handle == NULL) {
st->print_cr("Error: Cannot print dynamic libraries.");
return;
}
dlinfo(handle, RTLD_DI_LINKMAP, &map);
if (map == NULL) {
st->print_cr("Error: Cannot print dynamic libraries.");
return;
}
while (map->l_prev != NULL)
map = map->l_prev;
while (map != NULL) {
st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
map = map->l_next;
}
dlclose(handle);
#elif defined(__APPLE__)
uint32_t count;
uint32_t i;
count = _dyld_image_count();
for (i = 1; i < count; i++) {
const char *name = _dyld_get_image_name(i);
intptr_t slide = _dyld_get_image_vmaddr_slide(i);
st->print_cr(PTR_FORMAT " \t%s", slide, name);
}
#else
st->print_cr("Error: Cannot print dynamic libraries.");
#endif
}
void os::print_os_info_brief(outputStream* st) {
st->print("Bsd");
os::Posix::print_uname_info(st);
}
void os::print_os_info(outputStream* st) {
st->print("OS:");
st->print("Bsd");
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) {
// Nothing to do for now.
}
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();
// meminfo
st->print("\n/proc/meminfo:\n");
_print_ascii_file("/proc/meminfo", st);
st->cr();
}
// Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific
// but they're the same for all the bsd arch that we support
// and they're the same for solaris but there's no common place to put this.
const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
"ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
"ILL_COPROC", "ILL_BADSTK" };
const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
"FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
"FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
void os::print_siginfo(outputStream* st, void* siginfo) {
st->print("siginfo:");
const int buflen = 100;
char buf[buflen];
siginfo_t *si = (siginfo_t*)siginfo;
st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
st->print("si_errno=%s", buf);
} else {
st->print("si_errno=%d", si->si_errno);
}
const int c = si->si_code;
assert(c > 0, "unexpected si_code");
switch (si->si_signo) {
case SIGILL:
st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
st->print(", si_addr=" PTR_FORMAT, si->si_addr);
break;
case SIGFPE:
st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
st->print(", si_addr=" PTR_FORMAT, si->si_addr);
break;
case SIGSEGV:
st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
st->print(", si_addr=" PTR_FORMAT, si->si_addr);
break;
case SIGBUS:
st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
st->print(", si_addr=" PTR_FORMAT, si->si_addr);
break;
default:
st->print(", si_code=%d", si->si_code);
// no si_addr
}
if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
UseSharedSpaces) {
FileMapInfo* mapinfo = FileMapInfo::current_info();
if (mapinfo->is_in_shared_space(si->si_addr)) {
st->print("\n\nError accessing class data sharing archive." \
" Mapped file inaccessible during execution, " \
" possible disk/network problem.");
}
}
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, INTERRUPT_SIGNAL, 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 = realpath(dli_fname, buf);
}
if (rp == NULL)
return;
if (Arguments::created_by_gamma_launcher()) {
// Support for the gamma launcher. Typical value for buf is
// "<JAVA_HOME>/jre/lib///libjvm". 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 = realpath(java_home_var, buf);
if (rp == NULL)
return;
// determine if this is a legacy image or modules image
// modules image doesn't have "jre" subdirectory
len = strlen(buf);
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, "");
}
// 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 = realpath(dli_fname, buf);
if (rp == NULL)
return;
}
}
}
}
strcpy(saved_jvm_path, buf);
}
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 && 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
class Semaphore : public StackObj {
public:
Semaphore();
~Semaphore();
void signal();
void wait();
bool trywait();
bool timedwait(unsigned int sec, int nsec);
private:
jlong currenttime() const;
os_semaphore_t _semaphore;
};
Semaphore::Semaphore() : _semaphore(0) {
SEM_INIT(_semaphore, 0);
}
Semaphore::~Semaphore() {
SEM_DESTROY(_semaphore);
}
void Semaphore::signal() {
SEM_POST(_semaphore);
}
void Semaphore::wait() {
SEM_WAIT(_semaphore);
}
jlong Semaphore::currenttime() const {
struct timeval tv;
gettimeofday(&tv, NULL);
return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
}
#ifdef __APPLE__
bool Semaphore::trywait() {
return timedwait(0, 0);
}
bool Semaphore::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
bool Semaphore::trywait() {
return sem_trywait(&_semaphore) == 0;
}
bool Semaphore::timedwait(unsigned int sec, int nsec) {
struct timespec ts;
unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
while (1) {
int result = sem_timedwait(&_semaphore, &ts);
if (result == 0) {
return true;
} else if (errno == EINTR) {
continue;
} else if (errno == ETIMEDOUT) {
return false;
} else {
return false;
}
}
}
#endif // __APPLE__
static os_semaphore_t sig_sem;
static Semaphore sr_semaphore;
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(" PTR_FORMAT ", " SIZE_FORMAT
", %d) failed; error='%s' (errno=%d)", addr, size, exec,
strerror(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, 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);
}
static address _highest_vm_reserved_address = NULL;
// 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);
if (addr != MAP_FAILED) {
// anon_mmap() should only get called during VM initialization,
// don't need lock (actually we can skip locking even it can be called
// from multiple threads, because _highest_vm_reserved_address is just a
// hint about the upper limit of non-stack memory regions.)
if ((address)addr + bytes > _highest_vm_reserved_address) {
_highest_vm_reserved_address = (address)addr + bytes;
}
}
return addr == MAP_FAILED ? NULL : addr;
}
// Don't update _highest_vm_reserved_address, because there might be memory
// regions above addr + size. If so, releasing a memory region only creates
// a hole in the address space, it doesn't help prevent heap-stack collision.
//
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_size_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_size_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)
);
char msg[128];
// 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) {
jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
warning(msg);
}
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) {
jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
warning(msg);
}
return NULL;
}
// The memory is committed
MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, mtNone, CALLER_PC);
return addr;
}
bool os::release_memory_special(char* base, size_t bytes) {
MemTracker::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 {
tkr.discard();
return false;
}
}
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. Give up after max_tries. Note that reserve_memory() will
// automatically update _highest_vm_reserved_address if the call is
// successful. The variable tracks the highest memory address every reserved
// by JVM. It is used to detect heap-stack collision if running with
// fixed-stack BsdThreads. Because here we may attempt to reserve more
// space than needed, it could confuse the collision detecting code. To
// solve the problem, save current _highest_vm_reserved_address and
// calculate the correct value before return.
address old_highest = _highest_vm_reserved_address;
// 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) {
_highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
return requested_addr;
} else {
_highest_vm_reserved_address = old_highest;
return NULL;
}
}
size_t os::read(int fd, void *buf, unsigned int nBytes) {
RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
}
// TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
// Solaris uses poll(), bsd uses park().
// Poll() is likely a better choice, assuming that Thread.interrupt()
// generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
// SIGSEGV, see 4355769.
int os::sleep(Thread* thread, jlong millis, bool interruptible) {
assert(thread == Thread::current(), "thread consistency check");
ParkEvent * const slp = thread->_SleepEvent ;
slp->reset() ;
OrderAccess::fence() ;
if (interruptible) {
jlong prevtime = javaTimeNanos();
for (;;) {
if (os::is_interrupted(thread, true)) {
return OS_INTRPT;
}
jlong newtime = javaTimeNanos();
if (newtime - prevtime < 0) {
// time moving backwards, should only happen if no monotonic clock
// not a guarantee() because JVM should not abort on kernel/glibc bugs
assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
} else {
millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
}
if(millis <= 0) {
return OS_OK;
}
prevtime = newtime;
{
assert(thread->is_Java_thread(), "sanity check");
JavaThread *jt = (JavaThread *) thread;
ThreadBlockInVM tbivm(jt);
OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
jt->set_suspend_equivalent();
// cleared by handle_special_suspend_equivalent_condition() or
// java_suspend_self() via check_and_wait_while_suspended()
slp->park(millis);
// were we externally suspended while we were waiting?
jt->check_and_wait_while_suspended();
}
}
} else {
OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
jlong prevtime = javaTimeNanos();
for (;;) {
// It'd be nice to avoid the back-to-back javaTimeNanos() calls on
// the 1st iteration ...
jlong newtime = javaTimeNanos();
if (newtime - prevtime < 0) {
// time moving backwards, should only happen if no monotonic clock
// not a guarantee() because JVM should not abort on kernel/glibc bugs
assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
} else {
millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
}
if(millis <= 0) break ;
prevtime = newtime;
slp->park(millis);
}
return OS_OK ;
}
}
int os::naked_sleep() {
// %% make the sleep time an integer flag. for now use 1 millisec.
return os::sleep(Thread::current(), 1, false);
}
// 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::yield() {
sched_yield();
}
os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
void os::yield_all(int attempts) {
// Yields to all threads, including threads with lower priorities
// Threads on Bsd are all with same priority. The Solaris style
// os::yield_all() with nanosleep(1ms) is not necessary.
sched_yield();
}
// Called from the tight loops to possibly influence time-sharing heuristics
void os::loop_breaker(int attempts) {
os::yield_all(attempts);
}
////////////////////////////////////////////////////////////////////////////////
// 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. Now there is a single use-case for this:
// - calling get_thread_pc() on the VMThread by the flat-profiler task
// that runs in the watcher thread.
// 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.
//
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();
OSThread* osthread = thread->osthread();
assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
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 > 0 || sig < NSIG) {
SR_signum = sig;
}
}
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!");
}
////////////////////////////////////////////////////////////////////////////////
// interrupt support
void os::interrupt(Thread* thread) {
assert(Thread::current() == thread || Threads_lock->owned_by_self(),
"possibility of dangling Thread pointer");
OSThread* osthread = thread->osthread();
if (!osthread->interrupted()) {
osthread->set_interrupted(true);
// More than one thread can get here with the same value of osthread,
// resulting in multiple notifications. We do, however, want the store
// to interrupted() to be visible to other threads before we execute unpark().
OrderAccess::fence();
ParkEvent * const slp = thread->_SleepEvent ;
if (slp != NULL) slp->unpark() ;
}
// For JSR166. Unpark even if interrupt status already was set
if (thread->is_Java_thread())
((JavaThread*)thread)->parker()->unpark();
ParkEvent * ev = thread->_ParkEvent ;
if (ev != NULL) ev->unpark() ;
}
bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
assert(Thread::current() == thread || Threads_lock->owned_by_self(),
"possibility of dangling Thread pointer");
OSThread* osthread = thread->osthread();
bool interrupted = osthread->interrupted();
if (interrupted && clear_interrupted) {
osthread->set_interrupted(false);
// consider thread->_SleepEvent->reset() ... optional optimization
}
return interrupted;
}
///////////////////////////////////////////////////////////////////////////////////
// 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 os::Bsd::sigact[MAXSIGNUM];
unsigned int os::Bsd::sigs = 0;
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 ((( (unsigned int)1 << sig ) & sigs) != 0) {
return &sigact[sig];
}
return NULL;
}
void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
sigact[sig] = oldAct;
sigs |= (unsigned int)1 << sig;
}
// for diagnostic
int os::Bsd::sigflags[MAXSIGNUM];
int os::Bsd::get_our_sigflags(int sig) {
assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
return sigflags[sig];
}
void os::Bsd::set_our_sigflags(int sig, int flags) {
assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
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(err_msg("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;
}
#if __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 < MAXSIGNUM, "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]=" PTR32_FORMAT, *(uint32_t*)&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=" PTR32_FORMAT, 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) \
if (!sigismember(&check_signal_done, sig)) \
os::Bsd::check_signal_handler(sig)
// 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);
DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
}
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;
case INTERRUPT_SIGNAL:
jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
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);
} 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:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags);
// 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, ...);
extern bool signal_name(int signo, char* buf, size_t len);
const char* os::exception_name(int exception_code, char* buf, size_t size) {
if (0 < exception_code && exception_code <= SIGRTMAX) {
// signal
if (!signal_name(exception_code, buf, size)) {
jio_snprintf(buf, size, "SIG%d", exception_code);
}
return buf;
} else {
return NULL;
}
}
// 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 */
// first_hrtime = gethrtime();
// 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(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
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
}
// 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)
{
// 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 );
#ifndef PRODUCT
if(Verbose && PrintMiscellaneous)
tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
#endif
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 );
#ifndef PRODUCT
if(Verbose && PrintMiscellaneous)
tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
#endif
}
// 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 minimum allowable stack size for thread creation and to initialize
// the java system classes, including StackOverflowError - depends on page
// size. Add a page for compiler2 recursion in main thread.
// Add in 2*BytesPerWord times page size to account for VM stack during
// class initialization depending on 32 or 64 bit VM.
os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
(size_t)(StackYellowPages+StackRedPages+StackShadowPages+
2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
size_t threadStackSizeInBytes = ThreadStackSize * K;
if (threadStackSizeInBytes != 0 &&
threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
tty->print_cr("\nThe stack size specified is too small, "
"Specify at least %dk",
os::Bsd::min_stack_allowed/ K);
return JNI_ERR;
}
// Make the stack size a multiple of the page size so that
// the yellow/red zones can be guarded.
JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
vm_page_size()));
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) {
if (PrintMiscellaneous && (Verbose || WizardMode))
perror("os::init_2 getrlimit failed");
} 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) {
if (PrintMiscellaneous && (Verbose || WizardMode))
perror("os::init_2 setrlimit failed");
}
}
}
// 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::init2 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;
}
// this is called at the end of vm_initialization
void os::init_3(void) { }
// 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());
}
}
///
class PcFetcher : public os::SuspendedThreadTask {
public:
PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
ExtendedPC result();
protected:
void do_task(const os::SuspendedThreadTaskContext& context);
private:
ExtendedPC _epc;
};
ExtendedPC PcFetcher::result() {
guarantee(is_done(), "task is not done yet.");
return _epc;
}
void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
Thread* thread = context.thread();
OSThread* osthread = thread->osthread();
if (osthread->ucontext() != NULL) {
_epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
} else {
// NULL context is unexpected, double-check this is the VMThread
guarantee(thread->is_VM_thread(), "can only be called for VMThread");
}
}
// Suspends the target using the signal mechanism and then grabs the PC before
// resuming the target. Used by the flat-profiler only
ExtendedPC os::get_thread_pc(Thread* thread) {
// Make sure that it is called by the watcher for the VMThread
assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
assert(thread->is_VM_thread(), "Can only be called for VMThread");
PcFetcher fetcher(thread);
fetcher.run();
return fetcher.result();
}
int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
{
return pthread_cond_timedwait(_cond, _mutex, _abstime);
}
////////////////////////////////////////////////////////////////////////////////
// debug support
bool os::find(address addr, outputStream* st) {
Dl_info dlinfo;
memset(&dlinfo, 0, sizeof(dlinfo));
if (dladdr(addr, &dlinfo) != 0) {
st->print(PTR_FORMAT ": ", addr);
if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
st->print("%s+%#x", dlinfo.dli_sname,
addr - (intptr_t)dlinfo.dli_saddr);
} else if (dlinfo.dli_fbase != NULL) {
st->print("<offset %#x>", addr - (intptr_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 " PTR_FORMAT, 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, methodHandle* method,
JavaCallArguments* args, Thread* thread) {
f(value, method, args, thread);
}
void os::print_statistics() {
}
int 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);
}
bool os::check_heap(bool force) {
return true;
}
int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
return ::vsnprintf(buf, count, format, args);
}
// 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
#ifndef O_DELETE
#define O_DELETE 0x10000
#endif
// Open a file. Unlink the file immediately after open returns
// if the specified oflag has the O_DELETE flag set.
// O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
int os::open(const char *path, int oflag, int mode) {
if (strlen(path) > MAX_PATH - 1) {
errno = ENAMETOOLONG;
return -1;
}
int fd;
int o_delete = (oflag & O_DELETE);
oflag = oflag & ~O_DELETE;
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
if (o_delete != 0) {
::unlink(path);
}
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)) {
/*
* XXX: is the following call interruptible? If so, this might
* need to go through the INTERRUPT_IO() wrapper as for other
* blocking, interruptible calls in this file.
*/
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;
}
int os::socket_available(int fd, jint *pbytes) {
if (fd < 0)
return OS_OK;
int ret;
RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
//%% note ioctl can return 0 when successful, JVM_SocketAvailable
// is expected to return 0 on failure and 1 on success to the jdk.
return (ret == OS_ERR) ? 0 : 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);
}
}
// Refer to the comments in os_solaris.cpp park-unpark.
//
// Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
// hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
// For specifics regarding the bug see GLIBC BUGID 261237 :
// http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
// Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
// will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
// is used. (The simple C test-case provided in the GLIBC bug report manifests the
// hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
// and monitorenter when we're using 1-0 locking. All those operations may result in
// calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version
// of libpthread avoids the problem, but isn't practical.
//
// Possible remedies:
//
// 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work.
// This is palliative and probabilistic, however. If the thread is preempted
// between the call to compute_abstime() and pthread_cond_timedwait(), more
// than the minimum period may have passed, and the abstime may be stale (in the
// past) resultin in a hang. Using this technique reduces the odds of a hang
// but the JVM is still vulnerable, particularly on heavily loaded systems.
//
// 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
// of the usual flag-condvar-mutex idiom. The write side of the pipe is set
// NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
// reduces to poll()+read(). This works well, but consumes 2 FDs per extant
// thread.
//
// 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread
// that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing
// a timeout request to the chron thread and then blocking via pthread_cond_wait().
// This also works well. In fact it avoids kernel-level scalability impediments
// on certain platforms that don't handle lots of active pthread_cond_timedwait()
// timers in a graceful fashion.
//
// 4. When the abstime value is in the past it appears that control returns
// correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
// Subsequent timedwait/wait calls may hang indefinitely. Given that, we
// can avoid the problem by reinitializing the condvar -- by cond_destroy()
// followed by cond_init() -- after all calls to pthread_cond_timedwait().
// It may be possible to avoid reinitialization by checking the return
// value from pthread_cond_timedwait(). In addition to reinitializing the
// condvar we must establish the invariant that cond_signal() is only called
// within critical sections protected by the adjunct mutex. This prevents
// cond_signal() from "seeing" a condvar that's in the midst of being
// reinitialized or that is corrupt. Sadly, this invariant obviates the
// desirable signal-after-unlock optimization that avoids futile context switching.
//
// I'm also concerned that some versions of NTPL might allocate an auxilliary
// structure when a condvar is used or initialized. cond_destroy() would
// release the helper structure. Our reinitialize-after-timedwait fix
// put excessive stress on malloc/free and locks protecting the c-heap.
//
// We currently use (4). See the WorkAroundNTPLTimedWaitHang flag.
// It may be possible to refine (4) by checking the kernel and NTPL verisons
// and only enabling the work-around for vulnerable environments.
// utility to compute the abstime argument to timedwait:
// millis is the relative timeout time
// abstime will be the absolute timeout time
// TODO: replace compute_abstime() with unpackTime()
static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
if (millis < 0) millis = 0;
struct timeval now;
int status = gettimeofday(&now, NULL);
assert(status == 0, "gettimeofday");
jlong seconds = millis / 1000;
millis %= 1000;
if (seconds > 50000000) { // see man cond_timedwait(3T)
seconds = 50000000;
}
abstime->tv_sec = now.tv_sec + seconds;
long usec = now.tv_usec + millis * 1000;
if (usec >= 1000000) {
abstime->tv_sec += 1;
usec -= 1000000;
}
abstime->tv_nsec = usec * 1000;
return abstime;
}
// Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
// Conceptually TryPark() should be equivalent to park(0).
int os::PlatformEvent::TryPark() {
for (;;) {
const int v = _Event ;
guarantee ((v == 0) || (v == 1), "invariant") ;
if (Atomic::cmpxchg (0, &_Event, v) == v) return v ;
}
}
void os::PlatformEvent::park() { // AKA "down()"
// Invariant: Only the thread associated with the Event/PlatformEvent
// may call park().
// TODO: assert that _Assoc != NULL or _Assoc == Self
int v ;
for (;;) {
v = _Event ;
if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
}
guarantee (v >= 0, "invariant") ;
if (v == 0) {
// Do this the hard way by blocking ...
int status = pthread_mutex_lock(_mutex);
assert_status(status == 0, status, "mutex_lock");
guarantee (_nParked == 0, "invariant") ;
++ _nParked ;
while (_Event < 0) {
status = pthread_cond_wait(_cond, _mutex);
// for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
// Treat this the same as if the wait was interrupted
if (status == ETIMEDOUT) { status = EINTR; }
assert_status(status == 0 || status == EINTR, status, "cond_wait");
}
-- _nParked ;
_Event = 0 ;
status = pthread_mutex_unlock(_mutex);
assert_status(status == 0, status, "mutex_unlock");
// Paranoia to ensure our locked and lock-free paths interact
// correctly with each other.
OrderAccess::fence();
}
guarantee (_Event >= 0, "invariant") ;
}
int os::PlatformEvent::park(jlong millis) {
guarantee (_nParked == 0, "invariant") ;
int v ;
for (;;) {
v = _Event ;
if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
}
guarantee (v >= 0, "invariant") ;
if (v != 0) return OS_OK ;
// We do this the hard way, by blocking the thread.
// Consider enforcing a minimum timeout value.
struct timespec abst;
compute_abstime(&abst, millis);
int ret = OS_TIMEOUT;
int status = pthread_mutex_lock(_mutex);
assert_status(status == 0, status, "mutex_lock");
guarantee (_nParked == 0, "invariant") ;
++_nParked ;
// Object.wait(timo) will return because of
// (a) notification
// (b) timeout
// (c) thread.interrupt
//
// Thread.interrupt and object.notify{All} both call Event::set.
// That is, we treat thread.interrupt as a special case of notification.
// The underlying Solaris implementation, cond_timedwait, admits
// spurious/premature wakeups, but the JLS/JVM spec prevents the
// JVM from making those visible to Java code. As such, we must
// filter out spurious wakeups. We assume all ETIME returns are valid.
//
// TODO: properly differentiate simultaneous notify+interrupt.
// In that case, we should propagate the notify to another waiter.
while (_Event < 0) {
status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
if (status != 0 && WorkAroundNPTLTimedWaitHang) {
pthread_cond_destroy (_cond);
pthread_cond_init (_cond, NULL) ;
}
assert_status(status == 0 || status == EINTR ||
status == ETIMEDOUT,
status, "cond_timedwait");
if (!FilterSpuriousWakeups) break ; // previous semantics
if (status == ETIMEDOUT) break ;
// We consume and ignore EINTR and spurious wakeups.
}
--_nParked ;
if (_Event >= 0) {
ret = OS_OK;
}
_Event = 0 ;
status = pthread_mutex_unlock(_mutex);
assert_status(status == 0, status, "mutex_unlock");
assert (_nParked == 0, "invariant") ;
// Paranoia to ensure our locked and lock-free paths interact
// correctly with each other.
OrderAccess::fence();
return ret;
}
void os::PlatformEvent::unpark() {
// Transitions for _Event:
// 0 :=> 1
// 1 :=> 1
// -1 :=> either 0 or 1; must signal target thread
// That is, we can safely transition _Event from -1 to either
// 0 or 1. Forcing 1 is slightly more efficient for back-to-back
// unpark() calls.
// See also: "Semaphores in Plan 9" by Mullender & Cox
//
// Note: Forcing a transition from "-1" to "1" on an unpark() means
// that it will take two back-to-back park() calls for the owning
// thread to block. This has the benefit of forcing a spurious return
// from the first park() call after an unpark() call which will help
// shake out uses of park() and unpark() without condition variables.
if (Atomic::xchg(1, &_Event) >= 0) return;
// Wait for the thread associated with the event to vacate
int status = pthread_mutex_lock(_mutex);
assert_status(status == 0, status, "mutex_lock");
int AnyWaiters = _nParked;
assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
AnyWaiters = 0;
pthread_cond_signal(_cond);
}
status = pthread_mutex_unlock(_mutex);
assert_status(status == 0, status, "mutex_unlock");
if (AnyWaiters != 0) {
status = pthread_cond_signal(_cond);
assert_status(status == 0, status, "cond_signal");
}
// Note that we signal() _after dropping the lock for "immortal" Events.
// This is safe and avoids a common class of futile wakeups. In rare
// circumstances this can cause a thread to return prematurely from
// cond_{timed}wait() but the spurious wakeup is benign and the victim will
// simply re-test the condition and re-park itself.
}
// JSR166
// -------------------------------------------------------
/*
* The solaris and bsd implementations of park/unpark are fairly
* conservative for now, but can be improved. They currently use a
* mutex/condvar pair, plus a a count.
* Park decrements count if > 0, else does a condvar wait. Unpark
* sets count to 1 and signals condvar. Only one thread ever waits
* on the condvar. Contention seen when trying to park implies that someone
* is unparking you, so don't wait. And spurious returns are fine, so there
* is no need to track notifications.
*/
#define MAX_SECS 100000000
/*
* This code is common to bsd and solaris and will be moved to a
* common place in dolphin.
*
* The passed in time value is either a relative time in nanoseconds
* or an absolute time in milliseconds. Either way it has to be unpacked
* into suitable seconds and nanoseconds components and stored in the
* given timespec structure.
* Given time is a 64-bit value and the time_t used in the timespec is only
* a signed-32-bit value (except on 64-bit Bsd) we have to watch for
* overflow if times way in the future are given. Further on Solaris versions
* prior to 10 there is a restriction (see cond_timedwait) that the specified
* number of seconds, in abstime, is less than current_time + 100,000,000.
* As it will be 28 years before "now + 100000000" will overflow we can
* ignore overflow and just impose a hard-limit on seconds using the value
* of "now + 100,000,000". This places a limit on the timeout of about 3.17
* years from "now".
*/
static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
assert (time > 0, "convertTime");
struct timeval now;
int status = gettimeofday(&now, NULL);
assert(status == 0, "gettimeofday");
time_t max_secs = now.tv_sec + MAX_SECS;
if (isAbsolute) {
jlong secs = time / 1000;
if (secs > max_secs) {
absTime->tv_sec = max_secs;
}
else {
absTime->tv_sec = secs;
}
absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
}
else {
jlong secs = time / NANOSECS_PER_SEC;
if (secs >= MAX_SECS) {
absTime->tv_sec = max_secs;
absTime->tv_nsec = 0;
}
else {
absTime->tv_sec = now.tv_sec + secs;
absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
absTime->tv_nsec -= NANOSECS_PER_SEC;
++absTime->tv_sec; // note: this must be <= max_secs
}
}
}
assert(absTime->tv_sec >= 0, "tv_sec < 0");
assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
}
void Parker::park(bool isAbsolute, jlong time) {
// Ideally we'd do something useful while spinning, such
// as calling unpackTime().
// Optional fast-path check:
// Return immediately if a permit is available.
// We depend on Atomic::xchg() having full barrier semantics
// since we are doing a lock-free update to _counter.
if (Atomic::xchg(0, &_counter) > 0) return;
Thread* thread = Thread::current();
assert(thread->is_Java_thread(), "Must be JavaThread");
JavaThread *jt = (JavaThread *)thread;
// Optional optimization -- avoid state transitions if there's an interrupt pending.
// Check interrupt before trying to wait
if (Thread::is_interrupted(thread, false)) {
return;
}
// Next, demultiplex/decode time arguments
struct timespec absTime;
if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
return;
}
if (time > 0) {
unpackTime(&absTime, isAbsolute, time);
}
// Enter safepoint region
// Beware of deadlocks such as 6317397.
// The per-thread Parker:: mutex is a classic leaf-lock.
// In particular a thread must never block on the Threads_lock while
// holding the Parker:: mutex. If safepoints are pending both the
// the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
ThreadBlockInVM tbivm(jt);
// Don't wait if cannot get lock since interference arises from
// unblocking. Also. check interrupt before trying wait
if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
return;
}
int status ;
if (_counter > 0) { // no wait needed
_counter = 0;
status = pthread_mutex_unlock(_mutex);
assert (status == 0, "invariant") ;
// Paranoia to ensure our locked and lock-free paths interact
// correctly with each other and Java-level accesses.
OrderAccess::fence();
return;
}
#ifdef ASSERT
// Don't catch signals while blocked; let the running threads have the signals.
// (This allows a debugger to break into the running thread.)
sigset_t oldsigs;
sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
#endif
OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
jt->set_suspend_equivalent();
// cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
if (time == 0) {
status = pthread_cond_wait (_cond, _mutex) ;
} else {
status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
if (status != 0 && WorkAroundNPTLTimedWaitHang) {
pthread_cond_destroy (_cond) ;
pthread_cond_init (_cond, NULL);
}
}
assert_status(status == 0 || status == EINTR ||
status == ETIMEDOUT,
status, "cond_timedwait");
#ifdef ASSERT
pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
#endif
_counter = 0 ;
status = pthread_mutex_unlock(_mutex) ;
assert_status(status == 0, status, "invariant") ;
// Paranoia to ensure our locked and lock-free paths interact
// correctly with each other and Java-level accesses.
OrderAccess::fence();
// If externally suspended while waiting, re-suspend
if (jt->handle_special_suspend_equivalent_condition()) {
jt->java_suspend_self();
}
}
void Parker::unpark() {
int s, status ;
status = pthread_mutex_lock(_mutex);
assert (status == 0, "invariant") ;
s = _counter;
_counter = 1;
if (s < 1) {
if (WorkAroundNPTLTimedWaitHang) {
status = pthread_cond_signal (_cond) ;
assert (status == 0, "invariant") ;
status = pthread_mutex_unlock(_mutex);
assert (status == 0, "invariant") ;
} else {
status = pthread_mutex_unlock(_mutex);
assert (status == 0, "invariant") ;
status = pthread_cond_signal (_cond) ;
assert (status == 0, "invariant") ;
}
} else {
pthread_mutex_unlock(_mutex);
assert (status == 0, "invariant") ;
}
}
/* 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");
// 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
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