8234512: Missing pieces from JDK-8224816
Reviewed-by: rehn, pliden, kbarrett, gziemski
/*
* Copyright (c) 1999, 2019, 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 "jvm.h"
#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 "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/filemap.hpp"
#include "oops/oop.inline.hpp"
#include "os_bsd.inline.hpp"
#include "os_posix.inline.hpp"
#include "os_share_bsd.hpp"
#include "prims/jniFastGetField.hpp"
#include "prims/jvm_misc.hpp"
#include "runtime/arguments.hpp"
#include "runtime/atomic.hpp"
#include "runtime/extendedPC.hpp"
#include "runtime/globals.hpp"
#include "runtime/interfaceSupport.inline.hpp"
#include "runtime/java.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/objectMonitor.hpp"
#include "runtime/orderAccess.hpp"
#include "runtime/osThread.hpp"
#include "runtime/perfMemory.hpp"
#include "runtime/semaphore.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/align.hpp"
#include "utilities/decoder.hpp"
#include "utilities/defaultStream.hpp"
#include "utilities/events.hpp"
#include "utilities/growableArray.hpp"
#include "utilities/vmError.hpp"
// put OS-includes here
# include <dlfcn.h>
# include <errno.h>
# include <fcntl.h>
# include <inttypes.h>
# include <poll.h>
# include <pthread.h>
# include <pwd.h>
# include <signal.h>
# include <stdint.h>
# include <stdio.h>
# include <string.h>
# include <sys/ioctl.h>
# include <sys/mman.h>
# include <sys/param.h>
# include <sys/resource.h>
# include <sys/socket.h>
# include <sys/stat.h>
# include <sys/syscall.h>
# include <sys/sysctl.h>
# include <sys/time.h>
# include <sys/times.h>
# include <sys/types.h>
# include <sys/wait.h>
# include <time.h>
# include <unistd.h>
#if defined(__FreeBSD__) || defined(__NetBSD__)
#include <elf.h>
#endif
#ifdef __APPLE__
#include <mach-o/dyld.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)
////////////////////////////////////////////////////////////////////////////////
// global variables
julong os::Bsd::_physical_memory = 0;
#ifdef __APPLE__
mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
volatile uint64_t os::Bsd::_max_abstime = 0;
#else
int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
#endif
pthread_t os::Bsd::_main_thread;
int os::Bsd::_page_size = -1;
static jlong initial_time_count=0;
static int clock_tics_per_sec = 100;
// For diagnostics to print a message once. see run_periodic_checks
static sigset_t check_signal_done;
static bool check_signals = true;
// Signal number used to suspend/resume a thread
// do not use any signal number less than SIGSEGV, see 4355769
static int SR_signum = SIGUSR2;
sigset_t SR_sigset;
////////////////////////////////////////////////////////////////////////////////
// utility functions
static int SR_initialize();
julong os::available_memory() {
return Bsd::available_memory();
}
// available here means free
julong os::Bsd::available_memory() {
uint64_t available = physical_memory() >> 2;
#ifdef __APPLE__
mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
vm_statistics64_data_t vmstat;
kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
(host_info64_t)&vmstat, &count);
assert(kerr == KERN_SUCCESS,
"host_statistics64 failed - check mach_host_self() and count");
if (kerr == KERN_SUCCESS) {
available = vmstat.free_count * os::vm_page_size();
}
#endif
return available;
}
julong os::physical_memory() {
return Bsd::physical_memory();
}
// Return true if user is running as root.
bool os::have_special_privileges() {
static bool init = false;
static bool privileges = false;
if (!init) {
privileges = (getuid() != geteuid()) || (getgid() != getegid());
init = true;
}
return privileges;
}
// Cpu architecture string
#if defined(ZERO)
static char cpu_arch[] = ZERO_LIBARCH;
#elif defined(IA64)
static char cpu_arch[] = "ia64";
#elif defined(IA32)
static char cpu_arch[] = "i386";
#elif defined(AMD64)
static char cpu_arch[] = "amd64";
#elif defined(ARM)
static char cpu_arch[] = "arm";
#elif defined(PPC32)
static char cpu_arch[] = "ppc";
#elif defined(SPARC)
#ifdef _LP64
static char cpu_arch[] = "sparcv9";
#else
static char cpu_arch[] = "sparc";
#endif
#else
#error Add appropriate cpu_arch setting
#endif
// Compiler variant
#ifdef COMPILER2
#define COMPILER_VARIANT "server"
#else
#define COMPILER_VARIANT "client"
#endif
void os::Bsd::initialize_system_info() {
int mib[2];
size_t len;
int cpu_val;
julong mem_val;
// get processors count via hw.ncpus sysctl
mib[0] = CTL_HW;
mib[1] = HW_NCPU;
len = sizeof(cpu_val);
if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
assert(len == sizeof(cpu_val), "unexpected data size");
set_processor_count(cpu_val);
} else {
set_processor_count(1); // fallback
}
// get physical memory via hw.memsize sysctl (hw.memsize is used
// since it returns a 64 bit value)
mib[0] = CTL_HW;
#if defined (HW_MEMSIZE) // Apple
mib[1] = HW_MEMSIZE;
#elif defined(HW_PHYSMEM) // Most of BSD
mib[1] = HW_PHYSMEM;
#elif defined(HW_REALMEM) // Old FreeBSD
mib[1] = HW_REALMEM;
#else
#error No ways to get physmem
#endif
len = sizeof(mem_val);
if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
assert(len == sizeof(mem_val), "unexpected data size");
_physical_memory = mem_val;
} else {
_physical_memory = 256 * 1024 * 1024; // fallback (XXXBSD?)
}
#ifdef __OpenBSD__
{
// limit _physical_memory memory view on OpenBSD since
// datasize rlimit restricts us anyway.
struct rlimit limits;
getrlimit(RLIMIT_DATA, &limits);
_physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
}
#endif
}
#ifdef __APPLE__
static const char *get_home() {
const char *home_dir = ::getenv("HOME");
if ((home_dir == NULL) || (*home_dir == '\0')) {
struct passwd *passwd_info = getpwuid(geteuid());
if (passwd_info != NULL) {
home_dir = passwd_info->pw_dir;
}
}
return home_dir;
}
#endif
void os::init_system_properties_values() {
// The next steps are taken in the product version:
//
// Obtain the JAVA_HOME value from the location of libjvm.so.
// This library should be located at:
// <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
//
// If "/jre/lib/" appears at the right place in the path, then we
// assume libjvm.so is installed in a JDK and we use this path.
//
// Otherwise exit with message: "Could not create the Java virtual machine."
//
// The following extra steps are taken in the debugging version:
//
// If "/jre/lib/" does NOT appear at the right place in the path
// instead of exit check for $JAVA_HOME environment variable.
//
// If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
// then we append a fake suffix "hotspot/libjvm.so" to this path so
// it looks like libjvm.so is installed there
// <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
//
// Otherwise exit.
//
// Important note: if the location of libjvm.so changes this
// code needs to be changed accordingly.
// See ld(1):
// The linker uses the following search paths to locate required
// shared libraries:
// 1: ...
// ...
// 7: The default directories, normally /lib and /usr/lib.
#ifndef DEFAULT_LIBPATH
#ifndef OVERRIDE_LIBPATH
#define DEFAULT_LIBPATH "/lib:/usr/lib"
#else
#define DEFAULT_LIBPATH OVERRIDE_LIBPATH
#endif
#endif
// Base path of extensions installed on the system.
#define SYS_EXT_DIR "/usr/java/packages"
#define EXTENSIONS_DIR "/lib/ext"
#ifndef __APPLE__
// Buffer that fits several sprintfs.
// Note that the space for the colon and the trailing null are provided
// by the nulls included by the sizeof operator.
const size_t bufsize =
MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
(size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
// sysclasspath, java_home, dll_dir
{
char *pslash;
os::jvm_path(buf, bufsize);
// Found the full path to libjvm.so.
// Now cut the path to <java_home>/jre if we can.
*(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
pslash = strrchr(buf, '/');
if (pslash != NULL) {
*pslash = '\0'; // Get rid of /{client|server|hotspot}.
}
Arguments::set_dll_dir(buf);
if (pslash != NULL) {
pslash = strrchr(buf, '/');
if (pslash != NULL) {
*pslash = '\0'; // Get rid of /<arch>.
pslash = strrchr(buf, '/');
if (pslash != NULL) {
*pslash = '\0'; // Get rid of /lib.
}
}
}
Arguments::set_java_home(buf);
if (!set_boot_path('/', ':')) {
vm_exit_during_initialization("Failed setting boot class path.", NULL);
}
}
// Where to look for native libraries.
//
// Note: Due to a legacy implementation, most of the library path
// is set in the launcher. This was to accomodate linking restrictions
// on legacy Bsd implementations (which are no longer supported).
// Eventually, all the library path setting will be done here.
//
// However, to prevent the proliferation of improperly built native
// libraries, the new path component /usr/java/packages is added here.
// Eventually, all the library path setting will be done here.
{
// Get the user setting of LD_LIBRARY_PATH, and prepended it. It
// should always exist (until the legacy problem cited above is
// addressed).
const char *v = ::getenv("LD_LIBRARY_PATH");
const char *v_colon = ":";
if (v == NULL) { v = ""; v_colon = ""; }
// That's +1 for the colon and +1 for the trailing '\0'.
char *ld_library_path = NEW_C_HEAP_ARRAY(char,
strlen(v) + 1 +
sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
mtInternal);
sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
Arguments::set_library_path(ld_library_path);
FREE_C_HEAP_ARRAY(char, ld_library_path);
}
// Extensions directories.
sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
Arguments::set_ext_dirs(buf);
FREE_C_HEAP_ARRAY(char, buf);
#else // __APPLE__
#define SYS_EXTENSIONS_DIR "/Library/Java/Extensions"
#define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
const char *user_home_dir = get_home();
// The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
sizeof(SYS_EXTENSIONS_DIRS);
// Buffer that fits several sprintfs.
// Note that the space for the colon and the trailing null are provided
// by the nulls included by the sizeof operator.
const size_t bufsize =
MAX2((size_t)MAXPATHLEN, // for dll_dir & friends.
(size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
// sysclasspath, java_home, dll_dir
{
char *pslash;
os::jvm_path(buf, bufsize);
// Found the full path to libjvm.so.
// Now cut the path to <java_home>/jre if we can.
*(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
pslash = strrchr(buf, '/');
if (pslash != NULL) {
*pslash = '\0'; // Get rid of /{client|server|hotspot}.
}
#ifdef STATIC_BUILD
strcat(buf, "/lib");
#endif
Arguments::set_dll_dir(buf);
if (pslash != NULL) {
pslash = strrchr(buf, '/');
if (pslash != NULL) {
*pslash = '\0'; // Get rid of /lib.
}
}
Arguments::set_java_home(buf);
set_boot_path('/', ':');
}
// Where to look for native libraries.
//
// Note: Due to a legacy implementation, most of the library path
// is set in the launcher. This was to accomodate linking restrictions
// on legacy Bsd implementations (which are no longer supported).
// Eventually, all the library path setting will be done here.
//
// However, to prevent the proliferation of improperly built native
// libraries, the new path component /usr/java/packages is added here.
// Eventually, all the library path setting will be done here.
{
// Get the user setting of LD_LIBRARY_PATH, and prepended it. It
// should always exist (until the legacy problem cited above is
// addressed).
// Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
// can specify a directory inside an app wrapper
const char *l = ::getenv("JAVA_LIBRARY_PATH");
const char *l_colon = ":";
if (l == NULL) { l = ""; l_colon = ""; }
const char *v = ::getenv("DYLD_LIBRARY_PATH");
const char *v_colon = ":";
if (v == NULL) { v = ""; v_colon = ""; }
// Apple's Java6 has "." at the beginning of java.library.path.
// OpenJDK on Windows has "." at the end of java.library.path.
// OpenJDK on Linux and Solaris don't have "." in java.library.path
// at all. To ease the transition from Apple's Java6 to OpenJDK7,
// "." is appended to the end of java.library.path. Yes, this
// could cause a change in behavior, but Apple's Java6 behavior
// can be achieved by putting "." at the beginning of the
// JAVA_LIBRARY_PATH environment variable.
char *ld_library_path = NEW_C_HEAP_ARRAY(char,
strlen(v) + 1 + strlen(l) + 1 +
system_ext_size + 3,
mtInternal);
sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
v, v_colon, l, l_colon, user_home_dir);
Arguments::set_library_path(ld_library_path);
FREE_C_HEAP_ARRAY(char, ld_library_path);
}
// Extensions directories.
//
// Note that the space for the colon and the trailing null are provided
// by the nulls included by the sizeof operator (so actually one byte more
// than necessary is allocated).
sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
user_home_dir, Arguments::get_java_home());
Arguments::set_ext_dirs(buf);
FREE_C_HEAP_ARRAY(char, buf);
#undef SYS_EXTENSIONS_DIR
#undef SYS_EXTENSIONS_DIRS
#endif // __APPLE__
#undef SYS_EXT_DIR
#undef EXTENSIONS_DIR
}
////////////////////////////////////////////////////////////////////////////////
// breakpoint support
void os::breakpoint() {
BREAKPOINT;
}
extern "C" void breakpoint() {
// use debugger to set breakpoint here
}
////////////////////////////////////////////////////////////////////////////////
// signal support
debug_only(static bool signal_sets_initialized = false);
static sigset_t unblocked_sigs, vm_sigs;
void os::Bsd::signal_sets_init() {
// Should also have an assertion stating we are still single-threaded.
assert(!signal_sets_initialized, "Already initialized");
// Fill in signals that are necessarily unblocked for all threads in
// the VM. Currently, we unblock the following signals:
// SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
// by -Xrs (=ReduceSignalUsage));
// BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
// other threads. The "ReduceSignalUsage" boolean tells us not to alter
// the dispositions or masks wrt these signals.
// Programs embedding the VM that want to use the above signals for their
// own purposes must, at this time, use the "-Xrs" option to prevent
// interference with shutdown hooks and BREAK_SIGNAL thread dumping.
// (See bug 4345157, and other related bugs).
// In reality, though, unblocking these signals is really a nop, since
// these signals are not blocked by default.
sigemptyset(&unblocked_sigs);
sigaddset(&unblocked_sigs, SIGILL);
sigaddset(&unblocked_sigs, SIGSEGV);
sigaddset(&unblocked_sigs, SIGBUS);
sigaddset(&unblocked_sigs, SIGFPE);
sigaddset(&unblocked_sigs, SR_signum);
if (!ReduceSignalUsage) {
if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
}
if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
}
if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
}
}
// Fill in signals that are blocked by all but the VM thread.
sigemptyset(&vm_sigs);
if (!ReduceSignalUsage) {
sigaddset(&vm_sigs, BREAK_SIGNAL);
}
debug_only(signal_sets_initialized = true);
}
// These are signals that are unblocked while a thread is running Java.
// (For some reason, they get blocked by default.)
sigset_t* os::Bsd::unblocked_signals() {
assert(signal_sets_initialized, "Not initialized");
return &unblocked_sigs;
}
// These are the signals that are blocked while a (non-VM) thread is
// running Java. Only the VM thread handles these signals.
sigset_t* os::Bsd::vm_signals() {
assert(signal_sets_initialized, "Not initialized");
return &vm_sigs;
}
void os::Bsd::hotspot_sigmask(Thread* thread) {
//Save caller's signal mask before setting VM signal mask
sigset_t caller_sigmask;
pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
OSThread* osthread = thread->osthread();
osthread->set_caller_sigmask(caller_sigmask);
pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
if (!ReduceSignalUsage) {
if (thread->is_VM_thread()) {
// Only the VM thread handles BREAK_SIGNAL ...
pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
} else {
// ... all other threads block BREAK_SIGNAL
pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
}
}
}
//////////////////////////////////////////////////////////////////////////////
// create new thread
#ifdef __APPLE__
// library handle for calling objc_registerThreadWithCollector()
// without static linking to the libobjc library
#define OBJC_LIB "/usr/lib/libobjc.dylib"
#define OBJC_GCREGISTER "objc_registerThreadWithCollector"
typedef void (*objc_registerThreadWithCollector_t)();
extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
#endif
#ifdef __APPLE__
static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
// Additional thread_id used to correlate threads in SA
thread_identifier_info_data_t m_ident_info;
mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT;
thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
(thread_info_t) &m_ident_info, &count);
return m_ident_info.thread_id;
}
#endif
// Thread start routine for all newly created threads
static void *thread_native_entry(Thread *thread) {
thread->record_stack_base_and_size();
// Try to randomize the cache line index of hot stack frames.
// This helps when threads of the same stack traces evict each other's
// cache lines. The threads can be either from the same JVM instance, or
// from different JVM instances. The benefit is especially true for
// processors with hyperthreading technology.
static int counter = 0;
int pid = os::current_process_id();
alloca(((pid ^ counter++) & 7) * 128);
thread->initialize_thread_current();
OSThread* osthread = thread->osthread();
Monitor* sync = osthread->startThread_lock();
osthread->set_thread_id(os::Bsd::gettid());
log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
os::current_thread_id(), (uintx) pthread_self());
#ifdef __APPLE__
uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
guarantee(unique_thread_id != 0, "unique thread id was not found");
osthread->set_unique_thread_id(unique_thread_id);
#endif
// initialize signal mask for this thread
os::Bsd::hotspot_sigmask(thread);
// initialize floating point control register
os::Bsd::init_thread_fpu_state();
#ifdef __APPLE__
// register thread with objc gc
if (objc_registerThreadWithCollectorFunction != NULL) {
objc_registerThreadWithCollectorFunction();
}
#endif
// handshaking with parent thread
{
MutexLocker 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_without_safepoint_check();
}
}
// call one more level start routine
thread->call_run();
// Note: at this point the thread object may already have deleted itself.
// Prevent dereferencing it from here on out.
thread = NULL;
log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
os::current_thread_id(), (uintx) pthread_self());
return 0;
}
bool os::create_thread(Thread* thread, ThreadType thr_type,
size_t req_stack_size) {
assert(thread->osthread() == NULL, "caller responsible");
// Allocate the OSThread object
OSThread* osthread = new OSThread(NULL, NULL);
if (osthread == NULL) {
return false;
}
// set the correct thread state
osthread->set_thread_type(thr_type);
// Initial state is ALLOCATED but not INITIALIZED
osthread->set_state(ALLOCATED);
thread->set_osthread(osthread);
// init thread attributes
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
// calculate stack size if it's not specified by caller
size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
int status = pthread_attr_setstacksize(&attr, stack_size);
assert_status(status == 0, status, "pthread_attr_setstacksize");
ThreadState state;
{
pthread_t tid;
int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
char buf[64];
if (ret == 0) {
log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
(uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
} else {
log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
// Log some OS information which might explain why creating the thread failed.
log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
LogStream st(Log(os, thread)::info());
os::Posix::print_rlimit_info(&st);
os::print_memory_info(&st);
}
pthread_attr_destroy(&attr);
if (ret != 0) {
// Need to clean up stuff we've allocated so far
thread->set_osthread(NULL);
delete osthread;
return false;
}
// Store pthread info into the OSThread
osthread->set_pthread_id(tid);
// Wait until child thread is either initialized or aborted
{
Monitor* sync_with_child = osthread->startThread_lock();
MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
while ((state = osthread->get_state()) == ALLOCATED) {
sync_with_child->wait_without_safepoint_check();
}
}
}
// Aborted due to thread limit being reached
if (state == ZOMBIE) {
thread->set_osthread(NULL);
delete osthread;
return false;
}
// The thread is returned suspended (in state INITIALIZED),
// and is started higher up in the call chain
assert(state == INITIALIZED, "race condition");
return true;
}
/////////////////////////////////////////////////////////////////////////////
// attach existing thread
// bootstrap the main thread
bool os::create_main_thread(JavaThread* thread) {
assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
return create_attached_thread(thread);
}
bool os::create_attached_thread(JavaThread* thread) {
#ifdef ASSERT
thread->verify_not_published();
#endif
// Allocate the OSThread object
OSThread* osthread = new OSThread(NULL, NULL);
if (osthread == NULL) {
return false;
}
osthread->set_thread_id(os::Bsd::gettid());
// Store pthread info into the OSThread
#ifdef __APPLE__
uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
guarantee(unique_thread_id != 0, "just checking");
osthread->set_unique_thread_id(unique_thread_id);
#endif
osthread->set_pthread_id(::pthread_self());
// initialize floating point control register
os::Bsd::init_thread_fpu_state();
// Initial thread state is RUNNABLE
osthread->set_state(RUNNABLE);
thread->set_osthread(osthread);
// initialize signal mask for this thread
// and save the caller's signal mask
os::Bsd::hotspot_sigmask(thread);
log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
os::current_thread_id(), (uintx) pthread_self());
return true;
}
void os::pd_start_thread(Thread* thread) {
OSThread * osthread = thread->osthread();
assert(osthread->get_state() != INITIALIZED, "just checking");
Monitor* sync_with_child = osthread->startThread_lock();
MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
sync_with_child->notify();
}
// Free Bsd resources related to the OSThread
void os::free_thread(OSThread* osthread) {
assert(osthread != NULL, "osthread not set");
// We are told to free resources of the argument thread,
// but we can only really operate on the current thread.
assert(Thread::current()->osthread() == osthread,
"os::free_thread but not current thread");
// Restore caller's signal mask
sigset_t sigmask = osthread->caller_sigmask();
pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
delete osthread;
}
////////////////////////////////////////////////////////////////////////////////
// time support
// Time since start-up in seconds to a fine granularity.
// Used by VMSelfDestructTimer and the MemProfiler.
double os::elapsedTime() {
return ((double)os::elapsed_counter()) / os::elapsed_frequency();
}
jlong os::elapsed_counter() {
return javaTimeNanos() - initial_time_count;
}
jlong os::elapsed_frequency() {
return NANOSECS_PER_SEC; // nanosecond resolution
}
bool os::supports_vtime() { return true; }
double os::elapsedVTime() {
// better than nothing, but not much
return elapsedTime();
}
jlong os::javaTimeMillis() {
timeval time;
int status = gettimeofday(&time, NULL);
assert(status != -1, "bsd error");
return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
}
void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
timeval time;
int status = gettimeofday(&time, NULL);
assert(status != -1, "bsd error");
seconds = jlong(time.tv_sec);
nanos = jlong(time.tv_usec) * 1000;
}
#ifndef __APPLE__
#ifndef CLOCK_MONOTONIC
#define CLOCK_MONOTONIC (1)
#endif
#endif
#ifdef __APPLE__
void os::Bsd::clock_init() {
mach_timebase_info(&_timebase_info);
}
#else
void os::Bsd::clock_init() {
struct timespec res;
struct timespec tp;
if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
// yes, monotonic clock is supported
_clock_gettime = ::clock_gettime;
}
}
#endif
#ifdef __APPLE__
jlong os::javaTimeNanos() {
const uint64_t tm = mach_absolute_time();
const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
const uint64_t prev = Bsd::_max_abstime;
if (now <= prev) {
return prev; // same or retrograde time;
}
const uint64_t obsv = Atomic::cmpxchg(now, &Bsd::_max_abstime, prev);
assert(obsv >= prev, "invariant"); // Monotonicity
// If the CAS succeeded then we're done and return "now".
// If the CAS failed and the observed value "obsv" is >= now then
// we should return "obsv". If the CAS failed and now > obsv > prv then
// some other thread raced this thread and installed a new value, in which case
// we could either (a) retry the entire operation, (b) retry trying to install now
// or (c) just return obsv. We use (c). No loop is required although in some cases
// we might discard a higher "now" value in deference to a slightly lower but freshly
// installed obsv value. That's entirely benign -- it admits no new orderings compared
// to (a) or (b) -- and greatly reduces coherence traffic.
// We might also condition (c) on the magnitude of the delta between obsv and now.
// Avoiding excessive CAS operations to hot RW locations is critical.
// See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
return (prev == obsv) ? now : obsv;
}
#else // __APPLE__
jlong os::javaTimeNanos() {
if (os::supports_monotonic_clock()) {
struct timespec tp;
int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
assert(status == 0, "gettime error");
jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
return result;
} else {
timeval time;
int status = gettimeofday(&time, NULL);
assert(status != -1, "bsd error");
jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
return 1000 * usecs;
}
}
#endif // __APPLE__
void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
if (os::supports_monotonic_clock()) {
info_ptr->max_value = ALL_64_BITS;
// CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
info_ptr->may_skip_backward = false; // not subject to resetting or drifting
info_ptr->may_skip_forward = false; // not subject to resetting or drifting
} else {
// gettimeofday - based on time in seconds since the Epoch thus does not wrap
info_ptr->max_value = ALL_64_BITS;
// gettimeofday is a real time clock so it skips
info_ptr->may_skip_backward = true;
info_ptr->may_skip_forward = true;
}
info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
}
// Return the real, user, and system times in seconds from an
// arbitrary fixed point in the past.
bool os::getTimesSecs(double* process_real_time,
double* process_user_time,
double* process_system_time) {
struct tms ticks;
clock_t real_ticks = times(&ticks);
if (real_ticks == (clock_t) (-1)) {
return false;
} else {
double ticks_per_second = (double) clock_tics_per_sec;
*process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
*process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
*process_real_time = ((double) real_ticks) / ticks_per_second;
return true;
}
}
char * os::local_time_string(char *buf, size_t buflen) {
struct tm t;
time_t long_time;
time(&long_time);
localtime_r(&long_time, &t);
jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
t.tm_hour, t.tm_min, t.tm_sec);
return buf;
}
struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
return localtime_r(clock, res);
}
////////////////////////////////////////////////////////////////////////////////
// runtime exit support
// Note: os::shutdown() might be called very early during initialization, or
// called from signal handler. Before adding something to os::shutdown(), make
// sure it is async-safe and can handle partially initialized VM.
void os::shutdown() {
// allow PerfMemory to attempt cleanup of any persistent resources
perfMemory_exit();
// needs to remove object in file system
AttachListener::abort();
// flush buffered output, finish log files
ostream_abort();
// Check for abort hook
abort_hook_t abort_hook = Arguments::abort_hook();
if (abort_hook != NULL) {
abort_hook();
}
}
// Note: os::abort() might be called very early during initialization, or
// called from signal handler. Before adding something to os::abort(), make
// sure it is async-safe and can handle partially initialized VM.
void os::abort(bool dump_core, void* siginfo, const void* context) {
os::shutdown();
if (dump_core) {
#ifndef PRODUCT
fdStream out(defaultStream::output_fd());
out.print_raw("Current thread is ");
char buf[16];
jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
out.print_raw_cr(buf);
out.print_raw_cr("Dumping core ...");
#endif
::abort(); // dump core
}
::exit(1);
}
// Die immediately, no exit hook, no abort hook, no cleanup.
// Dump a core file, if possible, for debugging.
void os::die() {
if (TestUnresponsiveErrorHandler && !CreateCoredumpOnCrash) {
// For TimeoutInErrorHandlingTest.java, we just kill the VM
// and don't take the time to generate a core file.
os::signal_raise(SIGKILL);
} else {
// _exit() on BsdThreads only kills current thread
::abort();
}
}
// Information of current thread in variety of formats
pid_t os::Bsd::gettid() {
int retval = -1;
#ifdef __APPLE__ //XNU kernel
// despite the fact mach port is actually not a thread id use it
// instead of syscall(SYS_thread_selfid) as it certainly fits to u4
retval = ::pthread_mach_thread_np(::pthread_self());
guarantee(retval != 0, "just checking");
return retval;
#else
#ifdef __FreeBSD__
retval = syscall(SYS_thr_self);
#else
#ifdef __OpenBSD__
retval = syscall(SYS_getthrid);
#else
#ifdef __NetBSD__
retval = (pid_t) syscall(SYS__lwp_self);
#endif
#endif
#endif
#endif
if (retval == -1) {
return getpid();
}
}
intx os::current_thread_id() {
#ifdef __APPLE__
return (intx)::pthread_mach_thread_np(::pthread_self());
#else
return (intx)::pthread_self();
#endif
}
int os::current_process_id() {
return (int)(getpid());
}
// DLL functions
const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
// This must be hard coded because it's the system's temporary
// directory not the java application's temp directory, ala java.io.tmpdir.
#ifdef __APPLE__
// macosx has a secure per-user temporary directory
char temp_path_storage[PATH_MAX];
const char* os::get_temp_directory() {
static char *temp_path = NULL;
if (temp_path == NULL) {
int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
if (pathSize == 0 || pathSize > PATH_MAX) {
strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
}
temp_path = temp_path_storage;
}
return temp_path;
}
#else // __APPLE__
const char* os::get_temp_directory() { return "/tmp"; }
#endif // __APPLE__
// check if addr is inside libjvm.so
bool os::address_is_in_vm(address addr) {
static address libjvm_base_addr;
Dl_info dlinfo;
if (libjvm_base_addr == NULL) {
if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
libjvm_base_addr = (address)dlinfo.dli_fbase;
}
assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
}
if (dladdr((void *)addr, &dlinfo) != 0) {
if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
}
return false;
}
#define MACH_MAXSYMLEN 256
bool os::dll_address_to_function_name(address addr, char *buf,
int buflen, int *offset,
bool demangle) {
// buf is not optional, but offset is optional
assert(buf != NULL, "sanity check");
Dl_info dlinfo;
char localbuf[MACH_MAXSYMLEN];
if (dladdr((void*)addr, &dlinfo) != 0) {
// see if we have a matching symbol
if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
}
if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
return true;
}
// no matching symbol so try for just file info
if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
buf, buflen, offset, dlinfo.dli_fname, demangle)) {
return true;
}
}
// Handle non-dynamic manually:
if (dlinfo.dli_fbase != NULL &&
Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
dlinfo.dli_fbase)) {
if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) {
jio_snprintf(buf, buflen, "%s", localbuf);
}
return true;
}
}
buf[0] = '\0';
if (offset != NULL) *offset = -1;
return false;
}
// ported from solaris version
bool os::dll_address_to_library_name(address addr, char* buf,
int buflen, int* offset) {
// buf is not optional, but offset is optional
assert(buf != NULL, "sanity check");
Dl_info dlinfo;
if (dladdr((void*)addr, &dlinfo) != 0) {
if (dlinfo.dli_fname != NULL) {
jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
}
if (dlinfo.dli_fbase != NULL && offset != NULL) {
*offset = addr - (address)dlinfo.dli_fbase;
}
return true;
}
buf[0] = '\0';
if (offset) *offset = -1;
return false;
}
// Loads .dll/.so and
// in case of error it checks if .dll/.so was built for the
// same architecture as Hotspot is running on
#ifdef __APPLE__
void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
#ifdef STATIC_BUILD
return os::get_default_process_handle();
#else
log_info(os)("attempting shared library load of %s", filename);
void * result= ::dlopen(filename, RTLD_LAZY);
if (result != NULL) {
Events::log(NULL, "Loaded shared library %s", filename);
// Successful loading
log_info(os)("shared library load of %s was successful", filename);
return result;
}
const char* error_report = ::dlerror();
if (error_report == NULL) {
error_report = "dlerror returned no error description";
}
if (ebuf != NULL && ebuflen > 0) {
// Read system error message into ebuf
::strncpy(ebuf, error_report, ebuflen-1);
ebuf[ebuflen-1]='\0';
}
Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
log_info(os)("shared library load of %s failed, %s", filename, error_report);
return NULL;
#endif // STATIC_BUILD
}
#else
void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
#ifdef STATIC_BUILD
return os::get_default_process_handle();
#else
log_info(os)("attempting shared library load of %s", filename);
void * result= ::dlopen(filename, RTLD_LAZY);
if (result != NULL) {
Events::log(NULL, "Loaded shared library %s", filename);
// Successful loading
log_info(os)("shared library load of %s was successful", filename);
return result;
}
Elf32_Ehdr elf_head;
const char* const error_report = ::dlerror();
if (error_report == NULL) {
error_report = "dlerror returned no error description";
}
if (ebuf != NULL && ebuflen > 0) {
// Read system error message into ebuf
::strncpy(ebuf, error_report, ebuflen-1);
ebuf[ebuflen-1]='\0';
}
Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
log_info(os)("shared library load of %s failed, %s", filename, error_report);
int diag_msg_max_length=ebuflen-strlen(ebuf);
char* diag_msg_buf=ebuf+strlen(ebuf);
if (diag_msg_max_length==0) {
// No more space in ebuf for additional diagnostics message
return NULL;
}
int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
if (file_descriptor < 0) {
// Can't open library, report dlerror() message
return NULL;
}
bool failed_to_read_elf_head=
(sizeof(elf_head)!=
(::read(file_descriptor, &elf_head,sizeof(elf_head))));
::close(file_descriptor);
if (failed_to_read_elf_head) {
// file i/o error - report dlerror() msg
return NULL;
}
typedef struct {
Elf32_Half code; // Actual value as defined in elf.h
Elf32_Half compat_class; // Compatibility of archs at VM's sense
char elf_class; // 32 or 64 bit
char endianess; // MSB or LSB
char* name; // String representation
} arch_t;
#ifndef EM_486
#define EM_486 6 /* Intel 80486 */
#endif
#ifndef EM_MIPS_RS3_LE
#define EM_MIPS_RS3_LE 10 /* MIPS */
#endif
#ifndef EM_PPC64
#define EM_PPC64 21 /* PowerPC64 */
#endif
#ifndef EM_S390
#define EM_S390 22 /* IBM System/390 */
#endif
#ifndef EM_IA_64
#define EM_IA_64 50 /* HP/Intel IA-64 */
#endif
#ifndef EM_X86_64
#define EM_X86_64 62 /* AMD x86-64 */
#endif
static const arch_t arch_array[]={
{EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
{EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
{EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
{EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
{EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
{EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
{EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
{EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
{EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
{EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
{EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
{EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
{EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
{EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
{EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
{EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
};
#if (defined IA32)
static Elf32_Half running_arch_code=EM_386;
#elif (defined AMD64)
static Elf32_Half running_arch_code=EM_X86_64;
#elif (defined IA64)
static Elf32_Half running_arch_code=EM_IA_64;
#elif (defined __sparc) && (defined _LP64)
static Elf32_Half running_arch_code=EM_SPARCV9;
#elif (defined __sparc) && (!defined _LP64)
static Elf32_Half running_arch_code=EM_SPARC;
#elif (defined __powerpc64__)
static Elf32_Half running_arch_code=EM_PPC64;
#elif (defined __powerpc__)
static Elf32_Half running_arch_code=EM_PPC;
#elif (defined ARM)
static Elf32_Half running_arch_code=EM_ARM;
#elif (defined S390)
static Elf32_Half running_arch_code=EM_S390;
#elif (defined ALPHA)
static Elf32_Half running_arch_code=EM_ALPHA;
#elif (defined MIPSEL)
static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
#elif (defined PARISC)
static Elf32_Half running_arch_code=EM_PARISC;
#elif (defined MIPS)
static Elf32_Half running_arch_code=EM_MIPS;
#elif (defined M68K)
static Elf32_Half running_arch_code=EM_68K;
#else
#error Method os::dll_load requires that one of following is defined:\
IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
#endif
// Identify compatability class for VM's architecture and library's architecture
// Obtain string descriptions for architectures
arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
int running_arch_index=-1;
for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
if (running_arch_code == arch_array[i].code) {
running_arch_index = i;
}
if (lib_arch.code == arch_array[i].code) {
lib_arch.compat_class = arch_array[i].compat_class;
lib_arch.name = arch_array[i].name;
}
}
assert(running_arch_index != -1,
"Didn't find running architecture code (running_arch_code) in arch_array");
if (running_arch_index == -1) {
// Even though running architecture detection failed
// we may still continue with reporting dlerror() message
return NULL;
}
if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
return NULL;
}
#ifndef S390
if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
return NULL;
}
#endif // !S390
if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
if (lib_arch.name!=NULL) {
::snprintf(diag_msg_buf, diag_msg_max_length-1,
" (Possible cause: can't load %s-bit .so on a %s-bit platform)",
lib_arch.name, arch_array[running_arch_index].name);
} else {
::snprintf(diag_msg_buf, diag_msg_max_length-1,
" (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
lib_arch.code,
arch_array[running_arch_index].name);
}
}
return NULL;
#endif // STATIC_BUILD
}
#endif // !__APPLE__
void* os::get_default_process_handle() {
#ifdef __APPLE__
// MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
// to avoid finding unexpected symbols on second (or later)
// loads of a library.
return (void*)::dlopen(NULL, RTLD_FIRST);
#else
return (void*)::dlopen(NULL, RTLD_LAZY);
#endif
}
// XXX: Do we need a lock around this as per Linux?
void* os::dll_lookup(void* handle, const char* name) {
return dlsym(handle, name);
}
int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
outputStream * out = (outputStream *) param;
out->print_cr(INTPTR_FORMAT " \t%s", (intptr_t)base_address, name);
return 0;
}
void os::print_dll_info(outputStream *st) {
st->print_cr("Dynamic libraries:");
if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
st->print_cr("Error: Cannot print dynamic libraries.");
}
}
int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
#ifdef RTLD_DI_LINKMAP
Dl_info dli;
void *handle;
Link_map *map;
Link_map *p;
if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
dli.dli_fname == NULL) {
return 1;
}
handle = dlopen(dli.dli_fname, RTLD_LAZY);
if (handle == NULL) {
return 1;
}
dlinfo(handle, RTLD_DI_LINKMAP, &map);
if (map == NULL) {
dlclose(handle);
return 1;
}
while (map->l_prev != NULL)
map = map->l_prev;
while (map != NULL) {
// Value for top_address is returned as 0 since we don't have any information about module size
if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
dlclose(handle);
return 1;
}
map = map->l_next;
}
dlclose(handle);
#elif defined(__APPLE__)
for (uint32_t i = 1; i < _dyld_image_count(); i++) {
// Value for top_address is returned as 0 since we don't have any information about module size
if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
return 1;
}
}
return 0;
#else
return 1;
#endif
}
void os::get_summary_os_info(char* buf, size_t buflen) {
// These buffers are small because we want this to be brief
// and not use a lot of stack while generating the hs_err file.
char os[100];
size_t size = sizeof(os);
int mib_kern[] = { CTL_KERN, KERN_OSTYPE };
if (sysctl(mib_kern, 2, os, &size, NULL, 0) < 0) {
#ifdef __APPLE__
strncpy(os, "Darwin", sizeof(os));
#elif __OpenBSD__
strncpy(os, "OpenBSD", sizeof(os));
#else
strncpy(os, "BSD", sizeof(os));
#endif
}
char release[100];
size = sizeof(release);
int mib_release[] = { CTL_KERN, KERN_OSRELEASE };
if (sysctl(mib_release, 2, release, &size, NULL, 0) < 0) {
// if error, leave blank
strncpy(release, "", sizeof(release));
}
snprintf(buf, buflen, "%s %s", os, release);
}
void os::print_os_info_brief(outputStream* st) {
os::Posix::print_uname_info(st);
}
void os::print_os_info(outputStream* st) {
st->print("OS:");
os::Posix::print_uname_info(st);
os::Posix::print_rlimit_info(st);
os::Posix::print_load_average(st);
}
void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
// Nothing to do for now.
}
void os::get_summary_cpu_info(char* buf, size_t buflen) {
unsigned int mhz;
size_t size = sizeof(mhz);
int mib[] = { CTL_HW, HW_CPU_FREQ };
if (sysctl(mib, 2, &mhz, &size, NULL, 0) < 0) {
mhz = 1; // looks like an error but can be divided by
} else {
mhz /= 1000000; // reported in millions
}
char model[100];
size = sizeof(model);
int mib_model[] = { CTL_HW, HW_MODEL };
if (sysctl(mib_model, 2, model, &size, NULL, 0) < 0) {
strncpy(model, cpu_arch, sizeof(model));
}
char machine[100];
size = sizeof(machine);
int mib_machine[] = { CTL_HW, HW_MACHINE };
if (sysctl(mib_machine, 2, machine, &size, NULL, 0) < 0) {
strncpy(machine, "", sizeof(machine));
}
snprintf(buf, buflen, "%s %s %d MHz", model, machine, mhz);
}
void os::print_memory_info(outputStream* st) {
xsw_usage swap_usage;
size_t size = sizeof(swap_usage);
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);
if((sysctlbyname("vm.swapusage", &swap_usage, &size, NULL, 0) == 0) || (errno == ENOMEM)) {
if (size >= offset_of(xsw_usage, xsu_used)) {
st->print(", swap " UINT64_FORMAT "k",
((julong) swap_usage.xsu_total) >> 10);
st->print("(" UINT64_FORMAT "k free)",
((julong) swap_usage.xsu_avail) >> 10);
}
}
st->cr();
}
static void print_signal_handler(outputStream* st, int sig,
char* buf, size_t buflen);
void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
st->print_cr("Signal Handlers:");
print_signal_handler(st, SIGSEGV, buf, buflen);
print_signal_handler(st, SIGBUS , buf, buflen);
print_signal_handler(st, SIGFPE , buf, buflen);
print_signal_handler(st, SIGPIPE, buf, buflen);
print_signal_handler(st, SIGXFSZ, buf, buflen);
print_signal_handler(st, SIGILL , buf, buflen);
print_signal_handler(st, SR_signum, buf, buflen);
print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
}
static char saved_jvm_path[MAXPATHLEN] = {0};
// Find the full path to the current module, libjvm
void os::jvm_path(char *buf, jint buflen) {
// Error checking.
if (buflen < MAXPATHLEN) {
assert(false, "must use a large-enough buffer");
buf[0] = '\0';
return;
}
// Lazy resolve the path to current module.
if (saved_jvm_path[0] != 0) {
strcpy(buf, saved_jvm_path);
return;
}
char dli_fname[MAXPATHLEN];
bool ret = dll_address_to_library_name(
CAST_FROM_FN_PTR(address, os::jvm_path),
dli_fname, sizeof(dli_fname), NULL);
assert(ret, "cannot locate libjvm");
char *rp = NULL;
if (ret && dli_fname[0] != '\0') {
rp = os::Posix::realpath(dli_fname, buf, buflen);
}
if (rp == NULL) {
return;
}
if (Arguments::sun_java_launcher_is_altjvm()) {
// Support for the java launcher's '-XXaltjvm=<path>' option. Typical
// value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
// or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
// appears at the right place in the string, then assume we are
// installed in a JDK and we're done. Otherwise, check for a
// JAVA_HOME environment variable and construct a path to the JVM
// being overridden.
const char *p = buf + strlen(buf) - 1;
for (int count = 0; p > buf && count < 5; ++count) {
for (--p; p > buf && *p != '/'; --p)
/* empty */ ;
}
if (strncmp(p, "/jre/lib/", 9) != 0) {
// Look for JAVA_HOME in the environment.
char* java_home_var = ::getenv("JAVA_HOME");
if (java_home_var != NULL && java_home_var[0] != 0) {
char* jrelib_p;
int len;
// Check the current module name "libjvm"
p = strrchr(buf, '/');
assert(strstr(p, "/libjvm") == p, "invalid library name");
rp = os::Posix::realpath(java_home_var, buf, buflen);
if (rp == NULL) {
return;
}
// determine if this is a legacy image or modules image
// modules image doesn't have "jre" subdirectory
len = strlen(buf);
assert(len < buflen, "Ran out of buffer space");
jrelib_p = buf + len;
// Add the appropriate library subdir
snprintf(jrelib_p, buflen-len, "/jre/lib");
if (0 != access(buf, F_OK)) {
snprintf(jrelib_p, buflen-len, "/lib");
}
// Add the appropriate client or server subdir
len = strlen(buf);
jrelib_p = buf + len;
snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
if (0 != access(buf, F_OK)) {
snprintf(jrelib_p, buflen-len, "%s", "");
}
// If the path exists within JAVA_HOME, add the JVM library name
// to complete the path to JVM being overridden. Otherwise fallback
// to the path to the current library.
if (0 == access(buf, F_OK)) {
// Use current module name "libjvm"
len = strlen(buf);
snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
} else {
// Fall back to path of current library
rp = os::Posix::realpath(dli_fname, buf, buflen);
if (rp == NULL) {
return;
}
}
}
}
}
strncpy(saved_jvm_path, buf, MAXPATHLEN);
saved_jvm_path[MAXPATHLEN - 1] = '\0';
}
void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
// no prefix required, not even "_"
}
void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
// no suffix required
}
////////////////////////////////////////////////////////////////////////////////
// sun.misc.Signal support
static void UserHandler(int sig, void *siginfo, void *context) {
// Ctrl-C is pressed during error reporting, likely because the error
// handler fails to abort. Let VM die immediately.
if (sig == SIGINT && VMError::is_error_reported()) {
os::die();
}
os::signal_notify(sig);
}
void* os::user_handler() {
return CAST_FROM_FN_PTR(void*, UserHandler);
}
extern "C" {
typedef void (*sa_handler_t)(int);
typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
}
void* os::signal(int signal_number, void* handler) {
struct sigaction sigAct, oldSigAct;
sigfillset(&(sigAct.sa_mask));
sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
if (sigaction(signal_number, &sigAct, &oldSigAct)) {
// -1 means registration failed
return (void *)-1;
}
return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
}
void os::signal_raise(int signal_number) {
::raise(signal_number);
}
// The following code is moved from os.cpp for making this
// code platform specific, which it is by its very nature.
// Will be modified when max signal is changed to be dynamic
int os::sigexitnum_pd() {
return NSIG;
}
// a counter for each possible signal value
static volatile jint pending_signals[NSIG+1] = { 0 };
static Semaphore* sig_sem = NULL;
static void jdk_misc_signal_init() {
// Initialize signal structures
::memset((void*)pending_signals, 0, sizeof(pending_signals));
// Initialize signal semaphore
sig_sem = new Semaphore();
}
void os::signal_notify(int sig) {
if (sig_sem != NULL) {
Atomic::inc(&pending_signals[sig]);
sig_sem->signal();
} else {
// Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
// initialization isn't called.
assert(ReduceSignalUsage, "signal semaphore should be created");
}
}
static int check_pending_signals() {
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;
}
}
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()
sig_sem->wait();
// 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.
sig_sem->signal();
thread->java_suspend_self();
}
} while (threadIsSuspended);
}
}
int os::signal_wait() {
return check_pending_signals();
}
////////////////////////////////////////////////////////////////////////////////
// Virtual Memory
int os::vm_page_size() {
// Seems redundant as all get out
assert(os::Bsd::page_size() != -1, "must call os::init");
return os::Bsd::page_size();
}
// Solaris allocates memory by pages.
int os::vm_allocation_granularity() {
assert(os::Bsd::page_size() != -1, "must call os::init");
return os::Bsd::page_size();
}
// Rationale behind this function:
// current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
// mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
// samples for JITted code. Here we create private executable mapping over the code cache
// and then we can use standard (well, almost, as mapping can change) way to provide
// info for the reporting script by storing timestamp and location of symbol
void bsd_wrap_code(char* base, size_t size) {
static volatile jint cnt = 0;
if (!UseOprofile) {
return;
}
char buf[PATH_MAX + 1];
int num = Atomic::add(1, &cnt);
snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
os::get_temp_directory(), os::current_process_id(), num);
unlink(buf);
int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
if (fd != -1) {
off_t rv = ::lseek(fd, size-2, SEEK_SET);
if (rv != (off_t)-1) {
if (::write(fd, "", 1) == 1) {
mmap(base, size,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
}
}
::close(fd);
unlink(buf);
}
}
static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
int err) {
warning("INFO: os::commit_memory(" INTPTR_FORMAT ", " SIZE_FORMAT
", %d) failed; error='%s' (errno=%d)", (intptr_t)addr, size, exec,
os::errno_name(err), err);
}
// NOTE: Bsd kernel does not really reserve the pages for us.
// All it does is to check if there are enough free pages
// left at the time of mmap(). This could be a potential
// problem.
bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
#ifdef __OpenBSD__
// XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
if (::mprotect(addr, size, prot) == 0) {
return true;
}
#else
uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
if (res != (uintptr_t) MAP_FAILED) {
return true;
}
#endif
// Warn about any commit errors we see in non-product builds just
// in case mmap() doesn't work as described on the man page.
NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
return false;
}
bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
bool exec) {
// alignment_hint is ignored on this OS
return pd_commit_memory(addr, size, exec);
}
void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
const char* mesg) {
assert(mesg != NULL, "mesg must be specified");
if (!pd_commit_memory(addr, size, exec)) {
// add extra info in product mode for vm_exit_out_of_memory():
PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
}
}
void os::pd_commit_memory_or_exit(char* addr, size_t size,
size_t alignment_hint, bool exec,
const char* mesg) {
// alignment_hint is ignored on this OS
pd_commit_memory_or_exit(addr, size, exec, mesg);
}
void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
}
void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
::madvise(addr, bytes, MADV_DONTNEED);
}
void os::numa_make_global(char *addr, size_t bytes) {
}
void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
}
bool os::numa_topology_changed() { return false; }
size_t os::numa_get_groups_num() {
return 1;
}
int os::numa_get_group_id() {
return 0;
}
size_t os::numa_get_leaf_groups(int *ids, size_t size) {
if (size > 0) {
ids[0] = 0;
return 1;
}
return 0;
}
int os::numa_get_group_id_for_address(const void* address) {
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
Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with PROT_NONE", p2i(addr), p2i(addr+size));
return ::mprotect(addr, size, PROT_NONE) == 0;
#else
uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
return res != (uintptr_t) MAP_FAILED;
#endif
}
bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
return os::commit_memory(addr, size, !ExecMem);
}
// If this is a growable mapping, remove the guard pages entirely by
// munmap()ping them. If not, just call uncommit_memory().
bool os::remove_stack_guard_pages(char* addr, size_t size) {
return os::uncommit_memory(addr, size);
}
// If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
// at 'requested_addr'. If there are existing memory mappings at the same
// location, however, they will be overwritten. If 'fixed' is false,
// 'requested_addr' is only treated as a hint, the return value may or
// may not start from the requested address. Unlike Bsd mmap(), this
// function returns NULL to indicate failure.
static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
char * addr;
int flags;
flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
if (fixed) {
assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
flags |= MAP_FIXED;
}
// Map reserved/uncommitted pages PROT_NONE so we fail early if we
// touch an uncommitted page. Otherwise, the read/write might
// succeed if we have enough swap space to back the physical page.
addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
flags, -1, 0);
return addr == MAP_FAILED ? NULL : addr;
}
static int anon_munmap(char * addr, size_t size) {
return ::munmap(addr, size) == 0;
}
char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
size_t alignment_hint) {
return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
}
bool os::pd_release_memory(char* addr, size_t size) {
return anon_munmap(addr, size);
}
static bool bsd_mprotect(char* addr, size_t size, int prot) {
// Bsd wants the mprotect address argument to be page aligned.
char* bottom = (char*)align_down((intptr_t)addr, os::Bsd::page_size());
// According to SUSv3, mprotect() should only be used with mappings
// established by mmap(), and mmap() always maps whole pages. Unaligned
// 'addr' likely indicates problem in the VM (e.g. trying to change
// protection of malloc'ed or statically allocated memory). Check the
// caller if you hit this assert.
assert(addr == bottom, "sanity check");
size = align_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(bottom), p2i(bottom+size), prot);
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("os::reserve_memory_special should not be called on BSD.");
return NULL;
}
bool os::release_memory_special(char* base, size_t bytes) {
fatal("os::release_memory_special should not be called on BSD.");
return false;
}
size_t os::large_page_size() {
return _large_page_size;
}
bool os::can_commit_large_page_memory() {
// Does not matter, we do not support huge pages.
return false;
}
bool os::can_execute_large_page_memory() {
// Does not matter, we do not support huge pages.
return false;
}
char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
assert(file_desc >= 0, "file_desc is not valid");
char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
if (result != NULL) {
if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
}
}
return result;
}
// 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) {
// Assert only that the size is a multiple of the page size, since
// that's all that mmap requires, and since that's all we really know
// about at this low abstraction level. If we need higher alignment,
// we can either pass an alignment to this method or verify alignment
// in one of the methods further up the call chain. See bug 5044738.
assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
// Repeatedly allocate blocks until the block is allocated at the
// right spot.
// Bsd mmap allows caller to pass an address as hint; give it a try first,
// if kernel honors the hint then we can return immediately.
char * addr = anon_mmap(requested_addr, bytes, false);
if (addr == requested_addr) {
return requested_addr;
}
if (addr != NULL) {
// mmap() is successful but it fails to reserve at the requested address
anon_munmap(addr, bytes);
}
return NULL;
}
// Sleep forever; naked call to OS-specific sleep; use with CAUTION
void os::infinite_sleep() {
while (true) { // sleep forever ...
::sleep(100); // ... 100 seconds at a time
}
}
// Used to convert frequent JVM_Yield() to nops
bool os::dont_yield() {
return DontYieldALot;
}
void os::naked_yield() {
sched_yield();
}
////////////////////////////////////////////////////////////////////////////////
// thread priority support
// Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
// only supports dynamic priority, static priority must be zero. For real-time
// applications, Bsd supports SCHED_RR which allows static priority (1-99).
// However, for large multi-threaded applications, SCHED_RR is not only slower
// than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
// of 5 runs - Sep 2005).
//
// The following code actually changes the niceness of kernel-thread/LWP. It
// has an assumption that setpriority() only modifies one kernel-thread/LWP,
// not the entire user process, and user level threads are 1:1 mapped to kernel
// threads. It has always been the case, but could change in the future. For
// this reason, the code should not be used as default (ThreadPriorityPolicy=0).
// It is only used when ThreadPriorityPolicy=1 and may require system level permission
// (e.g., root privilege or CAP_SYS_NICE capability).
#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) {
if (geteuid() != 0) {
if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
"e.g., being the root user. If the necessary permission is not " \
"possessed, changes to priority will be silently ignored.");
}
}
}
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);
return (ret == 0) ? OS_OK : OS_ERR;
#elif defined(__APPLE__) || defined(__NetBSD__)
struct sched_param sp;
int policy;
if (pthread_getschedparam(thread->osthread()->pthread_id(), &policy, &sp) != 0) {
return OS_ERR;
}
sp.sched_priority = newpri;
if (pthread_setschedparam(thread->osthread()->pthread_id(), 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;
int res = pthread_getschedparam(thread->osthread()->pthread_id(), &policy, &sp);
if (res != 0) {
*priority_ptr = -1;
return OS_ERR;
} else {
*priority_ptr = sp.sched_priority;
return OS_OK;
}
#else
*priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
#endif
return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
}
////////////////////////////////////////////////////////////////////////////////
// suspend/resume support
// The low-level signal-based suspend/resume support is a remnant from the
// old VM-suspension that used to be for java-suspension, safepoints etc,
// within hotspot. Currently used by JFR's OSThreadSampler
//
// The remaining code is greatly simplified from the more general suspension
// code that used to be used.
//
// The protocol is quite simple:
// - suspend:
// - sends a signal to the target thread
// - polls the suspend state of the osthread using a yield loop
// - target thread signal handler (SR_handler) sets suspend state
// and blocks in sigsuspend until continued
// - resume:
// - sets target osthread state to continue
// - sends signal to end the sigsuspend loop in the SR_handler
//
// Note that the SR_lock plays no role in this suspend/resume protocol,
// but is checked for NULL in SR_handler as a thread termination indicator.
// The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
//
// Note that resume_clear_context() and suspend_save_context() are needed
// by SR_handler(), so that fetch_frame_from_ucontext() works,
// which in part is used by:
// - Forte Analyzer: AsyncGetCallTrace()
// - StackBanging: get_frame_at_stack_banging_point()
static void resume_clear_context(OSThread *osthread) {
osthread->set_ucontext(NULL);
osthread->set_siginfo(NULL);
}
static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
osthread->set_ucontext(context);
osthread->set_siginfo(siginfo);
}
// Handler function invoked when a thread's execution is suspended or
// resumed. We have to be careful that only async-safe functions are
// called here (Note: most pthread functions are not async safe and
// should be avoided.)
//
// Note: sigwait() is a more natural fit than sigsuspend() from an
// interface point of view, but sigwait() prevents the signal hander
// from being run. libpthread would get very confused by not having
// its signal handlers run and prevents sigwait()'s use with the
// mutex granting granting signal.
//
// Currently only ever called on the VMThread or JavaThread
//
#ifdef __APPLE__
static OSXSemaphore sr_semaphore;
#else
static PosixSemaphore sr_semaphore;
#endif
static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
// Save and restore errno to avoid confusing native code with EINTR
// after sigsuspend.
int old_errno = errno;
Thread* thread = Thread::current_or_null_safe();
assert(thread != NULL, "Missing current thread in SR_handler");
// On some systems we have seen signal delivery get "stuck" until the signal
// mask is changed as part of thread termination. Check that the current thread
// has not already terminated (via SR_lock()) - else the following assertion
// will fail because the thread is no longer a JavaThread as the ~JavaThread
// destructor has completed.
if (thread->SR_lock() == NULL) {
return;
}
assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
OSThread* osthread = thread->osthread();
os::SuspendResume::State current = osthread->sr.state();
if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
suspend_save_context(osthread, siginfo, context);
// attempt to switch the state, we assume we had a SUSPEND_REQUEST
os::SuspendResume::State state = osthread->sr.suspended();
if (state == os::SuspendResume::SR_SUSPENDED) {
sigset_t suspend_set; // signals for sigsuspend()
// get current set of blocked signals and unblock resume signal
pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
sigdelset(&suspend_set, SR_signum);
sr_semaphore.signal();
// wait here until we are resumed
while (1) {
sigsuspend(&suspend_set);
os::SuspendResume::State result = osthread->sr.running();
if (result == os::SuspendResume::SR_RUNNING) {
sr_semaphore.signal();
break;
} else if (result != os::SuspendResume::SR_SUSPENDED) {
ShouldNotReachHere();
}
}
} else if (state == os::SuspendResume::SR_RUNNING) {
// request was cancelled, continue
} else {
ShouldNotReachHere();
}
resume_clear_context(osthread);
} else if (current == os::SuspendResume::SR_RUNNING) {
// request was cancelled, continue
} else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
// ignore
} else {
// ignore
}
errno = old_errno;
}
static int SR_initialize() {
struct sigaction act;
char *s;
// Get signal number to use for suspend/resume
if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
int sig = ::strtol(s, 0, 10);
if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769.
sig < NSIG) { // Must be legal signal and fit into sigflags[].
SR_signum = sig;
} else {
warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
}
}
assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
"SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
sigemptyset(&SR_sigset);
sigaddset(&SR_sigset, SR_signum);
// Set up signal handler for suspend/resume
act.sa_flags = SA_RESTART|SA_SIGINFO;
act.sa_handler = (void (*)(int)) SR_handler;
// SR_signum is blocked by default.
// 4528190 - We also need to block pthread restart signal (32 on all
// supported Bsd platforms). Note that BsdThreads need to block
// this signal for all threads to work properly. So we don't have
// to use hard-coded signal number when setting up the mask.
pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
if (sigaction(SR_signum, &act, 0) == -1) {
return -1;
}
// Save signal flag
os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
return 0;
}
static int sr_notify(OSThread* osthread) {
int status = pthread_kill(osthread->pthread_id(), SR_signum);
assert_status(status == 0, status, "pthread_kill");
return status;
}
// "Randomly" selected value for how long we want to spin
// before bailing out on suspending a thread, also how often
// we send a signal to a thread we want to resume
static const int RANDOMLY_LARGE_INTEGER = 1000000;
static const int RANDOMLY_LARGE_INTEGER2 = 100;
// returns true on success and false on error - really an error is fatal
// but this seems the normal response to library errors
static bool do_suspend(OSThread* osthread) {
assert(osthread->sr.is_running(), "thread should be running");
assert(!sr_semaphore.trywait(), "semaphore has invalid state");
// mark as suspended and send signal
if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
// failed to switch, state wasn't running?
ShouldNotReachHere();
return false;
}
if (sr_notify(osthread) != 0) {
ShouldNotReachHere();
}
// managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
while (true) {
if (sr_semaphore.timedwait(2)) {
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(2)) {
if (osthread->sr.is_running()) {
return;
}
}
} else {
ShouldNotReachHere();
}
}
guarantee(osthread->sr.is_running(), "Must be running!");
}
///////////////////////////////////////////////////////////////////////////////////
// signal handling (except suspend/resume)
// This routine may be used by user applications as a "hook" to catch signals.
// The user-defined signal handler must pass unrecognized signals to this
// routine, and if it returns true (non-zero), then the signal handler must
// return immediately. If the flag "abort_if_unrecognized" is true, then this
// routine will never retun false (zero), but instead will execute a VM panic
// routine kill the process.
//
// If this routine returns false, it is OK to call it again. This allows
// the user-defined signal handler to perform checks either before or after
// the VM performs its own checks. Naturally, the user code would be making
// a serious error if it tried to handle an exception (such as a null check
// or breakpoint) that the VM was generating for its own correct operation.
//
// This routine may recognize any of the following kinds of signals:
// SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
// It should be consulted by handlers for any of those signals.
//
// The caller of this routine must pass in the three arguments supplied
// to the function referred to in the "sa_sigaction" (not the "sa_handler")
// field of the structure passed to sigaction(). This routine assumes that
// the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
//
// Note that the VM will print warnings if it detects conflicting signal
// handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
//
extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
void* ucontext,
int abort_if_unrecognized);
static 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
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 = os::Posix::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;
}
// for diagnostic
int sigflags[NSIG];
int os::Bsd::get_our_sigflags(int sig) {
assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
return sigflags[sig];
}
void os::Bsd::set_our_sigflags(int sig, int flags) {
assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
if (sig > 0 && sig < NSIG) {
sigflags[sig] = flags;
}
}
void os::Bsd::set_signal_handler(int sig, bool set_installed) {
// Check for overwrite.
struct sigaction oldAct;
sigaction(sig, (struct sigaction*)NULL, &oldAct);
void* oldhand = oldAct.sa_sigaction
? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
: CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
if (AllowUserSignalHandlers || !set_installed) {
// Do not overwrite; user takes responsibility to forward to us.
return;
} else if (UseSignalChaining) {
// save the old handler in jvm
os::Posix::save_preinstalled_handler(sig, oldAct);
// libjsig also interposes the sigaction() call below and saves the
// old sigaction on it own.
} else {
fatal("Encountered unexpected pre-existing sigaction handler "
"%#lx for signal %d.", (long)oldhand, sig);
}
}
struct sigaction sigAct;
sigfillset(&(sigAct.sa_mask));
sigAct.sa_handler = SIG_DFL;
if (!set_installed) {
sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
} else {
sigAct.sa_sigaction = signalHandler;
sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
}
#ifdef __APPLE__
// Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
// (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
// if the signal handler declares it will handle it on alternate stack.
// Notice we only declare we will handle it on alt stack, but we are not
// actually going to use real alt stack - this is just a workaround.
// Please see ux_exception.c, method catch_mach_exception_raise for details
// link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
if (sig == SIGSEGV) {
sigAct.sa_flags |= SA_ONSTACK;
}
#endif
// Save flags, which are set by ours
assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
sigflags[sig] = sigAct.sa_flags;
int ret = sigaction(sig, &sigAct, &oldAct);
assert(ret == 0, "check");
void* oldhand2 = oldAct.sa_sigaction
? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
: CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
assert(oldhand2 == oldhand, "no concurrent signal handler installation");
}
// install signal handlers for signals that HotSpot needs to
// handle in order to support Java-level exception handling.
void os::Bsd::install_signal_handlers() {
if (!signal_handlers_are_installed) {
signal_handlers_are_installed = true;
// signal-chaining
typedef void (*signal_setting_t)();
signal_setting_t begin_signal_setting = NULL;
signal_setting_t end_signal_setting = NULL;
begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
if (begin_signal_setting != NULL) {
end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
get_signal_action = CAST_TO_FN_PTR(get_signal_t,
dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
libjsig_is_loaded = true;
assert(UseSignalChaining, "should enable signal-chaining");
}
if (libjsig_is_loaded) {
// Tell libjsig jvm is setting signal handlers
(*begin_signal_setting)();
}
set_signal_handler(SIGSEGV, true);
set_signal_handler(SIGPIPE, true);
set_signal_handler(SIGBUS, true);
set_signal_handler(SIGILL, true);
set_signal_handler(SIGFPE, true);
set_signal_handler(SIGXFSZ, true);
#if defined(__APPLE__)
// In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
// signals caught and handled by the JVM. To work around this, we reset the mach task
// signal handler that's placed on our process by CrashReporter. This disables
// CrashReporter-based reporting.
//
// This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
// on caught fatal signals.
//
// Additionally, gdb installs both standard BSD signal handlers, and mach exception
// handlers. By replacing the existing task exception handler, we disable gdb's mach
// exception handling, while leaving the standard BSD signal handlers functional.
kern_return_t kr;
kr = task_set_exception_ports(mach_task_self(),
EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
MACH_PORT_NULL,
EXCEPTION_STATE_IDENTITY,
MACHINE_THREAD_STATE);
assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
#endif
if (libjsig_is_loaded) {
// Tell libjsig jvm finishes setting signal handlers
(*end_signal_setting)();
}
// We don't activate signal checker if libjsig is in place, we trust ourselves
// and if UserSignalHandler is installed all bets are off
if (CheckJNICalls) {
if (libjsig_is_loaded) {
log_debug(jni, resolve)("Info: libjsig is activated, all active signal checking is disabled");
check_signals = false;
}
if (AllowUserSignalHandlers) {
log_debug(jni, resolve)("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
check_signals = false;
}
}
}
}
/////
// glibc on Bsd platform uses non-documented flag
// to indicate, that some special sort of signal
// trampoline is used.
// We will never set this flag, and we should
// ignore this flag in our diagnostic
#ifdef SIGNIFICANT_SIGNAL_MASK
#undef SIGNIFICANT_SIGNAL_MASK
#endif
#define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
static const char* get_signal_handler_name(address handler,
char* buf, int buflen) {
int offset;
bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
if (found) {
// skip directory names
const char *p1, *p2;
p1 = buf;
size_t len = strlen(os::file_separator());
while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
} else {
jio_snprintf(buf, buflen, PTR_FORMAT, handler);
}
return buf;
}
static void print_signal_handler(outputStream* st, int sig,
char* buf, size_t buflen) {
struct sigaction sa;
sigaction(sig, NULL, &sa);
// See comment for SIGNIFICANT_SIGNAL_MASK define
sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
st->print("%s: ", os::exception_name(sig, buf, buflen));
address handler = (sa.sa_flags & SA_SIGINFO)
? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
: CAST_FROM_FN_PTR(address, sa.sa_handler);
if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
st->print("SIG_DFL");
} else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
st->print("SIG_IGN");
} else {
st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
}
st->print(", sa_mask[0]=");
os::Posix::print_signal_set_short(st, &sa.sa_mask);
address rh = VMError::get_resetted_sighandler(sig);
// May be, handler was resetted by VMError?
if (rh != NULL) {
handler = rh;
sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
}
st->print(", sa_flags=");
os::Posix::print_sa_flags(st, sa.sa_flags);
// Check: is it our handler?
if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
// It is our signal handler
// check for flags, reset system-used one!
if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
st->print(
", flags was changed from " PTR32_FORMAT ", consider using jsig library",
os::Bsd::get_our_sigflags(sig));
}
}
st->cr();
}
#define DO_SIGNAL_CHECK(sig) \
do { \
if (!sigismember(&check_signal_done, sig)) { \
os::Bsd::check_signal_handler(sig); \
} \
} while (0)
// This method is a periodic task to check for misbehaving JNI applications
// under CheckJNI, we can add any periodic checks here
void os::run_periodic_checks() {
if (check_signals == false) return;
// SEGV and BUS if overridden could potentially prevent
// generation of hs*.log in the event of a crash, debugging
// such a case can be very challenging, so we absolutely
// check the following for a good measure:
DO_SIGNAL_CHECK(SIGSEGV);
DO_SIGNAL_CHECK(SIGILL);
DO_SIGNAL_CHECK(SIGFPE);
DO_SIGNAL_CHECK(SIGBUS);
DO_SIGNAL_CHECK(SIGPIPE);
DO_SIGNAL_CHECK(SIGXFSZ);
// ReduceSignalUsage allows the user to override these handlers
// see comments at the very top and jvm_md.h
if (!ReduceSignalUsage) {
DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
DO_SIGNAL_CHECK(BREAK_SIGNAL);
}
DO_SIGNAL_CHECK(SR_signum);
}
typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
static os_sigaction_t os_sigaction = NULL;
void os::Bsd::check_signal_handler(int sig) {
char buf[O_BUFLEN];
address jvmHandler = NULL;
struct sigaction act;
if (os_sigaction == NULL) {
// only trust the default sigaction, in case it has been interposed
os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
if (os_sigaction == NULL) return;
}
os_sigaction(sig, (struct sigaction*)NULL, &act);
act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
address thisHandler = (act.sa_flags & SA_SIGINFO)
? CAST_FROM_FN_PTR(address, act.sa_sigaction)
: CAST_FROM_FN_PTR(address, act.sa_handler);
switch (sig) {
case SIGSEGV:
case SIGBUS:
case SIGFPE:
case SIGPIPE:
case SIGILL:
case SIGXFSZ:
jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
break;
case SHUTDOWN1_SIGNAL:
case SHUTDOWN2_SIGNAL:
case SHUTDOWN3_SIGNAL:
case BREAK_SIGNAL:
jvmHandler = (address)user_handler();
break;
default:
if (sig == SR_signum) {
jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
} else {
return;
}
break;
}
if (thisHandler != jvmHandler) {
tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
// No need to check this sig any longer
sigaddset(&check_signal_done, sig);
// Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
exception_name(sig, buf, O_BUFLEN));
}
} else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
tty->print("expected:");
os::Posix::print_sa_flags(tty, os::Bsd::get_our_sigflags(sig));
tty->cr();
tty->print(" found:");
os::Posix::print_sa_flags(tty, act.sa_flags);
tty->cr();
// No need to check this sig any longer
sigaddset(&check_signal_done, sig);
}
// Dump all the signal
if (sigismember(&check_signal_done, sig)) {
print_signal_handlers(tty, buf, O_BUFLEN);
}
}
extern void report_error(char* file_name, int line_no, char* title,
char* format, ...);
// this is called _before_ the most of global arguments have been parsed
void os::init(void) {
char dummy; // used to get a guess on initial stack address
clock_tics_per_sec = CLK_TCK;
init_random(1234567);
Bsd::set_page_size(getpagesize());
if (Bsd::page_size() == -1) {
fatal("os_bsd.cpp: os::init: sysconf failed (%s)", os::strerror(errno));
}
init_page_sizes((size_t) Bsd::page_size());
Bsd::initialize_system_info();
// _main_thread points to the thread that created/loaded the JVM.
Bsd::_main_thread = pthread_self();
Bsd::clock_init();
initial_time_count = javaTimeNanos();
os::Posix::init();
}
// To install functions for atexit system call
extern "C" {
static void perfMemory_exit_helper() {
perfMemory_exit();
}
}
// this is called _after_ the global arguments have been parsed
jint os::init_2(void) {
// This could be set after os::Posix::init() but all platforms
// have to set it the same so we have to mirror Solaris.
DEBUG_ONLY(os::set_mutex_init_done();)
os::Posix::init_2();
// 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();
// Initialize data for jdk.internal.misc.Signal
if (!ReduceSignalUsage) {
jdk_misc_signal_init();
}
// Check and sets minimum stack sizes against command line options
if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
return JNI_ERR;
}
if (MaxFDLimit) {
// set the number of file descriptors to max. print out error
// if getrlimit/setrlimit fails but continue regardless.
struct rlimit nbr_files;
int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
if (status != 0) {
log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
} else {
nbr_files.rlim_cur = nbr_files.rlim_max;
#ifdef __APPLE__
// Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
// you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
// be used instead
nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
#endif
status = setrlimit(RLIMIT_NOFILE, &nbr_files);
if (status != 0) {
log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
}
}
}
// at-exit methods are called in the reverse order of their registration.
// atexit functions are called on return from main or as a result of a
// call to exit(3C). There can be only 32 of these functions registered
// and atexit() does not set errno.
if (PerfAllowAtExitRegistration) {
// only register atexit functions if PerfAllowAtExitRegistration is set.
// atexit functions can be delayed until process exit time, which
// can be problematic for embedded VM situations. Embedded VMs should
// call DestroyJavaVM() to assure that VM resources are released.
// note: perfMemory_exit_helper atexit function may be removed in
// the future if the appropriate cleanup code can be added to the
// VM_Exit VMOperation's doit method.
if (atexit(perfMemory_exit_helper) != 0) {
warning("os::init_2 atexit(perfMemory_exit_helper) failed");
}
}
// initialize thread priority policy
prio_init();
#ifdef __APPLE__
// dynamically link to objective c gc registration
void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
if (handleLibObjc != NULL) {
objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
}
#endif
return JNI_OK;
}
// Mark the polling page as unreadable
void os::make_polling_page_unreadable(void) {
if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
fatal("Could not disable polling page");
}
}
// Mark the polling page as readable
void os::make_polling_page_readable(void) {
if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
fatal("Could not enable polling page");
}
}
int os::active_processor_count() {
// User has overridden the number of active processors
if (ActiveProcessorCount > 0) {
log_trace(os)("active_processor_count: "
"active processor count set by user : %d",
ActiveProcessorCount);
return ActiveProcessorCount;
}
return _processor_count;
}
#ifdef __APPLE__
static volatile int* volatile apic_to_processor_mapping = NULL;
static volatile int next_processor_id = 0;
static inline volatile int* get_apic_to_processor_mapping() {
volatile int* mapping = OrderAccess::load_acquire(&apic_to_processor_mapping);
if (mapping == NULL) {
// Calculate possible number space for APIC ids. This space is not necessarily
// in the range [0, number_of_processors).
uint total_bits = 0;
for (uint i = 0;; ++i) {
uint eax = 0xb; // Query topology leaf
uint ebx;
uint ecx = i;
uint edx;
__asm__ ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
uint level_type = (ecx >> 8) & 0xFF;
if (level_type == 0) {
// Invalid level; end of topology
break;
}
uint level_apic_id_shift = eax & ((1u << 5) - 1);
total_bits += level_apic_id_shift;
}
uint max_apic_ids = 1u << total_bits;
mapping = NEW_C_HEAP_ARRAY(int, max_apic_ids, mtInternal);
for (uint i = 0; i < max_apic_ids; ++i) {
mapping[i] = -1;
}
if (!Atomic::replace_if_null(mapping, &apic_to_processor_mapping)) {
FREE_C_HEAP_ARRAY(int, mapping);
mapping = OrderAccess::load_acquire(&apic_to_processor_mapping);
}
}
return mapping;
}
uint os::processor_id() {
volatile int* mapping = get_apic_to_processor_mapping();
uint eax = 0xb;
uint ebx;
uint ecx = 0;
uint edx;
__asm__ ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
// Map from APIC id to a unique logical processor ID in the expected
// [0, num_processors) range.
uint apic_id = edx;
int processor_id = Atomic::load(&mapping[apic_id]);
while (processor_id < 0) {
if (Atomic::cmpxchg(-2, &mapping[apic_id], -1)) {
Atomic::store(Atomic::add(1, &next_processor_id) - 1, &mapping[apic_id]);
}
processor_id = Atomic::load(&mapping[apic_id]);
}
return (uint)processor_id;
}
#endif
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::bind_to_processor(uint processor_id) {
// Not yet implemented.
return false;
}
void os::SuspendedThreadTask::internal_do_task() {
if (do_suspend(_thread->osthread())) {
SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
do_task(context);
do_resume(_thread->osthread());
}
}
////////////////////////////////////////////////////////////////////////////////
// debug support
bool os::find(address addr, outputStream* st) {
Dl_info dlinfo;
memset(&dlinfo, 0, sizeof(dlinfo));
if (dladdr(addr, &dlinfo) != 0) {
st->print(INTPTR_FORMAT ": ", (intptr_t)addr);
if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
st->print("%s+%#x", dlinfo.dli_sname,
(uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_saddr));
} else if (dlinfo.dli_fbase != NULL) {
st->print("<offset %#x>", (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_fbase));
} else {
st->print("<absolute address>");
}
if (dlinfo.dli_fname != NULL) {
st->print(" in %s", dlinfo.dli_fname);
}
if (dlinfo.dli_fbase != NULL) {
st->print(" at " INTPTR_FORMAT, (intptr_t)dlinfo.dli_fbase);
}
st->cr();
if (Verbose) {
// decode some bytes around the PC
address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
address lowest = (address) dlinfo.dli_sname;
if (!lowest) lowest = (address) dlinfo.dli_fbase;
if (begin < lowest) begin = lowest;
Dl_info dlinfo2;
if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
&& end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
end = (address) dlinfo2.dli_saddr;
}
Disassembler::decode(begin, end, st);
}
return true;
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
// misc
// This does not do anything on Bsd. This is basically a hook for being
// able to use structured exception handling (thread-local exception filters)
// on, e.g., Win32.
void os::os_exception_wrapper(java_call_t f, JavaValue* value,
const methodHandle& method, JavaCallArguments* args,
Thread* thread) {
f(value, method, args, thread);
}
void os::print_statistics() {
}
bool os::message_box(const char* title, const char* message) {
int i;
fdStream err(defaultStream::error_fd());
for (i = 0; i < 78; i++) err.print_raw("=");
err.cr();
err.print_raw_cr(title);
for (i = 0; i < 78; i++) err.print_raw("-");
err.cr();
err.print_raw_cr(message);
for (i = 0; i < 78; i++) err.print_raw("=");
err.cr();
char buf[16];
// Prevent process from exiting upon "read error" without consuming all CPU
while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
return buf[0] == 'y' || buf[0] == 'Y';
}
static inline struct timespec get_mtime(const char* filename) {
struct stat st;
int ret = os::stat(filename, &st);
assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
#ifdef __APPLE__
return st.st_mtimespec;
#else
return st.st_mtim;
#endif
}
int os::compare_file_modified_times(const char* file1, const char* file2) {
struct timespec filetime1 = get_mtime(file1);
struct timespec filetime2 = get_mtime(file2);
int diff = filetime1.tv_sec - filetime2.tv_sec;
if (diff == 0) {
return filetime1.tv_nsec - filetime2.tv_nsec;
}
return diff;
}
// Is a (classpath) directory empty?
bool os::dir_is_empty(const char* path) {
DIR *dir = NULL;
struct dirent *ptr;
dir = opendir(path);
if (dir == NULL) return true;
// Scan the directory
bool result = true;
while (result && (ptr = readdir(dir)) != NULL) {
if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
result = false;
}
}
closedir(dir);
return result;
}
// This code originates from JDK's sysOpen and open64_w
// from src/solaris/hpi/src/system_md.c
int os::open(const char *path, int oflag, int mode) {
if (strlen(path) > MAX_PATH - 1) {
errno = ENAMETOOLONG;
return -1;
}
int fd;
fd = ::open(path, oflag, mode);
if (fd == -1) return -1;
// If the open succeeded, the file might still be a directory
{
struct stat buf;
int ret = ::fstat(fd, &buf);
int st_mode = buf.st_mode;
if (ret != -1) {
if ((st_mode & S_IFMT) == S_IFDIR) {
errno = EISDIR;
::close(fd);
return -1;
}
} else {
::close(fd);
return -1;
}
}
// All file descriptors that are opened in the JVM and not
// specifically destined for a subprocess should have the
// close-on-exec flag set. If we don't set it, then careless 3rd
// party native code might fork and exec without closing all
// appropriate file descriptors (e.g. as we do in closeDescriptors in
// UNIXProcess.c), and this in turn might:
//
// - cause end-of-file to fail to be detected on some file
// descriptors, resulting in mysterious hangs, or
//
// - might cause an fopen in the subprocess to fail on a system
// suffering from bug 1085341.
//
// (Yes, the default setting of the close-on-exec flag is a Unix
// design flaw)
//
// See:
// 1085341: 32-bit stdio routines should support file descriptors >255
// 4843136: (process) pipe file descriptor from Runtime.exec not being closed
// 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
//
#ifdef FD_CLOEXEC
{
int flags = ::fcntl(fd, F_GETFD);
if (flags != -1) {
::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
}
}
#endif
return fd;
}
// create binary file, rewriting existing file if required
int os::create_binary_file(const char* path, bool rewrite_existing) {
int oflags = O_WRONLY | O_CREAT;
if (!rewrite_existing) {
oflags |= O_EXCL;
}
return ::open(path, oflags, S_IREAD | S_IWRITE);
}
// return current position of file pointer
jlong os::current_file_offset(int fd) {
return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
}
// move file pointer to the specified offset
jlong os::seek_to_file_offset(int fd, jlong offset) {
return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
}
// This code originates from JDK's sysAvailable
// from src/solaris/hpi/src/native_threads/src/sys_api_td.c
int os::available(int fd, jlong *bytes) {
jlong cur, end;
int mode;
struct stat buf;
if (::fstat(fd, &buf) >= 0) {
mode = buf.st_mode;
if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
int n;
if (::ioctl(fd, FIONREAD, &n) >= 0) {
*bytes = n;
return 1;
}
}
}
if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
return 0;
} else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
return 0;
} else if (::lseek(fd, cur, SEEK_SET) == -1) {
return 0;
}
*bytes = end - cur;
return 1;
}
// Map a block of memory.
char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
char *addr, size_t bytes, bool read_only,
bool allow_exec) {
int prot;
int flags;
if (read_only) {
prot = PROT_READ;
flags = MAP_SHARED;
} else {
prot = PROT_READ | PROT_WRITE;
flags = MAP_PRIVATE;
}
if (allow_exec) {
prot |= PROT_EXEC;
}
if (addr != NULL) {
flags |= MAP_FIXED;
}
char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
fd, file_offset);
if (mapped_address == MAP_FAILED) {
return NULL;
}
return mapped_address;
}
// Remap a block of memory.
char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
char *addr, size_t bytes, bool read_only,
bool allow_exec) {
// same as map_memory() on this OS
return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
allow_exec);
}
// Unmap a block of memory.
bool os::pd_unmap_memory(char* addr, size_t bytes) {
return munmap(addr, bytes) == 0;
}
// current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
// are used by JVM M&M and JVMTI to get user+sys or user CPU time
// of a thread.
//
// current_thread_cpu_time() and thread_cpu_time(Thread*) returns
// the fast estimate available on the platform.
jlong os::current_thread_cpu_time() {
#ifdef __APPLE__
return os::thread_cpu_time(Thread::current(), true /* user + sys */);
#else
Unimplemented();
return 0;
#endif
}
jlong os::thread_cpu_time(Thread* thread) {
#ifdef __APPLE__
return os::thread_cpu_time(thread, true /* user + sys */);
#else
Unimplemented();
return 0;
#endif
}
jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
#ifdef __APPLE__
return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
#else
Unimplemented();
return 0;
#endif
}
jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
#ifdef __APPLE__
struct thread_basic_info tinfo;
mach_msg_type_number_t tcount = THREAD_INFO_MAX;
kern_return_t kr;
thread_t mach_thread;
mach_thread = thread->osthread()->thread_id();
kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
if (kr != KERN_SUCCESS) {
return -1;
}
if (user_sys_cpu_time) {
jlong nanos;
nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
return nanos;
} else {
return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
}
#else
Unimplemented();
return 0;
#endif
}
void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
info_ptr->may_skip_backward = false; // elapsed time not wall time
info_ptr->may_skip_forward = false; // elapsed time not wall time
info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
}
void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
info_ptr->may_skip_backward = false; // elapsed time not wall time
info_ptr->may_skip_forward = false; // elapsed time not wall time
info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
}
bool os::is_thread_cpu_time_supported() {
#ifdef __APPLE__
return true;
#else
return false;
#endif
}
// System loadavg support. Returns -1 if load average cannot be obtained.
// Bsd doesn't yet have a (official) notion of processor sets,
// so just return the system wide load average.
int os::loadavg(double loadavg[], int nelem) {
return ::getloadavg(loadavg, nelem);
}
void os::pause() {
char filename[MAX_PATH];
if (PauseAtStartupFile && PauseAtStartupFile[0]) {
jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
} else {
jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
}
int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
if (fd != -1) {
struct stat buf;
::close(fd);
while (::stat(filename, &buf) == 0) {
(void)::poll(NULL, 0, 100);
}
} else {
jio_fprintf(stderr,
"Could not open pause file '%s', continuing immediately.\n", filename);
}
}
// Darwin has no "environ" in a dynamic library.
#ifdef __APPLE__
#include <crt_externs.h>
#define environ (*_NSGetEnviron())
#else
extern char** environ;
#endif
// Run the specified command in a separate process. Return its exit value,
// or -1 on failure (e.g. can't fork a new process).
// Unlike system(), this function can be called from signal handler. It
// doesn't block SIGINT et al.
int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
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;
}
}
}
// Get the default path to the core file
// Returns the length of the string
int os::get_core_path(char* buffer, size_t bufferSize) {
int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
// Truncate if theoretical string was longer than bufferSize
n = MIN2(n, (int)bufferSize);
return n;
}
bool os::supports_map_sync() {
return false;
}
#ifndef PRODUCT
void TestReserveMemorySpecial_test() {
// No tests available for this platform
}
#endif
bool os::start_debugging(char *buf, int buflen) {
int len = (int)strlen(buf);
char *p = &buf[len];
jio_snprintf(p, buflen-len,
"\n\n"
"Do you want to debug the problem?\n\n"
"To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT " (" INTPTR_FORMAT ")\n"
"Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
"Otherwise, press RETURN to abort...",
os::current_process_id(), os::current_process_id(),
os::current_thread_id(), os::current_thread_id());
bool yes = os::message_box("Unexpected Error", buf);
if (yes) {
// yes, user asked VM to launch debugger
jio_snprintf(buf, sizeof(buf), "gdb /proc/%d/exe %d",
os::current_process_id(), os::current_process_id());
os::fork_and_exec(buf);
yes = false;
}
return yes;
}