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/*
* Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2021, Azul Systems, Inc. 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.
*
*/
#include "precompiled.hpp"
#include "cds/cds_globals.hpp"
#include "cds/metaspaceShared.hpp"
#include "classfile/classLoader.hpp"
#include "classfile/javaClasses.hpp"
#include "classfile/javaThreadStatus.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/vmClasses.hpp"
#include "classfile/vmSymbols.hpp"
#include "compiler/compileBroker.hpp"
#include "compiler/compileTask.hpp"
#include "compiler/compilerThread.hpp"
#include "gc/shared/barrierSet.hpp"
#include "gc/shared/barrierSetNMethod.hpp"
#include "gc/shared/gcVMOperations.hpp"
#include "gc/shared/oopStorage.hpp"
#include "gc/shared/oopStorageSet.hpp"
#include "gc/shared/stringdedup/stringDedup.hpp"
#include "jfr/jfrEvents.hpp"
#include "jvm.h"
#include "jvmtifiles/jvmtiEnv.hpp"
#include "logging/log.hpp"
#include "logging/logAsyncWriter.hpp"
#include "logging/logConfiguration.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/iterator.hpp"
#include "memory/oopFactory.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/klass.inline.hpp"
#include "oops/oop.inline.hpp"
#include "oops/symbol.hpp"
#include "prims/jvm_misc.hpp"
#include "runtime/arguments.hpp"
#include "runtime/fieldDescriptor.inline.hpp"
#include "runtime/flags/jvmFlagLimit.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/globals.hpp"
#include "runtime/interfaceSupport.inline.hpp"
#include "runtime/java.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/javaThread.inline.hpp"
#include "runtime/jniHandles.inline.hpp"
#include "runtime/jniPeriodicChecker.hpp"
#include "runtime/monitorDeflationThread.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/nonJavaThread.hpp"
#include "runtime/objectMonitor.inline.hpp"
#include "runtime/osThread.hpp"
#include "runtime/safepoint.hpp"
#include "runtime/safepointMechanism.inline.hpp"
#include "runtime/safepointVerifiers.hpp"
#include "runtime/serviceThread.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/statSampler.hpp"
#include "runtime/stubCodeGenerator.hpp"
#include "runtime/thread.inline.hpp"
#include "runtime/threads.hpp"
#include "runtime/threadSMR.inline.hpp"
#include "runtime/timer.hpp"
#include "runtime/timerTrace.hpp"
#include "runtime/vmOperations.hpp"
#include "runtime/vm_version.hpp"
#include "services/attachListener.hpp"
#include "services/management.hpp"
#include "services/memTracker.hpp"
#include "services/threadIdTable.hpp"
#include "services/threadService.hpp"
#include "utilities/dtrace.hpp"
#include "utilities/events.hpp"
#include "utilities/macros.hpp"
#include "utilities/systemMemoryBarrier.hpp"
#include "utilities/vmError.hpp"
#if INCLUDE_JVMCI
#include "jvmci/jvmci.hpp"
#include "jvmci/jvmciEnv.hpp"
#endif
#ifdef COMPILER2
#include "opto/idealGraphPrinter.hpp"
#endif
#if INCLUDE_RTM_OPT
#include "runtime/rtmLocking.hpp"
#endif
#if INCLUDE_JFR
#include "jfr/jfr.hpp"
#endif
// Initialization after module runtime initialization
void universe_post_module_init(); // must happen after call_initPhase2
static void initialize_class(Symbol* class_name, TRAPS) {
Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
InstanceKlass::cast(klass)->initialize(CHECK);
}
// Creates the initial ThreadGroup
static Handle create_initial_thread_group(TRAPS) {
Handle system_instance = JavaCalls::construct_new_instance(
vmClasses::ThreadGroup_klass(),
vmSymbols::void_method_signature(),
CHECK_NH);
Universe::set_system_thread_group(system_instance());
Handle string = java_lang_String::create_from_str("main", CHECK_NH);
Handle main_instance = JavaCalls::construct_new_instance(
vmClasses::ThreadGroup_klass(),
vmSymbols::threadgroup_string_void_signature(),
system_instance,
string,
CHECK_NH);
return main_instance;
}
// Creates the initial Thread, and sets it to running.
static void create_initial_thread(Handle thread_group, JavaThread* thread,
TRAPS) {
InstanceKlass* ik = vmClasses::Thread_klass();
assert(ik->is_initialized(), "must be");
instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
// Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
// constructor calls Thread.current(), which must be set here for the
// initial thread.
java_lang_Thread::set_thread(thread_oop(), thread);
thread->set_threadOopHandles(thread_oop());
Handle string = java_lang_String::create_from_str("main", CHECK);
JavaValue result(T_VOID);
JavaCalls::call_special(&result, thread_oop,
ik,
vmSymbols::object_initializer_name(),
vmSymbols::threadgroup_string_void_signature(),
thread_group,
string,
CHECK);
// Set thread status to running since main thread has
// been started and running.
java_lang_Thread::set_thread_status(thread_oop(),
JavaThreadStatus::RUNNABLE);
}
// Extract version and vendor specific information from
// java.lang.VersionProps fields.
// Returned char* is allocated in the thread's resource area
// so must be copied for permanency.
static const char* get_java_version_info(InstanceKlass* ik,
Symbol* field_name) {
fieldDescriptor fd;
bool found = ik != NULL &&
ik->find_local_field(field_name,
vmSymbols::string_signature(), &fd);
if (found) {
oop name_oop = ik->java_mirror()->obj_field(fd.offset());
if (name_oop == NULL) {
return NULL;
}
const char* name = java_lang_String::as_utf8_string(name_oop);
return name;
} else {
return NULL;
}
}
// ======= Threads ========
// The Threads class links together all active threads, and provides
// operations over all threads. It is protected by the Threads_lock,
// which is also used in other global contexts like safepointing.
// ThreadsListHandles are used to safely perform operations on one
// or more threads without the risk of the thread exiting during the
// operation.
//
// Note: The Threads_lock is currently more widely used than we
// would like. We are actively migrating Threads_lock uses to other
// mechanisms in order to reduce Threads_lock contention.
int Threads::_number_of_threads = 0;
int Threads::_number_of_non_daemon_threads = 0;
int Threads::_return_code = 0;
uintx Threads::_thread_claim_token = 1; // Never zero.
#ifdef ASSERT
bool Threads::_vm_complete = false;
#endif
// General purpose hook into Java code, run once when the VM is initialized.
// The Java library method itself may be changed independently from the VM.
static void call_postVMInitHook(TRAPS) {
Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
if (klass != NULL) {
JavaValue result(T_VOID);
JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
vmSymbols::void_method_signature(),
CHECK);
}
}
// All NonJavaThreads (i.e., every non-JavaThread in the system).
void Threads::non_java_threads_do(ThreadClosure* tc) {
NoSafepointVerifier nsv;
for (NonJavaThread::Iterator njti; !njti.end(); njti.step()) {
tc->do_thread(njti.current());
}
}
// All JavaThreads
#define ALL_JAVA_THREADS(X) \
for (JavaThread* X : *ThreadsSMRSupport::get_java_thread_list())
// All JavaThreads
void Threads::java_threads_do(ThreadClosure* tc) {
assert_locked_or_safepoint(Threads_lock);
// ALL_JAVA_THREADS iterates through all JavaThreads.
ALL_JAVA_THREADS(p) {
tc->do_thread(p);
}
}
// All JavaThreads + all non-JavaThreads (i.e., every thread in the system).
void Threads::threads_do(ThreadClosure* tc) {
assert_locked_or_safepoint(Threads_lock);
java_threads_do(tc);
non_java_threads_do(tc);
}
void Threads::possibly_parallel_threads_do(bool is_par, ThreadClosure* tc) {
uintx claim_token = Threads::thread_claim_token();
ALL_JAVA_THREADS(p) {
if (p->claim_threads_do(is_par, claim_token)) {
tc->do_thread(p);
}
}
VMThread* vmt = VMThread::vm_thread();
if (vmt->claim_threads_do(is_par, claim_token)) {
tc->do_thread(vmt);
}
}
// The system initialization in the library has three phases.
//
// Phase 1: java.lang.System class initialization
// java.lang.System is a primordial class loaded and initialized
// by the VM early during startup. java.lang.System.<clinit>
// only does registerNatives and keeps the rest of the class
// initialization work later until thread initialization completes.
//
// System.initPhase1 initializes the system properties, the static
// fields in, out, and err. Set up java signal handlers, OS-specific
// system settings, and thread group of the main thread.
static void call_initPhase1(TRAPS) {
Klass* klass = vmClasses::System_klass();
JavaValue result(T_VOID);
JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
vmSymbols::void_method_signature(), CHECK);
}
// Phase 2. Module system initialization
// This will initialize the module system. Only java.base classes
// can be loaded until phase 2 completes.
//
// Call System.initPhase2 after the compiler initialization and jsr292
// classes get initialized because module initialization runs a lot of java
// code, that for performance reasons, should be compiled. Also, this will
// enable the startup code to use lambda and other language features in this
// phase and onward.
//
// After phase 2, The VM will begin search classes from -Xbootclasspath/a.
static void call_initPhase2(TRAPS) {
TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
Klass* klass = vmClasses::System_klass();
JavaValue result(T_INT);
JavaCallArguments args;
args.push_int(DisplayVMOutputToStderr);
args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
if (result.get_jint() != JNI_OK) {
vm_exit_during_initialization(); // no message or exception
}
universe_post_module_init();
}
// Phase 3. final setup - set security manager, system class loader and TCCL
//
// This will instantiate and set the security manager, set the system class
// loader as well as the thread context class loader. The security manager
// and system class loader may be a custom class loaded from -Xbootclasspath/a,
// other modules or the application's classpath.
static void call_initPhase3(TRAPS) {
Klass* klass = vmClasses::System_klass();
JavaValue result(T_VOID);
JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
vmSymbols::void_method_signature(), CHECK);
}
void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
create_vm_init_libraries();
}
initialize_class(vmSymbols::java_lang_String(), CHECK);
// Inject CompactStrings value after the static initializers for String ran.
java_lang_String::set_compact_strings(CompactStrings);
// Initialize java_lang.System (needed before creating the thread)
initialize_class(vmSymbols::java_lang_System(), CHECK);
// The VM creates & returns objects of this class. Make sure it's initialized.
initialize_class(vmSymbols::java_lang_Class(), CHECK);
initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
Handle thread_group = create_initial_thread_group(CHECK);
Universe::set_main_thread_group(thread_group());
initialize_class(vmSymbols::java_lang_Thread(), CHECK);
create_initial_thread(thread_group, main_thread, CHECK);
// The VM creates objects of this class.
initialize_class(vmSymbols::java_lang_Module(), CHECK);
#ifdef ASSERT
InstanceKlass *k = vmClasses::UnsafeConstants_klass();
assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
#endif
// initialize the hardware-specific constants needed by Unsafe
initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
// The VM preresolves methods to these classes. Make sure that they get initialized
initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
// Phase 1 of the system initialization in the library, java.lang.System class initialization
call_initPhase1(CHECK);
// Get the Java runtime name, version, and vendor info after java.lang.System is initialized.
// Some values are actually configure-time constants but some can be set via the jlink tool and
// so must be read dynamically. We treat them all the same.
InstanceKlass* ik = SystemDictionary::find_instance_klass(THREAD, vmSymbols::java_lang_VersionProps(),
Handle(), Handle());
{
ResourceMark rm(main_thread);
JDK_Version::set_java_version(get_java_version_info(ik, vmSymbols::java_version_name()));
JDK_Version::set_runtime_name(get_java_version_info(ik, vmSymbols::java_runtime_name_name()));
JDK_Version::set_runtime_version(get_java_version_info(ik, vmSymbols::java_runtime_version_name()));
JDK_Version::set_runtime_vendor_version(get_java_version_info(ik, vmSymbols::java_runtime_vendor_version_name()));
JDK_Version::set_runtime_vendor_vm_bug_url(get_java_version_info(ik, vmSymbols::java_runtime_vendor_vm_bug_url_name()));
}
// an instance of OutOfMemory exception has been allocated earlier
initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
}
void Threads::initialize_jsr292_core_classes(TRAPS) {
TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
}
jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
extern void JDK_Version_init();
// Preinitialize version info.
VM_Version::early_initialize();
// Check version
if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
// Initialize library-based TLS
ThreadLocalStorage::init();
// Initialize the output stream module
ostream_init();
// Process java launcher properties.
Arguments::process_sun_java_launcher_properties(args);
// Initialize the os module
os::init();
MACOS_AARCH64_ONLY(os::current_thread_enable_wx(WXWrite));
// Record VM creation timing statistics
TraceVmCreationTime create_vm_timer;
create_vm_timer.start();
// Initialize system properties.
Arguments::init_system_properties();
// So that JDK version can be used as a discriminator when parsing arguments
JDK_Version_init();
// Update/Initialize System properties after JDK version number is known
Arguments::init_version_specific_system_properties();
// Make sure to initialize log configuration *before* parsing arguments
LogConfiguration::initialize(create_vm_timer.begin_time());
// Parse arguments
// Note: this internally calls os::init_container_support()
jint parse_result = Arguments::parse(args);
if (parse_result != JNI_OK) return parse_result;
// Initialize NMT right after argument parsing to keep the pre-NMT-init window small.
MemTracker::initialize();
os::init_before_ergo();
jint ergo_result = Arguments::apply_ergo();
if (ergo_result != JNI_OK) return ergo_result;
// Final check of all ranges after ergonomics which may change values.
if (!JVMFlagLimit::check_all_ranges()) {
return JNI_EINVAL;
}
// Final check of all 'AfterErgo' constraints after ergonomics which may change values.
bool constraint_result = JVMFlagLimit::check_all_constraints(JVMFlagConstraintPhase::AfterErgo);
if (!constraint_result) {
return JNI_EINVAL;
}
if (PauseAtStartup) {
os::pause();
}
HOTSPOT_VM_INIT_BEGIN();
// Timing (must come after argument parsing)
TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
// Initialize the os module after parsing the args
jint os_init_2_result = os::init_2();
if (os_init_2_result != JNI_OK) return os_init_2_result;
#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
// Initialize assert poison page mechanism.
if (ShowRegistersOnAssert) {
initialize_assert_poison();
}
#endif // CAN_SHOW_REGISTERS_ON_ASSERT
SafepointMechanism::initialize();
jint adjust_after_os_result = Arguments::adjust_after_os();
if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
// Initialize output stream logging
ostream_init_log();
// Convert -Xrun to -agentlib: if there is no JVM_OnLoad
// Must be before create_vm_init_agents()
if (Arguments::init_libraries_at_startup()) {
convert_vm_init_libraries_to_agents();
}
// Launch -agentlib/-agentpath and converted -Xrun agents
if (Arguments::init_agents_at_startup()) {
create_vm_init_agents();
}
// Initialize Threads state
_number_of_threads = 0;
_number_of_non_daemon_threads = 0;
// Initialize global data structures and create system classes in heap
vm_init_globals();
#if INCLUDE_JVMCI
if (JVMCICounterSize > 0) {
JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtJVMCI);
memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
} else {
JavaThread::_jvmci_old_thread_counters = NULL;
}
#endif // INCLUDE_JVMCI
// Initialize OopStorage for threadObj
JavaThread::_thread_oop_storage = OopStorageSet::create_strong("Thread OopStorage", mtThread);
// Attach the main thread to this os thread
JavaThread* main_thread = new JavaThread();
main_thread->set_thread_state(_thread_in_vm);
main_thread->initialize_thread_current();
// must do this before set_active_handles
main_thread->record_stack_base_and_size();
main_thread->register_thread_stack_with_NMT();
main_thread->set_active_handles(JNIHandleBlock::allocate_block());
MACOS_AARCH64_ONLY(main_thread->init_wx());
if (!main_thread->set_as_starting_thread()) {
vm_shutdown_during_initialization(
"Failed necessary internal allocation. Out of swap space");
main_thread->smr_delete();
*canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
return JNI_ENOMEM;
}
// Enable guard page *after* os::create_main_thread(), otherwise it would
// crash Linux VM, see notes in os_linux.cpp.
main_thread->stack_overflow_state()->create_stack_guard_pages();
if (UseSystemMemoryBarrier) {
if (!SystemMemoryBarrier::initialize()) {
vm_shutdown_during_initialization("Failed to initialize the requested system memory barrier synchronization.");
return JNI_EINVAL;
}
log_debug(os)("Using experimental system memory barrier synchronization");
}
// Initialize Java-Level synchronization subsystem
ObjectMonitor::Initialize();
ObjectSynchronizer::initialize();
// Initialize global modules
jint status = init_globals();
if (status != JNI_OK) {
main_thread->smr_delete();
*canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
return status;
}
JFR_ONLY(Jfr::on_create_vm_1();)
// Should be done after the heap is fully created
main_thread->cache_global_variables();
{ MutexLocker mu(Threads_lock);
Threads::add(main_thread);
}
// Any JVMTI raw monitors entered in onload will transition into
// real raw monitor. VM is setup enough here for raw monitor enter.
JvmtiExport::transition_pending_onload_raw_monitors();
// Create the VMThread
{ TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
VMThread::create();
VMThread* vmthread = VMThread::vm_thread();
if (!os::create_thread(vmthread, os::vm_thread)) {
vm_exit_during_initialization("Cannot create VM thread. "
"Out of system resources.");
}
// Wait for the VM thread to become ready, and VMThread::run to initialize
// Monitors can have spurious returns, must always check another state flag
{
MonitorLocker ml(Notify_lock);
os::start_thread(vmthread);
while (!vmthread->is_running()) {
ml.wait();
}
}
}
assert(Universe::is_fully_initialized(), "not initialized");
if (VerifyDuringStartup) {
// Make sure we're starting with a clean slate.
VM_Verify verify_op;
VMThread::execute(&verify_op);
}
// We need this to update the java.vm.info property in case any flags used
// to initially define it have been changed. This is needed for both CDS
// since UseSharedSpaces may be changed after java.vm.info
// is initially computed. See Abstract_VM_Version::vm_info_string().
// This update must happen before we initialize the java classes, but
// after any initialization logic that might modify the flags.
Arguments::update_vm_info_property(VM_Version::vm_info_string());
JavaThread* THREAD = JavaThread::current(); // For exception macros.
HandleMark hm(THREAD);
// Always call even when there are not JVMTI environments yet, since environments
// may be attached late and JVMTI must track phases of VM execution
JvmtiExport::enter_early_start_phase();
// Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
JvmtiExport::post_early_vm_start();
initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
quicken_jni_functions();
// No more stub generation allowed after that point.
StubCodeDesc::freeze();
// Set flag that basic initialization has completed. Used by exceptions and various
// debug stuff, that does not work until all basic classes have been initialized.
set_init_completed();
LogConfiguration::post_initialize();
Metaspace::post_initialize();
MutexLocker::post_initialize();
HOTSPOT_VM_INIT_END();
// record VM initialization completion time
#if INCLUDE_MANAGEMENT
Management::record_vm_init_completed();
#endif // INCLUDE_MANAGEMENT
// Signal Dispatcher needs to be started before VMInit event is posted
os::initialize_jdk_signal_support(CHECK_JNI_ERR);
// Start Attach Listener if +StartAttachListener or it can't be started lazily
if (!DisableAttachMechanism) {
AttachListener::vm_start();
if (StartAttachListener || AttachListener::init_at_startup()) {
AttachListener::init();
}
}
// Launch -Xrun agents
// Must be done in the JVMTI live phase so that for backward compatibility the JDWP
// back-end can launch with -Xdebug -Xrunjdwp.
if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
create_vm_init_libraries();
}
Chunk::start_chunk_pool_cleaner_task();
// Start the service thread
// The service thread enqueues JVMTI deferred events and does various hashtable
// and other cleanups. Needs to start before the compilers start posting events.
ServiceThread::initialize();
// Start the monitor deflation thread:
MonitorDeflationThread::initialize();
// initialize compiler(s)
#if defined(COMPILER1) || COMPILER2_OR_JVMCI
#if INCLUDE_JVMCI
bool force_JVMCI_intialization = false;
if (EnableJVMCI) {
// Initialize JVMCI eagerly when it is explicitly requested.
// Or when JVMCILibDumpJNIConfig or JVMCIPrintProperties is enabled.
force_JVMCI_intialization = EagerJVMCI || JVMCIPrintProperties || JVMCILibDumpJNIConfig;
if (!force_JVMCI_intialization) {
// 8145270: Force initialization of JVMCI runtime otherwise requests for blocking
// compilations via JVMCI will not actually block until JVMCI is initialized.
force_JVMCI_intialization = UseJVMCICompiler && (!UseInterpreter || !BackgroundCompilation);
}
}
#endif
CompileBroker::compilation_init_phase1(CHECK_JNI_ERR);
// Postpone completion of compiler initialization to after JVMCI
// is initialized to avoid timeouts of blocking compilations.
if (JVMCI_ONLY(!force_JVMCI_intialization) NOT_JVMCI(true)) {
CompileBroker::compilation_init_phase2();
}
#endif
// Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
// It is done after compilers are initialized, because otherwise compilations of
// signature polymorphic MH intrinsics can be missed
// (see SystemDictionary::find_method_handle_intrinsic).
initialize_jsr292_core_classes(CHECK_JNI_ERR);
// This will initialize the module system. Only java.base classes can be
// loaded until phase 2 completes
call_initPhase2(CHECK_JNI_ERR);
JFR_ONLY(Jfr::on_create_vm_2();)
// Always call even when there are not JVMTI environments yet, since environments
// may be attached late and JVMTI must track phases of VM execution
JvmtiExport::enter_start_phase();
// Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
JvmtiExport::post_vm_start();
// Final system initialization including security manager and system class loader
call_initPhase3(CHECK_JNI_ERR);
// cache the system and platform class loaders
SystemDictionary::compute_java_loaders(CHECK_JNI_ERR);
#if INCLUDE_CDS
// capture the module path info from the ModuleEntryTable
ClassLoader::initialize_module_path(THREAD);
if (HAS_PENDING_EXCEPTION) {
java_lang_Throwable::print(PENDING_EXCEPTION, tty);
vm_exit_during_initialization("ClassLoader::initialize_module_path() failed unexpectedly");
}
#endif
#if INCLUDE_JVMCI
if (force_JVMCI_intialization) {
JVMCI::initialize_compiler(CHECK_JNI_ERR);
CompileBroker::compilation_init_phase2();
}
#endif
// Always call even when there are not JVMTI environments yet, since environments
// may be attached late and JVMTI must track phases of VM execution
JvmtiExport::enter_live_phase();
// Make perfmemory accessible
PerfMemory::set_accessible(true);
// Notify JVMTI agents that VM initialization is complete - nop if no agents.
JvmtiExport::post_vm_initialized();
JFR_ONLY(Jfr::on_create_vm_3();)
#if INCLUDE_MANAGEMENT
Management::initialize(THREAD);
if (HAS_PENDING_EXCEPTION) {
// management agent fails to start possibly due to
// configuration problem and is responsible for printing
// stack trace if appropriate. Simply exit VM.
vm_exit(1);
}
#endif // INCLUDE_MANAGEMENT
StatSampler::engage();
if (CheckJNICalls) JniPeriodicChecker::engage();
#if INCLUDE_RTM_OPT
RTMLockingCounters::init();
#endif
call_postVMInitHook(THREAD);
// The Java side of PostVMInitHook.run must deal with all
// exceptions and provide means of diagnosis.
if (HAS_PENDING_EXCEPTION) {
CLEAR_PENDING_EXCEPTION;
}
{
MutexLocker ml(PeriodicTask_lock);
// Make sure the WatcherThread can be started by WatcherThread::start()
// or by dynamic enrollment.
WatcherThread::make_startable();
// Start up the WatcherThread if there are any periodic tasks
// NOTE: All PeriodicTasks should be registered by now. If they
// aren't, late joiners might appear to start slowly (we might
// take a while to process their first tick).
if (PeriodicTask::num_tasks() > 0) {
WatcherThread::start();
}
}
create_vm_timer.end();
#ifdef ASSERT
_vm_complete = true;
#endif
if (DumpSharedSpaces) {
MetaspaceShared::preload_and_dump();
ShouldNotReachHere();
}
return JNI_OK;
}
// type for the Agent_OnLoad and JVM_OnLoad entry points
extern "C" {
typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
}
// Find a command line agent library and return its entry point for
// -agentlib: -agentpath: -Xrun
// num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
static OnLoadEntry_t lookup_on_load(AgentLibrary* agent,
const char *on_load_symbols[],
size_t num_symbol_entries) {
OnLoadEntry_t on_load_entry = NULL;
void *library = NULL;
if (!agent->valid()) {
char buffer[JVM_MAXPATHLEN];
char ebuf[1024] = "";
const char *name = agent->name();
const char *msg = "Could not find agent library ";
// First check to see if agent is statically linked into executable
if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) {
library = agent->os_lib();
} else if (agent->is_absolute_path()) {
library = os::dll_load(name, ebuf, sizeof ebuf);
if (library == NULL) {
const char *sub_msg = " in absolute path, with error: ";
size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
// If we can't find the agent, exit.
vm_exit_during_initialization(buf, NULL);
FREE_C_HEAP_ARRAY(char, buf);
}
} else {
// Try to load the agent from the standard dll directory
if (os::dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
name)) {
library = os::dll_load(buffer, ebuf, sizeof ebuf);
}
if (library == NULL) { // Try the library path directory.
if (os::dll_build_name(buffer, sizeof(buffer), name)) {
library = os::dll_load(buffer, ebuf, sizeof ebuf);
}
if (library == NULL) {
const char *sub_msg = " on the library path, with error: ";
const char *sub_msg2 = "\nModule java.instrument may be missing from runtime image.";
size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) +
strlen(ebuf) + strlen(sub_msg2) + 1;
char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
if (!agent->is_instrument_lib()) {
jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
} else {
jio_snprintf(buf, len, "%s%s%s%s%s", msg, name, sub_msg, ebuf, sub_msg2);
}
// If we can't find the agent, exit.
vm_exit_during_initialization(buf, NULL);
FREE_C_HEAP_ARRAY(char, buf);
}
}
}
agent->set_os_lib(library);
agent->set_valid();
}
// Find the OnLoad function.
on_load_entry =
CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent,
false,
on_load_symbols,
num_symbol_entries));
return on_load_entry;
}
// Find the JVM_OnLoad entry point
static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
}
// Find the Agent_OnLoad entry point
static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
}
// For backwards compatibility with -Xrun
// Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
// treated like -agentpath:
// Must be called before agent libraries are created
void Threads::convert_vm_init_libraries_to_agents() {
AgentLibrary* agent;
AgentLibrary* next;
for (agent = Arguments::libraries(); agent != NULL; agent = next) {
next = agent->next(); // cache the next agent now as this agent may get moved off this list
OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
// If there is an JVM_OnLoad function it will get called later,
// otherwise see if there is an Agent_OnLoad
if (on_load_entry == NULL) {
on_load_entry = lookup_agent_on_load(agent);
if (on_load_entry != NULL) {
// switch it to the agent list -- so that Agent_OnLoad will be called,
// JVM_OnLoad won't be attempted and Agent_OnUnload will
Arguments::convert_library_to_agent(agent);
} else {
vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
}
}
}
}
// Create agents for -agentlib: -agentpath: and converted -Xrun
// Invokes Agent_OnLoad
// Called very early -- before JavaThreads exist
void Threads::create_vm_init_agents() {
extern struct JavaVM_ main_vm;
AgentLibrary* agent;
JvmtiExport::enter_onload_phase();
for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
// CDS dumping does not support native JVMTI agent.
// CDS dumping supports Java agent if the AllowArchivingWithJavaAgent diagnostic option is specified.
if (Arguments::is_dumping_archive()) {
if(!agent->is_instrument_lib()) {
vm_exit_during_cds_dumping("CDS dumping does not support native JVMTI agent, name", agent->name());
} else if (!AllowArchivingWithJavaAgent) {
vm_exit_during_cds_dumping(
"Must enable AllowArchivingWithJavaAgent in order to run Java agent during CDS dumping");
}
}
OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
if (on_load_entry != NULL) {
// Invoke the Agent_OnLoad function
jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
if (err != JNI_OK) {
vm_exit_during_initialization("agent library failed to init", agent->name());
}
} else {
vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
}
}
JvmtiExport::enter_primordial_phase();
}
extern "C" {
typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
}
void Threads::shutdown_vm_agents() {
// Send any Agent_OnUnload notifications
const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols);
extern struct JavaVM_ main_vm;
for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
// Find the Agent_OnUnload function.
Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
os::find_agent_function(agent,
false,
on_unload_symbols,
num_symbol_entries));
// Invoke the Agent_OnUnload function
if (unload_entry != NULL) {
JavaThread* thread = JavaThread::current();
ThreadToNativeFromVM ttn(thread);
HandleMark hm(thread);
(*unload_entry)(&main_vm);
}
}
}
// Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
// Invokes JVM_OnLoad
void Threads::create_vm_init_libraries() {
extern struct JavaVM_ main_vm;
AgentLibrary* agent;
for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
if (on_load_entry != NULL) {
// Invoke the JVM_OnLoad function
JavaThread* thread = JavaThread::current();
ThreadToNativeFromVM ttn(thread);
HandleMark hm(thread);
jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
if (err != JNI_OK) {
vm_exit_during_initialization("-Xrun library failed to init", agent->name());
}
} else {
vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
}
}
}
// Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
// the program falls off the end of main(). Another VM exit path is through
// vm_exit() when the program calls System.exit() to return a value or when
// there is a serious error in VM. The two shutdown paths are not exactly
// the same, but they share Shutdown.shutdown() at Java level and before_exit()
// and VM_Exit op at VM level.
//
// Shutdown sequence:
// + Shutdown native memory tracking if it is on
// + Wait until we are the last non-daemon thread to execute
// <-- every thing is still working at this moment -->
// + Call java.lang.Shutdown.shutdown(), which will invoke Java level
// shutdown hooks
// + Call before_exit(), prepare for VM exit
// > run VM level shutdown hooks (they are registered through JVM_OnExit(),
// currently the only user of this mechanism is File.deleteOnExit())
// > stop StatSampler, watcher thread,
// post thread end and vm death events to JVMTI,
// stop signal thread
// + Call JavaThread::exit(), it will:
// > release JNI handle blocks, remove stack guard pages
// > remove this thread from Threads list
// <-- no more Java code from this thread after this point -->
// + Stop VM thread, it will bring the remaining VM to a safepoint and stop
// the compiler threads at safepoint
// <-- do not use anything that could get blocked by Safepoint -->
// + Disable tracing at JNI/JVM barriers
// + Set _vm_exited flag for threads that are still running native code
// + Call exit_globals()
// > deletes tty
// > deletes PerfMemory resources
// + Delete this thread
// + Return to caller
void Threads::destroy_vm() {
JavaThread* thread = JavaThread::current();
#ifdef ASSERT
_vm_complete = false;
#endif
// Wait until we are the last non-daemon thread to execute, or
// if we are a daemon then wait until the last non-daemon thread has
// executed.
bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
int expected = daemon ? 0 : 1;
{
MonitorLocker nu(Threads_lock);
while (Threads::number_of_non_daemon_threads() > expected)
// This wait should make safepoint checks, wait without a timeout.
nu.wait(0);
}
EventShutdown e;
if (e.should_commit()) {
e.set_reason("No remaining non-daemon Java threads");
e.commit();
}
// Hang forever on exit if we are reporting an error.
if (ShowMessageBoxOnError && VMError::is_error_reported()) {
os::infinite_sleep();
}
os::wait_for_keypress_at_exit();
// run Java level shutdown hooks
thread->invoke_shutdown_hooks();
before_exit(thread);
thread->exit(true);
// We are no longer on the main thread list but could still be in a
// secondary list where another thread may try to interact with us.
// So wait until all such interactions are complete before we bring
// the VM to the termination safepoint. Normally this would be done
// using thread->smr_delete() below where we delete the thread, but
// we can't call that after the termination safepoint is active as
// we will deadlock on the Threads_lock. Once all interactions are
// complete it is safe to directly delete the thread at any time.
ThreadsSMRSupport::wait_until_not_protected(thread);
// Stop VM thread.
{
// 4945125 The vm thread comes to a safepoint during exit.
// GC vm_operations can get caught at the safepoint, and the
// heap is unparseable if they are caught. Grab the Heap_lock
// to prevent this. The GC vm_operations will not be able to
// queue until after the vm thread is dead. After this point,
// we'll never emerge out of the safepoint before the VM exits.
// Assert that the thread is terminated so that acquiring the
// Heap_lock doesn't cause the terminated thread to participate in
// the safepoint protocol.
assert(thread->is_terminated(), "must be terminated here");
MutexLocker ml(Heap_lock);
VMThread::wait_for_vm_thread_exit();
assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
VMThread::destroy();
}
// Now, all Java threads are gone except daemon threads. Daemon threads
// running Java code or in VM are stopped by the Safepoint. However,
// daemon threads executing native code are still running. But they
// will be stopped at native=>Java/VM barriers. Note that we can't
// simply kill or suspend them, as it is inherently deadlock-prone.
VM_Exit::set_vm_exited();
// Clean up ideal graph printers after the VMThread has started
// the final safepoint which will block all the Compiler threads.
// Note that this Thread has already logically exited so the
// clean_up() function's use of a JavaThreadIteratorWithHandle
// would be a problem except set_vm_exited() has remembered the
// shutdown thread which is granted a policy exception.
#if defined(COMPILER2) && !defined(PRODUCT)
IdealGraphPrinter::clean_up();
#endif
notify_vm_shutdown();
// exit_globals() will delete tty
exit_globals();
// Deleting the shutdown thread here is safe. See comment on
// wait_until_not_protected() above.
delete thread;
#if INCLUDE_JVMCI
if (JVMCICounterSize > 0) {
FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
}
#endif
LogConfiguration::finalize();
}
jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
if (version == JNI_VERSION_1_1) return JNI_TRUE;
return is_supported_jni_version(version);
}
jboolean Threads::is_supported_jni_version(jint version) {
if (version == JNI_VERSION_1_2) return JNI_TRUE;
if (version == JNI_VERSION_1_4) return JNI_TRUE;
if (version == JNI_VERSION_1_6) return JNI_TRUE;
if (version == JNI_VERSION_1_8) return JNI_TRUE;
if (version == JNI_VERSION_9) return JNI_TRUE;
if (version == JNI_VERSION_10) return JNI_TRUE;
if (version == JNI_VERSION_19) return JNI_TRUE;
if (version == JNI_VERSION_20) return JNI_TRUE;
return JNI_FALSE;
}
void Threads::add(JavaThread* p, bool force_daemon) {
// The threads lock must be owned at this point
assert(Threads_lock->owned_by_self(), "must have threads lock");
BarrierSet::barrier_set()->on_thread_attach(p);
// Once a JavaThread is added to the Threads list, smr_delete() has
// to be used to delete it. Otherwise we can just delete it directly.
p->set_on_thread_list();
_number_of_threads++;
oop threadObj = p->threadObj();
bool daemon = true;
// Bootstrapping problem: threadObj can be null for initial
// JavaThread (or for threads attached via JNI)
if (!force_daemon &&
(threadObj == nullptr || !java_lang_Thread::is_daemon(threadObj))) {
_number_of_non_daemon_threads++;
daemon = false;
}
ThreadService::add_thread(p, daemon);
// Maintain fast thread list
ThreadsSMRSupport::add_thread(p);
// Increase the ObjectMonitor ceiling for the new thread.
ObjectSynchronizer::inc_in_use_list_ceiling();
// Possible GC point.
Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p));
// Make new thread known to active EscapeBarrier
EscapeBarrier::thread_added(p);
}
void Threads::remove(JavaThread* p, bool is_daemon) {
// Extra scope needed for Thread_lock, so we can check
// that we do not remove thread without safepoint code notice
{ MonitorLocker ml(Threads_lock);
if (ThreadIdTable::is_initialized()) {
// This cleanup must be done before the current thread's GC barrier
// is detached since we need to touch the threadObj oop.
jlong tid = SharedRuntime::get_java_tid(p);
ThreadIdTable::remove_thread(tid);
}
// BarrierSet state must be destroyed after the last thread transition
// before the thread terminates. Thread transitions result in calls to
// StackWatermarkSet::on_safepoint(), which performs GC processing,
// requiring the GC state to be alive.
BarrierSet::barrier_set()->on_thread_detach(p);
if (p->is_exiting()) {
// If we got here via JavaThread::exit(), then we remember that the
// thread's GC barrier has been detached. We don't do this when we get
// here from another path, e.g., cleanup_failed_attach_current_thread().
p->set_terminated(JavaThread::_thread_gc_barrier_detached);
}
assert(ThreadsSMRSupport::get_java_thread_list()->includes(p), "p must be present");
// Maintain fast thread list
ThreadsSMRSupport::remove_thread(p);
_number_of_threads--;
if (!is_daemon) {
_number_of_non_daemon_threads--;
// If this is the last non-daemon thread then we need to do
// a notify on the Threads_lock so a thread waiting
// on destroy_vm will wake up. But that thread could be a daemon
// or non-daemon, so we notify for both the 0 and 1 case.
if (number_of_non_daemon_threads() <= 1) {
ml.notify_all();
}
}
ThreadService::remove_thread(p, is_daemon);
// Make sure that safepoint code disregard this thread. This is needed since
// the thread might mess around with locks after this point. This can cause it
// to do callbacks into the safepoint code. However, the safepoint code is not aware
// of this thread since it is removed from the queue.
p->set_terminated(JavaThread::_thread_terminated);
// Notify threads waiting in EscapeBarriers
EscapeBarrier::thread_removed(p);
} // unlock Threads_lock
// Reduce the ObjectMonitor ceiling for the exiting thread.
ObjectSynchronizer::dec_in_use_list_ceiling();
// Since Events::log uses a lock, we grab it outside the Threads_lock
Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p));
}
// Operations on the Threads list for GC. These are not explicitly locked,
// but the garbage collector must provide a safe context for them to run.
// In particular, these things should never be called when the Threads_lock
// is held by some other thread. (Note: the Safepoint abstraction also
// uses the Threads_lock to guarantee this property. It also makes sure that
// all threads gets blocked when exiting or starting).
void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
ALL_JAVA_THREADS(p) {
p->oops_do(f, cf);
}
VMThread::vm_thread()->oops_do(f, cf);
}
void Threads::change_thread_claim_token() {
if (++_thread_claim_token == 0) {
// On overflow of the token counter, there is a risk of future
// collisions between a new global token value and a stale token
// for a thread, because not all iterations visit all threads.
// (Though it's pretty much a theoretical concern for non-trivial
// token counter sizes.) To deal with the possibility, reset all
// the thread tokens to zero on global token overflow.
struct ResetClaims : public ThreadClosure {
virtual void do_thread(Thread* t) {
t->claim_threads_do(false, 0);
}
} reset_claims;
Threads::threads_do(&reset_claims);
// On overflow, update the global token to non-zero, to
// avoid the special "never claimed" initial thread value.
_thread_claim_token = 1;
}
}
#ifdef ASSERT
void assert_thread_claimed(const char* kind, Thread* t, uintx expected) {
const uintx token = t->threads_do_token();
assert(token == expected,
"%s " PTR_FORMAT " has incorrect value " UINTX_FORMAT " != "
UINTX_FORMAT, kind, p2i(t), token, expected);
}
void Threads::assert_all_threads_claimed() {
ALL_JAVA_THREADS(p) {
assert_thread_claimed("Thread", p, _thread_claim_token);
}
assert_thread_claimed("VMThread", VMThread::vm_thread(), _thread_claim_token);
}
#endif // ASSERT
class ParallelOopsDoThreadClosure : public ThreadClosure {
private:
OopClosure* _f;
CodeBlobClosure* _cf;
public:
ParallelOopsDoThreadClosure(OopClosure* f, CodeBlobClosure* cf) : _f(f), _cf(cf) {}
void do_thread(Thread* t) {
t->oops_do(_f, _cf);
}
};
void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf) {
ParallelOopsDoThreadClosure tc(f, cf);
possibly_parallel_threads_do(is_par, &tc);
}
void Threads::metadata_do(MetadataClosure* f) {
ALL_JAVA_THREADS(p) {
p->metadata_do(f);
}
}
class ThreadHandlesClosure : public ThreadClosure {
void (*_f)(Metadata*);
public:
ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
virtual void do_thread(Thread* thread) {
thread->metadata_handles_do(_f);
}
};
void Threads::metadata_handles_do(void f(Metadata*)) {
// Only walk the Handles in Thread.
ThreadHandlesClosure handles_closure(f);
threads_do(&handles_closure);
}
// Get count Java threads that are waiting to enter the specified monitor.
GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
int count,
address monitor) {
GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
int i = 0;
for (JavaThread* p : *t_list) {
if (!p->can_call_java()) continue;
// The first stage of async deflation does not affect any field
// used by this comparison so the ObjectMonitor* is usable here.
address pending = (address)p->current_pending_monitor();
if (pending == monitor) { // found a match
if (i < count) result->append(p); // save the first count matches
i++;
}
}
return result;
}
JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list,
address owner) {
// NULL owner means not locked so we can skip the search
if (owner == NULL) return NULL;
for (JavaThread* p : *t_list) {
// first, see if owner is the address of a Java thread
if (owner == (address)p) return p;
}
// Cannot assert on lack of success here since this function may be
// used by code that is trying to report useful problem information
// like deadlock detection.
if (UseHeavyMonitors) return NULL;
// If we didn't find a matching Java thread and we didn't force use of
// heavyweight monitors, then the owner is the stack address of the
// Lock Word in the owning Java thread's stack.
//
JavaThread* the_owner = NULL;
for (JavaThread* q : *t_list) {
if (q->is_lock_owned(owner)) {
the_owner = q;
break;
}
}
// cannot assert on lack of success here; see above comment
return the_owner;
}
JavaThread* Threads::owning_thread_from_monitor(ThreadsList* t_list, ObjectMonitor* monitor) {
address owner = (address)monitor->owner();
return owning_thread_from_monitor_owner(t_list, owner);
}
class PrintOnClosure : public ThreadClosure {
private:
outputStream* _st;
public:
PrintOnClosure(outputStream* st) :
_st(st) {}
virtual void do_thread(Thread* thread) {
if (thread != NULL) {
thread->print_on(_st);
_st->cr();
}
}
};
// Threads::print_on() is called at safepoint by VM_PrintThreads operation.
void Threads::print_on(outputStream* st, bool print_stacks,
bool internal_format, bool print_concurrent_locks,
bool print_extended_info) {
char buf[32];
st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
st->print_cr("Full thread dump %s (%s %s):",
VM_Version::vm_name(),
VM_Version::vm_release(),
VM_Version::vm_info_string());
st->cr();
#if INCLUDE_SERVICES
// Dump concurrent locks
ConcurrentLocksDump concurrent_locks;
if (print_concurrent_locks) {
concurrent_locks.dump_at_safepoint();
}
#endif // INCLUDE_SERVICES
ThreadsSMRSupport::print_info_on(st);
st->cr();
ALL_JAVA_THREADS(p) {
ResourceMark rm;
p->print_on(st, print_extended_info);
if (print_stacks) {
if (internal_format) {
p->trace_stack();
} else {
p->print_stack_on(st);
}
}
st->cr();
#if INCLUDE_SERVICES
if (print_concurrent_locks) {
concurrent_locks.print_locks_on(p, st);
}
#endif // INCLUDE_SERVICES
}
PrintOnClosure cl(st);
cl.do_thread(VMThread::vm_thread());
Universe::heap()->gc_threads_do(&cl);
if (StringDedup::is_enabled()) {
StringDedup::threads_do(&cl);
}
cl.do_thread(WatcherThread::watcher_thread());
cl.do_thread(AsyncLogWriter::instance());
st->flush();
}
void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
int buflen, bool* found_current) {
if (this_thread != NULL) {
bool is_current = (current == this_thread);
*found_current = *found_current || is_current;
st->print("%s", is_current ? "=>" : " ");
st->print(PTR_FORMAT, p2i(this_thread));
st->print(" ");
this_thread->print_on_error(st, buf, buflen);
st->cr();
}
}
class PrintOnErrorClosure : public ThreadClosure {
outputStream* _st;
Thread* _current;
char* _buf;
int _buflen;
bool* _found_current;
public:
PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
int buflen, bool* found_current) :
_st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current) {}
virtual void do_thread(Thread* thread) {
Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
}
};
// Threads::print_on_error() is called by fatal error handler. It's possible
// that VM is not at safepoint and/or current thread is inside signal handler.
// Don't print stack trace, as the stack may not be walkable. Don't allocate
// memory (even in resource area), it might deadlock the error handler.
void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
int buflen) {
ThreadsSMRSupport::print_info_on(st);
st->cr();
bool found_current = false;
st->print_cr("Java Threads: ( => current thread )");
ALL_JAVA_THREADS(thread) {
print_on_error(thread, st, current, buf, buflen, &found_current);
}
st->cr();
st->print_cr("Other Threads:");
print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
print_on_error(AsyncLogWriter::instance(), st, current, buf, buflen, &found_current);
if (Universe::heap() != NULL) {
PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
Universe::heap()->gc_threads_do(&print_closure);
}
if (StringDedup::is_enabled()) {
PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
StringDedup::threads_do(&print_closure);
}
if (!found_current) {
st->cr();
st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
current->print_on_error(st, buf, buflen);
st->cr();
}
st->cr();
st->print_cr("Threads with active compile tasks:");
print_threads_compiling(st, buf, buflen);
}
void Threads::print_threads_compiling(outputStream* st, char* buf, int buflen, bool short_form) {
ALL_JAVA_THREADS(thread) {
if (thread->is_Compiler_thread()) {
CompilerThread* ct = (CompilerThread*) thread;
// Keep task in local variable for NULL check.
// ct->_task might be set to NULL by concurring compiler thread
// because it completed the compilation. The task is never freed,
// though, just returned to a free list.
CompileTask* task = ct->task();
if (task != NULL) {
thread->print_name_on_error(st, buf, buflen);
st->print(" ");
task->print(st, NULL, short_form, true);
}
}
}
}
void Threads::verify() {
ALL_JAVA_THREADS(p) {
p->verify();
}
VMThread* thread = VMThread::vm_thread();
if (thread != NULL) thread->verify();
}
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