jdk/src/hotspot/share/cds/aotThread.cpp
Leonid Mesnik f5e4cd7f0d 8372039: post_sampled_object_alloc is called while lock is handled
Reviewed-by: sspitsyn, eosterlund, amenkov
2025-12-02 23:48:58 +00:00

115 lines
4.1 KiB
C++

/*
* Copyright (c) 2024, 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
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*/
#include "cds/aotStreamedHeapLoader.hpp"
#include "cds/aotThread.hpp"
#include "cds/heapShared.hpp"
#include "classfile/javaClasses.hpp"
#include "classfile/javaThreadStatus.hpp"
#include "classfile/vmClasses.hpp"
#include "classfile/vmSymbols.hpp"
#include "jfr/jfr.hpp"
#include "runtime/javaThread.inline.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/osThread.hpp"
#include "runtime/thread.hpp"
#include "runtime/threads.hpp"
#include "utilities/exceptions.hpp"
AOTThread* AOTThread::_aot_thread;
bool AOTThread::_started;
// Starting the AOTThread is tricky. We wish to start it as early as possible, as
// that increases the amount of curling this thread can do for the application thread
// that is concurrently starting. But there are complications starting a thread this
// early. The java.lang.Thread class is not initialized and we may not execute any
// Java bytecodes yet. This is an internal thread, so we try to keep the bookkeeping
// minimal and use a logical ThreadIdentifier for JFR and monitor identity. The real
// thread object is created just after the main thread creates its Thread object, after
// the Thread class has been initialized.
void AOTThread::initialize() {
#if INCLUDE_CDS_JAVA_HEAP
EXCEPTION_MARK;
// Spin up a thread without thread oop, because the java.lang classes
// have not yet been initialized, and hence we can't allocate the Thread
// object yet.
AOTThread* thread = new AOTThread(&aot_thread_entry);
_aot_thread = thread;
#if INCLUDE_JVMTI
// The line below hides JVMTI events from this thread (cf. should_hide_jvmti_events())
// This is important because this thread runs before JVMTI monitors are set up appropriately.
// Therefore, callbacks would not work as intended. JVMTI has no business peeking at how we
// materialize primordial objects from the AOT cache.
thread->disable_jvmti_events();
#endif
JavaThread::vm_exit_on_osthread_failure(thread);
_started = true;
// Note that the Thread class is not initialized yet at this point. We
// can run a bit concurrently until the Thread class is initialized; then
// materialize_thread_object is called to inflate the thread object.
// The thread needs an identifier. This thread is fine with a temporary ID
// assignment; it will terminate soon anyway.
int64_t tid = ThreadIdentifier::next();
thread->set_monitor_owner_id(tid);
{
MutexLocker mu(THREAD, Threads_lock);
Threads::add(thread);
}
JFR_ONLY(Jfr::on_java_thread_start(THREAD, thread);)
os::start_thread(thread);
#endif
}
void AOTThread::materialize_thread_object() {
#if INCLUDE_CDS_JAVA_HEAP
if (!_started) {
// No thread object to materialize
return;
}
EXCEPTION_MARK;
HandleMark hm(THREAD);
Handle thread_oop = JavaThread::create_system_thread_object("AOTThread", CHECK);
java_lang_Thread::release_set_thread(thread_oop(), _aot_thread);
_aot_thread->set_threadOopHandles(thread_oop());
#endif
}
void AOTThread::aot_thread_entry(JavaThread* jt, TRAPS) {
#if INCLUDE_CDS_JAVA_HEAP
AOTStreamedHeapLoader::materialize_objects();
_aot_thread = nullptr; // AOT thread will get destroyed after this point
#endif
}