|
/*
* Copyright (c) 2018, 2021, 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.
*/
#include "precompiled.hpp"
#include "classfile/classLoaderDataGraph.hpp"
#include "classfile/systemDictionary.hpp"
#include "code/codeBehaviours.hpp"
#include "code/codeCache.hpp"
#include "code/dependencyContext.hpp"
#include "gc/shared/gcBehaviours.hpp"
#include "gc/shared/suspendibleThreadSet.hpp"
#include "gc/z/zBarrier.inline.hpp"
#include "gc/z/zLock.inline.hpp"
#include "gc/z/zNMethod.hpp"
#include "gc/z/zStat.hpp"
#include "gc/z/zUnload.hpp"
#include "memory/metaspaceUtils.hpp"
#include "oops/access.inline.hpp"
static const ZStatSubPhase ZSubPhaseConcurrentClassesUnlink("Concurrent Classes Unlink");
static const ZStatSubPhase ZSubPhaseConcurrentClassesPurge("Concurrent Classes Purge");
class ZPhantomIsAliveObjectClosure : public BoolObjectClosure {
public:
virtual bool do_object_b(oop o) {
return ZBarrier::is_alive_barrier_on_phantom_oop(o);
}
};
class ZIsUnloadingOopClosure : public OopClosure {
private:
ZPhantomIsAliveObjectClosure _is_alive;
bool _is_unloading;
public:
ZIsUnloadingOopClosure() :
_is_alive(),
_is_unloading(false) {}
virtual void do_oop(oop* p) {
const oop o = RawAccess<>::oop_load(p);
if (o != NULL && !_is_alive.do_object_b(o)) {
_is_unloading = true;
}
}
virtual void do_oop(narrowOop* p) {
ShouldNotReachHere();
}
bool is_unloading() const {
return _is_unloading;
}
};
class ZIsUnloadingBehaviour : public IsUnloadingBehaviour {
public:
virtual bool has_dead_oop(CompiledMethod* method) const {
nmethod* const nm = method->as_nmethod();
ZReentrantLock* const lock = ZNMethod::lock_for_nmethod(nm);
ZLocker<ZReentrantLock> locker(lock);
ZIsUnloadingOopClosure cl;
ZNMethod::nmethod_oops_do_inner(nm, &cl);
return cl.is_unloading();
}
};
class ZCompiledICProtectionBehaviour : public CompiledICProtectionBehaviour {
public:
virtual bool lock(CompiledMethod* method) {
nmethod* const nm = method->as_nmethod();
ZReentrantLock* const lock = ZNMethod::lock_for_nmethod(nm);
lock->lock();
return true;
}
virtual void unlock(CompiledMethod* method) {
nmethod* const nm = method->as_nmethod();
ZReentrantLock* const lock = ZNMethod::lock_for_nmethod(nm);
lock->unlock();
}
virtual bool is_safe(CompiledMethod* method) {
if (SafepointSynchronize::is_at_safepoint()) {
return true;
}
nmethod* const nm = method->as_nmethod();
ZReentrantLock* const lock = ZNMethod::lock_for_nmethod(nm);
return lock->is_owned();
}
};
ZUnload::ZUnload(ZWorkers* workers) :
_workers(workers) {
if (!ClassUnloading) {
return;
}
static ZIsUnloadingBehaviour is_unloading_behaviour;
IsUnloadingBehaviour::set_current(&is_unloading_behaviour);
static ZCompiledICProtectionBehaviour ic_protection_behaviour;
CompiledICProtectionBehaviour::set_current(&ic_protection_behaviour);
}
void ZUnload::prepare() {
if (!ClassUnloading) {
return;
}
CodeCache::increment_unloading_cycle();
DependencyContext::cleaning_start();
}
void ZUnload::unlink() {
if (!ClassUnloading) {
return;
}
ZStatTimer timer(ZSubPhaseConcurrentClassesUnlink);
SuspendibleThreadSetJoiner sts;
bool unloading_occurred;
{
MutexLocker ml(ClassLoaderDataGraph_lock);
unloading_occurred = SystemDictionary::do_unloading(ZStatPhase::timer());
}
Klass::clean_weak_klass_links(unloading_occurred);
ZNMethod::unlink(_workers, unloading_occurred);
DependencyContext::cleaning_end();
}
void ZUnload::purge() {
if (!ClassUnloading) {
return;
}
ZStatTimer timer(ZSubPhaseConcurrentClassesPurge);
{
SuspendibleThreadSetJoiner sts;
ZNMethod::purge();
}
ClassLoaderDataGraph::purge(/*at_safepoint*/false);
CodeCache::purge_exception_caches();
}
void ZUnload::finish() {
// Resize and verify metaspace
MetaspaceGC::compute_new_size();
DEBUG_ONLY(MetaspaceUtils::verify();)
}
¤ Dauer der Verarbeitung: 0.16 Sekunden
(vorverarbeitet)
¤
|
Haftungshinweis
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung ist noch experimentell.
|
