70 lines
2.3 KiB
Java
70 lines
2.3 KiB
Java
/*
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* Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package gc.g1.unloading.keepref;
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import gc.g1.unloading.check.cleanup.CleanupAction;
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import gc.g1.unloading.loading.LibLoader;
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/**
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* This holder keeps reference through JNI local reference.
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*/
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public class JNILocalRefHolder implements RefHolder {
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static {
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//Force loading library
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new LibLoader().hashCode();
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}
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// We use this field to transfer object into native JNI call. Idea is to avoid transferring link through method
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// arguments.
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private Object objectToKeep;
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private native void holdWithJNILocalReference(Object syncObject);
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@Override
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public Object hold(Object object) {
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objectToKeep = object;
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final Object syncObject = new Object();
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Thread keepingThread = new Thread(new Runnable() {
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@Override
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public void run() {
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synchronized (syncObject) {
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holdWithJNILocalReference(syncObject);
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}
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}
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});
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keepingThread.setDaemon(true);
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keepingThread.start();
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return new CleanupAction() {
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@Override
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public void cleanup() throws Exception {
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synchronized (syncObject) {
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syncObject.notify();
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}
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}
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};
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}
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}
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