com.sun.webkit.Invoker Maven / Gradle / Ivy
/*
* Copyright (c) 2012, 2016, 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* 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.
*/
package com.sun.webkit;
import com.sun.webkit.perf.PerfLogger;
import java.util.concurrent.locks.ReentrantLock;
public abstract class Invoker {
private static Invoker instance;
private static final PerfLogger locksLog = PerfLogger.getLogger("Locks");
public static synchronized void setInvoker(Invoker invoker) {
instance = invoker;
}
public static synchronized Invoker getInvoker() {
return instance;
}
/*
* Acquires the lock if it's not yet held by the current thread.
*
* @returns {@code true} if the lock has been acquired, otherwise {@code false}
*/
protected boolean lock(ReentrantLock lock) {
if (lock.getHoldCount() == 0) {
lock.lock();
locksLog.resumeCount(isEventThread() ? "EventThread" : "RenderThread");
return true;
}
return false;
}
/*
* Releases the lock if it's held by the current thread.
*
* @returns {@code true} if the lock has been released, otherwise {@code false}
*/
protected boolean unlock(ReentrantLock lock) {
if (lock.getHoldCount() != 0) {
locksLog.suspendCount(isEventThread() ? "EventThread" : "RenderThread");
lock.unlock();
return true;
}
return false;
}
protected abstract boolean isEventThread();
/**
* Throws {@link IllegalStateException} if the current thread is not
* the event thread.
* @throws IllegalStateException if the current thread is not the event
* thread
*/
public void checkEventThread() {
if (!isEventThread()) {
throw new IllegalStateException("Current thread is not event thread"
+ ", current thread: " + Thread.currentThread().getName());
}
}
public abstract void invokeOnEventThread(Runnable r);
public abstract void postOnEventThread(Runnable r);
}