/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
***************************************************************************************
*/
package com.espertech.esper.core.service;
import com.espertech.esper.util.ThreadLogUtil;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
/**
* Simple read-write lock based on {@link java.util.concurrent.locks.ReentrantReadWriteLock} that associates a
* name with the lock and traces read/write locking and unlocking.
*/
public class StatementAgentInstanceRWLockImpl implements StatementAgentInstanceLock {
private final ReentrantReadWriteLock lock;
/**
* Ctor.
*
* @param isFair true if a fair lock, false if not
*/
public StatementAgentInstanceRWLockImpl(boolean isFair) {
lock = new ReentrantReadWriteLock(isFair);
}
/**
* Lock write lock.
*/
public void acquireWriteLock() {
if (ThreadLogUtil.ENABLED_TRACE) {
ThreadLogUtil.traceLock(ACQUIRE_TEXT + " write ", lock);
}
lock.writeLock().lock();
if (ThreadLogUtil.ENABLED_TRACE) {
ThreadLogUtil.traceLock(ACQUIRED_TEXT + " write ", lock);
}
}
public boolean acquireWriteLock(long msecTimeout) {
if (ThreadLogUtil.ENABLED_TRACE) {
ThreadLogUtil.traceLock(ACQUIRE_TEXT + " write ", lock);
}
boolean result = false;
try {
result = lock.writeLock().tryLock(msecTimeout, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
if (ThreadLogUtil.ENABLED_TRACE) {
ThreadLogUtil.traceLock(ACQUIRED_TEXT + " write ", lock);
}
return result;
}
/**
* Unlock write lock.
*/
public void releaseWriteLock() {
if (ThreadLogUtil.ENABLED_TRACE) {
ThreadLogUtil.traceLock(RELEASE_TEXT + " write ", lock);
}
lock.writeLock().unlock();
if (ThreadLogUtil.ENABLED_TRACE) {
ThreadLogUtil.traceLock(RELEASED_TEXT + " write ", lock);
}
}
/**
* Lock read lock.
*/
public void acquireReadLock() {
if (ThreadLogUtil.ENABLED_TRACE) {
ThreadLogUtil.traceLock(ACQUIRE_TEXT + " read ", lock);
}
lock.readLock().lock();
if (ThreadLogUtil.ENABLED_TRACE) {
ThreadLogUtil.traceLock(ACQUIRED_TEXT + " read ", lock);
}
}
/**
* Unlock read lock.
*/
public void releaseReadLock() {
if (ThreadLogUtil.ENABLED_TRACE) {
ThreadLogUtil.traceLock(RELEASE_TEXT + " read ", lock);
}
lock.readLock().unlock();
if (ThreadLogUtil.ENABLED_TRACE) {
ThreadLogUtil.traceLock(RELEASED_TEXT + " read ", lock);
}
}
public String toString() {
return this.getClass().getSimpleName();
}
public boolean addAcquiredLock(Lock lock) {
throw new UnsupportedOperationException("Lock-acquisition not supported, please check the use of tables");
}
}