org.nd4j.linalg.util.AtomicThrowable Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2015-2018 Skymind, Inc.
*
* This program and the accompanying materials are made available under the
* terms of the Apache License, Version 2.0 which is available at
* https://www.apache.org/licenses/LICENSE-2.0.
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
* SPDX-License-Identifier: Apache-2.0
******************************************************************************/
package org.nd4j.linalg.util;
import java.util.concurrent.locks.ReentrantReadWriteLock;
/**
* This class provides thread-safe holder for Throwable
*
* @author [email protected]
*/
public class AtomicThrowable {
protected volatile Throwable t = null;
protected ReentrantReadWriteLock lock;
/**
* This method creates new instance
*/
public AtomicThrowable() {
// unfortunately we want fair queue here, to avoid situations when we return null after exception
lock = new ReentrantReadWriteLock(true);
}
/**
* This method creates new instance with given initial state
* @param e
*/
public AtomicThrowable(Exception e) {
this();
t = e;
}
/**
* This method returns current state
* @return
*/
public Throwable get() {
try {
lock.readLock().lock();
return t;
} finally {
lock.readLock().unlock();
}
}
/**
* This method updates state with given Throwable
* @param t
*/
public void set(Throwable t) {
try {
lock.writeLock().lock();
this.t = t;
} finally {
lock.writeLock().unlock();
}
}
/**
* This method updates state only if it wasn't set before
*
* @param t
*/
public void setIfFirst(Throwable t) {
try {
lock.writeLock().lock();
if (this.t == null)
this.t = t;
} finally {
lock.writeLock().unlock();
}
}
/**
* This method returns TRUE if internal state holds error, FALSE otherwise
*
* @return
*/
public boolean isTriggered() {
try {
lock.readLock().lock();
return t != null;
} finally {
lock.readLock().unlock();
}
}
}