org.nd4j.common.primitives.Atomic 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.common.primitives;
import lombok.NoArgsConstructor;
import java.io.IOException;
import java.io.Serializable;
import java.util.Objects;
import java.util.concurrent.locks.ReentrantReadWriteLock;
/**
*
* @param
*/
@NoArgsConstructor
public class Atomic implements Serializable {
private volatile T value;
private transient ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
public Atomic(T initialValue) {
this.value = initialValue;
}
/**
* This method assigns new value
* @param value
*/
public void set(T value) {
try {
lock.writeLock().lock();
this.value = value;
} finally {
lock.writeLock().unlock();
}
}
/**
* This method returns current value
* @return
*/
public T get() {
try {
lock.readLock().lock();
return this.value;
} finally {
lock.readLock().unlock();
}
}
/**
* This method implements compare-and-swap
*
* @param expected
* @param newValue
* @return true if value was swapped, false otherwise
*/
public boolean cas(T expected, T newValue) {
try {
lock.writeLock().lock();
if (Objects.equals(value, expected)) {
this.value = newValue;
return true;
} else
return false;
} finally {
lock.writeLock().unlock();
}
}
private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
lock = new ReentrantReadWriteLock();
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Atomic atomic = (Atomic) o;
try {
this.lock.readLock().lock();
atomic.lock.readLock().lock();
return Objects.equals(this.value, atomic.value);
} catch (Exception e) {
throw new RuntimeException(e);
} finally {
atomic.lock.readLock().unlock();
this.lock.readLock().unlock();
}
}
@Override
public int hashCode() {
try {
this.lock.readLock().lock();
return Objects.hash(value);
} finally {
this.lock.readLock().unlock();
}
}
}