eu.binjr.common.concurrent.ReadWriteLockHelper Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of binjr-core Show documentation
Show all versions of binjr-core Show documentation
A Time Series Data Browser
/*
* Copyright 2017-2018 Frederic Thevenet
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://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.
*/
package eu.binjr.common.concurrent;
import eu.binjr.common.function.*;
import java.util.Optional;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
/**
* An helper class that wraps a {@link ReadWriteLock} instance and provides methods to streamline usage and avoid common inattention mistakes,
* such as locking one the lock and unlocking the other in the {@code finally} block.
*
* @author Frederic Thevenet
*/
public class ReadWriteLockHelper {
private final ReadWriteLock lock;
private final LockHelper readLockHelper;
private final LockHelper writeLockHelper;
/**
* Creates a new instance of the {@link ReadWriteLockHelper} class that wraps a new instance of {@link ReentrantReadWriteLock}
*/
public ReadWriteLockHelper() {
this(new ReentrantReadWriteLock());
}
/**
* Creates a new instance of the {@link ReadWriteLockHelper} class for the provided lock.
*
* @param lock the {@link ReadWriteLock} instance to wrap.
*/
public ReadWriteLockHelper(ReadWriteLock lock) {
this.lock = lock;
this.readLockHelper = new LockHelper(lock.readLock());
this.writeLockHelper = new LockHelper(lock.writeLock());
}
/**
* Gets the underlying ReadWriteLock instance.
*
* @return the underlying ReadWriteLock instance.
*/
public ReadWriteLock getLock() {
return lock;
}
/**
* Returns an helper providing methods to run lambdas within the context of the read lock.
*
* @return an helper providing methods to run lambdas within the context of the read lock.
*/
public LockHelper read() {
return readLockHelper;
}
/**
* Returns an helper providing methods to run lambdas within the context of the write lock.
*
* @return an helper providing methods to run lambdas within the context of the write lock.
*/
public LockHelper write() {
return writeLockHelper;
}
/**
* An helper providing methods to run lambdas within the context of supplied lock.
*/
public static class LockHelper {
private final Lock lock;
/**
* Constructor
*
* @param lock Lock
*/
private LockHelper(Lock lock) {
this.lock = lock;
}
//region *** lock method overloads ***
/**
* Encapsulated the evaluation of the supplied {@link CheckedSupplier} within the boundaries of the lock.
*
* @param operation the {@link CheckedSupplier} to evaluate.
* @param the return type for the {@link CheckedSupplier}.
* @param the type of the exception thrown by the {@link CheckedSupplier}.
* @return the return of the {@link CheckedSupplier}.
* @throws E the exception thrown by the {@link CheckedSupplier}.
*/
public R lock(CheckedSupplier operation) throws E {
lock.lock();
try {
return operation.get();
} finally {
lock.unlock();
}
}
/**
* Encapsulated the evaluation of the supplied {@link CheckedFunction} within the boundaries of the lock.
*
* @param operation the {@link CheckedFunction} to apply.
* @param t the parameter to pass the {@link CheckedFunction}
* @param the type of he parameter to pass the {@link CheckedFunction}
* @param the return type for the {@link CheckedFunction}.
* @param the type of the exception thrown by the {@link CheckedFunction}.
* @return the result of the {@link CheckedFunction}.
* @throws E the exception thrown by the {@link CheckedFunction}.
*/
public R lock(CheckedFunction operation, T t) throws E {
lock.lock();
try {
return operation.apply(t);
} finally {
lock.unlock();
}
}
/**
* Encapsulated the evaluation of the supplied {@link CheckedBiFunction} within the boundaries of the lock.
*
* @param operation the {@link CheckedBiFunction} to apply.
* @param t the first parameter to pass the {@link CheckedBiFunction}.
* @param u the second parameter to pass the {@link CheckedBiFunction}.
* @param the type of the first parameter of the {@link CheckedBiFunction}.
* @param the type of the first parameter of the {@link CheckedBiFunction}.
* @param the return type for the {@link CheckedBiFunction}.
* @param the type of the exception thrown by the {@link CheckedBiFunction}.
* @return the result of the {@link CheckedFunction}.
* @throws E the exception thrown by the {@link CheckedBiFunction}.
*/
public R lock(CheckedBiFunction operation, T t, U u) throws E {
lock.lock();
try {
return operation.apply(t, u);
} finally {
lock.unlock();
}
}
/**
* Encapsulated the evaluation of the supplied {@link CheckedRunnable} within the boundaries of the lock.
*
* @param operation the {@link CheckedRunnable} to evaluate.
* @param the type of the exception thrown by the {@link CheckedRunnable}.
* @throws E the exception thrown by the {@link CheckedRunnable}.
*/
public void lock(CheckedRunnable operation) throws E {
lock.lock();
try {
operation.run();
} finally {
lock.unlock();
}
}
/**
* Encapsulated the evaluation of the supplied {@link CheckedConsumer} within the boundaries of the lock.
*
* @param operation the {@link CheckedConsumer} to evaluate.
* @param t the parameter to pass the {@link CheckedConsumer}
* @param the type of the parameter to pass the {@link CheckedConsumer}
* @param the type of the exception thrown by the {@link CheckedConsumer}.
* @throws E the exception thrown by the {@link CheckedConsumer}.
*/
public void lock(CheckedConsumer operation, T t) throws E {
lock.lock();
try {
operation.accept(t);
} finally {
lock.unlock();
}
}
//endregion
//region *** tryLock method overloads ***
/**
* Tries to acquire the lock and if successful, evaluates the supplied {@link CheckedSupplier} within the boundaries of the lock.
*
* @param operation the {@link CheckedSupplier} to evaluate.
* @param the return type for the {@link CheckedSupplier}.
* @param the type of the exception thrown by the {@link CheckedSupplier}.
* @return An {@link Optional} that contains the return value of the {@link CheckedSupplier} if the lock could be acquired
* @throws E the exception thrown by the {@link CheckedSupplier}.
*/
public Optional tryLock(CheckedSupplier operation) throws E {
if (lock.tryLock()) {
try {
return Optional.ofNullable(operation.get());
} finally {
lock.unlock();
}
}
return Optional.empty();
}
/**
* Tries to acquire the lock and if successful, evaluates the supplied {@link CheckedFunction} within the boundaries of the lock.
*
* @param operation the {@link CheckedFunction} to apply.
* @param t the parameter to pass the {@link CheckedFunction}
* @param the type of he parameter to pass the {@link CheckedFunction}
* @param the return type for the {@link CheckedFunction}.
* @param the type of the exception thrown by the {@link CheckedFunction}.
* @return the result of the {@link CheckedFunction}.
* @throws E the exception thrown by the {@link CheckedFunction}.
*/
public Optional tryLock(CheckedFunction operation, T t) throws E {
if (lock.tryLock()) {
try {
return Optional.ofNullable(operation.apply(t));
} finally {
lock.unlock();
}
}
return Optional.empty();
}
/**
* Tries to acquire the lock and if successful, evaluates the supplied {@link CheckedBiFunction} within the boundaries of the lock.
*
* @param operation the {@link CheckedBiFunction} to apply.
* @param t the first parameter to pass the {@link CheckedBiFunction}.
* @param u the second parameter to pass the {@link CheckedBiFunction}.
* @param the type of the first parameter of the {@link CheckedBiFunction}.
* @param the type of the first parameter of the {@link CheckedBiFunction}.
* @param the return type for the {@link CheckedBiFunction}.
* @param the type of the exception thrown by the {@link CheckedBiFunction}.
* @return the result of the {@link CheckedFunction}.
* @throws E the exception thrown by the {@link CheckedBiFunction}.
*/
public Optional tryLock(CheckedBiFunction operation, T t, U u) throws E {
if (lock.tryLock()) {
try {
return Optional.ofNullable(operation.apply(t, u));
} finally {
lock.unlock();
}
}
return Optional.empty();
}
/**
* Tries to acquire the lock and if successful, evaluates the supplied {@link CheckedRunnable} within the boundaries of the lock.
*
* @param operation the {@link CheckedRunnable} to evaluate.
* @param the type of the exception thrown by the {@link CheckedRunnable}.
* @return true if the lock was acquired, false otherwise.
* @throws E the exception thrown by the {@link CheckedRunnable}.
*/
public boolean tryLock(CheckedRunnable operation) throws E {
if (lock.tryLock()) {
try {
operation.run();
} finally {
lock.unlock();
}
return true;
}
return false;
}
/**
* Tries to acquire the lock and if successful, evaluates the supplied {@link CheckedConsumer} within the boundaries of the lock.
*
* @param operation the {@link CheckedConsumer} to evaluate.
* @param t the parameter to pass the {@link CheckedConsumer}
* @param the type of the parameter to pass the {@link CheckedConsumer}
* @param the type of the exception thrown by the {@link CheckedConsumer}.
* @return true if the lock was acquired, false otherwise.
* @throws E the exception thrown by the {@link CheckedConsumer}.
*/
public boolean tryLock(CheckedConsumer operation, T t) throws E {
if (lock.tryLock()) {
try {
operation.accept(t);
} finally {
lock.unlock();
}
return true;
}
return false;
}
//endregion
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy