com.mastfrog.util.function.FunctionalLock Maven / Gradle / Ivy
/*
* The MIT License
*
* Copyright 2017 Tim Boudreau.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.mastfrog.util.function;
import com.mastfrog.function.throwing.ThrowingRunnable;
import com.mastfrog.function.throwing.ThrowingSupplier;
import com.mastfrog.util.thread.ThreadLocalBoolean;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock.ReadLock;
import java.util.concurrent.locks.ReentrantReadWriteLock.WriteLock;
import java.util.function.Supplier;
import com.mastfrog.util.thread.QuietAutoCloseable;
/**
* A wrapper around a ReentrantReadWriteLock that exposes operations on it as
* AutoCloseable and functional operations.
*
* @author Tim Boudreau
*/
public class FunctionalLock {
private final ReentrantReadWriteLock lock;
private final ReadLock readLock;
private final WriteLock writeLock;
private final ThreadLocalBoolean inReadAccess = new ThreadLocalBoolean();
public FunctionalLock() {
this(false);
}
public FunctionalLock(boolean fair) {
lock = new ReentrantReadWriteLock(fair);
readLock = lock.readLock();
writeLock = lock.writeLock();
}
public final boolean isFair() {
return lock.isFair();
}
public int getReadLockCount() {
return lock.getReadLockCount();
}
public boolean isWriteLocked() {
return lock.isWriteLocked();
}
public boolean isWriteLockedByCurrentThread() {
return lock.isWriteLockedByCurrentThread();
}
public int getWriteHoldCount() {
return lock.getWriteHoldCount();
}
public int getReadHoldCount() {
return lock.getReadHoldCount();
}
public final boolean hasQueuedThreads() {
return lock.hasQueuedThreads();
}
public final boolean hasQueuedThread(Thread thread) {
return lock.hasQueuedThread(thread);
}
public final int getQueueLength() {
return lock.getQueueLength();
}
public boolean hasWaiters(Condition condition) {
return lock.hasWaiters(condition);
}
public int getWaitQueueLength(Condition condition) {
return lock.getWaitQueueLength(condition);
}
@Override
public String toString() {
return lock.toString();
}
public boolean isReadAccessOnCurrentThread() {
return inReadAccess.get();
}
public Condition newReadLockCondition() {
return readLock.newCondition();
}
public Condition newWriteLockCondition() {
return writeLock.newCondition();
}
public void underReadLock(ThrowingRunnable r) throws Exception {
readLock.lock();
inReadAccess.toggleDuring(() -> {
try {
r.run();
} finally {
readLock.unlock();
}
});
Thread.currentThread().getId();
}
private void checkLockOrderForWriteAccess() {
if (inReadAccess.get() && lock.getReadLockCount() > 0) {
throw new IllegalThreadStateException("Read and write locks acquired out of "
+ "order - going from read to write will deadlock");
}
}
public void underWriteLock(ThrowingRunnable r) throws Exception {
checkLockOrderForWriteAccess();
writeLock.lock();
try {
r.run();
} finally {
writeLock.unlock();
}
}
public void runUnderReadLock(Runnable r) {
readLock.lock();
inReadAccess.toggle(() -> {
try {
r.run();
} finally {
readLock.unlock();
}
});
}
public void runUnderWriteLock(Runnable r) {
checkLockOrderForWriteAccess();
writeLock.lock();
try {
r.run();
} finally {
writeLock.unlock();
}
}
public T supplyUnderReadLock(ThrowingSupplier r) throws Exception {
readLock.lock();
return inReadAccess.toggleAndGetOrThrow(() -> {
try {
return r.get();
} finally {
readLock.unlock();
}
});
}
public T supplyUnderWriteLock(ThrowingSupplier r) throws Exception {
checkLockOrderForWriteAccess();
writeLock.lock();
try {
return r.get();
} finally {
writeLock.unlock();
}
}
public T getUnderReadLock(Supplier r) {
readLock.lock();
return inReadAccess.toggleAndGet(() -> {
try {
return r.get();
} finally {
readLock.unlock();
}
});
}
public T getUnderWriteLock(Supplier r) {
checkLockOrderForWriteAccess();
writeLock.lock();
try {
return r.get();
} finally {
writeLock.unlock();
}
}
public QuietAutoCloseable withReadLock() {
boolean old = inReadAccess.get();
inReadAccess.set(true);
readLock.lock();
return () -> {
readLock.unlock();
inReadAccess.set(old);
};
}
public QuietAutoCloseable withWriteLock() {
checkLockOrderForWriteAccess();
writeLock.lock();
return () -> {
writeLock.unlock();
};
}
// Interruptible versions
public void underReadLockInterruptibly(ThrowingRunnable r) throws Exception {
readLock.lockInterruptibly();
inReadAccess.toggleDuring(() -> {
try {
r.run();
} finally {
readLock.unlock();
}
});
Thread.currentThread().getId();
}
public void underWriteLockInterruptibly(ThrowingRunnable r) throws Exception {
checkLockOrderForWriteAccess();
writeLock.lockInterruptibly();
try {
r.run();
} finally {
writeLock.unlock();
}
}
public void runUnderReadLockInterruptibly(Runnable r) throws InterruptedException {
readLock.lockInterruptibly();
inReadAccess.toggle(() -> {
try {
r.run();
} finally {
readLock.unlock();
}
});
}
public void runUnderWriteLockInterruptibly(Runnable r) throws InterruptedException {
checkLockOrderForWriteAccess();
writeLock.lockInterruptibly();
try {
r.run();
} finally {
writeLock.unlock();
}
}
public T supplyUnderReadLockInterruptibly(ThrowingSupplier r) throws Exception {
readLock.lockInterruptibly();
return inReadAccess.toggleAndGetOrThrow(() -> {
try {
return r.get();
} finally {
readLock.unlock();
}
});
}
public T supplyUnderWriteLockInterruptibly(ThrowingSupplier r) throws Exception {
checkLockOrderForWriteAccess();
writeLock.lockInterruptibly();
try {
return r.get();
} finally {
writeLock.unlock();
}
}
public T getUnderReadLockInterruptibly(Supplier r) throws InterruptedException {
readLock.lockInterruptibly();
return inReadAccess.toggleAndGet(() -> {
try {
return r.get();
} finally {
readLock.unlock();
}
});
}
public T getUnderWriteLockInterruptibly(Supplier r) throws InterruptedException {
checkLockOrderForWriteAccess();
writeLock.lockInterruptibly();
try {
return r.get();
} finally {
writeLock.unlock();
}
}
public QuietAutoCloseable withReadLockInterruptibly() throws InterruptedException {
boolean old = inReadAccess.get();
inReadAccess.set(true);
readLock.lockInterruptibly();
return () -> {
readLock.unlock();
inReadAccess.set(old);
};
}
public QuietAutoCloseable withWriteLockInterruptibly() throws InterruptedException {
checkLockOrderForWriteAccess();
writeLock.lockInterruptibly();
return () -> {
writeLock.unlock();
};
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy