org.redisson.api.RCountDownLatch Maven / Gradle / Ivy
/**
* Copyright 2018 Nikita Koksharov
*
* 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 org.redisson.api;
import java.util.concurrent.TimeUnit;
/**
* Distributed implementation of {@link java.util.concurrent.CountDownLatch}
*
* It has an advantage over {@link java.util.concurrent.CountDownLatch} --
* count can be set via {@link #trySetCount} method.
*
* @author Nikita Koksharov
*
*/
public interface RCountDownLatch extends RObject, RCountDownLatchAsync {
/**
* Causes the current thread to wait until the latch has counted down to
* zero, unless the thread is {@linkplain Thread#interrupt interrupted}.
*
* If the current count is zero then this method returns immediately.
*
*
If the current count is greater than zero then the current
* thread becomes disabled for thread scheduling purposes and lies
* dormant until one of two things happen:
*
* - The count reaches zero due to invocations of the
* {@link #countDown} method; or
*
- Some other thread {@linkplain Thread#interrupt interrupts}
* the current thread.
*
*
* If the current thread:
*
* - has its interrupted status set on entry to this method; or
*
- is {@linkplain Thread#interrupt interrupted} while waiting,
*
* then {@link InterruptedException} is thrown and the current thread's
* interrupted status is cleared.
*
* @throws InterruptedException if the current thread is interrupted
* while waiting
*/
void await() throws InterruptedException;
/**
* Causes the current thread to wait until the latch has counted down to
* zero, unless the thread is {@linkplain Thread#interrupt interrupted},
* or the specified waiting time elapses.
*
* If the current count is zero then this method returns immediately
* with the value {@code true}.
*
*
If the current count is greater than zero then the current
* thread becomes disabled for thread scheduling purposes and lies
* dormant until one of three things happen:
*
* - The count reaches zero due to invocations of the
* {@link #countDown} method; or
*
- Some other thread {@linkplain Thread#interrupt interrupts}
* the current thread; or
*
- The specified waiting time elapses.
*
*
* If the count reaches zero then the method returns with the
* value {@code true}.
*
*
If the current thread:
*
* - has its interrupted status set on entry to this method; or
*
- is {@linkplain Thread#interrupt interrupted} while waiting,
*
* then {@link InterruptedException} is thrown and the current thread's
* interrupted status is cleared.
*
* If the specified waiting time elapses then the value {@code false}
* is returned. If the time is less than or equal to zero, the method
* will not wait at all.
*
* @param timeout the maximum time to wait
* @param unit the time unit of the {@code timeout} argument
* @return {@code true} if the count reached zero and {@code false}
* if the waiting time elapsed before the count reached zero
* @throws InterruptedException if the current thread is interrupted
* while waiting
*/
boolean await(long timeout, TimeUnit unit) throws InterruptedException;
/**
* Decrements the count of the latch, releasing all waiting threads if
* the count reaches zero.
*
*
If the current count is greater than zero then it is decremented.
* If the new count is zero then all waiting threads are re-enabled for
* thread scheduling purposes.
*
*
If the current count equals zero then nothing happens.
*/
void countDown();
/**
* Returns the current count.
*
*
This method is typically used for debugging and testing purposes.
*
* @return the current count
*/
long getCount();
/**
* Sets new count value only if previous count already has reached zero
* or is not set at all.
*
* @param count - number of times {@link #countDown} must be invoked
* before threads can pass through {@link #await}
* @return true if new count setted
* false if previous count has not reached zero
*/
boolean trySetCount(long count);
}