Module com.aoapps.concurrent

Package com.aoapps.concurrent

Class ConcurrencyReducer<R>

java.lang.Object

com.aoapps.concurrent.ConcurrencyReducer<R>

public class ConcurrencyReducer<R>
extends Object

Limits the concurrency to a resource. When a second thread tries to access the same resource as a previous thread, it will share the results that are obtained by the previous thread.

Constructor Summary

Constructors

Constructor	Description
ConcurrencyReducer()

Method Summary

Modifier and Type	Method	Description
R	executeSerialized(Callable<? extends R> callable)	Executes a callable at most once.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ConcurrencyReducer

public ConcurrencyReducer()

Method Details

executeSerialized

public R executeSerialized(Callable<? extends R> callable)
                    throws InterruptedException,
ExecutionException

Executes a callable at most once. If a callable is in the process of being executed by a different thread, the current thread will wait and use the results obtained by the other thread.

Consider the following scenario:

1. Thread A invokes MySQL: "CHECK TABLE example FAST QUICK"
2. Thread B invokes MySQL: "CHECK TABLE example FAST QUICK" before Thread A has finished
3. Thread B wait for results determined by Thread A
4. Thread A completes, passes results to Thread B
5. Threads A and B both return the results obtained only by Thread A

Throws:

InterruptedException

ExecutionException