Package org.apache.hadoop.fs.impl.prefetch

Class ExecutorServiceFuturePool

java.lang.Object

org.apache.hadoop.fs.impl.prefetch.ExecutorServiceFuturePool

public class ExecutorServiceFuturePool
extends java.lang.Object

A FuturePool implementation backed by a java.util.concurrent.ExecutorService. If a piece of work has started, it cannot (currently) be cancelled. This class is a simplified version of com.twitter:util-core_2.11 ExecutorServiceFuturePool designed to avoid depending on that Scala library. One problem with using a Scala library is that many downstream projects (eg Apache Spark) use Scala, and they might want to use a different version of Scala from the version that Hadoop chooses to use.

Constructor Summary

Constructors

Constructor	Description
ExecutorServiceFuturePool(java.util.concurrent.ExecutorService executor)

Method Summary

Modifier and Type	Method	Description
java.util.concurrent.Future<java.lang.Void>	executeFunction(java.util.function.Supplier<java.lang.Void> f)
java.util.concurrent.Future<java.lang.Void>	executeRunnable(java.lang.Runnable r)
void	shutdown(org.slf4j.Logger logger, long timeout, java.util.concurrent.TimeUnit unit)	Utility to shutdown the ExecutorService used by this class.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

ExecutorServiceFuturePool

public ExecutorServiceFuturePool(java.util.concurrent.ExecutorService executor)

Method Detail

executeFunction

public java.util.concurrent.Future<java.lang.Void> executeFunction(java.util.function.Supplier<java.lang.Void> f)

Parameters:

f - function to run in future on executor pool

Returns:

future

Throws:

java.util.concurrent.RejectedExecutionException - can be thrown

java.lang.NullPointerException - if f param is null

executeRunnable

public java.util.concurrent.Future<java.lang.Void> executeRunnable(java.lang.Runnable r)

Parameters:

r - runnable to run in future on executor pool

Returns:

future

Throws:

java.util.concurrent.RejectedExecutionException - can be thrown

java.lang.NullPointerException - if r param is null

shutdown

public void shutdown(org.slf4j.Logger logger,
                     long timeout,
                     java.util.concurrent.TimeUnit unit)

Utility to shutdown the ExecutorService used by this class. Will wait up to a certain timeout for the ExecutorService to gracefully shutdown.

Parameters:

logger - Logger

timeout - the maximum time to wait

unit - the time unit of the timeout argument

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object