io.pravega.common.concurrent

Class ExecutorServiceHelpers

java.lang.Object

io.pravega.common.concurrent.ExecutorServiceHelpers

public final class ExecutorServiceHelpers
extends java.lang.Object

Helper methods for ExecutorService.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ExecutorServiceHelpers.Snapshot

Constructor Summary

Constructors

Constructor and Description
ExecutorServiceHelpers()

Method Summary

Modifier and Type	Method and Description
static void	execute(RunnableWithException task, java.util.function.Consumer<java.lang.Throwable> exceptionHandler, java.lang.Runnable runFinally, java.util.concurrent.Executor executor) Executes the given task on the given Executor.
static java.util.concurrent.ThreadPoolExecutor	getShrinkingExecutor(int maxThreadCount, int threadTimeout, java.lang.String poolName) Operates like Executors.cachedThreadPool but with a custom thread timeout and pool name.
static ExecutorServiceHelpers.Snapshot	getSnapshot(java.util.concurrent.ExecutorService service) Gets a snapshot of the given ExecutorService.
static java.util.concurrent.ThreadFactory	getThreadFactory(java.lang.String groupName) Creates and returns a thread factory that will create threads with the given name prefix.
static java.util.concurrent.ScheduledExecutorService	newScheduledThreadPool(int size, java.lang.String poolName) Creates a new ScheduledExecutorService that will use daemon threads with appropriate names the threads.
static void	shutdown(java.time.Duration timeout, java.util.concurrent.ExecutorService... pools) Shuts down the given ExecutorServices in two phases: 1.
static void	shutdown(java.util.concurrent.ExecutorService... pools) Shuts down the given ExecutorServices in two phases, using a timeout of 5 seconds: 1.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExecutorServiceHelpers

public ExecutorServiceHelpers()

Method Detail

getThreadFactory

public static java.util.concurrent.ThreadFactory getThreadFactory(java.lang.String groupName)

Creates and returns a thread factory that will create threads with the given name prefix.

Parameters:

groupName - the name of the threads

Returns:

a thread factory

newScheduledThreadPool

public static java.util.concurrent.ScheduledExecutorService newScheduledThreadPool(int size,
                                                                                   java.lang.String poolName)

Creates a new ScheduledExecutorService that will use daemon threads with appropriate names the threads.

Parameters:

size - The number of threads in the threadpool

poolName - The name of the pool (this will be printed in logs)

Returns:

A new executor service.

getSnapshot

public static ExecutorServiceHelpers.Snapshot getSnapshot(java.util.concurrent.ExecutorService service)

Gets a snapshot of the given ExecutorService.

Parameters:

service - The ExecutorService to request a snapshot on.

Returns:

A Snapshot of the given ExecutorService, or null if not supported.

getShrinkingExecutor

public static java.util.concurrent.ThreadPoolExecutor getShrinkingExecutor(int maxThreadCount,
                                                                           int threadTimeout,
                                                                           java.lang.String poolName)

Operates like Executors.cachedThreadPool but with a custom thread timeout and pool name.

Parameters:

maxThreadCount - The maximum number of threads to allow in the pool.

threadTimeout - the number of milliseconds that a thread should sit idle before shutting down.

poolName - The name of the threadpool.

Returns:

A new threadPool

execute

public static void execute(RunnableWithException task,
                           java.util.function.Consumer<java.lang.Throwable> exceptionHandler,
                           java.lang.Runnable runFinally,
                           java.util.concurrent.Executor executor)

Executes the given task on the given Executor.

Parameters:

task - The RunnableWithException to execute.

exceptionHandler - A Consumer that will be invoked in case the task threw an Exception. This is not invoked if the executor could not execute the given task.

runFinally - A Runnable that is guaranteed to be invoked at the end of this execution. If the executor did accept the task, it will be invoked after the task is complete (or ended in failure). If the executor did not accept the task, it will be executed when this method returns.

executor - An Executor to execute the task on.

shutdown

public static void shutdown(java.util.concurrent.ExecutorService... pools)

Shuts down the given ExecutorServices in two phases, using a timeout of 5 seconds: 1. Prevents new tasks from being submitted. 2. Awaits for currently running tasks to terminate. If they don't terminate within the given timeout, they will be forcibly cancelled.

Parameters:

pools - The ExecutorServices to shut down.

shutdown

public static void shutdown(java.time.Duration timeout,
                            java.util.concurrent.ExecutorService... pools)

Shuts down the given ExecutorServices in two phases: 1. Prevents new tasks from being submitted. 2. Awaits for currently running tasks to terminate. If they don't terminate within the given timeout, they will be forcibly cancelled. This is implemented as per the guidelines in the ExecutorService Javadoc: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ExecutorService.html

Parameters:

timeout - Grace period that will be given to tasks to complete.

pools - The ExecutorServices to shut down.