Package org.elasticsearch.common.util

Class CancellableThreads

java.lang.Object

org.elasticsearch.common.util.CancellableThreads

public class CancellableThreads
extends java.lang.Object

A utility class for multi threaded operation that needs to be cancellable via interrupts. Every cancellable operation should be executed via execute(Interruptable), which will capture the executing thread and make sure it is interrupted in the case of cancellation. Cancellation policy: This class does not support external interruption via Thread#interrupt(). Always use #cancel() instead.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CancellableThreads.ExecutionCancelledException
static interface	CancellableThreads.Interruptable
static interface	CancellableThreads.IOInterruptable

Constructor Summary

Constructors

Constructor	Description
CancellableThreads()

Method Summary

Modifier and Type	Method	Description
void	cancel(java.lang.String reason)	cancel all current running operations.
void	checkForCancel()	call this will throw an exception if operation was cancelled.
void	execute(CancellableThreads.Interruptable interruptable)	run the Interruptable, capturing the executing thread.
void	executeIO(CancellableThreads.IOInterruptable interruptable)	run the Interruptable, capturing the executing thread.
boolean	isCancelled()
protected void	onCancel(java.lang.String reason, java.lang.Exception suppressedException)	called if checkForCancel() was invoked after the operation was cancelled.

Methods inherited from class java.lang.Object

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

Constructor Detail

CancellableThreads

public CancellableThreads()

Method Detail

isCancelled

public boolean isCancelled()

checkForCancel

public void checkForCancel()

call this will throw an exception if operation was cancelled. Override onCancel(String, Exception) for custom failure logic

onCancel

protected void onCancel(java.lang.String reason,
                        @Nullable
                        java.lang.Exception suppressedException)

called if checkForCancel() was invoked after the operation was cancelled. the default implementation always throws an CancellableThreads.ExecutionCancelledException, suppressing any other exception that occurred before cancellation

Parameters:

reason - reason for failure supplied by the caller of cancel(java.lang.String)

suppressedException - any error that was encountered during the execution before the operation was cancelled.

execute

public void execute(CancellableThreads.Interruptable interruptable)

run the Interruptable, capturing the executing thread. Concurrent calls to cancel(String) will interrupt this thread causing the call to prematurely return.

Parameters:

interruptable - code to run

executeIO

public void executeIO(CancellableThreads.IOInterruptable interruptable)
               throws java.io.IOException

run the Interruptable, capturing the executing thread. Concurrent calls to cancel(String) will interrupt this thread causing the call to prematurely return.

Parameters:

interruptable - code to run

Throws:

java.io.IOException

cancel

public void cancel(java.lang.String reason)

cancel all current running operations. Future calls to checkForCancel() will be failed with the given reason