com.netflix.hystrix.util

Class HystrixTimer

java.lang.Object

com.netflix.hystrix.util.HystrixTimer

public class HystrixTimer
extends Object

Timer used by HystrixCommand to timeout async executions and HystrixCollapser to trigger batch executions.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	HystrixTimer.TimerListener

Method Summary

Methods

Modifier and Type	Method and Description
Reference<HystrixTimer.TimerListener>	addTimerListener(HystrixTimer.TimerListener listener) Add a HystrixTimer.TimerListener that will be executed until it is garbage collected or removed by clearing the returned Reference.
static HystrixTimer	getInstance() Retrieve the global instance.
static void	reset() Clears all listeners.
protected void	startThreadIfNeeded() Since we allow resetting the timer (shutting down the thread) we need to lazily re-start it if it starts being used again.

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static HystrixTimer getInstance()

Retrieve the global instance.

reset

public static void reset()

Clears all listeners.

NOTE: This will result in race conditions if addTimerListener(com.netflix.hystrix.util.HystrixTimer.TimerListener) is being concurrently called.

addTimerListener

public Reference<HystrixTimer.TimerListener> addTimerListener(HystrixTimer.TimerListener listener)

Add a HystrixTimer.TimerListener that will be executed until it is garbage collected or removed by clearing the returned Reference.

NOTE: It is the responsibility of code that adds a listener via this method to clear this listener when completed.

 // add a TimerListener 
 Reference<TimerListener> listener = HystrixTimer.getInstance().addTimerListener(listenerImpl);
 
 // sometime later, often in a thread shutdown, request cleanup, servlet filter or something similar the listener must be shutdown via the clear() method
 listener.clear();
 

Parameters:

listener - TimerListener implementation that will be triggered according to its getIntervalTimeInMilliseconds() method implementation.

Returns:

reference to the TimerListener that allows cleanup via the clear() method

startThreadIfNeeded

protected void startThreadIfNeeded()

Since we allow resetting the timer (shutting down the thread) we need to lazily re-start it if it starts being used again.

This does the lazy initialization and start of the thread in a thread-safe manner while having little cost the rest of the time.