org.threadly.concurrent.future

Class WatchdogCache

java.lang.Object

org.threadly.concurrent.future.WatchdogCache

public class WatchdogCache
extends java.lang.Object

A class which handles a collection of Watchdog instances. Because the timeout for Watchdog is set in the constructor Watchdog.Watchdog(long, boolean), you can use this class to be more flexible and set the timeout at the time of watching the future.

Since:

4.0.0

Constructor Summary

Constructors

Constructor and Description
WatchdogCache(boolean sendInterruptOnFutureCancel) Constructs a new WatchdogCache.
WatchdogCache(SubmitterScheduler scheduler, boolean sendInterruptOnFutureCancel) Constructs a new WatchdogCache with a scheduler of your choosing.

Method Summary

Modifier and Type	Method and Description
void	watch(ListenableFuture<?> future, long timeoutInMillis) Watch a given ListenableFuture to ensure that it completes within the provided time limit.

Methods inherited from class java.lang.Object

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

Constructor Detail

WatchdogCache

public WatchdogCache(boolean sendInterruptOnFutureCancel)

Constructs a new WatchdogCache. This constructor will use a default static scheduler (which is lazily constructed). This should be fine in most cases, but you can provide your own scheduler if you want to avoid the thread creation (which is shared among all instances that were constructed with this constructor or Watchdog.Watchdog(long, boolean)}.

Parameters:

sendInterruptOnFutureCancel - If true, and a thread is provided with the future, an interrupt will be sent on timeout

WatchdogCache

public WatchdogCache(SubmitterScheduler scheduler,
                     boolean sendInterruptOnFutureCancel)

Constructs a new WatchdogCache with a scheduler of your choosing. It is critical that this scheduler has a free thread available to inspect futures which may not have completed in the given timeout. You may want to use a org.threadly.concurrent.limiter to ensure that there are threads available.

Parameters:

scheduler - Scheduler to schedule task to look for expired futures

sendInterruptOnFutureCancel - If true, and a thread is provided with the future, an interrupt will be sent on timeout

Method Detail

watch

public void watch(ListenableFuture<?> future,
                  long timeoutInMillis)

Watch a given ListenableFuture to ensure that it completes within the provided time limit. If the future is not marked as done by the time limit then it will be completed by invoking Future.cancel(boolean). Weather a true or false will be provided to interrupt the running thread is dependent on how this WatchdogCache was constructed.

Parameters:

future - Future to inspect to ensure completion

timeoutInMillis - Time in milliseconds that future should be completed within