com.android.testutils

Class VirtualTimeScheduler

java.lang.Object

com.android.testutils.VirtualTimeScheduler

All Implemented Interfaces:

java.util.concurrent.Executor, java.util.concurrent.ExecutorService, java.util.concurrent.ScheduledExecutorService

public class VirtualTimeScheduler
extends java.lang.Object
implements java.util.concurrent.ScheduledExecutorService

VirtualTimeScheduler is a ScheduledExecutorService that uses a virtual notion of time. Actions are queued and can be inspected. Time can be advanced on-demand and metadata on how many actions are queued and have been executed can be retrieved.

This scheduler is ideally suited to use in tests as it avoids having to have tests sleep which would make the tests inherently flaky.

Constructor Summary

Constructors

Constructor and Description
VirtualTimeScheduler()

Method Summary

Modifier and Type	Method and Description
long	advanceBy(long intervalNanos) advanceBy will run all actions scheduled within the interval specified from the current time.
long	advanceBy(long interval, java.util.concurrent.TimeUnit unit) advanceBy will run all actions scheduled within the interval (converted to nanos) specified from the current time.
long	advanceTo(long endTimeNanos) advanceTo will run all actions scheduled between CurrentTimeNanos and endTimeNanos.
boolean	awaitTermination(long timeout, java.util.concurrent.TimeUnit unit)
void	execute(java.lang.Runnable command)
long	getActionsExecuted()
long	getActionsQueued()
long	getCurrentTimeNanos()
long	getFurthestScheduledTimeNanos()
java.util.PriorityQueue<VirtualTimeFuture<?>>	getQueue()
<T> java.util.List<java.util.concurrent.Future<T>>	invokeAll(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks)
<T> java.util.List<java.util.concurrent.Future<T>>	invokeAll(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks, long timeout, java.util.concurrent.TimeUnit unit)
<T> T	invokeAny(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks)
<T> T	invokeAny(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks, long timeout, java.util.concurrent.TimeUnit unit)
boolean	isShutdown()
boolean	isTerminated()
<V> java.util.concurrent.ScheduledFuture<V>	schedule(java.util.concurrent.Callable<V> callable, long delay, java.util.concurrent.TimeUnit unit)
java.util.concurrent.ScheduledFuture<?>	schedule(java.lang.Runnable command, long delay, java.util.concurrent.TimeUnit unit)
java.util.concurrent.ScheduledFuture<?>	scheduleAtFixedRate(java.lang.Runnable command, long initialDelay, long period, java.util.concurrent.TimeUnit unit)
java.util.concurrent.ScheduledFuture<?>	scheduleWithFixedDelay(java.lang.Runnable command, long initialDelay, long delay, java.util.concurrent.TimeUnit unit)
void	shutdown()
java.util.List<java.lang.Runnable>	shutdownNow()
<T> java.util.concurrent.Future<T>	submit(java.util.concurrent.Callable<T> task)
java.util.concurrent.Future<?>	submit(java.lang.Runnable task)
<T> java.util.concurrent.Future<T>	submit(java.lang.Runnable task, T result)

Methods inherited from class java.lang.Object

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

Constructor Detail

VirtualTimeScheduler

public VirtualTimeScheduler()

Method Detail

schedule

public java.util.concurrent.ScheduledFuture<?> schedule(java.lang.Runnable command,
                                                        long delay,
                                                        java.util.concurrent.TimeUnit unit)

Specified by:

schedule in interface java.util.concurrent.ScheduledExecutorService

schedule

public <V> java.util.concurrent.ScheduledFuture<V> schedule(java.util.concurrent.Callable<V> callable,
                                                            long delay,
                                                            java.util.concurrent.TimeUnit unit)

Specified by:

schedule in interface java.util.concurrent.ScheduledExecutorService

scheduleAtFixedRate

public java.util.concurrent.ScheduledFuture<?> scheduleAtFixedRate(java.lang.Runnable command,
                                                                   long initialDelay,
                                                                   long period,
                                                                   java.util.concurrent.TimeUnit unit)

Specified by:

scheduleAtFixedRate in interface java.util.concurrent.ScheduledExecutorService

scheduleWithFixedDelay

public java.util.concurrent.ScheduledFuture<?> scheduleWithFixedDelay(java.lang.Runnable command,
                                                                      long initialDelay,
                                                                      long delay,
                                                                      java.util.concurrent.TimeUnit unit)

Specified by:

scheduleWithFixedDelay in interface java.util.concurrent.ScheduledExecutorService

shutdown

public void shutdown()

Specified by:

shutdown in interface java.util.concurrent.ExecutorService

shutdownNow

public java.util.List<java.lang.Runnable> shutdownNow()

Specified by:

shutdownNow in interface java.util.concurrent.ExecutorService

isShutdown

public boolean isShutdown()

Specified by:

isShutdown in interface java.util.concurrent.ExecutorService

isTerminated

public boolean isTerminated()

Specified by:

isTerminated in interface java.util.concurrent.ExecutorService

awaitTermination

public boolean awaitTermination(long timeout,
                                java.util.concurrent.TimeUnit unit)
                         throws java.lang.InterruptedException

Specified by:

awaitTermination in interface java.util.concurrent.ExecutorService

Throws:

java.lang.InterruptedException

submit

public <T> java.util.concurrent.Future<T> submit(java.util.concurrent.Callable<T> task)

Specified by:

submit in interface java.util.concurrent.ExecutorService

submit

public <T> java.util.concurrent.Future<T> submit(java.lang.Runnable task,
                                                 T result)

Specified by:

submit in interface java.util.concurrent.ExecutorService

submit

public java.util.concurrent.Future<?> submit(java.lang.Runnable task)

Specified by:

submit in interface java.util.concurrent.ExecutorService

invokeAll

public <T> java.util.List<java.util.concurrent.Future<T>> invokeAll(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks)
                                                             throws java.lang.InterruptedException

Specified by:

invokeAll in interface java.util.concurrent.ExecutorService

Throws:

java.lang.InterruptedException

invokeAll

public <T> java.util.List<java.util.concurrent.Future<T>> invokeAll(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks,
                                                                    long timeout,
                                                                    java.util.concurrent.TimeUnit unit)
                                                             throws java.lang.InterruptedException

Specified by:

invokeAll in interface java.util.concurrent.ExecutorService

Throws:

java.lang.InterruptedException

invokeAny

public <T> T invokeAny(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks)
                throws java.lang.InterruptedException,
                       java.util.concurrent.ExecutionException

Specified by:

invokeAny in interface java.util.concurrent.ExecutorService

Throws:

java.lang.InterruptedException

java.util.concurrent.ExecutionException

invokeAny

public <T> T invokeAny(java.util.Collection<? extends java.util.concurrent.Callable<T>> tasks,
                       long timeout,
                       java.util.concurrent.TimeUnit unit)
                throws java.lang.InterruptedException,
                       java.util.concurrent.ExecutionException,
                       java.util.concurrent.TimeoutException

Specified by:

invokeAny in interface java.util.concurrent.ExecutorService

Throws:

java.lang.InterruptedException

java.util.concurrent.ExecutionException

java.util.concurrent.TimeoutException

execute

public void execute(java.lang.Runnable command)

Specified by:

execute in interface java.util.concurrent.Executor

advanceBy

public long advanceBy(long interval,
                      java.util.concurrent.TimeUnit unit)

advanceBy will run all actions scheduled within the interval (converted to nanos) specified from the current time.

Parameters:

interval - time in unit to advance.

unit - for interval to advance.

Returns:

amount of actions executed.

advanceBy

public long advanceBy(long intervalNanos)

advanceBy will run all actions scheduled within the interval specified from the current time.

Parameters:

intervalNanos - time in nano seconds to advance.

Returns:

amount of actions executed.

advanceTo

public long advanceTo(long endTimeNanos)

advanceTo will run all actions scheduled between CurrentTimeNanos and endTimeNanos.

Parameters:

endTimeNanos - time in nano seconds to advance to.

Returns:

amount of actions executed.

getActionsExecuted

public long getActionsExecuted()

Returns:

the total number of actions executed by this scheduler.

getActionsQueued

public long getActionsQueued()

Returns:

the number of actions currently queued on this scheduler.

getFurthestScheduledTimeNanos

public long getFurthestScheduledTimeNanos()

Returns:

the furthest time an action is/was scheduled at within this scheduler.

getCurrentTimeNanos

public long getCurrentTimeNanos()

Returns:

the current virtual time of this scheduler.

getQueue

public java.util.PriorityQueue<VirtualTimeFuture<?>> getQueue()

Returns:

a copy of the PriorityQueue of queued futures.