Package com.google.common.util.concurrent

Class SimpleTimeLimiter

java.lang.Object

com.google.common.util.concurrent.SimpleTimeLimiter

All Implemented Interfaces:

TimeLimiter

@GwtIncompatible
public final class SimpleTimeLimiter
extends java.lang.Object
implements TimeLimiter

A TimeLimiter that runs method calls in the background using an ExecutorService. If the time limit expires for a given method call, the thread running the call will be interrupted.

Since:

1.0

Author:

Kevin Bourrillion, Jens Nyman

Method Summary

Modifier and Type	Method	Description
<T extends @Nullable java.lang.Object> T	callUninterruptiblyWithTimeout(java.util.concurrent.Callable<T> callable, long timeoutDuration, java.util.concurrent.TimeUnit timeoutUnit)	Invokes a specified Callable, timing out after the specified time limit.
<T extends @Nullable java.lang.Object> T	callWithTimeout(java.util.concurrent.Callable<T> callable, long timeoutDuration, java.util.concurrent.TimeUnit timeoutUnit)	Invokes a specified Callable, timing out after the specified time limit.
static SimpleTimeLimiter	create(java.util.concurrent.ExecutorService executor)	Creates a TimeLimiter instance using the given executor service to execute method calls.
<T> T	newProxy(T target, java.lang.Class<T> interfaceType, long timeoutDuration, java.util.concurrent.TimeUnit timeoutUnit)	Returns an instance of interfaceType that delegates all method calls to the target object, enforcing the specified time limit on each call.
void	runUninterruptiblyWithTimeout(java.lang.Runnable runnable, long timeoutDuration, java.util.concurrent.TimeUnit timeoutUnit)	Invokes a specified Runnable, timing out after the specified time limit.
void	runWithTimeout(java.lang.Runnable runnable, long timeoutDuration, java.util.concurrent.TimeUnit timeoutUnit)	Invokes a specified Runnable, timing out after the specified time limit.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.google.common.util.concurrent.TimeLimiter

callUninterruptiblyWithTimeout, callWithTimeout, newProxy, runUninterruptiblyWithTimeout, runWithTimeout

Method Detail

create

public static SimpleTimeLimiter create(java.util.concurrent.ExecutorService executor)

Creates a TimeLimiter instance using the given executor service to execute method calls.

Warning: using a bounded executor may be counterproductive! If the thread pool fills up, any time callers spend waiting for a thread may count toward their time limit, and in this case the call may even time out before the target method is ever invoked.

Parameters:

executor - the ExecutorService that will execute the method calls on the target objects; for example, a Executors.newCachedThreadPool().

Since:

22.0

newProxy

public <T> T newProxy(T target,
                      java.lang.Class<T> interfaceType,
                      long timeoutDuration,
                      java.util.concurrent.TimeUnit timeoutUnit)

Description copied from interface: TimeLimiter

Returns an instance of interfaceType that delegates all method calls to the target object, enforcing the specified time limit on each call. This time-limited delegation is also performed for calls to Object.equals(java.lang.Object), Object.hashCode(), and Object.toString().

If the target method call finishes before the limit is reached, the return value or exception is propagated to the caller exactly as-is. If, on the other hand, the time limit is reached, the proxy will attempt to abort the call to the target, and will throw an UncheckedTimeoutException to the caller.

It is important to note that the primary purpose of the proxy object is to return control to the caller when the timeout elapses; aborting the target method call is of secondary concern. The particular nature and strength of the guarantees made by the proxy is implementation-dependent. However, it is important that each of the methods on the target object behaves appropriately when its thread is interrupted.

For example, to return the value of target.someMethod(), but substitute DEFAULT_VALUE if this method call takes over 50 ms, you can use this code:

   TimeLimiter limiter = . . .;
   TargetType proxy = limiter.newProxy(
       target, TargetType.class, 50, TimeUnit.MILLISECONDS);
   try {
     return proxy.someMethod();
   } catch (UncheckedTimeoutException e) {
     return DEFAULT_VALUE;
   }
 

Specified by:

newProxy in interface TimeLimiter

Parameters:

target - the object to proxy

interfaceType - the interface you wish the returned proxy to implement

timeoutDuration - with timeoutUnit, the maximum length of time that callers are willing to wait on each method call to the proxy

timeoutUnit - with timeoutDuration, the maximum length of time that callers are willing to wait on each method call to the proxy

Returns:

a time-limiting proxy

callWithTimeout

@CanIgnoreReturnValue
public <T extends @Nullable java.lang.Object> T callWithTimeout(java.util.concurrent.Callable<T> callable,
                                                                long timeoutDuration,
                                                                java.util.concurrent.TimeUnit timeoutUnit)
                                                         throws java.util.concurrent.TimeoutException,
                                                                java.lang.InterruptedException,
                                                                java.util.concurrent.ExecutionException

Description copied from interface: TimeLimiter

Invokes a specified Callable, timing out after the specified time limit. If the target method call finishes before the limit is reached, the return value or a wrapped exception is propagated. If, on the other hand, the time limit is reached, we attempt to abort the call to the target, and throw a TimeoutException to the caller.

Specified by:

callWithTimeout in interface TimeLimiter

Parameters:

callable - the Callable to execute

timeoutDuration - with timeoutUnit, the maximum length of time to wait

timeoutUnit - with timeoutDuration, the maximum length of time to wait

Returns:

the result returned by the Callable

Throws:

java.util.concurrent.TimeoutException - if the time limit is reached

java.lang.InterruptedException - if the current thread was interrupted during execution

java.util.concurrent.ExecutionException - if callable throws a checked exception

callUninterruptiblyWithTimeout

@CanIgnoreReturnValue
public <T extends @Nullable java.lang.Object> T callUninterruptiblyWithTimeout(java.util.concurrent.Callable<T> callable,
                                                                               long timeoutDuration,
                                                                               java.util.concurrent.TimeUnit timeoutUnit)
                                                                        throws java.util.concurrent.TimeoutException,
                                                                               java.util.concurrent.ExecutionException

Description copied from interface: TimeLimiter

Invokes a specified Callable, timing out after the specified time limit. If the target method call finishes before the limit is reached, the return value or a wrapped exception is propagated. If, on the other hand, the time limit is reached, we attempt to abort the call to the target, and throw a TimeoutException to the caller.

The difference with TimeLimiter.callWithTimeout(Callable, long, TimeUnit) is that this method will ignore interrupts on the current thread.

Specified by:

callUninterruptiblyWithTimeout in interface TimeLimiter

Parameters:

callable - the Callable to execute

timeoutDuration - with timeoutUnit, the maximum length of time to wait

timeoutUnit - with timeoutDuration, the maximum length of time to wait

Returns:

the result returned by the Callable

Throws:

java.util.concurrent.TimeoutException - if the time limit is reached

java.util.concurrent.ExecutionException - if callable throws a checked exception

runWithTimeout

public void runWithTimeout(java.lang.Runnable runnable,
                           long timeoutDuration,
                           java.util.concurrent.TimeUnit timeoutUnit)
                    throws java.util.concurrent.TimeoutException,
                           java.lang.InterruptedException

Description copied from interface: TimeLimiter

Invokes a specified Runnable, timing out after the specified time limit. If the target method run finishes before the limit is reached, this method returns or a wrapped exception is propagated. If, on the other hand, the time limit is reached, we attempt to abort the run, and throw a TimeoutException to the caller.

Specified by:

runWithTimeout in interface TimeLimiter

Parameters:

runnable - the Runnable to execute

timeoutDuration - with timeoutUnit, the maximum length of time to wait

timeoutUnit - with timeoutDuration, the maximum length of time to wait

Throws:

java.util.concurrent.TimeoutException - if the time limit is reached

java.lang.InterruptedException - if the current thread was interrupted during execution

runUninterruptiblyWithTimeout

public void runUninterruptiblyWithTimeout(java.lang.Runnable runnable,
                                          long timeoutDuration,
                                          java.util.concurrent.TimeUnit timeoutUnit)
                                   throws java.util.concurrent.TimeoutException

Description copied from interface: TimeLimiter

Invokes a specified Runnable, timing out after the specified time limit. If the target method run finishes before the limit is reached, this method returns or a wrapped exception is propagated. If, on the other hand, the time limit is reached, we attempt to abort the run, and throw a TimeoutException to the caller.

The difference with TimeLimiter.runWithTimeout(Runnable, long, TimeUnit) is that this method will ignore interrupts on the current thread.

Specified by:

runUninterruptiblyWithTimeout in interface TimeLimiter

Parameters:

runnable - the Runnable to execute

timeoutDuration - with timeoutUnit, the maximum length of time to wait

timeoutUnit - with timeoutDuration, the maximum length of time to wait

Throws:

java.util.concurrent.TimeoutException - if the time limit is reached