/*
 * Copyright (C) 2006 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.util.concurrent;

import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtIncompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

Imposes a time limit on method calls.
Author:Kevin Bourrillion, Jens Nyman
Since:1.0
/** * Imposes a time limit on method calls. * * @author Kevin Bourrillion * @author Jens Nyman * @since 1.0 */
@Beta @GwtIncompatible public 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, 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;
  }
Params:
  • 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
Throws:
Returns:a time-limiting proxy
/** * Returns an instance of {@code interfaceType} that delegates all method calls to the {@code * target} object, enforcing the specified time limit on each call. This time-limited delegation * is also performed for calls to {@link Object#equals}, {@link Object#hashCode}, and {@link * Object#toString}. * * <p>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 {@link * UncheckedTimeoutException} to the caller. * * <p>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. * * <p>For example, to return the value of {@code target.someMethod()}, but substitute {@code * DEFAULT_VALUE} if this method call takes over 50 ms, you can use this code: * * <pre> * TimeLimiter limiter = . . .; * TargetType proxy = limiter.newProxy( * target, TargetType.class, 50, TimeUnit.MILLISECONDS); * try { * return proxy.someMethod(); * } catch (UncheckedTimeoutException e) { * return DEFAULT_VALUE; * } * </pre> * * @param target the object to proxy * @param interfaceType the interface you wish the returned proxy to implement * @param timeoutDuration with timeoutUnit, the maximum length of time that callers are willing to * wait on each method call to the proxy * @param timeoutUnit with timeoutDuration, the maximum length of time that callers are willing to * wait on each method call to the proxy * @return a time-limiting proxy * @throws IllegalArgumentException if {@code interfaceType} is a regular class, enum, or * annotation type, rather than an interface */
<T> T newProxy(T target, Class<T> interfaceType, long timeoutDuration, TimeUnit timeoutUnit);
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.
Params:
  • 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
Throws:
Returns:the result returned by the Callable
Since:22.0
/** * 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 {@link TimeoutException} to the caller. * * @param callable the Callable to execute * @param timeoutDuration with timeoutUnit, the maximum length of time to wait * @param timeoutUnit with timeoutDuration, the maximum length of time to wait * @return the result returned by the Callable * @throws TimeoutException if the time limit is reached * @throws InterruptedException if the current thread was interrupted during execution * @throws ExecutionException if {@code callable} throws a checked exception * @throws UncheckedExecutionException if {@code callable} throws a {@code RuntimeException} * @throws ExecutionError if {@code callable} throws an {@code Error} * @since 22.0 */
@CanIgnoreReturnValue <T> T callWithTimeout(Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit) throws TimeoutException, InterruptedException, ExecutionException;
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 callWithTimeout(Callable<Object>, long, TimeUnit) is that this method will ignore interrupts on the current thread.

Params:
  • 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
Throws:
Returns:the result returned by the Callable
Since:22.0
/** * 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 {@link TimeoutException} to the caller. * * <p>The difference with {@link #callWithTimeout(Callable, long, TimeUnit)} is that this method * will ignore interrupts on the current thread. * * @param callable the Callable to execute * @param timeoutDuration with timeoutUnit, the maximum length of time to wait * @param timeoutUnit with timeoutDuration, the maximum length of time to wait * @return the result returned by the Callable * @throws TimeoutException if the time limit is reached * @throws ExecutionException if {@code callable} throws a checked exception * @throws UncheckedExecutionException if {@code callable} throws a {@code RuntimeException} * @throws ExecutionError if {@code callable} throws an {@code Error} * @since 22.0 */
@CanIgnoreReturnValue <T> T callUninterruptiblyWithTimeout( Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit) throws TimeoutException, ExecutionException;
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.
Params:
  • 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:
Since:22.0
/** * 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 {@link TimeoutException} to the caller. * * @param runnable the Runnable to execute * @param timeoutDuration with timeoutUnit, the maximum length of time to wait * @param timeoutUnit with timeoutDuration, the maximum length of time to wait * @throws TimeoutException if the time limit is reached * @throws InterruptedException if the current thread was interrupted during execution * @throws UncheckedExecutionException if {@code runnable} throws a {@code RuntimeException} * @throws ExecutionError if {@code runnable} throws an {@code Error} * @since 22.0 */
void runWithTimeout(Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit) throws TimeoutException, InterruptedException;
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 runWithTimeout(Runnable, long, TimeUnit) is that this method will ignore interrupts on the current thread.

Params:
  • 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:
Since:22.0
/** * 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 {@link TimeoutException} to the caller. * * <p>The difference with {@link #runWithTimeout(Runnable, long, TimeUnit)} is that this method * will ignore interrupts on the current thread. * * @param runnable the Runnable to execute * @param timeoutDuration with timeoutUnit, the maximum length of time to wait * @param timeoutUnit with timeoutDuration, the maximum length of time to wait * @throws TimeoutException if the time limit is reached * @throws UncheckedExecutionException if {@code runnable} throws a {@code RuntimeException} * @throws ExecutionError if {@code runnable} throws an {@code Error} * @since 22.0 */
void runUninterruptiblyWithTimeout(Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit) throws TimeoutException; }