001/*
002 * Copyright (C) 2006 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
005 * in compliance with the License. You may obtain a copy of the License at
006 *
007 * http://www.apache.org/licenses/LICENSE-2.0
008 *
009 * Unless required by applicable law or agreed to in writing, software distributed under the License
010 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
011 * or implied. See the License for the specific language governing permissions and limitations under
012 * the License.
013 */
014
015package com.google.common.util.concurrent;
016
017import com.google.common.annotations.Beta;
018import com.google.common.annotations.GwtIncompatible;
019import com.google.errorprone.annotations.CanIgnoreReturnValue;
020import com.google.errorprone.annotations.DoNotMock;
021import java.util.concurrent.Callable;
022import java.util.concurrent.ExecutionException;
023import java.util.concurrent.TimeUnit;
024import java.util.concurrent.TimeoutException;
025import org.checkerframework.checker.nullness.qual.Nullable;
026
027/**
028 * Imposes a time limit on method calls.
029 *
030 * @author Kevin Bourrillion
031 * @author Jens Nyman
032 * @since 1.0
033 */
034@Beta
035@DoNotMock("Use FakeTimeLimiter")
036@GwtIncompatible
037@SuppressWarnings("GoodTime") // should have java.time.Duration overloads
038@ElementTypesAreNonnullByDefault
039public interface TimeLimiter {
040
041  /**
042   * Returns an instance of {@code interfaceType} that delegates all method calls to the {@code
043   * target} object, enforcing the specified time limit on each call. This time-limited delegation
044   * is also performed for calls to {@link Object#equals}, {@link Object#hashCode}, and {@link
045   * Object#toString}.
046   *
047   * <p>If the target method call finishes before the limit is reached, the return value or
048   * exception is propagated to the caller exactly as-is. If, on the other hand, the time limit is
049   * reached, the proxy will attempt to abort the call to the target, and will throw an {@link
050   * UncheckedTimeoutException} to the caller.
051   *
052   * <p>It is important to note that the primary purpose of the proxy object is to return control to
053   * the caller when the timeout elapses; aborting the target method call is of secondary concern.
054   * The particular nature and strength of the guarantees made by the proxy is
055   * implementation-dependent. However, it is important that each of the methods on the target
056   * object behaves appropriately when its thread is interrupted.
057   *
058   * <p>For example, to return the value of {@code target.someMethod()}, but substitute {@code
059   * DEFAULT_VALUE} if this method call takes over 50 ms, you can use this code:
060   *
061   * <pre>
062   *   TimeLimiter limiter = . . .;
063   *   TargetType proxy = limiter.newProxy(
064   *       target, TargetType.class, 50, TimeUnit.MILLISECONDS);
065   *   try {
066   *     return proxy.someMethod();
067   *   } catch (UncheckedTimeoutException e) {
068   *     return DEFAULT_VALUE;
069   *   }
070   * </pre>
071   *
072   * @param target the object to proxy
073   * @param interfaceType the interface you wish the returned proxy to implement
074   * @param timeoutDuration with timeoutUnit, the maximum length of time that callers are willing to
075   *     wait on each method call to the proxy
076   * @param timeoutUnit with timeoutDuration, the maximum length of time that callers are willing to
077   *     wait on each method call to the proxy
078   * @return a time-limiting proxy
079   * @throws IllegalArgumentException if {@code interfaceType} is a regular class, enum, or
080   *     annotation type, rather than an interface
081   */
082  <T> T newProxy(T target, Class<T> interfaceType, long timeoutDuration, TimeUnit timeoutUnit);
083
084  /**
085   * Invokes a specified Callable, timing out after the specified time limit. If the target method
086   * call finishes before the limit is reached, the return value or a wrapped exception is
087   * propagated. If, on the other hand, the time limit is reached, we attempt to abort the call to
088   * the target, and throw a {@link TimeoutException} to the caller.
089   *
090   * @param callable the Callable to execute
091   * @param timeoutDuration with timeoutUnit, the maximum length of time to wait
092   * @param timeoutUnit with timeoutDuration, the maximum length of time to wait
093   * @return the result returned by the Callable
094   * @throws TimeoutException if the time limit is reached
095   * @throws InterruptedException if the current thread was interrupted during execution
096   * @throws ExecutionException if {@code callable} throws a checked exception
097   * @throws UncheckedExecutionException if {@code callable} throws a {@code RuntimeException}
098   * @throws ExecutionError if {@code callable} throws an {@code Error}
099   * @since 22.0
100   */
101  @CanIgnoreReturnValue
102  <T extends @Nullable Object> T callWithTimeout(
103      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
104      throws TimeoutException, InterruptedException, ExecutionException;
105
106  /**
107   * Invokes a specified Callable, timing out after the specified time limit. If the target method
108   * call finishes before the limit is reached, the return value or a wrapped exception is
109   * propagated. If, on the other hand, the time limit is reached, we attempt to abort the call to
110   * the target, and throw a {@link TimeoutException} to the caller.
111   *
112   * <p>The difference with {@link #callWithTimeout(Callable, long, TimeUnit)} is that this method
113   * will ignore interrupts on the current thread.
114   *
115   * @param callable the Callable to execute
116   * @param timeoutDuration with timeoutUnit, the maximum length of time to wait
117   * @param timeoutUnit with timeoutDuration, the maximum length of time to wait
118   * @return the result returned by the Callable
119   * @throws TimeoutException if the time limit is reached
120   * @throws ExecutionException if {@code callable} throws a checked exception
121   * @throws UncheckedExecutionException if {@code callable} throws a {@code RuntimeException}
122   * @throws ExecutionError if {@code callable} throws an {@code Error}
123   * @since 22.0
124   */
125  @CanIgnoreReturnValue
126  <T extends @Nullable Object> T callUninterruptiblyWithTimeout(
127      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
128      throws TimeoutException, ExecutionException;
129
130  /**
131   * Invokes a specified Runnable, timing out after the specified time limit. If the target method
132   * run finishes before the limit is reached, this method returns or a wrapped exception is
133   * propagated. If, on the other hand, the time limit is reached, we attempt to abort the run, and
134   * throw a {@link TimeoutException} to the caller.
135   *
136   * @param runnable the Runnable to execute
137   * @param timeoutDuration with timeoutUnit, the maximum length of time to wait
138   * @param timeoutUnit with timeoutDuration, the maximum length of time to wait
139   * @throws TimeoutException if the time limit is reached
140   * @throws InterruptedException if the current thread was interrupted during execution
141   * @throws UncheckedExecutionException if {@code runnable} throws a {@code RuntimeException}
142   * @throws ExecutionError if {@code runnable} throws an {@code Error}
143   * @since 22.0
144   */
145  void runWithTimeout(Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit)
146      throws TimeoutException, InterruptedException;
147
148  /**
149   * Invokes a specified Runnable, timing out after the specified time limit. If the target method
150   * run finishes before the limit is reached, this method returns or a wrapped exception is
151   * propagated. If, on the other hand, the time limit is reached, we attempt to abort the run, and
152   * throw a {@link TimeoutException} to the caller.
153   *
154   * <p>The difference with {@link #runWithTimeout(Runnable, long, TimeUnit)} is that this method
155   * will ignore interrupts on the current thread.
156   *
157   * @param runnable the Runnable to execute
158   * @param timeoutDuration with timeoutUnit, the maximum length of time to wait
159   * @param timeoutUnit with timeoutDuration, the maximum length of time to wait
160   * @throws TimeoutException if the time limit is reached
161   * @throws UncheckedExecutionException if {@code runnable} throws a {@code RuntimeException}
162   * @throws ExecutionError if {@code runnable} throws an {@code Error}
163   * @since 22.0
164   */
165  void runUninterruptiblyWithTimeout(Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit)
166      throws TimeoutException;
167}