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 static com.google.common.base.Preconditions.checkArgument;
018import static com.google.common.base.Preconditions.checkNotNull;
019import static com.google.common.util.concurrent.Uninterruptibles.getUninterruptibly;
020
021import com.google.common.annotations.GwtIncompatible;
022import com.google.common.annotations.J2ktIncompatible;
023import com.google.common.collect.ObjectArrays;
024import com.google.common.collect.Sets;
025import com.google.errorprone.annotations.CanIgnoreReturnValue;
026import java.lang.reflect.InvocationHandler;
027import java.lang.reflect.InvocationTargetException;
028import java.lang.reflect.Method;
029import java.lang.reflect.Proxy;
030import java.util.Set;
031import java.util.concurrent.Callable;
032import java.util.concurrent.ExecutionException;
033import java.util.concurrent.ExecutorService;
034import java.util.concurrent.Executors;
035import java.util.concurrent.Future;
036import java.util.concurrent.TimeUnit;
037import java.util.concurrent.TimeoutException;
038import javax.annotation.CheckForNull;
039import org.checkerframework.checker.nullness.qual.Nullable;
040
041/**
042 * A TimeLimiter that runs method calls in the background using an {@link ExecutorService}. If the
043 * time limit expires for a given method call, the thread running the call will be interrupted.
044 *
045 * @author Kevin Bourrillion
046 * @author Jens Nyman
047 * @since 1.0
048 */
049@J2ktIncompatible
050@GwtIncompatible
051@ElementTypesAreNonnullByDefault
052public final class SimpleTimeLimiter implements TimeLimiter {
053
054  private final ExecutorService executor;
055
056  private SimpleTimeLimiter(ExecutorService executor) {
057    this.executor = checkNotNull(executor);
058  }
059
060  /**
061   * Creates a TimeLimiter instance using the given executor service to execute method calls.
062   *
063   * <p><b>Warning:</b> using a bounded executor may be counterproductive! If the thread pool fills
064   * up, any time callers spend waiting for a thread may count toward their time limit, and in this
065   * case the call may even time out before the target method is ever invoked.
066   *
067   * @param executor the ExecutorService that will execute the method calls on the target objects;
068   *     for example, a {@link Executors#newCachedThreadPool()}.
069   * @since 22.0
070   */
071  public static SimpleTimeLimiter create(ExecutorService executor) {
072    return new SimpleTimeLimiter(executor);
073  }
074
075  @Override
076  public <T> T newProxy(
077      T target, Class<T> interfaceType, long timeoutDuration, TimeUnit timeoutUnit) {
078    checkNotNull(target);
079    checkNotNull(interfaceType);
080    checkNotNull(timeoutUnit);
081    checkPositiveTimeout(timeoutDuration);
082    checkArgument(interfaceType.isInterface(), "interfaceType must be an interface type");
083
084    Set<Method> interruptibleMethods = findInterruptibleMethods(interfaceType);
085
086    InvocationHandler handler =
087        new InvocationHandler() {
088          @Override
089          @CheckForNull
090          public Object invoke(Object obj, Method method, @CheckForNull @Nullable Object[] args)
091              throws Throwable {
092            Callable<@Nullable Object> callable =
093                () -> {
094                  try {
095                    return method.invoke(target, args);
096                  } catch (InvocationTargetException e) {
097                    throw throwCause(e, false /* combineStackTraces */);
098                  }
099                };
100            return callWithTimeout(
101                callable, timeoutDuration, timeoutUnit, interruptibleMethods.contains(method));
102          }
103        };
104    return newProxy(interfaceType, handler);
105  }
106
107  // TODO: replace with version in common.reflect if and when it's open-sourced
108  private static <T> T newProxy(Class<T> interfaceType, InvocationHandler handler) {
109    Object object =
110        Proxy.newProxyInstance(
111            interfaceType.getClassLoader(), new Class<?>[] {interfaceType}, handler);
112    return interfaceType.cast(object);
113  }
114
115  @ParametricNullness
116  private <T extends @Nullable Object> T callWithTimeout(
117      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit, boolean amInterruptible)
118      throws Exception {
119    checkNotNull(callable);
120    checkNotNull(timeoutUnit);
121    checkPositiveTimeout(timeoutDuration);
122
123    Future<T> future = executor.submit(callable);
124
125    try {
126      return amInterruptible
127          ? future.get(timeoutDuration, timeoutUnit)
128          : getUninterruptibly(future, timeoutDuration, timeoutUnit);
129    } catch (InterruptedException e) {
130      future.cancel(true);
131      throw e;
132    } catch (ExecutionException e) {
133      throw throwCause(e, true /* combineStackTraces */);
134    } catch (TimeoutException e) {
135      future.cancel(true);
136      throw new UncheckedTimeoutException(e);
137    }
138  }
139
140  @CanIgnoreReturnValue
141  @Override
142  @ParametricNullness
143  public <T extends @Nullable Object> T callWithTimeout(
144      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
145      throws TimeoutException, InterruptedException, ExecutionException {
146    checkNotNull(callable);
147    checkNotNull(timeoutUnit);
148    checkPositiveTimeout(timeoutDuration);
149
150    Future<T> future = executor.submit(callable);
151
152    try {
153      return future.get(timeoutDuration, timeoutUnit);
154    } catch (InterruptedException | TimeoutException e) {
155      future.cancel(true /* mayInterruptIfRunning */);
156      throw e;
157    } catch (ExecutionException e) {
158      wrapAndThrowExecutionExceptionOrError(e.getCause());
159      throw new AssertionError();
160    }
161  }
162
163  @CanIgnoreReturnValue
164  @Override
165  @ParametricNullness
166  public <T extends @Nullable Object> T callUninterruptiblyWithTimeout(
167      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
168      throws TimeoutException, ExecutionException {
169    checkNotNull(callable);
170    checkNotNull(timeoutUnit);
171    checkPositiveTimeout(timeoutDuration);
172
173    Future<T> future = executor.submit(callable);
174
175    try {
176      return getUninterruptibly(future, timeoutDuration, timeoutUnit);
177    } catch (TimeoutException e) {
178      future.cancel(true /* mayInterruptIfRunning */);
179      throw e;
180    } catch (ExecutionException e) {
181      wrapAndThrowExecutionExceptionOrError(e.getCause());
182      throw new AssertionError();
183    }
184  }
185
186  @Override
187  public void runWithTimeout(Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit)
188      throws TimeoutException, InterruptedException {
189    checkNotNull(runnable);
190    checkNotNull(timeoutUnit);
191    checkPositiveTimeout(timeoutDuration);
192
193    Future<?> future = executor.submit(runnable);
194
195    try {
196      future.get(timeoutDuration, timeoutUnit);
197    } catch (InterruptedException | TimeoutException e) {
198      future.cancel(true /* mayInterruptIfRunning */);
199      throw e;
200    } catch (ExecutionException e) {
201      wrapAndThrowRuntimeExecutionExceptionOrError(e.getCause());
202      throw new AssertionError();
203    }
204  }
205
206  @Override
207  public void runUninterruptiblyWithTimeout(
208      Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit) throws TimeoutException {
209    checkNotNull(runnable);
210    checkNotNull(timeoutUnit);
211    checkPositiveTimeout(timeoutDuration);
212
213    Future<?> future = executor.submit(runnable);
214
215    try {
216      getUninterruptibly(future, timeoutDuration, timeoutUnit);
217    } catch (TimeoutException e) {
218      future.cancel(true /* mayInterruptIfRunning */);
219      throw e;
220    } catch (ExecutionException e) {
221      wrapAndThrowRuntimeExecutionExceptionOrError(e.getCause());
222      throw new AssertionError();
223    }
224  }
225
226  private static Exception throwCause(Exception e, boolean combineStackTraces) throws Exception {
227    Throwable cause = e.getCause();
228    if (cause == null) {
229      throw e;
230    }
231    if (combineStackTraces) {
232      StackTraceElement[] combined =
233          ObjectArrays.concat(cause.getStackTrace(), e.getStackTrace(), StackTraceElement.class);
234      cause.setStackTrace(combined);
235    }
236    if (cause instanceof Exception) {
237      throw (Exception) cause;
238    }
239    if (cause instanceof Error) {
240      throw (Error) cause;
241    }
242    // The cause is a weird kind of Throwable, so throw the outer exception.
243    throw e;
244  }
245
246  private static Set<Method> findInterruptibleMethods(Class<?> interfaceType) {
247    Set<Method> set = Sets.newHashSet();
248    for (Method m : interfaceType.getMethods()) {
249      if (declaresInterruptedEx(m)) {
250        set.add(m);
251      }
252    }
253    return set;
254  }
255
256  private static boolean declaresInterruptedEx(Method method) {
257    for (Class<?> exType : method.getExceptionTypes()) {
258      // debate: == or isAssignableFrom?
259      if (exType == InterruptedException.class) {
260        return true;
261      }
262    }
263    return false;
264  }
265
266  private void wrapAndThrowExecutionExceptionOrError(Throwable cause) throws ExecutionException {
267    if (cause instanceof Error) {
268      throw new ExecutionError((Error) cause);
269    } else if (cause instanceof RuntimeException) {
270      throw new UncheckedExecutionException(cause);
271    } else {
272      throw new ExecutionException(cause);
273    }
274  }
275
276  private void wrapAndThrowRuntimeExecutionExceptionOrError(Throwable cause) {
277    if (cause instanceof Error) {
278      throw new ExecutionError((Error) cause);
279    } else {
280      throw new UncheckedExecutionException(cause);
281    }
282  }
283
284  private static void checkPositiveTimeout(long timeoutDuration) {
285    checkArgument(timeoutDuration > 0, "timeout must be positive: %s", timeoutDuration);
286  }
287}