Source code

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// TODO: b/227335009 - Maybe change interruption behavior, but it requires thought.
052@SuppressWarnings("Interruption")
053public final class SimpleTimeLimiter implements TimeLimiter {
054
055  private final ExecutorService executor;
056
057  private SimpleTimeLimiter(ExecutorService executor) {
058    this.executor = checkNotNull(executor);
059  }
060
061  /**
062   * Creates a TimeLimiter instance using the given executor service to execute method calls.
063   *
064   * <p><b>Warning:</b> using a bounded executor may be counterproductive! If the thread pool fills
065   * up, any time callers spend waiting for a thread may count toward their time limit, and in this
066   * case the call may even time out before the target method is ever invoked.
067   *
068   * @param executor the ExecutorService that will execute the method calls on the target objects;
069   *     for example, a {@link Executors#newCachedThreadPool()}.
070   * @since 22.0
071   */
072  public static SimpleTimeLimiter create(ExecutorService executor) {
073    return new SimpleTimeLimiter(executor);
074  }
075
076  @Override
077  public <T> T newProxy(
078      T target, Class<T> interfaceType, long timeoutDuration, TimeUnit timeoutUnit) {
079    checkNotNull(target);
080    checkNotNull(interfaceType);
081    checkNotNull(timeoutUnit);
082    checkPositiveTimeout(timeoutDuration);
083    checkArgument(interfaceType.isInterface(), "interfaceType must be an interface type");
084
085    Set<Method> interruptibleMethods = findInterruptibleMethods(interfaceType);
086
087    InvocationHandler handler =
088        new InvocationHandler() {
089          @Override
090          @CheckForNull
091          public Object invoke(Object obj, Method method, @CheckForNull @Nullable Object[] args)
092              throws Throwable {
093            Callable<@Nullable Object> callable =
094                () -> {
095                  try {
096                    return method.invoke(target, args);
097                  } catch (InvocationTargetException e) {
098                    throw throwCause(e, false /* combineStackTraces */);
099                  }
100                };
101            return callWithTimeout(
102                callable, timeoutDuration, timeoutUnit, interruptibleMethods.contains(method));
103          }
104        };
105    return newProxy(interfaceType, handler);
106  }
107
108  // TODO: replace with version in common.reflect if and when it's open-sourced
109  private static <T> T newProxy(Class<T> interfaceType, InvocationHandler handler) {
110    Object object =
111        Proxy.newProxyInstance(
112            interfaceType.getClassLoader(), new Class<?>[] {interfaceType}, handler);
113    return interfaceType.cast(object);
114  }
115
116  @ParametricNullness
117  private <T extends @Nullable Object> T callWithTimeout(
118      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit, boolean amInterruptible)
119      throws Exception {
120    checkNotNull(callable);
121    checkNotNull(timeoutUnit);
122    checkPositiveTimeout(timeoutDuration);
123
124    Future<T> future = executor.submit(callable);
125
126    try {
127      return amInterruptible
128          ? future.get(timeoutDuration, timeoutUnit)
129          : getUninterruptibly(future, timeoutDuration, timeoutUnit);
130    } catch (InterruptedException e) {
131      future.cancel(true);
132      throw e;
133    } catch (ExecutionException e) {
134      throw throwCause(e, true /* combineStackTraces */);
135    } catch (TimeoutException e) {
136      future.cancel(true);
137      throw new UncheckedTimeoutException(e);
138    }
139  }
140
141  @CanIgnoreReturnValue
142  @Override
143  @ParametricNullness
144  public <T extends @Nullable Object> T callWithTimeout(
145      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
146      throws TimeoutException, InterruptedException, ExecutionException {
147    checkNotNull(callable);
148    checkNotNull(timeoutUnit);
149    checkPositiveTimeout(timeoutDuration);
150
151    Future<T> future = executor.submit(callable);
152
153    try {
154      return future.get(timeoutDuration, timeoutUnit);
155    } catch (InterruptedException | TimeoutException e) {
156      future.cancel(true /* mayInterruptIfRunning */);
157      throw e;
158    } catch (ExecutionException e) {
159      wrapAndThrowExecutionExceptionOrError(e.getCause());
160      throw new AssertionError();
161    }
162  }
163
164  @CanIgnoreReturnValue
165  @Override
166  @ParametricNullness
167  public <T extends @Nullable Object> T callUninterruptiblyWithTimeout(
168      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
169      throws TimeoutException, ExecutionException {
170    checkNotNull(callable);
171    checkNotNull(timeoutUnit);
172    checkPositiveTimeout(timeoutDuration);
173
174    Future<T> future = executor.submit(callable);
175
176    try {
177      return getUninterruptibly(future, timeoutDuration, timeoutUnit);
178    } catch (TimeoutException e) {
179      future.cancel(true /* mayInterruptIfRunning */);
180      throw e;
181    } catch (ExecutionException e) {
182      wrapAndThrowExecutionExceptionOrError(e.getCause());
183      throw new AssertionError();
184    }
185  }
186
187  @Override
188  public void runWithTimeout(Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit)
189      throws TimeoutException, InterruptedException {
190    checkNotNull(runnable);
191    checkNotNull(timeoutUnit);
192    checkPositiveTimeout(timeoutDuration);
193
194    Future<?> future = executor.submit(runnable);
195
196    try {
197      future.get(timeoutDuration, timeoutUnit);
198    } catch (InterruptedException | TimeoutException e) {
199      future.cancel(true /* mayInterruptIfRunning */);
200      throw e;
201    } catch (ExecutionException e) {
202      wrapAndThrowRuntimeExecutionExceptionOrError(e.getCause());
203      throw new AssertionError();
204    }
205  }
206
207  @Override
208  public void runUninterruptiblyWithTimeout(
209      Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit) throws TimeoutException {
210    checkNotNull(runnable);
211    checkNotNull(timeoutUnit);
212    checkPositiveTimeout(timeoutDuration);
213
214    Future<?> future = executor.submit(runnable);
215
216    try {
217      getUninterruptibly(future, timeoutDuration, timeoutUnit);
218    } catch (TimeoutException e) {
219      future.cancel(true /* mayInterruptIfRunning */);
220      throw e;
221    } catch (ExecutionException e) {
222      wrapAndThrowRuntimeExecutionExceptionOrError(e.getCause());
223      throw new AssertionError();
224    }
225  }
226
227  private static Exception throwCause(Exception e, boolean combineStackTraces) throws Exception {
228    Throwable cause = e.getCause();
229    if (cause == null) {
230      throw e;
231    }
232    if (combineStackTraces) {
233      StackTraceElement[] combined =
234          ObjectArrays.concat(cause.getStackTrace(), e.getStackTrace(), StackTraceElement.class);
235      cause.setStackTrace(combined);
236    }
237    if (cause instanceof Exception) {
238      throw (Exception) cause;
239    }
240    if (cause instanceof Error) {
241      throw (Error) cause;
242    }
243    // The cause is a weird kind of Throwable, so throw the outer exception.
244    throw e;
245  }
246
247  private static Set<Method> findInterruptibleMethods(Class<?> interfaceType) {
248    Set<Method> set = Sets.newHashSet();
249    for (Method m : interfaceType.getMethods()) {
250      if (declaresInterruptedEx(m)) {
251        set.add(m);
252      }
253    }
254    return set;
255  }
256
257  private static boolean declaresInterruptedEx(Method method) {
258    for (Class<?> exType : method.getExceptionTypes()) {
259      // debate: == or isAssignableFrom?
260      if (exType == InterruptedException.class) {
261        return true;
262      }
263    }
264    return false;
265  }
266
267  private void wrapAndThrowExecutionExceptionOrError(Throwable cause) throws ExecutionException {
268    if (cause instanceof Error) {
269      throw new ExecutionError((Error) cause);
270    } else if (cause instanceof RuntimeException) {
271      throw new UncheckedExecutionException(cause);
272    } else {
273      throw new ExecutionException(cause);
274    }
275  }
276
277  private void wrapAndThrowRuntimeExecutionExceptionOrError(Throwable cause) {
278    if (cause instanceof Error) {
279      throw new ExecutionError((Error) cause);
280    } else {
281      throw new UncheckedExecutionException(cause);
282    }
283  }
284
285  private static void checkPositiveTimeout(long timeoutDuration) {
286    checkArgument(timeoutDuration > 0, "timeout must be positive: %s", timeoutDuration);
287  }
288}