1 /*
2 * Copyright (C) 2006 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14
15 package com.google.common.util.concurrent;
16
17 import static com.google.common.base.Preconditions.checkArgument;
18 import static com.google.common.base.Preconditions.checkNotNull;
19
20 import com.google.common.annotations.Beta;
21 import com.google.common.annotations.GwtIncompatible;
22 import com.google.common.collect.ObjectArrays;
23 import com.google.common.collect.Sets;
24 import com.google.errorprone.annotations.CanIgnoreReturnValue;
25 import java.lang.reflect.InvocationHandler;
26 import java.lang.reflect.InvocationTargetException;
27 import java.lang.reflect.Method;
28 import java.lang.reflect.Proxy;
29 import java.util.Set;
30 import java.util.concurrent.Callable;
31 import java.util.concurrent.ExecutionException;
32 import java.util.concurrent.ExecutorService;
33 import java.util.concurrent.Executors;
34 import java.util.concurrent.Future;
35 import java.util.concurrent.TimeUnit;
36 import java.util.concurrent.TimeoutException;
37 import javax.annotation.CheckForNull;
38 import org.checkerframework.checker.nullness.qual.Nullable;
39
40 /**
41 * A TimeLimiter that runs method calls in the background using an {@link ExecutorService}. If the
42 * time limit expires for a given method call, the thread running the call will be interrupted.
43 *
44 * @author Kevin Bourrillion
45 * @author Jens Nyman
46 * @since 1.0
47 */
48 @Beta
49 @GwtIncompatible
50 @ElementTypesAreNonnullByDefault
51 public final class SimpleTimeLimiter implements TimeLimiter {
52
53 private final ExecutorService executor;
54
55 private SimpleTimeLimiter(ExecutorService executor) {
56 this.executor = checkNotNull(executor);
57 }
58
59 /**
60 * Creates a TimeLimiter instance using the given executor service to execute method calls.
61 *
62 * <p><b>Warning:</b> using a bounded executor may be counterproductive! If the thread pool fills
63 * up, any time callers spend waiting for a thread may count toward their time limit, and in this
64 * case the call may even time out before the target method is ever invoked.
65 *
66 * @param executor the ExecutorService that will execute the method calls on the target objects;
67 * for example, a {@link Executors#newCachedThreadPool()}.
68 * @since 22.0
69 */
70 public static SimpleTimeLimiter create(ExecutorService executor) {
71 return new SimpleTimeLimiter(executor);
72 }
73
74 @Override
75 public <T> T newProxy(
76 final T target,
77 Class<T> interfaceType,
78 final long timeoutDuration,
79 final TimeUnit timeoutUnit) {
80 checkNotNull(target);
81 checkNotNull(interfaceType);
82 checkNotNull(timeoutUnit);
83 checkPositiveTimeout(timeoutDuration);
84 checkArgument(interfaceType.isInterface(), "interfaceType must be an interface type");
85
86 final Set<Method> interruptibleMethods = findInterruptibleMethods(interfaceType);
87
88 InvocationHandler handler =
89 new InvocationHandler() {
90 @Override
91 @CheckForNull
92 public Object invoke(
93 Object obj, final Method method, @CheckForNull final @Nullable Object[] args)
94 throws Throwable {
95 Callable<@Nullable Object> callable =
96 new Callable<@Nullable Object>() {
97 @Override
98 @CheckForNull
99 public Object call() throws Exception {
100 try {
101 return method.invoke(target, args);
102 } catch (InvocationTargetException e) {
103 throw throwCause(e, false /* combineStackTraces */);
104 }
105 }
106 };
107 return callWithTimeout(
108 callable, timeoutDuration, timeoutUnit, interruptibleMethods.contains(method));
109 }
110 };
111 return newProxy(interfaceType, handler);
112 }
113
114 // TODO: replace with version in common.reflect if and when it's open-sourced
115 private static <T> T newProxy(Class<T> interfaceType, InvocationHandler handler) {
116 Object object =
117 Proxy.newProxyInstance(
118 interfaceType.getClassLoader(), new Class<?>[] {interfaceType}, handler);
119 return interfaceType.cast(object);
120 }
121
122 private <T extends @Nullable Object> T callWithTimeout(
123 Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit, boolean amInterruptible)
124 throws Exception {
125 checkNotNull(callable);
126 checkNotNull(timeoutUnit);
127 checkPositiveTimeout(timeoutDuration);
128
129 Future<T> future = executor.submit(callable);
130
131 try {
132 if (amInterruptible) {
133 try {
134 return future.get(timeoutDuration, timeoutUnit);
135 } catch (InterruptedException e) {
136 future.cancel(true);
137 throw e;
138 }
139 } else {
140 return Uninterruptibles.getUninterruptibly(future, timeoutDuration, timeoutUnit);
141 }
142 } catch (ExecutionException e) {
143 throw throwCause(e, true /* combineStackTraces */);
144 } catch (TimeoutException e) {
145 future.cancel(true);
146 throw new UncheckedTimeoutException(e);
147 }
148 }
149
150 @CanIgnoreReturnValue
151 @Override
152 public <T extends @Nullable Object> T callWithTimeout(
153 Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
154 throws TimeoutException, InterruptedException, ExecutionException {
155 checkNotNull(callable);
156 checkNotNull(timeoutUnit);
157 checkPositiveTimeout(timeoutDuration);
158
159 Future<T> future = executor.submit(callable);
160
161 try {
162 return future.get(timeoutDuration, timeoutUnit);
163 } catch (InterruptedException | TimeoutException e) {
164 future.cancel(true /* mayInterruptIfRunning */);
165 throw e;
166 } catch (ExecutionException e) {
167 wrapAndThrowExecutionExceptionOrError(e.getCause());
168 throw new AssertionError();
169 }
170 }
171
172 @CanIgnoreReturnValue
173 @Override
174 public <T extends @Nullable Object> T callUninterruptiblyWithTimeout(
175 Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
176 throws TimeoutException, ExecutionException {
177 checkNotNull(callable);
178 checkNotNull(timeoutUnit);
179 checkPositiveTimeout(timeoutDuration);
180
181 Future<T> future = executor.submit(callable);
182
183 try {
184 return Uninterruptibles.getUninterruptibly(future, timeoutDuration, timeoutUnit);
185 } catch (TimeoutException e) {
186 future.cancel(true /* mayInterruptIfRunning */);
187 throw e;
188 } catch (ExecutionException e) {
189 wrapAndThrowExecutionExceptionOrError(e.getCause());
190 throw new AssertionError();
191 }
192 }
193
194 @Override
195 public void runWithTimeout(Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit)
196 throws TimeoutException, InterruptedException {
197 checkNotNull(runnable);
198 checkNotNull(timeoutUnit);
199 checkPositiveTimeout(timeoutDuration);
200
201 Future<?> future = executor.submit(runnable);
202
203 try {
204 future.get(timeoutDuration, timeoutUnit);
205 } catch (InterruptedException | TimeoutException e) {
206 future.cancel(true /* mayInterruptIfRunning */);
207 throw e;
208 } catch (ExecutionException e) {
209 wrapAndThrowRuntimeExecutionExceptionOrError(e.getCause());
210 throw new AssertionError();
211 }
212 }
213
214 @Override
215 public void runUninterruptiblyWithTimeout(
216 Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit) throws TimeoutException {
217 checkNotNull(runnable);
218 checkNotNull(timeoutUnit);
219 checkPositiveTimeout(timeoutDuration);
220
221 Future<?> future = executor.submit(runnable);
222
223 try {
224 Uninterruptibles.getUninterruptibly(future, timeoutDuration, timeoutUnit);
225 } catch (TimeoutException e) {
226 future.cancel(true /* mayInterruptIfRunning */);
227 throw e;
228 } catch (ExecutionException e) {
229 wrapAndThrowRuntimeExecutionExceptionOrError(e.getCause());
230 throw new AssertionError();
231 }
232 }
233
234 private static Exception throwCause(Exception e, boolean combineStackTraces) throws Exception {
235 Throwable cause = e.getCause();
236 if (cause == null) {
237 throw e;
238 }
239 if (combineStackTraces) {
240 StackTraceElement[] combined =
241 ObjectArrays.concat(cause.getStackTrace(), e.getStackTrace(), StackTraceElement.class);
242 cause.setStackTrace(combined);
243 }
244 if (cause instanceof Exception) {
245 throw (Exception) cause;
246 }
247 if (cause instanceof Error) {
248 throw (Error) cause;
249 }
250 // The cause is a weird kind of Throwable, so throw the outer exception.
251 throw e;
252 }
253
254 private static Set<Method> findInterruptibleMethods(Class<?> interfaceType) {
255 Set<Method> set = Sets.newHashSet();
256 for (Method m : interfaceType.getMethods()) {
257 if (declaresInterruptedEx(m)) {
258 set.add(m);
259 }
260 }
261 return set;
262 }
263
264 private static boolean declaresInterruptedEx(Method method) {
265 for (Class<?> exType : method.getExceptionTypes()) {
266 // debate: == or isAssignableFrom?
267 if (exType == InterruptedException.class) {
268 return true;
269 }
270 }
271 return false;
272 }
273
274 private void wrapAndThrowExecutionExceptionOrError(Throwable cause) throws ExecutionException {
275 if (cause instanceof Error) {
276 throw new ExecutionError((Error) cause);
277 } else if (cause instanceof RuntimeException) {
278 throw new UncheckedExecutionException(cause);
279 } else {
280 throw new ExecutionException(cause);
281 }
282 }
283
284 private void wrapAndThrowRuntimeExecutionExceptionOrError(Throwable cause) {
285 if (cause instanceof Error) {
286 throw new ExecutionError((Error) cause);
287 } else {
288 throw new UncheckedExecutionException(cause);
289 }
290 }
291
292 private static void checkPositiveTimeout(long timeoutDuration) {
293 checkArgument(timeoutDuration > 0, "timeout must be positive: %s", timeoutDuration);
294 }
295 }