/*
* 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 static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.ObjectArrays;
import com.google.common.collect.Sets;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
/**
* A TimeLimiter that runs method calls in the background using an {@link ExecutorService}. If the
* time limit expires for a given method call, the thread running the call will be interrupted.
*
* @author Kevin Bourrillion
* @author Jens Nyman
* @since 1.0
*/
@Beta
@GwtIncompatible
public final class SimpleTimeLimiter implements TimeLimiter {
private final ExecutorService executor;
/**
* Constructs a TimeLimiter instance using the given executor service to execute proxied method
* calls.
*
* <p><b>Warning:</b> using a bounded executor may be counterproductive! If the thread pool fills
* up, any time callers spend waiting for a thread may count toward their time limit, and in this
* case the call may even time out before the target method is ever invoked.
*
* @param executor the ExecutorService that will execute the method calls on the target objects;
* for example, a {@link Executors#newCachedThreadPool()}.
* @deprecated Use {@link #create(ExecutorService)} instead. This method is scheduled to be
* removed in Guava 23.0.
*/
@Deprecated
public SimpleTimeLimiter(ExecutorService executor) {
this.executor = checkNotNull(executor);
}
/**
* Constructs a TimeLimiter instance using a {@link Executors#newCachedThreadPool()} to execute
* proxied method calls.
*
* <p><b>Warning:</b> using a bounded executor may be counterproductive! If the thread pool fills
* up, any time callers spend waiting for a thread may count toward their time limit, and in this
* case the call may even time out before the target method is ever invoked.
*
* @deprecated Use {@link #create(ExecutorService)} instead with {@code
* Executors.newCachedThreadPool()}. This method is scheduled to be removed in Guava 23.0.
*/
@Deprecated
public SimpleTimeLimiter() {
this(Executors.newCachedThreadPool());
}
/**
* Creates a TimeLimiter instance using the given executor service to execute method calls.
*
* <p><b>Warning:</b> using a bounded executor may be counterproductive! If the thread pool fills
* up, any time callers spend waiting for a thread may count toward their time limit, and in this
* case the call may even time out before the target method is ever invoked.
*
* @param executor the ExecutorService that will execute the method calls on the target objects;
* for example, a {@link Executors#newCachedThreadPool()}.
* @since 22.0
*/
public static SimpleTimeLimiter create(ExecutorService executor) {
return new SimpleTimeLimiter(executor);
}
@Override
public <T> T newProxy(
final T target,
Class<T> interfaceType,
final long timeoutDuration,
final TimeUnit timeoutUnit) {
checkNotNull(target);
checkNotNull(interfaceType);
checkNotNull(timeoutUnit);
checkPositiveTimeout(timeoutDuration);
checkArgument(interfaceType.isInterface(), "interfaceType must be an interface type");
final Set<Method> interruptibleMethods = findInterruptibleMethods(interfaceType);
InvocationHandler handler =
new InvocationHandler() {
@Override
public Object invoke(Object obj, final Method method, final Object[] args)
throws Throwable {
Callable<Object> callable =
new Callable<Object>() {
@Override
public Object call() throws Exception {
try {
return method.invoke(target, args);
} catch (InvocationTargetException e) {
throw throwCause(e, false /* combineStackTraces */);
}
}
};
return callWithTimeout(
callable, timeoutDuration, timeoutUnit, interruptibleMethods.contains(method));
}
};
return newProxy(interfaceType, handler);
}
// TODO: should this actually throw only ExecutionException?
@Deprecated
@CanIgnoreReturnValue
@Override
public <T> T callWithTimeout(
Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit, boolean amInterruptible)
throws Exception {
checkNotNull(callable);
checkNotNull(timeoutUnit);
checkPositiveTimeout(timeoutDuration);
Future<T> future = executor.submit(callable);
try {
if (amInterruptible) {
try {
return future.get(timeoutDuration, timeoutUnit);
} catch (InterruptedException e) {
future.cancel(true);
throw e;
}
} else {
return Uninterruptibles.getUninterruptibly(future, timeoutDuration, timeoutUnit);
}
} catch (ExecutionException e) {
throw throwCause(e, true /* combineStackTraces */);
} catch (TimeoutException e) {
future.cancel(true);
throw new UncheckedTimeoutException(e);
}
}
@Override
public <T> T callWithTimeout(Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
throws TimeoutException, InterruptedException, ExecutionException {
checkNotNull(callable);
checkNotNull(timeoutUnit);
checkPositiveTimeout(timeoutDuration);
Future<T> future = executor.submit(callable);
try {
return future.get(timeoutDuration, timeoutUnit);
} catch (InterruptedException | TimeoutException e) {
future.cancel(true /* mayInterruptIfRunning */);
throw e;
} catch (ExecutionException e) {
wrapAndThrowExecutionExceptionOrError(e.getCause());
throw new AssertionError();
}
}
@Override
public <T> T callUninterruptiblyWithTimeout(
Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
throws TimeoutException, ExecutionException {
checkNotNull(callable);
checkNotNull(timeoutUnit);
checkPositiveTimeout(timeoutDuration);
Future<T> future = executor.submit(callable);
try {
return Uninterruptibles.getUninterruptibly(future, timeoutDuration, timeoutUnit);
} catch (TimeoutException e) {
future.cancel(true /* mayInterruptIfRunning */);
throw e;
} catch (ExecutionException e) {
wrapAndThrowExecutionExceptionOrError(e.getCause());
throw new AssertionError();
}
}
@Override
public void runWithTimeout(Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit)
throws TimeoutException, InterruptedException {
checkNotNull(runnable);
checkNotNull(timeoutUnit);
checkPositiveTimeout(timeoutDuration);
Future<?> future = executor.submit(runnable);
try {
future.get(timeoutDuration, timeoutUnit);
} catch (InterruptedException | TimeoutException e) {
future.cancel(true /* mayInterruptIfRunning */);
throw e;
} catch (ExecutionException e) {
wrapAndThrowRuntimeExecutionExceptionOrError(e.getCause());
throw new AssertionError();
}
}
@Override
public void runUninterruptiblyWithTimeout(
Runnable runnable, long timeoutDuration, TimeUnit timeoutUnit) throws TimeoutException {
checkNotNull(runnable);
checkNotNull(timeoutUnit);
checkPositiveTimeout(timeoutDuration);
Future<?> future = executor.submit(runnable);
try {
Uninterruptibles.getUninterruptibly(future, timeoutDuration, timeoutUnit);
} catch (TimeoutException e) {
future.cancel(true /* mayInterruptIfRunning */);
throw e;
} catch (ExecutionException e) {
wrapAndThrowRuntimeExecutionExceptionOrError(e.getCause());
throw new AssertionError();
}
}
private static Exception throwCause(Exception e, boolean combineStackTraces) throws Exception {
Throwable cause = e.getCause();
if (cause == null) {
throw e;
}
if (combineStackTraces) {
StackTraceElement[] combined =
ObjectArrays.concat(cause.getStackTrace(), e.getStackTrace(), StackTraceElement.class);
cause.setStackTrace(combined);
}
if (cause instanceof Exception) {
throw (Exception) cause;
}
if (cause instanceof Error) {
throw (Error) cause;
}
// The cause is a weird kind of Throwable, so throw the outer exception.
throw e;
}
private static Set<Method> findInterruptibleMethods(Class<?> interfaceType) {
Set<Method> set = Sets.newHashSet();
for (Method m : interfaceType.getMethods()) {
if (declaresInterruptedEx(m)) {
set.add(m);
}
}
return set;
}
private static boolean declaresInterruptedEx(Method method) {
for (Class<?> exType : method.getExceptionTypes()) {
// debate: == or isAssignableFrom?
if (exType == InterruptedException.class) {
return true;
}
}
return false;
}
// TODO: replace with version in common.reflect if and when it's open-sourced
private static <T> T newProxy(Class<T> interfaceType, InvocationHandler handler) {
Object object =
Proxy.newProxyInstance(
interfaceType.getClassLoader(), new Class<?>[] {interfaceType}, handler);
return interfaceType.cast(object);
}
private void wrapAndThrowExecutionExceptionOrError(Throwable cause) throws ExecutionException {
if (cause instanceof Error) {
throw new ExecutionError((Error) cause);
} else if (cause instanceof RuntimeException) {
throw new UncheckedExecutionException(cause);
} else {
throw new ExecutionException(cause);
}
}
private void wrapAndThrowRuntimeExecutionExceptionOrError(Throwable cause) {
if (cause instanceof Error) {
throw new ExecutionError((Error) cause);
} else {
throw new UncheckedExecutionException(cause);
}
}
private static void checkPositiveTimeout(long timeoutDuration) {
checkArgument(timeoutDuration > 0, "timeout must be positive: %s", timeoutDuration);
}
}