| // Copyright 2010 The Bazel Authors. All Rights Reserved. |
| // |
| // 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.testing.junit.runner.internal; |
| |
| import sun.misc.Signal; |
| import sun.misc.SignalHandler; |
| |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| import javax.inject.Inject; |
| |
| /** |
| * Helper class to install signal handlers. |
| */ |
| public class SignalHandlers { |
| private final HandlerInstaller handlerInstaller; |
| |
| /** |
| * Creates a handler installer that installs signal handlers. |
| */ |
| public static HandlerInstaller createRealHandlerInstaller() { |
| return new HandlerInstaller() { |
| @Override |
| public SignalHandler install(Signal signal, SignalHandler handler) { |
| return Signal.handle(signal, handler); |
| } |
| }; |
| } |
| |
| @Inject |
| public SignalHandlers(HandlerInstaller installer) { |
| this.handlerInstaller = installer; |
| } |
| |
| /** |
| * Adds the given signal handler to the existing ones. |
| * |
| * <p>Signal handlers are responsible to catch any exception if the following |
| * handlers need to be executed when a handler throws an exception. |
| * |
| * @param signal The signal to handle. |
| * @param signalHandler The handler to install. |
| */ |
| public void installHandler(Signal signal, final SignalHandler signalHandler) { |
| final AtomicReference<SignalHandler> previousHandlerReference = |
| new AtomicReference<>(); |
| previousHandlerReference.set(handlerInstaller.install(signal, new SignalHandler() { |
| @Override |
| public void handle(Signal signal) { |
| signalHandler.handle(signal); |
| SignalHandler previousHandler = previousHandlerReference.get(); |
| if (previousHandler != null) { |
| previousHandler.handle(signal); |
| } |
| } |
| })); |
| } |
| |
| /** |
| * Wraps sun.misc.Signal#handle(sun.misc.Signal, sun.misc.SignalHandler) |
| * to help with testing. |
| */ |
| public interface HandlerInstaller { |
| /** |
| * @see sun.misc.Signal#handle(sun.misc.Signal, sun.misc.SignalHandler) |
| */ |
| SignalHandler install(Signal signal, SignalHandler handler); |
| } |
| } |