| // Copyright 2014 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.devtools.build.lib.server.signal; |
| |
| import com.google.common.base.Preconditions; |
| import sun.misc.Signal; |
| import sun.misc.SignalHandler; |
| |
| /** |
| * A facade around sun.misc.Signal providing special-purpose SIGINT handling. |
| * |
| * <p>We use this code in preference to using sun.misc directly since the latter is deprecated, and |
| * depending on it causes the jdk1.6 javac to emit an unsuppressable warning that sun.misc is |
| * "Sun proprietary API and may be removed in a future release". |
| */ |
| public abstract class InterruptSignalHandler implements Runnable { |
| |
| private static final Signal SIGINT = new Signal("INT"); |
| |
| private SignalHandler oldHandler; |
| |
| /** |
| * Constructs an InterruptSignalHandler instance. Until the uninstall() |
| * method is invoked, the delivery of a SIGINT signal to this process will |
| * cause the run() method to be invoked in another thread. |
| */ |
| protected InterruptSignalHandler() { |
| this.oldHandler = Signal.handle(SIGINT, signal -> run()); |
| } |
| |
| /** Disables SIGINT handling. */ |
| public final synchronized void uninstall() { |
| Preconditions.checkNotNull(oldHandler, "uninstall() already called"); |
| Signal.handle(SIGINT, oldHandler); |
| oldHandler = null; |
| } |
| } |