/*
* The MIT License
*
* Copyright (c) 2010, InfraDNA, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package hudson.util;
import hudson.ExtensionList;
import hudson.ExtensionPoint;
import hudson.model.Hudson;
import hudson.util.ProcessTree.OSProcess;
import java.io.IOException;
import java.io.Serializable;
/**
* Extension point that defines more elaborate way of killing processes, such as
* sudo or pfexec, for {@link ProcessTree}.
*
* <h2>Lifecycle</h2>
* <p>
* Each implementation of {@link ProcessKiller} is instantiated once on the master.
* Whenever a process needs to be killed, those implementations are serialized and sent over
* to the appropriate slave, then the {@link #kill(OSProcess)} method is invoked
* to attempt to kill the process.
*
* <p>
* One of the consequences of this design is that the implementation should be stateless
* and concurrent-safe. That is, the {@link #kill(OSProcess)} method can be invoked by multiple threads
* concurrently on the single instance.
*
* <p>
* Another consequence of this design is that if your {@link ProcessKiller} requires configuration,
* it needs to be serializable, and configuration needs to be updated atomically, as another
* thread may be calling into {@link #kill(OSProcess)} just when you are updating your configuration.
*
* @author jpederzolli
* @author Kohsuke Kawaguchi
* @since 1.362
*/
public abstract class ProcessKiller implements ExtensionPoint, Serializable {
/**
* Returns all the registered {@link ProcessKiller} descriptors.
*/
public static ExtensionList<ProcessKiller> all() {
return Hudson.getInstance().getExtensionList(ProcessKiller.class);
}
/**
* Attempts to kill the given process.
*
* @param process process to be killed. Always a {@linkplain ProcessTree.Local local process}.
* @return
* true if the killing was successful, and Hudson won't try to use other {@link ProcessKiller}
* implementations to kill the process. false if the killing failed or is unattempted, and Hudson will continue
* to use the rest of the {@link ProcessKiller} implementations to try to kill the process.
* @throws IOException
* The caller will log this exception and otherwise treat as if the method returned false, and moves on
* to the next killer.
* @throws InterruptedException
* if the callee performs a time consuming operation and if the thread is canceled, do not catch
* {@link InterruptedException} and just let it thrown from the method.
*/
public abstract boolean kill(ProcessTree.OSProcess process) throws IOException, InterruptedException;
private static final long serialVersionUID = 1L;
}