hudson.model.queue.QueueTaskDispatcher Maven / Gradle / Ivy
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/*******************************************************************************
*
* Copyright (c) 2010, InfraDNA, Inc.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
*
*
*
*
*******************************************************************************/
package hudson.model.queue;
import hudson.Extension;
import hudson.ExtensionList;
import hudson.ExtensionPoint;
import hudson.model.Hudson;
import hudson.model.Node;
import hudson.model.Queue;
import hudson.model.Queue.Task;
/**
* Vetos the execution of a task on a node
*
* To register your dispatcher implementations, put
*
* @{@link Extension} on your subtypes.
*
* @author Kohsuke Kawaguchi
* @since 1.360
*/
public abstract class QueueTaskDispatcher implements ExtensionPoint {
/**
* Called whenever {@link Queue} is considering to execute the given task on
* a given node.
*
*
Implementations can return null to indicate that the assignment is
* fine, or it can return a non-null instance to block the execution of the
* task on the given node.
*
*
Queue doesn't remember/cache the response from dispatchers, and
* instead it'll keep asking. The upside of this is that it's very easy to
* block execution for a limited time period ( as you just need to return
* null when it's ready to execute.) The downside of this is that the
* decision needs to be made quickly.
*
*
Vetos are additive. When multiple {@link QueueTaskDispatcher}s are in
* the system, the task won't run on the given node if any one of them
* returns a non-null value. (This relationship is also the same with
* built-in check logic.)
*/
public abstract CauseOfBlockage canTake(Node node, Task task);
public CauseOfBlockage canTake(Node node, Queue.BuildableItem item) {
return canTake(node,item.task);
}
public CauseOfBlockage canRun(Queue.Item item) {
return null;
}
/**
* All registered {@link QueueTaskDispatcher}s.
*/
public static ExtensionList all() {
return Hudson.getInstance().getExtensionList(QueueTaskDispatcher.class);
}
}