/*
* The MIT License
*
* Copyright 2015 Jesse Glick.
*
* 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 jenkins.model.queue;
import hudson.model.Executor;
import hudson.model.OneOffExecutor;
import hudson.model.Queue.FlyweightTask;
import hudson.model.Resource;
import hudson.model.ResourceActivity;
import hudson.model.ResourceController;
import hudson.model.ResourceList;
import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import javax.annotation.concurrent.GuardedBy;
import org.kohsuke.accmod.Restricted;
import org.kohsuke.accmod.restrictions.NoExternalUse;
/**
* Special means of indicating that an executable will proceed in the background without consuming a native thread ({@link Executor}).
* May be thrown from {@link Executable#run} after doing any preparatory work synchronously.
* <p>{@link Executor#isActive} will remain true (even though {@link Executor#isAlive} is not) until {@link #completed} is called.
* The thrower will need to hold on to a reference to this instance as a handle to call {@link #completed}.
* <p>The execution may not extend into another Jenkins session; if you wish to model a long-running execution, you must schedule a new task after restart.
* This class is not serializable anyway.
* <p>Mainly intended for use with {@link OneOffExecutor} (from a {@link FlyweightTask}), of which there could be many,
* but could also be used with a heavyweight executor even though the number of executors is bounded by node configuration.
* <p>{@link ResourceController}/{@link ResourceActivity}/{@link ResourceList}/{@link Resource} are not currently supported.
* Nor are {@link hudson.model.Queue.Task#getSubTasks} other than the primary task.
* @since 1.607
*/
public abstract class AsynchronousExecution extends RuntimeException {
@GuardedBy("this")
private Executor executor;
/**
* Initially null, and usually stays null.
* If {@link #completed} is called before {@link #setExecutor}, then either {@link #NULL} for success, or the error.
*/
@GuardedBy("this")
private @CheckForNull Throwable result;
/** Constructor for subclasses. */
protected AsynchronousExecution() {}
/**
* Called in lieu of {@link Thread#interrupt} by {@link Executor#interrupt()} and its overloads.
* As with the standard Java method, you are requested to cease work as soon as possible, but there is no enforcement of this.
* You might also want to call {@link Executor#recordCauseOfInterruption} on {@link #getExecutor}.
* @param forShutdown if true, this interruption is because Jenkins is shutting down (and thus {@link Computer#interrupt} was called from {@link Jenkins#cleanUp}); otherwise, a normal interrupt such as by {@link Executor#doStop()}
*/
public abstract void interrupt(boolean forShutdown);
/**
* Allows an executable to indicate whether it is currently doing something which should prevent Jenkins from being shut down safely.
* You may return false if it is fine for an administrator to exit/restart Jenkins despite this executable still being running.
* (If so, {@link #interrupt} will be passed {@code forShutdown=true}.)
* @return traditionally always true
* @see hudson.model.RestartListener.Default#isReadyToRestart
*/
public abstract boolean blocksRestart();
/**
* Allows an executable to control whether or not to display {@code executorCell.jelly}.
*
* <p>
* If this method returns false, the asynchronous execution becomes invisible from UI.
*
* @return traditionally always true
*/
public abstract boolean displayCell();
/**
* Obtains the associated executor.
* @return Associated Executor. May be {@code null} if {@link #setExecutor(hudson.model.Executor)}
* has not been called yet.
*/
@CheckForNull
public synchronized final Executor getExecutor() {
return executor;
}
@Restricted(NoExternalUse.class)
public synchronized final void setExecutor(@Nonnull Executor executor) {
assert this.executor==null;
this.executor = executor;
if (result!=null) {
executor.completedAsynchronous( result!=NULL ? result : null );
result = null;
}
}
/**
* To be called when the task is actually complete.
* @param error normally null (preferable to handle errors yourself), but may be specified to simulate an exception from {@link Executable#run}, as per {@link ExecutorListener#taskCompletedWithProblems}
*/
public synchronized final void completed(@CheckForNull Throwable error) {
if (executor!=null) {
executor.completedAsynchronous(error);
} else {
result = error == null ? NULL : error;
}
}
/** @see #result */
private static final Throwable NULL = new Throwable("NULL");
}