/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001-2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Ant", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.tools.ant.taskdefs;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.TaskContainer;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Location;
import org.apache.tools.ant.util.StringUtils;
import java.util.Vector;
import java.util.Enumeration;
/**
* Executes the contained tasks in separate threads, continuing
* once all are completed.
* <p>
* @author Thomas Christen <a href="mailto:chr@active.ch">chr@active.ch</a>
* @author Conor MacNeill
* @since Ant 1.4
*
* @ant.task category="control"
*/
public class Parallel extends Task
implements TaskContainer {
/** Collection holding the nested tasks */
private Vector nestedTasks = new Vector();
/**
* Add a nested task to execute in parallel.
* @param nestedTask Nested task to be executed in parallel
*/
public void addTask(Task nestedTask) throws BuildException {
nestedTasks.addElement(nestedTask);
}
/**
* Block execution until the specified time or for a
* specified amount of milliseconds and if defined,
* execute the wait status.
*/
public void execute() throws BuildException {
TaskThread[] threads = new TaskThread[nestedTasks.size()];
int threadNumber = 0;
for (Enumeration e = nestedTasks.elements(); e.hasMoreElements();
threadNumber++) {
Task nestedTask = (Task) e.nextElement();
threads[threadNumber] = new TaskThread(threadNumber, nestedTask);
}
// now start all threads
for (int i = 0; i < threads.length; ++i) {
threads[i].start();
}
// now join to all the threads
for (int i = 0; i < threads.length; ++i) {
try {
threads[i].join();
} catch (InterruptedException ie) {
// who would interrupt me at a time like this?
}
}
// now did any of the threads throw an exception
StringBuffer exceptionMessage = new StringBuffer();
int numExceptions = 0;
Throwable firstException = null;
Location firstLocation = Location.UNKNOWN_LOCATION;;
for (int i = 0; i < threads.length; ++i) {
Throwable t = threads[i].getException();
if (t != null) {
numExceptions++;
if (firstException == null) {
firstException = t;
}
if (t instanceof BuildException &&
firstLocation == Location.UNKNOWN_LOCATION) {
firstLocation = ((BuildException) t).getLocation();
}
exceptionMessage.append(StringUtils.LINE_SEP);
exceptionMessage.append(t.getMessage());
}
}
if (numExceptions == 1) {
if (firstException instanceof BuildException) {
throw (BuildException) firstException;
} else {
throw new BuildException(firstException);
}
} else if (numExceptions > 1) {
throw new BuildException(exceptionMessage.toString(),
firstLocation);
}
}
/**
* thread that execs a task
*/
class TaskThread extends Thread {
private Throwable exception;
private Task task;
private int taskNumber;
/**
* Construct a new TaskThread.<p>
*
* @param task the Task to be executed in a seperate thread
*/
TaskThread(int taskNumber, Task task) {
this.task = task;
this.taskNumber = taskNumber;
}
/**
* Executes the task within a thread and takes care about
* Exceptions raised within the task.
*/
public void run() {
try {
task.perform();
} catch (Throwable t) {
exception = t;
}
}
/**
* get any exception that got thrown during execution;
* @return an exception or null for no exception/not yet finished
*/
public Throwable getException() {
return exception;
}
}
}