/**
* The method being executes when the status of the workContainer is RUNNABLE. There is no check
* whether or not the status is runnable before executing this method, so checking if the status
* is actually RUNNABLE is a good check.
*/
@Override
public void run() {
// If it isn't runnable, it should't run. (Never happened besides from aborted jobs).
if (status.getStatus() != Status.RUNNABLE) {
// If it was just aborted, then we just quit, say nothing about it.
if (status.getStatus() != Status.ABORTED) {
// Hasn't happened yet. If it does, then that is very very bad!
throw new RuntimeException(
"The workContainer was told to work, although its status is currently " + status);
}
return;
}
resetSubJobId();
subJobsCommitted = false;
// Running the thing is easy, it should be.
// work() and join() gets treated completely the same. Only difference being if earlier jobs are
// passed on.
E result;
if (results == null) {
result = job.work(scheduler);
} else {
result = job.join(results, scheduler);
}
if (!subJobsCommitted) {
// We just need to submit an result.
this.result = result;
// I'm only submitting the result, if i can change the status to HAS_RESULT. And it is
// synchronized because i changes the state of the object.
synchronized (this) {
if (status.setStatus(Status.HAS_RESULT)) {
env.submitResult(this);
}
}
} else {
subJobLock.lock();
try {
// This is if all the results have already gotten back, since that happens multithreaded,
// that can happen.
if (missingJobs.size() == 0) {
runAgain(); // Not running it again right now, just putting it in the queue.
} else {
status.setStatus(Status.NEED_RESULTS); // Waiting.
}
} finally {
subJobLock.unlock();
}
}
}
/**
* Submits a result that this workcontainer has been waiting for. This method is thread safe.
*
* @param id of the job. (The ID thats only unique inside this workcontainer).
* @param result
*/
public void putResult(int id, E result) {
subJobLock.lock();
try {
// Making the list if it isn't there.
if (results == null) {
results = new ArrayList<E>();
}
// Expanding it if we need more room.
while (id >= results.size()) {
results.add(null);
}
Integer key = new Integer(id);
if (missingJobs.containsKey(key)) {
missingJobs.remove(key);
results.set(id, result);
// Everything that is a state change of this object, is synchronized to the object.
synchronized (this) {
if (missingJobs.size() == 0 && status.getStatus() == Status.NEED_RESULTS) {
runAgain();
}
}
}
} finally {
subJobLock.unlock();
}
}
/**
* Hold the result when it is ready, if there is no result ready, it will throw an
* RuntimeException.
*
* @return the result calculated by the job this WorkContainer contains.
*/
public E getResult() {
if (status.getStatus() != Status.HAS_RESULT)
System.out.println("Status is " + status + ", but yet someone accessed the result. ");
return result;
}
/**
* Returns the current status of this job, if it is RUNNABLE, NEED_RESULTS or HAS_RESULTS.
*
* @return current status of this job.
*/
public Status getStatus() {
return status.getStatus();
}