/**
* Private method that blocks until the task has completed, re-throwing any exception resulting
* from the task failing.
*/
private void waitForTask(ScheduledTaskImpl task, boolean unbounded) throws Exception {
Throwable t = null;
try {
// NOTE: calling executeTask() directly means that we're trying
// to run the transaction in the calling thread, so there are
// actually more threads running tasks simulaneously than there
// are threads in the scheduler pool. This could be changed to
// hand-off the task and wait for the result if we wanted more
// direct control over concurrent transactions
executeTask(task, unbounded, false);
// wait for the task to complete...at this point it may have
// already completed, or else it is being re-tried in a
// scheduler thread
t = task.get();
} catch (InterruptedException ie) {
// we were interrupted, so try to cancel the task, re-throwing
// the interruption if that succeeds or looking at the result
// if the task completes before it can be cancelled
if (task.cancel(false)) {
backingQueue.notifyCancelled(task);
throw ie;
}
if (task.isCancelled()) {
throw ie;
}
t = task.get();
}
// if the result of the task was a permananent failure, then
// re-throw the exception
if (t != null) {
if (t instanceof Exception) {
throw (Exception) t;
}
throw (Error) t;
}
}
