///////////////////////////////
// YieldingFlexibleGangWorker
///////////////////////////////
void YieldingFlexibleGangWorker::loop() {
int previous_sequence_number = 0;
Monitor* gang_monitor = gang()->monitor();
MutexLockerEx ml(gang_monitor, Mutex::_no_safepoint_check_flag);
WorkData data;
int id;
while (true) {
// Check if there is work to do or if we have been asked
// to terminate
gang()->internal_worker_poll(&data);
if (data.terminate()) {
// We have been asked to terminate.
assert(gang()->task() == NULL, "No task binding");
// set_status(TERMINATED);
return;
} else if (data.task() != NULL &&
data.sequence_number() != previous_sequence_number) {
// There is work to be done.
// First check if we need to become active or if there
// are already the requisite number of workers
if (gang()->started_workers() == yf_gang()->active_workers()) {
// There are already enough workers, we do not need to
// to run; fall through and wait on monitor.
} else {
// We need to pitch in and do the work.
assert(gang()->started_workers() < yf_gang()->active_workers(),
"Unexpected state");
id = gang()->started_workers();
gang()->internal_note_start();
// Now, release the gang mutex and do the work.
{
MutexUnlockerEx mul(gang_monitor, Mutex::_no_safepoint_check_flag);
data.task()->work(id); // This might include yielding
}
// Reacquire monitor and note completion of this worker
gang()->internal_note_finish();
// Update status of task based on whether all workers have
// finished or some have yielded
assert(data.task() == gang()->task(), "Confused task binding");
if (gang()->finished_workers() == yf_gang()->active_workers()) {
switch (data.yf_task()->status()) {
case ABORTING: {
data.yf_task()->set_status(ABORTED);
break;
}
case ACTIVE:
case COMPLETING: {
data.yf_task()->set_status(COMPLETED);
break;
}
default:
ShouldNotReachHere();
}
gang_monitor->notify_all(); // Notify overseer
} else { // at least one worker is still working or yielded
assert(gang()->finished_workers() < yf_gang()->active_workers(),
"Counts inconsistent");
switch (data.yf_task()->status()) {
case ACTIVE: {
// first, but not only thread to complete
data.yf_task()->set_status(COMPLETING);
break;
}
case YIELDING: {
if (gang()->finished_workers() + yf_gang()->yielded_workers()
== yf_gang()->active_workers()) {
data.yf_task()->set_status(YIELDED);
gang_monitor->notify_all(); // notify overseer
}
break;
}
case ABORTING:
case COMPLETING: {
break; // nothing to do
}
default: // everything else: INACTIVE, YIELDED, ABORTED, COMPLETED
ShouldNotReachHere();
}
}
}
}
// Remember the sequence number
previous_sequence_number = data.sequence_number();
// Wait for more work
gang_monitor->wait(Mutex::_no_safepoint_check_flag);
}
}
