Java Scheduled Executor Service wait all threads complete

Question

ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(4);
for (int i = 0; i < 4; i++)
{Runnable autoUpdate = new autoUpdateWork(i);
ScheduledFuture<?> scheduleAtFixedRate = scheduler.scheduleAtFixedRate(autoUpdate, 0, 60, TimeUnit.SECONDS);
}
if (scheduleAtFixedRate != null)
    {    
        while(!scheduleAtFixedRate.isDone())
        //wait...
    }
//PointA :until all threads are finished, do sth, then invoke the scheduled task with 60 sec interval    again.

So far the above is my code. But seems it would never get to PointA.. Please help, thanks!

Answer 1

instead of doing

if (scheduleAtFixedRate != null)
{    
    while(!scheduleAtFixedRate.isDone())
    //wait...
}

In your Runnable class add a volatile variable like below.

public  volatile boolean isRunning = false;

and once your thread completes the work, change it to true and in your checking part put like .

while(!autoUpdate.isRunning);