CODEWITHSUNDEEP
javamultithreadingexecutorservicejava.util.concurrent
Kevin
Kevin

Reputation: 1657

ExecutorService awaitTermination gets stuck

I made a fixed size thread pool with Executors.newFixedThreadPool(2), and I executed 10 Runnable objects. I set breakpoints and traced through the execution. However, fixedSizeThreadPool.awaitTermination() does not allow me to continue even though all the tasks are done.

Basically:

ExecutorService fixedThreadPool = Executors.newFixedThreadPool(2);
for (int i = 0; i < 10; ++i) {
    fixedSizeThreadPool.execute(myRunables[i]);
}
try {
    fixedSizeThreadPool.awaitTermination(timeout, timeoutUnits);
} catch (Exception e) { }
System.out.println("done!");

But this always gets stuck on awaitTermination. What's wrong?

Upvotes: 22

Views: 13193

Answers (2)

Paul Bellora
Paul Bellora

Reputation: 55213

As Peter pointed out, shutdown() must be called first.

source: javadoc

Upvotes: 34

emboss
emboss

Reputation: 39620

You could also use ExecutorService#invokeAll. It blocks until all tasks are done or the timeout is reached. It's a little cleaner than using shutdown, if your ExecutorService contains other tasks as well especially scheduled tasks. These would also be affected by a call to shutdown.

Upvotes: 2

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