CODEWITHSUNDEEP
javamultithreading
ToyElephant
ToyElephant

Reputation: 205

Shared executor service among various worker

I want to use a common thread pool among various reader objects. Each reader will read asynchronously using a thread from the pool. Here is how I define my executor :

public static ExecutorService executor = Executors.newFixedThreadPool();

I want to use it in TableReader objects. For example, there is a function readRows which will look like this :

executor.submit(new AsyncRowReader(...));

However, I am not sure how to handle the shutdown() step. The TableReader is part of a jar which can be used like this :

TableReader r = new TableReader(...);
while (not done) {
  r.readRow(...);
}

There could be multiple TableReader objects from a single application. I can shutdown the executor service once all of these are done. How can I detect that there no more tasks running? Is there a different type of thread pool I can use?

Upvotes: 1

Views: 999

Answers (1)

Chris Mowforth
Chris Mowforth

Reputation: 6723

Sounds like you need an ExecutorCompletionService:

ExecutorCompletionService completionService = new ExecutorCompletionService(executor);

while (completionService.poll() != null) {
    System.out.println("Still working...");
}

executor.shutdown();

Upvotes: 1

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