Create a simple queue with Java threads

Question

I'm trying to create a simple queue with Java Thread that would allow a loop, say a for loop with 10 iterations, to iterate n (< 10) threads at a time and wait until those threads are finished before continuing to iterate.

Here's a better way to illustrate my problem:

for (int i = 1; i <= 10; i++) {
    new Thread ( do_some_work() );

    if ( no_available_threads ) {
        wait_until_available_threads();
    }
}

do_some_work() {
    // do something that takes a long time
}

Basically what I want to do is a copy of this: Thread and Queue

How can I achieve this the most painless way?

Answer 1

I would use the Java 5 Executors instead of rolling your own. Something like the following:

ExecutorService service = Executors.newFixedThreadPool(10);
// now submit our jobs
service.submit(new Runnable() {
    public void run() {
        do_some_work();
    }
});
// you can submit any number of jobs and the 10 threads will work on them
// in order
...
// when no more to submit, call shutdown, submitted jobs will continue to run
service.shutdown();
// now wait for the jobs to finish
service.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);