CODEWITHSUNDEEP
javamultithreadingexecutorservice
fortm
fortm

Reputation: 4208

Wait for Executors

THere is a loop to borrow Objects from A GenericObjectPool and submit to a Executor in each loop. Then, the caller has to wait for all Exectuors to complete.

Here is present code - 

private ImplClass implObject;
private Future future;

for (Iterator iter = anArrayList.iterator(); iter.hasNext();) {

    //Gets a GenericObjectPool Object
    implObject = (ImplClass) this.getImplPool().borrowObject();

    future = getExecutorServices().submit(implObject);
}


// Wait for Exectuor to complete
while (!future.isDone()) {
    try {
        Thread.sleep(Global.WaitTime());

    } catch (InterruptedException iex) {
    }
}

But this is wrong as future waits for only last Thread. Should I create an Array of Futures to monitor each executor ?

Upvotes: 0

Views: 154

Answers (2)

Eyal Schneider
Eyal Schneider

Reputation: 22456

ExecutorService has a specific method for that: ExecutorService.invokeAll(tasks)

The ExecutorCompletionService mentioned in Ralf's answer can also be helpful - it allows you to process results by the caller thread as they arrive.

Upvotes: 1

Sean Landsman
Sean Landsman

Reputation: 7197

How about this?:

List<Callable> tasks = new ArrayList<Callable>();
for (Iterator iter = anArrayList.iterator(); iter.hasNext();) {
    //Gets a GenericObjectPool Object
    implObject = (ImplClass) this.getImplPool().borrowObject();      
    tasks.add(implObject);
}
List<Future<Object>> futures = getExecutorServices().invokeAll(tasks);

Upvotes: 1

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