I had to implement a blocking queue for ExecutorCompletionService. LinkedBlockingQueue could be very easily extended right now to implement the java 7 LinkedBlockingDeque. Right now LinkedBlockingQueue just synchronizes and depends on LinkedList implementation. But I wrote a very complete unit test suite so we if we want to put a more concurrent design here, we have a complete test suite to verify against.# Please enter the commit message for your changes. Lines starting