Java: Synchronize an ExecutorService necessary?

Question

I have a class containing an ExecutorService that can be shared between threads:

class MyExecutor {
    ExecutorService e = Executors.newSingleThreadExecutor();
    ....
    .... 
    public void add(Runnable r) {
         e.executre(r);
    } 
}

Is it necessary to synchronize the ExecutorService object in the add method since the add method can be called from differens threads or is the ExecutorService thread safe?

Answer 1

ExecutorService has to use a thread safe queue (Which it does by default). This is all that is needed.

Answer 2

No, there is no need to synchronize calls to add() method.