Akka封锁要求会封锁其他演员吗？

Question

Say we have:

• Thread 1 containing Actors A, B, and C.
• Thread 2 containing Actor Y.
• Thread 3 containing Actor Z.
• Actors A and B are listening for messages from Actor Y.

Actor C then makes a blocking request to Actor Z.

Before the request returns, Actor Y sends a few messages to Actors A and B.

Can Actors A and B receive the messages before Actor C completes?

Or is it a must that Actor C complete before Actors A and B can receive the messages?

I included Actor Y to allow the possibility of it sending messages while Z is processing the request from C.

All threads are on different physical cores - they run in parallel.

Answer 1

Actor may process a message from queue on any thread - they are not pinned to concrete threads by default (if you don't use pinned dispatcher). Simply saying different messages from same queue may be processed on different threads (choosed by dispatcher).

I suppose that by "thread containg actor" you mean containg in one or several moments (messages) of time. Because dispatcher is free (by default) to choose any thread for any message of any actor/mailbox. In practice it may choose the same thread sometimes but not always.

So, if one thread is blocked, dispatcher (by default) goes to another. A and B may receive messages before C completes if you have enough threads.

However, blocking itself is a bad practice for Akka ( Blocking Needs Careful Management ).

Let it be reactive!