COM+ Unleashed

Asynchronous Operations

Wait a minute. Isn't the whole MSMQ system asynchronous? Well, yes, with the exception of one call. The Receive operation, as you have seen, can be a blocking call, and it provides a timeout setting for this reason. It is possible to queue a Receive operation for later completion, just as you queue outbound messages for later delivery. The workings of asynchronous Receive operations greatly complicate the simple nature of a basic synchronous Receive call. Several different approaches are provided that give developers the flexibility to select a mechanism that works well within the framework of their application. Three factors often motivate developers to complicate their applications with this asynchronous stuff:

• Performance ...