In This Chapter
Introduction to Message Queues
Creating and Configuring Message Queues
Creating Messages Suitable for Message Queues
Sending and Receiving Messages
Adjusting Message Queue Behavior
The ipcs Utility
The topic of inter-process communication is an important one because it allows us the ability to build systems out of numerous communicating asynchronous processes. This is beneficial because we can naturally segment the functionality of a large system into a number of distinct elements. Because GNU/Linux processes utilize independent memory spaces, a function in one process cannot call another in a different process. Message queues provide one means to permit communication and coordination between processes. In this chapter, we ll review the message queue model (which conforms to the SystemV UNIX model), as well as explore some sample code that utilizes the message queue API.