Book Image

ZeroMQ

By : Faruk Akgul
Book Image

ZeroMQ

By: Faruk Akgul

Overview of this book

<p>ØMQ (also spelled ZeroMQ, 0MQ, or ZMQ) is a high-performance asynchronous messaging library aimed at use in scalable distributed or concurrent applications. It provides a message queue, but unlike message-oriented middleware, a ØMQ system can run without a dedicated message broker. The library is designed to have a familiar socket-style API.<br /><br />"ZeroMQ" teaches you to use ZeroMQ through examples in C programming language. You will learn how to use fundamental patterns of message/queuing with a step-by-step tutorial approach and how to apply them. Then, you’ll learn how to use high level APIs and to work with multiple sockets and multithreaded programs through many examples.<br /><br />This book looks at how message/queue works in general and what kinds of problems it solves. Then, it explains how ZeroMQ works and how it differs from other message/queue libraries and how it can be used in different scenarios.<br /><br />You will also learn how to apply essential message/queue design patterns in different scenarios, and how they differ from each other. It shows you practical examples you can apply. You will also learn how to work with multiple sockets.<br /><br />You will learn the basics of ZeroMQ as well as how to use different patterns.</p>
Table of Contents (12 chapters)

Getting ZeroMQ context


You must have realized by now that all examples we have done so far start with zmq_ctx_new(3). ZeroMQ applications always start with creating a context. All sockets are put inside a single process using the context, which acts as in-process sockets since they are the fastest way to connect threads in a single process. ZeroMQ context is thread safe and you may share it with multiple threads.

Note

If ZeroMQ context cannot be created, it returns NULL.

Even though it is possible to create multiple contexts, which would be considered as separate ZeroMQ applications, it is a better idea to create one ZeroMQ context rather than multiple ones.