5 Concurrency in Go

This chapter presents Go’s approach to and implementation of concurrency. Unlike many recent procedural and object-oriented languages, Go doesn’t provide a threading model for concurrency. Instead, it uses the concept of event-style goroutines and channels for communication between them. Concurrency is cheap (resource-wise) and much easier to manage than traditional thread pools. This chapter first focuses on goroutines, which are functions capable of running concurrently. Then it dives into channels, Go’s mechanism for handling communicating between goroutines. We’ll also look at mutexes, which are synchronization primitives that enable locking of resources as a way of enforcing consistency in concurrent systems.

5.1 Understanding Go’s concurrency model

Roughly speaking, concurrency is a program’s ability to do multiple things at the same time. In practice, when we talk about concurrent programs, we mean programs that have two or more tasks that run independently, at about the same time, but remain part of the same program.

5.2 Working with goroutines

5.2.1 Waiting for goroutines

5.2.2 Locking with a mutex

5.3 Working with channels

5.3.1 Using channels

5.3.2 Closing channels

5.3.3 Locking with buffered channels

Summary