Programming Crystal

Creating Concurrent Code

For concurrent processing, Crystal uses the same CSP (communicating sequential processes) model as Go: lightweight processes called fibers that communicate data through channels. It does this faster and less resource-intensive than Node.js, for example. You learned about fibers and channels in Chapter 3, ​Executing Code Concurrently Through Fibers​. Before getting into more detail, let’s examine Crystal’s execution mechanism.

How Does a Crystal Program Execute?

When a Crystal program starts up, a main fiber (main for short) runs to execute your top-level code. In that code, one can spawn many other fibers, which are queued. In the background, Crystal operates a minimal runtime that consists of the following components: ...