### Build session state

A "build session" represents a single invocation of Gradle, for example when you run `gradlew build`.
A session runs the build one or more times.
For example, when continuous build is enabled, the session may run the build many times, but when it is disabled, the session will run the build once only.

For any non-trivial change, we need to be able to answer these questions:

* Why is this change done? What's the use case?
* For user facing features, what will the API look like?
* What test cases should it have? What could go wrong?
* How will it roughly be implemented? We'll happily provide code pointers to save you time.

        worker3["Worker process"]
        daemon --> worker3
    
```

These are all Java processes. Each process has a corresponding "runtime".
All source code in Gradle is written to target one or more of these runtimes.
Most source code targets the daemon and the remaining code either targets a single runtime, for example the Gradle client, or is shared across multiple runtimes.

## Composition by architecture modules