GoRoutines

Goroutines are a fundamental building block of concurrency in the Go programming language. A goroutine is a lightweight thread of execution that the Go runtime schedules and multiplexes onto a smaller pool of operating system threads. They enable concurrent execution with relatively low overhead compared with OS threads.

Management and scheduling: The runtime maintains many goroutines and assigns them to OS threads using a scheduler. The number of OS threads is controlled by GOMAXPROCS; the Go scheduler supports multiplexing many thousands of goroutines on a handful of OS threads. Scheduling is preemptive and aims to provide responsiveness.

Creation and stack: Goroutines are created by the go keyword followed by a function call. Each goroutine starts with a small initial stack (traditionally a few kilobytes) that grows or shrinks automatically.

Communication and synchronization: Goroutines communicate primarily through channels and the select statement; the language provides other synchronization primitives in the sync package. This supports a CSP-style approach to concurrency and helps coordinate work across multiple goroutines.

Usage and caveats: Goroutines simplify concurrent programming but require attention to synchronization and potential data races; the race detector can help identify issues. Goroutine lifecycles can lead to resource leaks if created but not properly managed, and deadlocks can occur if communication and synchronization are not carefully designed.