04Concurrency

Concurrency

IntermediateModule 046 topics~5h 40m

Topics, in order

01 Goroutines and the SchedulerA goroutine is a function running independently, with its own small stack, managed by the Go runtime rather than the operating system. Starting one costs a few kilobytes and well under a … Intermediate 1h 02 ChannelsA channel is a typed conduit between goroutines: one sends a value, another receives it. An unbuffered channel is a rendezvous — the send completes only when a receiver takes the value, so … Intermediate 55 min 03 Select, Context and Cancellationselect waits on several channel operations at once and runs whichever is ready first. It is how a goroutine waits for work or a timeout or a stop signal. Intermediate 55 min 04 Sync and AtomicsWhen several goroutines touch the same data and at least one writes, access must be synchronized. Go gives you three tools at three price points. An atomic operation updates one word in a … Intermediate 55 min 05 The Memory Model and Data RacesA data race is two goroutines accessing the same variable at the same time, at least one writing, with nothing ordering them. The Go memory model is the specification of what "ordering them" … Advanced 50 min 06 Concurrency PatternsAlmost all concurrent Go is built from a handful of shapes: a worker pool (bounded parallelism), a pipeline (stages connected by channels), fan-out / fan-in (spread work, collect results), a … Advanced 1h 5m

About this module

Goroutines are why most people choose Go. This module explains what one actually is, how the runtime runs millions of them on a handful of threads, and how to write concurrent code that is correct — not merely code that happens to pass its tests.

#	Lesson	The question it answers
01	Goroutines and the Scheduler	What is a goroutine, and who decides when it runs?
02	Channels	What is a channel made of, and what do send, receive and close really do?
03	Select, Context and Cancellation	How do I wait on several things and stop work that is no longer wanted?
04	Sync and Atomics	When do I use a mutex, an atomic or a channel?
05	The Memory Model and Data Races	What exactly is a data race, and what does Go guarantee?
06	Concurrency Patterns	How are worker pools, pipelines and bounded concurrency built — without leaks?

When you finish you can draw the scheduler, predict what any channel operation does, write a cancellable worker pool, and explain why a program with a data race has no defined behaviour.