Concurrency

Writing a program as several tasks whose lifetimes overlap, so one can make progress while another waits.

Depth 1 · Foundation

You can tell waiting from computing, and see that overlapping the waits makes a job take about as long as its slowest task instead of the sum of all of them.

Depths of understanding

1
Foundation
You can tell waiting from computing, and see that overlapping the waits makes a job take about as long as its slowest task instead of the sum of all of them.
Opens after
Functions in codeA task is a function you start; you need to write and call functions before you run several of them at once.
2
Deeper
You organise concurrent work as a few workers taking jobs from a queue and sending back results, so threads share messages instead of variables.
Master depth 1 first
ThreadWorker pools are built from threads; know how to start and join one before handing jobs to several.