You have independent pieces of work A, B, and C. C must run only after both A and B have finished, the order of A and B doesn't matter, and they don't nest inside each other. Tell me every way you know to implement that, with the pros and cons.
DispatchGroup notify, concurrent queue plus barrier, DispatchSemaphore wait twice (blocking), OperationQueue addDependency, Swift Concurrency async let/TaskGroup. New code uses async let, legacy uses a group, and semaphores are banned on main.
ConcurrencyShort answerBasics
When a screen appears you call three APIs in parallel, profile, feed, and notifications…
#dispatchgroup #async-let
ConcurrencyShort answerBasics
You're building an image pipeline: download, resize, then save to the disk cache, and…
#operationqueue
ConcurrencyMultiple choiceBasics
In this cache built on a GCD concurrent queue, which statement about the role of the…
#barrier
ConcurrencyMultiple choiceAdvanced
Which of the following statements about structured concurrency (async let, TaskGroup) are…
#async-let