Execute submitted tasks on a reusable, usually bounded set of workers.

Decouple work production from processing through a buffer or channel.

Represent a value or failure that will be supplied later.

Recursively split work into independent tasks and join their results.

Let idle workers take queued work from busier workers.

Provide exclusive ownership of a critical section or shared invariant.

Control concurrent access with a count of available permits.

Encapsulate shared state with mutually exclusive methods and condition waiting.

Allow concurrent readers while granting writers exclusive access.

Hold participants until all have completed the current phase.

Associate an independent value with each thread.

Make state safe to share by preventing changes after construction.

Receive events and dispatch their handlers sequentially on one execution context.

Demultiplex readiness notifications and invoke synchronous handlers.

Start asynchronous operations and dispatch handlers when they complete.

Isolate mutable state inside entities that process asynchronous messages.

Compose independent sequential processes that coordinate through explicit channels.

Separate method invocation from execution by placing requests in a queue owned by an object.