Crate forte

An async-compatible thread-pool aiming for “speed through simplicity”.

Forte is a parallel & async work scheduler designed to accommodate very large workloads with many short-lived tasks. It replicates the rayon_core api but with native support for futures and async tasks. Its design was prompted by the needs of the bevy game engine, but should be applicable to any problem that involves running both synchronous and asynchronous work concurrently.

The thread-pool provided by this crate does not employ work-stealing. Forte instead uses “Heartbeat Scheduling”, an alternative load-balancing technique that (theoretically) provides provably small overheads and good utilization. The end effect is that work is only parallelized every so often, allowing more work to be done sequentially on each thread and amortizing the synchronization overhead.

Acknowledgments

Large portions of the code are direct ports from various versions of rayon_core, with minor simplifications and improvements. We also relied upon chili and spice for reference while writing the heartbeat scheduling. Support for futures is based on an approach sketched out by members of the rayon community to whom we are deeply indebted.

Structs

Scope

A scope which can spawn a number of non-static jobs and async tasks. See ThreadPool::scope for more information.

ThreadPool

The ThreadPool object is used to orchestrate and distribute work to a pool of threads, and is generally the main entry point to using Forte.

Worker

Holds the local context for a thread pool member, which allows queuing, executing, and sharing jobs on the pool.

Enums

Yield

Describes the outcome of a call to Worker::yield_now or Worker::yield_local.

Functions

block_on

Blocks the thread waiting for a future to complete.

join

Executes two closures on the current thread pool and returns the results.

scope

Creates a scope that allows spawning non-static jobs.

spawn

Spawns a thread onto the current thread pool.

spawn_async

Spawns an async closure onto the current thread pool.

spawn_future

Spawns a future onto the current thread pool.