Turbo-wakers 🚀 #1263
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Turbo-wakers 🚀 #1263
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This is a `core` patch to make wakers 1 word (the task pointer) instead of 2 (task pointer + vtable). It allows having the "waker optimization" we had a while back on `WakerRegistration/AtomicWaker`, but EVERYWHERE, without patching all crates. Advantages: - Less memory usage. - Faster. - `AtomicWaker` can actually use atomics to load/store the waker, No critical section needed. - No `dyn` call, which means `cargo-call-stack` can now see through wakes. Disadvantages: - You have to patch `core`... - Breaks all executors and other things that create wakers, unless they opt in to using the new `from_ptr` API. How to use: - Run this shell script to patch `core`. https://gist.github.com/Dirbaio/c67da7cf318515181539122c9d32b395 - Enable `build-std` - Enable `build-std-features = core/turbowakers` - Enable feature `turbowakers` in `embassy-executor`, `embassy-sync`. - Make sure you have no other crate creating wakers other than `embassy-executor`. These will panic at runtime. Note that the patched `core` is equivalent to the unpached one when the `turbowakers` feature is not enabled, so it should be fine to leave it there.
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This is a
corepatch to make wakers 1 word (the task pointer) instead of 2 (task pointer + vtable). It allows having the "waker optimization" we had a while back onWakerRegistration/AtomicWaker, but EVERYWHERE, without patching all crates.Advantages:
AtomicWakercan actually use atomics to load/store the waker, No critical section needed.dyncall, which meanscargo-call-stackcan now see through wakes.Disadvantages:
core...from_ptrAPI.How to use:
core. https://gist.github.com/Dirbaio/c67da7cf318515181539122c9d32b395build-stdbuild-std-features = core/turbowakersturbowakersinembassy-executor,embassy-sync.embassy-executor. These will panic at runtime.Note that the patched
coreis equivalent to the unpached one when theturbowakersfeature is not enabled, so it should be fine to leave it there.