diff --git a/embassy-executor/src/lib.rs b/embassy-executor/src/lib.rs index 6a2e493a2..553ed76d3 100644 --- a/embassy-executor/src/lib.rs +++ b/embassy-executor/src/lib.rs @@ -1,4 +1,5 @@ #![cfg_attr(not(any(feature = "arch-std", feature = "arch-wasm")), no_std)] +#![cfg_attr(feature = "nightly", feature(waker_getters))] #![allow(clippy::new_without_default)] #![doc = include_str!("../README.md")] #![warn(missing_docs)] diff --git a/embassy-executor/src/raw/waker.rs b/embassy-executor/src/raw/waker.rs index 522853e34..75641c257 100644 --- a/embassy-executor/src/raw/waker.rs +++ b/embassy-executor/src/raw/waker.rs @@ -1,4 +1,3 @@ -use core::mem; use core::task::{RawWaker, RawWakerVTable, Waker}; use super::{wake_task, TaskHeader, TaskRef}; @@ -33,20 +32,35 @@ pub(crate) unsafe fn from_task(p: TaskRef) -> Waker { /// /// Panics if the waker is not created by the Embassy executor. pub fn task_from_waker(waker: &Waker) -> TaskRef { - // safety: OK because WakerHack has the same layout as Waker. - // This is not really guaranteed because the structs are `repr(Rust)`, it is - // indeed the case in the current implementation. - // TODO use waker_getters when stable. https://github.com/rust-lang/rust/issues/96992 - let hack: &WakerHack = unsafe { mem::transmute(waker) }; - if hack.vtable != &VTABLE { - panic!("Found waker not created by the Embassy executor. `embassy_time::Timer` only works with the Embassy executor.") + #[cfg(not(feature = "nightly"))] + { + struct WakerHack { + data: *const (), + vtable: &'static RawWakerVTable, + } + + // safety: OK because WakerHack has the same layout as Waker. + // This is not really guaranteed because the structs are `repr(Rust)`, it is + // indeed the case in the current implementation. + // TODO use waker_getters when stable. https://github.com/rust-lang/rust/issues/96992 + let hack: &WakerHack = unsafe { core::mem::transmute(waker) }; + if hack.vtable != &VTABLE { + panic!("Found waker not created by the Embassy executor. `embassy_time::Timer` only works with the Embassy executor.") + } + + // safety: our wakers are always created with `TaskRef::as_ptr` + unsafe { TaskRef::from_ptr(hack.data as *const TaskHeader) } } - // safety: our wakers are always created with `TaskRef::as_ptr` - unsafe { TaskRef::from_ptr(hack.data as *const TaskHeader) } -} + #[cfg(feature = "nightly")] + { + let raw_waker = waker.as_raw(); -struct WakerHack { - data: *const (), - vtable: &'static RawWakerVTable, + if raw_waker.vtable() != &VTABLE { + panic!("Found waker not created by the Embassy executor. `embassy_time::Timer` only works with the Embassy executor.") + } + + // safety: our wakers are always created with `TaskRef::as_ptr` + unsafe { TaskRef::from_ptr(raw_waker.data() as *const TaskHeader) } + } }