Merge pull request #3069 from zjp-CN/waker-getters

minimize cfg code in task_from_waker

1 files changed, 23 insertions, 26 deletions

diff --git a/embassy-executor/src/raw/waker.rs b/embassy-executor/src/raw/waker.rs
index 75641c257..8d3910a25 100644
--- a/embassy-executor/src/raw/waker.rs
+++ b/embassy-executor/src/raw/waker.rs
@@ -32,35 +32,32 @@ 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 {
-    #[cfg(not(feature = "nightly"))]
-    {
-        struct WakerHack {
-            data: *const (),
-            vtable: &'static RawWakerVTable,
+    let (vtable, data) = {
+        #[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) };
+            (hack.vtable, hack.data)
         }
 
-        // 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.")
+        #[cfg(feature = "nightly")]
+        {
+            let raw_waker = waker.as_raw();
+            (raw_waker.vtable(), raw_waker.data())
         }
+    };
 
-        // 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();
-
-        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) }
+    if 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(data as *const TaskHeader) }
 }