Implement data and vtable getters for RawWaker

Author: oxalica

library/core/src/task/wake.rs

@@ -43,6 +43,22 @@ impl RawWaker {
     pub const fn new(data: *const (), vtable: &'static RawWakerVTable) -> RawWaker {
         RawWaker { data, vtable }
     }
+
+    /// Get the `data` pointer used to create this `RawWaker`.
+    #[inline]
+    #[must_use]
+    #[unstable(feature = "waker_getters", issue = "87021")]
+    pub fn data(&self) -> *const () {
+        self.data
+    }
+
+    /// Get the `vtable` pointer used to create this `RawWaker`.
+    #[inline]
+    #[must_use]
+    #[unstable(feature = "waker_getters", issue = "87021")]
+    pub fn vtable(&self) -> &'static RawWakerVTable {
+        self.vtable
+    }
 }
 
 /// A virtual function pointer table (vtable) that specifies the behavior
@@ -260,6 +276,14 @@ impl Waker {
     pub unsafe fn from_raw(waker: RawWaker) -> Waker {
         Waker { waker }
     }
+
+    /// Get a reference to the underlying [`RawWaker`].
+    #[inline]
+    #[must_use]
+    #[unstable(feature = "waker_getters", issue = "87021")]
+    pub fn as_raw(&self) -> &RawWaker {
+        &self.waker
+    }
 }
 
 #[stable(feature = "futures_api", since = "1.36.0")]

library/core/tests/lib.rs

@@ -81,6 +81,7 @@
 #![feature(unzip_option)]
 #![feature(const_array_from_ref)]
 #![feature(const_slice_from_ref)]
+#![feature(waker_getters)]
 #![deny(unsafe_op_in_unsafe_fn)]
 
 extern crate test;
@@ -121,3 +122,4 @@ mod task;
 mod time;
 mod tuple;
 mod unicode;
+mod waker;

library/core/tests/waker.rs

@@ -0,0 +1,22 @@
+use std::ptr;
+use std::task::{RawWaker, RawWakerVTable, Waker};
+
+#[test]
+fn test_waker_getters() {
+    let raw_waker = RawWaker::new(42usize as *mut (), &WAKER_VTABLE);
+    assert_eq!(raw_waker.data() as usize, 42);
+    assert!(ptr::eq(raw_waker.vtable(), &WAKER_VTABLE));
+
+    let waker = unsafe { Waker::from_raw(raw_waker) };
+    let waker2 = waker.clone();
+    let raw_waker2 = waker2.as_raw();
+    assert_eq!(raw_waker2.data() as usize, 43);
+    assert!(ptr::eq(raw_waker2.vtable(), &WAKER_VTABLE));
+}
+
+static WAKER_VTABLE: RawWakerVTable = RawWakerVTable::new(
+    |data| RawWaker::new((data as usize + 1) as *mut (), &WAKER_VTABLE),
+    |_| {},
+    |_| {},
+    |_| {},
+);