From ae09340350fd8b7aa7a00a81132a7e77772504cb Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Fri, 9 Aug 2024 18:05:57 +0200 Subject: [PATCH] make LocalWaker::will_wake consistent with Waker::will_wake --- library/core/src/task/wake.rs | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/library/core/src/task/wake.rs b/library/core/src/task/wake.rs index 8ce3eb2ea3921..29932c0d1ffeb 100644 --- a/library/core/src/task/wake.rs +++ b/library/core/src/task/wake.rs @@ -502,6 +502,8 @@ impl Waker { #[must_use] #[stable(feature = "futures_api", since = "1.36.0")] pub fn will_wake(&self, other: &Waker) -> bool { + // We optimize this by comparing vtable addresses instead of vtable contents. + // This is permitted since the function is documented as best-effort. let RawWaker { data: a_data, vtable: a_vtable } = self.waker; let RawWaker { data: b_data, vtable: b_vtable } = other.waker; a_data == b_data && ptr::eq(a_vtable, b_vtable) @@ -761,7 +763,11 @@ impl LocalWaker { #[must_use] #[unstable(feature = "local_waker", issue = "118959")] pub fn will_wake(&self, other: &LocalWaker) -> bool { - self.waker == other.waker + // We optimize this by comparing vtable addresses instead of vtable contents. + // This is permitted since the function is documented as best-effort. + let RawWaker { data: a_data, vtable: a_vtable } = self.waker; + let RawWaker { data: b_data, vtable: b_vtable } = other.waker; + a_data == b_data && ptr::eq(a_vtable, b_vtable) } /// Creates a new `LocalWaker` from [`RawWaker`].