From 91c2d4850e31da1bbd49fc668ae79533e7ac3ab4 Mon Sep 17 00:00:00 2001 From: Daniel Carosone Date: Fri, 2 Oct 2020 19:56:17 +1000 Subject: [PATCH] Shared access is useful with interior mutability --- book/en/src/by-example/resources.md | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/book/en/src/by-example/resources.md b/book/en/src/by-example/resources.md index d67a72ff48..9831e55b3b 100644 --- a/book/en/src/by-example/resources.md +++ b/book/en/src/by-example/resources.md @@ -114,7 +114,9 @@ are required to access the resource even if the resource is contended by several tasks running at different priorities. The downside is that the task only gets a shared reference (`&-`) to the resource, limiting the operations it can perform on it, but where a shared reference is enough this approach reduces the number -of required locks. +of required locks. In addition to simple immutable data, this shared access can +be useful where the resource type safely implements interior mutability, with +appropriate locking or atomic operations of its own. Note that in this release of RTIC it is not possible to request both exclusive access (`&mut-`) and shared access (`&-`) to the *same* resource from different