From 329bb3a2230fd2c26edde116c7dad2f9a37c199d Mon Sep 17 00:00:00 2001 From: Botahamec Date: Mon, 27 May 2024 00:33:16 -0400 Subject: Fixed UB pertaining to Box --- src/collection.rs | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'src/collection.rs') diff --git a/src/collection.rs b/src/collection.rs index 27ec1c4..8227362 100644 --- a/src/collection.rs +++ b/src/collection.rs @@ -1,4 +1,5 @@ use std::marker::PhantomData; +use std::ptr::NonNull; use crate::{key::Keyable, lockable::RawLock}; @@ -85,10 +86,17 @@ pub struct RefLockCollection<'a, L> { // This type caches the sorting order of the locks and the fact that it doesn't // contain any duplicates. pub struct BoxedLockCollection { - data: Box, - locks: Vec<&'static dyn RawLock>, // As far as you know, it's static. - // Believe it or not, saying the lifetime - // is static when it's not isn't UB + // Box isn't used directly because it requires that the data not be + // aliased. To resolve this, we'll have to ensure that only one of the + // following is true at any given time: + // + // 1. We have a mutable reference to the data + // 2. We have immutable references to the data and locks + // + // This is enforced by having #1 be true for a mutable or owned reference + // to the value, and #2 is true for an immutable reference. + data: NonNull, + locks: Vec>, } /// Locks a collection of locks using a retrying algorithm. -- cgit v1.2.3