Giacomo Stevanato e543941fb9 Improve soundness of CommandQueue (#4863) ... # Objective This PR aims to improve the soundness of `CommandQueue`. In particular it aims to: - make it sound to store commands that contain padding or uninitialized bytes; - avoid uses of commands after moving them in the queue's buffer (`std::mem::forget` is technically a use of its argument); - remove useless checks: `self.bytes.as_mut_ptr().is_null()` is always `false` because even `Vec`s that haven't allocated use a dangling pointer. Moreover the same pointer was used to write the command, so it ought to be valid for reads if it was for writes. ## Solution - To soundly store padding or uninitialized bytes `CommandQueue` was changed to contain a `Vec<MaybeUninit<u8>>` instead of `Vec<u8>`; - To avoid uses of the command through `std::mem::forget`, `ManuallyDrop` was used. ## Other observations While writing this PR I noticed that `CommandQueue` doesn't seem to drop the commands that weren't applied. While this is a pretty niche case (you would have to be manually using `CommandQueue`/`std::mem::swap`ping one), I wonder if it should be documented anyway.		2022-05-30 22:45:09 +00:00
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command_queue.rs	Improve soundness of CommandQueue (#4863)	2022-05-30 22:45:09 +00:00
mod.rs	Add Commands::new_from_entities (#4423)	2022-05-14 14:40:09 +00:00