Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

clarify interaction of pin drop guarantee and panics #71607

Merged
merged 1 commit into from
May 22, 2020
Merged

clarify interaction of pin drop guarantee and panics #71607

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 4 additions & 2 deletions src/libcore/pin.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -139,10 +139,12 @@
//! otherwise invalidating the memory used to store the data is restricted, too.
//! Concretely, for pinned data you have to maintain the invariant
//! that *its memory will not get invalidated or repurposed from the moment it gets pinned until
//! when [`drop`] is called*. Memory can be invalidated by deallocation, but also by
//! when [`drop`] is called*. Only once [`drop`] returns or panics, the memory may be reused.
//!
//! Memory can be "invalidated" by deallocation, but also by
//! replacing a [`Some(v)`] by [`None`], or calling [`Vec::set_len`] to "kill" some elements
//! off of a vector. It can be repurposed by using [`ptr::write`] to overwrite it without
//! calling the destructor first.
//! calling the destructor first. None of this is allowed for pinned data without calling [`drop`].
//!
//! This is exactly the kind of guarantee that the intrusive linked list from the previous
//! section needs to function correctly.
Expand Down