From 8a9c45e7d4e9f8d7e155c3a90ca07afc65e87238 Mon Sep 17 00:00:00 2001 From: Laurenz Date: Thu, 30 May 2024 14:46:47 +0200 Subject: Fix race condition in interners (#4300) --- crates/typst-syntax/src/file.rs | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'crates/typst-syntax/src') diff --git a/crates/typst-syntax/src/file.rs b/crates/typst-syntax/src/file.rs index b76cb9e3..356337f3 100644 --- a/crates/typst-syntax/src/file.rs +++ b/crates/typst-syntax/src/file.rs @@ -36,17 +36,20 @@ impl FileId { #[track_caller] pub fn new(package: Option, path: VirtualPath) -> Self { // Try to find an existing entry that we can reuse. + // + // We could check with just a read lock, but if the pair is not yet + // present, we would then need to recheck after acquiring a write lock, + // which is probably not worth it. let pair = (package, path); - if let Some(&id) = INTERNER.read().unwrap().to_id.get(&pair) { + let mut interner = INTERNER.write().unwrap(); + if let Some(&id) = interner.to_id.get(&pair) { return id; } - let mut interner = INTERNER.write().unwrap(); - let num = interner.from_id.len().try_into().expect("out of file ids"); - // Create a new entry forever by leaking the pair. We can't leak more // than 2^16 pair (and typically will leak a lot less), so its not a // big deal. + let num = interner.from_id.len().try_into().expect("out of file ids"); let id = FileId(num); let leaked = Box::leak(Box::new(pair)); interner.to_id.insert(leaked, id); -- cgit v1.2.3