phosek added a comment. In https://reviews.llvm.org/D49355#1188520, @aaronpuchert wrote:
> Could you explain what annotations like `LOCK_UNLOCK` are useful for? What do > they check? The annotation should certainly not be necessary. > > Shouldn't you just use `REQUIRES(!...)` or `EXCLUDES(...)`? If a function > locks and unlocks a mutex, I don't see a reason to have annotations on it, > other than for preventing double locks. But for that we have negative > capabilities. The purpose here indeed is to avoid double locks. I tried using `EXCLUDES(...)` but that doesn't work because `RegisterIsolatePortWithName` <https://github.com/flutter/engine/blob/master/lib/ui/isolate_name_server/isolate_name_server.h#L31> calls `LookupIsolatePortByNameUnprotected` <https://github.com/flutter/engine/blob/master/lib/ui/isolate_name_server/isolate_name_server.h#L39> which has `EXCLUSIVE_LOCKS_REQUIRED(...)` annotation. I also tried using the negative annotation but that reports far too many warnings in the existing code which makes it unusable. I'm fine changing the code, but unless there's a simple workaround I'd still argue for a revert, because the change even if correct has broken an existing usage pattern that worked fine for a long time before and is used in large codebases. Repository: rC Clang https://reviews.llvm.org/D49355 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
