[Mlir-commits] [mlir] [mlir] DistinctAttributeAllocator: fix race (PR #132935)

[Emilio Cota]

cota wrote:

> Would introducing a lock in disableThreadLocalStorage avoid the problem as well?

That lock would protect `useThreadLocalAllocator` and we'd have to acquire the lock on all the other accesses to it. It's easier to reuse the existing lock.

> When reviewing I was under the impression that we can check this flags safely since they are only set in single-thread code 

`DistinctAttributeAllocator` is a member of `MLIRContext` and therefore can be accessed by different threads when  threading is enabled. We should either (1) have the bitfields in DistinctAttributeAllocator as immutable members, therefore being read-only and thus requiring no atomics, or (2) properly deal with multi-threaded accesses if we don't want the bitfields to be immutable. I think @abulavin should make the call since they have all the context.

https://github.com/llvm/llvm-project/pull/132935