async_context_threadsafe_background: fix incorrect mutex assertion in cross-core execute_sync() #2528

2025-06-16T10:11:09-05:00

schkovich commented

2025-06-16 10:11:09 -05:00

(Migrated from github.com)

In multicore configurations, async_context_threadsafe_background_execute_sync() contained an overly strict assertion used during cross-core calls:

hard_assert(!recursive_mutex_enter_count(&self->lock_mutex));

This check fails whenever the lock_mutex is held — regardless of who owns it — even in valid situations where the async core is processing background work.

The assertion does not check ownership, only that the enter_count is zero, which leads to false-positive failures on valid cross-core calls.

This patch replaces the enter-count check with a core-aware assertion:

hard_assert(self->lock_mutex.owner != calling_core);

This ensures the current core does not recursively hold the mutex, preventing deadlocks while allowing valid usage where the other core owns the lock.

The patch ensures that both get_core_num() and hard_assert() remain inlined as in the original implementation, preserving the performance characteristics under -Os and RelWithDebInfo builds.

Fixes #2527

In multicore configurations, `async_context_threadsafe_background_execute_sync()` contained an overly strict assertion used during cross-core calls: ```c hard_assert(!recursive_mutex_enter_count(&self->lock_mutex)); ``` This check fails whenever the `lock_mutex` is held — regardless of *who* owns it — even in valid situations where the async core is processing background work. The assertion does **not check ownership**, only that the `enter_count` is zero, which leads to false-positive failures on valid cross-core calls. This patch replaces the enter-count check with a core-aware assertion: ```c hard_assert(self->lock_mutex.owner != calling_core); ``` This ensures the current core does not recursively hold the mutex, preventing deadlocks while allowing valid usage where the *other* core owns the lock. The patch ensures that both `get_core_num()` and `hard_assert()` remain inlined as in the original implementation, preserving the performance characteristics under `-Os` and `RelWithDebInfo` builds. Fixes #2527

				`@ -138,8 +138,15 @@ static void lock_release(async_context_threadsafe_background_t *self) {`
				`uint32_t async_context_threadsafe_background_execute_sync(async_context_t self_base, uint32_t (func)(void param), void param) {`

Rows
Columns