- a_store(&f->lock, 0);
-
- /* The following read is technically invalid under situations
- * of self-synchronized destruction. Another thread may have
- * called fclose as soon as the above store has completed.
- * Nonetheless, since FILE objects always live in memory
- * obtained by malloc from the heap, it's safe to assume
- * the dereferences below will not fault. In the worst case,
- * a spurious syscall will be made. If the implementation of
- * malloc changes, this assumption needs revisiting. */
-
- if (f->waiters) __wake(&f->lock, 1, 1);
+ if (a_swap(&f->lock, 0) & MAYBE_WAITERS)
+ __wake(&f->lock, 1, 1);