What blocks mutex in a channel - a goroutine or a memory area?

Mutex (mutual exclusion) in Go blocks a goroutine, not a memory region. When a goroutine tries to acquire a mutex, if it is already occupied, the goroutine is suspended (blocked) until the mutex is released.

It is important to understand that the mutex does not block the memory area or data directly, but manages access to them by synchronizing the execution of goroutines. This prevents multiple goroutines from accessing shared resources simultaneously, ensuring data correctness.

Thus, it is the goroutine that is blocked, waiting for the mutex to be released, not the memory or other goroutines.