Recursive mutexes are a terrible idea, except maybe in context. In a world where you can SendMessage a message to yourself or to another window in the same thr

Recursive mutexes are a terrible idea, except maybe in context. In a world where you can SendMessage a message to yourself or to another window in the same thread, process the message synchronously, and then return back to where you were, you have essentially uncontrolled reentrancy. If you want to throw mutexes into the mix, they pretty much need to be recursive. Then you get to acquire the mutex in a message handler to protect against other threads, and everything sort of works. In my own code, I try fairly hard to avoid this sort of reentrancy.