Type of Lwt mutexes

create () creates a new mutex, which is initially unlocked

lock mutex lockcs the mutex, that is:

• if the mutex is unlocked, then it is marked as locked and lock returns immediately

• if it is locked, then lock waits for all threads waiting on the mutex to terminate, then it resumes when the last one unlocks the mutex

Note: threads are woken up in the same order they try to lock the mutex

unlock mutex unlock the mutex if no threads is waiting on it. Otherwise it will eventually removes the first one and resumes it.

locked mutex returns whether mutex is currently locked

is_empty mutex returns true if they are no thread waiting on the mutex, and false otherwise

with_lock lock f is used to lock a mutex within a block scope. The function f () is called with the mutex locked, and its result is returned from the call to with_lock. If an exception is raised from f, the mutex is also unlocked before the scope of with_lock is exited.