: sig end
The type of binary semaphores.
val make : bool -> t
make b returns a new binary semaphore. If b is true , the initial value of the semaphore is 1, meaning "available". If b is false , the initial value of the semaphore is 0, meaning "unavailable".
val release : t -> unit
release s sets the value of semaphore s to 1, putting it in the "available" state. If other threads are waiting on s , one of them is restarted.
val acquire : t -> unit
acquire s blocks the calling thread until the semaphore s has value 1 (is available), then atomically sets it to 0 and returns.
val try_acquire : t -> bool
try_acquire s immediately returns false if the semaphore s has value 0. If s has value 1, its value is atomically set to 0 and try_acquire s returns true .