plucky (3) Semaphore.Counting.3o.gz

NAME

       Semaphore.Counting - no description

Module

       Module   Semaphore.Counting

Documentation

       Module Counting
        : sig end

       type t

       The type of counting semaphores.

       val make : int -> t

       make n returns a new counting semaphore, with initial value n .  The initial value n must be nonnegative.

       Raises Invalid_argument if n < 0

       val release : t -> unit

       release  s  increments  the  value  of  semaphore s .  If other threads are waiting on s , one of them is
       restarted.  If the current value of s is equal to max_int , the value of the semaphore is unchanged and a
       Sys_error exception is raised to signal overflow.

       Raises Sys_error if the value of the semaphore would overflow max_int

       val acquire : t -> unit

       acquire  s  blocks  the  calling  thread  until  the  value  of  semaphore s is not zero, then atomically
       decrements the value of s and returns.

       val try_acquire : t -> bool

       try_acquire s immediately returns false if the value of semaphore s is zero.  Otherwise, the value  of  s
       is atomically decremented and try_acquire s returns true .

       val get_value : t -> int

       get_value  s returns the current value of semaphore s .  The current value can be modified at any time by
       concurrent Semaphore.Counting.release and Semaphore.Counting.acquire operations.   Hence,  the  get_value
       operation is racy, and its result should only be used for debugging or informational messages.