# Module Condition

    module Condition: sig .. end

Condition variables to synchronize between threads.

Condition variables are used when one thread wants to wait until another thread has finished doing something: the former thread 'waits' on the condition variable, the latter thread 'signals' the condition when it is done. Condition variables should always be protected by a mutex. The typical use is (if `D` is a shared data structure, `m` its mutex, and `c` is a condition variable):

         Mutex.lock m;
         while (* some predicate P over D is not satisfied *) do
           Condition.wait c m
         done;
         (* Modify D *)
         if (* the predicate P over D is now satified *) then Condition.signal c;
         Mutex.unlock m

    type t

The type of condition variables.

    val create : unit -> t

Return a new condition variable.

    val wait : t -> Mutex.t -> unit

`wait c m` atomically unlocks the mutex `m` and suspends the calling process on the condition variable `c`. The process will restart after the condition variable `c` has been signalled. The mutex `m` is locked again before `wait` returns.

    val signal : t -> unit

`signal c` restarts one of the processes waiting on the condition variable `c`.

    val broadcast : t -> unit

`broadcast c` restarts all processes waiting on the condition variable `c`.