lib/cml/core-cml/cvar.sml

   1 (* cvar.sml
   2  * 2004 Matthew Fluet (mfluet@acm.org)
   3  *  Ported to MLton threads.
   4  *)
   5
   6 (* ???
   7  * COPYRIGHT (c) 1995 AT&T Bell Laboratories.
   8  * COPYRIGHT (c) 1989-1991 John H. Reppy
   9  *)
  10
  11 structure CVar : CVAR =
  12    struct
  13       structure R = RepTypes
  14
  15
  16       (* Condition variables are essentially unit valued ivars, and
  17        * are used for various internal synchronization conditions
  18        * (e.g., nack events, I/O synchronization, and thread termination).
  19        *)
  20       datatype cvar = datatype R.cvar
  21       datatype cvar_state = datatype R.cvar_state
  22
  23       fun new () = CVAR (ref (CVAR_unset []))
  24    end