-- ImagerForkContext.mesa

-- Mik Lamming - July 30, 1986 5:34:19 pm PDT

DIRECTORY Imager;

ImagerForkContext: CEDAR DEFINITIONS

~ BEGIN

Create: PROC [contextA, contextB: Imager.Context] RETURNS [contextAB: Imager.Context] ;

Creates a forking context. Calls on contextAB get passed though to contextA then contextB.

If the call returns a result and both contexts are active at the time of the call then contextB's result is returned. N.B. DoSave Callback Procs are invoked once, not twice!

Activate: PROC [contextAB: Imager.Context, a, b: BOOLEAN] ;

GetContexts: PROC [contextAB: Imager.Context] RETURNS [contextA, contextB: Imager.Context] ;

END.