1 Gestalt Constants
   

Gestalt Constants

Before calling any Mac OS system software functions from a preemptive task , you should call the Gestalt function with the gestaltMPCallableAPIsAttr selector set to determine which preemptively safe system calls are allowed.

enum {
    gestaltMPCallableAPIsAttr   = 'mpsc'),
    gestaltMPFileManager        = 0,    
    gestaltMPDeviceManager      = 1 
    };

Constant Descriptions

gestaltMPCallableAPIsAttr
The Gestalt selector passed to determine the availability of preemptive system software functions. The Gestalt function produces a 32-bit value that you should test to determine which what type of preemptive calls are allowed.

gestaltMPFileManager
If this bit is set, you can call the preemptively safe File Manager functions listed in Preemptive Task-Safe Mac OS System Software Functions .

gestaltMPDeviceManager
If this bit is set, you can call the preemptively safe Device Manager functions listed in Preemptive Task-Safe Mac OS System Software Functions .
Note that for functions that are shared between managers (for example, PBCloseSync ), you should check the bit that is appropriate for the manager you want to call.

VERSION NOTES
Introduced with Multiprocessing Services 2.1.
© 1999 Apple Computer, Inc. – (Last Updated 17 Nov 99)