Preemptive Task–Safe Mac OS System Software Functions

This appendix lists Mac OS 9 system software calls that you can call directly from a Multiprocessing Services task without using a remote procedure call. Other system software functions are not preemptive task–safe, so you must call them through a callback as described in Making Remote Procedure Calls.

These preemptive task–safe functions cause the calling task to block until the call is completed. However, unlike a remote procedure call, the called function does not have to wait until the calling process receives processor time; it executes asynchronously as if it was an interrupt call.

This appendix contains the following tables of functions::