Processor Affinity Functions

RTX provides a number of functions for managing processor affinity for a specific thread or process.

GetProcessAffinityMask retrieves the process affinity mask for the specified process and the system affinity mask for the Real-Time Subsystem.
SetProcessAffinityMask sets a processor affinity mask for specified process.
SetThreadAffinityMask sets a processor affinity mask for the specified thread. A thread affinity mask must be a subset of the process affinity mask for the containing process of a thread. A thread can only run on the processors its process can run on. If you do not specify a processor affinity mask for a thread, the thread will inherit the processor affinity mask from its process. Finally, a thread must be suspended before you can set its affinity.
SetThreadIdealProcessor sets a preferred processor for a thread. The RTSS subsystem always schedules threads on their preferred processor. If you do not specify a preferred processor for a thread, it will run on the lowest-numbered processor in its affinity mask.
RtCreateTimerEx creates a timer associated with the specified clock, and returns a handle to the timer. Use this call, instead of RtCreateTimer, if you are developing for an RTX dedicated system and want to set the processor affinity for the timer handler. If you use RtCreateTimer, the timer handler affinity will default to the affinity of the calling thread.

RtGetProcessAffinityMask allows a Win32 application to get the processor affinity mask for an RTSS process, and also to retrieve the system affinity mask for the Real-Time Subsystem.
RtSetProcessAffinityMask allows a Win32 application to set the processor affinity mask for an RTSS process.

The functions above that set and retrieve processor affinity masks (GetProcessAffinityMask, SetProcessAffinityMask, SetThreadAffinityMask, RtGetProcessAffinityMask, and RtSetProcessAffinityMask) use bitmasks to represent the mask. See Specifying a Processor Affinity Bitmask for details.

NOTE: See the Affinity Masks section of Using the Real-Time API for information on when to use RtGetProcessAffinityMask versus GetProcessAffinityMask.