eRTOS provides several 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 kernel.
- SetProcessAffinityMask sets a processor affinity mask for a 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 same processors as its process. 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 Process kernel 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. A thread must be suspended before you can set its ideal processor.
- RtCreateTimerEx creates a timer associated with the specified clock and returns a handle to the timer. Use this call, instead of RtCreateTimer, if you 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.
The functions above that set and retrieve processor affinity masks (GetProcessAffinityMask, SetProcessAffinityMask, SetThreadAffinityMask, RtCreateTimerEx, RtGetProcessAffinityMask, and RtSetProcessAffinityMask) use bitmasks to represent the mask. See Specifying a Processor Affinity Bitmask below for details.
Note: See the Affinity Masks section of Using the Real-Time API for information on when to use RtGetProcessAffinityMask versus GetProcessAffinityMask.
