Achieving realtime 1 millisecond accurate events without suffering from thread scheduling

Question

Problem

I am creating a Windows 7 based C# WPF application using .Net 4.5, and one its major features is to <

Answer 1

Which of the 5 options is guaranteed to fix this problem?

This depends on what accuracy your are trying to achieve. If you're aiming for say +/- 1ms, you have a reasonable chance to get it done without points 3) to 5). The combination of points 1) and 2) is the way to go:

• Split your code into time critical parts and less time critical parts (GUI etc.) and put them into separate processes. Let them comunicate by means of decent IPC (pipes, shared memory, and alike).
• Raise the process priority class and the thread priority of the time critical process. Unfortunately, the c# ThreadPriority Enumeration only permits THREAD_PRIORITY_HIGHEST(2) as the maximimum priority. Therefore you'd have to look into the SetThreadPriority function which allows access to THREAD_PRIORITY_TIME_CRITICAL (15). The Process::PriorityClass Property allows to access REALTIME_PRIORITY_CLASS (24). Note: Code running at such priorities will push all other code out of the way. You'd have to make the code with very littly computation and very safe.
• Use the ProcessThread::ProcessorAffinity property to adjust proper core usage. Hint: you may want to keep your time critical threads away from CPU_0 (property value 0x0001) because the Windows kernel prefers this CPU for specific operations. Example: On a platform with 4 logical processors you'd specifiy the ProcessoreAffinity property with 0x000E to exclude CPU_0.
• The systems timer resolution is often set by other applications. Therefore, it is only predictable when you dictate the systems timer resolution. Some applications/drivers even set the timer resolution to 0.5ms. This may be beyond youre setting and can lead to hiccups in you application. See this SO answer on how to set the timer resolution to 0.5ms. (Note: The support of this resolution is platform dependent.)

General remarks: All depends on load. Windows can do pretty well despite the fact that it is not a "realtime OS". However, also realtime systems rely on low load. Nothing is guaranteed, not even on an RT-OS when it is heavily loaded.