SetThreadIdealProcessor

The SetThreadIdealProcessor function sets a preferred processor for a thread. The system schedules threads on their preferred processors whenever possible.

DWORD SetThreadIdealProcessor(
  HANDLE hThread,         // handle to the thread
  DWORD dwIdealProcessor  // ideal processor number
);

Parameters

hThread

[in] Handle to the thread whose preferred processor is to be set. The handle must have the THREAD_SET_INFORMATION access right associated with it. For more information, see Thread Security and Access Rights.

dwIdealProcessor

[in] Specifies the number of the preferred processor for the thread. A value of MAXIMUM_PROCESSORS tells the system that the thread has no preferred processor.

Return Values

If the function succeeds, the return value is the previous preferred processor or MAXIMUM_PROCESSORS if the thread does not have a preferred processor.

If the function fails, the return value is – 1. To get extended error information, call GetLastError.

Remarks

You can use the GetSystemInfo function to determine the number of processors on the computer. You can also use the GetProcessAffinityMask function to check the processors on which the thread is allowed to run. Note that GetProcessAffinityMask returns a bit mask whereas SetThreadIdealProcessor uses an integer value to represent the processor.

Requirements

  Windows NT/2000: Requires Windows NT 4.0 or later.
  Windows 95/98: Unsupported.
  Header: Declared in Winbase.h; include Windows.h.
  Library: Use Kernel32.lib.

See Also

Processes and Threads Overview, Process and Thread Functions, GetProcessAffinityMask, GetSystemInfo, OpenThread, SetThreadAffinityMask