SetThreadAffinityMask info  Overview  Group

The SetThreadAffinityMask function sets a processor affinity mask for a specified thread.

A thread affinity mask is a bit vector in which each bit represents the processors that a thread is allowed to run on.

A thread affinity mask must be a proper subset of the process affinity mask for the containing process of a thread. A thread is only allowed to run on the processors its process is allowed to run on.

DWORD SetThreadAffinityMask (

HANDLE hThread,	// handle to the thread of interest
DWORD dwThreadAffinityMask	// a thread affinity mask
);

Parameters

hThread

A handle to the thread whose affinity mask the function sets.

Windows NT: This handle must have the THREAD_SET_INFORMATION access right associated with it. For more information, see Thread Objects.

dwThreadAffinityMask

Windows 95: This value must be 1.

Windows NT: Specifies an affinity mask for the thread.

Return Values

If the function succeeds, the return value is nonzero.

Windows 95: The return value is 1. To succeed, hThread must be valid and dwThreadAffinityMask must be 1.

Windows NT: The return value is the thread’s previous affinity mask.

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

See Also

GetProcessAffinityMask, SetThreadIdealProcessor