GetThreadGroupAffinity function (processtopologyapi.h)

Article
02/22/2024

Retrieves the processor group affinity of the specified thread.

Syntax

BOOL GetThreadGroupAffinity(
  [in]  HANDLE          hThread,
  [out] PGROUP_AFFINITY GroupAffinity
);

Parameters

[in] hThread

A handle to the thread for which the processor group affinity is desired.

The handle must have the THREAD_QUERY_INFORMATION or THREAD_QUERY_LIMITED_INFORMATION access right. For more information, see Thread Security and Access Rights.

[out] GroupAffinity

A pointer to a GROUP_AFFINITY structure to receive the group affinity of the thread.

Return value

If the function succeeds, the return value is nonzero.

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

Remarks

Starting with Windows 11 and Windows Server 2022, on a system with more than 64 processors, process and thread affinities span all processors in the system, across all processor groups, by default. The GetThreadGroupAffinity function retrieves the group affinity over the thread's primary group.

To compile an application that uses this function, set _WIN32_WINNT >= 0x0601. For more information, see Using the Windows Headers.

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only]
Minimum supported server	Windows Server 2008 R2 [desktop apps only]
Target Platform	Windows
Header	processtopologyapi.h (include Windows.h)
Library	Kernel32.lib
DLL	Kernel32.dll