Skip to main content
InitializeProcThreadAttributeList function

Initializes the specified list of attributes for process and thread creation.


BOOL WINAPI InitializeProcThreadAttributeList(
  _Out_opt_  LPPROC_THREAD_ATTRIBUTE_LIST lpAttributeList,
  _In_       DWORD                        dwAttributeCount,
  _Reserved_ DWORD                        dwFlags,
  _Inout_    PSIZE_T                      lpSize


lpAttributeList [out, optional]

The attribute list. This parameter can be NULL to determine the buffer size required to support the specified number of attributes.

dwAttributeCount [in]

The count of attributes to be added to the list.


This parameter is reserved and must be zero.

lpSize [in, out]

If lpAttributeList is not NULL, this parameter specifies the size in bytes of the lpAttributeList buffer on input. On output, this parameter receives the size in bytes of the initialized attribute list.

If lpAttributeList is NULL, this parameter receives the required buffer size in bytes.

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, call GetLastError.


First, call this function with the dwAttributeCount parameter set to the maximum number of attributes you will be using and the lpAttributeList to NULL. The function returns the required buffer size in bytes in the lpSize parameter.

Note  This initial call will return an error by design. This is expected behavior.

Allocate enough space for the data in the lpAttributeList buffer and call the function again to initialize the buffer.

To add attributes to the list, call the UpdateProcThreadAttribute function. To specify these attributes when creating a process, specify EXTENDED_STARTUPINFO_PRESENT in the dwCreationFlag parameter and a STARTUPINFOEX structure in the lpStartupInfo parameter. Note that you can specify the same STARTUPINFOEX structure to multiple child processes.

When you have finished using the list, call the DeleteProcThreadAttributeList function.


Minimum supported client

Windows Vista [desktop apps only]

Minimum supported server

Windows Server 2008 [desktop apps only]


WinBase.h on Windows Vista, Windows 7, Windows Server 2008 and Windows Server 2008 R2 (include Windows.h);
Processthreadsapi.h on Windows 8 and Windows Server 2012





See also

Process and Thread Functions