I have a question about the paramether of GetPriorityClass Function (and [in] attribute)

The GetPriorityClass function in Windows retrieves the priority class of a specified process. The function has the following signature:

cppCopy code
DWORD WINAPI GetPriorityClass(

  _In_ HANDLE hProcess

);

The parameter hProcess is of type HANDLE and represents a handle to the process for which you want to retrieve the priority class.

In the function signature, the _In_ attribute is used as a form of Hungarian notation to indicate that the parameter is an input parameter. The _In_ attribute is not required and does not affect the functionality of the function. It is commonly used in Windows API documentation to provide additional information about the parameter.

In the case of GetPriorityClass, the _In_ attribute indicates that the hProcess parameter is used as an input to the function to specify the process handle for which you want to retrieve the priority class.

To use the GetPriorityClass function, you need to provide a valid process handle as the hProcess parameter. This handle can be obtained using functions such as OpenProcess or GetCurrentProcess. After calling GetPriorityClass, it returns the priority class of the specified process, which you can then use in your application as needed.

Keep in mind that when working with process handles and priority classes, you need to handle errors and validate the returned values appropriately to ensure your program operates correctly.