This is the function type of the callback used for the #GSource returned by g_pollable_input_stream_create_source() and g_pollable_output_stream_create_source().
the #GPollableInputStream or #GPollableOutputStream
This is the function type of the callback used for the #GSource returned by g_pollable_input_stream_create_source() and g_pollable_output_stream_create_source().