About gtk_object_set_data()

["chao yeaj" <yeajchao gmail com>]

Hello  everyone

       I have a check button
      and the check button may have an associated data,which is an
source id returned by g_timeout_add()  function
       I do this,because,the check button may be need a function
periodically  changing its attributes

      to manage the   source id returned by g_timeout_add()
      i use gtk_object_set_data() function to set the id to the
object's data filed

       during the check button's life time, i may remove the data
using g_source_remove,and may create the data again  using
g_timeout_add()

       What I am not clear is that: when the check button is
destroying ,how gtk  manage the  data i set to the object?