Re: GtkListStore and Threads problems

[Peter Bloomfield <peterbloomfield bellsouth net>]

On 06/15/2005 10:11:53 AM Wed, Lorena Salinas wrote:
> Here is part of the function...
>
> valid = gtk_tree_model_get_iter_first (GTK_TREE_MODEL
> (my_model),
> &iter);
>
> while (valid) {
>
> gtk_tree_model_get (GTK_TREE_MODEL (my_model), &iter,
>   MYMODEL_COL_STATUS, &status,
> -1);
>
> /* do some long calculations.... */
>
> gdk_threads_enter(); /* get GTK thread lock */
>
> gtk_list_store_set (GTK_LIST_STORE (my_model), &iter,
> MYMODEL_COL_STATUS,STATUS_NORMAL,
> -1);
>
> gdk_threads_leave(); /* release GTK thread lock */
>
> valid = gtk_tree_model_iter_next (GTK_TREE_MODEL (my_model),
> &iter);
>
> }
>
>
> This is the only place where I update the model...
> Is it valid to assume that iter is the same, that it hasn't
> changed?

The iter shouldn't have changed, and if the model isn't changed  
the iter should still be valid.  But your original errors were  
coming from gtk_sequence_* functions, which are called from   
gtk_list_store_iter_next() as well as (possibly)  
gtk_list_store_set(), and you call gtk_list_store_iter_next()  
without holding the lock.

You could organize the loop around a path instead of an iter, and  
then when you really need an iter:
- grab the lock;
- initialize the iter;
- use the iter to get or set;
- drop the lock;
and get on with those really long calculations.

Peter