Question about deprecated Gdk thread lock functions

[Nicolas Soubeiran <nicolas soubeiran gmail com>]

I have a question on how I can upgrade my code (Gtk+ v.2.18) that uses
the deprecated GDK_THREAD_ENTER/LEAVE API.
In my case I compute pixbuf in separated threads and I have to lock
the GdkPixbuf creation:

/* thread function */
void _compute_pixbuf ( ...)
{
 gchar* pixels;
 GdkPixbuf *pixbuf;
/* actual pixel computation */
 ...
/* when ok build the pixbuf (critical section )*/
GDK_THREAD_ENTER()
pixbuf = gdk_pixbuf_new_from_data(pixels...);
GDK_THREAD_LEAVE();
 /* post computation */
}

If I remove the GDK_THREAD_ENTER/LEAVE pair, my program aborts (memory
fault) in the gdk_pixbuf_new_from_data function.