Re: gtk_label_get_text() string duping

[Tim Janik <timj gtk org>]

On 28 Jun 2000, Federico Mena Quintero wrote:

> Tim Janik <timj@gtk.org> writes:
> 
> > i don't hate you, in fact you're right ;)
> > just "const" can be a pain in the ass for C programers as some
> > code const-correct and others don't. those that do will use
> > 
> > const char *my_label = gtk_label_get_text (foo);
> > 
> > and are fine, while those that don't will do:
> > 
> > char *my_label = gtk_label_get_text (foo);
> > 
> > and get a warning if gtk_label_get_text() returns const gchar*.
> 
> Well, in that case it is tough luck for them.  I prefer to provide an
> API that is as self-documenting as possible, and moreover correct,
> than an API that caters to lazy users :-)

jup, that's why i brough up the gtk_label_get_text() duping issue.
however, even owen and me weren't there in the very beginning, and
later we decided we didn't want to convert everything over to return
const gchar*, because in contrast to the s/get/dup/ thingy, that can
not be fixed by a script in third party code.

> > > As Owen pointed out this has issues with threading, but hey, what the
> > > hell :-)
> > 
> > that's a problem only occouring at the glib level and only needs to
> > be solved _there_ ;)
> 
> Say two threads have a pointer to the label.
> 
> 	Thread 1 is scheduled:
> 
> 		const char *s = gtk_label_get_text (label);
> 
> 	Thread 2 is scheduled:
> 
> 		gtk_label_set_text (label, "squawk");
> 
> 	Thread 1 is scheduled:
> 
> 		printf ("%s is not what I think it is\n", s);
> 
> I guess that is the application's problem, anyways, since it is
> futzing with the label on more than one thread.

right, if not, that argument could be made to copy *everything* returned
from accessors and never provide peek variants, since you'll have the
same problem with accessing a container's child from one thread and
removing it from the container in another, i.e.:

	Thread 1 is scheduled:

		GtkWidget *child = GTK_BIN (button)->child;
	
	Thread 2 is scheduled:
	
		gtk_widget_set (button, "label", "squawk", NULL);
	
	Thread 1 is scheduled:
	
		printf ("guess i'll segfault with this: %s\n",
		        gtk_label_get_text (GTK_LABEL (child)));

> 
>   Federico
> 

---
ciaoTJ