Re: Still confused on new thread starting idle functions to update UI.

[Andrew Potter <agpotter gmail com>]

On Tue, Dec 3, 2013 at 11:02 AM, David Buchan <pdbuchan yahoo com> wrote:
> These darn threads and idle functions still baffle me. I'm sorry to be such a pest.
> I want to periodically update a textview as new information comes available. Sometimes this information can 
> come in quickly (roughly every tenth of a second). Each update is a single line of text.
> The thread allocates memory for the character string, and the idle function does not free it. Instead, the 
> thread free's the memory just before it stops. It waits a bit to make sure the idle function has finished 
> using the memory containing the message.
> This may seem awkward and unnecessary, but if I just use a single character string, it is possible for the 
> thread to replace the contents of the string with the next message while an idle function is still working 
> with the previous message.

Hi David,
I have two solutions.
The first would be to simply pass a strdup() of your message to
g_idle_add() and then free() it in the callback.
If you are concerned about memory fragmentation, another solution
would be to box up a GString with a GMutex. In your thread you would
lock the mutex and append to the string, and then unlock the mutex. In
the callback, lock the mutex, process the string (by which I think you
are just dumping into a GtkTextBuffer), clear the GString, and then
unlock the mutex.

Good luck :)