- \ref GRAS_tut_tour_globals_use
- \ref GRAS_tut_tour_callback_pitfall
- \ref GRAS_tut_tour_callback_recap
-
+
<hr>
\section GRAS_tut_tour_globals_intro Introduction
the several instances of your process, leading to bad problems.
Instead, you you have to put all globals in a structure, and let GRAS handle
-it with the gras_userdata_* functions (there is only 3 of them ;).
+it with the gras_userdata_* functions (there is only 3 of them ;).
\section GRAS_tut_tour_globals_use Putting globals into action
We will now modify the example to add a "kill" message, and let the server
loop on incoming messages until it gets such a message. We only need a
-boolean, so the structure is quite simple:
-\don'tinclude 05-globals.c
+boolean, so the structure is quite simple:
+\dontinclude 05-globals.c
\skip struct
\until server_data
-
+
Then, we need to create this structure in the process main function. We
could use either gras_userdata_new() or gras_userdata_set(). The former is an
helper macro mallocing the space needed by the structure and passing it to
gras using the latter function. If you go for gras_userdata_set(), you
should pass it a pointer to your data you want to retrieve afterward.
-\don'tinclude 05-globals.c
+\dontinclude 05-globals.c
\skip userdata_new
\until userdata_new
Once you declared a global that way, retriving this (for example in a
callback) is really easy:
-\don'tinclude 05-globals.c
+\dontinclude 05-globals.c
\skip userdata_get
\until userdata_get
We can now write the callback, which simply retrive the globals and change
the value of the <tt>kileld</tt> field.
-\don'tinclude 05-globals.c
+\dontinclude 05-globals.c
\skip kill_cb
\until end_of_kill_callback
\verbatim int server(int argc, char *argv[]) {
server_data_t globals=gras_user_new(server_data_t);
/* other variable definition */
-
+
gras_init(&argc, argv);
-
+
/* rest of the code */
}\endverbatim
