Correct connection sequence to maximize chances of e.g.: getting connected :)

[Enrico Mioso]

thank you very very much!! Really.
Enrico



On Thu, 7 May 2020, Aleksander Morgado wrote:

> Date: Thu, 7 May 2020 09:34:46
> From: Aleksander Morgado <aleksander at aleksander.es>
> To: Enrico Mioso <mrkiko.rs at gmail.com>
> Cc: "ModemManager (development)" <modemmanager-devel at lists.freedesktop.org>,
>     marco.perini1993 at gmail.com
> Subject: Re: Correct connection sequence to maximize chances of e.g.: getting
>     connected :)
> 
> Hey!
>
>> Sorry for deleting the quoted text every time, but without doing so, answers may result complicated to read confortably for me.
>>
>> So, in the end I came to the conclusion that using GObjects is probably the best course of cation :)
>>
>> So I am studying the GLib GObjects page for details, and started writing some code to try to understand things better.
>>
>> Goal: implement a GObject who can act as a container for:
>> - MMObjects, MMModem objects, MMModemVoice objects
>> - (long) integers for GSignals handlers and other data.
>> I managed to get my code to compile, but would like some hints / recommendations on how I may proceed.
>>
>
> Ok.
>
>> My header:
>> #ifndef __main_h__
>> #define __main_h__
>>
>> #include <glib-object.h>
>> #include <libmm-glib.h>
>>
>> G_BEGIN_DECLS
>> #define AV_TYPE_MODEM av_modem_get_type()
>> G_DECLARE_DERIVABLE_TYPE(AvModem, av_modem, AV, MODEM, GObject)
>>
>
> In your case, you're probably not going to create subclasses of the
> AvModem object, so you can easier use G_DECLARE_FINAL_TYPE and
> completely avoid the need of having a "private" struct. With final
> types, you can have all your internal data in the AvModem struct
> itself.
>
>
>> struct _AvModemClass {
>>         MMObjectClass parent_class;
>>
>>         /* functions ... */
>
> The functions in the class are only needed if you're going to subclass
> the class, which you're not going to.
>
>>         /* padding with things like
>>         gpointer padding[12];
>>         */
>
> And padding is only required if you're making this class "public", in
> order to leave some safe space to grow the class in the future. You
> can also ignore this.
>
>> };
>>
>> AvModem *av_modem_new(void);
>>
>> G_END_DECLS
>>
>> #endif
>>
>>
>> Source:
>> #include <glib.h>
>> #include <main.h>
>> #include <libmm-glib.h>
>>
>> typedef struct {
>>         gchar *filename;
>> } AvModemPrivate;
>>
>
> As said, if you use a final type you could add the filename variable
> in the AvModem struct itself in the header. The ModemManager sources
> don't do this because these macros were introduced in newer GLib
> versions; we could probably do some porting now that we require newer
> releases as well.
>
>> G_DEFINE_TYPE_WITH_PRIVATE (AvModem, av_modem, G_TYPE_OBJECT)
>>
>> static void av_modem_init(AvModem *self) {
>>         g_print("__FUNCTION__ invoked\n");
>>         AvModemPrivate *priv = av_modem_get_instance_private(self);
>>
>>         /* here we would g_object_new and things */
>>         /* initialize all public and private members to reasonable default values.
>>          * They are all automatically initialized to 0 to begin with. */
>> }
>>
>> static void av_modem_dispose(GObject *gobject) {
>>         g_print("__FUNCTION__ invoked\n");
>>         AvModemPrivate *priv = av_modem_get_instance_private(AV_MODEM(gobject));
>>
>>         /* In dispose(), you are supposed to free all types referenced from this
>>          * object which might themselves hold a reference to self. Generally,
>>          * the most simple solution is to unref all members on which you own a
>>          * reference.
>>          */
>>
>>         /* time to g_object_clear things */
>
> Yes. It's very important that pointers in dispose() are re-set to NULL
> after freeing. E.g. use g_clear_object(), g_clear_pointer() and such.
> This is because dispose may be called multiple times.
>
>>         G_OBJECT_CLASS (av_modem_parent_class)->dispose (gobject);
>> }
>>
>> static void av_modem_finalize(GObject *gobject) {
>>         g_print("__FUNCTION__ invoked\n");
>>         AvModemPrivate *priv = av_modem_get_instance_private(AV_MODEM(gobject));
>>
>>         /* e.g.: g_free for filename */
>
> Finalize is only called once, so no need to re-set pointers to NULL
> after freeing.
>
>>         G_OBJECT_CLASS (av_modem_parent_class)->finalize (gobject);
>> }
>>
>> static void av_modem_class_init(AvModemClass *klass) {
>>         g_print("__FUNCTION__ invoked\n");
>>         GObjectClass *object_class = G_OBJECT_CLASS (klass);
>>         object_class->dispose = av_modem_dispose;
>>         object_class->finalize = av_modem_finalize;
>> }
>>
>>
>>
>> gint main(void) {
>>         return 0;
>> }
>>
>> I see you use various convenience macros in libmm-glib headers, but I am trying to do things step by step to understand them.
>
> The convenience macros are probably older GLib macros. The new macros
> require less amount of them.
>
>> I may have used GBoxed to wrap my own structs instead, but I am trying to do what's better.
>
> You only need GBoxed for your own structs if they're going to be set
> as object properties.
>
>> I absoulutely need refcounting in this scenario. :)
>>
>
> Yes! (which is good)
>
> -- 
> Aleksander
> https://aleksander.es
>