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ofono
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atmodem: Add reference counting to cb_data 

the cb_data can be used by creating the structure with cb_data_new,
and then there are two possibilities:
- use it in a single callback function, and destroy it with a call to
  g_free.
  Example:
  - calling function:
    struct cb_data *cbd = cb_data_new(cb, data);
    if (g_at_chat_send(chat, buf, NULL, at_cgatt_cb, cbd, g_free) > 0)
	return;
    g_free(cbd);
  - called function (here at_cgatt_cb):
	static void at_cgatt_cb(gboolean ok, GAtResult *result,
						gpointer user_data)
	{
		struct cb_data *cbd = user_data;
		ofono_gprs_cb_t cb = cbd->cb;
		struct ofono_error error;

		decode_at_error(&error,
				g_at_result_final_response(result));

		cb(&error, cbd->data);
	}
    note the absence of explicit g_free(cbd);

- pass it through a train of callback functions, adding a reference at
  each pass cb_data_ref, and removing it with cb_data_unref.
  the use of cb_data_ref would replace a new object creation, while the
  use of cb_data_unref the use of g_free.
  Example:
  - calling function:
	struct cb_data *cbd = cb_data_new(cb, data);
	// no cb_ref at the creation
	if (g_at_chat_send(chat, buf, NULL,
				at_lte_set_default_attach_info_cb,
				cbd, cb_data_unref) > 0)
		goto end;
	cb_data_unref(cbd);
  - called function 1 (at_lte_set_default_attach_info_cb):
	static void at_lte_set_default_attach_info_cb(gboolean ok,
				GAtResult *result, gpointer user_data)
	{
		struct cb_data *cbd = user_data;

		cbd = cb_data_ref(cbd);
		if (g_at_chat_send(chat, buf, NULL,
				at_cgatt_cb, cbd, cb_data_unref) > 0)
			return;
		cb_data_unref(cbd);
	}
  - called function 2 (at_cgatt_cb):
    like above. no call to g_free or cb_data_unref. The terminal function
    doesn't need to know about the reference scheme.
This commit is contained in:
Giacinto Cifelli 2018-10-25 07:46:27 +02:00 committed by Denis Kenzior
parent f20da0e7f9
commit eed785a4d7
1 changed files with 18 additions and 0 deletions
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18
drivers/atmodem/atutil.h
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@ -104,6 +104,7 @@ char *at_util_get_cgdcont_command(guint cid, enum ofono_gprs_proto proto,
const char *apn);
struct cb_data {
gint ref_count;
void *cb;
void *data;
void *user;
@ -114,12 +115,29 @@ static inline struct cb_data *cb_data_new(void *cb, void *data)
struct cb_data *ret;
ret = g_new0(struct cb_data, 1);
ret->ref_count = 1;
ret->cb = cb;
ret->data = data;
return ret;
}
static inline struct cb_data *cb_data_ref(struct cb_data *cbd)
{
cbd->ref_count++;
return cbd;
}
static inline void cb_data_unref(gpointer user_data)
{
struct cb_data *cbd = user_data;
if (--cbd->ref_count)
return;
g_free(cbd);
}
static inline int at_util_convert_signal_strength(int strength)
{
int result;