Re: [PATCH v3] bluetooth: Add reference count for bluetooth utils

[Marcel Holtmann <marcel@holtmann.org>]

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Hi Fred,

> diff --git a/plugins/bluetooth.c b/plugins/bluetooth.c
> index 602c6da..8202381 100644
> --- a/plugins/bluetooth.c
> +++ b/plugins/bluetooth.c
> @@ -40,6 +40,7 @@
>  static DBusConnection *connection;
>  static GHashTable *uuid_hash = NULL;
>  static GHashTable *adapter_address_hash = NULL;
> +static gint ref_count;

you need a better name for this. This is too generic. Maybe using
bluetooth_refcount is better.

>  void bluetooth_create_path(const char *dev_addr, const char *adapter_addr,
>  				char *buf, int size)
> @@ -504,12 +505,12 @@ static guint adapter_added_watch;
>  static guint adapter_removed_watch;
>  static guint property_watch;
>  
> -int bluetooth_register_uuid(const char *uuid, struct bluetooth_profile *profile)
> +static int bluetooth_ref(void)
>  {
>  	int err;
>  
> -	if (uuid_hash)
> -		goto done;
> +	if (ref_count > 0)
> +		return 0;

This is pretty much wrong. A reference count can't work this way. You
need to track the number of times this has been taken.

	g_atomic_int_inc(&bluetooth_refcount);

	if (bluetooth_refcount > 1)
		return 0;

In addition, I think the return value is pointless, just make sure to
decrease the reference count in an error case.

> +static void bluetooth_unref(void)
>  {
> -	g_hash_table_remove(uuid_hash, uuid);
> +	gboolean is_zero;
> +
> +	is_zero = g_atomic_int_dec_and_test(&ref_count);
>  
> -	if (g_hash_table_size(uuid_hash))
> +	if (is_zero == FALSE)
>  		return;

I know that we have it like this in GAtChat, but just do the check right
away is fine.

	if (g_atomic_int_dec_and_test(&bluetooth_refcount) == FALSE)
		return;

Regards

Marcel