Re: [PATCH 18/20] dbus: Classic dbus driver->name_acquire and public API.

[Denis Kenzior <denkenz@gmail.com>]

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Hi Andrew,

On 03/13/2016 10:41 PM, Andrew Zaborowski wrote:
> ---
>   ell/dbus.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   ell/dbus.h |  5 ++++
>   2 files changed, 94 insertions(+)

I'd reflow this patch and one preceding it like this:

1. kdbus name_acquire variant
2. dbus1 name acquire variant
3. public API + driver method definitions

>
> diff --git a/ell/dbus.c b/ell/dbus.c
> index c5cc1fc..6c267ae 100644
> --- a/ell/dbus.c
> +++ b/ell/dbus.c
> @@ -822,6 +822,84 @@ static bool classic_get_name_owner(struct l_dbus *bus, const char *name)
>   	return true;
>   }
>
> +struct name_request {
> +	l_dbus_name_acquire_func_t callback;
> +	void *user_data;
> +	struct l_dbus *dbus;
> +};
> +
> +enum dbus_name_flag {
> +	DBUS_NAME_FLAG_ALLOW_REPLACEMENT	= 0x1,
> +	DBUS_NAME_FLAG_REPLACE_EXISTING		= 0x2,
> +	DBUS_NAME_FLAG_DO_NOT_QUEUE		= 0x4,
> +};
> +
> +enum dbus_name_reply {
> +	DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER	= 1,
> +	DBUS_REQUEST_NAME_REPLY_IN_QUEUE	= 2,
> +	DBUS_REQUEST_NAME_REPLY_EXISTS		= 3,
> +	DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER	= 4,
> +};
> +
> +static void request_name_reply_cb(struct l_dbus_message *reply, void *user_data)
> +{
> +	struct name_request *req = user_data;
> +	bool success = false, queued = false;
> +	uint32_t retval;
> +
> +	if (!req->callback)
> +		return;
> +
> +	/* No name owner yet */
> +	if (l_dbus_message_is_error(reply))
> +		goto call_back;
> +
> +	/* Shouldn't happen */
> +	if (!l_dbus_message_get_arguments(reply, "u", &retval))
> +		goto call_back;
> +
> +	success = (retval == DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER) ||
> +		(retval == DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER) ||
> +		(retval == DBUS_REQUEST_NAME_REPLY_IN_QUEUE);
> +	queued = (retval == DBUS_REQUEST_NAME_REPLY_IN_QUEUE);
> +
> +call_back:
> +	req->callback(req->dbus, success, queued, req->user_data);
> +}
> +
> +static uint32_t classic_name_acquire(struct l_dbus *dbus, const char *name,
> +					bool allow_replacement,
> +					bool replace_existing, bool queue,
> +					l_dbus_name_acquire_func_t callback,
> +					void *user_data)
> +{
> +	struct name_request *req;
> +	struct l_dbus_message *message;
> +	uint32_t flags = 0;
> +
> +	req = l_new(struct name_request, 1);
> +	req->dbus = dbus;
> +	req->user_data = user_data;
> +	req->callback = callback;
> +
> +	message = l_dbus_message_new_method_call(dbus, DBUS_SERVICE_DBUS,
> +							DBUS_PATH_DBUS,
> +							L_DBUS_INTERFACE_DBUS,
> +							"RequestName");
> +
> +	if (allow_replacement)
> +		flags |= DBUS_NAME_FLAG_ALLOW_REPLACEMENT;
> +	if (replace_existing)
> +		flags |= DBUS_NAME_FLAG_REPLACE_EXISTING;
> +	if (!queue)
> +		flags |= DBUS_NAME_FLAG_DO_NOT_QUEUE;
> +
> +	l_dbus_message_set_arguments(message, "su", name, flags);
> +
> +	return send_message(dbus, false, message, request_name_reply_cb,
> +				req, free);
> +}
> +
>   static const struct l_dbus_ops classic_ops = {
>   	.version = 1,
>   	.send_message = classic_send_message,
> @@ -833,6 +911,7 @@ static const struct l_dbus_ops classic_ops = {
>   		.remove_match = classic_remove_match,
>   		.get_name_owner = classic_get_name_owner,
>   	},
> +	.name_acquire = classic_name_acquire,
>   };
>
>   static void name_owner_changed_cb(struct l_dbus_message *message,
> @@ -2048,3 +2127,13 @@ LIB_EXPORT bool l_dbus_remove_signal_watch(struct l_dbus *dbus, unsigned int id)
>   {
>   	return _dbus_filter_remove_rule(dbus->filter, id);
>   }
> +
> +LIB_EXPORT uint32_t l_dbus_name_acquire(struct l_dbus *dbus, const char *name,
> +				bool allow_replacement, bool replace_existing,
> +				bool queue, l_dbus_name_acquire_func_t callback,
> +				void *user_data)
> +{
> +	return dbus->driver->name_acquire(dbus, name, allow_replacement,
> +						replace_existing, queue,
> +						callback, user_data);
> +}
> diff --git a/ell/dbus.h b/ell/dbus.h
> index 0b82899..f4b2527 100644
> --- a/ell/dbus.h
> +++ b/ell/dbus.h
> @@ -256,6 +256,11 @@ unsigned int l_dbus_add_signal_watch(struct l_dbus *dbus,
>   					const char *member, ...);
>   bool l_dbus_remove_signal_watch(struct l_dbus *dbus, unsigned int id);
>
> +uint32_t l_dbus_name_acquire(struct l_dbus *dbus, const char *name,
> +				bool allow_replacement, bool replace_existing,
> +				bool queue, l_dbus_name_acquire_func_t callback,
> +				void *user_data);
> +

What's the uint32_t return for?

>   #ifdef __cplusplus
>   }
>   #endif
>