osd-contiki/core/net/rime/announcement.h
adamdunkels be846d8c90 A new experimental network primitive called an 'announcement'. An
announcement is an (ID, value) tuple that is disseminated to local
area neighbors. An application or protocol can explicitly listen to
announcements from neighbors. When an announcement is heard, a
callback is invoked.

Announcements can be used for a variety of network mechanisms such as
neighbor discovery, node-level service discovery, or routing metric
dissemination.

Application programs and protocols register announcements with the
announcement module. An announcement back-end, implemented by the
system, takes care of sending out announcements over the radio, as
well as collecting announcements heard from neighbors.
2009-02-05 19:32:01 +00:00

247 lines
8.2 KiB
C

/**
* \addtogroup rime
* @{
*/
/**
* \defgroup rimeannouncement Announcements
* @{
*
* The Announcement primitive does local area announcements. An
* announcement is an (ID, value) tuple that is disseminated to local
* area neighbors. An application or protocol can explicitly listen to
* announcements from neighbors. When an announcement is heard, a
* callback is invoked.
*
* Announcements can be used for a variety of network mechanisms such
* as neighbor discovery, node-level service discovery, or routing
* metric dissemination.
*
* Application programs and protocols register announcements with the
* announcement module. An announcement back-end, implemented by the
* system, takes care of sending out announcements over the radio, as
* well as collecting announcements heard from neighbors.
*
*/
/*
* Copyright (c) 2008, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* $Id: announcement.h,v 1.1 2009/02/05 19:32:01 adamdunkels Exp $
*/
/**
* \file
* Header file for the announcement primitive
* \author
* Adam Dunkels <adam@sics.se>
*/
#ifndef __ANNOUNCEMENT_H__
#define __ANNOUNCEMENT_H__
#include "net/rime/rimeaddr.h"
struct announcement;
typedef void (*announcement_callback_t)(struct announcement *a,
rimeaddr_t *from,
uint16_t id, uint16_t val);
struct announcement {
struct announcement *next;
uint16_t id;
uint16_t value;
announcement_callback_t callback;
};
/**
* \name Application API
* *{
*/
/**
* \brief Register an announcement
* \param a A pointer to a struct announcement
* \param id The identifying number of the announcement
* \param value The initial value of the announcement
* \param callback A pointer to a callback function that is called
* when an announcement is heard
*
* This function registers an announcement with the
* announcement module. The state of the announcement is
* held in a struct announcement variable, which is passed
* as an argument to this function. This variable must be
* allocated by the caller. An announcement is identified
* with a 16-bit number, which is passed as a parameter to
* the function. The announcement also has an initial
* value, that can later be changed with
* announcement_set_value().
*
*/
void announcement_register(struct announcement *a,
uint16_t id, uint16_t value,
announcement_callback_t callback);
/**
* \brief Remove a previously registered announcement
* \param a A pointer to a struct announcement that has
* previously been registered
*
* This function removes an announcement that has
* previously been registered with
* announcement_register().
*
*/
void announcement_remove(struct announcement *a);
/**
* \brief Set the value of an announcement
* \param a A pointer to a struct announcement that has
* previously been registered
*
* This function sets the value of an announcement that
* has previously been registered with
* announcement_register().
*
*/
void announcement_set_value(struct announcement *a, uint16_t value);
/**
* \brief Set the identifier of an announcement
* \param a A pointer to a struct announcement that has
* previously been registered
*
* This function sets the identifier of an announcement
* that has previously been registered with
* announcement_register().
*
*/
void announcement_set_id(struct announcement *a, uint16_t id);
/**
* \brief Listen for announcements for a spefic amount of
* announcement periods
* \param periods The number of periods to listen for announcement
*
* This function starts to listen for announcements for
* the specified amount of announcement periods. This
* function is called to ensure that the announcement
* module hears announcements from neighbors. The
* announcement module may hear announcements even if
* listening is not explicitly enabled, but with listening
* enabled, more announcements will be heard.
*
*/
void announcement_listen(int periods);
/**
* @}
*/
/**
* \name System API
* *{
*/
/**
* \brief Initialize the announcement module
*
* This function initializes the announcement module, and
* is called by the system at boot up.
*/
void announcement_init(void);
/**
* \brief Get the list of registered announcements
* \return The list of registered announcements
*
* This function returns the list of registered
* announcements. This function is used by the back-end to
* compile announcement packets from the registered
* announcements.
*
* The announcement list is an ordinary Contiki list, as
* defined by the \ref list "list module".
*
*/
struct announcement *announcement_list(void);
/**
* \brief Inform the announcement module of an incoming announcement
* \param from The address of the sender of the announcement
* \param id The identifier of the announcement
* \param value The value of the announcement
*
* This function is called by the back-end to inform the
* announcement module that an announcement from a
* neighbor has been heard.
*
*/
void announcement_heard(rimeaddr_t *from, uint16_t id, uint16_t value);
/**
* \brief Register a listen callback with the announcement module
* \param callback A pointer to a callback function
*
* This function is called by the back-end to register a
* listen callback with the announcement module. The
* listen callback function is called by the announcement
* module as part of the announcement_listen() function.
*
*/
void announcement_register_listen_callback(void (*callback)(int time));
/**
* \brief Register an observer callback with the announcement module
* \param observer A pointer to an observer function
*
* This function is callback by the back-end to register
* an observer callback with the announcement module. The
* observer callback is called by the announcement module
* when an announcement is registered, removed, or have
* its identifier or value updated.
*
* The back-end may chose to send out a new announcement
* message with the updated values.
*
*/
void announcement_register_observer_callback(void (*observer)(uint16_t id,
uint16_t value));
/**
* @}
*/
#endif /* __ANNOUNCE_H__ */
/** @} */
/** @} */