AMiRo-OS

/*

µRtWare is a lightweight publish/subscribe middleware for real-time

applications. It was developed as part of the software habitat for the

Autonomous Mini Robot [1] (AMiRo) but can be used for other purposes as well.

Copyright (C) 2018..2020  Thomas Schöpping et al.

This program is free software: you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation, either version 3 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include <urtware.h>

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/* LOCAL DEFINITIONS                                                          */

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/* EXPORTED VARIABLES                                                         */

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/* LOCAL TYPES                                                                */

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/* LOCAL VARIABLES                                                            */

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/* LOCAL FUNCTIONS                                                            */

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/* EXPORTED FUNCTIONS                                                         */

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/**

 * @brief   Initialize the topic.

 *

 * @param[in] topic  The topic to initialize. Must not be NULL.

 * @param[in] id  Unique, numeric identifier of the topic.

 * @param[in] mandatoryMessage Starting message of the topic. Must not be NULL.

 *

 * @return  Returns URT_STATUS_OK on success.

 *          Returns URT_STATUS_TOPIC_DUPLICATE if another topic with the same identifier already exists.

 */

urt_status_t urtTopicInit(urt_topic_t* topic, urt_topicid_t id, urt_message_t* mandatoryMessage)

{

  urtDebugAssert(topic);

  urtDebugAssert(mandatoryMessage);

  topic->next = NULL;

  topic->id = id;

  urtMutexInit(&topic->lock);

  urtEventSourceInit(&topic->evtSource);

  topic->numHrtSubscribers = 0;

  urtCondvarInit(&topic->hrtReleased);

  topic->mandatoryMessage = *mandatoryMessage;

  topic->latestMessage = &topic->mandatoryMessage;

  #if (URT_CFG_PUBSUB_QOS_RATECHECKS)

    topic->hrtSubscribers = nullptr;

    //add later: timer init;

  #endif /* URT_CFG_PUBSUB_QOS_RATECHECKS */

  #if (URT_CFG_PUBSUB_PROFILING)

    topic->numMessagesPublished = 0;

    topic->numMessagesDiscarded = 0;

    topic->numSubscribers = 0;

  #endif /* URT_CFG_PUBSUB_PROFILING */

  topic->latestMessage->next = topic->latestMessage;

  urtMutexLock(&topic->lock);

  urt_topic_t* topicTemp = topic;

  while (topicTemp != NULL && topicTemp->id < id)

      topicTemp = topicTemp->next;

  if (topicTemp == NULL)

  {

    urtCoreAddTopic(topic);

    urtMutexUnlock(&topic->lock);

    return URT_STATUS_OK;

  }

  else if (topicTemp->id > id)

  {

    topicTemp->next = topic;

    urtMutexUnlock(&topic->lock);

    return URT_STATUS_OK;

  }

  else

  {

    urtMutexUnlock(&topic->lock);

    return URT_STATUS_TOPIC_DUPLICATE;

  }

}