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/>.

'/

/'### INTRO ##################################################################'/

@startuml

title **µRtWare**\nurtHrtSubscriberUnsubscribe()\n

/'### PARAMETERS & RETURN ####################################################'/

note

  -- **subscriber** : urt_hrtsubscriber_t* --

  The HRT subscriber to be unsubscribed.

  Must not be ""NULL"".

  ====

  -- **return** : urt_status_t --

  Returns ""URT_STATUS_OK"" on sucess.

  Returns ""URT_STATUS_UNSUBSCRIBE_NOTOPIC"" if the subscriber is not associated to a topic.

endnote

/'### PROCEDURE ##############################################################'/

start

if (Associated to a topic?) then (yes)

  :lock topic;

  fork

    :unregister event;

    note

      Must be within lock because of HRT counter.

    endnote

  fork again

    :decrement topic's HRT counter;

  fork again

    #EEEEEE:..//URT_CFG_PUBSUB_PROFILING == true//..\ndecrement counter of subscribers (@topic);

  fork again

    partition "//URT_CFG_PUBSUB_QOS_RATECHECKS == true//" #EEEEEE {

      #EEEEEE:remove self from topic's list of HRT subscribers;

      if (Was the most critical subscriber?) then (yes)

        #EEEEEE:update QoS rate timer (@topic) wrt. most critical HRT subscriber;

      else (no)

      endif

    }

  fork again

    partition "fetch pending messages" {

      :access last read message;

      while (Timestamp of next message is younger?) is (yes)

        :proceed to next message;

        fork

          :decrement message's HRT counter;

        fork again

          #EEEEEE:..//URT_CFG_PUBSUB_PROFILING == true//..\ndecremnt message's consumer counter;

        endfork

      endwhile (no)

      if (The HRT counter of any message became 0?) then (yes)

        :signal topic's condition variable;

      else (no)

      endif

    }

  endfork

  :unlock topic;

  :reset members;

  note

    -- urt_basesubscriber_t --

    * **topic** ← ""NULL""

    * **lastMessage** ← ""NULL""

    * **lastMessageTime** ← 0

  endnote

  stop

  note

    Returns ""URT_STATUS_OK"".

  endnote

else (no)

  stop

  note

    Returns ""URT_STATUS_UNSUBSCRIBE_NOTOPIC"".

  endnote

endif

/'### OUTRO ##################################################################'/

@enduml