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/>.

'/

/' Fetch a message and update/copy all data. '/

!function $fetch_message()

  partition "fetch message" {

    fork

      :update message pointer;

    fork again

        :copy timestamp of message;

    fork again

      :copy message payload;

    fork again

      if (Optional output argument ""latency"" given?) then (yes)

        :set ""latency"" value (now - message origin time);

      else (no)

      endif

    endfork

  }

!endfunction

/' Find the latest message in the circular message buffer. '/

!function $find_latest_message()

  partition "find latest message" {

    :access last read message;

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

      :proceed to next message;

    endwhile (no)

  }

!endfunction

/' Find the oldest message in the circular message buffer. '/

!function $find_oldest_message()

  partition "find oldest valid message" {

    if (Timestamp of last read message euqals local copy?) then (yes)

    else (no)

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

        :proceed to next message;

      endwhile (no)

    endif

    :proceed to next message;

  }

!endfunction