urtware / doc / activitydiagrams / subscriber / urtSubscriberSubscribeSrt.uml @ 7491c395
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µRtWare is a lightweight publish/subscribe middleware for real-time |
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applications. It was developed as part of the software habitat for the |
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Autonomous Mini Robot [1] (AMiRo) but can be used for other purposes as well. |
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Copyright (C) 2018..2020 Thomas Schöpping et al. |
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This program is free software: you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation, either version 3 of the License, or |
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(at your option) any later version. |
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|
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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|
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You should have received a copy of the GNU General Public License |
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along with this program. If not, see <http://www.gnu.org/licenses/>. |
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/'### INTRO ##################################################################'/ |
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|
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@startuml |
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title **µRtWare**\nurtSubscriberSrt()\n |
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!include ../../functions.iuml |
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/'### PARAMETERS & START #####################################################'/ |
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|
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start |
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note |
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-- ""**subscriber** : urt_subscriber_t*"" -- |
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The subscriber which shall subscribe to a topic. |
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Must not be ""NULL"". |
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-- ""**topic** : urt_topic_t*"" -- |
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The topic to subscribe to. |
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Must not be ""NULL"". |
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-- ""**messages** : urt_message_t*"" -- |
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List of messages to be contributed to the topic. |
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Those messages must not be associated to another topic. |
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Once a message was contributed, it cannot be removed from the topic anymore. |
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-- ""**usefulnesscb** : urt_srtusefulnessfunc_t*"" -- |
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Pointer to a function to calculate usefulness of a message. |
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Must not be ""NULL"". |
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-- ""**cbparams** : void*"" -- |
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Optional parameters for the usefulness callback. |
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May be ""NULL"" if the callback expects no parameters. |
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end note |
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/'### PROCEDURE ##############################################################'/ |
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|
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if (Is topic already set?) then (yes) |
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:return ""URT_STATUS_ERROR""; |
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else (no) |
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fork |
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:set SRT data; |
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fork again |
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:set topic; |
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endfork |
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:lock topic; |
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fork |
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if (Messages to contribute?) then (yes) |
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partition "contribute messages" { |
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:set next pointer of topic's latest message to first message to contribute; |
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:set next pointer of last message to contribute to the message after the topic's latest message; |
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} |
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else (no) |
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endif |
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fork again |
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:set message pointer to topic's latest message; |
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fork again |
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:register to topic's event source; |
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endfork |
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:unlock topic; |
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:return ""URT_STATUS_OK""; |
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endif |
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/'### STOP & RETURN ##########################################################'/ |
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stop |
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note |
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-- **return** ""urt_status_t"" -- |
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Returns ""URT_STATUS_ERROR"" if the subscriber was already associated to a topic. |
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end note |
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/'### OUTRO ##################################################################'/ |
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|
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@enduml |