urtware / doc / activitydiagrams / subscriber / hrtsubscriber / urtHrtSubscriberFetchLatestMessage.uml @ dd31cb03
History | View | Annotate | Download (4.25 KB)
1 | dd31cb03 | Thomas Schöpping | /' |
---|---|---|---|
2 | µRtWare is a lightweight publish/subscribe middleware for real-time |
||
3 | applications. It was developed as part of the software habitat for the |
||
4 | Autonomous Mini Robot [1] (AMiRo) but can be used for other purposes as well. |
||
5 | |||
6 | Copyright (C) 2018..2020 Thomas Schöpping et al. |
||
7 | |||
8 | This program is free software: you can redistribute it and/or modify |
||
9 | it under the terms of the GNU General Public License as published by |
||
10 | the Free Software Foundation, either version 3 of the License, or |
||
11 | (at your option) any later version. |
||
12 | |||
13 | This program is distributed in the hope that it will be useful, |
||
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
||
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
||
16 | GNU General Public License for more details. |
||
17 | |||
18 | You should have received a copy of the GNU General Public License |
||
19 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
||
20 | '/ |
||
21 | |||
22 | /'### INTRO ##################################################################'/ |
||
23 | |||
24 | @startuml |
||
25 | |||
26 | title **µRtWare**\nurtHrtSubscriberFetchLatestMessage()\n |
||
27 | |||
28 | !include ../functions.iuml |
||
29 | |||
30 | /'### PARAMETERS & RETURN ####################################################'/ |
||
31 | |||
32 | note |
||
33 | -- **subscriber** : urt_hrtsubscriber_t* -- |
||
34 | The HRT subscriber that shall fetch the message. |
||
35 | Must not be ""NULL"". |
||
36 | -- **payload** : void* -- |
||
37 | Pointer where to copy the payload to. |
||
38 | May be ""NULL"" for messages without payload. |
||
39 | -- **bytes** : size_t -- |
||
40 | Payload size in bytes. |
||
41 | -- **latency** : urt_delay_t* -- |
||
42 | The latency can be returned by reference. |
||
43 | May be ""NULL"". |
||
44 | ==== |
||
45 | -- **return** : urt_status_t -- |
||
46 | Returns ""URT_STATUS_OK"" on success. |
||
47 | Returns ""URT_STATUS_FETCH_NOTOPIC"" if the subscriber is not associated to a topic. |
||
48 | Retruns ""URT_STATUS_FETCH_NOMESSAGE"" if there is no new message to fetch. |
||
49 | Returns ""URT_STATUS_JITTERVIOLATION"" if the message's latency violated the maximum expected jitter. |
||
50 | endnote |
||
51 | |||
52 | /'### PROCEDURE ##############################################################'/ |
||
53 | |||
54 | start |
||
55 | if (Associated to a topic?) then (yes) |
||
56 | :lock topic; |
||
57 | partition "find latest message" { |
||
58 | :access ""lastMessage""; |
||
59 | while (Timestamp of next message is younger?) is (yes) |
||
60 | fork |
||
61 | :proceed to next message; |
||
62 | fork |
||
63 | :decrement message's counter of HRT consumers; |
||
64 | fork again |
||
65 | #EEEEEE:..//URT_CFG_PUBSUB_PROFILING == true//..\ndecrement message's counter of consumers; |
||
66 | fork again |
||
67 | #EEEEEE:..//URT_CFG_PUBSUB_QOS_DEADLINECHECKS == true//..\nreset QoS deadline timer; |
||
68 | endfork |
||
69 | fork again |
||
70 | #EEEEEE:..//URT_CFG:PUBSUB_PROFILING == true//..\nincrement counter of received messages; |
||
71 | endfork |
||
72 | if (HRT counter of a message became 0?) then (yes) |
||
73 | :signal topic's condition variable; |
||
74 | else (no) |
||
75 | endif |
||
76 | endwhile (no) |
||
77 | } |
||
78 | if (Timestamp equals local copy?) then (yes) |
||
79 | :unlock topic; |
||
80 | stop |
||
81 | note |
||
82 | Returns ""URT_STATUS_FETCH_NOMESSAGE"". |
||
83 | endnote |
||
84 | else (no) |
||
85 | :calculate message latency; |
||
86 | fork |
||
87 | #EEEEEE:..//URT:CFG_PUBSUB_PROFILING == true//..\naccumulate ""sumLatencies"" value; |
||
88 | fork again |
||
89 | if (Optional ""latency"" output argument given?) then (yes) |
||
90 | :set ""latency"" value; |
||
91 | else (no) |
||
92 | endif |
||
93 | endfork |
||
94 | endif |
||
95 | partition "//URT_CFG_PUBSUB_QOS_JITTERCHECKS == true || URT_CFG_PUBSUB_PROFILING == true//" #EEEEEE { |
||
96 | if (Latency is within allowed jitter range?) then (yes) |
||
97 | if (Latency is lower than ""minlatency""?) then (yes) |
||
98 | #EEEEEE:update ""minLatency"" value; |
||
99 | elseif (Latency is greater than ""maxLatency"" value?) then (yes) |
||
100 | #EEEEEE:update ""maxLatency"" value; |
||
101 | else (no) |
||
102 | endif |
||
103 | else (no) |
||
104 | partition "//URT_CFG_PUBSUB_QOS_JITTERCHECKS == true//" #EEEEEE { |
||
105 | #EEEEEE:unlock topic; |
||
106 | #EEEEEE:call ""urtCoreStopNodes(URT_STATUS_JITTERVIOLATION)""; |
||
107 | stop |
||
108 | note |
||
109 | Returns ""URT_STATUS_JITTERVIOLATION"". |
||
110 | endnote |
||
111 | } |
||
112 | endif |
||
113 | } |
||
114 | fork |
||
115 | $fetch_message() |
||
116 | fork again |
||
117 | #EEEEEE:..//URT_CFG_PUBSUB_QOS_DEADLINECHECKS == true//..\nreset QoS deadline timer; |
||
118 | endfork |
||
119 | :unlock topic; |
||
120 | stop |
||
121 | note |
||
122 | Returns ""URT_STATUS_OK"". |
||
123 | endnote |
||
124 | else (no) |
||
125 | stop |
||
126 | note |
||
127 | Returns ""URT_STATUS_ERROR"". |
||
128 | endnote |
||
129 | endif |
||
130 | |||
131 | /'### OUTRO ##################################################################'/ |
||
132 | |||
133 | @enduml |