Ph.D. - geht es zur Homepage der Informatik des Fachbereiches 3 ...
Ph.D. - geht es zur Homepage der Informatik des Fachbereiches 3 ...
Ph.D. - geht es zur Homepage der Informatik des Fachbereiches 3 ...
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Chapter 7. openETCS Meta Model<br />
Listing 7.6: gFunctionBlock constraint 1<br />
The OCL closure [63, pp. 30-31] statement (lin<strong>es</strong> 4 to 7) is not only used to check this constraint<br />
for each graph instance separately but also to include gSubFunctionBlock graphs referenced by<br />
oSubFunction object decompositions. In other words, if an input port is already connected in a<br />
gMainFunctionBlock graph and also in a gSubFunctionBlock graph included by a oSubFunction<br />
object, this constraints fails. Due to the easy usage of this complex operation, the closure<br />
statement is also used for further constraints.<br />
Because oVariableStorage objects do not have any input ports, an additional constraint for<br />
their input count must be defined.<br />
1 context CProject<br />
2 inv : m_GraphSet−>s e l e c t (m_Type = ’ gMainFunctionBlock ’ or m_Type =<br />
’ gSubFunctionBlock ’ )−>f o r A l l (<br />
3 graph |<br />
4 graph . m_ObjectSet−>s e l e c t (m_Type = ’ oSubFunction ’ ) . m_pDecomposition−>c l o s u r e (<br />
5 subgraph |<br />
6 subgraph . m_ObjectSet−>s e l e c t (m_Type = ’ oSubFunction ’ ) . m_pDecomposition<br />
7 )−>i n c l u d i n g ( graph )−>f o r A l l (<br />
8 graph |<br />
9 graph . m_ObjectSet−>s e l e c t (m_Type = ’ o V a r i a b l e S t o r a g e ’ )−>f o r A l l (<br />
10 o b j e c t |<br />
11 graph . m_BindingSet−>s e l e c t ( m_Connection . m_Calls−>e x i s t s (<br />
12 m_pObject = o b j e c t and m_pRole . m_Type = ’ DataInput ’<br />
13 ) )−>s i z e ( ) = 1<br />
14 )<br />
15 )<br />
16 )<br />
Listing 7.7: gFunctionBlock constraint 2<br />
Regarding the inclusion of gSubFunctionBlock graphs, it is important that a model instance<br />
do<strong>es</strong> not hold a recursive inclusion of gSubFunctionBlock graphs by oSubFunction objects.<br />
Recursive inclusion means that a parent graph which includ<strong>es</strong> a child graph by an oSubFunction<br />
object is also included in the child graph repr<strong>es</strong>entation – or any other further child graph – by<br />
another oSubFunction object.<br />
1 context CProject<br />
2 inv : m_GraphSet−>s e l e c t (m_Type = ’ gMainFunctionBlock ’ or m_Type =<br />
’ gSubFunctionBlock ’ )−>f o r A l l (<br />
3 graph |<br />
4 l e t s u b o b j e c t s : Collection (GOPPRR: : CObject ) =<br />
5 graph . m_ObjectSet−>s e l e c t (m_Type = ’ oSubFunction ’ ) . m_pDecomposition−>c l o s u r e (<br />
6 subgraph |<br />
7 subgraph . m_ObjectSet−>s e l e c t (m_Type = ’ oSubFunction ’ ) . m_pDecomposition<br />
8 )−>i n c l u d i n g ( graph ) . m_ObjectSet−>f l a t t e n ( )−>s e l e c t (m_Type = ’ oSubFunction ’ )<br />
9 i n<br />
10 s u b o b j e c t s −>s i z e ( ) = s u b o b j e c t s −>a s S e t ( )−>s i z e ( )<br />
11 )<br />
Listing 7.8: gFunctionBlock constraint 3<br />
The constraint that each instance of oSubFunction must have a decomposition is not extremely<br />
nec<strong>es</strong>sary, but it is defined to ensure model correctn<strong>es</strong>s.<br />
100
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