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 ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
7.5. Static Semantics for Models<br />
A proper EVC implementation always needs exact one initial state. In a gEVCStateMachine<br />
graph this is modelled by the Boolean property IsInitial of the oMode object type. Thus, in a<br />
certain graph exact one oMode object must have this property set to true while all others are<br />
false.<br />
1 context CProject<br />
2 inv : m_GraphSet−>s e l e c t (m_Type = ’ gEVCStateMachine ’ )−>f o r A l l (<br />
3 graph |<br />
4 graph . m_ObjectSet−>s e l e c t (<br />
5 o b j e c t |<br />
6 o b j e c t . m_Type = ’ oMode ’ and o b j e c t . m_Properti<strong>es</strong>−>any (m_Type = ’ I s I n i t i a l ’ ) . m_Value<br />
= ’T ’<br />
7 )−>s i z e ( ) = 1<br />
8 )<br />
Listing 7.4: gEVCStateMachine constraint 3<br />
Furthermore, it must be ensured that all possible transitions from a certain oMode object<br />
have different prioriti<strong>es</strong>. Otherwise, it is not possible to uniquely decide in a concurrent<br />
situation, which transition is going to be used.<br />
1 context CProject<br />
2 inv : m_GraphSet−>s e l e c t (m_Type = ’ gEVCStateMachine ’ )−>f o r A l l (<br />
3 graph |<br />
4 graph . m_ObjectSet−>s e l e c t (m_Type = ’ oMode ’ )−>f o r A l l (<br />
5 mode |<br />
6 graph . m_BindingSet−>s e l e c t ( m_Connection . m_Calls−>e x i s t s ( m_pObject =<br />
mode ) ) . m_pRelationship . m_Properti<strong>es</strong>−>s e l e c t (m_Type =<br />
’ P r i o r i t y ’ )−>isUnique (m_Value)<br />
7 )<br />
8 )<br />
Listing 7.5: gEVCStateMachine constraint 4<br />
7.5.2. gMainFunctionBlock and gSubFunctionBlock<br />
As both graph typ<strong>es</strong> define data flows, the first constraint is that each input port – independent<br />
from its data type – should be connected only with one data flow. Multiple inputs are not<br />
semantically meaningful.<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_PortSet−>f o r A l l (<br />
10 port |<br />
11 graph . m_BindingSet−>s e l e c t ( m_Connection . m_Calls−>e x i s t s (<br />
12 m_pPort = port and m_pRole . m_Type = ’ DataInput ’<br />
13 ) )−>s i z e ( ) = 1<br />
14 )<br />
15 )<br />
16 )<br />
99
Change language