2. Model-based Specification:
Concurrent Append Problem
class Cell {
Cell next;
int val;
void append(int x) {
if (x == this.val)
return;
if (this.next == null) {
this.next = new Cell ();
this.next.val = x;
} else
this.next.append(x);
}
}
Adapted from
[Rensink et al., ICGT 2004]
0 append(1) 0 1
0 append(1); append(2) 0 1 2
0 append(1) || append(1) 0 1
0 append(1) || append(2)
0 1 2
0 2 1
or
MODEL REPRESENTATION
0 append(0) 0
given when then
SCENARIOS
PROPERTIES
1. Uniqueness (no sharing)
2. Caller and callee cannot
have the value at the same
time (isolation)
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool
4. ATL Execution Modes
• Out-place MT
• Normal mode (batch)
• Incremental mode
• Incremental ATL: live trafo, forward propagation [Tisi10]
• ReactiveATL: live trafo, reacts to external events, lazy [Martínez17]
• In-place MT:
• Refining mode ATL2006: copy strategy
• Refining mode ATL2010 [Tisi11]:
• Generate updates
• Reorder them to preserve ATL properties
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool
5. Problem Model: EMF and ATL (refining)
DATA MODEL
REPRESENTATION
BEHAVIOUR MODEL
REPRESENTATION
Append Next
Found Return
rule Append {
from
a1 : append!Append (
a1.active and
a1.this.next. oclIsUndefined () and
a1.this.val <> a1.x
)
to
a1__ref : append!Append (
return <- true ,
x <- ’’
),
c2 : append!Cell (
val <- a1.x,
previous <- a1.this
)
}
matched rules source pattern element
filter condition
target
pattern
element
binding expression: OCL
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool
6. Drawbacks of ATL (refining)
Append(1);
Append(2)
rule Append {
from
a1 : append!Append (
a1.active and
a1.this.next. oclIsUndefined () and
a1.this.val <> a1.x
)
to
a1__ref : append!Append (
return <- true ,
x <- ’’
),
incorrect
incomplete
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool
8. ATL as System Specification Language
• Append
rule Append {
from a1 : append!Append (
a1.active and a1.this.val <> a1.x
and a1.this.next. oclIsUndefined ()
) using {
c1 : append!Cell = a1.this;
} to a1__ref : append!Append (
x <- ’’,
active <- false ,
return <- true
),
c2 : append!Cell (
val <- a1.x
),
c1__ref : append!Cell (
next <- c2
)
}
Append(2)
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool
Several source
elements
update
9. ATL as System Spec. Language
• Next
rule Next {
from a1 : append!Append (
a1.active=true and a1.x <> a1.this.val
and a1.callee. oclIsUndefined ()
) using {
c : append!Cell = a1.this.next;
} to a1__ref : append!Append (
active <- false ,
x <- ’’,
callee <- a2
),
a2 : append!Append (
active <- true ,
x <- a1.x,
this <- c
)
}
Next(1)
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool
10. ATL as System Spec.
• Found
rule Found {
from a1 : append!Append (
a1.active and a1.x = a1.this.val
) to a1__ref : append!Append (
x <- ’’,
active <- false ,
return <- true
)
} Found(5)
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool
11. ATL as System Spec.
• Return
rule Return {
from a1 : append!Append (
a1.return = true and
not(a1.caller. oclIsUndefined ())
and a1.callee. oclIsUndefined ()
) using {
caller : append!Append = a1.caller;
} to caller__ref : append!Append (
return <- true ,
callee__unset <- a1
)
}
Return(5)
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool
removing reference
12. FMA-ATL: Scheduling
• FMA-ATL [Boronat17]: out-place ATL trafos
• Scheduler for rules: matching up-front
• Interpreter for rule actions, based on FMA
• Maude implementation
• Main modification:
traceGlobal = TG1
traceLocal = TL1
ruleStore = RS
helperStore = HS
matchPool = MP1
domains = DS1
rtClasses = RTC
mode = in-place
3 : AtlMatchingConfig
traceGlobal = TG2
traceLocal = TL2
ruleStore = RS
helperStore = HS
matchPool = MP2
domains = DS2
rtClasses = RTC
3 : AtlMatchingConfig
traceGlobal = TG1
traceLocal = TL1
ruleStore = RS
helperStore = HS
domains = DS1
rtClasses = RTC
: AtlConfig
rule = RN
match = V |-> O
: Match
match
model = OS1
loc = LOC1
1 : Domain
queryDomain
traceGlobal = TG2
traceLocal = TL2
domains = DS2
: AtlFinalConfig
E-Schedule-InPlace
+ATL
)
when IS=evalOcl( CT . allInstances() -> select( V | FC ) -> asSequence(), OS1, LOC1) / O in IS /
name = RN
var = V
varType = C
filter = FC
2 : AtlRule
ruleStore
name = DN1
model = OS1
loc = LOC1
1 : Domain
domains
name = DN1
model = OS1
loc = LOC1
2 : Domain
domains
name = RN
var = V
varType = C
filter = FC
2 : AtlRule
ruleStore
traceGlobal : Map<Tuple(source:Oid,var:ValExpr),Tuple(rule:ValExpr,target:Oid)>
traceLocal : Map<Tuple(source:Oid,var:ValExpr),Tuple(rule:ValExpr,target:Oid)>
rtClasses: String [0..*] {set}
mode : AtlMode
stmt : FmaStmt
AtlMatchingConfigAtlMatchingFinal
Config
self.matchPool.isEmpty()
AtlConfig
AtlFinalConfig
self.match.oclIsUndefined()
atlStmt : AtlStmt
rule : ValueExpr
match : Map<VarExpr,ValueExpr>
Match
*matchPool match0..1
AtlDomainConfig
AtlDomainFinalConfig
self.actions.isEmpty()
name : VarExpr
new : Map<QualifiedCid,Oid>
model : ObjectSet
loc : Map<Oid,Location>*
domains
Env
1
env
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool
13. Verification
Append(2) Next(1) Found(5) Return(5)
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool
• Model transformation as simulation
• Verification
• Branching structure is generated by Maude
• Two techniques
• model checking of LTL properties, assuming a finite state space
• (bounded) model checking of state properties (invariants)
![Model-based Specification:
Concurrent Append Problem
class Cell {
Cell next;
int val;
void append(int x) {
if (x == this.val)
return;
if (this.next == null) {
this.next = new Cell ();
this.next.val = x;
} else
this.next.append(x);
}
}
Adapted from
[Rensink et al., ICGT 2004]
0 append(1) 0 1
0 append(1); append(2) 0 1 2
0 append(1) || append(1) 0 1
0 append(1) || append(2)
0 1 2
0 2 1
or
MODEL REPRESENTATION
0 append(0) 0
given when then
SCENARIOS
PROPERTIES
1. Uniqueness (no sharing)
2. Caller and callee cannot
have the value at the same
time (isolation)
Problem
Current
Possibilities
System
spec
Property
Spec DiscussionTool](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)