27.08.2007 Stepan Potiyenko Verification of Specifications in Modeling Languages using Basic Protocols.

27.08.2007

Stepan Potiyenko

Verification of Specifications in Modeling Languages using Basic Protocols

27.08.20072

Technology overview

Basic Protocols(Hoare triples)

Specialized verification tools (static checking, model checking, …)

manualformalization

Requirements SpecificationsEnglish text

Formal ModelMSC, SDL, UML, ...

automatictranslation

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Agents and Environment

Environment with attributes ab

x

Agent• states• local attributes• behavior

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Basic Protocols

Basic Protocol is a triple

where: x is a list of parameters, – is a precondition, u – process (action), – post condition

)( ux

Forall ms;

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MSC usage

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MSC diagram

alt

loop i=0,i<N

opt

Basic protocols

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alt

loop i=0,i<N

opt

MSC diagram Basic protocols

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alt

loop i=0,i<N

opt

MSC diagram Basic protocols

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alt

loop i=0,i<N

opt

MSC diagram Basic protocols

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Basic Protocols for the MSC diagram

MSC usage

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SDL usage

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SDL in terms of BP

System specification – ENVIRONMENT

Process, functional system component - AGENT

Signals, timers – EVENTS

SDL usage

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system

block 1

e e

n

n

vv II r r o

o

n

n

m

m

e e

nn tt

block 2

block 3

process 2

process 3

process 1

process 4

process 5

Example of structure description of SDL model

Structure linearization

system

process 1(block 1)

process 2(block 1,2)

process 4(block 3)

process 3(block 1,2)

process 5(block 3)

e n v i r o n m e n te n v i r o n m e n t

Linearized structure

SDL usage

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p_1:

state s1;

input i;

p_1_s_1:

task x:=x+y;

p_1_s_2:

task

call prc(x);

p_1_s_3:

nextstate s2;

p_1:

state s2 ...

Control flow label is

agent state expression

state s1;

input i;

task x:=x+y;

task

call prc(x);

nextstate s2;

state s2 ...

s1

i

x := x+y;

call prc(x);

s2

SDL usage Control flow labeling

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task x:=x+y;

p_1_s_2:

task call prc(x);

p_1_s_3:

nextstate s2;

States processing

ProcP(p, p_1 );(ProcP p.state = s1) &get_head(p.queue) = i

ProcP(p, p_1_s_1 );last_signal := i;

SENDER := sender(i);remove_head(p.queue)

ProcP#pp_1:

state s1;

input i;

p_1_s_1:

p_1: state s2; ProcP(p, p_1);(ProcP p.state = s2) &

...

SDL usage

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SDL usage Input and save processing

state s1;

save k;

input i;

...

input j;

...

s1

i jk

ProcP(p, p_1 );(ProcP p.state = s1) &get_head(p.queue) = k

ProcP(p, p_1 );add_tail(p.saved, k);

remove_head(p.queue)

ProcP#p

ProcP(p, p_1 );(ProcP p.state = s1) &

~(get_head(p.queue) = i) &~( … = j) & ~( … = k)

ProcP(p, p_1_s_1 );remove_head(p.queue)

ProcP#pProcP(p, p_1 );

(ProcP p.state = s1) &get_head(p.queue) = i

ProcP(p, p_1_s_1 );last_signal := i;

SENDER := sender(i);remove_head(p.queue);

copy_head(p.queue, p.saved);

ProcP#p

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decision x;

(1): task t1:=1;

(<0): output sig;

enddecision;

...

Decision processing (labeling)

t1 := 1;

x

sig

1 <0

p_1_d_1:

decision x;

(x=1):(task t1:=1;

join p_1_d_2);

(x<0): (output sig;

join p_1_d_2);

enddecision;

p_1_d_2: ...

SDL usage

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Decision processing (BP)

p_1_d_1:

decision x;

(x=1):(task t1:=1;

join p_1_d_2 );

(x<0): (output sig;

join p_1_d_2 );

enddecision;

p_1_d_2: ...

ProcP(p, p_1_d_2 );t1 := 1

ProcP(p, p_1_d_1 );(x = 1)

ProcP#p

ProcP(p, p_1_d_2 );add_tail(T1 P1.queue, sig)

ProcP(p, p_1_d_1 );(x < 0)

ProcP#p

SDL usage

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PROCEDURE fun_name FPAR loc_v;

Local variables declaration

start:

desicion (loc_v)

(1): task u:=1;

(<0): task u:=0;

enddecision;

return;

ENDPROCEDURE;

task t1:=1;

p_7:

task

call fun_name(t1);

p_8:

Procedure calls processingSDL usage

ProcP(p, fun_name );add_head(return_seq, p_8);

loc_v := t1

ProcP(p, p_7 )

ProcP#p

ProcP(p, head(return_seq))

ProcP(p, return )

ProcP#p

ProcP(p, return );[ret values];

[flush loc vars]

return_seq: (ret_control_flow, …, Nil)return_val: (values_set, …, Nil)

stack

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UML usage

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Diagram types and perspectives

Sequence diagrams – analogously to MSC. Architecture diagrams, state chart diagrams –

analogously to SDL system with blocks, processes and state transitions.

Packages and classes structure is linearized (multiplicity, generalization).

UML usage

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Plans

It would be great completely to specify subset of UML notations that are translated to BPSL.

The problem of N instances should be resolved.