Stepan Potiyenko Verification of Specifications in Modeling Languages using Basic Protocols

Technology overview Basic Protocols (Hoare triples) Specialized verification tools (static checking, model checking, …) manual formalization Requirements Specifications English text Formal Model MSC, SDL, UML,... automatic translation

Agents and Environment Environment with attributes a b x Agent states local attributes behavior

Basic Protocols Basic Protocol is a triple where: x is a list of parameters,  – is a precondition, u – process (action),  – post condition Forall ms;

MSC usage

MSC diagram alt loop i=0,i<N opt Basic protocols

alt loop i=0,i<N opt MSC diagram Basic protocols

alt loop i=0,i<N opt MSC diagram Basic protocols

alt loop i=0,i<N opt MSC diagram Basic protocols

Basic Protocols for the MSC diagram MSC usage

SDL usage

SDL in terms of BP System specification – ENVIRONMENT Process, functional system component - AGENT Signals, timers – EVENTS SDL usage

system block 1 envenv I I ronmen ronmen t tenvenv I I ronmen ronmen t t I t 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 t Linearized structure SDL usage

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

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#p p_1: state s1; input i; p_1_s_1: p_1: state s2; ProcP(p, p_1); (ProcP p.state = s2) &... SDL usage

SDL usage Input and save processing state s1; save k; input i;... input j;... s1 ij k 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#p 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); copy_head(p.queue, p.saved); ProcP#p

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

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

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 processing SDL 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

UML usage

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

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.