Examples with RelRf com.dat3m.dartagnan.wmm.relation.base.memory.RelRf used on opensource projects

Example 1 with RelRf

use of com.dat3m.dartagnan.wmm.relation.base.memory.RelRf in project Dat3M by hernanponcedeleon.

the class PropertyEncoder method encodeLiveness.

public BooleanFormula encodeLiveness(SolverContext ctx) {
    // Further, we assume that the spinloops are indeed correct, i.e., side-effect free
    class SpinLoop {

        public List<Load> loads = new ArrayList<>();

        public Event bound;
    }
    logger.info("Encoding liveness");
    Map<Thread, List<SpinLoop>> spinloopsMap = new HashMap<>();
    // Find spinloops of all threads
    for (Thread t : program.getThreads()) {
        List<Event> spinStarts = t.getEvents().stream().filter(e -> e instanceof Label && e.is(Tag.SPINLOOP)).collect(Collectors.toList());
        List<SpinLoop> spinLoops = new ArrayList<>();
        spinloopsMap.put(t, spinLoops);
        for (Event start : spinStarts) {
            SpinLoop loop = new SpinLoop();
            Event cur = start.getSuccessor();
            while (!cur.is(Tag.SPINLOOP)) {
                if (cur.is(Tag.READ)) {
                    loop.loads.add((Load) cur);
                }
                cur = cur.getSuccessor();
            }
            loop.bound = cur;
            spinLoops.add(loop);
        }
    }
    BooleanFormulaManager bmgr = ctx.getFormulaManager().getBooleanFormulaManager();
    RelRf rf = (RelRf) memoryModel.getRelationRepository().getRelation(RelationNameRepository.RF);
    RelCo co = (RelCo) memoryModel.getRelationRepository().getRelation(RelationNameRepository.CO);
    // Compute "stuckness": A thread is stuck if it reaches a spinloop bound event
    // while reading from a co-maximal write.
    Map<Thread, BooleanFormula> isStuckMap = new HashMap<>();
    for (Thread t : program.getThreads()) {
        List<SpinLoop> loops = spinloopsMap.get(t);
        if (loops.isEmpty()) {
            continue;
        }
        BooleanFormula isStuck = bmgr.makeFalse();
        for (SpinLoop pair : loops) {
            BooleanFormula allCoMaximalLoad = bmgr.makeTrue();
            for (Load load : pair.loads) {
                BooleanFormula coMaximalLoad = bmgr.makeFalse();
                for (Tuple rfEdge : rf.getMaxTupleSet().getBySecond(load)) {
                    coMaximalLoad = bmgr.or(coMaximalLoad, bmgr.and(rf.getSMTVar(rfEdge, ctx), co.getLastCoVar(rfEdge.getFirst(), ctx)));
                }
                allCoMaximalLoad = bmgr.and(allCoMaximalLoad, coMaximalLoad);
            }
            isStuck = bmgr.or(isStuck, bmgr.and(pair.bound.exec(), allCoMaximalLoad));
        }
        isStuckMap.put(t, isStuck);
    }
    // LivenessViolation <=> allStuckOrDone /\ atLeastOneStuck
    BooleanFormula allStuckOrDone = bmgr.makeTrue();
    BooleanFormula atLeastOneStuck = bmgr.makeFalse();
    for (Thread t : program.getThreads()) {
        BooleanFormula isStuck = isStuckMap.getOrDefault(t, bmgr.makeFalse());
        BooleanFormula isDone = t.getCache().getEvents(FilterBasic.get(Tag.BOUND)).stream().map(e -> bmgr.not(e.exec())).reduce(bmgr.makeTrue(), bmgr::and);
        atLeastOneStuck = bmgr.or(atLeastOneStuck, isStuck);
        allStuckOrDone = bmgr.and(allStuckOrDone, bmgr.or(isStuck, isDone));
    }
    // We use the SMT variable to extract from the model if the property was violated
    BooleanFormula enc = bmgr.equivalence(LIVENESS.getSMTVariable(ctx), bmgr.and(allStuckOrDone, atLeastOneStuck));
    return bmgr.and(LIVENESS.getSMTVariable(ctx), enc);
}