#vulnerable code 
                                void update(int[] input, int target, float lr) {
        assert (target >= 0);
        assert (target < osz_);
        if (input.length == 0) return;
        computeHidden(input, hidden_);
        if (args_.loss == Args.loss_name.ns) {
            loss_ += negativeSampling(target, lr);
        } else if (args_.loss == Args.loss_name.hs) {
            loss_ += hierarchicalSoftmax(target, lr);
        } else {
            loss_ += softmax(target, lr);
        }
        nexamples_ += 1;

        if (args_.model == Args.model_name.sup) {
            grad_.mul(1.0f / input.length);
        }
        synchronized (this) {
            for (int i : input) {
                wi_.addRow(grad_, i, 1.0f);
            }
        }
    } 
                            #location 5 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                                Model(Matrix wi,
          Matrix wo,
          Args args,
          int seed) {
        hidden_ = new Vector(args.dim);
        output_ = new Vector(wo.m_);
        grad_ = new Vector(args.dim);
        random = new Random(seed);
        wi_ = wi;
        wo_ = wo;
        args_ = args;
        isz_ = wi.m_;
        osz_ = wo.m_;
        hsz_ = args.dim;
        negpos = 0;
        loss_ = 0.0f;
        nexamples_ = 1;
    }