Method enqueue

tests/relacy/relacy/test/main.cpp:47–70

    }

    void enqueue(void* data)
    {
        node_t* n = new node_t;
        n->VAR(next) = 0;
        n->VAR(data) = data;
        bool was_empty = false;

        pthread_mutex_lock(&mtx);
        if (VAR(head) == 0)
        {
            was_empty = true;
            VAR(head) = n;
            VAR(tail) = n;
        }
        else
        {
            VAR(tail)->VAR(next) = n;
            VAR(tail) = n;
        }
        pthread_mutex_unlock(&mtx);

        if (was_empty)
            pthread_cond_broadcast(&cv);
    }

    void* dequeue()
    {