model: change DEBUG() statement to ASSERT()

Now that I've fixed the model-checking bug that produced this error, turn this
error message into a fail-stop ASSERT() statement. This way, I won't ignore a
bug like this in the future!

diff --git a/model.cc b/model.cc
index e3238258a3aa86b0570ff8ed8159eb62e27a899c..76789684df9e641fd4417ff5eccf0116b33f2133 100644 (file)
--- a/model.cc
+++ b/model.cc
@@ -86,8 +86,9 @@ Thread * ModelChecker::schedule_next_thread()
        if (nextThread == THREAD_ID_T_NONE)
                return NULL;
        t = thread_map[id_to_int(nextThread)];
-       if (t == NULL)
-               DEBUG("*** error: thread not in thread_map: id = %d\n", nextThread);
+
+       ASSERT(t != NULL);
+
        return t;
 }