sls updates

- add SINGLE_THREAD mode
- add interface to retrieve "best" model so far

src/ast/sls/bv_sls.cpp

@@ -61,6 +61,17 @@ namespace bv {
         }
     }
 
+
+    void sls::set_model() {
+        if (!m_set_model)
+            return;
+        if (m_repair_roots.size() >= m_min_repair_size)
+            return;
+        m_min_repair_size = m_repair_roots.size();
+        IF_VERBOSE(2, verbose_stream() << "(sls-update-model :num-unsat " << m_min_repair_size << ")\n");
+        m_set_model(*get_model());
+    }
+
     void sls::init_repair_goal(app* t) {
         m_eval.init_eval(t);
     }
@@ -94,6 +105,9 @@ namespace bv {
         if (m_to_repair.empty())
             return;
 
+        // refresh the best model so far to a callback
+        set_model();
+
         // add fresh units, if any
         bool new_assertion = false;
         while (m_get_unit) {
@@ -130,7 +144,7 @@ namespace bv {
             return m_rand() % 2 == 0;
         };
         m_eval.init_eval(m_terms.assertions(), eval);
-        init_repair();
+        init_repair();        
         // m_engine_init = false;
     }
 
@@ -295,10 +309,12 @@ namespace bv {
         model_ref mdl = alloc(model, m);         
         auto& terms = m_eval.sort_assertions(m_terms.assertions());
         for (expr* e : terms) {
+#if 0
             if (!m_eval.re_eval_is_correct(to_app(e))) {
                 verbose_stream() << "missed evaluation #" << e->get_id() << " " << mk_bounded_pp(e, m) << "\n";
                 m_eval.display_value(verbose_stream(), e) << "\n";
             }
+#endif
             if (!is_uninterp_const(e))
                 continue;
 

src/ast/sls/bv_sls.h

@@ -54,10 +54,13 @@ namespace bv {
         bool                m_engine_model = false;
         bool                m_engine_init = false;
         std::function<expr_ref()> m_get_unit;
+        std::function<void(model& mdl)> m_set_model;
+        unsigned            m_min_repair_size = UINT_MAX;
         
         std::pair<bool, app*> next_to_repair();
         
         void init_repair_goal(app* e);
+        void set_model();
         void try_repair_down(app* e);
         void try_repair_up(app* e);
         void set_repair_down(expr* e) { m_repair_down = e->get_id(); }
@@ -96,6 +99,11 @@ namespace bv {
         */
         void init_unit(std::function<expr_ref()> get_unit) { m_get_unit = get_unit; }
 
+        /**
+        * Add callback to set model
+        */
+        void set_model(std::function<void(model& mdl)> f) { m_set_model = f; }
+
         /**
         * Run (bounded) local search to find feasible assignments.
         */