ensure parallel mode works under push/pop

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/math/lp/lp_bound_propagator.cpp

@@ -22,6 +22,9 @@ void lp_bound_propagator::try_add_bound(mpq const& v, unsigned j, bool is_low, b
     if (strict)
         kind = static_cast<lconstraint_kind>(kind / 2);
     
+//    static unsigned s_count = 0, a_count = 0;
+//    ++a_count;
+//    if ((a_count % 100000) == 0) std::cout << s_count << " / " << a_count << "\n";
     if (!bound_is_interesting(j, kind, v))
         return;
      unsigned k; // index to ibounds
@@ -29,10 +32,12 @@ void lp_bound_propagator::try_add_bound(mpq const& v, unsigned j, bool is_low, b
          if (try_get_value(m_improved_lower_bounds, j, k)) {
              auto & found_bound = m_ibounds[k];
              if (v > found_bound.m_bound || (v == found_bound.m_bound && found_bound.m_strict == false && strict)) {
+//                 ++s_count;
                  found_bound = implied_bound(v, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict);
                  TRACE("try_add_bound", m_lar_solver.print_implied_bound(found_bound, tout););
              }
          } else {
+//             ++s_count;
              m_improved_lower_bounds[j] = m_ibounds.size();
              m_ibounds.push_back(implied_bound(v, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict));
              TRACE("try_add_bound", m_lar_solver.print_implied_bound(m_ibounds.back(), tout););
@@ -41,10 +46,12 @@ void lp_bound_propagator::try_add_bound(mpq const& v, unsigned j, bool is_low, b
          if (try_get_value(m_improved_upper_bounds, j, k)) {
              auto & found_bound = m_ibounds[k];
              if (v < found_bound.m_bound || (v == found_bound.m_bound && found_bound.m_strict == false && strict)) {
+//                 ++s_count;
                  found_bound = implied_bound(v, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict);
                  TRACE("try_add_bound", m_lar_solver.print_implied_bound(found_bound, tout););
              }
          } else {
+//             ++s_count;
              m_improved_upper_bounds[j] = m_ibounds.size();
              m_ibounds.push_back(implied_bound(v, j, is_low, coeff_before_j_is_pos, row_or_term_index, strict));
              TRACE("try_add_bound", m_lar_solver.print_implied_bound(m_ibounds.back(), tout););

src/smt/smt_context.cpp

@@ -155,15 +155,16 @@ namespace smt {
         return std::min(m_relevancy_lvl, m_fparams.m_relevancy_lvl);
     }
 
-    void context::copy(context& src_ctx, context& dst_ctx) {
+    void context::copy(context& src_ctx, context& dst_ctx, bool override_base) {
         ast_manager& dst_m = dst_ctx.get_manager();
         ast_manager& src_m = src_ctx.get_manager();
         src_ctx.pop_to_base_lvl();
 
-        if (src_ctx.m_base_lvl > 0) {
+        if (!override_base && src_ctx.m_base_lvl > 0) {
+            INVOKE_DEBUGGER();
             throw default_exception("Cloning contexts within a user-scope is not allowed");
         }
-        SASSERT(src_ctx.m_base_lvl == 0);
+        SASSERT(src_ctx.m_base_lvl == 0 || override_base);
 
         ast_translation tr(src_m, dst_m, false);
 

src/smt/smt_context.h

@@ -1539,7 +1539,7 @@ namespace smt {
         */
         context * mk_fresh(symbol const * l = nullptr,  smt_params * smtp = nullptr, params_ref const & p = params_ref());
 
-        static void copy(context& src, context& dst);
+        static void copy(context& src, context& dst, bool override_base = false);
 
         /**
            \brief Translate context to use new manager m.

src/smt/smt_parallel.cpp

@@ -33,9 +33,9 @@ namespace smt {
         unsigned thread_max_conflicts = ctx.get_fparams().m_threads_max_conflicts;
         unsigned max_conflicts = ctx.get_fparams().m_max_conflicts;
 
-#if 0
+#if 1
-        // TBD: try first sequential with a low conflict budget to make super easy problems cheap
+        // try first sequential with a low conflict budget to make super easy problems cheap
-        ctx.get_fparams().m_max_conflicts = std::min(thread_max_conflicts, 20);
+        ctx.get_fparams().m_max_conflicts = std::min(thread_max_conflicts, 40u);
         result = ctx.check(asms.size(), asms.c_ptr());
         if (result != l_undef || ctx.m_num_conflicts < max_conflicts) {
             return result;
@@ -65,7 +65,7 @@ namespace smt {
             pms.push_back(new_m);
             pctxs.push_back(alloc(context, *new_m, ctx.get_fparams(), ctx.get_params())); 
             context& new_ctx = *pctxs.back();
-            context::copy(ctx, new_ctx);
+            context::copy(ctx, new_ctx, true);
             new_ctx.set_random_seed(i + ctx.get_fparams().m_random_seed);
             ast_translation tr(*new_m, m);
             pasms.push_back(tr(asms));