adding rlimit resource limit facility to provide platform and architecture independent method for canceling activities

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

src/sat/sat_bceq.cpp

@@ -497,7 +497,7 @@ namespace sat {
         flet<unsigned> _bound_maxc(m_solver.m_config.m_max_conflicts, 1500);
 
         use_list     ul;        
-        solver       s(m_solver.m_params, 0);
+        solver       s(m_solver.m_params, m_solver.rlimit(), 0);
         s.m_config.m_bcd            = false;
         s.m_config.m_minimize_core  = false;
         s.m_config.m_optimize_model = false;

src/sat/sat_solver.cpp

@@ -31,8 +31,9 @@ Revision History:
 
 namespace sat {
 
-    solver::solver(params_ref const & p, extension * ext):
+    solver::solver(params_ref const & p, reslimit& l, extension * ext):
         m_cancel(false),
+        m_rlimit(l),
         m_config(p),
         m_ext(ext),
         m_cleaner(*this),

src/sat/sat_solver.h

@@ -38,6 +38,7 @@ Revision History:
 #include"statistics.h"
 #include"stopwatch.h"
 #include"trace.h"
+#include"rlimit.h"
 
 namespace sat {
 
@@ -71,6 +72,7 @@ namespace sat {
         struct abort_solver {};
     protected:
         volatile bool           m_cancel;
+        reslimit&               m_rlimit;
         config                  m_config;
         stats                   m_stats;
         extension *             m_ext;
@@ -145,7 +147,7 @@ namespace sat {
         friend class bceq;
         friend struct mk_stat;
     public:
-        solver(params_ref const & p, extension * ext);
+        solver(params_ref const & p, reslimit& l, extension * ext);
         ~solver();
 
         // -----------------------
@@ -238,6 +240,7 @@ namespace sat {
         clause_offset get_offset(clause const & c) const { return m_cls_allocator.get_offset(&c); }
         void checkpoint() {
             if (m_cancel) throw solver_exception(Z3_CANCELED_MSG);
+            if (!m_rlimit.inc()) { m_cancel = true; throw solver_exception(Z3_CANCELED_MSG); }
             ++m_num_checkpoints;
             if (m_num_checkpoints < 10) return;
             m_num_checkpoints = 0;
@@ -415,6 +418,7 @@ namespace sat {
         void user_push();
         void user_pop(unsigned num_scopes);
         void pop_to_base_level();
+        reslimit& rlimit() { return m_rlimit; }
         // -----------------------
         //
         // Simplification

src/sat/sat_solver/inc_sat_solver.cpp

@@ -63,7 +63,7 @@ class inc_sat_solver : public solver {
     typedef obj_map<expr, sat::literal> dep2asm_t;
 public:
     inc_sat_solver(ast_manager& m, params_ref const& p):
-        m(m), m_solver(p,0), 
+        m(m), m_solver(p, m.limit(), 0), 
         m_params(p), m_optimize_model(false), 
         m_fmls(m), 
         m_asmsf(m),

src/sat/tactic/sat_tactic.cpp

@@ -34,7 +34,7 @@ class sat_tactic : public tactic {
         
         imp(ast_manager & _m, params_ref const & p):
             m(_m),
-            m_solver(p, 0),
+            m_solver(p, m.limit(), 0),
             m_params(p) {
             SASSERT(!m.proofs_enabled());
         }