reachability: sequential reachability for kripkecube

* README, configure.ac, spot/mc/Makefile.am,
spot/mc/reachability.hh: here.

README

@@ -284,6 +284,7 @@ spot/             Sources for libspot.
    kripke/        Kripke Structure interface.
    tl/            Temporal Logic formulas and algorithms.
    misc/          Miscellaneous support files.
+   mc/            All algorithms useful for model checking
    parseaut/      Parser for automata in multiple formats.
    parsetl/       Parser for LTL/PSL formulas.
    priv/          Private algorithms, used internally but not exported.

configure.ac

@@ -234,6 +234,7 @@ AC_CONFIG_FILES([
   spot/ltsmin/Makefile
   spot/Makefile
   spot/misc/Makefile
+  spot/mc/Makefile
   spot/parseaut/Makefile
   spot/parsetl/Makefile
   spot/priv/Makefile

spot/mc/Makefile.am

@@ -0,0 +1,30 @@
+## -*- coding: utf-8 -*-
+## Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Laboratoire
+## de Recherche et Développement de l'Epita (LRDE).
+## Copyright (C) 2003, 2004 Laboratoire d'Informatique de Paris 6 (LIP6),
+## département Systèmes Répartis Coopératifs (SRC), Université Pierre
+## et Marie Curie.
+##
+## This file is part of Spot, a model checking library.
+##
+## Spot is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or
+## (at your option) any later version.
+##
+## Spot is distributed in the hope that it will be useful, but WITHOUT
+## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+## or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+## License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+AM_CPPFLAGS = -I$(top_builddir) -I$(top_srcdir) $(BUDDY_CPPFLAGS)
+AM_CXXFLAGS = $(WARNING_CXXFLAGS)
+
+mcdir = $(pkgincludedir)/mc
+
+mc_HEADERS = reachability.hh
+
+noinst_LTLIBRARIES = libmc.la

spot/mc/reachability.hh

@@ -0,0 +1,117 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2015, 2016 Laboratoire de Recherche et
+// Developpement de l'Epita
+//
+// This file is part of Spot, a model checking library.
+//
+// Spot is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+//
+// Spot is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+// License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include <spot/kripke/kripke.hh>
+
+namespace spot
+{
+  /// \brief This template class provide a sequential reachability
+  /// of a kripkecube. The algorithm uses a single DFS since it
+  /// is the most efficient in a sequential setting
+  template<typename State, typename SuccIterator,
+	   typename StateHash, typename StateEqual,
+	   typename Visitor>
+  class SPOT_API seq_reach_kripke
+  {
+  public:
+    seq_reach_kripke(kripkecube<State, SuccIterator>& sys):
+      sys_(sys)
+    {
+      assert(is_a_kripkecube(sys));
+      visited.reserve(2000000);
+      todo.reserve(100000);
+    }
+
+    ~seq_reach_kripke()
+    {
+      // States will be destroyed by the system, so just clear map
+      visited.clear();
+    }
+
+    Visitor& self()
+    {
+      return static_cast<Visitor&>(*this);
+    }
+
+    void run()
+    {
+      self().setup();
+      State initial = sys_.initial();
+      todo.push_back({initial, sys_.succ(initial)});
+      visited[initial] = ++dfs_number;
+      self().push(initial, dfs_number);
+      while (!todo.empty())
+      	{
+      	  if (todo.back().it->done())
+      	    {
+      	      sys_.recycle(todo.back().it);
+      	      todo.pop_back();
+      	    }
+      	  else
+      	    {
+      	      ++transitions;
+      	      State dst = todo.back().it->state();
+      	      auto it  = visited.insert({dst, dfs_number+1});
+	      if (it.second)
+      		{
+		  ++dfs_number;
+      		  self().push(dst, dfs_number);
+      		  self().edge(visited[todo.back().s], dfs_number);
+      		  todo.back().it->next();
+      		  todo.push_back({dst, sys_.succ(dst)});
+      		}
+      	      else
+      		{
+      		  self().edge(visited[todo.back().s], visited[dst]);
+      		  todo.back().it->next();
+      		}
+      	    }
+      	}
+      self().finalize();
+    }
+
+    unsigned int states()
+    {
+      return dfs_number;
+    }
+
+    unsigned int trans()
+    {
+      return transitions;
+    }
+
+  protected:
+    struct todo_element
+    {
+      State s;
+      SuccIterator* it;
+    };
+    kripkecube<State, SuccIterator>& sys_;
+    std::vector<todo_element> todo;
+    // FIXME: The system already handle a set of visited states so
+    // this map is redundant: an we avoid this new map?
+    typedef std::unordered_map<const State, int,
+    			       StateHash, StateEqual> visited_map;
+    visited_map visited;
+    unsigned int dfs_number = 0;
+    unsigned int transitions = 0;
+  };
+}