From 6f64fa47ccef54748112a4f1910633ffd53f1a79 Mon Sep 17 00:00:00 2001
From: Gabriel Corona <gabriel.corona@loria.fr>
Date: Fri, 1 Apr 2016 11:10:33 +0200
Subject: [PATCH] [mc] Create LivenessChecker::backtrack()

This simplifies its caller and avoids a weird goto.
---
 src/mc/LivenessChecker.cpp | 56 ++++++++++++++++++--------------------
 src/mc/LivenessChecker.hpp |  1 +
 2 files changed, 28 insertions(+), 29 deletions(-)

diff --git a/src/mc/LivenessChecker.cpp b/src/mc/LivenessChecker.cpp
index 2034ebf126..40ad38df1e 100644
--- a/src/mc/LivenessChecker.cpp
+++ b/src/mc/LivenessChecker.cpp
@@ -368,7 +368,10 @@ int LivenessChecker::main(void)
        MC_state_interleave_size(current_pair->graph_state.get()), current_pair->num,
        current_pair->requests);
 
-    if (current_pair->requests > 0) {
+    if (current_pair->requests == 0) {
+      this->backtrack();
+      continue;
+    }
 
       std::shared_ptr<VisitedPair> reached_pair;
       if (current_pair->automaton_state->type == 1 && !current_pair->exploration_started
@@ -389,7 +392,7 @@ int LivenessChecker::main(void)
 
         XBT_DEBUG("Pair already visited (equal to pair %d), exploration on the current path stopped.", visited_num);
         current_pair->requests = 0;
-        goto backtracking;
+        this->backtrack();
 
       }else{
 
@@ -462,33 +465,6 @@ int LivenessChecker::main(void)
 
       } /* End of visited_pair test */
 
-    } else {
-
-    backtracking:
-      if(visited_num == -1)
-        XBT_DEBUG("No more request to execute. Looking for backtracking point.");
-
-      /* Traverse the stack backwards until a pair with a non empty interleave
-         set is found, deleting all the pairs that have it empty in the way. */
-      while (!livenessStack_.empty()) {
-        std::shared_ptr<simgrid::mc::Pair> current_pair = livenessStack_.back();
-        livenessStack_.pop_back();
-        if (current_pair->requests > 0) {
-          /* We found a backtracking point */
-          XBT_DEBUG("Backtracking to depth %d", current_pair->depth);
-          livenessStack_.push_back(std::move(current_pair));
-          this->replay();
-          XBT_DEBUG("Backtracking done");
-          break;
-        }else{
-          XBT_DEBUG("Delete pair %d at depth %d", current_pair->num, current_pair->depth);
-          if (current_pair->automaton_state->type == 1)
-            this->removeAcceptancePair(current_pair->num);
-        }
-      }
-
-    } /* End of if (current_pair->requests > 0) else ... */
-
   }
 
   XBT_INFO("No property violation found.");
@@ -496,6 +472,28 @@ int LivenessChecker::main(void)
   return SIMGRID_MC_EXIT_SUCCESS;
 }
 
+void LivenessChecker::backtrack()
+{
+  /* Traverse the stack backwards until a pair with a non empty interleave
+     set is found, deleting all the pairs that have it empty in the way. */
+  while (!livenessStack_.empty()) {
+    std::shared_ptr<simgrid::mc::Pair> current_pair = livenessStack_.back();
+    livenessStack_.pop_back();
+    if (current_pair->requests > 0) {
+      /* We found a backtracking point */
+      XBT_DEBUG("Backtracking to depth %d", current_pair->depth);
+      livenessStack_.push_back(std::move(current_pair));
+      this->replay();
+      XBT_DEBUG("Backtracking done");
+      break;
+    } else {
+      XBT_DEBUG("Delete pair %d at depth %d", current_pair->num, current_pair->depth);
+      if (current_pair->automaton_state->type == 1)
+        this->removeAcceptancePair(current_pair->num);
+    }
+  }
+}
+
 int LivenessChecker::run()
 {
   XBT_INFO("Check the liveness property %s", _sg_mc_property_file);
diff --git a/src/mc/LivenessChecker.hpp b/src/mc/LivenessChecker.hpp
index b9e1475cce..4906dba685 100644
--- a/src/mc/LivenessChecker.hpp
+++ b/src/mc/LivenessChecker.hpp
@@ -80,6 +80,7 @@ private:
   void replay();
   void removeAcceptancePair(int pair_num);
   void purgeVisitedPairs();
+  void backtrack();
 public:
   std::list<std::shared_ptr<VisitedPair>> acceptancePairs_;
   std::list<std::shared_ptr<Pair>> livenessStack_;
-- 
2.20.1