From: mlaurent <mathieu.laurent@ens-rennes.fr>
Date: Fri, 10 Feb 2023 17:51:01 +0000 (+0100)
Subject: Fix for MC DPOR algorithm
X-Git-Tag: v3.34~436^2~18
X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/75e982c8df081076c4d1c40e94552c4159b46feb

Fix for MC DPOR algorithm
---

diff --git a/src/mc/api/State.cpp b/src/mc/api/State.cpp
index 66f7868985..eb193df584 100644
--- a/src/mc/api/State.cpp
+++ b/src/mc/api/State.cpp
@@ -30,6 +30,16 @@ std::size_t State::count_todo() const
   return boost::range::count_if(this->actors_to_run_, [](auto& pair) { return pair.second.is_todo(); });
 }
 
+    void State::mark_all_todo() 
+{
+    for (auto & [aid, actor] : actors_to_run_) {
+
+	if (actor.is_enabled() and not actor.is_done() and not actor.is_todo())
+	    actor.mark_todo();
+	
+    }
+}
+    
 Transition* State::get_transition() const
 {
   return transition_.get();
@@ -40,8 +50,18 @@ aid_t State::next_transition() const
   XBT_DEBUG("Search for an actor to run. %zu actors to consider", actors_to_run_.size());
   for (auto const& [aid, actor] : actors_to_run_) {
     /* Only consider actors (1) marked as interleaving by the checker and (2) currently enabled in the application */
-    if (not actor.is_todo() || not actor.is_enabled())
-      continue;
+      if (not actor.is_todo() || not actor.is_enabled()) {
+
+	  if (not actor.is_todo())
+	      XBT_DEBUG("Can't run actor %ld because it is not todo", aid); 
+
+	  if (not actor.is_enabled())
+	      XBT_DEBUG("Can't run actor %ld because it is not enabled", aid);
+
+	  continue;
+
+
+      }
 
     return aid;
   }
diff --git a/src/mc/api/State.hpp b/src/mc/api/State.hpp
index b6da4d53c1..03b482dd36 100644
--- a/src/mc/api/State.hpp
+++ b/src/mc/api/State.hpp
@@ -41,6 +41,8 @@ public:
   long get_num() const { return num_; }
   std::size_t count_todo() const;
   void mark_todo(aid_t actor) { actors_to_run_.at(actor).mark_todo(); }
+  void set_done(aid_t actor) {actors_to_run_.at(actor).set_done();}
+  void mark_all_todo(); 
   bool is_done(aid_t actor) const { return actors_to_run_.at(actor).is_done(); }
   Transition* get_transition() const;
   void set_transition(Transition* t) { transition_.reset(t); }
diff --git a/src/mc/explo/DFSExplorer.cpp b/src/mc/explo/DFSExplorer.cpp
index 57b2202482..f1fa21bfeb 100644
--- a/src/mc/explo/DFSExplorer.cpp
+++ b/src/mc/explo/DFSExplorer.cpp
@@ -131,12 +131,15 @@ void DFSExplorer::run()
     if (next < 0) { // If there is no more transition in the current state, backtrack.
       XBT_DEBUG("There remains %lu actors, but none to interleave (depth %zu).", state->get_actor_count(),
                 stack_.size() + 1);
-
+      
       if (state->get_actor_count() == 0) {
         mc_model_checker->finalize_app();
         XBT_VERB("Execution came to an end at %s (state: %ld, depth: %zu)", get_record_trace().to_string().c_str(),
                  state->get_num(), stack_.size());
+	stack_.pop_back();
+
       }
+      
       this->backtrack();
       continue;
     }
@@ -191,7 +194,6 @@ void DFSExplorer::backtrack()
   backtrack_count_++;
   XBT_VERB("Backtracking from %s", get_record_trace().to_string().c_str());
   on_backtracking_signal(get_remote_app());
-  stack_.pop_back();
 
   get_remote_app().check_deadlock();
 
@@ -203,6 +205,7 @@ void DFSExplorer::backtrack()
   while (not stack_.empty() && not found_backtracking_point) {
     std::unique_ptr<State> state = std::move(stack_.back());
     stack_.pop_back();
+    state->set_done(state->get_transition()->aid_);
     if (reduction_mode_ == ReductionMode::dpor) {
       aid_t issuer_id = state->get_transition()->aid_;
       for (auto i = stack_.rbegin(); i != stack_.rend(); ++i) {
@@ -210,16 +213,21 @@ void DFSExplorer::backtrack()
         if (state->get_transition()->aid_ == prev_state->get_transition()->aid_) {
           XBT_DEBUG("Simcall >>%s<< and >>%s<< with same issuer %ld", state->get_transition()->to_string().c_str(),
                     prev_state->get_transition()->to_string().c_str(), issuer_id);
-          break;
+          continue;
         } else if (prev_state->get_transition()->depends(state->get_transition())) {
           XBT_VERB("Dependent Transitions:");
           XBT_VERB("  %s (state=%ld)", prev_state->get_transition()->to_string().c_str(), prev_state->get_num());
           XBT_VERB("  %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num());
 
-          if (not prev_state->is_done(issuer_id))
-            prev_state->mark_todo(issuer_id);
-          else
-            XBT_DEBUG("Actor %ld is in done set", issuer_id);
+	  if (prev_state->is_actor_enabled(issuer_id)){
+	      if (not prev_state->is_done(issuer_id))
+		  prev_state->mark_todo(issuer_id);
+	      else
+		  XBT_DEBUG("Actor %ld is already in done set: no need to explore it again", issuer_id);
+	  } else {
+	      XBT_DEBUG("Actor %ld is not enabled: DPOR may be failing, to stay sound, we are marking every enabled transition todo", issuer_id);
+	      prev_state->mark_all_todo();
+	  }
           break;
         } else {
           XBT_VERB("INDEPENDENT Transitions:");
@@ -233,7 +241,7 @@ void DFSExplorer::backtrack()
       XBT_DEBUG("Delete state %ld at depth %zu", state->get_num(), stack_.size() + 1);
 
     } else {
-      XBT_DEBUG("Back-tracking to state %ld at depth %zu", state->get_num(), stack_.size() + 1);
+	XBT_DEBUG("Back-tracking to state %ld at depth %zu: %ld transitions left to be explored", state->get_num(), stack_.size() + 1, state->count_todo());
       stack_.push_back(std::move(state)); // Put it back on the stack
       found_backtracking_point = true;
     }