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Automatically remove nodes from parents
[simgrid.git] / src / mc / api / State.cpp
index dae2c6f..fb2a806 100644 (file)
@@ -4,8 +4,12 @@
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
 #include "src/mc/api/State.hpp"
+#include "src/mc/api/strategy/BasicStrategy.hpp"
+#include "src/mc/api/strategy/WaitStrategy.hpp"
+#include "src/mc/explo/Exploration.hpp"
 #include "src/mc/mc_config.hpp"
 
+#include <algorithm>
 #include <boost/range/algorithm.hpp>
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_state, mc, "Logging specific to MC states");
@@ -14,105 +18,217 @@ namespace simgrid::mc {
 
 long State::expended_states_ = 0;
 
-State::State(const RemoteApp& remote_app) : num_(++expended_states_)
+State::State(RemoteApp& remote_app) : num_(++expended_states_)
 {
-  remote_app.get_actors_status(actors_to_run_);
+  XBT_VERB("Creating a guide for the state");
+  if (_sg_mc_strategy == "none")
+    strategy_ = std::make_shared<BasicStrategy>();
+  else if (_sg_mc_strategy == "nb_wait")
+    strategy_ = std::make_shared<WaitStrategy>();
+  else
+    THROW_IMPOSSIBLE;
 
-  transition_.reset(new Transition());
+  remote_app.get_actors_status(strategy_->actors_to_run_);
+
+#if SIMGRID_HAVE_STATEFUL_MC
   /* Stateful model checking */
-  if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination) {
-    system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_);
-  }
+  if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
+    system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
+                                                            *remote_app.get_remote_process_memory());
+#endif
 }
 
-State::State(const RemoteApp& remote_app, const State* previous_state) : num_(++expended_states_)
+State::State(RemoteApp& remote_app, std::shared_ptr<State> parent_state)
+    : incoming_transition_(parent_state->get_transition_out()), num_(++expended_states_), parent_state_(parent_state)
 {
-
-  remote_app.get_actors_status(actors_to_run_);
-
-  transition_.reset(new Transition());
-  /* Stateful model checking */
-  if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination) {
-    system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_);
-  }
-
-  /* For each actor in the previous sleep set, keep it if it is not dependent with current transition.
-   * And if we kept it and the actor is enabled in this state, mark the actor as already done, so that
-   * it is not explored*/
-  for (auto & [aid, transition] : previous_state->get_sleep_set()) {
-      
-      if (not previous_state->get_transition()->depends(&transition)) {
-             
-         sleep_set_.emplace(aid, transition);
-         if (actors_to_run_.count(aid) != 0) {
-             XBT_DEBUG("Actor %ld will not be explored, for it is in the sleep set", aid);
-
-             actors_to_run_.at(aid).mark_done();
-         }
-      }
-      else
-         XBT_DEBUG("Transition >>%s<< removed from the sleep set because it was dependent with >>%s<<", transition.to_string().c_str(), previous_state->get_transition()->to_string().c_str());
-  
+  if (_sg_mc_strategy == "none")
+    strategy_ = std::make_shared<BasicStrategy>();
+  else if (_sg_mc_strategy == "nb_wait")
+    strategy_ = std::make_shared<WaitStrategy>();
+  else
+    THROW_IMPOSSIBLE;
+  *strategy_ = *(parent_state->strategy_);
+
+  remote_app.get_actors_status(strategy_->actors_to_run_);
+
+#if SIMGRID_HAVE_STATEFUL_MC /* Stateful model checking */
+  if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
+    system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
+                                                            *remote_app.get_remote_process_memory());
+#endif
+
+  /* If we want sleep set reduction, copy the sleep set and eventually removes things from it */
+  if (_sg_mc_sleep_set) {
+    /* For each actor in the previous sleep set, keep it if it is not dependent with current transition.
+     * And if we kept it and the actor is enabled in this state, mark the actor as already done, so that
+     * it is not explored*/
+    for (auto& [aid, transition] : parent_state_->get_sleep_set()) {
+      if (not incoming_transition_->depends(&transition)) {
+        sleep_set_.try_emplace(aid, transition);
+        if (strategy_->actors_to_run_.count(aid) != 0) {
+          XBT_DEBUG("Actor %ld will not be explored, for it is in the sleep set", aid);
+
+          strategy_->actors_to_run_.at(aid).mark_done();
+        }
+      } else
+        XBT_DEBUG("Transition >>%s<< removed from the sleep set because it was dependent with incoming >>%s<<",
+                  transition.to_string().c_str(), incoming_transition_->to_string().c_str());
+    }
   }
-    
 }
-    
+
 std::size_t State::count_todo() const
 {
-  return boost::range::count_if(this->actors_to_run_, [](auto& pair) { return pair.second.is_todo(); });
+  return boost::range::count_if(this->strategy_->actors_to_run_, [](auto& pair) { return pair.second.is_todo(); });
 }
 
-    void State::mark_all_todo() 
+std::size_t State::count_todo_multiples() const
 {
-    for (auto & [aid, actor] : actors_to_run_) {
+  size_t count = 0;
+  for (auto const& [_, actor] : strategy_->actors_to_run_)
+    if (actor.is_todo())
+      count += actor.get_times_not_considered();
 
-       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();
+  return count;
 }
 
 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_) {
+  XBT_DEBUG("Search for an actor to run. %zu actors to consider", strategy_->actors_to_run_.size());
+  for (auto const& [aid, actor] : strategy_->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() || actor.is_done()) {
-
-         if (not actor.is_todo())
-             XBT_DEBUG("Can't run actor %ld because it is not todo", aid); 
+    if (not actor.is_todo() || not actor.is_enabled() || actor.is_done()) {
+      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);
+      if (not actor.is_enabled())
+        XBT_DEBUG("Can't run actor %ld because it is not enabled", aid);
 
-         if (actor.is_done())
-             XBT_DEBUG("Can't run actor %ld because it has already been done", aid);
+      if (actor.is_done())
+        XBT_DEBUG("Can't run actor %ld because it has already been done", aid);
 
-         
-         continue;
+      continue;
+    }
 
+    return aid;
+  }
+  return -1;
+}
 
-      }
+std::pair<aid_t, int> State::next_transition_guided() const
+{
+  return strategy_->next_transition();
+}
 
-    return aid;
+aid_t State::next_odpor_transition() const
+{
+  const auto first_single_process_branch =
+      std::find_if(wakeup_tree_.begin(), wakeup_tree_.end(),
+                   [=](const odpor::WakeupTreeNode* node) { return node->is_single_process(); });
+  if (first_single_process_branch != wakeup_tree_.end()) {
+    const auto* wakeup_tree_node = *first_single_process_branch;
+    xbt_assert(wakeup_tree_node->get_sequence().size() == 1, "We claimed that the selected branch "
+                                                             "contained only a single process, yet more "
+                                                             "than one process was actually contained in it :(");
+    return wakeup_tree_node->get_first_actor();
   }
   return -1;
 }
-void State::execute_next(aid_t next)
+
+// This should be done in GuidedState, or at least interact with it
+std::shared_ptr<Transition> State::execute_next(aid_t next, RemoteApp& app)
 {
-  /* This actor is ready to be executed. Prepare its execution when simcall_handle will be called on it */
-  const unsigned times_considered = actors_to_run_.at(next).do_consider();
+  // First, warn the guide, so it knows how to build a proper child state
+  strategy_->execute_next(next, app);
+
+  // This actor is ready to be executed. Execution involves three phases:
+
+  // 1. Identify the appropriate ActorState to prepare for execution
+  // when simcall_handle will be called on it
+  auto& actor_state                        = strategy_->actors_to_run_.at(next);
+  const unsigned times_considered          = actor_state.do_consider();
+  const auto* expected_executed_transition = actor_state.get_transition(times_considered).get();
+  xbt_assert(expected_executed_transition != nullptr,
+             "Expected a transition with %u times considered to be noted in actor %ld", times_considered, next);
 
   XBT_DEBUG("Let's run actor %ld (times_considered = %u)", next, times_considered);
 
+  // 2. Execute the actor according to the preparation above
   Transition::executed_transitions_++;
+  auto* just_executed = app.handle_simcall(next, times_considered, true);
+  xbt_assert(just_executed->type_ == expected_executed_transition->type_,
+             "The transition that was just executed by actor %ld, viz:\n"
+             "%s\n"
+             "is not what was purportedly scheduled to execute, which was:\n"
+             "%s\n",
+             next, just_executed->to_string().c_str(), expected_executed_transition->to_string().c_str());
+
+  // 3. Update the state with the newest information. This means recording
+  // both
+  //  1. what action was last taken from this state (viz. `executed_transition`)
+  //  2. what action actor `next` was able to take given `times_considered`
+  // The latter update is important as *more* information is potentially available
+  // about a transition AFTER it has executed.
+  outgoing_transition_ = std::shared_ptr<Transition>(just_executed);
+
+  actor_state.set_transition(outgoing_transition_, times_considered);
+  app.wait_for_requests();
+
+  return outgoing_transition_;
+}
+
+std::unordered_set<aid_t> State::get_backtrack_set() const
+{
+  std::unordered_set<aid_t> actors;
+  for (const auto& [aid, state] : get_actors_list()) {
+    if (state.is_todo() or state.is_done()) {
+      actors.insert(aid);
+    }
+  }
+  return actors;
+}
 
-  transition_.reset(mc_model_checker->handle_simcall(next, times_considered, true));
-  mc_model_checker->wait_for_requests();
+void State::seed_wakeup_tree_if_needed(const odpor::Execution& prior)
+{
+  // TODO: Note that the next action taken by the actor may be updated
+  // after it executes. But we will have already inserted it into the
+  // tree and decided upon "happens-before" at that point for different
+  // executions :(
+  if (wakeup_tree_.empty()) {
+    if (const aid_t next = std::get<0>(next_transition_guided()); next >= 0) {
+      wakeup_tree_.insert(prior, odpor::PartialExecution{strategy_->actors_to_run_.at(next).get_transition()});
+    }
+  }
+}
+
+void State::sprout_tree_from_parent_state()
+{
+  xbt_assert(parent_state_ != nullptr, "Attempting to construct a wakeup tree for the root state "
+                                       "(or what appears to be, rather for state without a parent defined)");
+  const auto p      = parent_state_->get_transition_out()->aid_;
+  const auto branch = std::find_if(
+      parent_state_->wakeup_tree_.begin(), parent_state_->wakeup_tree_.end(),
+      [=](const odpor::WakeupTreeNode* node) { return node->is_single_process() && node->get_first_actor() == p; });
+  xbt_assert(branch != parent_state_->wakeup_tree_.end(),
+             "Attempted to create a subtree from the wakeup tree of the parent "
+             "state using actor `%ld`, but no such subtree could be found. "
+             "This implies that the wakeup tree management is broken, "
+             "and more specifically that subtree formation is not working "
+             "as intended; for if this state was generated by the parent "
+             "having taken an action by actor `%ld`, this implies that "
+             "ODPOR found `%ld` as a candidate branch prior",
+             p, p, p);
+  this->wakeup_tree_ = odpor::WakeupTree::make_subtree_rooted_at(*branch);
 }
+
+void State::remove_subtree_starting_with(aid_t p)
+{
+  const auto branch = std::find_if(wakeup_tree_.begin(), wakeup_tree_.end(), [=](const odpor::WakeupTreeNode* node) {
+    return node->is_single_process() && node->get_first_actor() == p;
+  });
+  xbt_assert(branch != wakeup_tree_.end(), "Attempted to remove a subtree of this state's "
+                                           "wakeup tree that does not exist");
+  this->wakeup_tree_.remove_subtree_rooted_at(*branch);
+}
+
 } // namespace simgrid::mc