src/mc/mc_visited.cpp

   1 /* Copyright (c) 2011-2015. The SimGrid Team.
   2  * All rights reserved.                                                     */
   3
   4 /* This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the license (GNU LGPL) which comes with this package. */
   6
   7 #include <unistd.h>
   8 #include <sys/wait.h>
   9
  10 #include <memory>
  11 #include <algorithm>
  12
  13 #include <xbt/automaton.h>
  14 #include <xbt/log.h>
  15 #include <xbt/sysdep.h>
  16 #include <xbt/dynar.h>
  17 #include <xbt/dynar.hpp>
  18 #include <xbt/fifo.h>
  19
  20 #include "src/mc/mc_comm_pattern.h"
  21 #include "src/mc/mc_safety.h"
  22 #include "src/mc/LivenessChecker.hpp"
  23 #include "src/mc/mc_private.h"
  24 #include "src/mc/Process.hpp"
  25 #include "src/mc/mc_smx.h"
  26
  27 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_visited, mc,
  28                                 "Logging specific to state equaity detection mechanisms");
  29
  30 namespace simgrid {
  31 namespace mc {
  32
  33 std::vector<std::unique_ptr<simgrid::mc::VisitedState>> visited_states;
  34
  35 static int is_exploration_stack_state(simgrid::mc::VisitedState* state){
  36   xbt_fifo_item_t item = xbt_fifo_get_first_item(mc_stack);
  37   while (item) {
  38     if (((simgrid::mc::State*)xbt_fifo_get_item_content(item))->num == state->num){
  39       ((simgrid::mc::State*)xbt_fifo_get_item_content(item))->in_visited_states = 0;
  40       return 1;
  41     }
  42     item = xbt_fifo_get_next_item(item);
  43   }
  44   return 0;
  45 }
  46
  47 /**
  48  * \brief Save the current state
  49  * \return Snapshot of the current state.
  50  */
  51 VisitedState::VisitedState()
  52 {
  53   simgrid::mc::Process* process = &(mc_model_checker->process());
  54   this->heap_bytes_used = mmalloc_get_bytes_used_remote(
  55     process->get_heap()->heaplimit,
  56     process->get_malloc_info());
  57
  58   this->nb_processes =
  59     mc_model_checker->process().simix_processes().size();
  60
  61   this->system_state = simgrid::mc::take_snapshot(mc_stats->expanded_states);
  62   this->num = mc_stats->expanded_states;
  63   this->other_num = -1;
  64 }
  65
  66 VisitedState::~VisitedState()
  67 {
  68 }
  69
  70 static void prune_visited_states()
  71 {
  72   while (visited_states.size() > (std::size_t) _sg_mc_visited) {
  73     XBT_DEBUG("Try to remove visited state (maximum number of stored states reached)");
  74     auto min_element = std::min_element(visited_states.begin(), visited_states.end(),
  75       [](std::unique_ptr<simgrid::mc::VisitedState>& a, std::unique_ptr<simgrid::mc::VisitedState>& b) {
  76         return a->num < b->num;
  77       });
  78     xbt_assert(min_element != visited_states.end());
  79     // and drop it:
  80     visited_states.erase(min_element);
  81     XBT_DEBUG("Remove visited state (maximum number of stored states reached)");
  82   }
  83 }
  84
  85 static int snapshot_compare(simgrid::mc::VisitedState* state1, simgrid::mc::VisitedState* state2)
  86 {
  87   simgrid::mc::Snapshot* s1 = state1->system_state.get();
  88   simgrid::mc::Snapshot* s2 = state2->system_state.get();
  89   int num1 = state1->num;
  90   int num2 = state2->num;
  91   return snapshot_compare(num1, s1, num2, s2);
  92 }
  93
  94 /**
  95  * \brief Checks whether a given state has already been visited by the algorithm.
  96  */
  97 std::unique_ptr<simgrid::mc::VisitedState> is_visited_state(simgrid::mc::State* graph_state, bool compare_snpashots)
  98 {
  99
 100
 101   std::unique_ptr<simgrid::mc::VisitedState> new_state =
 102     std::unique_ptr<simgrid::mc::VisitedState>(new VisitedState());
 103   graph_state->system_state = new_state->system_state;
 104   graph_state->in_visited_states = 1;
 105   XBT_DEBUG("Snapshot %p of visited state %d (exploration stack state %d)", new_state->system_state, new_state->num, graph_state->num);
 106
 107   auto range = std::equal_range(visited_states.begin(), visited_states.end(),
 108     new_state.get(), simgrid::mc::DerefAndCompareByNbProcessesAndUsedHeap());
 109
 110       if (compare_snpashots) {
 111
 112         for (auto i = range.first; i != range.second; ++i) {
 113           auto& visited_state = *i;
 114           if (snapshot_compare(visited_state.get(), new_state.get()) == 0) {
 115             // The state has been visited:
 116
 117             std::unique_ptr<simgrid::mc::VisitedState> old_state =
 118               std::move(visited_state);
 119
 120             if (old_state->other_num == -1)
 121               new_state->other_num = old_state->num;
 122             else
 123               new_state->other_num = old_state->other_num;
 124
 125             if (dot_output == nullptr)
 126               XBT_DEBUG("State %d already visited ! (equal to state %d)",
 127                 new_state->num, old_state->num);
 128             else
 129               XBT_DEBUG(
 130                 "State %d already visited ! (equal to state %d (state %d in dot_output))",
 131                 new_state->num, old_state->num, new_state->other_num);
 132
 133             /* Replace the old state with the new one (with a bigger num)
 134                (when the max number of visited states is reached,  the oldest
 135                one is removed according to its number (= with the min number) */
 136             XBT_DEBUG("Replace visited state %d with the new visited state %d",
 137               old_state->num, new_state->num);
 138
 139             visited_state = std::move(new_state);
 140             return std::move(old_state);
 141           }
 142         }
 143       }
 144
 145   XBT_DEBUG("Insert new visited state %d (total : %lu)", new_state->num, (unsigned long) visited_states.size());
 146   visited_states.insert(range.first, std::move(new_state));
 147   prune_visited_states();
 148   return nullptr;
 149 }
 150
 151 }
 152 }