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 (((mc_state_t)xbt_fifo_get_item_content(item))->num == state->num){
  39       ((mc_state_t)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   if(!is_exploration_stack_state(this))
  69     delete this->system_state;
  70 }
  71
  72 VisitedPair::VisitedPair(int pair_num, xbt_automaton_state_t automaton_state, xbt_dynar_t atomic_propositions, mc_state_t graph_state)
  73 {
  74   simgrid::mc::Process* process = &(mc_model_checker->process());
  75
  76   this->graph_state = graph_state;
  77   if(this->graph_state->system_state == nullptr)
  78     this->graph_state->system_state = simgrid::mc::take_snapshot(pair_num);
  79   this->heap_bytes_used = mmalloc_get_bytes_used_remote(
  80     process->get_heap()->heaplimit,
  81     process->get_malloc_info());
  82
  83   this->nb_processes =
  84     mc_model_checker->process().simix_processes().size();
  85
  86   this->automaton_state = automaton_state;
  87   this->num = pair_num;
  88   this->other_num = -1;
  89   this->acceptance_removed = 0;
  90   this->visited_removed = 0;
  91   this->acceptance_pair = 0;
  92   this->atomic_propositions = simgrid::xbt::unique_ptr<s_xbt_dynar_t>(
  93     xbt_dynar_new(sizeof(int), nullptr));
  94
  95   unsigned int cursor = 0;
  96   int value;
  97   xbt_dynar_foreach(atomic_propositions, cursor, value)
  98       xbt_dynar_push_as(this->atomic_propositions.get(), int, value);
  99 }
 100
 101 static int is_exploration_stack_pair(simgrid::mc::VisitedPair* pair){
 102   xbt_fifo_item_t item = xbt_fifo_get_first_item(mc_stack);
 103   while (item) {
 104     if (((simgrid::mc::Pair*)xbt_fifo_get_item_content(item))->num == pair->num){
 105       ((simgrid::mc::Pair*)xbt_fifo_get_item_content(item))->visited_pair_removed = 1;
 106       return 1;
 107     }
 108     item = xbt_fifo_get_next_item(item);
 109   }
 110   return 0;
 111 }
 112
 113 VisitedPair::~VisitedPair()
 114 {
 115   if( !is_exploration_stack_pair(this))
 116     MC_state_delete(this->graph_state, 1);
 117 }
 118
 119 static void prune_visited_states()
 120 {
 121   while (visited_states.size() > (std::size_t) _sg_mc_visited) {
 122     XBT_DEBUG("Try to remove visited state (maximum number of stored states reached)");
 123     auto min_element = std::min_element(visited_states.begin(), visited_states.end(),
 124       [](std::unique_ptr<simgrid::mc::VisitedState>& a, std::unique_ptr<simgrid::mc::VisitedState>& b) {
 125         return a->num < b->num;
 126       });
 127     xbt_assert(min_element != visited_states.end());
 128     // and drop it:
 129     visited_states.erase(min_element);
 130     XBT_DEBUG("Remove visited state (maximum number of stored states reached)");
 131   }
 132 }
 133
 134 /**
 135  * \brief Checks whether a given state has already been visited by the algorithm.
 136  */
 137 std::unique_ptr<simgrid::mc::VisitedState> is_visited_state(mc_state_t graph_state, bool compare_snpashots)
 138 {
 139
 140
 141   std::unique_ptr<simgrid::mc::VisitedState> new_state =
 142     std::unique_ptr<simgrid::mc::VisitedState>(new VisitedState());
 143   graph_state->system_state = new_state->system_state;
 144   graph_state->in_visited_states = 1;
 145   XBT_DEBUG("Snapshot %p of visited state %d (exploration stack state %d)", new_state->system_state, new_state->num, graph_state->num);
 146
 147   auto range = std::equal_range(visited_states.begin(), visited_states.end(),
 148     new_state.get(), simgrid::mc::DerefAndCompareByNbProcessesAndUsedHeap());
 149
 150       if (compare_snpashots) {
 151
 152         for (auto i = range.first; i != range.second; ++i) {
 153           auto& visited_state = *i;
 154           if (snapshot_compare(visited_state.get(), new_state.get()) == 0) {
 155             // The state has been visited:
 156
 157             std::unique_ptr<simgrid::mc::VisitedState> old_state =
 158               std::move(visited_state);
 159
 160             if (old_state->other_num == -1)
 161               new_state->other_num = old_state->num;
 162             else
 163               new_state->other_num = old_state->other_num;
 164
 165             if (dot_output == nullptr)
 166               XBT_DEBUG("State %d already visited ! (equal to state %d)",
 167                 new_state->num, old_state->num);
 168             else
 169               XBT_DEBUG(
 170                 "State %d already visited ! (equal to state %d (state %d in dot_output))",
 171                 new_state->num, old_state->num, new_state->other_num);
 172
 173             /* Replace the old state with the new one (with a bigger num)
 174                (when the max number of visited states is reached,  the oldest
 175                one is removed according to its number (= with the min number) */
 176             XBT_DEBUG("Replace visited state %d with the new visited state %d",
 177               old_state->num, new_state->num);
 178
 179             visited_state = std::move(new_state);
 180             return std::move(old_state);
 181           }
 182         }
 183       }
 184
 185   XBT_DEBUG("Insert new visited state %d (total : %lu)", new_state->num, (unsigned long) visited_states.size());
 186   visited_states.insert(range.first, std::move(new_state));
 187   prune_visited_states();
 188   return nullptr;
 189 }
 190
 191 }
 192 }