src/mc/VisitedState.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
  12 #include <boost/range/algorithm.hpp>
  13
  14 #include <xbt/log.h>
  15 #include <xbt/sysdep.h>
  16
  17 #include "src/mc/mc_comm_pattern.h"
  18 #include "src/mc/mc_safety.h"
  19 #include "src/mc/mc_private.h"
  20 #include "src/mc/Process.hpp"
  21 #include "src/mc/mc_smx.h"
  22 #include "src/mc/VisitedState.hpp"
  23
  24 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_VisitedState, mc,
  25                                 "Logging specific to state equaity detection mechanisms");
  26
  27 namespace simgrid {
  28 namespace mc {
  29
  30 static int snapshot_compare(simgrid::mc::VisitedState* state1, simgrid::mc::VisitedState* state2)
  31 {
  32   simgrid::mc::Snapshot* s1 = state1->system_state.get();
  33   simgrid::mc::Snapshot* s2 = state2->system_state.get();
  34   int num1 = state1->num;
  35   int num2 = state2->num;
  36   return snapshot_compare(num1, s1, num2, s2);
  37 }
  38
  39 /**
  40  * \brief Save the current state
  41  * \return Snapshot of the current state.
  42  */
  43 VisitedState::VisitedState(unsigned long state_number)
  44 {
  45   simgrid::mc::Process* process = &(mc_model_checker->process());
  46   this->heap_bytes_used = mmalloc_get_bytes_used_remote(
  47     process->get_heap()->heaplimit,
  48     process->get_malloc_info());
  49
  50   this->nb_processes =
  51     mc_model_checker->process().simix_processes().size();
  52
  53   this->system_state = simgrid::mc::take_snapshot(state_number);
  54   this->num = state_number;
  55   this->other_num = -1;
  56 }
  57
  58 VisitedState::~VisitedState()
  59 {
  60 }
  61
  62 void VisitedStates::prune()
  63 {
  64   while (states_.size() > (std::size_t) _sg_mc_visited) {
  65     XBT_DEBUG("Try to remove visited state (maximum number of stored states reached)");
  66     auto min_element = boost::range::min_element(states_,
  67       [](std::unique_ptr<simgrid::mc::VisitedState>& a, std::unique_ptr<simgrid::mc::VisitedState>& b) {
  68         return a->num < b->num;
  69       });
  70     xbt_assert(min_element != states_.end());
  71     // and drop it:
  72     states_.erase(min_element);
  73     XBT_DEBUG("Remove visited state (maximum number of stored states reached)");
  74   }
  75 }
  76
  77 /**
  78  * \brief Checks whether a given state has already been visited by the algorithm.
  79  */
  80 std::unique_ptr<simgrid::mc::VisitedState> VisitedStates::addVisitedState(
  81   unsigned long state_number, simgrid::mc::State* graph_state, bool compare_snpashots)
  82 {
  83   std::unique_ptr<simgrid::mc::VisitedState> new_state =
  84     std::unique_ptr<simgrid::mc::VisitedState>(new VisitedState(state_number));
  85   graph_state->system_state = new_state->system_state;
  86   XBT_DEBUG("Snapshot %p of visited state %d (exploration stack state %d)",
  87     new_state->system_state.get(), new_state->num, graph_state->num);
  88
  89   auto range = boost::range::equal_range(states_,
  90     new_state.get(), simgrid::mc::DerefAndCompareByNbProcessesAndUsedHeap());
  91
  92   if (compare_snpashots)
  93     for (auto i = range.first; i != range.second; ++i) {
  94       auto& visited_state = *i;
  95       if (snapshot_compare(visited_state.get(), new_state.get()) == 0) {
  96         // The state has been visited:
  97
  98         std::unique_ptr<simgrid::mc::VisitedState> old_state =
  99           std::move(visited_state);
 100
 101         if (old_state->other_num == -1)
 102           new_state->other_num = old_state->num;
 103         else
 104           new_state->other_num = old_state->other_num;
 105
 106         if (dot_output == nullptr)
 107           XBT_DEBUG("State %d already visited ! (equal to state %d)",
 108             new_state->num, old_state->num);
 109         else
 110           XBT_DEBUG(
 111             "State %d already visited ! (equal to state %d (state %d in dot_output))",
 112             new_state->num, old_state->num, new_state->other_num);
 113
 114         /* Replace the old state with the new one (with a bigger num)
 115            (when the max number of visited states is reached,  the oldest
 116            one is removed according to its number (= with the min number) */
 117         XBT_DEBUG("Replace visited state %d with the new visited state %d",
 118           old_state->num, new_state->num);
 119
 120         visited_state = std::move(new_state);
 121         return old_state;
 122       }
 123     }
 124
 125   XBT_DEBUG("Insert new visited state %d (total : %lu)", new_state->num, (unsigned long) states_.size());
 126   states_.insert(range.first, std::move(new_state));
 127   this->prune();
 128   return nullptr;
 129 }
 130
 131 }
 132 }