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->actors_count = mc_model_checker->process().actors().size();
  51
  52   this->system_state = simgrid::mc::take_snapshot(state_number);
  53   this->num = state_number;
  54   this->original_num = -1;
  55 }
  56
  57 VisitedState::~VisitedState()
  58 {
  59 }
  60
  61 void VisitedStates::prune()
  62 {
  63   while (states_.size() > (std::size_t)_sg_mc_max_visited_states) {
  64     XBT_DEBUG("Try to remove visited state (maximum number of stored states reached)");
  65     auto min_element = boost::range::min_element(states_,
  66       [](std::unique_ptr<simgrid::mc::VisitedState>& a, std::unique_ptr<simgrid::mc::VisitedState>& b) {
  67         return a->num < b->num;
  68       });
  69     xbt_assert(min_element != states_.end());
  70     // and drop it:
  71     states_.erase(min_element);
  72     XBT_DEBUG("Remove visited state (maximum number of stored states reached)");
  73   }
  74 }
  75
  76 /** \brief Checks whether a given state has already been visited by the algorithm.
  77  */
  78 std::unique_ptr<simgrid::mc::VisitedState> VisitedStates::addVisitedState(
  79   unsigned long state_number, simgrid::mc::State* graph_state, bool compare_snpashots)
  80 {
  81   std::unique_ptr<simgrid::mc::VisitedState> new_state =
  82     std::unique_ptr<simgrid::mc::VisitedState>(new VisitedState(state_number));
  83   graph_state->system_state = new_state->system_state;
  84   XBT_DEBUG("Snapshot %p of visited state %d (exploration stack state %d)",
  85     new_state->system_state.get(), new_state->num, graph_state->num);
  86
  87   auto range =
  88       boost::range::equal_range(states_, new_state.get(), simgrid::mc::DerefAndCompareByActorsCountAndUsedHeap());
  89
  90   if (compare_snpashots)
  91     for (auto i = range.first; i != range.second; ++i) {
  92       auto& visited_state = *i;
  93       if (snapshot_compare(visited_state.get(), new_state.get()) == 0) {
  94         // The state has been visited:
  95
  96         std::unique_ptr<simgrid::mc::VisitedState> old_state =
  97           std::move(visited_state);
  98
  99         if (old_state->original_num == -1) // I'm the copy of an original process
 100           new_state->original_num = old_state->num;
 101         else // I'm the copy of a copy
 102           new_state->original_num = old_state->original_num;
 103
 104         if (dot_output == nullptr)
 105           XBT_DEBUG("State %d already visited ! (equal to state %d)",
 106                     new_state->num, old_state->num);
 107         else
 108           XBT_DEBUG("State %d already visited ! (equal to state %d (state %d in dot_output))",
 109                     new_state->num, old_state->num, new_state->original_num);
 110
 111         /* Replace the old state with the new one (with a bigger num)
 112            (when the max number of visited states is reached,  the oldest
 113            one is removed according to its number (= with the min number) */
 114         XBT_DEBUG("Replace visited state %d with the new visited state %d",
 115           old_state->num, new_state->num);
 116
 117         visited_state = std::move(new_state);
 118         return old_state;
 119       }
 120     }
 121
 122   XBT_DEBUG("Insert new visited state %d (total : %lu)", new_state->num, (unsigned long) states_.size());
 123   states_.insert(range.first, std::move(new_state));
 124   this->prune();
 125   return nullptr;
 126 }
 127
 128 }
 129 }