model.cc

   1 #include <stdio.h>
   2
   3 #include "model.h"
   4 #include "schedule.h"
   5 #include "common.h"
   6
   7 ModelChecker *model;
   8
   9 ModelChecker::ModelChecker()
  10 {
  11         /* First thread created (system_thread) will have id 1 */
  12         this->used_thread_id = 0;
  13         /* Initialize default scheduler */
  14         this->scheduler = new Scheduler();
  15
  16         this->current_action = NULL;
  17         this->exploring = NULL;
  18         this->nextThread = THREAD_ID_T_NONE;
  19
  20         rootNode = new TreeNode(NULL);
  21         currentNode = rootNode;
  22         action_trace = new action_list_t();
  23 }
  24
  25 ModelChecker::~ModelChecker()
  26 {
  27         delete action_trace;
  28         delete this->scheduler;
  29         delete rootNode;
  30 }
  31
  32 void ModelChecker::assign_id(Thread *t)
  33 {
  34         t->set_id(++used_thread_id);
  35 }
  36
  37 void ModelChecker::add_system_thread(Thread *t)
  38 {
  39         this->system_thread = t;
  40 }
  41
  42 Thread *ModelChecker::schedule_next_thread()
  43 {
  44         Thread *t;
  45         if (nextThread == THREAD_ID_T_NONE)
  46                 return NULL;
  47         t = thread_map[nextThread];
  48         if (t == NULL)
  49                 DEBUG("*** error: thread not in thread_map: id = %d\n", nextThread);
  50         return t;
  51 }
  52
  53 ModelAction *ModelChecker::get_last_conflict(ModelAction *act)
  54 {
  55         void *loc = act->get_location();
  56         action_type type = act->get_type();
  57         thread_id_t id = act->get_tid();
  58
  59         switch (type) {
  60                 case THREAD_CREATE:
  61                 case THREAD_YIELD:
  62                 case THREAD_JOIN:
  63                         return NULL;
  64                 case ATOMIC_READ:
  65                 case ATOMIC_WRITE:
  66                 default:
  67                         break;
  68         }
  69         action_list_t::reverse_iterator rit;
  70         for (rit = action_trace->rbegin(); rit != action_trace->rend(); rit++) {
  71                 ModelAction *prev = *rit;
  72                 if (prev->get_location() != loc)
  73                         continue;
  74                 if (type == ATOMIC_READ && prev->get_type() != ATOMIC_WRITE)
  75                         continue;
  76                 /* Conflict from the same thread is not really a conflict */
  77                 if (id == prev->get_tid())
  78                         return NULL;
  79                 return prev;
  80         }
  81         return NULL;
  82 }
  83
  84 void ModelChecker::set_backtracking(ModelAction *act)
  85 {
  86         ModelAction *prev;
  87         TreeNode *node;
  88
  89         prev = get_last_conflict(act);
  90         if (prev == NULL)
  91                 return;
  92
  93         node = prev->get_node();
  94
  95         /* Check if this has been explored already */
  96         if (node->hasBeenExplored(act->get_tid()))
  97                 return;
  98         /* If this is a new backtracking point, mark the tree */
  99         if (node->setBacktrack(act->get_tid()) != 0)
 100                 return;
 101
 102         printf("Setting backtrack: conflict = %d, instead tid = %d\n",
 103                         prev->get_tid(), act->get_tid());
 104         prev->print();
 105         act->print();
 106
 107         Backtrack *back = new Backtrack(prev, action_trace);
 108         backtrack_list.push_back(back);
 109 }
 110
 111 void ModelChecker::check_current_action(void)
 112 {
 113         ModelAction *next = this->current_action;
 114
 115         if (!next) {
 116                 DEBUG("trying to push NULL action...\n");
 117                 return;
 118         }
 119         next->set_node(currentNode);
 120         set_backtracking(next);
 121         currentNode = currentNode->exploreChild(next->get_tid());
 122         this->action_trace->push_back(next);
 123 }
 124
 125 void ModelChecker::print_trace(void)
 126 {
 127         action_list_t::iterator it;
 128
 129         printf("\n");
 130         printf("---------------------------------------------------------------------\n");
 131         printf("Total nodes created: %d\n\n", TreeNode::getTotalNodes());
 132
 133         for (it = action_trace->begin(); it != action_trace->end(); it++) {
 134                 DBG();
 135                 (*it)->print();
 136         }
 137         printf("---------------------------------------------------------------------\n");
 138 }
 139
 140 int ModelChecker::add_thread(Thread *t)
 141 {
 142         thread_map[t->get_id()] = t;
 143         return 0;
 144 }
 145
 146 int ModelChecker::switch_to_master(ModelAction *act)
 147 {
 148         Thread *old, *next;
 149
 150         DBG();
 151         old = thread_current();
 152         set_current_action(act);
 153         old->set_state(THREAD_READY);
 154         next = system_thread;
 155         return old->swap(next);
 156 }
 157
 158 ModelAction::ModelAction(action_type_t type, memory_order order, void *loc, int value)
 159 {
 160         Thread *t = thread_current();
 161         ModelAction *act = this;
 162
 163         act->type = type;
 164         act->order = order;
 165         act->location = loc;
 166         act->tid = t->get_id();
 167         act->value = value;
 168 }
 169
 170 void ModelAction::print(void)
 171 {
 172         const char *type_str;
 173         switch (this->type) {
 174         case THREAD_CREATE:
 175                 type_str = "thread create";
 176                 break;
 177         case THREAD_YIELD:
 178                 type_str = "thread yield";
 179                 break;
 180         case THREAD_JOIN:
 181                 type_str = "thread join";
 182                 break;
 183         case ATOMIC_READ:
 184                 type_str = "atomic read";
 185                 break;
 186         case ATOMIC_WRITE:
 187                 type_str = "atomic write";
 188                 break;
 189         default:
 190                 type_str = "unknown type";
 191         }
 192
 193         printf("Thread: %d\tAction: %s\tMO: %d\tLoc: %#014zx\tValue: %d\n", tid, type_str, order, (size_t)location, value);
 194 }