scanalysis.cc

   1 #include "scanalysis.h"
   2 #include "action.h"
   3 #include "threads-model.h"
   4 #include "clockvector.h"
   5 #include "execution.h"
   6
   7 SCAnalysis::SCAnalysis(const ModelExecution *execution) :
   8         cvmap(),
   9         cyclic(false),
  10         badrfset(),
  11         lastwrmap(),
  12         threadlists(1),
  13         execution(execution)
  14 {
  15 }
  16
  17 SCAnalysis::~SCAnalysis() {
  18 }
  19
  20 void SCAnalysis::print_list(action_list_t *list) {
  21         model_print("---------------------------------------------------------------------\n");
  22         if (cyclic)
  23                 model_print("Not SC\n");
  24         unsigned int hash = 0;
  25
  26         for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
  27                 const ModelAction *act = *it;
  28                 if (act->get_seq_number() > 0) {
  29                         if (badrfset.contains(act))
  30                                 model_print("BRF ");
  31                         act->print();
  32                         if (badrfset.contains(act)) {
  33                                 model_print("Desired Rf: %u \n",badrfset.get(act)->get_seq_number());
  34                         }
  35                 }
  36                 hash = hash ^ (hash << 3) ^ ((*it)->hash());
  37         }
  38         model_print("HASH %u\n", hash);
  39         model_print("---------------------------------------------------------------------\n");
  40 }
  41
  42 void SCAnalysis::analyze(action_list_t *actions) {
  43         buildVectors(actions);
  44         computeCV(actions);
  45         action_list_t *list = generateSC(actions);
  46         check_rf(list);
  47         print_list(list);
  48 }
  49
  50 void SCAnalysis::check_rf(action_list_t *list) {
  51         for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
  52                 const ModelAction *act = *it;
  53                 if (act->is_read()) {
  54                         if (act->get_reads_from()!=lastwrmap.get(act->get_location()))
  55                                 badrfset.put(act,lastwrmap.get(act->get_location()));
  56                 }
  57                 if (act->is_write())
  58                         lastwrmap.put(act->get_location(), act);
  59         }
  60 }
  61
  62 bool SCAnalysis::merge(ClockVector *cv, const ModelAction *act, const ModelAction *act2) {
  63         ClockVector * cv2=cvmap.get(act2);
  64         if (cv2==NULL)
  65                 return true;
  66         if (cv2->getClock(act->get_tid()) >= act->get_seq_number() && act->get_seq_number() != 0) {
  67                 cyclic=true;
  68                 //refuse to introduce cycles into clock vectors
  69                 return false;
  70         }
  71
  72         return cv->merge(cv2);
  73 }
  74
  75 ModelAction * SCAnalysis::getNextAction() {
  76         ModelAction *act = NULL;
  77         /* Find the earliest in SC ordering */
  78         for (int i = 0; i <= maxthreads; i++) {
  79                 action_list_t *threadlist = &threadlists[i];
  80                 if (threadlist->empty())
  81                         continue;
  82                 ModelAction *first = threadlist->front();
  83                 if (act==NULL) {
  84                         act = first;
  85                         continue;
  86                 }
  87                 ClockVector *cv = cvmap.get(act);
  88                 if (cv->synchronized_since(first)) {
  89                         act = first;
  90                 }
  91         }
  92         if (act == NULL)
  93                 return act;
  94
  95         /* Find the model action with the earliest sequence number in case of a cycle.
  96          */
  97
  98         for (int i = 0; i <= maxthreads; i++) {
  99                 action_list_t *threadlist = &threadlists[i];
 100                 if (threadlist->empty())
 101                         continue;
 102                 ModelAction *first = threadlist->front();
 103                 ClockVector *cvfirst = cvmap.get(first);
 104                 if (first->get_seq_number()<act->get_seq_number()) {
 105                         bool candidate=true;
 106                         for (int j = 0; j <= maxthreads; j++) {
 107                                 action_list_t *threadlist2 = &threadlists[j];
 108                                 if (threadlist2->empty())
 109                                         continue;
 110                                 ModelAction *check = threadlist2->front();
 111                                 if ((check!=first) &&
 112                                                 cvfirst->synchronized_since(check)) {
 113                                         candidate=false;
 114                                         break;
 115                                 }
 116                         }
 117                         if (candidate)
 118                                 act=first;
 119                 }
 120         }
 121
 122         /* See if hb demands an earlier action. */
 123         for (int i = 0; i <= maxthreads; i++) {
 124                 action_list_t *threadlist = &threadlists[i];
 125                 if (threadlist->empty())
 126                         continue;
 127                 ModelAction *first = threadlist->front();
 128                 ClockVector *cv = act->get_cv();
 129                 if (cv->synchronized_since(first)) {
 130                         act = first;
 131                 }
 132         }
 133         return act;
 134 }
 135
 136 action_list_t * SCAnalysis::generateSC(action_list_t *list) {
 137         action_list_t *sclist = new action_list_t();
 138         while (true) {
 139                 ModelAction *act = getNextAction();
 140                 if (act == NULL)
 141                         break;
 142                 thread_id_t tid = act->get_tid();
 143                 //remove action
 144                 threadlists[id_to_int(tid)].pop_front();
 145                 //add ordering constraints from this choice
 146                 if (updateConstraints(act)) {
 147                         //propagate changes if we have them
 148                         bool oc=cyclic;
 149                         computeCV(list);
 150                         if (!oc && cyclic)
 151                                 model_print("XXXXXXXXXXXXXX\n");
 152                 }
 153                 //add action to end
 154                 sclist->push_back(act);
 155         }
 156         return sclist;
 157 }
 158
 159 void SCAnalysis::buildVectors(action_list_t *list) {
 160         maxthreads = 0;
 161         for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
 162                 ModelAction *act = *it;
 163                 int threadid = id_to_int(act->get_tid());
 164                 if (threadid > maxthreads) {
 165                         threadlists.resize(threadid + 1);
 166                         maxthreads = threadid;
 167                 }
 168                 threadlists[threadid].push_back(act);
 169         }
 170 }
 171
 172 bool SCAnalysis::updateConstraints(ModelAction *act) {
 173         bool changed = false;
 174         for (int i = 0; i <= maxthreads; i++) {
 175                 thread_id_t tid = int_to_id(i);
 176                 if (tid == act->get_tid())
 177                         continue;
 178
 179                 action_list_t *list = &threadlists[id_to_int(tid)];
 180                 for (action_list_t::iterator rit = list->begin(); rit != list->end(); rit++) {
 181                         ModelAction *write = *rit;
 182                         if (!write->is_write())
 183                                 continue;
 184                         ClockVector *writecv = cvmap.get(write);
 185                         if (writecv->synchronized_since(act))
 186                                 break;
 187                         if (write->get_location() == act->get_location()) {
 188                                 //write is sc after act
 189                                 merge(writecv, write, act);
 190                                 changed = true;
 191                                 break;
 192                         }
 193                 }
 194         }
 195         return changed;
 196 }
 197
 198 bool SCAnalysis::processRead(ModelAction *read, ClockVector *cv) {
 199         bool changed = false;
 200
 201         /* Merge in the clock vector from the write */
 202         const ModelAction *write = read->get_reads_from();
 203         ClockVector *writecv = cvmap.get(write);
 204         changed |= merge(cv, read, write) && (*read < *write);
 205
 206         for (int i = 0; i <= maxthreads; i++) {
 207                 thread_id_t tid = int_to_id(i);
 208                 if (tid == read->get_tid())
 209                         continue;
 210                 if (tid == write->get_tid())
 211                         continue;
 212                 action_list_t *list = execution->get_actions_on_obj(read->get_location(), tid);
 213                 if (list == NULL)
 214                         continue;
 215                 for (action_list_t::reverse_iterator rit = list->rbegin(); rit != list->rend(); rit++) {
 216                         ModelAction *write2 = *rit;
 217                         if (!write2->is_write())
 218                                 continue;
 219
 220                         ClockVector *write2cv = cvmap.get(write2);
 221                         if (write2cv == NULL)
 222                                 continue;
 223
 224                         /* write -sc-> write2 &&
 225                                  write -rf-> R =>
 226                                  R -sc-> write2 */
 227                         if (write2cv->synchronized_since(write)) {
 228                                 changed |= merge(write2cv, write2, read);
 229                         }
 230
 231                         //looking for earliest write2 in iteration to satisfy this
 232                         /* write2 -sc-> R &&
 233                                  write -rf-> R =>
 234                                  write2 -sc-> write */
 235                         if (cv->synchronized_since(write2)) {
 236                                 changed |= writecv==NULL || merge(writecv, write, write2);
 237                                 break;
 238                         }
 239                 }
 240         }
 241         return changed;
 242 }
 243
 244 void SCAnalysis::computeCV(action_list_t *list) {
 245         bool changed = true;
 246         bool firsttime = true;
 247         ModelAction **last_act = (ModelAction **)model_calloc(1, (maxthreads + 1) * sizeof(ModelAction *));
 248         while (changed) {
 249                 changed = changed&firsttime;
 250                 firsttime = false;
 251
 252                 for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
 253                         ModelAction *act = *it;
 254                         ModelAction *lastact = last_act[id_to_int(act->get_tid())];
 255                         if (act->is_thread_start())
 256                                 lastact = execution->get_thread(act)->get_creation();
 257                         last_act[id_to_int(act->get_tid())] = act;
 258                         ClockVector *cv = cvmap.get(act);
 259                         if (cv == NULL) {
 260                                 cv = new ClockVector(NULL, act);
 261                                 cvmap.put(act, cv);
 262                         }
 263                         if (lastact != NULL) {
 264                                 merge(cv, act, lastact);
 265                         }
 266                         if (act->is_thread_join()) {
 267                                 Thread *joinedthr = act->get_thread_operand();
 268                                 ModelAction *finish = execution->get_last_action(joinedthr->get_id());
 269                                 changed |= merge(cv, act, finish);
 270                         }
 271                         if (act->is_read()) {
 272                                 changed |= processRead(act, cv);
 273                         }
 274                 }
 275                 /* Reset the last action array */
 276                 if (changed) {
 277                         bzero(last_act, (maxthreads + 1) * sizeof(ModelAction *));
 278                 }
 279         }
 280         model_free(last_act);
 281 }