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