scanalysis.cc

   1 #include "scanalysis.h"
   2 #include "action.h"
   3 #include "threads-model.h"
   4 #include "clockvector.h"
   5
   6 SCAnalysis::SCAnalysis() {
   7         cvmap=new HashTable<const ModelAction *, ClockVector *, uintptr_t, 4>();
   8         cycleset=new HashTable<const ModelAction *, const ModelAction *, uintptr_t, 4>();
   9         threadlists=new SnapVector<action_list_t>(1);
  10 }
  11
  12 SCAnalysis::~SCAnalysis() {
  13         delete cvmap;
  14         delete cycleset;
  15         delete threadlists;
  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         for(int i=0;i<=maxthreads;i++) {
  55                 action_list_t * threadlist=&(*threadlists)[i];
  56                 if (threadlist->empty())
  57                         continue;
  58                 ModelAction *first=threadlist->front();
  59                 if (act==NULL) {
  60                         act=first;
  61                         continue;
  62                 }
  63                 ClockVector *cv=cvmap->get(act);
  64                 if (cv->synchronized_since(first)) {
  65                         act=first;
  66                 }
  67         }
  68         if (act==NULL)
  69                 return act;
  70         //print cycles in a nice way to avoid confusion
  71         //make sure thread starts appear after the create
  72         if (act->is_thread_start()) {
  73                 ModelAction *createact=model->get_thread(act)->get_creation();
  74                 if (createact) {
  75                         action_list_t *threadlist=&(*threadlists)[id_to_int(createact->get_tid())];
  76                         if (!threadlist->empty()) {
  77                                 ModelAction *first=threadlist->front();
  78                                 if (first->get_seq_number() <= createact->get_seq_number())
  79                                         act=first;
  80                         }
  81                 }
  82         }
  83
  84         //make sure that joins appear after the thread is finished
  85         if (act->is_thread_join()) {
  86                 int jointhread=id_to_int(act->get_thread_operand()->get_id());
  87                 action_list_t *threadlist=&(*threadlists)[jointhread];
  88                 if (!threadlist->empty()) {
  89                         act=threadlist->front();
  90                 }
  91         }
  92
  93         return act;
  94 }
  95
  96 action_list_t * SCAnalysis::generateSC(action_list_t *list) {
  97         action_list_t *sclist=new action_list_t();
  98         while (true) {
  99                 ModelAction * act=getNextAction();
 100                 if (act==NULL)
 101                         break;
 102                 thread_id_t tid=act->get_tid();
 103                 //remove action
 104                 (*threadlists)[id_to_int(tid)].pop_front();
 105                 //add ordering constraints from this choice
 106                 if (updateConstraints(act)) {
 107                         //propagate changes if we have them
 108                         computeCV(list);
 109                 }
 110                 //add action to end
 111                 sclist->push_back(act);
 112         }
 113         return sclist;
 114 }
 115
 116 void SCAnalysis::buildVectors(action_list_t *list) {
 117         maxthreads=0;
 118         for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
 119                 ModelAction *act = *it;
 120                 int threadid=id_to_int(act->get_tid());
 121                 if (threadid > maxthreads) {
 122                         threadlists->resize(threadid+1);
 123                         maxthreads=threadid;
 124                 }
 125                 (*threadlists)[threadid].push_back(act);
 126         }
 127 }
 128
 129 bool SCAnalysis::updateConstraints(ModelAction *act) {
 130         bool changed=false;
 131         ClockVector *actcv = cvmap->get(act);
 132         for(int i=0;i<=maxthreads;i++) {
 133                 thread_id_t tid=int_to_id(i);
 134                 if (tid==act->get_tid())
 135                         continue;
 136
 137                 action_list_t * list=&(*threadlists)[id_to_int(tid)];
 138                 for (action_list_t::iterator rit = list->begin(); rit != list->end(); rit++) {
 139                         ModelAction *write = *rit;
 140                         if (!write->is_write())
 141                                 continue;
 142                         ClockVector *writecv = cvmap->get(write);
 143                         if (writecv->synchronized_since(act))
 144                                 break;
 145                         if (write->get_location() == act->get_location()) {
 146                                 //write is sc after act
 147                                 merge(writecv, write, actcv);
 148                                 changed=true;
 149                                 break;
 150                         }
 151                 }
 152         }
 153         return changed;
 154 }
 155
 156 bool SCAnalysis::processRead(ModelAction *read, ClockVector *cv) {
 157         bool changed=false;
 158
 159         /* Merge in the clock vector from the write */
 160         const ModelAction *write=read->get_reads_from();
 161         ClockVector *writecv=cvmap->get(write);
 162         changed |= writecv == NULL || (merge(cv, read, writecv) && (*read < *write));
 163
 164         for(int i=0;i<=maxthreads;i++) {
 165                 thread_id_t tid=int_to_id(i);
 166                 if (tid==read->get_tid())
 167                         continue;
 168                 if (tid==write->get_tid())
 169                         continue;
 170                 action_list_t * list=model->get_actions_on_obj(read->get_location(), tid);
 171                 if (list==NULL)
 172                         continue;
 173                 for (action_list_t::reverse_iterator rit = list->rbegin(); rit != list->rend(); rit++) {
 174                         ModelAction *write2 = *rit;
 175                         if (!write2->is_write())
 176                                 continue;
 177
 178                         ClockVector *write2cv = cvmap->get(write2);
 179                         if (write2cv == NULL)
 180                                 continue;
 181
 182                         /* write -sc-> write2 &&
 183                                  write -rf-> R =>
 184                                  R -sc-> write2 */
 185                         if (write2cv->synchronized_since(write)) {
 186                                 changed |= merge(write2cv, write2, cv);
 187                         }
 188
 189                         //looking for earliest write2 in iteration to satisfy this
 190                         /* write2 -sc-> R &&
 191                                  write -rf-> R =>
 192                                  write2 -sc-> write */
 193                         if (cv->synchronized_since(write2)) {
 194                                 changed |= writecv == NULL || merge(writecv, write, write2cv);
 195                                 break;
 196                         }
 197                 }
 198         }
 199         return changed;
 200 }
 201
 202
 203 void SCAnalysis::computeCV(action_list_t *list) {
 204         bool changed=true;
 205         bool firsttime=true;
 206         ModelAction **last_act=(ModelAction **)model_calloc(1,(maxthreads+1)*sizeof(ModelAction *));
 207         while(changed) {
 208                 changed=changed&firsttime;
 209                 firsttime=false;
 210
 211                 for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
 212                         ModelAction *act = *it;
 213                         ModelAction *lastact = last_act[id_to_int(act->get_tid())];
 214                         if (act->is_thread_start())
 215                                 lastact=model->get_thread(act)->get_creation();
 216                         ClockVector *lastcv=(lastact != NULL) ? cvmap->get(lastact) : NULL;
 217                         last_act[id_to_int(act->get_tid())]=act;
 218                         ClockVector *cv=cvmap->get(act);
 219                         if ( cv == NULL ) {
 220                                 cv = new ClockVector(lastcv, act);
 221                                 cvmap->put(act, cv);
 222                         } else if ( lastcv != NULL ) {
 223                                 merge(cv, act, lastcv);
 224                         }
 225                         if (act->is_thread_join()) {
 226                                 Thread *joinedthr = act->get_thread_operand();
 227                                 ModelAction *finish = model->get_last_action(joinedthr->get_id());
 228                                 ClockVector *finishcv = cvmap->get(finish);
 229                                 changed |= (finishcv == NULL) || merge(cv, act, finishcv);
 230                         }
 231                         if (act->is_read()) {
 232                                 changed|=processRead(act, cv);
 233                         }
 234                 }
 235                 /* Reset the last action array */
 236                 if (changed) {
 237                         bzero(last_act, (maxthreads+1)*sizeof(ModelAction *));
 238                 }
 239         }
 240         model_free(last_act);
 241 }