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         threadlists=new SnapVector<action_list_t>(1);
   9 }
  10
  11 SCAnalysis::~SCAnalysis() {
  12         delete cvmap;
  13         delete threadlists;
  14 }
  15
  16 void SCAnalysis::print_list(action_list_t *list) {
  17         action_list_t::iterator it;
  18
  19         model_print("---------------------------------------------------------------------\n");
  20
  21         unsigned int hash = 0;
  22
  23         for (it = list->begin(); it != list->end(); it++) {
  24                 const ModelAction *act = *it;
  25                 if (act->get_seq_number() > 0)
  26                         act->print();
  27                 hash = hash^(hash<<3)^((*it)->hash());
  28         }
  29         model_print("HASH %u\n", hash);
  30         model_print("---------------------------------------------------------------------\n");
  31 }
  32
  33 void SCAnalysis::analyze(action_list_t * actions) {
  34         buildVectors(actions);
  35         computeCV(actions);
  36         action_list_t *list=generateSC(actions);
  37         print_list(list);
  38 }
  39
  40 ModelAction * SCAnalysis::getNextAction() {
  41         ModelAction *act=NULL;
  42         for(int i=0;i<=maxthreads;i++) {
  43                 action_list_t * threadlist=&(*threadlists)[i];
  44                 if (threadlist->empty())
  45                         continue;
  46                 ModelAction *first=threadlist->front();
  47                 if (act==NULL) {
  48                         act=first;
  49                         continue;
  50                 }
  51                 ClockVector *cv=cvmap->get(act);
  52                 if (cv->synchronized_since(first)) {
  53                         act=first;
  54                 }
  55         }
  56         return act;
  57 }
  58
  59 action_list_t * SCAnalysis::generateSC(action_list_t *list) {
  60         action_list_t *sclist=new action_list_t();
  61         while (true) {
  62                 ModelAction * act=getNextAction();
  63                 if (act==NULL)
  64                         break;
  65                 thread_id_t tid=act->get_tid();
  66                 //remove action
  67                 (*threadlists)[id_to_int(tid)].pop_front();
  68                 //add ordering constraints from this choice
  69                 if (updateConstraints(act)) {
  70                         //propagate changes if we have them
  71                         computeCV(list);
  72                 }
  73                 //add action to end
  74                 sclist->push_back(act);
  75         }
  76         return sclist;
  77 }
  78
  79 void SCAnalysis::buildVectors(action_list_t *list) {
  80         maxthreads=0;
  81         for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
  82                 ModelAction *act = *it;
  83                 int threadid=id_to_int(act->get_tid());
  84                 if (threadid > maxthreads) {
  85                         threadlists->resize(threadid+1);
  86                         maxthreads=threadid;
  87                 }
  88                 (*threadlists)[threadid].push_back(act);
  89         }
  90 }
  91
  92 bool SCAnalysis::updateConstraints(ModelAction *act) {
  93         bool changed=false;
  94         ClockVector *actcv = cvmap->get(act);
  95         for(int i=0;i<=maxthreads;i++) {
  96                 thread_id_t tid=int_to_id(i);
  97                 if (tid==act->get_tid())
  98                         continue;
  99
 100                 action_list_t * list=&(*threadlists)[id_to_int(tid)];
 101                 for (action_list_t::iterator rit = list->begin(); rit != list->end(); rit++) {
 102                         ModelAction *write = *rit;
 103                         if (!write->is_write())
 104                                 continue;
 105                         ClockVector *writecv = cvmap->get(write);
 106                         if (writecv->synchronized_since(act))
 107                                 break;
 108                         if (write->get_location() == act->get_location()) {
 109                                 //write is sc after act
 110                                 writecv->merge(actcv);
 111                                 changed=true;
 112                                 break;
 113                         }
 114                 }
 115         }
 116         return changed;
 117 }
 118
 119 bool SCAnalysis::processRead(ModelAction *read, ClockVector *cv) {
 120         bool changed=false;
 121
 122         /* Merge in the clock vector from the write */
 123         const ModelAction *write=read->get_reads_from();
 124         ClockVector *writecv=cvmap->get(write);
 125         changed|= ( writecv == NULL || cv->merge(writecv) && (*read < *write));
 126
 127         for(int i=0;i<=maxthreads;i++) {
 128                 thread_id_t tid=int_to_id(i);
 129                 if (tid==read->get_tid())
 130                         continue;
 131                 if (tid==write->get_tid())
 132                         continue;
 133                 action_list_t * list=model->get_actions_on_obj(read->get_location(), tid);
 134                 if (list==NULL)
 135                         continue;
 136                 for (action_list_t::reverse_iterator rit = list->rbegin(); rit != list->rend(); rit++) {
 137                         ModelAction *write2 = *rit;
 138                         if (!write2->is_write())
 139                                 continue;
 140
 141                         ClockVector *write2cv = cvmap->get(write2);
 142                         if (write2cv == NULL)
 143                                 continue;
 144
 145                         /* write -sc-> write2 &&
 146                                  write -rf-> R =>
 147                                  R -sc-> write2 */
 148                         if (write2cv->synchronized_since(write)) {
 149                                 changed |= write2cv->merge(cv);
 150                         }
 151
 152                         //looking for earliest write2 in iteration to satisfy this
 153                         /* write2 -sc-> R &&
 154                                  write -rf-> R =>
 155                                  write2 -sc-> write */
 156                         if (cv->synchronized_since(write2)) {
 157                                 changed |= writecv == NULL || writecv->merge(write2cv);
 158                                 break;
 159                         }
 160                 }
 161         }
 162         return changed;
 163 }
 164
 165
 166 void SCAnalysis::computeCV(action_list_t *list) {
 167         bool changed=true;
 168         bool firsttime=true;
 169         ModelAction **last_act=(ModelAction **)model_calloc(1,(maxthreads+1)*sizeof(ModelAction *));
 170         while(changed) {
 171                 changed=changed&firsttime;
 172                 firsttime=false;
 173
 174                 for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
 175                         ModelAction *act = *it;
 176                         ModelAction *lastact = last_act[id_to_int(act->get_tid())];
 177                         if (act->is_thread_start())
 178                                 lastact=model->get_thread(act)->get_creation();
 179                         ClockVector *lastcv=(lastact != NULL) ? cvmap->get(lastact) : NULL;
 180                         last_act[id_to_int(act->get_tid())]=act;
 181                         ClockVector *cv=cvmap->get(act);
 182                         if ( cv == NULL ) {
 183                                 cv = new ClockVector(lastcv, act);
 184                                 cvmap->put(act, cv);
 185                         } else if ( lastcv != NULL ) {
 186                                         cv->merge(lastcv);
 187                         }
 188                         if (act->is_thread_join()) {
 189                                 Thread *joinedthr = act->get_thread_operand();
 190                                 ModelAction *finish = model->get_last_action(joinedthr->get_id());
 191                                 ClockVector *finishcv = cvmap->get(finish);
 192                                 changed |= (finishcv == NULL) || cv->merge(finishcv);
 193                         }
 194                         if (act->is_read()) {
 195                                 changed|=processRead(act, cv);
 196                         }
 197                 }
 198                 /* Reset the last action array */
 199                 if (changed) {
 200                         bzero(last_act, (maxthreads+1)*sizeof(ModelAction *));
 201                 }
 202         }
 203         model_free(last_act);
 204 }