Merge demsky's SC analysis fixup
authorBrian Norris <banorris@uci.edu>
Fri, 3 May 2013 16:51:20 +0000 (09:51 -0700)
committerBrian Norris <banorris@uci.edu>
Fri, 3 May 2013 16:51:41 +0000 (09:51 -0700)
1  2 
scanalysis.cc

diff --combined scanalysis.cc
index 2f7fd361cab5a3126cf5d330df0f30caa768942d,e6cbddc71e4f01f70f176e7c63ad5917c25888b2..98dd8eb43d43bd729a59139dff778a93ceb9fd48
@@@ -30,7 -30,7 +30,7 @@@ void SCAnalysis::print_list(action_list
                                model_print("BRF ");
                        act->print();
                        if (badrfset.contains(act)) {
 -                              model_print("Desired Rf: %u \n",badrfset.get(act)->get_seq_number());
 +                              model_print("Desired Rf: %u \n", badrfset.get(act)->get_seq_number());
                        }
                }
                hash = hash ^ (hash << 3) ^ ((*it)->hash());
@@@ -40,8 -40,6 +40,6 @@@
  }
  
  void SCAnalysis::analyze(action_list_t *actions) {
-       buildVectors(actions);
-       computeCV(actions);
        action_list_t *list = generateSC(actions);
        check_rf(list);
        print_list(list);
@@@ -51,8 -49,8 +49,8 @@@ void SCAnalysis::check_rf(action_list_
        for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
                const ModelAction *act = *it;
                if (act->is_read()) {
 -                      if (act->get_reads_from()!=lastwrmap.get(act->get_location()))
 -                              badrfset.put(act,lastwrmap.get(act->get_location()));
 +                      if (act->get_reads_from() != lastwrmap.get(act->get_location()))
 +                              badrfset.put(act, lastwrmap.get(act->get_location()));
                }
                if (act->is_write())
                        lastwrmap.put(act->get_location(), act);
  }
  
  bool SCAnalysis::merge(ClockVector *cv, const ModelAction *act, const ModelAction *act2) {
 -      ClockVector * cv2=cvmap.get(act2);
 -      if (cv2==NULL)
 +      ClockVector *cv2 = cvmap.get(act2);
 +      if (cv2 == NULL)
                return true;
        if (cv2->getClock(act->get_tid()) >= act->get_seq_number() && act->get_seq_number() != 0) {
 -              cyclic=true;
 +              cyclic = true;
                //refuse to introduce cycles into clock vectors
                return false;
        }
        return cv->merge(cv2);
  }
  
ModelAction * SCAnalysis::getNextAction() {
-       ModelAction *act = NULL;
-       /* Find the earliest in SC ordering */
-       for (int i = 0; i <= maxthreads; i++) {
-               action_list_t *threadlist = &threadlists[i];
-               if (threadlist->empty())
int SCAnalysis::getNextActions(ModelAction ** array) {
+       int count=0;
+       for (int t = 0; t <= maxthreads; t++) {
+               action_list_t *tlt = &threadlists[t];
+               if (tlt->empty())
                        continue;
-               ModelAction *first = threadlist->front();
-               if (act == NULL) {
-                       act = first;
+               ModelAction *act = tlt->front();
+               ClockVector *cv = cvmap.get(act);
+               
+               /* Find the earliest in SC ordering */
+               for (int i = 0; i <= maxthreads; i++) {
+                       if ( i == t )
+                               continue;
+                       action_list_t *threadlist = &threadlists[i];
+                       if (threadlist->empty())
+                               continue;
+                       ModelAction *first = threadlist->front();
+                       if (cv->synchronized_since(first)) {
+                               act = NULL;
+                               break;
+                       }
+               }
+               if (act != NULL) {
+                       array[count++]=act;
+               }
+       }
+       if (count != 0)
+               return count;
+       for (int t = 0; t <= maxthreads; t++) {
+               action_list_t *tlt = &threadlists[t];
+               if (tlt->empty())
                        continue;
+               ModelAction *act = tlt->front();
+               ClockVector *cv = act->get_cv();
+               
+               /* Find the earliest in SC ordering */
+               for (int i = 0; i <= maxthreads; i++) {
+                       if ( i == t )
+                               continue;
+                       action_list_t *threadlist = &threadlists[i];
+                       if (threadlist->empty())
+                               continue;
+                       ModelAction *first = threadlist->front();
+                       if (cv->synchronized_since(first)) {
+                               act = NULL;
+                               break;
+                       }
                }
-               ClockVector *cv = cvmap.get(act);
-               if (cv->synchronized_since(first)) {
-                       act = first;
+               if (act != NULL) {
+                       array[count++]=act;
                }
        }
-       if (act == NULL)
-               return act;
  
-       /* Find the model action with the earliest sequence number in case of a cycle.
-        */
+       ASSERT(count==0 || cyclic);
  
-       for (int i = 0; i <= maxthreads; i++) {
-               action_list_t *threadlist = &threadlists[i];
-               if (threadlist->empty())
-                       continue;
-               ModelAction *first = threadlist->front();
-               ClockVector *cvfirst = cvmap.get(first);
-               if (first->get_seq_number() < act->get_seq_number()) {
-                       bool candidate = true;
-                       for (int j = 0; j <= maxthreads; j++) {
-                               action_list_t *threadlist2 = &threadlists[j];
-                               if (threadlist2->empty())
+       return count;
+ }
+ ModelAction * SCAnalysis::pruneArray(ModelAction **array,int count) {
+       /* No choice */
+       if (count == 1)
+               return array[0];
+       /* Choose first non-write action */
+       ModelAction *nonwrite=NULL;
+       for(int i=0;i<count;i++) {
+               if (!array[i]->is_write())
+                       if (nonwrite==NULL || nonwrite->get_seq_number() > array[i]->get_seq_number())
+                               nonwrite = array[i];
+       }
+       if (nonwrite != NULL)
+               return nonwrite;
+       
+       /* Look for non-conflicting action */
+       ModelAction *nonconflict=NULL;
+       for(int a=0;a<count;a++) {
+               ModelAction *act=array[a];
+               for (int i = 0; i <= maxthreads && act != NULL; i++) {
+                       thread_id_t tid = int_to_id(i);
+                       if (tid == act->get_tid())
+                               continue;
+                       
+                       action_list_t *list = &threadlists[id_to_int(tid)];
+                       for (action_list_t::iterator rit = list->begin(); rit != list->end(); rit++) {
+                               ModelAction *write = *rit;
+                               if (!write->is_write())
                                        continue;
-                               ModelAction *check = threadlist2->front();
-                               if ((check != first) &&
-                                               cvfirst->synchronized_since(check)) {
-                                       candidate = false;
+                               ClockVector *writecv = cvmap.get(write);
+                               if (writecv->synchronized_since(act))
+                                       break;
+                               if (write->get_location() == act->get_location()) {
+                                       //write is sc after act
+                                       act = NULL;
                                        break;
                                }
                        }
-                       if (candidate)
-                               act = first;
                }
-       }
-       /* See if hb demands an earlier action. */
-       for (int i = 0; i <= maxthreads; i++) {
-               action_list_t *threadlist = &threadlists[i];
-               if (threadlist->empty())
-                       continue;
-               ModelAction *first = threadlist->front();
-               ClockVector *cv = act->get_cv();
-               if (cv->synchronized_since(first)) {
-                       act = first;
+               if (act != NULL) {
+                       if (nonconflict == NULL || nonconflict->get_seq_number() > act->get_seq_number())
+                               nonconflict=act;
                }
        }
-       return act;
+       return nonconflict;
  }
  
  action_list_t * SCAnalysis::generateSC(action_list_t *list) {
+       int numactions=buildVectors(list);
+       computeCV(list);
        action_list_t *sclist = new action_list_t();
+       ModelAction **array = (ModelAction **)model_calloc(1, (maxthreads + 1) * sizeof(ModelAction *));
+       int * choices = (int *) model_calloc(1, sizeof(int)*numactions);
+       int endchoice = 0;
+       int currchoice = 0;
+       int lastchoice = -1;
        while (true) {
-               ModelAction *act = getNextAction();
-               if (act == NULL)
+               int numActions = getNextActions(array);
+               if (numActions == 0)
                        break;
+               ModelAction * act=pruneArray(array, numActions);
+               if (act == NULL) {
+                       if (currchoice < endchoice) {
+                               act = array[choices[currchoice]];
+                               //check whether there is still another option
+                               if ((choices[currchoice]+1)<numActions)
+                                       lastchoice=currchoice;
+                               currchoice++;
+                       } else {
+                               act = array[0];
+                               choices[currchoice]=0;
+                               if (numActions>1)
+                                       lastchoice=currchoice;
+                               currchoice++;
+                       }
+               }
                thread_id_t tid = act->get_tid();
                //remove action
                threadlists[id_to_int(tid)].pop_front();
                //add ordering constraints from this choice
                if (updateConstraints(act)) {
                        //propagate changes if we have them
-                       bool oc = cyclic;
+                       bool prevc=cyclic;
                        computeCV(list);
-                       if (!oc && cyclic)
-                               model_print("XXXXXXXXXXXXXX\n");
+                       if (!prevc && cyclic) {
+                               model_print("ROLLBACK in SC\n");
+                               //check whether we have another choice
+                               if (lastchoice != -1) {
+                                       //have to reset everything
+                                       choices[lastchoice]++;
+                                       endchoice=lastchoice+1;
+                                       currchoice=0;
+                                       lastchoice=-1;
+                                       reset(list);
+                                       buildVectors(list);
+                                       computeCV(list);
+                                       sclist->clear();
+                                       continue;
+                               }
+                       }
                }
                //add action to end
                sclist->push_back(act);
        }
+       model_free(array);
        return sclist;
  }
  
void SCAnalysis::buildVectors(action_list_t *list) {
int SCAnalysis::buildVectors(action_list_t *list) {
        maxthreads = 0;
+       int numactions = 0;
        for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
                ModelAction *act = *it;
+               numactions++;
                int threadid = id_to_int(act->get_tid());
                if (threadid > maxthreads) {
                        threadlists.resize(threadid + 1);
                }
                threadlists[threadid].push_back(act);
        }
+       return numactions;
+ }
+ void SCAnalysis::reset(action_list_t *list) {
+       for (int t = 0; t <= maxthreads; t++) {
+               action_list_t *tlt = &threadlists[t];
+               tlt->clear();
+       }
+       for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
+               ModelAction *act = *it;
+               delete cvmap.get(act);
+               cvmap.put(act, NULL);
+       }
+       cyclic=false;   
  }
  
  bool SCAnalysis::updateConstraints(ModelAction *act) {
@@@ -233,7 -332,7 +332,7 @@@ bool SCAnalysis::processRead(ModelActio
                                 write -rf-> R =>
                                 write2 -sc-> write */
                        if (cv->synchronized_since(write2)) {
 -                              changed |= writecv==NULL || merge(writecv, write, write2);
 +                              changed |= writecv == NULL || merge(writecv, write, write2);
                                break;
                        }
                }