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         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 = execution->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 = execution->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 void SCAnalysis::computeCV(action_list_t *list) {
 203         bool changed = true;
 204         bool firsttime = true;
 205         ModelAction **last_act = (ModelAction **)model_calloc(1, (maxthreads + 1) * sizeof(ModelAction *));
 206         while (changed) {
 207                 changed = changed&firsttime;
 208                 firsttime = false;
 209
 210                 for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
 211                         ModelAction *act = *it;
 212                         ModelAction *lastact = last_act[id_to_int(act->get_tid())];
 213                         if (act->is_thread_start())
 214                                 lastact = execution->get_thread(act)->get_creation();
 215                         ClockVector *lastcv = (lastact != NULL) ? cvmap.get(lastact) : NULL;
 216                         last_act[id_to_int(act->get_tid())] = act;
 217                         ClockVector *cv = cvmap.get(act);
 218                         if (cv == NULL) {
 219                                 cv = new ClockVector(lastcv, act);
 220                                 cvmap.put(act, cv);
 221                         } else if (lastcv != NULL) {
 222                                 merge(cv, act, lastcv);
 223                         }
 224                         if (act->is_thread_join()) {
 225                                 Thread *joinedthr = act->get_thread_operand();
 226                                 ModelAction *finish = execution->get_last_action(joinedthr->get_id());
 227                                 ClockVector *finishcv = cvmap.get(finish);
 228                                 changed |= (finishcv == NULL) || merge(cv, act, finishcv);
 229                         }
 230                         if (act->is_read()) {
 231                                 changed |= processRead(act, cv);
 232                         }
 233                 }
 234                 /* Reset the last action array */
 235                 if (changed) {
 236                         bzero(last_act, (maxthreads + 1) * sizeof(ModelAction *));
 237                 }
 238         }
 239         model_free(last_act);
 240 }