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         execution(execution)
   9 {
  10         cvmap = new HashTable <const ModelAction *, ClockVector *, uintptr_t, 4>();
  11         cycleset = new HashTable <const ModelAction *, const ModelAction *, uintptr_t, 4>();
  12         threadlists = new SnapVector <action_list_t>(1);
  13 }
  14
  15 SCAnalysis::~SCAnalysis() {
  16         delete cvmap;
  17         delete cycleset;
  18         delete threadlists;
  19 }
  20
  21 void SCAnalysis::print_list(action_list_t *list) {
  22         action_list_t::iterator it;
  23
  24         model_print("---------------------------------------------------------------------\n");
  25
  26         unsigned int hash = 0;
  27
  28         for (it = list->begin(); it != list->end(); it++) {
  29                 const ModelAction *act = *it;
  30                 if (act->get_seq_number() > 0) {
  31                         if (cycleset->contains(act))
  32                                 model_print("CYC");
  33                         act->print();
  34                 }
  35                 hash = hash ^ (hash << 3) ^ ((*it)->hash());
  36         }
  37         model_print("HASH %u\n", hash);
  38         model_print("---------------------------------------------------------------------\n");
  39 }
  40
  41 void SCAnalysis::analyze(action_list_t *actions) {
  42         buildVectors(actions);
  43         computeCV(actions);
  44         action_list_t *list = generateSC(actions);
  45         print_list(list);
  46 }
  47
  48 bool SCAnalysis::merge(ClockVector *cv, const ModelAction *act, ClockVector *cv2) {
  49         if (cv2->getClock(act->get_tid()) >= act->get_seq_number() && act->get_seq_number() != 0) {
  50                 cycleset->put(act, act);
  51         }
  52         return cv->merge(cv2);
  53 }
  54
  55 ModelAction * SCAnalysis::getNextAction() {
  56         ModelAction *act = NULL;
  57         for (int i = 0; i <= maxthreads; i++) {
  58                 action_list_t *threadlist = &(*threadlists)[i];
  59                 if (threadlist->empty())
  60                         continue;
  61                 ModelAction *first = threadlist->front();
  62                 if (act == NULL) {
  63                         act = first;
  64                         continue;
  65                 }
  66                 ClockVector *cv = cvmap->get(act);
  67                 if (cv->synchronized_since(first)) {
  68                         act = first;
  69                 }
  70         }
  71         if (act == NULL)
  72                 return act;
  73         //print cycles in a nice way to avoid confusion
  74         //make sure thread starts appear after the create
  75         if (act->is_thread_start()) {
  76                 ModelAction *createact = execution->get_thread(act)->get_creation();
  77                 if (createact) {
  78                         action_list_t *threadlist = &(*threadlists)[id_to_int(createact->get_tid())];
  79                         if (!threadlist->empty()) {
  80                                 ModelAction *first = threadlist->front();
  81                                 if (first->get_seq_number() <= createact->get_seq_number())
  82                                         act = first;
  83                         }
  84                 }
  85         }
  86
  87         //make sure that joins appear after the thread is finished
  88         if (act->is_thread_join()) {
  89                 int jointhread = id_to_int(act->get_thread_operand()->get_id());
  90                 action_list_t *threadlist = &(*threadlists)[jointhread];
  91                 if (!threadlist->empty()) {
  92                         act = threadlist->front();
  93                 }
  94         }
  95
  96         return act;
  97 }
  98
  99 action_list_t * SCAnalysis::generateSC(action_list_t *list) {
 100         action_list_t *sclist = new action_list_t();
 101         while (true) {
 102                 ModelAction *act = getNextAction();
 103                 if (act == NULL)
 104                         break;
 105                 thread_id_t tid = act->get_tid();
 106                 //remove action
 107                 (*threadlists)[id_to_int(tid)].pop_front();
 108                 //add ordering constraints from this choice
 109                 if (updateConstraints(act)) {
 110                         //propagate changes if we have them
 111                         computeCV(list);
 112                 }
 113                 //add action to end
 114                 sclist->push_back(act);
 115         }
 116         return sclist;
 117 }
 118
 119 void SCAnalysis::buildVectors(action_list_t *list) {
 120         maxthreads = 0;
 121         for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
 122                 ModelAction *act = *it;
 123                 int threadid = id_to_int(act->get_tid());
 124                 if (threadid > maxthreads) {
 125                         threadlists->resize(threadid + 1);
 126                         maxthreads = threadid;
 127                 }
 128                 (*threadlists)[threadid].push_back(act);
 129         }
 130 }
 131
 132 bool SCAnalysis::updateConstraints(ModelAction *act) {
 133         bool changed = false;
 134         ClockVector *actcv = cvmap->get(act);
 135         for (int i = 0; i <= maxthreads; i++) {
 136                 thread_id_t tid = int_to_id(i);
 137                 if (tid == act->get_tid())
 138                         continue;
 139
 140                 action_list_t *list = &(*threadlists)[id_to_int(tid)];
 141                 for (action_list_t::iterator rit = list->begin(); rit != list->end(); rit++) {
 142                         ModelAction *write = *rit;
 143                         if (!write->is_write())
 144                                 continue;
 145                         ClockVector *writecv = cvmap->get(write);
 146                         if (writecv->synchronized_since(act))
 147                                 break;
 148                         if (write->get_location() == act->get_location()) {
 149                                 //write is sc after act
 150                                 merge(writecv, write, actcv);
 151                                 changed = true;
 152                                 break;
 153                         }
 154                 }
 155         }
 156         return changed;
 157 }
 158
 159 bool SCAnalysis::processRead(ModelAction *read, ClockVector *cv) {
 160         bool changed = false;
 161
 162         /* Merge in the clock vector from the write */
 163         const ModelAction *write = read->get_reads_from();
 164         ClockVector *writecv = cvmap->get(write);
 165         changed |= writecv == NULL || (merge(cv, read, writecv) && (*read < *write));
 166
 167         for (int i = 0; i <= maxthreads; i++) {
 168                 thread_id_t tid = int_to_id(i);
 169                 if (tid == read->get_tid())
 170                         continue;
 171                 if (tid == write->get_tid())
 172                         continue;
 173                 action_list_t *list = execution->get_actions_on_obj(read->get_location(), tid);
 174                 if (list == NULL)
 175                         continue;
 176                 for (action_list_t::reverse_iterator rit = list->rbegin(); rit != list->rend(); rit++) {
 177                         ModelAction *write2 = *rit;
 178                         if (!write2->is_write())
 179                                 continue;
 180
 181                         ClockVector *write2cv = cvmap->get(write2);
 182                         if (write2cv == NULL)
 183                                 continue;
 184
 185                         /* write -sc-> write2 &&
 186                                  write -rf-> R =>
 187                                  R -sc-> write2 */
 188                         if (write2cv->synchronized_since(write)) {
 189                                 changed |= merge(write2cv, write2, cv);
 190                         }
 191
 192                         //looking for earliest write2 in iteration to satisfy this
 193                         /* write2 -sc-> R &&
 194                                  write -rf-> R =>
 195                                  write2 -sc-> write */
 196                         if (cv->synchronized_since(write2)) {
 197                                 changed |= writecv == NULL || merge(writecv, write, write2cv);
 198                                 break;
 199                         }
 200                 }
 201         }
 202         return changed;
 203 }
 204
 205 void SCAnalysis::computeCV(action_list_t *list) {
 206         bool changed = true;
 207         bool firsttime = true;
 208         ModelAction **last_act = (ModelAction **)model_calloc(1, (maxthreads + 1) * sizeof(ModelAction *));
 209         while (changed) {
 210                 changed = changed&firsttime;
 211                 firsttime = false;
 212
 213                 for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
 214                         ModelAction *act = *it;
 215                         ModelAction *lastact = last_act[id_to_int(act->get_tid())];
 216                         if (act->is_thread_start())
 217                                 lastact = execution->get_thread(act)->get_creation();
 218                         ClockVector *lastcv = (lastact != NULL) ? cvmap->get(lastact) : NULL;
 219                         last_act[id_to_int(act->get_tid())] = act;
 220                         ClockVector *cv = cvmap->get(act);
 221                         if (cv == NULL) {
 222                                 cv = new ClockVector(lastcv, act);
 223                                 cvmap->put(act, cv);
 224                         } else if (lastcv != NULL) {
 225                                 merge(cv, act, lastcv);
 226                         }
 227                         if (act->is_thread_join()) {
 228                                 Thread *joinedthr = act->get_thread_operand();
 229                                 ModelAction *finish = execution->get_last_action(joinedthr->get_id());
 230                                 ClockVector *finishcv = cvmap->get(finish);
 231                                 changed |= (finishcv == NULL) || merge(cv, act, finishcv);
 232                         }
 233                         if (act->is_read()) {
 234                                 changed |= processRead(act, cv);
 235                         }
 236                 }
 237                 /* Reset the last action array */
 238                 if (changed) {
 239                         bzero(last_act, (maxthreads + 1) * sizeof(ModelAction *));
 240                 }
 241         }
 242         model_free(last_act);
 243 }