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         cyclic(false),
  10         badrfset(),
  11         lastwrmap(),
  12         threadlists(1),
  13         execution(execution)
  14 {
  15 }
  16
  17 SCAnalysis::~SCAnalysis() {
  18 }
  19
  20 void SCAnalysis::print_list(action_list_t *list) {
  21         model_print("---------------------------------------------------------------------\n");
  22         if (cyclic)
  23                 model_print("Not SC\n");
  24         unsigned int hash = 0;
  25
  26         for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
  27                 const ModelAction *act = *it;
  28                 if (act->get_seq_number() > 0) {
  29                         if (badrfset.contains(act))
  30                                 model_print("BRF ");
  31                         act->print();
  32                         if (badrfset.contains(act)) {
  33                                 model_print("Desired Rf: %u \n",badrfset.get(act)->get_seq_number());
  34                         }
  35                 }
  36                 hash = hash ^ (hash << 3) ^ ((*it)->hash());
  37         }
  38         model_print("HASH %u\n", hash);
  39         model_print("---------------------------------------------------------------------\n");
  40 }
  41
  42 void SCAnalysis::analyze(action_list_t *actions) {
  43         buildVectors(actions);
  44         computeCV(actions);
  45         action_list_t *list = generateSC(actions);
  46         check_rf(list);
  47         print_list(list);
  48 }
  49
  50 void SCAnalysis::check_rf(action_list_t *list) {
  51         for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
  52                 const ModelAction *act = *it;
  53                 if (act->is_read()) {
  54                         if (act->get_reads_from()!=lastwrmap.get(act->get_location()))
  55                                 badrfset.put(act,lastwrmap.get(act->get_location()));
  56                 }
  57                 if (act->is_write())
  58                         lastwrmap.put(act->get_location(), act);
  59         }
  60 }
  61
  62 bool SCAnalysis::merge(ClockVector *cv, const ModelAction *act, const ModelAction *act2) {
  63         ClockVector * cv2=cvmap.get(act2);
  64         if (cv2==NULL)
  65                 return true;
  66         if (cv2->getClock(act->get_tid()) >= act->get_seq_number() && act->get_seq_number() != 0) {
  67                 cyclic=true;
  68                 //refuse to introduce cycles into clock vectors
  69                 return false;
  70         }
  71
  72         return cv->merge(cv2);
  73 }
  74
  75 ModelAction * SCAnalysis::getNextAction() {
  76         ModelAction *act = NULL;
  77         /* Find the earliest in SC ordering */
  78         for (int i = 0; i <= maxthreads; i++) {
  79                 action_list_t *threadlist = &threadlists[i];
  80                 if (threadlist->empty())
  81                         continue;
  82                 ModelAction *first = threadlist->front();
  83                 if (act==NULL) {
  84                         act=first;
  85                         continue;
  86                 }
  87                 ClockVector *cv = cvmap.get(act);
  88                 if (cv->synchronized_since(first)) {
  89                         act = first;
  90                 }
  91         }
  92         if (act == NULL)
  93                 return act;
  94
  95
  96         /* Find the model action with the earliest sequence number in case of a cycle.
  97          */
  98
  99         for (int i = 0; i <= maxthreads; i++) {
 100                 action_list_t *threadlist = &threadlists[i];
 101                 if (threadlist->empty())
 102                         continue;
 103                 ModelAction *first = threadlist->front();
 104                 ClockVector *cv = cvmap.get(act);
 105                 ClockVector *cvfirst = cvmap.get(first);
 106                 if (first->get_seq_number()<act->get_seq_number()&&
 107                                 (cv->synchronized_since(first)||!cvfirst->synchronized_since(act))) {
 108                         act=first;
 109                 }
 110         }
 111
 112         /* See if hb demands an earlier action. */
 113         for (int i = 0; i <= maxthreads; i++) {
 114                 action_list_t *threadlist = &threadlists[i];
 115                 if (threadlist->empty())
 116                         continue;
 117                 ModelAction *first = threadlist->front();
 118                 ClockVector *cv = act->get_cv();
 119                 if (cv->synchronized_since(first)) {
 120                         act = first;
 121                 }
 122         }
 123         return act;
 124 }
 125
 126 action_list_t * SCAnalysis::generateSC(action_list_t *list) {
 127         action_list_t *sclist = new action_list_t();
 128         while (true) {
 129                 ModelAction *act = getNextAction();
 130                 if (act == NULL)
 131                         break;
 132                 thread_id_t tid = act->get_tid();
 133                 //remove action
 134                 threadlists[id_to_int(tid)].pop_front();
 135                 //add ordering constraints from this choice
 136                 if (updateConstraints(act)) {
 137                         //propagate changes if we have them
 138                         computeCV(list);
 139                 }
 140                 //add action to end
 141                 sclist->push_back(act);
 142         }
 143         return sclist;
 144 }
 145
 146 void SCAnalysis::buildVectors(action_list_t *list) {
 147         maxthreads = 0;
 148         for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
 149                 ModelAction *act = *it;
 150                 int threadid = id_to_int(act->get_tid());
 151                 if (threadid > maxthreads) {
 152                         threadlists.resize(threadid + 1);
 153                         maxthreads = threadid;
 154                 }
 155                 threadlists[threadid].push_back(act);
 156         }
 157 }
 158
 159 bool SCAnalysis::updateConstraints(ModelAction *act) {
 160         bool changed = false;
 161         for (int i = 0; i <= maxthreads; i++) {
 162                 thread_id_t tid = int_to_id(i);
 163                 if (tid == act->get_tid())
 164                         continue;
 165
 166                 action_list_t *list = &threadlists[id_to_int(tid)];
 167                 for (action_list_t::iterator rit = list->begin(); rit != list->end(); rit++) {
 168                         ModelAction *write = *rit;
 169                         if (!write->is_write())
 170                                 continue;
 171                         ClockVector *writecv = cvmap.get(write);
 172                         if (writecv->synchronized_since(act))
 173                                 break;
 174                         if (write->get_location() == act->get_location()) {
 175                                 //write is sc after act
 176                                 merge(writecv, write, act);
 177                                 changed = true;
 178                                 break;
 179                         }
 180                 }
 181         }
 182         return changed;
 183 }
 184
 185 bool SCAnalysis::processRead(ModelAction *read, ClockVector *cv) {
 186         bool changed = false;
 187
 188         /* Merge in the clock vector from the write */
 189         const ModelAction *write = read->get_reads_from();
 190         ClockVector *writecv = cvmap.get(write);
 191         changed |= merge(cv, read, write) && (*read < *write);
 192
 193         for (int i = 0; i <= maxthreads; i++) {
 194                 thread_id_t tid = int_to_id(i);
 195                 if (tid == read->get_tid())
 196                         continue;
 197                 if (tid == write->get_tid())
 198                         continue;
 199                 action_list_t *list = execution->get_actions_on_obj(read->get_location(), tid);
 200                 if (list == NULL)
 201                         continue;
 202                 for (action_list_t::reverse_iterator rit = list->rbegin(); rit != list->rend(); rit++) {
 203                         ModelAction *write2 = *rit;
 204                         if (!write2->is_write())
 205                                 continue;
 206
 207                         ClockVector *write2cv = cvmap.get(write2);
 208                         if (write2cv == NULL)
 209                                 continue;
 210
 211                         /* write -sc-> write2 &&
 212                                  write -rf-> R =>
 213                                  R -sc-> write2 */
 214                         if (write2cv->synchronized_since(write)) {
 215                                 changed |= merge(write2cv, write2, read);
 216                         }
 217
 218                         //looking for earliest write2 in iteration to satisfy this
 219                         /* write2 -sc-> R &&
 220                                  write -rf-> R =>
 221                                  write2 -sc-> write */
 222                         if (cv->synchronized_since(write2)) {
 223                                 changed |= writecv==NULL || merge(writecv, write, write2);
 224                                 break;
 225                         }
 226                 }
 227         }
 228         return changed;
 229 }
 230
 231 void SCAnalysis::computeCV(action_list_t *list) {
 232         bool changed = true;
 233         bool firsttime = true;
 234         ModelAction **last_act = (ModelAction **)model_calloc(1, (maxthreads + 1) * sizeof(ModelAction *));
 235         while (changed) {
 236                 changed = changed&firsttime;
 237                 firsttime = false;
 238
 239                 for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
 240                         ModelAction *act = *it;
 241                         ModelAction *lastact = last_act[id_to_int(act->get_tid())];
 242                         if (act->is_thread_start())
 243                                 lastact = execution->get_thread(act)->get_creation();
 244                         last_act[id_to_int(act->get_tid())] = act;
 245                         ClockVector *cv = cvmap.get(act);
 246                         if (cv == NULL) {
 247                                 cv = new ClockVector(NULL, act);
 248                                 cvmap.put(act, cv);
 249                         }
 250                         if (lastact != NULL) {
 251                                 merge(cv, act, lastact);
 252                         }
 253                         if (act->is_thread_join()) {
 254                                 Thread *joinedthr = act->get_thread_operand();
 255                                 ModelAction *finish = execution->get_last_action(joinedthr->get_id());
 256                                 changed |= merge(cv, act, finish);
 257                         }
 258                         if (act->is_read()) {
 259                                 changed |= processRead(act, cv);
 260                         }
 261                 }
 262                 /* Reset the last action array */
 263                 if (changed) {
 264                         bzero(last_act, (maxthreads + 1) * sizeof(ModelAction *));
 265                 }
 266         }
 267         model_free(last_act);
 268 }