SCAnalysis::SCAnalysis(const ModelExecution *execution) :
cvmap(),
- cycleset(),
+ cyclic(false),
+ badrfset(),
+ lastwrmap(),
threadlists(1),
execution(execution)
{
}
void SCAnalysis::print_list(action_list_t *list) {
- action_list_t::iterator it;
-
model_print("---------------------------------------------------------------------\n");
-
+ if (cyclic)
+ model_print("Not SC\n");
unsigned int hash = 0;
- for (it = list->begin(); it != list->end(); it++) {
+ for (action_list_t::iterator it = list->begin(); it != list->end(); it++) {
const ModelAction *act = *it;
if (act->get_seq_number() > 0) {
- if (cycleset.contains(act))
- model_print("CYC");
+ if (badrfset.contains(act))
+ model_print("BRF ");
act->print();
+ if (badrfset.contains(act)) {
+ model_print("Desired Rf: %u \n",badrfset.get(act)->get_seq_number());
+ }
}
hash = hash ^ (hash << 3) ^ ((*it)->hash());
}
}
void SCAnalysis::analyze(action_list_t *actions) {
- buildVectors(actions);
- computeCV(actions);
action_list_t *list = generateSC(actions);
+ check_rf(list);
print_list(list);
}
-bool SCAnalysis::merge(ClockVector *cv, const ModelAction *act, ClockVector *cv2) {
+void SCAnalysis::check_rf(action_list_t *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->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)
+ return true;
if (cv2->getClock(act->get_tid()) >= act->get_seq_number() && act->get_seq_number() != 0) {
- cycleset.put(act, act);
+ cyclic=true;
+ //refuse to introduce cycles into clock vectors
+ return false;
}
+
return cv->merge(cv2);
}
-ModelAction * SCAnalysis::getNextAction() {
- ModelAction *act = NULL;
- for (int i = 0; i <= maxthreads; i++) {
- action_list_t *threadlist = &threadlists[i];
- if (threadlist->empty())
- continue;
- ModelAction *first = threadlist->front();
- if (act == NULL) {
- act = first;
+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 *act = tlt->front();
ClockVector *cv = cvmap.get(act);
- if (cv->synchronized_since(first)) {
- act = first;
+
+ /* 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 (act == NULL)
- return act;
- //print cycles in a nice way to avoid confusion
- //make sure thread starts appear after the create
- if (act->is_thread_start()) {
- ModelAction *createact = execution->get_thread(act)->get_creation();
- if (createact) {
- action_list_t *threadlist = &threadlists[id_to_int(createact->get_tid())];
- if (!threadlist->empty()) {
- ModelAction *first = threadlist->front();
- if (first->get_seq_number() <= createact->get_seq_number())
- act = first;
+ 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;
}
}
+ if (act != NULL) {
+ array[count++]=act;
+ }
}
- //make sure that joins appear after the thread is finished
- if (act->is_thread_join()) {
- int jointhread = id_to_int(act->get_thread_operand()->get_id());
- action_list_t *threadlist = &threadlists[jointhread];
- if (!threadlist->empty()) {
- act = threadlist->front();
+ ASSERT(count==0 || cyclic);
+
+ 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;
+ 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 (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 prevc=cyclic;
computeCV(list);
+ 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) {
bool changed = false;
- ClockVector *actcv = cvmap.get(act);
for (int i = 0; i <= maxthreads; i++) {
thread_id_t tid = int_to_id(i);
if (tid == act->get_tid())
break;
if (write->get_location() == act->get_location()) {
//write is sc after act
- merge(writecv, write, actcv);
+ merge(writecv, write, act);
changed = true;
break;
}
/* Merge in the clock vector from the write */
const ModelAction *write = read->get_reads_from();
ClockVector *writecv = cvmap.get(write);
- changed |= writecv == NULL || (merge(cv, read, writecv) && (*read < *write));
+ changed |= merge(cv, read, write) && (*read < *write);
for (int i = 0; i <= maxthreads; i++) {
thread_id_t tid = int_to_id(i);
write -rf-> R =>
R -sc-> write2 */
if (write2cv->synchronized_since(write)) {
- changed |= merge(write2cv, write2, cv);
+ changed |= merge(write2cv, write2, read);
}
//looking for earliest write2 in iteration to satisfy this
write -rf-> R =>
write2 -sc-> write */
if (cv->synchronized_since(write2)) {
- changed |= writecv == NULL || merge(writecv, write, write2cv);
+ changed |= writecv==NULL || merge(writecv, write, write2);
break;
}
}
ModelAction *lastact = last_act[id_to_int(act->get_tid())];
if (act->is_thread_start())
lastact = execution->get_thread(act)->get_creation();
- ClockVector *lastcv = (lastact != NULL) ? cvmap.get(lastact) : NULL;
last_act[id_to_int(act->get_tid())] = act;
ClockVector *cv = cvmap.get(act);
if (cv == NULL) {
- cv = new ClockVector(lastcv, act);
+ cv = new ClockVector(NULL, act);
cvmap.put(act, cv);
- } else if (lastcv != NULL) {
- merge(cv, act, lastcv);
+ }
+ if (lastact != NULL) {
+ merge(cv, act, lastact);
}
if (act->is_thread_join()) {
Thread *joinedthr = act->get_thread_operand();
ModelAction *finish = execution->get_last_action(joinedthr->get_id());
- ClockVector *finishcv = cvmap.get(finish);
- changed |= (finishcv == NULL) || merge(cv, act, finishcv);
+ changed |= merge(cv, act, finish);
}
if (act->is_read()) {
changed |= processRead(act, cv);
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