Support for -x option
[model-checker.git] / scanalysis.cc
index daf41f8a19ba4395d61dff065f71422a422547dc..6fc1e0810e88013005eb64b93a92de22b6d3a20f 100644 (file)
@@ -3,31 +3,92 @@
 #include "threads-model.h"
 #include "clockvector.h"
 #include "execution.h"
+#include <sys/time.h>
 
-SCAnalysis::SCAnalysis(const ModelExecution *execution) :
+
+SCAnalysis::SCAnalysis() :
        cvmap(),
-       cycleset(),
+       cyclic(false),
+       badrfset(),
+       lastwrmap(),
        threadlists(1),
-       execution(execution)
+       execution(NULL),
+       print_always(false),
+       print_buggy(true),
+       print_nonsc(false),
+       time(false),
+       stats((struct sc_statistics *)model_calloc(1, sizeof(struct sc_statistics)))
 {
 }
 
 SCAnalysis::~SCAnalysis() {
+       delete(stats);
 }
 
-void SCAnalysis::print_list(action_list_t *list) {
-       action_list_t::iterator it;
+void SCAnalysis::setExecution(ModelExecution * execution) {
+       this->execution=execution;
+}
 
-       model_print("---------------------------------------------------------------------\n");
+const char * SCAnalysis::name() {
+       const char * name = "SC";
+       return name;
+}
+
+void SCAnalysis::finish() {
+       if (time)
+               model_print("Elapsed time in usec %llu\n", stats->elapsedtime);
+       model_print("SC count: %u\n", stats->sccount);
+       model_print("Non-SC count: %u\n", stats->nonsccount);
+       model_print("Total actions: %llu\n", stats->actions);
+       unsigned long long actionperexec=(stats->actions)/(stats->sccount+stats->nonsccount);
+       model_print("Actions per execution: %llu\n", actionperexec);
+}
+
+bool SCAnalysis::option(char * opt) {
+       if (strcmp(opt, "verbose")==0) {
+               print_always=true;
+               return false;
+       } else if (strcmp(opt, "buggy")==0) {
+               return false;
+       } else if (strcmp(opt, "quiet")==0) {
+               print_buggy=false;
+               return false;
+       } else if (strcmp(opt, "nonsc")==0) {
+               print_nonsc=true;
+               return false;
+       } else if (strcmp(opt, "time")==0) {
+               time=true;
+               return false;
+       } else if (strcmp(opt, "help") != 0) {
+               model_print("Unrecognized option: %s\n", opt);
+       }
 
+       model_print("SC Analysis options\n");
+       model_print("verbose -- print all feasible executions\n");
+       model_print("buggy -- print only buggy executions (default)\n");
+       model_print("nonsc -- print non-sc execution\n");
+       model_print("quiet -- print nothing\n");
+       model_print("time -- time execution of scanalysis\n");
+       model_print("\n");
+       
+       return true;
+}
+
+void SCAnalysis::print_list(action_list_t *list) {
+       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());
        }
@@ -36,87 +97,231 @@ void SCAnalysis::print_list(action_list_t *list) {
 }
 
 void SCAnalysis::analyze(action_list_t *actions) {
-       buildVectors(actions);
-       computeCV(actions);
+
+       struct timeval start;
+       struct timeval finish;
+       if (time)
+               gettimeofday(&start, NULL);
        action_list_t *list = generateSC(actions);
-       print_list(list);
+       check_rf(list);
+       if (print_always || (print_buggy && execution->have_bug_reports())|| (print_nonsc && cyclic))
+               print_list(list);
+       if (time) {
+               gettimeofday(&finish, NULL);
+               stats->elapsedtime+=((finish.tv_sec*1000000+finish.tv_usec)-(start.tv_sec*1000000+start.tv_usec));
+       }
+       update_stats();
 }
 
-bool SCAnalysis::merge(ClockVector *cv, const ModelAction *act, ClockVector *cv2) {
+void SCAnalysis::update_stats() {
+       if (cyclic) {
+               stats->nonsccount++;
+       } else {
+               stats->sccount++;
+       }
+}
+
+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);
+       stats->actions+=numactions;
+
+       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);
@@ -124,11 +329,25 @@ void SCAnalysis::buildVectors(action_list_t *list) {
                }
                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())
@@ -144,7 +363,7 @@ bool SCAnalysis::updateConstraints(ModelAction *act) {
                                break;
                        if (write->get_location() == act->get_location()) {
                                //write is sc after act
-                               merge(writecv, write, actcv);
+                               merge(writecv, write, act);
                                changed = true;
                                break;
                        }
@@ -159,7 +378,7 @@ bool SCAnalysis::processRead(ModelAction *read, ClockVector *cv) {
        /* 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);
@@ -183,7 +402,7 @@ bool SCAnalysis::processRead(ModelAction *read, ClockVector *cv) {
                                 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
@@ -191,7 +410,7 @@ bool SCAnalysis::processRead(ModelAction *read, ClockVector *cv) {
                                 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;
                        }
                }
@@ -212,20 +431,19 @@ void SCAnalysis::computeCV(action_list_t *list) {
                        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);