X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=scanalysis.cc;h=17763870814aeac14e528bcef8aa7b02e902e947;hp=abed220873450b67ad5776509a8210f2c5457c51;hb=698f6194f9e5cc5905727c1798c36fede8c7ce8a;hpb=5566833b04fb088b315dcde5148e05a9ea80c2df

diff --git a/scanalysis.cc b/scanalysis.cc
index abed220..1776387 100644
--- a/scanalysis.cc
+++ b/scanalysis.cc
@@ -3,31 +3,89 @@
 #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);
+}
+
+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());
 	}
@@ -36,94 +94,229 @@ 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) {
-	if (cv2->getClock(act->get_tid()) >= act->get_seq_number() && act->get_seq_number() != 0) {
-		cycleset.put(act, act);
+void SCAnalysis::update_stats() {
+	if (cyclic) {
+		stats->nonsccount++;
+	} else {
+		stats->sccount++;
 	}
-	return cv->merge(cv2);
 }
 
-ModelAction * SCAnalysis::getNextAction() {
-	ModelAction *act = NULL;
-	/* Find the earliest in SC ordering */
-	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;
-			continue;
-		}
-		ClockVector *cv = cvmap.get(act);
-		if (cv->synchronized_since(first)) {
-			act = first;
+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) {
+		cyclic = true;
+		//refuse to introduce cycles into clock vectors
+		return false;
 	}
-	if (act == NULL)
-		return act;
 
+	return cv->merge(cv2);
+}
 
-	/* Find the model action with the earliest sequence number in case of a cycle.
-	 */
+int SCAnalysis::getNextActions(ModelAction ** array) {
+	int count=0;
 
-	for (int i = 0; i <= maxthreads; i++) {
-		action_list_t *threadlist = &threadlists[i];
-		if (threadlist->empty())
+	for (int t = 0; t <= maxthreads; t++) {
+		action_list_t *tlt = &threadlists[t];
+		if (tlt->empty())
 			continue;
-		ModelAction *first = threadlist->front();
+		ModelAction *act = tlt->front();
 		ClockVector *cv = cvmap.get(act);
-		ClockVector *cvfirst = cvmap.get(first);
-		if (first->get_seq_number()<act->get_seq_number()&&
-				(cv->synchronized_since(first)||!cvfirst->synchronized_since(act))) {
-			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;
 		}
 	}
-
-	/* See if hb demands an earlier action. */
-	for (int i = 0; i <= maxthreads; i++) {
-		action_list_t *threadlist = &threadlists[i];
-		if (threadlist->empty())
+	if (count != 0)
+		return count;
+	for (int t = 0; t <= maxthreads; t++) {
+		action_list_t *tlt = &threadlists[t];
+		if (tlt->empty())
 			continue;
-		ModelAction *first = threadlist->front();
+		ModelAction *act = tlt->front();
 		ClockVector *cv = act->get_cv();
-		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;
+		}
+	}
+
+	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);
@@ -131,11 +324,25 @@ 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())
@@ -151,7 +358,7 @@ 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;
 			}
@@ -166,7 +373,7 @@ 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);
@@ -190,7 +397,7 @@ 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
@@ -198,7 +405,7 @@ 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;
 			}
 		}
@@ -219,20 +426,19 @@ 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);