X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=model.cc;h=cd20321bb8c76a4c76adb1b43c29d8c2c7e6b4b5;hp=700f25c017b1d44aa310eee2f4518c7e051abf1c;hb=60ac5360eee87e572b9dd445f8837280213b0382;hpb=21f8ca7067d5d6810ea819a183ea50f863c17752

diff --git a/model.cc b/model.cc
index 700f25c0..cd20321b 100644
--- a/model.cc
+++ b/model.cc
@@ -172,7 +172,7 @@ unsigned int ModelChecker::get_num_threads() const
 }
 
 /** @return The currently executing Thread. */
-Thread * ModelChecker::get_current_thread()
+Thread * ModelChecker::get_current_thread() const
 {
 	return scheduler->get_current_thread();
 }
@@ -183,7 +183,8 @@ modelclock_t ModelChecker::get_next_seq_num()
 	return ++priv->used_sequence_numbers;
 }
 
-Node * ModelChecker::get_curr_node() {
+Node * ModelChecker::get_curr_node() const
+{
 	return node_stack->get_head();
 }
 
@@ -520,6 +521,7 @@ bool ModelChecker::next_execution()
 ModelAction * ModelChecker::get_last_conflict(ModelAction *act)
 {
 	switch (act->get_type()) {
+	case ATOMIC_FENCE:
 	case ATOMIC_READ:
 	case ATOMIC_WRITE:
 	case ATOMIC_RMW: {
@@ -1401,14 +1403,48 @@ bool ModelChecker::r_modification_order(ModelAction *curr, const ModelAction *rf
 	bool added = false;
 	ASSERT(curr->is_read());
 
+	/* Last SC fence in the current thread */
+	ModelAction *last_sc_fence_local = get_last_seq_cst_fence(curr->get_tid(), NULL);
+
 	/* Iterate over all threads */
 	for (i = 0; i < thrd_lists->size(); i++) {
+		/* Last SC fence in thread i */
+		ModelAction *last_sc_fence_thread_local = NULL;
+		if (int_to_id((int)i) != curr->get_tid())
+			last_sc_fence_thread_local = get_last_seq_cst_fence(int_to_id(i), NULL);
+
+		/* Last SC fence in thread i, before last SC fence in current thread */
+		ModelAction *last_sc_fence_thread_before = NULL;
+		if (last_sc_fence_local)
+			last_sc_fence_thread_before = get_last_seq_cst_fence(int_to_id(i), last_sc_fence_local);
+
 		/* Iterate over actions in thread, starting from most recent */
 		action_list_t *list = &(*thrd_lists)[i];
 		action_list_t::reverse_iterator rit;
 		for (rit = list->rbegin(); rit != list->rend(); rit++) {
 			ModelAction *act = *rit;
 
+			if (act->is_write() && act != rf && act != curr) {
+				/* C++, Section 29.3 statement 5 */
+				if (curr->is_seqcst() && last_sc_fence_thread_local &&
+						*act < *last_sc_fence_thread_local) {
+					mo_graph->addEdge(act, rf);
+					added = true;
+				}
+				/* C++, Section 29.3 statement 4 */
+				else if (act->is_seqcst() && last_sc_fence_local &&
+						*act < *last_sc_fence_local) {
+					mo_graph->addEdge(act, rf);
+					added = true;
+				}
+				/* C++, Section 29.3 statement 6 */
+				else if (last_sc_fence_thread_before &&
+						*act < *last_sc_fence_thread_before) {
+					mo_graph->addEdge(act, rf);
+					added = true;
+				}
+			}
+
 			/*
 			 * Include at most one act per-thread that "happens
 			 * before" curr. Don't consider reflexively.
@@ -1534,15 +1570,23 @@ bool ModelChecker::w_modification_order(ModelAction *curr)
 	if (curr->is_seqcst()) {
 		/* We have to at least see the last sequentially consistent write,
 			 so we are initialized. */
-		ModelAction *last_seq_cst = get_last_seq_cst(curr);
+		ModelAction *last_seq_cst = get_last_seq_cst_write(curr);
 		if (last_seq_cst != NULL) {
 			mo_graph->addEdge(last_seq_cst, curr);
 			added = true;
 		}
 	}
 
+	/* Last SC fence in the current thread */
+	ModelAction *last_sc_fence_local = get_last_seq_cst_fence(curr->get_tid(), NULL);
+
 	/* Iterate over all threads */
 	for (i = 0; i < thrd_lists->size(); i++) {
+		/* Last SC fence in thread i, before last SC fence in current thread */
+		ModelAction *last_sc_fence_thread_before = NULL;
+		if (last_sc_fence_local && int_to_id((int)i) != curr->get_tid())
+			last_sc_fence_thread_before = get_last_seq_cst_fence(int_to_id(i), last_sc_fence_local);
+
 		/* Iterate over actions in thread, starting from most recent */
 		action_list_t *list = &(*thrd_lists)[i];
 		action_list_t::reverse_iterator rit;
@@ -1569,6 +1613,13 @@ bool ModelChecker::w_modification_order(ModelAction *curr)
 					continue;
 			}
 
+			/* C++, Section 29.3 statement 7 */
+			if (last_sc_fence_thread_before && act->is_write() &&
+					*act < *last_sc_fence_thread_before) {
+				mo_graph->addEdge(act, curr);
+				added = true;
+			}
+
 			/*
 			 * Include at most one act per-thread that "happens
 			 * before" curr
@@ -1984,7 +2035,7 @@ ModelAction * ModelChecker::get_last_action(thread_id_t tid) const
  * check
  * @return The last seq_cst write
  */
-ModelAction * ModelChecker::get_last_seq_cst(ModelAction *curr) const
+ModelAction * ModelChecker::get_last_seq_cst_write(ModelAction *curr) const
 {
 	void *location = curr->get_location();
 	action_list_t *list = get_safe_ptr_action(obj_map, location);
@@ -1996,6 +2047,35 @@ ModelAction * ModelChecker::get_last_seq_cst(ModelAction *curr) const
 	return NULL;
 }
 
+/**
+ * Gets the last memory_order_seq_cst fence (in the total global sequence)
+ * performed in a particular thread, prior to a particular fence.
+ * @param tid The ID of the thread to check
+ * @param before_fence The fence from which to begin the search; if NULL, then
+ * search for the most recent fence in the thread.
+ * @return The last prior seq_cst fence in the thread, if exists; otherwise, NULL
+ */
+ModelAction * ModelChecker::get_last_seq_cst_fence(thread_id_t tid, const ModelAction *before_fence) const
+{
+	/* All fences should have NULL location */
+	action_list_t *list = get_safe_ptr_action(obj_map, NULL);
+	action_list_t::reverse_iterator rit = list->rbegin();
+
+	if (before_fence) {
+		for (; rit != list->rend(); rit++)
+			if (*rit == before_fence)
+				break;
+
+		ASSERT(*rit == before_fence);
+		rit++;
+	}
+
+	for (; rit != list->rend(); rit++)
+		if ((*rit)->is_fence() && (tid == (*rit)->get_tid()) && (*rit)->is_seqcst())
+			return *rit;
+	return NULL;
+}
+
 /**
  * Gets the last unlock operation performed on a particular mutex (i.e., memory
  * location). This function identifies the mutex according to the current
@@ -2016,7 +2096,7 @@ ModelAction * ModelChecker::get_last_unlock(ModelAction *curr) const
 	return NULL;
 }
 
-ModelAction * ModelChecker::get_parent_action(thread_id_t tid)
+ModelAction * ModelChecker::get_parent_action(thread_id_t tid) const
 {
 	ModelAction *parent = get_last_action(tid);
 	if (!parent)
@@ -2029,7 +2109,7 @@ ModelAction * ModelChecker::get_parent_action(thread_id_t tid)
  * @param tid The thread whose clock vector we want
  * @return Desired clock vector
  */
-ClockVector * ModelChecker::get_cv(thread_id_t tid)
+ClockVector * ModelChecker::get_cv(thread_id_t tid) const
 {
 	return get_parent_action(tid)->get_cv();
 }
@@ -2233,16 +2313,16 @@ void ModelChecker::build_reads_from_past(ModelAction *curr)
 	unsigned int i;
 	ASSERT(curr->is_read());
 
-	ModelAction *last_seq_cst = NULL;
+	ModelAction *last_sc_write = NULL;
 
 	/* Track whether this object has been initialized */
 	bool initialized = false;
 
 	if (curr->is_seqcst()) {
-		last_seq_cst = get_last_seq_cst(curr);
+		last_sc_write = get_last_seq_cst_write(curr);
 		/* We have to at least see the last sequentially consistent write,
 			 so we are initialized. */
-		if (last_seq_cst != NULL)
+		if (last_sc_write != NULL)
 			initialized = true;
 	}
 
@@ -2259,15 +2339,20 @@ void ModelChecker::build_reads_from_past(ModelAction *curr)
 				continue;
 
 			/* Don't consider more than one seq_cst write if we are a seq_cst read. */
-			if (!curr->is_seqcst() || (!act->is_seqcst() && (last_seq_cst == NULL || !act->happens_before(last_seq_cst))) || act == last_seq_cst) {
-				if (!curr->get_sleep_flag() || curr->is_seqcst() || sleep_can_read_from(curr, act)) {
-					DEBUG("Adding action to may_read_from:\n");
-					if (DBG_ENABLED()) {
-						act->print();
-						curr->print();
-					}
-					curr->get_node()->add_read_from(act);
+			bool allow_read = true;
+
+			if (curr->is_seqcst() && (act->is_seqcst() || (last_sc_write != NULL && act->happens_before(last_sc_write))) && act != last_sc_write)
+				allow_read = false;
+			else if (curr->get_sleep_flag() && !curr->is_seqcst() && !sleep_can_read_from(curr, act))
+				allow_read = false;
+
+			if (allow_read) {
+				DEBUG("Adding action to may_read_from:\n");
+				if (DBG_ENABLED()) {
+					act->print();
+					curr->print();
 				}
+				curr->get_node()->add_read_from(act);
 			}
 
 			/* Include at most one act per-thread that "happens before" curr */