X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=model.cc;h=715a2584f36a1538528489d60f987142ad0f2a77;hb=84d0cd2f078f4cb15c318a0fef2515feab570375;hp=dbca58e7394f5e3eb9a4f7b68a54c67aff4a5346;hpb=20f8e2bc8677046c4bd7cb0bb80696ced41301f2;p=model-checker.git

diff --git a/model.cc b/model.cc
index dbca58e..715a258 100644
--- a/model.cc
+++ b/model.cc
@@ -858,6 +858,56 @@ bool ModelChecker::process_write(ModelAction *curr)
 	return updated_mod_order || updated_promises;
 }
 
+/**
+ * Process a fence ModelAction
+ * @param curr The ModelAction to process
+ * @return True if synchronization was updated
+ */
+bool ModelChecker::process_fence(ModelAction *curr)
+{
+	/*
+	 * fence-relaxed: no-op
+	 * fence-release: only log the occurence (not in this function), for
+	 *   use in later synchronization
+	 * fence-acquire (this function): search for hypothetical release
+	 *   sequences
+	 */
+	bool updated = false;
+	if (curr->is_acquire()) {
+		action_list_t *list = action_trace;
+		action_list_t::reverse_iterator rit;
+		/* Find X : is_read(X) && X --sb-> curr */
+		for (rit = list->rbegin(); rit != list->rend(); rit++) {
+			ModelAction *act = *rit;
+			if (act == curr)
+				continue;
+			if (act->get_tid() != curr->get_tid())
+				continue;
+			/* Stop at the beginning of the thread */
+			if (act->is_thread_start())
+				break;
+			/* Stop once we reach a prior fence-acquire */
+			if (act->is_fence() && act->is_acquire())
+				break;
+			if (!act->is_read())
+				continue;
+			/* read-acquire will find its own release sequences */
+			if (act->is_acquire())
+				continue;
+
+			/* Establish hypothetical release sequences */
+			rel_heads_list_t release_heads;
+			get_release_seq_heads(curr, act, &release_heads);
+			for (unsigned int i = 0; i < release_heads.size(); i++)
+				if (!curr->synchronize_with(release_heads[i]))
+					set_bad_synchronization();
+			if (release_heads.size() != 0)
+				updated = true;
+		}
+	}
+	return updated;
+}
+
 /**
  * @brief Process the current action for thread-related activity
  *
@@ -1173,6 +1223,9 @@ Thread * ModelChecker::check_current_action(ModelAction *curr)
 			if (act->is_write() && process_write(act))
 				update = true;
 
+			if (act->is_fence() && process_fence(act))
+				update_all = true;
+
 			if (act->is_mutex_op() && process_mutex(act))
 				update_all = true;
 
@@ -1464,18 +1517,21 @@ bool ModelChecker::r_modification_order(ModelAction *curr, const ModelAction *rf
 						*act < *last_sc_fence_thread_local) {
 					mo_graph->addEdge(act, rf);
 					added = true;
+					break;
 				}
 				/* 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;
+					break;
 				}
 				/* 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;
+					break;
 				}
 			}
 
@@ -1652,6 +1708,7 @@ bool ModelChecker::w_modification_order(ModelAction *curr)
 					*act < *last_sc_fence_thread_before) {
 				mo_graph->addEdge(act, curr);
 				added = true;
+				break;
 			}
 
 			/*