From: Philippe Proulx <eeppeliteloop@gmail.com>
Date: Mon, 5 Jun 2017 16:52:29 +0000 (-0400)
Subject: Fix: do not allow a notif. iter. to call the user's "next" method once finalized
X-Git-Tag: v2.0.0-pre1~55
X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=commitdiff_plain;h=8f9d7550c162149e4cc7baf4456aa767d0020423

Fix: do not allow a notif. iter. to call the user's "next" method once finalized

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/include/babeltrace/graph/notification-iterator-internal.h b/include/babeltrace/graph/notification-iterator-internal.h
index 7b748e7b..f5454744 100644
--- a/include/babeltrace/graph/notification-iterator-internal.h
+++ b/include/babeltrace/graph/notification-iterator-internal.h
@@ -180,4 +180,22 @@ const char *bt_notification_iterator_status_string(
 	}
 };
 
+static inline
+const char *bt_notification_iterator_state_string(
+		enum bt_notification_iterator_state state)
+{
+	switch (state) {
+	case BT_NOTIFICATION_ITERATOR_STATE_ACTIVE:
+		return "BT_NOTIFICATION_ITERATOR_STATE_ACTIVE";
+	case BT_NOTIFICATION_ITERATOR_STATE_ENDED:
+		return "BT_NOTIFICATION_ITERATOR_STATE_ENDED";
+	case BT_NOTIFICATION_ITERATOR_STATE_FINALIZED:
+		return "BT_NOTIFICATION_ITERATOR_STATE_FINALIZED";
+	case BT_NOTIFICATION_ITERATOR_STATE_FINALIZED_AND_ENDED:
+		return "BT_NOTIFICATION_ITERATOR_STATE_FINALIZED_AND_ENDED";
+	default:
+		return "(unknown)";
+	}
+};
+
 #endif /* BABELTRACE_COMPONENT_NOTIFICATION_ITERATOR_INTERNAL_H */
diff --git a/lib/graph/iterator.c b/lib/graph/iterator.c
index 1a295cb3..70930bc7 100644
--- a/lib/graph/iterator.c
+++ b/lib/graph/iterator.c
@@ -1474,17 +1474,25 @@ enum bt_notification_iterator_status ensure_queue_has_notifications(
 
 	assert(iterator);
 	BT_LOGD("Ensuring that notification iterator's queue has at least one notification: "
-		"iter-addr=%p, queue-size=%u",
-		iterator, iterator->queue->length);
+		"iter-addr=%p, queue-size=%u, iter-state=%s",
+		iterator, iterator->queue->length,
+		bt_notification_iterator_state_string(iterator->state));
 
 	if (iterator->queue->length > 0) {
-		/* We already have enough */
+		/*
+		 * We already have enough. Even if this notification
+		 * iterator is finalized, its user can still flush its
+		 * current queue's content by calling its "next" method
+		 * since this content is local and has no impact on what
+		 * used to be the iterator's upstream component.
+		 */
 		BT_LOGD_STR("Queue already has at least one notification.");
 		goto end;
 	}
 
 	switch (iterator->state) {
 	case BT_NOTIFICATION_ITERATOR_STATE_FINALIZED_AND_ENDED:
+	case BT_NOTIFICATION_ITERATOR_STATE_FINALIZED:
 		BT_LOGD_STR("Notification iterator's \"next\" called, but it is finalized.");
 		status = BT_NOTIFICATION_ITERATOR_STATUS_CANCELED;
 		goto end;
@@ -1551,20 +1559,12 @@ enum bt_notification_iterator_status ensure_queue_has_notifications(
 				goto end;
 			}
 
-			if (iterator->state == BT_NOTIFICATION_ITERATOR_STATE_FINALIZED) {
-				iterator->state =
-					BT_NOTIFICATION_ITERATOR_STATE_FINALIZED_AND_ENDED;
-
-				if (iterator->queue->length == 0) {
-					status = BT_NOTIFICATION_ITERATOR_STATUS_CANCELED;
-				}
-			} else {
-				iterator->state =
-					BT_NOTIFICATION_ITERATOR_STATE_ENDED;
+			assert(iterator->state ==
+				BT_NOTIFICATION_ITERATOR_STATE_ACTIVE);
+			iterator->state = BT_NOTIFICATION_ITERATOR_STATE_ENDED;
 
-				if (iterator->queue->length == 0) {
-					status = BT_NOTIFICATION_ITERATOR_STATUS_END;
-				}
+			if (iterator->queue->length == 0) {
+				status = BT_NOTIFICATION_ITERATOR_STATUS_END;
 			}
 
 			BT_LOGD("Set new status: status=%s",