plugins/common/muxing: compare stream class clock classes

When comparing two streams and all else is equal about the stream and
their classes, compare the clock classes attached to the stream classes.

My use case for this is that I'm writing a test where two source
components send a stream beginning message to a muxer components.  The
only difference between the two is the clock classes associated to the
stream classes.  Some stream classes have an associated clock class,
some don't.  In other cases, the stream classes differ only by some
properties of their clock classes.  I want to be sure that the messages
will come out of the muxer's priority heap in a stable order.

Change-Id: I113704dac4ff952573c3dd96acd33b295425a863
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/12054
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>

diff --git a/src/plugins/common/muxing/muxing.c b/src/plugins/common/muxing/muxing.c
index a923b62ea9d6e035ef599a1d67aaeea4581122ba..35bfad133229190a5f05623b80b794909e072db6 100644 (file)
--- a/src/plugins/common/muxing/muxing.c
+++ b/src/plugins/common/muxing/muxing.c
@@ -232,6 +232,7 @@ int compare_streams(const bt_stream *left_stream, const bt_stream *right_stream)
        const char *left_stream_name, *right_stream_name,
              *left_stream_class_name, *right_stream_class_name;
        const bt_stream_class *left_stream_class, *right_stream_class;
+       const bt_clock_class *left_cc, *right_cc;
 
        /*
         * No need to compare stream id as it was checked earlier and if we are
@@ -339,59 +340,74 @@ int compare_streams(const bt_stream *left_stream, const bt_stream *right_stream)
                goto end;
        }
 
-       if (!bt_stream_class_supports_packets(left_stream_class)) {
-               /* Skip all packet related checks. */
-               goto end;
-       }
+       if (bt_stream_class_supports_packets(left_stream_class)) {
+               /*
+               * Compare stream class presence of discarded packets beginning default
+               * clock snapshot.
+               */
+               if (bt_stream_class_packets_have_beginning_default_clock_snapshot(left_stream_class) &&
+                               !bt_stream_class_packets_have_beginning_default_clock_snapshot(right_stream_class)) {
+                       ret = 1;
+                       goto end;
+               } else if (!bt_stream_class_packets_have_beginning_default_clock_snapshot(left_stream_class) &&
+                               bt_stream_class_packets_have_beginning_default_clock_snapshot(right_stream_class)) {
+                       ret = -1;
+                       goto end;
+               }
 
-       /*
-        * Compare stream class presence of discarded packets beginning default
-        * clock snapshot.
-        */
-       if (bt_stream_class_packets_have_beginning_default_clock_snapshot(left_stream_class) &&
-                       !bt_stream_class_packets_have_beginning_default_clock_snapshot(right_stream_class)) {
-               ret = 1;
-               goto end;
-       } else if (!bt_stream_class_packets_have_beginning_default_clock_snapshot(left_stream_class) &&
-                       bt_stream_class_packets_have_beginning_default_clock_snapshot(right_stream_class)) {
-               ret = -1;
-               goto end;
-       }
+               /*
+               * Compare stream class presence of discarded packets end default clock
+               * snapshot.
+               */
+               if (bt_stream_class_packets_have_end_default_clock_snapshot(left_stream_class) &&
+                               !bt_stream_class_packets_have_end_default_clock_snapshot(right_stream_class)) {
+                       ret = 1;
+                       goto end;
+               } else if (!bt_stream_class_packets_have_end_default_clock_snapshot(left_stream_class) &&
+                               bt_stream_class_packets_have_end_default_clock_snapshot(right_stream_class)) {
+                       ret = -1;
+                       goto end;
+               }
 
-       /*
-        * Compare stream class presence of discarded packets end default clock
-        * snapshot.
-        */
-       if (bt_stream_class_packets_have_end_default_clock_snapshot(left_stream_class) &&
-                       !bt_stream_class_packets_have_end_default_clock_snapshot(right_stream_class)) {
-               ret = 1;
-               goto end;
-       } else if (!bt_stream_class_packets_have_end_default_clock_snapshot(left_stream_class) &&
-                       bt_stream_class_packets_have_end_default_clock_snapshot(right_stream_class)) {
-               ret = -1;
-               goto end;
+               /* Compare stream class support of discarded packets. */
+               if (bt_stream_class_supports_discarded_packets(left_stream_class) &&
+                               !bt_stream_class_supports_discarded_packets(right_stream_class)) {
+                       ret = 1;
+                       goto end;
+               } else if (!bt_stream_class_supports_discarded_packets(left_stream_class) &&
+                               bt_stream_class_supports_discarded_packets(right_stream_class)) {
+                       ret = -1;
+                       goto end;
+               }
+
+               /* Compare stream class discarded packets default clock snapshot. */
+               if (bt_stream_class_discarded_packets_have_default_clock_snapshots(left_stream_class) &&
+                               !bt_stream_class_discarded_packets_have_default_clock_snapshots(right_stream_class)) {
+                       ret = 1;
+                       goto end;
+               } else if (!bt_stream_class_discarded_packets_have_default_clock_snapshots(left_stream_class) &&
+                               bt_stream_class_discarded_packets_have_default_clock_snapshots(right_stream_class)) {
+                       ret = -1;
+                       goto end;
+               }
        }
 
-       /* Compare stream class support of discarded packets. */
-       if (bt_stream_class_supports_discarded_packets(left_stream_class) &&
-                       !bt_stream_class_supports_discarded_packets(right_stream_class)) {
-               ret = 1;
-               goto end;
-       } else if (!bt_stream_class_supports_discarded_packets(left_stream_class) &&
-                       bt_stream_class_supports_discarded_packets(right_stream_class)) {
+       /* Compare the clock classes associated to the stream classes. */
+       left_cc = bt_stream_class_borrow_default_clock_class_const(left_stream_class);
+       right_cc = bt_stream_class_borrow_default_clock_class_const(right_stream_class);
+
+       if (!left_cc && !right_cc) {
+               ret = compare_clock_classes(left_cc, right_cc);
+
+               if (ret != 0) {
+                       goto end;
+               }
+       } else if (left_cc && !right_cc) {
                ret = -1;
                goto end;
-       }
-
-       /* Compare stream class discarded packets default clock snapshot. */
-       if (bt_stream_class_discarded_packets_have_default_clock_snapshots(left_stream_class) &&
-                       !bt_stream_class_discarded_packets_have_default_clock_snapshots(right_stream_class)) {
+       } else if (!left_cc && right_cc) {
                ret = 1;
                goto end;
-       } else if (!bt_stream_class_discarded_packets_have_default_clock_snapshots(left_stream_class) &&
-                       bt_stream_class_discarded_packets_have_default_clock_snapshots(right_stream_class)) {
-               ret = -1;
-               goto end;
        }
 
 end:
@@ -632,7 +648,7 @@ int compare_messages_same_type(struct messages_to_compare *msgs)
        int ret = 0;
 
        /*
-        * Both messages are of the same type, we must compare characterics of
+        * Both messages are of the same type, we must compare characteristics of
         * the messages such as the attributes of the event in a event message.
         */
        BT_ASSERT_DBG(bt_message_get_type(msgs->left.msg) ==