ctf: notif-iter: ensure that all packets refer to the same stream class

Disallow, within the same packet sequence (decoded by a single CTF notif
iter instance), two packets to be described by two different stream
classes, which would also mean two different streams. Log a specific
warning message when this happens, e.g.:

    07-05 12:05:04.235 17923 17923 W PLUGIN-CTF-NOTIF-ITER
    set_current_stream_class@notif-iter.c:961 Two packets refer to two
    different stream classes within the same packet sequence:
    notit-addr=0xd97b20, prev-stream-class-addr=0xdc0b20,
    prev-stream-class-name="(null)", prev-stream-class-id=33,
    next-stream-class-addr=0xdc13d0, next-stream-class-name="(null)",
    next-stream-class-id=34, trace-addr=0xda3650, trace-name="ctf2"

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

diff --git a/plugins/ctf/common/notif-iter/notif-iter.c b/plugins/ctf/common/notif-iter/notif-iter.c
index e02bfb8085ca9c3bf7884417b93e91e3e74c1e4f..e6b85753b48e7d1c56cba8cd4c4009013de7d656 100644 (file)
--- a/plugins/ctf/common/notif-iter/notif-iter.c
+++ b/plugins/ctf/common/notif-iter/notif-iter.c
@@ -877,6 +877,7 @@ enum bt_ctf_notif_iter_status set_current_stream_class(
        enum bt_ctf_notif_iter_status status = BT_CTF_NOTIF_ITER_STATUS_OK;
        struct bt_ctf_field_type *packet_header_type = NULL;
        struct bt_ctf_field_type *stream_id_field_type = NULL;
+       struct bt_ctf_stream_class *new_stream_class = NULL;
        uint64_t stream_id;
 
        /* Clear the current stream class field path cache. */
@@ -928,10 +929,9 @@ single_stream_class:
                notit, stream_id, notit->meta.trace,
                bt_ctf_trace_get_name(notit->meta.trace));
 
-       BT_PUT(notit->meta.stream_class);
-       notit->meta.stream_class = bt_ctf_trace_get_stream_class_by_id(
+       new_stream_class = bt_ctf_trace_get_stream_class_by_id(
                notit->meta.trace, stream_id);
-       if (!notit->meta.stream_class) {
+       if (!new_stream_class) {
                BT_LOGW("No stream class with ID of stream class ID to use in trace: "
                        "notit-addr=%p, stream-class-id=%" PRIu64 ", "
                        "trace-addr=%p, trace-name=\"%s\"",
@@ -941,6 +941,31 @@ single_stream_class:
                goto end;
        }
 
+       if (notit->meta.stream_class) {
+               if (new_stream_class != notit->meta.stream_class) {
+                       BT_LOGW("Two packets refer to two different stream classes within the same packet sequence: "
+                               "notit-addr=%p, prev-stream-class-addr=%p, "
+                               "prev-stream-class-name=\"%s\", "
+                               "prev-stream-class-id=%" PRId64 ", "
+                               "next-stream-class-addr=%p, "
+                               "next-stream-class-name=\"%s\", "
+                               "next-stream-class-id=%" PRId64 ", "
+                               "trace-addr=%p, trace-name=\"%s\"",
+                               notit, notit->meta.stream_class,
+                               bt_ctf_stream_class_get_name(notit->meta.stream_class),
+                               bt_ctf_stream_class_get_id(notit->meta.stream_class),
+                               new_stream_class,
+                               bt_ctf_stream_class_get_name(new_stream_class),
+                               bt_ctf_stream_class_get_id(new_stream_class),
+                               notit->meta.trace,
+                               bt_ctf_trace_get_name(notit->meta.trace));
+                       status = BT_CTF_NOTIF_ITER_STATUS_ERROR;
+                       goto end;
+               }
+       } else {
+               BT_MOVE(notit->meta.stream_class, new_stream_class);
+       }
+
        BT_LOGV("Set current stream class: "
                "notit-addr=%p, stream-class-addr=%p, "
                "stream-class-name=\"%s\", stream-class-id=%" PRId64,
@@ -967,7 +992,7 @@ single_stream_class:
 end:
        BT_PUT(packet_header_type);
        BT_PUT(stream_id_field_type);
-
+       bt_put(new_stream_class);
        return status;
 }
 
@@ -1673,11 +1698,15 @@ int bt_ctf_notif_iter_switch_packet(struct bt_ctf_notif_iter *notit)
 {
        int ret = 0;
 
+       /*
+        * We don't put the stream class here because we need to make
+        * sure that all the packets processed by the same notification
+        * iterator refer to the same stream class (the first one).
+        */
        assert(notit);
        BT_LOGV("Switching packet: notit-addr=%p, cur=%zu",
                notit, notit->buf.at);
        stack_clear(notit->stack);
-       BT_PUT(notit->meta.stream_class);
        BT_PUT(notit->meta.event_class);
        BT_PUT(notit->packet);
        BT_PUT(notit->cur_timestamp_end);