From: Francis Deslauriers <francis.deslauriers@efficios.com>
Date: Wed, 26 Jun 2019 22:06:23 +0000 (-0400)
Subject: ctf: decoding: accommodate LTTng `event-after-packet` timestamp quirk
X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=commitdiff_plain;h=7d1ac606018744f051104fc184e581411c52bd3d

ctf: decoding: accommodate LTTng `event-after-packet` timestamp quirk

See prior commit titled:
  src.ctf.fs: index: accommodate bug in LTTng tracers
for an explanation of the non-compliance of some LTTng traces.

How this commit fixes the decoding for the affected traces
==========================================================
When about to emit a packet end message, check if the said packet is
affect by LTTng's `event-after-packet` bug. If it's the case, omit to
update the default_clock_snapshot to the `timestamp_end` of the packet.
This will expand the packet time span to the contain all its events.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: I205caf0243c1d6f270bdb1b6508bb55a0806ba19
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1550
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>
---

diff --git a/src/plugins/ctf/common/metadata/ctf-meta.h b/src/plugins/ctf/common/metadata/ctf-meta.h
index 884fe69e..798c3b6a 100644
--- a/src/plugins/ctf/common/metadata/ctf-meta.h
+++ b/src/plugins/ctf/common/metadata/ctf-meta.h
@@ -313,6 +313,7 @@ struct ctf_trace_class {
 
 	struct {
 		bool lttng_crash;
+		bool lttng_event_after_packet;
 	} quirks;
 };
 
diff --git a/src/plugins/ctf/common/msg-iter/msg-iter.c b/src/plugins/ctf/common/msg-iter/msg-iter.c
index 404119fa..537ad136 100644
--- a/src/plugins/ctf/common/msg-iter/msg-iter.c
+++ b/src/plugins/ctf/common/msg-iter/msg-iter.c
@@ -2550,6 +2550,24 @@ void create_msg_packet_end(struct bt_msg_iter *notit, bt_message **message)
 		}
 	}
 
+	/*
+	 * Check if may be affected by lttng event-after-packet `timestamp_end`
+	 * quirk.
+	 */
+	if (notit->meta.tc->quirks.lttng_event_after_packet) {
+		/*
+		 * Check if `timestamp_end` is smaller then the current
+		 * default_clock_snapshot (which is set to the last event
+		 * decoded). It means the trace is affected by the lttng
+		 * `event-after-packet` packet `timestamp_end` quirk and must
+		 * be fixed up by omitting to update the default clock snapshot
+		 * to the `timestamp_end` as is typically done.
+		 */
+		if (notit->snapshots.end_clock < notit->default_clock_snapshot) {
+			update_default_cs = false;
+		}
+	}
+
 	/* Update default clock from packet's end time. */
 	if (notit->snapshots.end_clock != UINT64_C(-1) && update_default_cs) {
 		notit->default_clock_snapshot = notit->snapshots.end_clock;
diff --git a/src/plugins/ctf/fs-src/fs.c b/src/plugins/ctf/fs-src/fs.c
index 8b6b54ea..d6ea57d9 100644
--- a/src/plugins/ctf/fs-src/fs.c
+++ b/src/plugins/ctf/fs-src/fs.c
@@ -2236,6 +2236,7 @@ int fix_packet_index_tracer_bugs(struct ctf_fs_component *ctf_fs)
 				BT_LOGE_STR("Failed to fix LTTng event-after-packet bug.");
 				goto end;
 			}
+			trace->metadata->tc->quirks.lttng_event_after_packet = true;
 		}
 
 		if (is_tracer_affected_by_barectf_event_before_packet_bug(