X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Flive.c;h=5d3449d4f451f49aaf64a6f3506a4b93c1affc3c;hp=cacad2916f281d7589f3324b536d1ecef4853419;hb=3b463131be76ea826a7e74f9b88422573e3a2076;hpb=7591bab11eceedc6a0d1e02fd6f85592267a63b5

diff --git a/src/bin/lttng-relayd/live.c b/src/bin/lttng-relayd/live.c
index cacad2916..5d3449d4f 100644
--- a/src/bin/lttng-relayd/live.c
+++ b/src/bin/lttng-relayd/live.c
@@ -267,7 +267,7 @@ end_unlock:
 static
 int make_viewer_streams(struct relay_session *session,
 		enum lttng_viewer_seek seek_t, uint32_t *nb_total, uint32_t *nb_unsent,
-		uint32_t *nb_created)
+		uint32_t *nb_created, bool *closed)
 {
 	int ret;
 	struct lttng_ht_iter iter;
@@ -281,6 +281,10 @@ int make_viewer_streams(struct relay_session *session,
 	 */
 	pthread_mutex_lock(&session->lock);
 
+	if (session->connection_closed) {
+		*closed = true;
+	}
+
 	/*
 	 * Create viewer streams for relay streams that are ready to be
 	 * used for a the given session id only.
@@ -862,6 +866,7 @@ int viewer_get_new_streams(struct relay_connection *conn)
 	struct lttng_viewer_new_streams_response response;
 	struct relay_session *session;
 	uint64_t session_id;
+	bool closed = false;
 
 	assert(conn);
 
@@ -897,7 +902,7 @@ int viewer_get_new_streams(struct relay_connection *conn)
 	response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_OK);
 
 	ret = make_viewer_streams(session, LTTNG_VIEWER_SEEK_LAST, &nb_total, &nb_unsent,
-			&nb_created);
+			&nb_created, &closed);
 	if (ret < 0) {
 		goto end_put_session;
 	}
@@ -906,12 +911,11 @@ int viewer_get_new_streams(struct relay_connection *conn)
 	response.streams_count = htobe32(nb_streams);
 
 	/*
-	 * If the session is closed and we have no new streams to send,
-	 * it means that the viewer has already received the whole trace
-	 * for this session and should now close it.
+	 * If the session is closed, HUP when there are no more streams.
 	 */
-	if (nb_total == 0 && session->connection_closed) {
+	if (closed && nb_total == 0) {
 		send_streams = 0;
+		response.streams_count = 0;
 		response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_HUP);
 		goto send_reply;
 	}
@@ -964,6 +968,7 @@ int viewer_attach_session(struct relay_connection *conn)
 	struct lttng_viewer_attach_session_request request;
 	struct lttng_viewer_attach_session_response response;
 	struct relay_session *session = NULL;
+	bool closed = false;
 
 	assert(conn);
 
@@ -1022,12 +1027,26 @@ int viewer_attach_session(struct relay_connection *conn)
 		goto send_reply;
 	}
 
-	ret = make_viewer_streams(session, seek_type, &nb_streams, NULL, NULL);
+	ret = make_viewer_streams(session, seek_type, &nb_streams, NULL,
+			NULL, &closed);
 	if (ret < 0) {
 		goto end_put_session;
 	}
 	response.streams_count = htobe32(nb_streams);
 
+	/*
+	 * If the session is closed when the viewer is attaching, it
+	 * means some of the streams may have been concurrently removed,
+	 * so we don't allow the viewer to attach, even if there are
+	 * streams available.
+	 */
+	if (closed) {
+		send_streams = 0;
+		response.streams_count = 0;
+		response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_HUP);
+		goto send_reply;
+	}
+
 send_reply:
 	health_code_update();
 	ret = send_response(conn->sock, &response, sizeof(response));
@@ -1610,7 +1629,15 @@ int viewer_get_metadata(struct relay_connection *conn)
 
 	vstream = viewer_stream_get_by_id(be64toh(request.stream_id));
 	if (!vstream) {
-		reply.status = htobe32(LTTNG_VIEWER_NO_NEW_METADATA);
+		/*
+		 * The metadata stream can be closed by a CLOSE command
+		 * just before we attach. It can also be closed by
+		 * per-pid tracing during tracing. Therefore, it is
+		 * possible that we cannot find this viewer stream.
+		 * Reply back to the client with an error if we cannot
+		 * find it.
+		 */
+		reply.status = htobe32(LTTNG_VIEWER_METADATA_ERR);
 		goto send_reply;
 	}
 	pthread_mutex_lock(&vstream->stream->lock);