X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fcommon%2Fconsumer%2Fconsumer-stream.cpp;h=c24ea6bca60762dcab04d8ddc147c7608276c60e;hb=1970828049d051d5cb485dfab995081b4550fd2a;hp=e466c01551be7d73755f05483c89987dfd6d87b2;hpb=947bd0978b3d17b34eb1158cc6439eb1d4e5b6c3;p=lttng-tools.git

diff --git a/src/common/consumer/consumer-stream.cpp b/src/common/consumer/consumer-stream.cpp
index e466c0155..c24ea6bca 100644
--- a/src/common/consumer/consumer-stream.cpp
+++ b/src/common/consumer/consumer-stream.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Julien Desfossez <julien.desfossez@polymtl.ca>
+ * Copyright (C) 2011 EfficiOS Inc.
  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
  *
@@ -419,6 +419,7 @@ static int consumer_stream_sync_metadata_index(
 		const struct stream_subbuffer *subbuffer,
 		struct lttng_consumer_local_data *ctx)
 {
+	bool missed_metadata_flush;
 	int ret;
 
 	/* Block until all the metadata is sent. */
@@ -431,18 +432,34 @@ static int consumer_stream_sync_metadata_index(
 
 	pthread_mutex_lock(&stream->metadata_timer_lock);
 	stream->waiting_on_metadata = false;
-	if (stream->missed_metadata_flush) {
+	missed_metadata_flush = stream->missed_metadata_flush;
+	if (missed_metadata_flush) {
 		stream->missed_metadata_flush = false;
-		pthread_mutex_unlock(&stream->metadata_timer_lock);
-		(void) stream->read_subbuffer_ops.send_live_beacon(stream);
-	} else {
-		pthread_mutex_unlock(&stream->metadata_timer_lock);
 	}
+	pthread_mutex_unlock(&stream->metadata_timer_lock);
 	if (ret < 0) {
 		goto end;
 	}
 
 	ret = consumer_stream_send_index(stream, subbuffer, ctx);
+	/*
+	 * Send the live inactivity beacon to handle the situation where
+	 * the live timer is prevented from sampling this stream
+	 * because the stream lock was being held while this stream is
+	 * waiting on metadata. This ensures live viewer progress in the
+	 * unlikely scenario where a live timer would be prevented from
+	 * locking a stream lock repeatedly due to a steady flow of
+	 * incoming metadata, for a stream which is mostly inactive.
+	 *
+	 * It is important to send the inactivity beacon packet to
+	 * relayd _after_ sending the index associated with the data
+	 * that was just sent, otherwise this can cause live viewers to
+	 * observe timestamps going backwards between an inactivity
+	 * beacon and a following trace packet.
+	 */
+	if (missed_metadata_flush) {
+		(void) stream->read_subbuffer_ops.send_live_beacon(stream);
+	}
 end:
 	return ret;
 }
@@ -652,6 +669,7 @@ struct lttng_consumer_stream *consumer_stream_create(
 		goto error;
 	}
 
+	stream->send_node = CDS_LIST_HEAD_INIT(stream->send_node);
 	stream->chan = channel;
 	stream->key = stream_key;
 	stream->trace_chunk = trace_chunk;
@@ -1043,6 +1061,8 @@ void consumer_stream_destroy(struct lttng_consumer_stream *stream,
 {
 	LTTNG_ASSERT(stream);
 
+	cds_list_del_init(&stream->send_node);
+
 	/* Stream is in monitor mode. */
 	if (stream->monitor) {
 		struct lttng_consumer_channel *free_chan = NULL;
@@ -1075,6 +1095,7 @@ void consumer_stream_destroy(struct lttng_consumer_stream *stream,
 			 * If the stream is not visible globally, this needs to be done
 			 * outside of the consumer data lock section.
 			 */
+			destroy_close_stream(stream);
 			free_chan = unref_channel(stream);
 		}