X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fcommon%2Fust-consumer%2Fust-consumer.c;h=a951788bd9025ee0c95a6db925f5313758696f2c;hb=9dfbcccfb87c30a74c6059b24bfc053bdcddee54;hp=baa81d450aae793b084d2450450d0f793b7b9d20;hpb=cc84d37b5c13ad6a373137efc5d408ff099dceb4;p=lttng-tools.git

diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index baa81d450..a951788bd 100644
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -768,10 +768,19 @@ static int flush_channel(uint64_t chan_key)
 		health_code_update();
 
 		pthread_mutex_lock(&stream->lock);
+
+		/*
+		 * Protect against concurrent teardown of a stream.
+		 */
+		if (cds_lfht_is_node_deleted(&stream->node.node)) {
+			goto next;
+		}
+
 		if (!stream->quiescent) {
 			ustctl_flush_buffer(stream->ustream, 0);
 			stream->quiescent = true;
 		}
+next:
 		pthread_mutex_unlock(&stream->lock);
 	}
 error:
@@ -1180,7 +1189,7 @@ static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
 				produced_pos, nb_packets_per_stream,
 				stream->max_sb_size);
 
-		while (consumed_pos < produced_pos) {
+		while ((long) (consumed_pos - produced_pos) < 0) {
 			ssize_t read_len;
 			unsigned long len, padded_len;
 
@@ -2255,6 +2264,13 @@ int commit_one_metadata_packet(struct lttng_consumer_stream *stream)
 			stream->ust_metadata_pushed);
 	ret = write_len;
 
+	/*
+	 * Switch packet (but don't open the next one) on every commit of
+	 * a metadata packet. Since the subbuffer is fully filled (with padding,
+	 * if needed), the stream is "quiescent" after this commit.
+	 */
+	ustctl_flush_buffer(stream->ustream, 1);
+	stream->quiescent = true;
 end:
 	pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
 	return ret;
@@ -2299,7 +2315,6 @@ int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
 		retry = 1;
 	}
 
-	ustctl_flush_buffer(metadata->ustream, 1);
 	ret = ustctl_snapshot(metadata->ustream);
 	if (ret < 0) {
 		if (errno != EAGAIN) {
@@ -2489,7 +2504,6 @@ retry:
 			if (ret <= 0) {
 				goto end;
 			}
-			ustctl_flush_buffer(stream->ustream, 1);
 			goto retry;
 		}