Fix: metadata stream is not marked as quiescent after packet commit

[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c

diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index cc77739ce301c0954c59d2a7437126e5829061f9..878e2e2212b6613d2de394783462248526d57529 100644 (file)
--- 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:
@@ -2321,6 +2330,13 @@ 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;
@@ -2365,7 +2381,6 @@ 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) {
@@ -2555,7 +2570,6 @@ retry:
                        if (ret <= 0) {
                                goto end;
                        }
-                       ustctl_flush_buffer(stream->ustream, 1);
                        goto retry;
                }