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:
* Clean up the stream completly because the next snapshot will use a new
* metadata stream.
*/
- pthread_mutex_lock(&metadata_stream->lock);
consumer_stream_destroy(metadata_stream, NULL);
cds_list_del(&metadata_stream->send_node);
metadata_channel->metadata_stream = NULL;
end_channel_error:
if (channel) {
- pthread_mutex_unlock(&channel->lock);
/*
* Free channel here since no one has a reference to it. We don't
* free after that because a stream can store this pointer.
struct ustctl_consumer_stream *ustream)
{
int ret;
+ uint64_t packet_size, content_size, timestamp_begin, timestamp_end,
+ events_discarded, stream_id, stream_instance_id,
+ packet_seq_num;
- ret = ustctl_get_timestamp_begin(ustream, &index->timestamp_begin);
+ ret = ustctl_get_timestamp_begin(ustream, ×tamp_begin);
if (ret < 0) {
PERROR("ustctl_get_timestamp_begin");
goto error;
}
- index->timestamp_begin = htobe64(index->timestamp_begin);
- ret = ustctl_get_timestamp_end(ustream, &index->timestamp_end);
+ ret = ustctl_get_timestamp_end(ustream, ×tamp_end);
if (ret < 0) {
PERROR("ustctl_get_timestamp_end");
goto error;
}
- index->timestamp_end = htobe64(index->timestamp_end);
- ret = ustctl_get_events_discarded(ustream, &index->events_discarded);
+ ret = ustctl_get_events_discarded(ustream, &events_discarded);
if (ret < 0) {
PERROR("ustctl_get_events_discarded");
goto error;
}
- index->events_discarded = htobe64(index->events_discarded);
- ret = ustctl_get_content_size(ustream, &index->content_size);
+ ret = ustctl_get_content_size(ustream, &content_size);
if (ret < 0) {
PERROR("ustctl_get_content_size");
goto error;
}
- index->content_size = htobe64(index->content_size);
- ret = ustctl_get_packet_size(ustream, &index->packet_size);
+ ret = ustctl_get_packet_size(ustream, &packet_size);
if (ret < 0) {
PERROR("ustctl_get_packet_size");
goto error;
}
- index->packet_size = htobe64(index->packet_size);
- ret = ustctl_get_stream_id(ustream, &index->stream_id);
+ ret = ustctl_get_stream_id(ustream, &stream_id);
if (ret < 0) {
PERROR("ustctl_get_stream_id");
goto error;
}
- index->stream_id = htobe64(index->stream_id);
- ret = ustctl_get_instance_id(ustream, &index->stream_instance_id);
+ ret = ustctl_get_instance_id(ustream, &stream_instance_id);
if (ret < 0) {
PERROR("ustctl_get_instance_id");
goto error;
}
- index->stream_instance_id = htobe64(index->stream_instance_id);
- ret = ustctl_get_sequence_number(ustream, &index->packet_seq_num);
+ ret = ustctl_get_sequence_number(ustream, &packet_seq_num);
if (ret < 0) {
PERROR("ustctl_get_sequence_number");
goto error;
}
- index->packet_seq_num = htobe64(index->packet_seq_num);
+
+ *index = (typeof(*index)) {
+ .offset = index->offset,
+ .packet_size = htobe64(packet_size),
+ .content_size = htobe64(content_size),
+ .timestamp_begin = htobe64(timestamp_begin),
+ .timestamp_end = htobe64(timestamp_end),
+ .events_discarded = htobe64(events_discarded),
+ .stream_id = htobe64(stream_id),
+ .stream_instance_id = htobe64(stream_instance_id),
+ .packet_seq_num = htobe64(packet_seq_num),
+ };
error:
return ret;
* interacting with sessiond, else we cause a deadlock with live
* awaiting on metadata to be pushed out.
*
+ * The RCU read side lock must be held by the caller.
+ *
* Return 0 if new metadatda is available, EAGAIN if the metadata stream
* is empty or a negative value on error.
*/
int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *metadata)
+ struct lttng_consumer_stream *metadata_stream)
{
int ret;
int retry = 0;
+ struct lttng_consumer_channel *metadata_channel;
assert(ctx);
- assert(metadata);
+ assert(metadata_stream);
- pthread_mutex_unlock(&metadata->lock);
+ metadata_channel = metadata_stream->chan;
+ pthread_mutex_unlock(&metadata_stream->lock);
/*
* Request metadata from the sessiond, but don't wait for the flush
* because we locked the metadata thread.
*/
- ret = lttng_ustconsumer_request_metadata(ctx, metadata->chan, 0, 0);
- pthread_mutex_lock(&metadata->lock);
+ ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 0);
+ pthread_mutex_lock(&metadata_stream->lock);
if (ret < 0) {
goto end;
}
- ret = commit_one_metadata_packet(metadata);
+ /*
+ * The metadata stream and channel can be deleted while the
+ * metadata stream lock was released. The streamed is checked
+ * for deletion before we use it further.
+ *
+ * Note that it is safe to access a logically-deleted stream since its
+ * existence is still guaranteed by the RCU read side lock. However,
+ * it should no longer be used. The close/deletion of the metadata
+ * channel and stream already guarantees that all metadata has been
+ * consumed. Therefore, there is nothing left to do in this function.
+ */
+ if (consumer_stream_is_deleted(metadata_stream)) {
+ DBG("Metadata stream %" PRIu64 " was deleted during the metadata synchronization",
+ metadata_stream->key);
+ ret = 0;
+ goto end;
+ }
+
+ ret = commit_one_metadata_packet(metadata_stream);
if (ret <= 0) {
goto end;
} else if (ret > 0) {
retry = 1;
}
- ret = ustctl_snapshot(metadata->ustream);
+ ret = ustctl_snapshot(metadata_stream->ustream);
if (ret < 0) {
if (errno != EAGAIN) {
ERR("Sync metadata, taking UST snapshot");