From: Mathieu Desnoyers Date: Mon, 5 Jan 2015 02:25:08 +0000 (-0500) Subject: Fix: data pending: allow empty streams X-Git-Tag: v2.5.4~27 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=32b2dbc0b7aed43943b973f56a4c447f1c66269b;p=lttng-tools.git Fix: data pending: allow empty streams There are cases where a stream can be completely empty (no packet to write) with UST: for instance, if a traced application is either preempted for a long time, terminated, or stopped, between reserve and commit. This will make the consumer consider that this stream has no data ready. If this situation occurs in the first sub-buffer of a stream, this stream will have no data at all (0 bytes). Therefore, we need to let the data pending check consider that no data is pending in this situation, otherwise it can make the data pending check always return that there is data pending. Signed-off-by: Mathieu Desnoyers Signed-off-by: Jérémie Galarneau --- diff --git a/src/common/consumer.c b/src/common/consumer.c index 755aa5ee8..8bac35e7d 100644 --- a/src/common/consumer.c +++ b/src/common/consumer.c @@ -3547,15 +3547,6 @@ int consumer_data_pending(uint64_t id) */ ret = cds_lfht_is_node_deleted(&stream->node.node); if (!ret) { - /* - * An empty output file is not valid. We need at least one packet - * generated per stream, even if it contains no event, so it - * contains at least one packet header. - */ - if (stream->output_written == 0) { - pthread_mutex_unlock(&stream->lock); - goto data_pending; - } /* Check the stream if there is data in the buffers. */ ret = data_pending(stream); if (ret == 1) {