Fix: missing check for metadata data pending

Signed-off-by: David Goulet <dgoulet@efficios.com>

diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index 9b1675e8be94b89b560dcd77db1e36e5fedb8775..08161c27e1f3ff2fc4932c87701171a15a96c743 100644 (file)
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -1746,6 +1746,12 @@ int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
        }
 
        if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) {
+               uint64_t contiguous, pushed;
+
+               /* Ease our life a bit. */
+               contiguous = stream->chan->metadata_cache->contiguous;
+               pushed = stream->ust_metadata_pushed;
+
                /*
                 * We can simply check whether all contiguously available data
                 * has been pushed to the ring buffer, since the push operation
@@ -1757,10 +1763,10 @@ int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
                 * metadata has been consumed from the metadata stream.
                 */
                DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64,
-                       stream->chan->metadata_cache->contiguous,
-                       stream->ust_metadata_pushed);
-               if (stream->chan->metadata_cache->contiguous
-                               != stream->ust_metadata_pushed) {
+                               contiguous, pushed);
+               assert(contiguous - pushed >= 0);
+               if ((contiguous != pushed) ||
+                               (contiguous - pushed > 0 || contiguous == 0)) {
                        ret = 1;        /* Data is pending */
                        goto end;
                }