lttng_ustconsumer_del_channel(channel);
lttng_ustconsumer_free_channel(channel);
}
+
+ if (channel->trace_chunk) {
+ lttng_trace_chunk_put(channel->trace_chunk);
+ }
+
free(channel);
}
}
static
-void metadata_stream_reset_cache(struct lttng_consumer_stream *stream)
+void metadata_stream_reset_cache_consumed_position(
+ struct lttng_consumer_stream *stream)
{
DBG("Reset metadata cache of session %" PRIu64,
stream->chan->session_id);
stream->ust_metadata_pushed = 0;
- stream->metadata_version = stream->chan->metadata_cache->version;
- stream->reset_metadata_flag = 1;
}
/*
* Write up to one packet from the metadata cache to the channel.
*
- * Returns the number of bytes pushed in the cache, or a negative value
- * on error.
+ * Returns the number of bytes pushed from the cache into the ring buffer, or a
+ * negative value on error.
*/
static
int commit_one_metadata_packet(struct lttng_consumer_stream *stream)
int ret;
pthread_mutex_lock(&stream->chan->metadata_cache->lock);
- if (stream->chan->metadata_cache->max_offset
- == stream->ust_metadata_pushed) {
- ret = 0;
- goto end;
+ if (stream->chan->metadata_cache->max_offset ==
+ stream->ust_metadata_pushed) {
+ /*
+ * In the context of a user space metadata channel, a
+ * change in version can be detected in two ways:
+ * 1) During the pre-consume of the `read_subbuffer` loop,
+ * 2) When populating the metadata ring buffer (i.e. here).
+ *
+ * This function is invoked when there is no metadata
+ * available in the ring-buffer. If all data was consumed
+ * up to the size of the metadata cache, there is no metadata
+ * to insert in the ring-buffer.
+ *
+ * However, the metadata version could still have changed (a
+ * regeneration without any new data will yield the same cache
+ * size).
+ *
+ * The cache's version is checked for a version change and the
+ * consumed position is reset if one occurred.
+ *
+ * This check is only necessary for the user space domain as
+ * it has to manage the cache explicitly. If this reset was not
+ * performed, no metadata would be consumed (and no reset would
+ * occur as part of the pre-consume) until the metadata size
+ * exceeded the cache size.
+ */
+ if (stream->metadata_version !=
+ stream->chan->metadata_cache->version) {
+ metadata_stream_reset_cache_consumed_position(stream);
+ consumer_stream_metadata_set_version(stream,
+ stream->chan->metadata_cache->version);
+ } else {
+ ret = 0;
+ goto end;
+ }
}
write_len = ustctl_write_one_packet_to_channel(stream->chan->uchan,
* 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,
+enum sync_metadata_status lttng_ustconsumer_sync_metadata(
+ struct lttng_consumer_local_data *ctx,
struct lttng_consumer_stream *metadata_stream)
{
int ret;
- int retry = 0;
+ enum sync_metadata_status status;
struct lttng_consumer_channel *metadata_channel;
assert(ctx);
ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 0);
pthread_mutex_lock(&metadata_stream->lock);
if (ret < 0) {
+ status = SYNC_METADATA_STATUS_ERROR;
goto end;
}
if (consumer_stream_is_deleted(metadata_stream)) {
DBG("Metadata stream %" PRIu64 " was deleted during the metadata synchronization",
metadata_stream->key);
- ret = 0;
+ status = SYNC_METADATA_STATUS_NO_DATA;
goto end;
}
ret = commit_one_metadata_packet(metadata_stream);
- if (ret <= 0) {
+ if (ret < 0) {
+ status = SYNC_METADATA_STATUS_ERROR;
goto end;
} else if (ret > 0) {
- retry = 1;
+ status = SYNC_METADATA_STATUS_NEW_DATA;
+ } else /* ret == 0 */ {
+ status = SYNC_METADATA_STATUS_NO_DATA;
+ goto end;
}
ret = ustctl_snapshot(metadata_stream->ustream);
if (ret < 0) {
- if (errno != EAGAIN) {
- ERR("Sync metadata, taking UST snapshot");
- goto end;
- }
- DBG("No new metadata when syncing them.");
- /* No new metadata, exit. */
- ret = ENODATA;
+ ERR("Failed to take a snapshot of the metadata ring-buffer positions, ret = %d", ret);
+ status = SYNC_METADATA_STATUS_ERROR;
goto end;
}
- /*
- * After this flush, we still need to extract metadata.
- */
- if (retry) {
- ret = EAGAIN;
- }
-
end:
- return ret;
+ return status;
}
/*
goto end;
}
- subbuf->info.metadata.version = stream->chan->metadata_cache->version;
+ subbuf->info.metadata.version = stream->metadata_version;
end:
return ret;
stream->read_subbuffer_ops.extract_subbuffer_info =
extract_metadata_subbuffer_info;
stream->read_subbuffer_ops.reset_metadata =
- metadata_stream_reset_cache;
+ metadata_stream_reset_cache_consumed_position;
if (stream->chan->is_live) {
stream->read_subbuffer_ops.on_sleep = signal_metadata;
ret = consumer_stream_enable_metadata_bucketization(
projects / lttng-tools.git / blobdiff