kref_init(&metadata_cache->refcount);
session->metadata_cache = metadata_cache;
INIT_LIST_HEAD(&metadata_cache->metadata_stream);
+ memcpy(&metadata_cache->uuid, &session->uuid,
+ sizeof(metadata_cache->uuid));
list_add(&session->list, &sessions);
mutex_unlock(&sessions_mutex);
return session;
/*
* Ensure we support mutiple get_next / put sequences followed
- * by put_next.
+ * by put_next. The metadata stream lock internally protects
+ * reading the metadata cache. It can indeed be read
+ * concurrently by "get_next_subbuf" and "flush" operations on
+ * the buffer invoked by different processes.
*/
+ mutex_lock(&stream->lock);
WARN_ON(stream->metadata_in < stream->metadata_out);
if (stream->metadata_in != stream->metadata_out)
- return 0;
+ goto end;
len = stream->metadata_cache->metadata_written -
stream->metadata_in;
if (!len)
- return 0;
+ goto end;
reserve_len = min_t(size_t,
stream->transport->ops.packet_avail_size(chan),
len);
ret = reserve_len;
end:
+ mutex_unlock(&stream->lock);
return ret;
}
MODULE_DESCRIPTION("LTTng Events");
MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
__stringify(LTTNG_MODULES_MINOR_VERSION) "."
- __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION));
+ __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
+ LTTNG_MODULES_EXTRAVERSION);