+ /* FD on which to write the index data. */
+ int index_fd;
+ /* FD on which to read the index data for the viewer. */
+ int read_index_fd;
+
+ char *path_name;
+ char *channel_name;
+ /* on-disk circular buffer of tracefiles */
+ uint64_t tracefile_size;
+ uint64_t tracefile_size_current;
+ uint64_t tracefile_count;
+ uint64_t tracefile_count_current;
+ /* To inform the viewer up to where it can go back in time. */
+ uint64_t oldest_tracefile_id;
+
+ uint64_t total_index_received;
+ struct relay_viewer_stream *viewer_stream;
+ uint64_t last_net_seq_num;
+
+ /*
+ * This node is added to the *control* connection hash table and the
+ * pointer is copied in here so we can access it when deleting this object.
+ * When deleting this, the ctf trace ht MUST NOT be destroyed. This happens
+ * at connection deletion.
+ */
+ struct lttng_ht_node_str ctf_trace_node;
+ struct lttng_ht *ctf_traces_ht;
+
+ /*
+ * To protect from concurrent read/update between the
+ * streaming-side and the viewer-side.
+ * This lock must be held, we reading/updating the
+ * ctf_trace pointer.
+ */
+ pthread_mutex_t lock;
+
+ struct ctf_trace *ctf_trace;
+ /*
+ * If the stream is inactive, this field is updated with the live beacon
+ * timestamp end, when it is active, this field == -1ULL.
+ */
+ uint64_t beacon_ts_end;
+ /*
+ * To protect the update of the close_write_flag and the checks of
+ * the tracefile_count_current.
+ * It is taken before checking whenever we need to know if the
+ * writer and reader are working in the same tracefile.
+ */
+ pthread_mutex_t viewer_stream_rotation_lock;
+
+ /* Information telling us when to close the stream */
+ unsigned int close_flag:1;
+ /* Indicate if the stream was initialized for a data pending command. */
+ unsigned int data_pending_check_done:1;
+ unsigned int metadata_flag:1;
+ /*
+ * To detect when we start overwriting old data, it is used to
+ * update the oldest_tracefile_id.
+ */
+ unsigned int tracefile_overwrite:1;
+};
+
+/*
+ * Shadow copy of the relay_stream structure for the viewer side. The only
+ * fields updated by the writer (streaming side) after allocation are :
+ * total_index_received and close_flag. Everything else is updated by the
+ * reader (viewer side).
+ */
+struct relay_viewer_stream {
+ uint64_t stream_handle;
+ uint64_t session_id;
+ int read_fd;
+ int index_read_fd;
+ char *path_name;
+ char *channel_name;
+ uint64_t last_sent_index;
+ uint64_t total_index_received;
+ uint64_t tracefile_count;
+ uint64_t tracefile_count_current;
+ /* Stop after reading this tracefile. */
+ uint64_t tracefile_count_last;
+ struct lttng_ht_node_u64 stream_n;
+ struct rcu_head rcu_node;
+ struct ctf_trace *ctf_trace;
+ /*
+ * This lock blocks only when the writer is about to start overwriting
+ * a file currently read by the reader.
+ *
+ * This is nested INSIDE the viewer_stream_rotation_lock.
+ */
+ pthread_mutex_t overwrite_lock;
+ /* Information telling us if the stream is a metadata stream. */
+ unsigned int metadata_flag:1;
+ /*
+ * Information telling us that the stream is closed in write, so
+ * we don't expect new indexes and we can read up to EOF.
+ */
+ unsigned int close_write_flag:1;
+ /*
+ * If the streaming side closes a FD in use in the viewer side,
+ * it sets this flag to inform that it is a normal error.
+ */
+ unsigned int abort_flag:1;