+ /*
+ * When we have written the data and index corresponding to this
+ * seq_num, rotate the tracefile (session rotation). The path_name is
+ * already up-to-date.
+ * This is set to -1ULL when no rotation is pending.
+ *
+ * Always access with stream lock held.
+ */
+ uint64_t rotate_at_seq_num;
+ /*
+ * This is the id of the chunk where we are writing to if no rotation is
+ * pending (rotate_at_seq_num == -1ULL). If a rotation is pending, this
+ * is the chunk_id we will have after the rotation. It must be updated
+ * atomically with rotate_at_seq_num.
+ *
+ * Always access with stream lock held.
+ */
+ uint64_t chunk_id;