-typedef std::vector<std::string> ReplayAction;
-
-XBT_PUBLIC_DATA std::ifstream* action_fs;
-XBT_PUBLIC int replay_runner(int argc, char* argv[]);
-}
-}
-
-typedef std::function<void(simgrid::xbt::ReplayAction&)> action_fun;
-XBT_PUBLIC void xbt_replay_action_register(const char* action_name, action_fun function);
+using ReplayAction = std::vector<std::string>;
+
+/** Launch a replaying actor of the given name.
+ *
+ * If trace_filename is nullptr, then the tracefile is shared between all instances, and was passed using
+ * xbt_replay_set_tracefile(). If trace_filename is not nullptr, then it's not shared and this trace file is for this
+ * actor only */
+XBT_PUBLIC int replay_runner(const char* actor_name, const char* trace_filename = nullptr);
+} // namespace simgrid::xbt
+
+using action_fun = std::function<void(simgrid::xbt::ReplayAction&)>;
+XBT_PUBLIC void xbt_replay_action_register(const char* action_name, const action_fun& function);