+ xbt_assert(s4u::Engine::instance_ == nullptr, "It is currently forbidden to create more than one instance of s4u::Engine");
+ s4u::Engine::instance_ = this;
+
+ SIMIX_global_init(argc, argv);
+}
+
+s4u::Engine *s4u::Engine::instance() {
+ if (s4u::Engine::instance_ == nullptr)
+ new Engine(0,nullptr);
+ return s4u::Engine::instance_;
+}
+
+double s4u::Engine::getClock() {
+ return SIMIX_get_clock();