+/* Become an actor in the simulation
+ *
+ * Currently this can only be called by the main thread (once) and only work with some thread factories
+ * (currently ThreadContextFactory).
+ *
+ * In the future, it might be extended in order to attach other threads created by a third party library.
+ */
+
+ActorImplPtr ActorImpl::attach(std::string name, void* data, s4u::Host* host,
+ std::unordered_map<std::string, std::string>* properties)
+{
+ // This is mostly a copy/paste from create(), it'd be nice to share some code between those two functions.
+
+ XBT_DEBUG("Attach process %s on host '%s'", name.c_str(), host->get_cname());
+
+ if (not host->is_on()) {
+ XBT_WARN("Cannot launch process '%s' on failed host '%s'", name.c_str(), host->get_cname());
+ return nullptr;
+ }
+
+ ActorImpl* actor = new ActorImpl(xbt::string(name), host);
+ /* Actor data */
+ actor->set_user_data(data);
+ actor->code = nullptr;
+
+ XBT_VERB("Create context %s", actor->get_cname());
+ xbt_assert(simix_global != nullptr, "simix is not initialized, please call MSG_init first");
+ actor->context_ = simix_global->context_factory->attach(actor);
+
+ /* Add properties */
+ if (properties != nullptr)
+ for (auto const& kv : *properties)
+ actor->set_property(kv.first, kv.second);
+
+ /* Add the process to it's host process list */
+ host->pimpl_->process_list_.push_back(*actor);
+
+ /* Now insert it in the global process list and in the process to run list */
+ simix_global->process_list[actor->get_pid()] = actor;
+ XBT_DEBUG("Inserting [%p] %s(%s) in the to_run list", actor, actor->get_cname(), host->get_cname());
+ simix_global->actors_to_run.push_back(actor);
+ intrusive_ptr_add_ref(actor);
+
+ auto* context = dynamic_cast<simgrid::kernel::context::AttachContext*>(actor->context_);
+ xbt_assert(nullptr != context, "Not a suitable context");
+ context->attach_start();
+
+ /* The on_creation() signal must be delayed until there, where the pid and everything is set */
+ simgrid::s4u::ActorPtr tmp = actor->iface(); // Passing this directly to on_creation will lead to crashes
+ simgrid::s4u::Actor::on_creation(tmp);
+
+ return ActorImplPtr(actor);
+}
+/** @brief Detach an actor attached with `attach()`
+ *
+ * This is called when the current actor has finished its job.
+ * Used in the main thread, it waits for the simulation to finish before returning. When it returns, the other
+ * simulated actors and the maestro are destroyed.
+ */
+void ActorImpl::detach()
+{
+ auto* context = dynamic_cast<context::AttachContext*>(context::Context::self());
+ if (context == nullptr)
+ xbt_die("Not a suitable context");
+
+ context->get_actor()->cleanup();
+ context->attach_stop();
+}