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+/* Copyright (c) 2006-2021. The SimGrid Team. All rights reserved. */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+/* This example shows how to declare and start your actors.
+ *
+ * The first step is to declare the code of your actors (what they do exactly does not matter to this example) and then
+ * you ask SimGrid to start your actors. There is three ways of doing so:
+ * - Directly, by instantiating your actor as parameter to Actor::create()
+ * - By first registering your actors before instantiating it
+ * - Through the deployment file.
+ *
+ * This example shows all these solutions, even if you obviously should use only one of these solutions to start your
+ * actors. The most advised solution is to use a deployment file, as it creates a clear separation between your
+ * application and the settings to test it. This is a better scientific methodology. Actually, starting an actor with
+ * Actor::create() is mostly useful to start an actor from another actor.
+ */
+
+#include <simgrid/s4u.hpp>
+#include <string>
+namespace sg4 = simgrid::s4u;
+
+// This declares a logging channel so that XBT_INFO can be used later
+XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_actor_create, "The logging channel used in this example");
+
+/* Our first class of actors is simply implemented with a function, that takes a single string as parameter.
+ *
+ * Later, this actor class is instantiated within the simulation.
+ */
+static void receiver(const std::string& mailbox_name)
+{
+ sg4::Mailbox* mailbox = sg4::Mailbox::by_name(mailbox_name);
+
+ XBT_INFO("Hello s4u, I'm ready to get any message you'd want on %s", mailbox->get_cname());
+
+ auto msg1 = mailbox->get_unique<std::string>();
+ auto msg2 = mailbox->get_unique<std::string>();
+ auto msg3 = mailbox->get_unique<std::string>();
+ XBT_INFO("I received '%s', '%s' and '%s'", msg1->c_str(), msg2->c_str(), msg3->c_str());
+ XBT_INFO("I'm done. See you.");
+}
+
+/* Our second class of actors is also a function */
+static void forwarder(int argc, char** argv)
+{
+ xbt_assert(argc >= 3, "Actor forwarder requires 2 parameters, but got only %d", argc - 1);
+ sg4::Mailbox* in = sg4::Mailbox::by_name(argv[1]);
+ sg4::Mailbox* out = sg4::Mailbox::by_name(argv[2]);
+ auto* msg = in->get<std::string>();
+ XBT_INFO("Forward '%s'.", msg->c_str());
+ out->put(msg, msg->size());
+}
+
+/* Declares a third class of actors which sends a message to the mailbox 'mb42'.
+ * The sent message is what was passed as parameter on creation (or 'GaBuZoMeu' by default)
+ *
+ * Later, this actor class is instantiated twice in the simulation.
+ */
+class Sender {
+public:
+ std::string mbox = "mb42";
+ std::string msg = "GaBuZoMeu";
+ explicit Sender() = default; /* Sending the default message */
+ explicit Sender(const std::string& arg) : msg(arg) { /* Sending the specified message */}
+ explicit Sender(std::vector<std::string> args)
+ {
+ /* This constructor is used when we start the actor from the deployment file */
+ /* args[0] is the actor's name, so the first parameter is args[1] */
+
+ xbt_assert(args.size() >= 3, "The sender is expecting 2 parameters from the deployment file but got %zu",
+ args.size() - 1);
+ msg = args[1];
+ mbox = args[2];
+ }
+ void operator()() const /* This is the main code of the actor */
+ {
+ XBT_INFO("Hello s4u, I have something to send");
+ sg4::Mailbox* mailbox = sg4::Mailbox::by_name(mbox);
+
+ mailbox->put(new std::string(msg), msg.size());
+ XBT_INFO("I'm done. See you.");
+ }
+};
+
+/* Here comes the main function of your program */
+int main(int argc, char** argv)
+{
+ /* When your program starts, you have to first start a new simulation engine, as follows */
+ sg4::Engine e(&argc, argv);
+
+ /* Then you should load a platform file, describing your simulated platform */
+ e.load_platform("../../platforms/small_platform.xml");
+
+ /* And now you have to ask SimGrid to actually start your actors.
+ *
+ * The easiest way to do so is to implement the behavior of your actor in a single function,
+ * as we do here for the receiver actors. This function can take any kind of parameters, as
+ * long as the last parameters of Actor::create() match what your function expects.
+ */
+ sg4::Actor::create("receiver", sg4::Host::by_name("Fafard"), &receiver, "mb42");
+
+ /* If your actor is getting more complex, you probably want to implement it as a class instead,
+ * as we do here for the sender actors. The main behavior goes into operator()() of the class.
+ *
+ * You can then directly start your actor, as follows: */
+ sg4::Actor::create("sender1", sg4::Host::by_name("Tremblay"), Sender());
+ /* If you want to pass parameters to your class, that's very easy: just use your constructors */
+ sg4::Actor::create("sender2", sg4::Host::by_name("Jupiter"), Sender("GloubiBoulga"));
+
+ /* But starting actors directly is considered as a bad experimental habit, since it ties the code
+ * you want to test with the experimental scenario. Starting your actors from an external deployment
+ * file in XML ensures that you can test your code in several scenarios without changing the code itself.
+ *
+ * For that, you first need to register your function or your actor as follows.
+ * Actor classes must have a (std::vector<std::string>) constructor,
+ * and actor functions must be of type int(*)(int argc, char**argv). */
+ e.register_actor<Sender>("sender"); // The sender class is passed as a template parameter here
+ e.register_function("forwarder", &forwarder);
+ /* Once actors and functions are registered, just load the deployment file */
+ e.load_deployment("s4u-actor-create_d.xml");
+
+ /* Once every actors are started in the engine, the simulation can start */
+ e.run();
+
+ /* Once the simulation is done, the program is ended */
+ return 0;
+}
