1 /* Copyright (c) 2006-2021. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 /* This example shows how to declare and start your actors.
8 * The first step is to declare the code of your actors (what they do exactly does not matter to this example) and then
9 * you ask SimGrid to start your actors. There is three ways of doing so:
10 * - Directly, by instantiating your actor as parameter to Actor::create()
11 * - By first registering your actors before instantiating it
12 * - Through the deployment file.
14 * This example shows all these solutions, even if you obviously should use only one of these solutions to start your
15 * actors. The most advised solution is to use a deployment file, as it creates a clear separation between your
16 * application and the settings to test it. This is a better scientific methodology. Actually, starting an actor with
17 * Actor::create() is mostly useful to start an actor from another actor.
20 #include <simgrid/s4u.hpp>
22 namespace sg4 = simgrid::s4u;
24 // This declares a logging channel so that XBT_INFO can be used later
25 XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_actor_create, "The logging channel used in this example");
27 /* Our first class of actors is simply implemented with a function, that takes a single string as parameter.
29 * Later, this actor class is instantiated within the simulation.
31 static void receiver(const std::string& mailbox_name)
33 sg4::Mailbox* mailbox = sg4::Mailbox::by_name(mailbox_name);
35 XBT_INFO("Hello s4u, I'm ready to get any message you'd want on %s", mailbox->get_cname());
37 auto msg1 = mailbox->get_unique<std::string>();
38 auto msg2 = mailbox->get_unique<std::string>();
39 auto msg3 = mailbox->get_unique<std::string>();
40 XBT_INFO("I received '%s', '%s' and '%s'", msg1->c_str(), msg2->c_str(), msg3->c_str());
41 XBT_INFO("I'm done. See you.");
44 /* Our second class of actors is also a function */
45 static void forwarder(int argc, char** argv)
47 xbt_assert(argc >= 3, "Actor forwarder requires 2 parameters, but got only %d", argc - 1);
48 sg4::Mailbox* in = sg4::Mailbox::by_name(argv[1]);
49 sg4::Mailbox* out = sg4::Mailbox::by_name(argv[2]);
50 auto* msg = in->get<std::string>();
51 XBT_INFO("Forward '%s'.", msg->c_str());
52 out->put(msg, msg->size());
55 /* Declares a third class of actors which sends a message to the mailbox 'mb42'.
56 * The sent message is what was passed as parameter on creation (or 'GaBuZoMeu' by default)
58 * Later, this actor class is instantiated twice in the simulation.
62 std::string mbox = "mb42";
63 std::string msg = "GaBuZoMeu";
64 explicit Sender() = default; /* Sending the default message */
65 explicit Sender(const std::string& arg) : msg(arg) { /* Sending the specified message */}
66 explicit Sender(std::vector<std::string> args)
68 /* This constructor is used when we start the actor from the deployment file */
69 /* args[0] is the actor's name, so the first parameter is args[1] */
71 xbt_assert(args.size() >= 3, "The sender is expecting 2 parameters from the deployment file but got %zu",
76 void operator()() const /* This is the main code of the actor */
78 XBT_INFO("Hello s4u, I have something to send");
79 sg4::Mailbox* mailbox = sg4::Mailbox::by_name(mbox);
81 mailbox->put(new std::string(msg), msg.size());
82 XBT_INFO("I'm done. See you.");
86 /* Here comes the main function of your program */
87 int main(int argc, char** argv)
89 /* When your program starts, you have to first start a new simulation engine, as follows */
90 sg4::Engine e(&argc, argv);
92 /* Then you should load a platform file, describing your simulated platform */
93 e.load_platform("../../platforms/small_platform.xml");
95 /* And now you have to ask SimGrid to actually start your actors.
97 * The easiest way to do so is to implement the behavior of your actor in a single function,
98 * as we do here for the receiver actors. This function can take any kind of parameters, as
99 * long as the last parameters of Actor::create() match what your function expects.
101 sg4::Actor::create("receiver", sg4::Host::by_name("Fafard"), &receiver, "mb42");
103 /* If your actor is getting more complex, you probably want to implement it as a class instead,
104 * as we do here for the sender actors. The main behavior goes into operator()() of the class.
106 * You can then directly start your actor, as follows: */
107 sg4::Actor::create("sender1", sg4::Host::by_name("Tremblay"), Sender());
108 /* If you want to pass parameters to your class, that's very easy: just use your constructors */
109 sg4::Actor::create("sender2", sg4::Host::by_name("Jupiter"), Sender("GloubiBoulga"));
111 /* But starting actors directly is considered as a bad experimental habit, since it ties the code
112 * you want to test with the experimental scenario. Starting your actors from an external deployment
113 * file in XML ensures that you can test your code in several scenarios without changing the code itself.
115 * For that, you first need to register your function or your actor as follows.
116 * Actor classes must have a (std::vector<std::string>) constructor,
117 * and actor functions must be of type int(*)(int argc, char**argv). */
118 e.register_actor<Sender>("sender"); // The sender class is passed as a template parameter here
119 e.register_function("forwarder", &forwarder);
120 /* Once actors and functions are registered, just load the deployment file */
121 e.load_deployment("s4u-actor-create_d.xml");
123 /* Once every actors are started in the engine, the simulation can start */
126 /* Once the simulation is done, the program is ended */