1 /* Copyright (c) 2006-2020. 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>
23 // This declares a logging channel so that XBT_INFO can be used later
24 XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_actor_create, "The logging channel used in this example");
26 /* Our first class of actors is simply implemented with a function, that takes a single string as parameter.
28 * Later, this actor class is instantiated within the simulation.
30 static void receiver(const std::string& mailbox_name)
32 simgrid::s4u::Mailbox* mailbox = simgrid::s4u::Mailbox::by_name(mailbox_name);
34 XBT_INFO("Hello s4u, I'm ready to get any message you'd want on %s", mailbox->get_cname());
36 const std::string* msg1 = static_cast<std::string*>(mailbox->get());
37 const std::string* msg2 = static_cast<std::string*>(mailbox->get());
38 const std::string* msg3 = static_cast<std::string*>(mailbox->get());
39 XBT_INFO("I received '%s', '%s' and '%s'", msg1->c_str(), msg2->c_str(), msg3->c_str());
43 XBT_INFO("I'm done. See you.");
46 /* Our second class of actors is also a function */
47 static void forwarder(int argc, char** argv)
49 xbt_assert(argc >= 3, "Actor forwarder requires 2 parameters, but got only %d", argc - 1);
50 simgrid::s4u::Mailbox* in = simgrid::s4u::Mailbox::by_name(argv[1]);
51 simgrid::s4u::Mailbox* out = simgrid::s4u::Mailbox::by_name(argv[2]);
52 std::string* msg = static_cast<std::string*>(in->get());
53 XBT_INFO("Forward '%s'.", msg->c_str());
54 out->put(msg, msg->size());
57 /* Declares a third class of actors which sends a message to the mailbox 'mb42'.
58 * The sent message is what was passed as parameter on creation (or 'GaBuZoMeu' by default)
60 * Later, this actor class is instantiated twice in the simulation.
64 std::string mbox = "mb42";
65 std::string msg = "GaBuZoMeu";
66 explicit Sender() = default; /* Sending the default message */
67 explicit Sender(const std::string& arg) : msg(arg) { /* Sending the specified message */}
68 explicit Sender(std::vector<std::string> args)
70 /* This constructor is used when we start the actor from the deployment file */
71 /* args[0] is the actor's name, so the first parameter is args[1] */
73 xbt_assert(args.size() >= 3, "The sender is expecting 2 parameters from the deployment file but got %zu",
78 void operator()() const /* This is the main code of the actor */
80 XBT_INFO("Hello s4u, I have something to send");
81 simgrid::s4u::Mailbox* mailbox = simgrid::s4u::Mailbox::by_name(mbox);
83 mailbox->put(new std::string(msg), msg.size());
84 XBT_INFO("I'm done. See you.");
88 /* Here comes the main function of your program */
89 int main(int argc, char** argv)
91 /* When your program starts, you have to first start a new simulation engine, as follows */
92 simgrid::s4u::Engine e(&argc, argv);
94 /* Then you should load a platform file, describing your simulated platform */
95 e.load_platform("../../platforms/small_platform.xml");
97 /* And now you have to ask SimGrid to actually start your actors.
99 * The easiest way to do so is to implement the behavior of your actor in a single function,
100 * as we do here for the receiver actors. This function can take any kind of parameters, as
101 * long as the last parameters of Actor::create() match what your function expects.
103 simgrid::s4u::Actor::create("receiver", simgrid::s4u::Host::by_name("Fafard"), &receiver, "mb42");
105 /* If your actor is getting more complex, you probably want to implement it as a class instead,
106 * as we do here for the sender actors. The main behavior goes into operator()() of the class.
108 * You can then directly start your actor, as follows: */
109 simgrid::s4u::Actor::create("sender1", simgrid::s4u::Host::by_name("Tremblay"), Sender());
110 /* If you want to pass parameters to your class, that's very easy: just use your constructors */
111 simgrid::s4u::Actor::create("sender2", simgrid::s4u::Host::by_name("Jupiter"), Sender("GloubiBoulga"));
113 /* But starting actors directly is considered as a bad experimental habit, since it ties the code
114 * you want to test with the experimental scenario. Starting your actors from an external deployment
115 * file in XML ensures that you can test your code in several scenarios without changing the code itself.
117 * For that, you first need to register your function or your actor as follows.
118 * Actor classes must have a (std::vector<std::string>) constructor,
119 * and actor functions must be of type int(*)(int argc, char**argv). */
120 e.register_actor<Sender>("sender"); // The sender class is passed as a template parameter here
121 e.register_function("forwarder", &forwarder);
122 /* Once actors and functions are registered, just load the deployment file */
123 e.load_deployment("s4u-actor-create_d.xml");
125 /* Once every actors are started in the engine, the simulation can start */
128 /* Once the simulation is done, the program is ended */