replace old and counter-intuitive simdag-throttling example by modern comm-throttling

[simgrid.git] / examples / cpp / comm-throttling / s4u-comm-throttling.cpp

diff --git a/examples/cpp/comm-throttling/s4u-comm-throttling.cpp b/examples/cpp/comm-throttling/s4u-comm-throttling.cpp
new file mode 100644 (file)
index 0000000..4a5069a
--- /dev/null
+++ b/examples/cpp/comm-throttling/s4u-comm-throttling.cpp
@@ -0,0 +1,56 @@
+/* Copyright (c) 2007-2021. 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. */
+
+#include <simgrid/s4u.hpp>
+namespace sg4 = simgrid::s4u;
+
+XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_comm_throttling, "Messages specific for this s4u example");
+
+static void sender(sg4::Mailbox* mailbox)
+{
+  XBT_INFO("Send at full bandwidth");
+
+  /* - First send a 2.5e8 Bytes payload at full bandwidth (1.25e8 Bps) */
+  auto* payload = new double(sg4::Engine::get_clock());
+  mailbox->put(payload, 2.5e8);
+
+  XBT_INFO("Throttle the bandwidth at the Comm level");
+  /* - ... then send it again but throttle the Comm */
+  payload = new double(sg4::Engine::get_clock());
+  /* get a handler on the comm first */
+  sg4::CommPtr comm = mailbox->put_init(payload, 2.5e8);
+
+  /* let throttle the communication. It amounts to set the rate of the comm to half the nominal bandwidth of the link,
+   * i.e., 1.25e8 / 2. This second communication will thus take approximately twice as long as the first one*/
+  comm->set_rate(1.25e8 / 2)->wait();
+}
+
+static void receiver(sg4::Mailbox* mailbox)
+{
+  /* - Receive the first payload sent at full bandwidth */
+  auto sender_time          = mailbox->get_unique<double>();
+  double communication_time = sg4::Engine::get_clock() - *sender_time;
+  XBT_INFO("Payload received (full bandwidth) in %f seconds", communication_time);
+
+  /*  - ... Then receive the second payload sent with a throttled Comm */
+  sender_time        = mailbox->get_unique<double>();
+  communication_time = sg4::Engine::get_clock() - *sender_time;
+  XBT_INFO("Payload received (throttled) in %f seconds", communication_time);
+}
+
+int main(int argc, char* argv[])
+{
+  sg4::Engine e(&argc, argv);
+  e.load_platform(argv[1]);
+
+  sg4::Mailbox* mbox = e.mailbox_by_name_or_create("Mailbox");
+
+  sg4::Actor::create("sender", e.host_by_name("node-0.simgrid.org"), sender, mbox);
+  sg4::Actor::create("receiver", e.host_by_name("node-1.simgrid.org"), receiver, mbox);
+
+  e.run();
+
+  return 0;
+}