=====================
SimGrid was conceived as a tool to study distributed algorithms. Its
-modern S4U interface makes it easy to assess Cloud, P2P, HPC, IoT and
-similar settings.
-
-A typical SimGrid simulation is composed of several **Actors**
-|api_s4u_Actor|_ , that execute user-provided functions. The actors
-have to explicitly use the S4U interface to express their computation,
-communication, disk usage and other **Activities** |api_s4u_Activity|_
-, so that they get reflected within the simulator. These activities
-take place on **Resources** (CPUs, links, disks). SimGrid predicts the
-time taken by each activity and orchestrates accordingly the actors
-waiting for the completion of these activities.
-
-.. |api_s4u_Actor| image:: /img/extlink.png
- :align: middle
- :width: 12
-.. _api_s4u_Actor: api/classsimgrid_1_1s4u_1_1Actor.html#class-documentation
+modern :ref:`S4U interface <S4U_doc>` makes it easy to assess Cloud,
+P2P, HPC, IoT and similar settings.
-.. |api_s4u_Activity| image:: /img/extlink.png
- :align: middle
- :width: 12
-.. _api_s4u_Activity: api/classsimgrid_1_1s4u_1_1Activity.html#class-documentation
+A typical SimGrid simulation is composed of several |Actors|_, that
+execute user-provided functions. The actors have to explicitly use the
+S4U interface to express their computation, communication, disk usage
+and other |Activities|_, so that they get reflected within the
+simulator. These activities take place on **Resources** (|Hosts|_,
+|Links|_, |Storages|_). SimGrid predicts the time taken by each
+activity and orchestrates accordingly the actors waiting for the
+completion of these activities.
+Each actor executes a user-provided function on a simulated |Host|_
+with which it can interact. Communications are not directly sent to
+actors, but posted onto a |Mailbox|_ that serve as rendez-vous point
+between communicating processes.
-Each actor executes a user-provided function on a simulated **Host**
-|api_s4u_Host|_ with which it can interact. Communications are not
-directly sent to actors, but posted onto **Mailboxes**
-|api_s4u_Mailbox|_ that serve as rendez-vous points between
-communicating processes.
+.. |Actors| replace:: **Actors**
+.. _Actors: api/classsimgrid_1_1s4u_1_1Actor.html
-.. |api_s4u_Host| image:: /img/extlink.png
- :align: middle
- :width: 12
-.. _api_s4u_Host: api/classsimgrid_1_1s4u_1_1Host.html#class-documentation
+.. |Activities| replace:: **Activities**
+.. _Activities: api/classsimgrid_1_1s4u_1_1Activity.html
+
+.. |Hosts| replace:: **Hosts**
+.. _Hosts: api/classsimgrid_1_1s4u_1_1Host.html
+
+.. |Links| replace:: **Links**
+.. _Links: api/classsimgrid_1_1s4u_1_1Link.html
+
+.. |Storages| replace:: **Storages**
+.. _Storages: api/classsimgrid_1_1s4u_1_1Storage.html
+
+.. |VirtualMachines| replace:: **VirtualMachines**
+.. _VirtualMachines: api/classsimgrid_1_1s4u_1_1VirtualMachine.html
+
+.. |Host| replace:: **Host**
+.. _Host: api/classsimgrid_1_1s4u_1_1Host.html
+
+.. |Link| replace:: **Link**
+.. _Link: api/classsimgrid_1_1s4u_1_1Link.html
+
+.. |Mailbox| replace:: **Mailbox**
+.. _Mailbox: api/classsimgrid_1_1s4u_1_1Mailbox.html
+
+.. |Barrier| replace:: **Barrier**
+.. _Barrier: api/classsimgrid_1_1s4u_1_1Barrier.html
+
+.. |ConditionVariable| replace:: **ConditionVariable**
+.. _ConditionVariable: api/classsimgrid_1_1s4u_1_1ConditionVariable.html
+
+.. |Mutex| replace:: **Mutex**
+.. _Mutex: api/classsimgrid_1_1s4u_1_1Mutex.html
-.. |api_s4u_Mailbox| image:: /img/extlink.png
- :align: middle
- :width: 12
-.. _api_s4u_Mailbox: api/classsimgrid_1_1s4u_1_1Mailbox.html#class-documentation
**In the remainder of this tutorial**, you will discover a simple yet
fully functioning example of SimGrid simulation: the Master/Workers
This section introduces a first example of SimGrid simulation. This
simple application is composed of two kind of actors: the **master**
is in charge of distributing some computational tasks to a set of
-**workers** that execute them.
+**workers** that execute them.
.. image:: /tuto_s4u/img/intro.svg
:align: center
:cpp:func:`simgrid::s4u::Mailbox::put`. Also, :c:macro:`XBT_INFO` is used
as a replacement to printf() or to cout to ensure that the messages
are nicely logged along with the simulated time and actor name.
-
-
+
+
.. literalinclude:: ../../examples/s4u/app-masterworkers/s4u-app-masterworkers-fun.cpp
:language: c++
:start-after: master-begin
Starting the Simulation
.......................
-
+
And this is it. In only a few lines, we defined the algorithm of our
master/workers examples.
Platform files define the virtual platform on which the provided
application will take place. In contains one or several **Network
-Zone** |api_s4u_NetZone|_ that contain both **Host-** |api_s4u_Host|_
-and **Link-** |api_s4u_Link|_ Resources, as well as routing
-information.
+Zone** |api_s4u_NetZone|_ that contain both |Host|_ and |Link|_
+Resources, as well as routing information.
Such files can get rather long and boring, so the example below is
only an excerpts of the full ``examples/platforms/small_platform.xml``
route between the hosts Tremblay and Fafard is given. This path
traverses 6 links (named 4, 3, 2, 0, 1 and 8). There are several
examples of platforms in the archive under ``examples/platforms``.
-
+
.. |api_s4u_NetZone| image:: /img/extlink.png
:align: middle
:width: 12
This time, we have all parts: once the program is compiled, we can
execute it as follows. Note how the XBT_INFO() requests turned into
informative messages.
-
+
.. literalinclude:: ../../examples/s4u/app-masterworkers/s4u-app-masterworkers.tesh
:language: shell
:start-after: s4u-app-masterworkers-fun
:prepend: $$$ ./masterworkers platform.xml deploy.xml
:append: $$$
:dedent: 2
-
+
Improve it Yourself
-------------------
round-robin algorithm performs very well. Would it still hold true
when transfer time is not negligible? What if some tasks are
performed faster on some specific nodes?
-
+
- The network topology interconnecting the master and the workers
may be quite complicated. How does such a topology impact the
previous result?
make master-workers
./master-workers small_platform.xml master-workers_d.xml
-For a more "fancy" output, you can use simgrid-colorizer.
+For a more "fancy" output, you can use simgrid-colorizer.
.. code-block:: shell
.. image:: /tuto_s4u/img/vite-screenshot.png
:align: center
-
+
If you want the full power to visualize SimGrid traces, you need
to use R. As a start, you can download this `starter script
<https://framagit.org/simgrid/simgrid/raw/master/docs/source/tuto_s4u/draw_gantt.R>`_
...
}
-
+
Wrap up
.......
the involved parties.
Please refer to the full `API of Mailboxes
-<api/classsimgrid_1_1s4u_1_1Mailbox.html#class-documentation>`_
-|api_s4u_Mailbox|_ for more details.
+<api/classsimgrid_1_1s4u_1_1Mailbox.html#class-documentation>`_ for
+more details.
Lab 2: Using the Whole Platform
mailbox they should use. We can still do so: the master should build
such a parameter before using it in the ``Actor::create()`` call. The
master could even pass directly the mailbox as a parameter to the
-workers.
+workers.
Since we want later to study concurrent applications, it is advised to
use a mailbox name that is unique over the simulation even if there is
-more than one master.
+more than one master.
One possibility for that is to use the actor ID (aid) of each worker
as a mailbox name. The master can retrieve the aid of the newly
.. todo::
Include here the minimal setting to view something in R.
-
+
Lab 5: Better Scheduling
------------------------
- Add a performance measurement mechanism, enabling the master to make smart scheduling choices.
- Test your code on other platforms, from the ``examples/platforms``
directory in your archive.
-
+
What is the largest number of tasks requiring 50e6 flops and 1e5
bytes that you manage to distribute and process in one hour on
``g5k.xml`` ?
- Optimize not only for the amount of tasks handled, but also for the
- total energy dissipated.
+ total energy dissipated.
- And so on. If you come up with a really nice extension, please share
- it with us so that we can extend this tutorial.
+ it with us so that we can extend this tutorial.
After this Tutorial
-------------------
