examples/s4u/README.rst

   1 .. S4U (Simgrid for you) is the modern interface of SimGrid, which new project should use.
   2 ..
   3 .. This file follows the ReStructured syntax to be included in the
   4 .. documentation, but it should remain readable directly.
   5
   6
   7 S4U Examples
   8 ************
   9
  10 SimGrid comes with an extensive set of examples, documented on this
  11 page. Most of them only demonstrate one single feature, with some
  12 larger examplars listed below.
  13
  14 The C++ examples can be found under examples/s4u while python examples
  15 are in examples/python. Each such directory contains the source code (also listed
  16 from this page), and the so-called tesh file containing how to call
  17 the binary obtained by compiling this example and also the expected
  18 output. Tesh files are used to turn each of our examples into an
  19 integration test. Some examples also contain other files, on need.
  20
  21 A good way to bootstrap your own project is to copy and combine some
  22 of the provided examples to constitute the skeleton of what you plan
  23 to simulate.
  24
  25 ===========================
  26 Actors: the Active Entities
  27 ===========================
  28
  29 .. _s4u_ex_actors:
  30
  31 Starting and Stoping Actors
  32 ---------------------------
  33
  34   - **Creating actors:**
  35     Most actors are started from the deployment XML file, because this
  36     is a :ref:`better scientific habbit <howto_science>`, but you can
  37     also create them directly from your code.
  38
  39     .. tabs::
  40
  41        .. group-tab:: C++
  42
  43           You create actors either:
  44
  45           - Directly with :cpp:func:`simgrid::s4u::Actor::create`
  46           - From XML with :cpp:func:`simgrid::s4u::Engine::register_actor` (if your actor is a class)
  47             or :cpp:func:`simgrid::s4u::Engine::register_function` (if your actor is a function)
  48             and then :cpp:func:`simgrid::s4u::Engine::load_deployment`
  49
  50           .. showfile:: examples/s4u/actor-create/s4u-actor-create.cpp
  51              :language: cpp
  52
  53        .. group-tab:: Python
  54
  55           You create actors either:
  56
  57           - Directly with :py:func:`simgrid.Actor.create()`
  58           - From XML with :py:func:`simgrid.Engine.register_actor()` and then :py:func:`simgrid.Engine.load_deployment()`
  59
  60           .. showfile:: examples/python/actor-create/actor-create.py
  61
  62        .. group-tab:: XML
  63
  64           The following file is used in both C++ and Python.
  65
  66           .. showfile:: examples/python/actor-create/actor-create_d.xml
  67              :language: xml
  68
  69   - **React to the end of actors:** You can attach callbacks to the end of
  70     actors. There is several ways of doing so, depending on whether you want to
  71     attach your callback to a given actor and on how you define the end of a
  72     given actor. User code probably want to react to the termination of an actor
  73     while some plugins want to react to the destruction (memory collection) of
  74     actors.
  75
  76     .. tabs::
  77
  78        .. group-tab:: C++
  79
  80           This example shows how to attach a callback to:
  81
  82           - the end of a specific actor: :cpp:func:`simgrid::s4u::this_actor::on_exit()`
  83           - the end of any actor: :cpp:member:`simgrid::s4u::Actor::on_termination()`
  84           - the destruction of any actor: :cpp:member:`simgrid::s4u::Actor::on_destruction()`
  85
  86           .. showfile:: examples/s4u/actor-exiting/s4u-actor-exiting.cpp
  87              :language: cpp
  88
  89   - **Kill actors:**
  90     Actors can forcefully stop other actors.
  91
  92     .. tabs::
  93
  94        .. group-tab:: C++
  95
  96           See also :cpp:func:`void simgrid::s4u::Actor::kill(void)`, :cpp:func:`void simgrid::s4u::Actor::kill_all()`, :cpp:func:`simgrid::s4u::this_actor::exit`.
  97
  98           .. showfile:: examples/s4u/actor-kill/s4u-actor-kill.cpp
  99              :language: cpp
 100
 101        .. group-tab:: Python
 102
 103           See also :py:func:`simgrid.Actor.kill`, :py:func:`simgrid.Actor.kill_all`, :py:func:`simgrid.this_actor.exit`.
 104
 105           .. showfile:: examples/python/actor-kill/actor-kill.py
 106
 107   - **Controling the actor life cycle from the XML:**
 108     You can specify a start time and a kill time in the deployment file.
 109
 110     .. tabs::
 111
 112        .. group-tab:: C++
 113
 114           This file is not really interesting: the important matter is in the XML file.
 115
 116           .. showfile:: examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp
 117              :language: cpp
 118
 119        .. group-tab:: XML
 120
 121           This demonstrates the ``start_time`` and ``kill_time`` attribute of the :ref:`pf_tag_actor` tag.
 122
 123           .. showfile:: examples/s4u/actor-lifetime/s4u-actor-lifetime_d.xml
 124              :language: xml
 125
 126   - **Daemonize actors:**
 127     Some actors may be intended to simulate daemons that run in background. This example show how to transform a regular
 128     actor into a daemon that will be automatically killed once the simulation is over.
 129
 130     .. tabs::
 131
 132        .. group-tab:: C++
 133
 134           See also :cpp:func:`simgrid::s4u::Actor::daemonize()` and :cpp:func:`simgrid::s4u::Actor::is_daemon()`.
 135
 136           .. showfile:: examples/s4u/actor-daemon/s4u-actor-daemon.cpp
 137              :language: cpp
 138
 139        .. group-tab:: Python
 140
 141           See also :py:func:`simgrid.Actor.daemonize()` and :py:func:`simgrid.Actor.is_daemon()`.
 142
 143           .. showfile:: examples/python/actor-daemon/actor-daemon.py
 144
 145 Inter-Actors Interactions
 146 -------------------------
 147
 148 See also the examples on :ref:`inter-actors communications
 149 <s4u_ex_communication>` and the ones on :ref:`classical
 150 synchronization objects <s4u_ex_IPC>`.
 151
 152   - **Suspend and Resume actors:**
 153     Actors can be suspended and resumed during their executions.
 154
 155     - |cpp| `examples/s4u/actor-suspend/s4u-actor-suspend.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-suspend/s4u-actor-suspend.cpp>`_
 156       :cpp:func:`simgrid::s4u::this_actor::suspend()`,
 157       :cpp:func:`simgrid::s4u::Actor::suspend()`, :cpp:func:`simgrid::s4u::Actor::resume()`, :cpp:func:`simgrid::s4u::Actor::is_suspended()`.
 158     - |py|  `examples/python/actor-suspend/actor-suspend.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-suspend/actor-suspend.py>`_
 159       :py:func:`simgrid.this_actor.suspend()`,
 160       :py:func:`simgrid.Actor.suspend()`, :py:func:`simgrid.Actor.resume()`, :py:func:`simgrid.Actor.is_suspended()`.
 161
 162   - **Migrating Actors:**
 163     Actors can move or be moved from a host to another very easily.
 164
 165     - |cpp| `examples/s4u/actor-migrate/s4u-actor-migrate.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-migrate/s4u-actor-migrate.cpp>`_
 166       :cpp:func:`simgrid::s4u::this_actor::migrate()`
 167     - |py|  `examples/python/actor-migrate/actor-migrate.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-migrate/actor-migrate.py>`_
 168       :py:func:`simgrid.this_actor.migrate()`
 169
 170   - **Waiting for the termination of an actor:** (joining on it)
 171     You can block the current actor until the end of another actor.
 172
 173     - |cpp| `examples/s4u/actor-join/s4u-actor-join.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-join/s4u-actor-join.cpp>`_
 174       :cpp:func:`simgrid::s4u::Actor::join()`
 175     - |py|  `examples/python/actor-join/actor-join.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-join/actor-join.py>`_
 176       :py:func:`simgrid.Actor.join()`
 177
 178   - **Yielding to other actors**.
 179     The ```yield()``` function interrupts the execution of the current
 180     actor, leaving a chance to the other actors that are ready to run
 181     at this timestamp.
 182
 183     - |cpp| `examples/s4u/actor-yield/s4u-actor-yield.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-yield/s4u-actor-yield.cpp>`_
 184       :cpp:func:`simgrid::s4u::this_actor::yield()`
 185     - |py|  `examples/python/actor-yield/actor-yield.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-yield/actor-yield.py>`_
 186       :py:func:`simgrid.this_actor.yield_()`
 187
 188 Traces Replay as a Workload
 189 ---------------------------
 190
 191 This section details how to run trace-driven simulations. It is very
 192 handy when you want to test an algorithm or protocol that only react
 193 to external events. For example, many P2P protocols react to user
 194 requests, but do nothing if there is no such event.
 195
 196 In such situations, you should write your protocol in C++, and separate
 197 the workload that you want to play onto your protocol in a separate
 198 text file. Declare a function handling each type of the events in your
 199 trace, register them using :cpp:func:`xbt_replay_action_register()` in
 200 your main, and then run the simulation.
 201
 202 Then, you can either have one trace file containing all your events,
 203 or a file per simulated process: the former may be easier to work
 204 with, but the second is more efficient on very large traces. Check
 205 also the tesh files in the example directories for details.
 206
 207   - **Communication replay:**
 208     Presents a set of event handlers reproducing classical communication
 209     primitives (asynchronous send/receive at the moment).
 210     |br| `examples/s4u/replay-comm/s4u-replay-comm.cpp  <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/replay-comm/s4u-replay-comm.cpp>`_
 211
 212   - **I/O replay:**
 213     Presents a set of event handlers reproducing classical I/O
 214     primitives (open, read, close).
 215     |br| `examples/s4u/replay-io/s4u-replay-io.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/replay-io/s4u-replay-io.cpp>`_
 216
 217 ==========================
 218 Activities: what Actors do
 219 ==========================
 220
 221 .. _s4u_ex_communication:
 222
 223 Communications on the Network
 224 -----------------------------
 225
 226  - **Basic asynchronous communications:**
 227    Illustrates how to have non-blocking communications, that are
 228    communications running in the background leaving the process free
 229    to do something else during their completion.
 230
 231    - |cpp| `examples/s4u/async-wait/s4u-async-wait.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-wait/s4u-async-wait.cpp>`_
 232      :cpp:func:`simgrid::s4u::Mailbox::put_async()` and :cpp:func:`simgrid::s4u::Comm::wait()`
 233    - |py|  `examples/python/async-wait/async-wait.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/async-wait/async-wait.py>`_
 234      :py:func:`simgrid.Mailbox.put_async()` :py:func:`simgrid.Comm.wait()`
 235
 236  - **Waiting for all communications in a set:**
 237    The `wait_all()` function is useful when you want to block until
 238    all activities in a given set have completed.
 239
 240    - |cpp| `examples/s4u/async-waitall/s4u-async-waitall.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-waitall/s4u-async-waitall.cpp>`_
 241      :cpp:func:`simgrid::s4u::Comm::wait_all()`
 242    - |py| `examples/python/async-waitall/async-waitall.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/async-waitall/async-waitall.py>`_
 243      :py:func:`simgrid.Comm.wait_all()`
 244
 245  - **Waiting for the first completed communication in a set:**
 246    The `wait_any()` function is useful
 247    when you want to block until one activity of the set completes, no
 248    matter which terminates first.
 249
 250    - |cpp| `examples/s4u/async-waitany/s4u-async-waitany.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-waitany/s4u-async-waitany.cpp>`_
 251      :cpp:func:`simgrid::s4u::Comm::wait_any()`
 252    - |py| `examples/python/async-waitany/async-waitany.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/async-waitany/async-waitany.py>`_
 253      :py:func:`simgrid.Comm.wait_any()`
 254
 255 .. todo:: review the `ready` and `waituntil` examples and add them here.
 256
 257 .. _s4u_ex_execution:
 258
 259 Executions on the CPU
 260 ---------------------
 261
 262   - **Basic execution:**
 263     The computations done in your program are not reported to the
 264     simulated world, unless you explicitly request the simulator to pause
 265     the actor until a given amount of flops gets computed on its simulated
 266     host. Some executions can be given an higher priority so that they
 267     get more resources.
 268
 269     - |cpp| `examples/s4u/exec-basic/s4u-exec-basic.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-basic/s4u-exec-basic.cpp>`_
 270     - |py|  `examples/python/exec-basic/exec-basic.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/exec-basic/exec-basic.py>`_
 271
 272   - **Asynchronous execution:**
 273     You can start asynchronous executions, just like you would fire
 274     background threads.
 275
 276     - |cpp| `examples/s4u/exec-async/s4u-exec-async.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-async/s4u-exec-async.cpp>`_
 277     - |py|  `examples/python/exec-async/exec-async.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/exec-async/exec-async.py>`_
 278
 279   - **Remote execution:**
 280     You can start executions on remote hosts, or even change the host
 281     on which they occur during their execution.
 282
 283     - |cpp| `examples/s4u/exec-remote/s4u-exec-remote.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-remote/s4u-exec-remote.cpp>`_
 284     - |py| `examples/python/exec-remote/exec-remote.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/exec-remote/exec-remote.py>`_
 285
 286   - **Parallel executions:**
 287     These objects are convenient abstractions of parallel
 288     computational kernels that span over several machines, such as a
 289     PDGEM and the other ScaLAPACK routines. Note that this only works
 290     with the "ptask_L07" host model (``--cfg=host/model:ptask_L07``).
 291     |br| `examples/s4u/exec-ptask/s4u-exec-ptask.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-ptask/s4u-exec-ptask.cpp>`_
 292
 293   - **Using Pstates on a host:**
 294     `examples/platforms/energy_platform.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/energy_platform.xml>`_
 295     shows how define a set of pstates in the XML. The current pstate
 296     of an host can then be accessed and changed from the program.
 297
 298     - |cpp| `examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp>`_
 299       :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
 300     - |py|  `examples/python/exec-dvfs/exec-dvfs.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/exec-dvfs/exec-dvfs.py>`_
 301       :py:func:`Host.get_pstate_speed` and :py:func:`Host.set_pstate`.
 302
 303 I/O on Disks and Files
 304 ----------------------
 305
 306 SimGrid provides two levels of abstraction to interact with the
 307 simulated disks. At the simplest level, you simply create read and
 308 write actions on the disk resources.
 309
 310   - **Access to raw disk devices:**
 311     This example illustrates how to simply read and write data on a
 312     simulated disk resource.
 313     |br| `examples/s4u/io-disk-raw/s4u-io-disk-raw.cpp  <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/io-disk-raw/s4u-io-disk-raw.cpp>`_
 314
 315 The FileSystem plugin provides a more detailed view, with the
 316 classical operations over files: open, move, unlink, and of course
 317 read and write. The file and disk sizes are also dealt with and can
 318 result in short reads and short write, as in reality.
 319
 320   - **File Management:**
 321     This example illustrates the use of operations on files
 322     (read, write, seek, tell, unlink, etc).
 323     |br| `examples/s4u/io-file-system/s4u-io-file-system.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/io-file-system/s4u-io-file-system.cpp>`_
 324
 325   - **Remote I/O:**
 326     I/O operations on files can also be done in a remote fashion,
 327     i.e. when the accessed disk is not mounted on the caller's host.
 328     |br| `examples/s4u/io-file-remote/s4u-io-file-remote.cpp  <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/io-file-remote/s4u-io-file-remote.cpp>`_
 329
 330 .. _s4u_ex_IPC:
 331
 332 Classical synchronization objects
 333 ---------------------------------
 334
 335  - **Mutex:**
 336    Shows how to use simgrid::s4u::Mutex synchronization objects.
 337    |br| `examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp>`_
 338
 339  - **Barrier:**
 340    Shows how to use simgrid::s4u::Barrier synchronization objects.
 341    |br| `examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp>`_
 342
 343  - **Semaphore:**
 344    Shows how to use simgrid::s4u::Semaphore synchronization objects.
 345    |br| `examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp>`_
 346
 347 =============================
 348 Interacting with the Platform
 349 =============================
 350
 351  - **Retrieving the list of hosts matching a given criteria:**
 352    Shows how to filter the actors that match a given criteria.
 353    |br| `examples/s4u/engine-filtering/s4u-engine-filtering.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/engine-filtering/s4u-engine-filtering.cpp>`_
 354
 355  - **User-defined properties:**
 356    You can attach arbitrary information to most platform elements from
 357    the XML file, and then interact with these values from your
 358    program. Note that the changes are not written permanently on disk,
 359    in the XML file nor anywhere else. They only last until the end of
 360    your simulation.
 361
 362    - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
 363    - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
 364    - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
 365    - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
 366
 367    |br| `examples/s4u/platform-properties/s4u-platform-properties.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/platform-properties/s4u-platform-properties.cpp>`_
 368    |br| `examples/s4u/platform-properties/s4u-platform-properties_d.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/platform-properties/s4u-platform-properties_d.xml>`_
 369    |br| `examples/platforms/prop.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/prop.xml>`_
 370
 371  - **Specifying state profiles:** shows how to specify when the
 372    resources must be turned off and on again, and how to react to such
 373    failures in your code.
 374
 375    |br| `examples/platforms/small_platform_failures.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/small_platform_failures.xml>`_
 376    |br| The state profiles in `examples/platforms/profiles <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/profiles>`_
 377
 378  - **Specifying speed profiles:** shows how to specify an external
 379    load to resources, variating their peak speed over time.
 380
 381    |br| `examples/platforms/small_platform_profile.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/small_platform_profile.xml>`_
 382    |br| The speed, bandwidth and latency profiles in `examples/platforms/profiles  <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/profiles>`_
 383
 384 =================
 385 Energy Simulation
 386 =================
 387
 388   - **Describing the energy profiles in the platform:**
 389     This platform file contains the energy profile of each links and
 390     hosts, which is necessary to get energy consumption predictions.
 391     As usual, you should not trust our example, and you should strive
 392     to double-check that your instantiation matches your target platform.
 393     |br| `examples/platforms/energy_platform.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/energy_platform.xml>`_
 394
 395   - **Consumption due to the CPU:**
 396     This example shows how to retrieve the amount of energy consumed
 397     by the CPU during computations, and the impact of the pstate.
 398     |br| `examples/s4u/energy-exec/s4u-energy-exec.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-exec/s4u-energy-exec.cpp>`_
 399
 400   - **Consumption due to the network:**
 401     This example shows how to retrieve and display the energy consumed
 402     by the network during communications.
 403     |br| `examples/s4u/energy-link/s4u-energy-link.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-link/s4u-energy-link.cpp>`_
 404
 405   - **Modeling the shutdown and boot of hosts:**
 406     Simple example of model of model for the energy consumption during
 407     the host boot and shutdown periods.
 408     |br| `examples/s4u/energy-boot/platform_boot.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-boot/platform_boot.xml>`_
 409     |br| `examples/s4u/energy-boot/s4u-energy-boot.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-boot/s4u-energy-boot.cpp>`_
 410
 411 =======================
 412 Tracing and Visualizing
 413 =======================
 414
 415 Tracing can be activated by various configuration options which
 416 are illustrated in these example. See also the
 417 :ref:`full list of options related to tracing <tracing_tracing_options>`.
 418
 419 It is interesting to run the process-create example with the following
 420 options to see the task executions:
 421
 422   - **Platform Tracing:**
 423     This program is a toy example just loading the platform, so that
 424     you can play with the platform visualization. Recommanded options:
 425     ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
 426     |br| `examples/s4u/trace-platform/s4u-trace-platform.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/trace-platform/s4u-trace-platform.cpp>`_
 427
 428 ========================
 429 Larger SimGrid Examplars
 430 ========================
 431
 432 This section contains application examples that are somewhat larger
 433 than the previous examples.
 434
 435   - **Ping Pong:**
 436     This simple example just sends one message back and forth.
 437     The tesh file laying in the directory show how to start the simulator binary, highlighting how to pass options to
 438     the simulators (as detailed in Section :ref:`options`).
 439     |br| `examples/s4u/app-pingpong/s4u-app-pingpong.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-pingpong/s4u-app-pingpong.cpp>`_
 440
 441   - **Token ring:**
 442     Shows how to implement a classical communication pattern, where a
 443     token is exchanged along a ring to reach every participant.
 444     |br| `examples/s4u/app-token-ring/s4u-app-token-ring.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-token-ring/s4u-app-token-ring.cpp>`_
 445
 446   - **Master Workers:**
 447     Another good old example, where one Master process has a bunch of task to dispatch to a set of several Worker
 448     processes. This example comes in two equivalent variants, one
 449     where the actors are specified as simple functions (which is easier to
 450     understand for newcomers) and one where the actors are specified
 451     as classes (which is more powerful for the users wanting to build
 452     their own projects upon the example).
 453     |br| `examples/s4u/app-masterworkers/s4u-app-masterworkers-class.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-masterworkers/s4u-app-masterworkers-class.cpp>`_
 454     |br| `examples/s4u/app-masterworkers/s4u-app-masterworkers-fun.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-masterworkers/s4u-app-masterworkers-fun.cpp>`_
 455
 456 Data diffusion
 457 --------------
 458
 459   - **Bit Torrent:**
 460     Classical protocol for Peer-to-Peer data diffusion.
 461     |br| `examples/s4u/app-bittorrent/s4u-bittorrent.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-bittorrent/s4u-bittorrent.cpp>`_
 462
 463   - **Chained Send:**
 464     Data broadcast over a ring of processes.
 465     |br| `examples/s4u/app-chainsend/s4u-app-chainsend.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-chainsend/s4u-app-chainsend.cpp>`_
 466
 467 Distributed Hash Tables (DHT)
 468 -----------------------------
 469
 470   - **Chord Protocol**
 471     One of the most famous DHT protocol.
 472     |br| `examples/s4u/dht-chord/s4u-dht-chord.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/dht-chord/s4u-dht-chord.cpp>`_
 473
 474 .. _s4u_ex_clouds:
 475
 476 Simulating Clouds
 477 -----------------
 478
 479   - **Cloud basics**
 480     This example starts some computations both on PMs and VMs, and
 481     migrates some VMs around.
 482     |br| `examples/s4u/cloud-simple/s4u-cloud-simple.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/cloud-simple/s4u-cloud-simple.cpp>`_
 483
 484 .. TODO:: document here the examples about clouds and plugins
 485
 486 =======================
 487 Model-Checking Examples
 488 =======================
 489
 490 The model-checker can be used to exhaustively search for issues in the
 491 tested application. It must be activated at compile time, but this
 492 mode is rather experimental in SimGrid (as of v3.22). You should not
 493 enable it unless you really want to formally verify your applications:
 494 SimGrid is slower and maybe less robust when MC is enabled.
 495
 496   - **Failing assert**
 497     In this example, two actors send some data to a central server,
 498     which asserts that the messages are always received in the same order.
 499     This is obviously wrong, and the model-checker correctly finds a
 500     counter-example to that assertion.
 501     |br| `examples/s4u/mc-failing-assert/s4u-mc-failing-assert.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/mc-failing-assert/s4u-mc-failing-assert.cpp>`_
 502
 503 .. |br| raw:: html
 504
 505    <br />
 506
 507 .. |cpp| image:: /img/lang_cpp.png
 508    :align: middle
 509    :width: 12
 510
 511 .. |py| image:: /img/lang_python.png
 512    :align: middle
 513    :width: 12