examples/s4u/README.rst

   1 .. S4U (Simgrid for you) is the next interface of SimGrid, expected to be released with SimGrid 4.0.
   2 ..
   3 .. Even if it is not completely rock stable yet, it may well already fit
   4 .. your needs. You are welcome to try it and report any interface
   5 .. glitches that you see. Be however warned that the interface may change
   6 .. until the final release.  You will have to adapt your code on the way.
   7 ..
   8 .. This file follows the ReStructured syntax to be included in the
   9 .. documentation, but it should remain readable directly.
  10
  11
  12 S4U Examples
  13 ************
  14
  15 SimGrid comes with an extensive set of examples, documented on this
  16 page. Most of them only demonstrate one single feature, with some
  17 larger examplars listed below.
  18
  19 The C++ examples can be found under examples/s4u while python examples
  20 are in examples/python. Each such directory contains the source code (also listed
  21 from this page), and the so-called tesh file containing how to call
  22 the binary obtained by compiling this example and also the expected
  23 output. Tesh files are used to turn each of our examples into an
  24 integration test. Some examples also contain other files, on need.
  25
  26 A good way to bootstrap your own project is to copy and combine some
  27 of the provided examples to constitute the skeleton of what you plan
  28 to simulate.
  29
  30 ===========================
  31 Actors: the Active Entities
  32 ===========================
  33
  34 .. _s4u_ex_actors:
  35
  36 Starting and Stoping Actors
  37 ---------------------------
  38
  39   - **Creating actors:**
  40     Most actors are started from the deployment XML file, but there is other methods.
  41     This example show them all.
  42     `examples/python/actor-create/actor-create_d.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-create/actor-create_d.xml>`_
  43
  44     - |cpp| `examples/s4u/actor-create/s4u-actor-create.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-create/s4u-actor-create.cpp>`_
  45     - |py|  `examples/python/actor-create/actor-create.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-create/actor-create.py>`_
  46
  47   - **React to the end of actors:**
  48     You can attach a callback to the end of actors. There is two ways
  49     of doing so, depending of whether you want your callback to be
  50     executed when a specific actor ends (with ```this_actor::on_exit()```)
  51     or whether it should be executed when any actor ends (with
  52     ```Actor::on_destruction()```)
  53
  54     - |cpp| `examples/s4u/actor-exiting/s4u-actor-exiting.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-exiting/s4u-actor-exiting.cpp>`_
  55
  56   - **Kill actors:**
  57     Actors can forcefully stop other actors.
  58
  59     - |cpp| `examples/s4u/actor-kill/s4u-actor-kill.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-kill/s4u-actor-kill.cpp>`_
  60       :cpp:func:`void simgrid::s4u::Actor::kill(void)`,
  61       :cpp:func:`void simgrid::s4u::Actor::kill_all()`,
  62       :cpp:func:`simgrid::s4u::this_actor::exit`.
  63     - |py| `examples/python/actor-kill/actor-kill.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-kill/actor-kill.py>`_
  64       :py:func:`simgrid.Actor.kill`,
  65       :py:func:`simgrid.Actor.kill_all`,
  66       :py:func:`simgrid.this_actor.exit`.
  67
  68   - **Controling the actor life cycle from the XML:**
  69     You can specify a start time and a kill time in the deployment
  70     file.
  71     |br| `examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp>`_
  72     |br| `examples/s4u/actor-lifetime/s4u-actor-lifetime_d.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-lifetime/s4u-actor-lifetime_d.xml>`_
  73
  74   - **Daemonize actors:**
  75     Some actors may be intended to simulate daemons that run in background. This example show how to transform a regular
  76     actor into a daemon that will be automatically killed once the simulation is over.
  77
  78     - |cpp| `examples/s4u/actor-daemon/s4u-actor-daemon.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-daemon/s4u-actor-daemon.cpp>`_
  79     - |py|  `examples/python/actor-daemon/actor-daemon.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-daemon/actor-daemon.py>`_
  80
  81 Inter-Actors Interactions
  82 -------------------------
  83
  84 See also the examples on :ref:`inter-actors communications
  85 <s4u_ex_communication>` and the ones on :ref:`classical
  86 synchronization objects <s4u_ex_IPC>`.
  87
  88   - **Suspend and Resume actors:**
  89     Actors can be suspended and resumed during their executions.
  90
  91     - |cpp| `examples/s4u/actor-suspend/s4u-actor-suspend.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-suspend/s4u-actor-suspend.cpp>`_
  92       :cpp:func:`simgrid::s4u::this_actor::suspend()`,
  93       :cpp:func:`simgrid::s4u::Actor::suspend()`, :cpp:func:`simgrid::s4u::Actor::resume()`, :cpp:func:`simgrid::s4u::Actor::is_suspended()`.
  94     - |py|  `examples/python/actor-suspend/actor-suspend.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-suspend/actor-suspend.py>`_
  95       :py:func:`simgrid.this_actor.suspend()`,
  96       :py:func:`simgrid.Actor.suspend()`, :py:func:`simgrid.Actor.resume()`, :py:func:`simgrid.Actor.is_suspended()`.
  97
  98   - **Migrating Actors:**
  99     Actors can move or be moved from a host to another very easily.
 100
 101     - |cpp| `examples/s4u/actor-migrate/s4u-actor-migrate.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-migrate/s4u-actor-migrate.cpp>`_
 102       :cpp:func:`simgrid::s4u::this_actor::migrate()`
 103     - |py|  `examples/python/actor-migrate/actor-migrate.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-migrate/actor-migrate.py>`_
 104       :py:func:`simgrid.this_actor.migrate()`
 105
 106   - **Waiting for the termination of an actor:** (joining on it)
 107     You can block the current actor until the end of another actor.
 108
 109     - |cpp| `examples/s4u/actor-join/s4u-actor-join.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-join/s4u-actor-join.cpp>`_
 110       :cpp:func:`simgrid::s4u::Actor::join()`
 111     - |py|  `examples/python/actor-join/actor-join.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-join/actor-join.py>`_
 112       :py:func:`simgrid.Actor.join()`
 113
 114   - **Yielding to other actors**.
 115     The ```yield()``` function interrupts the execution of the current
 116     actor, leaving a chance to the other actors that are ready to run
 117     at this timestamp.
 118
 119     - |cpp| `examples/s4u/actor-yield/s4u-actor-yield.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-yield/s4u-actor-yield.cpp>`_
 120       :cpp:func:`simgrid::s4u::this_actor::yield()`
 121     - |py|  `examples/python/actor-yield/actor-yield.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-yield/actor-yield.py>`_
 122       :py:func:`simgrid.this_actor.yield_()`
 123
 124 Traces Replay as a Workload
 125 ---------------------------
 126
 127 This section details how to run trace-driven simulations. It is very
 128 handy when you want to test an algorithm or protocol that only react
 129 to external events. For example, many P2P protocols react to user
 130 requests, but do nothing if there is no such event.
 131
 132 In such situations, you should write your protocol in C++, and separate
 133 the workload that you want to play onto your protocol in a separate
 134 text file. Declare a function handling each type of the events in your
 135 trace, register them using :cpp:func:`xbt_replay_action_register()` in
 136 your main, and then run the simulation.
 137
 138 Then, you can either have one trace file containing all your events,
 139 or a file per simulated process: the former may be easier to work
 140 with, but the second is more efficient on very large traces. Check
 141 also the tesh files in the example directories for details.
 142
 143   - **Communication replay:**
 144     Presents a set of event handlers reproducing classical communication
 145     primitives (asynchronous send/receive at the moment).
 146     |br| `examples/s4u/replay-comm/s4u-replay-comm.cpp  <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/replay-comm/s4u-replay-comm.cpp>`_
 147
 148   - **I/O replay:**
 149     Presents a set of event handlers reproducing classical I/O
 150     primitives (open, read, close).
 151     |br| `examples/s4u/replay-storage/s4u-replay-storage.cpp  <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/replay-storage/s4u-replay-storage.cpp>`_
 152
 153 ==========================
 154 Activities: what Actors do
 155 ==========================
 156
 157 .. _s4u_ex_communication:
 158
 159 Communications on the Network
 160 -----------------------------
 161
 162  - **Basic asynchronous communications:**
 163    Illustrates how to have non-blocking communications, that are
 164    communications running in the background leaving the process free
 165    to do something else during their completion.
 166
 167    - |cpp| `examples/s4u/async-wait/s4u-async-wait.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-wait/s4u-async-wait.cpp>`_
 168      :cpp:func:`simgrid::s4u::Mailbox::put_async()` and :cpp:func:`simgrid::s4u::Comm::wait()`
 169    - |py|  `examples/python/async-wait/async-wait.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/async-wait/async-wait.py>`_
 170      :py:func:`simgrid.Mailbox.put_async()` :py:func:`simgrid.Comm.wait()`
 171
 172  - **Waiting for all communications in a set:**
 173    The `wait_all()` function is useful when you want to block until
 174    all activities in a given set have completed.
 175
 176    - |cpp| `examples/s4u/async-waitall/s4u-async-waitall.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-waitall/s4u-async-waitall.cpp>`_
 177      :cpp:func:`simgrid::s4u::Comm::wait_all()`
 178    - |py| `examples/python/async-waitall/async-waitall.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/async-waitall/async-waitall.py>`_
 179      :py:func:`simgrid.Comm.wait_all()`
 180
 181  - **Waiting for the first completed communication in a set:**
 182    The `wait_any()` function is useful
 183    when you want to block until one activity of the set completes, no
 184    matter which terminates first.
 185
 186    - |cpp| `examples/s4u/async-waitany/s4u-async-waitany.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-waitany/s4u-async-waitany.cpp>`_
 187      :cpp:func:`simgrid::s4u::Comm::wait_any()`
 188    - |py| `examples/python/async-waitany/async-waitany.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/async-waitany/async-waitany.py>`_
 189      :py:func:`simgrid.Comm.wait_any()`
 190
 191 .. todo:: review the `ready` and `waituntil` examples and add them here.
 192
 193 .. _s4u_ex_execution:
 194
 195 Executions on the CPU
 196 ---------------------
 197
 198   - **Basic execution:**
 199     The computations done in your program are not reported to the
 200     simulated world, unless you explicitely request the simulator to pause
 201     the actor until a given amount of flops gets computed on its simulated
 202     host. Some executions can be given an higher priority so that they
 203     get more resources.
 204
 205     - |cpp| `examples/s4u/exec-basic/s4u-exec-basic.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-basic/s4u-exec-basic.cpp>`_
 206     - |py|  `examples/python/exec-basic/exec-basic.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/exec-basic/exec-basic.py>`_
 207
 208   - **Asynchronous execution:**
 209     You can start asynchronous executions, just like you would fire
 210     background threads.
 211
 212     - |cpp| `examples/s4u/exec-async/s4u-exec-async.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-async/s4u-exec-async.cpp>`_
 213     - |py|  `examples/python/exec-async/exec-async.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/exec-async/exec-async.py>`_
 214
 215   - **Remote execution:**
 216     You can start executions on remote hosts, or even change the host
 217     on which they occur during their execution.
 218
 219     - |cpp| `examples/s4u/exec-remote/s4u-exec-remote.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-remote/s4u-exec-remote.cpp>`_
 220     - |py| `examples/python/exec-remote/exec-remote.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/exec-remote/exec-remote.py>`_
 221
 222   - **Parallel executions:**
 223     These objects are convenient abstractions of parallel
 224     computational kernels that span over several machines, such as a
 225     PDGEM and the other ScaLAPACK routines. Note that this only works
 226     with the "ptask_L07" host model (``--cfg=host/model:ptask_L07``).
 227     |br| `examples/s4u/exec-ptask/s4u-exec-ptask.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-ptask/s4u-exec-ptask.cpp>`_
 228
 229   - **Using Pstates on a host:**
 230     `examples/platforms/energy_platform.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/energy_platform.xml>`_
 231     shows how define a set of pstates in the XML. The current pstate
 232     of an host can then be accessed and changed from the program.
 233
 234     - |cpp| `examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp>`_
 235       :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
 236     - |py|  `examples/python/exec-dvfs/exec-dvfs.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/exec-dvfs/exec-dvfs.py>`_
 237       :py:func:`Host.get_pstate_speed` and :py:func:`Host.set_pstate`.
 238
 239 I/O on Disks and Files
 240 ----------------------
 241
 242 SimGrid provides two levels of abstraction to interact with the
 243 simulated storages. At the simplest level, you simply create read and
 244 write actions on the storage resources.
 245
 246   - **Access to raw storage devices:**
 247     This example illustrates how to simply read and write data on a
 248     simulated storage resource.
 249     |br| `examples/s4u/io-storage-raw/s4u-io-storage-raw.cpp  <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/io-storage-raw/s4u-io-storage-raw.cpp>`_
 250
 251 The FileSystem plugin provides a more detailed view, with the
 252 classical operations over files: open, move, unlink, and of course
 253 read and write. The file and disk sizes are also dealt with and can
 254 result in short reads and short write, as in reality.
 255
 256   - **File Management:**
 257     This example illustrates the use of operations on files
 258     (read, write, seek, tell, unlink, etc).
 259     |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>`_
 260
 261   - **Remote I/O:**
 262     I/O operations on files can also be done in a remote fashion,
 263     i.e. when the accessed disk is not mounted on the caller's host.
 264     |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>`_
 265
 266 .. _s4u_ex_IPC:
 267
 268 Classical synchronization objects
 269 ---------------------------------
 270
 271  - **Mutex:**
 272    Shows how to use simgrid::s4u::Mutex synchronization objects.
 273    |br| `examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp>`_
 274
 275  - **Barrier:**
 276    Shows how to use simgrid::s4u::Barrier synchronization objects.
 277    |br| `examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp>`_
 278
 279  - **Semaphore:**
 280    Shows how to use simgrid::s4u::Semaphore synchronization objects.
 281    |br| `examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp>`_
 282
 283 =============================
 284 Interacting with the Platform
 285 =============================
 286
 287  - **Retrieving the list of hosts matching a given criteria:**
 288    Shows how to filter the actors that match a given criteria.
 289    |br| `examples/s4u/engine-filtering/s4u-engine-filtering.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/engine-filtering/s4u-engine-filtering.cpp>`_
 290
 291  - **User-defined properties:**
 292    You can attach arbitrary information to most platform elements from
 293    the XML file, and then interact with these values from your
 294    program. Note that the changes are not written permanently on disk,
 295    in the XML file nor anywhere else. They only last until the end of
 296    your simulation.
 297
 298    - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
 299    - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
 300    - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
 301    - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
 302
 303    |br| `examples/s4u/platform-properties/s4u-platform-properties.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/platform-properties/s4u-platform-properties.cpp>`_
 304    |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>`_
 305    |br| `examples/platforms/prop.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/prop.xml>`_
 306
 307  - **Specifying state profiles:** shows how to specify when the
 308    resources must be turned off and on again, and how to react to such
 309    failures in your code.
 310
 311    |br| `examples/platforms/small_platform_failures.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/small_platform_failures.xml>`_
 312    |br| The state profiles in `examples/platforms/profiles <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/profiles>`_
 313
 314  - **Specifying speed profiles:** shows how to specify an external
 315    load to resources, variating their peak speed over time.
 316
 317    |br| `examples/platforms/small_platform_profile.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/small_platform_profile.xml>`_
 318    |br| The speed, bandwidth and latency profiles in `examples/platforms/profiles  <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/profiles>`_
 319
 320 =================
 321 Energy Simulation
 322 =================
 323
 324   - **Describing the energy profiles in the platform:**
 325     This platform file contains the energy profile of each links and
 326     hosts, which is necessary to get energy consumption predictions.
 327     As usual, you should not trust our example, and you should strive
 328     to double-check that your instanciation matches your target platform.
 329     |br| `examples/platforms/energy_platform.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/energy_platform.xml>`_
 330
 331   - **Consumption due to the CPU:**
 332     This example shows how to retrieve the amount of energy consumed
 333     by the CPU during computations, and the impact of the pstate.
 334     |br| `examples/s4u/energy-exec/s4u-energy-exec.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-exec/s4u-energy-exec.cpp>`_
 335
 336   - **Consumption due to the network:**
 337     This example shows how to retrieve and display the energy consumed
 338     by the network during communications.
 339     |br| `examples/s4u/energy-link/s4u-energy-link.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-link/s4u-energy-link.cpp>`_
 340
 341   - **Modeling the shutdown and boot of hosts:**
 342     Simple example of model of model for the energy consumption during
 343     the host boot and shutdown periods.
 344     |br| `examples/s4u/energy-boot/platform_boot.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-boot/platform_boot.xml>`_
 345     |br| `examples/s4u/energy-boot/s4u-energy-boot.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-boot/s4u-energy-boot.cpp>`_
 346
 347 =======================
 348 Tracing and Visualizing
 349 =======================
 350
 351 Tracing can be activated by various configuration options which
 352 are illustrated in these example. See also the
 353 :ref:`full list of options related to tracing <tracing_tracing_options>`.
 354
 355 It is interesting to run the process-create example with the following
 356 options to see the task executions:
 357
 358   - **Platform Tracing:**
 359     This program is a toy example just loading the platform, so that
 360     you can play with the platform visualization. Recommanded options:
 361     ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
 362     |br| `examples/s4u/trace-platform/s4u-trace-platform.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/trace-platform/s4u-trace-platform.cpp>`_
 363
 364 ========================
 365 Larger SimGrid Examplars
 366 ========================
 367
 368 This section contains application examples that are somewhat larger
 369 than the previous examples.
 370
 371   - **Ping Pong:**
 372     This simple example just sends one message back and forth.
 373     The tesh file laying in the directory show how to start the simulator binary, highlighting how to pass options to
 374     the simulators (as detailed in Section :ref:`options`).
 375     |br| `examples/s4u/app-pingpong/s4u-app-pingpong.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-pingpong/s4u-app-pingpong.cpp>`_
 376
 377   - **Token ring:**
 378     Shows how to implement a classical communication pattern, where a
 379     token is exchanged along a ring to reach every participant.
 380     |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>`_
 381
 382   - **Master Workers:**
 383     Another good old example, where one Master process has a bunch of task to dispatch to a set of several Worker
 384     processes. This example comes in two equivalent variants, one
 385     where the actors are specified as simple functions (which is easier to
 386     understand for newcomers) and one where the actors are specified
 387     as classes (which is more powerful for the users wanting to build
 388     their own projects upon the example).
 389     |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>`_
 390     |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>`_
 391
 392 Data diffusion
 393 --------------
 394
 395   - **Bit Torrent:**
 396     Classical protocol for Peer-to-Peer data diffusion.
 397     |br| `examples/s4u/app-bittorrent/s4u-bittorrent.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-bittorrent/s4u-bittorrent.cpp>`_
 398
 399   - **Chained Send:**
 400     Data broadcast over a ring of processes.
 401     |br| `examples/s4u/app-chainsend/s4u-app-chainsend.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-chainsend/s4u-app-chainsend.cpp>`_
 402
 403 Distributed Hash Tables (DHT)
 404 -----------------------------
 405
 406   - **Chord Protocol**
 407     One of the most famous DHT protocol.
 408     |br| `examples/s4u/dht-chord/s4u-dht-chord.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/dht-chord/s4u-dht-chord.cpp>`_
 409
 410 .. _s4u_ex_clouds:
 411
 412 Simulating Clouds
 413 -----------------
 414
 415   - **Cloud basics**
 416     This example starts some computations both on PMs and VMs, and
 417     migrates some VMs around.
 418     |br| `examples/s4u/cloud-simple/s4u-cloud-simple.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/cloud-simple/s4u-cloud-simple.cpp>`_
 419
 420 .. TODO:: document here the examples about clouds and plugins
 421
 422 =======================
 423 Model-Checking Examples
 424 =======================
 425
 426 The model-checker can be used to exhaustively search for issues in the
 427 tested application. It must be activated at compile time, but this
 428 mode is rather experimental in SimGrid (as of v3.22). You should not
 429 enable it unless you really want to formally verify your applications:
 430 SimGrid is slower and maybe less robust when MC is enabled.
 431
 432   - **Failing assert**
 433     In this example, two actors send some data to a central server,
 434     which asserts that the messages are always received in the same order.
 435     This is obviously wrong, and the model-checker correctly finds a
 436     counter-example to that assertion.
 437     |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>`_
 438
 439 .. |br| raw:: html
 440
 441    <br />
 442
 443 .. |cpp| image:: /img/lang_cpp.png
 444    :align: middle
 445    :width: 12
 446
 447 .. |py| image:: /img/lang_python.png
 448    :align: middle
 449    :width: 12