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
  35 Starting and Stoping Actors
  36 ---------------------------
  37
  38   - **Creating actors:**
  39     Most actors are started from the deployment XML file, but there is other methods.
  40     This example show them all.
  41     `examples/python/actor-create/actor-create_d.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-create/actor-create_d.xml>`_
  42
  43     - |cpp| `examples/s4u/actor-create/s4u-actor-create.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-create/s4u-actor-create.cpp>`_
  44     - |py|  `examples/python/actor-create/actor-create.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-create/actor-create.py>`_
  45
  46   - **Kill actors:**
  47     Actors can forcefully stop other actors.
  48
  49     - |cpp| `examples/s4u/actor-kill/s4u-actor-kill.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-kill/s4u-actor-kill.cpp>`_
  50       :cpp:func:`void simgrid::s4u::Actor::kill(void)`,
  51       :cpp:func:`void simgrid::s4u::Actor::kill_all()`,
  52       :cpp:func:`simgrid::s4u::this_actor::exit`.
  53     - |py| `examples/python/actor-kill/actor-kill.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-kill/actor-kill.py>`_
  54       :py:func:`simgrid.Actor.kill`,
  55       :py:func:`simgrid.Actor.kill_all`,
  56       :py:func:`simgrid.this_actor.exit`.
  57
  58   - **Controling the actor life cycle from the XML:**
  59     You can specify a start time and a kill time in the deployment
  60     file.
  61     |br| `examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp>`_
  62     |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>`_
  63
  64   - **Daemonize actors:**
  65     Some actors may be intended to simulate daemons that run in background. This example show how to transform a regular
  66     actor into a daemon that will be automatically killed once the simulation is over.
  67
  68     - |cpp| `examples/s4u/actor-daemon/s4u-actor-daemon.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-daemon/s4u-actor-daemon.cpp>`_
  69     - |py|  `examples/python/actor-daemon/actor-daemon.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-daemon/actor-daemon.py>`_
  70
  71 Inter-Actors Interactions
  72 -------------------------
  73
  74   - **Suspend and Resume actors:**
  75     Actors can be suspended and resumed during their executions.
  76
  77     - |cpp| `examples/s4u/actor-suspend/s4u-actor-suspend.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-suspend/s4u-actor-suspend.cpp>`_
  78       :cpp:func:`simgrid::s4u::this_actor::suspend()`,
  79       :cpp:func:`simgrid::s4u::Actor::suspend()`, :cpp:func:`simgrid::s4u::Actor::resume()`, :cpp:func:`simgrid::s4u::Actor::is_suspended()`.
  80     - |py|  `examples/python/actor-suspend/actor-suspend.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-suspend/actor-suspend.py>`_
  81       :py:func:`simgrid.this_actor.suspend()`,
  82       :py:func:`simgrid.Actor.suspend()`, :py:func:`simgrid.Actor.resume()`, :py:func:`simgrid.Actor.is_suspended()`.
  83
  84   - **Migrating Actors:**
  85     Actors can move or be moved from a host to another very easily.
  86
  87     - |cpp| `examples/s4u/actor-migrate/s4u-actor-migrate.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-migrate/s4u-actor-migrate.cpp>`_
  88       :cpp:func:`simgrid::s4u::this_actor::migrate()`
  89     - |py|  `examples/python/actor-migrate/actor-migrate.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-migrate/actor-migrate.py>`_
  90       :py:func:`simgrid.this_actor.migrate()`
  91
  92   - **Waiting for the termination of an actor:** (joining on it)
  93     You can block the current actor until the end of another actor.
  94
  95     - |cpp| `examples/s4u/actor-join/s4u-actor-join.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-join/s4u-actor-join.cpp>`_
  96       :cpp:func:`simgrid::s4u::Actor::join()`
  97     - |py|  `examples/python/actor-join/actor-join.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-join/actor-join.py>`_
  98       :py:func:`simgrid.Actor.join()`
  99
 100   - **Yielding to other actors**.
 101     The ```yield()``` function interrupts the execution of the current
 102     actor, leaving a chance to the other actors that are ready to run
 103     at this timestamp.
 104
 105     - |cpp| `examples/s4u/actor-yield/s4u-actor-yield.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-yield/s4u-actor-yield.cpp>`_
 106       :cpp:func:`simgrid::s4u::this_actor::yield()`
 107     - |py|  `examples/python/actor-yield/actor-yield.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-yield/actor-yield.py>`_
 108       :py:func:`simgrid.this_actor.yield_()`
 109
 110 Traces Replay as a Workload
 111 ---------------------------
 112
 113 This section details how to run trace-driven simulations. It is very
 114 handy when you want to test an algorithm or protocol that only react
 115 to external events. For example, many P2P protocols react to user
 116 requests, but do nothing if there is no such event.
 117
 118 In such situations, you should write your protocol in C++, and separate
 119 the workload that you want to play onto your protocol in a separate
 120 text file. Declare a function handling each type of the events in your
 121 trace, register them using :cpp:func:`xbt_replay_action_register()` in
 122 your main, and then run the simulation.
 123
 124 Then, you can either have one trace file containing all your events,
 125 or a file per simulated process: the former may be easier to work
 126 with, but the second is more efficient on very large traces. Check
 127 also the tesh files in the example directories for details.
 128
 129   - **Communication replay:**
 130     Presents a set of event handlers reproducing classical communication
 131     primitives (asynchronous send/receive at the moment).
 132     |br| `examples/s4u/replay-comm/s4u-replay-comm.cpp  <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/replay-comm/s4u-replay-comm.cpp>`_
 133
 134   - **I/O replay:**
 135     Presents a set of event handlers reproducing classical I/O
 136     primitives (open, read, close).
 137     |br| `examples/s4u/replay-storage/s4u-replay-storage.cpp  <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/replay-storage/s4u-replay-storage.cpp>`_
 138
 139 ==========================
 140 Activities: what Actors do
 141 ==========================
 142
 143 Communications on the Network
 144 -----------------------------
 145
 146  - **Basic asynchronous communications:**
 147    Illustrates how to have non-blocking communications, that are
 148    communications running in the background leaving the process free
 149    to do something else during their completion. The main functions
 150    involved are :cpp:func:`simgrid::s4u::Mailbox::put_async()` and
 151    :cpp:func:`simgrid::s4u::Comm::wait()`.
 152    |br| `examples/s4u/async-wait/s4u-async-wait.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-wait/s4u-async-wait.cpp>`_
 153
 154  - **Waiting for all communications in a set:**
 155    The :cpp:func:`simgrid::s4u::Comm::wait_all()` function is useful
 156    when you want to block until all activities in a given set have
 157    completed.
 158    |br| `examples/s4u/async-waitall/s4u-async-waitall.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-waitall/s4u-async-waitall.cpp>`_
 159
 160  - **Waiting for the first completed communication in a set:**
 161    The :cpp:func:`simgrid::s4u::Comm::wait_any()` function is useful
 162    when you want to block until one activity of the set completes, no
 163    matter which terminates first.
 164    |br| `examples/s4u/async-waitany/s4u-async-waitany.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-waitany/s4u-async-waitany.cpp>`_
 165
 166 .. todo:: add the `ready` example here
 167
 168 .. _s4u_ex_execution:
 169
 170 Executions on the CPU
 171 ---------------------
 172
 173   - **Basic execution:**
 174     The computations done in your program are not reported to the
 175     simulated world, unless you explicitely request the simulator to pause
 176     the actor until a given amount of flops gets computed on its simulated
 177     host. Some executions can be given an higher priority so that they
 178     get more resources.
 179
 180     - |cpp| `examples/s4u/exec-basic/s4u-exec-basic.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-basic/s4u-exec-basic.cpp>`_
 181     - |py|  `examples/python/exec-basic/exec-basic.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/exec-basic/exec-basic.py>`_
 182
 183   - **Asynchronous execution:**
 184     You can start asynchronous executions, just like you would fire
 185     background threads.
 186     |br| `examples/s4u/exec-async/s4u-exec-async.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-async/s4u-exec-async.cpp>`_
 187
 188   - **Monitoring asynchronous executions:**
 189     This example shows how to start an asynchronous execution, and
 190     monitor its status.
 191     |br| `examples/s4u/exec-monitor/s4u-exec-monitor.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-monitor/s4u-exec-monitor.cpp>`_
 192
 193   - **Remote execution:**
 194     Before its start, you can change the host on which a given execution will occur.
 195     |br| `examples/s4u/exec-remote/s4u-exec-remote.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-remote/s4u-exec-remote.cpp>`_
 196
 197   - **Using Pstates on a host:**
 198     Shows how define a set of pstatesfor a host in the XML, and how the current
 199     pstate can be accessed/changed with :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
 200     |br| `examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp>`_
 201     |br| `examples/platforms/energy_platform.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/energy_platform.xml>`_
 202
 203   - **Parallel executions:**
 204     These objects are convenient abstractions of parallel
 205     computational kernels that span over several machines, such as a
 206     PDGEM and the other ScaLAPACK routines.
 207     |br| `examples/s4u/exec-ptask/s4u-exec-ptask.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-ptask/s4u-exec-ptask.cpp>`_
 208
 209 I/O on Disks and Files
 210 ----------------------
 211
 212 SimGrid provides two levels of abstraction to interact with the
 213 simulated storages. At the simplest level, you simply create read and
 214 write actions on the storage resources.
 215
 216   - **Access to raw storage devices:**
 217     This example illustrates how to simply read and write data on a
 218     simulated storage resource.
 219     |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>`_
 220
 221 The FileSystem plugin provides a more detailed view, with the
 222 classical operations over files: open, move, unlink, and of course
 223 read and write. The file and disk sizes are also dealt with and can
 224 result in short reads and short write, as in reality.
 225
 226   - **File Management:**
 227     This example illustrates the use of operations on files
 228     (read, write, seek, tell, unlink, etc).
 229     |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>`_
 230
 231   - **Remote I/O:**
 232     I/O operations on files can also be done in a remote fashion,
 233     i.e. when the accessed disk is not mounted on the caller's host.
 234     |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>`_
 235
 236 Classical synchronization objects
 237 ---------------------------------
 238
 239  - **Mutex:**
 240    Shows how to use simgrid::s4u::Mutex synchronization objects.
 241    |br| `examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp>`_
 242
 243  - **Barrier:**
 244    Shows how to use simgrid::s4u::Barrier synchronization objects.
 245    |br| `examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp>`_
 246
 247  - **Semaphore:**
 248    Shows how to use simgrid::s4u::Semaphore synchronization objects.
 249    |br| `examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp>`_
 250
 251 =============================
 252 Interacting with the Platform
 253 =============================
 254
 255  - **Retrieving the list of hosts matching a given criteria:**
 256    Shows how to filter the actors that match a given criteria.
 257    |br| `examples/s4u/engine-filtering/s4u-engine-filtering.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/engine-filtering/s4u-engine-filtering.cpp>`_
 258
 259  - **User-defined properties:**
 260    You can attach arbitrary information to most platform elements from
 261    the XML file, and then interact with these values from your
 262    program. Note that the changes are not written permanently on disk,
 263    in the XML file nor anywhere else. They only last until the end of
 264    your simulation.
 265
 266    - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
 267    - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
 268    - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
 269    - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
 270
 271    |br| `examples/s4u/platform-properties/s4u-platform-properties.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/platform-properties/s4u-platform-properties.cpp>`_
 272    |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>`_
 273    |br| `examples/platforms/prop.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/prop.xml>`_
 274
 275 =================
 276 Energy Simulation
 277 =================
 278
 279   - **Describing the energy profiles in the platform:**
 280     This platform file contains the energy profile of each links and
 281     hosts, which is necessary to get energy consumption predictions.
 282     As usual, you should not trust our example, and you should strive
 283     to double-check that your instanciation matches your target platform.
 284     |br| `examples/platforms/energy_platform.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/energy_platform.xml>`_
 285
 286   - **Consumption due to the CPU:**
 287     This example shows how to retrieve the amount of energy consumed
 288     by the CPU during computations, and the impact of the pstate.
 289     |br| `examples/s4u/energy-exec/s4u-energy-exec.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-exec/s4u-energy-exec.cpp>`_
 290
 291   - **Consumption due to the network:**
 292     This example shows how to retrieve and display the energy consumed
 293     by the network during communications.
 294     |br| `examples/s4u/energy-link/s4u-energy-link.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-link/s4u-energy-link.cpp>`_
 295
 296   - **Modeling the shutdown and boot of hosts:**
 297     Simple example of model of model for the energy consumption during
 298     the host boot and shutdown periods.
 299     |br| `examples/s4u/energy-boot/platform_boot.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-boot/platform_boot.xml>`_
 300     |br| `examples/s4u/energy-boot/s4u-energy-boot.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-boot/s4u-energy-boot.cpp>`_
 301
 302 =======================
 303 Tracing and Visualizing
 304 =======================
 305
 306 Tracing can be activated by various configuration options which
 307 are illustrated in these example. See also the
 308 :ref:`full list of options related to tracing <tracing_tracing_options>`.
 309
 310 It is interesting to run the process-create example with the following
 311 options to see the task executions:
 312
 313   - **Platform Tracing:**
 314     This program is a toy example just loading the platform, so that
 315     you can play with the platform visualization. Recommanded options:
 316     ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
 317     |br| `examples/s4u/trace-platform/s4u-trace-platform.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/trace-platform/s4u-trace-platform.cpp>`_
 318
 319 ========================
 320 Larger SimGrid Examplars
 321 ========================
 322
 323 This section contains application examples that are somewhat larger
 324 than the previous examples.
 325
 326   - **Ping Pong:**
 327     This simple example just sends one message back and forth.
 328     The tesh file laying in the directory show how to start the simulator binary, highlighting how to pass options to
 329     the simulators (as detailed in Section :ref:`options`).
 330     |br| `examples/s4u/app-pingpong/s4u-app-pingpong.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-pingpong/s4u-app-pingpong.cpp>`_
 331
 332   - **Token ring:**
 333     Shows how to implement a classical communication pattern, where a
 334     token is exchanged along a ring to reach every participant.
 335     |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>`_
 336
 337   - **Master Workers:**
 338     Another good old example, where one Master process has a bunch of task to dispatch to a set of several Worker
 339     processes. This example comes in two equivalent variants, one
 340     where the actors are specified as simple functions (which is easier to
 341     understand for newcomers) and one where the actors are specified
 342     as classes (which is more powerful for the users wanting to build
 343     their own projects upon the example).
 344     |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>`_
 345     |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>`_
 346
 347 Data diffusion
 348 --------------
 349
 350   - **Bit Torrent:**
 351     Classical protocol for Peer-to-Peer data diffusion.
 352     |br| `examples/s4u/app-bittorrent/s4u-bittorrent.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-bittorrent/s4u-bittorrent.cpp>`_
 353
 354   - **Chained Send:**
 355     Data broadcast over a ring of processes.
 356     |br| `examples/s4u/app-chainsend/s4u-app-chainsend.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-chainsend/s4u-app-chainsend.cpp>`_
 357
 358 Distributed Hash Tables (DHT)
 359 -----------------------------
 360
 361   - **Chord Protocol**
 362     One of the most famous DHT protocol.
 363     |br| `examples/s4u/dht-chord/s4u-dht-chord.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/dht-chord/s4u-dht-chord.cpp>`_
 364
 365 .. TODO:: document here the examples about plugins
 366
 367 .. |br| raw:: html
 368
 369    <br />
 370
 371 .. |cpp| image:: /img/lang_cpp.png
 372    :align: middle
 373    :width: 12
 374
 375 .. |py| image:: /img/lang_python.png
 376    :align: middle
 377    :width: 12