1 .. S4U (Simgrid for you) is the modern interface of SimGrid, which new project should use.
3 .. This file follows the ReStructured syntax to be included in the
4 .. documentation, but it should remain readable directly.
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.
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.
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
27 ===========================
28 Actors: the Active Entities
29 ===========================
31 Starting and Stoping Actors
32 ---------------------------
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.
41 .. example-tab:: examples/s4u/actor-create/s4u-actor-create.cpp
43 You create actors either:
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`
50 .. example-tab:: examples/python/actor-create/actor-create.py
52 You create actors either:
54 - Directly with :py:func:`simgrid.Actor.create()`
55 - From XML with :py:func:`simgrid.Engine.register_actor()` and then :py:func:`simgrid.Engine.load_deployment()`
57 .. example-tab:: examples/c/actor-create/actor-create.c
59 You create actors either:
61 - Directly with :cpp:func:`sg_actor_create()` followed by :cpp:func:`sg_actor_start`.
62 - From XML with :cpp:func:`simgrid_register_function` and then :cpp:func:`simgrid_load_deployment`.
64 .. example-tab:: examples/python/actor-create/actor-create_d.xml
66 The following file is used in both C++ and Python.
68 - **React to the end of actors:** You can attach callbacks to the end of
69 actors. There is several ways of doing so, depending on whether you want to
70 attach your callback to a given actor and on how you define the end of a
71 given actor. User code probably want to react to the termination of an actor
72 while some plugins want to react to the destruction (memory collection) of
77 .. example-tab:: examples/s4u/actor-exiting/s4u-actor-exiting.cpp
79 This example shows how to attach a callback to:
81 - the end of a specific actor: :cpp:func:`simgrid::s4u::this_actor::on_exit()`
82 - the end of any actor: :cpp:member:`simgrid::s4u::Actor::on_termination()`
83 - the destruction of any actor: :cpp:member:`simgrid::s4u::Actor::on_destruction()`
86 Actors can forcefully stop other actors.
90 .. example-tab:: examples/s4u/actor-kill/s4u-actor-kill.cpp
92 See also :cpp:func:`void simgrid::s4u::Actor::kill(void)`, :cpp:func:`void simgrid::s4u::Actor::kill_all()`,
93 :cpp:func:`simgrid::s4u::this_actor::exit`, :cpp:func:`simgrid::s4u::this_actor::on_exit`.
95 .. example-tab:: examples/python/actor-kill/actor-kill.py
97 See also :py:func:`simgrid.Actor.kill`, :py:func:`simgrid.Actor.kill_all`, :py:func:`simgrid.this_actor.exit`,
98 :py:func:`simgrid.this_actor.on_exit`.
100 .. example-tab:: examples/c/actor-kill/actor-kill.c
102 See also :cpp:func:`sg_actor_kill`, :cpp:func:`sg_actor_kill_all`, :cpp:func:`sg_actor_exit`, :cpp:func:`sg_actor_on_exit`.
104 - **Controling the actor life cycle from the XML:**
105 You can specify a start time and a kill time in the deployment file.
109 .. example-tab:: examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp
111 This file is not really interesting: the important matter is in the XML file.
113 .. example-tab:: examples/s4u/actor-lifetime/s4u-actor-lifetime_d.xml
115 This demonstrates the ``start_time`` and ``kill_time`` attribute of the :ref:`pf_tag_actor` tag.
117 - **Daemonize actors:**
118 Some actors may be intended to simulate daemons that run in background. This example show how to transform a regular
119 actor into a daemon that will be automatically killed once the simulation is over.
123 .. example-tab:: examples/s4u/actor-daemon/s4u-actor-daemon.cpp
125 See also :cpp:func:`simgrid::s4u::Actor::daemonize()` and :cpp:func:`simgrid::s4u::Actor::is_daemon()`.
127 .. example-tab:: examples/python/actor-daemon/actor-daemon.py
129 See also :py:func:`simgrid.Actor.daemonize()` and :py:func:`simgrid.Actor.is_daemon()`.
131 .. example-tab:: examples/c/actor-daemon/actor-daemon.c
133 See also :cpp:func:`sg_actor_daemonize` and :cpp:func:`sg_actor_is_daemon`.
135 Inter-Actors Interactions
136 -------------------------
138 See also the examples on :ref:`inter-actors communications
139 <s4u_ex_communication>` and the ones on :ref:`classical
140 synchronization objects <s4u_ex_IPC>`.
142 - **Suspend and Resume actors:**
143 Actors can be suspended and resumed during their executions.
147 .. example-tab:: examples/s4u/actor-suspend/s4u-actor-suspend.cpp
149 See also :cpp:func:`simgrid::s4u::this_actor::suspend()`,
150 :cpp:func:`simgrid::s4u::Actor::suspend()`, :cpp:func:`simgrid::s4u::Actor::resume()` and
151 :cpp:func:`simgrid::s4u::Actor::is_suspended()`.
153 .. example-tab:: examples/python/actor-suspend/actor-suspend.py
155 See also :py:func:`simgrid.this_actor.suspend()`,
156 :py:func:`simgrid.Actor.suspend()`, :py:func:`simgrid.Actor.resume()` and
157 :py:func:`simgrid.Actor.is_suspended()`.
159 - **Migrating Actors:**
160 Actors can move or be moved from a host to another very easily.
164 .. example-tab:: examples/s4u/actor-migrate/s4u-actor-migrate.cpp
166 See also :cpp:func:`simgrid::s4u::this_actor::migrate()` and :cpp:func:`simgrid::s4u::Actor::migrate()`.
168 .. example-tab:: examples/python/actor-migrate/actor-migrate.py
170 See also :py:func:`simgrid.this_actor.migrate()` and :py:func:`simgrid.Actor.migrate()`.
172 - **Waiting for the termination of an actor:** (joining on it)
173 You can block the current actor until the end of another actor.
177 .. example-tab:: examples/s4u/actor-join/s4u-actor-join.cpp
179 See also :cpp:func:`simgrid::s4u::Actor::join()`.
181 .. example-tab:: examples/python/actor-join/actor-join.py
183 See also :py:func:`simgrid.Actor.join()`.
185 .. example-tab:: examples/c/actor-join/actor-join.c
187 See also :cpp:func:`sg_actor_join`.
189 - **Yielding to other actors**.
190 The ```yield()``` function interrupts the execution of the current
191 actor, leaving a chance to the other actors that are ready to run
196 .. example-tab:: examples/s4u/actor-yield/s4u-actor-yield.cpp
198 See also :cpp:func:`simgrid::s4u::this_actor::yield()`.
200 .. example-tab:: examples/python/actor-yield/actor-yield.py
202 See also :py:func:`simgrid.this_actor.yield_()`.
204 Traces Replay as a Workload
205 ---------------------------
207 This section details how to run trace-driven simulations. It is very
208 handy when you want to test an algorithm or protocol that only react
209 to external events. For example, many P2P protocols react to user
210 requests, but do nothing if there is no such event.
212 In such situations, you should write your protocol in C++, and separate
213 the workload that you want to play onto your protocol in a separate
214 text file. Declare a function handling each type of the events in your
215 trace, register them using :cpp:func:`xbt_replay_action_register()` in
216 your main, and then run the simulation.
218 Then, you can either have one trace file containing all your events,
219 or a file per simulated process: the former may be easier to work
220 with, but the second is more efficient on very large traces. Check
221 also the tesh files in the example directories for details.
223 - **Communication replay:**
224 Presents a set of event handlers reproducing classical communication
225 primitives (asynchronous send/receive at the moment).
229 .. example-tab:: examples/s4u/replay-comm/s4u-replay-comm.cpp
232 Presents a set of event handlers reproducing classical I/O
233 primitives (open, read, close).
237 .. example-tab:: examples/s4u/replay-io/s4u-replay-io.cpp
239 ==========================
240 Activities: what Actors do
241 ==========================
243 .. _s4u_ex_communication:
245 Communications on the Network
246 -----------------------------
248 - **Basic asynchronous communications:**
249 Illustrates how to have non-blocking communications, that are
250 communications running in the background leaving the process free
251 to do something else during their completion.
255 .. example-tab:: examples/s4u/async-wait/s4u-async-wait.cpp
257 See also :cpp:func:`simgrid::s4u::Mailbox::put_async()` and :cpp:func:`simgrid::s4u::Comm::wait()`.
259 .. example-tab:: examples/python/async-wait/async-wait.py
261 See also :py:func:`simgrid.Mailbox.put_async()` and :py:func:`simgrid.Comm.wait()`.
263 - **Waiting for all communications in a set:**
264 The ``wait_all()`` function is useful when you want to block until
265 all activities in a given set have completed.
269 .. example-tab:: examples/s4u/async-waitall/s4u-async-waitall.cpp
271 See also :cpp:func:`simgrid::s4u::Comm::wait_all()`.
273 .. example-tab:: examples/python/async-waitall/async-waitall.py
275 See also :py:func:`simgrid.Comm.wait_all()`.
277 - **Waiting for the first completed communication in a set:**
278 The ``wait_any()`` function is useful
279 when you want to block until one activity of the set completes, no
280 matter which terminates first.
284 .. example-tab:: examples/s4u/async-waitany/s4u-async-waitany.cpp
286 See also :cpp:func:`simgrid::s4u::Comm::wait_any()`.
288 .. example-tab:: examples/python/async-waitany/async-waitany.py
290 See also :py:func:`simgrid.Comm.wait_any()`.
292 .. example-tab:: examples/c/async-waitany/async-waitany.c
294 See also :cpp:func:`sg_comm_wait_any`.
296 .. _s4u_ex_execution:
298 Executions on the CPU
299 ---------------------
301 - **Basic execution:**
302 The computations done in your program are not reported to the
303 simulated world, unless you explicitly request the simulator to pause
304 the actor until a given amount of flops gets computed on its simulated
305 host. Some executions can be given an higher priority so that they
310 .. example-tab:: examples/s4u/exec-basic/s4u-exec-basic.cpp
312 See also :cpp:func:`void simgrid::s4u::this_actor::execute(double)`
313 and :cpp:func:`void simgrid::s4u::this_actor::execute(double, double)`.
315 .. example-tab:: examples/python/exec-basic/exec-basic.py
317 See also :py:func:`simgrid.this_actor.execute()`.
319 - **Asynchronous execution:**
320 You can start asynchronous executions, just like you would fire
325 .. example-tab:: examples/s4u/exec-async/s4u-exec-async.cpp
327 See also :cpp:func:`simgrid::s4u::this_actor::exec_init()`,
328 :cpp:func:`simgrid::s4u::Activity::start()`,
329 :cpp:func:`simgrid::s4u::Activity::wait()`,
330 :cpp:func:`simgrid::s4u::Activity::get_remaining()`,
331 :cpp:func:`simgrid::s4u::Exec::get_remaining_ratio()`,
332 :cpp:func:`simgrid::s4u::this_actor::exec_async()` and
333 :cpp:func:`simgrid::s4u::Activity::cancel()`.
335 .. example-tab:: examples/python/exec-async/exec-async.py
337 See also :py:func:`simgrid.this_actor::exec_init()`,
338 :py:func:`simgrid.Activity::start()`,
339 :py:func:`simgrid.Activity.wait()`,
340 :py:func:`simgrid.Activity.get_remaining()`,
341 :py:func:`simgrid.Exec.get_remaining_ratio()`,
342 :py:func:`simgrid.this_actor.exec_async()` and
343 :py:func:`simgrid.Activity.cancel()`.
345 - **Remote execution:**
346 You can start executions on remote hosts, or even change the host
347 on which they occur during their execution.
351 .. example-tab:: examples/s4u/exec-remote/s4u-exec-remote.cpp
353 See also :cpp:func:`simgrid::s4u::Exec::set_host()`.
355 .. example-tab:: examples/python/exec-remote/exec-remote.py
357 See also :py:func:`simgrid.Exec.set_host()`.
359 - **Parallel executions:**
360 These objects are convenient abstractions of parallel
361 computational kernels that span over several machines, such as a
362 PDGEM and the other ScaLAPACK routines. Note that this only works
363 with the "ptask_L07" host model (``--cfg=host/model:ptask_L07``).
367 .. example-tab:: examples/s4u/exec-ptask/s4u-exec-ptask.cpp
369 See also :cpp:func:`simgrid::s4u::this_actor::parallel_execute()`.
371 - **Using Pstates on a host:**
372 This example shows how define a set of pstates in the XML. The current pstate
373 of an host can then be accessed and changed from the program.
377 .. example-tab:: examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp
379 See also :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
381 .. example-tab:: examples/python/exec-dvfs/exec-dvfs.py
383 See also :py:func:`Host.get_pstate_speed` and :py:func:`Host.set_pstate`.
385 .. example-tab:: examples/platforms/energy_platform.xml
389 I/O on Disks and Files
390 ----------------------
392 SimGrid provides two levels of abstraction to interact with the
393 simulated disks. At the simplest level, you simply create read and
394 write actions on the disk resources.
396 - **Access to raw disk devices:**
397 This example illustrates how to simply read and write data on a
398 simulated disk resource.
402 .. example-tab:: examples/s4u/io-disk-raw/s4u-io-disk-raw.cpp
404 .. example-tab:: examples/platforms/hosts_with_disks.xml
406 This shows how to declare disks in XML.
408 The FileSystem plugin provides a more detailed view, with the
409 classical operations over files: open, move, unlink, and of course
410 read and write. The file and disk sizes are also dealt with and can
411 result in short reads and short write, as in reality.
413 - **File Management:**
414 This example illustrates the use of operations on files
415 (read, write, seek, tell, unlink, etc).
419 .. example-tab:: examples/s4u/io-file-system/s4u-io-file-system.cpp
422 I/O operations on files can also be done in a remote fashion,
423 i.e. when the accessed disk is not mounted on the caller's host.
427 .. example-tab:: examples/s4u/io-file-remote/s4u-io-file-remote.cpp
431 Classical synchronization objects
432 ---------------------------------
435 Shows how to use :cpp:type:`simgrid::s4u::Barrier` synchronization objects.
439 .. example-tab:: examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp
441 - **Condition variable:**
442 Shows how to use :cpp:type:`simgrid::s4u::ConditionVariable` synchronization objects.
446 .. example-tab:: examples/s4u/synchro-condition-variable/s4u-synchro-condition-variable.cpp
449 Shows how to use :cpp:type:`simgrid::s4u::Mutex` synchronization objects.
453 .. example-tab:: examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp
456 Shows how to use :cpp:type:`simgrid::s4u::Semaphore` synchronization objects.
460 .. example-tab:: examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp
462 =============================
463 Interacting with the Platform
464 =============================
466 - **User-defined properties:**
467 You can attach arbitrary information to most platform elements from
468 the XML file, and then interact with these values from your
469 program. Note that the changes are not written permanently on disk,
470 in the XML file nor anywhere else. They only last until the end of
475 .. example-tab:: examples/s4u/platform-properties/s4u-platform-properties.cpp
477 - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
478 - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
479 - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
480 - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
486 .. showfile:: examples/s4u/platform-properties/s4u-platform-properties_d.xml
492 .. showfile:: examples/platforms/prop.xml
495 - **Retrieving the netzones matching a given criteria:**
496 Shows how to filter the cluster netzones.
500 .. example-tab:: examples/s4u/routing-get-clusters/s4u-routing-get-clusters.cpp
502 - **Retrieving the list of hosts matching a given criteria:**
503 Shows how to filter the actors that match a given criteria.
507 .. example-tab:: examples/s4u/engine-filtering/s4u-engine-filtering.cpp
509 - **Specifying state profiles:** shows how to specify when the
510 resources must be turned off and on again, and how to react to such
511 failures in your code. See also :ref:`howto_churn`.
515 .. example-tab:: examples/s4u/platform-failures/s4u-platform-failures.cpp
519 .. showfile:: examples/platforms/small_platform_failures.xml
522 .. showfile:: examples/platforms/profiles/jupiter_state.profile
524 .. showfile:: examples/platforms/profiles/bourassa_state.profile
526 .. showfile:: examples/platforms/profiles/fafard_state.profile
528 - **Specifying speed profiles:** shows how to specify an external
529 load to resources, variating their peak speed over time.
533 .. example-tab:: examples/s4u/platform-profile/s4u-platform-profile.cpp
537 .. showfile:: examples/platforms/small_platform_profile.xml
540 .. showfile:: examples/platforms/profiles/jupiter_speed.profile
542 .. showfile:: examples/platforms/profiles/link1_bandwidth.profile
544 .. showfile:: examples/platforms/profiles/link1_latency.profile
550 - **Describing the energy profiles in the platform:**
551 This platform file contains the energy profile of each links and
552 hosts, which is necessary to get energy consumption predictions.
553 As usual, you should not trust our example, and you should strive
554 to double-check that your instantiation matches your target platform.
558 .. example-tab:: examples/platforms/energy_platform.xml
560 - **Consumption due to the CPU:**
561 This example shows how to retrieve the amount of energy consumed
562 by the CPU during computations, and the impact of the pstate.
566 .. example-tab:: examples/s4u/energy-exec/s4u-energy-exec.cpp
568 - **Consumption due to the network:**
569 This example shows how to retrieve and display the energy consumed
570 by the network during communications.
574 .. example-tab:: examples/s4u/energy-link/s4u-energy-link.cpp
576 - **Modeling the shutdown and boot of hosts:**
577 Simple example of model of model for the energy consumption during
578 the host boot and shutdown periods.
582 .. example-tab:: examples/s4u/energy-boot/platform_boot.xml
584 .. example-tab:: examples/s4u/energy-boot/s4u-energy-boot.cpp
586 =======================
587 Tracing and Visualizing
588 =======================
590 Tracing can be activated by various configuration options which
591 are illustrated in these example. See also the
592 :ref:`full list of options related to tracing <tracing_tracing_options>`.
594 It is interesting to run the process-create example with the following
595 options to see the task executions:
597 - **Platform Tracing:**
598 This program is a toy example just loading the platform, so that
599 you can play with the platform visualization. Recommanded options:
600 ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
604 .. example-tab:: examples/s4u/trace-platform/s4u-trace-platform.cpp
606 ========================
607 Larger SimGrid Examplars
608 ========================
610 This section contains application examples that are somewhat larger
611 than the previous examples.
614 This simple example just sends one message back and forth.
615 The tesh file laying in the directory show how to start the simulator binary, highlighting how to pass options to
616 the simulators (as detailed in Section :ref:`options`).
620 .. example-tab:: examples/s4u/app-pingpong/s4u-app-pingpong.cpp
623 Shows how to implement a classical communication pattern, where a
624 token is exchanged along a ring to reach every participant.
628 .. example-tab:: examples/s4u/app-token-ring/s4u-app-token-ring.cpp
630 - **Master Workers:**
631 Another good old example, where one Master process has a bunch of task to dispatch to a set of several Worker
638 This example comes in two equivalent variants, one where the actors
639 are specified as simple functions (which is easier to understand for
640 newcomers) and one where the actors are specified as classes (which is
641 more powerful for the users wanting to build their own projects upon
644 .. showfile:: examples/s4u/app-masterworkers/s4u-app-masterworkers-class.cpp
647 .. showfile:: examples/s4u/app-masterworkers/s4u-app-masterworkers-fun.cpp
654 Classical protocol for Peer-to-Peer data diffusion.
660 .. showfile:: examples/s4u/app-bittorrent/s4u-bittorrent.cpp
663 .. showfile:: examples/s4u/app-bittorrent/s4u-peer.cpp
666 .. showfile:: examples/s4u/app-bittorrent/s4u-tracker.cpp
670 Data broadcast over a ring of processes.
674 .. example-tab:: examples/s4u/app-chainsend/s4u-app-chainsend.cpp
676 Distributed Hash Tables (DHT)
677 -----------------------------
680 One of the most famous DHT protocol.
686 .. showfile:: examples/s4u/dht-chord/s4u-dht-chord.cpp
689 .. showfile:: examples/s4u/dht-chord/s4u-dht-chord-node.cpp
693 Another well-known DHT protocol.
699 .. showfile:: examples/s4u/dht-kademlia/s4u-dht-kademlia.cpp
702 .. showfile:: examples/s4u/dht-kademlia/routing_table.cpp
705 .. showfile:: examples/s4u/dht-kademlia/answer.cpp
708 .. showfile:: examples/s4u/dht-kademlia/node.cpp
717 This example starts some computations both on PMs and VMs, and
718 migrates some VMs around.
722 .. example-tab:: examples/s4u/cloud-simple/s4u-cloud-simple.cpp
725 This example shows how to migrate VMs between PMs.
729 .. example-tab:: examples/s4u/cloud-migration/s4u-cloud-migration.cpp
731 =======================
732 Model-Checking Examples
733 =======================
735 The model-checker can be used to exhaustively search for issues in the
736 tested application. It must be activated at compile time, but this
737 mode is rather experimental in SimGrid (as of v3.22). You should not
738 enable it unless you really want to formally verify your applications:
739 SimGrid is slower and maybe less robust when MC is enabled.
742 In this example, two actors send some data to a central server,
743 which asserts that the messages are always received in the same order.
744 This is obviously wrong, and the model-checker correctly finds a
745 counter-example to that assertion.
749 .. example-tab:: examples/s4u/mc-failing-assert/s4u-mc-failing-assert.cpp
755 .. |cpp| image:: /img/lang_cpp.png
759 .. |py| image:: /img/lang_python.png