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()`
85 .. example-tab:: examples/c/actor-exiting/actor-exiting.c
87 This example shows how to attach a callback to the end of a specific actor with
88 :cpp:func:`sg_actor_on_exit()`.
91 Actors can forcefully stop other actors.
95 .. example-tab:: examples/s4u/actor-kill/s4u-actor-kill.cpp
97 See also :cpp:func:`void simgrid::s4u::Actor::kill(void)`, :cpp:func:`void simgrid::s4u::Actor::kill_all()`,
98 :cpp:func:`simgrid::s4u::this_actor::exit`, :cpp:func:`simgrid::s4u::this_actor::on_exit`.
100 .. example-tab:: examples/python/actor-kill/actor-kill.py
102 See also :py:func:`simgrid.Actor.kill`, :py:func:`simgrid.Actor.kill_all`, :py:func:`simgrid.this_actor.exit`,
103 :py:func:`simgrid.this_actor.on_exit`.
105 .. example-tab:: examples/c/actor-kill/actor-kill.c
107 See also :cpp:func:`sg_actor_kill`, :cpp:func:`sg_actor_kill_all`, :cpp:func:`sg_actor_exit`, :cpp:func:`sg_actor_on_exit`.
109 - **Controling the actor life cycle from the XML:**
110 You can specify a start time and a kill time in the deployment file.
114 .. example-tab:: examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp
116 This file is not really interesting: the important matter is in the XML file.
118 .. example-tab:: examples/s4u/actor-lifetime/s4u-actor-lifetime_d.xml
120 This demonstrates the ``start_time`` and ``kill_time`` attribute of the :ref:`pf_tag_actor` tag.
122 .. example-tab:: examples/c/actor-lifetime/actor-lifetime.c
124 This file is not really interesting: the important matter is in the XML file.
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.
132 .. example-tab:: examples/s4u/actor-daemon/s4u-actor-daemon.cpp
134 See also :cpp:func:`simgrid::s4u::Actor::daemonize()` and :cpp:func:`simgrid::s4u::Actor::is_daemon()`.
136 .. example-tab:: examples/python/actor-daemon/actor-daemon.py
138 See also :py:func:`simgrid.Actor.daemonize()` and :py:func:`simgrid.Actor.is_daemon()`.
140 .. example-tab:: examples/c/actor-daemon/actor-daemon.c
142 See also :cpp:func:`sg_actor_daemonize` and :cpp:func:`sg_actor_is_daemon`.
144 Inter-Actors Interactions
145 -------------------------
147 See also the examples on :ref:`inter-actors communications
148 <s4u_ex_communication>` and the ones on :ref:`classical
149 synchronization objects <s4u_ex_IPC>`.
151 - **Suspend and Resume actors:**
152 Actors can be suspended and resumed during their executions.
156 .. example-tab:: examples/s4u/actor-suspend/s4u-actor-suspend.cpp
158 See also :cpp:func:`simgrid::s4u::this_actor::suspend()`,
159 :cpp:func:`simgrid::s4u::Actor::suspend()`, :cpp:func:`simgrid::s4u::Actor::resume()`, and
160 :cpp:func:`simgrid::s4u::Actor::is_suspended()`.
162 .. example-tab:: examples/python/actor-suspend/actor-suspend.py
164 See also :py:func:`simgrid.this_actor.suspend()`,
165 :py:func:`simgrid.Actor.suspend()`, :py:func:`simgrid.Actor.resume()`, and
166 :py:func:`simgrid.Actor.is_suspended()`.
168 .. example-tab:: examples/c/actor-suspend/actor-suspend.c
170 See also :cpp:func:`sg_actor_suspend()`, :cpp:func:`sg_actor_resume()`, and
171 :cpp:func:`sg_actor_is_suspended()`.
173 - **Migrating Actors:**
174 Actors can move or be moved from a host to another very easily. It amount to setting them on a new host.
178 .. example-tab:: examples/s4u/actor-migrate/s4u-actor-migrate.cpp
180 See also :cpp:func:`simgrid::s4u::this_actor::set_host()` and :cpp:func:`simgrid::s4u::Actor::set_host()`.
182 .. example-tab:: examples/python/actor-migrate/actor-migrate.py
184 See also :py:func:`simgrid.this_actor.set_host()` and :py:func:`simgrid.Actor.set_host()`.
186 .. example-tab:: examples/c/actor-migrate/actor-migrate.c
188 See also :cpp:func:`sg_actor_set_host()`.
190 - **Waiting for the termination of an actor:** (joining on it)
191 You can block the current actor until the end of another actor.
195 .. example-tab:: examples/s4u/actor-join/s4u-actor-join.cpp
197 See also :cpp:func:`simgrid::s4u::Actor::join()`.
199 .. example-tab:: examples/python/actor-join/actor-join.py
201 See also :py:func:`simgrid.Actor.join()`.
203 .. example-tab:: examples/c/actor-join/actor-join.c
205 See also :cpp:func:`sg_actor_join`.
207 - **Yielding to other actors**.
208 The ```yield()``` function interrupts the execution of the current
209 actor, leaving a chance to the other actors that are ready to run
214 .. example-tab:: examples/s4u/actor-yield/s4u-actor-yield.cpp
216 See also :cpp:func:`simgrid::s4u::this_actor::yield()`.
218 .. example-tab:: examples/python/actor-yield/actor-yield.py
220 See also :py:func:`simgrid.this_actor.yield_()`.
222 .. example-tab:: examples/c/actor-yield/actor-yield.c
224 See also :cpp:func:`sg_actor_yield()`.
226 Traces Replay as a Workload
227 ---------------------------
229 This section details how to run trace-driven simulations. It is very
230 handy when you want to test an algorithm or protocol that only react
231 to external events. For example, many P2P protocols react to user
232 requests, but do nothing if there is no such event.
234 In such situations, you should write your protocol in C++, and separate
235 the workload that you want to play onto your protocol in a separate
236 text file. Declare a function handling each type of the events in your
237 trace, register them using :cpp:func:`xbt_replay_action_register()` in
238 your main, and then run the simulation.
240 Then, you can either have one trace file containing all your events,
241 or a file per simulated process: the former may be easier to work
242 with, but the second is more efficient on very large traces. Check
243 also the tesh files in the example directories for details.
245 - **Communication replay:**
246 Presents a set of event handlers reproducing classical communication
247 primitives (asynchronous send/receive at the moment).
251 .. example-tab:: examples/s4u/replay-comm/s4u-replay-comm.cpp
254 Presents a set of event handlers reproducing classical I/O
255 primitives (open, read, close).
259 .. example-tab:: examples/s4u/replay-io/s4u-replay-io.cpp
261 ==========================
262 Activities: what Actors do
263 ==========================
265 .. _s4u_ex_communication:
267 Communications on the Network
268 -----------------------------
270 - **Basic asynchronous communications:**
271 Illustrates how to have non-blocking communications, that are
272 communications running in the background leaving the process free
273 to do something else during their completion.
277 .. example-tab:: examples/s4u/async-wait/s4u-async-wait.cpp
279 See also :cpp:func:`simgrid::s4u::Mailbox::put_async()` and :cpp:func:`simgrid::s4u::Comm::wait()`.
281 .. example-tab:: examples/python/async-wait/async-wait.py
283 See also :py:func:`simgrid.Mailbox.put_async()` and :py:func:`simgrid.Comm.wait()`.
285 .. example-tab:: examples/c/async-wait/async-wait.c
287 See also :cpp:func:`sg_mailbox_put_async()` and :cpp:func:`sg_comm__wait()`.
289 - **Waiting for all communications in a set:**
290 The ``wait_all()`` function is useful when you want to block until
291 all activities in a given set have completed.
295 .. example-tab:: examples/s4u/async-waitall/s4u-async-waitall.cpp
297 See also :cpp:func:`simgrid::s4u::Comm::wait_all()`.
299 .. example-tab:: examples/python/async-waitall/async-waitall.py
301 See also :py:func:`simgrid.Comm.wait_all()`.
303 .. example-tab:: examples/c/async-waitall/async-waitall.c
305 See also :cpp:func:`sg_comm_wait_all()`.
307 - **Waiting for the first completed communication in a set:**
308 The ``wait_any()`` function is useful
309 when you want to block until one activity of the set completes, no
310 matter which terminates first.
314 .. example-tab:: examples/s4u/async-waitany/s4u-async-waitany.cpp
316 See also :cpp:func:`simgrid::s4u::Comm::wait_any()`.
318 .. example-tab:: examples/python/async-waitany/async-waitany.py
320 See also :py:func:`simgrid.Comm.wait_any()`.
322 .. example-tab:: examples/c/async-waitany/async-waitany.c
324 See also :cpp:func:`sg_comm_wait_any`.
326 .. _s4u_ex_execution:
328 Executions on the CPU
329 ---------------------
331 - **Basic execution:**
332 The computations done in your program are not reported to the
333 simulated world, unless you explicitly request the simulator to pause
334 the actor until a given amount of flops gets computed on its simulated
335 host. Some executions can be given an higher priority so that they
340 .. example-tab:: examples/s4u/exec-basic/s4u-exec-basic.cpp
342 See also :cpp:func:`void simgrid::s4u::this_actor::execute(double)`
343 and :cpp:func:`void simgrid::s4u::this_actor::execute(double, double)`.
345 .. example-tab:: examples/python/exec-basic/exec-basic.py
347 See also :py:func:`simgrid.this_actor.execute()`.
349 .. example-tab:: examples/c/exec-basic/exec-basic.c
351 See also :cpp:func:`void sg_actor_execute(double)`
352 and :cpp:func:`void sg_actor_execute_with_priority(double, double)`.
354 - **Asynchronous execution:**
355 You can start asynchronous executions, just like you would fire
360 .. example-tab:: examples/s4u/exec-async/s4u-exec-async.cpp
362 See also :cpp:func:`simgrid::s4u::this_actor::exec_init()`,
363 :cpp:func:`simgrid::s4u::Activity::start()`,
364 :cpp:func:`simgrid::s4u::Activity::wait()`,
365 :cpp:func:`simgrid::s4u::Activity::get_remaining()`,
366 :cpp:func:`simgrid::s4u::Exec::get_remaining_ratio()`,
367 :cpp:func:`simgrid::s4u::this_actor::exec_async()` and
368 :cpp:func:`simgrid::s4u::Activity::cancel()`.
370 .. example-tab:: examples/python/exec-async/exec-async.py
372 See also :py:func:`simgrid.this_actor::exec_init()`,
373 :py:func:`simgrid.Activity::start()`,
374 :py:func:`simgrid.Activity.wait()`,
375 :py:func:`simgrid.Activity.get_remaining()`,
376 :py:func:`simgrid.Exec.get_remaining_ratio()`,
377 :py:func:`simgrid.this_actor.exec_async()` and
378 :py:func:`simgrid.Activity.cancel()`.
380 - **Remote execution:**
381 You can start executions on remote hosts, or even change the host
382 on which they occur during their execution.
386 .. example-tab:: examples/s4u/exec-remote/s4u-exec-remote.cpp
388 See also :cpp:func:`simgrid::s4u::Exec::set_host()`.
390 .. example-tab:: examples/python/exec-remote/exec-remote.py
392 See also :py:func:`simgrid.Exec.set_host()`.
394 .. example-tab:: examples/c/exec-remote/exec-remote.c
396 See also :cpp:func:`sg_exec_set_host()`.
398 - **Parallel executions:**
399 These objects are convenient abstractions of parallel
400 computational kernels that span over several machines, such as a
401 PDGEM and the other ScaLAPACK routines. Note that this only works
402 with the "ptask_L07" host model (``--cfg=host/model:ptask_L07``).
406 .. example-tab:: examples/s4u/exec-ptask/s4u-exec-ptask.cpp
408 See also :cpp:func:`simgrid::s4u::this_actor::parallel_execute()`.
410 - **Using Pstates on a host:**
411 This example shows how define a set of pstates in the XML. The current pstate
412 of an host can then be accessed and changed from the program.
416 .. example-tab:: examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp
418 See also :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
420 .. example-tab:: examples/c/exec-dvfs/exec-dvfs.c
422 See also :cpp:func:`sg_host_get_pstate_speed` and :cpp:func:`sg_host_set_pstate`.
424 .. example-tab:: examples/python/exec-dvfs/exec-dvfs.py
426 See also :py:func:`Host.get_pstate_speed` and :py:func:`Host.set_pstate`.
428 .. example-tab:: examples/platforms/energy_platform.xml
432 I/O on Disks and Files
433 ----------------------
435 SimGrid provides two levels of abstraction to interact with the
436 simulated disks. At the simplest level, you simply create read and
437 write actions on the disk resources.
439 - **Access to raw disk devices:**
440 This example illustrates how to simply read and write data on a
441 simulated disk resource.
445 .. example-tab:: examples/s4u/io-disk-raw/s4u-io-disk-raw.cpp
447 .. example-tab:: examples/c/io-disk-raw/io-disk-raw.c
449 .. example-tab:: examples/platforms/hosts_with_disks.xml
451 This shows how to declare disks in XML.
453 The FileSystem plugin provides a more detailed view, with the
454 classical operations over files: open, move, unlink, and of course
455 read and write. The file and disk sizes are also dealt with and can
456 result in short reads and short write, as in reality.
458 - **File Management:**
459 This example illustrates the use of operations on files
460 (read, write, seek, tell, unlink, etc).
464 .. example-tab:: examples/s4u/io-file-system/s4u-io-file-system.cpp
467 I/O operations on files can also be done in a remote fashion,
468 i.e. when the accessed disk is not mounted on the caller's host.
472 .. example-tab:: examples/s4u/io-file-remote/s4u-io-file-remote.cpp
474 .. example-tab:: examples/c/io-file-remote/io-file-remote.c
478 Classical synchronization objects
479 ---------------------------------
482 Shows how to use :cpp:type:`simgrid::s4u::Barrier` synchronization objects.
486 .. example-tab:: examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp
488 - **Condition variable:**
489 Shows how to use :cpp:type:`simgrid::s4u::ConditionVariable` synchronization objects.
493 .. example-tab:: examples/s4u/synchro-condition-variable/s4u-synchro-condition-variable.cpp
496 Shows how to use :cpp:type:`simgrid::s4u::Mutex` synchronization objects.
500 .. example-tab:: examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp
503 Shows how to use :cpp:type:`simgrid::s4u::Semaphore` synchronization objects.
507 .. example-tab:: examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp
509 =============================
510 Interacting with the Platform
511 =============================
513 - **User-defined properties:**
514 You can attach arbitrary information to most platform elements from
515 the XML file, and then interact with these values from your
516 program. Note that the changes are not written permanently on disk,
517 in the XML file nor anywhere else. They only last until the end of
522 .. example-tab:: examples/s4u/platform-properties/s4u-platform-properties.cpp
524 - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
525 - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
526 - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
527 - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
533 .. showfile:: examples/s4u/platform-properties/s4u-platform-properties_d.xml
539 .. showfile:: examples/platforms/prop.xml
542 - **Retrieving the netzones matching a given criteria:**
543 Shows how to filter the cluster netzones.
547 .. example-tab:: examples/s4u/routing-get-clusters/s4u-routing-get-clusters.cpp
549 - **Retrieving the list of hosts matching a given criteria:**
550 Shows how to filter the actors that match a given criteria.
554 .. example-tab:: examples/s4u/engine-filtering/s4u-engine-filtering.cpp
556 - **Specifying state profiles:** shows how to specify when the
557 resources must be turned off and on again, and how to react to such
558 failures in your code. See also :ref:`howto_churn`.
562 .. example-tab:: examples/s4u/platform-failures/s4u-platform-failures.cpp
566 .. showfile:: examples/platforms/small_platform_failures.xml
569 .. showfile:: examples/platforms/profiles/jupiter_state.profile
571 .. showfile:: examples/platforms/profiles/bourassa_state.profile
573 .. showfile:: examples/platforms/profiles/fafard_state.profile
575 - **Specifying speed profiles:** shows how to specify an external
576 load to resources, variating their peak speed over time.
580 .. example-tab:: examples/s4u/platform-profile/s4u-platform-profile.cpp
584 .. showfile:: examples/platforms/small_platform_profile.xml
587 .. showfile:: examples/platforms/profiles/jupiter_speed.profile
589 .. showfile:: examples/platforms/profiles/link1_bandwidth.profile
591 .. showfile:: examples/platforms/profiles/link1_latency.profile
597 - **Describing the energy profiles in the platform:**
598 This platform file contains the energy profile of each links and
599 hosts, which is necessary to get energy consumption predictions.
600 As usual, you should not trust our example, and you should strive
601 to double-check that your instantiation matches your target platform.
605 .. example-tab:: examples/platforms/energy_platform.xml
607 - **Consumption due to the CPU:**
608 This example shows how to retrieve the amount of energy consumed
609 by the CPU during computations, and the impact of the pstate.
613 .. example-tab:: examples/s4u/energy-exec/s4u-energy-exec.cpp
615 .. example-tab:: examples/c/energy-exec/energy-exec.c
617 - **Consumption due to the network:**
618 This example shows how to retrieve and display the energy consumed
619 by the network during communications.
623 .. example-tab:: examples/s4u/energy-link/s4u-energy-link.cpp
625 - **Modeling the shutdown and boot of hosts:**
626 Simple example of model of model for the energy consumption during
627 the host boot and shutdown periods.
631 .. example-tab:: examples/s4u/energy-boot/platform_boot.xml
633 .. example-tab:: examples/s4u/energy-boot/s4u-energy-boot.cpp
635 =======================
636 Tracing and Visualizing
637 =======================
639 Tracing can be activated by various configuration options which
640 are illustrated in these example. See also the
641 :ref:`full list of options related to tracing <tracing_tracing_options>`.
643 It is interesting to run the process-create example with the following
644 options to see the task executions:
646 - **Platform Tracing:**
647 This program is a toy example just loading the platform, so that
648 you can play with the platform visualization. Recommanded options:
649 ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
653 .. example-tab:: examples/s4u/trace-platform/s4u-trace-platform.cpp
655 ========================
656 Larger SimGrid Examplars
657 ========================
659 This section contains application examples that are somewhat larger
660 than the previous examples.
663 This simple example just sends one message back and forth.
664 The tesh file laying in the directory show how to start the simulator binary, highlighting how to pass options to
665 the simulators (as detailed in Section :ref:`options`).
669 .. example-tab:: examples/s4u/app-pingpong/s4u-app-pingpong.cpp
671 .. example-tab:: examples/c/app-pingpong/app-pingpong.c
674 Shows how to implement a classical communication pattern, where a
675 token is exchanged along a ring to reach every participant.
679 .. example-tab:: examples/s4u/app-token-ring/s4u-app-token-ring.cpp
681 .. example-tab:: examples/c/app-token-ring/app-token-ring.c
683 - **Master Workers:**
684 Another good old example, where one Master process has a bunch of task to dispatch to a set of several Worker
691 This example comes in two equivalent variants, one where the actors
692 are specified as simple functions (which is easier to understand for
693 newcomers) and one where the actors are specified as classes (which is
694 more powerful for the users wanting to build their own projects upon
697 .. showfile:: examples/s4u/app-masterworkers/s4u-app-masterworkers-class.cpp
700 .. showfile:: examples/s4u/app-masterworkers/s4u-app-masterworkers-fun.cpp
707 Classical protocol for Peer-to-Peer data diffusion.
713 .. showfile:: examples/s4u/app-bittorrent/s4u-bittorrent.cpp
716 .. showfile:: examples/s4u/app-bittorrent/s4u-peer.cpp
719 .. showfile:: examples/s4u/app-bittorrent/s4u-tracker.cpp
723 Data broadcast over a ring of processes.
727 .. example-tab:: examples/s4u/app-chainsend/s4u-app-chainsend.cpp
731 .. showfile:: examples/c/app-chainsend/chainsend.c
734 .. showfile:: examples/c/app-chainsend/broadcaster.c
737 .. showfile:: examples/c/app-chainsend/peer.c
740 Distributed Hash Tables (DHT)
741 -----------------------------
744 One of the most famous DHT protocol.
750 .. showfile:: examples/s4u/dht-chord/s4u-dht-chord.cpp
753 .. showfile:: examples/s4u/dht-chord/s4u-dht-chord-node.cpp
757 Another well-known DHT protocol.
763 .. showfile:: examples/s4u/dht-kademlia/s4u-dht-kademlia.cpp
766 .. showfile:: examples/s4u/dht-kademlia/routing_table.cpp
769 .. showfile:: examples/s4u/dht-kademlia/answer.cpp
772 .. showfile:: examples/s4u/dht-kademlia/node.cpp
781 This example starts some computations both on PMs and VMs, and
782 migrates some VMs around.
786 .. example-tab:: examples/s4u/cloud-simple/s4u-cloud-simple.cpp
788 .. example-tab:: examples/c/cloud-simple/cloud-simple.c
791 This example shows how to migrate VMs between PMs.
795 .. example-tab:: examples/s4u/cloud-migration/s4u-cloud-migration.cpp
797 .. example-tab:: examples/c/cloud-migration/cloud-migration.c
799 =======================
800 Model-Checking Examples
801 =======================
803 The model-checker can be used to exhaustively search for issues in the
804 tested application. It must be activated at compile time, but this
805 mode is rather experimental in SimGrid (as of v3.22). You should not
806 enable it unless you really want to formally verify your applications:
807 SimGrid is slower and maybe less robust when MC is enabled.
810 In this example, two actors send some data to a central server,
811 which asserts that the messages are always received in the same order.
812 This is obviously wrong, and the model-checker correctly finds a
813 counter-example to that assertion.
817 .. example-tab:: examples/s4u/mc-failing-assert/s4u-mc-failing-assert.cpp
823 .. |cpp| image:: /img/lang_cpp.png
827 .. |py| image:: /img/lang_python.png