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 - **Daemonize actors:**
123 Some actors may be intended to simulate daemons that run in background. This example show how to transform a regular
124 actor into a daemon that will be automatically killed once the simulation is over.
128 .. example-tab:: examples/s4u/actor-daemon/s4u-actor-daemon.cpp
130 See also :cpp:func:`simgrid::s4u::Actor::daemonize()` and :cpp:func:`simgrid::s4u::Actor::is_daemon()`.
132 .. example-tab:: examples/python/actor-daemon/actor-daemon.py
134 See also :py:func:`simgrid.Actor.daemonize()` and :py:func:`simgrid.Actor.is_daemon()`.
136 .. example-tab:: examples/c/actor-daemon/actor-daemon.c
138 See also :cpp:func:`sg_actor_daemonize` and :cpp:func:`sg_actor_is_daemon`.
140 Inter-Actors Interactions
141 -------------------------
143 See also the examples on :ref:`inter-actors communications
144 <s4u_ex_communication>` and the ones on :ref:`classical
145 synchronization objects <s4u_ex_IPC>`.
147 - **Suspend and Resume actors:**
148 Actors can be suspended and resumed during their executions.
152 .. example-tab:: examples/s4u/actor-suspend/s4u-actor-suspend.cpp
154 See also :cpp:func:`simgrid::s4u::this_actor::suspend()`,
155 :cpp:func:`simgrid::s4u::Actor::suspend()`, :cpp:func:`simgrid::s4u::Actor::resume()`, and
156 :cpp:func:`simgrid::s4u::Actor::is_suspended()`.
158 .. example-tab:: examples/python/actor-suspend/actor-suspend.py
160 See also :py:func:`simgrid.this_actor.suspend()`,
161 :py:func:`simgrid.Actor.suspend()`, :py:func:`simgrid.Actor.resume()`, and
162 :py:func:`simgrid.Actor.is_suspended()`.
164 .. example-tab:: examples/c/actor-suspend/actor-suspend.c
166 See also :cpp:func:`sg_actor_suspend()`, :cpp:func:`sg_actor_resume()`, and
167 :cpp:func:`sg_actor_is_suspended()`.
169 - **Migrating Actors:**
170 Actors can move or be moved from a host to another very easily. It amount to setting them on a new host.
174 .. example-tab:: examples/s4u/actor-migrate/s4u-actor-migrate.cpp
176 See also :cpp:func:`simgrid::s4u::this_actor::set_host()` and :cpp:func:`simgrid::s4u::Actor::set_host()`.
178 .. example-tab:: examples/python/actor-migrate/actor-migrate.py
180 See also :py:func:`simgrid.this_actor.set_host()` and :py:func:`simgrid.Actor.set_host()`.
182 .. example-tab:: examples/c/actor-migrate/actor-migrate.c
184 See also :cpp:func:`sg_actor_set_host()`.
186 - **Waiting for the termination of an actor:** (joining on it)
187 You can block the current actor until the end of another actor.
191 .. example-tab:: examples/s4u/actor-join/s4u-actor-join.cpp
193 See also :cpp:func:`simgrid::s4u::Actor::join()`.
195 .. example-tab:: examples/python/actor-join/actor-join.py
197 See also :py:func:`simgrid.Actor.join()`.
199 .. example-tab:: examples/c/actor-join/actor-join.c
201 See also :cpp:func:`sg_actor_join`.
203 - **Yielding to other actors**.
204 The ```yield()``` function interrupts the execution of the current
205 actor, leaving a chance to the other actors that are ready to run
210 .. example-tab:: examples/s4u/actor-yield/s4u-actor-yield.cpp
212 See also :cpp:func:`simgrid::s4u::this_actor::yield()`.
214 .. example-tab:: examples/python/actor-yield/actor-yield.py
216 See also :py:func:`simgrid.this_actor.yield_()`.
218 .. example-tab:: examples/c/actor-yield/actor-yield.c
220 See also :cpp:func:`sg_actor_yield()`.
222 Traces Replay as a Workload
223 ---------------------------
225 This section details how to run trace-driven simulations. It is very
226 handy when you want to test an algorithm or protocol that only react
227 to external events. For example, many P2P protocols react to user
228 requests, but do nothing if there is no such event.
230 In such situations, you should write your protocol in C++, and separate
231 the workload that you want to play onto your protocol in a separate
232 text file. Declare a function handling each type of the events in your
233 trace, register them using :cpp:func:`xbt_replay_action_register()` in
234 your main, and then run the simulation.
236 Then, you can either have one trace file containing all your events,
237 or a file per simulated process: the former may be easier to work
238 with, but the second is more efficient on very large traces. Check
239 also the tesh files in the example directories for details.
241 - **Communication replay:**
242 Presents a set of event handlers reproducing classical communication
243 primitives (asynchronous send/receive at the moment).
247 .. example-tab:: examples/s4u/replay-comm/s4u-replay-comm.cpp
250 Presents a set of event handlers reproducing classical I/O
251 primitives (open, read, close).
255 .. example-tab:: examples/s4u/replay-io/s4u-replay-io.cpp
257 ==========================
258 Activities: what Actors do
259 ==========================
261 .. _s4u_ex_communication:
263 Communications on the Network
264 -----------------------------
266 - **Basic asynchronous communications:**
267 Illustrates how to have non-blocking communications, that are
268 communications running in the background leaving the process free
269 to do something else during their completion.
273 .. example-tab:: examples/s4u/async-wait/s4u-async-wait.cpp
275 See also :cpp:func:`simgrid::s4u::Mailbox::put_async()` and :cpp:func:`simgrid::s4u::Comm::wait()`.
277 .. example-tab:: examples/python/async-wait/async-wait.py
279 See also :py:func:`simgrid.Mailbox.put_async()` and :py:func:`simgrid.Comm.wait()`.
281 - **Waiting for all communications in a set:**
282 The ``wait_all()`` function is useful when you want to block until
283 all activities in a given set have completed.
287 .. example-tab:: examples/s4u/async-waitall/s4u-async-waitall.cpp
289 See also :cpp:func:`simgrid::s4u::Comm::wait_all()`.
291 .. example-tab:: examples/c/async-waitall/async-waitall.c
293 See also :cpp:func:`sg_comm_wait_all()`.
295 .. example-tab:: examples/python/async-waitall/async-waitall.py
297 See also :py:func:`simgrid.Comm.wait_all()`.
299 - **Waiting for the first completed communication in a set:**
300 The ``wait_any()`` function is useful
301 when you want to block until one activity of the set completes, no
302 matter which terminates first.
306 .. example-tab:: examples/s4u/async-waitany/s4u-async-waitany.cpp
308 See also :cpp:func:`simgrid::s4u::Comm::wait_any()`.
310 .. example-tab:: examples/python/async-waitany/async-waitany.py
312 See also :py:func:`simgrid.Comm.wait_any()`.
314 .. example-tab:: examples/c/async-waitany/async-waitany.c
316 See also :cpp:func:`sg_comm_wait_any`.
318 .. _s4u_ex_execution:
320 Executions on the CPU
321 ---------------------
323 - **Basic execution:**
324 The computations done in your program are not reported to the
325 simulated world, unless you explicitly request the simulator to pause
326 the actor until a given amount of flops gets computed on its simulated
327 host. Some executions can be given an higher priority so that they
332 .. example-tab:: examples/s4u/exec-basic/s4u-exec-basic.cpp
334 See also :cpp:func:`void simgrid::s4u::this_actor::execute(double)`
335 and :cpp:func:`void simgrid::s4u::this_actor::execute(double, double)`.
337 .. example-tab:: examples/python/exec-basic/exec-basic.py
339 See also :py:func:`simgrid.this_actor.execute()`.
341 - **Asynchronous execution:**
342 You can start asynchronous executions, just like you would fire
347 .. example-tab:: examples/s4u/exec-async/s4u-exec-async.cpp
349 See also :cpp:func:`simgrid::s4u::this_actor::exec_init()`,
350 :cpp:func:`simgrid::s4u::Activity::start()`,
351 :cpp:func:`simgrid::s4u::Activity::wait()`,
352 :cpp:func:`simgrid::s4u::Activity::get_remaining()`,
353 :cpp:func:`simgrid::s4u::Exec::get_remaining_ratio()`,
354 :cpp:func:`simgrid::s4u::this_actor::exec_async()` and
355 :cpp:func:`simgrid::s4u::Activity::cancel()`.
357 .. example-tab:: examples/python/exec-async/exec-async.py
359 See also :py:func:`simgrid.this_actor::exec_init()`,
360 :py:func:`simgrid.Activity::start()`,
361 :py:func:`simgrid.Activity.wait()`,
362 :py:func:`simgrid.Activity.get_remaining()`,
363 :py:func:`simgrid.Exec.get_remaining_ratio()`,
364 :py:func:`simgrid.this_actor.exec_async()` and
365 :py:func:`simgrid.Activity.cancel()`.
367 - **Remote execution:**
368 You can start executions on remote hosts, or even change the host
369 on which they occur during their execution.
373 .. example-tab:: examples/s4u/exec-remote/s4u-exec-remote.cpp
375 See also :cpp:func:`simgrid::s4u::Exec::set_host()`.
377 .. example-tab:: examples/python/exec-remote/exec-remote.py
379 See also :py:func:`simgrid.Exec.set_host()`.
381 - **Parallel executions:**
382 These objects are convenient abstractions of parallel
383 computational kernels that span over several machines, such as a
384 PDGEM and the other ScaLAPACK routines. Note that this only works
385 with the "ptask_L07" host model (``--cfg=host/model:ptask_L07``).
389 .. example-tab:: examples/s4u/exec-ptask/s4u-exec-ptask.cpp
391 See also :cpp:func:`simgrid::s4u::this_actor::parallel_execute()`.
393 - **Using Pstates on a host:**
394 This example shows how define a set of pstates in the XML. The current pstate
395 of an host can then be accessed and changed from the program.
399 .. example-tab:: examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp
401 See also :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
403 .. example-tab:: examples/c/exec-dvfs/exec-dvfs.c
405 See also :cpp:func:`sg_host_get_pstate_speed` and :cpp:func:`sg_host_set_pstate`.
407 .. example-tab:: examples/python/exec-dvfs/exec-dvfs.py
409 See also :py:func:`Host.get_pstate_speed` and :py:func:`Host.set_pstate`.
411 .. example-tab:: examples/platforms/energy_platform.xml
415 I/O on Disks and Files
416 ----------------------
418 SimGrid provides two levels of abstraction to interact with the
419 simulated disks. At the simplest level, you simply create read and
420 write actions on the disk resources.
422 - **Access to raw disk devices:**
423 This example illustrates how to simply read and write data on a
424 simulated disk resource.
428 .. example-tab:: examples/s4u/io-disk-raw/s4u-io-disk-raw.cpp
430 .. example-tab:: examples/c/io-disk-raw/io-disk-raw.c
432 .. example-tab:: examples/platforms/hosts_with_disks.xml
434 This shows how to declare disks in XML.
436 The FileSystem plugin provides a more detailed view, with the
437 classical operations over files: open, move, unlink, and of course
438 read and write. The file and disk sizes are also dealt with and can
439 result in short reads and short write, as in reality.
441 - **File Management:**
442 This example illustrates the use of operations on files
443 (read, write, seek, tell, unlink, etc).
447 .. example-tab:: examples/s4u/io-file-system/s4u-io-file-system.cpp
450 I/O operations on files can also be done in a remote fashion,
451 i.e. when the accessed disk is not mounted on the caller's host.
455 .. example-tab:: examples/s4u/io-file-remote/s4u-io-file-remote.cpp
457 .. example-tab:: examples/c/io-file-remote/io-file-remote.c
461 Classical synchronization objects
462 ---------------------------------
465 Shows how to use :cpp:type:`simgrid::s4u::Barrier` synchronization objects.
469 .. example-tab:: examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp
471 - **Condition variable:**
472 Shows how to use :cpp:type:`simgrid::s4u::ConditionVariable` synchronization objects.
476 .. example-tab:: examples/s4u/synchro-condition-variable/s4u-synchro-condition-variable.cpp
479 Shows how to use :cpp:type:`simgrid::s4u::Mutex` synchronization objects.
483 .. example-tab:: examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp
486 Shows how to use :cpp:type:`simgrid::s4u::Semaphore` synchronization objects.
490 .. example-tab:: examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp
492 =============================
493 Interacting with the Platform
494 =============================
496 - **User-defined properties:**
497 You can attach arbitrary information to most platform elements from
498 the XML file, and then interact with these values from your
499 program. Note that the changes are not written permanently on disk,
500 in the XML file nor anywhere else. They only last until the end of
505 .. example-tab:: examples/s4u/platform-properties/s4u-platform-properties.cpp
507 - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
508 - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
509 - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
510 - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
516 .. showfile:: examples/s4u/platform-properties/s4u-platform-properties_d.xml
522 .. showfile:: examples/platforms/prop.xml
525 - **Retrieving the netzones matching a given criteria:**
526 Shows how to filter the cluster netzones.
530 .. example-tab:: examples/s4u/routing-get-clusters/s4u-routing-get-clusters.cpp
532 - **Retrieving the list of hosts matching a given criteria:**
533 Shows how to filter the actors that match a given criteria.
537 .. example-tab:: examples/s4u/engine-filtering/s4u-engine-filtering.cpp
539 - **Specifying state profiles:** shows how to specify when the
540 resources must be turned off and on again, and how to react to such
541 failures in your code. See also :ref:`howto_churn`.
545 .. example-tab:: examples/s4u/platform-failures/s4u-platform-failures.cpp
549 .. showfile:: examples/platforms/small_platform_failures.xml
552 .. showfile:: examples/platforms/profiles/jupiter_state.profile
554 .. showfile:: examples/platforms/profiles/bourassa_state.profile
556 .. showfile:: examples/platforms/profiles/fafard_state.profile
558 - **Specifying speed profiles:** shows how to specify an external
559 load to resources, variating their peak speed over time.
563 .. example-tab:: examples/s4u/platform-profile/s4u-platform-profile.cpp
567 .. showfile:: examples/platforms/small_platform_profile.xml
570 .. showfile:: examples/platforms/profiles/jupiter_speed.profile
572 .. showfile:: examples/platforms/profiles/link1_bandwidth.profile
574 .. showfile:: examples/platforms/profiles/link1_latency.profile
580 - **Describing the energy profiles in the platform:**
581 This platform file contains the energy profile of each links and
582 hosts, which is necessary to get energy consumption predictions.
583 As usual, you should not trust our example, and you should strive
584 to double-check that your instantiation matches your target platform.
588 .. example-tab:: examples/platforms/energy_platform.xml
590 - **Consumption due to the CPU:**
591 This example shows how to retrieve the amount of energy consumed
592 by the CPU during computations, and the impact of the pstate.
596 .. example-tab:: examples/s4u/energy-exec/s4u-energy-exec.cpp
598 .. example-tab:: examples/c/energy-exec/energy-exec.c
600 - **Consumption due to the network:**
601 This example shows how to retrieve and display the energy consumed
602 by the network during communications.
606 .. example-tab:: examples/s4u/energy-link/s4u-energy-link.cpp
608 - **Modeling the shutdown and boot of hosts:**
609 Simple example of model of model for the energy consumption during
610 the host boot and shutdown periods.
614 .. example-tab:: examples/s4u/energy-boot/platform_boot.xml
616 .. example-tab:: examples/s4u/energy-boot/s4u-energy-boot.cpp
618 =======================
619 Tracing and Visualizing
620 =======================
622 Tracing can be activated by various configuration options which
623 are illustrated in these example. See also the
624 :ref:`full list of options related to tracing <tracing_tracing_options>`.
626 It is interesting to run the process-create example with the following
627 options to see the task executions:
629 - **Platform Tracing:**
630 This program is a toy example just loading the platform, so that
631 you can play with the platform visualization. Recommanded options:
632 ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
636 .. example-tab:: examples/s4u/trace-platform/s4u-trace-platform.cpp
638 ========================
639 Larger SimGrid Examplars
640 ========================
642 This section contains application examples that are somewhat larger
643 than the previous examples.
646 This simple example just sends one message back and forth.
647 The tesh file laying in the directory show how to start the simulator binary, highlighting how to pass options to
648 the simulators (as detailed in Section :ref:`options`).
652 .. example-tab:: examples/s4u/app-pingpong/s4u-app-pingpong.cpp
654 .. example-tab:: examples/c/app-pingpong/app-pingpong.c
657 Shows how to implement a classical communication pattern, where a
658 token is exchanged along a ring to reach every participant.
662 .. example-tab:: examples/s4u/app-token-ring/s4u-app-token-ring.cpp
664 .. example-tab:: examples/c/app-token-ring/app-token-ring.c
666 - **Master Workers:**
667 Another good old example, where one Master process has a bunch of task to dispatch to a set of several Worker
674 This example comes in two equivalent variants, one where the actors
675 are specified as simple functions (which is easier to understand for
676 newcomers) and one where the actors are specified as classes (which is
677 more powerful for the users wanting to build their own projects upon
680 .. showfile:: examples/s4u/app-masterworkers/s4u-app-masterworkers-class.cpp
683 .. showfile:: examples/s4u/app-masterworkers/s4u-app-masterworkers-fun.cpp
690 Classical protocol for Peer-to-Peer data diffusion.
696 .. showfile:: examples/s4u/app-bittorrent/s4u-bittorrent.cpp
699 .. showfile:: examples/s4u/app-bittorrent/s4u-peer.cpp
702 .. showfile:: examples/s4u/app-bittorrent/s4u-tracker.cpp
706 Data broadcast over a ring of processes.
710 .. example-tab:: examples/s4u/app-chainsend/s4u-app-chainsend.cpp
714 .. showfile:: examples/c/app-chainsend/chainsend.c
717 .. showfile:: examples/c/app-chainsend/broadcaster.c
720 .. showfile:: examples/c/app-chainsend/peer.c
723 Distributed Hash Tables (DHT)
724 -----------------------------
727 One of the most famous DHT protocol.
733 .. showfile:: examples/s4u/dht-chord/s4u-dht-chord.cpp
736 .. showfile:: examples/s4u/dht-chord/s4u-dht-chord-node.cpp
740 Another well-known DHT protocol.
746 .. showfile:: examples/s4u/dht-kademlia/s4u-dht-kademlia.cpp
749 .. showfile:: examples/s4u/dht-kademlia/routing_table.cpp
752 .. showfile:: examples/s4u/dht-kademlia/answer.cpp
755 .. showfile:: examples/s4u/dht-kademlia/node.cpp
764 This example starts some computations both on PMs and VMs, and
765 migrates some VMs around.
769 .. example-tab:: examples/s4u/cloud-simple/s4u-cloud-simple.cpp
771 .. example-tab:: examples/c/cloud-simple/cloud-simple.c
774 This example shows how to migrate VMs between PMs.
778 .. example-tab:: examples/s4u/cloud-migration/s4u-cloud-migration.cpp
780 .. example-tab:: examples/c/cloud-migration/cloud-migration.c
782 =======================
783 Model-Checking Examples
784 =======================
786 The model-checker can be used to exhaustively search for issues in the
787 tested application. It must be activated at compile time, but this
788 mode is rather experimental in SimGrid (as of v3.22). You should not
789 enable it unless you really want to formally verify your applications:
790 SimGrid is slower and maybe less robust when MC is enabled.
793 In this example, two actors send some data to a central server,
794 which asserts that the messages are always received in the same order.
795 This is obviously wrong, and the model-checker correctly finds a
796 counter-example to that assertion.
800 .. example-tab:: examples/s4u/mc-failing-assert/s4u-mc-failing-assert.cpp
806 .. |cpp| image:: /img/lang_cpp.png
810 .. |py| image:: /img/lang_python.png