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.
11 SimGrid comes with an extensive set of examples, documented on this
12 page. Most of them only demonstrate one single feature, with some
13 larger exemplars listed below.
15 The C++ examples can be found under examples/cpp while python examples
16 are in examples/python. Each such directory contains the source code (also listed
17 from this page), and the so-called tesh file containing how to call
18 the binary obtained by compiling this example and also the expected
19 output. Tesh files are used to turn each of our examples into an
20 integration test. Some examples also contain other files, on need.
22 A good way to bootstrap your own project is to copy and combine some
23 of the provided examples to constitute the skeleton of what you plan
28 ===========================
29 Actors: the Active Entities
30 ===========================
32 Starting and Stopping Actors
33 ----------------------------
35 .. _s4u_ex_actors_create:
40 Most actors are started from the deployment XML file because this
41 is a :ref:`better scientific habit <howto_science>`, but you can
42 also create them directly from your code.
46 .. example-tab:: examples/cpp/actor-create/s4u-actor-create.cpp
48 You create actors either:
50 - Directly with :cpp:func:`simgrid::s4u::Actor::create`
51 - From XML with :cpp:func:`simgrid::s4u::Engine::register_actor` (if your actor is a class)
52 or :cpp:func:`simgrid::s4u::Engine::register_function` (if your actor is a function)
53 and then :cpp:func:`simgrid::s4u::Engine::load_deployment`
55 .. example-tab:: examples/python/actor-create/actor-create.py
57 You create actors either:
59 - Directly with :py:func:`simgrid.Actor.create()`
60 - From XML with :py:func:`simgrid.Engine.register_actor()` and then :py:func:`simgrid.Engine.load_deployment()`
62 .. example-tab:: examples/c/actor-create/actor-create.c
64 You create actors either:
66 - Directly with :cpp:func:`sg_actor_create` followed by :cpp:func:`sg_actor_start`.
67 - From XML with :cpp:func:`simgrid_register_function` and then :cpp:func:`simgrid_load_deployment`.
69 .. example-tab:: examples/python/actor-create/actor-create_d.xml
71 The following file is used in both C++ and Python.
73 Reacting to actors' end
74 ^^^^^^^^^^^^^^^^^^^^^^^
76 You can attach callbacks to the end of actors. There are several ways of doing so, depending on whether you want to
77 attach your callback to a given actor and on how you define the end of a
78 given actor. User code probably wants to react to the termination of an actor
79 while some plugins want to react to the destruction (memory collection) of
84 .. example-tab:: examples/cpp/actor-exiting/s4u-actor-exiting.cpp
86 This example shows how to attach a callback to:
88 - the end of a specific actor: :cpp:func:`simgrid::s4u::Actor::on_exit()`
89 - the end of any actor: :cpp:func:`simgrid::s4u::Actor::on_termination_cb`
90 - the destruction of any actor: :cpp:func:`simgrid::s4u::Actor::on_destruction_cb`
92 .. example-tab:: examples/c/actor-exiting/actor-exiting.c
94 This example shows how to attach a callback to the end of a specific actor with
95 :cpp:func:`sg_actor_on_exit()`.
100 Actors can forcefully stop other actors.
104 .. example-tab:: examples/cpp/actor-kill/s4u-actor-kill.cpp
106 See also :cpp:func:`void simgrid::s4u::Actor::kill(void)`, :cpp:func:`void simgrid::s4u::Actor::kill_all()`,
107 :cpp:func:`simgrid::s4u::this_actor::exit`, :cpp:func:`simgrid::s4u::Actor::on_exit`.
109 .. example-tab:: examples/python/actor-kill/actor-kill.py
111 See also :py:func:`simgrid.Actor.kill()`, :py:func:`simgrid.Actor.kill_all()`, :py:func:`simgrid.this_actor.exit()`,
112 :py:func:`simgrid.this_actor.on_exit`.
114 .. example-tab:: examples/c/actor-kill/actor-kill.c
116 See also :cpp:func:`sg_actor_kill`, :cpp:func:`sg_actor_kill_all`, :cpp:func:`sg_actor_exit`, :cpp:func:`sg_actor_on_exit`.
118 Actors' life cycle from XML_reference
119 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
121 You can specify a start time and a kill time in the deployment file.
125 .. example-tab:: examples/cpp/actor-lifetime/s4u-actor-lifetime.cpp
127 This file is not really interesting: the important matter is in the XML file.
129 .. example-tab:: examples/cpp/actor-lifetime/s4u-actor-lifetime_d.xml
131 This demonstrates the ``start_time`` and ``kill_time`` attribute of the :ref:`pf_tag_actor` tag.
133 .. example-tab:: examples/python/actor-lifetime/actor-lifetime.py
135 This file is not really interesting: the important matter is in the XML file.
137 .. example-tab:: examples/c/actor-lifetime/actor-lifetime.c
139 This file is not really interesting: the important matter is in the XML file.
144 Some actors may be intended to simulate daemons that run in the background.
145 This example shows how to transform a regular
146 actor into a daemon that will be automatically killed once the simulation is over.
150 .. example-tab:: examples/cpp/actor-daemon/s4u-actor-daemon.cpp
152 See also :cpp:func:`simgrid::s4u::Actor::daemonize()` and :cpp:func:`simgrid::s4u::Actor::is_daemon()`.
154 .. example-tab:: examples/python/actor-daemon/actor-daemon.py
156 See also :py:func:`simgrid.Actor.daemonize()` and :py:func:`simgrid.Actor.is_daemon()`.
158 .. example-tab:: examples/c/actor-daemon/actor-daemon.c
160 See also :cpp:func:`sg_actor_daemonize` and :cpp:func:`sg_actor_is_daemon`.
162 Specifying the stack size
163 ^^^^^^^^^^^^^^^^^^^^^^^^^
165 The stack size can be specified by default on the command line,
166 globally by changing the configuration with :cpp:func:`simgrid::s4u::Engine::set_config`,
167 or for a specific actor using :cpp:func:`simgrid::s4u::Actor::set_stacksize` before its start.
171 .. example-tab:: examples/cpp/actor-stacksize/s4u-actor-stacksize.cpp
173 .. example-tab:: examples/c/actor-stacksize/actor-stacksize.c
175 Inter-Actors Interactions
176 -------------------------
178 See also the examples on :ref:`inter-actors communications
179 <s4u_ex_communication>` and the ones on :ref:`classical
180 synchronization objects <s4u_ex_IPC>`.
182 Suspending/resuming Actors
183 ^^^^^^^^^^^^^^^^^^^^^^^^^^
185 Actors can be suspended and resumed during their executions.
189 .. example-tab:: examples/cpp/actor-suspend/s4u-actor-suspend.cpp
191 See also :cpp:func:`simgrid::s4u::this_actor::suspend()`,
192 :cpp:func:`simgrid::s4u::Actor::suspend()`, :cpp:func:`simgrid::s4u::Actor::resume()`, and
193 :cpp:func:`simgrid::s4u::Actor::is_suspended()`.
195 .. example-tab:: examples/python/actor-suspend/actor-suspend.py
197 See also :py:func:`simgrid.this_actor.suspend()`,
198 :py:func:`simgrid.Actor.suspend()`, :py:func:`simgrid.Actor.resume()`, and
199 :py:func:`simgrid.Actor.is_suspended()`.
201 .. example-tab:: examples/c/actor-suspend/actor-suspend.c
203 See also :cpp:func:`sg_actor_suspend()`, :cpp:func:`sg_actor_resume()`, and
204 :cpp:func:`sg_actor_is_suspended()`.
209 Actors can move or be moved from a host to another very easily. It amounts to setting them on a new host.
213 .. example-tab:: examples/cpp/actor-migrate/s4u-actor-migrate.cpp
215 See also :cpp:func:`simgrid::s4u::this_actor::set_host()` and :cpp:func:`simgrid::s4u::Actor::set_host()`.
217 .. example-tab:: examples/python/actor-migrate/actor-migrate.py
219 See also :py:attr:`simgrid.Actor.host`.
221 .. example-tab:: examples/c/actor-migrate/actor-migrate.c
223 See also :cpp:func:`sg_actor_set_host()`.
225 Waiting for the termination of an actor (joining on it)
226 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
228 You can block the current actor until the end of another actor.
232 .. example-tab:: examples/cpp/actor-join/s4u-actor-join.cpp
234 See also :cpp:func:`simgrid::s4u::Actor::join()`.
236 .. example-tab:: examples/python/actor-join/actor-join.py
238 See also :py:func:`simgrid.Actor.join()`.
240 .. example-tab:: examples/c/actor-join/actor-join.c
242 See also :cpp:func:`sg_actor_join`.
244 Yielding to other actors
245 ^^^^^^^^^^^^^^^^^^^^^^^^
247 The ```yield()``` function interrupts the execution of the current
248 actor, leaving a chance to the other actors that are ready to run
253 .. example-tab:: examples/cpp/actor-yield/s4u-actor-yield.cpp
255 See also :cpp:func:`simgrid::s4u::this_actor::yield()`.
257 .. example-tab:: examples/python/actor-yield/actor-yield.py
259 See also :py:func:`simgrid.this_actor.yield_()`.
261 .. example-tab:: examples/c/actor-yield/actor-yield.c
263 See also :cpp:func:`sg_actor_yield()`.
265 Traces Replay as a Workload
266 ---------------------------
268 This section details how to run trace-driven simulations. It is very
269 handy when you want to test an algorithm or protocol that only reacts
270 to external events. For example, many P2P protocols react to user
271 requests, but do nothing if there is no such event.
273 In such situations, you should write your protocol in C++, and separate
274 the workload that you want to play onto your protocol in a separate
275 text file. Declare a function handling each type of the events in your
276 trace, register them using :cpp:func:`xbt_replay_action_register()` in
277 your main, and then run the simulation.
279 Then, you can either have one trace file containing all your events,
280 or a file per simulated process: the former may be easier to work
281 with, but the second is more efficient on very large traces. Check
282 also the tesh files in the example directories for details.
287 Presents a set of event handlers reproducing classical communication primitives (asynchronous send/receive at the moment).
291 .. example-tab:: examples/cpp/replay-comm/s4u-replay-comm.cpp
296 Presents a set of event handlers reproducing classical I/O primitives (open, read, close).
300 .. example-tab:: examples/cpp/replay-io/s4u-replay-io.cpp
302 ==========================
303 Activities: what Actors do
304 ==========================
306 .. _s4u_ex_communication:
308 Communications on the Network
309 -----------------------------
314 This simple example just sends one message back and forth.
315 The tesh file laying in the directory shows how to start the simulator binary, highlighting how to pass options to
316 the simulators (as detailed in Section :ref:`options`).
320 .. example-tab:: examples/cpp/comm-pingpong/s4u-comm-pingpong.cpp
322 .. example-tab:: examples/python/comm-pingpong/comm-pingpong.py
324 .. example-tab:: examples/c/comm-pingpong/comm-pingpong.c
326 Basic asynchronous communications
327 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
329 Illustrates how to have non-blocking communications, that are communications running in the background leaving the process
330 free to do something else during their completion.
334 .. example-tab:: examples/cpp/comm-wait/s4u-comm-wait.cpp
336 See also :cpp:func:`simgrid::s4u::Mailbox::put_async()` and :cpp:func:`simgrid::s4u::Comm::wait()`.
338 .. example-tab:: examples/python/comm-wait/comm-wait.py
340 See also :py:func:`simgrid.Mailbox.put_async()` and :py:func:`simgrid.Comm.wait()`.
342 .. example-tab:: examples/c/comm-wait/comm-wait.c
344 See also :cpp:func:`sg_mailbox_put_async()` and :cpp:func:`sg_comm_wait()`.
346 Waiting for communications with timeouts
347 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
349 This example is very similar to the previous one, simply adding how to declare timeouts when waiting on asynchronous communication.
353 .. example-tab:: examples/cpp/comm-waituntil/s4u-comm-waituntil.cpp
355 See also :cpp:func:`simgrid::s4u::Activity::wait_until()` and :cpp:func:`simgrid::s4u::Comm::wait_for()`.
357 .. example-tab:: examples/python/comm-waituntil/comm-waituntil.py
359 See also :py:func:`simgrid.Comm.wait_until()`
361 Suspending communications
362 ^^^^^^^^^^^^^^^^^^^^^^^^^
364 The ``suspend()`` and ``resume()`` functions block the progression of a given communication for a while and then unblock it.
365 ``is_suspended()`` returns whether that activity is currently blocked or not.
369 .. example-tab:: examples/cpp/comm-suspend/s4u-comm-suspend.cpp
371 See also :cpp:func:`simgrid::s4u::Activity::suspend()`
372 :cpp:func:`simgrid::s4u::Activity::resume()` and
373 :cpp:func:`simgrid::s4u::Activity::is_suspended()`.
375 .. example-tab:: examples/python/comm-suspend/comm-suspend.py
377 See also :py:func:`simgrid.Comm::suspend()` and
378 :py:func:`simgrid.Comm.resume()`.
380 Waiting for all communications in a set
381 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
383 The ``wait_all()`` function is useful when you want to block until all activities in a given set have been completed.
387 .. example-tab:: examples/cpp/comm-waitall/s4u-comm-waitall.cpp
389 See also :cpp:func:`simgrid::s4u::Comm::wait_all()`.
391 .. example-tab:: examples/python/comm-waitall/comm-waitall.py
393 See also :py:func:`simgrid.Comm.wait_all()`.
395 .. example-tab:: examples/c/comm-waitall/comm-waitall.c
397 See also :cpp:func:`sg_comm_wait_all()`.
399 Waiting for the first completed communication in a set
400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
402 The ``wait_any()`` blocks until one activity of the set completes, no matter which terminates first.
406 .. example-tab:: examples/cpp/comm-waitany/s4u-comm-waitany.cpp
408 See also :cpp:func:`simgrid::s4u::Comm::wait_any()`.
410 .. example-tab:: examples/python/comm-waitany/comm-waitany.py
412 See also :py:func:`simgrid.Comm.wait_any()`.
414 .. example-tab:: examples/c/comm-waitany/comm-waitany.c
416 See also :cpp:func:`sg_comm_wait_any`.
418 Testing whether at least one communication completed
419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
421 The ``test_any()`` returns whether at least one activity of the set has completed, or -1.
425 .. example-tab:: examples/cpp/comm-testany/s4u-comm-testany.cpp
427 See also :cpp:func:`simgrid::s4u::Comm::test_any()`.
429 .. example-tab:: examples/python/comm-testany/comm-testany.py
431 See also :py:func:`simgrid.Comm.test_any()`.
433 .. _s4u_ex_comm_failure:
435 Dealing with network failures
436 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
438 This examples shows how to survive to network exceptions that occur when a link is turned off. In this case, any blocking operation
439 such as ``put``, ``get`` or ``wait`` will raise an exception that you can catch and react to. See also :ref:`howto_churn` and
440 :ref:`this example <s4u_ex_platform_state_profile>` on how to attach a state profile to hosts and react to execution failures.
444 .. example-tab:: examples/cpp/comm-failure/s4u-comm-failure.cpp
446 .. example-tab:: examples/python/comm-failure/comm-failure.py
448 .. _s4u_ex_comm_host2host:
450 Direct host-to-host communication
451 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
453 This example demonstrates the direct communication mechanism, that allows to send data from one host to another without
454 relying on the mailbox mechanism.
458 .. example-tab:: examples/cpp/comm-host2host/s4u-comm-host2host.cpp
460 See also :cpp:func:`simgrid::s4u::Comm::sendto_init()` and :cpp:func:`simgrid::s4u::Comm::sendto_async()`.
462 .. example-tab:: examples/python/comm-host2host/comm-host2host.py
464 See also :py:func:`simgrid.Comm.sendto_init()` and :py:func:`simgrid.Comm.sendto_async()`.
466 .. _s4u_ex_execution:
468 Executions on the CPU
469 ---------------------
474 The computations done in your program are not reported to the
475 simulated world unless you explicitly request the simulator to pause
476 the actor until a given amount of flops gets computed on its simulated
477 host. Some executions can be given a higher priority so that they
482 .. example-tab:: examples/cpp/exec-basic/s4u-exec-basic.cpp
484 See also :cpp:func:`void simgrid::s4u::this_actor::execute(double)`
485 and :cpp:func:`void simgrid::s4u::this_actor::execute(double, double)`.
487 .. example-tab:: examples/python/exec-basic/exec-basic.py
489 See also :py:func:`simgrid.this_actor.execute()`.
491 .. example-tab:: examples/c/exec-basic/exec-basic.c
493 See also :cpp:func:`void sg_actor_execute(double)`
494 and :cpp:func:`void sg_actor_execute_with_priority(double, double)`.
496 Asynchronous execution
497 ^^^^^^^^^^^^^^^^^^^^^^
499 You can start asynchronous executions, just like you would fire background threads.
503 .. example-tab:: examples/cpp/exec-async/s4u-exec-async.cpp
505 See also :cpp:func:`simgrid::s4u::this_actor::exec_init()`,
506 :cpp:func:`simgrid::s4u::Activity::start()`,
507 :cpp:func:`simgrid::s4u::Activity::wait()`,
508 :cpp:func:`simgrid::s4u::Activity::get_remaining()`,
509 :cpp:func:`simgrid::s4u::Exec::get_remaining_ratio()`,
510 :cpp:func:`simgrid::s4u::this_actor::exec_async()` and
511 :cpp:func:`simgrid::s4u::Activity::cancel()`.
513 .. example-tab:: examples/python/exec-async/exec-async.py
515 See also :py:func:`simgrid.this_actor.exec_init()`,
516 :py:func:`simgrid.Exec.start()`,
517 :py:func:`simgrid.Exec.wait()`,
518 :py:attr:`simgrid.Exec.remaining`,
519 :py:attr:`simgrid.Exec.remaining_ratio`,
520 :py:func:`simgrid.this_actor.exec_async()` and
521 :py:func:`simgrid.Exec.cancel()`.
523 .. example-tab:: examples/c/exec-async/exec-async.c
525 See also :cpp:func:`sg_actor_exec_init()`,
526 :cpp:func:`sg_exec_start()`,
527 :cpp:func:`sg_exec_wait()`,
528 :cpp:func:`sg_exec_get_remaining()`,
529 :cpp:func:`sg_exec_get_remaining_ratio()`,
530 :cpp:func:`sg_actor_exec_async()` and
531 :cpp:func:`sg_exec_cancel()`,
536 You can start executions on remote hosts, or even change the host on which they occur during their execution.
537 This is naturally not very realistic, but it's something handy to have.
541 .. example-tab:: examples/cpp/exec-remote/s4u-exec-remote.cpp
543 See also :cpp:func:`simgrid::s4u::Exec::set_host()`.
545 .. example-tab:: examples/python/exec-remote/exec-remote.py
547 See also :py:attr:`simgrid.Exec.host`.
549 .. example-tab:: examples/c/exec-remote/exec-remote.c
551 See also :cpp:func:`sg_exec_set_host()`.
558 These objects are convenient abstractions of parallel
559 computational kernels that span over several machines, such as a
560 PDGEM and the other ScaLAPACK routines. Note that this only works
561 with the "ptask_L07" host model (``--cfg=host/model:ptask_L07``).
563 This example demonstrates several kinds of parallel tasks: regular
564 ones, communication-only (without computation), computation-only
565 (without communication), synchronization-only (neither
566 communication nor computation). It also shows how to reconfigure a
567 task after its start, to change the number of hosts it runs onto.
568 This allows simulating malleable tasks.
572 .. example-tab:: examples/cpp/exec-ptask/s4u-exec-ptask.cpp
574 See also :cpp:func:`simgrid::s4u::this_actor::parallel_execute()`.
576 .. example-tab:: examples/python/exec-ptask/exec-ptask.py
578 See also :ref:`simgrid.this_actor.parallel_execute()`
580 Ptasks play well with the host energy plugin, as shown in this example.
581 There is not much new compared to the above ptask example or the
582 :ref:`examples about energy <s4u_ex_energy>`. It just works.
586 .. example-tab:: examples/cpp/energy-exec-ptask/s4u-energy-exec-ptask.cpp
588 .. example-tab:: examples/c/energy-exec-ptask/energy-exec-ptask.c
595 This example shows how to define a set of pstates in the XML. The current pstate
596 of a host can then be accessed and changed from the program.
600 .. example-tab:: examples/cpp/exec-dvfs/s4u-exec-dvfs.cpp
602 See also :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
604 .. example-tab:: examples/c/exec-dvfs/exec-dvfs.c
606 See also :cpp:func:`sg_host_get_pstate_speed` and :cpp:func:`sg_host_set_pstate`.
608 .. example-tab:: examples/python/exec-dvfs/exec-dvfs.py
610 See also :py:func:`simgrid.Host.pstate_speed()` and :py:attr:`simgrid.Host.pstate`.
612 .. example-tab:: examples/platforms/energy_platform.xml
614 The important parts are in the :ref:`pf_tag_host` tag. The ``pstate`` attribute is the initial pstate while the ``speed`` attribute must
615 be a comma-separated list of values: the speed at each pstate. This platform file also describes the ``wattage_per_state`` and
616 ``wattage_off`` properties, that are used by the :ref:`plugin_host_energy` plugin.
620 I/O on Disks and Files
621 ----------------------
623 SimGrid provides two levels of abstraction to interact with the
624 simulated disks. At the simplest level, you simply create read and
625 write actions on the disk resources.
627 Access to raw disk devices
628 ^^^^^^^^^^^^^^^^^^^^^^^^^^
630 This example illustrates how to simply read and write data on a simulated disk resource.
634 .. example-tab:: examples/cpp/io-disk-raw/s4u-io-disk-raw.cpp
636 .. example-tab:: examples/c/io-disk-raw/io-disk-raw.c
638 .. example-tab:: examples/platforms/hosts_with_disks.xml
640 This shows how to declare disks in XML.
645 The FileSystem plugin provides a more detailed view, with the
646 classical operations over files: open, move, unlink, and of course,
647 read and write. The file and disk sizes are also dealt with and can
648 result in short reads and short writes, as in reality.
650 - **File Management:**
651 This example illustrates the use of operations on files
652 (read, write, seek, tell, unlink, etc).
656 .. example-tab:: examples/cpp/io-file-system/s4u-io-file-system.cpp
659 I/O operations on files can also be done remotely,
660 i.e. when the accessed disk is not mounted on the caller's host.
664 .. example-tab:: examples/cpp/io-file-remote/s4u-io-file-remote.cpp
666 .. example-tab:: examples/c/io-file-remote/io-file-remote.c
670 Classical synchronization objects
671 ---------------------------------
676 Shows how to use :cpp:type:`simgrid::s4u::Barrier` synchronization objects.
680 .. example-tab:: examples/cpp/synchro-barrier/s4u-synchro-barrier.cpp
682 .. example-tab:: examples/python/synchro-barrier/synchro-barrier.py
684 Condition variable: basic usage
685 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
687 Shows how to use :cpp:type:`simgrid::s4u::ConditionVariable` synchronization objects.
691 .. example-tab:: examples/cpp/synchro-condition-variable/s4u-synchro-condition-variable.cpp
693 Condition variable: timeouts
694 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
696 Shows how to specify timeouts when blocking on condition variables.
700 .. example-tab:: examples/cpp/synchro-condition-variable-waituntil/s4u-synchro-condition-variable-waituntil.cpp
705 Shows how to use :cpp:type:`simgrid::s4u::Mutex` synchronization objects.
709 .. example-tab:: examples/cpp/synchro-mutex/s4u-synchro-mutex.cpp
711 .. example-tab:: examples/python/synchro-mutex/synchro-mutex.py
716 Shows how to use :cpp:type:`simgrid::s4u::Semaphore` synchronization objects.
720 .. example-tab:: examples/cpp/synchro-semaphore/s4u-synchro-semaphore.cpp
722 .. example-tab:: examples/python/synchro-semaphore/synchro-semaphore.py
724 .. example-tab:: examples/c/synchro-semaphore/synchro-semaphore.c
726 =============================
727 Interacting with the Platform
728 =============================
730 User-defined properties
731 -----------------------
733 You can attach arbitrary information to most platform elements from the XML file, and then interact with these values from your
734 program. Note that the changes are not written permanently on disk, in the XML file nor anywhere else. They only last until the end of
739 .. example-tab:: examples/cpp/platform-properties/s4u-platform-properties.cpp
741 - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
742 - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
743 - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
744 - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
746 .. example-tab:: examples/c/platform-properties/platform-properties.c
748 - :cpp:func:`sg_actor_get_property_value()`
749 - :cpp:func:`sg_host_get_property_value()` and :cpp:func:sg_host_set_property_value()`
750 - :cpp:func:`sg_zone_get_property_value()` and :cpp:func:`sg_zone_set_property_value()`
756 .. showfile:: examples/platforms/prop.xml
762 Retrieving the netzones matching given criteria
763 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
765 Shows how to filter the cluster netzones.
769 .. example-tab:: examples/cpp/routing-get-clusters/s4u-routing-get-clusters.cpp
771 Retrieving the list of hosts matching given criteria
772 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
774 Shows how to filter the actors that match given criteria.
778 .. example-tab:: examples/cpp/engine-filtering/s4u-engine-filtering.cpp
783 .. _s4u_ex_platform_state_profile:
785 Specifying state profiles
786 ^^^^^^^^^^^^^^^^^^^^^^^^^
788 Shows how to specify when the resources must be turned off and on again, and how to react to such
789 failures in your code. See also :ref:`howto_churn` and :ref:`this example <s4u_ex_comm_failure>`
790 on how to react to communication failures.
794 .. example-tab:: examples/cpp/platform-failures/s4u-platform-failures.cpp
796 .. example-tab:: examples/c/platform-failures/platform-failures.c
798 .. example-tab:: examples/python/platform-failures/platform-failures.py
802 .. showfile:: examples/platforms/small_platform_failures.xml
805 .. showfile:: examples/platforms/profiles/jupiter_state.profile
807 .. showfile:: examples/platforms/profiles/fafard_state.profile
809 Specifying speed profiles
810 ^^^^^^^^^^^^^^^^^^^^^^^^^
812 Shows how to specify an external load to resources, variating their peak speed over time.
816 .. example-tab:: examples/cpp/platform-profile/s4u-platform-profile.cpp
818 .. example-tab:: examples/python/platform-profile/platform-profile.py
822 .. showfile:: examples/platforms/small_platform_profile.xml
825 .. showfile:: examples/platforms/profiles/jupiter_speed.profile
827 .. showfile:: examples/platforms/profiles/link1_bandwidth.profile
829 .. showfile:: examples/platforms/profiles/link1_latency.profile
831 Modifying the platform
832 ----------------------
834 Serializing communications
835 ^^^^^^^^^^^^^^^^^^^^^^^^^^
837 This example shows how to limit the amount of communications going through a given link.
838 It is very similar to the other asynchronous communication examples, but messages get serialized by the platform.
839 Without this call to ``Link::set_concurrency_limit(2)``, all messages would be received at the exact same timestamp since
840 they are initiated at the same instant and are of the same size. But with this extra configuration to the link, at most 2
841 messages can travel through the link at the same time.
845 .. example-tab:: examples/cpp/platform-comm-serialize/s4u-platform-comm-serialize.cpp
847 See also :cpp:func:`simgrid::s4u::Link::set_concurrency_limit()`.
849 .. example-tab:: examples/python/platform-comm-serialize/platform-comm-serialize.py
851 See also :py:func:`simgrid.Link.set_concurrency_limit()`.
862 Describing the energy profiles in the platform
863 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
865 The first platform file contains the energy profile of each link and host for a wired network, which is necessary to get energy consumption
866 predictions. The second platform file is the equivalent for a wireless network. As usual, you should not trust our example, and you should
867 strive to double-check that your instantiation matches your target platform.
873 .. showfile:: examples/platforms/energy_platform.xml
876 .. showfile:: examples/platforms/wifi_energy.xml
882 CPU energy consumption
883 ^^^^^^^^^^^^^^^^^^^^^^
885 This example shows how to retrieve the amount of energy consumed by the CPU during computations, and the impact of the pstate.
889 .. example-tab:: examples/cpp/energy-exec/s4u-energy-exec.cpp
891 .. example-tab:: examples/c/energy-exec/energy-exec.c
893 Virtual machines consumption
894 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
896 This example is very similar to the previous one, adding VMs to the picture.
900 .. example-tab:: examples/cpp/energy-vm/s4u-energy-vm.cpp
902 .. example-tab:: examples/c/energy-vm/energy-vm.c
904 Wired network energy consumption
905 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
907 This example shows how to retrieve and display the energy consumed by the wired network during communications.
911 .. example-tab:: examples/cpp/energy-link/s4u-energy-link.cpp
913 WiFi network energy consumption
914 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
916 This example shows how to retrieve and display the energy consumed by the wireless network during communications.
920 .. example-tab:: examples/cpp/energy-wifi/s4u-energy-wifi.cpp
922 Modeling the shutdown and boot of hosts
923 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
925 Simple example of a model for the energy consumption during the host boot and shutdown periods.
929 .. example-tab:: examples/platforms/energy_boot.xml
931 .. example-tab:: examples/cpp/energy-boot/s4u-energy-boot.cpp
933 =======================
934 Tracing and Visualizing
935 =======================
937 Tracing can be activated by various configuration options which are illustrated in these examples. See also the
938 :ref:`full list of options related to tracing <tracing_tracing_options>`.
939 The following introduces some option sets of interest that you may want to pass to your simulators.
942 These tracing examples should be integrated in the examples to not duplicate the C++ files.
943 A full command line to see the result in the right tool (vite/FrameSoc) should be given along with some screenshots.
951 This program is a toy example just loading the platform so that you can play with the platform visualization. Recommended options:
952 ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
956 .. example-tab:: examples/cpp/trace-platform/s4u-trace-platform.cpp
961 This example declares several tracing categories that are used to
962 classify its tasks. When the program is executed, the tracing mechanism
963 registers the resource utilization of hosts and links according to these
964 categories. Recommended options:
965 ``--cfg=tracing:yes --cfg=tracing/categorized:yes --cfg=tracing/uncategorized:yes``
969 .. example-tab:: examples/cpp/trace-categories/s4u-trace-categories.cpp
971 Master Workers tracing
972 ^^^^^^^^^^^^^^^^^^^^^^
974 This is an augmented version of our basic master/worker example using
975 several tracing features. It traces resource usage, sorted out in several
976 categories; Trace marks and user variables are also used. Recommended
977 options: ``--cfg=tracing/categorized:yes --cfg=tracing/uncategorized:yes``
981 .. example-tab:: examples/cpp/trace-masterworkers/s4u-trace-masterworkers.cpp
983 .. example-tab:: examples/python/app-masterworkers/app-masterworkers.py
985 Process migration tracing
986 ^^^^^^^^^^^^^^^^^^^^^^^^^
988 This version is enhanced so that the process migrations can be displayed
989 as arrows in a Gantt-chart visualization. Recommended options to that
990 extend: ``--cfg=tracing:yes --cfg=tracing/actor:yes``
994 .. example-tab:: examples/cpp/trace-process-migration/s4u-trace-process-migration.cpp
996 Tracing user variables
997 ----------------------
999 You can also attach your own variables to any resource described in the platform
1000 file. The following examples illustrate this feature. They have to be run with
1001 the following options: ``--cfg=tracing:yes --cfg=tracing/platform:yes``
1003 Attaching variables to Hosts
1004 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1008 .. example-tab:: examples/cpp/trace-host-user-variables/s4u-trace-host-user-variables.cpp
1010 Attaching variables to Links
1011 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1013 The tricky part is that you have to know the name of the link you want to enhance with a variable.
1017 .. example-tab:: examples/cpp/trace-link-user-variables/s4u-trace-link-user-variables.cpp
1019 Attaching variables to network routes
1020 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1022 It is often easier to update a given variable for all links of a given network path (identified by its source and destination hosts) instead of
1023 knowing the name of each specific link.
1027 .. example-tab:: examples/cpp/trace-route-user-variables/s4u-trace-route-user-variables.cpp
1029 ========================
1030 Larger SimGrid Exemplars
1031 ========================
1033 This section contains application examples that are somewhat larger than the previous examples.
1041 Shows how to implement a classical communication pattern, where a token is exchanged along a ring to reach every participant.
1045 .. example-tab:: examples/cpp/app-token-ring/s4u-app-token-ring.cpp
1047 .. example-tab:: examples/c/app-token-ring/app-token-ring.c
1052 Another good old example, where one Master actor has a bunch of tasks to dispatch to a set of several Worker actors.
1053 This example is used in the :ref:`SimGrid tutorial <usecase_simalgo>`.
1059 This example comes in two equivalent variants, one where the actors
1060 are specified as simple functions (which is easier to understand for
1061 newcomers) and one where the actors are specified as classes (which is
1062 more powerful for the users wanting to build their own projects upon
1065 .. showfile:: examples/cpp/app-masterworkers/s4u-app-masterworkers-class.cpp
1068 .. showfile:: examples/cpp/app-masterworkers/s4u-app-masterworkers-fun.cpp
1073 .. showfile:: examples/c/app-masterworker/app-masterworker.c
1076 .. example-tab:: examples/python/app-masterworkers/app-masterworkers.py
1084 Classical protocol for Peer-to-Peer data diffusion.
1090 .. showfile:: examples/cpp/app-bittorrent/s4u-bittorrent.cpp
1093 .. showfile:: examples/cpp/app-bittorrent/s4u-peer.cpp
1096 .. showfile:: examples/cpp/app-bittorrent/s4u-tracker.cpp
1101 .. showfile:: examples/c/app-bittorrent/app-bittorrent.c
1104 .. showfile:: examples/c/app-bittorrent/bittorrent-peer.c
1107 .. showfile:: examples/c/app-bittorrent/tracker.c
1113 Data broadcast over a ring of processes.
1117 .. example-tab:: examples/cpp/app-chainsend/s4u-app-chainsend.cpp
1121 .. showfile:: examples/c/app-chainsend/chainsend.c
1124 .. showfile:: examples/c/app-chainsend/broadcaster.c
1127 .. showfile:: examples/c/app-chainsend/peer.c
1130 Distributed Hash Tables (DHT)
1131 -----------------------------
1136 One of the most famous DHT protocol.
1142 .. showfile:: examples/cpp/dht-chord/s4u-dht-chord.cpp
1145 .. showfile:: examples/cpp/dht-chord/s4u-dht-chord-node.cpp
1151 Another well-known DHT protocol.
1157 .. showfile:: examples/cpp/dht-kademlia/s4u-dht-kademlia.cpp
1160 .. showfile:: examples/cpp/dht-kademlia/routing_table.cpp
1163 .. showfile:: examples/cpp/dht-kademlia/answer.cpp
1166 .. showfile:: examples/cpp/dht-kademlia/node.cpp
1171 .. showfile:: examples/c/dht-kademlia/dht-kademlia.c
1174 .. showfile:: examples/c/dht-kademlia/routing_table.c
1177 .. showfile:: examples/c/dht-kademlia/answer.c
1180 .. showfile:: examples/c/dht-kademlia/message.c
1183 .. showfile:: examples/c/dht-kademlia/node.c
1189 Yet another well-known DHT protocol.
1193 .. example-tab:: examples/c/dht-pastry/dht-pastry.c
1203 This example starts some computations both on PMs and VMs and migrates some VMs around.
1207 .. example-tab:: examples/cpp/cloud-simple/s4u-cloud-simple.cpp
1209 .. example-tab:: examples/c/cloud-simple/cloud-simple.c
1214 This example shows how to migrate VMs between PMs.
1218 .. example-tab:: examples/cpp/cloud-migration/s4u-cloud-migration.cpp
1220 .. example-tab:: examples/c/cloud-migration/cloud-migration.c
1222 =======================
1223 Model-Related Examples
1224 =======================
1229 This simple ping-pong example demonstrates how to use the bindings to the Network
1230 Simulator. The most interesting is probably not the C++ files since
1231 they are unchanged from the other simulations, but the associated files,
1232 such as the platform file to see how to declare a platform to be used
1233 with the ns-3 bindings of SimGrid and the tesh file to see how to
1234 start a simulation in these settings.
1238 .. example-tab:: examples/cpp/network-ns3/s4u-network-ns3.cpp
1244 .. showfile:: examples/platforms/small_platform_one_link_routes.xml
1250 This demonstrates how to declare a wifi zone in your platform and
1251 how to use it in your simulation. For that, you should have a link
1252 whose sharing policy is set to `WIFI`. Such links can have more
1253 than one bandwidth value (separated by commas), corresponding to
1254 the several SNR level of your wifi link.
1256 In this case, SimGrid automatically switches to validated
1257 performance models of wifi networks, where the time is shared
1258 between users instead of the bandwidth for wired links (the
1259 corresponding publication is currently being written).
1261 If your wifi link provides more than one SNR level, you can switch
1262 the level of a given host using
1263 :cpp:func:`simgrid::s4u::Link::set_host_wifi_rate`. By default,
1264 the first level is used.
1268 .. example-tab:: examples/cpp/network-wifi/s4u-network-wifi.cpp
1274 .. showfile:: examples/platforms/wifi.xml
1283 It is possible to extend SimGrid without modifying its internals by
1284 attaching code to the existing signals and by adding extra data to the
1285 simulation objects through extensions. How to do that is not exactly
1286 documented yet, and you should look for examples in the src/plugins
1289 This section documents how the existing plugins can be used. Remember
1290 that you are very welcome to modify the plugins to fit your needs. It
1291 should be much easier than modifying the SimGrid kernel.
1293 Monitoring the host load
1294 ------------------------
1298 .. example-tab:: examples/cpp/plugin-host-load/s4u-plugin-host-load.cpp
1300 .. example-tab:: examples/c/plugin-host-load/plugin-host-load.c
1302 Monitoring the link load
1303 ------------------------
1307 .. example-tab:: examples/cpp/plugin-link-load/s4u-plugin-link-load.cpp
1309 =======================
1310 Model-Checking Examples
1311 =======================
1313 The model-checker can be used to exhaustively search for issues in the tested application. It must be activated at compile-time, but this
1314 mode is rather experimental in SimGrid (as of v3.25). We are working on it :)
1319 In this example, two actors send some data to a central server, which asserts that the messages are always received in the same order.
1320 This is wrong, and the model-checker correctly finds a counter-example to that assertion.
1324 .. example-tab:: examples/cpp/mc-failing-assert/s4u-mc-failing-assert.cpp