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 .. _s4u_ex_mailbox_ready:
363 Checking for incoming communications
364 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
366 This example uses ``Mailbox.ready()`` to check for completed communications. When this function returns true, then at least a message
367 is arrived, so you know that ``Mailbox.get()`` will complete imediately. This is thus another way toward asynchronous communications.
371 .. example-tab:: examples/cpp/comm-ready/s4u-comm-ready.cpp
373 See also :cpp:func:`simgrid::s4u::Mailbox::ready()`.
375 .. example-tab:: examples/python/comm-ready/comm-ready.py
377 See also :py:func:`simgrid.Mailbox.ready()`
380 Suspending communications
381 ^^^^^^^^^^^^^^^^^^^^^^^^^
383 The ``suspend()`` and ``resume()`` functions block the progression of a given communication for a while and then unblock it.
384 ``is_suspended()`` returns whether that activity is currently blocked or not.
388 .. example-tab:: examples/cpp/comm-suspend/s4u-comm-suspend.cpp
390 See also :cpp:func:`simgrid::s4u::Activity::suspend()`
391 :cpp:func:`simgrid::s4u::Activity::resume()` and
392 :cpp:func:`simgrid::s4u::Activity::is_suspended()`.
394 .. example-tab:: examples/python/comm-suspend/comm-suspend.py
396 See also :py:func:`simgrid.Comm::suspend()` and
397 :py:func:`simgrid.Comm.resume()`.
399 Waiting for all communications in a set
400 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
402 The ``wait_all()`` function is useful when you want to block until all activities in a given set have been completed.
406 .. example-tab:: examples/cpp/comm-waitall/s4u-comm-waitall.cpp
408 See also :cpp:func:`simgrid::s4u::Comm::wait_all()`.
410 .. example-tab:: examples/python/comm-waitall/comm-waitall.py
412 See also :py:func:`simgrid.Comm.wait_all()`.
414 .. example-tab:: examples/c/comm-waitall/comm-waitall.c
416 See also :cpp:func:`sg_comm_wait_all()`.
418 Waiting for the first completed communication in a set
419 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
421 The ``wait_any()`` blocks until one activity of the set completes, no matter which terminates first.
425 .. example-tab:: examples/cpp/comm-waitany/s4u-comm-waitany.cpp
427 See also :cpp:func:`simgrid::s4u::Comm::wait_any()`.
429 .. example-tab:: examples/python/comm-waitany/comm-waitany.py
431 See also :py:func:`simgrid.Comm.wait_any()`.
433 .. example-tab:: examples/c/comm-waitany/comm-waitany.c
435 See also :cpp:func:`sg_comm_wait_any`.
437 Testing whether at least one communication completed
438 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
440 The ``test_any()`` returns whether at least one activity of the set has completed, or -1.
444 .. example-tab:: examples/cpp/comm-testany/s4u-comm-testany.cpp
446 See also :cpp:func:`simgrid::s4u::Comm::test_any()`.
448 .. example-tab:: examples/python/comm-testany/comm-testany.py
450 See also :py:func:`simgrid.Comm.test_any()`.
452 .. _s4u_ex_comm_failure:
454 Dealing with network failures
455 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
457 This examples shows how to survive to network exceptions that occur when a link is turned off, or when the actor with whom
458 you communicate fails because its host is turned off. In this case, any blocking operation such as ``put``, ``get`` or
459 ``wait`` will raise an exception that you can catch and react to. See also :ref:`howto_churn`,
460 :ref:`this example <s4u_ex_platform_state_profile>` on how to attach a state profile to hosts and
461 :ref:`that example <s4u_ex_exec_failure>` on how to react to host failures.
465 .. example-tab:: examples/cpp/comm-failure/s4u-comm-failure.cpp
467 .. example-tab:: examples/python/comm-failure/comm-failure.py
469 .. _s4u_ex_comm_host2host:
471 Direct host-to-host communication
472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
474 This example demonstrates the direct communication mechanism, that allows to send data from one host to another without
475 relying on the mailbox mechanism.
479 .. example-tab:: examples/cpp/comm-host2host/s4u-comm-host2host.cpp
481 See also :cpp:func:`simgrid::s4u::Comm::sendto_init()` and :cpp:func:`simgrid::s4u::Comm::sendto_async()`.
483 .. example-tab:: examples/python/comm-host2host/comm-host2host.py
485 See also :py:func:`simgrid.Comm.sendto_init()` and :py:func:`simgrid.Comm.sendto_async()`.
487 .. _s4u_ex_execution:
489 Executions on the CPU
490 ---------------------
495 The computations done in your program are not reported to the
496 simulated world unless you explicitly request the simulator to pause
497 the actor until a given amount of flops gets computed on its simulated
498 host. Some executions can be given a higher priority so that they
503 .. example-tab:: examples/cpp/exec-basic/s4u-exec-basic.cpp
505 See also :cpp:func:`void simgrid::s4u::this_actor::execute(double)`
506 and :cpp:func:`void simgrid::s4u::this_actor::execute(double, double)`.
508 .. example-tab:: examples/python/exec-basic/exec-basic.py
510 See also :py:func:`simgrid.this_actor.execute()`.
512 .. example-tab:: examples/c/exec-basic/exec-basic.c
514 See also :cpp:func:`void sg_actor_execute(double)`
515 and :cpp:func:`void sg_actor_execute_with_priority(double, double)`.
517 Asynchronous execution
518 ^^^^^^^^^^^^^^^^^^^^^^
520 You can start asynchronous executions, just like you would fire background threads.
524 .. example-tab:: examples/cpp/exec-async/s4u-exec-async.cpp
526 See also :cpp:func:`simgrid::s4u::this_actor::exec_init()`,
527 :cpp:func:`simgrid::s4u::Activity::start()`,
528 :cpp:func:`simgrid::s4u::Activity::wait()`,
529 :cpp:func:`simgrid::s4u::Activity::get_remaining()`,
530 :cpp:func:`simgrid::s4u::Exec::get_remaining_ratio()`,
531 :cpp:func:`simgrid::s4u::this_actor::exec_async()` and
532 :cpp:func:`simgrid::s4u::Activity::cancel()`.
534 .. example-tab:: examples/python/exec-async/exec-async.py
536 See also :py:func:`simgrid.this_actor.exec_init()`,
537 :py:func:`simgrid.Exec.start()`,
538 :py:func:`simgrid.Exec.wait()`,
539 :py:attr:`simgrid.Exec.remaining`,
540 :py:attr:`simgrid.Exec.remaining_ratio`,
541 :py:func:`simgrid.this_actor.exec_async()` and
542 :py:func:`simgrid.Exec.cancel()`.
544 .. example-tab:: examples/c/exec-async/exec-async.c
546 See also :cpp:func:`sg_actor_exec_init()`,
547 :cpp:func:`sg_exec_start()`,
548 :cpp:func:`sg_exec_wait()`,
549 :cpp:func:`sg_exec_get_remaining()`,
550 :cpp:func:`sg_exec_get_remaining_ratio()`,
551 :cpp:func:`sg_actor_exec_async()` and
552 :cpp:func:`sg_exec_cancel()`,
557 You can start executions on remote hosts, or even change the host on which they occur during their execution.
558 This is naturally not very realistic, but it's something handy to have.
562 .. example-tab:: examples/cpp/exec-remote/s4u-exec-remote.cpp
564 See also :cpp:func:`simgrid::s4u::Exec::set_host()`.
566 .. example-tab:: examples/python/exec-remote/exec-remote.py
568 See also :py:attr:`simgrid.Exec.host`.
570 .. example-tab:: examples/c/exec-remote/exec-remote.c
572 See also :cpp:func:`sg_exec_set_host()`.
579 These objects are convenient abstractions of parallel
580 computational kernels that span over several machines, such as a
581 PDGEM and the other ScaLAPACK routines. Note that this only works
582 with the "ptask_L07" host model (``--cfg=host/model:ptask_L07``).
584 This example demonstrates several kinds of parallel tasks: regular
585 ones, communication-only (without computation), computation-only
586 (without communication), synchronization-only (neither
587 communication nor computation). It also shows how to reconfigure a
588 task after its start, to change the number of hosts it runs onto.
589 This allows simulating malleable tasks.
593 .. example-tab:: examples/cpp/exec-ptask/s4u-exec-ptask.cpp
595 See also :cpp:func:`simgrid::s4u::this_actor::parallel_execute()`.
597 .. example-tab:: examples/python/exec-ptask/exec-ptask.py
599 See also :ref:`simgrid.this_actor.parallel_execute()`
601 Ptasks play well with the host energy plugin, as shown in this example.
602 There is not much new compared to the above ptask example or the
603 :ref:`examples about energy <s4u_ex_energy>`. It just works.
607 .. example-tab:: examples/cpp/energy-exec-ptask/s4u-energy-exec-ptask.cpp
609 .. example-tab:: examples/c/energy-exec-ptask/energy-exec-ptask.c
611 .. _s4u_ex_exec_failure:
613 Dealing with host failures
614 ^^^^^^^^^^^^^^^^^^^^^^^^^^
616 This examples shows how to survive to host failure exceptions that occur when an host is turned off. The actor do not get notified when the host
617 on which they run is turned off: they are just terminated in this case, and their ``on_exit()`` callback gets executed. For remote executions on
618 failing hosts however, any blocking operation such as ``exec`` or ``wait`` will raise an exception that you can catch and react to. See also
620 :ref:`this example <s4u_ex_platform_state_profile>` on how to attach a state profile to hosts, and
621 :ref:`that example <s4u_ex_comm_failure>` on how to react to networ failures.
625 .. example-tab:: examples/cpp/exec-failure/s4u-exec-failure.cpp
632 This example shows how to define a set of pstates in the XML. The current pstate
633 of a host can then be accessed and changed from the program.
637 .. example-tab:: examples/cpp/exec-dvfs/s4u-exec-dvfs.cpp
639 See also :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
641 .. example-tab:: examples/c/exec-dvfs/exec-dvfs.c
643 See also :cpp:func:`sg_host_get_pstate_speed` and :cpp:func:`sg_host_set_pstate`.
645 .. example-tab:: examples/python/exec-dvfs/exec-dvfs.py
647 See also :py:func:`simgrid.Host.pstate_speed()` and :py:attr:`simgrid.Host.pstate`.
649 .. example-tab:: examples/platforms/energy_platform.xml
651 The important parts are in the :ref:`pf_tag_host` tag. The ``pstate`` attribute is the initial pstate while the ``speed`` attribute must
652 be a comma-separated list of values: the speed at each pstate. This platform file also describes the ``wattage_per_state`` and
653 ``wattage_off`` properties, that are used by the :ref:`plugin_host_energy` plugin.
657 I/O on Disks and Files
658 ----------------------
660 SimGrid provides two levels of abstraction to interact with the
661 simulated disks. At the simplest level, you simply create read and
662 write actions on the disk resources.
664 Access to raw disk devices
665 ^^^^^^^^^^^^^^^^^^^^^^^^^^
667 This example illustrates how to simply read and write data on a simulated disk resource.
671 .. example-tab:: examples/cpp/io-disk-raw/s4u-io-disk-raw.cpp
673 .. example-tab:: examples/c/io-disk-raw/io-disk-raw.c
675 .. example-tab:: examples/platforms/hosts_with_disks.xml
677 This shows how to declare disks in XML.
682 The FileSystem plugin provides a more detailed view, with the
683 classical operations over files: open, move, unlink, and of course,
684 read and write. The file and disk sizes are also dealt with and can
685 result in short reads and short writes, as in reality.
687 - **File Management:**
688 This example illustrates the use of operations on files
689 (read, write, seek, tell, unlink, etc).
693 .. example-tab:: examples/cpp/io-file-system/s4u-io-file-system.cpp
696 I/O operations on files can also be done remotely,
697 i.e. when the accessed disk is not mounted on the caller's host.
701 .. example-tab:: examples/cpp/io-file-remote/s4u-io-file-remote.cpp
703 .. example-tab:: examples/c/io-file-remote/io-file-remote.c
707 Classical synchronization objects
708 ---------------------------------
713 Shows how to use :cpp:type:`simgrid::s4u::Barrier` synchronization objects.
717 .. example-tab:: examples/cpp/synchro-barrier/s4u-synchro-barrier.cpp
719 .. example-tab:: examples/python/synchro-barrier/synchro-barrier.py
721 Condition variable: basic usage
722 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
724 Shows how to use :cpp:type:`simgrid::s4u::ConditionVariable` synchronization objects.
728 .. example-tab:: examples/cpp/synchro-condition-variable/s4u-synchro-condition-variable.cpp
730 Condition variable: timeouts
731 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
733 Shows how to specify timeouts when blocking on condition variables.
737 .. example-tab:: examples/cpp/synchro-condition-variable-waituntil/s4u-synchro-condition-variable-waituntil.cpp
742 Shows how to use :cpp:type:`simgrid::s4u::Mutex` synchronization objects.
746 .. example-tab:: examples/cpp/synchro-mutex/s4u-synchro-mutex.cpp
748 .. example-tab:: examples/python/synchro-mutex/synchro-mutex.py
753 Shows how to use :cpp:type:`simgrid::s4u::Semaphore` synchronization objects.
757 .. example-tab:: examples/cpp/synchro-semaphore/s4u-synchro-semaphore.cpp
759 .. example-tab:: examples/python/synchro-semaphore/synchro-semaphore.py
761 .. example-tab:: examples/c/synchro-semaphore/synchro-semaphore.c
763 =============================
764 Interacting with the Platform
765 =============================
767 User-defined properties
768 -----------------------
770 You can attach arbitrary information to most platform elements from the XML file, and then interact with these values from your
771 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
776 .. example-tab:: examples/cpp/platform-properties/s4u-platform-properties.cpp
778 - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
779 - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
780 - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
781 - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
783 .. example-tab:: examples/c/platform-properties/platform-properties.c
785 - :cpp:func:`sg_actor_get_property_value()`
786 - :cpp:func:`sg_host_get_property_value()` and :cpp:func:sg_host_set_property_value()`
787 - :cpp:func:`sg_zone_get_property_value()` and :cpp:func:`sg_zone_set_property_value()`
793 .. showfile:: examples/platforms/prop.xml
799 Retrieving the netzones matching given criteria
800 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
802 Shows how to filter the cluster netzones.
806 .. example-tab:: examples/cpp/routing-get-clusters/s4u-routing-get-clusters.cpp
808 Retrieving the list of hosts matching given criteria
809 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
811 Shows how to filter the actors that match given criteria.
815 .. example-tab:: examples/cpp/engine-filtering/s4u-engine-filtering.cpp
820 .. _s4u_ex_platform_state_profile:
822 Specifying state profiles
823 ^^^^^^^^^^^^^^^^^^^^^^^^^
825 Shows how to specify when the resources must be turned off and on again, and how to react to such
826 failures in your code. See also :ref:`howto_churn`,
827 :ref:`this example <s4u_ex_comm_failure>` on how to react to communication failures, and
828 :ref:`that example <s4u_ex_exec_failure>` on how to react to host failures.
832 .. example-tab:: examples/cpp/platform-failures/s4u-platform-failures.cpp
834 .. example-tab:: examples/c/platform-failures/platform-failures.c
836 .. example-tab:: examples/python/platform-failures/platform-failures.py
840 .. showfile:: examples/platforms/small_platform_failures.xml
843 .. showfile:: examples/platforms/profiles/jupiter_state.profile
845 .. showfile:: examples/platforms/profiles/fafard_state.profile
847 Specifying speed profiles
848 ^^^^^^^^^^^^^^^^^^^^^^^^^
850 Shows how to specify an external load to resources, variating their peak speed over time.
854 .. example-tab:: examples/cpp/platform-profile/s4u-platform-profile.cpp
856 .. example-tab:: examples/python/platform-profile/platform-profile.py
860 .. showfile:: examples/platforms/small_platform_profile.xml
863 .. showfile:: examples/platforms/profiles/jupiter_speed.profile
865 .. showfile:: examples/platforms/profiles/link1_bandwidth.profile
867 .. showfile:: examples/platforms/profiles/link1_latency.profile
869 Modifying the platform
870 ----------------------
872 Serializing communications
873 ^^^^^^^^^^^^^^^^^^^^^^^^^^
875 This example shows how to limit the amount of communications going through a given link.
876 It is very similar to the other asynchronous communication examples, but messages get serialized by the platform.
877 Without this call to ``Link::set_concurrency_limit(2)``, all messages would be received at the exact same timestamp since
878 they are initiated at the same instant and are of the same size. But with this extra configuration to the link, at most 2
879 messages can travel through the link at the same time.
883 .. example-tab:: examples/cpp/platform-comm-serialize/s4u-platform-comm-serialize.cpp
885 See also :cpp:func:`simgrid::s4u::Link::set_concurrency_limit()`.
887 .. example-tab:: examples/python/platform-comm-serialize/platform-comm-serialize.py
889 See also :py:func:`simgrid.Link.set_concurrency_limit()`.
900 Describing the energy profiles in the platform
901 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
903 The first platform file contains the energy profile of each link and host for a wired network, which is necessary to get energy consumption
904 predictions. The second platform file is the equivalent for a wireless network. As usual, you should not trust our example, and you should
905 strive to double-check that your instantiation matches your target platform.
911 .. showfile:: examples/platforms/energy_platform.xml
914 .. showfile:: examples/platforms/wifi_energy.xml
920 CPU energy consumption
921 ^^^^^^^^^^^^^^^^^^^^^^
923 This example shows how to retrieve the amount of energy consumed by the CPU during computations, and the impact of the pstate.
927 .. example-tab:: examples/cpp/energy-exec/s4u-energy-exec.cpp
929 .. example-tab:: examples/c/energy-exec/energy-exec.c
931 Virtual machines consumption
932 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
934 This example is very similar to the previous one, adding VMs to the picture.
938 .. example-tab:: examples/cpp/energy-vm/s4u-energy-vm.cpp
940 .. example-tab:: examples/c/energy-vm/energy-vm.c
942 Wired network energy consumption
943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
945 This example shows how to retrieve and display the energy consumed by the wired network during communications.
949 .. example-tab:: examples/cpp/energy-link/s4u-energy-link.cpp
951 WiFi network energy consumption
952 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
954 This example shows how to retrieve and display the energy consumed by the wireless network during communications.
958 .. example-tab:: examples/cpp/energy-wifi/s4u-energy-wifi.cpp
960 Modeling the shutdown and boot of hosts
961 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
963 Simple example of a model for the energy consumption during the host boot and shutdown periods.
967 .. example-tab:: examples/platforms/energy_boot.xml
969 .. example-tab:: examples/cpp/energy-boot/s4u-energy-boot.cpp
971 =======================
972 Tracing and Visualizing
973 =======================
975 Tracing can be activated by various configuration options which are illustrated in these examples. See also the
976 :ref:`full list of options related to tracing <tracing_tracing_options>`.
977 The following introduces some option sets of interest that you may want to pass to your simulators.
980 These tracing examples should be integrated in the examples to not duplicate the C++ files.
981 A full command line to see the result in the right tool (vite/FrameSoc) should be given along with some screenshots.
989 This program is a toy example just loading the platform so that you can play with the platform visualization. Recommended options:
990 ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
994 .. example-tab:: examples/cpp/trace-platform/s4u-trace-platform.cpp
999 This example declares several tracing categories that are used to
1000 classify its tasks. When the program is executed, the tracing mechanism
1001 registers the resource utilization of hosts and links according to these
1002 categories. Recommended options:
1003 ``--cfg=tracing:yes --cfg=tracing/categorized:yes --cfg=tracing/uncategorized:yes``
1007 .. example-tab:: examples/cpp/trace-categories/s4u-trace-categories.cpp
1009 Master Workers tracing
1010 ^^^^^^^^^^^^^^^^^^^^^^
1012 This is an augmented version of our basic master/worker example using
1013 several tracing features. It traces resource usage, sorted out in several
1014 categories; Trace marks and user variables are also used. Recommended
1015 options: ``--cfg=tracing/categorized:yes --cfg=tracing/uncategorized:yes``
1019 .. example-tab:: examples/cpp/trace-masterworkers/s4u-trace-masterworkers.cpp
1021 .. example-tab:: examples/python/app-masterworkers/app-masterworkers.py
1023 Process migration tracing
1024 ^^^^^^^^^^^^^^^^^^^^^^^^^
1026 This version is enhanced so that the process migrations can be displayed
1027 as arrows in a Gantt-chart visualization. Recommended options to that
1028 extend: ``--cfg=tracing:yes --cfg=tracing/actor:yes``
1032 .. example-tab:: examples/cpp/trace-process-migration/s4u-trace-process-migration.cpp
1034 Tracing user variables
1035 ----------------------
1037 You can also attach your own variables to any resource described in the platform
1038 file. The following examples illustrate this feature. They have to be run with
1039 the following options: ``--cfg=tracing:yes --cfg=tracing/platform:yes``
1041 Attaching variables to Hosts
1042 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1046 .. example-tab:: examples/cpp/trace-host-user-variables/s4u-trace-host-user-variables.cpp
1048 Attaching variables to Links
1049 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1051 The tricky part is that you have to know the name of the link you want to enhance with a variable.
1055 .. example-tab:: examples/cpp/trace-link-user-variables/s4u-trace-link-user-variables.cpp
1057 Attaching variables to network routes
1058 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1060 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
1061 knowing the name of each specific link.
1065 .. example-tab:: examples/cpp/trace-route-user-variables/s4u-trace-route-user-variables.cpp
1067 ========================
1068 Larger SimGrid Exemplars
1069 ========================
1071 This section contains application examples that are somewhat larger than the previous examples.
1079 Shows how to implement a classical communication pattern, where a token is exchanged along a ring to reach every participant.
1083 .. example-tab:: examples/cpp/app-token-ring/s4u-app-token-ring.cpp
1085 .. example-tab:: examples/c/app-token-ring/app-token-ring.c
1090 Another good old example, where one Master actor has a bunch of tasks to dispatch to a set of several Worker actors.
1091 This example is used in the :ref:`SimGrid tutorial <usecase_simalgo>`.
1097 This example comes in two equivalent variants, one where the actors
1098 are specified as simple functions (which is easier to understand for
1099 newcomers) and one where the actors are specified as classes (which is
1100 more powerful for the users wanting to build their own projects upon
1103 .. showfile:: examples/cpp/app-masterworkers/s4u-app-masterworkers-class.cpp
1106 .. showfile:: examples/cpp/app-masterworkers/s4u-app-masterworkers-fun.cpp
1111 .. showfile:: examples/c/app-masterworker/app-masterworker.c
1114 .. example-tab:: examples/python/app-masterworkers/app-masterworkers.py
1122 Classical protocol for Peer-to-Peer data diffusion.
1128 .. showfile:: examples/cpp/app-bittorrent/s4u-bittorrent.cpp
1131 .. showfile:: examples/cpp/app-bittorrent/s4u-peer.cpp
1134 .. showfile:: examples/cpp/app-bittorrent/s4u-tracker.cpp
1139 .. showfile:: examples/c/app-bittorrent/app-bittorrent.c
1142 .. showfile:: examples/c/app-bittorrent/bittorrent-peer.c
1145 .. showfile:: examples/c/app-bittorrent/tracker.c
1151 Data broadcast over a ring of processes.
1155 .. example-tab:: examples/cpp/app-chainsend/s4u-app-chainsend.cpp
1159 .. showfile:: examples/c/app-chainsend/chainsend.c
1162 .. showfile:: examples/c/app-chainsend/broadcaster.c
1165 .. showfile:: examples/c/app-chainsend/peer.c
1168 Distributed Hash Tables (DHT)
1169 -----------------------------
1174 One of the most famous DHT protocol.
1180 .. showfile:: examples/cpp/dht-chord/s4u-dht-chord.cpp
1183 .. showfile:: examples/cpp/dht-chord/s4u-dht-chord-node.cpp
1189 Another well-known DHT protocol.
1195 .. showfile:: examples/cpp/dht-kademlia/s4u-dht-kademlia.cpp
1198 .. showfile:: examples/cpp/dht-kademlia/routing_table.cpp
1201 .. showfile:: examples/cpp/dht-kademlia/answer.cpp
1204 .. showfile:: examples/cpp/dht-kademlia/node.cpp
1209 .. showfile:: examples/c/dht-kademlia/dht-kademlia.c
1212 .. showfile:: examples/c/dht-kademlia/routing_table.c
1215 .. showfile:: examples/c/dht-kademlia/answer.c
1218 .. showfile:: examples/c/dht-kademlia/message.c
1221 .. showfile:: examples/c/dht-kademlia/node.c
1227 Yet another well-known DHT protocol.
1231 .. example-tab:: examples/c/dht-pastry/dht-pastry.c
1241 This example starts some computations both on PMs and VMs and migrates some VMs around.
1245 .. example-tab:: examples/cpp/cloud-simple/s4u-cloud-simple.cpp
1247 .. example-tab:: examples/c/cloud-simple/cloud-simple.c
1252 This example shows how to migrate VMs between PMs.
1256 .. example-tab:: examples/cpp/cloud-migration/s4u-cloud-migration.cpp
1258 .. example-tab:: examples/c/cloud-migration/cloud-migration.c
1260 =======================
1261 Model-Related Examples
1262 =======================
1267 This simple ping-pong example demonstrates how to use the bindings to the Network
1268 Simulator. The most interesting is probably not the C++ files since
1269 they are unchanged from the other simulations, but the associated files,
1270 such as the platform file to see how to declare a platform to be used
1271 with the ns-3 bindings of SimGrid and the tesh file to see how to
1272 start a simulation in these settings.
1276 .. example-tab:: examples/cpp/network-ns3/s4u-network-ns3.cpp
1282 .. showfile:: examples/platforms/small_platform_one_link_routes.xml
1288 This demonstrates how to declare a wifi zone in your platform and
1289 how to use it in your simulation. For that, you should have a link
1290 whose sharing policy is set to `WIFI`. Such links can have more
1291 than one bandwidth value (separated by commas), corresponding to
1292 the several SNR level of your wifi link.
1294 In this case, SimGrid automatically switches to validated
1295 performance models of wifi networks, where the time is shared
1296 between users instead of the bandwidth for wired links (the
1297 corresponding publication is currently being written).
1299 If your wifi link provides more than one SNR level, you can switch
1300 the level of a given host using
1301 :cpp:func:`simgrid::s4u::Link::set_host_wifi_rate`. By default,
1302 the first level is used.
1306 .. example-tab:: examples/cpp/network-wifi/s4u-network-wifi.cpp
1312 .. showfile:: examples/platforms/wifi.xml
1321 It is possible to extend SimGrid without modifying its internals by
1322 attaching code to the existing signals and by adding extra data to the
1323 simulation objects through extensions. How to do that is not exactly
1324 documented yet, and you should look for examples in the src/plugins
1327 This section documents how the existing plugins can be used. Remember
1328 that you are very welcome to modify the plugins to fit your needs. It
1329 should be much easier than modifying the SimGrid kernel.
1331 Monitoring the host load
1332 ------------------------
1336 .. example-tab:: examples/cpp/plugin-host-load/s4u-plugin-host-load.cpp
1338 .. example-tab:: examples/c/plugin-host-load/plugin-host-load.c
1340 Monitoring the link load
1341 ------------------------
1345 .. example-tab:: examples/cpp/plugin-link-load/s4u-plugin-link-load.cpp
1347 =======================
1348 Model-Checking Examples
1349 =======================
1351 The model-checker can be used to exhaustively search for issues in the tested application. It must be activated at compile-time, but this
1352 mode is rather experimental in SimGrid (as of v3.25). We are working on it :)
1357 In this example, two actors send some data to a central server, which asserts that the messages are always received in the same order.
1358 This is wrong, and the model-checker correctly finds a counter-example to that assertion.
1362 .. example-tab:: examples/cpp/mc-failing-assert/s4u-mc-failing-assert.cpp