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 There is two ways of declaring timeouts in SimGrid. ``waituntil`` let you specify the deadline until when you want to wait, while
350 ``waitfor`` expects the maximal wait duration.
351 This example is very similar to the previous one, simply adding how to declare timeouts when waiting on asynchronous communication.
355 .. example-tab:: examples/cpp/comm-waituntil/s4u-comm-waituntil.cpp
357 See also :cpp:func:`simgrid::s4u::Activity::wait_until()` and :cpp:func:`simgrid::s4u::Comm::wait_for()`.
359 .. example-tab:: examples/python/comm-waituntil/comm-waituntil.py
361 See also :py:func:`simgrid.Comm.wait_until()`
363 .. _s4u_ex_mailbox_ready:
365 Checking for incoming communications
366 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
368 This example uses ``Mailbox.ready()`` to check for completed communications. When this function returns true, then at least a message
369 is arrived, so you know that ``Mailbox.get()`` will complete imediately. This is thus another way toward asynchronous communications.
373 .. example-tab:: examples/cpp/comm-ready/s4u-comm-ready.cpp
375 See also :cpp:func:`simgrid::s4u::Mailbox::ready()`.
377 .. example-tab:: examples/python/comm-ready/comm-ready.py
379 See also :py:func:`simgrid.Mailbox.ready()`
382 Suspending communications
383 ^^^^^^^^^^^^^^^^^^^^^^^^^
385 The ``suspend()`` and ``resume()`` functions block the progression of a given communication for a while and then unblock it.
386 ``is_suspended()`` returns whether that activity is currently blocked or not.
390 .. example-tab:: examples/cpp/comm-suspend/s4u-comm-suspend.cpp
392 See also :cpp:func:`simgrid::s4u::Activity::suspend()`
393 :cpp:func:`simgrid::s4u::Activity::resume()` and
394 :cpp:func:`simgrid::s4u::Activity::is_suspended()`.
396 .. example-tab:: examples/python/comm-suspend/comm-suspend.py
398 See also :py:func:`simgrid.Comm::suspend()` and
399 :py:func:`simgrid.Comm.resume()`.
401 Waiting for all communications in a set
402 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
404 The ``wait_all()`` function is useful when you want to block until all activities in a given set have been completed.
408 .. example-tab:: examples/cpp/comm-waitall/s4u-comm-waitall.cpp
410 See also :cpp:func:`simgrid::s4u::Comm::wait_all()`.
412 .. example-tab:: examples/python/comm-waitall/comm-waitall.py
414 See also :py:func:`simgrid.Comm.wait_all()`.
416 .. example-tab:: examples/c/comm-waitall/comm-waitall.c
418 See also :cpp:func:`sg_comm_wait_all()`.
420 Waiting for the first completed communication in a set
421 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
423 The ``wait_any()`` blocks until one activity of the set completes, no matter which terminates first.
427 .. example-tab:: examples/cpp/comm-waitany/s4u-comm-waitany.cpp
429 See also :cpp:func:`simgrid::s4u::Comm::wait_any()`.
431 .. example-tab:: examples/python/comm-waitany/comm-waitany.py
433 See also :py:func:`simgrid.Comm.wait_any()`.
435 .. example-tab:: examples/c/comm-waitany/comm-waitany.c
437 See also :cpp:func:`sg_comm_wait_any`.
439 Testing whether at least one communication completed
440 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
442 The ``test_any()`` returns whether at least one activity of the set has completed, or -1.
446 .. example-tab:: examples/cpp/comm-testany/s4u-comm-testany.cpp
448 See also :cpp:func:`simgrid::s4u::Comm::test_any()`.
450 .. example-tab:: examples/python/comm-testany/comm-testany.py
452 See also :py:func:`simgrid.Comm.test_any()`.
454 .. _s4u_ex_comm_failure:
456 Dealing with network failures
457 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
459 This examples shows how to survive to network exceptions that occur when a link is turned off, or when the actor with whom
460 you communicate fails because its host is turned off. In this case, any blocking operation such as ``put``, ``get`` or
461 ``wait`` will raise an exception that you can catch and react to. See also :ref:`howto_churn`,
462 :ref:`this example <s4u_ex_platform_state_profile>` on how to attach a state profile to hosts and
463 :ref:`that example <s4u_ex_exec_failure>` on how to react to host failures.
467 .. example-tab:: examples/cpp/comm-failure/s4u-comm-failure.cpp
469 .. example-tab:: examples/python/comm-failure/comm-failure.py
471 .. _s4u_ex_comm_host2host:
473 Direct host-to-host communication
474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
476 This example demonstrates the direct communication mechanism, that allows to send data from one host to another without
477 relying on the mailbox mechanism.
481 .. example-tab:: examples/cpp/comm-host2host/s4u-comm-host2host.cpp
483 See also :cpp:func:`simgrid::s4u::Comm::sendto_init()` and :cpp:func:`simgrid::s4u::Comm::sendto_async()`.
485 .. example-tab:: examples/python/comm-host2host/comm-host2host.py
487 See also :py:func:`simgrid.Comm.sendto_init()` and :py:func:`simgrid.Comm.sendto_async()`.
489 .. _s4u_ex_execution:
491 Executions on the CPU
492 ---------------------
497 The computations done in your program are not reported to the
498 simulated world unless you explicitly request the simulator to pause
499 the actor until a given amount of flops gets computed on its simulated
500 host. Some executions can be given a higher priority so that they
505 .. example-tab:: examples/cpp/exec-basic/s4u-exec-basic.cpp
507 See also :cpp:func:`void simgrid::s4u::this_actor::execute(double)`
508 and :cpp:func:`void simgrid::s4u::this_actor::execute(double, double)`.
510 .. example-tab:: examples/python/exec-basic/exec-basic.py
512 See also :py:func:`simgrid.this_actor.execute()`.
514 .. example-tab:: examples/c/exec-basic/exec-basic.c
516 See also :cpp:func:`void sg_actor_execute(double)`
517 and :cpp:func:`void sg_actor_execute_with_priority(double, double)`.
519 Asynchronous execution
520 ^^^^^^^^^^^^^^^^^^^^^^
522 You can start asynchronous executions, just like you would fire background threads.
526 .. example-tab:: examples/cpp/exec-async/s4u-exec-async.cpp
528 See also :cpp:func:`simgrid::s4u::this_actor::exec_init()`,
529 :cpp:func:`simgrid::s4u::Activity::start()`,
530 :cpp:func:`simgrid::s4u::Activity::wait()`,
531 :cpp:func:`simgrid::s4u::Activity::get_remaining()`,
532 :cpp:func:`simgrid::s4u::Exec::get_remaining_ratio()`,
533 :cpp:func:`simgrid::s4u::this_actor::exec_async()` and
534 :cpp:func:`simgrid::s4u::Activity::cancel()`.
536 .. example-tab:: examples/python/exec-async/exec-async.py
538 See also :py:func:`simgrid.this_actor.exec_init()`,
539 :py:func:`simgrid.Exec.start()`,
540 :py:func:`simgrid.Exec.wait()`,
541 :py:attr:`simgrid.Exec.remaining`,
542 :py:attr:`simgrid.Exec.remaining_ratio`,
543 :py:func:`simgrid.this_actor.exec_async()` and
544 :py:func:`simgrid.Exec.cancel()`.
546 .. example-tab:: examples/c/exec-async/exec-async.c
548 See also :cpp:func:`sg_actor_exec_init()`,
549 :cpp:func:`sg_exec_start()`,
550 :cpp:func:`sg_exec_wait()`,
551 :cpp:func:`sg_exec_get_remaining()`,
552 :cpp:func:`sg_exec_get_remaining_ratio()`,
553 :cpp:func:`sg_actor_exec_async()` and
554 :cpp:func:`sg_exec_cancel()`,
559 You can start executions on remote hosts, or even change the host on which they occur during their execution.
560 This is naturally not very realistic, but it's something handy to have.
564 .. example-tab:: examples/cpp/exec-remote/s4u-exec-remote.cpp
566 See also :cpp:func:`simgrid::s4u::Exec::set_host()`.
568 .. example-tab:: examples/python/exec-remote/exec-remote.py
570 See also :py:attr:`simgrid.Exec.host`.
572 .. example-tab:: examples/c/exec-remote/exec-remote.c
574 See also :cpp:func:`sg_exec_set_host()`.
581 These objects are convenient abstractions of parallel
582 computational kernels that span over several machines, such as a
583 PDGEM and the other ScaLAPACK routines. Note that this only works
584 with the "ptask_L07" host model (``--cfg=host/model:ptask_L07``).
586 This example demonstrates several kinds of parallel tasks: regular
587 ones, communication-only (without computation), computation-only
588 (without communication), synchronization-only (neither
589 communication nor computation). It also shows how to reconfigure a
590 task after its start, to change the number of hosts it runs onto.
591 This allows simulating malleable tasks.
595 .. example-tab:: examples/cpp/exec-ptask/s4u-exec-ptask.cpp
597 See also :cpp:func:`simgrid::s4u::this_actor::parallel_execute()`.
599 .. example-tab:: examples/python/exec-ptask/exec-ptask.py
601 See also :ref:`simgrid.this_actor.parallel_execute()`
603 Ptasks play well with the host energy plugin, as shown in this example.
604 There is not much new compared to the above ptask example or the
605 :ref:`examples about energy <s4u_ex_energy>`. It just works.
609 .. example-tab:: examples/cpp/energy-exec-ptask/s4u-energy-exec-ptask.cpp
611 .. example-tab:: examples/c/energy-exec-ptask/energy-exec-ptask.c
613 .. _s4u_ex_exec_failure:
615 Dealing with host failures
616 ^^^^^^^^^^^^^^^^^^^^^^^^^^
618 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
619 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
620 failing hosts however, any blocking operation such as ``exec`` or ``wait`` will raise an exception that you can catch and react to. See also
622 :ref:`this example <s4u_ex_platform_state_profile>` on how to attach a state profile to hosts, and
623 :ref:`that example <s4u_ex_comm_failure>` on how to react to networ failures.
627 .. example-tab:: examples/cpp/exec-failure/s4u-exec-failure.cpp
634 This example shows how to define a set of pstates in the XML. The current pstate
635 of a host can then be accessed and changed from the program.
639 .. example-tab:: examples/cpp/exec-dvfs/s4u-exec-dvfs.cpp
641 See also :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
643 .. example-tab:: examples/c/exec-dvfs/exec-dvfs.c
645 See also :cpp:func:`sg_host_get_pstate_speed` and :cpp:func:`sg_host_set_pstate`.
647 .. example-tab:: examples/python/exec-dvfs/exec-dvfs.py
649 See also :py:func:`simgrid.Host.pstate_speed()` and :py:attr:`simgrid.Host.pstate`.
651 .. example-tab:: examples/platforms/energy_platform.xml
653 The important parts are in the :ref:`pf_tag_host` tag. The ``pstate`` attribute is the initial pstate while the ``speed`` attribute must
654 be a comma-separated list of values: the speed at each pstate. This platform file also describes the ``wattage_per_state`` and
655 ``wattage_off`` properties, that are used by the :ref:`plugin_host_energy` plugin.
659 I/O on Disks and Files
660 ----------------------
662 SimGrid provides two levels of abstraction to interact with the
663 simulated disks. At the simplest level, you simply create read and
664 write actions on the disk resources.
666 Access to raw disk devices
667 ^^^^^^^^^^^^^^^^^^^^^^^^^^
669 This example illustrates how to simply read and write data on a simulated disk resource.
673 .. example-tab:: examples/cpp/io-disk-raw/s4u-io-disk-raw.cpp
675 .. example-tab:: examples/c/io-disk-raw/io-disk-raw.c
677 .. example-tab:: examples/platforms/hosts_with_disks.xml
679 This shows how to declare disks in XML.
681 Asynchronous raw accesses
682 ^^^^^^^^^^^^^^^^^^^^^^^^^
684 As most other activities, raw IO accesses can be used asynchronously, as illustrated in this example.
688 .. example-tab:: examples/cpp/io-async/s4u-io-async.cpp
693 The FileSystem plugin provides a more detailed view, with the
694 classical operations over files: open, move, unlink, and of course,
695 read and write. The file and disk sizes are also dealt with and can
696 result in short reads and short writes, as in reality.
698 - **File Management:**
699 This example illustrates the use of operations on files
700 (read, write, seek, tell, unlink, etc).
704 .. example-tab:: examples/cpp/io-file-system/s4u-io-file-system.cpp
707 I/O operations on files can also be done remotely,
708 i.e. when the accessed disk is not mounted on the caller's host.
712 .. example-tab:: examples/cpp/io-file-remote/s4u-io-file-remote.cpp
714 .. example-tab:: examples/c/io-file-remote/io-file-remote.c
718 Classical synchronization objects
719 ---------------------------------
724 Shows how to use :cpp:type:`simgrid::s4u::Barrier` synchronization objects.
728 .. example-tab:: examples/cpp/synchro-barrier/s4u-synchro-barrier.cpp
730 .. example-tab:: examples/python/synchro-barrier/synchro-barrier.py
732 Condition variable: basic usage
733 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
735 Shows how to use :cpp:type:`simgrid::s4u::ConditionVariable` synchronization objects.
739 .. example-tab:: examples/cpp/synchro-condition-variable/s4u-synchro-condition-variable.cpp
741 Condition variable: timeouts
742 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
744 Shows how to specify timeouts when blocking on condition variables.
748 .. example-tab:: examples/cpp/synchro-condition-variable-waituntil/s4u-synchro-condition-variable-waituntil.cpp
753 Shows how to use :cpp:type:`simgrid::s4u::Mutex` synchronization objects.
757 .. example-tab:: examples/cpp/synchro-mutex/s4u-synchro-mutex.cpp
759 .. example-tab:: examples/python/synchro-mutex/synchro-mutex.py
764 Shows how to use :cpp:type:`simgrid::s4u::Semaphore` synchronization objects.
768 .. example-tab:: examples/cpp/synchro-semaphore/s4u-synchro-semaphore.cpp
770 .. example-tab:: examples/python/synchro-semaphore/synchro-semaphore.py
772 .. example-tab:: examples/c/synchro-semaphore/synchro-semaphore.c
774 =============================
775 Interacting with the Platform
776 =============================
778 User-defined properties
779 -----------------------
781 You can attach arbitrary information to most platform elements from the XML file, and then interact with these values from your
782 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
787 .. example-tab:: examples/cpp/platform-properties/s4u-platform-properties.cpp
789 - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
790 - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
791 - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
792 - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
794 .. example-tab:: examples/c/platform-properties/platform-properties.c
796 - :cpp:func:`sg_actor_get_property_value()`
797 - :cpp:func:`sg_host_get_property_value()` and :cpp:func:sg_host_set_property_value()`
798 - :cpp:func:`sg_zone_get_property_value()` and :cpp:func:`sg_zone_set_property_value()`
804 .. showfile:: examples/platforms/prop.xml
810 Retrieving the netzones matching given criteria
811 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
813 Shows how to filter the cluster netzones.
817 .. example-tab:: examples/cpp/routing-get-clusters/s4u-routing-get-clusters.cpp
819 Retrieving the list of hosts matching given criteria
820 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
822 Shows how to filter the actors that match given criteria.
826 .. example-tab:: examples/cpp/engine-filtering/s4u-engine-filtering.cpp
831 .. _s4u_ex_platform_state_profile:
833 Specifying state profiles
834 ^^^^^^^^^^^^^^^^^^^^^^^^^
836 Shows how to specify when the resources must be turned off and on again, and how to react to such
837 failures in your code. See also :ref:`howto_churn`,
838 :ref:`this example <s4u_ex_comm_failure>` on how to react to communication failures, and
839 :ref:`that example <s4u_ex_exec_failure>` on how to react to host failures.
843 .. example-tab:: examples/cpp/platform-failures/s4u-platform-failures.cpp
845 .. example-tab:: examples/c/platform-failures/platform-failures.c
847 .. example-tab:: examples/python/platform-failures/platform-failures.py
851 .. showfile:: examples/platforms/small_platform_failures.xml
854 .. showfile:: examples/platforms/profiles/jupiter_state.profile
856 .. showfile:: examples/platforms/profiles/fafard_state.profile
858 Specifying speed profiles
859 ^^^^^^^^^^^^^^^^^^^^^^^^^
861 Shows how to specify an external load to resources, variating their peak speed over time.
865 .. example-tab:: examples/cpp/platform-profile/s4u-platform-profile.cpp
867 .. example-tab:: examples/python/platform-profile/platform-profile.py
871 .. showfile:: examples/platforms/small_platform_profile.xml
874 .. showfile:: examples/platforms/profiles/jupiter_speed.profile
876 .. showfile:: examples/platforms/profiles/link1_bandwidth.profile
878 .. showfile:: examples/platforms/profiles/link1_latency.profile
880 Modifying the platform
881 ----------------------
883 Serializing communications
884 ^^^^^^^^^^^^^^^^^^^^^^^^^^
886 This example shows how to limit the amount of communications going through a given link.
887 It is very similar to the other asynchronous communication examples, but messages get serialized by the platform.
888 Without this call to ``Link::set_concurrency_limit(2)``, all messages would be received at the exact same timestamp since
889 they are initiated at the same instant and are of the same size. But with this extra configuration to the link, at most 2
890 messages can travel through the link at the same time.
894 .. example-tab:: examples/cpp/platform-comm-serialize/s4u-platform-comm-serialize.cpp
896 See also :cpp:func:`simgrid::s4u::Link::set_concurrency_limit()`.
898 .. example-tab:: examples/python/platform-comm-serialize/platform-comm-serialize.py
900 See also :py:func:`simgrid.Link.set_concurrency_limit()`.
911 Describing the energy profiles in the platform
912 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
914 The first platform file contains the energy profile of each link and host for a wired network, which is necessary to get energy consumption
915 predictions. The second platform file is the equivalent for a wireless network. As usual, you should not trust our example, and you should
916 strive to double-check that your instantiation matches your target platform.
922 .. showfile:: examples/platforms/energy_platform.xml
925 .. showfile:: examples/platforms/wifi_energy.xml
931 CPU energy consumption
932 ^^^^^^^^^^^^^^^^^^^^^^
934 This example shows how to retrieve the amount of energy consumed by the CPU during computations, and the impact of the pstate.
938 .. example-tab:: examples/cpp/energy-exec/s4u-energy-exec.cpp
940 .. example-tab:: examples/c/energy-exec/energy-exec.c
942 Virtual machines consumption
943 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
945 This example is very similar to the previous one, adding VMs to the picture.
949 .. example-tab:: examples/cpp/energy-vm/s4u-energy-vm.cpp
951 .. example-tab:: examples/c/energy-vm/energy-vm.c
953 Wired network energy consumption
954 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
956 This example shows how to retrieve and display the energy consumed by the wired network during communications.
960 .. example-tab:: examples/cpp/energy-link/s4u-energy-link.cpp
962 WiFi network energy consumption
963 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
965 This example shows how to retrieve and display the energy consumed by the wireless network during communications.
969 .. example-tab:: examples/cpp/energy-wifi/s4u-energy-wifi.cpp
971 Modeling the shutdown and boot of hosts
972 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
974 Simple example of a model for the energy consumption during the host boot and shutdown periods.
978 .. example-tab:: examples/platforms/energy_boot.xml
980 .. example-tab:: examples/cpp/energy-boot/s4u-energy-boot.cpp
982 =======================
983 Tracing and Visualizing
984 =======================
986 Tracing can be activated by various configuration options which are illustrated in these examples. See also the
987 :ref:`full list of options related to tracing <tracing_tracing_options>`.
988 The following introduces some option sets of interest that you may want to pass to your simulators.
991 These tracing examples should be integrated in the examples to not duplicate the C++ files.
992 A full command line to see the result in the right tool (vite/FrameSoc) should be given along with some screenshots.
1000 This program is a toy example just loading the platform so that you can play with the platform visualization. Recommended options:
1001 ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
1005 .. example-tab:: examples/cpp/trace-platform/s4u-trace-platform.cpp
1010 This example declares several tracing categories that are used to
1011 classify its tasks. When the program is executed, the tracing mechanism
1012 registers the resource utilization of hosts and links according to these
1013 categories. Recommended options:
1014 ``--cfg=tracing:yes --cfg=tracing/categorized:yes --cfg=tracing/uncategorized:yes``
1018 .. example-tab:: examples/cpp/trace-categories/s4u-trace-categories.cpp
1020 Master Workers tracing
1021 ^^^^^^^^^^^^^^^^^^^^^^
1023 This is an augmented version of our basic master/worker example using
1024 several tracing features. It traces resource usage, sorted out in several
1025 categories; Trace marks and user variables are also used. Recommended
1026 options: ``--cfg=tracing/categorized:yes --cfg=tracing/uncategorized:yes``
1030 .. example-tab:: examples/cpp/trace-masterworkers/s4u-trace-masterworkers.cpp
1032 .. example-tab:: examples/python/app-masterworkers/app-masterworkers.py
1034 Process migration tracing
1035 ^^^^^^^^^^^^^^^^^^^^^^^^^
1037 This version is enhanced so that the process migrations can be displayed
1038 as arrows in a Gantt-chart visualization. Recommended options to that
1039 extend: ``--cfg=tracing:yes --cfg=tracing/actor:yes``
1043 .. example-tab:: examples/cpp/trace-process-migration/s4u-trace-process-migration.cpp
1045 Tracing user variables
1046 ----------------------
1048 You can also attach your own variables to any resource described in the platform
1049 file. The following examples illustrate this feature. They have to be run with
1050 the following options: ``--cfg=tracing:yes --cfg=tracing/platform:yes``
1052 Attaching variables to Hosts
1053 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1057 .. example-tab:: examples/cpp/trace-host-user-variables/s4u-trace-host-user-variables.cpp
1059 Attaching variables to Links
1060 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1062 The tricky part is that you have to know the name of the link you want to enhance with a variable.
1066 .. example-tab:: examples/cpp/trace-link-user-variables/s4u-trace-link-user-variables.cpp
1068 Attaching variables to network routes
1069 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1071 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
1072 knowing the name of each specific link.
1076 .. example-tab:: examples/cpp/trace-route-user-variables/s4u-trace-route-user-variables.cpp
1078 ========================
1079 Larger SimGrid Exemplars
1080 ========================
1082 This section contains application examples that are somewhat larger than the previous examples.
1090 Shows how to implement a classical communication pattern, where a token is exchanged along a ring to reach every participant.
1094 .. example-tab:: examples/cpp/app-token-ring/s4u-app-token-ring.cpp
1096 .. example-tab:: examples/c/app-token-ring/app-token-ring.c
1101 Another good old example, where one Master actor has a bunch of tasks to dispatch to a set of several Worker actors.
1102 This example is used in the :ref:`SimGrid tutorial <usecase_simalgo>`.
1108 This example comes in two equivalent variants, one where the actors
1109 are specified as simple functions (which is easier to understand for
1110 newcomers) and one where the actors are specified as classes (which is
1111 more powerful for the users wanting to build their own projects upon
1114 .. showfile:: examples/cpp/app-masterworkers/s4u-app-masterworkers-class.cpp
1117 .. showfile:: examples/cpp/app-masterworkers/s4u-app-masterworkers-fun.cpp
1122 .. showfile:: examples/c/app-masterworker/app-masterworker.c
1125 .. example-tab:: examples/python/app-masterworkers/app-masterworkers.py
1133 Classical protocol for Peer-to-Peer data diffusion.
1139 .. showfile:: examples/cpp/app-bittorrent/s4u-bittorrent.cpp
1142 .. showfile:: examples/cpp/app-bittorrent/s4u-peer.cpp
1145 .. showfile:: examples/cpp/app-bittorrent/s4u-tracker.cpp
1150 .. showfile:: examples/c/app-bittorrent/app-bittorrent.c
1153 .. showfile:: examples/c/app-bittorrent/bittorrent-peer.c
1156 .. showfile:: examples/c/app-bittorrent/tracker.c
1162 Data broadcast over a ring of processes.
1166 .. example-tab:: examples/cpp/app-chainsend/s4u-app-chainsend.cpp
1170 .. showfile:: examples/c/app-chainsend/chainsend.c
1173 .. showfile:: examples/c/app-chainsend/broadcaster.c
1176 .. showfile:: examples/c/app-chainsend/peer.c
1179 Distributed Hash Tables (DHT)
1180 -----------------------------
1185 One of the most famous DHT protocol.
1191 .. showfile:: examples/cpp/dht-chord/s4u-dht-chord.cpp
1194 .. showfile:: examples/cpp/dht-chord/s4u-dht-chord-node.cpp
1200 Another well-known DHT protocol.
1206 .. showfile:: examples/cpp/dht-kademlia/s4u-dht-kademlia.cpp
1209 .. showfile:: examples/cpp/dht-kademlia/routing_table.cpp
1212 .. showfile:: examples/cpp/dht-kademlia/answer.cpp
1215 .. showfile:: examples/cpp/dht-kademlia/node.cpp
1220 .. showfile:: examples/c/dht-kademlia/dht-kademlia.c
1223 .. showfile:: examples/c/dht-kademlia/routing_table.c
1226 .. showfile:: examples/c/dht-kademlia/answer.c
1229 .. showfile:: examples/c/dht-kademlia/message.c
1232 .. showfile:: examples/c/dht-kademlia/node.c
1238 Yet another well-known DHT protocol.
1242 .. example-tab:: examples/c/dht-pastry/dht-pastry.c
1252 This example starts some computations both on PMs and VMs and migrates some VMs around.
1256 .. example-tab:: examples/cpp/cloud-simple/s4u-cloud-simple.cpp
1258 .. example-tab:: examples/c/cloud-simple/cloud-simple.c
1263 This example shows how to migrate VMs between PMs.
1267 .. example-tab:: examples/cpp/cloud-migration/s4u-cloud-migration.cpp
1269 .. example-tab:: examples/c/cloud-migration/cloud-migration.c
1271 =======================
1272 Model-Related Examples
1273 =======================
1278 This simple ping-pong example demonstrates how to use the bindings to the Network
1279 Simulator. The most interesting is probably not the C++ files since
1280 they are unchanged from the other simulations, but the associated files,
1281 such as the platform file to see how to declare a platform to be used
1282 with the ns-3 bindings of SimGrid and the tesh file to see how to
1283 start a simulation in these settings.
1287 .. example-tab:: examples/cpp/network-ns3/s4u-network-ns3.cpp
1293 .. showfile:: examples/platforms/small_platform_one_link_routes.xml
1299 This demonstrates how to declare a wifi zone in your platform and
1300 how to use it in your simulation. For that, you should have a link
1301 whose sharing policy is set to `WIFI`. Such links can have more
1302 than one bandwidth value (separated by commas), corresponding to
1303 the several SNR level of your wifi link.
1305 In this case, SimGrid automatically switches to validated
1306 performance models of wifi networks, where the time is shared
1307 between users instead of the bandwidth for wired links (the
1308 corresponding publication is currently being written).
1310 If your wifi link provides more than one SNR level, you can switch
1311 the level of a given host using
1312 :cpp:func:`simgrid::s4u::Link::set_host_wifi_rate`. By default,
1313 the first level is used.
1317 .. example-tab:: examples/cpp/network-wifi/s4u-network-wifi.cpp
1323 .. showfile:: examples/platforms/wifi.xml
1332 It is possible to extend SimGrid without modifying its internals by
1333 attaching code to the existing signals and by adding extra data to the
1334 simulation objects through extensions. How to do that is not exactly
1335 documented yet, and you should look for examples in the src/plugins
1338 This section documents how the existing plugins can be used. Remember
1339 that you are very welcome to modify the plugins to fit your needs. It
1340 should be much easier than modifying the SimGrid kernel.
1342 Monitoring the host load
1343 ------------------------
1347 .. example-tab:: examples/cpp/plugin-host-load/s4u-plugin-host-load.cpp
1349 .. example-tab:: examples/c/plugin-host-load/plugin-host-load.c
1351 Monitoring the link load
1352 ------------------------
1356 .. example-tab:: examples/cpp/plugin-link-load/s4u-plugin-link-load.cpp
1358 =======================
1359 Model-Checking Examples
1360 =======================
1362 The model-checker can be used to exhaustively search for issues in the tested application. It must be activated at compile-time, but this
1363 mode is rather experimental in SimGrid (as of v3.25). We are working on it :)
1368 In this example, two actors send some data to a central server, which asserts that the messages are always received in the same order.
1369 This is wrong, and the model-checker correctly finds a counter-example to that assertion.
1373 .. example-tab:: examples/cpp/mc-failing-assert/s4u-mc-failing-assert.cpp