1 .. S4U (Simgrid for you) is the next interface of SimGrid, expected to be released with SimGrid 4.0.
3 .. Even if it is not completely rock stable yet, it may well already fit
4 .. your needs. You are welcome to try it and report any interface
5 .. glitches that you see. Be however warned that the interface may change
6 .. until the final release. You will have to adapt your code on the way.
8 .. This file follows the ReStructured syntax to be included in the
9 .. documentation, but it should remain readable directly.
15 SimGrid comes with an extensive set of examples, documented on this
16 page. Most of them only demonstrate one single feature, with some
17 larger examplars listed below.
19 The C++ examples can be found under examples/s4u while python examples
20 are in examples/python. Each such directory contains the source code (also listed
21 from this page), and the so-called tesh file containing how to call
22 the binary obtained by compiling this example and also the expected
23 output. Tesh files are used to turn each of our examples into an
24 integration test. Some examples also contain other files, on need.
26 A good way to bootstrap your own project is to copy and combine some
27 of the provided examples to constitute the skeleton of what you plan
30 ===========================
31 Actors: the Active Entities
32 ===========================
35 Starting and Stoping Actors
36 ---------------------------
38 - **Creating actors:**
39 Most actors are started from the deployment XML file, but there is other methods.
40 This example show them all.
41 |br| |cpp| `examples/s4u/actor-create/s4u-actor-create.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-create/s4u-actor-create.cpp>`_
42 |br| |py| `examples/python/actor-create/actor-create.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-create/actor-create.py>`_
45 Actors can forcefully stop other actors with the
46 :cpp:func:`void simgrid::s4u::Actor::kill(void)` or the
47 :cpp:func:`void simgrid::s4u::Actor::kill(aid_t)` methods.
48 |br| `examples/s4u/actor-kill/s4u-actor-kill.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-kill/s4u-actor-kill.cpp>`_
50 - **Controling the actor life cycle from the XML:**
51 You can specify a start time and a kill time in the deployment
53 |br| `examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp>`_
54 |br| `examples/s4u/actor-lifetime/s4u-actor-lifetime_d.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-lifetime/s4u-actor-lifetime_d.xml>`_
56 - **Daemonize actors:**
57 Some actors may be intended to simulate daemons that run in background. This example show how to transform a regular
58 actor into a daemon that will be automatically killed once the simulation is over.
59 |br| `examples/s4u/actor-daemon/s4u-actor-daemon.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-daemon/s4u-actor-daemon.cpp>`_
61 Inter-Actors Interactions
62 -------------------------
64 - **Suspend and Resume actors:**
65 Actors can be suspended and resumed during their executions thanks
66 to :cpp:func:`simgrid::s4u::Actor::suspend()` and
67 :cpp:func:`simgrid::s4u::Actor::resume()`.
68 |br| `examples/s4u/actor-suspend/s4u-actor-suspend.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-suspend/s4u-actor-suspend.cpp>`_
70 - **Migrating Actors:**
71 Actors can move or be moved from a host to another very easily.
72 |br| |cpp| `examples/s4u/actor-migration/s4u-actor-migration.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-migration/s4u-actor-migration.cpp>`_
73 :cpp:func:`simgrid::s4u::this_actor::migrate()` |cpp|
74 |br| |py| `examples/python/actor-migration/actor-migration.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-migration/actor-migration.py>`_
75 :py:func:`simgrid.this_actor.migrate()` |py|
77 - **Waiting for the termination of an actor:** (joining on it)
78 :cpp:func:`simgrid::s4u::Actor::join()` allows to block the current
79 actor until the end of the receiving actor.
80 |br| `examples/s4u/actor-join/s4u-actor-join.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-join/s4u-actor-join.cpp>`_
82 - **Yielding to other actors**.
83 The ```yield()``` function interrupts the execution of the current
84 actor, leaving a chance to the other actors that are ready to run
86 |br| |cpp| `examples/s4u/actor-yield/s4u-actor-yield.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-yield/s4u-actor-yield.cpp>`_
87 :cpp:func:`simgrid::s4u::this_actor::yield()` |cpp|
88 |br| |py| `examples/python/actor-yield/actor-yield.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/actor-yield/actor-yield.py>`_
89 :py:func:`simgrid.this_actor.yield_()` |py|
91 Traces Replay as a Workload
92 ---------------------------
94 This section details how to run trace-driven simulations. It is very
95 handy when you want to test an algorithm or protocol that only react
96 to external events. For example, many P2P protocols react to user
97 requests, but do nothing if there is no such event.
99 In such situations, you should write your protocol in C++, and separate
100 the workload that you want to play onto your protocol in a separate
101 text file. Declare a function handling each type of the events in your
102 trace, register them using :cpp:func:`xbt_replay_action_register()` in
103 your main, and then run the simulation.
105 Then, you can either have one trace file containing all your events,
106 or a file per simulated process: the former may be easier to work
107 with, but the second is more efficient on very large traces. Check
108 also the tesh files in the example directories for details.
110 - **Communication replay:**
111 Presents a set of event handlers reproducing classical communication
112 primitives (asynchronous send/receive at the moment).
113 |br| `examples/s4u/replay-comm/s4u-replay-comm.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/replay-comm/s4u-replay-comm.cpp>`_
116 Presents a set of event handlers reproducing classical I/O
117 primitives (open, read, close).
118 |br| `examples/s4u/replay-storage/s4u-replay-storage.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/replay-storage/s4u-replay-storage.cpp>`_
120 ==========================
121 Activities: what Actors do
122 ==========================
124 Communications on the Network
125 -----------------------------
127 - **Basic asynchronous communications:**
128 Illustrates how to have non-blocking communications, that are
129 communications running in the background leaving the process free
130 to do something else during their completion. The main functions
131 involved are :cpp:func:`simgrid::s4u::Mailbox::put_async()` and
132 :cpp:func:`simgrid::s4u::Comm::wait()`.
133 |br| `examples/s4u/async-wait/s4u-async-wait.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-wait/s4u-async-wait.cpp>`_
135 - **Waiting for all communications in a set:**
136 The :cpp:func:`simgrid::s4u::Comm::wait_all()` function is useful
137 when you want to block until all activities in a given set have
139 |br| `examples/s4u/async-waitall/s4u-async-waitall.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-waitall/s4u-async-waitall.cpp>`_
141 - **Waiting for the first completed communication in a set:**
142 The :cpp:func:`simgrid::s4u::Comm::wait_any()` function is useful
143 when you want to block until one activity of the set completes, no
144 matter which terminates first.
145 |br| `examples/s4u/async-waitany/s4u-async-waitany.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-waitany/s4u-async-waitany.cpp>`_
147 .. todo:: add the `ready` example here
149 .. _s4u_ex_execution:
151 Executions on the CPU
152 ---------------------
154 - **Basic execution:**
155 The computations done in your program are not reported to the
156 simulated world, unless you explicitely request the simulator to pause
157 the actor until a given amount of flops gets computed on its simulated
158 host. Some executions can be given an higher priority so that they
160 |br| |cpp| `examples/s4u/exec-basic/s4u-exec-basic.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-basic/s4u-exec-basic.cpp>`_
161 |br| |py| `examples/python/exec-basic/exec-basic.py <https://framagit.org/simgrid/simgrid/tree/master/examples/python/exec-basic/exec-basic.py>`_
163 - **Asynchronous execution:**
164 You can start asynchronous executions, just like you would fire
166 |br| `examples/s4u/exec-async/s4u-exec-async.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-async/s4u-exec-async.cpp>`_
168 - **Monitoring asynchronous executions:**
169 This example shows how to start an asynchronous execution, and
171 |br| `examples/s4u/exec-monitor/s4u-exec-monitor.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-monitor/s4u-exec-monitor.cpp>`_
173 - **Remote execution:**
174 Before its start, you can change the host on which a given execution will occur.
175 |br| `examples/s4u/exec-remote/s4u-exec-remote.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-remote/s4u-exec-remote.cpp>`_
177 - **Using Pstates on a host:**
178 Shows how define a set of pstatesfor a host in the XML, and how the current
179 pstate can be accessed/changed with :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
180 |br| `examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp>`_
181 |br| `examples/platforms/energy_platform.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/energy_platform.xml>`_
183 - **Parallel executions:**
184 These objects are convenient abstractions of parallel
185 computational kernels that span over several machines, such as a
186 PDGEM and the other ScaLAPACK routines.
187 |br| `examples/s4u/exec-ptask/s4u-exec-ptask.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-ptask/s4u-exec-ptask.cpp>`_
189 I/O on Disks and Files
190 ----------------------
192 SimGrid provides two levels of abstraction to interact with the
193 simulated storages. At the simplest level, you simply create read and
194 write actions on the storage resources.
196 - **Access to raw storage devices:**
197 This example illustrates how to simply read and write data on a
198 simulated storage resource.
199 |br| `examples/s4u/io-storage-raw/s4u-io-storage-raw.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/io-storage-raw/s4u-io-storage-raw.cpp>`_
201 The FileSystem plugin provides a more detailed view, with the
202 classical operations over files: open, move, unlink, and of course
203 read and write. The file and disk sizes are also dealt with and can
204 result in short reads and short write, as in reality.
206 - **File Management:**
207 This example illustrates the use of operations on files
208 (read, write, seek, tell, unlink, etc).
209 |br| `examples/s4u/io-file-system/s4u-io-file-system.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/io-file-system/s4u-io-file-system.cpp>`_
212 I/O operations on files can also be done in a remote fashion,
213 i.e. when the accessed disk is not mounted on the caller's host.
214 |br| `examples/s4u/io-file-remote/s4u-io-file-remote.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/io-file-remote/s4u-io-file-remote.cpp>`_
216 Classical synchronization objects
217 ---------------------------------
220 Shows how to use simgrid::s4u::Mutex synchronization objects.
221 |br| `examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp>`_
224 Shows how to use simgrid::s4u::Barrier synchronization objects.
225 |br| `examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp>`_
228 Shows how to use simgrid::s4u::Semaphore synchronization objects.
229 |br| `examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp>`_
231 =============================
232 Interacting with the Platform
233 =============================
235 - **Retrieving the list of hosts matching a given criteria:**
236 Shows how to filter the actors that match a given criteria.
237 |br| `examples/s4u/engine-filtering/s4u-engine-filtering.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/engine-filtering/s4u-engine-filtering.cpp>`_
239 - **User-defined properties:**
240 You can attach arbitrary information to most platform elements from
241 the XML file, and then interact with these values from your
242 program. Note that the changes are not written permanently on disk,
243 in the XML file nor anywhere else. They only last until the end of
246 - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
247 - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
248 - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
249 - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
251 |br| `examples/s4u/platform-properties/s4u-platform-properties.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/platform-properties/s4u-platform-properties.cpp>`_
252 |br| `examples/s4u/platform-properties/s4u-platform-properties_d.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/platform-properties/s4u-platform-properties_d.xml>`_
253 |br| `examples/platforms/prop.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/prop.xml>`_
259 - **Describing the energy profiles in the platform:**
260 This platform file contains the energy profile of each links and
261 hosts, which is necessary to get energy consumption predictions.
262 As usual, you should not trust our example, and you should strive
263 to double-check that your instanciation matches your target platform.
264 |br| `examples/platforms/energy_platform.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/energy_platform.xml>`_
266 - **Consumption due to the CPU:**
267 This example shows how to retrieve the amount of energy consumed
268 by the CPU during computations, and the impact of the pstate.
269 |br| `examples/s4u/energy-exec/s4u-energy-exec.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-exec/s4u-energy-exec.cpp>`_
271 - **Consumption due to the network:**
272 This example shows how to retrieve and display the energy consumed
273 by the network during communications.
274 |br| `examples/s4u/energy-link/s4u-energy-link.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-link/s4u-energy-link.cpp>`_
276 - **Modeling the shutdown and boot of hosts:**
277 Simple example of model of model for the energy consumption during
278 the host boot and shutdown periods.
279 |br| `examples/s4u/energy-boot/platform_boot.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-boot/platform_boot.xml>`_
280 |br| `examples/s4u/energy-boot/s4u-energy-boot.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-boot/s4u-energy-boot.cpp>`_
282 =======================
283 Tracing and Visualizing
284 =======================
286 Tracing can be activated by various configuration options which
287 are illustrated in these example. See also the
288 :ref:`full list of options related to tracing <tracing_tracing_options>`.
290 It is interesting to run the process-create example with the following
291 options to see the task executions:
293 - **Platform Tracing:**
294 This program is a toy example just loading the platform, so that
295 you can play with the platform visualization. Recommanded options:
296 ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
297 |br| `examples/s4u/trace-platform/s4u-trace-platform.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/trace-platform/s4u-trace-platform.cpp>`_
299 ========================
300 Larger SimGrid Examplars
301 ========================
303 This section contains application examples that are somewhat larger
304 than the previous examples.
307 This simple example just sends one message back and forth.
308 The tesh file laying in the directory show how to start the simulator binary, highlighting how to pass options to
309 the simulators (as detailed in Section :ref:`options`).
310 |br| `examples/s4u/app-pingpong/s4u-app-pingpong.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-pingpong/s4u-app-pingpong.cpp>`_
313 Shows how to implement a classical communication pattern, where a
314 token is exchanged along a ring to reach every participant.
315 |br| `examples/s4u/app-token-ring/s4u-app-token-ring.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-token-ring/s4u-app-token-ring.cpp>`_
317 - **Master Workers:**
318 Another good old example, where one Master process has a bunch of task to dispatch to a set of several Worker
319 processes. This example comes in two equivalent variants, one
320 where the actors are specified as simple functions (which is easier to
321 understand for newcomers) and one where the actors are specified
322 as classes (which is more powerful for the users wanting to build
323 their own projects upon the example).
324 |br| `examples/s4u/app-masterworkers/s4u-app-masterworkers-class.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-masterworkers/s4u-app-masterworkers-class.cpp>`_
325 |br| `examples/s4u/app-masterworkers/s4u-app-masterworkers-fun.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-masterworkers/s4u-app-masterworkers-fun.cpp>`_
331 Classical protocol for Peer-to-Peer data diffusion.
332 |br| `examples/s4u/app-bittorrent/s4u-bittorrent.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-bittorrent/s4u-bittorrent.cpp>`_
335 Data broadcast over a ring of processes.
336 |br| `examples/s4u/app-chainsend/s4u-app-chainsend.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-chainsend/s4u-app-chainsend.cpp>`_
338 Distributed Hash Tables (DHT)
339 -----------------------------
342 One of the most famous DHT protocol.
343 |br| `examples/s4u/dht-chord/s4u-dht-chord.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/dht-chord/s4u-dht-chord.cpp>`_
345 .. TODO:: document here the examples about plugins
351 .. |cpp| image:: /img/lang_cpp.png
355 .. |py| image:: /img/lang_python.png