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 Each of these examples can be found in a subdirectory under
20 examples/s4u in the archive. It 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| `examples/s4u/actor-create/s4u-actor-create.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-create/s4u-actor-create.cpp>`_
44 Actors can forcefully stop other actors with the
45 :cpp:func:`void simgrid::s4u::Actor::kill(void)` or the
46 :cpp:func:`void simgrid::s4u::Actor::kill(aid_t)` methods.
47 |br| `examples/s4u/actor-kill/s4u-actor-kill.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-kill/s4u-actor-kill.cpp>`_
49 - **Controling the actor life cycle from the XML:**
50 You can specify a start time and a kill time in the deployment
52 |br| `examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-lifetime/s4u-actor-lifetime.cpp>`_
53 |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>`_
55 - **Daemonize actors:**
56 Some actors may be intended to simulate daemons that run in background. This example show how to transform a regular
57 actor into a daemon that will be automatically killed once the simulation is over.
58 |br| `examples/s4u/actor-daemon/s4u-actor-daemon.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-daemon/s4u-actor-daemon.cpp>`_
60 Inter-Actors Interactions
61 -------------------------
63 - **Suspend and Resume actors:**
64 Actors can be suspended and resumed during their executions thanks
65 to :cpp:func:`simgrid::s4u::Actor::suspend()` and
66 :cpp:func:`simgrid::s4u::Actor::resume()`.
67 |br| `examples/s4u/actor-suspend/s4u-actor-suspend.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-suspend/s4u-actor-suspend.cpp>`_
69 - **Migrating Actors:**
70 Actors can move or be moved from a host to another with
71 :cpp:func:`simgrid::s4u::this_actor::migrate()`.
72 |br| `examples/s4u/actor-migration/s4u-actor-migration.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-migration/s4u-actor-migration.cpp>`_
74 - **Waiting for the termination of an actor:** (joining on it)
75 :cpp:func:`simgrid::s4u::Actor::join()` allows to block the current
76 actor until the end of the receiving actor.
77 |br| `examples/s4u/actor-join/s4u-actor-join.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-join/s4u-actor-join.cpp>`_
79 - **Yielding to other actor**.
80 The :cpp:func:`simgrid::s4u::this_actor::yield()` function interrupts the
81 execution of the current actor, leaving a chance to the other actors
82 that are ready to run at this timestamp.
83 |br| `examples/s4u/actor-yield/s4u-actor-yield.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/actor-yield/s4u-actor-yield.cpp>`_
85 Traces Replay as a Workload
86 ---------------------------
88 This section details how to run trace-driven simulations. It is very
89 handy when you want to test an algorithm or protocol that only react
90 to external events. For example, many P2P protocols react to user
91 requests, but do nothing if there is no such event.
93 In such situations, you should write your protocol in C++, and separate
94 the workload that you want to play onto your protocol in a separate
95 text file. Declare a function handling each type of the events in your
96 trace, register them using :cpp:func:`xbt_replay_action_register()` in
97 your main, and then run the simulation.
99 Then, you can either have one trace file containing all your events,
100 or a file per simulated process: the former may be easier to work
101 with, but the second is more efficient on very large traces. Check
102 also the tesh files in the example directories for details.
104 - **Communication replay:**
105 Presents a set of event handlers reproducing classical communication
106 primitives (asynchronous send/receive at the moment).
107 |br| `examples/s4u/replay-comm/s4u-replay-comm.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/replay-comm/s4u-replay-comm.cpp>`_
110 Presents a set of event handlers reproducing classical I/O
111 primitives (open, read, close).
112 |br| `examples/s4u/replay-storage/s4u-replay-storage.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/replay-storage/s4u-replay-storage.cpp>`_
114 ==========================
115 Activities: what Actors do
116 ==========================
118 Communications on the Network
119 -----------------------------
121 - **Basic asynchronous communications:**
122 Illustrates how to have non-blocking communications, that are
123 communications running in the background leaving the process free
124 to do something else during their completion. The main functions
125 involved are :cpp:func:`simgrid::s4u::Mailbox::put_async()` and
126 :cpp:func:`simgrid::s4u::Comm::wait()`.
127 |br| `examples/s4u/async-wait/s4u-async-wait.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-wait/s4u-async-wait.cpp>`_
129 - **Waiting for all communications in a set:**
130 The :cpp:func:`simgrid::s4u::Comm::wait_all()` function is useful
131 when you want to block until all activities in a given set have
133 |br| `examples/s4u/async-waitall/s4u-async-waitall.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-waitall/s4u-async-waitall.cpp>`_
135 - **Waiting for the first completed communication in a set:**
136 The :cpp:func:`simgrid::s4u::Comm::wait_any()` function is useful
137 when you want to block until one activity of the set completes, no
138 matter which terminates first.
139 |br| `examples/s4u/async-waitany/s4u-async-waitany.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/async-waitany/s4u-async-waitany.cpp>`_
141 .. todo:: add the `ready` example here
143 Executions on the CPU
144 ---------------------
146 - **Basic execution:**
147 The computations done in your program are not reported to the
148 simulated world, unless you explicitely request the simulator to pause
149 the actor until a given amount of flops gets computed on its simulated
150 host. Some executions can be given an higher priority so that they
152 |br| `examples/s4u/exec-basic/s4u-exec-basic.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-basic/s4u-exec-basic.cpp>`_
154 - **Asynchronous execution:**
155 You can start asynchronous executions, just like you would fire
157 |br| `examples/s4u/exec-async/s4u-exec-async.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-async/s4u-exec-async.cpp>`_
159 - **Monitoring asynchronous executions:**
160 This example shows how to start an asynchronous execution, and
162 |br| `examples/s4u/exec-monitor/s4u-exec-monitor.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-monitor/s4u-exec-monitor.cpp>`_
164 - **Remote execution:**
165 Before its start, you can change the host on which a given execution will occur.
166 |br| `examples/s4u/exec-remote/s4u-exec-remote.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-remote/s4u-exec-remote.cpp>`_
168 - **Using Pstates on a host:**
169 Shows how define a set of pstatesfor a host in the XML, and how the current
170 pstate can be accessed/changed with :cpp:func:`simgrid::s4u::Host::get_pstate_speed` and :cpp:func:`simgrid::s4u::Host::set_pstate`.
171 |br| `examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-dvfs/s4u-exec-dvfs.cpp>`_
172 |br| `examples/platforms/energy_platform.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/energy_platform.xml>`_
174 - **Parallel tasks:**
175 These objects are convenient abstractions of parallel
176 computational kernels that span over several machines.
177 |br| `examples/s4u/exec-ptask/s4u-exec-ptask.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/exec-ptask/s4u-exec-ptask.cpp>`_
179 I/O on Disks and Files
180 ----------------------
182 SimGrid provides two levels of abstraction to interact with the
183 simulated storages. At the simplest level, you simply create read and
184 write actions on the storage resources.
186 - **Access to raw storage devices:**
187 This example illustrates how to simply read and write data on a
188 simulated storage resource.
189 |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>`_
191 The FileSystem plugin provides a more detailed view, with the
192 classical operations over files: open, move, unlink, and of course
193 read and write. The file and disk sizes are also dealt with and can
194 result in short reads and short write, as in reality.
196 - **File Management:**
197 This example illustrates the use of operations on files
198 (read, write, seek, tell, unlink, etc).
199 |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>`_
202 I/O operations on files can also be done in a remote fashion,
203 i.e. when the accessed disk is not mounted on the caller's host.
204 |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>`_
206 Classical synchronization objects
207 ---------------------------------
210 Shows how to use simgrid::s4u::Mutex synchronization objects.
211 |br| `examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-mutex/s4u-synchro-mutex.cpp>`_
214 Shows how to use simgrid::s4u::Barrier synchronization objects.
215 |br| `examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-barrier/s4u-synchro-barrier.cpp>`_
218 Shows how to use simgrid::s4u::Semaphore synchronization objects.
219 |br| `examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/synchro-semaphore/s4u-synchro-semaphore.cpp>`_
221 =============================
222 Interacting with the Platform
223 =============================
225 - **Retrieving the list of hosts matching a given criteria:**
226 Shows how to filter the actors that match a given criteria.
227 |br| `examples/s4u/engine-filtering/s4u-engine-filtering.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/engine-filtering/s4u-engine-filtering.cpp>`_
229 - **User-defined properties:**
230 You can attach arbitrary information to most platform elements from
231 the XML file, and then interact with these values from your
232 program. Note that the changes are not written permanently on disk,
233 in the XML file nor anywhere else. They only last until the end of
236 - :cpp:func:`simgrid::s4u::Actor::get_property()` and :cpp:func:`simgrid::s4u::Actor::set_property()`
237 - :cpp:func:`simgrid::s4u::Host::get_property()` and :cpp:func:`simgrid::s4u::Host::set_property()`
238 - :cpp:func:`simgrid::s4u::Link::get_property()` and :cpp:func:`simgrid::s4u::Link::set_property()`
239 - :cpp:func:`simgrid::s4u::NetZone::get_property()` and :cpp:func:`simgrid::s4u::NetZone::set_property()`
241 |br| `examples/s4u/platform-properties/s4u-platform-properties.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/platform-properties/s4u-platform-properties.cpp>`_
242 |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>`_
243 |br| `examples/platforms/prop.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/prop.xml>`_
249 - **Describing the energy profiles in the platform:**
250 This platform file contains the energy profile of each links and
251 hosts, which is necessary to get energy consumption predictions.
252 As usual, you should not trust our example, and you should strive
253 to double-check that your instanciation matches your target platform.
254 |br| `examples/platforms/energy_platform.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/energy_platform.xml>`_
256 - **Consumption due to the CPU:**
257 This example shows how to retrieve the amount of energy consumed
258 by the CPU during computations, and the impact of the pstate.
259 |br| `examples/s4u/energy-exec/s4u-energy-exec.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-exec/s4u-energy-exec.cpp>`_
261 - **Consumption due to the network:**
262 This example shows how to retrieve and display the energy consumed
263 by the network during communications.
264 |br| `examples/s4u/energy-link/s4u-energy-link.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-link/s4u-energy-link.cpp>`_
266 - **Modeling the shutdown and boot of hosts:**
267 Simple example of model of model for the energy consumption during
268 the host boot and shutdown periods.
269 |br| `examples/s4u/energy-boot/platform_boot.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-boot/platform_boot.xml>`_
270 |br| `examples/s4u/energy-boot/s4u-energy-boot.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/energy-boot/s4u-energy-boot.cpp>`_
272 =======================
273 Tracing and Visualizing
274 =======================
276 Tracing can be activated by various configuration options which
277 are illustrated in these example. See also the
278 :ref:`full list of options related to tracing <tracing_tracing_options>`.
280 It is interesting to run the process-create example with the following
281 options to see the task executions:
283 - **Platform Tracing:**
284 This program is a toy example just loading the platform, so that
285 you can play with the platform visualization. Recommanded options:
286 ``--cfg=tracing:yes --cfg=tracing/categorized:yes``
287 |br| `examples/s4u/trace-platform/s4u-trace-platform.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/trace-platform/s4u-trace-platform.cpp>`_
289 ========================
290 Larger SimGrid Examplars
291 ========================
293 This section contains application examples that are somewhat larger
294 than the previous examples.
297 This simple example just sends one message back and forth.
298 The tesh file laying in the directory show how to start the simulator binary, highlighting how to pass options to
299 the simulators (as detailed in Section :ref:`options`).
300 |br| `examples/s4u/app-pingpong/s4u-app-pingpong.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-pingpong/s4u-app-pingpong.cpp>`_
303 Shows how to implement a classical communication pattern, where a
304 token is exchanged along a ring to reach every participant.
305 |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>`_
307 - **Master Workers:**
308 Another good old example, where one Master process has a bunch of task to dispatch to a set of several Worker
309 processes. This example comes in two equivalent variants, one
310 where the actors are specified as simple functions (which is easier to
311 understand for newcomers) and one where the actors are specified
312 as classes (which is more powerful for the users wanting to build
313 their own projects upon the example).
314 |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>`_
315 |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>`_
321 Classical protocol for Peer-to-Peer data diffusion.
322 |br| `examples/s4u/app-bittorrent/s4u-bittorrent.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-bittorrent/s4u-bittorrent.cpp>`_
325 Data broadcast over a ring of processes.
326 |br| `examples/s4u/app-chainsend/s4u-app-chainsend.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/app-chainsend/s4u-app-chainsend.cpp>`_
328 Distributed Hash Tables (DHT)
329 -----------------------------
332 One of the most famous DHT protocol.
333 |br| `examples/s4u/dht-chord/s4u-dht-chord.cpp <https://framagit.org/simgrid/simgrid/tree/master/examples/s4u/dht-chord/s4u-dht-chord.cpp>`_
335 .. TODO:: document here the examples about plugins