1 #####################################################################
2 ########################### CORE ###################################
3 #####################################################################
5 /** \addtogroup GRAS_API
7 \section GRAS_funct Offered functionnalities
8 - <b>Communication facilities</b>: Exchanging messages between peers
9 - \ref GRAS_dd : any data which may transit on the network must be
10 described beforehand so that GRAS can handle the platform
11 heterogeneity and convert them if needed.
12 - \ref GRAS_sock : this is how to open a communication channel to
13 other processes, and retrive information about them.
14 - \ref GRAS_msg : communications are message oriented. You have to
15 describe all possible messages and their payload beforehand, and
16 can then attach callbacks to the arrival of a given kind of message.
17 - \ref GRAS_timer : this is how to program repetitive and delayed
18 tasks, not unlike cron(8) and at(1). This cannot be used to timeout
19 a function (like setitimer(2) or signal(2) games could do).
20 - <b>Virtualization</b>: Running both on top of the simulator and on
21 top of real platforms, and portability support.
22 - \ref GRAS_virtu : You naturally don't want to call the
23 gettimeofday(2) function in simulation mode since it would give
24 you the time on the host running the simulation, not the time in
25 the simulated world (you are belonging to).\n
26 This a system call virtualization layer, which also acts as a
28 - \ref GRAS_globals : The use of globals is forbidden since the
29 "processes" are threads in simulation mode. \n
30 This is how to let GRAS handle your globals properly.
31 - \ref GRAS_emul : Support to emulate code excution (ie, reporting
32 execution time into the simulator and having code sections specific
33 to simulation or to real mode).
34 - <b>Project management tools</b>: Here are some tools which may help
35 you setting up a GRAS project.\n
36 Setting up and building a GRAS application is complicated by the
37 library schizoid. The code to setup the environment differs
38 depending on whether you run on the simulator on a real platform.
39 And then, you'll have to deal with the usual distributed
40 application development difficulties.
41 - \ref GRAS_main_generation : Since processes are threads in
42 simulation mode and regular processes in the real world, GRAS does
43 generate your main functions for you.
47 \section GRAS_example Examples
49 There is for now rather few examples of GRAS, but it's better than
57 /** @defgroup GRAS_dd Data description */
58 /** @defgroup GRAS_sock Sockets */
59 /** @defgroup GRAS_msg Messages */
60 /** @defgroup GRAS_timer Timers */
62 /** @defgroup GRAS_globals Globals */
63 /** @defgroup GRAS_emul Emulation support */
64 /** @defgroup GRAS_virtu Syscalls */
68 #####################################################################
69 ######################### EXTRA PAGES ##############################
70 #####################################################################
72 ---------------------------------------------------------------------
73 --------------------- main() generation -----------------------------
74 ---------------------------------------------------------------------
76 /** \page GRAS_main_generation main() and GRAS
78 <center><table><tr><td><b>Top</b> <td> [\ref index]::[\ref GRAS_API]
79 <tr><td><b>Prev</b> <td> [\ref GRAS_emul]
80 <tr><td><b>Next</b> <td> [\ref GRAS_compile] </table></center>
83 \section GRAS_maingen_toc Table of content
85 - \ref GRAS_maingen_intro
86 - \ref GRAS_maingen_script
87 - \ref GRAS_maingen_make
91 \section GRAS_maingen_intro What's the matter with main() functions in GRAS?
93 In simulation mode, all processes are run as thread of the same process
94 while they are real processes in the real life. Unfortunately, the main
95 function of a real process must be called <tt>main</tt> while this
96 function must not use this name for threads.
98 To deal with this, you should call the main function of your processes
99 with another name (usually, the process function such as client, server,
100 or such). Then GRAS can generate the wrapper functions adapted to the
101 real and simulated modes.
103 \section GRAS_maingen_script Generating the main()s automatically
105 This is done by the gras_stub_generator program, which gets installed on
106 <tt>make install</tt> (the source resides in the tools/gras/ directory).
107 Here is the calling syntax:
108 \verbatim gras_stub_generator <project_name> <deployment_file.xml>\endverbatim
110 It parses the deployment file, searching for all the kind of processes
111 you have in your project. It then generates the following C files:
112 - a <tt>_<project_name>_<process_kind>.c</tt> file for each process kind you
114 They are used to launch your project in real life. They
115 contain a main() in charge of initializing the GRAS infrastructure and
116 launching your code afterward.
117 - a <tt>_<project_name>_simulator.c</tt> file.\n
118 This file is suited to the simulation mode. It contains a main()
119 function initializing the simulator and launching your project within.
121 For this to work, the name of process described in your deployment file
122 should match the name of a function in your code, which prototype is for
123 example: \verbatim int client(int argc,char *argv[]);\endverbatim
125 Unfortunately, all this is still partially documented. I guess I ought
126 to improve this situation somehow. In the meanwhile, check the generated
127 code and maybe also the GRAS \ref GRAS_example, sorry.
129 \section GRAS_maingen_make Integration within an hand-made Makefile
131 The easiest to set it up is to add the following chunk at the end of
132 your Makefile (or Makefile.am), putting the right values into NAME and
134 \verbatim NAME=your_project_name
135 PROCESSES=list of processes type in your project
137 $(foreach proc, $(PROCESSES), _$(NAME)_$(proc).c) _$(NAME)_simulator.c: $(NAME).c $(NAME)_deployment.xml
138 path/to/gras_stub_generator $(NAME) $(NAME)_deployment.xml >/dev/null
141 Of course, your personal millage may vary. For the \ref GRAS_ex_ping, may read:
142 \verbatim _ping_client.c _ping_server.c _ping_simulator.c: ping.c ping_deployment.xml
143 $(top_srcdir)/tools/gras/gras_stub_generator ping ping_deployment.xml >/dev/null
147 Actually, gras_stub_generator also generates some makefiles both for
148 local compilation and remote code distribution and installation. See the
149 section \ref GRAS_compile for more details.
153 ---------------------------------------------------------------------
154 ------------------------- Compiling ---------------------------------
155 ---------------------------------------------------------------------
157 /** \page GRAS_compile Compiling your GRAS project
159 <center><table><tr><td><b>Top</b> <td> [\ref index]::[\ref GRAS_API]
160 <tr><td><b>Prev</b> <td> [\ref GRAS_main_generation]
161 <tr><td><b>Next</b> <td> [\ref GRAS_ex_ping] </table></center>
163 As explained in section \ref GRAS_main_generation, the
164 gras_stub_generator tool can be used to generate the system
165 initialization code in your projet. While we were at this, this tool
166 also generates the makefiles you will need to compile your project
169 Code source deployment and remote compilation also constitutes a
170 challenging area in distributed applications development. The GRASPE
171 (GRAS Platform Expender) tool was designed to make this less painful.
173 \section GRAS_compile_toc Table of content
175 - \ref GRAS_compile_local
176 - \ref GRAS_compile_local_install
177 - \ref GRAS_compile_local_helpfiles
178 - \ref GRAS_compile_local_makefile
179 - \ref GRAS_compile_remote
183 \section GRAS_compile_local Local compilation of GRAS projects
185 \subsection GRAS_compile_local_install Installing SimGrid and GRAS
187 To compile locally a GRAS project, you first need to install SimGrid on
188 your machine. Use the --prefix flag to the configure script to specify
189 where you want to install the toolkit (refere to section \ref
190 faq_compiling for more information)
192 \subsection GRAS_compile_local_helpfiles Simulation description files
194 Then, you will probably need to write a platform description file and
195 application deployment description file to feed the simulator with. This
196 part is unfortunatelly not documented enough. Files examples can be
197 found along with the MSG \ref MSG_ex_master_slave example.
199 \note yes, both platform and application description files are portable
200 between MSG and GRAS. Actually, there depend on the SURF, not on the
201 programming environment you use.
203 For the first try, you could probably reuse the provided platform file
204 as is while you will need to adapt the application file to fit your
207 To generate new platform files, we usually use the Tiers Topology
208 Generator (ask google about it) and annotate the generated graph with
209 home-made scripts to let them fit the SURF. Those scripts live in the
210 tools/platform_generation/ directory of the distribution.
212 \subsection GRAS_compile_local_makefile Generating a Makefile usable for your project
214 From the information contained in the application description file, the
215 gras_stub_generator tool can create a Makefile which can be used to
216 seamlessly compile your project. Just go to the directory containing all
217 your project files, and type:
219 \verbatim path/to/gras_stub_generator [project_name] [application_deployment.file] >/dev/null
222 The first argument is the name of your project, such as
223 "MyLovelyApplication" while the second one is the application deployment
226 Several files get generated by this command. One C file per kind of
227 process in your project (such as "master" and "slave") plus one C file
228 for simulating your project. All those files are (or should ;) described
229 in section \ref GRAS_main_generation.
231 The most intersting file in this context is
232 [project_name].Makefile.local (you can safely ignore the others for
233 now). To use it, simply type (from your project main directory):
235 \verbatim GRAS_ROOT=/path/to/simgrid/installation make -f [project_name].Makefile.local
238 And that's it, all the binaries are built and linked against the correct
241 \section GRAS_compile_remote Distribution and remote compilation of GRAS projects
243 Actually, there is two somehow parallel ways to do so since both Arnaud
244 and Martin gave it a try. Merging both approaches is underway. As usual,
245 if you want to help, you're welcome ;)
249 #####################################################################
250 ######################### EXAMPLES #################################
251 #####################################################################
253 ---------------------------------------------------------------------
254 ------------------------- Ping Pong ---------------------------------
255 ---------------------------------------------------------------------
257 /** \page GRAS_ex_ping The classical Ping-Pong in GRAS
259 <center><table><tr><td><b>Top</b> <td> [\ref index]::[\ref GRAS_API]
260 <tr><td><b>Prev</b> <td> [\ref GRAS_compile]
261 <tr><td><b>Next</b> <td> [\ref GRAS_ex_mmrpc] </table></center>
263 This example implements the very classical ping-pong in GRAS. It
264 involves a client (initiating the ping-pong) and a server (answering to
267 It works the following way:
268 - Both the client and the server register all needed messages
269 - The server registers a callback to the ping message, which sends pong
271 - The client sends the ping message to the server, and waits for the
272 pong message as an answer.
274 This example resides in the <b>examples/gras/ping/ping.c</b> file. Yes, both
275 the code of the client and of the server is placed in the same file. See
276 the \ref GRAS_main_generation section if wondering.
278 \section GRAS_ex_ping_toc Table of contents of the ping example
279 - \ref GRAS_ex_ping_common
280 - \ref GRAS_ex_ping_initial
281 - \ref GRAS_ex_ping_register
282 - \ref GRAS_ex_ping_server
283 - \ref GRAS_ex_ping_serdata
284 - \ref GRAS_ex_ping_sercb
285 - \ref GRAS_ex_ping_sermain
286 - \ref GRAS_ex_ping_client
287 - \ref GRAS_ex_ping_climain
291 \dontinclude gras/ping/ping.c
293 \section GRAS_ex_ping_common 1) Common code to the client and the server
295 \subsection GRAS_ex_ping_initial 1.a) Initial settings
297 Let's first load the gras header and declare a logging category (see
298 \ref XBT_log for more info on logging).
303 \subsection GRAS_ex_ping_register 1.b) Register the messages
305 This function, called by both the client and the server is in charge of
306 declaring the existing messages to GRAS. Since the payload does not
307 involve any newly created types but only int, this is quite easy.
308 (to exchange more complicated types, see \ref GRAS_dd or
309 \ref GRAS_ex_mmrpc for an example).
311 \skip register_messages
314 [Back to \ref GRAS_ex_ping_toc]
316 \section GRAS_ex_ping_server 2) Server's code
318 \subsection GRAS_ex_ping_serdata 2.a) The server's globals
320 In order to ensure the communication between the "main" and the callback
321 of the server, we need to declare some globals. We have to put them in a
322 struct definition so that they can be handled properly in GRAS (see the
323 \ref GRAS_globals for more info).
328 \subsection GRAS_ex_ping_sercb 2.b) The callback to the ping message
330 Here is the callback run when the server receives any ping message (this
331 will be registered later by the server).
333 \skip server_cb_ping_handler
334 \until end_of_server_cb_ping_handler
336 \subsection GRAS_ex_ping_sermain 2.c) The "main" of the server
338 This is the "main" of the server. As explained in the \ref
339 GRAS_main_generation, you must not write any main()
340 function yourself. Instead, you just have to write a regular function
341 like this one which will act as a main.
346 [Back to \ref GRAS_ex_ping_toc]
348 \section GRAS_ex_ping_client 3) Client's code
350 \subsection GRAS_ex_ping_climain 3.a) Client's "main" function
352 This function is quite straightforward, and the inlined comments should
353 be enough to understand it.
358 [Back to \ref GRAS_ex_ping_toc]
361 ---------------------------------------------------------------------
362 -------------------------- MM RPC -----------------------------------
363 ---------------------------------------------------------------------
365 /** \page GRAS_ex_mmrpc A simple RPC for matrix multiplication
367 <center><table><tr><td><b>Top</b> <td> [\ref index]::[\ref GRAS_API]
368 <tr><td><b>Prev</b> <td> [\ref GRAS_ex_ping]
369 <tr><td><b>Next</b> <td> [\ref GRAS_ex_timer] </table></center>
371 This example implements a remote matrix multiplication. It involves a client
372 (creating the matrices and sending the multiplications requests) and a server
373 (computing the multiplication on client's behalf).
375 This example also constitutes a more advanced example of data description
376 mechanisms, since the message payload type is a bit more complicated than in
377 other examples such as the ping one (\ref GRAS_ex_ping).
379 It works the following way (not very different from the ping example):
380 - Both the client and the server register all needed messages and datatypes
381 - The server registers a callback to the "request" message, which computes
382 what needs to be and returns the result to the expeditor.
383 - The client creates two matrices, ask for their multiplication and check
386 This example resides in the <b>examples/gras/mmrpc/mmrpc.c</b> file. (See
387 the \ref GRAS_main_generation section if wondering why both the server
388 and the client live in the same source file)
390 \section GRAS_ex_mmrpc_toc Table of contents of the mmrpc example
391 - \ref GRAS_ex_mmrpc_common
392 - \ref GRAS_ex_mmrpc_initial
393 - \ref GRAS_ex_mmrpc_dataregister
394 - \ref GRAS_ex_mmrpc_msgregister
395 - \ref GRAS_ex_mmrpc_server
396 - \ref GRAS_ex_mmrpc_sercb
397 - \ref GRAS_ex_mmrpc_sermain
398 - \ref GRAS_ex_mmrpc_client
399 - \ref GRAS_ex_mmrpc_climain
403 \dontinclude gras/mmrpc/mmrpc.c
405 \section GRAS_ex_mmrpc_common 1) Common code to the client and the server
407 \subsection GRAS_ex_mmrpc_initial 1.a) Initial settings
409 Let's first load the gras header, specify the matrix size and declare a
410 logging category (see \ref XBT_log for more info on logging).
415 \subsection GRAS_ex_mmrpc_dataregister 1.b) Register the data types
417 The messages involved in this example do use structures as payload,
418 so we have to declare it to GRAS. Hopefully, this can be done easily by enclosing
419 the structure declaration within a \ref GRAS_DEFINE_TYPE macro call. It will then copy this
420 declaration into an hidden string variable, which can be automatically parsed at
421 run time. Of course, the declaration is also copied unmodified by this macro, so that it
422 gets parsed by the compiler also.
424 There is some semantic that GRAS cannot guess alone and you need to <i>annotate</i>
425 your declaration to add some. For example, the ctn pointer can be a reference to an
426 object or a whole array (in which case you also has to specify its size). This is done
427 with the GRAS_ANNOTE call. It is removed from the text passed to the compiler, but it helps
428 GRAS getting some information about the semantic of your data. Here, it says that \a ctn is an
429 array, which size is the result of the operation \a rows * \a cols (with \a rows and \a cols
430 being the other fields of the structure).
432 Please note that this annotation mechanism is not as robust and cool as this example seems to
433 imply. If you want to use it yourself, you'd better use the exact right syntax, which is
434 detailed in the \ref GRAS_dd section.
436 \skip GRAS_DEFINE_TYPE
439 \subsection GRAS_ex_mmrpc_msgregister 1.c) Register the messages
441 This function, called by both the client and the server is in charge of
442 declaring the existing messages to GRAS. Note the use of the \ref gras_datadesc_by_symbol
443 function to parse and retrieve the structure declaration which were passed to \ref GRAS_DEFINE_TYPE
446 The datatype description builded that way can then be used to build an array datatype or
449 \skip register_messages
452 [Back to \ref GRAS_ex_mmrpc_toc]
454 \section GRAS_ex_mmrpc_server 2) Server's code
456 \subsection GRAS_ex_mmrpc_sercb 2.a) The callback to the mmrpc message
458 Here is the callback run when the server receives any mmrpc message (this
459 will be registered later by the server). Note the way we get the message
460 payload. In the ping example, there was one additional level of pointer
461 indirection (see \ref GRAS_ex_ping_sercb). This is because the payload is
462 an array here (ie a pointer) whereas it is a scalar in the ping example.
464 \skip server_cb_request_handler
465 \until end_of_server_cb_request_handler
467 \subsection GRAS_ex_mmrpc_sermain 2.b) The "main" of the server
469 This is the "main" of the server. As explained in the \ref
470 GRAS_main_generation, you must not write any main()
471 function yourself. Instead, you just have to write a regular function
472 like this one which will act as a main.
477 [Back to \ref GRAS_ex_mmrpc_toc]
479 \section GRAS_ex_mmrpc_client 3) Client's code
481 \subsection GRAS_ex_mmrpc_climain 3.a) Client's "main" function
483 This function is quite straightforward, and the inlined comments should
484 be enough to understand it.
489 [Back to \ref GRAS_ex_mmrpc_toc]
492 ---------------------------------------------------------------------
493 ---------------------------- Timers ---------------------------------
494 ---------------------------------------------------------------------
496 /** \page GRAS_ex_timer Some timer games
498 <center><table><tr><td><b>Top</b> <td> [\ref index]::[\ref GRAS_API]
499 <tr><td><b>Prev</b> <td> [\ref GRAS_ex_mmrpc]
500 <tr><td> Next <td> </table></center>
502 This example fools around with the GRAS timers (\ref GRAS_timer). It is
503 mainly a regression test, since it uses almost all timer features.
505 The main program registers a repetititive task and a delayed one, and
506 then loops until the <tt>still_to_do</tt> variables of its globals reach
507 0. The delayed task set it to 5, and the repetititive one decrease it
508 each time. Here is an example of output:
509 \verbatim Initialize GRAS
511 [1108335471] Programming the repetitive_action with a frequency of 1.000000 sec
512 [1108335471] Programming the delayed_action for after 2.000000 sec
513 [1108335471] Have a rest
514 [1108335472] Canceling the delayed_action.
515 [1108335472] Re-programming the delayed_action for after 2.000000 sec
516 [1108335472] Repetitive_action has nothing to do yet
517 [1108335473] Repetitive_action has nothing to do yet
518 [1108335473] delayed_action setting globals->still_to_do to 5
519 [1108335474] repetitive_action decrementing globals->still_to_do. New value: 4
520 [1108335475] repetitive_action decrementing globals->still_to_do. New value: 3
521 [1108335476] repetitive_action decrementing globals->still_to_do. New value: 2
522 [1108335477] repetitive_action decrementing globals->still_to_do. New value: 1
523 [1108335478] repetitive_action decrementing globals->still_to_do. New value: 0
524 Exiting GRAS\endverbatim
527 - \ref GRAS_ex_timer_decl
528 - \ref GRAS_ex_timer_delay
529 - \ref GRAS_ex_timer_repeat
530 - \ref GRAS_ex_timer_main
534 \section GRAS_ex_timer_decl 1. Declarations and headers
538 \section GRAS_ex_timer_delay 2. Source code of the delayed action
539 \skip repetitive_action
540 \until end_of_repetitive_action
542 \section GRAS_ex_timer_repeat 3. Source code of the repetitive action
544 \until end_of_delayed_action
546 \section GRAS_ex_timer_main 4. Source code of main function