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>[\ref GRAS_API]</center>
80 \section GRAS_maingen_toc Table of content
82 - \ref GRAS_maingen_intro
83 - \ref GRAS_maingen_script
84 - \ref GRAS_maingen_make
88 \section GRAS_maingen_intro What's the matter with main() functions in GRAS?
90 In simulation mode, all processes are run as thread of the same process
91 while they are real processes in the real life. Unfortunately, the main
92 function of a real process must be called <tt>main</tt> while this
93 function must not use this name for threads.
95 To deal with this, you should call the main function of your processes
96 with another name (usually, the process function such as client, server,
97 or such). Then GRAS can generate the wrapper functions adapted to the
98 real and simulated modes.
100 \section GRAS_maingen_script Generating the main()s automatically
102 This is done by the gras_stub_generator program, which gets installed on
103 <tt>make install</tt> (the source resides in the tools/gras/ directory).
104 Here is the calling syntax:
105 \verbatim gras_stub_generator <project_name> <deployment_file.xml>\endverbatim
107 It parses the deployment file, searching for all the kind of processes
108 you have in your project. It then generates the following C files:
109 - a <tt>_<project_name>_<process_kind>.c</tt> file for each process kind you
111 They are used to launch your project in real life. They
112 contain a main() in charge of initializing the GRAS infrastructure and
113 launching your code afterward.
114 - a <tt>_<project_name>_simulator.c</tt> file.\n
115 This file is suited to the simulation mode. It contains a main()
116 function initializing the simulator and launching your project within.
118 For this to work, the name of process described in your deployment file
119 should match the name of a function in your code, which prototype is for
120 example: \verbatim int client(int argc,char *argv[]);\endverbatim
122 Unfortunately, all this is still partially documented. I guess I ought
123 to improve this situation somehow. In the meanwhile, check the generated
124 code and maybe also the GRAS \ref GRAS_example, sorry.
126 \section GRAS_maingen_make Integration within an hand-made Makefile
128 The easiest to set it up is to add the following chunk at the end of
129 your Makefile (or Makefile.am), putting the right values into NAME and
131 \verbatim NAME=your_project_name
132 PROCESSES=list of processes type in your project
134 $(foreach proc, $(PROCESSES), _$(NAME)_$(proc).c) _$(NAME)_simulator.c: $(NAME).c $(NAME)_deployment.xml
135 path/to/gras_stub_generator $(NAME) $(NAME)_deployment.xml >/dev/null
138 Of course, your personal millage may vary. For the \ref GRAS_ex_ping, may read:
139 \verbatim _ping_client.c _ping_server.c _ping_simulator.c: ping.c ping_deployment.xml
140 $(top_srcdir)/tools/gras/gras_stub_generator ping ping_deployment.xml >/dev/null
144 Actually, gras_stub_generator also generates some makefiles both for
145 local compilation and remote code distribution and installation. See the
146 section \ref GRAS_compile for more details.
150 ---------------------------------------------------------------------
151 ------------------------- Compiling ---------------------------------
152 ---------------------------------------------------------------------
154 /** \page GRAS_compile Compiling your GRAS project
156 <center>[\ref GRAS_API]</center>
158 As explained in section \ref GRAS_main_generation, the
159 gras_stub_generator tool can be used to generate the system
160 initialization code in your projet. While we were at this, this tool
161 also generates the makefiles you will need to compile your project
164 Code source deployment and remote compilation also constitutes a
165 challenging area in distributed applications development. The GRASPE
166 (GRAS Platform Expender) tool was designed to make this less painful.
168 \section GRAS_compile_toc Table of content
170 - \ref GRAS_compile_local
171 - \ref GRAS_compile_local_install
172 - \ref GRAS_compile_local_helpfiles
173 - \ref GRAS_compile_local_makefile
174 - \ref GRAS_compile_remote
178 \section GRAS_compile_local Local compilation of GRAS projects
180 \subsection GRAS_compile_local_install Installing SimGrid and GRAS
182 To compile locally a GRAS project, you first need to install SimGrid on
183 your machine. Use the --prefix flag to the configure script to specify
184 where you want to install the toolkit (refere to section \ref
185 faq_compiling for more information)
187 \subsection GRAS_compile_local_helpfiles Simulation description files
189 Then, you will probably need to write a platform description file and
190 application deployment description file to feed the simulator with. This
191 part is unfortunatelly not documented enough. Files examples can be
192 found along with the MSG \ref MSG_ex_master_slave example.
194 \note yes, both platform and application description files are portable
195 between MSG and GRAS. Actually, there depend on the SURF, not on the
196 programming environment you use.
198 For the first try, you could probably reuse the provided platform file
199 as is while you will need to adapt the application file to fit your
202 To generate new platform files, we usually use the Tiers Topology
203 Generator (ask google about it) and annotate the generated graph with
204 home-made scripts to let them fit the SURF. Those scripts live in the
205 tools/platform_generation/ directory of the distribution.
207 \subsection GRAS_compile_local_makefile Generating a Makefile usable for your project
209 From the information contained in the application description file, the
210 gras_stub_generator tool can create a Makefile which can be used to
211 seamlessly compile your project. Just go to the directory containing all
212 your project files, and type:
214 \verbatim path/to/gras_stub_generator [project_name] [application_deployment.file] >/dev/null
217 The first argument is the name of your project, such as
218 "MyLovelyApplication" while the second one is the application deployment
221 Several files get generated by this command. One C file per kind of
222 process in your project (such as "master" and "slave") plus one C file
223 for simulating your project. All those files are (or should ;) described
224 in section \ref GRAS_main_generation.
226 The most intersting file in this context is
227 [project_name].Makefile.local (you can safely ignore the others for
228 now). To use it, simply type (from your project main directory):
230 \verbatim GRAS_ROOT=/path/to/simgrid/installation make -f [project_name].Makefile.local
233 And that's it, all the binaries are built and linked against the correct
236 \section GRAS_compile_remote Distribution and remote compilation of GRAS projects
238 Actually, there is two somehow parallel ways to do so since both Arnaud
239 and Martin gave it a try. Merging both approaches is underway. As usual,
240 if you want to help, you're welcome ;)
244 #####################################################################
245 ######################### EXAMPLES #################################
246 #####################################################################
248 ---------------------------------------------------------------------
249 ------------------------- Ping Pong ---------------------------------
250 ---------------------------------------------------------------------
252 /** \page GRAS_ex_ping The classical Ping-Pong in GRAS
254 <center>[\ref GRAS_API]</center>
256 This example implements the very classical ping-pong in GRAS. It
257 involves a client (initiating the ping-pong) and a server (answering to
260 It works the following way:
261 - Both the client and the server register all needed messages
262 - The server registers a callback to the ping message, which sends pong
264 - The client sends the ping message to the server, and waits for the
265 pong message as an answer.
267 This example resides in the <b>examples/gras/ping/ping.c</b> file. Yes, both
268 the code of the client and of the server is placed in the same file. See
269 the \ref GRAS_main_generation section if wondering.
271 \section GRAS_ex_ping_toc Table of contents of the ping example
272 - \ref GRAS_ex_ping_common
273 - \ref GRAS_ex_ping_initial
274 - \ref GRAS_ex_ping_register
275 - \ref GRAS_ex_ping_server
276 - \ref GRAS_ex_ping_serdata
277 - \ref GRAS_ex_ping_sercb
278 - \ref GRAS_ex_ping_sermain
279 - \ref GRAS_ex_ping_client
280 - \ref GRAS_ex_ping_climain
284 \dontinclude gras/ping/ping.c
286 \section GRAS_ex_ping_common 1) Common code to the client and the server
288 \subsection GRAS_ex_ping_initial 1.a) Initial settings
290 Let's first load the gras header and declare a logging category (see
291 \ref XBT_log for more info on logging).
296 \subsection GRAS_ex_ping_register 1.b) Register the messages
298 This function, called by both the client and the server is in charge of
299 declaring the existing messages to GRAS. Since the payload does not
300 involve any newly created types but only int, this is quite easy.
301 (to exchange more complicated types, see \ref GRAS_dd or
302 \ref GRAS_ex_mmrpc for an example).
304 \skip register_messages
307 [Back to \ref GRAS_ex_ping_toc]
309 \section GRAS_ex_ping_server 2) Server's code
311 \subsection GRAS_ex_ping_serdata 2.a) The server's globals
313 In order to ensure the communication between the "main" and the callback
314 of the server, we need to declare some globals. We have to put them in a
315 struct definition so that they can be handled properly in GRAS (see the
316 \ref GRAS_globals for more info).
321 \subsection GRAS_ex_ping_sercb 2.b) The callback to the ping message
323 Here is the callback run when the server receives any ping message (this
324 will be registered later by the server).
326 \skip server_cb_ping_handler
327 \until end_of_server_cb_ping_handler
329 \subsection GRAS_ex_ping_sermain 2.c) The "main" of the server
331 This is the "main" of the server. As explained in the \ref
332 GRAS_main_generation, you must not write any main()
333 function yourself. Instead, you just have to write a regular function
334 like this one which will act as a main.
339 [Back to \ref GRAS_ex_ping_toc]
341 \section GRAS_ex_ping_client 3) Client's code
343 \subsection GRAS_ex_ping_climain 3.a) Client's "main" function
345 This function is quite straightforward, and the inlined comments should
346 be enough to understand it.
351 [Back to \ref GRAS_ex_ping_toc]
354 ---------------------------------------------------------------------
355 -------------------------- MM RPC -----------------------------------
356 ---------------------------------------------------------------------
358 /** \page GRAS_ex_mmrpc A simple RPC for matrix multiplication
360 <center>[\ref GRAS_API]</center>
362 This example implements a remote matrix multiplication. It involves a client
363 (creating the matrices and sending the multiplications requests) and a server
364 (computing the multiplication on client's behalf).
366 This example also constitutes a more advanced example of data description
367 mechanisms, since the message payload type is a bit more complicated than in
368 other examples such as the ping one (\ref GRAS_ex_ping).
370 It works the following way (not very different from the ping example):
371 - Both the client and the server register all needed messages and datatypes
372 - The server registers a callback to the "request" message, which computes
373 what needs to be and returns the result to the expeditor.
374 - The client creates two matrices, ask for their multiplication and check
377 This example resides in the <b>examples/gras/mmrpc/mmrpc.c</b> file. (See
378 the \ref GRAS_main_generation section if wondering why both the server
379 and the client live in the same source file)
381 \section GRAS_ex_mmrpc_toc Table of contents of the mmrpc example
382 - \ref GRAS_ex_mmrpc_common
383 - \ref GRAS_ex_mmrpc_initial
384 - \ref GRAS_ex_mmrpc_dataregister
385 - \ref GRAS_ex_mmrpc_msgregister
386 - \ref GRAS_ex_mmrpc_server
387 - \ref GRAS_ex_mmrpc_sercb
388 - \ref GRAS_ex_mmrpc_sermain
389 - \ref GRAS_ex_mmrpc_client
390 - \ref GRAS_ex_mmrpc_climain
394 \dontinclude gras/mmrpc/mmrpc.c
396 \section GRAS_ex_mmrpc_common 1) Common code to the client and the server
398 \subsection GRAS_ex_mmrpc_initial 1.a) Initial settings
400 Let's first load the gras header, specify the matrix size and declare a
401 logging category (see \ref XBT_log for more info on logging).
406 \subsection GRAS_ex_mmrpc_dataregister 1.b) Register the data types
408 The messages involved in this example do use structures as payload,
409 so we have to declare it to GRAS. Hopefully, this can be done easily by enclosing
410 the structure declaration within a GRAS_DEFINE macro call. It will then copy this
411 declaration into an hidden string variable, which can be automatically parsed at
412 run time. Of course, the declaration is also copied unmodified by this macro, so that it
413 gets parsed by the compiler also.
415 There is some semantic that GRAS cannot guess alone and you need to <i>annotate</i>
416 your declaration to add some. For example, the ctn pointer can be a reference to an
417 object or a whole array (in which case you also has to specify its size). This is done
418 with the GRAS_ANNOTE call. It is removed from the text passed to the compiler, but it helps
419 GRAS getting some information about the semantic of your data. Here, it says that \a ctn is an
420 array, which size is the result of the operation \a rows * \a cols (with \a rows and \a cols
421 being the other fields of the structure).
423 Please note that this annotation mechanism is not as robust and cool as this example seems to
424 imply. If you want to use it yourself, you'd better use the exact right syntax, which is
425 detailed in the \ref GRAS_dd section.
430 \subsection GRAS_ex_mmrpc_msgregister 1.c) Register the messages
432 This function, called by both the client and the server is in charge of
433 declaring the existing messages to GRAS. Note the use of the \ref gras_datadesc_by_symbol
434 function to parse and retrieve the structure declaration which were passed to \ref GRAS_DEFINE
437 The datatype description builded that way can then be used to build an array datatype or
440 \skip register_messages
443 [Back to \ref GRAS_ex_mmrpc_toc]
445 \section GRAS_ex_mmrpc_server 2) Server's code
447 \subsection GRAS_ex_mmrpc_sercb 2.a) The callback to the mmrpc message
449 Here is the callback run when the server receives any mmrpc message (this
450 will be registered later by the server). Note the way we get the message
451 payload. In the ping example, there was one additional level of pointer
452 indirection (see \ref GRAS_ex_ping_sercb). This is because the payload is
453 an array here (ie a pointer) whereas it is a scalar in the ping example.
455 \skip server_cb_request_handler
456 \until end_of_server_cb_request_handler
458 \subsection GRAS_ex_mmrpc_sermain 2.b) The "main" of the server
460 This is the "main" of the server. As explained in the \ref
461 GRAS_main_generation, you must not write any main()
462 function yourself. Instead, you just have to write a regular function
463 like this one which will act as a main.
468 [Back to \ref GRAS_ex_mmrpc_toc]
470 \section GRAS_ex_mmrpc_client 3) Client's code
472 \subsection GRAS_ex_mmrpc_climain 3.a) Client's "main" function
474 This function is quite straightforward, and the inlined comments should
475 be enough to understand it.
480 [Back to \ref GRAS_ex_mmrpc_toc]
483 ---------------------------------------------------------------------
484 ---------------------------- Timers ---------------------------------
485 ---------------------------------------------------------------------
487 /** \page GRAS_ex_timer Some timer games
489 <center>[\ref GRAS_API]</center>
491 This example fools around with the GRAS timers (\ref GRAS_timer). It is
492 mainly a regression test, since it uses almost all timer features.
494 The main program registers a repetititive task and a delayed one, and
495 then loops until the <tt>still_to_do</tt> variables of its globals reach
496 0. The delayed task set it to 5, and the repetititive one decrease it
497 each time. Here is an example of output:
498 \verbatim Initialize GRAS
500 [1108335471] Programming the repetitive_action with a frequency of 1.000000 sec
501 [1108335471] Programming the delayed_action for after 2.000000 sec
502 [1108335471] Have a rest
503 [1108335472] Canceling the delayed_action.
504 [1108335472] Re-programming the delayed_action for after 2.000000 sec
505 [1108335472] Repetitive_action has nothing to do yet
506 [1108335473] Repetitive_action has nothing to do yet
507 [1108335473] delayed_action setting globals->still_to_do to 5
508 [1108335474] repetitive_action decrementing globals->still_to_do. New value: 4
509 [1108335475] repetitive_action decrementing globals->still_to_do. New value: 3
510 [1108335476] repetitive_action decrementing globals->still_to_do. New value: 2
511 [1108335477] repetitive_action decrementing globals->still_to_do. New value: 1
512 [1108335478] repetitive_action decrementing globals->still_to_do. New value: 0
513 Exiting GRAS\endverbatim
516 - \ref GRAS_ex_timer_decl
517 - \ref GRAS_ex_timer_delay
518 - \ref GRAS_ex_timer_repeat
519 - \ref GRAS_ex_timer_main
523 \section GRAS_ex_timer_decl 1. Declarations and headers
527 \section GRAS_ex_timer_delay 2. Source code of the delayed action
528 \skip repetitive_action
529 \until end_of_repetitive_action
531 \section GRAS_ex_timer_repeat 3. Source code of the repetitive action
533 \until end_of_delayed_action
535 \section GRAS_ex_timer_main 4. Source code of main function