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
56 /** @defgroup GRAS_dd Data description */
57 /** @defgroup GRAS_sock Sockets */
58 /** @defgroup GRAS_msg Messages */
59 /** @defgroup GRAS_timer Timers */
61 /** @defgroup GRAS_globals Globals */
62 /** @defgroup GRAS_emul Emulation support */
63 /** @defgroup GRAS_virtu Syscalls */
67 #####################################################################
68 ######################### EXTRA PAGES ##############################
69 #####################################################################
71 ---------------------------------------------------------------------
72 --------------------- main() generation -----------------------------
73 ---------------------------------------------------------------------
75 /** \page GRAS_main_generation main() and GRAS
77 <center>[\ref GRAS_API]</center>
79 \section GRAS_maingen_toc Table of content
81 - \ref GRAS_maingen_intro
82 - \ref GRAS_maingen_script
83 - \ref GRAS_maingen_make
87 \section GRAS_maingen_intro What's the matter with main() functions in GRAS?
89 In simulation mode, all processes are run as thread of the same process
90 while they are real processes in the real life. Unfortunately, the main
91 function of a real process must be called <tt>main</tt> while this
92 function must not use this name for threads.
94 To deal with this, you should call the main function of your processes
95 with another name (usually, the process function such as client, server,
96 or such). Then GRAS can generate the wrapper functions adapted to the
97 real and simulated modes.
99 \section GRAS_maingen_script Generating the main()s automatically
101 This is done by the gras_stub_generator program, which gets installed on
102 <tt>make install</tt> (the source resides in the tools/gras/ directory).
103 Here is the calling syntax:
104 \verbatim gras_stub_generator <project_name> <deployment_file.xml>\endverbatim
106 It parses the deployment file, searching for all the kind of processes
107 you have in your project. It then generates the following C files:
108 - a <tt>_<project_name>_<process_kind>.c</tt> file for each process kind you
110 They are used to launch your project in real life. They
111 contain a main() in charge of initializing the GRAS infrastructure and
112 launching your code afterward.
113 - a <tt>_<project_name>_simulator.c</tt> file.\n
114 This file is suited to the simulation mode. It contains a main()
115 function initializing the simulator and launching your project within.
117 For this to work, the name of process described in your deployment file
118 should match the name of a function in your code, which prototype is for
119 example: \verbatim int client(int argc,char *argv[]);\endverbatim
121 Unfortunately, all this is still partially documented. I guess I ought
122 to improve this situation somehow. In the meanwhile, check the generated
123 code and maybe also the GRAS \ref GRAS_example, sorry.
125 \section GRAS_maingen_make Integration within an hand-made Makefile
127 The easiest to set it up is to add the following chunk at the end of
128 your Makefile (or Makefile.am), putting the right values into NAME and
130 \verbatim NAME=your_project_name
131 PROCESSES=list of processes type in your project
133 $(foreach proc, $(PROCESSES), _$(NAME)_$(proc).c) _$(NAME)_simulator.c: $(NAME).c $(NAME)_deployment.xml
134 path/to/gras_stub_generator $(NAME) $(NAME)_deployment.xml >/dev/null
137 Of course, your personal millage may vary. For the \ref GRAS_ex_ping, may read:
138 \verbatim _ping_client.c _ping_server.c _ping_simulator.c: ping.c ping_deployment.xml
139 $(top_srcdir)/tools/gras/gras_stub_generator ping ping_deployment.xml >/dev/null
143 Actually, gras_stub_generator also generates some makefiles both for
144 local compilation and remote code distribution and installation. See the
145 section \ref GRAS_compile for more details.
149 ---------------------------------------------------------------------
150 ------------------------- Compiling ---------------------------------
151 ---------------------------------------------------------------------
153 /** \page GRAS_compile Compiling your GRAS project
155 <center>[\ref GRAS_API]</center>
157 As explained in section \ref GRAS_main_generation, the
158 gras_stub_generator tool can be used to generate the system
159 initialization code in your projet. While we were at this, this tool
160 also generates the makefiles you will need to compile your project
163 Code source deployment and remote compilation also constitutes a
164 challenging area in distributed applications development. The GRASPE
165 (GRAS Platform Expender) tool was designed to make this less painful.
167 \section GRAS_compile_toc Table of content
169 - \ref GRAS_compile_local
170 - \ref GRAS_compile_local_install
171 - \ref GRAS_compile_local_helpfiles
172 - \ref GRAS_compile_local_makefile
173 - \ref GRAS_compile_remote
177 \section GRAS_compile_local Local compilation of GRAS projects
179 \subsection GRAS_compile_local_install Installing SimGrid and GRAS
181 To compile locally a GRAS project, you first need to install SimGrid on
182 your machine. Use the --prefix flag to the configure script to specify
183 where you want to install the toolkit (refere to section \ref
184 faq_compiling for more information)
186 \subsection GRAS_compile_local_helpfiles Simulation description files
188 Then, you will probably need to write a platform description file and
189 application deployment description file to feed the simulator with. This
190 part is unfortunatelly not documented enough. Files examples can be
191 found along with the MSG \ref MSG_ex_master_slave example.
193 \note yes, both platform and application description files are portable
194 between MSG and GRAS. Actually, there depend on the SURF, not on the
195 programming environment you use.
197 For the first try, you could probably reuse the provided platform file
198 as is while you will need to adapt the application file to fit your
201 To generate new platform files, we usually use the Tiers Topology
202 Generator (ask google about it) and annotate the generated graph with
203 home-made scripts to let them fit the SURF. Those scripts live in the
204 tools/platform_generation/ directory of the distribution.
206 \subsection GRAS_compile_local_makefile Generating a Makefile usable for your project
208 From the information contained in the application description file, the
209 gras_stub_generator tool can create a Makefile which can be used to
210 seamlessly compile your project. Just go to the directory containing all
211 your project files, and type:
213 \verbatim path/to/gras_stub_generator [project_name] [application_deployment.file] >/dev/null
216 The first argument is the name of your project, such as
217 "MyLovelyApplication" while the second one is the application deployment
220 Several files get generated by this command. One C file per kind of
221 process in your project (such as "master" and "slave") plus one C file
222 for simulating your project. All those files are (or should ;) described
223 in section \ref GRAS_main_generation.
225 The most intersting file in this context is
226 [project_name].Makefile.local (you can safely ignore the others for
227 now). To use it, simply type (from your project main directory):
229 \verbatim GRAS_ROOT=/path/to/simgrid/installation make -f [project_name].Makefile.local
232 And that's it, all the binaries are built and linked against the correct
235 \section GRAS_compile_remote Distribution and remote compilation of GRAS projects
237 Actually, there is two somehow parallel ways to do so since both Arnaud
238 and Martin gave it a try. Merging both approaches is underway. As usual,
239 if you want to help, you're welcome ;)
243 #####################################################################
244 ######################### EXAMPLES #################################
245 #####################################################################
247 ---------------------------------------------------------------------
248 ------------------------- Ping Pong ---------------------------------
249 ---------------------------------------------------------------------
251 /** \page GRAS_ex_ping The classical Ping-Pong in GRAS
253 <center>[\ref GRAS_API]</center>
255 This example implements the very classical ping-pong in GRAS. It
256 involves a client (initiating the ping-pong) and a server (answering to
259 It works the following way:
260 - Both the client and the server register all needed messages
261 - The server registers a callback to the ping message, which sends pong
263 - The client sends the ping message to the server, and waits for the
264 pong message as an answer.
266 This example resides in the <b>examples/gras/ping/ping.c</b> file. Yes, both
267 the code of the client and of the server is placed in the same file. See
268 the \ref GRAS_main_generation section if wondering.
270 \section GRAS_ex_ping_over Overview
271 - \ref GRAS_ex_ping_common
272 - \ref GRAS_ex_ping_initial
273 - \ref GRAS_ex_ping_register
274 - \ref GRAS_ex_ping_server
275 - \ref GRAS_ex_ping_serdata
276 - \ref GRAS_ex_ping_sercb
277 - \ref GRAS_ex_ping_sermain
278 - \ref GRAS_ex_ping_client
279 - \ref GRAS_ex_ping_climain
283 \dontinclude gras/ping/ping.c
285 \section GRAS_ex_ping_common 1) Common code to the client and the server
287 \subsection GRAS_ex_ping_initial 1.a) Initial settings
289 Let's first load the gras header and declare a logging category (see
290 \ref XBT_log for more info on logging).
295 \subsection GRAS_ex_ping_register 1.b) Register the messages
297 This function, called by both the client and the server is in charge of
298 declaring the existing messages to GRAS. Since the payload does not
299 involve any newly created types but only int, this is quite easy.
300 (to exchange more complicated types, see \ref GRAS_dd)
302 \skip register_messages
305 \section GRAS_ex_ping_server 2) Server's code
307 \subsection GRAS_ex_ping_serdata 2.a) The server's globals
309 In order to ensure the communication between the "main" and the callback
310 of the server, we need to declare some globals. We have to put them in a
311 struct definition so that they can be handled properly in GRAS (see the
312 \ref GRAS_globals for more info).
317 \subsection GRAS_ex_ping_sercb 2.b) The callback to the ping message
319 Here is the callback run when the server receives any ping message (this
320 will be registered later by the server).
322 \skip server_cb_ping_handler
323 \until end_of_server_cb_ping_handler
325 \subsection GRAS_ex_ping_sermain 2.c) The "main" of the server
327 This is the "main" of the server. As explained in the \ref
328 GRAS_main_generation, you don't have to (and shouldn't) write any main()
329 function yourself. Instead, you just have to write a regular function
330 like this one which will act as a main.
335 \section GRAS_ex_ping_client 3) Client's code
337 \subsection GRAS_ex_ping_climain 3.a) Client's "main" function
343 ---------------------------------------------------------------------
344 ---------------------------- Timers ---------------------------------
345 ---------------------------------------------------------------------
347 /** \page GRAS_ex_timer Some timer games
349 <center>[\ref GRAS_API]</center>
351 This example fools around with the GRAS timers (\ref GRAS_timer). It is
352 mainly a regression test, since it uses almost all timer features.
354 The main program registers a repetititive task and a delayed one, and
355 then loops until the <tt>still_to_do</tt> variables of its globals reach
356 0. The delayed task set it to 5, and the repetititive one decrease it
357 each time. Here is an example of output:
358 \verbatim Initialize GRAS
360 [1108335471] Programming the repetitive_action with a frequency of 1.000000 sec
361 [1108335471] Programming the delayed_action for after 2.000000 sec
362 [1108335471] Have a rest
363 [1108335472] Canceling the delayed_action.
364 [1108335472] Re-programming the delayed_action for after 2.000000 sec
365 [1108335472] Repetitive_action has nothing to do yet
366 [1108335473] Repetitive_action has nothing to do yet
367 [1108335473] delayed_action setting globals->still_to_do to 5
368 [1108335474] repetitive_action decrementing globals->still_to_do. New value: 4
369 [1108335475] repetitive_action decrementing globals->still_to_do. New value: 3
370 [1108335476] repetitive_action decrementing globals->still_to_do. New value: 2
371 [1108335477] repetitive_action decrementing globals->still_to_do. New value: 1
372 [1108335478] repetitive_action decrementing globals->still_to_do. New value: 0
373 Exiting GRAS\endverbatim
376 - \ref GRAS_ex_timer_decl
377 - \ref GRAS_ex_timer_delay
378 - \ref GRAS_ex_timer_repeat
379 - \ref GRAS_ex_timer_main
383 \section GRAS_ex_timer_decl 1. Declarations and headers
387 \section GRAS_ex_timer_delay 2. Source code of the delayed action
388 \skip repetitive_action
389 \until end_of_repetitive_action
391 \section GRAS_ex_timer_repeat 3. Source code of the repetitive action
393 \until end_of_delayed_action
395 \section GRAS_ex_timer_main 4. Source code of main function