/*! \page bindings Bindings
\htmlinclude .bindings.doc.toc
\section bindings_binding_Java Java Binding
Simgrid-Java documentation.
\section bindings_binding_Ruby Ruby Binding
Simgrid-Ruby documentation.
\section bindings_binding_lua Lua Binding
Most of Simgrid modules require a good level in C programming, since simgrid is used to be as standard C library.
Sometime users prefer using some kind of « easy scripts » or a language easier to code with, for their works,
which avoid dealing with C errors, and sometime an important gain of time.
Besides Java Binding, Lua and Ruby bindings are available since version 3.4 of Simgrid
for MSG Module, and we are currenlty working on bindings for other modules.
\subsection bindings_binding_lua_about What is lua ?
Lua is a lightweight, reflective, imperative and functional programming language,
designed as a scripting language with extensible semantics as a primary goal (see official web site here).
\subsubsection bindings_binding_lua_why Why lua ?
Lua is a fast, portable and powerful script language, quite simple to use for developpers.
it combines procedural features with powerful data description facilities,
by using a simple, yet powerful, mechanism of tables.
Lua has a relatively simple C API compared to other scripting languages,
and accordingly it provides a robust, easy to use it.
\subsubsection bindings_binding_lua_simgrid How to use lua in Simgrid ?
Actually, the use of lua in Simgrid is quite simple, you have just to follow the same steps as coding with C in Simgird :
- Coding functions coresponding to each process
- loading the platforme/deployment XML file that describe the environment of simulation
- and … Running the Simulation.
\dontinclude lua/masterslave/master.lua
\subsection bindings_binding_lua_example_master_slave Master/Slave Example
\li Master Code
\until end_of_master
we mainly use simgrid.Task.new(task_name,computation_size,communication_size) to create our MSG Task,
then simgrid.Task.send(task,alias) to send it.
we use also simgrid.Task.name(task), to get the task's name.
\dontinclude lua/masterslave/slave.lua
\li Slave Code
\until end_of_slave
Here, we see the use of simgrid.Task.recv(alias) to receive a task with a specific alias,
this function return directly the task recevied.
\dontinclude lua/masterslave/master_slave.lua
\li Set Environmenet and run application
\until simgrid.clean()
\subsection bindings_binding_lua_example_data Exchanging Data
You can also exchange data between Process using lua. for that, you have to deal with lua task as a table,
since lua is based itself on a mechanism of tables,
so you can exchange any kind of data (tables, matrix, strings,…) between process via tasks.
\li Sender process
\verbatim
task = simgrid.Task.new("data_task",task_comp,task_comm);
task['matrix'] = my_matrix;
task['table'] = my_table;
task['message'] = "Hello from (Lua || Simgrid ) !! "
…
simgrid.Task.send(task,alias)
\endverbatim
After creating task, we associate to it various kind of data with a specific key (string in this case)
to distinguish between data variables. The receiver will use this key to access easily to datas.
\li Receiver processe
\verbatim
task = simgrid.Task.recv(alias);
sender_matrix = task['matrix'];
sender_table = task['table'];
sender_message = task['message']
...
\endverbatim
Note that in lua, both sender and receiver share the same lua task.
So that the receiver could joint data directly on the received task without sending it back.
You can find a complet example (matrix multiplication case) in the file example/lua/mult_matrix.lua.
\subsection bindings_binding_lua_example_bypass Bypass XML
maybe you wonder if there is a way to bypass the XML files,
and describe your platform directly from the code, with lua bindings it's Possible !! how ?
We provide some additional (tricky?) functions in lua that allows you to set up your own platform without using the XML files
( this can be useful for large platforms, so a simple for loop will avoid you to deal with an annoying XML File ;) )
\li set Routing mode
\verbatim
simgrid.AS.new{id="AS0",mode="Full"};
\endverbatim
\li set Hosts
\verbatim
simgrid.Host.new{id="Tremblay",power=98095000};
simgrid.Host.new{id="Jupiter",power=76296000};
simgrid.Host.new{id="Fafard",power=76296000};
simgrid.Host.new{id="Ginette",power=48492000};
simgrid.Host.new{id="Bourassa",power=48492000};
\endverbatim
we use simgrid.Host.new{id=id_host,power=power_host} to instanciate our hosts.
\li set Links
\verbatim
for i=0,11 do
simgrid.Link.new{id=i,bandwidth=252750+ i*768,latency=0.000270544+i*0.087}; -- some crazy values ;)
end
\endverbatim
we used simgrid.Link.new{id=link_id,bandwidth=bw,latency=lat} with a simple for loop to create all links we need (much easier than XML hein ?)
\li set Routes
\verbatim
-- simgrid.Route.new(src_id,des_id,links_nb,links_list)
simgrid.Route.new("Tremblay","Jupiter",1,{"1"});
simgrid.Route.new("Tremblay","Fafard",6,{"0","1","2","3","4","8"});
simgrid.Route.new("Tremblay","Ginette",3,{"3","4","5"});
simgrid.Route.new("Tremblay","Bourassa",7,{"0","1","3","2","4","6","7"});
simgrid.Route.new("Jupiter","Tremblay",1,{"1"});
simgrid.Route.new("Jupiter","Fafard",7,{"0","1","2","3","4","8","9"});
simgrid.Route.new("Jupiter","Ginette",4,{"3","4","5","9"});
simgrid.Route.new("Jupiter","Bourassa",8,{"0","1","2","3","4","6","7","9"});
...
\endverbatim
for each host you have to specify which route to choose to access to the rest of hosts connected in the grid.
\li Save platform
\verbatim
simgrid.register_platform();
\endverbatim
Don't forget to register your platform, that SURF callbacks starts their work ;)
\li set application
\verbatim
simgrid.Host.setFunction("Tremblay","Master",4,{"20","550000000","1000000","4"});
simgrid.Host.setFunction("Bourassa","Slave",1,{"0"});
simgrid.Host.setFunction("Jupiter","Slave",1,{"1"});
simgrid.Host.setFunction("Fafard","Slave",1,{"2"});
simgrid.Host.setFunction("Ginette","Slave",1,{"3"});
\endverbatim
you don't need to use a deployment XML file, thanks to simgrid.Host.setFunction(host_id,function,args_number,args_list)
you can associate functions for each host with arguments if needed .
\li
\verbatim
simgrid.register_application();
\endverbatim
Yes, Here too you have to resgiter your application before running the simulation.
the full example is distributed in the file examples/lua/master_slave_bypass.lua
*/