\subsubsection faq_MIA_asynchronous I want to do asynchronous communications in MSG
-Up until now, there is no asynchronous communications in MSG. However,
-you can create as many process as you want so you should be able to do
-whatever you want... I've written a queue module to help implementing
-some asynchronous communications at low cost (creating thousands of
-process only to handle communications may be problematic in term of
-performance at some point). I'll add it in the distribution asap.
+In the past (version <= 3.4), there was no function to perform asynchronous communications.
+It could easily be implemented by creating new process when needed though. Since version 3.5,
+we have introduced the following functions:
+ - MSG_task_isend()
+ - MSG_task_irecv()
+ - MSG_comm_test()
+ - MSG_comm_wait()
+ - MSG_comm_waitall()
+ - MSG_comm_waitany()
+ - MSG_comm_destroy()
+
+We refer you to the description of these functions for more details on their usage as well
+as to the exemple section on \ref MSG_ex_asynchronous_communications.
\subsubsection faq_MIA_thread_synchronization I need to synchronize my MSG processes
-You obviously cannot use pthread_mutexes of pthread_conds. The best
-thing would be to propose similar structures. Unfortunately, we
-haven't found time to do it yet. However you can try to play with
-MSG_process_suspend() and MSG_process_resume(). You can even do some
-synchronization with fake communications (using MSG_task_get(),
+You obviously cannot use pthread_mutexes of pthread_conds since we handle every
+scheduling related decision within SimGrid.
+
+In the past (version <=3.3.4) you could do it by playing with
+MSG_process_suspend() and MSG_process_resume() or with fake communications (using MSG_task_get(),
MSG_task_put() and MSG_task_Iprobe()).
+Since version 3.4, you can use classical synchronization structures. See page \ref XBT_synchro or simply check in
+include/xbt/synchro_core.h.
+
\subsubsection faq_MIA_host_load Where is the get_host_load function hidden in MSG?
There is no such thing because its semantic wouldn't be really
SimGrid behavior. In particular, you can change the default cpu and
network models...
+\subsubsection faq_simgrid_configuration_fullduplex Using Fullduplex
+
+Experimental fullduplex support is now available on the svn branch. In order to fullduple to work your platform must have two links for each pair
+of interconnected hosts, see an example here:
+\verbatim
+ simgrid_svn_sources/exemples/msg/gtnets/fullduplex-p.xml
+\endverbatim
+
+Using fullduplex support ongoing and incoming communication flows are
+treated independently for most models. The exception is the LV08 model which
+adds 0.05 of usage on the opposite direction for each new created flow. This
+can be useful to simulate some important TCP phenomena such as ack compression.
+
+Running a fullduplex example:
+\verbatim
+ cd simgrid_svn_sources/exemples/msg/gtnets
+ ./gtnets fullduplex-p.xml fullduplex-d.xml --cfg=fullduplex:1
+\endverbatim
+
+
+
+
+
\subsubsection faq_simgrid_configuration_gtnets Using GTNetS
It is possible to use a packet-level network simulator
\li set Hosts
\verbatim
- simgrid.Host.new("Tremblay",98095000);
- simgrid.Host.new("Jupiter",76296000);
- simgrid.Host.new("Fafard",76296000);
- simgrid.Host.new("Ginette",48492000);
- simgrid.Host.new("Bourassa",48492000);
+ 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(host_id,power) to instanciate our hosts.
+ 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(i,252750+ i*768,0.000270544+i*0.087); -- some crazy values ;)
+ 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(link_id,bandwidth,latency) with a simple for loop to create all links we need ( much easier than XML hein ? )
+ 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
header files with tons of __declspec(dllexport) cruft. We only need to do so
for data, but there is no public data in SimGrid so we are good.
+
