[erlang-questions] ei_send multithreaded problem

lang er <>
Thu Mar 1 15:48:28 CET 2007


Hi Eduardo,

After the previus modification failed, I also modify code as what you
give.This time the normal status last for more time than before,
but eventually (about one hours later), I get this error again.

The data transfered between Cnode and Erlang process is large(240k/second).
I also run this program on a different machine, and use small
data (4k/second), it just work fine for more than 24 hours(and I exit it
manually).


Thanks!

BR
James
2007/3/1, Eduardo Figoli (INS) <>:
>
>  Try
>
> >  EnterCriticalSection(&CriticalSection);
>
> > erlang_pid *channel_connection_pid = (erlang_pid *)dwUser;
> >  ei_x_buff xbuf;
> >  ei_x_new_with_version(&xbuf);
> >  ei_x_encode_tuple_header(&xbuf,2);
> >  ei_x_encode_atom(&xbuf,"data");
> >  ei_x_encode_binary(&xbuf, pBuffer, dwBufSize);
> >  ei_send(acceptedFd, channel_connection_pid, xbuf.buff,xbuf.index);
> >  ei_x_free(&xbuf);
> >  LeaveCriticalSection(&CriticalSection);
>
>
>
>
> Regards Eduardo
>
>
>  ------------------------------
>
> *De:* lang er [mailto:]
> *Enviado el:* Jueves, 01 de Marzo de 2007 05:41 a.m.
> *Para:* Eduardo Figoli (INS)
> *CC:* 
> *Asunto:* Re: [erlang-questions] ei_send multithreaded problem
>
>
>
> Hi, Eduardo
>
>
> I add a critical section before and after ei_send,now the code look like
> this:
>
>
> > erlang_pid *channel_connection_pid = (erlang_pid *)dwUser;
> >  ei_x_buff xbuf;
> >  ei_x_new_with_version(&xbuf);
> >  ei_x_encode_tuple_header(&xbuf,2);
> >  ei_x_encode_atom(&xbuf,"data");
> >  ei_x_encode_binary(&xbuf, pBuffer, dwBufSize);
> >  EnterCriticalSection(&CriticalSection);
> >  ei_send(acceptedFd, channel_connection_pid, xbuf.buff,xbuf.index);
> >  LeaveCriticalSection(&CriticalSection);
> >  ei_x_free(&xbuf);
> >
>
>
> now the mormal running time is longer, but Erlang side still got "ERROR
> REPORT= Got invalid data on distribution channel, offending packet is:"
> error eventually.
>
>
> I  skip first 112 of the error message<<112,131,104,3,97...>>, and use
> binary_to_term,get term like:
>
>
>
> {2,'',<4761.49.0>}
>
>
>
> I search the maillisting again, and only get one post about this:
>
>
>
> http://www.erlang.org/pipermail/erlang-questions/2004-October/013383.html
>
>
>
> It looks like this problem is solved by using mutex
> http://www.erlang.org/pipermail/erlang-questions/2004-October/013385.html
>
> But I still have this problem.
>
>
>
> Any help is appreciable!
>
>
>
> BR
>
>
>
> James
>
>
>
>
> 2007/2/27, lang er <>:
> >
> > But in the erl_interface document, it said:
> >
> >
> > > If you are using Erl Interface functions in a threaded application
> based on POSIX threads or Solaris
> > > threads, then Erl Interface needs access to some of the
> synchronization facilities in your threads
> > > package, and you will need to specify additional compiler flags in
> order to indicate which of the
> > > packages you are using. Define REENTRANT and either STHREADS or
> PTHREADS. The default is to use
> > > POSIX threads if REENTRANT is specified.
> > > Note that both single threaded and default versions of the Erl
> interface and Ei libraries are provided.
> > > (The single threaded versions are named liberl interface st and libei
> st). Whether the default
> > > versions of the libraries have support for threads or not is
> determined by if the platform in question has
> > > support for POSIX or Solaris threads. To check this, have a look in
> the eidefs.mk file in the
> > > erl interface src directory.
> >
> >
> > I checked the eidefs.mk file, its content is:
> >
> >
> >
> >
> >
> > # Have the ei and erl_interface libs been compiled for threads?
> > EI_THREADS=true
> >
> > # Threads flags
> > THR_DEFS=-DWIN32_THREADS -DUSE_DECLSPEC_THREAD
> >
> > # Threads libs
> > THR_LIBS=
> >
> > # ----------------------------------------------------------------------
> >
> >
> > Doesn't it means I don't need use any synchronization facilities myself?
>
> >
> > Thanks!
> >
> > James
> >
> > 2007/2/26, Eduardo Figoli (INS) <>:
> >
> > >
> > >
> > >
> > >
> > > Have you tried using a critical section whenever calling ei_send?
> > >
> > >
> > >
> > > Regards, Eduardo
> > >
> > >
> > >
> > > ________________________________
>
> > >
> > > De:  [mailto: 
> ] En nombre de lang er
> > > Enviado el: Lunes, 26 de Febrero de 2007 01:05 p.m.
> > > Para: 
> > > Asunto: [erlang-questions] ei_send multithreaded problem
> > >
> > >
> > >
> > >
> > >
> > > I'm writing a c node using ei layer. This program is running under
> Window 2003 enterprise edition sp1, and otp_win32_R11B-3. The following is a
> fragment of my code:
> > >
> > >
> > >
> > > --------------------------------------------------------------------
> > >
> > >  erlang_pid *pid = (erlang_pid *)pUser;
> > >  ei_x_buff xbuf;
> > >  ei_x_new_with_version(&xbuf);
> > >  ei_x_encode_tuple_header(&xbuf,2);
> > >  ei_x_encode_atom(&xbuf,"data");
> > >  ei_x_encode_binary(&xbuf, buffer, bufSize);
> > >  ei_send(acceptedFd, pid, xbuf.buff,xbuf.index);
> > >  ei_x_free(&xbuf);
> > >
> > > ----------------------------------------------------------------------
> > >
> > >
> > >
> > >
> > >
> > > It is called inside a C callback function and may be called by many
> concurrent threads. pUser include a erlang_pid (correspond to a process in
> Erlang side).When some data come from network, a third party library
> will invoke this callback function, so ei_send pass these data to a
> corresponding Erlang process.(This process is an Erlang equivalent to a 3rd
> library thread. So if I start one process in Erlang side, the 3rd library
> will use one thread. If I start more than one process in Erlang , the 3rd
> library will use same number of threads.)
> > >
> > >
> > >
> > >
> > >
> > > Then, If I start one process in Erlang side, everything is OK. But If
> I start more than one process, the C node program will crash after some
> random time. If I comment  out ei_send line in above code fragment,
> everything is OK again.
> > >
> > >
> > >
> > > Do I miss anything to use ei_send in multithreaded environment?
> > >
> > >
> > >
> > > compiler: ms visual studio 2005
> > >
> > > debug mode use  ei_mdd.lib
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > Thanks,
> > >
> > > James
> > >
> > >
> >
> >
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://erlang.org/pipermail/erlang-questions/attachments/20070301/bd7576fb/attachment.html>


More information about the erlang-questions mailing list