Root takes care of splitting the message into pieces that matches the
buffersize of the system and sending them (see Fons' email to roottalk).
I suspect (if I didn't do anything wrong), that something goes wrong with
the synchronizing of these packages if the socket is in non-splitting mode.
cheers,
Judith
On Wed, 7 Apr 1999, John Zweizig wrote:
> It sounds like your problem is that you don't have a large enough system
> send buffer. The usual way to fix this is with setsockopt(SO_SNDBUF, nnnn)
> (nnn is the buffer size to be used), but I don't know how to translate
> this into root TSockets (I don't see it documented in the online TSocket
> class description) and you run the risk of getting errors if the buffer
> hasn't been fully transferred. The easy way around this is to use a
> blocking socket for your sends. The send() function then makes sure
> everything works out OK. This should only take a few extra milliseconds
> while the data are pushed out over the ethernet (or whatever you use) and
> you won't be able to respond to any further requests during that time anyway.
> Best regards,
>
> John
>
> On Wed, 7 Apr 1999, Judith Katzy wrote:
>
> >
> > hi there,
> >
> > I'd like to send messages of about 300k in a client server environment
> > using TSocket and TServerSocket.
> > Everything works fine as long as I use the blocking mode for
> > the socket. It also works, if I use the non-blocking mode and just send
> > small objects (280 bytes).
> > I get the following error on the server side, when I use the non-blocking
> > mode with a 300k messages:
> >
> > root [1] .x server.C
> > received mess 'waiting'
> > SysError in <TUnixSystem::UnixSend>: send (Resource temporarily
> > unavailable)
> > Error in <TUnixSystem::SendRaw>: cannot send buffer
> > server: error occcurred during sending event
> >
> > Attached, I send the macros server.C and client.C.
> >
> > My suspecion is, that something goes wrong when I send several
> > packets with TCP/IP in a non-blocking mode, even when the
> > sending is synchronized.
> >
> > thanks for any help,
> > Judith
> >
> > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > macro serroot.C
> > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > {
> > // just a large object (buf size about 300k), I take a data event here
> > TPhEvent *ev = dst->GetNextEvent() ;
> > TMessage smess(kMESS_OBJECT);
> > smess->WriteObject(ev);
> > TServerSocket *ss = new TServerSocket(9091, kTRUE);
> > TSocket *s0 = ss->Accept();
> > s0->SetOption(kNoBlock,1);
> > Int_t fSend,idx;
> >
> > Char_t str[32];
> > Int_t fRecv, fSend;
> >
> > while (1)
> > {
> > fRecv = s0->Recv(str,32);
> > if(fRecv != -4)
> > {
> > // client request new event
> > idx = !strcmp(str, "waiting") ? 0 : 1;
> > if(idx == 0)
> > {
> > printf("received mess '%s'\n",str);
> > //***fSend = s0->Send("xxx");
> > UInt_t what = smess->What();
> > // synchronize sending
> > smess->SetWhat(what || kMESS_ACK);
> > fSend = s0->Send(smess);
> > if(fSend==-1)
> > printf("server: error occcurred during sending event\n");
> > }
> > }
> > }
> > s0->Close();
> > ss->Close();
> > }
> >
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > macro client.C
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >
> > {
> > TSocket *csock = new TSocket("judithpc.phy.uic.edu", 9091);
> > csock->Send("waiting");
> > TMessage *mess;
> > Int_t fRecv;
> > Int_t idx;
> > Char_t cstr[256];
> > while (1) {
> > //** fRecv = csock->Recv(cstr,32);
> > fRecv = csock->Recv(mess);
> > if(fRecv!=-4){
> > if(fRecv<0)
> > {
> > printf("error message received, error code %d -return\n ",fRecv);
> > return;
> > }
> > //**printf("received %s\n",cstr);
> > TPhEvent *event = (TPhEvent *)mess->ReadObject(mess->GetClass());
> > printf("received %d, event %d\n",mess->What(),event->GetNEvent());
> > csock->Send("waiting");
> > delete mess;
> > }
> > }
> > csock->Close();
> > }
> >
> >
> >
> >
> >
>