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();
> }
>
>
>
>
>
This archive was generated by hypermail 2b29 : Tue Jan 04 2000 - 00:43:31 MET