Logo ROOT   6.14/05
Reference Guide
hclientbonj.C File Reference

Detailed Description

Client program which creates and fills a histogram.

Every 1000 fills the histogram is send to the server which displays the histogram.

To run this demo do the following:

The script argument "evol" can be used when using a modified version of the script where the clients and server are on systems with different versions of ROOT. When evol is set to kTRUE the socket will support automatic schema evolution between the client and the server.

#include "TBenchmark.h"
#include "TList.h"
#include "TInetAddress.h"
#include "TSocket.h"
#include "TMessage.h"
#include "TH1.h"
#include "TH2.h"
#include "TRandom.h"
#include "TBonjourRecord.h"
static Bool_t gEvo = kFALSE;
void ConnectToServer(const TInetAddress *hostb, Int_t port)
// Called by the Bonjour resolver with the host and port to which
// we can connect.
// Connect only once...
TInetAddress host = *hostb;
delete resolver;
printf("ConnectToServer: host = %s, port = %d\n", host.GetHostName(), port);
//--- Here starts original hclient.C code ---
// Open connection to server
TSocket *sock = new TSocket(host.GetHostName(), port);
// Wait till we get the start message
char str[32];
sock->Recv(str, 32);
// server tells us who we are
int idx = !strcmp(str, "go 0") ? 0 : 1;
Float_t messlen = 0;
Float_t cmesslen = 0;
if (idx == 1)
TH1 *hpx;
if (idx == 0) {
// Create the histogram
hpx = new TH1F("hpx","This is the px distribution",100,-4,4);
hpx->SetFillColor(48); // set nice fill-color
} else {
hpx = new TH2F("hpxpy","py vs px",40,-4,4,40,-4,4);
//TMessage mess(kMESS_OBJECT | kMESS_ACK);
// Fill histogram randomly
Float_t px, py;
const int kUPDATE = 1000;
for (int i = 0; i < 25000; i++) {
if (idx == 0)
if (i && (i%kUPDATE) == 0) {
mess.Reset(); // re-use TMessage object
mess.WriteObject(hpx); // write object in message buffer
sock->Send(mess); // send message
messlen += mess.Length();
cmesslen += mess.CompLength();
sock->Send("Finished"); // tell server we are finished
if (cmesslen > 0)
printf("Average compression ratio: %g\n", messlen/cmesslen);
// Close the socket
void UpdateBonjourRecords(TList *records)
// Browse for Bonjour record of type "_hserv2._tcp." in domain "local.".
// When found, create Bonjour resolver to get host and port of this record.
static Bool_t resolved = kFALSE;
// we can be called multiple times whenever a new server appears
printf("UpdateBonjourRecords (resolved = %s)\n", resolved ? "kTRUE" : "kFALSE");
if (resolved) return;
// Look for _hserv2._tcp. in local. domain and try to resolve it
TIter next(records);
while ((rec = (TBonjourRecord*) next())) {
if (!strcmp(rec->GetRegisteredType(), "_hserv2._tcp.") &&
!strcmp(rec->GetReplyDomain(), "local.")) {
resolver->Connect("RecordResolved(TInetAddress*,Int_t)", 0, 0,
resolved = kTRUE;
void hclientbonj(Bool_t evol=kFALSE)
gEvo = evol;
browser->Connect("CurrentBonjourRecordsChanged(TList*)", 0, 0,
Fons Rademakers

Definition in file hclientbonj.C.