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Reference Guide
parallelMergeClient.C
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1/// \file
2/// \ingroup tutorial_net
3/// Client program which creates and fills 2 histograms and a TTree.
4/// Every 1000000 fills the histograms and TTree is send to the server which displays the histogram.
5///
6/// To run this demo do the following:
7/// - Open at least 2 windows
8/// - Start ROOT in the first windows
9/// - Execute in the first window: .x fastMergeServer.C
10/// - Execute in the other windows: root.exe -b -l -q .x treeClient.C
11/// (You can put it in the background if wanted).
12/// If you want to run the hserv.C on a different host, just change
13/// "localhost" in the TSocket ctor below to the desired hostname.
14///
15/// \macro_code
16///
17/// \authors Fons Rademakers, Philippe Canal
18
19#include "TMessage.h"
20#include "TBenchmark.h"
21#include "TSocket.h"
22#include "TH2.h"
23#include "TTree.h"
25#include "TRandom.h"
26#include "TError.h"
27
28void parallelMergeClient()
29{
30 gBenchmark->Start("treeClient");
31
32 TParallelMergingFile *file = (TParallelMergingFile*)TFile::Open("mergedClient.root?pmerge=localhost:1095","RECREATE");
33
34 file->Write();
35 file->UploadAndReset(); // We do this early to get assigned an index.
36 UInt_t idx = file->fServerIdx; // This works on in ACLiC.
37
38 TH1 *hpx;
39 if (idx%2 == 0) {
40 // Create the histogram
41 hpx = new TH1F("hpx","This is the px distribution",100,-4,4);
42 hpx->SetFillColor(48); // set nice fill-color
43 } else {
44 hpx = new TH2F("hpxpy","py vs px",40,-4,4,40,-4,4);
45 }
46 Float_t px, py;
47 TTree *tree = new TTree("tree","tree");
48 tree->SetAutoFlush(4000000);
49 tree->Branch("px",&px);
50 tree->Branch("py",&py);
51
52 // Fill histogram randomly
54 const int kUPDATE = 1000000;
55 for (int i = 0; i < 25000000; ) {
56 gRandom->Rannor(px,py);
57 if (idx%2 == 0)
58 hpx->Fill(px);
59 else
60 hpx->Fill(px,py);
61 tree->Fill();
62 ++i;
63 if (i && (i%kUPDATE) == 0) {
64 file->Write();
65 }
66 }
67 file->Write();
68 delete file;
69
70 gBenchmark->Show("treeClient");
71}
unsigned int UInt_t
Definition: RtypesCore.h:42
float Float_t
Definition: RtypesCore.h:53
R__EXTERN TBenchmark * gBenchmark
Definition: TBenchmark.h:59
R__EXTERN TRandom * gRandom
Definition: TRandom.h:62
virtual void SetFillColor(Color_t fcolor)
Set the fill area color.
Definition: TAttFill.h:37
virtual void Start(const char *name)
Starts Benchmark with the specified name.
Definition: TBenchmark.cxx:174
virtual void Show(const char *name)
Stops Benchmark name and Prints results.
Definition: TBenchmark.cxx:157
static TFile * Open(const char *name, Option_t *option="", const char *ftitle="", Int_t compress=ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault, Int_t netopt=0)
Create / open a file.
Definition: TFile.cxx:3923
1-D histogram with a float per channel (see TH1 documentation)}
Definition: TH1.h:571
The TH1 histogram class.
Definition: TH1.h:56
virtual Int_t Fill(Double_t x)
Increment bin with abscissa X by 1.
Definition: TH1.cxx:3275
2-D histogram with a float per channel (see TH1 documentation)}
Definition: TH2.h:251
virtual void SetSeed(ULong_t seed=0)
Set the random generator seed.
Definition: TRandom.cxx:597
virtual void Rannor(Float_t &a, Float_t &b)
Return 2 numbers distributed following a gaussian with mean=0 and sigma=1.
Definition: TRandom.cxx:489
A TTree represents a columnar dataset.
Definition: TTree.h:72
Definition: file.py:1
Definition: tree.py:1