https://github.com/root-project/root
Tip revision: 1bb435ef147f40e8c477119d7791acca99f1819e authored by Philippe Canal on 12 June 2009, 18:47:18 UTC
Merge revisin 27108, 27109, 27768 from the trunk. Correct sizing and array dereferencing which were not correctly maintained during the code change to support flushing the write basket before streaming the branch)
Merge revisin 27108, 27109, 27768 from the trunk. Correct sizing and array dereferencing which were not correctly maintained during the code change to support flushing the write basket before streaming the branch)
Tip revision: 1bb435e
threads.cxx
#include "TApplication.h"
#include "TObject.h"
#include "TH1.h"
#include "TMath.h"
#include "TCanvas.h"
#include "TRandom.h"
#include "TThread.h"
/*
** Module name : threads
**
** Description :
** This file implements four functions, which shall perform some
** actions on objects like histograms and a canvas.
*/
// a global canvas for the drawing of histograms
TCanvas *c1;
// a pad for the histogram, will be used by thread mhs
TPad *pad1;
// a pad for the histogram, will be used by thread mhs2
TPad *pad2;
// a global histogram object, which will be accessed both by mhs and mhs1
TH1F *total0;
// thread function (filling histogram main and drawing total0 on pad1)
void *mhs(void *)
{
TThread::Printf("Start of mhs");
// change to the canvas and draw its correspondig pad 1
c1->cd();
c1->SetGrid();
pad1->Draw();
// creating a histogram is explicitely locked by a global mutex
TThread::Lock();
TH1F *main = new TH1F("main","Main contributor",100,-4,4);
TThread::UnLock();
// other operations needn't be locked
total0->Sumw2();
total0->SetMarkerStyle(21);
total0->SetMarkerSize(0.7);
main->SetFillColor(16);
// Fill histogram main randomly
gRandom->SetSeed();
const Int_t kUPDATE = 100;
Float_t xmain;
// run for a certain amount of events or
//for ( Int_t i=0; i<=100000; i++) {
// run forever
for ( Int_t i=0; ; i++) {
xmain = gRandom->Gaus(-1,1.5);
// filling of a histogram is locked to avoid data loss
TThread::Lock();
main->Fill(xmain);
total0->Fill(xmain);
TThread::UnLock();
// drawing of the histogram is locked automatically by ROOT
if (!(i%kUPDATE)) {
if (i == kUPDATE) {
pad1->cd();
total0->Draw("e1p");
}
pad1->Modified();
pad1->Update();
c1->Modified();
c1->Update();
}
// sleep for 1 ms: sleep not necessary, slows things only a bit down
// because the threads are actually doing nothing, which is eventually
// very fast ;-)
TThread::Sleep(0, 1000000);
}
TThread::Printf("End of mhs\n");
c1->Modified();
c1->Update();
return 0;
}
// thread function (filling total0)
void *mhs1(void *)
{
TThread::Printf("Start of mhs1");
// instantiation of objects has to be locked explicitly
TThread::Lock();
TH1F *s1 = new TH1F("s1","This is the first signal",100,-4,4);
TH1F *s2 = new TH1F("s2","This is the second signal",100,-4,4);
TThread::UnLock();
s1->SetFillColor(42);
s2->SetFillColor(46);
// Fill histograms randomly
gRandom->SetSeed();
Float_t xs1, xs2;
//for ( Int_t i=0; i<=100000; i++) {
for ( Int_t i=0; ; i++) {
xs1 = gRandom->Gaus(-0.5,0.5);
xs2 = gRandom->Gaus(1,0.3);
// locking avoids data loss
TThread::Lock();
s1->Fill(xs1,0.3);
s2->Fill(xs2,0.2);
total0->Fill(xs1,0.3);
total0->Fill(xs2,0.2);
TThread::UnLock();
// sleep for 6 ms: not necessary (see above)
TThread::Sleep(0, 6000000);
}
TThread::Printf("End of mhs1\n");
// wo is last draws the histogram a last time
pad1->cd();
total0->Draw("e1p");
c1->Modified();
c1->Update();
return 0;
}
// thread function: plays with its own histograms, draw on canvas in pad2
void *mhs2(void *)
{
TThread::Printf("Start of mhs2");
c1->cd();
pad2->Draw();
// Create some histograms: explicitly locked.
TThread::Lock();
TH1F *total = new TH1F("total2","This is the total distribution",100,-4,4);
TH1F *main = new TH1F("main2","Main contributor",100,-4,4);
TH1F *s1 = new TH1F("s12","This is the first signal",100,-4,4);
TH1F *s2 = new TH1F("s22","This is the second signal",100,-4,4);
TThread::UnLock();
total->Sumw2();
total->SetMarkerStyle(21);
total->SetMarkerSize(0.7);
main->SetFillColor(16);
s1->SetFillColor(42);
s2->SetFillColor(46);
// Fill histograms randomly
gRandom->SetSeed();
const Int_t kUPDATE = 100;
Float_t xs1, xs2, xmain;
// for ( Int_t i=0; i<=100000; i++) {
for ( Int_t i=0; ; i++) {
xmain = gRandom->Gaus(-1,1.5);
xs1 = gRandom->Gaus(-0.5,0.5);
xs2 = gRandom->Gaus(1,0.3);
// no locking here because nobody else uses these objects
main->Fill(xmain);
s1->Fill(xs1,0.3);
s2->Fill(xs2,0.2);
total->Fill(xmain);
total->Fill(xs1,0.3);
total->Fill(xs2,0.2);
if (!(i%kUPDATE)) {
if (i == kUPDATE) {
pad2->cd();
total->Draw("e1p");
}
pad2->Modified();
pad2->Update();
c1->Modified();
c1->Update();
}
// sleep for 1 ms: not necessary
TThread::Sleep(0, 1000000);
}
TThread::Printf("End of mhs2\n");
c1->Modified();
c1->Update();
return 0;
}
// thread to run Ps(): perform every 5 seconds a TThread::Ps()
void *top(void *)
{
TThread::Printf("Start of top");
for (Int_t i = 0; ;i++) {
TThread::Ps();
TThread::Sleep(5);
}
TThread::Printf("End of top");
return 0;
}
int main(int argc, char **argv)
{
TApplication theApp("h1Thread", &argc, argv);
// a global canvas for the drawing of histograms
c1 = new TCanvas("c1","The HSUM example",800,400);
// a pad for the histogram, will be used by thread mhs
pad1 = new TPad("pad1","This is pad1",0.02,0.02,0.48,0.98,33);
// a pad for the histogram, will be used by thread mhs2
pad2 = new TPad("pad2","This is pad2",0.52,0.02,0.98,0.98,33);
// a global histogram object, which will be accessed both by mhs and mhs1
total0 = new TH1F("total","This is the total distribution",100,-4,4);
// create the TThread instances
TThread *th1 = new TThread("th1",mhs);
TThread *th2 = new TThread("th2",mhs2);
TThread *th3 = new TThread("th3",mhs1);
// top thread
TThread *thp = new TThread("top",top);
th1->Run();
th2->Run();
th3->Run();
thp->Run();
printf("*** Exit the program by selecting Quit from the File menu ***\n");
theApp.Run(kTRUE);
th1->SetCancelAsynchronous();
th2->SetCancelAsynchronous();
th3->SetCancelAsynchronous();
thp->SetCancelAsynchronous();
th1->Kill();
th2->Kill();
th3->Kill();
thp->Kill();
printf("The END...\n");
return 0;
}