Refined way to generate random seed (#1841)

* Enable DPMJET

* Refined seeding

* Split of Dpmjet processe and fix in decay tables

Author: mbroz84

MC/config/PWGUD/external/generator/DecayTablesEvtGen/TAUTAU.ELPI.DEC

@@ -5,6 +5,6 @@ Decay tau+
 0.25 pi+     anti-nu_tau                                  TAUSCALARNU; #[Reconstructed PDG2011]
 0.25 pi+     pi0     anti-nu_tau                          TAUHADNU -0.108 0.775 0.149 1.364 0.400; #[Reconstructed PDG2011]
 0.25 pi0     pi0     pi+     anti-nu_tau                  TAUHADNU -0.108 0.775 0.149 1.364 0.400 1.23 0.4; #[Reconstructed PDG2011]
-0.25 anti-nu_tau  pi+     pi0     pi0     pi0             PYTHIA    41; #[Reconstructed PDG2011]
+0.25 anti-nu_tau  pi+     pi0     pi0     pi0             PHSP; #[Reconstructed PDG2011]
 Enddecay
 End

MC/config/PWGUD/external/generator/DecayTablesEvtGen/TAUTAU.POPI.DEC

@@ -5,6 +5,6 @@ Decay tau-
 0.25 pi-     nu_tau                                  TAUSCALARNU; #[Reconstructed PDG2011]
 0.25 pi-     pi0     nu_tau                          TAUHADNU -0.108 0.775 0.149 1.364 0.400; #[Reconstructed PDG2011]
 0.25 pi0     pi0     pi-     nu_tau                  TAUHADNU -0.108 0.775 0.149 1.364 0.400 1.23 0.4; #[Reconstructed PDG2011]
-0.25 nu_tau  pi-     pi0     pi0     pi0             PYTHIA    41; #[Reconstructed PDG2011]
+0.25 nu_tau  pi-     pi0     pi0     pi0             PHSP; #[Reconstructed PDG2011]
 Enddecay
 End

MC/config/PWGUD/external/generator/GeneratorStarlight.C

@@ -11,6 +11,23 @@ R__ADD_INCLUDE_PATH($STARlight_ROOT/include)
 
 //   usage: o2-sim -g external --configKeyValues 'GeneratorExternal.fileName=GeneratorStarlight.C;GeneratorExternal.funcName=GeneratorStarlight("kCohJpsiToMu")'
 
+unsigned int generateRandomSeed() {
+    // Use high-resolution clock for time-based seed
+    auto timeNow = std::chrono::high_resolution_clock::now();
+    auto timeSeed = static_cast<unsigned int>(timeNow.time_since_epoch().count());
+
+    // Random device for system entropy
+    std::random_device rd;
+
+    // Add process ID and thread ID for additional entropy
+    unsigned int pid = static_cast<unsigned int>(getpid());
+    unsigned int tid = static_cast<unsigned int>(std::hash<std::thread::id>()(std::this_thread::get_id()));
+
+    // Combine all entropy sources
+    unsigned int seed = timeSeed ^ (rd() << 1) ^ (pid << 2) ^ (tid << 3);
+    return seed;
+}
+
 namespace o2
 {
 namespace eventgen
@@ -104,7 +121,8 @@ class GeneratorStarlight_class : public Generator
     {"kIncohPsi2sToElPi",    4,  444011,   20, -1.0, -1.0,  100443, 1 }, //
     {"kIncohUpsilonToMu",    4,  553013,   20, -1.0, -1.0,  553, 0 }, //
     {"kIncohUpsilonToEl",    4,  553011,   20, -1.0, -1.0,  553, 0 }, //
-    {"kDpmjetSingle",        5,  113,   20, -1.0, -1.0,  -1, 0 }, //
+    {"kDpmjetSingleA",        5,  113,   20, -1.0, -1.0,  -1, 0 }, //
+    {"kDpmjetSingleC",        5,  113,   20, -1.0, -1.0,  -1, 0 }, //
     {"kTauLowToEl3Pi",       1,      15,  990,  3.5, 20.0,  -1, 1 }, // from 0.4 to 15 GeV
     {"kTauLowToPo3Pi",       1,      15,  990,  3.5, 20.0,  -1, 1 }, // from 0.4 to 15 GeV
     {"kTauLowToElMu",        1,      15,  990,  3.5, 20.0,  -1, 1 }, // from 0.4 to 15 GeV
@@ -128,12 +146,9 @@ class GeneratorStarlight_class : public Generator
 
   mPdgMother = slConfig[idx].pdg_mother;
   mDecayEvtGen = slConfig[idx].decay_EvtGen;  
-  
-  uint random_seed;
-  unsigned long long int random_value = 0; 
-  ifstream urandom("/dev/urandom", ios::in|ios::binary);
-  urandom.read(reinterpret_cast<char*>(&random_value), sizeof(random_seed));
-  
+
+  unsigned int random_seed = generateRandomSeed();
+
   setParameter(Form("BEAM_1_Z     =    %3i    #Z of target",targZ));
   setParameter(Form("BEAM_1_A     =    %3i    #A of target",targA));
   setParameter(Form("BEAM_2_Z     =    %3i    #Z of projectile",projZ));
@@ -278,7 +293,7 @@ class GeneratorStarlight_class : public Generator
 				   -1,
 				   slPart->GetPx(),
 				   slPart->GetPy(),
-				   slPart->GetPz(),
+				   (mSelectedConfiguration.compare("kDpmjetSingleC") == 0 ? -1.0*slPart->GetPz() : slPart->GetPz()),
 				   slPart->GetE(),
 				   vtx,vty,vtz,vtt);
 	  //particle.Print();
@@ -321,8 +336,7 @@ FairGenerator*
     system(TString::Format("cp %s ./my.input",dpmjetconf.c_str()));
 
     //Reset four seeds of the DPMJET random generator in the config
-    std::random_device rd;
-    std::mt19937 gen(rd());
+    std::mt19937 gen(generateRandomSeed());
     std::uniform_int_distribution<> dist(1, 168);
 
     std::string command = "awk -i inplace -v nums=\"";

MC/config/PWGUD/ini/makeStarlightConfig.py

@@ -17,7 +17,7 @@
 parser.add_argument('--rapidity', default='cent', choices=['cent_rap', 'muon_rap', 'cent_eta', 'muon_eta'],
                     help='Rapidity to select')
 
-parser.add_argument('--process',default=None, choices=['kTwoGammaToMuLow', 'kTwoGammaToElLow', 'kTwoGammaToMuMedium', 'kTwoGammaToElMedium', 'kTwoGammaToMuHigh', 'kTwoGammaToElHigh', 'kTwoGammaToRhoRho', 'kTwoGammaToF2', 'kCohRhoToPi', 'kCohRhoToElEl', 'kCohRhoToMuMu', 'kCohRhoToPiWithCont', 'kCohRhoToPiFlat', 'kCohPhiToKa', 'kDirectPhiToKaKa', 'kCohPhiToEl', 'kCohOmegaTo2Pi', 'kCohOmegaTo3Pi', 'kCohOmegaToPiPiPi', 'kCohRhoPrimeTo4Pi', 'kCohJpsiToMu', 'kCohJpsiToEl', 'kCohJpsiToElRad', 'kCohJpsiToProton', 'kCohPsi2sToMu','kCohPsi2sToEl', 'kCohPsi2sToMuPi', 'kCohPsi2sToElPi', 'kCohUpsilonToMu', 'kCohUpsilonToEl', 'kIncohRhoToPi', 'kIncohRhoToElEl', 'kIncohRhoToMuMu', 'kIncohRhoToPiWithCont', 'kIncohRhoToPiFlat', 'kIncohPhiToKa', 'kIncohOmegaTo2Pi', 'kIncohOmegaTo3Pi', 'kIncohOmegaToPiPiPi', 'kIncohRhoPrimeTo4Pi', 'kIncohJpsiToMu', 'kIncohJpsiToEl', 'kIncohJpsiToElRad', 'kIncohJpsiToProton', 'kIncohJpsiToLLbar', 'kIncohPsi2sToMu', 'kIncohPsi2sToEl', 'kIncohPsi2sToMuPi', 'kIncohPsi2sToElPi', 'kIncohUpsilonToMu', 'kIncohUpsilonToEl', 'kDpmjetSingle',  'kTauLowToEl3Pi', 'kTauLowToPo3Pi', 'kTauMediumToEl3Pi', 'kTauMediumToPo3Pi', 'kTauHighToEl3Pi', 'kTauHighToPo3Pi', 'kTauLowToElMu', 'kTauLowToElPiPi0', 'kTauLowToPoPiPi0'],
+parser.add_argument('--process',default=None, choices=['kTwoGammaToMuLow', 'kTwoGammaToElLow', 'kTwoGammaToMuMedium', 'kTwoGammaToElMedium', 'kTwoGammaToMuHigh', 'kTwoGammaToElHigh', 'kTwoGammaToRhoRho', 'kTwoGammaToF2', 'kCohRhoToPi', 'kCohRhoToElEl', 'kCohRhoToMuMu', 'kCohRhoToPiWithCont', 'kCohRhoToPiFlat', 'kCohPhiToKa', 'kDirectPhiToKaKa', 'kCohPhiToEl', 'kCohOmegaTo2Pi', 'kCohOmegaTo3Pi', 'kCohOmegaToPiPiPi', 'kCohRhoPrimeTo4Pi', 'kCohJpsiToMu', 'kCohJpsiToEl', 'kCohJpsiToElRad', 'kCohJpsiToProton', 'kCohPsi2sToMu','kCohPsi2sToEl', 'kCohPsi2sToMuPi', 'kCohPsi2sToElPi', 'kCohUpsilonToMu', 'kCohUpsilonToEl', 'kIncohRhoToPi', 'kIncohRhoToElEl', 'kIncohRhoToMuMu', 'kIncohRhoToPiWithCont', 'kIncohRhoToPiFlat', 'kIncohPhiToKa', 'kIncohOmegaTo2Pi', 'kIncohOmegaTo3Pi', 'kIncohOmegaToPiPiPi', 'kIncohRhoPrimeTo4Pi', 'kIncohJpsiToMu', 'kIncohJpsiToEl', 'kIncohJpsiToElRad', 'kIncohJpsiToProton', 'kIncohJpsiToLLbar', 'kIncohPsi2sToMu', 'kIncohPsi2sToEl', 'kIncohPsi2sToMuPi', 'kIncohPsi2sToElPi', 'kIncohUpsilonToMu', 'kIncohUpsilonToEl', 'kDpmjetSingleA', 'kDpmjetSingleC',  'kTauLowToEl3Pi', 'kTauLowToPo3Pi', 'kTauMediumToEl3Pi', 'kTauMediumToPo3Pi', 'kTauHighToEl3Pi', 'kTauHighToPo3Pi', 'kTauLowToElMu', 'kTauLowToElPiPi0', 'kTauLowToPoPiPi0'],
                     help='Process to switch on')