Store correct random seed in parameter container

fuhlig1 · ChristianTackeGSI · commit 92a0261b48f4 · 2023-11-16T19:54:52.000+01:00
Between Root 6.22 and 6.24 the return value of TRandom3::GetSeed() was changed. Since Root 6.24 the function GetSeed returns the current element of the state used to generate the random number which returns a fixed value of 624 for TRandom3. To get the seed value which was set by the function SetSeed one neeeds to use the GetSeed() function from the base class (gRandom->TRandom::GetSeed()), FairSoft apr21p2 does not have the problem but any later FairSoft version will save the wrong information in the parameter container FairBaseParSet irrespective of the seed value defined in Root. This commit fixes the issue and saves the correct seed value specified by gRandom->SetSeed(<your value>). (cherry picked from commit 20d0431)
diff --git a/base/steer/FairRunSim.cxx b/base/steer/FairRunSim.cxx
@@ -234,7 +234,7 @@ void FairRunSim::Init()
     }
     if (par) {
         par->SetContListStr(ContList);
-        par->SetRndSeed(gRandom->GetSeed());
+        par->SetRndSeed(gRandom->TRandom::GetSeed());
         par->setChanged();
         par->setInputVersion(fRunId, 1);
     }
diff --git a/templates/project_root_containers/MyProjGenerators/Pythia8Generator.h b/templates/project_root_containers/MyProjGenerators/Pythia8Generator.h
@@ -27,7 +27,7 @@ class FairPrimaryGenerator;
 class PyTr1Rng : public RndmEngine
 {
   public:
-    PyTr1Rng() { rng = new TRandom1(gRandom->GetSeed()); };
+    PyTr1Rng() { rng = new TRandom1(gRandom->TRandom::GetSeed()); };
     virtual ~PyTr1Rng(){};
 
     Double_t flat() { return rng->Rndm(); };
@@ -39,7 +39,7 @@ class PyTr1Rng : public RndmEngine
 class PyTr3Rng : public RndmEngine
 {
   public:
-    PyTr3Rng() { rng = new TRandom3(gRandom->GetSeed()); };
+    PyTr3Rng() { rng = new TRandom3(gRandom->TRandom::GetSeed()); };
     virtual ~PyTr3Rng(){};
 
     Double_t flat() { return rng->Rndm(); };
diff --git a/templates/project_stl_containers/MyProjGenerators/Pythia8Generator.h b/templates/project_stl_containers/MyProjGenerators/Pythia8Generator.h
@@ -27,7 +27,7 @@ class FairPrimaryGenerator;
 class PyTr1Rng : public RndmEngine
 {
   public:
-    PyTr1Rng() { rng = new TRandom1(gRandom->GetSeed()); };
+    PyTr1Rng() { rng = new TRandom1(gRandom->TRandom::GetSeed()); };
     virtual ~PyTr1Rng(){};
 
     Double_t flat() { return rng->Rndm(); };
@@ -39,7 +39,7 @@ class PyTr1Rng : public RndmEngine
 class PyTr3Rng : public RndmEngine
 {
   public:
-    PyTr3Rng() { rng = new TRandom3(gRandom->GetSeed()); };
+    PyTr3Rng() { rng = new TRandom3(gRandom->TRandom::GetSeed()); };
     virtual ~PyTr3Rng(){};
 
     Double_t flat() { return rng->Rndm(); };

Original file line number	Diff line number	Diff line change
`@@ -234,7 +234,7 @@ void FairRunSim::Init()`
`234`	`234`	`}`
`235`	`235`	`if (par) {`
`236`	`236`	`par->SetContListStr(ContList);`
`237`		`- par->SetRndSeed(gRandom->GetSeed());`
	`237`	`+ par->SetRndSeed(gRandom->TRandom::GetSeed());`
`238`	`238`	`par->setChanged();`
`239`	`239`	`par->setInputVersion(fRunId, 1);`
`240`	`240`	`}`