Merge pull request #56 from JeffersonLab/hotfix-random-seed

Hotfix random seed

include/remollRun.hh

@@ -24,6 +24,8 @@ class remollRun: public G4Run {
     static remollRunData* fRunData;
   public:
     static remollRunData* GetRunData();
+
+    static void UpdateSeed();
 };
 
 #endif //__REMOLLRUN_HH

include/remollRunData.hh

@@ -32,7 +32,7 @@ class remollRunData : public TObject {
 	const char *GetGenName(){ return fGenName; }
 
 	void SetBeamE(double E){ fBeamE = E; }
-	void SetSeed(unsigned int seed){ fSeed = seed; }
+	void SetSeed(unsigned long int seed){ fSeed = seed; }
 
 	void AddMagData(filedata_t d){fMagData.push_back(d);}
 	void SetMacroFile(const char *fn){ fMacro = remollTextFile(fn); }
@@ -48,7 +48,7 @@ class remollRunData : public TObject {
 	TTimeStamp fRunTime;
 
 	long int  fNthrown;
-	unsigned int  fSeed;
+	long int  fSeed;
 	double fBeamE;
 	char fGenName[__RUNSTR_LEN];
 

macros/tests/test_seed.mac

@@ -0,0 +1,23 @@
+# This will produce four files test_seed_$i.root, $i = 0,...,3.
+
+# The file test_seed_0.root should have a random seed and have unique content.
+# The file test_seed_1.root and test_seed_3.root should have identical content.
+# The file test_seed_2.root should have different content from test_seed_1.root and test_seed_3.root.
+
+/run/initialize
+
+/remoll/filename test_seed_0.root
+/run/beamOn 100
+
+/remoll/filename test_seed_1.root
+/remoll/seed 123456
+/run/beamOn 100
+
+/remoll/filename test_seed_2.root
+/remoll/seed 654321
+/run/beamOn 100
+
+/remoll/filename test_seed_3.root
+/remoll/seed 123456
+/run/beamOn 100
+

remoll.cc

@@ -35,6 +35,7 @@ typedef G4RunManager RunManager;
 #endif
 
 #include <ctime>
+#include <fstream>
 
 namespace {
   void PrintUsage() {
@@ -54,17 +55,16 @@ int main(int argc, char** argv) {
     clock_t tStart = clock();
 
 
-    // Initialize the CLHEP random engine
-    unsigned int seed = time(0) + (int) getpid();
-    unsigned int devrandseed = 0;
-    //  /dev/urandom doens't block
-    FILE *fdrand = fopen("/dev/urandom", "r");
-    if (fdrand) {
-	if (fread(&devrandseed, sizeof(int), 1, fdrand)) {
-	  seed += devrandseed;
-	} else G4cerr << "Can't read /dev/urandom." << G4endl;
-	fclose(fdrand);
-    }
+    // Initialize the random seed
+    G4long seed = time(0) + (int) getpid();
+    // Open /dev/urandom
+    std::ifstream urandom("/dev/urandom", std::ios::in | std::ios::binary);
+    // If stream is open
+    if (urandom) {
+      urandom.read(reinterpret_cast<char*>(&seed), sizeof(seed));
+      urandom.close();
+    } else G4cerr << "Can't read /dev/urandom." << G4endl;
+
 
     // Parse command line options
     G4String macro;
@@ -98,9 +98,8 @@ int main(int argc, char** argv) {
     #endif
 
     // Choose the Random engine
-    G4Random::setTheEngine(new CLHEP::RanecuEngine());
     G4Random::setTheSeed(seed);
-    remollRun::GetRunData()->SetSeed(seed);
+    remollRun::UpdateSeed();
 
     // Messenger
     remollMessenger* messenger = remollMessenger::GetInstance();

src/remollMessenger.cc

@@ -60,9 +60,9 @@ remollMessenger::~remollMessenger() { }
 void remollMessenger::SetNewValue(G4UIcommand* cmd, G4String newValue)
 {
     if( cmd == seedCmd ){
-	G4int seed = seedCmd->GetNewIntValue(newValue);
+	G4long seed = seedCmd->GetNewIntValue(newValue);
 	G4Random::setTheSeed(seed);
-	remollRun::GetRunData()->SetSeed(seed);
+	remollRun::UpdateSeed();
     }
 
     if( cmd == opticalCmd ){

src/remollRun.cc

@@ -1,5 +1,6 @@
 #include "remollRun.hh"
 
+#include "Randomize.hh"
 #include "G4Event.hh"
 #include "G4HCofThisEvent.hh"
 
@@ -16,6 +17,11 @@ remollRunData* remollRun::GetRunData()
   return fRunData;
 }
 
+void remollRun::UpdateSeed()
+{
+  GetRunData()->SetSeed(G4Random::getTheSeed());
+}
+
 remollRun::remollRun() { }
 
 remollRun::~remollRun() { }