From af46925c6902cd25087093c25368cac617b0f515 Mon Sep 17 00:00:00 2001
From: Roberto Preghenella <preghenella@bo.infn.it>
Date: Tue, 19 Jan 2021 11:42:47 +0100
Subject: [PATCH 1/2] Check for selective primary transport also in case of
 parallel sim

---
 .../include/SimulationDataFormat/Stack.h      |  2 ++
 DataFormats/simulation/src/Stack.cxx          | 28 ++++++++++++-------
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/DataFormats/simulation/include/SimulationDataFormat/Stack.h b/DataFormats/simulation/include/SimulationDataFormat/Stack.h
index ff55904d9342c..fee8d3e3c32f1 100644
--- a/DataFormats/simulation/include/SimulationDataFormat/Stack.h
+++ b/DataFormats/simulation/include/SimulationDataFormat/Stack.h
@@ -311,6 +311,8 @@ class Stack : public FairGenericStack
   /// \param iTrack  Track number
   void addHit(int iDet, Int_t iTrack);
 
+  void handleTransportPrimary(TParticle& p);
+
   ClassDefOverride(Stack, 1);
 };
 
diff --git a/DataFormats/simulation/src/Stack.cxx b/DataFormats/simulation/src/Stack.cxx
index 41f5f8fd1acd5..4b969c91865d2 100644
--- a/DataFormats/simulation/src/Stack.cxx
+++ b/DataFormats/simulation/src/Stack.cxx
@@ -230,13 +230,7 @@ void Stack::PushTrack(Int_t toBeDone, Int_t parentId, Int_t pdgCode, Double_t px
     p.SetBit(ParticleStatus::kKeep);
     p.SetBit(ParticleStatus::kPrimary);
     if (toBeDone == 1) {
-      if (mTransportPrimary(p, mPrimaryParticles)) {
-        p.SetBit(ParticleStatus::kToBeDone, 1);
-        mNumberOfPrimariesforTracking++;
-      } else {
-        p.SetBit(ParticleStatus::kToBeDone, 0);
-        p.SetBit(ParticleStatus::kInhibited, 1);
-      }
+      handleTransportPrimary(p);
     } else {
       p.SetBit(ParticleStatus::kToBeDone, 0);
     }
@@ -256,6 +250,20 @@ void Stack::PushTrack(Int_t toBeDone, Int_t parentId, Int_t pdgCode, Double_t px
   mStack.push(p);
 }
 
+void Stack::handleTransportPrimary(TParticle& p)
+{
+  // this function tests whether we really want to transport
+  // this particle and sets the relevant bits accordingly
+
+  if (mTransportPrimary(p, mPrimaryParticles)) {
+    p.SetBit(ParticleStatus::kToBeDone, 1);
+    mNumberOfPrimariesforTracking++;
+  } else {
+    p.SetBit(ParticleStatus::kToBeDone, 0);
+    p.SetBit(ParticleStatus::kInhibited, 1);
+  }
+}
+
 void Stack::PushTrack(int toBeDone, TParticle& p)
 {
   //  printf("stack -> Pushing Primary toBeDone %5d %5d parentId %5d pdgCode %5d is %5d entries %5d \n", toBeDone, p.TestBit(ParticleStatus::kToBeDone), p.GetFirstMother(), p.GetPdgCode(), p.GetStatusCode(),  mNumberOfEntriesInParticles);
@@ -266,12 +274,12 @@ void Stack::PushTrack(int toBeDone, TParticle& p)
   if (p.GetUniqueID() == 0) {
     // one to one mapping for primaries
     mIndexMap[mNumberOfPrimaryParticles] = mNumberOfPrimaryParticles;
-    mNumberOfPrimaryParticles++;
-    mPrimaryParticles.push_back(p);
     // Push particle on the stack
     if (p.TestBit(ParticleStatus::kPrimary) && p.TestBit(ParticleStatus::kToBeDone)) {
-      mNumberOfPrimariesforTracking++;
+      handleTransportPrimary(p);
     }
+    mNumberOfPrimaryParticles++;
+    mPrimaryParticles.push_back(p);
     mStack.push(p);
     mTracks->emplace_back(p);
   }

From 8ffd45ddb561dba66550a60261c4bfa914e1a1d1 Mon Sep 17 00:00:00 2001
From: Roberto Preghenella <preghenella@bo.infn.it>
Date: Tue, 19 Jan 2021 13:22:09 +0100
Subject: [PATCH 2/2] Add inhibited flag to MCTrack::PropEncoding and reduce
 hitmask bitfield

---
 .../include/SimulationDataFormat/MCTrack.h    | 20 +++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/DataFormats/simulation/include/SimulationDataFormat/MCTrack.h b/DataFormats/simulation/include/SimulationDataFormat/MCTrack.h
index 307e398453884..87f57c3a0f406 100644
--- a/DataFormats/simulation/include/SimulationDataFormat/MCTrack.h
+++ b/DataFormats/simulation/include/SimulationDataFormat/MCTrack.h
@@ -194,6 +194,14 @@ class MCTrackT
   }
   bool getToBeDone() const { return ((PropEncoding)mProp).toBeDone; }
 
+  void setInhibited(bool f)
+  {
+    auto prop = ((PropEncoding)mProp);
+    prop.inhibited = f;
+    mProp = prop.i;
+  }
+  bool getInhibited() const { return ((PropEncoding)mProp).inhibited; }
+
   /// get the string representation of the production process
   const char* getProdProcessAsString() const;
 
@@ -226,12 +234,15 @@ class MCTrackT
     struct {
       int storage : 1;  // encoding whether to store this track to the output
       int process : 6;  // encoding process that created this track (enough to store TMCProcess from ROOT)
-      int hitmask : 24; // encoding hits per detector
+      int hitmask : 21; // encoding hits per detector
+      int reserved1 : 1; // bit reserved for possible future purposes
+      int reserved2 : 1; // bit reserved for possible future purposes
+      int inhibited : 1; // whether tracking of this was inhibited
       int toBeDone : 1; // whether this (still) needs tracking --> we might more complete information to cover full ParticleStatus space
     };
   };
 
-  ClassDefNV(MCTrackT, 3);
+  ClassDefNV(MCTrackT, 4);
 };
 
 template <typename T>
@@ -318,6 +329,11 @@ inline MCTrackT<T>::MCTrackT(const TParticle& part)
   setProcess(part.GetUniqueID());
   // extract toBeDone flag
   setToBeDone(part.TestBit(ParticleStatus::kToBeDone));
+  // extract inhibited flag
+  if (part.TestBit(ParticleStatus::kInhibited)) {
+    setToBeDone(true); // if inhibited, it had to be done: restore flag
+    setInhibited(true);
+  }
 }
 
 template <typename T>