Merge branch 'MaterialEffectsUpdator_boost_thread_specific' into 'master'

move to boost::thread_specific_ptr for the TLS part

See merge request atlas/athena!14566

Former-commit-id: 0163d42a

Tracking/TrkExtrapolation/TrkExTools/TrkExTools/MaterialEffectsUpdator.h

@@ -184,47 +184,6 @@ class MaterialEffectsUpdator : public AthAlgTool,
       return;
     }
 
-  private:
-    /*
-     * Each instance (out of N) needs a have cache in order to accumulate calculation 
-     * between calls to its methods. In a Multi Thread environment we will 
-     * have pontially M threads running. So we need MxN cache instance.
-     *
-     * The solution adopted here is an effort to implement 
-     * "Schmidt, Douglas & Pryce, Nat & H. Harrison, Timothy. (1998). 
-     * Thread-Specific Storage for C/C++ - An Object
-     * Behavioral Pattern for Accessing per-Thread State Efficiently."
-     * Published in "More C++ Gems (SIGS Reference Library)".
-     * The solution in Figure 5 is adopted here. One could also adopt Figure 4 as 
-     * an alternative
-     *
-     * We have  M thread_local ptr to vectors. So one vector for each thread.  
-     * For the lookup each object needs a uniqueID. This is created in the initialize 
-     * by hashing the unique's instance full name. 
-     *
-     * Following https://google.github.io/styleguide/cppguide.html#thread_local
-     * the thread local is only exposed from inside a function. 
-     *
-     * Using thread_local unique_ptr<T>  achieves 
-     * the same behaviour as boost::thread_specific_ptr<T>
-     */
-
-    Cache& getTLSCache() const{ 
-
-      typedef std::vector<Cache> TLSCollection;
-      /* Initialize a unique ptr to default constructed TLSCollection*/
-      thread_local std::unique_ptr<TLSCollection> s_cacheStore= std::make_unique<TLSCollection>();        
-      
-      /* Resize the vector, to the requested number of Caches
-       * Default constructs elements
-       */
-      if (m_uniqueID>s_cacheStore->size()) {
-        s_cacheStore->resize(m_uniqueID);
-      } 
-      size_t index= m_uniqueID-1;
-      return s_cacheStore->operator[](index); 
-    }
-
   public:
     /* 
      * Public methods using the TLS cache.
@@ -359,7 +318,6 @@ class MaterialEffectsUpdator : public AthAlgTool,
     bool                         m_landauMode;                         //!< If in Landau mode, error propagation is done as for landaus 
     int                          m_validationDirection;                //!< validation direction
     //  ------------------------------
-    std::size_t                  m_uniqueID;              //!< UniqueID Hash based on the unique instance name
     double                       m_momentumCut;           //!< Minimal momentum cut for update
     double                       m_momentumMax;           //!< Maximal momentum cut for update
     double                       m_forcedMomentum;        //!< Forced momentum value
@@ -368,6 +326,27 @@ class MaterialEffectsUpdator : public AthAlgTool,
     ToolHandle< IMultipleScatteringUpdator > m_msUpdator; //!< AlgoTool for MultipleScatterin effects
     // the material mapper for the validation process
     ToolHandle< IMaterialMapper > m_materialMapper;            //!< the material mapper for recording the layer material 
+    
+    /*
+     *  TLS part
+     *  The solution adopted here is an effort to implement 
+     * "Schmidt, Douglas & Pryce, Nat & H. Harrison, Timothy. (1998). 
+     * Thread-Specific Storage for C/C++ - An Object
+     * Behavioral Pattern for Accessing per-Thread State Efficiently."
+     * Published in "More C++ Gems (SIGS Reference Library)".
+     * Adopted here via boost::thread_specific_ptr
+     */
+
+    mutable boost::thread_specific_ptr<Cache> m_cache_tls;
+    Cache& getTLSCache() const{ 
+      Cache* cache = m_cache_tls.get();
+      if (!cache) {
+        cache = new Cache();
+        m_cache_tls.reset( cache );
+      }
+      return *cache; 
+    }
+
 
   };
 } // end of namespace

Tracking/TrkExtrapolation/TrkExTools/src/MaterialEffectsUpdator.cxx

@@ -50,7 +50,6 @@ Trk::MaterialEffectsUpdator::MaterialEffectsUpdator(const std::string &t, const
   m_validationIgnoreUnmeasured(true),
   m_landauMode(false),
   m_validationDirection(1), 
-  m_uniqueID{1},
   m_momentumCut(50. * Gaudi::Units::MeV),
   m_momentumMax(10. * Gaudi::Units::TeV),
   m_forcedMomentum(2000. * Gaudi::Units::MeV),
@@ -89,23 +88,6 @@ Trk::MaterialEffectsUpdator::~MaterialEffectsUpdator() {
 StatusCode
 Trk::MaterialEffectsUpdator::initialize() {
 
-  /*
-   * Create a unique_ID (in range 1 ... N) based on the unique AlgTool name
-   * Initialize is a non-const method. We expect a small vector 
-   * and the initialize to run only a few times
-   */
-  size_t NameID=std::hash<std::string>{}(this->name());
-  
-  static std::unique_ptr< std::vector<size_t> > s_vectorNamedIDs
-    =std::make_unique<std::vector<size_t>>();
-  auto iter= std::find(s_vectorNamedIDs->begin(),s_vectorNamedIDs->end(),NameID);
-  if(iter==s_vectorNamedIDs->end()){
-    s_vectorNamedIDs->push_back(NameID);
-    m_uniqueID=s_vectorNamedIDs->size();
-  }else{
-    m_uniqueID = std::distance(s_vectorNamedIDs->begin(),iter) +1;
-  }
-
   ATH_MSG_INFO("Minimal momentum cut for material update : " << m_momentumCut << " MeV");
 
   // retrieve the EnergyLoss Updator and Material Effects updator