G4MaterialPropertiesTable.cc

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// $Id: G4MaterialPropertiesTable.cc 102806 2017-02-22 16:36:36Z gcosmo $
//
// 
// G4MaterialPropertiesTable Implementation
//
// File: G4MaterialPropertiesTable.cc 
// Version:     1.0
// Created:     1996-02-08
// Author:      Juliet Armstrong
// Updated:     2005-05-12 add SetGROUPVEL(), courtesy of
//              Horton-Smith (bug report #741), by P. Gumplinger
//              2002-11-05 add named material constants by P. Gumplinger
//              1999-11-05 Migration from G4RWTPtrHashDictionary to STL
//                         by John Allison
//              1997-03-26 by Peter Gumplinger
//              > cosmetics (only)
// mail:        gum@triumf.ca
//

#include "globals.hh"
#include "G4MaterialPropertiesTable.hh"
#include "G4PhysicalConstants.hh"
#include "G4Log.hh"

// Constructors

G4MaterialPropertiesTable::G4MaterialPropertiesTable()
{
}

// Destructor

G4MaterialPropertiesTable::~G4MaterialPropertiesTable()
{
  MPTiterator i;
  for (i = MPT.begin(); i != MPT.end(); ++i)
  {
    delete (*i).second;
  }
  MPT.clear();
  MPTC.clear();
}

// Methods

G4double G4MaterialPropertiesTable::GetConstProperty(const char *key) const
{
  // Returns the constant material property corresponding to a key

  MPTCiterator j;
  j = MPTC.find(G4String(key));
  if ( j != MPTC.end() ) return j->second;
  G4cout << "key: " << G4String(key) << G4endl;
  G4Exception("G4MaterialPropertiesTable::GetConstProperty()","mat202",
              FatalException, "Constant Material Property not found.");
  return 0.;
}

G4bool G4MaterialPropertiesTable::ConstPropertyExists(const char *key) const
{
  // Returns true if a const property 'key' exists

  MPTCiterator j;
  j = MPTC.find(G4String(key));
  if ( j != MPTC.end() ) return true;
  return false;
}

G4MaterialPropertyVector*
G4MaterialPropertiesTable::GetProperty(const char *key)
{
  // Returns a Material Property Vector corresponding to a key

  //Important Note for MT. adotti 17 Feb 2016
  //In previous implementation the following line was at the bottom of the
  //function causing a rare race-condition.
  //Moving this line here from the bottom solves the problem because:
  //1- Map is accessed only via operator[] (to insert) and find() (to search),
  //   and these are thread safe if done on separate elements.
  //   See notes on data-races at:
  //   http://www.cplusplus.com/reference/map/map/operator%5B%5D/
  //   http://www.cplusplus.com/reference/map/map/find/
  //2- So we have a data race if two threads access the same element (GROUPVEL)
  //   one in read and one in write mode. This was happening with the line
  //   at the bottom of the code, one thread in SetGROUPVEL(), 
  //   and the other here
  //3- SetGROUPVEL() is protected by a mutex that ensures that only
  //   one thread at the time will execute its code
  //4- The if() statement guarantees that only if two threads are searching
  //   the same problematic key (GROUPVEL) the mutex will be used.
  //   Different keys do not lock (good for performances)
  //5- As soon as a thread acquires the mutex in SetGROUPVEL it checks again
  //   if the map has GROUPVEL key, if so returns immediately.
  //   This "double check" allows to execute the heavy code to calculate
  //   group velocity only once even if two threads enter SetGROUPVEL together
  if (G4String(key) == "GROUPVEL") return SetGROUPVEL();

  MPTiterator i;
  i = MPT.find(G4String(key));
  if ( i != MPT.end() ) return i->second;
  return nullptr;
}

void G4MaterialPropertiesTable::AddEntry(const char *key,
                                         G4double    aPhotonEnergy,
                                         G4double    aPropertyValue)
{
  // Allows to add an entry pair directly to the Material Property Vector
  // given a key

  G4MaterialPropertyVector *targetVector=MPT [G4String(key)];
  if (targetVector != nullptr)
  {
    targetVector->InsertValues(aPhotonEnergy, aPropertyValue);
  }
  else
  {
    G4Exception("G4MaterialPropertiesTable::AddEntry()", "mat203",
                FatalException, "Material Property Vector not found.");
  }
}

void G4MaterialPropertiesTable::DumpTable()
{
  MPTiterator i;
  for (i = MPT.begin(); i != MPT.end(); ++i)
  {
    G4cout << (*i).first << G4endl;
    if ( (*i).second != 0 )
    {
      (*i).second->DumpValues();
    }
    else
    {
      G4Exception("G4MaterialPropertiesTable::DumpTable()", "mat204",
                  JustWarning, "NULL Material Property Vector Pointer.");
    }
  }
  MPTCiterator j;
  for (j = MPTC.begin(); j != MPTC.end(); ++j)
  {
    G4cout << j->first << G4endl;
    if ( j->second != 0 )
    {
      G4cout << j->second << G4endl;
    }
    else
    {
      G4Exception("G4MaterialPropertiesTable::DumpTable()", "mat202",
                  JustWarning, "No Material Constant Property.");
    }
  }
}

#ifdef G4MULTITHREADED
#include "G4AutoLock.hh"
namespace {
 G4Mutex materialPropertyTableMutex = G4MUTEX_INITIALIZER;
}
#endif

G4MaterialPropertyVector* G4MaterialPropertiesTable::SetGROUPVEL()
{
#ifdef G4MULTITHREADED
  G4AutoLock mptm(&materialPropertyTableMutex);
#endif

  // check if "GROUPVEL" already exists
  MPTiterator itr;
  itr = MPT.find("GROUPVEL");
  if(itr != MPT.end()) return itr->second;

  // fetch RINDEX data, give up if unavailable
  //
  G4MaterialPropertyVector *rindex = this->GetProperty("RINDEX");
  if (rindex==0)  { return 0; }

  // RINDEX exists but has no entries, give up
  //
  if ( rindex->GetVectorLength() == 0 ) { return 0; }

  // add GROUPVEL vector
  //
  G4MaterialPropertyVector* groupvel = new G4MaterialPropertyVector();

  // fill GROUPVEL vector using RINDEX values
  // rindex built-in "iterator" was advanced to first entry above
  //
  G4double E0 = rindex->Energy(0);
  G4double n0 = (*rindex)[0];

  if (E0 <= 0.)
  {
    G4Exception("G4MaterialPropertiesTable::SetGROUPVEL()", "mat205",
                FatalException, "Optical Photon Energy <= 0");
  }
                                                                                
  if ( rindex->GetVectorLength() >= 2 )
  {
    // good, we have at least two entries in RINDEX
    // get next energy/value pair

    G4double E1 = rindex->Energy(1);
    G4double n1 = (*rindex)[1];

    if (E1 <= 0.)
    {
      G4Exception("G4MaterialPropertiesTable::SetGROUPVEL()", "mat205",
                  FatalException, "Optical Photon Energy <= 0");
    }

    G4double vg;

    // add entry at first photon energy
    //
    vg = c_light/(n0+(n1-n0)/G4Log(E1/E0));

    // allow only for 'normal dispersion' -> dn/d(logE) > 0
    //
    if((vg<0) || (vg>c_light/n0))  { vg = c_light/n0; }

    groupvel->InsertValues( E0, vg );

    // add entries at midpoints between remaining photon energies
    //

    for (size_t i = 2; i < rindex->GetVectorLength(); i++)
    {
      vg = c_light/( 0.5*(n0+n1)+(n1-n0)/G4Log(E1/E0));

      // allow only for 'normal dispersion' -> dn/d(logE) > 0
      //
      if((vg<0) || (vg>c_light/(0.5*(n0+n1))))  { vg = c_light/(0.5*(n0+n1)); }
      groupvel->InsertValues( 0.5*(E0+E1), vg );

      // get next energy/value pair, or exit loop
      //
      E0 = E1;
      n0 = n1;
      E1 = rindex->Energy(i);
      n1 = (*rindex)[i];

      if (E1 <= 0.)
      {
        G4Exception("G4MaterialPropertiesTable::SetGROUPVEL()", "mat205",
                    FatalException, "Optical Photon Energy <= 0");
      }
    }

    // add entry at last photon energy
    //
    vg = c_light/(n1+(n1-n0)/G4Log(E1/E0));

    // allow only for 'normal dispersion' -> dn/d(logE) > 0
    //
    if((vg<0) || (vg>c_light/n1))  { vg = c_light/n1; }
    groupvel->InsertValues( E1, vg );
  }
  else // only one entry in RINDEX -- weird!
  {
    groupvel->InsertValues( E0, c_light/n0 );
  }
                                                                                
  this->AddProperty( "GROUPVEL", groupvel );
                                                                                
  return groupvel;
}