AllocatorPool.cpp

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// ============================================================================
// ============================================================================
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//
// ----------------------------------------------------------------------
// G4AllocatorPool
//
// Implementation file
//
// Author: G.Cosmo, November 2000
//
// ============================================================================
// Include files 
// ============================================================================
// GaudiKernel
// ============================================================================
#include "GaudiKernel/AllocatorPool.h"
// ============================================================================

// ************************************************************
// G4AllocatorPool constructor
// ************************************************************
//
GaudiUtils::AllocatorPool::AllocatorPool
( unsigned int sz )
  : esize(sz<sizeof(PoolLink) ? sizeof(PoolLink) : sz),
    csize(sz<1024/2-16 ? 1024-16 : sz*10-16)
{}

// ************************************************************
// G4AllocatorPool copy constructor
// ************************************************************
//
GaudiUtils::AllocatorPool::AllocatorPool(const AllocatorPool& right)
  : esize(right.esize), csize(right.csize)
{
  *this = right;
} 

// ************************************************************
// G4AllocatorPool operator=
// ************************************************************
//
GaudiUtils::AllocatorPool&
GaudiUtils::AllocatorPool::operator= 
(const GaudiUtils::AllocatorPool& right)
{
  if (&right == this) { return *this; }
  chunks  = right.chunks;
  head    = right.head;
  nchunks = right.nchunks;
  return *this;
}

// ************************************************************
// G4AllocatorPool destructor
// ************************************************************
//
GaudiUtils::AllocatorPool::~AllocatorPool()
{
  Reset();
}

// ************************************************************
// Reset
// ************************************************************
//
void GaudiUtils::AllocatorPool::Reset()
{
  // Free all chunks
  //
  PoolChunk* n = chunks;
  PoolChunk* p = nullptr;
  while (n)
  {
    p = n;
    n = n->next;
    delete p;
  }
  head = nullptr;
  chunks = nullptr;
  nchunks = 0;
}

// ************************************************************
// Grow
// ************************************************************
//
void GaudiUtils::AllocatorPool::Grow()
{
  // Allocate new chunk, organize it as a linked list of
  // elements of size 'esize'
  //
  auto  n = new PoolChunk(csize);
  n->next = chunks;
  chunks = n;
  ++nchunks;
  
  const int nelem = csize/esize;
  char* start = n->mem.get();
  char* last = &start[(nelem-1)*esize];
  for (char* p=start; p<last; p+=esize)
  {
    reinterpret_cast<PoolLink*>(p)->next
      = reinterpret_cast<PoolLink*>(p+esize);
  }
  reinterpret_cast<PoolLink*>(last)->next = nullptr;
  head = reinterpret_cast<PoolLink*>(start);
}


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// The END 
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