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00001 
+00007 /* Copyright, 2001 Nevrax Ltd.
+00008  *
+00009  * This file is part of NEVRAX NEL.
+00010  * NEVRAX NEL is free software; you can redistribute it and/or modify
+00011  * it under the terms of the GNU General Public License as published by
+00012  * the Free Software Foundation; either version 2, or (at your option)
+00013  * any later version.
+00014 
+00015  * NEVRAX NEL is distributed in the hope that it will be useful, but
+00016  * WITHOUT ANY WARRANTY; without even the implied warranty of
+00017  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+00018  * General Public License for more details.
+00019 
+00020  * You should have received a copy of the GNU General Public License
+00021  * along with NEVRAX NEL; see the file COPYING. If not, write to the
+00022  * Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+00023  * MA 02111-1307, USA.
+00024  */
+00025 
+00026 #ifndef NL_BLOCK_MEMORY_H
+00027 #define NL_BLOCK_MEMORY_H
+00028 
+00029 #include "nel/misc/types_nl.h"
+00030 #include <list>
+00031 #include <vector>
+00032 #include "nel/misc/debug.h"
+00033 
+00034 
+00035 namespace NLMISC 
+00036 {
+00037 
+00038 
+00039 // ***************************************************************************
+00041 extern  bool            NL3D_BlockMemoryAssertOnPurge;  // =true.
+00042 
+00043 
+00044 // ***************************************************************************
+00063 template<class T, bool __ctor_dtor__= true >
+00064 class CBlockMemory
+00065 {
+00066 public:
+00067 
+00069         CBlockMemory(uint blockSize= 16)
+00070         {
+00071                 nlassert(blockSize);
+00072                 _BlockSize= blockSize;
+00073                 _EltSize= std::max(sizeof(T), sizeof(void*));
+00074                 _NextFreeElt= NULL;
+00075                 _NAllocatedElts= 0;
+00076         }
+00077         // just copy setup from other blockMemory, don't copy data!
+00078         CBlockMemory(const CBlockMemory<T, __ctor_dtor__> &other)
+00079         {
+00080                 _BlockSize= other._BlockSize;
+00081                 // if other block is rebinded, don't copy its rebinded size.
+00082                 _EltSize= std::max(sizeof(T), sizeof(void*));
+00083                 // No elts allocated
+00084                 _NextFreeElt= NULL;
+00085                 _NAllocatedElts= 0;
+00086         }
+00089         ~CBlockMemory()
+00090         {
+00091                 purge();
+00092         }
+00093 
+00094 
+00096         T*                              allocate()
+00097         {
+00098                 // if not enough memory, aloc a block.
+00099                 if(!_NextFreeElt)
+00100                 {
+00101                         _Blocks.push_front(CBlock());
+00102                         buildBlock(*_Blocks.begin());
+00103                         // new free elt points to the beginning of this block.
+00104                         _NextFreeElt= (*_Blocks.begin()).Data;
+00105 #ifdef NL_DEBUG
+00106                         // if debug, must decal for begin check.
+00107                         _NextFreeElt= (uint32*)_NextFreeElt + 1;
+00108 #endif
+00109                 }
+00110 
+00111                 // choose next free elt.
+00112                 nlassert(_NextFreeElt);
+00113                 T*              ret= (T*)_NextFreeElt;
+00114 
+00115                 // update _NextFreeElt, so it points to the next free element.
+00116                 _NextFreeElt= *(void**)_NextFreeElt;
+00117                 
+00118                 // construct the allocated element.
+00119                 if( __ctor_dtor__ )
+00120 #undef new
+00121                         new (ret) T;
+00122 #define new NL_NEW
+00123 
+00124 
+00125                 // some simple Check.
+00126 #ifdef NL_DEBUG
+00127                 uint32  *checkStart= (uint32*)(void*)ret-1;
+00128                 uint32  *checkEnd  = (uint32*)((uint8*)(void*)ret+_EltSize);
+00129                 nlassert( *checkStart == CheckDeletedIdent);
+00130                 nlassert( *checkEnd   == CheckDeletedIdent);
+00131                 // if ok, mark this element as allocated.
+00132                 *checkStart= CheckAllocatedIdent;
+00133                 *checkEnd  = CheckAllocatedIdent;
+00134 #endif
+00135 
+00136                 _NAllocatedElts++;
+00137                 return ret;
+00138         }
+00139 
+00141         void                    free(T* ptr)
+00142         {
+00143                 if(!ptr)
+00144                         return;
+00145                 // some simple Check.
+00146                 nlassert(_NAllocatedElts>0);
+00147 #ifdef NL_DEBUG
+00148                 uint32  *checkStart= (uint32*)(void*)ptr-1;
+00149                 uint32  *checkEnd  = (uint32*)((uint8*)(void*)ptr+_EltSize);
+00150                 nlassert( *checkStart == CheckAllocatedIdent);
+00151                 nlassert( *checkEnd   == CheckAllocatedIdent);
+00152                 // if ok, mark this element as deleted.
+00153                 *checkStart= CheckDeletedIdent;
+00154                 *checkEnd  = CheckDeletedIdent;
+00155 #endif
+00156                 
+00157                 // destruct the element.
+00158                 if( __ctor_dtor__ )
+00159                         ptr->~T();
+00160 
+00161                 // just append this freed element to the list.
+00162                 *(void**)ptr= _NextFreeElt;
+00163                 _NextFreeElt= (void*) ptr;
+00164 
+00165                 _NAllocatedElts--;
+00166         }
+00167 
+00168 
+00174         void    purge ()
+00175         {
+00176                 if(NL3D_BlockMemoryAssertOnPurge)
+00177                         nlassert(_NAllocatedElts==0);
+00178 
+00179                 while(_Blocks.begin()!=_Blocks.end())
+00180                 {
+00181                         releaseBlock(*_Blocks.begin());
+00182                         _Blocks.erase(_Blocks.begin());
+00183                 }
+00184 
+00185                 _NextFreeElt= NULL;
+00186                 _NAllocatedElts= 0;
+00187         }
+00188 
+00189 
+00190 // ********************
+00191 public:
+00192 
+00193         // This is to be used with CSTLBlockAllocator only!!! It change the size of an element!!
+00194         void            __stl_alloc_changeEltSize(uint eltSize)
+00195         {
+00196                 // must not be used with object ctor/dtor behavior.
+00197                 nlassert(__ctor_dtor__ == false);
+00198                 // format size.
+00199                 eltSize= std::max(eltSize, sizeof(void*));
+00200                 // if not the same size as before
+00201                 if(_EltSize!= eltSize)
+00202                 {
+00203                         // verify that rebind is made before any allocation!!
+00204                         nlassert(_Blocks.empty());
+00205                         // change the size.
+00206                         _EltSize= eltSize;
+00207                 }
+00208         };
+00209         // This is to be used with CSTLBlockAllocator only!!!
+00210         uint            __stl_alloc_getEltSize() const
+00211         {
+00212                 return _EltSize;
+00213         }
+00214 
+00215 
+00216 private:
+00218         uint            _BlockSize;
+00220         uint            _EltSize;
+00222         sint            _NAllocatedElts;
+00224         void            *_NextFreeElt;
+00225 
+00226 
+00228         struct  CBlock
+00229         {
+00231                 void            *Data;
+00232         };
+00233 
+00235         std::list<CBlock>       _Blocks;
+00236 
+00237 
+00239         enum  TCheckIdent       { CheckAllocatedIdent= 0x01234567, CheckDeletedIdent= 0x89ABCDEF };
+00240 
+00241 
+00242 private:
+00243         void            buildBlock(CBlock &block)
+00244         {
+00245                 uint    i;
+00246                 uint32  nodeSize= _EltSize;
+00247 #ifdef NL_DEBUG
+00248                 // must allocate more size for mem checks in debug.
+00249                 nodeSize+= 2*sizeof(uint32);
+00250 #endif
+00251 
+00252                 // allocate.
+00253                 block.Data = (void*)new uint8 [_BlockSize * nodeSize];
+00254 
+00255                 // by default, all elements are not allocated, build the list of free elements.
+00256                 void    *ptr= block.Data;
+00257 #ifdef NL_DEBUG
+00258                 // if debug, must decal for begin check.
+00259                 ptr= (uint32*)ptr + 1;
+00260 #endif
+00261                 for(i=0; i<_BlockSize-1; i++)
+00262                 {
+00263                         // next elt.
+00264                         void    *next= (uint8*)ptr + nodeSize;
+00265                         // points to the next element in this array.
+00266                         *(void**)ptr= next;
+00267                         // next.
+00268                         ptr= next;
+00269                 }
+00270                 // last element points to NULL.
+00271                 *(void**)ptr= NULL;
+00272 
+00273 
+00274                 // If debug, must init all check values to CheckDeletedIdent.
+00275 #ifdef NL_DEBUG
+00276                 ptr= block.Data;
+00277                 // must decal for begin check.
+00278                 ptr= (uint32*)ptr + 1;
+00279                 // fill all nodes.
+00280                 for(i=0; i<_BlockSize; i++)
+00281                 {
+00282                         uint32  *checkStart= (uint32*)ptr-1;
+00283                         uint32  *checkEnd  = (uint32*)((uint8*)ptr+_EltSize);
+00284                         // mark this element as deleted.
+00285                         *checkStart= CheckDeletedIdent;
+00286                         *checkEnd  = CheckDeletedIdent;
+00287 
+00288                         // next elt.
+00289                         ptr= (uint8*)ptr + nodeSize;
+00290                 }
+00291 #endif
+00292 
+00293         }
+00294         void            releaseBlock(CBlock &block)
+00295         {
+00296                 delete [] ((uint8*)block.Data);
+00297         }
+00298 
+00299 };
+00300 
+00301 
+00302 } // NLMISC
+00303 
+00304 
+00305 #endif // NL_BLOCK_MEMORY_H
+00306 
+00307 /* End of block_memory.h */
+