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Documentation                       Search   block_memory.h Go to the documentation of this file. /* Copyright, 2001 Nevrax Ltd. * * This file is part of NEVRAX NEL. * NEVRAX NEL is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * NEVRAX NEL is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * You should have received a copy of the GNU General Public License * along with NEVRAX NEL; see the file COPYING. If not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, * MA 02111-1307, USA. */ #ifndef NL_BLOCK_MEMORY_H #define NL_BLOCK_MEMORY_H #include "nel/misc/types_nl.h" #include <list> #include <vector> #include "nel/misc/debug.h" namespace NLMISC { // *************************************************************************** extern bool NL3D_BlockMemoryAssertOnPurge; // =true. // *************************************************************************** template<class T, bool __ctor_dtor__= true > class CBlockMemory { public: CBlockMemory(uint blockSize= 16) { nlassert(blockSize); _BlockSize= blockSize; _EltSize= std::max(sizeof(T), sizeof(void*)); _NextFreeElt= NULL; _NAllocatedElts= 0; } // just copy setup from other blockMemory, don't copy data! CBlockMemory(const CBlockMemory<T, __ctor_dtor__> &other) { _BlockSize= other._BlockSize; // if other block is rebinded, don't copy its rebinded size. _EltSize= std::max(sizeof(T), sizeof(void*)); // No elts allocated _NextFreeElt= NULL; _NAllocatedElts= 0; } ~CBlockMemory() { purge(); } T* allocate() { // if not enough memory, aloc a block. if(!_NextFreeElt) { _Blocks.push_front(CBlock()); buildBlock(*_Blocks.begin()); // new free elt points to the beginning of this block. _NextFreeElt= (*_Blocks.begin()).Data; #ifdef NL_DEBUG // if debug, must decal for begin check. _NextFreeElt= (uint32*)_NextFreeElt + 1; #endif } // choose next free elt. nlassert(_NextFreeElt); T* ret= (T*)_NextFreeElt; // update _NextFreeElt, so it points to the next free element. _NextFreeElt= *(void**)_NextFreeElt; // construct the allocated element. if( __ctor_dtor__ ) #undef new new (ret) T; #define new NL_NEW // some simple Check. #ifdef NL_DEBUG uint32 *checkStart= (uint32*)(void*)ret-1; uint32 *checkEnd = (uint32*)((uint8*)(void*)ret+_EltSize); nlassert( *checkStart == CheckDeletedIdent); nlassert( *checkEnd == CheckDeletedIdent); // if ok, mark this element as allocated. *checkStart= CheckAllocatedIdent; *checkEnd = CheckAllocatedIdent; #endif _NAllocatedElts++; return ret; } void free(T* ptr) { if(!ptr) return; // some simple Check. nlassert(_NAllocatedElts>0); #ifdef NL_DEBUG uint32 *checkStart= (uint32*)(void*)ptr-1; uint32 *checkEnd = (uint32*)((uint8*)(void*)ptr+_EltSize); nlassert( *checkStart == CheckAllocatedIdent); nlassert( *checkEnd == CheckAllocatedIdent); // if ok, mark this element as deleted. *checkStart= CheckDeletedIdent; *checkEnd = CheckDeletedIdent; #endif // destruct the element. if( __ctor_dtor__ ) ptr->~T(); // just append this freed element to the list. *(void**)ptr= _NextFreeElt; _NextFreeElt= (void*) ptr; _NAllocatedElts--; } void purge () { if(NL3D_BlockMemoryAssertOnPurge) nlassert(_NAllocatedElts==0); while(_Blocks.begin()!=_Blocks.end()) { releaseBlock(*_Blocks.begin()); _Blocks.erase(_Blocks.begin()); } _NextFreeElt= NULL; _NAllocatedElts= 0; } // ******************** public: // This is to be used with CSTLBlockAllocator only!!! It change the size of an element!! void __stl_alloc_changeEltSize(uint eltSize) { // must not be used with object ctor/dtor behavior. nlassert(__ctor_dtor__ == false); // format size. eltSize= std::max(eltSize, sizeof(void*)); // if not the same size as before if(_EltSize!= eltSize) { // verify that rebind is made before any allocation!! nlassert(_Blocks.empty()); // change the size. _EltSize= eltSize; } }; // This is to be used with CSTLBlockAllocator only!!! uint __stl_alloc_getEltSize() const { return _EltSize; } private: uint _BlockSize; uint _EltSize; sint _NAllocatedElts; void *_NextFreeElt; struct CBlock { void *Data; }; std::list<CBlock> _Blocks; enum TCheckIdent { CheckAllocatedIdent= 0x01234567, CheckDeletedIdent= 0x89ABCDEF }; private: void buildBlock(CBlock &block) { uint i; uint32 nodeSize= _EltSize; #ifdef NL_DEBUG // must allocate more size for mem checks in debug. nodeSize+= 2*sizeof(uint32); #endif // allocate. block.Data = (void*)new uint8 [_BlockSize * nodeSize]; // by default, all elements are not allocated, build the list of free elements. void *ptr= block.Data; #ifdef NL_DEBUG // if debug, must decal for begin check. ptr= (uint32*)ptr + 1; #endif for(i=0; i<_BlockSize-1; i++) { // next elt. void *next= (uint8*)ptr + nodeSize; // points to the next element in this array. *(void**)ptr= next; // next. ptr= next; } // last element points to NULL. *(void**)ptr= NULL; // If debug, must init all check values to CheckDeletedIdent. #ifdef NL_DEBUG ptr= block.Data; // must decal for begin check. ptr= (uint32*)ptr + 1; // fill all nodes. for(i=0; i<_BlockSize; i++) { uint32 *checkStart= (uint32*)ptr-1; uint32 *checkEnd = (uint32*)((uint8*)ptr+_EltSize); // mark this element as deleted. *checkStart= CheckDeletedIdent; *checkEnd = CheckDeletedIdent; // next elt. ptr= (uint8*)ptr + nodeSize; } #endif } void releaseBlock(CBlock &block) { delete [] ((uint8*)block.Data); } }; } // NLMISC #endif // NL_BLOCK_MEMORY_H /* End of block_memory.h */