windows-nt/Source/XPSP1/NT/sdktools/fsdump/inc/bsfixalloc.h
2020-09-26 16:20:57 +08:00

116 lines
2.5 KiB
C++

/*++
Copyright (c) 2000-2001 Microsoft Corporation
Module Name:
bsfixalloc.h
Abstract:
Adapted rom MFC fixalloc.h
Author:
Stefan R. Steiner [ssteiner] 04-10-2000
Revision History:
--*/
#ifndef __H_BSFIXALLOC_
#define __H_BSFIXALLOC_
// fixalloc.h - declarations for fixed block allocator
#pragma pack(push, 8)
struct CBsPlex // warning variable length structure
{
CBsPlex* pNext;
DWORD dwReserved[1]; // align on 8 byte boundary
// BYTE data[maxNum*elementSize];
void* data() { return this+1; }
static CBsPlex* PASCAL Create(CBsPlex*& head, UINT nMax, UINT cbElement);
// like 'calloc' but no zero fill
// may throw memory exceptions
void FreeDataChain(); // free this one and links
};
#pragma pack(pop)
/////////////////////////////////////////////////////////////////////////////
// CBsFixedAlloc
class CBsFixedAlloc
{
// Constructors
public:
CBsFixedAlloc(UINT nAllocSize, UINT nBlockSize = 64);
// Attributes
UINT GetAllocSize() { return m_nAllocSize; }
// Operations
public:
void* Alloc(); // return a chunk of memory of nAllocSize
void Free(void* p); // free chunk of memory returned from Alloc
void FreeAll(); // free everything allocated from this allocator
// Implementation
public:
~CBsFixedAlloc();
protected:
struct CNode
{
CNode* pNext; // only valid when in free list
};
UINT m_nAllocSize; // size of each block from Alloc
UINT m_nBlockSize; // number of blocks to get at a time
CBsPlex* m_pBlocks; // linked list of blocks (is nBlocks*nAllocSize)
CNode* m_pNodeFree; // first free node (NULL if no free nodes)
CRITICAL_SECTION m_protect;
};
#ifndef _DEBUG
// DECLARE_FIXED_ALLOC -- used in class definition
#define DECLARE_FIXED_ALLOC(class_name) \
public: \
void* operator new(size_t size) \
{ \
ASSERT(size == s_alloc.GetAllocSize()); \
UNUSED(size); \
return s_alloc.Alloc(); \
} \
void* operator new(size_t, void* p) \
{ return p; } \
void operator delete(void* p) { s_alloc.Free(p); } \
void* operator new(size_t size, LPCSTR, int) \
{ \
ASSERT(size == s_alloc.GetAllocSize()); \
UNUSED(size); \
return s_alloc.Alloc(); \
} \
protected: \
static CBsFixedAlloc s_alloc \
// IMPLEMENT_FIXED_ALLOC -- used in class implementation file
#define IMPLEMENT_FIXED_ALLOC(class_name, block_size) \
CBsFixedAlloc class_name::s_alloc(sizeof(class_name), block_size) \
#else //!_DEBUG
#define DECLARE_FIXED_ALLOC(class_name) // nothing in debug
#define IMPLEMENT_FIXED_ALLOC(class_name, block_size) // nothing in debug
#endif //!_DEBUG
#endif // __H_BSFIXALLOC_