【Windows核心编程】重载类成员函数new / new[] / delete / delete[]

 // Heap.cpp : 定义控制台应用程序的入口点。
 //

 #include "stdafx.h"
 #include <Windows.h>
 #include <iostream>
 #include <new>
 using namespace std;

 int* p = new int();

 class CSomeClass
 {
 protected:
 static size_t s_Counts;
 static HANDLE s_hHeap;

 public:
 CSomeClass();
 CSomeClass(int value);
 virtual ~CSomeClass();

 //重载的该运算符为该类的成员函数
 //所以 这里的size_t参数分配的字节数不必显示指定，该参数为sizeof(该类)
 void* operator new(size_t);
 //void* operator new(size_t, const char* fileName, int line);
 void* operator new[](size_t);

 void operator delete(void* p);
 void operator delete[](void* p);
 //void operator delete(void* p, const char* fileName, int line);

 int m_value;

 };

 size_t CSomeClass::s_Counts = ;
 HANDLE CSomeClass::s_hHeap = NULL;
 CSomeClass::CSomeClass(){}

 CSomeClass::CSomeClass(int value) : m_value(value){}

 CSomeClass::~CSomeClass(){}

 void* CSomeClass::operator new(size_t size)
 //void* CSomeClass::operator new(size_t size, const char* fileName, int line)
 {
 //cout<<endl<<fileName<<", line "<<line<<endl;

 //如果是第一个实例，则创建堆
 if (NULL == s_hHeap)
 {
 s_hHeap = HeapCreate(HEAP_GENERATE_EXCEPTIONS, , );
 if (NULL == s_hHeap)
 {
 return NULL;
 }
 }

 void* p = HeapAlloc(s_hHeap, HEAP_ZERO_MEMORY | HEAP_GENERATE_EXCEPTIONS, size);
 if (NULL != p)
 {
 ++s_Counts;
 }

 return p;
 }

 void* CSomeClass::operator new[](size_t size)
 {
 //size大小为 sizeof(CSomeClass) * 个数 + 额外信息的大小

 //注意，这里这种做法可能会有问题，只有当额外信息的大小 小于 对象大小时才合理！！！

 //nums为对象的个数
 size_t nums = size / sizeof(CSomeClass);

 //sizeOfExtra的大小为存储额外信息的空间大小
 size_t sizeOfExtra = size % sizeof(CSomeClass);

 if (NULL == s_hHeap)
 {
 s_hHeap = HeapCreate(HEAP_GENERATE_EXCEPTIONS, , );
 if (NULL == s_hHeap)
 {
 return NULL;
 }
 }

 void* p = HeapAlloc(s_hHeap, HEAP_ZERO_MEMORY | HEAP_GENERATE_EXCEPTIONS, size);
 if (NULL != p)
 {
 s_Counts += nums;
 }

 return p;
 }

 void CSomeClass::operator delete(void* p)
 //void CSomeClass::operator delete(void* p, const char* fileName, int line)
 {
 if (NULL == p || NULL == s_hHeap)
 {
 return;
 }

 BOOL bRet = HeapFree(s_hHeap, , p);
 if (FALSE != bRet)
 {
 if (--s_Counts == )
 {
 HeapDestroy(s_hHeap);
 //CloseHandle(s_hHeap); //保留这一行 有异常 invalid handle
 s_hHeap = NULL;
 }
 }
 }

 void CSomeClass::operator delete[](void* p)
 {
 if (NULL == p || NULL == s_hHeap)
 {
 return;
 }

 size_t size = HeapSize(s_hHeap, , p);
 size_t nums = size / sizeof(CSomeClass);
 size_t sizeOfExtra = size % sizeof(CSomeClass);

 BOOL bRet = HeapFree(s_hHeap, , p);
 if (FALSE != bRet)
 {
 if ( == (s_Counts -= nums))
 {
 HeapDestroy(s_hHeap);
 s_hHeap = NULL;
 }
 }
 }

 #ifdef _DEBUG
 //#define new new(__FILE__, __LINE__)
 //#define delete delete(__FILE__, __LINE__)
 #endif

 int __cdecl _tmain(int argc, _TCHAR* argv[], _TCHAR* env[])
 {
 HANDLE hHeaps[] = {NULL};
 DWORD dwHeaps = GetProcessHeaps(sizeof(hHeaps) / sizeof(hHeaps[]), hHeaps);

 CSomeClass* pAddr2 = new CSomeClass[]();
 dwHeaps = GetProcessHeaps(sizeof(hHeaps) / sizeof(hHeaps[]), hHeaps);
 delete[] pAddr2;
 dwHeaps = GetProcessHeaps(sizeof(hHeaps) / sizeof(hHeaps[]), hHeaps);

 #pragma region 测试1
 int size = sizeof(CSomeClass);
 cout<<"sizeof(CSomeClass) is "<<size<<endl;

 CSomeClass* pObj = new CSomeClass(size * );
 pObj->m_value = ;
 CSomeClass* pObj2 = new CSomeClass();
 pObj2->m_value = ;

 delete pObj;
 //delete pObj2;
 #pragma endregion

 CSomeClass* pArr = new CSomeClass[];

 //UINT HeapCompact(HANDLE hHeap, DWORD fdwFlags)
 //BOOL HeapLock(HANDLE hHeap);
 //BOOL HeapUnLock(HANDLE hHeap);
 //BOOL HeapWalk(HANDLE hHEap, PROCESS_HEAP_ENTRY pHeapEntry)
 /*
 BOOL bRet = FALSE;
 PROCESS_HEAP_ENTRY phe;
 phe.lpData = NULL;

 HeapLock(hHeap);
 while(TRUE == (bRet = HeapWalk(hHeap, 0, &phe))
 {
 //do something
 phe.lpData = NULL;
 }

 HeapUnLock(hHeap);

 */

 return ;
 }

 /*
 int _tmain(int argc, _TCHAR* argv[])
 {
 HANDLE hHeap = HeapCreate(HEAP_GENERATE_EXCEPTIONS, 0, 0);
 if (NULL == hHeap)
 {
 cerr<<"Create heap error \n";
 return -1;
 }

 //BOOL bRet = HeapSetInformation(hHeap, HeapEnableTerminationOnCorruption, NULL, 0);

 ULONG HeapInformationValue = 2;
 BOOL bRet = HeapSetInformation(
 hHeap, HeapCompatibilityInformation, &HeapInformationValue, sizeof(HeapInformationValue));

 size_t size = 100;
 PVOID pAddr = HeapAlloc(hHeap, HEAP_ZERO_MEMORY | HEAP_GENERATE_EXCEPTIONS, size);
 if(NULL == pAddr)
 {
 HeapFree(hHeap, 0, pAddr); //释放申请的内存快
 HeapDestroy(hHeap); //销毁堆
 CloseHandle(hHeap); //关闭句柄
 cerr<<"HeapAlloc error \n";
 return -2;
 }

 *((int*)(pAddr)) = 100;
 cout<<"int pAddr is "<<*((int*)(pAddr))<<endl;

 cout<<"alloc size of heap is "<<HeapSize(hHeap, 0, pAddr)<<endl;

 PVOID pAddr2 = HeapReAlloc(hHeap, HEAP_GENERATE_EXCEPTIONS | HEAP_ZERO_MEMORY | HEAP_REALLOC_IN_PLACE_ONLY,
 pAddr, size * 20);
 if (NULL == pAddr2)
 {
 HeapFree(hHeap, 0, pAddr);
 HeapDestroy(hHeap);
 CloseHandle(hHeap);
 cerr<<"HeapReAlloc error \n";

 return -3;
 }
 cout<<"int pAddr2 is "<<*((int*)(pAddr2) + 1)<<endl;

 cout<<"Realloc size of heap is "<<HeapSize(hHeap, 0, pAddr2)<<endl;

 HeapFree(hHeap, 0, pAddr2);
 HeapDestroy(hHeap);
 CloseHandle(hHeap);
 cout<<"Heap opera is finish "<<endl;

 return 0;
 }

 */