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

 

 

 1 // Heap.cpp : 定义控制台应用程序的入口点。  2 //  3 
 4 #include "stdafx.h" 
 5 #include <Windows.h>
 6 #include <iostream>
 7 #include <new>
 8 using namespace std;  9 
 10 int* p = new int(10);  11 
 12 
 13 class CSomeClass  14 {  15 protected:  16 static size_t s_Counts;  17 static HANDLE s_hHeap;  18 
 19 
 20 public:  21 CSomeClass();  22 CSomeClass(int value);  23 virtual ~CSomeClass();  24 
 25 //重载的该运算符为该类的成员函数  26 //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)
 27 void* operator new(size_t);  28 //void* operator new(size_t, const char* fileName, int line); 
 29 void* operator new[](size_t);  30 
 31 void operator delete(void* p);  32 void operator delete[](void* p);  33 //void operator delete(void* p, const char* fileName, int line);
 34 
 35 
 36 int m_value;  37 
 38 };  39 
 40 size_t CSomeClass::s_Counts = 0;  41 HANDLE CSomeClass::s_hHeap = NULL;  42 CSomeClass::CSomeClass(){}  43 
 44 CSomeClass::CSomeClass(int value) : m_value(value){}  45 
 46 CSomeClass::~CSomeClass(){}  47 
 48 void* CSomeClass::operator new(size_t size)  49 //void* CSomeClass::operator new(size_t size, const char* fileName, int line)
 50 {  51 //cout<<endl<<fileName<<", line "<<line<<endl;  52 
 53 //如果是第一个实例，则创建堆
 54 if (NULL == s_hHeap)  55 {  56 s_hHeap = HeapCreate(HEAP_GENERATE_EXCEPTIONS, 0, 0);  57 if (NULL == s_hHeap)  58 {  59 return NULL;  60 }  61 }  62 
 63 void* p = HeapAlloc(s_hHeap, HEAP_ZERO_MEMORY | HEAP_GENERATE_EXCEPTIONS, size);  64 if (NULL != p)  65 {  66 ++s_Counts;  67 }  68 
 69 return p;  70 }  71 
 72 void* CSomeClass::operator new[](size_t size)  73 {  74 //size大小为 sizeof(CSomeClass) * 个数 + 额外信息的大小  75 
 76 //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！！！  77 
 78 //nums为对象的个数
 79 size_t nums = size / sizeof(CSomeClass);  80 
 81 //sizeOfExtra的大小为存储额外信息的空间大小
 82 size_t sizeOfExtra = size % sizeof(CSomeClass);  83 
 84 if (NULL == s_hHeap)  85 {  86 s_hHeap = HeapCreate(HEAP_GENERATE_EXCEPTIONS, 0, 0);  87 if (NULL == s_hHeap)  88 {  89 return NULL;  90 }  91 }  92 
 93 void* p = HeapAlloc(s_hHeap, HEAP_ZERO_MEMORY | HEAP_GENERATE_EXCEPTIONS, size);  94 if (NULL != p)  95 {  96 s_Counts += nums;  97 }  98 
 99 return p; 100 } 101 
102 
103 void CSomeClass::operator delete(void* p) 104 //void CSomeClass::operator delete(void* p, const char* fileName, int line)
105 { 106 if (NULL == p || NULL == s_hHeap) 107 { 108 return; 109 } 110 
111 BOOL bRet = HeapFree(s_hHeap, 0, p); 112 if (FALSE != bRet) 113 { 114 if (--s_Counts == 0) 115 { 116 HeapDestroy(s_hHeap); 117 //CloseHandle(s_hHeap); //保留这一行 有异常 invalid handle
118 s_hHeap = NULL; 119 } 120 } 121 } 122 
123 void CSomeClass::operator delete[](void* p) 124 { 125 if (NULL == p || NULL == s_hHeap) 126 { 127 return; 128 } 129 
130 size_t size = HeapSize(s_hHeap, 0, p); 131 size_t nums = size / sizeof(CSomeClass); 132 size_t sizeOfExtra = size % sizeof(CSomeClass); 133 
134 BOOL bRet = HeapFree(s_hHeap, 0, p); 135 if (FALSE != bRet) 136 { 137 if (0 == (s_Counts -= nums)) 138 { 139 HeapDestroy(s_hHeap); 140 s_hHeap = NULL; 141 } 142 } 143 } 144 
145 
146 #ifdef _DEBUG 147 //#define new new(__FILE__, __LINE__) 148 //#define delete delete(__FILE__, __LINE__)
149 #endif
150 
151  
152 
153 int __cdecl _tmain(int argc, _TCHAR* argv[], _TCHAR* env[]) 154 { 155 HANDLE hHeaps[25] = {NULL}; 156 DWORD dwHeaps = GetProcessHeaps(sizeof(hHeaps) / sizeof(hHeaps[0]), hHeaps); 157 
158 CSomeClass* pAddr2 = new CSomeClass[10](); 159 dwHeaps = GetProcessHeaps(sizeof(hHeaps) / sizeof(hHeaps[0]), hHeaps); 160 delete[] pAddr2; 161 dwHeaps = GetProcessHeaps(sizeof(hHeaps) / sizeof(hHeaps[0]), hHeaps); 162 
163 #pragma region 测试1
164 int size = sizeof(CSomeClass); 165 cout<<"sizeof(CSomeClass) is "<<size<<endl; 166 
167 CSomeClass* pObj = new CSomeClass(size * 2); 168 pObj->m_value = 100; 169 CSomeClass* pObj2 = new CSomeClass(); 170 pObj2->m_value = 200; 171 
172 delete pObj; 173 //delete pObj2; 
174 #pragma endregion
175 
176 
177 CSomeClass* pArr = new CSomeClass[10]; 178 
179 
180 //UINT HeapCompact(HANDLE hHeap, DWORD fdwFlags) 181 //BOOL HeapLock(HANDLE hHeap); 182 //BOOL HeapUnLock(HANDLE hHeap); 183 //BOOL HeapWalk(HANDLE hHEap, PROCESS_HEAP_ENTRY pHeapEntry)
184 /*
185 BOOL bRet = FALSE; 186 PROCESS_HEAP_ENTRY phe; 187 phe.lpData = NULL; 188 
189 HeapLock(hHeap); 190 while(TRUE == (bRet = HeapWalk(hHeap, 0, &phe)) 191 { 192 //do something 193 phe.lpData = NULL; 194 } 195 
196 HeapUnLock(hHeap); 197 
198 */
199 
200  
201 
202 
203 return 0; 204 } 205 
206 
207 /*
208 int _tmain(int argc, _TCHAR* argv[]) 209 { 210 HANDLE hHeap = HeapCreate(HEAP_GENERATE_EXCEPTIONS, 0, 0); 211 if (NULL == hHeap) 212 { 213 cerr<<"Create heap error \n"; 214 return -1; 215 } 216 
217 //BOOL bRet = HeapSetInformation(hHeap, HeapEnableTerminationOnCorruption, NULL, 0); 218 
219 ULONG HeapInformationValue = 2; 220 BOOL bRet = HeapSetInformation( 221 hHeap, HeapCompatibilityInformation, &HeapInformationValue, sizeof(HeapInformationValue)); 222 
223 
224 size_t size = 100; 225 PVOID pAddr = HeapAlloc(hHeap, HEAP_ZERO_MEMORY | HEAP_GENERATE_EXCEPTIONS, size); 226 if(NULL == pAddr) 227 { 228 HeapFree(hHeap, 0, pAddr); //释放申请的内存快 229 HeapDestroy(hHeap); //销毁堆 230 CloseHandle(hHeap); //关闭句柄 231 cerr<<"HeapAlloc error \n"; 232 return -2; 233 } 234 
235 *((int*)(pAddr)) = 100; 236 cout<<"int pAddr is "<<*((int*)(pAddr))<<endl; 237 
238 cout<<"alloc size of heap is "<<HeapSize(hHeap, 0, pAddr)<<endl; 239 
240 PVOID pAddr2 = HeapReAlloc(hHeap, HEAP_GENERATE_EXCEPTIONS | HEAP_ZERO_MEMORY | HEAP_REALLOC_IN_PLACE_ONLY, 241 pAddr, size * 20); 242 if (NULL == pAddr2) 243 { 244 HeapFree(hHeap, 0, pAddr); 245 HeapDestroy(hHeap); 246 CloseHandle(hHeap); 247 cerr<<"HeapReAlloc error \n"; 248 
249 return -3; 250 } 251 cout<<"int pAddr2 is "<<*((int*)(pAddr2) + 1)<<endl; 252 
253 cout<<"Realloc size of heap is "<<HeapSize(hHeap, 0, pAddr2)<<endl; 254 
255 HeapFree(hHeap, 0, pAddr2); 256 HeapDestroy(hHeap); 257 CloseHandle(hHeap); 258 cout<<"Heap opera is finish "<<endl; 259 
260 
261 return 0; 262 } 263 
264 */