Windows共享內存可以讓兩個進程對同一塊內存進行讀寫。
以下有2個進程,a.cpp生成A進程,b.cpp生成b進程。那么a進程將不停地讀名為"Global\\MyFileMappingObject"的共享內存塊,而b進程不停地寫名為"Global\\MyFileMappingObject"的共享內存塊。從而實現IPC。
//a.cpp #include <windows.h> #include <string.h> #include <string> #include <iostream> #include <tchar.h> using namespace std; #define BUF_SIZE 256 TCHAR szName[]=TEXT("Global\\MyFileMappingObject"); //指向同一塊共享內存的名字 int main(int argc, char *argv[]) { HANDLE hMapFile; LPCTSTR pBuf; hMapFile = CreateFileMapping( INVALID_HANDLE_VALUE, // use paging file NULL, // default security PAGE_READWRITE, // read/write access 0, // maximum object size (high-order DWORD) BUF_SIZE, // maximum object size (low-order DWORD) szName); // name of mapping object if (hMapFile == NULL) { _tprintf(TEXT("Could not create file mapping object (%d).\n"), GetLastError()); return 1; } pBuf = (LPTSTR) MapViewOfFile(hMapFile, // handle to map object FILE_MAP_ALL_ACCESS, // read/write permission 0, 0, BUF_SIZE); if (pBuf == NULL) { _tprintf(TEXT("Could not map view of file (%d).\n"), GetLastError()); CloseHandle(hMapFile); return 1; } //從main開始至此,A B process代碼一樣,都是獲取名為"Global\\MyFileMappingObject"的共享內存的指針 //以下代碼,A不停地讀共享內存pBuf while(1) { cout<<pBuf<<endl; cout<<"A process: hit keyboard to receive from B process"<<endl; getchar(); } UnmapViewOfFile(pBuf); CloseHandle(hMapFile); return 0; }
//b.cpp #include <iostream> #include <Windows.h> #include <tchar.h> using namespace std; #define BUF_SIZE 256 TCHAR szName[]=TEXT("Global\\MyFileMappingObject"); //指向同一塊共享內存的名字 int main() { HANDLE hMapFile; LPCTSTR pBuf; hMapFile = CreateFileMapping( INVALID_HANDLE_VALUE, // use paging file NULL, // default security PAGE_READWRITE, // read/write access 0, // maximum object size (high-order DWORD) BUF_SIZE, // maximum object size (low-order DWORD) szName); // name of mapping object if (hMapFile == NULL) { _tprintf(TEXT("Could not create file mapping object (%d).\n"), GetLastError()); return 1; } pBuf = (LPTSTR) MapViewOfFile(hMapFile, // handle to map object FILE_MAP_ALL_ACCESS, // read/write permission 0, 0, BUF_SIZE); if (pBuf == NULL) { _tprintf(TEXT("Could not map view of file (%d).\n"), GetLastError()); CloseHandle(hMapFile); return 1; } //從main開始至此,A B process代碼一樣,都是獲取名為"Global\\MyFileMappingObject"的共享內存的指針 //以下代碼,B不停寫共享內存pBuf while(1) { TCHAR s[BUF_SIZE]; cout<<"B process: plz input sth. to be transfered to A process."<<endl; cin>>s; memcpy((PVOID)pBuf, s, BUF_SIZE); } }