使用IMalloc接口来分配内存演示程序
使用IMalloc接口来分配内存演示程序
借助一个Win32程序展示了如何利用OLE的IMalloc接口来分配任务类型和共享类型的内存。
程序运行画面如下：
源码MALLOC.H：
- #ifndef _MALLOC_H_
- #define _MALLOC_H_
- LRESULT PASCAL MallocWndProc(HWND, UINT, WPARAM, LPARAM);
- #define CALLOCS 10
- /*
- * Application defined classes and types.
- */
- class CAppVars
- {
- friend LRESULT PASCAL MallocWndProc(HWND, UINT, WPARAM, LPARAM);
- protected:
- HINSTANCE m_hInst;
- HINSTANCE m_hInstPrev;
- UINT m_nCmdShow;
- HWND m_hWnd;
- LPMALLOC m_pIMalloc;
- BOOL m_fInitialized;
- ULONG m_rgcb[CALLOCS]; //Sizes to allocate
- LPVOID m_rgpv[CALLOCS]; //Allocated pointers
- public:
- CAppVars(HINSTANCE, HINSTANCE, UINT);
- ~CAppVars(void);
- BOOL FInit(void);
- void FreeAllocations(BOOL);
- };
- typedef CAppVars FAR* LPAPPVARS;
- #define CBWNDEXTRA sizeof(LONG)
- #define MALLOCWL_STRUCTURE 0
- #endif // _MALLOC_H_
如下是MALLOC.CPP文件内容：
- #include <windows.h>
- #include <ole2.h>
- #include <initguid.h>
- #include <ole2ver.h>
- #include "malloc.h"
- #include "resource.h"
- int PASCAL WinMain(HINSTANCE hInst, HINSTANCE hInstPrev, LPSTR pszCmdLine, int nCmdShow)
- {
- MSG msg;
- LPAPPVARS pAV;
- int cMsg = 96;
- #ifndef WIN32
- while(!SetMessageQueue(cMsg) && (cMsg-=8));
- #endif
- pAV = new CAppVars(hInst, hInstPrev, nCmdShow);
- if(NULL == pAV)
- {
- return -1;
- }
- if(pAV->FInit())
- {
- while(GetMessage(&msg, NULL, 0, 0))
- {
- TranslateMessage(&msg);
- DispatchMessage(&msg);
- }
- }
- delete pAV;
- return msg.wParam;
- }
- LRESULT PASCAL MallocWndProc(HWND hWnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
- {
- LPAPPVARS pAV;
- LPVOID pv;
- ULONG cb;
- UINT i;
- BOOL fResult = TRUE;
- HRESULT hr;
- pAV = (LPAPPVARS)GetWindowLong(hWnd, MALLOCWL_STRUCTURE);
- switch(iMsg)
- {
- case WM_NCCREATE:
- pAV = (LPAPPVARS)((LONG)((LPCREATESTRUCT)lParam)->lpCreateParams);
- SetWindowLong(hWnd, MALLOCWL_STRUCTURE, (LONG)pAV);
- return (DefWindowProc(hWnd, iMsg, wParam, lParam));
- case WM_DESTROY:
- PostQuitMessage(0);
- break;
- case WM_COMMAND:
- switch(LOWORD(wParam))
- {
- case IDM_IMALLOCCOGETMALLOCTASK:
- pAV->FreeAllocations(TRUE);
- hr = CoGetMalloc(MEMCTX_TASK, &pAV->m_pIMalloc);
- fResult = SUCCEEDED(hr);
- MessageBox(hWnd, ((fResult)? TEXT("CoGetMalloc(task) succeeded."):TEXT("CoGetMalloc(task) failed.")),
- TEXT("MALLOC"), MB_OK);
- break;
- case IDM_IMALLOCCOGETMALLOCSHARED:
- pAV->FreeAllocations(TRUE);
- hr=CoGetMalloc(MEMCTX_SHARED, &pAV->m_pIMalloc);
- fResult = SUCCEEDED(hr);
- MessageBox(hWnd, ((fResult)?TEXT("CoGetMalloc(shared) succeeded."):TEXT("CoGetMalloc(shared) failed.")),
- TEXT("MALLOC"), MB_OK);
- break;
- case IDM_IMALLOCRELEASE:
- pAV->FreeAllocations(TRUE);
- MessageBox(hWnd, TEXT("IMalloc::Release finished."), TEXT("Malloc"), MB_OK);
- break;
- case IDM_IMALLOCALLOC:
- if(NULL == pAV->m_pIMalloc)
- break;
- pAV->FreeAllocations(FALSE);
- for(i=0; i<CALLOCS; i++)
- {
- LPBYTE pb;
- ULONG iByte;
- cb = pAV->m_rgcb[i];
- pAV->m_rgpv[i]=pAV->m_pIMalloc->Alloc(cb);
- //Fill the memory with letters
- pb=(LPBYTE)pAV->m_rgpv[i];
- if(NULL!=pb)
- {
- for(iByte=0; iByte<cb; iByte++)
- {
- *pb++=('a'+i);
- }
- }
- fResult &= (NULL!=pAV->m_rgpv[i]);
- }
- MessageBox(hWnd, ((fResult)?TEXT("IMalloc::Alloc succeeded."):TEXT("IMalloc::Alloc failed.")),
- TEXT("MALLOC"), MB_OK);
- break;
- case IDM_IMALLOCFREE:
- pAV->FreeAllocations(FALSE);
- MessageBox(hWnd, TEXT("IMalloc::Free finished."), TEXT("Malloc"), MB_OK);
- break;
- case IDM_IMALLOCREALLOC:
- if(NULL == pAV->m_pIMalloc)
- break;
- for(i=0; i<CALLOCS; i++)
- {
- LPBYTE pb;
- ULONG iByte;
- pAV->m_rgcb[i]+=128;
- pv=pAV->m_pIMalloc->Realloc(pAV->m_rgpv[i], pAV->m_rgcb[i]);
- if(NULL!=pv)
- {
- pAV->m_rgpv[i]=pv;
- //Fill the new memory with something we can see.
- pb=(LPBYTE)pAV->m_rgpv[i];
- cb=pAV->m_rgcb[i];
- if(NULL!=pb)
- {
- for(iByte=cb-128; iByte<cb; iByte++)
- {
- *pb++=('a'+i);
- }
- }
- }
- else
- {
- fResult = FALSE;
- }
- }
- MessageBox(hWnd, ((fResult)?TEXT("IMalloc::Realloc succeeded."):TEXT("IMalloc::Realloc failed.")),
- TEXT("Malloc"), MB_OK);
- break;
- case IDM_IMALLOCGETSIZE:
- if(NULL==pAV->m_pIMalloc)
- {
- break;
- }
- for(i=0; i<CALLOCS; i++)
- {
- cb = pAV->m_pIMalloc->GetSize(pAV->m_rgpv[i]);
- /*
- * We test that the size is at least what we wanted.
- */
- fResult &= (pAV->m_rgcb[i] <= cb);
- }
- MessageBox(hWnd, ((fResult)?TEXT("IMalloc::GetSize matched."):TEXT("IMalloc::GetSize mismatch.")),
- TEXT("Malloc"), MB_OK);
- break;
- case IDM_IMALLOCDIDALLOC:
- if(NULL==pAV->m_pIMalloc)
- break;
- /*
- * DidAlloc may return -1 if it does not know if
- * it actually allocated something. In that case,
- * we just blindly & in a -1 with no effect.
- */
- for(i=0; i<CALLOCS; i++)
- {
- fResult &= pAV->m_pIMalloc->DidAlloc(pAV->m_rgpv[i]);
- }
- MessageBox(hWnd, ((fResult)?TEXT("IMalloc::DidAlloc is TRUE."):TEXT("IMalloc::DidAlloc is FALSE.")),
- TEXT("IMalloc"), MB_OK);
- break;
- case IDM_IMALLOCHEAPMINIMIZE:
- if(NULL!=pAV->m_pIMalloc)
- {
- pAV->m_pIMalloc->HeapMinimize();
- }
- MessageBox(hWnd, TEXT("IMalloc::HeapMinimize finished."), TEXT("Malloc"), MB_OK);
- break;
- case IDM_IMALLOCEXIT:
- PostMessage(hWnd, WM_CLOSE, 0, 0L);
- break;
- }
- break;
- default:
- return (DefWindowProc(hWnd, iMsg, wParam, lParam));
- }
- return 0L;
- }
- CAppVars::CAppVars(HINSTANCE hInst, HINSTANCE hInstPrev, UINT nCmdShow)
- {
- UINT i;
- ULONG cb;
- //Initialize WinMain parameter holders.
- m_hInst = hInst;
- m_hInstPrev = hInstPrev;
- m_nCmdShow = nCmdShow;
- m_hWnd = NULL;
- m_pIMalloc = NULL;
- m_fInitialized = FALSE;
- // 100 is arbitrary. IMalloc can handle larger.
- cb = 100;
- for(i=0; i<CALLOCS; i++)
- {
- m_rgcb[i] = cb;
- m_rgpv[i] = NULL;
- cb*=2;
- }
- return;
- }
- CAppVars::~CAppVars(void)
- {
- FreeAllocations(TRUE);
- //free the enumerator object if we have one.
- if(m_fInitialized)
- {
- CoUninitialize();
- }
- return;
- }
- BOOL CAppVars::FInit()
- {
- WNDCLASS wc;
- DWORD dwVer;
- //Make sure COMPOBJ.DLL is the right version
- dwVer = CoBuildVersion();
- if(rmm != HIWORD(dwVer) )
- return FALSE;
- //Call CoInitialize so that we can call other Co... functions
- if(FAILED(CoInitialize(NULL)))
- return FALSE;
- m_fInitialized = TRUE;
- if(!m_hInstPrev)
- {
- wc.style = CS_HREDRAW | CS_VREDRAW;
- wc.lpfnWndProc = MallocWndProc;
- wc.cbClsExtra = 0;
- wc.cbWndExtra = CBWNDEXTRA;
- wc.hInstance = m_hInst;
- wc.hIcon = LoadIcon(m_hInst, TEXT("Icon"));
- wc.hCursor = LoadCursor(NULL, IDC_ARROW);
- wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
- wc.lpszMenuName = MAKEINTRESOURCE(IDR_MENU1);
- wc.lpszClassName = TEXT("MALLOC");
- if(!RegisterClass(&wc))
- return FALSE;
- }
- m_hWnd = CreateWindow(TEXT("MALLOC"), TEXT("IMalloc Object Demo"),
- WS_OVERLAPPEDWINDOW, 35, 35, 350, 250, NULL, NULL, m_hInst, this);
- if(NULL == m_hWnd)
- {
- return FALSE;
- }
- ShowWindow(m_hWnd, m_nCmdShow);
- UpdateWindow(m_hWnd);
- return TRUE;
- }
- void CAppVars::FreeAllocations(BOOL fRelease)
- {
- UINT i;
- if(NULL == m_pIMalloc)
- {
- return;
- }
- for(i=0; i<CALLOCS; i++)
- {
- if(NULL!=m_rgpv[i])
- m_pIMalloc->Free(m_rgpv[i]);
- m_rgpv[i] = NULL;
- }
- if(fRelease)
- {
- m_pIMalloc->Release();
- m_pIMalloc = NULL;
- }
- }
任务型内存调用顺序大致如下：
| CoGetMalloc(Task,...) | 得到任务类型接口指针 |
| Alloc | 分配任务型内存 |
| Realloc | 再分配，扩充内存 |
| GetSize | 得到内存块大小 |
| DidAlloc | 确认内存是否已经分配 |
| HeapMinimize | 优化堆大小 |
| Free | 释放已经分配的内存 |
| Release | 释放接口指针 |
共享型内存调用顺序大致如下：
| CoGetMalloc(Shared,...) | 得到共享类型接口指针 |
| Alloc | 分配共享型内存 |
| Realloc | 再分配，扩充内存 |
| GetSize | 得到内存块大小 |
| DidAlloc | 确认内存是否已经分配 |
| HeapMinimize | 优化堆大小 |
| Free | 释放已经分配的内存 |
| Release | 释放接口指针 |
但是很不幸的是，我发现CoGetMalloc, 使用MEMCTX_SHARED即2作为dwMemContext参数进行调用,根本不能成功，如果你强行传入MEMCTX_SHARED，那么你将得到E_INVALIDARG这个错误。也就是说共享类型接口指针根本是胡扯啦~~~
HRESULT CoGetMalloc(DWORD dwMemContext, LPMALLOC * ppMalloc); MSDN上已经明文指定：dwMemContext [in] Reserved; value must be 1.即MEMCTX_TASK。by Loomman, QQ:28077188, MSN: [email protected] QQ裙：30515563 ☆程序天堂☆ 请尊重作者原创，转载注明来自裂帛一剑博客，谢谢合作。