I have seen in various posts that there are tricks to increasing the
largest continuous memory block available to an application on a
windows machine. I want to prove this is possible using a simple
example.
Here is my configuration.
-I am running vc++ 6.0 on winXP. (Came with book Starting with Visual
C++ by Wright)
-I have the 3GB switch set at run time
-I have the /largeaddressaware option set during the link
-I am using Virtual Memory Validator to see the largest memory block.
Free!!
Here is a very simple application from the book on page 385. It just
opens a window.
When this simple example is executed, the largest block available is
~1,190MB. I want to see if I can increase it.
From a post I got the following hint:
"Finally, the extra memory is not in a contiguous block with the
memory
below 2Gb, because msvcrt.dll, kernel32.dll, etc, load just below the
2Gb
line. However, the C/C++ run-time library will happily allocate memory
above 3Gb. In fact, it will seek out all the free memory available,
provided that you request it in small enough chunks that it can fit
them
into the available places in the address space that haven't got code
in
them."
The c++ code that opens up the hello window is given below. Please
show me how to modify it so that I can significantly increase the
memory block. I will make sure to provide the group detailed
instructions as to how to do this once I have succeeded.
thanks!! Here is the VC++ code for the hello window:
// HelloMFC.cpp : Defines the class behaviors for the application.
//
#include "stdafx.h"
#include "HelloMFC.h"
#include "MainFrm.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
/////////////////////////////////////////////////////////////////////////////
// CHelloMFCApp
BEGIN_MESSAGE_MAP(CHelloMFCApp, CWinApp)
//{{AFX_MSG_MAP(CHelloMFCApp)
ON_COMMAND(ID_APP_ABOUT, OnAppAbout)
// NOTE - the ClassWizard will add and remove mapping macros here.
// DO NOT EDIT what you see in these blocks of generated code!
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
/////////////////////////////////////////////////////////////////////////////
// CHelloMFCApp construction
CHelloMFCApp::CHelloMFCApp()
{
// TODO: add construction code here,
// Place all significant initialization in InitInstance
}
/////////////////////////////////////////////////////////////////////////////
// The one and only CHelloMFCApp object
CHelloMFCApp theApp;
/////////////////////////////////////////////////////////////////////////////
// CHelloMFCApp initialization
BOOL CHelloMFCApp::InitInstance()
{
AfxEnableControlContainer();
// Standard initialization
// If you are not using these features and wish to reduce the size
// of your final executable, you should remove from the following
// the specific initialization routines you do not need.
#ifdef _AFXDLL
Enable3dControls(); // Call this when using MFC in a shared DLL
#else
Enable3dControlsStatic(); // Call this when linking to MFC statically
#endif
// Change the registry key under which our settings are stored.
// TODO: You should modify this string to be something appropriate
// such as the name of your company or organization.
SetRegistryKey(_T("Local AppWizard-Generated Applications"));
// To create the main window, this code creates a new frame window
// object and then sets it as the application's main window object.
CMainFrame* pFrame = new CMainFrame;
m_pMainWnd = pFrame;
// create and load the frame with its resources
pFrame->LoadFrame(IDR_MAINFRAME,
WS_OVERLAPPEDWINDOW | FWS_ADDTOTITLE, NULL,
NULL);
// The one and only window has been initialized, so show and update
it.
pFrame->ShowWindow(SW_SHOW);
pFrame->UpdateWindow();
return TRUE;
}
/////////////////////////////////////////////////////////////////////////////
// CHelloMFCApp message handlers
/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About
class CAboutDlg : public CDialog
{
public:
CAboutDlg();
// Dialog Data
//{{AFX_DATA(CAboutDlg)
enum { IDD = IDD_ABOUTBOX };
//}}AFX_DATA
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CAboutDlg)
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV
support
//}}AFX_VIRTUAL
// Implementation
protected:
//{{AFX_MSG(CAboutDlg)
// No message handlers
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};
CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
//{{AFX_DATA_INIT(CAboutDlg)
//}}AFX_DATA_INIT
}
void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CAboutDlg)
//}}AFX_DATA_MAP
}
BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
//{{AFX_MSG_MAP(CAboutDlg)
// No message handlers
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
// App command to run the dialog
void CHelloMFCApp::OnAppAbout()
{
CAboutDlg aboutDlg;
aboutDlg.DoModal();
}
/////////////////////////////////////////////////////////////////////////////
// CHelloMFCApp message handlers
