内存管理[6]

本例效果图:

---

unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls;



type

  TForm1 = class(TForm)

    Button1: TButton;

    Button2: TButton;

    Memo1: TMemo;

    Memo2: TMemo;

    procedure Button1Click(Sender: TObject);

    procedure Button2Click(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



//测试堆的内存占用情况

procedure TForm1.Button1Click(Sender: TObject);

var

  MyHeap: THandle;

  mem: TMemoryStatus;

  m1,m2,m3: DWORD;

begin

  {获取当前内存可用状态}

  GlobalMemoryStatus(mem);

  m1 := mem.dwAvailPhys;     {可用物理内存}

  m2 := mem.dwAvailPageFile; {可用虚拟内存}

  m3 := mem.dwAvailVirtual;  {可用虚拟地址}



  {建立私有堆}

  MyHeap := HeapCreate(HEAP_NO_SERIALIZE, 1024*1204, 0); {建立 1 M 大小的堆}



  {再获取当前内存可用状态}

  GlobalMemoryStatus(mem);

  m1 := m1 - mem.dwAvailPhys;

  m2 := m2 - mem.dwAvailPageFile;

  m3 := m3 - mem.dwAvailVirtual;



  {显示堆占用内存的情况}

  Memo1.Clear;

  Memo1.Lines.Add(Format('占用物理内存: %d K', [m1 div 1024]));

  Memo1.Lines.Add(Format('占用虚拟内存: %d K', [m2 div 1024]));

  Memo1.Lines.Add(Format('占用虚拟地址: %d K', [m3 div 1024]));



  {释放堆}

  HeapDestroy(MyHeap);

end;



//同上个过程, 外加测试建立堆时页对齐的情况

procedure TForm1.Button2Click(Sender: TObject);

var

  MyHeap: THandle;

  mem: TMemoryStatus;

  m1,m2,m3: DWORD;

begin

  GlobalMemoryStatus(mem);

  m1 := mem.dwAvailPhys;     

  m2 := mem.dwAvailPageFile; 

  m3 := mem.dwAvailVirtual;



  {建立 1M + 1字节 大小的堆, 但实际大小会按页对齐, 结果应该是: 1M + 4K}

  MyHeap := HeapCreate(HEAP_NO_SERIALIZE, 1024*1204 + 1, 0);



  GlobalMemoryStatus(mem);

  m1 := m1 - mem.dwAvailPhys;

  m2 := m2 - mem.dwAvailPageFile;

  m3 := m3 - mem.dwAvailVirtual;



  Memo2.Clear;

  Memo2.Lines.Add(Format('占用物理内存: %d K', [m1 div 1024]));

  Memo2.Lines.Add(Format('占用虚拟内存: %d K', [m2 div 1024]));

  Memo2.Lines.Add(Format('占用虚拟地址: %d K', [m3 div 1024]));



  HeapDestroy(MyHeap);

end;



end.