内存管理六

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.