多线程编程（8）-多线程同步之CriticalSection（临界区）

多线程编程（8）-多线程同步之CriticalSection（临界区）2009-11-25 cnblogs.com 万一先看一段程序, 代码文件:

unit Unit1;
interface
uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 Dialogs, StdCtrls;
type
 TForm1 = class（TForm）
  ListBox1: TListBox;
  Button1: TButton;
  procedure FormCreate（Sender: TObject）;
  procedure Button1Click（Sender: TObject）;
 end;
var
 Form1: TForm1;
implementation
{$R *.dfm}
function MyThreadFun（p: Pointer）: DWORD; stdcall;
var
 i: Integer;
begin
 for i := 0 to 99 do Form1.ListBox1.Items.Add（IntToStr（i））;
 Result := 0;
end;
procedure TForm1.Button1Click（Sender: TObject）;
var
 ID: DWORD;
begin
 CreateThread（nil, 0, @MyThreadFun, nil, 0, ID）;
 CreateThread（nil, 0, @MyThreadFun, nil, 0, ID）;
 CreateThread（nil, 0, @MyThreadFun, nil, 0, ID）;
end;
procedure TForm1.FormCreate（Sender: TObject）;
begin
 ListBox1.Align := alLeft;
end;
end.

窗体文件:

object Form1: TForm1
 Left = 0
 Top = 0
 Caption = "Form1"
 ClientHeight = 154
 ClientWidth = 214
 Color = clBtnFace
 Font.Charset = DEFAULT_CHARSET
 Font.Color = clWindowText
 Font.Height = -11
 Font.Name = "Tahoma"
 Font.Style = []
 OldCreateOrder = False
 OnCreate = FormCreate
 PixelsPerInch = 96
 TextHeight = 13
 object ListBox1: TListBox
  Left = 9
  Top = 9
  Width = 121
  Height = 97
  ItemHeight = 13
  TabOrder = 0
 end
 object Button1: TButton
  Left = 131
  Top = 112
  Width = 75
  Height = 25
  Caption = "Button1"
  TabOrder = 1
  OnClick = Button1Click
 end
end

在这段程序中, 有三个线程几乎是同时建立, 向窗体中的 ListBox1 中写数据, 最后写出的结果是这样的:

能不能让它们别打架, 一个完了另一个再来？这就要用到多线程的同步技术.