delphi 怎么实现多线程的同步

发布网友发布时间：2022-04-30 23:54

共1个回答

热心网友时间：2022-06-20 20:53

多线程同步
　　"临界区"(CriticalSection): 当把一段代码放入一个临界区, 线程执行到临界区时就独占了, 让其他也要执行此代码的线程先等等;
　　使用格式如下:
var CS: TRTLCriticalSection;   {声明一个 TRTLCriticalSection 结构类型变量; 它应该是全局的}
InitializeCriticalSection(CS); {初始化}
EnterCriticalSection(CS);      {开始: 轮到我了其他线程走开}
LeaveCriticalSection(CS);      {结束: 其他线程可以来了}
DeleteCriticalSection(CS);     {删除: 注意不能过早删除}
多线程同步示例
　　
1 unit Unit1;
2
3 interface
4
5 uses
6   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
7   Dialogs, StdCtrls;
8
9 type
10   TForm1 = class(TForm)
11     ListBox1: TListBox;
12     Button1: TButton;
13     procere FormCreate(Sender: TObject);
14     procere FormDestroy(Sender: TObject);
15     procere Button1Click(Sender: TObject);
16   end;
17
18 var
19   Form1: TForm1;
20
21 implementation
22
23 {$R *.dfm}
24
25 var
26   CS: TRTLCriticalSection;
27
28 function MyThreadFun(p: Pointer): DWORD; stdcall;
29 var
30   i: Integer;
31 begin
32   EnterCriticalSection(CS);
33   for i := 0 to 99 do Form1.ListBox1.Items.Add(IntToStr(i));
34   LeaveCriticalSection(CS);
35   Result := 0;
36 end;
37
38 procere TForm1.Button1Click(Sender: TObject);
39 var
40   ID: DWORD;
41 begin
42   CreateThread(nil, 0, @MyThreadFun, nil, 0, ID);
43   CreateThread(nil, 0, @MyThreadFun, nil, 0, ID);
44   CreateThread(nil, 0, @MyThreadFun, nil, 0, ID);
45 end;
46
47 procere TForm1.FormCreate(Sender: TObject);
48 begin
49   ListBox1.Align := alLeft;
50   InitializeCriticalSection(CS);
51 end;
52
53 procere TForm1.FormDestroy(Sender: TObject);
54 begin
55   DeleteCriticalSection(CS);
56 end;
57
58 end.