delphi 线程同步(线程安全)

unit Unit1;

interface

uses

uSyncThread, Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,

System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type

TForm1 = class(TForm)

Button1: TButton;

Memo1: TMemo;

procedure Button1Click(Sender: TObject);

private

{ Private declarations }

public

{ Public declarations }

end;

var

Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);

begin

TWorkingThread.Create(False);

end;

end.

unit uSyncThread;

interface

uses

System.SyncObjs, System.SysUtils, System.Classes;

type

TWorkingThread = class(TThread)

private

{ Private declarations }

protected

procedure Execute; override;

public

procedure Work();

end;

implementation

uses

Unit1;

{

线程安全

1、多个线程共享一块数据，保证该数据执行的结果是正确的

解决方案

1、线程同步(线程安全) 、VCL控件大部分是线程不安全的

2、Delphi的具体实现方式

a) Synchronize

b) 临界区(TCriticalSection)

c) 互斥体(TMutex)

d) 信号量(TEvent)

e) TMonitor

3、使用场景

1、当多个线程访问一个对象(数据)时，为了保证数据的正确性我们需要同步

2、线程同步：可以保证数据的安全性，慢(效率低)

3、线程异步：快(效率高)、无法保证数据的安全性

4、扩展知识

1、线程池 System.Threading.TThreadPool

}

var

i: Integer;

CriticalSection: TCriticalSection;

{ TWorkingThread }

procedure TWorkingThread.Execute;

begin

FreeOnTerminate := True;

// Self.Synchronize(Work);

CriticalSection.Enter;

Work();

CriticalSection.Leave;

end;

procedure TWorkingThread.Work;

begin

while True do begin

Form1.Memo1.Lines.Add('线程编号：' + self.ThreadID.ToString + '，' + i.ToString);

if i = 10 then begin

Exit;

end;

inc(i);

Self.Sleep(100);

end;

initialization

CriticalSection := TCriticalSection.Create;

finalization

CriticalSection.Free;

end.

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