delphi中基于事件通知的多线程应用

以前写过写多线程,往往是一个死循环中采用sleep来把释放cpu的时间片 ,这几天写了个基于Event通知的线程,应用起来还不错,就帖上来,希望大家多多指教,见笑了.
//------------------------------------------
　　// 处理数据线程父类，实现方法由子类完成
　　// Add by hua 2007/08/07
　　//------------------------------------------
TPlayThread = class(TThread)
private
HEvent: THandle;
CS_Memory: TRTLCriticalSection ;
FData: array of byte;
FManager: TManager;
FMemory: TMemoryStream ;
FReadPos: integer;
procedure play; virtual;abstract;
function ReadData: Boolean; virtual ;
procedure ClearData;
public
constructor create(AManager: TManager);
destructor destroy; override;
procedure execute; override;
procedure WriteData(var ABuffer; ASize: DWORD); virtual ;
end;

　　//视频数据处理线程
TVideoPlayThread = class(TPlayThread)
private
procedure play; override;
end;

　　//音频数据处理线程
TAudioPlayThread = class(TPlayThread)
private
procedure play; override;
end;

　　//礼物数据处理线程
TPresentPlayThread = class(TPlayThread)
private
CHAT_Present: TCHAT_Present;
function ReadData: Boolean; override;
procedure play; override;
public
procedure WriteData(var ABuffer; Asize: DWORD); override;
end;
implementation

　　//以下为功能实现部分
{ TPlayThread }
procedure TPlayThread.ClearData;
begin
FReadPos := 0;
FMemory.Clear;
end;
constructor TPlayThread.create(AManager: TManager);
begin
InitializeCriticalSection(CS_Memory);
HEvent := CreateEvent(nil, False, False, nil);
FManager := AManager;
FMemory := TMemoryStream.Create;
FreeOnTerminate := true;
inherited Create(false);