unit untWorkThread;interfaceuses  Windows,Classes,SysUtils;type  TWorkItem=class  end;  TProcessWork=procedure (Sender:TObject;Work:TWorkItem) of Object;  TWorkThread=class(TThread)  private    FCriticalSection:TRTLCriticalSection;    hEvent:Cardinal;    FList:TList;    FProcessWork:TProcessWork;    procedure ProcessWork(Work:TWorkItem);    function GetWork(var AWork:TWorkItem):Boolean;  protected    procedure Execute;override;  public    procedure AddWork(AWork:TWorkItem);    constructor Create;    destructor Destroy; override;    property OnProcessWork:TProcessWork read FProcessWork write FProcessWork;  end;implementation{
    TWorkThread}constructor TWorkThread.Create;begin  InitializeCriticalSection(FCriticalSection);  hEvent:=CreateEvent(nil,False,False,nil);  FList:=TList.Create;  Self.FreeOnTerminate:=False;  inherited Create(False);end;destructor TWorkThread.Destroy;var  i:Integer;begin  for i:=FList.Count-1 downto 0 do TWorkItem(FList.Items[i]).Free;  DeleteCriticalSection(FCriticalSection);  FList.Free;  CloseHandle(hEvent);end;function TWorkThread.GetWork(var AWork:TWorkItem):Boolean;begin  Result:=False;  EnterCriticalSection(FCriticalSection);  try    if FList.Count>0 then    begin      AWork:=TWorkItem(FList.Items[0]);      FList.Delete(0);      Result:=True;    end;  finally    LeaveCriticalSection(FCriticalSection);  end;end;procedure TWorkThread.Execute;var  Work:TWorkItem;begin  while not Self.Terminated do  begin    WaitForSingleObject(hEvent,INFINITE);    while GetWork(Work) do    begin      ProcessWork(Work);      Work.Free;    end;  end;end;procedure TWorkThread.ProcessWork(Work:TWorkItem);begin  if Assigned(FProcessWork) then FProcessWork(Self,Work);end;procedure TWorkThread.AddWork(AWork:TWorkItem);begin  EnterCriticalSection(FCriticalSection);  try    FList.Add(AWork);  finally    LeaveCriticalSection(FCriticalSection);  end;  SetEvent(hEvent);end;end.