anchor.diff:        if (lvValidCount = 0) or (lvMemBlock = nil) then
         begin  // ûҪ͵
           FCurrentSendBufferLink := nil;  // û, ´ѹʱִͷ
  -        UnLock; //ӽ
           exit;      
         end; 
       end;
  
positive.code:       // ǰBufferΪnil ˳
        if FCurrentSendBufferLink = nil then
        begin
          UnLock; //ӽ
          Exit;
        end;
  
  
negative.code:     // ǰBufferΪnil ˳
      if FCurrentSendBufferLink = nil then
      begin
        if FSendBlock <> nil then
        begin
          FreeMemBlock(FSendBlock);
  