C#

while(isThreadRunning)
{
  ...
}

void StartStructureTimer(int time)
		{
			timStructure=new System.Threading.Timer(new TimerCallback(TimerStructureJob));
			timStructure.Change(time,0);
		}
		void TimerStructureJob(object state)
		{
			System.Threading.Timer tm=state as System.Threading.Timer;
			tm.Dispose();
			pdfDownloadStart();
		}
		void pdfDownloadStart()
		{
			try
			{
				signalMessage(string.Format("Searching Server {0} for newly added Files",fdo.FtpServer));
				dtList=p.getPdfNotDownloaded();
				if (dtList.Rows.Count>0)
				{
					signalMessage(string.Format("{0} Files Found for Download",dtList.Rows.Count));
					fdo.FilesToDownloadList=dtList;
					fdo.LocalDownloadDirectory=TempDirectory;
					Thread tPdf=new Thread(new ThreadStart(downloadFile));
					tPdf.Start();
					tPdf.Join();
					if (!fdo.DownloadStatus)
					{
						if (timDownload!=null)
							timDownload.Dispose();
						signalMessage("Download Failed\r\nretrying in 60 second");
						StartTimer(36000);
					}
					else if (fdo.DownloadStatus)
					{
						if (timDownload!=null)
							timDownload.Dispose();
						signalMessage("All Files Downloaded Successfully\r\nretrying in 60 second");
						StartTimer(36000); //when downloading finished then start again in 60 second
						return;
					}
					else
						StartTimer(36000); // 60 second
				}
				else
				{
					signalMessage("No Files Found\r\nretrying in 60 second");
					StartTimer(36000);
				}
			}
			catch(Exception ex)
			{
				if (!pdfStopped)
				{
					signalMessage("Failed downloading Files from Remote Server "+ex.Message+"\r\nretrying in 60 second");
					StartTimer(36000);
				}
				else
					signalMessage("Failed downloading Files from Remote Server "+ex.Message);
			}
		}