code: def createFileList(self):
          
          global childFileListDownload
          global filelistDownloadActive
          mypid = os.getpid()
          if mypid not in childFileListDownload or not childFileListDownload[mypid].is_alive():
              childFileListDownload[mypid] = multiproc.Process(target=self.createFileListHTTP)
              filelistDownloadActive = 1
              childFileListDownload[mypid].start()
              filelistDownloadActive = 0
docs: SRTM data is split into different directories, get a list of all of
              them and create a dictionary for easy lookup.