def UpdateModuleFileModificationTimes(self):
    if not self._dirty:
      return

    self._modification_times.clear()
    for name, module in self._modules.items():
      if not isinstance(module, types.ModuleType):
        continue
      module_file = self.GetModuleFile(module)
      if not module_file:
        continue
      try:
        self._modification_times[name] = (os.path.getmtime(module_file),
                                          module_file)
      except OSError, e:
        if e.errno not in FILE_MISSING_EXCEPTIONS:
          raise e

    self._dirty = False
Records the current modification times of all monitored modules.
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/tools/dev_appserver.py/ModuleManager.UpdateModuleFileModificationTimes