Synnefo » snf-ganeti » ganeti-local

      event = utils.WaitForFdCondition(sock, wait_for_event, timeout)

      event = utils.WaitForFdCondition(self.sock, select.POLLOUT,

                                       self.CONNECT_TIMEOUT)

def SingleWaitForFdCondition(fdobj, event, timeout):

  Immediately returns at the first interruption.

  @type fdobj: integer or object supporting a fileno() method

  @param fdobj: entity to wait for events on

  @type event: integer

  poller.register(fdobj, event)

    # TODO: If the main thread receives a signal and we have no timeout, we

    # could wait forever. This should check a global "quit" flag or something

    # every so often.

    io_events = poller.poll(timeout)

  except select.error, err:

    if err[0] != errno.EINTR:

      raise

    io_events = []

  if io_events and io_events[0][1] & check:

    return io_events[0][1]

  else:

    return None

class FdConditionWaiterHelper(object):

  """Retry helper for WaitForFdCondition.

  This class contains the retried and wait functions that make sure

  WaitForFdCondition can continue waiting until the timeout is actually

  expired.

  """

  def __init__(self, timeout):

    self.timeout = timeout

  def Poll(self, fdobj, event):

    result = SingleWaitForFdCondition(fdobj, event, self.timeout)

    if result is None:

      raise RetryAgain()

    else:

      return result

  def UpdateTimeout(self, timeout):

    self.timeout = timeout

def WaitForFdCondition(fdobj, event, timeout):

  """Waits for a condition to occur on the socket.

  Retries until the timeout is expired, even if interrupted.

  @type fdobj: integer or object supporting a fileno() method

  @param fdobj: entity to wait for events on

  @type event: integer

  @param event: ORed condition (see select module)

  @type timeout: float or None

  @param timeout: Timeout in seconds

  @rtype: int or None

  @return: None for timeout, otherwise occured conditions

  """

  if timeout is not None:

    retrywaiter = FdConditionWaiterHelper(timeout)

    result = Retry(retrywaiter.Poll, RETRY_REMAINING_TIME, timeout,

                   args=(fdobj, event), wait_fn=retrywaiter.UpdateTimeout)

  else:

    result = None

    while result is None:

      result = SingleWaitForFdCondition(fdobj, event, timeout)

  return result