Remove class "Timer"

Class "Timer" is not being used and the related unit tests
are failing quite often in py38 CI job.

Change-Id: Ib1d8f2f4adeadbd59c3dccc7be1546baedc4b978
Related-Bug: #1922563

neutron/common/utils.py

@@ -18,7 +18,6 @@
 
 """Utilities and helper functions."""
 
-import datetime
 import functools
 import importlib
 import os
@@ -37,7 +36,6 @@ from eventlet.green import subprocess
 import netaddr
 from neutron_lib import constants as n_const
 from neutron_lib.db import api as db_api
-from neutron_lib import exceptions as n_exc
 from neutron_lib.services.trunk import constants as trunk_constants
 from neutron_lib.utils import helpers
 from oslo_config import cfg
@@ -69,10 +67,6 @@ class WaitTimeout(Exception):
     """Default exception coming from wait_until_true() function."""
 
 
-class TimerTimeout(n_exc.NeutronException):
-    message = _('Timer timeout expired after %(timeout)s second(s).')
-
-
 class LockWithTimer(object):
     def __init__(self, threshold):
         self._threshold = threshold
@@ -869,72 +863,6 @@ def validate_rp_bandwidth(rp_bandwidths, device_names):
                 "device mappings") % {'dev_name': dev_name})
 
 
-class Timer(object):
-    """Timer context manager class
-
-    This class creates a context that:
-    - Triggers a timeout exception if the timeout is set.
-    - Returns the time elapsed since the context was initialized.
-    - Returns the time spent in the context once it's closed.
-
-    The timeout exception can be suppressed; when the time expires, the context
-    finishes without rising TimerTimeout.
-
-    NOTE(ralonsoh): this class, when a timeout is defined, cannot be used in
-    other than the main thread. When a timeout is defined, an alarm signal is
-    set. Only the main thread is allowed to set a signal handler and the signal
-    handlers are always executed in this main thread [1].
-    [1] https://docs.python.org/3/library/signal.html#signals-and-threads
-    """
-    def __init__(self, timeout=None, raise_exception=True):
-        self.start = self.delta = None
-        self._timeout = int(timeout) if timeout else None
-        self._timeout_flag = False
-        self._raise_exception = raise_exception
-
-    def _timeout_handler(self, *_):
-        self._timeout_flag = True
-        if self._raise_exception:
-            raise TimerTimeout(timeout=self._timeout)
-        self.__exit__()
-
-    def __enter__(self):
-        self.start = datetime.datetime.now()
-        if self._timeout:
-            signal.signal(signal.SIGALRM, self._timeout_handler)
-            signal.alarm(self._timeout)
-        return self
-
-    def __exit__(self, *_):
-        if self._timeout:
-            signal.alarm(0)
-        self.delta = datetime.datetime.now() - self.start
-
-    def __getattr__(self, item):
-        return getattr(self.delta, item)
-
-    def __iter__(self):
-        self._raise_exception = False
-        return self.__enter__()
-
-    def next(self):  # pragma: no cover
-        # NOTE(ralonsoh): Python 2 support.
-        if not self._timeout_flag:
-            return datetime.datetime.now()
-        raise StopIteration()
-
-    def __next__(self):  # pragma: no cover
-        # NOTE(ralonsoh): Python 3 support.
-        return self.next()
-
-    def __del__(self):
-        signal.alarm(0)
-
-    @property
-    def delta_time_sec(self):
-        return (datetime.datetime.now() - self.start).total_seconds()
-
-
 def collect_profiler_info():
     p = profiler.get()
     if p:

neutron/tests/functional/test_server.py

@@ -171,7 +171,7 @@ class TestNeutronServer(base.BaseLoggingTestCase):
 
         try:
             utils.wait_until_true(is_temp_file_ok, timeout=5, sleep=1)
-        except utils.TimerTimeout:
+        except utils.WaitTimeout:
             if not os.path.isfile(self.temp_file):
                 raise RuntimeError(
                     "Timed out waiting for file %(filename)s to be created" %

neutron/tests/unit/common/test_utils.py

@@ -16,7 +16,6 @@ import os.path
 import random
 import re
 import sys
-import time
 from unittest import mock
 
 import ddt
@@ -536,41 +535,6 @@ class TestRpBandwidthValidator(base.BaseTestCase):
                           self.not_valid_rp_bandwidth, self.device_name_set)
 
 
-class TimerTestCase(base.BaseTestCase):
-
-    def test__getattr(self):
-        with utils.Timer() as timer:
-            time.sleep(1)
-        self.assertLess(timer.total_seconds(), 2)
-        self.assertEqual(1, timer.delta.seconds)
-
-    def test__enter_with_timeout(self):
-        with utils.Timer(timeout=10) as timer:
-            time.sleep(1)
-        self.assertLess(timer.total_seconds(), 2)
-
-    def test__enter_with_timeout_exception(self):
-        msg = r'Timer timeout expired after 1 second\(s\).'
-        with self.assertRaisesRegex(utils.TimerTimeout, msg):
-            with utils.Timer(timeout=1):
-                time.sleep(2)
-
-    def test__enter_with_timeout_no_exception(self):
-        with utils.Timer(timeout=1, raise_exception=False):
-            time.sleep(2)
-
-    def test__iter(self):
-        iterations = []
-        for i in utils.Timer(timeout=2):
-            iterations.append(i)
-            time.sleep(1.1)
-        self.assertEqual(2, len(iterations))
-
-    def test_delta_time_sec(self):
-        with utils.Timer() as timer:
-            self.assertIsInstance(timer.delta_time_sec, float)
-
-
 class SpawnWithOrWithoutProfilerTestCase(
         testscenarios.WithScenarios, base.BaseTestCase):