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authorRodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>2018-04-19 14:58:38 +0100
committerEmma Foley <emma.l.foley@intel.com>2018-06-22 17:38:15 +0000
commit745db76a4cc99a1597a3570ecdc063d549839a15 (patch)
tree2cf4cc77089632d9b6e9e2fdd65bea293f30a891
parent2c77f9d9559b09299f8ef5cc3d07c847c685d79c (diff)
Add active wait function
Added function "wait_until_true". This function will make an active wait until the predicate passed as an argument returns True. If the timeout expires, the function will raise a generic exception or a user defined one passed as an argument. This function will be used in YARDSTICK-1127. JIRA: YARDSTICK-1128 Change-Id: I9854e465ac6b586bf4be39ab4b266d5625b39e30 Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com> (cherry picked from 099108aab37d1fae1b27f4e2e20136c234df1a52)
-rw-r--r--yardstick/common/exceptions.py8
-rw-r--r--yardstick/common/utils.py34
-rw-r--r--yardstick/tests/unit/common/test_utils.py42
3 files changed, 83 insertions, 1 deletions
diff --git a/yardstick/common/exceptions.py b/yardstick/common/exceptions.py
index c78fecc2c..ad246e046 100644
--- a/yardstick/common/exceptions.py
+++ b/yardstick/common/exceptions.py
@@ -166,6 +166,14 @@ class TaskRenderError(YardstickException):
message = 'Failed to render template:\n%(input_task)s'
+class TimerTimeout(YardstickException):
+ message = 'Timer timeout expired, %(timeout)s seconds'
+
+
+class WaitTimeout(YardstickException):
+ message = 'Wait timeout while waiting for condition'
+
+
class ScenarioCreateNetworkError(YardstickException):
message = 'Create Neutron Network Scenario failed'
diff --git a/yardstick/common/utils.py b/yardstick/common/utils.py
index 864e6258e..869db469b 100644
--- a/yardstick/common/utils.py
+++ b/yardstick/common/utils.py
@@ -23,9 +23,11 @@ import logging
import os
import random
import re
+import signal
import socket
import subprocess
import sys
+import time
import six
from flask import jsonify
@@ -34,6 +36,8 @@ from oslo_serialization import jsonutils
from oslo_utils import encodeutils
import yardstick
+from yardstick.common import exceptions
+
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)
@@ -418,15 +422,24 @@ class ErrorClass(object):
class Timer(object):
- def __init__(self):
+ def __init__(self, timeout=None):
super(Timer, self).__init__()
self.start = self.delta = None
+ self._timeout = int(timeout) if timeout else None
+
+ def _timeout_handler(self, *args):
+ raise exceptions.TimerTimeout(timeout=self._timeout)
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):
@@ -473,3 +486,22 @@ def open_relative_file(path, task_path):
if e.errno == errno.ENOENT:
return open(os.path.join(task_path, path))
raise
+
+
+def wait_until_true(predicate, timeout=60, sleep=1, exception=None):
+ """Wait until callable predicate is evaluated as True
+
+ :param predicate: (func) callable deciding whether waiting should continue
+ :param timeout: (int) timeout in seconds how long should function wait
+ :param sleep: (int) polling interval for results in seconds
+ :param exception: exception instance to raise on timeout. If None is passed
+ (default) then WaitTimeout exception is raised.
+ """
+ try:
+ with Timer(timeout=timeout):
+ while not predicate():
+ time.sleep(sleep)
+ except exceptions.TimerTimeout:
+ if exception and issubclass(exception, Exception):
+ raise exception # pylint: disable=raising-bad-type
+ raise exceptions.WaitTimeout
diff --git a/yardstick/tests/unit/common/test_utils.py b/yardstick/tests/unit/common/test_utils.py
index c61a95f3b..87995ac49 100644
--- a/yardstick/tests/unit/common/test_utils.py
+++ b/yardstick/tests/unit/common/test_utils.py
@@ -16,12 +16,14 @@ import mock
import os
import six
from six.moves import configparser
+import time
import unittest
import yardstick
from yardstick import ssh
from yardstick.common import constants
from yardstick.common import utils
+from yardstick.common import exceptions
class IterSubclassesTestCase(unittest.TestCase):
@@ -1149,3 +1151,43 @@ class ReadMeminfoTestCase(unittest.TestCase):
output = utils.read_meminfo(ssh_client)
mock_get_client.assert_called_once_with('/proc/meminfo', mock.ANY)
self.assertEqual(self.MEMINFO_DICT, output)
+
+
+class TimerTestCase(unittest.TestCase):
+
+ def test__getattr(self):
+ with utils.Timer() as timer:
+ time.sleep(1)
+ self.assertEqual(1, round(timer.total_seconds(), 0))
+ self.assertEqual(1, timer.delta.seconds)
+
+ def test__enter_with_timeout(self):
+ with utils.Timer(timeout=10) as timer:
+ time.sleep(1)
+ self.assertEqual(1, round(timer.total_seconds(), 0))
+
+ def test__enter_with_timeout_exception(self):
+ with self.assertRaises(exceptions.TimerTimeout):
+ with utils.Timer(timeout=1):
+ time.sleep(2)
+
+
+class WaitUntilTrueTestCase(unittest.TestCase):
+
+ def test_no_timeout(self):
+ self.assertIsNone(utils.wait_until_true(lambda: True,
+ timeout=1, sleep=1))
+
+ def test_timeout_generic_exception(self):
+ with self.assertRaises(exceptions.WaitTimeout):
+ self.assertIsNone(utils.wait_until_true(lambda: False,
+ timeout=1, sleep=1))
+
+ def test_timeout_given_exception(self):
+ class MyTimeoutException(exceptions.YardstickException):
+ message = 'My timeout exception'
+
+ with self.assertRaises(MyTimeoutException):
+ self.assertIsNone(
+ utils.wait_until_true(lambda: False, timeout=1, sleep=1,
+ exception=MyTimeoutException))