lock_test.py

# -*- coding: utf-8 -*-
#
# Copyright 2012-2015 Spotify AB
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

import os
import subprocess
import tempfile
import mock
from helpers import unittest

import luigi
import luigi.lock
import luigi.notifications

luigi.notifications.DEBUG = True


class TestCmd(unittest.TestCase):

    def test_getpcmd(self):
        p = subprocess.Popen(["sleep", "1"])
        self.assertTrue(
            luigi.lock.getpcmd(p.pid) in ["sleep 1", '[sleep]']
        )
        p.kill()


class LockTest(unittest.TestCase):

    def setUp(self):
        self.pid_dir = tempfile.mkdtemp()
        self.pid, self.cmd, self.pid_file = luigi.lock.get_info(self.pid_dir)

    def tearDown(self):
        if os.path.exists(self.pid_file):
            os.remove(self.pid_file)
        os.rmdir(self.pid_dir)

    def test_get_info(self):
        try:
            p = subprocess.Popen(["yes", u"à我ф"], stdout=subprocess.PIPE)
            pid, cmd, pid_file = luigi.lock.get_info(self.pid_dir, p.pid)
        finally:
            p.kill()
        self.assertEqual(cmd, u'yes à我ф')

    def test_acquiring_free_lock(self):
        acquired = luigi.lock.acquire_for(self.pid_dir)
        self.assertTrue(acquired)

    def test_acquiring_taken_lock(self):
        with open(self.pid_file, 'w') as f:
            f.write('%d\n' % (self.pid, ))

        acquired = luigi.lock.acquire_for(self.pid_dir)
        self.assertFalse(acquired)

    def test_acquiring_partially_taken_lock(self):
        with open(self.pid_file, 'w') as f:
            f.write('%d\n' % (self.pid, ))

        acquired = luigi.lock.acquire_for(self.pid_dir, 2)
        self.assertTrue(acquired)

        s = os.stat(self.pid_file)
        self.assertEqual(s.st_mode & 0o777, 0o777)

    def test_acquiring_lock_from_missing_process(self):
        fake_pid = 99999
        with open(self.pid_file, 'w') as f:
            f.write('%d\n' % (fake_pid, ))

        acquired = luigi.lock.acquire_for(self.pid_dir)
        self.assertTrue(acquired)

        s = os.stat(self.pid_file)
        self.assertEqual(s.st_mode & 0o777, 0o777)

    @mock.patch('os.kill')
    def test_take_lock_with_kill(self, kill_fn):
        with open(self.pid_file, 'w') as f:
            f.write('%d\n' % (self.pid,))

        kill_signal = 77777
        acquired = luigi.lock.acquire_for(self.pid_dir, kill_signal=kill_signal)
        self.assertTrue(acquired)
        kill_fn.assert_called_once_with(self.pid, kill_signal)

    @mock.patch('os.kill')
    @mock.patch('luigi.lock.getpcmd')
    def test_take_lock_has_only_one_extra_life(self, getpcmd, kill_fn):
        def side_effect(pid):
            if pid in [self.pid, self.pid + 1, self.pid + 2]:
                return self.cmd  # We could return something else too, actually
            else:
                return "echo something_else"

        getpcmd.side_effect = side_effect
        with open(self.pid_file, 'w') as f:
            f.write('{}\n{}\n'.format(self.pid + 1, self.pid + 2))

        kill_signal = 77777
        acquired = luigi.lock.acquire_for(self.pid_dir, kill_signal=kill_signal)
        self.assertFalse(acquired)  # So imagine +2 was runnig first, then +1 was run with --take-lock
        kill_fn.assert_any_call(self.pid + 1, kill_signal)
        kill_fn.assert_any_call(self.pid + 2, kill_signal)

    @mock.patch('luigi.lock.getpcmd')
    def test_cleans_old_pid_entries(self, getpcmd):
        assert self.pid > 10  # I've never seen so low pids so
        SAME_ENTRIES = {1, 2, 3, 4, 5, self.pid}
        ALL_ENTRIES = SAME_ENTRIES | {6, 7, 8, 9, 10}

        def side_effect(pid):
            if pid in SAME_ENTRIES:
                return self.cmd  # We could return something else too, actually
            elif pid == 8:
                return None
            else:
                return "echo something_else"

        getpcmd.side_effect = side_effect
        with open(self.pid_file, 'w') as f:
            f.writelines('{}\n'.format(pid) for pid in ALL_ENTRIES)

        acquired = luigi.lock.acquire_for(self.pid_dir, num_available=100)
        self.assertTrue(acquired)

        with open(self.pid_file, 'r') as f:
            self.assertEqual({int(pid_str.strip()) for pid_str in f}, SAME_ENTRIES)