From 740c5aabc85dd3a40d739f485311154ca241a71e Mon Sep 17 00:00:00 2001
From: Guido Trotter <ultrotter@google.com>
Date: Mon, 23 Jun 2008 12:50:15 +0000
Subject: [PATCH] Fix the zombie process unittest
The failure is because in high load, the parent gets to run before the
child has the chance to os._exit(), and therefore it is still running
when the parent does the check.
The fix removes the chance of this happening by waiting to receive a SIGCHLD
(but not calling wait()) before trying to test the pid.
Reviewed-by: imsnah
---
test/ganeti.utils_unittest.py | 36 ++++++++++++++++++++++++++++-------
1 file changed, 29 insertions(+), 7 deletions(-)
diff --git a/test/ganeti.utils_unittest.py b/test/ganeti.utils_unittest.py
index abc4a7692..c5f8cfda6 100755
--- a/test/ganeti.utils_unittest.py
+++ b/test/ganeti.utils_unittest.py
@@ -28,6 +28,7 @@ import tempfile
import os.path
import os
import md5
+import signal
import socket
import shutil
import re
@@ -43,16 +44,16 @@ from ganeti.utils import IsProcessAlive, Lock, Unlock, RunCmd, \
SetEtcHostsEntry, RemoveEtcHostsEntry
from ganeti.errors import LockError, UnitParseError
+def _ChildHandler(signal, stack):
+ global _ChildFlag
+ _ChildFlag = True
class TestIsProcessAlive(unittest.TestCase):
"""Testing case for IsProcessAlive"""
+
def setUp(self):
- # create a zombie and a (hopefully) non-existing process id
- self.pid_zombie = os.fork()
- if self.pid_zombie == 0:
- os._exit(0)
- elif self.pid_zombie < 0:
- raise SystemError("can't fork")
+ global _ChildFlag
+ # create a (most probably) non-existing process-id
self.pid_non_existing = os.fork()
if self.pid_non_existing == 0:
os._exit(0)
@@ -60,7 +61,18 @@ class TestIsProcessAlive(unittest.TestCase):
os.waitpid(self.pid_non_existing, 0)
else:
raise SystemError("can't fork")
+ _ChildFlag = False
+ # Use _ChildHandler for SIGCHLD
+ self.chldOrig = signal.signal(signal.SIGCHLD, _ChildHandler)
+ # create a zombie
+ self.pid_zombie = os.fork()
+ if self.pid_zombie == 0:
+ os._exit(0)
+ elif self.pid_zombie < 0:
+ raise SystemError("can't fork")
+ def tearDown(self):
+ signal.signal(signal.SIGCHLD, self.chldOrig)
def testExists(self):
mypid = os.getpid()
@@ -68,10 +80,20 @@ class TestIsProcessAlive(unittest.TestCase):
"can't find myself running")
def testZombie(self):
+ global _ChildFlag
+ timeout = 10
+
+ while not _ChildFlag:
+ if timeout >= 0:
+ time.sleep(0.2)
+ timeout -= 0.2
+ else:
+ self.fail("timed out waiting for child's signal")
+ break # not executed...
+
self.assert_(not IsProcessAlive(self.pid_zombie),
"zombie not detected as zombie")
-
def testNotExisting(self):
self.assert_(not IsProcessAlive(self.pid_non_existing),
"noexisting process detected")
--
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