Revision a87b4824
| b/lib/utils.py | ||
|---|---|---|
| 1192 | 1192 |
raise |
| 1193 | 1193 |
|
| 1194 | 1194 |
|
| 1195 |
class FileLock(object): |
|
| 1196 |
"""Utility class for file locks. |
|
| 1197 |
|
|
| 1198 |
""" |
|
| 1199 |
def __init__(self, filename): |
|
| 1200 |
self.filename = filename |
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| 1201 |
self.fd = open(self.filename, "w") |
|
| 1202 |
|
|
| 1203 |
def __del__(self): |
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| 1204 |
self.Close() |
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| 1205 |
|
|
| 1206 |
def Close(self): |
|
| 1207 |
if self.fd: |
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| 1208 |
self.fd.close() |
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| 1209 |
self.fd = None |
|
| 1210 |
|
|
| 1211 |
def _flock(self, flag, blocking, errmsg): |
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| 1212 |
assert self.fd, "Lock was closed" |
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| 1213 |
|
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| 1214 |
if not blocking: |
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| 1215 |
flag |= fcntl.LOCK_NB |
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| 1216 |
|
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| 1217 |
try: |
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| 1218 |
fcntl.flock(self.fd, flag) |
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| 1219 |
except IOError, err: |
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| 1220 |
logging.exception("fcntl.flock failed")
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| 1221 |
if err.errno in (errno.EAGAIN, ): |
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| 1222 |
raise errors.LockError(errmsg) |
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| 1223 |
raise |
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| 1224 |
|
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| 1225 |
def Exclusive(self, blocking=False): |
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| 1226 |
"""Locks the file in exclusive mode. |
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| 1227 |
|
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| 1228 |
""" |
|
| 1229 |
self._flock(fcntl.LOCK_EX, blocking, |
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| 1230 |
"Failed to lock %s in exclusive mode" % self.filename) |
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| 1231 |
|
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| 1232 |
def Shared(self, blocking=False): |
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| 1233 |
"""Locks the file in shared mode. |
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| 1234 |
|
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| 1235 |
""" |
|
| 1236 |
self._flock(fcntl.LOCK_SH, blocking, |
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| 1237 |
"Failed to lock %s in shared mode" % self.filename) |
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| 1238 |
|
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| 1239 |
def Unlock(self, blocking=True): |
|
| 1240 |
"""Unlocks the file. |
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| 1241 |
|
|
| 1242 |
According to "man flock", unlocking can also be a nonblocking operation: |
|
| 1243 |
"To make a non-blocking request, include LOCK_NB with any of the above |
|
| 1244 |
operations" |
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| 1245 |
|
|
| 1246 |
""" |
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| 1247 |
self._flock(fcntl.LOCK_UN, blocking, |
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| 1248 |
"Failed to unlock %s" % self.filename) |
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| 1249 |
|
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| 1250 |
|
|
| 1195 | 1251 |
class SignalHandler(object): |
| 1196 | 1252 |
"""Generic signal handler class. |
| 1197 | 1253 |
|
| b/test/ganeti.utils_unittest.py | ||
|---|---|---|
| 32 | 32 |
import socket |
| 33 | 33 |
import shutil |
| 34 | 34 |
import re |
| 35 |
import tempfile |
|
| 36 | 35 |
|
| 37 | 36 |
import ganeti |
| 38 | 37 |
import testutils |
| ... | ... | |
| 710 | 709 |
self._test(["a", "b"], ["a", "b"]) |
| 711 | 710 |
self._test(["a", "b", "a"], ["a", "b"]) |
| 712 | 711 |
|
| 712 |
|
|
| 713 | 713 |
class TestFirstFree(unittest.TestCase): |
| 714 | 714 |
"""Test case for the FirstFree function""" |
| 715 | 715 |
|
| ... | ... | |
| 721 | 721 |
self.failUnlessEqual(FirstFree([3, 4, 6], base=3), 5) |
| 722 | 722 |
self.failUnlessRaises(AssertionError, FirstFree, [0, 3, 4, 6], base=3) |
| 723 | 723 |
|
| 724 |
|
|
| 725 |
class TestFileLock(unittest.TestCase): |
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| 726 |
"""Test case for the FileLock class""" |
|
| 727 |
|
|
| 728 |
def setUp(self): |
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| 729 |
self.tmpfile = tempfile.NamedTemporaryFile() |
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| 730 |
self.lock = utils.FileLock(self.tmpfile.name) |
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| 731 |
|
|
| 732 |
def testSharedNonblocking(self): |
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| 733 |
self.lock.Shared(blocking=False) |
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| 734 |
self.lock.Close() |
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| 735 |
|
|
| 736 |
def testExclusiveNonblocking(self): |
|
| 737 |
self.lock.Exclusive(blocking=False) |
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| 738 |
self.lock.Close() |
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| 739 |
|
|
| 740 |
def testUnlockNonblocking(self): |
|
| 741 |
self.lock.Unlock(blocking=False) |
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| 742 |
self.lock.Close() |
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| 743 |
|
|
| 744 |
def testSharedBlocking(self): |
|
| 745 |
self.lock.Shared(blocking=True) |
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| 746 |
self.lock.Close() |
|
| 747 |
|
|
| 748 |
def testExclusiveBlocking(self): |
|
| 749 |
self.lock.Exclusive(blocking=True) |
|
| 750 |
self.lock.Close() |
|
| 751 |
|
|
| 752 |
def testUnlockBlocking(self): |
|
| 753 |
self.lock.Unlock(blocking=True) |
|
| 754 |
self.lock.Close() |
|
| 755 |
|
|
| 756 |
def testSharedExclusiveUnlock(self): |
|
| 757 |
self.lock.Shared(blocking=False) |
|
| 758 |
self.lock.Exclusive(blocking=False) |
|
| 759 |
self.lock.Unlock(blocking=False) |
|
| 760 |
self.lock.Close() |
|
| 761 |
|
|
| 762 |
def testExclusiveSharedUnlock(self): |
|
| 763 |
self.lock.Exclusive(blocking=False) |
|
| 764 |
self.lock.Shared(blocking=False) |
|
| 765 |
self.lock.Unlock(blocking=False) |
|
| 766 |
self.lock.Close() |
|
| 767 |
|
|
| 768 |
def testCloseShared(self): |
|
| 769 |
self.lock.Close() |
|
| 770 |
self.assertRaises(AssertionError, self.lock.Shared, blocking=False) |
|
| 771 |
|
|
| 772 |
def testCloseExclusive(self): |
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| 773 |
self.lock.Close() |
|
| 774 |
self.assertRaises(AssertionError, self.lock.Exclusive, blocking=False) |
|
| 775 |
|
|
| 776 |
def testCloseUnlock(self): |
|
| 777 |
self.lock.Close() |
|
| 778 |
self.assertRaises(AssertionError, self.lock.Unlock, blocking=False) |
|
| 779 |
|
|
| 780 |
|
|
| 724 | 781 |
if __name__ == '__main__': |
| 725 | 782 |
unittest.main() |
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