def acquire(self, hostId):
with self._globalLockMapSync:
self.log.info("Acquiring local lock for domain %s (id: %s)",
self._sdUUID, hostId)
lockFile = self._globalLockMap.get(self._sdUUID, None)
if lockFile:
try:
misc.NoIntrCall(fcntl.fcntl, lockFile, fcntl.F_GETFD)
except IOError as e:
# We found a stale file descriptor, removing.
del self._globalLockMap[self._sdUUID]
# Raise any other unkown error.
if e.errno != os.errno.EBADF:
raise
else:
self.log.debug(
"Local lock already acquired for domain "
"%s (id: %s)", self._sdUUID, hostId)
return # success, the lock was already acquired
lockFile = misc.NoIntrCall(os.open, self._idsPath, os.O_RDONLY)
try:
misc.NoIntrCall(fcntl.flock, lockFile,
fcntl.LOCK_EX | fcntl.LOCK_NB)
except IOError as e:
misc.NoIntrCall(os.close, lockFile)
if e.errno in (os.errno.EACCES, os.errno.EAGAIN):
raise se.AcquireLockFailure(self._sdUUID, e.errno,
"Cannot acquire local lock",
str(e))
raise
else:
self._globalLockMap[self._sdUUID] = lockFile
self.log.debug(
"Local lock for domain %s successfully acquired "
"(id: %s)", self._sdUUID, hostId)
def release(self):
with self._globalLockMapSync:
self.log.info("Releasing local lock for domain %s", self._sdUUID)
lockFile = self._globalLockMap.get(self._sdUUID, None)
if not lockFile:
self.log.debug("Local lock already released for domain %s",
self._sdUUID)
return
misc.NoIntrCall(os.close, lockFile)
del self._globalLockMap[self._sdUUID]
self.log.debug("Local lock for domain %s successfully released",
self._sdUUID)