def _checkForOrphans(filename):
if logger.isEnabledFor(logging.DEBUG):
logger.debug('Checking for orphan locks on ' + filename)
readLockDir = filename + readLockAppend
writeLockDir = filename + writeLockAppend
orphanRemoved = False
nowTime = time.time()
# check for read lock orphans
if os.path.exists(readLockDir):
for f in os.listdir(readLockDir):
fullpath = readLockDir + '/' + f
try:
statinfo = os.stat(fullpath)
if nowTime - ORPHAN_TIMEOUT > statinfo.st_mtime:
logger.warn("Orphan lock " + fullpath + " found and will be removed.")
os.remove(fullpath)
orphanRemoved = True
except OSError, e:
if e.errno != 2:
# 2 indicates file was removed by other process looking for orphans
logger.error("Error removing orphaned lock: " + str(e))
try:
if len(os.listdir(readLockDir)) == 0:
logger.warn("Orphan lock " + readLockDir + " found and will be removed.")
os.rmdir(readLockDir)
except OSError, e:
if e.errno != 2 and e.errno != 39:
# error 2 is no directory exists, implying a different read release
# raced and removed it first
# error 39 is directory is not empty, implying a different read
# added a pid file after we checked the dir's number of files
logger.error('Unable to remove orphaned read lock ' + readLockDir + ': ' + str(e))
def getLock(filename, mode):
t0 = time.time()
dirCheck(filename)
gotLock, fpath = _getLockInternal(filename, mode)
if gotLock:
if logger.isEnabledFor(logging.DEBUG):
logger.debug('Got lock on ' + str(filename))
else:
if logger.isEnabledFor(logging.DEBUG):
logger.debug(str(os.getpid()) + " failed to get lock")
t1=time.time()
if timeMap.has_key('getLock'):
timeMap['getLock']+=t1-t0
else:
timeMap['getLock']=t1-t0
return gotLock, fpath
def getLock(filename, mode):
t0 = time.time()
dirCheck(filename)
gotLock = False
startTime = time.time()
nowTime = time.time()
if mode == 'w' or mode == 'a':
lockOp = fcntl.LOCK_EX
fmode = os.O_RDWR
else:
lockOp = fcntl.LOCK_SH
fmode = os.O_RDONLY
fd = os.open(filename, fmode)
lockOp = lockOp | fcntl.LOCK_NB
if logger.isEnabledFor(logging.DEBUG):
logger.debug(
str(os.getpid()) + " Attempting to get lock on " + str(fd) +
" mode " + mode + " " + filename)
while not gotLock and (nowTime - startTime) < MAX_TIME_TO_WAIT:
try:
fcntl.lockf(fd, lockOp)
gotLock = True
except:
time.sleep(.1)
nowTime = time.time()
if gotLock:
if logger.isEnabledFor(logging.DEBUG):
logger.debug('Got lock on ' + str(fd))
else:
if logger.isEnabledFor(logging.DEBUG):
logger.debug(str(os.getpid()) + " failed to get lock")
os.close(fd)
t1 = time.time()
if timeMap.has_key('getLock'):
timeMap['getLock'] += t1 - t0
else:
timeMap['getLock'] = t1 - t0
return gotLock, fd
def releaseLock(fd):
t0 = time.time()
fcntl.lockf(fd, fcntl.LOCK_UN)
os.close(fd)
if logger.isEnabledFor(logging.DEBUG):
logger.debug('Released lock on ' + str(fd))
t1 = time.time()
if timeMap.has_key('releaseLock'):
timeMap['releaseLock'] += t1 - t0
else:
timeMap['releaseLock'] = t1 - t0
def _getLockInternal(filename, mode):
gotLock = False
lockPath = None
startTime = time.time()
if logger.isEnabledFor(logging.DEBUG):
logger.debug(str(os.getpid()) +" Attempting to get lock on mode " + mode + " " + filename)
readLockDir = filename + readLockAppend
writeLockDir = filename + writeLockAppend
count = 0
timeElapsed = time.time() - startTime
while not gotLock and timeElapsed < MAX_TIME_TO_WAIT:
count += 1
if count % 100 == 0:
# check for orphans every 100 tries
_checkForOrphans(filename)
if mode == 'r':
if os.path.exists(writeLockDir):
time.sleep(_getSleepTime(timeElapsed))
timeElapsed = time.time() - startTime
else:
try:
os.mkdir(readLockDir)
except OSError, e:
# error 17 is dir already exists, which we can ignore
if e.errno != 17:
raise e
try:
# Need to check to make sure write lock wasn't created
# between last check and our dir creation
if os.path.exists(writeLockDir):
os.rmdir(readLockDir)
continue
except OSError, e:
continue #Ignore error
try:
f = open(readLockDir + '/' + str(os.getpid()) + '.pid', 'w')
gotLock = True
lockPath = f.name
except IOError, e:
if e.errno != 2:
# 2 indicates directory is gone, could have had another
# process remove the read dir before the file was created
raise e
try:
if len(os.listdir(dirpath)) == 0:
os.rmdir(dirpath)
except OSError, e:
if e.errno != 2 and e.errno != 39:
# error 2 is no directory exists, implying a different read release
# raced and removed it first
# error 39 is directory is not empty, implying a different read
# added a pid file after we checked the dir's number of files
logger.warn('Unable to remove read lock ' + dirpath + ': ' + str(e))
else:
# it was a write
os.rmdir(lockPath)
if logger.isEnabledFor(logging.DEBUG):
logger.debug('Released lock on ' + str(lockPath))
t1=time.time()
if timeMap.has_key('releaseLock'):
timeMap['releaseLock']+=t1-t0
else:
timeMap['releaseLock']=t1-t0
def _checkForOrphans(filename):
if logger.isEnabledFor(logging.DEBUG):
logger.debug('Checking for orphan locks on ' + filename)
readLockDir = filename + readLockAppend
writeLockDir = filename + writeLockAppend