renew_lock

lockmgr.lockmgr.renew_lock(lock: Union[str, lockmgr.models.Lock], expires: int = 600, add_time: bool = False, **kwargs) → lockmgr.models.Lock[source]

Renew an existing lock for more expiry time.

Note: This function will NOT reduce a lock’s expiry time, only lengthen. If add_time is False, and the new expiration time expires is shorter than the lock’s existing expiration time, then the lock’s expiry time will be left untouched.

Example - Renew an existing lock:

>>> lk = get_lock('my_app:somelock', expires=10)
>>> sleep(5)
>>> lk = renew_lock(lk, 20)   # Change the expiry time to 20 seconds from now
>>> sleep(15)
>>> is_locked('my_app:somelock') # 15 seconds later, the lock is still locked
True

Example - Try to renew, but get a new lock if it’s already been released:

>>> lk = get_lock('my_app:somelock', expires=5)
>>> sleep(10)
>>> lk = renew_lock(lk, 20, create=True)   # If the lock is expired/non-existant, make a new lock
>>> sleep(15)
>>> is_locked('my_app:somelock') # 15 seconds later, the lock is still locked
True
Parameters

  • lock (Lock) – Name of the lock to renew

  • lock – A Lock object to renew

  • expires (int) – (Default: 600) If not add_time, then this is the new expiration time in seconds from now. If add_time, then this many seconds will be added to the expiration time of the lock.

  • add_time (bool) – (Default: False) If True, then expires seconds will be added to the existing lock expiration time, instead of setting the expiration time to now + expires

Key bool create

(Default: False) If True, then create a new lock if it doesn’t exist / already expired.

Key str locked_by

(Default: system hostname) What server/app is trying to obtain this lock?

Key int lock_process

(Optional) The process ID requesting the lock

Raises

LockNotFound – Raised if the requested lock doesn’t exist / is already expired and create is False.

Return Lock lock

The Lock object which was renewed