PyYADL 1.0.0

examples:

Create lock object

from PyYADL import RedisLock
lock = RedisLock(name='test_lock', prefix='my_app', ttl=60, existing_connection_pool=None, redis_host='127.0.0.1', redis_port=6379, redis_password='secret', redis_db=0)

Parameters meaning: * name - each resource should have unique lock name, which would be shared across all systems. Required * prefix - prefix useful to avoid conflicts in names. Optional * ttl - how many seconds lock will be active. If ttl <= 0, lock will be valid until release. Optional Default: -1 * existing_connection_pool already established connection pool Optional * redis_host Optional Default: localhost * redis_port Optional Default: 6379 * redis_password Optional * redis_db Optional Default: 0

Basic usage

from PyYADL import RedisLock

lock = RedisLock('test_lock')
lock.acquire()
lock.release()

Basic lock and release operations. If lock already acquired, will wait for release or ttl expire

from PyYADL import RedisLock

lock = RedisLock('test_lock')
with lock:
    # do some tasks
    pass

Lock and release using context manager

from PyYADL import RedisLock

lock1 = RedisLock('test_lock')
lock2 = RedisLock('test_lock')
lock1.acquire()
lock2.release()

Will raise RuntimeError (because lock is owned by other instance)

from PyYADL import RedisLock

lock1 = RedisLock('test_lock')
lock2 = RedisLock('test_lock')
lock1.acquire()
lock2.release(force=True)

Will release lock, because force parameter is set to True

from PyYADL import RedisLock

lock = RedisLock('test_lock')
status = lock.acquire(blocking=False)

Will acquire lock and return True, if lock released, otherwise return False without waiting

from PyYADL import RedisLock

lock = RedisLock('test_lock')
status = lock.acquire(timeout=12)

Will try to acquire lock for 12 seconds. In case of success will return True, otherwise return False

Usage

Examples

from PyYADL import RedisWriteLock

lock = RedisWriteLock('test_lock')
status = lock.acquire(blocking=True, timeout=20)

Equivalent of RedisLock class

from PyYADL import RedisReadLock

lock1 = RedisReadLock('test_lock')
lock2 = RedisReadLock('test_lock')
lock1.acquire()
lock2.acquire()

Will create two read locks (at the same time there can be many read locks)

from PyYADL import RedisReadLock, RedisWriteLock

lock1 = RedisReadLock('test_lock')
lock2 = RedisReadLock('test_lock')
lock3 = RedisWriteLock('test_lock')
lock1.acquire()
lock2.acquire()
lock3.acquire()

Will acquire only lock1 and lock2 (write lock can’t be obtained when other locks exists)

from PyYADL import RedisReadLock, RedisWriteLock

lock1 = RedisWriteLock('test_lock')
lock2 = RedisReadLock('test_lock')

lock1.acquire()
lock2.acquire()

Will acquire only lock1 (when write lock exists, read lock cannot be obtained)