Inspired by pythons new asyncio, this package implements the most basic synchronization primitives to work with ndb's tasklets for the Google AppEngine (GAE)

Install

pip install ndb-x

Usage

We have the three primitives Lock, Semaphore and BoundedSemaphore. Usage is, what you expect, straightforward:

from google.appengine.ext import ndb
from ndbx.locks import Lock


lock = Lock()


@ndb.tasklet
def work_async():
    # using a context-manager will release the lock automatically
    with (yield lock.acquire()):
        rv = yield do_something_async()


@ndb.tasklet
def traditional_flow():
    yield lock.acquire()
    try:
        # do something
    finally:
        lock.release()