CODEWITHSUNDEEP
pythontornado
user2003548
user2003548

Reputation: 4545

Is there a way to "lock" requests in tornado until something is done?

when i say lock ,i mean it switch to other coroutines and switch back until certain work is done.

the code would be write like these:

@waitUntil('myProcess')
@gen.coroutine
def query():
    do_query()


@waitUntil('myProcess')
@gen.coroutine
def process():
    result = yield do_myProcess(params)
    deal_result(result)

here's my waitUntil based on the answer toro.Lock. don't guarantee it is right,need test.

import toro

_locks = {}

def getLock(key):
    if key not in _locks:
        _locks[key] = toro.Lock()
    return _locks[key]


def waitUntil(key):
    def wrapped(func):
        @gen.coroutine
        def wrapped2(*args,**kwargs):
            with (yield getLock(key).acquire()):
                result = yield func(*args,**kwargs)
            return result
        return wrapped2
    return wrapped

Upvotes: 1

Views: 560

Answers (2)

lfagundes
lfagundes

Reputation: 3068

Since v4.2, tornado has locks: https://www.tornadoweb.org/en/stable/locks.html

try locks.Lock: 

>>> lock = locks.Lock()
>>>
>>> async def f():
...    async with lock:
...        # Do something holding the lock.
...        pass
...
...    # Now the lock is released.

see Lock documentation: https://www.tornadoweb.org/en/stable/locks.html#tornado.locks.Lock

Upvotes: 0

A. Jesse Jiryu Davis
A. Jesse Jiryu Davis

Reputation: 24007

Try toro.Lock, which I wrote for this purpose

lock = toro.Lock()

@gen.coroutine
def f():
   with (yield lock.acquire()):
       assert lock.locked()

   assert not lock.locked()

https://toro.readthedocs.org/en/stable/classes.html#lock

Upvotes: 1

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