aioeventlet can be used with trollius, coroutines written with yield From(...). Using aioeventlet with trollius is a good start to port project written for eventlet to trollius.
To use aioeventlet with trollius, set the event loop policy before using an event loop, example:
import aioeventlet
import trollius
trollius.set_event_loop_policy(aioeventlet.EventLoopPolicy())
# ....
Hello World:
import aioeventlet
import trollius as asyncio
def hello_world():
print("Hello World")
loop.stop()
asyncio.set_event_loop_policy(aioeventlet.EventLoopPolicy())
loop = asyncio.get_event_loop()
loop.call_soon(hello_world)
loop.run_forever()
loop.close()
See also
aioeventlet can be used with asyncio, coroutines written with yield from .... To use aioeventlet with asyncio, set the event loop policy before using an event loop. Example:
import aioeventlet
import asyncio
asyncio.set_event_loop_policy(aioeventlet.EventLoopPolicy())
# ....
Setting the event loop policy should be enough to examples of the asyncio documentation with the aioeventlet event loop.
Warning
Since aioeventlet relies on eventlet, eventlet port to Python 3 is not complete and asyncio requires Python 3.3 or newer: using aioeventlet with asyncio is not recommended yet. Using aioeventlet with trollius should be preferred right now. See the status of the eventlet port to Python 3.
Hello World:
import aioeventlet
import asyncio
def hello_world():
print("Hello World")
loop.stop()
asyncio.set_event_loop_policy(aioeventlet.EventLoopPolicy())
loop = asyncio.get_event_loop()
loop.call_soon(hello_world)
loop.run_forever()
loop.close()
See also
Running an event loop in a thread different than the main thread is currently experimental.
An eventlet Event object is not thread-safe, it must only be used in the same thread. Use threading.Event to signal events between threads, and threading.Queue to pass data between threads.
Use threading = eventlet.patcher.original('threading') to get the original threading instead of import threading.
It is not possible to run two aioeventlet event loops in the same thread.
To enable the debug mode globally when using trollius, set the environment variable TROLLIUSDEBUG to 1. To see debug traces, set the log level of the trollius logger to logging.DEBUG. The simplest configuration is:
import logging
# ...
logging.basicConfig(level=logging.DEBUG)
If you use asyncio, use the PYTHONASYNCIODEBUG environment variable instead of the TROLLIUSDEBUG variable.
You can also call loop.set_debug(True) to enable the debug mode of the event loop, but it enables less debug checks.
See also
Read the Develop with asyncio section of the asyncio documentation.
aioeventlet specific functions:
Warning
aioeventlet API is not considered as stable yet.
Wait for a future, a task, or a coroutine object from a greenthread.
Return the result or raise the exception of the future.
The function must not be called from the greenthread of the aioeventlet event loop.
Changed in version 0.4: Rename the function from wrap_future() to yield_future().
Changed in version 0.3: Coroutine objects are also accepted. Added the loop parameter. An exception is raised if it is called from the greenthread of the aioeventlet event loop.
Example of greenthread waiting for a trollius task. The progress() callback is called regulary to see that the event loop in not blocked:
import aioeventlet
import eventlet
import trollius as asyncio
from trollius import From, Return
def progress():
print("computation in progress...")
loop.call_later(0.5, progress)
@asyncio.coroutine
def coro_slow_sum(x, y):
yield From(asyncio.sleep(1.0))
raise Return(x + y)
def green_sum():
loop.call_soon(progress)
task = asyncio.async(coro_slow_sum(1, 2))
value = aioeventlet.yield_future(task)
print("1 + 2 = %s" % value)
loop.stop()
asyncio.set_event_loop_policy(aioeventlet.EventLoopPolicy())
eventlet.spawn(green_sum)
loop = asyncio.get_event_loop()
loop.run_forever()
loop.close()
Output:
computation in progress...
computation in progress...
computation in progress...
1 + 2 = 3
Wrap an eventlet GreenThread, or a greenlet, into a Future object.
The Future object waits for the completion of a greenthread. The result or the exception of the greenthread will be stored in the Future object.
The greenthread must be wrapped before its execution starts. If the greenthread is running or already finished, an exception is raised.
For greenlets, the run attribute must be set.
Changed in version 0.3: An exception is now raised if the greenthread is running or already finished. In debug mode, the exception is not more logged to sys.stderr for greenthreads.
Example of trollius coroutine waiting for a greenthread. The progress() callback is called regulary to see that the event loop in not blocked:
import aioeventlet
import eventlet
import trollius as asyncio
from trollius import From, Return
def progress():
print("computation in progress...")
loop.call_later(0.5, progress)
def slow_sum(x, y):
eventlet.sleep(1.0)
return x + y
@asyncio.coroutine
def coro_sum():
loop.call_soon(progress)
gt = eventlet.spawn(slow_sum, 1, 2)
fut = aioeventlet.wrap_greenthread(gt, loop=loop)
result = yield From(fut)
print("1 + 2 = %s" % result)
asyncio.set_event_loop_policy(aioeventlet.EventLoopPolicy())
loop = asyncio.get_event_loop()
loop.run_until_complete(coro_sum())
loop.close()
Output:
computation in progress...
computation in progress...
computation in progress...
1 + 2 = 3
Procedure for Python 2.7:
If pip is not installed yet, install pip: download get-pip.py and type:
\Python27\python.exe get-pip.py
Install aioeventlet with pip:
\Python27\python.exe -m pip install aioeventlet
pip also installs dependencies: eventlet and trollius
Requirements:
Type:
python setup.py install
The tox project can be used to build a virtual environment with all runtime and test dependencies and run tests against different Python versions (2.6, 2.7, 3.2, 3.3, 3.4).
To test all Python versions, just type:
tox
To run tests with Python 2.7, type:
tox -e py27
To run tests against other Python versions:
To run unit tests, the mock module is need on Python older than 3.3.
Run the following command:
python runtests.py -r