Asynchronous Components¶

Futures¶

Directly create a of Future:

import asyncio

o = asyncio.Future()

or, equivalently:

import pulsar

o = pulsar.Future()

Coroutines¶

A coroutine, a generator which consumes values. For example:

async def my_async_generator(...):
    await something_but_dont_care_what_it_returns()
    ...
    bla = await something_and_care_what_it_returns()
    return await do_something(bla)

a coroutine is obtained by calling the coroutine function:

o = my_async_generator()

Note that o is coroutine which has not yet started.

Task¶

An asyncio.Task, is a component which has been added to pulsar asynchronous engine. It is created via the async() function when applied to a generator function:

from pulsar import ensure_future

task = ensure_future(my_async_generator())

A Task is a subclass of Future and therefore it has the same API, for example, you can add callbacks to a task:

task.add_done_callback(...)

A task consumes a coroutine until the coroutine yield an asynchronous component not yet done. When this appends, the task pauses and returns the control of execution. Before it returns, it adds a callback to the Future on which the coroutine is blocked to resume the coroutine once the future is called. A task in this state is said to be suspended.