drincann/py-coroutine

协程调度器的底层实现(eventloop/eventqueue/asyncapi)

py-coro-impl

A stackless coroutine implementation in Python.

Contains coroutine-level timer, and a simple non-blocking socket implementation of the coroutine-level HTTP protocol interface.

run example

python3 test.py

import time
import math
from asynclib.core import Promise, LoopManager, Timer
from asynclib.asynchttp import get as asyncget


@LoopManager.asyncfun
def httpReq():
    responseData = yield from Promise(
        lambda resolve:
            asyncget(
                url='http://codingfor.life/doc/README.md',
                callback=lambda response: resolve(response)
            ),
    ).catch(lambda e: print(e))
    return responseData


@ LoopManager.asyncfun
def asyncmain():
    # async call
    print('async call start', '\n')
    start = time.time()
    print('async res: ', (yield from Promise.all([httpReq() for _ in range(10)])), '\n')
    print('promise all cost: ' +
          str(math.floor((time.time() - start) * 1000)) + 'ms', '\n')

    # sleep a while using Timer
    print('sleep 2000ms using coroutine timer', '\n')
    yield from Timer.sleep(2000)

    # sync call
    print('sync call start', '\n')
    start = time.time()
    for _ in range(10):
        print(f'sync res {_}: ', (yield from httpReq()), '\n')
    print('sync cost: ' +
          str(math.floor((time.time() - start) * 1000)) + 'ms', '\n')


asyncmain()

reference

• async socket api

  aosabook a-web-crawler-with-asyncio-coroutines

• event loop

  StackOverflow how-would-you-implement-a-basic-event-loop

  MDN Event loop

  The Node.js Event Loop, Timers, and process.nextTick

• promise

  https://www.promisejs.org/implementing/

• async function in v8

  https://v8.dev/blog/fast-async

• book: Operating System: The Three Easy Pieces

  http://pages.cs.wisc.edu/~remzi/OSTEP/

py-coroutine's Issues

fix(eventloop): win 下 selector 在无 I/O 任务时抛出 OSError 的问题

dc102c5

原因是 win 下默认的 selector 实现不允许在未注册任何 I/O 事件之前等待 I/O。

feature(asynclib.asynchttp.*): 复用 selector

现在每次 get 将另开线程等待 OS 调度，需要实现复用 selector。

feature(asynchttp): response 解析类实现

refactor(timer): 实现 timer 的最小堆

feature: 使用装饰器在调用时自动运行协程

feature(eventloop): 实现事件循环的自动结束

当所有异步任务结束后，停止事件循环，结束主线程。

可能需要抽象一个实体，对异步任务进行计数。

此外，还应考虑失败的异步任务，例如设置连接超时时间，抛出异常，令 Future 失败，这里还需要修改 Future。

refactor(timer): 在单独的线程中检查计时器

目前的计时器实现在事件循环线程，作为事件队列中的任务，iotime 会严重影响计时器的准确性。
最好能在新线程中唤醒正在阻塞的事件循环，从而准确执行定时器。

feature(asyncfs): 文件操作异步 api