asyncio剖析—Task作用(二)

code-python

函数调用伪代码图

  1. ensure_future
  2. wait
  3. gather
  4. 协程链原因 Collection.deque+动态进行过程中将hand 挂在deque队列中
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    #案例一
    async def hello2():
        print("hello")
        await asyncio.sleep(.0)

    loop=asyncio.get_event_loop()
    loop.run_until_complete(hello2())
    image
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#案例二
async def hello2():
    print("hello2 start")
    # await pause(hello2.__name__)
    print("hello2 end")

async def pause(name):
    print("pause",name)

async def hello():
    print("hello start")
    # await pause(hello.__name__)
    print("hello end")

loop=asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait([hello(),hello2(),pause("pasue"),hello()]))

#asyncio.wait 核心
#   fs = {ensure_future(f, loop=loop) for f in set(fs)}  task乱序
#   return (yield from _wait(fs, timeout, return_when, loop))  协程生成器
#   waiter = loop.create_future()  创建中断协程,标志这wait 协程任务已经完成

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案例三

async def hello2():
    print("hello2 start")
    # await pause(hello2.__name__)
    print("hello2 end")

async def pause(name):
    print("pause",name)

async def hello():
    print("hello start")
    # await pause(hello.__name__)
    print("hello end")

loop=asyncio.get_event_loop()
tasks=[]
for i in range(2):
    if i==0:
        tasks.append(asyncio.ensure_future(hello()))
    else:
        tasks.append(asyncio.ensure_future(hello2()))

loop.run_until_complete(asyncio.gather(*tasks))

image

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