asyncio剖析—Task作用(二)

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

   #案例一
   async def hello2():
       print("hello")
       await asyncio.sleep(.0)
   
   loop=asyncio.get_event_loop()
   loop.run_until_complete(hello2())

   

#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

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))