Making asyncio on our own! Joongi Kim (
) Lablup / KossLab 

Outline §    §   asyncio  async/await   §   : sleep 
 § Summary & Homework PyCon KR 2018 

  
Live Coding PyCon KR 2018 

async/await 
Live Coding PyCon KR 2018 

async/await
 § PEP-380:      
 • yield from 
: generator   generator •  caller  ! "(=generator)   
  ! " yield#    $  PyCon KR 2018 

async/await
 § PEP-492 : async await   
• yield from2 generator :4  – yield @04 <9,  def4 4
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 : sleep 
 Live Coding PyCon KR 2018 

Hints § "async_sleep"         §
  expire sleep ! task  •  %  )  "
· !*  ? • ' $  &(/#  ) ? § select   timeout  " PyCon KR 2018 

Summary PyCon KR 2018 

Summary § asyncio  
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' + /2! 7 Future , yield4,  Future ,   8 4  1 3: –  await ;.,%#  7 Can , yield6 •  1  /2"  *90 ! - caller, ) event loop# 5 – # run() 6 8 • $ 8 event loop future" "book-keeping"8 6 – # WAIT_* &( 8 PyCon KR 2018 

Summary • asyncio.Future – 
 Can     • asyncio.Task – 
 Task   • asyncio.BaseEventLoop – 
    § curio, trio
   I/O     ! PyCon KR 2018 

Homework § select *'$  selectors *'$ , . • kqueue / epoll !& % " • select   kqueue / epoll / IOCP % 
&% § Future "(+!  Can/Task . §  $  Can/Task - cancel!
, . • Cancellation $'  :   vs. generator.close() § trio/curio )#  %!# & § Javascript async/await,  $ & •  generator vs. #  Promise PyCon KR 2018 

Thanks! PyCon KR 2018 

Reference § PEP 342 – Coroutines via Enhanced Generators § PEP 380 – Syntax for Delegating to a Subgenerator § PEP 492 – Coroutines with async and await syntax § PEP-3156 – Asynchronous IO Support Rebooted: the "asyncio" Module § Jonas Obrist's "Artisanal Asyncio Adventures" Talks § CPython's asyncio module source code on GitHub § curio (https://github.com/dabeaz/curio) § trio (https://github.com/python-trio/trio) PyCon KR 2018