U
    g
                     @  s   d dl mZ d dlmZ d dlmZ d dlmZ d dlZddl	m
Z
mZmZ er\d dlmZ ejejd	d	d
G dd dZdS )    )annotations)defaultdict)asynccontextmanager)TYPE_CHECKINGN   )Event_core_util)AsyncIteratorF)eqslotsc                   @  sl   e Zd ZU dZejdd ddZded< ejeddZ	ded	< ejddd
Z
ded< edddddZdS )	Sequencera  A convenience class for forcing code in different tasks to run in an
    explicit linear order.

    Instances of this class implement a ``__call__`` method which returns an
    async context manager. The idea is that you pass a sequence number to
    ``__call__`` to say where this block of code should go in the linear
    sequence. Block 0 starts immediately, and then block N doesn't start until
    block N-1 has finished.

    Example:
      An extremely elaborate way to print the numbers 0-5, in order::

         async def worker1(seq):
             async with seq(0):
                 print(0)
             async with seq(4):
                 print(4)

         async def worker2(seq):
             async with seq(2):
                 print(2)
             async with seq(5):
                 print(5)

         async def worker3(seq):
             async with seq(1):
                 print(1)
             async with seq(3):
                 print(3)

         async def main():
            seq = trio.testing.Sequencer()
            async with trio.open_nursery() as nursery:
                nursery.start_soon(worker1, seq)
                nursery.start_soon(worker2, seq)
                nursery.start_soon(worker3, seq)

    c                   C  s   t tS )N)r   r    r   r   ;/tmp/pip-unpacked-wheel-ks04xdmi/trio/testing/_sequencer.py<lambda>:       zSequencer.<lambda>F)factoryinitzdefaultdict[int, Event]_sequence_pointszset[int]_claimed)defaultr   bool_brokenintzAsyncIterator[None])positionreturnc              	   C s   || j krtd| | jr&td| j | |dkrz| j|  I d H  W n> tjk
r   d| _| j D ]}|	  qttdd Y nX | jrtdz
d V  W 5 | j|d  	  X d S )Nz"Attempted to reuse sequence point zsequence broken!r   Tz+Sequencer wait cancelled -- sequence broken   )
r   RuntimeErrorr   addr   waitr   Z	Cancelledvaluesset)selfr   eventr   r   r   __call__@   s,    


zSequencer.__call__N)__name__
__module____qualname____doc__attrsfieldr   __annotations__r!   r   r   r   r$   r   r   r   r   r      s   
'r   )
__future__r   collectionsr   
contextlibr   typingr   r)    r   r   r	   collections.abcr
   finalZdefiner   r   r   r   r   <module>   s   