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pyudev._os.pipe
===============
Fallback implementations for pipe.
1. pipe2 from python os module
2. pipe2 from libc
3. pipe from python os module
The Pipe class wraps the chosen implementation.
.. moduleauthor:: Sebastian Wiesner <lunaryorn@gmail.com>
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SIGNATURES)�load_ctypes_library� O_CLOEXECi c C s" t � }| j||� |d |d fS )z�A ``pipe2`` implementation using ``pipe2`` from ctypes.
``libc`` is a :class:`ctypes.CDLL` object for libc. ``flags`` is an
integer providing the flags to ``pipe2``.
Return a pair of file descriptors ``(r, w)``.
r � )r �pipe2)�libc�flags�fds� r �/usr/lib/python3.6/pipe.py�
_pipe2_ctypes4 s r c C sX t j� }| t j@ dkr0x|D ]}t|t j� q W | t@ dkrTx|D ]}t|t� qBW |S )z�A ``pipe2`` implementation using :func:`os.pipe`.
``flags`` is an integer providing the flags to ``pipe2``.
.. warning::
This implementation is not atomic!
Return a pair of file descriptors ``(r, w)``.
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r c C s( t j | t jd�}t j | t j||B � dS )zwSet a flag on a file descriptor.
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r N)�fcntlZF_GETFDZF_SETFD)r �flagr r r r r k s r c C s( t j | t jd�}t j | t j||B � dS )z~Set a status flag on a file descriptor.
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r N)r ZF_GETFLZF_SETFL)r r r r r r r u s r c @ s, e Zd ZdZedd� �Zdd� Zdd� ZdS ) �Pipez�A unix pipe.
A pipe object provides two file objects: :attr:`source` is a readable file
object, and :attr:`sink` a writeable. Bytes written to :attr:`sink` appear
at :attr:`source`.
Open a pipe with :meth:`open()`.
c C s t tjtB �\}}| ||�S )zLOpen and return a new :class:`Pipe`.
The pipe uses non-blocking IO.)�_PIPE2r r r )�cls�source�sinkr r r �open� s z Pipe.openc C s$ t j|dd�| _t j|dd�| _dS )z�Create a new pipe object from the given file descriptors.
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Pipe.__init__c
C s z| j j� W d| jj� X dS )z Closes both sides of the pipe.N)r# �closer$ )r) r r r r+ � s z
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