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Edit File: monitor.pyc
� ݹ�Yc @` s� d Z d d l m Z m Z m Z m Z d d l Z d d l Z d d l Z d d l m Z d d l m Z d d l m Z m Z m Z m Z d d l m Z d d g Z d e f d � � YZ d e f d � � YZ d S( u� pyudev.monitor ============== Monitor implementation. .. moduleauthor:: Sebastian Wiesner <lunaryorn@googlemail.com> i ( t print_functiont divisiont unicode_literalst absolute_importN( t Thread( t closing( t ensure_byte_stringt ensure_unicode_stringt reraiset eintr_retry_call( t Deviceu Monitoru MonitorObservert Monitorc B` s� e Z d Z d d � Z d � Z d � Z e d d � � Z e d � � Z d � Z d d � Z d � Z d � Z d � Z e Z d � Z d � Z d � Z RS( u� Monitor udev events: >>> context = pyudev.Context() >>> monitor = pyudev.Monitor.from_netlink(context) >>> monitor.filter_by(subsystem='input') >>> for action, device in monitor: ... print('{0}: {1}'.format(action, device)) ... A :class:`Monitor` objects connects to the udev daemon and listens for changes to the device list. A monitor is created by connecting to the kernel daemon through netlink (see :meth:`from_netlink`). Alternatively, connections to arbitrary daemons can be made using :meth:`from_socket`, which is however only seldom of use. Once the monitor is created, you can add a filter using :meth:`filter_by()` or :meth:`filter_by_tag()` to drop incoming events in subsystems, which are not of interest to the application. If the monitor is eventually set up, you can either iterate over the :class:`Monitor` object to synchronously receive events (see :meth:`__iter__()`) or use a :class:`MonitorObserver` to asynchronously react on events. Moreover the monitor provides a real file descriptor (see :meth:`fileno()`), which is :func:`selectable <select.select>`, so you can also plug the monitor into custom notification mechanisms. Do *not* read or write on this file descriptor. Instances of this class can directly be given as ``udev_monitor *`` to functions wrapped through :mod:`ctypes`. c C` s+ | | _ | | _ | | _ | j | _ d S( N( t contextt _as_parameter_t _socket_patht _libudev( t selfR t monitor_pt socket_path( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt __init__P s c C` s2 t j � \ } } } | j | _ t | | � d S( N( t syst exc_infoR t filenameR ( R t _t exc_valuet traceback( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt _reraise_with_socket_pathV s c C` s | j j | � d S( N( R t udev_monitor_unref( R ( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt __del__[ s u udevc C` sa | d k r$ t d j | � � � n | j j | t | � � } | sT t d � � n | | | � S( u� Create a monitor by connecting to the kernel daemon through netlink. ``context`` is the :class:`Context` to use. ``source`` is a string, describing the event source. Two sources are available: ``'udev'`` (the default) Events emitted after udev as registered and configured the device. This is the absolutely recommended source for applications. ``'kernel'`` Events emitted directly after the kernel has seen the device. The device has not yet been configured by udev and might not be usable at all. **Never** use this, unless you know what you are doing. Return a new :class:`Monitor` object, which is connected to the given source. Raise :exc:`~exceptions.ValueError`, if an invalid source has been specified. Raise :exc:`~exceptions.EnvironmentError`, if the creation of the monitor failed. u kernelu udevu8 Invalid source: {0!r}. Must be one of "udev" or "kernel"u Could not create udev monitor( u kernelu udev( t ValueErrort formatR t udev_monitor_new_from_netlinkR t EnvironmentError( t clsR t sourcet monitor( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt from_netlink^ s c C` sL | j j | t | � � } | s9 t d j | � � � n | | | d | �S( u� Connect to an arbitrary udev daemon using the given ``socket_path``. ``context`` is the :class:`Context` to use. ``socket_path`` is a byte or unicode string, pointing to an existing socket. If the path starts with a ``@``, use an abstract namespace socket. If ``socket_path`` does not exist, fall back to an abstract namespace socket. The caller is responsible for permissions and cleanup of the socket file. Return a new :class:`Monitor` object, which is connected to the given socket. Raise :exc:`~exceptions.EnvironmentError`, if the creation of the monitor failed. u* Could not create monitor for socket: {0!r}R ( R t udev_monitor_new_from_socketR R R ( R! R R R# ( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt from_socket~ s c C` s | j j | � S( u� Return the file description associated with this monitor as integer. This is really a real file descriptor ;), which can be watched and :func:`select.select`\ ed. ( R t udev_monitor_get_fd( R ( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt fileno� s c C` sK t | � } | r! t | � } n | j j | | | � | j j | � d S( u' Filter incoming events. ``subsystem`` is a byte or unicode string with the name of a subsystem (e.g. ``'input'``). Only events originating from the given subsystem pass the filter and are handed to the caller. If given, ``device_type`` is a byte or unicode string specifying the device type. Only devices with the given device type are propagated to the caller. If ``device_type`` is not given, no additional filter for a specific device type is installed. These filters are executed inside the kernel, and client processes will usually not be woken up for device, that do not match these filters. .. versionchanged:: 0.15 This method can also be after :meth:`enable_receiving()` now N( R R t/ udev_monitor_filter_add_match_subsystem_devtypet udev_monitor_filter_update( R t subsystemt device_type( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt filter_by� s c C` s- | j j | t | � � | j j | � d S( u\ Filter incoming events by the given ``tag``. ``tag`` is a byte or unicode string with the name of a tag. Only events for devices which have this tag attached pass the filter and are handed to the caller. Like with :meth:`filter_by` this filter is also executed inside the kernel, so that client processes are usually not woken up for devices without the given ``tag``. .. udevversion:: 154 .. versionadded:: 0.9 .. versionchanged:: 0.15 This method can also be after :meth:`enable_receiving()` now N( R t! udev_monitor_filter_add_match_tagR R* ( R t tag( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt filter_by_tag� s c C` s$ | j j | � | j j | � d S( u Remove any filters installed with :meth:`filter_by()` or :meth:`filter_by_tag()` from this monitor. .. warning:: Up to udev 181 (and possibly even later versions) the underlying ``udev_monitor_filter_remove()`` seems to be broken. If used with affected versions this method always raises :exc:`~exceptions.ValueError`. Raise :exc:`~exceptions.EnvironmentError` if removal of installed filters failed. .. versionadded:: 0.15 N( R t udev_monitor_filter_removeR* ( R ( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt remove_filter� s c C` s6 y | j j | � Wn t k r1 | j � n Xd S( u� Switch the monitor into listing mode. Connect to the event source and receive incoming events. Only after calling this method, the monitor listens for incoming events. .. note:: This method is implicitly called by :meth:`__iter__`. You don't need to call it explicitly, if you are iterating over the monitor. N( R t udev_monitor_enable_receivingR R ( R ( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt enable_receiving� s c C` s9 y | j j | | � Wn t k r4 | j � n Xd S( uN Set the receive buffer ``size``. ``size`` is the requested buffer size in bytes, as integer. .. note:: The CAP_NET_ADMIN capability must be contained in the effective capability set of the caller for this method to succeed. Otherwise :exc:`~exceptions.EnvironmentError` will be raised, with ``errno`` set to :data:`~errno.EPERM`. Unprivileged processes typically lack this capability. You can check the capabilities of the current process with the python-prctl_ module: >>> import prctl >>> prctl.cap_effective.net_admin Raise :exc:`~exceptions.EnvironmentError`, if the buffer size could not bet set. .. versionadded:: 0.13 .. _python-prctl: http://packages.python.org/python-prctl N( R t$ udev_monitor_set_receive_buffer_sizeR R ( R t size( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt set_receive_buffer_size� s c C` sw y | j j | � } Wn t k r3 | j � n X| sI t d � � n t | j j | � � } | t | j | � f S( uo Receive a single device from the monitor. The caller must make sure, that there are events available in the event queue. The call blocks, until a device is available. If a device was available, return ``(action, device)``. ``device`` is the :class:`Device` object describing the device. ``action`` is a string describing the action. udev informs about the following actions: ``'add'`` A device has been added (e.g. a USB device was plugged in) ``'remove'`` A device has been removed (e.g. a USB device was unplugged) ``'change'`` Something about the device changed (e.g. a device property) ``'move'`` The device was renamed, moved, or re-parented Raise :exc:`~exceptions.EnvironmentError`, if no device could be read. u Could not receive device( R t udev_monitor_receive_deviceR R R t udev_device_get_actionR R ( R t device_pt action( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt receive_device s c c` st | j � t t j � � �R } | j | t j � x5 t ri t | j � } x | D] } | j � VqQ Wq5 WWd QXd S( u� Wait for incoming events and receive them upon arrival. This methods implicitly calls :meth:`enable_receiving`, and starts polling the :meth:`fileno` of this monitor. If a event comes in, it receives the corresponding device and yields it to the caller. The returned iterator is endless, and continues receiving devices without ever stopping. Yields ``(action, device)`` (see :meth:`receive_device` for a description). N( R4 R t selectt epollt registert EPOLLINt TrueR t pollR< ( R t notifiert eventst event( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt __iter__9 s N( t __name__t __module__t __doc__t NoneR R R t classmethodR$ R& R( R- R0 R2 R4 t startR7 R< RF ( ( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyR / s "t MonitorObserverc B` s2 e Z d Z d � Z d � Z d � Z d � Z RS( u$ A :class:`~threading.Thread` class to observe a :class:`Monitor` in background: >>> context = pyudev.Context() >>> monitor = pyudev.Monitor.from_netlink(context) >>> monitor.filter_by(subsystem='input') >>> def print_device_event(action, device): ... print('background event {0}: {1}'.format(action, device)) >>> observer = MonitorObserver(monitor, print_device_event, name='monitor-observer') >>> observer.daemon True >>> observer.start() In the above example, input device events will be printed in background, until :meth:`stop()` is called on ``observer``. .. note:: Instances of this class are always created as daemon thread. If you do not want to use daemon threads for monitoring, you need explicitly set :attr:`~threading.Thread.daemon` to ``False`` before invoking :meth:`~threading.Thread.start()`. .. versionadded:: 0.14 .. versionchanged:: 0.15 :meth:`Monitor.enable_receiving()` is implicitly called when the thread is started. c O` sJ t j | | | � | | _ t | _ t j � \ | _ | _ | | _ d S( u� Create a new observer for the given ``monitor``. ``monitor`` is the :class:`Monitor` to observe. ``event_handler`` is a callable with the signature ``event_handler(action, device)``, where ``action`` is a string describing the event (see :meth:`Monitor.receive_device`), and ``device`` is the :class:`Device` object that caused this event. This callable is invoked for every device event received through ``monitor``. .. warning:: ``event_handler`` is always invoked in this background thread, and *not* in the calling thread. ``args`` and ``kwargs`` are passed unchanged to the parent constructor of :class:`~threading.Thread`. N( R R R# RA t daemont ost pipet _stop_event_sourcet _stop_event_sinkt _handle_event( R R# t event_handlert argst kwargs( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyR o s c C` s� | j j � t t j � � �� } | j | j t j � | j | j t j � x� t r� xt t | j � D]c \ } } | | j k r� t j | j � d S| j j � } | rg | \ } } | j | | � qg qg WqQ WWd QXd S( N( R# R4 R R= R> R? RQ R@ RA R RB RO t closeR< RS ( R RC t fdR RE R; t device( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt run� s c C` sK | j d k r d Sz t j | j d � Wd t j | j � d | _ Xd S( uT Send a stop signal to the background thread. The background thread will eventually exit, but it may still be running when this method returns. This method is essentially the asynchronous equivalent to :meth:`stop()`. .. note:: The underlying :attr:`monitor` is *not* stopped. Ns ( RR RJ RO t writeRW ( R ( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt send_stop� s c C` s | j � | j � d S( u Stop the background thread. .. warning:: Calling this method from the ``event_handler`` results in a dead lock. If you need to stop the observer from ``event_handler``, use :meth:`send_stop`, and be prepared to get some more events before the observer actually exits. Send a stop signal to the backgroud (see :meth:`send_stop`) and waits for the background thread to exit (see :meth:`~threading.Thread.join`). After this method returns, it is guaranteed that the ``event_handler`` passed to :meth:`MonitorObserver.__init__()` is not longer called for any event from :attr:`monitor`. .. note:: The underlying :attr:`monitor` is *not* stopped. N( R\ t join( R ( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt stop� s ( RG RH RI R RZ R\ R^ ( ( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyRM P s ( RI t __future__R R R R RO R R= t threadingR t contextlibR t pyudev._utilR R R R t pyudev.coreR t __all__t objectR RM ( ( ( s2 /usr/lib/python2.7/site-packages/pyudev/monitor.pyt <module> s " " � "