diff --git a/pyudev/_libudev.py b/pyudev/_libudev.py

index efc27c9..7d97d35 100644

--- a/pyudev/_libudev.py

+++ b/pyudev/_libudev.py

@@ -284,6 +284,3 @@ def load_udev_library():

                 if errorchecker:

                     func.errcheck = errorchecker

     return libudev

-

-

-libudev = load_udev_library()

diff --git a/pyudev/_util.py b/pyudev/_util.py

index a99da08..c11b0b2 100644

--- a/pyudev/_util.py

+++ b/pyudev/_util.py

@@ -33,7 +33,6 @@ import os

 import sys

 import stat

-from pyudev._libudev import libudev

 if sys.version_info[0] == 2:

     from pyudev._py2util import *

@@ -101,7 +100,7 @@ def string_to_bool(value):

     return value == '1'

-def udev_list_iterate(entry):

+def udev_list_iterate(libudev, entry):

     """

     Iteration helper for udev list entry objects.

diff --git a/pyudev/core.py b/pyudev/core.py

index 83d2c7c..5017d80 100644

--- a/pyudev/core.py

+++ b/pyudev/core.py

@@ -35,7 +35,7 @@ except ImportError:

     from pyudev._compat import check_output

 from pyudev.device import Device

-from pyudev._libudev import libudev

+from pyudev._libudev import load_udev_library

 from pyudev._util import (ensure_unicode_string, ensure_byte_string,

                           udev_list_iterate, property_value_to_bytes)

@@ -89,10 +89,11 @@ class Context(object):

         """

         Create a new context.

         """

-        self._as_parameter_ = libudev.udev_new()

+        self._libudev = load_udev_library()

+        self._as_parameter_ = self._libudev.udev_new()

     def __del__(self):

-        libudev.udev_unref(self)

+        self._libudev.udev_unref(self)

     @property

     def sys_path(self):

@@ -102,7 +103,7 @@ class Context(object):

         The mount point can be overwritten using the environment variable

         :envvar:`SYSFS_PATH`.  Use this for testing purposes.

         """

-        return ensure_unicode_string(libudev.udev_get_sys_path(self))

+        return ensure_unicode_string(self._libudev.udev_get_sys_path(self))

     @property

     def device_path(self):

@@ -111,7 +112,7 @@ class Context(object):

         This can be overridden in the udev configuration.

         """

-        return ensure_unicode_string(libudev.udev_get_dev_path(self))

+        return ensure_unicode_string(self._libudev.udev_get_dev_path(self))

     @property

     def run_path(self):

@@ -123,7 +124,7 @@ class Context(object):

         .. versionadded:: 0.10

         """

-        return ensure_unicode_string(libudev.udev_get_run_path(self))

+        return ensure_unicode_string(self._libudev.udev_get_run_path(self))

     @property

     def log_priority(self):

@@ -142,11 +143,11 @@ class Context(object):

         .. versionadded:: 0.9

         """

-        return libudev.udev_get_log_priority(self)

+        return self._libudev.udev_get_log_priority(self)

     @log_priority.setter

     def log_priority(self, value):

-        libudev.udev_set_log_priority(self, value)

+        self._libudev.udev_set_log_priority(self, value)

     def list_devices(self, **kwargs):

         """

@@ -205,10 +206,11 @@ class Enumerator(object):

         if not isinstance(context, Context):

             raise TypeError('Invalid context object')

         self.context = context

-        self._as_parameter_ = libudev.udev_enumerate_new(context)

+        self._as_parameter_ = context._libudev.udev_enumerate_new(context)

+        self._libudev = context._libudev

     def __del__(self):

-        libudev.udev_enumerate_unref(self)

+        self._libudev.udev_enumerate_unref(self)

     def match(self, **kwargs):

         """

@@ -265,9 +267,9 @@ class Enumerator(object):

         Return the instance again.

         """

-        match = (libudev.udev_enumerate_add_match_subsystem

+        match = (self._libudev.udev_enumerate_add_match_subsystem

                  if not nomatch else

-                 libudev.udev_enumerate_add_nomatch_subsystem)

+                 self._libudev.udev_enumerate_add_nomatch_subsystem)

         match(self, ensure_byte_string(subsystem))

         return self

@@ -281,7 +283,7 @@ class Enumerator(object):

         .. versionadded:: 0.8

         """

-        libudev.udev_enumerate_add_match_sysname(

+        self._libudev.udev_enumerate_add_match_sysname(

             self, ensure_byte_string(sys_name))

         return self

@@ -301,7 +303,7 @@ class Enumerator(object):

         Return the instance again.

         """

-        libudev.udev_enumerate_add_match_property(

+        self._libudev.udev_enumerate_add_match_property(

             self, ensure_byte_string(property), property_value_to_bytes(value))

         return self

@@ -332,9 +334,9 @@ class Enumerator(object):

         Return the instance again.

         """

-        match = (libudev.udev_enumerate_add_match_sysattr

+        match = (self._libudev.udev_enumerate_add_match_sysattr

                  if not nomatch else

-                 libudev.udev_enumerate_add_nomatch_sysattr)

+                 self._libudev.udev_enumerate_add_nomatch_sysattr)

         match(self, ensure_byte_string(attribute),

               property_value_to_bytes(value))

         return self

@@ -351,7 +353,7 @@ class Enumerator(object):

         .. versionadded:: 0.6

         """

-        libudev.udev_enumerate_add_match_tag(self, ensure_byte_string(tag))

+        self._libudev.udev_enumerate_add_match_tag(self, ensure_byte_string(tag))

         return self

     def match_is_initialized(self):

@@ -372,7 +374,7 @@ class Enumerator(object):

         .. versionadded:: 0.8

         """

-        libudev.udev_enumerate_add_match_is_initialized(self)

+        self._libudev.udev_enumerate_add_match_is_initialized(self)

         return self

     def match_parent(self, parent):

@@ -389,7 +391,7 @@ class Enumerator(object):

         .. versionadded:: 0.13

         """

-        libudev.udev_enumerate_add_match_parent(self, parent)

+        self._libudev.udev_enumerate_add_match_parent(self, parent)

         return self

     def __iter__(self):

@@ -398,7 +400,7 @@ class Enumerator(object):

         Yield :class:`Device` objects.

         """

-        libudev.udev_enumerate_scan_devices(self)

-        entry = libudev.udev_enumerate_get_list_entry(self)

-        for name, _ in udev_list_iterate(entry):

+        self._libudev.udev_enumerate_scan_devices(self)

+        entry = self._libudev.udev_enumerate_get_list_entry(self)

+        for name, _ in udev_list_iterate(self._libudev, entry):

             yield Device.from_sys_path(self.context, name)

diff --git a/pyudev/device.py b/pyudev/device.py

index f9a4325..d5ae3da 100644

--- a/pyudev/device.py

+++ b/pyudev/device.py

@@ -32,7 +32,6 @@ import os

 from collections import Mapping, Container, Iterable

 from datetime import timedelta

-from pyudev._libudev import libudev

 from pyudev._util import (ensure_byte_string, ensure_unicode_string,

                           udev_list_iterate, string_to_bool,

                           get_device_type)

@@ -219,7 +218,7 @@ class Device(Mapping):

            Raise :exc:`DeviceNotFoundAtPathError` instead of

            :exc:`NoSuchDeviceError`

         """

-        device = libudev.udev_device_new_from_syspath(

+        device = context._libudev.udev_device_new_from_syspath(

             context, ensure_byte_string(sys_path))

         if not device:

             raise DeviceNotFoundAtPathError(sys_path)

@@ -247,7 +246,7 @@ class Device(Mapping):

         .. versionadded:: 0.5

         """

-        device = libudev.udev_device_new_from_subsystem_sysname(

+        device = context._libudev.udev_device_new_from_subsystem_sysname(

             context, ensure_byte_string(subsystem),

             ensure_byte_string(sys_name))

         if not device:

@@ -295,7 +294,7 @@ class Device(Mapping):

         if type not in ('char', 'block'):

             raise ValueError('Invalid type: {0!r}. Must be one of "char" '

                              'or "block".'.format(type))

-        device = libudev.udev_device_new_from_devnum(

+        device = context._libudev.udev_device_new_from_devnum(

             context, ensure_byte_string(type[0]), number)

         if not device:

             raise DeviceNotFoundByNumberError(type, number)

@@ -360,7 +359,7 @@ class Device(Mapping):

         .. versionadded:: 0.6

         """

-        device = libudev.udev_device_new_from_environment(context)

+        device = context._libudev.udev_device_new_from_environment(context)

         if not device:

             raise DeviceNotFoundInEnvironmentError()

         return cls(context, device)

@@ -368,9 +367,10 @@ class Device(Mapping):

     def __init__(self, context, _device):

         self.context = context

         self._as_parameter_ = _device

+        self._libudev = context._libudev

     def __del__(self):

-        libudev.udev_device_unref(self)

+        self._libudev.udev_device_unref(self)

     def __repr__(self):

         return 'Device({0.sys_path!r})'.format(self)

@@ -381,12 +381,12 @@ class Device(Mapping):

         The parent :class:`Device` or ``None``, if there is no parent

         device.

         """

-        parent = libudev.udev_device_get_parent(self)

+        parent = self._libudev.udev_device_get_parent(self)

         if not parent:

             return None

         # the parent device is not referenced, thus forcibly acquire a

         # reference

-        return Device(self.context, libudev.udev_device_ref(parent))

+        return Device(self.context, self._libudev.udev_device_ref(parent))

     @property

     def children(self):

@@ -432,12 +432,12 @@ class Device(Mapping):

         subsystem = ensure_byte_string(subsystem)

         if device_type is not None:

             device_type = ensure_byte_string(device_type)

-        parent = libudev.udev_device_get_parent_with_subsystem_devtype(

+        parent = self._libudev.udev_device_get_parent_with_subsystem_devtype(

             self, subsystem, device_type)

         if not parent:

             return None

         # parent device is not referenced, thus forcibly acquire a reference

-        return Device(self.context, libudev.udev_device_ref(parent))

+        return Device(self.context, self._libudev.udev_device_ref(parent))

     def traverse(self):

         """

@@ -458,7 +458,8 @@ class Device(Mapping):

         Absolute path of this device in ``sysfs`` including the ``sysfs``

         mount point as unicode string.

         """

-        return ensure_unicode_string(libudev.udev_device_get_syspath(self))

+        return ensure_unicode_string(

+            self._libudev.udev_device_get_syspath(self))

     @property

     def device_path(self):

@@ -470,21 +471,24 @@ class Device(Mapping):

         mount point.  However, the path is absolute and starts with a slash

         ``'/'``.

         """

-        return ensure_unicode_string(libudev.udev_device_get_devpath(self))

+        return ensure_unicode_string(

+            self._libudev.udev_device_get_devpath(self))

     @property

     def subsystem(self):

         """

         Name of the subsystem this device is part of as unicode string.

         """

-        return ensure_unicode_string(libudev.udev_device_get_subsystem(self))

+        return ensure_unicode_string(

+            self._libudev.udev_device_get_subsystem(self))

     @property

     def sys_name(self):

         """

         Device file name inside ``sysfs`` as unicode string.

         """

-        return ensure_unicode_string(libudev.udev_device_get_sysname(self))

+        return ensure_unicode_string(

+            self._libudev.udev_device_get_sysname(self))

     @property

     def sys_number(self):

@@ -508,7 +512,7 @@ class Device(Mapping):

         .. versionadded:: 0.11

         """

-        number = libudev.udev_device_get_sysnum(self)

+        number = self._libudev.udev_device_get_sysnum(self)

         if number is not None:

             return ensure_unicode_string(number)

@@ -529,7 +533,7 @@ class Device(Mapping):

         .. versionadded:: 0.10

         """

-        device_type = libudev.udev_device_get_devtype(self)

+        device_type = self._libudev.udev_device_get_devtype(self)

         if device_type is not None:

             return ensure_unicode_string(device_type)

@@ -541,7 +545,7 @@ class Device(Mapping):

         .. versionadded:: 0.5

         """

-        driver = libudev.udev_device_get_driver(self)

+        driver = self._libudev.udev_device_get_driver(self)

         if driver:

             return ensure_unicode_string(driver)

@@ -563,7 +567,7 @@ class Device(Mapping):

            this property is not necessary equal to the ``filename`` given to

            :meth:`from_device_file()`.

         """

-        node = libudev.udev_device_get_devnode(self)

+        node = self._libudev.udev_device_get_devnode(self)

         if node:

             return ensure_unicode_string(node)

@@ -591,7 +595,7 @@ class Device(Mapping):

         .. versionadded:: 0.11

         """

-        return libudev.udev_device_get_devnum(self)

+        return self._libudev.udev_device_get_devnum(self)

     @property

     def is_initialized(self):

@@ -614,7 +618,7 @@ class Device(Mapping):

         .. versionadded:: 0.8

         """

-        return bool(libudev.udev_device_get_is_initialized(self))

+        return bool(self._libudev.udev_device_get_is_initialized(self))

     @property

     def time_since_initialized(self):

@@ -631,7 +635,8 @@ class Device(Mapping):

         .. versionadded:: 0.8

         """

-        microseconds = libudev.udev_device_get_usec_since_initialized(self)

+        microseconds = self._libudev.udev_device_get_usec_since_initialized(

+            self)

         return timedelta(microseconds=microseconds)

     @property

@@ -650,8 +655,8 @@ class Device(Mapping):

         The property provides access to all such symbolic links, which were

         created by UDev for this device.

         """

-        devlinks = libudev.udev_device_get_devlinks_list_entry(self)

-        for name, _ in udev_list_iterate(devlinks):

+        devlinks = self._libudev.udev_device_get_devlinks_list_entry(self)

+        for name, _ in udev_list_iterate(self._libudev, devlinks):

             yield ensure_unicode_string(name)

     @property

@@ -713,19 +718,16 @@ class Device(Mapping):

         Return a generator yielding the names of all properties of this

         device as unicode strings.

         """

-        properties = libudev.udev_device_get_properties_list_entry(self)

-        for name, _ in udev_list_iterate(properties):

+        properties = self._libudev.udev_device_get_properties_list_entry(self)

+        for name, _ in udev_list_iterate(self._libudev, properties):

             yield ensure_unicode_string(name)

     def __len__(self):

         """

         Return the amount of properties defined for this device as integer.

         """

-        properties = libudev.udev_device_get_properties_list_entry(self)

-        i = 0

-        for i, _ in enumerate(udev_list_iterate(properties), start=1):

-            pass

-        return i

+        properties = self._libudev.udev_device_get_properties_list_entry(self)

+        return sum(1 for _ in udev_list_iterate(self._libudev, properties))

     def __getitem__(self, property):

         """

@@ -738,7 +740,7 @@ class Device(Mapping):

         :exc:`~exceptions.KeyError`, if the given property is not defined

         for this device.

         """

-        value = libudev.udev_device_get_property_value(

+        value = self._libudev.udev_device_get_property_value(

             self, ensure_byte_string(property))

         if value is None:

             raise KeyError(property)

@@ -814,14 +816,17 @@ class Tags(Iterable, Container):

     def __init__(self, device):

         self.device = device

-    if hasattr(libudev, 'udev_device_has_tag'):

-        def _has_tag(self, tag):

-            return bool(libudev.udev_device_has_tag(

+    def _has_tag(self, tag):

+        if hasattr(self._libudev, 'udev_device_has_tag'):

+            return bool(self._libudev.udev_device_has_tag(

                 self.device, ensure_byte_string(tag)))

-    else:

-        def _has_tag(self, tag):

+        else:

             return any(t == tag for t in self)

+    @property

+    def _libudev(self):

+        return self.device._libudev

+

     def __contains__(self, tag):

         """

         Check for existence of ``tag``.

@@ -839,8 +844,8 @@ class Tags(Iterable, Container):

         Yield each tag as unicode string.

         """

-        tags = libudev.udev_device_get_tags_list_entry(self.device)

-        for tag, _ in udev_list_iterate(tags):

+        tags = self._libudev.udev_device_get_tags_list_entry(self.device)

+        for tag, _ in udev_list_iterate(self._libudev, tags):

             yield ensure_unicode_string(tag)

@@ -876,29 +881,26 @@ class Attributes(Mapping):

     def __init__(self, device):

         self.device = device

+        self._libudev = device._libudev

-    if hasattr(libudev, 'udev_device_get_sysattr_list_entry'):

-        @property

-        def _attributes(self):

-            attrs = libudev.udev_device_get_sysattr_list_entry(self.device)

-            for attribute, _ in udev_list_iterate(attrs):

+    def _get_attributes(self):

+        if hasattr(self._libudev, 'udev_device_get_sysattr_list_entry'):

+            attrs = self._libudev.udev_device_get_sysattr_list_entry(

+                self.device)

+            for attribute, _ in udev_list_iterate(self._libudev, attrs):

                 yield ensure_unicode_string(attribute)

-    else:

-        @property

-        def _attributes(self):

+        else:

             sys_path = self.device.sys_path

-            return (fn for fn in os.listdir(sys_path) if

-                    _is_attribute_file(os.path.join(sys_path, fn)) and

-                    fn in self)

+            for filename in os.listdir(sys_path):

+                filepath = os.path.join(sys_path, filename)

+                if _is_attribute_file(filepath):

+                    yield filename

     def __len__(self):

         """

         Return the amount of attributes defined.

         """

-        i = 0

-        for i, _ in enumerate(self._attributes, start=1):

-            pass

-        return i

+        return sum(1 for _ in self._get_attributes())

     def __iter__(self):

         """

@@ -906,10 +908,10 @@ class Attributes(Mapping):

         Yield each attribute name as unicode string.

         """

-        return self._attributes

+        return self._get_attributes()

     def __contains__(self, attribute):

-        value = libudev.udev_device_get_sysattr_value(

+        value = self._libudev.udev_device_get_sysattr_value(

             self.device, ensure_byte_string(attribute))

         return value is not None

@@ -924,7 +926,7 @@ class Attributes(Mapping):

         :exc:`~exceptions.KeyError`, if the given attribute is not defined

         for this device.

         """

-        value = libudev.udev_device_get_sysattr_value(

+        value = self._libudev.udev_device_get_sysattr_value(

             self.device, ensure_byte_string(attribute))

         if value is None:

             raise KeyError(attribute)

diff --git a/pyudev/monitor.py b/pyudev/monitor.py

index 8153ecc..6a51564 100644

--- a/pyudev/monitor.py

+++ b/pyudev/monitor.py

@@ -36,7 +36,6 @@ import select

 from threading import Thread

 from contextlib import closing

-from pyudev._libudev import libudev

 from pyudev._util import ensure_byte_string, ensure_unicode_string, reraise

 from pyudev.core import Device

@@ -82,6 +81,7 @@ class Monitor(object):

         self.context = context

         self._as_parameter_ = monitor_p

         self._socket_path = socket_path

+        self._libudev = context._libudev

     def _reraise_with_socket_path(self):

         _, exc_value, traceback = sys.exc_info()

@@ -89,7 +89,7 @@ class Monitor(object):

         reraise(exc_value, traceback)

     def __del__(self):

-        libudev.udev_monitor_unref(self)

+        self._libudev.udev_monitor_unref(self)

     @classmethod

     def from_netlink(cls, context, source='udev'):

@@ -117,7 +117,7 @@ class Monitor(object):

         if source not in ('kernel', 'udev'):

             raise ValueError('Invalid source: {0!r}. Must be one of "udev" '

                              'or "kernel"'.format(source))

-        monitor = libudev.udev_monitor_new_from_netlink(

+        monitor = context._libudev.udev_monitor_new_from_netlink(

             context, ensure_byte_string(source))

         if not monitor:

             raise EnvironmentError('Could not create udev monitor')

@@ -140,7 +140,7 @@ class Monitor(object):

         socket.  Raise :exc:`~exceptions.EnvironmentError`, if the creation of

         the monitor failed.

         """

-        monitor = libudev.udev_monitor_new_from_socket(

+        monitor = context._libudev.udev_monitor_new_from_socket(

             context, ensure_byte_string(socket_path))

         if not monitor:

             raise EnvironmentError('Could not create monitor for socket: '

@@ -154,7 +154,7 @@ class Monitor(object):

         This is really a real file descriptor ;), which can be watched and

         :func:`select.select`\ ed.

         """

-        return libudev.udev_monitor_get_fd(self)

+        return self._libudev.udev_monitor_get_fd(self)

     def filter_by(self, subsystem, device_type=None):

         """

@@ -179,9 +179,9 @@ class Monitor(object):

         subsystem = ensure_byte_string(subsystem)

         if device_type:

             device_type = ensure_byte_string(device_type)

-        libudev.udev_monitor_filter_add_match_subsystem_devtype(

+        self._libudev.udev_monitor_filter_add_match_subsystem_devtype(

             self, subsystem, device_type)

-        libudev.udev_monitor_filter_update(self)

+        self._libudev.udev_monitor_filter_update(self)

     def filter_by_tag(self, tag):

         """

@@ -202,9 +202,9 @@ class Monitor(object):

         .. versionchanged:: 0.15

            This method can also be after :meth:`enable_receiving()` now

         """

-        libudev.udev_monitor_filter_add_match_tag(

+        self._libudev.udev_monitor_filter_add_match_tag(

             self, ensure_byte_string(tag))

-        libudev.udev_monitor_filter_update(self)

+        self._libudev.udev_monitor_filter_update(self)

     def remove_filter(self):

         """

@@ -223,8 +223,8 @@ class Monitor(object):

         .. versionadded:: 0.15

         """

-        libudev.udev_monitor_filter_remove(self)

-        libudev.udev_monitor_filter_update(self)

+        self._libudev.udev_monitor_filter_remove(self)

+        self._libudev.udev_monitor_filter_update(self)

     def enable_receiving(self):

         """

@@ -240,7 +240,7 @@ class Monitor(object):

            monitor.

         """

         try:

-            libudev.udev_monitor_enable_receiving(self)

+            self._libudev.udev_monitor_enable_receiving(self)

         except EnvironmentError:

             self._reraise_with_socket_path()

@@ -272,7 +272,7 @@ class Monitor(object):

         .. _python-prctl: http://packages.python.org/python-prctl

         """

         try:

-            libudev.udev_monitor_set_receive_buffer_size(self, size)

+            self._libudev.udev_monitor_set_receive_buffer_size(self, size)

         except EnvironmentError:

             self._reraise_with_socket_path()

@@ -301,13 +301,13 @@ class Monitor(object):

         read.

         """

         try:

-            device_p = libudev.udev_monitor_receive_device(self)

+            device_p = self._libudev.udev_monitor_receive_device(self)

         except EnvironmentError:

             self._reraise_with_socket_path()

         if not device_p:

             raise EnvironmentError('Could not receive device')

         action = ensure_unicode_string(

-            libudev.udev_device_get_action(device_p))

+            self._libudev.udev_device_get_action(device_p))

         return action, Device(self.context, device_p)

     def __iter__(self):