class ThreadedResolverTest(AsyncTestCase, _ResolverTestMixin):
    def setUp(self):
        super(ThreadedResolverTest, self).setUp()
        self.resolver = ThreadedResolver(io_loop=self.io_loop)

    def tearDown(self):
        self.resolver.close()
        super(ThreadedResolverTest, self).tearDown()

 def setUp(self):
     super(ThreadedResolverTest, self).setUp()
     self.resolver = ThreadedResolver(io_loop=self.io_loop)

 def setUp(self):
     super(ThreadedResolverTest, self).setUp()
     self.resolver = ThreadedResolver()

from tornado.ioloop import IOLoop
from tornado.netutil import ThreadedResolver

# When this module is imported, it runs getaddrinfo on a thread. Since
# the hostname is unicode, getaddrinfo attempts to import encodings.idna
# but blocks on the import lock. Verify that ThreadedResolver avoids
# this deadlock.

resolver = ThreadedResolver()
IOLoop.current().run_sync(lambda: resolver.resolve(u'localhost', 80))