Exemple #1
0
 def test_100_continue(self):
     # Run through a 100-continue interaction by hand:
     # When given Expect: 100-continue, we get a 100 response after the
     # headers, and then the real response after the body.
     stream = IOStream(socket.socket(), io_loop=self.io_loop)
     stream.connect(("localhost", self.get_http_port()), callback=self.stop)
     self.wait()
     stream.write(b("\r\n").join([
         b("POST /hello HTTP/1.1"),
         b("Content-Length: 1024"),
         b("Expect: 100-continue"),
         b("\r\n")
     ]),
                  callback=self.stop)
     self.wait()
     stream.read_until(b("\r\n\r\n"), self.stop)
     data = self.wait()
     self.assertTrue(data.startswith(b("HTTP/1.1 100 ")), data)
     stream.write(b("a") * 1024)
     stream.read_until(b("\r\n"), self.stop)
     first_line = self.wait()
     self.assertTrue(first_line.startswith(b("HTTP/1.1 200")), first_line)
     stream.read_until(b("\r\n\r\n"), self.stop)
     header_data = self.wait()
     headers = HTTPHeaders.parse(native_str(header_data.decode('latin1')))
     stream.read_bytes(int(headers["Content-Length"]), self.stop)
     body = self.wait()
     self.assertEqual(body, b("Got 1024 bytes in POST"))
Exemple #2
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 def test_100_continue(self):
     # Run through a 100-continue interaction by hand:
     # When given Expect: 100-continue, we get a 100 response after the
     # headers, and then the real response after the body.
     stream = IOStream(socket.socket(), io_loop=self.io_loop)
     stream.connect(("localhost", self.get_http_port()), callback=self.stop)
     self.wait()
     stream.write(b("\r\n").join([b("POST /hello HTTP/1.1"),
                               b("Content-Length: 1024"),
                               b("Expect: 100-continue"),
                               b("\r\n")]), callback=self.stop)
     self.wait()
     stream.read_until(b("\r\n\r\n"), self.stop)
     data = self.wait()
     self.assertTrue(data.startswith(b("HTTP/1.1 100 ")), data)
     stream.write(b("a") * 1024)
     stream.read_until(b("\r\n"), self.stop)
     first_line = self.wait()
     self.assertTrue(first_line.startswith(b("HTTP/1.1 200")), first_line)
     stream.read_until(b("\r\n\r\n"), self.stop)
     header_data = self.wait()
     headers = HTTPHeaders.parse(native_str(header_data.decode('latin1')))
     stream.read_bytes(int(headers["Content-Length"]), self.stop)
     body = self.wait()
     self.assertEqual(body, b("Got 1024 bytes in POST"))
Exemple #3
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    def test_read_until_close(self):
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
        s.connect(("localhost", self.get_http_port()))
        stream = IOStream(s, io_loop=self.io_loop)
        stream.write(b("GET / HTTP/1.0\r\n\r\n"))

        stream.read_until_close(self.stop)
        data = self.wait()
        self.assertTrue(data.startswith(b("HTTP/1.0 200")))
        self.assertTrue(data.endswith(b("Hello")))
Exemple #4
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 def test_unix_socket(self):
     sockfile = os.path.join(self.tmpdir, "test.sock")
     sock = netutil.bind_unix_socket(sockfile)
     app = Application([("/hello", HelloWorldRequestHandler)])
     server = HTTPServer(app, io_loop=self.io_loop)
     server.add_socket(sock)
     stream = IOStream(socket.socket(socket.AF_UNIX), io_loop=self.io_loop)
     stream.connect(sockfile, self.stop)
     self.wait()
     stream.write(b("GET /hello HTTP/1.0\r\n\r\n"))
     stream.read_until(b("\r\n"), self.stop)
     response = self.wait()
     self.assertEqual(response, b("HTTP/1.0 200 OK\r\n"))
     stream.read_until(b("\r\n\r\n"), self.stop)
     headers = HTTPHeaders.parse(self.wait().decode('latin1'))
     stream.read_bytes(int(headers["Content-Length"]), self.stop)
     body = self.wait()
     self.assertEqual(body, b("Hello world"))
Exemple #5
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class ConnectionCloseTest(AsyncHTTPTestCase, LogTrapTestCase):
    def get_app(self):
        return Application([('/', ConnectionCloseHandler, dict(test=self))])

    def test_connection_close(self):
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
        s.connect(("localhost", self.get_http_port()))
        self.stream = IOStream(s, io_loop=self.io_loop)
        self.stream.write(b("GET / HTTP/1.0\r\n\r\n"))
        self.wait()

    def on_handler_waiting(self):
        logging.info('handler waiting')
        self.stream.close()

    def on_connection_close(self):
        logging.info('connection closed')
        self.stop()
Exemple #6
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 def test_unix_socket(self):
     sockfile = os.path.join(self.tmpdir, "test.sock")
     sock = netutil.bind_unix_socket(sockfile)
     app = Application([("/hello", HelloWorldRequestHandler)])
     server = HTTPServer(app, io_loop=self.io_loop)
     server.add_socket(sock)
     stream = IOStream(socket.socket(socket.AF_UNIX), io_loop=self.io_loop)
     stream.connect(sockfile, self.stop)
     self.wait()
     stream.write(b("GET /hello HTTP/1.0\r\n\r\n"))
     stream.read_until(b("\r\n"), self.stop)
     response = self.wait()
     self.assertEqual(response, b("HTTP/1.0 200 OK\r\n"))
     stream.read_until(b("\r\n\r\n"), self.stop)
     headers = HTTPHeaders.parse(self.wait().decode('latin1'))
     stream.read_bytes(int(headers["Content-Length"]), self.stop)
     body = self.wait()
     self.assertEqual(body, b("Hello world"))
Exemple #7
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class ConnectionCloseTest(AsyncHTTPTestCase, LogTrapTestCase):
    def get_app(self):
        return Application([('/', ConnectionCloseHandler, dict(test=self))])

    def test_connection_close(self):
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
        s.connect(("localhost", self.get_http_port()))
        self.stream = IOStream(s, io_loop=self.io_loop)
        self.stream.write(b("GET / HTTP/1.0\r\n\r\n"))
        self.wait()

    def on_handler_waiting(self):
        logging.info('handler waiting')
        self.stream.close()

    def on_connection_close(self):
        logging.info('connection closed')
        self.stop()
Exemple #8
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class _HTTPConnection(object):
    _SUPPORTED_METHODS = set(["GET", "HEAD", "POST", "PUT", "DELETE"])

    def __init__(self, io_loop, client, request, release_callback,
                 final_callback, max_buffer_size):
        self.start_time = time.time()
        self.io_loop = io_loop
        self.client = client
        self.request = request
        self.release_callback = release_callback
        self.final_callback = final_callback
        self.code = None
        self.headers = None
        self.chunks = None
        self._decompressor = None
        # Timeout handle returned by IOLoop.add_timeout
        self._timeout = None
        with stack_context.StackContext(self.cleanup):
            parsed = urlparse.urlsplit(_unicode(self.request.url))
            if ssl is None and parsed.scheme == "https":
                raise ValueError("HTTPS requires either python2.6+ or "
                                 "curl_httpclient")
            if parsed.scheme not in ("http", "https"):
                raise ValueError("Unsupported url scheme: %s" %
                                 self.request.url)
            # urlsplit results have hostname and port results, but they
            # didn't support ipv6 literals until python 2.7.
            netloc = parsed.netloc
            if "@" in netloc:
                userpass, _, netloc = netloc.rpartition("@")
            match = re.match(r'^(.+):(\d+)$', netloc)
            if match:
                host = match.group(1)
                port = int(match.group(2))
            else:
                host = netloc
                port = 443 if parsed.scheme == "https" else 80
            if re.match(r'^\[.*\]$', host):
                # raw ipv6 addresses in urls are enclosed in brackets
                host = host[1:-1]
            if self.client.hostname_mapping is not None:
                host = self.client.hostname_mapping.get(host, host)

            if request.allow_ipv6:
                af = socket.AF_UNSPEC
            else:
                # We only try the first IP we get from getaddrinfo,
                # so restrict to ipv4 by default.
                af = socket.AF_INET

            addrinfo = socket.getaddrinfo(host, port, af, socket.SOCK_STREAM,
                                          0, 0)
            af, socktype, proto, canonname, sockaddr = addrinfo[0]

            if parsed.scheme == "https":
                ssl_options = {}
                if request.validate_cert:
                    ssl_options["cert_reqs"] = ssl.CERT_REQUIRED
                if request.ca_certs is not None:
                    ssl_options["ca_certs"] = request.ca_certs
                else:
                    ssl_options["ca_certs"] = _DEFAULT_CERTS
                if request.client_key is not None:
                    ssl_options["keyfile"] = request.client_key
                if request.client_cert is not None:
                    ssl_options["certfile"] = request.client_cert
                self.stream = SSLIOStream(socket.socket(af, socktype, proto),
                                          io_loop=self.io_loop,
                                          ssl_options=ssl_options,
                                          max_buffer_size=max_buffer_size)
            else:
                self.stream = IOStream(socket.socket(af, socktype, proto),
                                       io_loop=self.io_loop,
                                       max_buffer_size=max_buffer_size)
            timeout = min(request.connect_timeout, request.request_timeout)
            if timeout:
                self._timeout = self.io_loop.add_timeout(
                    self.start_time + timeout,
                    self._on_timeout)
            self.stream.set_close_callback(self._on_close)
            self.stream.connect(sockaddr,
                                functools.partial(self._on_connect, parsed))

    def _on_timeout(self):
        self._timeout = None
        self._run_callback(HTTPResponse(self.request, 599,
                                        request_time=time.time() - self.start_time,
                                        error=HTTPError(599, "Timeout")))
        self.stream.close()

    def _on_connect(self, parsed):
        if self._timeout is not None:
            self.io_loop.remove_timeout(self._timeout)
            self._timeout = None
        if self.request.request_timeout:
            self._timeout = self.io_loop.add_timeout(
                self.start_time + self.request.request_timeout,
                self._on_timeout)
        if (self.request.validate_cert and
            isinstance(self.stream, SSLIOStream)):
            match_hostname(self.stream.socket.getpeercert(),
                           parsed.hostname)
        if (self.request.method not in self._SUPPORTED_METHODS and
            not self.request.allow_nonstandard_methods):
            raise KeyError("unknown method %s" % self.request.method)
        for key in ('network_interface',
                    'proxy_host', 'proxy_port',
                    'proxy_username', 'proxy_password'):
            if getattr(self.request, key, None):
                raise NotImplementedError('%s not supported' % key)
        if "Host" not in self.request.headers:
            self.request.headers["Host"] = parsed.netloc
        username, password = None, None
        if parsed.username is not None:
            username, password = parsed.username, parsed.password
        elif self.request.auth_username is not None:
            username = self.request.auth_username
            password = self.request.auth_password
        if username is not None:
            auth = utf8(username) + b(":") + utf8(password)
            self.request.headers["Authorization"] = (b("Basic ") +
                                                     base64.b64encode(auth))
        if self.request.user_agent:
            self.request.headers["User-Agent"] = self.request.user_agent
        if not self.request.allow_nonstandard_methods:
            if self.request.method in ("POST", "PUT"):
                assert self.request.body is not None
            else:
                assert self.request.body is None
        if self.request.body is not None:
            self.request.headers["Content-Length"] = str(len(
                    self.request.body))
        if (self.request.method == "POST" and
            "Content-Type" not in self.request.headers):
            self.request.headers["Content-Type"] = "application/x-www-form-urlencoded"
        if self.request.use_gzip:
            self.request.headers["Accept-Encoding"] = "gzip"
        req_path = ((parsed.path or '/') +
                (('?' + parsed.query) if parsed.query else ''))
        request_lines = [utf8("%s %s HTTP/1.0" % (self.request.method,
                                                  req_path))]
        for k, v in self.request.headers.get_all():
            line = utf8(k) + b(": ") + utf8(v)
            if b('\n') in line:
                raise ValueError('Newline in header: ' + repr(line))
            request_lines.append(line)
        self.stream.write(b("\r\n").join(request_lines) + b("\r\n\r\n"))
        if self.request.body is not None:
            self.stream.write(self.request.body)
        self.stream.read_until_regex(b("\r?\n\r?\n"), self._on_headers)

    def _release(self):
        if self.release_callback is not None:
            release_callback = self.release_callback
            self.release_callback = None
            release_callback()

    def _run_callback(self, response):
        self._release()
        if self.final_callback is not None:
            final_callback = self.final_callback
            self.final_callback = None
            final_callback(response)

    @contextlib.contextmanager
    def cleanup(self):
        try:
            yield
        except Exception, e:
            logging.warning("uncaught exception", exc_info=True)
            self._run_callback(HTTPResponse(self.request, 599, error=e,
                                request_time=time.time() - self.start_time,
                                ))
Exemple #9
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class _HTTPConnection(object):
    _SUPPORTED_METHODS = set(["GET", "HEAD", "POST", "PUT", "DELETE"])

    def __init__(self, io_loop, client, request, release_callback,
                 final_callback, max_buffer_size):
        self.start_time = time.time()
        self.io_loop = io_loop
        self.client = client
        self.request = request
        self.release_callback = release_callback
        self.final_callback = final_callback
        self.code = None
        self.headers = None
        self.chunks = None
        self._decompressor = None
        # Timeout handle returned by IOLoop.add_timeout
        self._timeout = None
        with stack_context.StackContext(self.cleanup):
            parsed = urlparse.urlsplit(_unicode(self.request.url))
            if ssl is None and parsed.scheme == "https":
                raise ValueError("HTTPS requires either python2.6+ or "
                                 "curl_httpclient")
            if parsed.scheme not in ("http", "https"):
                raise ValueError("Unsupported url scheme: %s" %
                                 self.request.url)
            # urlsplit results have hostname and port results, but they
            # didn't support ipv6 literals until python 2.7.
            netloc = parsed.netloc
            if "@" in netloc:
                userpass, _, netloc = netloc.rpartition("@")
            match = re.match(r'^(.+):(\d+)$', netloc)
            if match:
                host = match.group(1)
                port = int(match.group(2))
            else:
                host = netloc
                port = 443 if parsed.scheme == "https" else 80
            if re.match(r'^\[.*\]$', host):
                # raw ipv6 addresses in urls are enclosed in brackets
                host = host[1:-1]
            if self.client.hostname_mapping is not None:
                host = self.client.hostname_mapping.get(host, host)

            if request.allow_ipv6:
                af = socket.AF_UNSPEC
            else:
                # We only try the first IP we get from getaddrinfo,
                # so restrict to ipv4 by default.
                af = socket.AF_INET

            addrinfo = socket.getaddrinfo(host, port, af, socket.SOCK_STREAM,
                                          0, 0)
            af, socktype, proto, canonname, sockaddr = addrinfo[0]

            if parsed.scheme == "https":
                ssl_options = {}
                if request.validate_cert:
                    ssl_options["cert_reqs"] = ssl.CERT_REQUIRED
                if request.ca_certs is not None:
                    ssl_options["ca_certs"] = request.ca_certs
                else:
                    ssl_options["ca_certs"] = _DEFAULT_CERTS
                if request.client_key is not None:
                    ssl_options["keyfile"] = request.client_key
                if request.client_cert is not None:
                    ssl_options["certfile"] = request.client_cert
                self.stream = SSLIOStream(socket.socket(af, socktype, proto),
                                          io_loop=self.io_loop,
                                          ssl_options=ssl_options,
                                          max_buffer_size=max_buffer_size)
            else:
                self.stream = IOStream(socket.socket(af, socktype, proto),
                                       io_loop=self.io_loop,
                                       max_buffer_size=max_buffer_size)
            timeout = min(request.connect_timeout, request.request_timeout)
            if timeout:
                self._timeout = self.io_loop.add_timeout(
                    self.start_time + timeout, self._on_timeout)
            self.stream.set_close_callback(self._on_close)
            self.stream.connect(sockaddr,
                                functools.partial(self._on_connect, parsed))

    def _on_timeout(self):
        self._timeout = None
        self._run_callback(
            HTTPResponse(self.request,
                         599,
                         request_time=time.time() - self.start_time,
                         error=HTTPError(599, "Timeout")))
        self.stream.close()

    def _on_connect(self, parsed):
        if self._timeout is not None:
            self.io_loop.remove_timeout(self._timeout)
            self._timeout = None
        if self.request.request_timeout:
            self._timeout = self.io_loop.add_timeout(
                self.start_time + self.request.request_timeout,
                self._on_timeout)
        if (self.request.validate_cert
                and isinstance(self.stream, SSLIOStream)):
            match_hostname(self.stream.socket.getpeercert(), parsed.hostname)
        if (self.request.method not in self._SUPPORTED_METHODS
                and not self.request.allow_nonstandard_methods):
            raise KeyError("unknown method %s" % self.request.method)
        for key in ('network_interface', 'proxy_host', 'proxy_port',
                    'proxy_username', 'proxy_password'):
            if getattr(self.request, key, None):
                raise NotImplementedError('%s not supported' % key)
        if "Host" not in self.request.headers:
            self.request.headers["Host"] = parsed.netloc
        username, password = None, None
        if parsed.username is not None:
            username, password = parsed.username, parsed.password
        elif self.request.auth_username is not None:
            username = self.request.auth_username
            password = self.request.auth_password
        if username is not None:
            auth = utf8(username) + b(":") + utf8(password)
            self.request.headers["Authorization"] = (b("Basic ") +
                                                     base64.b64encode(auth))
        if self.request.user_agent:
            self.request.headers["User-Agent"] = self.request.user_agent
        if not self.request.allow_nonstandard_methods:
            if self.request.method in ("POST", "PUT"):
                assert self.request.body is not None
            else:
                assert self.request.body is None
        if self.request.body is not None:
            self.request.headers["Content-Length"] = str(len(
                self.request.body))
        if (self.request.method == "POST"
                and "Content-Type" not in self.request.headers):
            self.request.headers[
                "Content-Type"] = "application/x-www-form-urlencoded"
        if self.request.use_gzip:
            self.request.headers["Accept-Encoding"] = "gzip"
        req_path = ((parsed.path or '/') +
                    (('?' + parsed.query) if parsed.query else ''))
        request_lines = [
            utf8("%s %s HTTP/1.0" % (self.request.method, req_path))
        ]
        for k, v in self.request.headers.get_all():
            line = utf8(k) + b(": ") + utf8(v)
            if b('\n') in line:
                raise ValueError('Newline in header: ' + repr(line))
            request_lines.append(line)
        self.stream.write(b("\r\n").join(request_lines) + b("\r\n\r\n"))
        if self.request.body is not None:
            self.stream.write(self.request.body)
        self.stream.read_until_regex(b("\r?\n\r?\n"), self._on_headers)

    def _release(self):
        if self.release_callback is not None:
            release_callback = self.release_callback
            self.release_callback = None
            release_callback()

    def _run_callback(self, response):
        self._release()
        if self.final_callback is not None:
            final_callback = self.final_callback
            self.final_callback = None
            final_callback(response)

    @contextlib.contextmanager
    def cleanup(self):
        try:
            yield
        except Exception, e:
            logging.warning("uncaught exception", exc_info=True)
            self._run_callback(
                HTTPResponse(
                    self.request,
                    599,
                    error=e,
                    request_time=time.time() - self.start_time,
                ))
Exemple #10
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class TestIOStream(AsyncHTTPTestCase, LogTrapTestCase):
    def get_app(self):
        return Application([('/', HelloHandler)])

    def make_iostream_pair(self, **kwargs):
        port = get_unused_port()
        [listener] = netutil.bind_sockets(port, '127.0.0.1',
                                          family=socket.AF_INET)
        streams = [None, None]
        def accept_callback(connection, address):
            streams[0] = IOStream(connection, io_loop=self.io_loop, **kwargs)
            self.stop()
        def connect_callback():
            streams[1] = client_stream
            self.stop()
        netutil.add_accept_handler(listener, accept_callback,
                                   io_loop=self.io_loop)
        client_stream = IOStream(socket.socket(), io_loop=self.io_loop,
                                 **kwargs)
        client_stream.connect(('127.0.0.1', port),
                              callback=connect_callback)
        self.wait(condition=lambda: all(streams))
        self.io_loop.remove_handler(listener.fileno())
        listener.close()
        return streams

    def test_read_zero_bytes(self):
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
        s.connect(("localhost", self.get_http_port()))
        self.stream = IOStream(s, io_loop=self.io_loop)
        self.stream.write(b("GET / HTTP/1.0\r\n\r\n"))

        # normal read
        self.stream.read_bytes(9, self.stop)
        data = self.wait()
        self.assertEqual(data, b("HTTP/1.0 "))

        # zero bytes
        self.stream.read_bytes(0, self.stop)
        data = self.wait()
        self.assertEqual(data, b(""))

        # another normal read
        self.stream.read_bytes(3, self.stop)
        data = self.wait()
        self.assertEqual(data, b("200"))

    def test_write_zero_bytes(self):
        # Attempting to write zero bytes should run the callback without
        # going into an infinite loop.
        server, client = self.make_iostream_pair()
        server.write(b(''), callback=self.stop)
        self.wait()
        # As a side effect, the stream is now listening for connection
        # close (if it wasn't already), but is not listening for writes
        self.assertEqual(server._state, IOLoop.READ|IOLoop.ERROR)

    def test_connection_refused(self):
        # When a connection is refused, the connect callback should not
        # be run.  (The kqueue IOLoop used to behave differently from the
        # epoll IOLoop in this respect)
        port = get_unused_port()
        stream = IOStream(socket.socket(), self.io_loop)
        self.connect_called = False
        def connect_callback():
            self.connect_called = True
        stream.set_close_callback(self.stop)
        stream.connect(("localhost", port), connect_callback)
        self.wait()
        self.assertFalse(self.connect_called)

    def test_connection_closed(self):
        # When a server sends a response and then closes the connection,
        # the client must be allowed to read the data before the IOStream
        # closes itself.  Epoll reports closed connections with a separate
        # EPOLLRDHUP event delivered at the same time as the read event,
        # while kqueue reports them as a second read/write event with an EOF
        # flag.
        response = self.fetch("/", headers={"Connection": "close"})
        response.rethrow()

    def test_read_until_close(self):
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
        s.connect(("localhost", self.get_http_port()))
        stream = IOStream(s, io_loop=self.io_loop)
        stream.write(b("GET / HTTP/1.0\r\n\r\n"))

        stream.read_until_close(self.stop)
        data = self.wait()
        self.assertTrue(data.startswith(b("HTTP/1.0 200")))
        self.assertTrue(data.endswith(b("Hello")))

    def test_streaming_callback(self):
        server, client = self.make_iostream_pair()
        try:
            chunks = []
            final_called = []
            def streaming_callback(data):
                chunks.append(data)
                self.stop()
            def final_callback(data):
                assert not data
                final_called.append(True)
                self.stop()
            server.read_bytes(6, callback=final_callback,
                              streaming_callback=streaming_callback)
            client.write(b("1234"))
            self.wait(condition=lambda: chunks)
            client.write(b("5678"))
            self.wait(condition=lambda: final_called)
            self.assertEqual(chunks, [b("1234"), b("56")])

            # the rest of the last chunk is still in the buffer
            server.read_bytes(2, callback=self.stop)
            data = self.wait()
            self.assertEqual(data, b("78"))
        finally:
            server.close()
            client.close()

    def test_streaming_until_close(self):
        server, client = self.make_iostream_pair()
        try:
            chunks = []
            def callback(data):
                chunks.append(data)
                self.stop()
            client.read_until_close(callback=callback,
                                    streaming_callback=callback)
            server.write(b("1234"))
            self.wait()
            server.write(b("5678"))
            self.wait()
            server.close()
            self.wait()
            self.assertEqual(chunks, [b("1234"), b("5678"), b("")])
        finally:
            server.close()
            client.close()

    def test_delayed_close_callback(self):
        # The scenario:  Server closes the connection while there is a pending
        # read that can be served out of buffered data.  The client does not
        # run the close_callback as soon as it detects the close, but rather
        # defers it until after the buffered read has finished.
        server, client = self.make_iostream_pair()
        try:
            client.set_close_callback(self.stop)
            server.write(b("12"))
            chunks = []
            def callback1(data):
                chunks.append(data)
                client.read_bytes(1, callback2)
                server.close()
            def callback2(data):
                chunks.append(data)
            client.read_bytes(1, callback1)
            self.wait()  # stopped by close_callback
            self.assertEqual(chunks, [b("1"), b("2")])
        finally:
            server.close()
            client.close()

    def test_close_buffered_data(self):
        # Similar to the previous test, but with data stored in the OS's
        # socket buffers instead of the IOStream's read buffer.  Out-of-band
        # close notifications must be delayed until all data has been
        # drained into the IOStream buffer. (epoll used to use out-of-band
        # close events with EPOLLRDHUP, but no longer)
        #
        # This depends on the read_chunk_size being smaller than the
        # OS socket buffer, so make it small.
        server, client = self.make_iostream_pair(read_chunk_size=256)
        try:
            server.write(b("A") * 512)
            client.read_bytes(256, self.stop)
            data = self.wait()
            self.assertEqual(b("A") * 256, data)
            server.close()
            # Allow the close to propagate to the client side of the
            # connection.  Using add_callback instead of add_timeout
            # doesn't seem to work, even with multiple iterations
            self.io_loop.add_timeout(time.time() + 0.01, self.stop)
            self.wait()
            client.read_bytes(256, self.stop)
            data = self.wait()
            self.assertEqual(b("A") * 256, data)
        finally:
            server.close()
            client.close()