def clear(self):
"""Reset the internal flag to ``False``.
Calls to `.wait` will block until `.set` is called.
"""
if self._future.done():
self._future = Future()
def test_completes_before_timeout(self):
future = Future()
self.io_loop.add_timeout(datetime.timedelta(seconds=0.1),
lambda: future.set_result('asdf'))
result = yield gen.with_timeout(datetime.timedelta(seconds=3600),
future, io_loop=self.io_loop)
self.assertEqual(result, 'asdf')
def test_iterator(self):
futures = [Future(), Future(), Future(), Future()]
self.finish_coroutines(0, futures)
g = gen.WaitIterator(*futures)
i = 0
while not g.done():
try:
r = yield g.next()
except ZeroDivisionError:
self.assertIs(g.current_future, futures[0],
'exception future invalid')
else:
if i == 0:
self.assertEqual(r, 24, 'iterator value incorrect')
self.assertEqual(g.current_index, 2, 'wrong index')
elif i == 2:
self.assertEqual(r, 42, 'iterator value incorrect')
self.assertEqual(g.current_index, 1, 'wrong index')
elif i == 3:
self.assertEqual(r, 84, 'iterator value incorrect')
self.assertEqual(g.current_index, 3, 'wrong index')
i += 1
def test_fails_before_timeout(self):
future = Future()
self.io_loop.add_timeout(
datetime.timedelta(seconds=0.1),
lambda: future.set_exception(ZeroDivisionError()))
with self.assertRaises(ZeroDivisionError):
yield gen.with_timeout(datetime.timedelta(seconds=3600),
future, io_loop=self.io_loop)
def __init__(self, addrinfo, io_loop, connect):
self.io_loop = io_loop
self.connect = connect
self.future = Future()
self.timeout = None
self.last_error = None
self.remaining = len(addrinfo)
self.primary_addrs, self.secondary_addrs = self.split(addrinfo)
def multi_future(children, quiet_exceptions=()):
"""Wait for multiple asynchronous futures in parallel.
This function is similar to `multi`, but does not support
`YieldPoints <YieldPoint>`.
.. versionadded:: 4.0
.. versionchanged:: 4.2
If multiple ``Futures`` fail, any exceptions after the first (which is
raised) will be logged. Added the ``quiet_exceptions``
argument to suppress this logging for selected exception types.
.. deprecated:: 4.3
Use `multi` instead.
"""
if isinstance(children, dict):
keys = list(children.keys())
children = children.values()
else:
keys = None
children = list(map(convert_yielded, children))
assert all(is_future(i) for i in children)
unfinished_children = set(children)
future = Future()
if not children:
future.set_result({} if keys is not None else [])
def callback(f):
unfinished_children.remove(f)
if not unfinished_children:
result_list = []
for f in children:
try:
result_list.append(f.result())
except Exception as e:
if future.done():
if not isinstance(e, quiet_exceptions):
app_log.error("Multiple exceptions in yield list",
exc_info=True)
else:
future.set_exc_info(sys.exc_info())
if not future.done():
if keys is not None:
future.set_result(dict(zip(keys, result_list)))
else:
future.set_result(result_list)
listening = set()
for f in children:
if f not in listening:
listening.add(f)
f.add_done_callback(callback)
return future
def capitalize(self, request_data, callback=None):
logging.info("capitalize")
self.request_data = request_data
self.stream = IOStream(socket.socket(), io_loop=self.io_loop)
self.stream.connect(('127.0.0.1', self.port),
callback=self.handle_connect)
self.future = Future()
if callback is not None:
self.future.add_done_callback(
stack_context.wrap(lambda future: callback(future.result())))
return self.future
def _create_stream(self, max_buffer_size, af, addr):
# Always connect in plaintext; we'll convert to ssl if necessary
# after one connection has completed.
try:
stream = IOStream(socket.socket(af),
io_loop=self.io_loop,
max_buffer_size=max_buffer_size)
except socket.error as e:
fu = Future()
fu.set_exception(e)
return fu
else:
return stream.connect(addr)
def get(self, timeout=None):
"""Remove and return an item from the queue.
Returns a Future which resolves once an item is available, or raises
`tornado.gen.TimeoutError` after a timeout.
"""
future = Future()
try:
future.set_result(self.get_nowait())
except QueueEmpty:
self._getters.append(future)
_set_timeout(future, timeout)
return future
def get_app(self):
self.close_future = Future()
return Application([
('/echo', EchoHandler, dict(close_future=self.close_future)),
('/non_ws', NonWebSocketHandler),
('/header', HeaderHandler, dict(close_future=self.close_future)),
('/close_reason', CloseReasonHandler,
dict(close_future=self.close_future)),
('/error_in_on_message', ErrorInOnMessageHandler,
dict(close_future=self.close_future)),
('/async_prepare', AsyncPrepareHandler,
dict(close_future=self.close_future)),
('/path_args/(.*)', PathArgsHandler,
dict(close_future=self.close_future)),
])
def setUp(self):
try:
super(TestIOStreamStartTLS, self).setUp()
self.listener, self.port = bind_unused_port()
self.server_stream = None
self.server_accepted = Future()
netutil.add_accept_handler(self.listener, self.accept)
self.client_stream = IOStream(socket.socket())
self.io_loop.add_future(self.client_stream.connect(
('127.0.0.1', self.port)), self.stop)
self.wait()
self.io_loop.add_future(self.server_accepted, self.stop)
self.wait()
except Exception as e:
print(e)
raise
def wait_for_exit(self, raise_error=True):
"""Returns a `.Future` which resolves when the process exits.
Usage::
ret = yield proc.wait_for_exit()
This is a coroutine-friendly alternative to `set_exit_callback`
(and a replacement for the blocking `subprocess.Popen.wait`).
By default, raises `subprocess.CalledProcessError` if the process
has a non-zero exit status. Use ``wait_for_exit(raise_error=False)``
to suppress this behavior and return the exit status without raising.
.. versionadded:: 4.2
"""
future = Future()
def callback(ret):
if ret != 0 and raise_error:
# Unfortunately we don't have the original args any more.
future.set_exception(CalledProcessError(ret, None))
else:
future.set_result(ret)
self.set_exit_callback(callback)
return future
def get_app(self):
self.close_future = Future()
return Application([
('/echo', EchoHandler,
dict(close_future=self.close_future,
compression_options=self.get_server_compression_options())),
])
def Task(func, *args, **kwargs):
"""Adapts a callback-based asynchronous function for use in coroutines.
Takes a function (and optional additional arguments) and runs it with
those arguments plus a ``callback`` keyword argument. The argument passed
to the callback is returned as the result of the yield expression.
.. versionchanged:: 4.0
``gen.Task`` is now a function that returns a `.Future`, instead of
a subclass of `YieldPoint`. It still behaves the same way when
yielded.
"""
future = Future()
def handle_exception(typ, value, tb):
if future.done():
return False
future.set_exc_info((typ, value, tb))
return True
def set_result(result):
if future.done():
return
future.set_result(result)
with stack_context.ExceptionStackContext(handle_exception):
func(*args, callback=_argument_adapter(set_result), **kwargs)
return future
def __init__(self, stream, is_client, params=None, context=None):
"""
:arg stream: an `.IOStream`
:arg bool is_client: client or server
:arg params: a `.HTTP1ConnectionParameters` instance or ``None``
:arg context: an opaque application-defined object that can be accessed
as ``connection.context``.
"""
self.is_client = is_client
self.stream = stream
if params is None:
params = HTTP1ConnectionParameters()
self.params = params
self.context = context
self.no_keep_alive = params.no_keep_alive
# The body limits can be altered by the delegate, so save them
# here instead of just referencing self.params later.
self._max_body_size = (self.params.max_body_size or
self.stream.max_buffer_size)
self._body_timeout = self.params.body_timeout
# _write_finished is set to True when finish() has been called,
# i.e. there will be no more data sent. Data may still be in the
# stream's write buffer.
self._write_finished = False
# True when we have read the entire incoming body.
self._read_finished = False
# _finish_future resolves when all data has been written and flushed
# to the IOStream.
self._finish_future = Future()
# If true, the connection should be closed after this request
# (after the response has been written in the server side,
# and after it has been read in the client)
self._disconnect_on_finish = False
self._clear_callbacks()
# Save the start lines after we read or write them; they
# affect later processing (e.g. 304 responses and HEAD methods
# have content-length but no bodies)
self._request_start_line = None
self._response_start_line = None
self._request_headers = None
# True if we are writing output with chunked encoding.
self._chunking_output = None
# While reading a body with a content-length, this is the
# amount left to read.
self._expected_content_remaining = None
# A Future for our outgoing writes, returned by IOStream.write.
self._pending_write = None
def sleep(duration):
"""Return a `.Future` that resolves after the given number of seconds.
When used with ``yield`` in a coroutine, this is a non-blocking
analogue to `time.sleep` (which should not be used in coroutines
because it is blocking)::
yield gen.sleep(0.5)
Note that calling this function on its own does nothing; you must
wait on the `.Future` it returns (usually by yielding it).
.. versionadded:: 4.1
"""
f = Future()
IOLoop.current().call_later(duration, lambda: f.set_result(None))
return f
def wait_for_messages(self, cursor=None):
# Construct a Future to return to our caller. This allows
# wait_for_messages to be yielded from a coroutine even though
# it is not a coroutine itself. We will set the result of the
# Future when results are available.
result_future = Future()
if cursor:
new_count = 0
for msg in reversed(self.cache):
if msg["id"] == cursor:
break
new_count += 1
if new_count:
result_future.set_result(self.cache[-new_count:])
return result_future
self.waiters.add(result_future)
return result_future
def wait(self, timeout=None):
"""Wait for `.notify`.
Returns a `.Future` that resolves ``True`` if the condition is notified,
or ``False`` after a timeout.
"""
waiter = Future()
self._waiters.append(waiter)
if timeout:
def on_timeout():
waiter.set_result(False)
self._garbage_collect()
io_loop = ioloop.IOLoop.current()
timeout_handle = io_loop.add_timeout(timeout, on_timeout)
waiter.add_done_callback(
lambda _: io_loop.remove_timeout(timeout_handle))
return waiter
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def write(self, chunk, callback=None):
"""Implements `.HTTPConnection.write`.
For backwards compatibility is is allowed but deprecated to
skip `write_headers` and instead call `write()` with a
pre-encoded header block.
"""
future = None
if self.stream.closed():
future = self._write_future = Future()
self._write_future.set_exception(iostream.StreamClosedError())
self._write_future.exception()
else:
if callback is not None:
self._write_callback = stack_context.wrap(callback)
else:
future = self._write_future = Future()
self._pending_write = self.stream.write(self._format_chunk(chunk))
self._pending_write.add_done_callback(self._on_write_complete)
return future
def _(d):
f = Future()
def errback(failure):
try:
failure.raiseException()
# Should never happen, but just in case
raise Exception("errback called without error")
except:
f.set_exc_info(sys.exc_info())
d.addCallbacks(f.set_result, errback)
return f
class ManualCapClient(BaseCapClient):
def capitalize(self, request_data, callback=None):
logging.info("capitalize")
self.request_data = request_data
self.stream = IOStream(socket.socket(), io_loop=self.io_loop)
self.stream.connect(('127.0.0.1', self.port),
callback=self.handle_connect)
self.future = Future()
if callback is not None:
self.future.add_done_callback(
stack_context.wrap(lambda future: callback(future.result())))
return self.future
def handle_connect(self):
logging.info("handle_connect")
self.stream.write(utf8(self.request_data + "\n"))
self.stream.read_until(b'\n', callback=self.handle_read)
def handle_read(self, data):
logging.info("handle_read")
self.stream.close()
try:
self.future.set_result(self.process_response(data))
except CapError as e:
self.future.set_exception(e)
def test_wait_for_handshake_already_waiting_error(self):
test = self
handshake_future = Future()
class TestServer(TCPServer):
def handle_stream(self, stream, address):
stream.wait_for_handshake(self.handshake_done)
test.assertRaises(RuntimeError, stream.wait_for_handshake)
def handshake_done(self):
handshake_future.set_result(None)
yield self.connect_to_server(TestServer)
yield handshake_future
def test_iterator_async_await(self):
# Recreate the previous test with py35 syntax. It's a little clunky
# because of the way the previous test handles an exception on
# a single iteration.
futures = [Future(), Future(), Future(), Future()]
self.finish_coroutines(0, futures)
self.finished = False
namespace = exec_test(globals(), locals(), """
async def f():
i = 0
g = gen.WaitIterator(*futures)
try:
async for r in g:
if i == 0:
self.assertEqual(r, 24, 'iterator value incorrect')
self.assertEqual(g.current_index, 2, 'wrong index')
else:
raise Exception("expected exception on iteration 1")
i += 1
except ZeroDivisionError:
i += 1
async for r in g:
if i == 2:
self.assertEqual(r, 42, 'iterator value incorrect')
self.assertEqual(g.current_index, 1, 'wrong index')
elif i == 3:
self.assertEqual(r, 84, 'iterator value incorrect')
self.assertEqual(g.current_index, 3, 'wrong index')
else:
raise Exception("didn't expect iteration %d" % i)
i += 1
self.finished = True
""")
yield namespace['f']()
self.assertTrue(self.finished)
def test_moment(self):
calls = []
@gen.coroutine
def f(name, yieldable):
for i in range(5):
calls.append(name)
yield yieldable
# First, confirm the behavior without moment: each coroutine
# monopolizes the event loop until it finishes.
immediate = Future()
immediate.set_result(None)
yield [f('a', immediate), f('b', immediate)]
self.assertEqual(''.join(calls), 'aaaaabbbbb')
# With moment, they take turns.
calls = []
yield [f('a', gen.moment), f('b', gen.moment)]
self.assertEqual(''.join(calls), 'ababababab')
self.finished = True
calls = []
yield [f('a', gen.moment), f('b', immediate)]
self.assertEqual(''.join(calls), 'abbbbbaaaa')
def put(self, item, timeout=None):
"""Put an item into the queue, perhaps waiting until there is room.
Returns a Future, which raises `tornado.gen.TimeoutError` after a
timeout.
"""
try:
self.put_nowait(item)
except QueueFull:
future = Future()
self._putters.append((item, future))
_set_timeout(future, timeout)
return future
else:
return gen._null_future
def test_wait_for_handshake_future(self):
test = self
handshake_future = Future()
class TestServer(TCPServer):
def handle_stream(self, stream, address):
test.assertIsNone(stream.socket.cipher())
test.io_loop.spawn_callback(self.handle_connection, stream)
@gen.coroutine
def handle_connection(self, stream):
yield stream.wait_for_handshake()
handshake_future.set_result(None)
yield self.connect_to_server(TestServer)
yield handshake_future
def test_wait_for_handshake_already_connected(self):
handshake_future = Future()
class TestServer(TCPServer):
def handle_stream(self, stream, address):
self.stream = stream
stream.wait_for_handshake(self.handshake_done)
def handshake_done(self):
self.stream.wait_for_handshake(self.handshake2_done)
def handshake2_done(self):
handshake_future.set_result(None)
yield self.connect_to_server(TestServer)
yield handshake_future
def test_wait_for_handshake_callback(self):
test = self
handshake_future = Future()
class TestServer(TCPServer):
def handle_stream(self, stream, address):
# The handshake has not yet completed.
test.assertIsNone(stream.socket.cipher())
self.stream = stream
stream.wait_for_handshake(self.handshake_done)
def handshake_done(self):
# Now the handshake is done and ssl information is available.
test.assertIsNotNone(self.stream.socket.cipher())
handshake_future.set_result(None)
yield self.connect_to_server(TestServer)
yield handshake_future
def acquire(self, timeout=None):
"""Decrement the counter. Returns a Future.
Block if the counter is zero and wait for a `.release`. The Future
raises `.TimeoutError` after the deadline.
"""
waiter = Future()
if self._value > 0:
self._value -= 1
waiter.set_result(_ReleasingContextManager(self))
else:
self._waiters.append(waiter)
if timeout:
def on_timeout():
waiter.set_exception(gen.TimeoutError())
self._garbage_collect()
io_loop = ioloop.IOLoop.current()
timeout_handle = io_loop.add_timeout(timeout, on_timeout)
waiter.add_done_callback(
lambda _: io_loop.remove_timeout(timeout_handle))
return waiter
