from __future__ import absolute_import, division, print_function, with_statement
import contextlib
import functools
import sys
import textwrap
import time
import platform
import weakref
from tornado.concurrent import return_future
from tornado.escape import url_escape
from tornado.httpclient import AsyncHTTPClient
from tornado.ioloop import IOLoop
from tornado.log import app_log
from tornado import stack_context
from tornado.testing import AsyncHTTPTestCase, AsyncTestCase, ExpectLog, gen_test
from tornado.test.util import unittest, skipOnTravis
from tornado.web import Application, RequestHandler, asynchronous, HTTPError
from tornado import gen
skipBefore33 = unittest.skipIf(sys.version_info < (3, 3), 'PEP 380 not available')
skipNotCPython = unittest.skipIf(platform.python_implementation() != 'CPython',
'Not CPython implementation')
class GenEngineTest(AsyncTestCase):
def setUp(self):
super(GenEngineTest, self).setUp()
self.named_contexts = []
def named_context(self, name):
@contextlib.contextmanager
def context():
self.named_contexts.append(name)
try:
yield
finally:
self.assertEqual(self.named_contexts.pop(), name)
return context
def run_gen(self, f):
f()
return self.wait()
def delay_callback(self, iterations, callback, arg):
"""Runs callback(arg) after a number of IOLoop iterations."""
if iterations == 0:
callback(arg)
else:
self.io_loop.add_callback(functools.partial(
self.delay_callback, iterations - 1, callback, arg))
@return_future
def async_future(self, result, callback):
self.io_loop.add_callback(callback, result)
def test_no_yield(self):
@gen.engine
def f():
self.stop()
self.run_gen(f)
def test_inline_cb(self):
@gen.engine
def f():
(yield gen.Callback("k1"))()
res = yield gen.Wait("k1")
self.assertTrue(res is None)
self.stop()
self.run_gen(f)
def test_ioloop_cb(self):
@gen.engine
def f():
self.io_loop.add_callback((yield gen.Callback("k1")))
yield gen.Wait("k1")
self.stop()
self.run_gen(f)
def test_exception_phase1(self):
@gen.engine
def f():
1 / 0
self.assertRaises(ZeroDivisionError, self.run_gen, f)
def test_exception_phase2(self):
@gen.engine
def f():
self.io_loop.add_callback((yield gen.Callback("k1")))
yield gen.Wait("k1")
1 / 0
self.assertRaises(ZeroDivisionError, self.run_gen, f)
def test_exception_in_task_phase1(self):
def fail_task(callback):
1 / 0
@gen.engine
def f():
try:
yield gen.Task(fail_task)
raise Exception("did not get expected exception")
except ZeroDivisionError:
self.stop()
self.run_gen(f)
def test_exception_in_task_phase2(self):
# This is the case that requires the use of stack_context in gen.engine
def fail_task(callback):
self.io_loop.add_callback(lambda: 1 / 0)
@gen.engine
def f():
try:
yield gen.Task(fail_task)
raise Exception("did not get expected exception")
except ZeroDivisionError:
self.stop()
self.run_gen(f)
def test_with_arg(self):
@gen.engine
def f():
(yield gen.Callback("k1"))(42)
res = yield gen.Wait("k1")
self.assertEqual(42, res)
self.stop()
self.run_gen(f)
def test_with_arg_tuple(self):
@gen.engine
def f():
(yield gen.Callback((1, 2)))((3, 4))
res = yield gen.Wait((1, 2))
self.assertEqual((3, 4), res)
self.stop()
self.run_gen(f)
def test_key_reuse(self):
@gen.engine
def f():
yield gen.Callback("k1")
yield gen.Callback("k1")
self.stop()
self.assertRaises(gen.KeyReuseError, self.run_gen, f)
def test_key_reuse_tuple(self):
@gen.engine
def f():
yield gen.Callback((1, 2))
yield gen.Callback((1, 2))
self.stop()
self.assertRaises(gen.KeyReuseError, self.run_gen, f)
def test_key_mismatch(self):
@gen.engine
def f():
yield gen.Callback("k1")
yield gen.Wait("k2")
self.stop()
self.assertRaises(gen.UnknownKeyError, self.run_gen, f)
def test_key_mismatch_tuple(self):
@gen.engine
def f():
yield gen.Callback((1, 2))
yield gen.Wait((2, 3))
self.stop()
self.assertRaises(gen.UnknownKeyError, self.run_gen, f)
def test_leaked_callback(self):
@gen.engine
def f():
yield gen.Callback("k1")
self.stop()
self.assertRaises(gen.LeakedCallbackError, self.run_gen, f)
def test_leaked_callback_tuple(self):
@gen.engine
def f():
yield gen.Callback((1, 2))
self.stop()
self.assertRaises(gen.LeakedCallbackError, self.run_gen, f)
def test_parallel_callback(self):
@gen.engine
def f():
for k in range(3):
self.io_loop.add_callback((yield gen.Callback(k)))
yield gen.Wait(1)
self.io_loop.add_callback((yield gen.Callback(3)))
yield gen.Wait(0)
yield gen.Wait(3)
yield gen.Wait(2)
self.stop()
self.run_gen(f)
def test_bogus_yield(self):
@gen.engine
def f():
yield 42
self.assertRaises(gen.BadYieldError, self.run_gen, f)
def test_bogus_yield_tuple(self):
@gen.engine
def f():
yield (1, 2)
self.assertRaises(gen.BadYieldError, self.run_gen, f)
def test_reuse(self):
@gen.engine
def f():
self.io_loop.add_callback((yield gen.Callback(0)))
yield gen.Wait(0)
self.stop()
self.run_gen(f)
self.run_gen(f)
def test_task(self):
@gen.engine
def f():
yield gen.Task(self.io_loop.add_callback)
self.stop()
self.run_gen(f)
def test_wait_all(self):
@gen.engine
def f():
(yield gen.Callback("k1"))("v1")
(yield gen.Callback("k2"))("v2")
results = yield gen.WaitAll(["k1", "k2"])
self.assertEqual(results, ["v1", "v2"])
self.stop()
self.run_gen(f)
def test_exception_in_yield(self):
@gen.engine
def f():
try:
yield gen.Wait("k1")
raise Exception("did not get expected exception")
except gen.UnknownKeyError:
pass
self.stop()
self.run_gen(f)
def test_resume_after_exception_in_yield(self):
@gen.engine
def f():
try:
yield gen.Wait("k1")
raise Exception("did not get expected exception")
except gen.UnknownKeyError:
pass
(yield gen.Callback("k2"))("v2")
self.assertEqual((yield gen.Wait("k2")), "v2")
self.stop()
self.run_gen(f)
def test_orphaned_callback(self):
@gen.engine
def f():
self.orphaned_callback = yield gen.Callback(1)
try:
self.run_gen(f)
raise Exception("did not get expected exception")
except gen.LeakedCallbackError:
pass
self.orphaned_callback()
def test_multi(self):
@gen.engine
def f():
(yield gen.Callback("k1"))("v1")
(yield gen.Callback("k2"))("v2")
results = yield [gen.Wait("k1"), gen.Wait("k2")]
self.assertEqual(results, ["v1", "v2"])
self.stop()
self.run_gen(f)
def test_multi_delayed(self):
@gen.engine
def f():
# callbacks run at different times
responses = yield [
gen.Task(self.delay_callback, 3, arg="v1"),
gen.Task(self.delay_callback, 1, arg="v2"),
]
self.assertEqual(responses, ["v1", "v2"])
self.stop()
self.run_gen(f)
@skipOnTravis
@gen_test
def test_multi_performance(self):
# Yielding a list used to have quadratic performance; make
# sure a large list stays reasonable. On my laptop a list of
# 2000 used to take 1.8s, now it takes 0.12.
start = time.time()
yield [gen.Task(self.io_loop.add_callback) for i in range(2000)]
end = time.time()
self.assertLess(end - start, 1.0)
@gen_test
def test_future(self):
result = yield self.async_future(1)
self.assertEqual(result, 1)
@gen_test
def test_multi_future(self):
results = yield [self.async_future(1), self.async_future(2)]
self.assertEqual(results, [1, 2])
def test_arguments(self):
@gen.engine
def f():
(yield gen.Callback("noargs"))()
self.assertEqual((yield gen.Wait("noargs")), None)
(yield gen.Callback("1arg"))(42)
self.assertEqual((yield gen.Wait("1arg")), 42)
(yield gen.Callback("kwargs"))(value=42)
result = yield gen.Wait("kwargs")
self.assertTrue(isinstance(result, gen.Arguments))
self.assertEqual(((), dict(value=42)), result)
self.assertEqual(dict(value=42), result.kwargs)
(yield gen.Callback("2args"))(42, 43)
result = yield gen.Wait("2args")
self.assertTrue(isinstance(result, gen.Arguments))
self.assertEqual(((42, 43), {}), result)
self.assertEqual((42, 43), result.args)
def task_func(callback):
callback(None, error="foo")
result = yield gen.Task(task_func)
self.assertTrue(isinstance(result, gen.Arguments))
self.assertEqual(((None,), dict(error="foo")), result)
self.stop()
self.run_gen(f)
def test_stack_context_leak(self):
# regression test: repeated invocations of a gen-based
# function should not result in accumulated stack_contexts
def _stack_depth():
head = stack_context._state.contexts[1]
length = 0
while head is not None:
length += 1
head = head.old_contexts[1]
return length
@gen.engine
def inner(callback):
yield gen.Task(self.io_loop.add_callback)
callback()
@gen.engine
def outer():
for i in range(10):
yield gen.Task(inner)
stack_increase = _stack_depth() - initial_stack_depth
self.assertTrue(stack_increase <= 2)
self.stop()
initial_stack_depth = _stack_depth()
self.run_gen(outer)
def test_stack_context_leak_exception(self):
# same as previous, but with a function that exits with an exception
@gen.engine
def inner(callback):
yield gen.Task(self.io_loop.add_callback)
1 / 0
@gen.engine
def outer():
for i in range(10):
try:
yield gen.Task(inner)
except ZeroDivisionError:
pass
stack_increase = len(stack_context._state.contexts) - initial_stack_depth
self.assertTrue(stack_increase <= 2)
self.stop()
initial_stack_depth = len(stack_context._state.contexts)
self.run_gen(outer)
def function_with_stack_context(self, callback):
# Technically this function should stack_context.wrap its callback
# upon entry. However, it is very common for this step to be
# omitted.
def step2():
self.assertEqual(self.named_contexts, ['a'])
self.io_loop.add_callback(callback)
with stack_context.StackContext(self.named_context('a')):
self.io_loop.add_callback(step2)
@gen_test
def test_wait_transfer_stack_context(self):
# Wait should not pick up contexts from where callback was invoked,
# even if that function improperly fails to wrap its callback.
cb = yield gen.Callback('k1')
self.function_with_stack_context(cb)
self.assertEqual(self.named_contexts, [])
yield gen.Wait('k1')
self.assertEqual(self.named_contexts, [])
@gen_test
def test_task_transfer_stack_context(self):
yield gen.Task(self.function_with_stack_context)
self.assertEqual(self.named_contexts, [])
def test_raise_after_stop(self):
# This pattern will be used in the following tests so make sure
# the exception propagates as expected.
@gen.engine
def f():
self.stop()
1 / 0
with self.assertRaises(ZeroDivisionError):
self.run_gen(f)
def test_sync_raise_return(self):
# gen.Return is allowed in @gen.engine, but it may not be used
# to return a value.
@gen.engine
def f():
self.stop(42)
raise gen.Return()
result = self.run_gen(f)
self.assertEqual(result, 42)
def test_async_raise_return(self):
@gen.engine
def f():
yield gen.Task(self.io_loop.add_callback)
self.stop(42)
raise gen.Return()
result = self.run_gen(f)
self.assertEqual(result, 42)
def test_sync_raise_return_value(self):
@gen.engine
def f():
raise gen.Return(42)
with self.assertRaises(gen.ReturnValueIgnoredError):
self.run_gen(f)
def test_sync_raise_return_value_tuple(self):
@gen.engine
def f():
raise gen.Return((1, 2))
with self.assertRaises(gen.ReturnValueIgnoredError):
self.run_gen(f)
def test_async_raise_return_value(self):
@gen.engine
def f():
yield gen.Task(self.io_loop.add_callback)
raise gen.Return(42)
with self.assertRaises(gen.ReturnValueIgnoredError):
self.run_gen(f)
def test_async_raise_return_value_tuple(self):
@gen.engine
def f():
yield gen.Task(self.io_loop.add_callback)
raise gen.Return((1, 2))
with self.assertRaises(gen.ReturnValueIgnoredError):
self.run_gen(f)
def test_return_value(self):
# It is an error to apply @gen.engine to a function that returns
# a value.
@gen.engine
def f():
return 42
with self.assertRaises(gen.ReturnValueIgnoredError):
self.run_gen(f)
def test_return_value_tuple(self):
# It is an error to apply @gen.engine to a function that returns
# a value.
@gen.engine
def f():
return (1, 2)
with self.assertRaises(gen.ReturnValueIgnoredError):
self.run_gen(f)
@skipNotCPython
def test_task_refcounting(self):
# On CPython, tasks and their arguments should be released immediately
# without waiting for garbage collection.
@gen.engine
def f():
class Foo(object):
pass
arg = Foo()
self.arg_ref = weakref.ref(arg)
task = gen.Task(self.io_loop.add_callback, arg=arg)
self.task_ref = weakref.ref(task)
yield task
self.stop()
self.run_gen(f)
self.assertIs(self.arg_ref(), None)
self.assertIs(self.task_ref(), None)
class GenCoroutineTest(AsyncTestCase):
def setUp(self):
# Stray StopIteration exceptions can lead to tests exiting prematurely,
# so we need explicit checks here to make sure the tests run all
# the way through.
self.finished = False
super(GenCoroutineTest, self).setUp()
def tearDown(self):
super(GenCoroutineTest, self).tearDown()
assert self.finished
@gen_test
def test_sync_gen_return(self):
@gen.coroutine
def f():
raise gen.Return(42)
result = yield f()
self.assertEqual(result, 42)
self.finished = True
@gen_test
def test_async_gen_return(self):
@gen.coroutine
def f():
yield gen.Task(self.io_loop.add_callback)
raise gen.Return(42)
result = yield f()
self.assertEqual(result, 42)
self.finished = True
@gen_test
def test_sync_return(self):
@gen.coroutine
def f():
return 42
result = yield f()
self.assertEqual(result, 42)
self.finished = True
@skipBefore33
@gen_test
def test_async_return(self):
# It is a compile-time error to return a value in a generator
# before Python 3.3, so we must test this with exec.
# Flatten the real global and local namespace into our fake globals:
# it's all global from the perspective of f().
global_namespace = dict(globals(), **locals())
local_namespace = {}
exec(textwrap.dedent("""
@gen.coroutine
def f():
yield gen.Task(self.io_loop.add_callback)
return 42
"""), global_namespace, local_namespace)
result = yield local_namespace['f']()
self.assertEqual(result, 42)
self.finished = True
@skipBefore33
@gen_test
def test_async_early_return(self):
# A yield statement exists but is not executed, which means
# this function "returns" via an exception. This exception
# doesn't happen before the exception handling is set up.
global_namespace = dict(globals(), **locals())
local_namespace = {}
exec(textwrap.dedent("""
@gen.coroutine
def f():
if True:
return 42
yield gen.Task(self.io_loop.add_callback)
"""), global_namespace, local_namespace)
result = yield local_namespace['f']()
self.assertEqual(result, 42)
self.finished = True
@gen_test
def test_sync_return_no_value(self):
@gen.coroutine
def f():
return
result = yield f()
self.assertEqual(result, None)
self.finished = True
@gen_test
def test_async_return_no_value(self):
# Without a return value we don't need python 3.3.
@gen.coroutine
def f():
yield gen.Task(self.io_loop.add_callback)
return
result = yield f()
self.assertEqual(result, None)
self.finished = True
@gen_test
def test_sync_raise(self):
@gen.coroutine
def f():
1 / 0
# The exception is raised when the future is yielded
# (or equivalently when its result method is called),
# not when the function itself is called).
future = f()
with self.assertRaises(ZeroDivisionError):
yield future
self.finished = True
@gen_test
def test_async_raise(self):
@gen.coroutine
def f():
yield gen.Task(self.io_loop.add_callback)
1 / 0
future = f()
with self.assertRaises(ZeroDivisionError):
yield future
self.finished = True
@gen_test
def test_pass_callback(self):
@gen.coroutine
def f():
raise gen.Return(42)
result = yield gen.Task(f)
self.assertEqual(result, 42)
self.finished = True
@gen_test
def test_replace_yieldpoint_exception(self):
# Test exception handling: a coroutine can catch one exception
# raised by a yield point and raise a different one.
@gen.coroutine
def f1():
1 / 0
@gen.coroutine
def f2():
try:
yield f1()
except ZeroDivisionError:
raise KeyError()
future = f2()
with self.assertRaises(KeyError):
yield future
self.finished = True
@gen_test
def test_swallow_yieldpoint_exception(self):
# Test exception handling: a coroutine can catch an exception
# raised by a yield point and not raise a different one.
@gen.coroutine
def f1():
1 / 0
@gen.coroutine
def f2():
try:
yield f1()
except ZeroDivisionError:
raise gen.Return(42)
result = yield f2()
self.assertEqual(result, 42)
self.finished = True
@gen_test
def test_replace_context_exception(self):
# Test exception handling: exceptions thrown into the stack context
# can be caught and replaced.
@gen.coroutine
def f2():
self.io_loop.add_callback(lambda: 1 / 0)
try:
yield gen.Task(self.io_loop.add_timeout,
self.io_loop.time() + 10)
except ZeroDivisionError:
raise KeyError()
future = f2()
with self.assertRaises(KeyError):
yield future
self.finished = True
@gen_test
def test_swallow_context_exception(self):
# Test exception handling: exceptions thrown into the stack context
# can be caught and ignored.
@gen.coroutine
def f2():
self.io_loop.add_callback(lambda: 1 / 0)
try:
yield gen.Task(self.io_loop.add_timeout,
self.io_loop.time() + 10)
except ZeroDivisionError:
raise gen.Return(42)
result = yield f2()
self.assertEqual(result, 42)
self.finished = True
class GenSequenceHandler(RequestHandler):
@asynchronous
@gen.engine
def get(self):
self.io_loop = self.request.connection.stream.io_loop
self.io_loop.add_callback((yield gen.Callback("k1")))
yield gen.Wait("k1")
self.write("1")
self.io_loop.add_callback((yield gen.Callback("k2")))
yield gen.Wait("k2")
self.write("2")
# reuse an old key
self.io_loop.add_callback((yield gen.Callback("k1")))
yield gen.Wait("k1")
self.finish("3")
class GenCoroutineSequenceHandler(RequestHandler):
@gen.coroutine
def get(self):
self.io_loop = self.request.connection.stream.io_loop
self.io_loop.add_callback((yield gen.Callback("k1")))
yield gen.Wait("k1")
self.write("1")
self.io_loop.add_callback((yield gen.Callback("k2")))
yield gen.Wait("k2")
self.write("2")
# reuse an old key
self.io_loop.add_callback((yield gen.Callback("k1")))
yield gen.Wait("k1")
self.finish("3")
class GenCoroutineUnfinishedSequenceHandler(RequestHandler):
@asynchronous
@gen.coroutine
def get(self):
self.io_loop = self.request.connection.stream.io_loop
self.io_loop.add_callback((yield gen.Callback("k1")))
yield gen.Wait("k1")
self.write("1")
self.io_loop.add_callback((yield gen.Callback("k2")))
yield gen.Wait("k2")
self.write("2")
# reuse an old key
self.io_loop.add_callback((yield gen.Callback("k1")))
yield gen.Wait("k1")
# just write, don't finish
self.write("3")
class GenTaskHandler(RequestHandler):
@asynchronous
@gen.engine
def get(self):
io_loop = self.request.connection.stream.io_loop
client = AsyncHTTPClient(io_loop=io_loop)
response = yield gen.Task(client.fetch, self.get_argument('url'))
response.rethrow()
self.finish(b"got response: " + response.body)
class GenExceptionHandler(RequestHandler):
@asynchronous
@gen.engine
def get(self):
# This test depends on the order of the two decorators.
io_loop = self.request.connection.stream.io_loop
yield gen.Task(io_loop.add_callback)
raise Exception("oops")
class GenCoroutineExceptionHandler(RequestHandler):
@asynchronous
@gen.coroutine
def get(self):
# This test depends on the order of the two decorators.
io_loop = self.request.connection.stream.io_loop
yield gen.Task(io_loop.add_callback)
raise Exception("oops")
class GenYieldExceptionHandler(RequestHandler):
@asynchronous
@gen.engine
def get(self):
io_loop = self.request.connection.stream.io_loop
# Test the interaction of the two stack_contexts.
def fail_task(callback):
io_loop.add_callback(lambda: 1 / 0)
try:
yield gen.Task(fail_task)
raise Exception("did not get expected exception")
except ZeroDivisionError:
self.finish('ok')
class UndecoratedCoroutinesHandler(RequestHandler):
@gen.coroutine
def prepare(self):
self.chunks = []
yield gen.Task(IOLoop.current().add_callback)
self.chunks.append('1')
@gen.coroutine
def get(self):
self.chunks.append('2')
yield gen.Task(IOLoop.current().add_callback)
self.chunks.append('3')
yield gen.Task(IOLoop.current().add_callback)
self.write(''.join(self.chunks))
class AsyncPrepareErrorHandler(RequestHandler):
@gen.coroutine
def prepare(self):
yield gen.Task(IOLoop.current().add_callback)
raise HTTPError(403)
def get(self):
self.finish('ok')
class GenWebTest(AsyncHTTPTestCase):
def get_app(self):
return Application([
('/sequence', GenSequenceHandler),
('/coroutine_sequence', GenCoroutineSequenceHandler),
('/coroutine_unfinished_sequence',
GenCoroutineUnfinishedSequenceHandler),
('/task', GenTaskHandler),
('/exception', GenExceptionHandler),
('/coroutine_exception', GenCoroutineExceptionHandler),
('/yield_exception', GenYieldExceptionHandler),
('/undecorated_coroutine', UndecoratedCoroutinesHandler),
('/async_prepare_error', AsyncPrepareErrorHandler),
])
def test_sequence_handler(self):
response = self.fetch('/sequence')
self.assertEqual(response.body, b"123")
def test_coroutine_sequence_handler(self):
response = self.fetch('/coroutine_sequence')
self.assertEqual(response.body, b"123")
def test_coroutine_unfinished_sequence_handler(self):
response = self.fetch('/coroutine_unfinished_sequence')
self.assertEqual(response.body, b"123")
def test_task_handler(self):
response = self.fetch('/task?url=%s' % url_escape(self.get_url('/sequence')))
self.assertEqual(response.body, b"got response: 123")
def test_exception_handler(self):
# Make sure we get an error and not a timeout
with ExpectLog(app_log, "Uncaught exception GET /exception"):
response = self.fetch('/exception')
self.assertEqual(500, response.code)
def test_coroutine_exception_handler(self):
# Make sure we get an error and not a timeout
with ExpectLog(app_log, "Uncaught exception GET /coroutine_exception"):
response = self.fetch('/coroutine_exception')
self.assertEqual(500, response.code)
def test_yield_exception_handler(self):
response = self.fetch('/yield_exception')
self.assertEqual(response.body, b'ok')
def test_undecorated_coroutines(self):
response = self.fetch('/undecorated_coroutine')
self.assertEqual(response.body, b'123')
def test_async_prepare_error_handler(self):
response = self.fetch('/async_prepare_error')
self.assertEqual(response.code, 403)
if __name__ == '__main__':
unittest.main()