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()