| __all__ = ['coroutine', |
| 'iscoroutinefunction', 'iscoroutine'] |
| |
| import functools |
| import inspect |
| import os |
| import sys |
| import traceback |
| |
| from . import events |
| from . import futures |
| from .log import logger |
| |
| # If you set _DEBUG to true, @coroutine will wrap the resulting |
| # generator objects in a CoroWrapper instance (defined below). That |
| # instance will log a message when the generator is never iterated |
| # over, which may happen when you forget to use "yield from" with a |
| # coroutine call. Note that the value of the _DEBUG flag is taken |
| # when the decorator is used, so to be of any use it must be set |
| # before you define your coroutines. A downside of using this feature |
| # is that tracebacks show entries for the CoroWrapper.__next__ method |
| # when _DEBUG is true. |
| _DEBUG = (not sys.flags.ignore_environment |
| and bool(os.environ.get('PYTHONASYNCIODEBUG'))) |
| |
| _PY35 = (sys.version_info >= (3, 5)) |
| |
| class CoroWrapper: |
| # Wrapper for coroutine in _DEBUG mode. |
| |
| def __init__(self, gen, func): |
| assert inspect.isgenerator(gen), gen |
| self.gen = gen |
| self.func = func |
| self._source_traceback = traceback.extract_stack(sys._getframe(1)) |
| |
| def __iter__(self): |
| return self |
| |
| def __next__(self): |
| return next(self.gen) |
| |
| def send(self, *value): |
| # We use `*value` because of a bug in CPythons prior |
| # to 3.4.1. See issue #21209 and test_yield_from_corowrapper |
| # for details. This workaround should be removed in 3.5.0. |
| if len(value) == 1: |
| value = value[0] |
| return self.gen.send(value) |
| |
| def throw(self, exc): |
| return self.gen.throw(exc) |
| |
| def close(self): |
| return self.gen.close() |
| |
| @property |
| def gi_frame(self): |
| return self.gen.gi_frame |
| |
| @property |
| def gi_running(self): |
| return self.gen.gi_running |
| |
| @property |
| def gi_code(self): |
| return self.gen.gi_code |
| |
| def __del__(self): |
| # Be careful accessing self.gen.frame -- self.gen might not exist. |
| gen = getattr(self, 'gen', None) |
| frame = getattr(gen, 'gi_frame', None) |
| if frame is not None and frame.f_lasti == -1: |
| func = events._format_callback(self.func, ()) |
| tb = ''.join(traceback.format_list(self._source_traceback)) |
| message = ('Coroutine %s was never yielded from\n' |
| 'Coroutine object created at (most recent call last):\n' |
| '%s' |
| % (func, tb.rstrip())) |
| logger.error(message) |
| |
| |
| def coroutine(func): |
| """Decorator to mark coroutines. |
| |
| If the coroutine is not yielded from before it is destroyed, |
| an error message is logged. |
| """ |
| if inspect.isgeneratorfunction(func): |
| coro = func |
| else: |
| @functools.wraps(func) |
| def coro(*args, **kw): |
| res = func(*args, **kw) |
| if isinstance(res, futures.Future) or inspect.isgenerator(res): |
| res = yield from res |
| return res |
| |
| if not _DEBUG: |
| wrapper = coro |
| else: |
| @functools.wraps(func) |
| def wrapper(*args, **kwds): |
| w = CoroWrapper(coro(*args, **kwds), func) |
| if w._source_traceback: |
| del w._source_traceback[-1] |
| w.__name__ = func.__name__ |
| if _PY35: |
| w.__qualname__ = func.__qualname__ |
| w.__doc__ = func.__doc__ |
| return w |
| |
| wrapper._is_coroutine = True # For iscoroutinefunction(). |
| return wrapper |
| |
| |
| def iscoroutinefunction(func): |
| """Return True if func is a decorated coroutine function.""" |
| return getattr(func, '_is_coroutine', False) |
| |
| |
| def iscoroutine(obj): |
| """Return True if obj is a coroutine object.""" |
| return isinstance(obj, CoroWrapper) or inspect.isgenerator(obj) |
| |
| |
| def _format_coroutine(coro): |
| assert iscoroutine(coro) |
| if _PY35: |
| coro_name = coro.__qualname__ |
| else: |
| coro_name = coro.__name__ |
| |
| filename = coro.gi_code.co_filename |
| if coro.gi_frame is not None: |
| lineno = coro.gi_frame.f_lineno |
| return '%s() at %s:%s' % (coro_name, filename, lineno) |
| else: |
| lineno = coro.gi_code.co_firstlineno |
| return '%s() done at %s:%s' % (coro_name, filename, lineno) |