def _io_callback(self, future, result, fd=None, events=None):
try:
state = self.connection.poll()
except (psycopg2.Warning, psycopg2.Error):
self.ioloop.remove_handler(self.fileno)
future_set_exc_info(future, sys.exc_info())
else:
try:
if state == POLL_OK:
self.ioloop.remove_handler(self.fileno)
future.set_result(result)
elif state == POLL_READ:
self.ioloop.update_handler(self.fileno, IOLoop.READ)
elif state == POLL_WRITE:
self.ioloop.update_handler(self.fileno, IOLoop.WRITE)
else:
future.set_exception(
psycopg2.OperationalError("poll() returned %s" %
state))
except IOError:
# Can happen when there are quite a lof of outstanding
# requests. See https://github.com/FSX/momoko/issues/127
self.ioloop.remove_handler(self.fileno)
future.set_exception(
psycopg2.OperationalError("IOError on socket"))
def when_available(fut):
try:
conn = fut.result()
except psycopg2.Error:
future_set_exc_info(future, sys.exc_info())
if retry and not keep:
self.putconn(retry[0])
return
log.debug("Obtained connection: %s", conn.fileno)
try:
future_or_result = method(conn, *args, **kwargs)
except Exception:
log.debug("Method failed synchronously")
return self._retry(retry, when_available, conn, keep, future)
if not async:
future.set_result(future_or_result)
if not keep:
self.putconn(conn)
return
def when_done(rfut):
try:
result = rfut.result()
except psycopg2.Error:
log.debug("Method failed Asynchronously")
return self._retry(retry, when_available, conn, keep,
future)
future.set_result(result)
if not keep:
self.putconn(conn)
self.ioloop.add_future(future_or_result, when_done)
def wrapper(*args, **kwargs):
# type: (*Any, **Any) -> Future[_T]
# This function is type-annotated with a comment to work around
# https://bitbucket.org/pypy/pypy/issues/2868/segfault-with-args-type-annotation-in
future = _create_future()
if contextvars is not None:
ctx_run = contextvars.copy_context().run # type: Callable
else:
ctx_run = _fake_ctx_run
try:
result = ctx_run(func, *args, **kwargs)
except (Return, StopIteration) as e:
result = _value_from_stopiteration(e)
except Exception:
future_set_exc_info(future, sys.exc_info())
try:
return future
finally:
# Avoid circular references
future = None # type: ignore
else:
if isinstance(result, Generator):
# Inline the first iteration of Runner.run. This lets us
# avoid the cost of creating a Runner when the coroutine
# never actually yields, which in turn allows us to
# use "optional" coroutines in critical path code without
# performance penalty for the synchronous case.
try:
yielded = ctx_run(next, result)
except (StopIteration, Return) as e:
future_set_result_unless_cancelled(
future, _value_from_stopiteration(e))
except Exception:
future_set_exc_info(future, sys.exc_info())
else:
# Provide strong references to Runner objects as long
# as their result future objects also have strong
# references (typically from the parent coroutine's
# Runner). This keeps the coroutine's Runner alive.
# We do this by exploiting the public API
# add_done_callback() instead of putting a private
# attribute on the Future.
# (GitHub issues #1769, #2229).
runner = Runner(ctx_run, result, future, yielded)
future.add_done_callback(lambda _: runner)
yielded = None
try:
return future
finally:
# Subtle memory optimization: if next() raised an exception,
# the future's exc_info contains a traceback which
# includes this stack frame. This creates a cycle,
# which will be collected at the next full GC but has
# been shown to greatly increase memory usage of
# benchmarks (relative to the refcount-based scheme
# used in the absence of cycles). We can avoid the
# cycle by clearing the local variable after we return it.
future = None # type: ignore
future_set_result_unless_cancelled(future, result)
return future
def errback(failure):
try:
failure.raiseException()
# Should never happen, but just in case
raise Exception("errback called without error")
except:
future_set_exc_info(f, sys.exc_info())
def greenlet_base():
try:
result = f(*args, **kwargs)
except Exception:
future_set_exc_info(future, sys.exc_info())
else:
future.set_result(result)
def abort_pending(f):
exc_info = sys.exc_info()
if any(exc_info):
# f.set_exc_info(exc_info)
concurrent.future_set_exc_info(f, exc_info)
else:
f.set_exception(exception(self.host, self.port))
def errback(failure):
try:
failure.raiseException()
# Should never happen, but just in case
raise Exception("errback called without error")
except:
future_set_exc_info(f, sys.exc_info())
def greenlet_base():
try:
result = f(*args, **kwargs)
except Exception:
future_set_exc_info(future, sys.exc_info())
else:
future.set_result(result)
def run(self):
"""Starts or resumes the generator, running until it reaches a
yield point that is not ready.
"""
if self.running or self.finished:
return
try:
self.running = True
while True:
future = self.future
if not future.done():
return
self.future = None
try:
exc_info = None
try:
value = future.result()
except Exception:
self.had_exception = True
exc_info = sys.exc_info()
future = None
if exc_info is not None:
try:
yielded = self.gen.throw(*exc_info)
finally:
# Break up a reference to itself
# for faster GC on CPython.
exc_info = None
else:
yielded = self.gen.send(value)
except (StopIteration, Return) as e:
self.finished = True
self.future = _null_future
if self.pending_callbacks and not self.had_exception:
# If we ran cleanly without waiting on all callbacks
# raise an error (really more of a warning). If we
# had an exception then some callbacks may have been
# orphaned, so skip the check in that case.
raise LeakedCallbackError(
"finished without waiting for callbacks %r" %
self.pending_callbacks)
future_set_result_unless_cancelled(
self.result_future, _value_from_stopiteration(e))
self.result_future = None
return
except Exception:
self.finished = True
self.future = _null_future
future_set_exc_info(self.result_future, sys.exc_info())
self.result_future = None
return
if not self.handle_yield(yielded):
return
yielded = None
finally:
self.running = False
def wrapper(*args, **kwargs):
future = _create_future()
if replace_callback and 'callback' in kwargs:
callback = kwargs.pop('callback')
IOLoop.current().add_future(
future, lambda future: callback(future.result()))
try:
result = func(*args, **kwargs)
except (Return, StopIteration) as e:
result = _value_from_stopiteration(e)
except Exception:
future_set_exc_info(future, sys.exc_info())
try:
return future
finally:
# Avoid circular references
future = None
else:
if isinstance(result, GeneratorType):
# Inline the first iteration of Runner.run. This lets us
# avoid the cost of creating a Runner when the coroutine
# never actually yields, which in turn allows us to
# use "optional" coroutines in critical path code without
# performance penalty for the synchronous case.
try:
orig_stack_contexts = stack_context._state.contexts
yielded = next(result)
if stack_context._state.contexts is not orig_stack_contexts:
yielded = _create_future()
yielded.set_exception(
stack_context.StackContextInconsistentError(
'stack_context inconsistency (probably caused '
'by yield within a "with StackContext" block)')
)
except (StopIteration, Return) as e:
future_set_result_unless_cancelled(
future, _value_from_stopiteration(e))
except Exception:
future_set_exc_info(future, sys.exc_info())
else:
_futures_to_runners[future] = Runner(
result, future, yielded)
yielded = None
try:
return future
finally:
# Subtle memory optimization: if next() raised an exception,
# the future's exc_info contains a traceback which
# includes this stack frame. This creates a cycle,
# which will be collected at the next full GC but has
# been shown to greatly increase memory usage of
# benchmarks (relative to the refcount-based scheme
# used in the absence of cycles). We can avoid the
# cycle by clearing the local variable after we return it.
future = None
future_set_result_unless_cancelled(future, result)
return future
def handle_exception(self, typ, value, tb):
if not self.running and not self.finished:
self.future = Future()
future_set_exc_info(self.future, (typ, value, tb))
self.run()
return True
else:
return False
def handle_exception(self, typ, value, tb):
if not self.running and not self.finished:
self.future = Future()
future_set_exc_info(self.future, (typ, value, tb))
self.run()
return True
else:
return False
def handle_yield(self, yielded):
# Lists containing YieldPoints require stack contexts;
# other lists are handled in convert_yielded.
if _contains_yieldpoint(yielded):
yielded = multi(yielded)
if isinstance(yielded, YieldPoint):
# YieldPoints are too closely coupled to the Runner to go
# through the generic convert_yielded mechanism.
self.future = Future()
def start_yield_point():
try:
yielded.start(self)
if yielded.is_ready():
future_set_result_unless_cancelled(
self.future, yielded.get_result())
else:
self.yield_point = yielded
except Exception:
self.future = Future()
future_set_exc_info(self.future, sys.exc_info())
if self.stack_context_deactivate is None:
# Start a stack context if this is the first
# YieldPoint we've seen.
with stack_context.ExceptionStackContext(
self.handle_exception) as deactivate:
self.stack_context_deactivate = deactivate
def cb():
start_yield_point()
self.run()
self.io_loop.add_callback(cb)
return False
else:
start_yield_point()
else:
try:
self.future = convert_yielded(yielded)
except BadYieldError:
self.future = Future()
future_set_exc_info(self.future, sys.exc_info())
if self.future is moment:
self.io_loop.add_callback(self.run)
return False
elif not self.future.done():
def inner(f):
# Break a reference cycle to speed GC.
f = None # noqa
self.run()
self.io_loop.add_future(self.future, inner)
return False
return True
def wrapper(*args, **kwargs):
# type: (*Any, **Any) -> Future[_T]
# This function is type-annotated with a comment to work around
# https://bitbucket.org/pypy/pypy/issues/2868/segfault-with-args-type-annotation-in
future = _create_future()
try:
result = func(*args, **kwargs)
except (Return, StopIteration) as e:
result = _value_from_stopiteration(e)
except Exception:
future_set_exc_info(future, sys.exc_info())
try:
return future
finally:
# Avoid circular references
future = None # type: ignore
else:
if isinstance(result, Generator):
# Inline the first iteration of Runner.run. This lets us
# avoid the cost of creating a Runner when the coroutine
# never actually yields, which in turn allows us to
# use "optional" coroutines in critical path code without
# performance penalty for the synchronous case.
try:
yielded = next(result)
except (StopIteration, Return) as e:
future_set_result_unless_cancelled(
future, _value_from_stopiteration(e)
)
except Exception:
future_set_exc_info(future, sys.exc_info())
else:
# Provide strong references to Runner objects as long
# as their result future objects also have strong
# references (typically from the parent coroutine's
# Runner). This keeps the coroutine's Runner alive.
# We do this by exploiting the public API
# add_done_callback() instead of putting a private
# attribute on the Future.
# (Github issues #1769, #2229).
runner = Runner(result, future, yielded)
future.add_done_callback(lambda _: runner)
yielded = None
try:
return future
finally:
# Subtle memory optimization: if next() raised an exception,
# the future's exc_info contains a traceback which
# includes this stack frame. This creates a cycle,
# which will be collected at the next full GC but has
# been shown to greatly increase memory usage of
# benchmarks (relative to the refcount-based scheme
# used in the absence of cycles). We can avoid the
# cycle by clearing the local variable after we return it.
future = None # type: ignore
future_set_result_unless_cancelled(future, result)
return future
def handle_exception(self, typ: Type[Exception], value: Exception,
tb: types.TracebackType) -> bool:
if not self.running and not self.finished:
self.future = Future()
future_set_exc_info(self.future, (typ, value, tb))
self.run()
return True
else:
return False
def wrapper(*args, **kwargs):
future = _create_future()
if replace_callback and 'callback' in kwargs:
callback = kwargs.pop('callback')
IOLoop.current().add_future(
future, lambda future: callback(future.result()))
try:
result = func(*args, **kwargs)
except (Return, StopIteration) as e:
result = _value_from_stopiteration(e)
except Exception:
future_set_exc_info(future, sys.exc_info())
try:
return future
finally:
# Avoid circular references
future = None
else:
if isinstance(result, GeneratorType):
# Inline the first iteration of Runner.run. This lets us
# avoid the cost of creating a Runner when the coroutine
# never actually yields, which in turn allows us to
# use "optional" coroutines in critical path code without
# performance penalty for the synchronous case.
try:
orig_stack_contexts = stack_context._state.contexts
yielded = next(result)
if stack_context._state.contexts is not orig_stack_contexts:
yielded = _create_future()
yielded.set_exception(
stack_context.StackContextInconsistentError(
'stack_context inconsistency (probably caused '
'by yield within a "with StackContext" block)'))
except (StopIteration, Return) as e:
future_set_result_unless_cancelled(future, _value_from_stopiteration(e))
except Exception:
future_set_exc_info(future, sys.exc_info())
else:
_futures_to_runners[future] = Runner(result, future, yielded)
yielded = None
try:
return future
finally:
# Subtle memory optimization: if next() raised an exception,
# the future's exc_info contains a traceback which
# includes this stack frame. This creates a cycle,
# which will be collected at the next full GC but has
# been shown to greatly increase memory usage of
# benchmarks (relative to the refcount-based scheme
# used in the absence of cycles). We can avoid the
# cycle by clearing the local variable after we return it.
future = None
future_set_result_unless_cancelled(future, result)
return future
def start_yield_point():
try:
yielded.start(self)
if yielded.is_ready():
future_set_result_unless_cancelled(self.future, yielded.get_result())
else:
self.yield_point = yielded
except Exception:
self.future = Future()
future_set_exc_info(self.future, sys.exc_info())
def start_yield_point():
try:
yielded.start(self)
if yielded.is_ready():
self.future.set_result(yielded.get_result())
else:
self.yield_point = yielded
except Exception:
self.future = Future()
future_set_exc_info(self.future, sys.exc_info())
def set_result(self, key, result):
"""Sets the result for ``key`` and attempts to resume the generator."""
self.results[key] = result
if self.yield_point is not None and self.yield_point.is_ready():
try:
self.future.set_result(self.yield_point.get_result())
except:
future_set_exc_info(self.future, sys.exc_info())
self.yield_point = None
self.run()
def future_set_exc_info(fut, exc_info):
"""
Sets the exception information of a `Future`, including the traceback.
"""
try:
# tornado >= 5
cc.future_set_exc_info(fut, exc_info)
except AttributeError:
# tornado < 5
fut.set_exc_info(exc_info)
def handle_exception(
self, typ: Type[Exception], value: Exception, tb: types.TracebackType
) -> bool:
if not self.running and not self.finished:
self.future = Future()
future_set_exc_info(self.future, (typ, value, tb))
self.run()
return True
else:
return False
def _register(self, future, registrator, fut):
try:
cursor = fut.result()
except Exception:
future_set_exc_info(future, sys.exc_info())
return
oid, array_oid = cursor.fetchone()
registrator(oid, array_oid)
future.set_result(None)
def handle_yield(self, yielded):
# Lists containing YieldPoints require stack contexts;
# other lists are handled in convert_yielded.
if _contains_yieldpoint(yielded):
yielded = multi(yielded)
if isinstance(yielded, YieldPoint):
# YieldPoints are too closely coupled to the Runner to go
# through the generic convert_yielded mechanism.
self.future = Future()
def start_yield_point():
try:
yielded.start(self)
if yielded.is_ready():
future_set_result_unless_cancelled(self.future, yielded.get_result())
else:
self.yield_point = yielded
except Exception:
self.future = Future()
future_set_exc_info(self.future, sys.exc_info())
if self.stack_context_deactivate is None:
# Start a stack context if this is the first
# YieldPoint we've seen.
with stack_context.ExceptionStackContext(
self.handle_exception) as deactivate:
self.stack_context_deactivate = deactivate
def cb():
start_yield_point()
self.run()
self.io_loop.add_callback(cb)
return False
else:
start_yield_point()
else:
try:
self.future = convert_yielded(yielded)
except BadYieldError:
self.future = Future()
future_set_exc_info(self.future, sys.exc_info())
if self.future is moment:
self.io_loop.add_callback(self.run)
return False
elif not self.future.done():
def inner(f):
# Break a reference cycle to speed GC.
f = None # noqa
self.run()
self.io_loop.add_future(
self.future, inner)
return False
return True
def set_result(self, key, result):
"""Sets the result for ``key`` and attempts to resume the generator."""
self.results[key] = result
if self.yield_point is not None and self.yield_point.is_ready():
try:
future_set_result_unless_cancelled(self.future,
self.yield_point.get_result())
except:
future_set_exc_info(self.future, sys.exc_info())
self.yield_point = None
self.run()
def on_ping_done(ping_fut):
try:
ping_fut.result()
except psycopg2.Error:
if conn.closed:
ping_future.set_exception(self._no_conn_available_error)
else:
future_set_exc_info(ping_future, sys.exc_info())
self.putconn(conn)
else:
ping_future.set_result(conn)
def run(self) -> None:
"""Starts or resumes the generator, running until it reaches a
yield point that is not ready.
"""
if self.running or self.finished:
return
try:
self.running = True
while True:
future = self.future
if future is None:
raise Exception("No pending future")
if not future.done():
return
self.future = None
try:
exc_info = None
try:
value = future.result()
except Exception:
exc_info = sys.exc_info()
future = None
if exc_info is not None:
try:
yielded = self.gen.throw(*exc_info) # type: ignore
finally:
# Break up a reference to itself
# for faster GC on CPython.
exc_info = None
else:
yielded = self.gen.send(value)
except (StopIteration, Return) as e:
self.finished = True
self.future = _null_future
future_set_result_unless_cancelled(
self.result_future, _value_from_stopiteration(e)
)
self.result_future = None # type: ignore
return
except Exception:
self.finished = True
self.future = _null_future
future_set_exc_info(self.result_future, sys.exc_info())
self.result_future = None # type: ignore
return
if not self.handle_yield(yielded):
return
yielded = None
finally:
self.running = False
def run(self) -> None:
"""Starts or resumes the generator, running until it reaches a
yield point that is not ready.
"""
if self.running or self.finished:
return
try:
self.running = True
while True:
future = self.future
if future is None:
raise Exception("No pending future")
if not future.done():
return
self.future = None
try:
exc_info = None
try:
value = future.result()
except Exception:
exc_info = sys.exc_info()
future = None
if exc_info is not None:
try:
yielded = self.gen.throw(*exc_info) # type: ignore
finally:
# Break up a reference to itself
# for faster GC on CPython.
exc_info = None
else:
yielded = self.gen.send(value)
except (StopIteration, Return) as e:
self.finished = True
self.future = _null_future
future_set_result_unless_cancelled(
self.result_future, _value_from_stopiteration(e)
)
self.result_future = None # type: ignore
return
except Exception:
self.finished = True
self.future = _null_future
future_set_exc_info(self.result_future, sys.exc_info())
self.result_future = None # type: ignore
return
if not self.handle_yield(yielded):
return
yielded = None
finally:
self.running = False
def _retry(self, retry, what, conn, keep, future):
if conn.closed:
if not retry:
retry.append(conn)
self.ioloop.add_future(conn.connect(), what)
return
else:
future.set_exception(self._no_conn_available_error)
else:
future_set_exc_info(future, sys.exc_info())
if not keep:
self.putconn(conn)
return
def run():
try:
result = func()
if result is not None:
from tornado.gen import convert_yielded
result = convert_yielded(result)
except Exception:
future_cell[0] = Future()
future_set_exc_info(future_cell[0], sys.exc_info())
else:
if is_future(result):
future_cell[0] = result
else:
future_cell[0] = Future()
future_cell[0].set_result(result)
self.add_future(future_cell[0], lambda future: self.stop())
def run():
try:
result = func()
if result is not None:
from tornado.gen import convert_yielded
result = convert_yielded(result)
except Exception:
future_cell[0] = Future()
future_set_exc_info(future_cell[0], sys.exc_info())
else:
if is_future(result):
future_cell[0] = result
else:
future_cell[0] = Future()
future_cell[0].set_result(result)
self.add_future(future_cell[0], lambda future: self.stop())
def run():
"""execute dest func"""
try:
result = func(*args, **kwargs)
if result is not None:
result = convert_yielded(result)
except Exception:
future_cell[0] = Future()
future_set_exc_info(future_cell[0], sys.exc_info())
else:
if is_future(result):
future_cell[0] = result
else:
future_cell[0] = Future()
future_cell[0].set_result(result)
IOLoop.current().add_future(future_cell[0],
lambda future: check_stop())
def run() -> None:
try:
result = func()
if result is not None:
from tornado.gen import convert_yielded
result = convert_yielded(result)
except Exception:
fut = Future() # type: Future[Any]
future_cell[0] = fut
future_set_exc_info(fut, sys.exc_info())
else:
if is_future(result):
future_cell[0] = result
else:
fut = Future()
future_cell[0] = fut
fut.set_result(result)
assert future_cell[0] is not None
self.add_future(future_cell[0], lambda future: self.stop())
def exec_statements(future):
try:
cursor = future.result()
cursors.append(cursor)
except Exception as error:
if auto_rollback and not self.closed:
self._rollback(transaction_future, error)
else:
future_set_exc_info(transaction_future, sys.exc_info())
return
try:
operation, parameters = next(queue)
except StopIteration:
transaction_future.set_result(cursors[1:-1])
return
f = self.execute(operation, parameters, cursor_factory)
self.ioloop.add_future(f, exec_statements)
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(future, 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)
def run() -> None:
try:
result = func()
if result is not None:
from tornado.gen import convert_yielded
result = convert_yielded(result)
except Exception:
fut = Future() # type: Future[Any]
future_cell[0] = fut
future_set_exc_info(fut, sys.exc_info())
else:
if is_future(result):
future_cell[0] = result
else:
fut = Future()
future_cell[0] = fut
fut.set_result(result)
assert future_cell[0] is not None
self.add_future(future_cell[0], lambda future: self.stop())
def handle_yield(self, yielded):
try:
self.future = convert_yielded(yielded)
except BadYieldError:
self.future = Future()
future_set_exc_info(self.future, sys.exc_info())
if self.future is moment:
self.io_loop.add_callback(self.run)
return False
elif not self.future.done():
def inner(f):
# Break a reference cycle to speed GC.
f = None # noqa
self.run()
self.io_loop.add_future(self.future, inner)
return False
return True
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(future, sys.exc_info())
if not future.done():
if keys is not None:
future_set_result_unless_cancelled(future,
dict(zip(keys, result_list)))
else:
future_set_result_unless_cancelled(future, result_list)
def handle_yield(self, yielded: _Yieldable) -> bool:
try:
self.future = convert_yielded(yielded)
except BadYieldError:
self.future = Future()
future_set_exc_info(self.future, sys.exc_info())
if self.future is moment:
self.io_loop.add_callback(self.run)
return False
elif self.future is None:
raise Exception("no pending future")
elif not self.future.done():
def inner(f: Any) -> None:
# Break a reference cycle to speed GC.
f = None # noqa
self.run()
self.io_loop.add_future(
self.future, inner)
return False
return True
def connect(self):
"""
Initiate asynchronous connect.
Returns future that resolves to this connection object.
"""
kwargs = {"async": True}
if self.connection_factory:
kwargs["connection_factory"] = self.connection_factory
if self.cursor_factory:
kwargs["cursor_factory"] = self.cursor_factory
future = Future()
self.connection = None
try:
self.connection = psycopg2.connect(self.dsn, **kwargs)
except psycopg2.Error:
self.connection = None
future_set_exc_info(future, sys.exc_info())
return future
self.fileno = self.connection.fileno()
if self.setsession:
on_connect_future = Future()
def on_connect(on_connect_future):
self.ioloop.add_future(self.transaction(self.setsession),
lambda x: future.set_result(self))
self.ioloop.add_future(on_connect_future, on_connect)
callback = partial(self._io_callback, on_connect_future, self)
else:
callback = partial(self._io_callback, future, self)
self.ioloop.add_handler(self.fileno, callback, IOLoop.WRITE)
self.ioloop.add_future(future, self._set_server_version)
self.ioloop.add_future(future, self._close_on_fail)
return future
def handle_yield(self, yielded: _Yieldable) -> bool:
try:
self.future = convert_yielded(yielded)
except BadYieldError:
self.future = Future()
future_set_exc_info(self.future, sys.exc_info())
if self.future is moment:
self.io_loop.add_callback(self.run)
return False
elif self.future is None:
raise Exception("no pending future")
elif not self.future.done():
def inner(f: Any) -> None:
# Break a reference cycle to speed GC.
f = None # noqa: F841
self.run()
self.io_loop.add_future(self.future, inner)
return False
return True
def handle_exception(typ, value, tb):
if future.done():
return False
future_set_exc_info(future, (typ, value, tb))
return True
def run(self):
"""Starts or resumes the generator, running until it reaches a
yield point that is not ready.
"""
if self.running or self.finished:
return
try:
self.running = True
while True:
future = self.future
if not future.done():
return
self.future = None
try:
orig_stack_contexts = stack_context._state.contexts
exc_info = None
try:
value = future.result()
except Exception:
self.had_exception = True
exc_info = sys.exc_info()
future = None
if exc_info is not None:
try:
yielded = self.gen.throw(*exc_info)
finally:
# Break up a reference to itself
# for faster GC on CPython.
exc_info = None
else:
yielded = self.gen.send(value)
if stack_context._state.contexts is not orig_stack_contexts:
self.gen.throw(
stack_context.StackContextInconsistentError(
'stack_context inconsistency (probably caused '
'by yield within a "with StackContext" block)'))
except (StopIteration, Return) as e:
self.finished = True
self.future = _null_future
if self.pending_callbacks and not self.had_exception:
# If we ran cleanly without waiting on all callbacks
# raise an error (really more of a warning). If we
# had an exception then some callbacks may have been
# orphaned, so skip the check in that case.
raise LeakedCallbackError(
"finished without waiting for callbacks %r" %
self.pending_callbacks)
future_set_result_unless_cancelled(self.result_future,
_value_from_stopiteration(e))
self.result_future = None
self._deactivate_stack_context()
return
except Exception:
self.finished = True
self.future = _null_future
future_set_exc_info(self.result_future, sys.exc_info())
self.result_future = None
self._deactivate_stack_context()
return
if not self.handle_yield(yielded):
return
yielded = None
finally:
self.running = False
def handle_exception(typ, value, tb):
if future.done():
return False
else:
future_set_exc_info(future, (typ, value, tb))
return True
def wrapper(*args, **kwargs):
future = _create_future()
if replace_callback and 'callback' in kwargs:
warnings.warn(
"callback arguments are deprecated, use the returned Future instead",
DeprecationWarning,
stacklevel=2)
callback = kwargs.pop('callback')
IOLoop.current().add_future(
future, lambda future: callback(future.result()))
try:
result = func(*args, **kwargs)
except (Return, StopIteration) as e:
result = _value_from_stopiteration(e)
except Exception:
future_set_exc_info(future, sys.exc_info())
try:
return future
finally:
# Avoid circular references
future = None
else:
if isinstance(result, GeneratorType):
# Inline the first iteration of Runner.run. This lets us
# avoid the cost of creating a Runner when the coroutine
# never actually yields, which in turn allows us to
# use "optional" coroutines in critical path code without
# performance penalty for the synchronous case.
try:
orig_stack_contexts = stack_context._state.contexts
yielded = next(result)
if stack_context._state.contexts is not orig_stack_contexts:
yielded = _create_future()
yielded.set_exception(
stack_context.StackContextInconsistentError(
'stack_context inconsistency (probably caused '
'by yield within a "with StackContext" block)')
)
except (StopIteration, Return) as e:
future_set_result_unless_cancelled(
future, _value_from_stopiteration(e))
except Exception:
future_set_exc_info(future, sys.exc_info())
else:
# Provide strong references to Runner objects as long
# as their result future objects also have strong
# references (typically from the parent coroutine's
# Runner). This keeps the coroutine's Runner alive.
# We do this by exploiting the public API
# add_done_callback() instead of putting a private
# attribute on the Future.
# (Github issues #1769, #2229).
runner = Runner(result, future, yielded)
future.add_done_callback(lambda _: runner)
yielded = None
try:
return future
finally:
# Subtle memory optimization: if next() raised an exception,
# the future's exc_info contains a traceback which
# includes this stack frame. This creates a cycle,
# which will be collected at the next full GC but has
# been shown to greatly increase memory usage of
# benchmarks (relative to the refcount-based scheme
# used in the absence of cycles). We can avoid the
# cycle by clearing the local variable after we return it.
future = None
future_set_result_unless_cancelled(future, result)
return future
