hub/venv/lib/python3.7/site-packages/ipykernel/trio_runner.py

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import builtins
import logging
import signal
import threading
import traceback
import warnings
import trio
class TrioRunner:
def __init__(self):
self._cell_cancel_scope = None
self._trio_token = None
def initialize(self, kernel, io_loop):
kernel.shell.set_trio_runner(self)
kernel.shell.run_line_magic('autoawait', 'trio')
kernel.shell.magics_manager.magics['line']['autoawait'] = \
lambda _: warnings.warn("Autoawait isn't allowed in Trio "
"background loop mode.")
bg_thread = threading.Thread(target=io_loop.start, daemon=True,
name='TornadoBackground')
bg_thread.start()
def interrupt(self, signum, frame):
if self._cell_cancel_scope:
self._cell_cancel_scope.cancel()
else:
raise Exception('Kernel interrupted but no cell is running')
def run(self):
old_sig = signal.signal(signal.SIGINT, self.interrupt)
def log_nursery_exc(exc):
exc = '\n'.join(traceback.format_exception(type(exc), exc,
exc.__traceback__))
logging.error('An exception occurred in a global nursery task.\n%s',
exc)
async def trio_main():
self._trio_token = trio.hazmat.current_trio_token()
async with trio.open_nursery() as nursery:
# TODO This hack prevents the nursery from cancelling all child
# tasks when an uncaught exception occurs, but it's ugly.
nursery._add_exc = log_nursery_exc
builtins.GLOBAL_NURSERY = nursery
await trio.sleep_forever()
trio.run(trio_main)
signal.signal(signal.SIGINT, old_sig)
def __call__(self, async_fn):
async def loc(coro):
self._cell_cancel_scope = trio.CancelScope()
with self._cell_cancel_scope:
return await coro
self._cell_cancel_scope = None
return trio.from_thread.run(loc, async_fn, trio_token=self._trio_token)