def frontend_request(blocking=True, timeout=None):
"""
Send a request to the frontend.
If blocking is True, The return value will be returned.
"""
if not get_ipython().kernel.frontend_comm.is_open():
raise CommError("Can't make a request to a closed comm")
# Get a reply from the last frontend to have sent a message
return get_ipython().kernel.frontend_call(blocking=blocking,
broadcast=False,
timeout=timeout)
def _get_call_return_value(self, call_dict, call_data, comm_id):
"""
Interupt the kernel if needed.
"""
settings = call_dict['settings']
blocking = 'blocking' in settings and settings['blocking']
if not self.kernel_client.is_alive():
if blocking:
raise RuntimeError("Kernel is dead")
else:
# The user has other problems
logger.info(
"Dropping message because kernel is dead: ",
str(call_dict)
)
return
settings = call_dict['settings']
interrupt = 'interrupt' in settings and settings['interrupt']
interrupt = interrupt or blocking
# Need to make sure any blocking call is replied rapidly.
if interrupt and not self.comm_channel_connected():
# Ask again for comm config
self.remote_call()._send_comm_config()
# Can not interrupt if comm not connected
interrupt = False
logger.debug(
"Dropping interrupt because comm is disconnected: " +
str(call_dict)
)
if blocking:
raise CommError("Cannot block on a disconnected comm")
try:
with self.comm_channel_manager(
comm_id, queue_message=not interrupt):
return super(KernelComm, self)._get_call_return_value(
call_dict, call_data, comm_id)
except RuntimeError as e:
if blocking:
raise
else:
# The user has other problems
logger.info(
"Dropping message because of exception: ",
str(e),
str(call_dict)
)
return
def comm_channel_manager(self, comm_id, queue_message=False):
"""Use comm_channel instead of shell_channel."""
if queue_message:
# Send without comm_channel
yield
return
if not self.comm_channel_connected():
# Ask again for comm config
self.remote_call()._send_comm_config()
raise CommError("Comm not connected.")
id_list = self.get_comm_id_list(comm_id)
for comm_id in id_list:
self._comms[comm_id]['comm']._send_channel = (
self.kernel_client.comm_channel)
try:
yield
finally:
for comm_id in id_list:
self._comms[comm_id]['comm']._send_channel = (
self.kernel_client.shell_channel)
def _wait_reply(self, call_id, call_name, timeout):
"""Wait until the frontend replies to a request."""
if call_id in self._reply_inbox:
return
# There is no get_ident in Py2
if not PY2 and self._main_thread_id != threading.get_ident():
# We can't call kernel.do_one_iteration from this thread.
# And we have no reason to think the main thread is not busy.
raise CommError("Can't make blocking calls from non-main threads.")
t_start = time.time()
while call_id not in self._reply_inbox:
if time.time() > t_start + timeout:
raise TimeoutError(
"Timeout while waiting for '{}' reply".format(call_name))
priority = 0
while priority is not None:
priority = self.kernel.do_one_iteration()
if priority is not None:
# For Python2
priority = priority.result()