##// END OF EJS Templates
Prevent qtconsole frontend freeze on lots of output....
Prevent qtconsole frontend freeze on lots of output. The output from the kernel is now clipped to last `buffer_size` before displaying and a timer is used to flush the pending output text instead of attempting to display text on every stream output from kernel. The timer interval is adjusted based on actual time taken to append a screenful of text to widget. This throttles the widget repaints and avoids choking the Qt event loop leaving time to handle other Qt events. Test cases: In [1]: for i in xrange(1000000): print i In [2]: range(100000) Without this commit the first input causes the qtconsole frontend to freeze, not responding to `Ctrl+C`.

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r11519:c7a90e39
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blocking.py
58 lines | 2.1 KiB | text/x-python | PythonLexer
""" Implements a fully blocking kernel client.
Useful for test suites and blocking terminal interfaces.
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2012 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING.txt, distributed as part of this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# IPython imports
from IPython.utils.io import raw_print
from IPython.utils.traitlets import Type
from IPython.kernel.blocking.channels import BlockingChannelMixin
# Local imports
from .channels import (
InProcessShellChannel,
InProcessIOPubChannel,
InProcessStdInChannel,
)
from .client import InProcessKernelClient
#-----------------------------------------------------------------------------
# Blocking kernel manager
#-----------------------------------------------------------------------------
class BlockingInProcessShellChannel(BlockingChannelMixin, InProcessShellChannel):
pass
class BlockingInProcessIOPubChannel(BlockingChannelMixin, InProcessIOPubChannel):
pass
class BlockingInProcessStdInChannel(BlockingChannelMixin, InProcessStdInChannel):
def call_handlers(self, msg):
""" Overridden for the in-process channel.
This methods simply calls raw_input directly.
"""
msg_type = msg['header']['msg_type']
if msg_type == 'input_request':
_raw_input = self.client.kernel._sys_raw_input
prompt = msg['content']['prompt']
raw_print(prompt, end='')
self.input(_raw_input())
class BlockingInProcessKernelClient(InProcessKernelClient):
# The classes to use for the various channels.
shell_channel_class = Type(BlockingInProcessShellChannel)
iopub_channel_class = Type(BlockingInProcessIOPubChannel)
stdin_channel_class = Type(BlockingInProcessStdInChannel)