def setup_kernel(cmd):
"""start an embedded kernel in a subprocess, and wait for it to be ready
Returns
-------
kernel_manager: connected KernelManager instance
"""
kernel = Popen([sys.executable, "-c", cmd], stdout=PIPE, stderr=PIPE, env=env)
connection_file = os.path.join(IPYTHONDIR, "profile_default", "security", "kernel-%i.json" % kernel.pid)
# wait for connection file to exist, timeout after 5s
tic = time.time()
while not os.path.exists(connection_file) and kernel.poll() is None and time.time() < tic + SETUP_TIMEOUT:
time.sleep(0.1)
if kernel.poll() is not None:
o, e = kernel.communicate()
e = py3compat.cast_unicode(e)
raise IOError("Kernel failed to start:\n%s" % e)
if not os.path.exists(connection_file):
if kernel.poll() is None:
kernel.terminate()
raise IOError("Connection file %r never arrived" % connection_file)
client = BlockingKernelClient(connection_file=connection_file)
client.load_connection_file()
client.start_channels()
try:
yield client
finally:
client.stop_channels()
kernel.terminate()
def setup_kernel(cmd):
"""start an embedded kernel in a subprocess, and wait for it to be ready
Returns
-------
kernel_manager: connected KernelManager instance
"""
kernel = Popen([sys.executable, '-c', cmd], stdout=PIPE, stderr=PIPE, env=env)
connection_file = os.path.join(IPYTHONDIR,
'profile_default',
'security',
'kernel-%i.json' % kernel.pid
)
# wait for connection file to exist, timeout after 5s
tic = time.time()
while not os.path.exists(connection_file) \
and kernel.poll() is None \
and time.time() < tic + SETUP_TIMEOUT:
time.sleep(0.1)
if kernel.poll() is not None:
o,e = kernel.communicate()
e = py3compat.cast_unicode(e)
raise IOError("Kernel failed to start:\n%s" % e)
if not os.path.exists(connection_file):
if kernel.poll() is None:
kernel.terminate()
raise IOError("Connection file %r never arrived" % connection_file)
client = BlockingKernelClient(connection_file=connection_file)
client.load_connection_file()
client.start_channels()
client.wait_for_ready()
try:
yield client
finally:
client.stop_channels()
kernel.terminate()
