Fix leak of IOLoopKernelManager object #361
Merged
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After analyzing various leaked items when running either Notebook or
Jupyter Kernel Gateway, one item that recurred across each kernel
startup and shutdown sequence was an instance of IOLoopKernelManager.
(Of course, when using JKG, this instance was KernelGatewayIOLoopKernelManager
since it derives from the former.)
The leak is caused by the circular references established in the
self._restarter
and
self.session.parent
members. This change breaks the circular reference whenthe restarter is stopped and during
cleanup()
of the kernel manager. Once thereferences are broken, the kernel manager instance can be garbage collected.