1  """A kernel manager for in-process kernels."""
   2  
   3  # Copyright (c) IPython Development Team.
   4  # Distributed under the terms of the Modified BSD License.
   5  
   6  from jupyter_client.manager import KernelManager
   7  from jupyter_client.managerabc import KernelManagerABC
   8  from jupyter_client.session import Session
   9  from traitlets import DottedObjectName, Instance, default
  10  
  11  from .constants import INPROCESS_KEY
  12  
  13  
  14  class InProcessKernelManager(KernelManager):
  15      """A manager for an in-process kernel.
  16  
  17      This class implements the interface of
  18      `jupyter_client.kernelmanagerabc.KernelManagerABC` and allows
  19      (asynchronous) frontends to be used seamlessly with an in-process kernel.
  20  
  21      See `jupyter_client.kernelmanager.KernelManager` for docstrings.
  22      """
  23  
  24      # The kernel process with which the KernelManager is communicating.
  25      kernel = Instance("ipykernel.inprocess.ipkernel.InProcessKernel", allow_none=True)
  26      # the client class for KM.client() shortcut
  27      client_class = DottedObjectName("ipykernel.inprocess.BlockingInProcessKernelClient")
  28  
  29      @default("blocking_class")
  30      def _default_blocking_class(self):
  31          from .blocking import BlockingInProcessKernelClient
  32  
  33          return BlockingInProcessKernelClient
  34  
  35      @default("session")
  36      def _default_session(self):
  37          # don't sign in-process messages
  38          return Session(key=INPROCESS_KEY, parent=self)
  39  
  40      # --------------------------------------------------------------------------
  41      # Kernel management methods
  42      # --------------------------------------------------------------------------
  43  
  44      def start_kernel(self, **kwds):
  45          """Start the kernel."""
  46          from ipykernel.inprocess.ipkernel import InProcessKernel
  47  
  48          self.kernel = InProcessKernel(parent=self, session=self.session)
  49  
  50      def shutdown_kernel(self):
  51          """Shutdown the kernel."""
  52          if self.kernel:
  53              self.kernel.iopub_thread.stop()
  54              self._kill_kernel()
  55  
  56      def restart_kernel(self, now=False, **kwds):
  57          """Restart the kernel."""
  58          self.shutdown_kernel()
  59          self.start_kernel(**kwds)
  60  
  61      @property
  62      def has_kernel(self):
  63          return self.kernel is not None
  64  
  65      def _kill_kernel(self):
  66          self.kernel = None
  67  
  68      def interrupt_kernel(self):
  69          """Interrupt the kernel."""
  70          msg = "Cannot interrupt in-process kernel."
  71          raise NotImplementedError(msg)
  72  
  73      def signal_kernel(self, signum):
  74          """Send a signal to the kernel."""
  75          msg = "Cannot signal in-process kernel."
  76          raise NotImplementedError(msg)
  77  
  78      def is_alive(self):
  79          """Test if the kernel is alive."""
  80          return self.kernel is not None
  81  
  82      def client(self, **kwargs):
  83          """Get a client for the kernel."""
  84          kwargs["kernel"] = self.kernel
  85          return super().client(**kwargs)
  86  
  87  
  88  # -----------------------------------------------------------------------------
  89  # ABC Registration
  90  # -----------------------------------------------------------------------------
  91  
  92  KernelManagerABC.register(InProcessKernelManager)
  93