more context cleanup

Author: blink1073

jupyter_client/client.py

@@ -11,6 +11,7 @@
 
 import zmq.asyncio
 from traitlets import Any
+from traitlets import Bool
 from traitlets import Instance
 from traitlets import Type
 
@@ -92,7 +93,10 @@ class KernelClient(ConnectionFileMixin):
     # The PyZMQ Context to use for communication with the kernel.
     context = Instance(zmq.asyncio.Context)
 
+    _created_context = Bool(False)
+
     def _context_default(self) -> zmq.asyncio.Context:
+        self._created_context = True
         return zmq.asyncio.Context()
 
     # The classes to use for the various channels
@@ -113,9 +117,16 @@ def _context_default(self) -> zmq.asyncio.Context:
     allow_stdin: bool = True
 
     def __del__(self):
-        """Clean up the context when garbage collected."""
-        if not self.channels_running:
+        if self._created_context and self.context and not self.context.closed:
+            if self.log:
+                self.log.debug("Destroying zmq context for %s", self)
             self.context.destroy()
+        try:
+            super_del = super().__del__
+        except AttributeError:
+            pass
+        else:
+            super_del()
 
     # --------------------------------------------------------------------------
     # Channel proxy methods

jupyter_client/multikernelmanager.py

@@ -97,6 +97,8 @@ def create_kernel_manager(*args: Any, **kwargs: Any) -> KernelManager:
 
     context = Instance("zmq.Context")
 
+    _created_context = Bool(False)
+
     _pending_kernels = Dict()
 
     @property
@@ -106,15 +108,24 @@ def _starting_kernels(self):
 
     @default("context")  # type:ignore[misc]
     def _context_default(self) -> zmq.Context:
+        self._created_context = True
         return zmq.Context()
 
     connection_dir = Unicode("")
 
     _kernels = Dict()
 
     def __del__(self):
-        """Clean up the context when garbage collected."""
-        self.context.destroy()
+        if self._created_context and self.context and not self.context.closed:
+            if self.log:
+                self.log.debug("Destroying zmq context for %s", self)
+            self.context.destroy()
+        try:
+            super_del = super().__del__
+        except AttributeError:
+            pass
+        else:
+            super_del()
 
     def list_kernel_ids(self) -> t.List[str]:
         """Return a list of the kernel ids of the active kernels."""