Toplevel await

.github/workflows/build.yml

@@ -122,8 +122,8 @@ jobs:
         with:
           activate-environment: xeus-python-kernel
           environment-file: environment.yml
-          python-version: "3.10"
-          mamba-version: "*"
+          python-version: '3.10'
+          mamba-version: '*'
 
       - name: Make sure the Mamba Python API is available
         run: |
@@ -153,8 +153,8 @@ jobs:
         with:
           activate-environment: xeus-python-kernel
           environment-file: environment.yml
-          python-version: "3.10"
-          mamba-version: "*"
+          python-version: '3.10'
+          mamba-version: '*'
 
       - name: Install
         run: pip install jupyterlite-xeus-python.tar.gz
@@ -177,7 +177,7 @@ jobs:
       - name: Install mamba
         uses: mamba-org/provision-with-micromamba@main
         with:
-          micromamba-version: "0.22.0"
+          micromamba-version: '0.22.0'
           environment-file: environment.yml
           environment-name: xeus-python-kernel
 
@@ -204,7 +204,7 @@ jobs:
         with:
           activate-environment: xeus-python-kernel
           environment-file: environment.yml
-          python-version: "3.10"
+          python-version: '3.10'
 
       - name: Install
         run: pip install jupyterlite-xeus-python.tar.gz

CHANGELOG.md

@@ -25,25 +25,28 @@
 ## v0.2.0
 
 ### What's Changed
-* Add docs by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/4
-* Fix build by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/5
-* Add Matplotlib to the env by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/7
-* Do not use xeus-python's master branch by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/8
-* Simplify dockerfile by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/9
-* Xeus python build addon by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/10
+
+- Add docs by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/4
+- Fix build by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/5
+- Add Matplotlib to the env by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/7
+- Do not use xeus-python's master branch by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/8
+- Simplify dockerfile by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/9
+- Xeus python build addon by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/10
 
 **Full Changelog**: https://github.com/jupyterlite/xeus-python-kernel/compare/0.1.0...0.2.0
 
 ## v0.1.0
 
 ### Contributions
-* Initial version by @DerThorsten in https://github.com/jupyterlite/xeus-python-kernel/commit/d28dbc1ec9c1dca3f861d79ee5930054c00d5998
-* Remove sleep + renames according to https://github.com/jupyter-xeus/xeus-python/pull/530 by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/1
-* Fix README by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/2
-* Add Docker build by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/3
+
+- Initial version by @DerThorsten in https://github.com/jupyterlite/xeus-python-kernel/commit/d28dbc1ec9c1dca3f861d79ee5930054c00d5998
+- Remove sleep + renames according to https://github.com/jupyter-xeus/xeus-python/pull/530 by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/1
+- Fix README by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/2
+- Add Docker build by @martinRenou in https://github.com/jupyterlite/xeus-python-kernel/pull/3
 
 ### Contributors
-* @DerThorsten started the project
-* @martinRenou made their first contribution in https://github.com/jupyterlite/xeus-python-kernel/pull/1
+
+- @DerThorsten started the project
+- @martinRenou made their first contribution in https://github.com/jupyterlite/xeus-python-kernel/pull/1
 
 **Full Changelog**: https://github.com/jupyterlite/xeus-python-kernel/commits/0.1.0

docs/environment.yml

@@ -10,7 +10,7 @@ dependencies:
   # - empack
 
   - pip:
-    - jupyterlite
-    - jupyterlite-sphinx
-    - jupyterlite-xeus-python==0.3.0
-    - empack
+      - jupyterlite
+      - jupyterlite-sphinx
+      - jupyterlite-xeus-python==0.3.0
+      - empack

docs/jupyterlite_config.json

@@ -1,5 +1,5 @@
 {
-    "XeusPythonEnv": {
-        "packages": ["numpy", "matplotlib", "ipyleaflet"]
-    }
+  "XeusPythonEnv": {
+    "packages": ["numpy", "matplotlib", "ipyleaflet"]
+  }
 }

environment.yml

@@ -8,4 +8,4 @@ dependencies:
   - emsdk >=3.1.11
   - empack >=0.5.3
   - pip:
-    - jupyterlite
+      - jupyterlite

src/worker.ts

@@ -6,6 +6,17 @@ declare function createXeusModule(options: any): any;
 
 globalThis.Module = {};
 
+// when a toplevel cell uses an await, the cell is implicitly
+// wrapped in a async function. Since the webloop - eventloop
+// implementation does not support `eventloop.run_until_complete(f)`
+// we need to convert the toplevel future in a javascript Promise
+// this `toplevel` promise is then awaited before we
+// execute the next cell. After the promise is awaited we need
+// to do some cleanup and delete the python proxy
+// (ie a js-wrapped python object) to avoid memory leaks
+globalThis.toplevel_promise = null;
+globalThis.toplevel_promise_py_proxy = null;
+
 // We alias self to ctx and give it our newly created type
 const ctx: Worker = self as any;
 let raw_xkernel: any;
@@ -61,6 +72,16 @@ const loadCppModulePromise = load();
 ctx.onmessage = async (event: MessageEvent): Promise<void> => {
   await loadCppModulePromise;
 
+  if (
+    globalThis.toplevel_promise !== null &&
+    globalThis.toplevel_promise_py_proxy !== null
+  ) {
+    await globalThis.toplevel_promise;
+    globalThis.toplevel_promise_py_proxy.delete();
+    globalThis.toplevel_promise_py_proxy = null;
+    globalThis.toplevel_promise = null;
+  }
+
   const data = event.data;
   const msg = data.msg;
   const msg_type = msg.header.msg_type;