Merge pull request #82 from rdeits/rd/fix-win-py8

Fix for Python 3.8 on Windows

Author: rdeits

.github/workflows/CI.yaml

@@ -1,14 +1,19 @@
 name: CI
 
-on: [push]
+on:
+  push:
+    branches:
+      - master
+  pull_request:
 
 jobs:
   build:
 
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         python-version: [3.6, 3.7, 3.8]
+        os: [ubuntu-latest, windows-latest]
 
     steps:
     - uses: actions/checkout@v2

src/meshcat/servers/zmqserver.py

@@ -359,6 +359,13 @@ def main():
     import argparse
     import sys
     import webbrowser
+    import platform
+    import asyncio
+
+    # Fix asyncio configuration on Windows for Python 3.8 and above.
+    # Workaround for https://github.com/tornadoweb/tornado/issues/2608
+    if sys.version_info >= (3, 8) and platform.system() == 'Windows':
+        asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
 
     parser = argparse.ArgumentParser(description="Serve the MeshCat HTML files and listen for ZeroMQ commands")
     parser.add_argument('--zmq-url', '-z', type=str, nargs="?", default=None)