Fix server lifecycle (cleanup)

yacv_server/server.py

@@ -2,6 +2,7 @@ import asyncio
 import atexit
 import os
 import signal
+import sys
 from threading import Thread
 from typing import Optional
 
@@ -20,6 +21,7 @@ class Server:
     app = web.Application()
     runner: web.AppRunner
     thread: Optional[Thread] = None
+    do_shutdown = asyncio.Event()
 
     def __init__(self, *args, **kwargs):
         # --- Routes ---
@@ -29,11 +31,12 @@ class Server:
         self.app.router.add_get('/{path:(.*/|)}', _index_handler)  # Any folder -> index.html
         self.app.router.add_static('/', path=FRONTEND_BASE_PATH, name='static_frontend')
         # --- Misc ---
-        self.runner = web.AppRunner(self.app)
+        self.loop = asyncio.new_event_loop()
 
     def start(self):
         """Starts the web server in the background"""
         assert self.thread is None, "Server already started"
+        # Start the server in a separate daemon thread
         self.thread = Thread(target=self.run_server, name='yacv_server', daemon=True)
         signal.signal(signal.SIGINT | signal.SIGTERM, self.stop)
         atexit.register(self.stop)
@@ -42,23 +45,34 @@ class Server:
     # noinspection PyUnusedLocal
     def stop(self, *args):
         """Stops the web server"""
-        print('Stopping server...')
         if self.thread is None:
             print('Cannot stop server because it is not running')
             return
-        asyncio.run(self.runner.shutdown())
-        asyncio.run(self.app.cleanup())
-        self.thread = None  # FIXME: Not properly cleaned up (join blocks forever)
-        print('Cleanup done')
+        # FIXME: Wait for at least one client to confirm ready before stopping in case we are too fast?
+        self.loop.call_soon_threadsafe(lambda *a: self.do_shutdown.set())
+        self.thread.join(timeout=12)
+        self.thread = None
+        if len(args) >= 1 and args[0] in (signal.SIGINT, signal.SIGTERM):
+            sys.exit(0)  # Exit with success
 
     def run_server(self):
         """Runs the web server"""
-        loop = asyncio.new_event_loop()
-        asyncio.set_event_loop(loop)
-        loop.run_until_complete(self.runner.setup())
-        site = web.TCPSite(self.runner, os.getenv('YACV_HOST', 'localhost'), int(os.getenv('YACV_PORT', 32323)))
-        loop.run_until_complete(site.start())
-        loop.run_forever()
+        asyncio.set_event_loop(self.loop)
+        self.loop.run_until_complete(self.run_server_async())
+        self.loop.stop()
+        self.loop.close()
+
+    async def run_server_async(self):
+        """Runs the web server (async)"""
+        runner = web.AppRunner(self.app)
+        await runner.setup()
+        site = web.TCPSite(runner, os.getenv('YACV_HOST', 'localhost'), int(os.getenv('YACV_PORT', 32323)))
+        await site.start()
+        # print(f'Server started at {site.name}')
+        # Wait for a signal to stop the server while running
+        await self.do_shutdown.wait()
+        # print('Shutting down server...')
+        await runner.cleanup()
 
     def show_object(self, obj: TopoDS_Shape):
         pass