Remove use of get_event_loop.

Refs #916 - get_event_loop is deprecated in Python 3.10.

Fix #534.

README.rst

@@ -48,15 +48,14 @@ Here's how a client sends and receives messages:
     #!/usr/bin/env python
 
     import asyncio
-    import websockets
+    from websockets import connect
 
     async def hello(uri):
-        async with websockets.connect(uri) as websocket:
+        async with connect(uri) as websocket:
             await websocket.send("Hello world!")
             await websocket.recv()
 
-    asyncio.get_event_loop().run_until_complete(
-        hello('ws://localhost:8765'))
+    asyncio.run(hello('ws://localhost:8765'))
 
 And here's an echo server:
 
@@ -65,15 +64,15 @@ And here's an echo server:
     #!/usr/bin/env python
 
     import asyncio
-    import websockets
+    from websockets import serve
 
     async def echo(websocket, path):
         async for message in websocket:
             await websocket.send(message)
 
-    asyncio.get_event_loop().run_until_complete(
-        websockets.serve(echo, 'localhost', 8765))
-    asyncio.get_event_loop().run_forever()
+    async def main():
+        async with serve(echo, 'localhost', 8765):
+            await asyncio.Future()  # run forever
 
 Does that look good?
 

compliance/test_client.py

@@ -45,5 +45,4 @@ async def run_tests(server, agent):
     await update_reports(server, agent)
 
 
-main = run_tests(SERVER, urllib.parse.quote(AGENT))
-asyncio.get_event_loop().run_until_complete(main)
+asyncio.run(run_tests(SERVER, urllib.parse.quote(AGENT)))

compliance/test_server.py

@@ -18,10 +18,12 @@ async def echo(ws, path):
         await ws.send(msg)
 
 
-start_server = websockets.serve(echo, HOST, PORT, max_size=2 ** 25, max_queue=1)
+async def main():
+    with websockets.serve(echo, HOST, PORT, max_size=2 ** 25, max_queue=1):
+        try:
+            await asyncio.Future()
+        except KeyboardInterrupt:
+            pass
 
-try:
-    asyncio.get_event_loop().run_until_complete(start_server)
-    asyncio.get_event_loop().run_forever()
-except KeyboardInterrupt:
-    pass
+
+asyncio.run(main)

docs/faq.rst

@@ -274,7 +274,8 @@ Can I use ``websockets`` synchronously, without ``async`` / ``await``?
 ......................................................................
 
 You can convert every asynchronous call to a synchronous call by wrapping it
-in ``asyncio.get_event_loop().run_until_complete(...)``.
+in ``asyncio.get_event_loop().run_until_complete(...)``. Unfortunately, this
+is deprecated as of Python 3.10.
 
 If this turns out to be impractical, you should use another library.
 

docs/heroku.rst

@@ -52,10 +52,11 @@ Here's the implementation of the app, an echo server. Save it in a file called
         async for message in websocket:
             await websocket.send(message)
 
-    start_server = websockets.serve(echo, "", int(os.environ["PORT"]))
+    async def main():
+        async with websockets.serve(echo, "", int(os.environ["PORT"])):
+            await asyncio.Future()  # run forever
 
-    asyncio.get_event_loop().run_until_complete(start_server)
-    asyncio.get_event_loop().run_forever()
+    asyncio.run(main)
 
 The server relies on the ``$PORT`` environment variable to tell on which port
 it will listen, according to Heroku's conventions.

example/basic_auth_client.py

@@ -11,4 +11,4 @@ async def hello():
         greeting = await websocket.recv()
         print(greeting)
 
-asyncio.get_event_loop().run_until_complete(hello())
+asyncio.run(hello())

example/basic_auth_server.py

@@ -9,12 +9,13 @@ async def hello(websocket, path):
     greeting = f"Hello {websocket.username}!"
     await websocket.send(greeting)
 
-start_server = websockets.serve(
-    hello, "localhost", 8765,
-    create_protocol=websockets.basic_auth_protocol_factory(
-        realm="example", credentials=("mary", "p@ssw0rd")
-    ),
-)
+async def main():
+    async with websockets.serve(
+        hello, "localhost", 8765,
+        create_protocol=websockets.basic_auth_protocol_factory(
+            realm="example", credentials=("mary", "p@ssw0rd")
+        ),
+    ):
+        await asyncio.Future()  # run forever
 
-asyncio.get_event_loop().run_until_complete(start_server)
-asyncio.get_event_loop().run_forever()
+asyncio.run(main)

example/client.py

@@ -16,4 +16,4 @@ async def hello():
         greeting = await websocket.recv()
         print(f"< {greeting}")
 
-asyncio.get_event_loop().run_until_complete(hello())
+asyncio.run(hello())

example/counter.py

@@ -63,7 +63,6 @@ async def counter(websocket, path):
         await unregister(websocket)
 
 
-start_server = websockets.serve(counter, "localhost", 6789)
-
-asyncio.get_event_loop().run_until_complete(start_server)
-asyncio.get_event_loop().run_forever()
+async def main():
+    async with websockets.serve(counter, "localhost", 6789):
+        await asyncio.Future()  # run forever

example/echo.py

@@ -7,7 +7,8 @@ async def echo(websocket, path):
     async for message in websocket:
         await websocket.send(message)
 
-start_server = websockets.serve(echo, "localhost", 8765)
+async def main():
+    async with websockets.serve(echo, "localhost", 8765):
+        await asyncio.Future()  # run forever
 
-asyncio.get_event_loop().run_until_complete(start_server)
-asyncio.get_event_loop().run_forever()
+asyncio.run(main)

example/health_check_server.py

@@ -14,9 +14,10 @@ async def echo(websocket, path):
     async for message in websocket:
         await websocket.send(message)
 
-start_server = websockets.serve(
-    echo, "localhost", 8765, process_request=health_check
-)
+async def main():
+    async with websockets.serve(
+        echo, "localhost", 8765, process_request=health_check
+    ):
+        await asyncio.Future()  # run forever
 
-asyncio.get_event_loop().run_until_complete(start_server)
-asyncio.get_event_loop().run_forever()
+asyncio.run(main)

example/hello.py

@@ -9,4 +9,4 @@ async def hello():
         await websocket.send("Hello world!")
         await websocket.recv()
 
-asyncio.get_event_loop().run_until_complete(hello())
+asyncio.run(hello())

example/secure_client.py

@@ -24,4 +24,4 @@ async def hello():
         greeting = await websocket.recv()
         print(f"< {greeting}")
 
-asyncio.get_event_loop().run_until_complete(hello())
+asyncio.run(hello())

example/secure_server.py

@@ -20,9 +20,10 @@ async def hello(websocket, path):
 localhost_pem = pathlib.Path(__file__).with_name("localhost.pem")
 ssl_context.load_cert_chain(localhost_pem)
 
-start_server = websockets.serve(
-    hello, "localhost", 8765, ssl=ssl_context
-)
+async def main():
+    async with websockets.serve(
+        hello, "localhost", 8765, ssl=ssl_context
+    ):
+        await asyncio.Future()  # run forever
 
-asyncio.get_event_loop().run_until_complete(start_server)
-asyncio.get_event_loop().run_forever()
+asyncio.run(main)

example/server.py

@@ -14,7 +14,8 @@ async def hello(websocket, path):
     await websocket.send(greeting)
     print(f"> {greeting}")
 
-start_server = websockets.serve(hello, "localhost", 8765)
+async def main():
+    async with websockets.serve(hello, "localhost", 8765):
+        await asyncio.Future()  # run forever
 
-asyncio.get_event_loop().run_until_complete(start_server)
-asyncio.get_event_loop().run_forever()
+asyncio.run(main)

example/show_time.py

@@ -13,7 +13,8 @@ async def time(websocket, path):
         await websocket.send(now)
         await asyncio.sleep(random.random() * 3)
 
-start_server = websockets.serve(time, "127.0.0.1", 5678)
+async def main():
+    async with websockets.serve(time, "localhost", 5678):
+        await asyncio.Future()  # run forever
 
-asyncio.get_event_loop().run_until_complete(start_server)
-asyncio.get_event_loop().run_forever()
+asyncio.run(main)

example/shutdown_client.py

@@ -7,13 +7,13 @@
 async def client():
     uri = "ws://localhost:8765"
     async with websockets.connect(uri) as websocket:
+        loop = asyncio.get_running_loop()
         # Close the connection when receiving SIGTERM.
-        loop = asyncio.get_event_loop()
         loop.add_signal_handler(
             signal.SIGTERM, loop.create_task, websocket.close())
 
         # Process messages received on the connection.
         async for message in websocket:
             ...
 
-asyncio.get_event_loop().run_until_complete(client())
+asyncio.run(client())

example/shutdown_server.py

@@ -8,15 +8,12 @@ async def echo(websocket, path):
     async for message in websocket:
         await websocket.send(message)
 
-async def echo_server(stop):
+async def server():
+    loop = asyncio.get_running_loop()
+    stop = loop.create_future()
+    # Set the stop condition when receiving SIGTERM.
+    loop.add_signal_handler(signal.SIGTERM, stop.set_result, None)
     async with websockets.serve(echo, "localhost", 8765):
         await stop
 
-loop = asyncio.get_event_loop()
-
-# The stop condition is set when receiving SIGTERM.
-stop = loop.create_future()
-loop.add_signal_handler(signal.SIGTERM, stop.set_result, None)
-
-# Run the server until the stop condition is met.
-loop.run_until_complete(echo_server(stop))
+asyncio.run(server())

example/unix_client.py

@@ -16,4 +16,4 @@ async def hello():
         greeting = await websocket.recv()
         print(f"< {greeting}")
 
-asyncio.get_event_loop().run_until_complete(hello())
+asyncio.run(hello())

example/unix_server.py

@@ -15,8 +15,9 @@ async def hello(websocket, path):
     await websocket.send(greeting)
     print(f"> {greeting}")
 
-socket_path = os.path.join(os.path.dirname(__file__), "socket")
-start_server = websockets.unix_serve(hello, socket_path)
+async def main():
+    socket_path = os.path.join(os.path.dirname(__file__), "socket")
+    async with websockets.unix_serve(hello, socket_path):
+        await asyncio.Future()  # run forever
 
-asyncio.get_event_loop().run_until_complete(start_server)
-asyncio.get_event_loop().run_forever()
+asyncio.run(main)

performance/mem_client.py

@@ -43,7 +43,7 @@ async def mem_client(client):
         await asyncio.sleep(CLIENTS * INTERVAL)
 
 
-asyncio.get_event_loop().run_until_complete(
+asyncio.run(
     asyncio.gather(*[mem_client(client) for client in range(CLIENTS + 1)])
 )
 

performance/mem_server.py

@@ -31,7 +31,11 @@ async def handler(ws, path):
     await asyncio.sleep(CLIENTS * INTERVAL)
 
 
-async def mem_server(stop):
+async def mem_server():
+    loop = asyncio.get_running_loop()
+    stop = loop.create_future()
+    # Set the stop condition when receiving SIGTERM.
+    loop.add_signal_handler(signal.SIGTERM, stop.set_result, None)
     async with websockets.serve(
         handler,
         "localhost",
@@ -44,19 +48,14 @@ async def mem_server(stop):
             )
         ],
     ):
+        tracemalloc.start()
         await stop
 
 
-loop = asyncio.get_event_loop()
+asyncio.run(mem_server())
 
-stop = loop.create_future()
-loop.add_signal_handler(signal.SIGINT, stop.set_result, None)
 
-tracemalloc.start()
-
-loop.run_until_complete(mem_server(stop))
-
-# First connection incurs non-representative setup costs.
+# First connection may incur non-representative setup costs.
 del MEM_SIZE[0]
 
 print(f"µ = {statistics.mean(MEM_SIZE) / 1024:.1f} KiB")