Move uvloop setup method to its own file

sanic/app.py

@@ -84,7 +84,7 @@ from sanic.response import BaseHTTPResponse, HTTPResponse
 from sanic.router import Router
 from sanic.server import AsyncioServer, HttpProtocol
 from sanic.server import Signal as ServerSignal
-from sanic.server import serve, serve_multiple, serve_single, use_uvloop
+from sanic.server import serve, serve_multiple, serve_single, try_use_uvloop
 from sanic.server.protocols.websocket_protocol import WebSocketProtocol
 from sanic.server.websockets.impl import ConnectionClosed
 from sanic.signals import Signal, SignalRouter
@@ -1103,7 +1103,7 @@ class Sanic(BaseSanic, metaclass=TouchUpMeta):
         )
 
         if self.config.USE_UVLOOP:
-            use_uvloop()
+            try_use_uvloop()
 
         try:
             self.is_running = True

sanic/server/__init__.py

@@ -1,49 +1,10 @@
-import asyncio
-import os
-
-from distutils.util import strtobool
-
-from sanic.compat import OS_IS_WINDOWS
-from sanic.log import error_logger
 from sanic.models.server_types import ConnInfo, Signal
 from sanic.server.async_server import AsyncioServer
+from sanic.server.loop import try_use_uvloop
 from sanic.server.protocols.http_protocol import HttpProtocol
 from sanic.server.runners import serve, serve_multiple, serve_single
 
 
-def use_uvloop() -> None:
-    """
-    Use uvloop instead of the default asyncio loop.
-    """
-    try:
-        import uvloop  # type: ignore
-
-        if strtobool(os.environ.get("SANIC_NO_UVLOOP", "no")):
-            error_logger.warning(
-                "You are running Sanic using uvloop, but the "
-                "'SANIC_NO_UVLOOP' environment variable (used to opt-out "
-                "of installing uvloop with Sanic) is set to true. If you "
-                "want to disable uvloop with Sanic, set the 'USE_UVLOOP' "
-                "configuration value to false."
-            )
-
-        if not isinstance(
-            asyncio.get_event_loop_policy(), uvloop.EventLoopPolicy
-        ):
-            asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())
-
-    except ImportError:
-        if not OS_IS_WINDOWS:
-            error_logger.warning(
-                "You are trying to use uvloop, but uvloop is not "
-                "installed in your system. In order to use uvloop "
-                "you must first install it. Otherwise, you can disable "
-                "uvloop completely by setting the 'USE_UVLOOP' "
-                "configuration value to false. Sanic will now continue "
-                "to run without using uvloop."
-            )
-
-
 __all__ = (
     "AsyncioServer",
     "ConnInfo",
@@ -52,4 +13,5 @@ __all__ = (
     "serve",
     "serve_multiple",
     "serve_single",
+    "try_use_uvloop",
 )

sanic/server/loop.py

@@ -0,0 +1,44 @@
+import asyncio
+import os
+
+from distutils.util import strtobool
+
+from sanic.compat import OS_IS_WINDOWS
+from sanic.log import error_logger
+
+
+def try_use_uvloop() -> None:
+    """
+    Use uvloop instead of the default asyncio loop.
+    """
+    if OS_IS_WINDOWS:  # uvloop is not compatible
+        return
+
+    try:
+        import uvloop  # type: ignore
+    except ImportError:
+        error_logger.warning(
+            "You are trying to use uvloop, but uvloop is not "
+            "installed in your system. In order to use uvloop "
+            "you must first install it. Otherwise, you can disable "
+            "uvloop completely by setting the 'USE_UVLOOP' "
+            "configuration value to false. Sanic will now continue "
+            "to run with the default event loop."
+        )
+        return
+
+    uvloop_install_removed = strtobool(os.environ.get("SANIC_NO_UVLOOP", "no"))
+    if uvloop_install_removed:
+        error_logger.info(
+            "You are requesting to run Sanic using uvloop, but the "
+            "install-time 'SANIC_NO_UVLOOP' environment variable (used to "
+            "opt-out of installing uvloop with Sanic) is set to true. If "
+            "you want to prevent Sanic from overriding the event loop policy "
+            "during runtime, set the 'USE_UVLOOP' configuration value to "
+            "false."
+        )
+
+    if not isinstance(
+        asyncio.get_event_loop_policy(), uvloop.EventLoopPolicy
+    ):
+        asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())

sanic/worker.py

@@ -9,7 +9,7 @@ from gunicorn.workers import base  # type: ignore
 
 from sanic.compat import UVLOOP_INSTALLED
 from sanic.log import logger
-from sanic.server import HttpProtocol, Signal, serve, use_uvloop
+from sanic.server import HttpProtocol, Signal, serve, try_use_uvloop
 from sanic.server.protocols.websocket_protocol import WebSocketProtocol
 
 
@@ -19,7 +19,7 @@ except ImportError:
     ssl = None  # type: ignore
 
 if UVLOOP_INSTALLED:
-    use_uvloop()
+    try_use_uvloop()
 
 
 class GunicornWorker(base.Worker):