Make use of uvloop optional

sanic/app.py

@@ -73,7 +73,7 @@ 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
+from sanic.server import serve, serve_multiple, serve_single, use_uvloop
 from sanic.server.protocols.websocket_protocol import WebSocketProtocol
 from sanic.server.websockets.impl import ConnectionClosed
 from sanic.signals import Signal, SignalRouter
@@ -206,6 +206,9 @@ class Sanic(BaseSanic, metaclass=TouchUpMeta):
         if self.config.REGISTER:
             self.__class__.register_app(self)
 
+        if self.config.USE_UVLOOP:
+            use_uvloop()
+
         self.router.ctx.app = self
         self.signal_router.ctx.app = self
 

sanic/config.py

@@ -36,6 +36,7 @@ DEFAULT_CONFIG = {
     "REQUEST_MAX_SIZE": 100000000,  # 100 megabytes
     "REQUEST_TIMEOUT": 60,  # 60 seconds
     "RESPONSE_TIMEOUT": 60,  # 60 seconds
+    "USE_UVLOOP": True,
     "WEBSOCKET_MAX_SIZE": 2 ** 20,  # 1 megabyte
     "WEBSOCKET_PING_INTERVAL": 20,
     "WEBSOCKET_PING_TIMEOUT": 20,
@@ -61,6 +62,7 @@ class Config(dict):
     REQUEST_TIMEOUT: int
     RESPONSE_TIMEOUT: int
     SERVER_NAME: str
+    USE_UVLOOP: bool
     WEBSOCKET_MAX_SIZE: int
     WEBSOCKET_PING_INTERVAL: int
     WEBSOCKET_PING_TIMEOUT: int

sanic/server/__init__.py

@@ -6,13 +6,18 @@ from sanic.server.protocols.http_protocol import HttpProtocol
 from sanic.server.runners import serve, serve_multiple, serve_single
 
 
-try:
-    import uvloop  # type: ignore
+def use_uvloop():
+    """
+    Use uvloop (if available) instead of the default
+    asyncio loop.
+    """
+    try:
+        import uvloop  # type: ignore
 
-    if not isinstance(asyncio.get_event_loop_policy(), uvloop.EventLoopPolicy):
-        asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())
-except ImportError:
-    pass
+        if not isinstance(asyncio.get_event_loop_policy(), uvloop.EventLoopPolicy):
+            asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())
+    except ImportError:
+        pass
 
 
 __all__ = (