Run change_callback in an asynchronous executor

NEWS.rst

@@ -7,6 +7,7 @@ unreleased
 * Drop ``python-livereload``.
 * Add ``starlette`` and ``uvicorn`` as dependencies.
 * Implement hot reloading via websockets.
+* Run Sphinx rebuilds in an asynchronous executor.
 
 2024.02.04 - 2024-02-04
 -----------------------

sphinx_autobuild/server.py

@@ -2,6 +2,7 @@
 
 import asyncio
 import os
+from concurrent.futures import ProcessPoolExecutor
 from contextlib import AbstractAsyncContextManager, asynccontextmanager
 
 import watchfiles
@@ -50,7 +51,9 @@ async def watch(self) -> None:
             *self.paths,
             watch_filter=lambda _, path: not self.ignore(path),
         ):
-            self.change_callback()
+            with ProcessPoolExecutor() as pool:
+                fut = pool.submit(self.change_callback)
+                await asyncio.wrap_future(fut)
             self.flag.set()
 
     async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None: