Added simple poll example with asyncio

Author: michalpokusa

docs/examples.rst

@@ -88,6 +88,18 @@ a running total of the last 10 samples.
     :emphasize-lines: 29,38
     :linenos:
 
+
+If you need to perform some action periodically, or there are multiple tasks that need to be done,
+it might be better to use ``asyncio`` module to handle them, which makes it really easy to add new tasks
+without needing to manually manage the timing of each task.
+
+``asyncio`` **is not included in CircuitPython by default, it has to be installed separately.**
+
+.. literalinclude:: ../examples/httpserver_start_and_poll_asyncio.py
+    :caption: examples/httpserver_start_and_poll_asyncio.py
+    :emphasize-lines: 5,33,42,45,50,55-62
+    :linenos:
+
 Server with MDNS
 ----------------
 

examples/httpserver_start_and_poll_asyncio.py

@@ -0,0 +1,62 @@
+# SPDX-FileCopyrightText: 2023 Michał Pokusa
+#
+# SPDX-License-Identifier: Unlicense
+
+from asyncio import create_task, gather, run, sleep as async_sleep
+import socketpool
+import wifi
+
+from adafruit_httpserver import (
+    Server,
+    REQUEST_HANDLED_RESPONSE_SENT,
+    Request,
+    FileResponse,
+)
+
+
+pool = socketpool.SocketPool(wifi.radio)
+server = Server(pool, "/static", debug=True)
+
+
+@server.route("/")
+def base(request: Request):
+    """
+    Serve the default index.html file.
+    """
+    return FileResponse(request, "index.html")
+
+
+# Start the server.
+server.start(str(wifi.radio.ipv4_address))
+
+
+async def handle_http_requests():
+    while True:
+        # Process any waiting requests
+        pool_result = server.poll()
+
+        if pool_result == REQUEST_HANDLED_RESPONSE_SENT:
+            # Do something only after handling a request
+            pass
+
+        await async_sleep(0)
+
+
+async def do_something_useful():
+    while True:
+        # Do something useful in this section,
+        # for example read a sensor and capture an average,
+        # or a running total of the last 10 samples
+        await async_sleep(1)
+
+        # If you want you can stop the server by calling server.stop() anywhere in your code
+
+
+async def main():
+    await gather(
+        create_task(handle_http_requests()),
+        create_task(do_something_useful()),
+    )
+
+
+run(main())