From 11045f3bbadf892ef583ceb3f5f9ab11f5e734fd Mon Sep 17 00:00:00 2001
From: Dark Dragon <darkdragon-001@web.de>
Date: Fri, 2 Jan 2026 02:01:23 +0100
Subject: [PATCH] Add callback datagram protocol

This avoids the need to create a child class of DatagramProtocol for many use-cases.
This aligns with TCP streams which can be created via asyncio.start_server(client_connected_cb, host, port).
---
 Lib/asyncio/datagrams.py | 76 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 Lib/asyncio/datagrams.py

diff --git a/Lib/asyncio/datagrams.py b/Lib/asyncio/datagrams.py
new file mode 100644
index 00000000000000..57c1c8df62475e
--- /dev/null
+++ b/Lib/asyncio/datagrams.py
@@ -0,0 +1,76 @@
+__all__ = ("CallbackDatagramProtocol", "start_datagram_endpoint")
+
+from . import coroutines
+from . import events
+from . import protocols
+
+
+class CallbackDatagramProtocol(protocols.DatagramProtocol):
+    def __init__(self, datagram_received_cb, error_received_cb, loop):
+        super().__init__()
+        self.transport = None
+        self.datagram_received_cb = datagram_received_cb
+        self.error_received_cb = error_received_cb
+        self._loop = loop
+
+    def connection_made(self, transport):
+        self.transport = transport
+
+    def connection_lost(self, exc):
+        self.transport = None
+
+    def datagram_received(self, data, addr):
+        res = self.datagram_received_cb(addr, data, self.transport)
+        if coroutines.iscoroutine(res):
+
+            def callback(task):
+                if task.cancelled():
+                    self.transport.close()
+                    return
+                exc = task.exception()
+                if exc is not None:
+                    self._loop.call_exception_handler(
+                        {
+                            "message": "Unhandled exception in datagram_received_cb",
+                            "exception": exc,
+                            "transport": self.transport,
+                        }
+                    )
+                    self.transport.close()
+                    return
+
+            self._task = self._loop.create_task(res)
+            self._task.add_done_callback(callback)
+
+    def error_received(self, exc):
+        res = self.error_received_cb(exc, self.transport)
+        if coroutines.iscoroutine(res):
+
+            def callback(task):
+                if task.cancelled():
+                    self.transport.close()
+                    return
+                exc = task.exception()
+                if exc is not None:
+                    self._loop.call_exception_handler(
+                        {
+                            "message": "Unhandled exception in error_received_cb",
+                            "exception": exc,
+                            "transport": self.transport,
+                        }
+                    )
+                    self.transport.close()
+                    return
+
+            self._task = self._loop.create_task(res)
+            self._task.add_done_callback(callback)
+
+
+async def start_datagram_endpoint(datagram_received_cb, error_received_cb, host=None, port=None, **kwds):
+    loop = events.get_running_loop()
+
+    def factory():
+        protocol = CallbackDatagramProtocol(datagram_received_cb, error_received_cb, loop=loop)
+        return protocol
+
+    return await loop.create_datagram_endpoint(factory, local_addr=(host, port), **kwds)