From 1124706ae43429d8798bf2d1aa010e9b8fe5ef49 Mon Sep 17 00:00:00 2001
From: Stefan Agner <stefan@agner.ch>
Date: Thu, 28 Mar 2024 00:18:16 +0100
Subject: [PATCH] [Python] Implement asyncio variant of CallAsync

Call Matter SDK in a asyncio friendly way. During posting of the task
onto the CHIP mainloop, it makes sure that the asyncio loop is not
blocked.
---
 src/controller/python/chip/ChipStack.py | 44 +++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/src/controller/python/chip/ChipStack.py b/src/controller/python/chip/ChipStack.py
index 6c0eb4dc1409ea..b6d29257f08162 100644
--- a/src/controller/python/chip/ChipStack.py
+++ b/src/controller/python/chip/ChipStack.py
@@ -26,6 +26,7 @@
 
 from __future__ import absolute_import, print_function
 
+import asyncio
 import builtins
 import logging
 import os
@@ -164,6 +165,31 @@ def Wait(self, timeoutMs: int = None):
             return self._res
 
 
+class AsyncSimpleCallableHandle:
+    """Class which handles Matter SDK Calls asyncio friendly"""
+
+    def __init__(self, callback, loop, future):
+        self._callback = callback
+        self._loop = loop
+        self._future = future
+        self._result = None
+        self._exception = None
+
+    def _done(self):
+        if self._exception:
+            self._future.set_exception(self._exception)
+        else:
+            self._future.set_result(self._result)
+
+    def __call__(self):
+        try:
+            self._result = self._callback()
+        except Exception as ex:
+            self._exception = ex
+        self._loop.call_soon_threadsafe(self._done)
+        pythonapi.Py_DecRef(py_object(self))
+
+
 _CompleteFunct = CFUNCTYPE(None, c_void_p, c_void_p)
 _ErrorFunct = CFUNCTYPE(None, c_void_p, c_void_p,
                         c_ulong, POINTER(DeviceStatusStruct))
@@ -367,6 +393,24 @@ def Call(self, callFunct, timeoutMs: int = None):
             return self.callbackRes
         return res
 
+    async def CallAsync(self, callFunct, timeoutMs: int = None):
+        '''Run a Python function on CHIP stack, and wait for the response.
+        This function will post a task on CHIP mainloop and waits for the call response in a asyncio friendly manner.
+        '''
+        loop = asyncio.get_event_loop()
+        future = loop.create_future()
+        callObj = AsyncSimpleCallableHandle(callFunct, loop, future)
+        pythonapi.Py_IncRef(py_object(callObj))
+
+        res = self._ChipStackLib.pychip_DeviceController_PostTaskOnChipThread(
+            self.cbHandleChipThreadRun, py_object(callObj))
+
+        if not res.is_success:
+            pythonapi.Py_DecRef(py_object(callObj))
+            raise res.to_exception()
+
+        return await asyncio.wait_for(future, timeoutMs / 1000 if timeoutMs else None)
+
     def CallAsyncWithCallback(self, callFunct):
         '''Run a Python function on CHIP stack, and wait for the application specific response.
         This function is a wrapper of PostTaskOnChipThread, which includes some handling of application specific logics.