fix(multiprocess_predictor): dont block main process when running inf…

…erence

src/nrtk_explorer/app/images/annotations.py

@@ -75,7 +75,7 @@ async def get_annotations(
         )
 
         to_detect = {id: id_to_image[id] for id in misses}
-        predictions = predictor.infer(to_detect)
+        predictions = await predictor.infer(to_detect)
         for id, annotations in predictions.items():
             self.cache.add_item(
                 id, annotations, self.add_to_cache_callback, self.delete_from_cache_callback

src/nrtk_explorer/library/multiprocess_predictor.py

@@ -1,4 +1,5 @@
 import multiprocessing
+import asyncio
 import signal
 import threading
 import logging
@@ -8,6 +9,7 @@
 
 
 def _child_worker(request_queue, result_queue, model_name, force_cpu):
+    signal.signal(signal.SIGINT, signal.SIG_IGN)  # Ignore Ctrl+C in child
     logger = logging.getLogger(__name__)
     predictor = Predictor(model_name=model_name, force_cpu=force_cpu)
 
@@ -105,32 +107,38 @@ def set_model(self, model_name, force_cpu=False):
             )
             return self._wait_for_response(req_id)
 
-    def infer(self, images):
+    async def infer(self, images):
         if not images:
             return {}
         with self._lock:
             req_id = str(uuid.uuid4())
             new_req = {"command": "INFER", "req_id": req_id, "payload": {"images": images}}
             self._request_queue.put(new_req)
 
-        resp = self._wait_for_response(req_id)
+        resp = await self.__wait_for_response(req_id)
         return resp.get("result")
 
-    def reset(self):
-        with self._lock:
-            req_id = str(uuid.uuid4())
-            self._request_queue.put({"command": "RESET", "req_id": req_id})
-            return self._wait_for_response(req_id)
+    async def __wait_for_response(self, req_id):
+        return await asyncio.get_event_loop().run_in_executor(None, self._get_response, req_id, 40)
 
     def _wait_for_response(self, req_id):
+        return self._get_response(req_id, 40)
+
+    def _get_response(self, req_id, timeout=40):
         while True:
             try:
-                r_id, data = self._result_queue.get(timeout=40)
+                r_id, data = self._result_queue.get(timeout=timeout)
             except queue.Empty:
                 raise TimeoutError("No response from worker.")
             if r_id == req_id:
                 return data
 
+    def reset(self):
+        with self._lock:
+            req_id = str(uuid.uuid4())
+            self._request_queue.put({"command": "RESET", "req_id": req_id})
+            return self._wait_for_response(req_id)
+
     def shutdown(self):
         with self._lock:
             try: