use manual python calls instead of pytest

tests/test_averaging.py

@@ -1,14 +1,17 @@
 import asyncio
+import gc
 import random
 import time
+from contextlib import suppress
 
 import numpy as np
+import psutil
 import pytest
 import torch
 
 import hivemind
 import hivemind.averaging.averager
-from conftest import cleanup_children
+from hivemind import MPFuture, get_logger
 from hivemind.averaging.allreduce import AveragingMode
 from hivemind.averaging.key_manager import GroupKeyManager
 from hivemind.averaging.load_balancing import load_balance_peers
@@ -16,6 +19,29 @@ from hivemind.p2p import PeerID
 from hivemind.proto.runtime_pb2 import CompressionType
 from test_utils.dht_swarms import launch_dht_instances
 
+logger = get_logger(__name__)
+
+
+def cleanup_children():
+    yield
+
+    gc.collect()  # Call .__del__() for removed objects
+
+    children = psutil.Process().children(recursive=True)
+    if children:
+        logger.info(f"Cleaning up {len(children)} leftover child processes")
+        for child in children:
+            with suppress(psutil.NoSuchProcess):
+                child.terminate()
+        psutil.wait_procs(children, timeout=1)
+        for child in children:
+            with suppress(psutil.NoSuchProcess):
+                child.kill()
+
+    # Broken code or killing of child processes may leave the MPFuture backend corrupted
+    MPFuture.reset_backend()
+
+
 
 @pytest.mark.forked
 @pytest.mark.asyncio