add proper cleanup to test files

Author: keenan-simpson

cuda_core/tests/test_memory.py

@@ -392,6 +392,9 @@ def mempool_child_process(importer, queue):
 
 
 def test_ipc_mempool():
+    # Set multiprocessing start method before creating any multiprocessing objects
+    multiprocessing.set_start_method("spawn", force=True)
+
     device = Device()
     device.set_current()
     stream = device.create_stream()
@@ -427,7 +430,6 @@ def test_ipc_mempool():
             ipc_buffer = mr.export_buffer(buffer)
 
             # Start child process
-            multiprocessing.set_start_method("spawn", force=True)
             process = multiprocessing.Process(target=mempool_child_process, args=(importer, queue))
             process.start()