Fix weakref bound method

Author: thewhaleking

async_substrate_interface/utils/cache.py

@@ -423,11 +423,15 @@ async def __call__(self, *args: Any, **kwargs: Any) -> Any:
 class _WeakMethod:
     """
     Weak reference to a bound method that allows the instance to be garbage collected.
+    Preserves the method's signature for introspection.
     """
 
     def __init__(self, method):
         self._func = method.__func__
         self._instance_ref = weakref.ref(method.__self__)
+        # Store the bound method's signature (without 'self') for inspect.signature() to find.
+        # We capture this once at creation time to avoid holding references to the bound method.
+        self.__signature__ = inspect.signature(method)
 
     def __call__(self, *args, **kwargs):
         instance = self._instance_ref()

tests/unit_tests/asyncio_/test_substrate_interface.py

@@ -147,6 +147,10 @@ async def test_runtime_switching():
 
 @pytest.mark.asyncio
 async def test_memory_leak():
+    import gc
+
+    # Stop any existing tracemalloc and start fresh
+    tracemalloc.stop()
     tracemalloc.start()
     two_mb = 2 * 1024 * 1024
 
@@ -160,6 +164,7 @@ async def test_memory_leak():
     for i in range(5):
         subtensor = await get_async_substrate_interface(LATENT_LITE_ENTRYPOINT)
         await subtensor.close()
+        gc.collect()
 
         snapshot = tracemalloc.take_snapshot()
         stats = snapshot.compare_to(baseline_snapshot, "lineno")

tests/unit_tests/sync/test_substrate_interface.py

@@ -94,6 +94,10 @@ def test_runtime_switching():
 
 
 def test_memory_leak():
+    import gc
+
+    # Stop any existing tracemalloc and start fresh
+    tracemalloc.stop()
     tracemalloc.start()
     two_mb = 2 * 1024 * 1024
 
@@ -107,6 +111,7 @@ def test_memory_leak():
     for i in range(5):
         subtensor = SubstrateInterface(LATENT_LITE_ENTRYPOINT)
         subtensor.close()
+        gc.collect()
 
         snapshot = tracemalloc.take_snapshot()
         stats = snapshot.compare_to(baseline_snapshot, "lineno")