fixed refcount leakage when unboxing from cache

rpyc/core/netref.py

@@ -10,7 +10,7 @@
 
 
 _local_netref_attrs = frozenset([
-    '____conn__', '____oid__', '__class__', '__cmp__', '__del__', '__delattr__',
+    '____conn__', '____oid__', '____refcount__', '__class__', '__cmp__', '__del__', '__delattr__',
     '__dir__', '__doc__', '__getattr__', '__getattribute__', '__hash__',
     '__init__', '__metaclass__', '__module__', '__new__', '__reduce__',
     '__reduce_ex__', '__repr__', '__setattr__', '__slots__', '__str__',
@@ -116,18 +116,20 @@ class BaseNetref(object):
     """
     # this is okay with py3k -- see below
     __metaclass__ = NetrefMetaclass
-    __slots__ = ["____conn__", "____oid__", "__weakref__"]
+    __slots__ = ["____conn__", "____oid__", "__weakref__", "____refcount__"]
     def __init__(self, conn, oid):
         self.____conn__ = conn
         self.____oid__ = oid
+        self.____refcount__ = 1
     def __del__(self):
-        try:
-            asyncreq(self, consts.HANDLE_DEL)
-        except Exception:
-            # raised in a destructor, most likely on program termination,
-            # when the connection might have already been closed.
-            # it's safe to ignore all exceptions here
-            pass
+        for _ in xrange(self.____refcount__):
+            try:
+                asyncreq(self, consts.HANDLE_DEL)
+            except Exception:
+                # raised in a destructor, most likely on program termination,
+                # when the connection might have already been closed.
+                # it's safe to ignore all exceptions here
+                pass
 
     def __getattribute__(self, name):
         if name in _local_netref_attrs:

rpyc/core/protocol.py

@@ -298,7 +298,11 @@ def _unbox(self, package):
         if label == consts.LABEL_REMOTE_REF:
             oid, clsname, modname = value
             if oid in self._proxy_cache:
-                return self._proxy_cache[oid]
+                proxy = self._proxy_cache[oid]
+                proxy.____refcount__ += 1  # other side increased refcount on boxing,
+                                           # if I'm returning from cache instead of new object,
+                                           # must increase refcount to match
+                return proxy
             proxy = self._netref_factory(oid, clsname, modname)
             self._proxy_cache[oid] = proxy
             return proxy