Simpler connection ownership

Replaced one extra ref with boxedcall owning the
connection always, ensuring it is closed unless
tp_init is successful

Author: rogerbinns

apsw/tests/aiotest.py

@@ -109,7 +109,9 @@ def hook(arg):
                 BC.configure = BC.configure1
                 BC.close = BC.close1
                 self.assertRaisesRegex(RuntimeError, ".*only be called once.*", apsw.Connection.as_async, "")
-                apsw.connections()[0].close()
+                # we can't guarantee exactly when gc runs for the failure above
+                if apsw.connections():
+                    apsw.connections()[0].close()
                 self.assertIs(unraised.exc_type, ZeroDivisionError)
                 unraised = None
         finally:

src/async.c

@@ -31,7 +31,6 @@ typedef struct BoxedCall
       PyObject *connection;
       PyObject *args;
       PyObject *kwargs;
-      int call_success;
     } ConnectionInit;
 
     /* note this must be the largest member of the union because
@@ -79,16 +78,9 @@ BoxedCall_clear(PyObject *self_)
     return;
 
   case ConnectionInit:
-    Py_DECREF(self->ConnectionInit.connection);
     Py_DECREF(self->ConnectionInit.args);
     Py_XDECREF(self->ConnectionInit.kwargs);
-    if (!self->ConnectionInit.call_success)
-    {
-      /* this causes close on init failure so threads don't get leaked
-         because our original code in as_async can't know about
-         downstream failures  */
-      Py_DECREF(self->ConnectionInit.connection);
-    }
+    Py_DECREF(self->ConnectionInit.connection);
     break;
 
   case FastCallWithKeywords: {
@@ -143,11 +135,8 @@ BoxedCall_internal_call(BoxedCall *self)
       if (0
           == Py_TYPE(self->ConnectionInit.connection)
                  ->tp_init(self->ConnectionInit.connection, self->ConnectionInit.args, self->ConnectionInit.kwargs))
-      {
         result = Py_NewRef(self->ConnectionInit.connection);
-        self->ConnectionInit.call_success = 1;
-      }
-        break;
+      break;
     case FastCallWithKeywords:
       result = self->FastCallWithKeywords.function(
           self->FastCallWithKeywords.object, self->FastCallWithKeywords.fast_args + 1,

src/connection.c

@@ -805,10 +805,10 @@ Connection_as_async(PyObject *klass_, PyObject *args, PyObject *kwargs)
   if (!connection)
     goto error;
   boxed_call->call_type = ConnectionInit;
-  boxed_call->ConnectionInit.connection = Py_NewRef((PyObject *)connection);
+  /* the boxed call now owns the connection */
+  boxed_call->ConnectionInit.connection = ((PyObject *)connection);
   boxed_call->ConnectionInit.args = Py_NewRef(args);
   boxed_call->ConnectionInit.kwargs = Py_XNewRef(kwargs);
-  boxed_call->ConnectionInit.call_success = 0;
   connection->async_controller = NULL;
 
   if(!PyContextVar_Get(async_controller_context_var, NULL, &connection->async_controller))