[Libguestfs] [PATCH libnbd v2 08/10] python: Hold a refcount to persistent AIO buffer until command completion.

--- generator/generator | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/generator/generator b/generator/generator index 8c055a9..1252bdb 100755 --- a/generator/generator +++ b/generator/generator @@ -4262,6 +4262,20 @@ let print_python_binding name { args; optargs; ret; may_set_error } = | OFlags (n, _) -> pr " %s_u32 = %s;\n" n n ) optargs; + (* If there is a BytesPersistIn/Out parameter then we need to + * increment the refcount and save the pointer into + * completion_callback.user_data so we can decrement the + * refcount on command completion. + *) + List.iter ( + function + | BytesPersistIn (n, _) | BytesPersistOut (n, _) -> + pr " /* Increment refcount since buffer may be saved by libnbd. */\n"; + pr " Py_INCREF (%s);\n" n; + pr " completion_user_data->buf = %s;\n" n; + | _ -> () + ) args; + (* Call the underlying C function. *) pr " ret = nbd_%s (h" name; List.iter ( @@ -4389,7 +4403,8 @@ let generate_python_methods_c () = pr " * and freed in the free_user_data function below.\n"; pr " */\n"; pr "struct user_data {\n"; - pr " PyObject *fn; /* Pointer to Python function. */\n"; + pr " PyObject *fn; /* Optional pointer to Python function. */\n"; + pr " PyObject *buf; /* Optional pointer to persistent buffer. */\n"; pr "};\n"; pr "\n"; pr "static struct user_data *\n"; @@ -4408,7 +4423,10 @@ let generate_python_methods_c () = pr "{\n"; pr " struct user_data *data = user_data;\n"; pr "\n"; - pr " Py_DECREF (data->fn);\n"; + pr " if (data->fn != NULL)\n"; + pr " Py_DECREF (data->fn);\n"; + pr " if (data->buf != NULL)\n"; + pr " Py_DECREF (data->buf);\n"; pr " free (data);\n"; pr "}\n"; pr "\n"; -- 2.22.0