From 4cbaa23f1f4a3510176a1f38489834203f71b2b6 Mon Sep 17 00:00:00 2001 From: Sebastian Keller Date: Thu, 16 Mar 2023 22:35:49 +0100 Subject: [PATCH] function: Always initialize callback return value When callback_closure() exits early, for example due to being called during GC, the return value would not be initialized. This value is often non-zero. If the callback is a source func of an idle or a timeout this would then get interpreted as G_SOURCE_CONTINUE and the same would repeat in the next iteration. If this happens fast enough, this results in the entire process being seemingly frozen while spamming the log with error messages. To fix this always initialize the return value to 0 or a comparable neutral value. Related: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/1868 --- gi/function.cpp | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/gi/function.cpp b/gi/function.cpp index 7c0064c8..5d69ed8a 100644 --- a/gi/function.cpp +++ b/gi/function.cpp @@ -308,6 +308,15 @@ void GjsCallbackTrampoline::callback_closure(GIArgument** args, void* result) { JSContext *context; GITypeInfo ret_type; + g_callable_info_load_return_type(m_info, &ret_type); + + // Fill in the result with some hopefully neutral value + if (g_type_info_get_tag(&ret_type) != GI_TYPE_TAG_VOID) { + GIArgument argument = {}; + gjs_gi_argument_init_default(&ret_type, &argument); + set_return_ffi_arg_from_giargument(&ret_type, result, &argument); + } + if (G_UNLIKELY(!gjs_closure_is_valid(m_js_function))) { warn_about_illegal_js_callback( "during shutdown", @@ -382,7 +391,6 @@ void GjsCallbackTrampoline::callback_closure(GIArgument** args, void* result) { JS::RootedValue rval(context); - g_callable_info_load_return_type(m_info, &ret_type); GIArgument* error_argument = nullptr; if (g_callable_info_can_throw_gerror(m_info)) @@ -406,14 +414,6 @@ void GjsCallbackTrampoline::callback_closure(GIArgument** args, void* result) { m_info.ns(), m_info.name()); } - // Fill in the result with some hopefully neutral value - if (g_type_info_get_tag(&ret_type) != GI_TYPE_TAG_VOID) { - GIArgument argument = {}; - g_callable_info_load_return_type(m_info, &ret_type); - gjs_gi_argument_init_default(&ret_type, &argument); - set_return_ffi_arg_from_giargument(&ret_type, result, &argument); - } - // If the callback has a GError** argument and invoking the closure // returned an error, try to make a GError from it if (error_argument && rval.isObject()) { -- 2.35.1