I'm working on a Unity project, and dealing with WebGL plugin, which is called "jslib" by Unity.
While the unity recommend using UnitySendMessage when jslib interactive with c#, I prefer using a delegate as callback. In a small test code it worked. But when It runs to a trigger event code, strange error happens.
c#:
public class Test : MonoBehaviour {
public void Start()
{
UserLoginDispatcher.GetInstance ().onLoginOver += onLoginOver;
}
public void OnDestroy()
{
UserLoginDispatcher.GetInstance ().onLoginOver -= onLoginOver;
}
//[MonoPInvokeCallback(typeof(System.Action<string, string, SDKError>))]
public static void onLoginOver(string context, string pluginId, SDKError err)
{
string errmsg = err == null ? "" : err.errmsg;
LogFormat ("Login Over with context " + context + ", pluginId " + pluginId + ", errmsg:" + errmsg);
}
static void LogFormat(string format, params object[] param)
{
string log = string.Format (format, param);
Debug.Log (log);
}
}
public class UserLoginDispatcher {
private static UserLoginDispatcher s_Instance = new UserLoginDispatcher ();
public static UserLoginDispatcher GetInstance()
{
return s_Instance;
}
public delegate void UserLoginCallback(string context, string pluginId, SDKError error);
public event UserLoginCallback onLoginOver;
public void ProcessLoginOver(string context, string pluginId, SDKError error)
{
onLoginOver (context, pluginId, error);
}
}
public class WebGLPluginManager
{
[DllImport("__Internal")]
private static extern int Plugin_addLoginOverCB (LoginCBDelegate nativeCb);
private delegate void LoginCBDelegate(string context, string pluginId, int errno, int channelerrno, string errmsg);
[MonoPInvokeCallback(typeof(LoginCBDelegate))]
private static void OnLoginOver(string context, string pluginId, int errno, int channelerrno, string errmsg)
{
SDK.GetInstance ().loginDispatcher.ProcessLoginOver (context, pluginId, new SDKError (errno, channelerrno, errmsg));
}
public void Init()
{
Plugin_addLoginOverCB(OnLoginOver);
}
}
In jslib:
...//login succeed:
Runtime.dynCall("viiiii", .....);
While ProcessLoginOver in UserLoginDispatcher is called, the onLoginOver in test throw a error:
Invalid function pointer called with signature 'viiii'. Perhaps this is an invalid value (e.g. caused by calling a virtual method on a NULL pointer)? Or calling a function with an incorrect type, which will fail? (it is worth building your source files with -Werror (warnings are errors), as warnings can indicate undefined behavior which can cause this)
But if I try to call this event directly in c# code, it can be successfully triggered.
The stack of error call:
Uncaught abort(68) at Error
at jsStackTrace (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23794:12)
at stackTrace (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23808:11)
at abort (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:464638:43)
at nullFunc_viiii (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:50912:2)
at Array.b68 (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:455121:2)
at ftCall_viiii (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:6602:49)
at mftCall_viiii (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:732323:2)
at _UserLoginCallback_Invoke_m2599958513 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:533179:4)
at _UserLoginCallback_Invoke_m2599958513 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:533170:14)
at _UserLoginDispatcher_ProcessLoginOver_m2254139378 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:562185:2)
at _WebGLPluginManager_OnLoginOver_m1528063286 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:548824:2)
at Array.asm._WebGLPluginManager_OnLoginOver_m1528063286 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:921460:59)
....
the stack of directly c# call
Login Over with context a test session 12:13:28, pluginId DefaultUserLogin, errmsg:
at __Z13GetStacktracei [GetStacktrace(int)] (blob:http://localhost:60912/6467252d-2f87-4a2c-9967-31868825bff3:2275897:2)
at __Z17DebugStringToFileRK21DebugStringToFileData [DebugStringToFile(DebugStringToFileData const&)] (blob:http://localhost:60912/6467252d-2f87-4a2c-9967-31868825bff3:1247009:5)
at __Z17DebugStringToFilePKciS0_i15LogMessageFlagsiiPFvRK11CppLogEntryE [DebugStringToFile(char const*, int, char const*, int, LogMessageFlags, int, int, void (*)(CppLogEntry const&))] (blob:http://localhost:60912/6467252d-2f87-4a2c-9967-31868825bff3:2562904:2)
at __Z35DebugLogHandler_CUSTOM_Internal_Log7LogTypeP12Il2CppStringP12Il2CppObject [DebugLogHandler_CUSTOM_Internal_Log(LogType, Il2CppString*, Il2CppObject*)] (blob:http://localhost:60912/6467252d-2f87-4a2c-9967-31868825bff3:2126846:2)
at Array.UnityLoader.d9fd6255ccad354c9cc5ad72abf13dcc.asm.__Z35DebugLogHandler_CUSTOM_Internal_Log7LogTypeP12Il2CppStringP12Il2CppObject [DebugLogHandler_CUSTOM_Internal_Log(LogType, Il2CppString*, Il2CppObject*)] (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:145057:93)
at ftCall_viii (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:7197:48)
at mftCall_viii (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:747533:2)
at _DebugLogHandler_Internal_Log_m1116757358 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:719622:2)
at Array._DebugLogHandler_LogFormat_m2613962716 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:620933:2)
at mftCall_viiiiii (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:708880:40)
at __ZN23InterfaceActionInvoker4IiP18Object_t3753624189P8String_tP24ObjectU5BU5D_t2405707486E6InvokeEjP11Il2CppClassP12Il2CppObjectiS1_S3_S5_ [InterfaceActionInvoker4<int, Object_t3753624189*, String_t*, ObjectU5BU5D_t2405707486*>::Invoke(unsigned int, Il2CppClass*, Il2CppObject*, int, Object_t3753624189*, String_t*, ObjectU5BU5D_t2405707486*)] (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:394923:2)
at Array._Logger_Log_m314997607 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:564686:3)
at mftCall_viiii (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:732320:39)
at __ZN23InterfaceActionInvoker2IiP12Il2CppObjectE6InvokeEjP11Il2CppClassS1_iS1_ [InterfaceActionInvoker2<int, Il2CppObject*>::Invoke(unsigned int, Il2CppClass*, Il2CppObject*, int, Il2CppObject*)] (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:412747:2)
at _Debug_Log_m2324883804 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:619913:2)
at _Test_LogFormat_m983122927 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:579589:2)
at Array._Test_onLoginOver_m2512123873 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:383768:2)
at mftCall_viiiii (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:720078:40)
at _UserLoginCallback_Invoke_m2599958513 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:533182:4)
at _UserLoginDispatcher_ProcessLoginOver_m2254139378 (eval at loadDynamicLibrary (blob:http://localhost:60912/134eecaa-92a2-4615-b5b2-0a2ab6d2ed73:23235:19), <anonymous>:562185:2)
....
I noticed that in direct c# call, the dynCall is using mftCall_viiiii, while in jslib call, the dynCall is using mftCall_viiii, may be that's why the function call failed. That's odd, why would this happen?
Fixed it by myself!
In fact that is my little mistake: I just forget to initialize loginDispatcher, so this ptr is 0 when enter loginDispatcher, then the behaviour is very confusing.
The code did not throw any exception when "this" is a 0, because it is translated from c code. It continue to run, till the event Invoke function , at last the function table don't have this function and complained, so I see the very confusing error report!
ps: c# delegate in asm.js act as follow: If this ptr is 0, the delegate is treated as a static function ,if this ptr is not 0, the delegate is treated as a member function. That's why when this ptr is 0, mftCall_viiii is called instead of mftCall_viiiii