无法从C函数调用目标C方法

I am using MVC architecture for a GUI application. The model class has some C functions. One of the C functions calls some methods of Objective-C class. I call those methods using an object of that class. The strange thing happening is that methods previously to the an xyz method are called perfectly but when that xyz method is called, that method and the methods after it aren't getting executed. I don't get any errors. So can't figure out what exactly is happening. Any ideas as to what might be the reason for this?I am using MVC architecture for a GUI applicati