public void RegisterSubclass(Type type) {
TypeInfo typeInfo = type.GetTypeInfo();
if (!typeInfo.IsSubclassOf(typeof(ParseObject))) {
throw new ArgumentException("Cannot register a type that is not a subclass of ParseObject");
}
String className = ObjectSubclassInfo.GetClassName(typeInfo);
try {
// Perform this as a single independent transaction, so we can never get into an
// intermediate state where we *theoretically* register the wrong class due to a
// TOCTTOU bug.
mutex.EnterWriteLock();
ObjectSubclassInfo previousInfo = null;
if (registeredSubclasses.TryGetValue(className, out previousInfo)) {
if (typeInfo.IsAssignableFrom(previousInfo.TypeInfo)) {
// Previous subclass is more specific or equal to the current type, do nothing.
return;
} else if (previousInfo.TypeInfo.IsAssignableFrom(typeInfo)) {
// Previous subclass is parent of new child, fallthrough and actually register
// this class.
/* Do nothing */
} else {
throw new ArgumentException(
"Tried to register both " + previousInfo.TypeInfo.FullName + " and " + typeInfo.FullName +
" as the ParseObject subclass of " + className + ". Cannot determine the right class " +
"to use because neither inherits from the other."
);
}
}
ConstructorInfo constructor = type.FindConstructor();
if (constructor == null) {
throw new ArgumentException("Cannot register a type that does not implement the default constructor!");
}
registeredSubclasses[className] = new ObjectSubclassInfo(type, constructor);
} finally {
mutex.ExitWriteLock();
}
Action toPerform = null;
if (registerActions.TryGetValue(className, out toPerform)) {
toPerform();
}
}
