Rails Ruby on Rails

Hi, we are experiencing random 'undefined method' errors while creating objects in an heavily threaded environment, here's an example:

caught exception in vendor/lib/ruby/gems/1.8/gems/activerecord-2.3.4/lib/active_record/attribute_method
s.rb:255:in method_missing'

undefined method uuid=' for #<OurObject:0xdef731> ... etc etc

with random I mean very rarely and apparently only once after application startup. In OurObject 'uuid' is the primary key. The code which leads to the exception is the following:

o = new(params)
o.uuid = params['uuid']

We think this might be a race in how method_missing override (in attribute_methods.rb) checks if all attribute methods have been defined before invoking super on ruby's own method_missing.

If we check the define_attribute_methods we see the following:

def define_attribute_methods

return if generated_methods?

...

end

This means that define_attribute_methods returns if any number (even just one out of hunders ) of methods have been added to the @generated_methods instance set for the object columns.

Considering this along with the fact that these are all class methods without mutex protection, is it possible in an heavily threaded environment for two objects of the same class, in separate threads, to invoke define_attribute_methods at the same time making one of the two bailing out prematurely because generated_methods? was satisfied that at least one attribute method was set (by the other thread) ?

This would lead to method_missing skipping this conditional:

if !self.class.generated_methods?

self.class.define_attribute_methods
if self.class.generated_methods.include?(method_name)
  return self.send(method_id, *args, &block)
end

end

...and eventually hitting the super which would cause the exception.

Unfortunately I don't have time to create a test for this.

Thanks