On Mon, Oct 12, 2009 at 10:15 PM, Oleg G. <ojo...@gmail.com> wrote:
>
> After reading Naftoli's post i checked the way inner object laziness
> is implemented. And it appears to be not thread safe.
>
It is not threadsafe. This is a known defect and is supposed to be
addressed in 2.8. But, the cost of a failure is dual initialization of the
field.
> Following code:
>
> class A { val a = 1 }
> class B { object b extends A }
>
> Generates getter for b as follows:
>
> public final B$b$ b();
> Code:
> 0: aload_0
> 1: getfield #18; //Field b$module:LB$b$;
> 4: ifnonnull 19
> 7: aload_0
> 8: new #20; //class B$b$
> 11: dup
> 12: aload_0
> 13: invokespecial #23; //Method B$b$."<init>":(LB;)V
> 16: putfield #18; //Field b$module:LB$b$;
> 19: aload_0
> 20: getfield #18; //Field b$module:LB$b$;
> 23: areturn
>
> Looks like its not synchronized? I also looked at lazy vals generated
> code (when i was thinking on val based Records) and dropped the idea
> because of synchronization for every single access to a field.
>
That's not the case. There's only a synchronization if the initial
non-synchronized test fails.
> >
>
--
Lift, the simply functional web framework http://liftweb.net
Beginning Scala http://www.apress.com/book/view/1430219890
Follow me: http://twitter.com/dpp
Surf the harmonics
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Lift" group.
To post to this group, send email to liftweb@googlegroups.com
To unsubscribe from this group, send email to
liftweb+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/liftweb?hl=en
-~----------~----~----~----~------~----~------~--~---
