Actually, I think Go is some kind of multi-thraeding (goroutine is only a useful mechanism on the "threads" and can't help to avoid multi-threads difficulties (but this design helps to reduce difficulties)).
> Thus, you would have to traverse the entire linked data structure to transfer ownership of every node. This is O(n) work.
Correct.
> Making things worse, you would have to make sure that the ownership transfer is atomic - no other part of the program should see the data structure in a “partially transferred” state.
Correct. Guild::Channel#transfer_ownership() does it.
Basically, share big linked data with multiple threads is difficult (simply we need to lock every access).
> Another example: Say you initially have a guild with three objects, Foo, Bar and Qux, where Foo and Bar point to Qux. If I transfer ownership of Foo, should Qux be transferred as well?
Foo -> Qux; Bar -> Qux
Yes, Qux also moved. Programmer can know by "exception" when accessing Qux via Bar after transfer.
This "realization" is the key of Guild. On threads, we can't realize that Qux is shared mutable.
Like sub-process, but share many things like bytecodes (ISeq in MRI context), class and module objects (and method tables) and so on. Also we can share immutable objects (deeply frozen objects) like threads.
Quoted from slides:
> GC/Heap
> * Share it. Do stop the world parallel marking- and lazy concurrent sweeping.
> * Synchronize only at page acquire timing. No any synchronization at creation time.
This is mistake. I said "I don't think so". 30% is not enough.