Ruby

=begin
= GC design

See attached image.

== Heap data structure

• ObjectSpace can contains several heaps (now, has only `eden')
• A Heap contains pagse.
• A Page contains slots.
• A Slot represents Ruby's object. This is also known as RVALUE.

== GC strategy

=== Conservertive GC

See http://en.wikipedia.org/wiki/Garbage_collection_%28computer_science%29#Precise_vs._conservative_and_internal_pointers

=== RGenGC

• This is a type of generational.
• Can combine with pre-tenuring.

=== Marking technique

• Non-recursive marking
• Bitmap marking

=== Sweeping technique

• Lazy sweeping

=end