Some Ruby tidbits

Today I watched A Day in the Life of a Ruby Object - Jemma Issroff, which is a very educational video about how Ruby handles memory. It also touches a bit on how GC works in ruby, too.

I learnt from this video:

• If an object needs more memory than a slot in Ruby heap, Ruby allocates memory inside OS heap instead. Therefore, it’s possible that our program uses more memory than what is shown as the memory consumption of a Ruby process.

• The ruby slot size is 16kb, and it can store something like a 23-characters string. If we allocate a bigger object, like 24-characters string, Ruby allocates memory inside OS heap. There is a performance hit in that case.

• We can use ObjectSpace.dump to dump memory information of an object (we need to require objspace before using).

• We can use GC.stat to show GC information