Kurt Stephens

This patch reduces the stack buffer memory footprint of dead Threads as early as possible, rather than waiting until the Thread can be GCed.

This is applicable only to the zero-copy context switch patch.

http://code.google.com/p/rubyenterpriseedition/issues/detail?id=57

http://blog.phusion.nl/2011/02/12/ruby-enterprise-edition-1-8-7-2011-01-...

Simple patch for C WeakRefs in MRI 1.9.
Should be portable to MRI 1.8.

http://redmine.ruby-lang.org/issues/show/4168

https://github.com/kstephens/ruby/commit/0942a955c649c39d3be4db13dbfb0ba...

Type tags in MRI Ruby VALUE

Internally, values in MRI Ruby are 32-bit (at least for 32-bit processors). Some of the least-significant bits are used to store type information. See the VALUE definition in include/ruby/ruby.h. Using type tag bits avoids allocating additional memory for commonly-used immutable values, like integers.

Ruby uses a single-bit tag of 0x01 as the Fixnum type tag. The remaining bits, are used to store the Fixnum’s signed value. This is an immediate value; it doesn’t require storage for the Fixnum value to be allocated, unlike the heap space that would be required for a String. Other types will use different tag bits.