[tsuyoshi]

Anyone who has written an extension to a garbage-collected language in C will have run into this issue. Personally I've written extensions for Guile, OCaml, Ruby, MLton, and Java, and all of them have tricky rules for making your C code safe for garbage collection. Using volatile is the wrong way to do this though... this tells me that the people figuring this stuff out for Ruby don't really know C that well.