I looked into this on JRuby/JVM last night, and found that they have
recently added a nonstandard API for getting GC notifications as they
happen. And they happen *after* the GC has occurred. They're
informational.

Would be neat to have something standard in Ruby...especially now that
I know we can implement it (on Java 7u4+ anyway).

FWIW, here's a gist I posted last night that implements
GC::Profiler.report entirely in Ruby using the JVM APIs:

https://gist.github.com/3754108

- Charlie

On Fri, Sep 14, 2012 at 9:13 AM, rogerdpack (Roger Pack)
<rogerpack2005 / gmail.com> wrote:
>
> Issue #7022 has been updated by rogerdpack (Roger Pack).
>
>
> hmm...correct me if I'm wrong (I'm trying to maintain the ruby-prof gem here) will the dtrace probes in #2565 help me if I'm running profiling in windows?  Actually if a hook were added for "GC DONE" or the like, I could query using the API at that point, which would probably be enough. Feedbacks?
> ----------------------------------------
> Feature #7022: add event hook for garbage collection
> https://bugs.ruby-lang.org/issues/7022#change-29308
>
> Author: rogerdpack (Roger Pack)
> Status: Open
> Priority: Normal
> Assignee:
> Category:
> Target version:
>
>
> It would be useful for profilers to have more insight into garbage collection.  Feature request: add event hooks for garbage collect start/stop.  For the lazy sweep, start and stop events would also be interesting.
> Thanks.
>
>
> --
> http://bugs.ruby-lang.org/
>