From: Mathieu Bouchard <matju@...>
Date: 2001-10-15T17:05:17+09:00
Subject: [ruby-talk:22556] Re: Forcing full GC?

On Mon, 15 Oct 2001, Aristarkh A Zagorodnikov wrote:
> 		Hello!
> 	Is there a way to force GC to reclaim _all_ unused objects
> (disregarding time which it may take). I'm trying to create a
> long-running application (some sort of data server), and it slowly
> increases in size (gets 20 megs from initial 2.9 megs after several
> hours of hard load) while ObjectSpace iterators does not indicate any
> object growth. Quick'n'dirty hacks even at C source level are accepted
> ;))

If there is any moment at which the process size gets at 20 megs, it is
likely that it will stay at that size, unless you have very large
Arrays/Hashes/Strings (usually 128 kilobytes), which get allocated
separately by GLIBC (last time I checked), and thus reduce the process
size.

If the increase is really gradual while the amount of data stays low, this
may indicate a memory-leak in one of the libraries you use.

Or else, there may be an Array or Hash that you store lots of
non-allocated objects in (Fixnum, Symbol), which don't show up in
ObjectSpace. You may try something like this:

ObjectSpace.each_object {|x|
	case x when Array,Hash,String
		puts "#{x.id} length=#{x.length}" if x.length > 1000
	end
}

However, if a large array loses elements, it seems that its capacity
shrinks (to length*2) only when length*10<capacity; i don't know about the
others.

________________________________________________________________
Mathieu Bouchard                   http://hostname.2y.net/~matju