Why isn't my Ruby object deleted when the last reference goes out of scope?
- by Andrew Clegg
Hi gurus, I've found a weird effect when trying to track down a memory leak in a Rails app. Can anyone explain what's going on here?
Save this script as a plain Ruby script (Rails not necessary):
class Fnord
def to_s
'fnord'
end
end
def test
f = Fnord.new
end
test
GC.start
sleep 2
ObjectSpace.each_object do |o|
puts o if o.is_a? Fnord
end
When I run this via
ruby 1.8.7 (2009-06-12 patchlevel 174) [i486-linux]
I get the following:
bash $ ruby var_test
fnord
Although the variable f is out of scope, there are no other references to the single Fnord object, and I've garbage collected, the object still seems to exist. Is this a nefarious memory leak of some sort, or am I completely missing something about Ruby?
Further, if I change the test method to this:
def test
f = Fnord.new
f = nil
end
I get no output. But surely this should not change the semantics here?
Many thanks!
