Incorrect checksum for freed object?

Ruby Apps Ferret
#1

I’m using ferret (0.9.4) in rails, but outside of the “acts_as_ferret”
plugin. Whenever I use a QueryFilter (even a very simple one), the
server
will crash after one, two, or three reloads of a page (same page, same
query, same filter). It’s very non-deterministic and I can’t seem to
reproduce it outside of my application environment (I can’t get it to
fail
in my unit tests).

The error always occurs AFTER my controller method returns (not when I
make
the calls). Also, the error does not always look the same. Sometimes
it
ends in a Bus Error, other times a Segmentation Fault, but always
“incorrect
checksum for freed object”.

This started when I migrated to 0.9.4 from 0.3.2

Thoughts?

Thanks,
Shad

ruby(1895,0xa000ed98) malloc: *** error for object 0x266b1f0: incorrect
checksum for freed object - object was probably modified after being
freed,
break at szone_error to debug
ruby(1895,0xa000ed98) malloc: *** set a breakpoint in szone_error to
debug
ruby(1895,0xa000ed98) malloc: *** error for object 0x266ace0: incorrect
checksum for freed object - object was probably modified after being
freed,
break at szone_error to debug
ruby(1895,0xa000ed98) malloc: *** set a breakpoint in szone_error to
debug
/usr/lib/ruby/1.8/timeout.rb:40: [BUG] Segmentation fault
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]

Abort trap

ruby(1883,0xa000ed98) malloc: *** error for object 0x2198160: incorrect
checksum for freed object - object was probably modified after being
freed,
break at szone_error to debug
ruby(1883,0xa000ed98) malloc: *** set a breakpoint in szone_error to
debug
/usr/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/webrick_server.rb:148: [BUG]
Bus
Error
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]

Abort trap

#2

I’ve just done some more testing and I’m getting odd behaviour. It
appears there’s some sort of odd race condition. The following code
runs on my machine perfectly (powerbook g4):

def test_index
options = {:dir=>Ferret::Store::FSDirectory.new( $index_dir, false
), :auto_flush=>true}
idx = Ferret::Index::Index.new( options )
begin
query = Ferret::Search::BooleanQuery.new
query.add_query Ferret::Search::TermQuery.new(
Ferret::Index::Term.new( “name”, “type”) )
filter = Ferret::Search::QueryFilter.new( query )

  idx.search_each( "name:type", :filter=>filter ) do |doc,score|
    puts idx[doc]["name"]
  end
ensure
  idx.close
end

end

BUT, If I insert an extra line most anywhere (just before the last
“end” for instance) then I get the following error:

ruby(2776) malloc: *** error for object 0x2679330: incorrect checksum
for freed object - object was probably modified after being freed,
break at szone_error to debug
ruby(2776) malloc: *** set a breakpoint in szone_error to debug

I have not modified the logic of this test case AT ALL, I only added
one extra line. Also, this is reproducable.

  • add extra line: fail, fail, fail
  • remove line: works, works, works
  • add extra line: fail, fail

etc.

Not sure what to do at this point, so I will most likely roll back to
the 0.3.2 version I was using before.

Thanks,
Shad