I tried to call an external library which worked in older version of Ruby On Rails with DL, but I couldn't get it working in newer version of Ruby On Rails using fiddle, the error message is "stack level too deep". I tried several new versions of Ruby without success. After some digging, it seems that it works in Ruby script, but not if I use thread, see codes posted below, I suspect that it might be an issue with stack size (when use thread) ? I actually tried to comment out codes to generate newer external library to find out where the crash is, and find that the program crashes at a loop with 20000 loops when computing entries for a 4X20000 matrix. Any advice to fix this? Thanks! Working ruby script: require 'fiddle/import' module Libm extend Fiddle::Importer dlload '/Library/WebServer/smart/lib/libsamplesize.dylib' extern 'long Calculate(long, double, double, char*)' end errmsg = " " puts Libm.Calculate( 1000, 0.2, 0.9, errmsg) Not working in thread: require 'fiddle/import' module Libm extend Fiddle::Importer dlload '/Library/WebServer/smart/lib/libsamplesize.dylib' extern 'long Calculate(long, double, double, char*)' end puts "Started At #{Time.now}" errmsg = " " thr1=Thread.new{ puts Libm.Calculate( 1000, 0.2, 0.9, errmsg)} thr1.join puts "End at #{Time.now}" -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/17ab8be0-571f-42da-83c0-1fbedc9810b2%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.