From: Alexey Verkhovsky <alex@...>
Date: 2006-01-23T07:45:11+09:00
Subject: Re: Debugging endless loops

Eero Saynatkari wrote:

>>Say, we have a Ruby app going into an endless loop (or perhaps a thread
>>deadlock) mode. Let us further assume that it happens in production and
>>you don't know how to reproduce it anywhere else. How would you debug 
>>this?
>>    
>>
>Can you do ruby -rdebug program.rb instead of running it normally?
>  
>
By the conditions of our imaginary problem, we only reproduce our 
endless loop in the production environment, and -rdebug makes a typical 
Ruby code two orders of magnitude slower, so this wouldn't do.

Florian Groß wrote:
 > This might work and give you a remote debugging back door. I'm just 
not sure if it will survive deadlocks:
 > require 'breakpoint'
...
 > You can then connect to your application with breakpoint_client.

Hi, Florian,
Remote 'breakpointer' might be a workable idea. But when I am in IRB, 
how do I get stack traces for all currently running threads?
Rest assured, I do know where to find 'breakpoint' library - I keep 
telling about it to everyone pissed off or puzzled by the absence of a 
decent debugger in the Ruby world.

Alex