From: Paul Brannan <pbrannan@...>
Date: 2002-08-10T01:33:35+09:00
Subject: Re: Are All C Destructors Guaranteed to Be Called?

On Fri, Aug 09, 2002 at 11:24:27PM +0900, William Djaja Tjokroaminata wrote:
> Are all C destructors, i.e., the "free" function that is specified in
> Data_Make_Struct (VALUE, c-type, mark, "free", c-type*), guaranteed to be
> called when the Ruby script/process exits?

They get called when the object needs to be destroyed.  I think all
objects are supposed to be destroyed at exit.

> I put "printf" on all the "free" functions, and one of them did not get
> called.  Is it a sign that something is still not clean?  How about
> circular reference (I think I have one in my code)?  Will circular
> reference cause the free function not called at the end of the
> script/process?

1) Can you reproduce this behavior in a small test case?
2) Ruby uses mark/sweep instead of reference counting, so circular
   references won't cause an object to not get GC'd.  What *can* happen
   is that an object doesn't get destroyed because someone is keeping a
   reference who is not supposed to be keeping a reference, but both
   objects should be destroyed at exit.

Paul