Re: zmailer - memory leaks

[Scott Schwartz <schwartz@groucho.cse.psu.edu>]

| For leaks, again, Purify is the best I know of. 

Granted it is very well engineered.  But if you haven't got it...

| gc_malloc can be fooled in many ways -- it's
| conservative failure mode is essential for the allocation/free function,
| but is not what you want for leak detection.  

As I said before, you can compile it with an option to report leaks rather
than reclaiming them.  As far as I can tell, that's how purify finds leaks
too.

| It also falls down if the
| program being checked has its own layers on top of malloc/free, as
| Zmailer does.  (I haven't looked at gc_malloc since 1988, it may well
| have improved since then)

I don't know about "falls down".  Whenever a garbage collection is triggered,
it runs around and finds unreferenced memory.  On a sparc it uses non-
portable stack grubbing to make stack traces. 

If you should happen to try it out, please let me know. You've
obviously put some work into thinking about these issues, and
I'd like to hear what you think about how Boehm's code compares with
the others.