On Jan 14, 4:24 pm, "Joel B. Mohler" <[EMAIL PROTECTED]> wrote:
> Micheal pointed out that a Ctrl+c signal to singular could produce some
> corruption because of an ungraceful termination of singular C++ code.  Now, I
> guess this is obviously true and it occurs to me that it really has nothing
> to do with singular.  So, I tried the following:
> sage: R.<x>=ZZ[]
> sage: f=R([ZZ.random_element(15)*x^i for i in range(10000)])
> .... wait a long time and press Ctrl+c
>
> Sure enough, the memory usage in top slowly climbs and doesn't (always) drop
> back after the Ctrl+c.  I garbage collect:
> sage: import gc
> sage: gc.collect()
> and the memory usage still doesn't go down.  So, I guess the memory is leaked.
> It could be that I'm reading top wrong ... memory columns never seem to make
> sense to me.
>
> Some questions:  Did everyone already know this?

Pretty much. :)  (I've raised the issue more than once, but nobody has
come up with a solution yet.)

> Does anyone care that Ctrl+c
> can leak memory from c/c++ libs?

It's worse than just leaking memory; as far as I know, it's quite
possible that hitting Ctrl-c at the exact wrong time could cause
corruption that would make subsequent computations crash or return
wrong answers.

>  Is the problem somehow worse for singular
> (it's semantics for when functions delete/modify their parameter seem just a
> bit nebulous to me)?

Not that I know of.

> --
> Joel

Carl Witty

--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at http://groups.google.com/group/sage-devel
URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/
-~----------~----~----~----~------~----~------~--~---

Reply via email to