[datatable-help] Random segfaults

[Chris Neff]

It is crashing several times an hour for me to the point where this is
unusable. Setting the alloccol option didn't help. Is there a way I
can go back to the old shallow copy ways of 1.7.3?

2011/12/14 Timothée Carayol <timothee.carayol at gmail.com>:
> Hi --
>
> I have been having many unreproducible bugs with R 2.14, data.table
> 1.7.4 and ubuntu 64 bits about 10 days ago. Data was getting
> corrupted, and then R crashed. I had to go back to data.frame for the
> bits of code affected. I was doing a lot of rather unsafe
> manipulations with row names, rbind and cbinds.
> I didn't file a report, nor signal it, as it was occurring seemingly
> at random, and I was doing operations which aren't really what
> data.table was made for (tons of little manipulations on small data);
> still I guess I should now signal that 2.14 didn't fix everything for
> me. I do not know whether bugs subsist on post-1.7.4 versions.
>
> t
>
> On Wed, Dec 14, 2011 at 5:31 PM, Matthew Dowle <mdowle at mdowle.plus.com> wrote:
>>
>> Maybe, worth a try. Are you loading any data.table objects from disk?
>>
>>> 64 bit 2.12.1 linux.
>>>
>>> Is there an option I can set in my session in order to work around the
>>> truelength issue? I don't care if I lose some of the over-allocation
>>> niceties if it stops things from crashing. Looking at the truelength
>>> help, would just doing:
>>>
>>> options(datatable.alloc=quote(1000))
>>>
>>> stop this? I never have more than about 50 columns at a time.
>>>
>>> On 14 December 2011 11:43, Matthew Dowle <mdowle at mdowle.plus.com> wrote:
>>>>
>>>> You're R < 2.14.0, right?  I'm really struggling in R < 2.14.0 to make
>>>> over-allocation work because R only started to initialize truelength to
>>>> 0
>>>> in R 2.14.0+. Before that it's unitialized (random). Trouble is my
>>>> attempts in R < 2.14.0 to work around that work fine for me in linux
>>>> 32bit
>>>> when I test in R 2.13.2, and I even test in 2.12.0 too. I test on 64bit
>>>> too but just 2.14.0.  CRAN is also showing errors on 2.13.2 (old-rel)
>>>> for
>>>> both mac and windows.
>>>>
>>>> So, this is a pre-2.14.0 (only) problem that I'll continue to try and
>>>> fix.
>>>>
>>>> Are you 64bit pre-2.14.0? Which OS?  If you are 64bit linux then it adds
>>>> weight to me installing pre-2.14.0 on my 64bit instance in an effort to
>>>> reproduce.
>>>>
>>>>
>>>>> This will be a crappy help request because I can't seem to reproduce
>>>>> it, but the past few days I've been getting a lot of segfaults.  The
>>>>> only common thing between every crash is that it happens when I do
>>>>>
>>>>> DT[, z := x]
>>>>>
>>>>> where z was not a column that existed in DT before, and x is either an
>>>>> existing column of DT or a separate variable, doesn't matter.  Beyond
>>>>> that I can't reproduce a set of steps that gets R to crash.  This is
>>>>> with the latest SVN version.
>>>>>
>>>>> Is there more information I can provide to help track this down?
>>>>> _______________________________________________
>>>>> datatable-help mailing list
>>>>> datatable-help at lists.r-forge.r-project.org
>>>>> https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/datatable-help
>>>>>
>>>>
>>>>
>>>
>>
>>
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