garu / clone Goto Github PK

malloc(): unaligned tcache chunk detected
[1]    9772 IOT instruction (core dumped)  perl -d:Trace -I./lib ./t/04.message.t

(gdb) where
#0  0x00005555556629e9 in Perl_hfree_next_entry ()
#1  0x000055555568245d in Perl_sv_clear ()
#2  0x0000555555682d02 in Perl_sv_free2 ()
#3  0x00005555556ae6c9 in Perl_leave_scope ()
#4  0x0000555555673adf in Perl_pp_leavesub ()
#5  0x0000555555669fe6 in Perl_runops_standard ()
#6  0x00005555555cbcdc in perl_run ()
#7  0x000055555559f52a in main ()

Please see http://www.perlmonks.org/?node_id=665353 for a description of
a problem that Clone causes when a Class::DBI app runs on mod_perl/Win32
with multiple ThreadsPerChild.

t/dclone.t, t/tied.pl, and t/dump.pl files in Clone-0.39 distribution have this license declaration:

#  You may redistribute only under the terms of the Artistic License,
#  as specified in the README file that comes with the distribution.

README mentions only "the same terms as Perl itself" so I believe you refer to this Artistic License <https://dev.perl.org/licenses/artistic.html>.

My issue is that some distributor do not consider this Artistic license free enough, e.g. Fedora, and cannot distribute these files. Would it be possible for you to change the license for the three files to be the same as the other files as it reads in the README:

This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

I.e. GPL or Artistic?

Hi there! Thank you for submitting this issue and for your patience. While I am the current maintainer of Clone, I was not the author of those files. I'm going to try and contact him to see if we can make a new release with the revised test files. Otherwise, I'm not sure how to proceed (do feel free to advise if you have knowledge on possible legal implications). Finally, as a suggestion, what if the current Fedora package maintainer removes those files from the Fedora Clone package? They are not required for the installation nor the use of Clone.

Thank you!

garu

On Wed Jul 11 09:36:36 2018, ppisar wrote:
> t/dclone.t, t/tied.pl, and t/dump.pl files in Clone-0.39 distribution
> have this license declaration:
> 
> #  You may redistribute only under the terms of the Artistic License,
> #  as specified in the README file that comes with the distribution.
> 
> README mentions only "the same terms as Perl itself" so I believe you
> refer to this Artistic License
> <https://dev.perl.org/licenses/artistic.html>.
> 
> My issue is that some distributor do not consider this Artistic
> license free enough, e.g. Fedora, and cannot distribute these files.
> Would it be possible for you to change the license for the three files
> to be the same as the other files as it reads in the README:
> 
> This module is free software; you can redistribute it and/or
> modify it under the same terms as Perl itself.
> 
> I.e. GPL or Artistic?

Math::BigInt::GMP objects cannot be cloned with Clone.pm:

$ perl5.18.4 -MMath::BigInt=only,GMP -MClone=clone -E 'say clone(Math::BigInt->new(42))->bstr'
failed to fetch mpz pointer at /opt/perl-5.18.4/lib/site_perl/5.18.4/Math/BigInt.pm line 3347.

Storable can deal with it:

$ perl5.18.4 -MMath::BigInt=only,GMP -MStorable=dclone -E 'say dclone(Math::BigInt->new(42))->bstr'
42

However, Storable cannot handle some types Clone can handle (most notably, Regexp).

A solution could be to invent a hook mechanism just as in Storable (STORABLE_freeze and STORABLE_thaw), or even better, re-use the Storable hooks if they are available.

A more simpler solution would be to just document this limitation, and point to other clone modules which may handle this (i.e. Storable).

In this special situation it would be possible to fallback to the pure perl Math::BigInt implementation (using "use Math::BigInt only => 'Calc'"), but this would be a huge performance hit when doing real calculations.

Hi,

I'm trying to use Clone::clone to copy a hash which is shared among threads,
but when the result is accessed, Perl dies with
"Can't locate object method "FETCH" via package "threads::shared::tie" 
at ..."

Here's an example:

Hi Jim,

I don't think Clone is thread-safe. Are you able to reproduce the issue if you use Storable's dclone() instead of Clone's clone()?

Thanks!

On 05/15/2014 03:16 PM, Breno G. de Oliveira via RT wrote:
| I don't think Clone is thread-safe.
| Are you able to reproduce the issue if you use Storable's dclone() 
instead of Clone's clone()?

I'm not familiar with Storable, but gave it a try.   The result of 
dclone() can not be
de-referenced either, but the error is different:

# The next statement crashes with:
# Can't locate object method "FETCH" via package "threads::shared::tie"
print $b->{foo}, "\n";

Unfortunately threads::shared implements the sharing with tie-s to threads::shared::tie, but it makes zero sense to have a clone take part in the sharing -- if you wanted that, you would use the original variable, not the clone... Clone and Storable will (dirtily) have to special case that an remove all tie-s to threads::shared::tie, to be able to cooperate with threads::shared. Note that threads::shared itself has the same problem, you can't send a structure over a Thread::Queue and return the sent object over this or another Threads::Queue, this will crash after one or more iterations (I don't remember).

Ralf

https://rt.perl.org/Public/Bug/Display.html?id=38443

Date:	Mon, 06 Feb 2006 16:43:36 +0100

:)

t/07magic.t ...... 1/10 SV = PVMG(0x150f510) at 0x1361a28
  REFCNT = 1
  FLAGS = (SMG,POK,pPOK,UTF8)
  IV = 0
  NV = 0
  PV = 0x1443290 "a\r\n"\0 [UTF8 "a\r\n"]
  CUR = 3
  LEN = 10
  MAGIC = 0x1491cf0
    MG_VIRTUAL = &PL_vtbl_utf8
    MG_TYPE = PERL_MAGIC_utf8(w)
    MG_LEN = -1
    MG_PTR = 0x140ff40
       0: 2 -> 2
       1: 0 -> 0
SV = PVMG(0x150f570) at 0x14e5758
  REFCNT = 1
  FLAGS = (SMG,POK,pPOK,UTF8)
  IV = 0
  NV = 0
  PV = 0x1490f70 "a\r\n"\0 [UTF8 "a\r\n"]
  CUR = 3
  LEN = 10
  MAGIC = 0xd81d50
    MG_VIRTUAL = &PL_vtbl_utf8
    MG_TYPE = PERL_MAGIC_utf8(w)
    MG_LEN = -1
    MG_PTR = 0x1459110
       0: 2 -> 2
       1: 0 -> 0
t/07magic.t ...... ok    

This comes from the discussion of [rt.cpan.org #97508]:

$ ulimit -s
8192
$ perl -e 'use Clone qw(clone); $t = [$t] for 1..30000; clone $t'
$ perl -e 'use Clone qw(clone); $t = [$t] for 1..40000; clone $t'
Segmentation fault (core dumped)
$ ulimit -s 16348
$ perl -e 'use Clone qw(clone); $t = [$t] for 1..40000; clone $t'
$ perl -e 'use Clone qw(clone); $t = [$t] for 1..60000; clone $t'
$ perl -e 'use Clone qw(clone); $t = [$t] for 1..70000; clone $t'
Segmentation fault (core dumped)
$ dpkg -l perl libclone-perl | grep ii
ii  libclone-perl  0.36-1           amd64  module for recursively copying Perl datatypes
ii  perl           5.18.2-2ubuntu1  amd64  Larry Wall's Practical Extraction and Report Language

The same happens with:
$ perl -e 'use threads; $t = [$t] for 1..30000; (async {})->join'
Segmentation fault (core dumped)
$ perl -e 'use Storable qw(dclone); $t = [$t] for 1..30000; dclone $t'
Segmentation fault (core dumped)

According to this stack trace (generated by stsc) this is a recursion only involving av_clone() and sv_clone() from auto/Clone/Clone.so , which is completely internal to the Clone distribution:

http://perlpunks.de/paste/show/563ba05b.425c.da?plain=1

I would humbly suggest switching from recursion to some explicitly coded iterative traversal (e.g. maintaining an explicit recursion stack in the heap).

Ralf

Hi,

Your very-useful module Clone does not seem to handle weakened refs:
They always clone as undef.

Please run the test script below to see the problem.
(bug observed in Clone version 0.38, the latest in CPAN)

Thanks,
-Jim Avera

P.S. The author email in the source ([email protected]) bounced.

Old package separator "'" deprecated at ./t/dump.pl line 30.

After cloning, my DBI database handles barf with:

Can't call prepare method on handle DBI::db=HASH(0x25755c8) after 
take_imp_data() at ../lib/Radio/Four/Programme.pm line 104.

A DBH is something can't be cloned (at least by Clone) since there are
too many underlying objects like C structures, file handles, etc that
Clone doesn't handle.  

A DBI database handle does have it's own clone method. I have considered
having Clone check an object for a native clone method and using that in
preference of it's own, but I think it might be a little too ambitious
for me.

via RT wrote:
> <URL: http://rt.cpan.org/Ticket/Display.html?id=21328 >
>
> A DBH is something can't be cloned (at least by Clone) since there are
> too many underlying objects like C structures, file handles, etc that
> Clone doesn't handle.  
>
> A DBI database handle does have it's own clone method. I have considered
> having Clone check an object for a native clone method and using that in
> preference of it's own, but I think it might be a little too ambitious
> for me.
>
>   
Having Clone check a blessed reference for a clone method should be 
really simple, using UNIVERSAL isa, so why not give it a shot?  Sounds 
like a great return for a little investment...!

Just a thought. I could supply you a patch ?

Lee

-- 
Lee Goddard
Server-side Systems Ltd
London N1 :: 0208 369 6832

Hi Lee,

I'm glad you wrote, I had lost your previous email when I deleted an 
entire month of archived messages.

By all means, if you want to supply a patch I will gladly look at it.

Sincerely,
Ray Finch
<[email protected]>

On Mon, 9 Oct 2006, [email protected] via RT wrote:

>
>       Queue: Clone
> Ticket <URL: http://rt.cpan.org/Ticket/Display.html?id=21328 >
>
> via RT wrote:
>> <URL: http://rt.cpan.org/Ticket/Display.html?id=21328 >
>>
>> A DBH is something can't be cloned (at least by Clone) since there are
>> too many underlying objects like C structures, file handles, etc that
>> Clone doesn't handle.
>>
>> A DBI database handle does have it's own clone method. I have considered
>> having Clone check an object for a native clone method and using that in
>> preference of it's own, but I think it might be a little too ambitious
>> for me.
>>
>>
> Having Clone check a blessed reference for a clone method should be
> really simple, using UNIVERSAL isa, so why not give it a shot?  Sounds
> like a great return for a little investment...!
>
> Just a thought. I could supply you a patch ?
>
> Lee
>
> -- 
> Lee Goddard
> Server-side Systems Ltd
> London N1 :: 0208 369 6832
>
>
>

Installing the dependencies failed: Module 'Clone' is not installed, 
Installed version (2.72_01) of Encode is not in range '3.01'
! Bailing out the installation for HTTP-Message-6.24.