perl5.10 Devel::Size behaviour changed?

sang1986 has asked for the wisdom of the Perl Monks concerning the following question:

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Re: perl5.10 Devel::Size behaviour changed? by ikegami (Patriarch) on Aug 25, 2009 at 13:58 UTC
I get: `>c:\progs\perl580\bin\perl test.pl SIZE : 268 >c:\progs\perl588\bin\perl test.pl SIZE : 268 >c:\progs\perl5100\bin\perl test.pl SIZE : 312` [download] 4.4 bytes per element. Or I loop 100 times: `>c:\progs\perl580\bin\perl test.pl SIZE : 2156 >c:\progs\perl588\bin\perl test.pl SIZE : 2156 >c:\progs\perl5100\bin\perl test.pl SIZE : 2200` [download] Still only 44 extra bytes. So they're tied to the array, not the elements. Adding Devel::Peek to the mix: >c:\progs\perl588\bin\perl test.pl SIZE : 2156 SV = RV(0x185d34c) at 0x1820714 REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x236da4 SV = PVAV(0x23bfcc) at 0x236da4 REFCNT = 2 FLAGS = (PADBUSY,PADMY) IV = 0 NV = 0 ARRAY = 0x18799ac FILL = 99 MAX = 123 ARYLEN = 0x0 FLAGS = (REAL) >c:\progs\perl5100\bin\perl test.pl SIZE : 2200 SV = RV(0x1950668) at 0x195065c REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x1829944 SV = PVAV(0x23a120) at 0x1829944 REFCNT = 2 FLAGS = (PADMY,RMG) MAGIC = 0x1823f0c MG_VIRTUAL = &PL_vtbl_arylen_p MG_TYPE = PERL_MAGIC_arylen_p(@) MG_FLAGS = 0x02 REFCOUNTED ARRAY = 0x183502c FILL = 99 MAX = 123 ARYLEN = 0x0 FLAGS = (REAL) [download] I wonder why the array comes with magic attached! Update: Added Devel::Peek dump.	[reply] [d/l] [select]
Re^2: perl5.10 Devel::Size behaviour changed? by ikegami (Patriarch) on Aug 25, 2009 at 14:10 UTC
I couldn't leave it at that. It seems that Devel::Size actually modifies the array! >perl -MDevel::Size=total_size -MDevel::Peek -e"my @a; total_size(\@a) + if $ARGV[0]; Dump \@a,1" 0 SV = RV(0x239ba8) at 0x239b9c REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x1829954 SV = PVAV(0x23aa60) at 0x1829954 REFCNT = 2 FLAGS = (PADMY) ARRAY = 0x0 FILL = -1 MAX = -1 ARYLEN = 0x0 FLAGS = (REAL) >perl -MDevel::Size=total_size -MDevel::Peek -e"my @a; total_size(\@a) + if $ARGV[0]; Dump \@a,1" 1 SV = RV(0x239ba8) at 0x239b9c REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x1829954 SV = PVAV(0x23aa60) at 0x1829954 REFCNT = 2 FLAGS = (PADMY,RMG) MAGIC = 0x1824014 MG_VIRTUAL = &PL_vtbl_arylen_p MG_TYPE = PERL_MAGIC_arylen_p(@) MG_FLAGS = 0x02 REFCOUNTED ARRAY = 0x0 FILL = -1 MAX = -1 ARYLEN = 0x0 FLAGS = (REAL) [download] It's similar but different than using `$#a`: >perl -MDevel::Size=total_size -MDevel::Peek -e"my @a; $#a if $ARGV[0] +; Dump \@a,1" 0 SV = RV(0x239260) at 0x239254 REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x182991c SV = PVAV(0x23a168) at 0x182991c REFCNT = 2 FLAGS = (PADMY) ARRAY = 0x0 FILL = -1 MAX = -1 ARYLEN = 0x0 FLAGS = (REAL) >perl -MDevel::Size=total_size -MDevel::Peek -e"my @a; $#a if $ARGV[0] +; Dump \@a,1" 1 SV = RV(0x239340) at 0x239334 REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x182991c SV = PVAV(0x23a168) at 0x182991c REFCNT = 2 FLAGS = (PADMY,RMG) MAGIC = 0x1823de4 MG_VIRTUAL = &PL_vtbl_arylen_p MG_TYPE = PERL_MAGIC_arylen_p(@) MG_FLAGS = 0x02 REFCOUNTED MG_OBJ = 0x239254 SV = PVMG(0x18fb364) at 0x239254 REFCNT = 1 FLAGS = (GMG,SMG) IV = 0 NV = 0 PV = 0 MAGIC = 0x1823f0c MG_VIRTUAL = &PL_vtbl_arylen MG_TYPE = PERL_MAGIC_arylen(#) MG_OBJ = 0x182991c ARRAY = 0x0 FILL = -1 MAX = -1 ARYLEN = 0x239254 FLAGS = (REAL) [download]	[reply] [d/l] [select]
Re^3: perl5.10 Devel::Size behaviour changed? (bug report) by ikegami (Patriarch) on Sep 04, 2009 at 17:56 UTC
Reported the addition of magic: rt://49437	[reply]
Re^4: perl5.10 Devel::Size behaviour changed? (bug report) by BrowserUk (Patriarch) on Sep 04, 2009 at 18:24 UTC
Re^5: perl5.10 Devel::Size behaviour changed? (reason for magic) by ikegami (Patriarch) on Sep 04, 2009 at 20:40 UTC
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Re^5: perl5.10 Devel::Size behaviour changed? (bug report) by ikegami (Patriarch) on Sep 04, 2009 at 18:38 UTC
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Re: perl5.10 Devel::Size behaviour changed? by dave_the_m (Monsignor) on Aug 25, 2009 at 12:45 UTC
There is no way 5.10.0 is using twice as much memory as 5.8.6 under normal circumstances. I would strongly suspect that you're using a 32-bit 5.8.6 and a 64-bit 5.10.0. Either that or you're using an old version of Devel::Size that doesn't know about the new SV header arrangements in 5.10.0 (which in general use less memory than 5.8.x). Dave.	[reply]
Re: perl5.10 Devel::Size behaviour changed? by Anonymous Monk on Aug 25, 2009 at 09:55 UTC
The behavior hasn't changed, the size is different.	[reply]
Re: perl5.10 Devel::Size behaviour changed? by BrowserUk (Patriarch) on Aug 25, 2009 at 17:48 UTC
Which version of D::S are you using? This one or this one And which builds of perl? 32-bit or 64-bit? Both the same? Same platform? Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. RIP PCW It is as I've been saying!(Audio until 20090817)	[reply]
Re^2: perl5.10 Devel::Size behaviour changed? by sang1986 (Novice) on Sep 04, 2009 at 10:46 UTC
It turns out I was using a 64-bit 5.10 and 32-bit 5.8.6. but in some cases I see a more than twice difference between the 2 versions. The 32-bit 5.8.6 gives me 851144. The 64-bit 5.10 gives me this alarming huge number 49563404. Any idea in what cases this could be so?	[reply]
Re^3: perl5.10 Devel::Size behaviour changed? by sang1986 (Novice) on Sep 04, 2009 at 10:54 UTC
take this example. I get 56 with 5.8 32-bit but 176 with 64-bit perl5.10. `perl -MDevel::Size=total_size -MDevel::Peek -e 'my @a; my $s = total_s +ize(\@a);print "\nSIZE : $s\n"; Dump \@a, 1' SIZE : 56 SV = RV(0x822f26c) at 0x8184a60 REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x8184b14 SV = PVAV(0x8186c54) at 0x8184b14 REFCNT = 2 FLAGS = (PADBUSY,PADMY) IV = 0 NV = 0 ARRAY = 0x0 FILL = -1 MAX = -1 ARYLEN = 0x0 FLAGS = (REAL)` [download] with 5.10 sankaran@invest5.hyd:/u/sankaran/base/src/perl/Deshaw/PDL> /usr/local +/bin/perl5.10 -MDevel::Size=total_size -MDevel::Peek -e 'my @a; my $ +s = total_size(\@a);print "\nSIZE : $s\n"; Dump \@a, 1' SIZE : 176 SV = RV(0x417520) at 0x417510 REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x4b1ba8 SV = PVAV(0x41a388) at 0x4b1ba8 REFCNT = 2 FLAGS = (PADMY,RMG) MAGIC = 0x57dd10 MG_VIRTUAL = &PL_vtbl_arylen_p MG_TYPE = PERL_MAGIC_arylen_p(@) MG_FLAGS = 0x02 REFCOUNTED ARRAY = 0x0 FILL = -1 MAX = -1 ARYLEN = 0x0 FLAGS = (REAL) [download]	[reply] [d/l] [select]
Re^3: perl5.10 Devel::Size behaviour changed? by BrowserUk (Patriarch) on Sep 04, 2009 at 12:53 UTC
Again, I ask: which version of Devel::Size are you using? Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. RIP PCW It is as I've been saying!(Audio until 20090817)	[reply]
Re^4: perl5.10 Devel::Size behaviour changed? by sang1986 (Novice) on Sep 04, 2009 at 17:18 UTC
Re^4: perl5.10 Devel::Size behaviour changed? by sang1986 (Novice) on Sep 09, 2009 at 04:38 UTC
Re^5: perl5.10 Devel::Size behaviour changed? by BrowserUk (Patriarch) on Sep 09, 2009 at 08:53 UTC
Re^5: perl5.10 Devel::Size behaviour changed? by Anonymous Monk on Sep 09, 2009 at 07:31 UTC
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