Re: Perl object memory overhead

There's no difference, since an allocated hash is already set up for being blessed.

push @l,{} for 1..3e7;     # allocate 3 mill. anon hashes
system "ps -o vsz= -p $$"; # get memory usage of process
$_ = bless $_ for @l;      # bless each hash into 'main'
system "ps -o vsz= -p $$"; # again get memory usage
__END__
2650968
2650968
[download]

which shows: making an anonymous hash into an object means blessing it into a namespace. That operation signifies no overhead as far as memory is concerned, since the namespace bits are already allocated in the first place.

update: added comments

update: AnomalousMonk correctly noted that 3e7 for 3 millions is wrong by an order of magnitude. Who else noticed? ;)

perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'

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Re^2: Perl object memory overhead by LanX (Saint) on Feb 10, 2021 at 23:54 UTC
> `system "ps -o vsz= -p $$";` do you happen to know how to best replicate this on windows? FWIW: I was experimenting with something like PS D:\tmp\pm> perl -e'print `powershell (ps -id $$).pm`' 1564672 [download] not sure if there is a better way (or if it's fully equivalent). Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]
Re^3: Perl object memory overhead by shmem (Chancellor) on Feb 12, 2021 at 00:53 UTC
Sadly (or not :-) no. I don't do Windows if I can avoid it, only on specific points if needed. In which cases almost always perl provides me longbow and sword to attack the enemy's bugs, e.g. patching binaries inplace or such :P perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'	[reply]