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Posted by smallpond on March 29, 2008, 11:58 am
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> smallpond a =E9crit :
>
>
>
> >> smallpond a =E9crit :
>
> >>>> Based on the fact that perl contains many memory leaks,
> >>>> A universal way to measure how many memory is malloced is required.
> >>>> Is there standard way to measure how many memory a process has
> >>>> allacated, which run with cygwin perl, active perl, and strawberry pe=
rl?
> >>>> This should help to localize which code makes memory leaks.
> >>> perldoc perlfaq3
> >>> See:
> >>> How can I make my Perl program take less memory?
> >>> How can I free an array or hash so my program shrinks?
> >> It is interesting, but it does not seam to solve my substitution issue.=
>
> >> However I does not understand this:
>
> >> =AB Memory allocated to lexicals (i.e. my() variabl=
es)
> >> cannot be reclaimed or reused even if they go out of scope. It i=
s
> >> reserved in case the variables come back into scope. Memory allo=
cated
> >> to global variables can be reused (within your program) by using=
> >> undef()ing and/or delete(). =BB
>
> >> Aren't my variables local variables?
> >> Why aren't they freed when function terminates?
>
> > sub foo {
> > my $v =3D 5;
> > return $v;
> > }
>
> > In C, once the function terminates $v is gone and a pointer
> > to it will fail. In perl this reference is legal and the
> > space will not be reclaimed.
>
> > In your sample of code above, when you pass a string to a sub,
> > perl will make a copy. If you pass a reference it will not.
> > This isn't a memory leak in perl, it's a memory leak in your
> > program.
>
> As you suggested, I tried to replace scalar by references, but this does
> not look like saving memory (might be 10 Mbytes, I mean just the size of
> the main variable):
>
The sub call was just answering your question about
locals.
Each of these:
$$d =3D~ s/x(.....)/$1a/g ;
is making string copies in $1. $1 is a persistent
variable. perl 5.10 has new regex syntax for
avoiding use of $1, $2 etc.
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