Seems I found workaround:
package DB;
use strict;
use warnings;
our $level = 0;
sub test {
my $x = 0;
$x += $level;
print ">LEVEL: $level; VALUE: $x", \$x,"\n";
local $level = $level +1;
$^D |= (1<<30) if $level < 3;
main::t0();
print "<LEVEL: $level; VALUE: $x", \$x,"\n";
return;
}
sub DB {
test();
}
1;
$ perl -I. -d:DB t3.pl
>LEVEL: 0; VALUE: 0SCALAR(0xd05008)
>LEVEL: 1; VALUE: 1SCALAR(0xcfb6c8)
>LEVEL: 2; VALUE: 2SCALAR(0xd29ea8)
<LEVEL: 3; VALUE: 2SCALAR(0xd29ea8)
<LEVEL: 2; VALUE: 1SCALAR(0xcfb6c8)
<LEVEL: 1; VALUE: 0SCALAR(0xd05008)
01.09.2016, 20:19, "KES" <[email protected]>:
> Hi, I am trying to write perl debugger which will allow to debug debugger
> commands. So I play with '$^D |= (1<<30)' much.
> This allows me to reenter DB::DB and do my staff.
>
> Here is minified example which shows that memory for '$x' variable is not
> allocated again for DB::DB reentrance.
>
> $ cat t3.pl
> #!/usr/bin/env perl
>
> sub t0 {}
>
> 1;
>
> $ cat Devel/DB.pm
> package DB;
>
> use strict;
> use warnings;
>
> our $level = 0;
>
> sub DB {
> my $x = 0;
> $x += $level;
> print ">LEVEL: $level; VALUE: $x", \$x,"\n";
> local $level = $level +1;
> $^D |= (1<<30) if $level < 3;
> main::t0();
> print "<LEVEL: $level; VALUE: $x", \$x,"\n";
> return;
> }
>
> 1;
>
> $ perl -I. -d:DB t3.pl
>> LEVEL: 0; VALUE: 0SCALAR(0x1ceb008)
>> LEVEL: 1; VALUE: 1SCALAR(0x1ceb008)
>> LEVEL: 2; VALUE: 2SCALAR(0x1ceb008)
>
> <LEVEL: 3; VALUE: 2SCALAR(0x1ceb008)
> Use of uninitialized value $x in concatenation (.) or string at Devel/DB.pm
> line 15.
> <LEVEL: 2; VALUE: SCALAR(0x1ceb008)
> Use of uninitialized value $x in concatenation (.) or string at Devel/DB.pm
> line 15.
> <LEVEL: 1; VALUE: SCALAR(0x1ceb008)
>
> Here we see that for each reentrance the address of $x pointer same place.
>
> mst guess: that my weird reentrancy means the 'sub DB' pad stack isn't
> getting pushed to allocate a new pad
>
> Is this a bug?
> May someone advice workaround for this until this will be fixed?
> Thanks.
