fork&Perl BUG

[Andrew Belashov]

John-Mark Gurney wrote:
> Andrew Belashov wrote this message on Fri, Jul 25, 2003 at 14:52 +0400:
> 
>>My script working perfectly on FreeBSD 4.7R i386.
> 
> 
> Does it work perfectly on 5.1-R?

Yes, it work right on FreeBSD 5.1-R/i386.

I'm still work above this problem.

My new script crashing Perl at sparc64 depending on memory usege.

Good example:
--------------------------------------------------------------
bel at trash$ perl perlbug.pl 40000
........................................
Main: sum = 19904.3003875081, cnt = 40000
Child sleeping...
Child pid = 89373
Parent working...
Parent: sum = 19904.3003875081, cnt = 40000
Parent waiting a child...
Child working...
Child: sum = 19904.3003875081, cnt = 40000
Child exiting...
Parent exiting...
--------------------------------------------------------------

Bad example:
--------------------------------------------------------------
bel at trash$ perl perlbug.pl 80000
................................................................................
Main: sum = 39912.0714518987, cnt = 80000
Child pid = 89383
Parent working...
perl in realloc(): warning: modified (chunk-) pointer
Out of memory!
Attempt to free unreferenced scalar at perlbug.pl line 13.
perl in free(): warning: modified (chunk-) pointer
Parent: sum = 39912.0714518987, cnt = 80000
Parent waiting a child...
Parent exiting...
--------------------------------------------------------------

Any ideas?
How to localize problem?
-------------- next part --------------
#!/usr/bin/perl -w

use IO::Handle;

my %arr;
my @tmpl = ('.', '/', '0'..'9', 'a'..'z', 'A'..'Z');
my $lentmpl = @tmpl;

sub docheck {
 my $prefix = shift;
 my $sum = 0; my $cnt = 0;
 foreach my $key (keys(%arr)) {
  $sum += $arr{$key}; $cnt++;
 }
 print "$prefix: sum = $sum, cnt = $cnt\n";
}

my $maxsize = shift;

STDOUT->autoflush(1);
STDIN->autoflush(1);
STDERR->autoflush(1);

for (my $i = 0; $i < $maxsize; $i++) {
 my $key = '';
 foreach my $j (0..7) {
  $key .= $tmpl[rand($lentmpl)];
 }
 $arr{$key} = rand;
 print "." if (($i % 1000) == 0);
}

print "\n";

&docheck('Main');

die "fork()" unless defined(my $pid = fork());

if ($pid) {
 print "Child pid = $pid\n";
 print "Parent working...\n";
 &docheck('Parent');
 print "Parent waiting a child...\n";
 wait();
 print "Parent exiting...\n";
 exit(0);
} else {
 print "Child sleeping...\n";
 sleep(30);
 print "Child working...\n";
 &docheck('Child');
 print "Child exiting...\n";
 exit(0);
}