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Postings from October 2003
On Sat, Oct 25, 2003 at 02:44:12PM -0400, Jack Steadman wrote:
>
> i've got another reproducible case for you. the following code, running on
> 5.8.1 with the leak patch installed, still leaks memory:
>
> #!/usr/bin/perl
>
> use strict;
> use threads;
> use threads::shared;
> use Thread::Queue;
>
> my $top = &share({});
> $top->{mid} = &share({});
>
> my $i = 0;
> my $state = 1;
> while (1) {
>
> ## any array/hash/object reference
> my $queue = new Thread::Queue;
>
> if ($state) {
> print "adding key $i\n";
> $top->{mid}->{$i} = $queue;
> } else {
> print "deleting key $i (sort of)\n";
> $top->{mid}->{$i} = undef;
> }
>
> $i++;
> if ($i > 10) {
> $i = 0;
> $state = ($state) ? 0 : 1;
> }
> }
>
> as i said earlier (and elizabeth verified), deleting the hash key with a
> 'delete $top->{mid}->{$i};' causes a seg fault, so i've tried setting them
> to undef to at least get the object assigned to the key to be destroyed.
I've fixed this leak too with patch #21564 (see below). It just adds the
SAVETMPS stuff to the other branch of sharedsv_scalar_store() too.
A strong candidate for integrating in 5.8.2, Nick!
However, the delete coredump is still there. Since this occurs in
free_tmps(), I strongly suspect its related to the memory leaks, and that
the solution will probably involve bundling up ENTER/SAVETMPS into the
SHARED_CONTEXT macro etc, to ensure this safety net is in place at all
points; however I probably won't get a chance to look into this further
for the next few days. (Been in Deepest Darkest Cornwall for the last 4
days without email access, and am just starting to catch up.)
Dave.
--
The optimist believes that he lives in the best of all possible worlds.
As does the pessimist.
Change 21564 by davem@davem-percy on 2003/10/27 22:01:12
Fix more shared threads leaks: add SAVETMPS to the second branch
of sharedsv_scalar_store().
Affected files ...
... //depot/perl/ext/threads/shared/shared.xs#40 edit
Differences ...
==== //depot/perl/ext/threads/shared/shared.xs#40 (text) ====
@@ -463,12 +463,16 @@
else {
SvTEMP_off(sv);
SHARED_CONTEXT;
+ ENTER;
+ SAVETMPS;
sv_setsv_nomg(SHAREDSvPTR(shared), sv);
if(SvOBJECT(sv)) {
SV* fake_stash = newSVpv(HvNAME(SvSTASH(sv)),0);
SvOBJECT_on(SHAREDSvPTR(shared));
SvSTASH(SHAREDSvPTR(shared)) = (HV*)fake_stash;
}
+ FREETMPS;
+ LEAVE;
CALLER_CONTEXT;
}
if (!allowed) {