From @jdv

Hello,

The code below, when it decides to manifest (~ 1 in 10 for me at the
moment),
produces something like​:

*** Error in `/home/jdv/rakudo/install/bin/moar'​: double free or
corruption (!prev)​: 0x00007ff7f4009c30 ***
*** Error in `/home/jdv/rakudo/install/bin/moar'​: double free or
corruption (!prev)​: 0x00007ff7f4009c30 ***
*** Error in `/home/jdv/rakudo/install/bin/moar'​: double free or
corruption (!prev)​: 0x00007ff7f4009c30 ***
...
Aborted (core dumped)

or

Segmentation fault (core dumped)

or other similar looking outputs.

And here's the code​:

use v6;

for 1..15 {

  my $lock = Lock.new;
  my $cond = $lock.condition;
  my $todo = 0;
  my $done = 0;
  my @​in = 1..100;
  my @​out;

  loop ( my $i = 0; $i < @​in; $i++ ) {
  my $in := @​in[$i];
  my $out := @​out[$i];
  $lock.protect( {
  $*SCHEDULER.cue( {
  $out = $in * 10;
  $lock.protect( {
  $done++;
  $cond.signal if $done == $todo;
  } );
  } );
  $todo++;
  } );
  }

  $lock.protect( { $cond.wait unless $done == $todo; } );

  say @​out;

}

And here's what I'm running​:

[jdv@​wieldy ~]$ perl6 -v
This is perl6 version 2015.07.1-3-g6bbb56f built on MoarVM version
2015.07
[jdv@​wieldy ~]$

-jdv

From @lizmat

On 28 Jul 2015, at 13​:48, Justin DeVuyst (via RT) <perl6-bugs-followup@​perl.org> wrote​:

# New Ticket Created by Justin DeVuyst
# Please include the string​: [perl #​125705]
# in the subject line of all future correspondence about this issue.
# <URL​: https://rt-archive.perl.org/perl6/Ticket/Display.html?id=125705 >

Hello,

The code below, when it decides to manifest (~ 1 in 10 for me at the
moment),
produces something like​:

*** Error in `/home/jdv/rakudo/install/bin/moar'​: double free or
corruption (!prev)​: 0x00007ff7f4009c30 ***
*** Error in `/home/jdv/rakudo/install/bin/moar'​: double free or
corruption (!prev)​: 0x00007ff7f4009c30 ***
*** Error in `/home/jdv/rakudo/install/bin/moar'​: double free or
corruption (!prev)​: 0x00007ff7f4009c30 ***
...
Aborted (core dumped)

or

Segmentation fault (core dumped)

or other similar looking outputs.

And here's the code​:

use v6;

for 1..15 {

my $lock = Lock\.new;
my $cond = $lock\.condition;
my $todo = 0;
my $done = 0;
my @​in = 1\.\.100;
my @​out;

loop \( my $i = 0; $i \< @&#8203;in; $i\+\+ \) \{
    my $in := @&#8203;in\[$i\];
    my $out := @&#8203;out\[$i\];
    $lock\.protect\( \{
        $\*SCHEDULER\.cue\( \{
            $out = $in \* 10;
            $lock\.protect\( \{
                $done\+\+;
                $cond\.signal if $done == $todo;
            \} \);
        \} \);

Is it wise (or even sane) to use the same lock inside protected code with that lock???

        $todo\+\+;
    \} \);
\}

$lock\.protect\( \{ $cond\.wait unless $done == $todo; \} \);

say @​out;

}

And here's what I'm running​:

[jdv@​wieldy ~]$ perl6 -v
This is perl6 version 2015.07.1-3-g6bbb56f built on MoarVM version
2015.07
[jdv@​wieldy ~]$

-jdv

The RT System itself - Status changed from 'new' to 'open'

From @jnthn

On Tue Jul 28 04​:48​:54 2015, jdv79 wrote​:

Hello,

The code below, when it decides to manifest (~ 1 in 10 for me at the
moment),
produces something like​:

*** Error in `/home/jdv/rakudo/install/bin/moar'​: double free or
corruption (!prev)​: 0x00007ff7f4009c30 ***
*** Error in `/home/jdv/rakudo/install/bin/moar'​: double free or
corruption (!prev)​: 0x00007ff7f4009c30 ***
*** Error in `/home/jdv/rakudo/install/bin/moar'​: double free or
corruption (!prev)​: 0x00007ff7f4009c30 ***
...
Aborted (core dumped)

or

Segmentation fault (core dumped)

or other similar looking outputs.

Was most likely due to the recently fixed invocation data race. I can't get it to crash at all now, so added a test to S17-lowlevel/lock.t.

/jnthn

@jnthn - Status changed from 'open' to 'resolved'