Re: Crash with ForkManager on Windows

[holli]

Try wrapping the relevant parts of your code in try/catch blocks and see if it is dying somewhere unexpectedly.

[amitsq]

ok i did that. Can't see why value shouldn't be defined though :/

 
Can't call method "start" on an undefined value at  line 18.
Can't call method "finish" on an undefined value at .\multithreadsTe\3
+.pl line 25.
</code 

which basically are following lines in my code:
<code>
line 18: $pm->start and next LINKS;
line 25: $pm->finish;

my modified code again:

#!d:\perl\bin\perl.exe

use Parallel::ForkManager;
use LWP::Simple;
use Try::Tiny;
try{
  my $pm = Parallel::ForkManager->new(6);}
catch {print "error 1 \n"; exit;};

LINKS:
for my $link ('http://us.a1.yimg.com/us.yimg.com/i/ww/m5v9.gif',
  'http://hooboy.no-such-host.int/',
  'http://www.yahoo.com',
  'http://www.ora.com/ask_tim/graphics/asktim_header_main.gif',
  'http://www.guardian.co.uk/',
  'http://www.pixunlimited.co.uk/siteheaders/Guardian.gif') {
  
  try {
    $pm->start and next LINKS;    }
  catch { warn $_;
    print "### ", $link, " \n error 2 \n"; next;};
  try{
      my ($content_type, $document_length, $modified_time, $expires, $
+server) = head($link);
      print "$link fetched: declared lenght $document_length, \n";   }
  catch{print "error 3 \n";};

  try{$pm->finish; }
  catch{ warn $_; print "error 4 \n";};
    
    
  };

[holli]

Can't see why value shouldn't be defined though

Because you defined $pm lexically in the try - block and you don't have strict on.

Edit:
I just ran your code with the issue fixed but experience no crashes (Win 8.1, ActivePerl 5.24). I think there is something broken with your installation of the module and or Perl itself. I suggest a clean reinstall of both.

[amitsq]

sorry my bad.

I corrected that, and it results in no error msg output anymore. But it crashed again, with again no error output on the console although the catch blocks are implemented.

i am afraid it's a problem with the installation.

usually i install new moduls per package manager, so i removed the ForkManager Modul and tried to install it from the console:

  New CPAN.pm version (v2.16) available.
  [Currently running version is v1.9800]
  You might want to try
    install CPAN
    reload cpan
  to both upgrade CPAN.pm and run the new version without leaving
  the current session.

then i updated Cpan.pm, and now the error when trying to install forkmanager is:

PS cpan Parallel-ForkManager
Set up gcc environment - gcc.exe (rubenvb-4.5.4) 4.5.4
Loading internal null logger. Install Log::Log4perl for logging messag
+es
CPAN: Term::ANSIColor loaded ok (v4.02)
CPAN: Storable loaded ok (v2.45)
Reading 'D:\Perl64\cpan\Metadata'
  Database was generated on Thu, 21 Sep 2017 05:41:02 GMT
Warning: Cannot install Parallel-ForkManager, don't know what it is.
Try the command

    i /Parallel-ForkManager/

to find objects with matching identifiers.
CPAN: Time::HiRes loaded ok (v1.9726)

[soonix]

By wrapping the

my $pm = Parallel::ForkManager->new(6);

into a try block, $pm now is local to that new block … I think strict would have told you about it.