| Subject: | "uninitialized value in subroutine lock" warning |
Greetings,
Looks like I got an small bug in IPC::ShareLite. If I opt to use the default lock type for the lock() method, I started getting some warnings during program output:
$ ./queue_dequeue3.pl -n 10 -c 2
producer is 4749
producer is 4750
** producer just got out of the pool with PID 4750 and exit code: 0
consumer is 4752
** producer just got out of the pool with PID 4749 and exit code: 0
consumer is 4753
Waiting for Children...
Use of uninitialized value in subroutine entry at /home/alceu/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/x86_64-linux/IPC/ShareLite.pm line 361.
Use of uninitialized value in subroutine entry at /home/alceu/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/x86_64-linux/IPC/ShareLite.pm line 361.
Use of uninitialized value in subroutine entry at /home/alceu/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/x86_64-linux/IPC/ShareLite.pm line 361.
Use of uninitialized value in subroutine entry at /home/alceu/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/x86_64-linux/IPC/ShareLite.pm line 361.
** consumer just got out of the pool with PID 4752 and exit code: 0
Use of uninitialized value in subroutine entry at /home/alceu/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/x86_64-linux/IPC/ShareLite.pm line 361.
Use of uninitialized value in subroutine entry at /home/alceu/perl5/perlbrew/perls/perl-5.16.3/lib/site_perl/5.16.3/x86_64-linux/IPC/ShareLite.pm line 361.
I took a look at the code mentioned in the warning:
sub lock {
my $self = shift;
my $response = sharelite_lock( $self->{share}, shift() );
return undef if ( $response == -1 );
return 0 if ( $response == 1 ); # operation failed due to LOCK_NB
return 1;
}
Looks like a simple test to see if the shift() returns something would avoid the warning and simplify the call to sharelite_lock().
I was using perl 5.16.3 during the tests.
Changing my code to explicit use LOCK_EX resolved the warnings.
Regards,
Alceu