| Subject: | semget fails when there a semaphore with semid 0 |
| Date: | Wed, 7 Oct 2015 21:16:07 +0300 |
| To: | bug-Log-Log4perl [...] rt.cpan.org |
| From: | Siarhei Kuchynski <siarhei.kuchynski [...] gmail.com> |
Hi
When a semaphore with specified key (0x6f6e616e) and semid = 0 already
exists, semget fails for this semaphore:
bash-4.0# ipcs -s
Show quoted text
------ Semaphore Arrays --------
key semid owner perms nsems
0x6f6e616e 0 root 777 1
with the following error message
semget(1869504878) failed: at
/usr/share/perl5/vendor_perl//Log/Log4perl/Util/Semaphore.pm line 64.
This is caused by line 64 of Log::Log4perl::Util::Semaphore.pm
63 print "Semaphore '$self->{key}' already exists\n" if INTERNAL_DEBUG;
64 $self->{id} = semget( $self->{ikey}, 1, 0 )
65 or die "semget($self->{ikey}) failed: $!";
semget returns ID 0 for the key 1869504878 and dies, though 0 should be
considered to be valid ID
According to http://perldoc.perl.org/functions/semget.html:
*semget KEY,NSEMS,FLAGS*
Calls the System V IPC function semget(2). Returns the semaphore id, or the
undefined value on error.
It seems that init method should call die only if semget returns undefined
value, not zero.
Could you please take a look?
Thanks,
Siarhei