| Subject: | interrupted flock system call |
Hi all,
I detected a serious problem with the PreFork[Simple] Servers. It is possible that the flock system call (inside accept()) gets interrupted, and this seems to shut down all servers:
Feb 28 16:49:34 localhost /usr/bin/proxprox[15043]: 2005/02/28-16:49:34 Couldn't get lock on file "/tmp/file5C7ZXb" [Interrupted system call] at line 241 in file /usr/share/perl5/Net/Server/PreForkSimple.pm
Feb 28 16:49:34 localhost /usr/bin/proxprox[15043]: 2005/02/28-16:49:34 Server closing!
Feb 28 16:49:34 localhost /usr/bin/proxprox[13136]: 2005/02/28-16:49:34 Server closing!
The attached patch solves the problem.
I use Version 0.87 of Net::Server on debian sarge.
perl version: v5.8.4 built for i386-linux-thread-multi
Linux version: Linux tequila 2.6.8-1-686 #1 Thu Nov 25 04:34:30 UTC 2004 i686 GNU/Linux
--- PreForkSimple.pm.org 2005-03-01 11:31:36.000000000 +0100
+++ PreForkSimple.pm 2005-03-01 11:35:55.000000000 +0100
@@ -21,7 +21,7 @@
use strict;
use vars qw($VERSION @ISA $LOCK_EX $LOCK_UN);
-use POSIX qw(WNOHANG);
+use POSIX qw(errno_h WNOHANG);
use Fcntl ();
use Net::Server ();
use Net::Server::SIG qw(register_sig check_sigs);
@@ -238,8 +238,11 @@
if( $prop->{serialize} eq 'flock' ){
open(LOCK,">$prop->{lock_file}")
|| $self->fatal("Couldn't open lock file \"$prop->{lock_file}\" [$!]");
- flock(LOCK,Fcntl::LOCK_EX())
- || $self->fatal("Couldn't get lock on file \"$prop->{lock_file}\" [$!]");
+
+ while( !flock(LOCK,Fcntl::LOCK_EX()) ) {
+ next if ( $! = EINTR );
+ $self->fatal("Couldn't get lock on file \"$prop->{lock_file}\" [$!]");
+ }
}elsif( $prop->{serialize} eq 'semaphore' ){
$prop->{sem}->op( 0, -1, IPC::SysV::SEM_UNDO() )