/usr/share/perl5/Arch/RunLimit.pm is in libarch-perl 0.5.2-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 | # Arch Perl library, Copyright (C) 2004 Mikhael Goikhman
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
use 5.005;
use strict;
package Arch::RunLimit;
sub new ($%) {
my $class = shift;
my %init = @_;
my $self = {
limit => exists $init{limit}? $init{limit}: 5,
timeout => exists $init{timeout}? $init{timeout}: 30 * 60,
file => $init{file} || "/please/specify/run-limit-file",
exceeded => undef,
added => 0,
};
$self->{exceeded} = 0 if $self->{limit} <= 0 || $self->{timeout} <= 0;
bless $self, $class;
return $self;
}
sub exceeded ($) {
my $self = shift;
return $self->{exceeded} if defined $self->{exceeded};
my ($hostname, $aliases, $addrtype, $length, $addr) = gethostent();
my $hostip = join('.', unpack("C$length", $addr)) if $length && $addr;
$hostname ||= "unknown-host";
$hostip ||= "127.0.0.1";
die "Internal: Unexpected hostname ($hostname)\n" if $hostname =~ /\s/;
die "Internal: Unexpected hostip ($hostip)\n" if $hostip =~ /\s/;
$self->{host_id} = "$hostname=$hostip";
$self->{proc_able} = -d "/proc" && -d "/proc/$$",
$self->{run_id} = "$^T $$ $self->{host_id}\n";
$self->_update_run_limit_file(1);
return $self->{exceeded};
}
sub _update_run_limit_file ($$) {
my $self = shift;
my $add_self = shift;
return if $self->{exceeded};
my $file = $self->{file};
unless (-f $file) {
open FH, ">$file" or die "Can't create run-limit file ($file)\n";
close FH;
}
open FH, "+<$file" or die "Can't open $file for updating: $!\n";
flock FH, 2; # wait for exclusive lock
seek FH, 0, 0; # rewind to beginning
my @content = <FH>; # get current content
print STDERR map { "run limit old: $_" } @content
if $ENV{DEBUG} && ("$ENV{DEBUG}" & "\2") ne "\0";
@content = grep {
/^(\d+) (\d+) ([^\s]+)\n/ && (
$3 ne $self->{host_id} || time() - $1 < $self->{timeout} &&
(!$self->{proc_able} || -d "/proc/$2")
);
} @content;
if ($add_self) {
if (@content >= $self->{limit}) {
$self->{exceeded} = 1;
} else {
$self->{exceeded} = 0;
$self->{added} = 1;
push @content, $self->{run_id};
}
} else {
@content = grep { $_ ne $self->{run_id} } @content;
}
print STDERR map { "run limit new: $_" } @content
if $ENV{DEBUG} && ("$ENV{DEBUG}" & "\2") ne "\0";
seek FH, 0, 0; # rewind again
truncate FH, 0; # empty the file
print FH @content; # print the new content
close FH; # release file
}
sub DESTROY ($) {
my $self = shift;
return unless $self->{added} && defined $self->{exceeded};
$self->_update_run_limit_file(0);
}
1;
__END__
=head1 NAME
Arch::RunLimit - class to enforce a limit on the number of running
processes
=head1 SYNOPSIS
use Arch::RunLimit
my $limit = Arch::RunLimit->new(file => $limit_file);
die "run-limit exceeded" if $limit->exceeded;
=head1 DESCRIPTION
Arch::RunLimit provides an easy way to enforce a limit on the number
of concurrently running processes.
=head1 METHODS
The following methods are available:
B<new>,
B<exceeded>.
=over 4
=item B<new> I<%opts>
Create a new Arch::RunLimit object with the specified options:
=over 4
=item B<file> (mandatory)
The file used to keep track of the number of processes.
=item B<limit>
The maximum number of concurrently running processes. Defaults to C<5>.
=item B<timeout>
The timeout after which a process is assumed to be terminated in
seconds. Defaults to C<1800> (30 minutes).
=back
=item B<exceeded>
Return C<1> if the number of concurrently running processes has been
exceeded, C<0> otherwise.
=back
=head1 BUGS
Awaiting your reports.
=head1 AUTHORS
Mikhael Goikhman (migo@homemail.com--Perl-GPL/arch-perl--devel).
Enno Cramer (uebergeek@web.de--2003/arch-perl--devel).
=cut
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