src/functions/functions.lock

   1 #!/bin/bash
   2 ###############################################################################
   3 #                                                                             #
   4 # IPFire.org - A linux based firewall                                         #
   5 # Copyright (C) 2012  Michael Tremer & Christian Schmidt                      #
   6 #                                                                             #
   7 # This program is free software: you can redistribute it and/or modify        #
   8 # it under the terms of the GNU General Public License as published by        #
   9 # the Free Software Foundation, either version 3 of the License, or           #
  10 # (at your option) any later version.                                         #
  11 #                                                                             #
  12 # This program is distributed in the hope that it will be useful,             #
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of              #
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
  15 # GNU General Public License for more details.                                #
  16 #                                                                             #
  17 # You should have received a copy of the GNU General Public License           #
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
  19 #                                                                             #
  20 ###############################################################################
  21
  22 lock() {
  23         local lock="${1}"
  24         shift
  25
  26         # Move locks with name only into lock directory
  27         if [ "${lock:0:1}" != "/" ]; then
  28                 lock="${LOCK_DIR}/${lock}"
  29         fi
  30
  31         local timeout="60"
  32
  33         # Make partent directory
  34         make_parent_directory "${lock}"
  35
  36         (
  37                 log DEBUG "Trying to acquire lock ${lock}"
  38
  39                 # Try to acquire lock on fd 9
  40                 if ! flock -w "${timeout}" 9; then
  41                         log ERROR "Failed to acquire lock ${lock} after ${timeout} seconds"
  42                         exit ${EXIT_ERROR}
  43                 fi
  44
  45                 log DEBUG "Acquired lock ${lock}"
  46
  47                 # Remember return code
  48                 ret=${EXIT_OK}
  49
  50                 # Run command
  51                 "$@" || ret=$?
  52
  53                 log DEBUG "Released lock ${lock}"
  54
  55                 exit ${ret}
  56         ) 9>${lock} || exit $?
  57 }