ruby/trema/process.rb
#
# Trema process.
#
# Copyright (C) 2008-2013 NEC Corporation
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License, version 2, as
# published by the Free Software Foundation.
#
# 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.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
module Trema
#
# A class responsible for terminating processes.
#
class Process
#
# @overload read(pid_file)
# Reads a process identification file and saves the process name
# process id and effective user id. The process name is inferred from the
# +:pid_file+.
# @param [String] pid_file the full path name of the pid file.
#
# @overload read(pid_file, name)
# Reads a process identification file and saves the process name
# process id and effective user id.
# @param [String] pid_file the full path name of the pid file.
# @param [String] name the process name.
#
# @return [Process] the object that encapsulates the process details.
#
def self.read pid_file, name = nil
name = File.basename( pid_file, ".pid" ) if name.nil?
return new( pid_file, name )
end
def initialize pid_file, name
@name = name
@pid_file = pid_file
begin
@pid = IO.read( @pid_file ).chomp.to_i
@uid = File.stat( @pid_file ).uid
rescue
@pid_file = nil
end
end
#
# kills an active process.
#
# @raise [RuntimeError] if failed to kill the process after a
# maximum number of attempts.
#
# @return [void]
#
def kill!
return if @pid_file.nil?
return if dead?
puts "Shutting down #{ @name }..." if $verbose
10.times do
if @uid == 0
sh "sudo kill #{ @pid } 2>/dev/null" rescue nil
else
sh "kill #{ @pid } 2>/dev/null" rescue nil
end
return
# return if dead?
end
raise "Failed to shut down #{ @name }"
end
################################################################################
private
################################################################################
#
# @return [Boolean] whether a process is not alive or not.
#
def dead?
`ps ax | grep -E "^[[:blank:]]*#{ @pid }"`.empty?
end
end
end
### Local variables:
### mode: Ruby
### coding: utf-8
### indent-tabs-mode: nil
### End: