lib/drb/extservm.rb

   1 =begin
   2  external service manager
   3         Copyright (c) 2000 Masatoshi SEKI
   4 =end
   5
   6 require 'drb/drb'
   7 require 'thread'
   8 require 'monitor'
   9
  10 module DRb
  11   class ExtServManager
  12     include DRbUndumped
  13     include MonitorMixin
  14
  15     @@command = {}
  16
  17     def self.command
  18       @@command
  19     end
  20
  21     def self.command=(cmd)
  22       @@command = cmd
  23     end
  24
  25     def initialize
  26       super()
  27       @cond = new_cond
  28       @servers = {}
  29       @waiting = []
  30       @queue = Queue.new
  31       @thread = invoke_thread
  32       @uri = nil
  33     end
  34     attr_accessor :uri
  35
  36     def service(name)
  37       synchronize do
  38         while true
  39           server = @servers[name]
  40           return server if server && server.alive?
  41           invoke_service(name)
  42           @cond.wait
  43         end
  44       end
  45     end
  46
  47     def regist(name, ro)
  48       synchronize do
  49         @servers[name] = ro
  50         @cond.signal
  51       end
  52       self
  53     end
  54
  55     def unregist(name)
  56       synchronize do
  57         @servers.delete(name)
  58       end
  59     end
  60
  61     private
  62     def invoke_thread
  63       Thread.new do
  64         while true
  65           name = @queue.pop
  66           invoke_service_command(name, @@command[name])
  67         end
  68       end
  69     end
  70
  71     def invoke_service(name)
  72       @queue.push(name)
  73     end
  74
  75     def invoke_service_command(name, command)
  76       raise "invalid command. name: #{name}" unless command
  77       synchronize do
  78         return if @servers.include?(name)
  79         @servers[name] = false
  80       end
  81       uri = @uri || DRb.uri
  82       if RUBY_PLATFORM =~ /mswin32/ && /NT/ =~ ENV["OS"]
  83         system(%Q'cmd /c start "ruby" /b #{command} #{uri} #{name}')
  84       else
  85         system("#{command} #{uri} #{name} &")
  86       end
  87     end
  88   end
  89 end