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Class: DRb::DRbServer

Do not use. This class is for internal use only.
Relationships & Source Files
Namespace Children
Modules:
InvokeMethod18Mixin
Classes:
InvokeMethod
Inherits: Object
Defined in: lib/drb/drb.rb,
lib/drb/invokemethod.rb

Overview

Class representing a drb server instance.

A DRbServer must be running in the local process before any incoming dRuby calls can be accepted, or any local objects can be passed as dRuby references to remote processes, even if those local objects are never actually called remotely. You do not need to start a DRbServer in the local process if you are only making outgoing dRuby calls passing marshalled parameters.

Unless multiple servers are being used, the local DRbServer is normally started by calling start_service.

Constant Summary

Class Attribute Summary

  • .verbose rw

    Get the default value of the :verbose option.

  • .verbose=(on) rw

    Set the default value of the :verbose option.

Class Method Summary

Instance Attribute Summary

  • #alive? ⇒ Boolean readonly

    Is this server alive?

  • #config readonly

    The configuration of this DRbServer.

  • #front readonly

    The front object of the DRbServer.

  • #thread readonly

    The main thread of this DRbServer.

  • #uri readonly

    The URI of this DRbServer.

  • #verbose rw

    Get whether the server is in verbose mode.

  • #verbose=(v) rw

    Set whether to operate in verbose mode.

Instance Method Summary

Constructor Details

.new(uri = nil, front = nil, config_or_acl = nil) ⇒ DRbServer

Create a new DRbServer instance.

#uri is the URI to bind to. This is normally of the form ‘druby://<hostname>:<port>’ where <hostname> is a hostname of the local machine. If nil, then the system’s default hostname will be bound to, on a port selected by the system; these value can be retrieved from the #uri attribute. ‘druby:’ specifies the default dRuby transport protocol: another protocol, such as ‘drbunix:’, can be specified instead.

#front is the front object for the server, that is, the object to which remote method calls on the server will be passed. If nil, then the server will not accept remote method calls.

If config_or_acl is a hash, it is the configuration to use for this server. The following options are recognised:

:idconv

an id-to-object conversion object. This defaults

to an instance of the class DRb::DRbIdConv.
:verbose

if true, all unsuccessful remote calls on objects

in the server will be logged to $stdout. false
by default.
:tcp_acl

the access control list for this server. See

the ACL class from the main dRuby distribution.
:load_limit

the maximum message size in bytes accepted by

the server.  Defaults to 25 MB (26214400).
:argc_limit

the maximum number of arguments to a remote

method accepted by the server.  Defaults to
256

The default values of these options can be modified on a class-wide basis by the class methods #default_argc_limit, #default_load_limit, #default_acl, #default_id_conv, and #verbose=

If config_or_acl is not a hash, but is not nil, it is assumed to be the access control list for this server. See the :tcp_acl option for more details.

If no other server is currently set as the primary server, this will become the primary server.

The server will immediately start running in its own thread.

[ GitHub ] 

  


# File 'lib/drb/drb.rb', line 1454



def initialize(uri=nil, front=nil, config_or_acl=nil)
  if Hash === config_or_acl
    config = config_or_acl.dup
  else
    acl = config_or_acl || @@acl
    config = {
      :tcp_acl => acl
    }
  end

  @config = self.class.make_config(config)

  @protocol = DRbProtocol.open_server(uri, @config)
  @uri = @protocol.uri
  @exported_uri = [@uri]

  @front = front
  @idconv = @config[:idconv]

  @grp = ThreadGroup.new
  @thread = run

  DRb.regist_server(self)
end


  







Class Attribute Details



  

    .verbose   (rw)
  



  

    

Get the default value of the :verbose option.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1397



def self.verbose
  @@verbose
end


  








  

    .verbose=(on)   (rw)
  



  

    

Set the default value of the :verbose option.



See #new().  The initial default value is false.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1392



def self.verbose=(on)
  @@verbose = on
end


  







Class Method Details



  

    .default_acl(acl)  
  



  

    

Set the default access control list to acl.  The default ::ACL is nil.



See also DRb::ACL and #new()


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1374



def self.default_acl(acl)
  @@acl = acl
end


  








  

    .default_argc_limit(argc)  
  



  

    

Set the default value for the :argc_limit option.



See #new().  The initial default value is 256.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1360



def self.default_argc_limit(argc)
  @@argc_limit = argc
end


  








  

    .default_id_conv(idconv)  
  



  

    

Set the default value for the :id_conv option.



See #new().  The initial default value is a DRbIdConv instance.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1381



def self.default_id_conv(idconv)
  @@idconv = idconv
end


  








  

    .default_load_limit(sz)  
  



  

    

Set the default value for the :load_limit option.



See #new().  The initial default value is 25 MB.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1367



def self.default_load_limit(sz)
  @@load_limit = sz
end


  








  

    .default_safe_level(level)  
  

  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1385



def self.default_safe_level(level) # :nodoc:
  # Remove in Ruby 3.0
end


  








  

    .make_config(hash = {})  
  

  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1401



def self.make_config(hash={})  # :nodoc:
  default_config = {
    :idconv => @@idconv,
    :verbose => @@verbose,
    :tcp_acl => @@acl,
    :load_limit => @@load_limit,
    :argc_limit => @@argc_limit,
  }
  default_config.update(hash)
end


  







Instance Attribute Details



  

    #alive?  ⇒ Boolean  (readonly)
  



  

    

Is this server alive?


  





  


  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1514



def alive?
  @thread.alive?
end


  








  

    #config   (readonly)
  



  

    

The configuration of this DRbServer


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1496



attr_reader :config


  








  

    #front   (readonly)
  



  

    

The front object of the DRbServer.



This object receives remote method calls made on the server’s URI alone, with an object id.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1493



attr_reader :front


  








  

    #thread   (readonly)
  



  

    

The main thread of this DRbServer.



This is the thread that listens for and accepts connections from clients, not that handles each client’s request-response session.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1487



attr_reader :thread


  








  

    #uri   (readonly)
  



  

    

The URI of this DRbServer.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1480



attr_reader :uri


  








  

    #verbose   (rw)
  



  

    

Get whether the server is in verbose mode.



In verbose mode, failed calls are logged to stdout.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1511



def verbose; @config[:verbose]; end


  








  

    #verbose=(v)   (rw)
  



  

    

Set whether to operate in verbose mode.



In verbose mode, failed calls are logged to stdout.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1506



def verbose=(v); @config[:verbose]=v; end


  







Instance Method Details



  

    #any_to_s(obj)   (private)
  



  

    

Coerce an object to a string, providing our own representation if to_s is not defined for the object.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1588



def any_to_s(obj)
  "#{obj}:#{obj.class}"
rescue
  Kernel.instance_method(:to_s).bind_call(obj)
end


  








  

    #check_insecure_method(obj, msg_id)  
  



  

    

Check that a method is callable via dRuby.



obj is the object we want to invoke the method on. msg_id is the method name, as a Symbol.



If the method is an insecure method (see #insecure_method?) a SecurityError is thrown.  If the method is private or undefined, a NameError is thrown.


  





  
Raises:


    
  
  • 
    (ArgumentError)
  
    • 





  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1602



def check_insecure_method(obj, msg_id)
  return true if Proc === obj && msg_id == :__drb_yield
  raise(ArgumentError, "#{any_to_s(msg_id)} is not a symbol") unless Symbol == msg_id.class
  raise(SecurityError, "insecure method `#{msg_id}'") if insecure_method?(msg_id)

  case obj
  when Object
    if obj.private_methods.include?(msg_id)
      desc = any_to_s(obj)
      raise NoMethodError, "private method `#{msg_id}' called for #{desc}"
    elsif obj.protected_methods.include?(msg_id)
      desc = any_to_s(obj)
      raise NoMethodError, "protected method `#{msg_id}' called for #{desc}"
    else
      true
    end
  else
    if Kernel.instance_method(:private_methods).bind(obj).call.include?(msg_id)
      desc = any_to_s(obj)
      raise NoMethodError, "private method `#{msg_id}' called for #{desc}"
    elsif Kernel.instance_method(:protected_methods).bind(obj).call.include?(msg_id)
      desc = any_to_s(obj)
      raise NoMethodError, "protected method `#{msg_id}' called for #{desc}"
    else
      true
    end
  end
end


  








  

    #error_print(exception)  
  

  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1701



def error_print(exception)
  exception.backtrace.inject(true) do |first, x|
    if first
      $stderr.puts "#{x}: #{exception} (#{exception.class})"
    else
      $stderr.puts "\tfrom #{x}"
    end
    false
  end
end


  








  

    #here?(uri)  ⇒ Boolean 
  



  

    

Is #uri the URI for this server?


  





  


  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1519



def here?(uri)
  @exported_uri.include?(uri)
end


  








  

    #insecure_method?(msg_id)  ⇒ Boolean  (private)
  



  

    

Has a method been included in the list of insecure methods?


  





  


  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1582



def insecure_method?(msg_id)
  INSECURE_METHOD.include?(msg_id)
end


  








  

    #main_loop  
  



  

    

The main loop performed by a DRbServer’s internal thread.



Accepts a connection from a client, and starts up its own thread to handle it.  This thread loops, receiving requests from the client, invoking them on a local object, and returning responses, until the client closes the connection or a local method call fails.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1719



def main_loop
  client0 = @protocol.accept
  return nil if !client0
  Thread.start(client0) do |client|
    @grp.add Thread.current
    Thread.current['DRb'] = { 'client' => client ,
                              'server' => self }
    DRb.mutex.synchronize do
      client_uri = client.uri
      @exported_uri << client_uri unless @exported_uri.include?(client_uri)
    end
    loop do
      begin
        succ = false
        invoke_method = InvokeMethod.new(self, client)
        succ, result = invoke_method.perform
        error_print(result) if !succ && verbose
        unless DRbConnError === result && result.message == 'connection closed'
          client.send_reply(succ, result)
        end
      rescue Exception => e
        error_print(e) if verbose
      ensure
        client.close unless succ
        if Thread.current['DRb']['stop_service']
          shutdown
          break
        end
        break unless succ
      end
    end
  end
end


  








  

    #run   (private)
  



  

    

Starts the ::DRb main loop in a new thread.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1563



def run
  Thread.start do
    begin
      while main_loop
      end
    ensure
      @protocol.close if @protocol
    end
  end
end


  








  

    #safe_level  
  

  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1498



def safe_level # :nodoc:
  # Remove in Ruby 3.0
  0
end


  








  

    #shutdown   (private)
  

  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1548



def shutdown
  current = Thread.current
  if @protocol.respond_to? :shutdown
    @protocol.shutdown
  else
    [@thread, *@grp.list].each { |thread|
      thread.kill unless thread == current # xxx: Thread#kill
    }
  end
  @thread.join unless @thread == current
end


  








  

    #stop_service  
  



  

    

Stop this server.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1524



def stop_service
  DRb.remove_server(self)
  if  Thread.current['DRb'] && Thread.current['DRb']['server'] == self
    Thread.current['DRb']['stop_service'] = true
  else
    shutdown
  end
end


  








  

    #to_id(obj)  
  



  

    

Convert a local object to a dRuby reference.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1541



def to_id(obj)
  return nil if obj.__id__ == front.__id__
  @idconv.to_id(obj)
end


  








  

    #to_obj(ref)  
  



  

    

Convert a dRuby reference to the local object it refers to.


  



  [ GitHub ]


  

  


# File 'lib/drb/drb.rb', line 1534



def to_obj(ref)
  return front if ref.nil?
  return front[ref.to_s] if DRbURIOption === ref
  @idconv.to_obj(ref)
end