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authorJari Vetoniemi <jari.vetoniemi@indooratlas.com>2020-03-16 18:49:26 +0900
committerJari Vetoniemi <jari.vetoniemi@indooratlas.com>2020-03-30 00:39:06 +0900
commitfcbf63e62c627deae76c1b8cb8c0876c536ed811 (patch)
tree64cb17de3f41a2b6fef2368028fbd00349946994 /jni/ruby/lib/drb/drb.rb
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+#
+# = drb/drb.rb
+#
+# Distributed Ruby: _dRuby_ version 2.0.4
+#
+# Copyright (c) 1999-2003 Masatoshi SEKI. You can redistribute it and/or
+# modify it under the same terms as Ruby.
+#
+# Author:: Masatoshi SEKI
+#
+# Documentation:: William Webber (william@williamwebber.com)
+#
+# == Overview
+#
+# dRuby is a distributed object system for Ruby. It allows an object in one
+# Ruby process to invoke methods on an object in another Ruby process on the
+# same or a different machine.
+#
+# The Ruby standard library contains the core classes of the dRuby package.
+# However, the full package also includes access control lists and the
+# Rinda tuple-space distributed task management system, as well as a
+# large number of samples. The full dRuby package can be downloaded from
+# the dRuby home page (see *References*).
+#
+# For an introduction and examples of usage see the documentation to the
+# DRb module.
+#
+# == References
+#
+# [http://www2a.biglobe.ne.jp/~seki/ruby/druby.html]
+# The dRuby home page, in Japanese. Contains the full dRuby package
+# and links to other Japanese-language sources.
+#
+# [http://www2a.biglobe.ne.jp/~seki/ruby/druby.en.html]
+# The English version of the dRuby home page.
+#
+# [http://pragprog.com/book/sidruby/the-druby-book]
+# The dRuby Book: Distributed and Parallel Computing with Ruby
+# by Masatoshi Seki and Makoto Inoue
+#
+# [http://www.ruby-doc.org/docs/ProgrammingRuby/html/ospace.html]
+# The chapter from *Programming* *Ruby* by Dave Thomas and Andy Hunt
+# which discusses dRuby.
+#
+# [http://www.clio.ne.jp/home/web-i31s/Flotuard/Ruby/PRC2K_seki/dRuby.en.html]
+# Translation of presentation on Ruby by Masatoshi Seki.
+
+require 'socket'
+require 'thread'
+require 'fcntl'
+require 'drb/eq'
+
+#
+# == Overview
+#
+# dRuby is a distributed object system for Ruby. It is written in
+# pure Ruby and uses its own protocol. No add-in services are needed
+# beyond those provided by the Ruby runtime, such as TCP sockets. It
+# does not rely on or interoperate with other distributed object
+# systems such as CORBA, RMI, or .NET.
+#
+# dRuby allows methods to be called in one Ruby process upon a Ruby
+# object located in another Ruby process, even on another machine.
+# References to objects can be passed between processes. Method
+# arguments and return values are dumped and loaded in marshalled
+# format. All of this is done transparently to both the caller of the
+# remote method and the object that it is called upon.
+#
+# An object in a remote process is locally represented by a
+# DRb::DRbObject instance. This acts as a sort of proxy for the
+# remote object. Methods called upon this DRbObject instance are
+# forwarded to its remote object. This is arranged dynamically at run
+# time. There are no statically declared interfaces for remote
+# objects, such as CORBA's IDL.
+#
+# dRuby calls made into a process are handled by a DRb::DRbServer
+# instance within that process. This reconstitutes the method call,
+# invokes it upon the specified local object, and returns the value to
+# the remote caller. Any object can receive calls over dRuby. There
+# is no need to implement a special interface, or mixin special
+# functionality. Nor, in the general case, does an object need to
+# explicitly register itself with a DRbServer in order to receive
+# dRuby calls.
+#
+# One process wishing to make dRuby calls upon another process must
+# somehow obtain an initial reference to an object in the remote
+# process by some means other than as the return value of a remote
+# method call, as there is initially no remote object reference it can
+# invoke a method upon. This is done by attaching to the server by
+# URI. Each DRbServer binds itself to a URI such as
+# 'druby://example.com:8787'. A DRbServer can have an object attached
+# to it that acts as the server's *front* *object*. A DRbObject can
+# be explicitly created from the server's URI. This DRbObject's
+# remote object will be the server's front object. This front object
+# can then return references to other Ruby objects in the DRbServer's
+# process.
+#
+# Method calls made over dRuby behave largely the same as normal Ruby
+# method calls made within a process. Method calls with blocks are
+# supported, as are raising exceptions. In addition to a method's
+# standard errors, a dRuby call may also raise one of the
+# dRuby-specific errors, all of which are subclasses of DRb::DRbError.
+#
+# Any type of object can be passed as an argument to a dRuby call or
+# returned as its return value. By default, such objects are dumped
+# or marshalled at the local end, then loaded or unmarshalled at the
+# remote end. The remote end therefore receives a copy of the local
+# object, not a distributed reference to it; methods invoked upon this
+# copy are executed entirely in the remote process, not passed on to
+# the local original. This has semantics similar to pass-by-value.
+#
+# However, if an object cannot be marshalled, a dRuby reference to it
+# is passed or returned instead. This will turn up at the remote end
+# as a DRbObject instance. All methods invoked upon this remote proxy
+# are forwarded to the local object, as described in the discussion of
+# DRbObjects. This has semantics similar to the normal Ruby
+# pass-by-reference.
+#
+# The easiest way to signal that we want an otherwise marshallable
+# object to be passed or returned as a DRbObject reference, rather
+# than marshalled and sent as a copy, is to include the
+# DRb::DRbUndumped mixin module.
+#
+# dRuby supports calling remote methods with blocks. As blocks (or
+# rather the Proc objects that represent them) are not marshallable,
+# the block executes in the local, not the remote, context. Each
+# value yielded to the block is passed from the remote object to the
+# local block, then the value returned by each block invocation is
+# passed back to the remote execution context to be collected, before
+# the collected values are finally returned to the local context as
+# the return value of the method invocation.
+#
+# == Examples of usage
+#
+# For more dRuby samples, see the +samples+ directory in the full
+# dRuby distribution.
+#
+# === dRuby in client/server mode
+#
+# This illustrates setting up a simple client-server drb
+# system. Run the server and client code in different terminals,
+# starting the server code first.
+#
+# ==== Server code
+#
+# require 'drb/drb'
+#
+# # The URI for the server to connect to
+# URI="druby://localhost:8787"
+#
+# class TimeServer
+#
+# def get_current_time
+# return Time.now
+# end
+#
+# end
+#
+# # The object that handles requests on the server
+# FRONT_OBJECT=TimeServer.new
+#
+# $SAFE = 1 # disable eval() and friends
+#
+# DRb.start_service(URI, FRONT_OBJECT)
+# # Wait for the drb server thread to finish before exiting.
+# DRb.thread.join
+#
+# ==== Client code
+#
+# require 'drb/drb'
+#
+# # The URI to connect to
+# SERVER_URI="druby://localhost:8787"
+#
+# # Start a local DRbServer to handle callbacks.
+# #
+# # Not necessary for this small example, but will be required
+# # as soon as we pass a non-marshallable object as an argument
+# # to a dRuby call.
+# #
+# # Note: this must be called at least once per process to take any effect.
+# # This is particularly important if your application forks.
+# DRb.start_service
+#
+# timeserver = DRbObject.new_with_uri(SERVER_URI)
+# puts timeserver.get_current_time
+#
+# === Remote objects under dRuby
+#
+# This example illustrates returning a reference to an object
+# from a dRuby call. The Logger instances live in the server
+# process. References to them are returned to the client process,
+# where methods can be invoked upon them. These methods are
+# executed in the server process.
+#
+# ==== Server code
+#
+# require 'drb/drb'
+#
+# URI="druby://localhost:8787"
+#
+# class Logger
+#
+# # Make dRuby send Logger instances as dRuby references,
+# # not copies.
+# include DRb::DRbUndumped
+#
+# def initialize(n, fname)
+# @name = n
+# @filename = fname
+# end
+#
+# def log(message)
+# File.open(@filename, "a") do |f|
+# f.puts("#{Time.now}: #{@name}: #{message}")
+# end
+# end
+#
+# end
+#
+# # We have a central object for creating and retrieving loggers.
+# # This retains a local reference to all loggers created. This
+# # is so an existing logger can be looked up by name, but also
+# # to prevent loggers from being garbage collected. A dRuby
+# # reference to an object is not sufficient to prevent it being
+# # garbage collected!
+# class LoggerFactory
+#
+# def initialize(bdir)
+# @basedir = bdir
+# @loggers = {}
+# end
+#
+# def get_logger(name)
+# if !@loggers.has_key? name
+# # make the filename safe, then declare it to be so
+# fname = name.gsub(/[.\/\\\:]/, "_").untaint
+# @loggers[name] = Logger.new(name, @basedir + "/" + fname)
+# end
+# return @loggers[name]
+# end
+#
+# end
+#
+# FRONT_OBJECT=LoggerFactory.new("/tmp/dlog")
+#
+# $SAFE = 1 # disable eval() and friends
+#
+# DRb.start_service(URI, FRONT_OBJECT)
+# DRb.thread.join
+#
+# ==== Client code
+#
+# require 'drb/drb'
+#
+# SERVER_URI="druby://localhost:8787"
+#
+# DRb.start_service
+#
+# log_service=DRbObject.new_with_uri(SERVER_URI)
+#
+# ["loga", "logb", "logc"].each do |logname|
+#
+# logger=log_service.get_logger(logname)
+#
+# logger.log("Hello, world!")
+# logger.log("Goodbye, world!")
+# logger.log("=== EOT ===")
+#
+# end
+#
+# == Security
+#
+# As with all network services, security needs to be considered when
+# using dRuby. By allowing external access to a Ruby object, you are
+# not only allowing outside clients to call the methods you have
+# defined for that object, but by default to execute arbitrary Ruby
+# code on your server. Consider the following:
+#
+# # !!! UNSAFE CODE !!!
+# ro = DRbObject::new_with_uri("druby://your.server.com:8989")
+# class << ro
+# undef :instance_eval # force call to be passed to remote object
+# end
+# ro.instance_eval("`rm -rf *`")
+#
+# The dangers posed by instance_eval and friends are such that a
+# DRbServer should generally be run with $SAFE set to at least
+# level 1. This will disable eval() and related calls on strings
+# passed across the wire. The sample usage code given above follows
+# this practice.
+#
+# A DRbServer can be configured with an access control list to
+# selectively allow or deny access from specified IP addresses. The
+# main druby distribution provides the ACL class for this purpose. In
+# general, this mechanism should only be used alongside, rather than
+# as a replacement for, a good firewall.
+#
+# == dRuby internals
+#
+# dRuby is implemented using three main components: a remote method
+# call marshaller/unmarshaller; a transport protocol; and an
+# ID-to-object mapper. The latter two can be directly, and the first
+# indirectly, replaced, in order to provide different behaviour and
+# capabilities.
+#
+# Marshalling and unmarshalling of remote method calls is performed by
+# a DRb::DRbMessage instance. This uses the Marshal module to dump
+# the method call before sending it over the transport layer, then
+# reconstitute it at the other end. There is normally no need to
+# replace this component, and no direct way is provided to do so.
+# However, it is possible to implement an alternative marshalling
+# scheme as part of an implementation of the transport layer.
+#
+# The transport layer is responsible for opening client and server
+# network connections and forwarding dRuby request across them.
+# Normally, it uses DRb::DRbMessage internally to manage marshalling
+# and unmarshalling. The transport layer is managed by
+# DRb::DRbProtocol. Multiple protocols can be installed in
+# DRbProtocol at the one time; selection between them is determined by
+# the scheme of a dRuby URI. The default transport protocol is
+# selected by the scheme 'druby:', and implemented by
+# DRb::DRbTCPSocket. This uses plain TCP/IP sockets for
+# communication. An alternative protocol, using UNIX domain sockets,
+# is implemented by DRb::DRbUNIXSocket in the file drb/unix.rb, and
+# selected by the scheme 'drbunix:'. A sample implementation over
+# HTTP can be found in the samples accompanying the main dRuby
+# distribution.
+#
+# The ID-to-object mapping component maps dRuby object ids to the
+# objects they refer to, and vice versa. The implementation to use
+# can be specified as part of a DRb::DRbServer's configuration. The
+# default implementation is provided by DRb::DRbIdConv. It uses an
+# object's ObjectSpace id as its dRuby id. This means that the dRuby
+# reference to that object only remains meaningful for the lifetime of
+# the object's process and the lifetime of the object within that
+# process. A modified implementation is provided by DRb::TimerIdConv
+# in the file drb/timeridconv.rb. This implementation retains a local
+# reference to all objects exported over dRuby for a configurable
+# period of time (defaulting to ten minutes), to prevent them being
+# garbage-collected within this time. Another sample implementation
+# is provided in sample/name.rb in the main dRuby distribution. This
+# allows objects to specify their own id or "name". A dRuby reference
+# can be made persistent across processes by having each process
+# register an object using the same dRuby name.
+#
+module DRb
+
+ # Superclass of all errors raised in the DRb module.
+ class DRbError < RuntimeError; end
+
+ # Error raised when an error occurs on the underlying communication
+ # protocol.
+ class DRbConnError < DRbError; end
+
+ # Class responsible for converting between an object and its id.
+ #
+ # This, the default implementation, uses an object's local ObjectSpace
+ # __id__ as its id. This means that an object's identification over
+ # drb remains valid only while that object instance remains alive
+ # within the server runtime.
+ #
+ # For alternative mechanisms, see DRb::TimerIdConv in rdb/timeridconv.rb
+ # and DRbNameIdConv in sample/name.rb in the full drb distribution.
+ class DRbIdConv
+
+ # Convert an object reference id to an object.
+ #
+ # This implementation looks up the reference id in the local object
+ # space and returns the object it refers to.
+ def to_obj(ref)
+ ObjectSpace._id2ref(ref)
+ end
+
+ # Convert an object into a reference id.
+ #
+ # This implementation returns the object's __id__ in the local
+ # object space.
+ def to_id(obj)
+ obj.nil? ? nil : obj.__id__
+ end
+ end
+
+ # Mixin module making an object undumpable or unmarshallable.
+ #
+ # If an object which includes this module is returned by method
+ # called over drb, then the object remains in the server space
+ # and a reference to the object is returned, rather than the
+ # object being marshalled and moved into the client space.
+ module DRbUndumped
+ def _dump(dummy) # :nodoc:
+ raise TypeError, 'can\'t dump'
+ end
+ end
+
+ # Error raised by the DRb module when an attempt is made to refer to
+ # the context's current drb server but the context does not have one.
+ # See #current_server.
+ class DRbServerNotFound < DRbError; end
+
+ # Error raised by the DRbProtocol module when it cannot find any
+ # protocol implementation support the scheme specified in a URI.
+ class DRbBadURI < DRbError; end
+
+ # Error raised by a dRuby protocol when it doesn't support the
+ # scheme specified in a URI. See DRb::DRbProtocol.
+ class DRbBadScheme < DRbError; end
+
+ # An exception wrapping a DRb::DRbUnknown object
+ class DRbUnknownError < DRbError
+
+ # Create a new DRbUnknownError for the DRb::DRbUnknown object +unknown+
+ def initialize(unknown)
+ @unknown = unknown
+ super(unknown.name)
+ end
+
+ # Get the wrapped DRb::DRbUnknown object.
+ attr_reader :unknown
+
+ def self._load(s) # :nodoc:
+ Marshal::load(s)
+ end
+
+ def _dump(lv) # :nodoc:
+ Marshal::dump(@unknown)
+ end
+ end
+
+ # An exception wrapping an error object
+ class DRbRemoteError < DRbError
+
+ # Creates a new remote error that wraps the Exception +error+
+ def initialize(error)
+ @reason = error.class.to_s
+ super("#{error.message} (#{error.class})")
+ set_backtrace(error.backtrace)
+ end
+
+ # the class of the error, as a string.
+ attr_reader :reason
+ end
+
+ # Class wrapping a marshalled object whose type is unknown locally.
+ #
+ # If an object is returned by a method invoked over drb, but the
+ # class of the object is unknown in the client namespace, or
+ # the object is a constant unknown in the client namespace, then
+ # the still-marshalled object is returned wrapped in a DRbUnknown instance.
+ #
+ # If this object is passed as an argument to a method invoked over
+ # drb, then the wrapped object is passed instead.
+ #
+ # The class or constant name of the object can be read from the
+ # +name+ attribute. The marshalled object is held in the +buf+
+ # attribute.
+ class DRbUnknown
+
+ # Create a new DRbUnknown object.
+ #
+ # +buf+ is a string containing a marshalled object that could not
+ # be unmarshalled. +err+ is the error message that was raised
+ # when the unmarshalling failed. It is used to determine the
+ # name of the unmarshalled object.
+ def initialize(err, buf)
+ case err.to_s
+ when /uninitialized constant (\S+)/
+ @name = $1
+ when /undefined class\/module (\S+)/
+ @name = $1
+ else
+ @name = nil
+ end
+ @buf = buf
+ end
+
+ # The name of the unknown thing.
+ #
+ # Class name for unknown objects; variable name for unknown
+ # constants.
+ attr_reader :name
+
+ # Buffer contained the marshalled, unknown object.
+ attr_reader :buf
+
+ def self._load(s) # :nodoc:
+ begin
+ Marshal::load(s)
+ rescue NameError, ArgumentError
+ DRbUnknown.new($!, s)
+ end
+ end
+
+ def _dump(lv) # :nodoc:
+ @buf
+ end
+
+ # Attempt to load the wrapped marshalled object again.
+ #
+ # If the class of the object is now known locally, the object
+ # will be unmarshalled and returned. Otherwise, a new
+ # but identical DRbUnknown object will be returned.
+ def reload
+ self.class._load(@buf)
+ end
+
+ # Create a DRbUnknownError exception containing this object.
+ def exception
+ DRbUnknownError.new(self)
+ end
+ end
+
+ # An Array wrapper that can be sent to another server via DRb.
+ #
+ # All entries in the array will be dumped or be references that point to
+ # the local server.
+
+ class DRbArray
+
+ # Creates a new DRbArray that either dumps or wraps all the items in the
+ # Array +ary+ so they can be loaded by a remote DRb server.
+
+ def initialize(ary)
+ @ary = ary.collect { |obj|
+ if obj.kind_of? DRbUndumped
+ DRbObject.new(obj)
+ else
+ begin
+ Marshal.dump(obj)
+ obj
+ rescue
+ DRbObject.new(obj)
+ end
+ end
+ }
+ end
+
+ def self._load(s) # :nodoc:
+ Marshal::load(s)
+ end
+
+ def _dump(lv) # :nodoc:
+ Marshal.dump(@ary)
+ end
+ end
+
+ # Handler for sending and receiving drb messages.
+ #
+ # This takes care of the low-level marshalling and unmarshalling
+ # of drb requests and responses sent over the wire between server
+ # and client. This relieves the implementor of a new drb
+ # protocol layer with having to deal with these details.
+ #
+ # The user does not have to directly deal with this object in
+ # normal use.
+ class DRbMessage
+ def initialize(config) # :nodoc:
+ @load_limit = config[:load_limit]
+ @argc_limit = config[:argc_limit]
+ end
+
+ def dump(obj, error=false) # :nodoc:
+ obj = make_proxy(obj, error) if obj.kind_of? DRbUndumped
+ begin
+ str = Marshal::dump(obj)
+ rescue
+ str = Marshal::dump(make_proxy(obj, error))
+ end
+ [str.size].pack('N') + str
+ end
+
+ def load(soc) # :nodoc:
+ begin
+ sz = soc.read(4) # sizeof (N)
+ rescue
+ raise(DRbConnError, $!.message, $!.backtrace)
+ end
+ raise(DRbConnError, 'connection closed') if sz.nil?
+ raise(DRbConnError, 'premature header') if sz.size < 4
+ sz = sz.unpack('N')[0]
+ raise(DRbConnError, "too large packet #{sz}") if @load_limit < sz
+ begin
+ str = soc.read(sz)
+ rescue
+ raise(DRbConnError, $!.message, $!.backtrace)
+ end
+ raise(DRbConnError, 'connection closed') if str.nil?
+ raise(DRbConnError, 'premature marshal format(can\'t read)') if str.size < sz
+ DRb.mutex.synchronize do
+ begin
+ save = Thread.current[:drb_untaint]
+ Thread.current[:drb_untaint] = []
+ Marshal::load(str)
+ rescue NameError, ArgumentError
+ DRbUnknown.new($!, str)
+ ensure
+ Thread.current[:drb_untaint].each do |x|
+ x.untaint
+ end
+ Thread.current[:drb_untaint] = save
+ end
+ end
+ end
+
+ def send_request(stream, ref, msg_id, arg, b) # :nodoc:
+ ary = []
+ ary.push(dump(ref.__drbref))
+ ary.push(dump(msg_id.id2name))
+ ary.push(dump(arg.length))
+ arg.each do |e|
+ ary.push(dump(e))
+ end
+ ary.push(dump(b))
+ stream.write(ary.join(''))
+ rescue
+ raise(DRbConnError, $!.message, $!.backtrace)
+ end
+
+ def recv_request(stream) # :nodoc:
+ ref = load(stream)
+ ro = DRb.to_obj(ref)
+ msg = load(stream)
+ argc = load(stream)
+ raise(DRbConnError, "too many arguments") if @argc_limit < argc
+ argv = Array.new(argc, nil)
+ argc.times do |n|
+ argv[n] = load(stream)
+ end
+ block = load(stream)
+ return ro, msg, argv, block
+ end
+
+ def send_reply(stream, succ, result) # :nodoc:
+ stream.write(dump(succ) + dump(result, !succ))
+ rescue
+ raise(DRbConnError, $!.message, $!.backtrace)
+ end
+
+ def recv_reply(stream) # :nodoc:
+ succ = load(stream)
+ result = load(stream)
+ [succ, result]
+ end
+
+ private
+ def make_proxy(obj, error=false) # :nodoc:
+ if error
+ DRbRemoteError.new(obj)
+ else
+ DRbObject.new(obj)
+ end
+ end
+ end
+
+ # Module managing the underlying network protocol(s) used by drb.
+ #
+ # By default, drb uses the DRbTCPSocket protocol. Other protocols
+ # can be defined. A protocol must define the following class methods:
+ #
+ # [open(uri, config)] Open a client connection to the server at +uri+,
+ # using configuration +config+. Return a protocol
+ # instance for this connection.
+ # [open_server(uri, config)] Open a server listening at +uri+,
+ # using configuration +config+. Return a
+ # protocol instance for this listener.
+ # [uri_option(uri, config)] Take a URI, possibly containing an option
+ # component (e.g. a trailing '?param=val'),
+ # and return a [uri, option] tuple.
+ #
+ # All of these methods should raise a DRbBadScheme error if the URI
+ # does not identify the protocol they support (e.g. "druby:" for
+ # the standard Ruby protocol). This is how the DRbProtocol module,
+ # given a URI, determines which protocol implementation serves that
+ # protocol.
+ #
+ # The protocol instance returned by #open_server must have the
+ # following methods:
+ #
+ # [accept] Accept a new connection to the server. Returns a protocol
+ # instance capable of communicating with the client.
+ # [close] Close the server connection.
+ # [uri] Get the URI for this server.
+ #
+ # The protocol instance returned by #open must have the following methods:
+ #
+ # [send_request (ref, msg_id, arg, b)]
+ # Send a request to +ref+ with the given message id and arguments.
+ # This is most easily implemented by calling DRbMessage.send_request,
+ # providing a stream that sits on top of the current protocol.
+ # [recv_reply]
+ # Receive a reply from the server and return it as a [success-boolean,
+ # reply-value] pair. This is most easily implemented by calling
+ # DRb.recv_reply, providing a stream that sits on top of the
+ # current protocol.
+ # [alive?]
+ # Is this connection still alive?
+ # [close]
+ # Close this connection.
+ #
+ # The protocol instance returned by #open_server().accept() must have
+ # the following methods:
+ #
+ # [recv_request]
+ # Receive a request from the client and return a [object, message,
+ # args, block] tuple. This is most easily implemented by calling
+ # DRbMessage.recv_request, providing a stream that sits on top of
+ # the current protocol.
+ # [send_reply(succ, result)]
+ # Send a reply to the client. This is most easily implemented
+ # by calling DRbMessage.send_reply, providing a stream that sits
+ # on top of the current protocol.
+ # [close]
+ # Close this connection.
+ #
+ # A new protocol is registered with the DRbProtocol module using
+ # the add_protocol method.
+ #
+ # For examples of other protocols, see DRbUNIXSocket in drb/unix.rb,
+ # and HTTP0 in sample/http0.rb and sample/http0serv.rb in the full
+ # drb distribution.
+ module DRbProtocol
+
+ # Add a new protocol to the DRbProtocol module.
+ def add_protocol(prot)
+ @protocol.push(prot)
+ end
+ module_function :add_protocol
+
+ # Open a client connection to +uri+ with the configuration +config+.
+ #
+ # The DRbProtocol module asks each registered protocol in turn to
+ # try to open the URI. Each protocol signals that it does not handle that
+ # URI by raising a DRbBadScheme error. If no protocol recognises the
+ # URI, then a DRbBadURI error is raised. If a protocol accepts the
+ # URI, but an error occurs in opening it, a DRbConnError is raised.
+ def open(uri, config, first=true)
+ @protocol.each do |prot|
+ begin
+ return prot.open(uri, config)
+ rescue DRbBadScheme
+ rescue DRbConnError
+ raise($!)
+ rescue
+ raise(DRbConnError, "#{uri} - #{$!.inspect}")
+ end
+ end
+ if first && (config[:auto_load] != false)
+ auto_load(uri, config)
+ return open(uri, config, false)
+ end
+ raise DRbBadURI, 'can\'t parse uri:' + uri
+ end
+ module_function :open
+
+ # Open a server listening for connections at +uri+ with
+ # configuration +config+.
+ #
+ # The DRbProtocol module asks each registered protocol in turn to
+ # try to open a server at the URI. Each protocol signals that it does
+ # not handle that URI by raising a DRbBadScheme error. If no protocol
+ # recognises the URI, then a DRbBadURI error is raised. If a protocol
+ # accepts the URI, but an error occurs in opening it, the underlying
+ # error is passed on to the caller.
+ def open_server(uri, config, first=true)
+ @protocol.each do |prot|
+ begin
+ return prot.open_server(uri, config)
+ rescue DRbBadScheme
+ end
+ end
+ if first && (config[:auto_load] != false)
+ auto_load(uri, config)
+ return open_server(uri, config, false)
+ end
+ raise DRbBadURI, 'can\'t parse uri:' + uri
+ end
+ module_function :open_server
+
+ # Parse +uri+ into a [uri, option] pair.
+ #
+ # The DRbProtocol module asks each registered protocol in turn to
+ # try to parse the URI. Each protocol signals that it does not handle that
+ # URI by raising a DRbBadScheme error. If no protocol recognises the
+ # URI, then a DRbBadURI error is raised.
+ def uri_option(uri, config, first=true)
+ @protocol.each do |prot|
+ begin
+ uri, opt = prot.uri_option(uri, config)
+ # opt = nil if opt == ''
+ return uri, opt
+ rescue DRbBadScheme
+ end
+ end
+ if first && (config[:auto_load] != false)
+ auto_load(uri, config)
+ return uri_option(uri, config, false)
+ end
+ raise DRbBadURI, 'can\'t parse uri:' + uri
+ end
+ module_function :uri_option
+
+ def auto_load(uri, config) # :nodoc:
+ if uri =~ /^drb([a-z0-9]+):/
+ require("drb/#{$1}") rescue nil
+ end
+ end
+ module_function :auto_load
+ end
+
+ # The default drb protocol which communicates over a TCP socket.
+ #
+ # The DRb TCP protocol URI looks like:
+ # <code>druby://<host>:<port>?<option></code>. The option is optional.
+
+ class DRbTCPSocket
+ # :stopdoc:
+ private
+ def self.parse_uri(uri)
+ if uri =~ /^druby:\/\/(.*?):(\d+)(\?(.*))?$/
+ host = $1
+ port = $2.to_i
+ option = $4
+ [host, port, option]
+ else
+ raise(DRbBadScheme, uri) unless uri =~ /^druby:/
+ raise(DRbBadURI, 'can\'t parse uri:' + uri)
+ end
+ end
+
+ public
+
+ # Open a client connection to +uri+ (DRb URI string) using configuration
+ # +config+.
+ #
+ # This can raise DRb::DRbBadScheme or DRb::DRbBadURI if +uri+ is not for a
+ # recognized protocol. See DRb::DRbServer.new for information on built-in
+ # URI protocols.
+ def self.open(uri, config)
+ host, port, = parse_uri(uri)
+ host.untaint
+ port.untaint
+ soc = TCPSocket.open(host, port)
+ self.new(uri, soc, config)
+ end
+
+ # Returns the hostname of this server
+ def self.getservername
+ host = Socket::gethostname
+ begin
+ Socket::gethostbyname(host)[0]
+ rescue
+ 'localhost'
+ end
+ end
+
+ # For the families available for +host+, returns a TCPServer on +port+.
+ # If +port+ is 0 the first available port is used. IPv4 servers are
+ # preferred over IPv6 servers.
+ def self.open_server_inaddr_any(host, port)
+ infos = Socket::getaddrinfo(host, nil,
+ Socket::AF_UNSPEC,
+ Socket::SOCK_STREAM,
+ 0,
+ Socket::AI_PASSIVE)
+ families = Hash[*infos.collect { |af, *_| af }.uniq.zip([]).flatten]
+ return TCPServer.open('0.0.0.0', port) if families.has_key?('AF_INET')
+ return TCPServer.open('::', port) if families.has_key?('AF_INET6')
+ return TCPServer.open(port)
+ # :stopdoc:
+ end
+
+ # Open a server listening for connections at +uri+ using
+ # configuration +config+.
+ def self.open_server(uri, config)
+ uri = 'druby://:0' unless uri
+ host, port, _ = parse_uri(uri)
+ config = {:tcp_original_host => host}.update(config)
+ if host.size == 0
+ host = getservername
+ soc = open_server_inaddr_any(host, port)
+ else
+ soc = TCPServer.open(host, port)
+ end
+ port = soc.addr[1] if port == 0
+ config[:tcp_port] = port
+ uri = "druby://#{host}:#{port}"
+ self.new(uri, soc, config)
+ end
+
+ # Parse +uri+ into a [uri, option] pair.
+ def self.uri_option(uri, config)
+ host, port, option = parse_uri(uri)
+ return "druby://#{host}:#{port}", option
+ end
+
+ # Create a new DRbTCPSocket instance.
+ #
+ # +uri+ is the URI we are connected to.
+ # +soc+ is the tcp socket we are bound to. +config+ is our
+ # configuration.
+ def initialize(uri, soc, config={})
+ @uri = uri
+ @socket = soc
+ @config = config
+ @acl = config[:tcp_acl]
+ @msg = DRbMessage.new(config)
+ set_sockopt(@socket)
+ @shutdown_pipe_r, @shutdown_pipe_w = IO.pipe
+ end
+
+ # Get the URI that we are connected to.
+ attr_reader :uri
+
+ # Get the address of our TCP peer (the other end of the socket
+ # we are bound to.
+ def peeraddr
+ @socket.peeraddr
+ end
+
+ # Get the socket.
+ def stream; @socket; end
+
+ # On the client side, send a request to the server.
+ def send_request(ref, msg_id, arg, b)
+ @msg.send_request(stream, ref, msg_id, arg, b)
+ end
+
+ # On the server side, receive a request from the client.
+ def recv_request
+ @msg.recv_request(stream)
+ end
+
+ # On the server side, send a reply to the client.
+ def send_reply(succ, result)
+ @msg.send_reply(stream, succ, result)
+ end
+
+ # On the client side, receive a reply from the server.
+ def recv_reply
+ @msg.recv_reply(stream)
+ end
+
+ public
+
+ # Close the connection.
+ #
+ # If this is an instance returned by #open_server, then this stops
+ # listening for new connections altogether. If this is an instance
+ # returned by #open or by #accept, then it closes this particular
+ # client-server session.
+ def close
+ if @socket
+ @socket.close
+ @socket = nil
+ end
+ close_shutdown_pipe
+ end
+
+ def close_shutdown_pipe
+ if @shutdown_pipe_r && !@shutdown_pipe_r.closed?
+ @shutdown_pipe_r.close
+ @shutdown_pipe_r = nil
+ end
+ if @shutdown_pipe_w && !@shutdown_pipe_w.closed?
+ @shutdown_pipe_w.close
+ @shutdown_pipe_w = nil
+ end
+ end
+ private :close_shutdown_pipe
+
+ # On the server side, for an instance returned by #open_server,
+ # accept a client connection and return a new instance to handle
+ # the server's side of this client-server session.
+ def accept
+ while true
+ s = accept_or_shutdown
+ return nil unless s
+ break if (@acl ? @acl.allow_socket?(s) : true)
+ s.close
+ end
+ if @config[:tcp_original_host].to_s.size == 0
+ uri = "druby://#{s.addr[3]}:#{@config[:tcp_port]}"
+ else
+ uri = @uri
+ end
+ self.class.new(uri, s, @config)
+ end
+
+ def accept_or_shutdown
+ readables, = IO.select([@socket, @shutdown_pipe_r])
+ if readables.include? @shutdown_pipe_r
+ return nil
+ end
+ @socket.accept
+ end
+ private :accept_or_shutdown
+
+ # Graceful shutdown
+ def shutdown
+ @shutdown_pipe_w.close if @shutdown_pipe_w && !@shutdown_pipe_w.closed?
+ end
+
+ # Check to see if this connection is alive.
+ def alive?
+ return false unless @socket
+ if IO.select([@socket], nil, nil, 0)
+ close
+ return false
+ end
+ true
+ end
+
+ def set_sockopt(soc) # :nodoc:
+ soc.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1)
+ soc.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) if defined? Fcntl::FD_CLOEXEC
+ end
+ end
+
+ module DRbProtocol
+ @protocol = [DRbTCPSocket] # default
+ end
+
+ class DRbURIOption # :nodoc: I don't understand the purpose of this class...
+ def initialize(option)
+ @option = option.to_s
+ end
+ attr_reader :option
+ def to_s; @option; end
+
+ def ==(other)
+ return false unless DRbURIOption === other
+ @option == other.option
+ end
+
+ def hash
+ @option.hash
+ end
+
+ alias eql? ==
+ end
+
+ # Object wrapping a reference to a remote drb object.
+ #
+ # Method calls on this object are relayed to the remote
+ # object that this object is a stub for.
+ class DRbObject
+
+ # Unmarshall a marshalled DRbObject.
+ #
+ # If the referenced object is located within the local server, then
+ # the object itself is returned. Otherwise, a new DRbObject is
+ # created to act as a stub for the remote referenced object.
+ def self._load(s)
+ uri, ref = Marshal.load(s)
+
+ if DRb.here?(uri)
+ obj = DRb.to_obj(ref)
+ if ((! obj.tainted?) && Thread.current[:drb_untaint])
+ Thread.current[:drb_untaint].push(obj)
+ end
+ return obj
+ end
+
+ self.new_with(uri, ref)
+ end
+
+ # Creates a DRb::DRbObject given the reference information to the remote
+ # host +uri+ and object +ref+.
+
+ def self.new_with(uri, ref)
+ it = self.allocate
+ it.instance_variable_set(:@uri, uri)
+ it.instance_variable_set(:@ref, ref)
+ it
+ end
+
+ # Create a new DRbObject from a URI alone.
+ def self.new_with_uri(uri)
+ self.new(nil, uri)
+ end
+
+ # Marshall this object.
+ #
+ # The URI and ref of the object are marshalled.
+ def _dump(lv)
+ Marshal.dump([@uri, @ref])
+ end
+
+ # Create a new remote object stub.
+ #
+ # +obj+ is the (local) object we want to create a stub for. Normally
+ # this is +nil+. +uri+ is the URI of the remote object that this
+ # will be a stub for.
+ def initialize(obj, uri=nil)
+ @uri = nil
+ @ref = nil
+ if obj.nil?
+ return if uri.nil?
+ @uri, option = DRbProtocol.uri_option(uri, DRb.config)
+ @ref = DRbURIOption.new(option) unless option.nil?
+ else
+ @uri = uri ? uri : (DRb.uri rescue nil)
+ @ref = obj ? DRb.to_id(obj) : nil
+ end
+ end
+
+ # Get the URI of the remote object.
+ def __drburi
+ @uri
+ end
+
+ # Get the reference of the object, if local.
+ def __drbref
+ @ref
+ end
+
+ undef :to_s
+ undef :to_a if respond_to?(:to_a)
+
+ # Routes respond_to? to the referenced remote object.
+ def respond_to?(msg_id, priv=false)
+ case msg_id
+ when :_dump
+ true
+ when :marshal_dump
+ false
+ else
+ method_missing(:respond_to?, msg_id, priv)
+ end
+ end
+
+ # Routes method calls to the referenced remote object.
+ def method_missing(msg_id, *a, &b)
+ if DRb.here?(@uri)
+ obj = DRb.to_obj(@ref)
+ DRb.current_server.check_insecure_method(obj, msg_id)
+ return obj.__send__(msg_id, *a, &b)
+ end
+
+ succ, result = self.class.with_friend(@uri) do
+ DRbConn.open(@uri) do |conn|
+ conn.send_message(self, msg_id, a, b)
+ end
+ end
+
+ if succ
+ return result
+ elsif DRbUnknown === result
+ raise result
+ else
+ bt = self.class.prepare_backtrace(@uri, result)
+ result.set_backtrace(bt + caller)
+ raise result
+ end
+ end
+
+ # Given the +uri+ of another host executes the block provided.
+ def self.with_friend(uri) # :nodoc:
+ friend = DRb.fetch_server(uri)
+ return yield() unless friend
+
+ save = Thread.current['DRb']
+ Thread.current['DRb'] = { 'server' => friend }
+ return yield
+ ensure
+ Thread.current['DRb'] = save if friend
+ end
+
+ # Returns a modified backtrace from +result+ with the +uri+ where each call
+ # in the backtrace came from.
+ def self.prepare_backtrace(uri, result) # :nodoc:
+ prefix = "(#{uri}) "
+ bt = []
+ result.backtrace.each do |x|
+ break if /`__send__'$/ =~ x
+ if /^\(druby:\/\// =~ x
+ bt.push(x)
+ else
+ bt.push(prefix + x)
+ end
+ end
+ bt
+ end
+
+ def pretty_print(q) # :nodoc:
+ q.pp_object(self)
+ end
+
+ def pretty_print_cycle(q) # :nodoc:
+ q.object_address_group(self) {
+ q.breakable
+ q.text '...'
+ }
+ end
+ end
+
+ # Class handling the connection between a DRbObject and the
+ # server the real object lives on.
+ #
+ # This class maintains a pool of connections, to reduce the
+ # overhead of starting and closing down connections for each
+ # method call.
+ #
+ # This class is used internally by DRbObject. The user does
+ # not normally need to deal with it directly.
+ class DRbConn
+ POOL_SIZE = 16 # :nodoc:
+ @mutex = Mutex.new
+ @pool = []
+
+ def self.open(remote_uri) # :nodoc:
+ begin
+ conn = nil
+
+ @mutex.synchronize do
+ #FIXME
+ new_pool = []
+ @pool.each do |c|
+ if conn.nil? and c.uri == remote_uri
+ conn = c if c.alive?
+ else
+ new_pool.push c
+ end
+ end
+ @pool = new_pool
+ end
+
+ conn = self.new(remote_uri) unless conn
+ succ, result = yield(conn)
+ return succ, result
+
+ ensure
+ if conn
+ if succ
+ @mutex.synchronize do
+ @pool.unshift(conn)
+ @pool.pop.close while @pool.size > POOL_SIZE
+ end
+ else
+ conn.close
+ end
+ end
+ end
+ end
+
+ def initialize(remote_uri) # :nodoc:
+ @uri = remote_uri
+ @protocol = DRbProtocol.open(remote_uri, DRb.config)
+ end
+ attr_reader :uri # :nodoc:
+
+ def send_message(ref, msg_id, arg, block) # :nodoc:
+ @protocol.send_request(ref, msg_id, arg, block)
+ @protocol.recv_reply
+ end
+
+ def close # :nodoc:
+ @protocol.close
+ @protocol = nil
+ end
+
+ def alive? # :nodoc:
+ return false unless @protocol
+ @protocol.alive?
+ end
+ end
+
+ # 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 DRb.start_service.
+ class DRbServer
+ @@acl = nil
+ @@idconv = DRbIdConv.new
+ @@secondary_server = nil
+ @@argc_limit = 256
+ @@load_limit = 256 * 102400
+ @@verbose = false
+ @@safe_level = 0
+
+ # Set the default value for the :argc_limit option.
+ #
+ # See #new(). The initial default value is 256.
+ def self.default_argc_limit(argc)
+ @@argc_limit = argc
+ end
+
+ # Set the default value for the :load_limit option.
+ #
+ # See #new(). The initial default value is 25 MB.
+ def self.default_load_limit(sz)
+ @@load_limit = sz
+ end
+
+ # Set the default access control list to +acl+. The default ACL is +nil+.
+ #
+ # See also DRb::ACL and #new()
+ def self.default_acl(acl)
+ @@acl = acl
+ end
+
+ # Set the default value for the :id_conv option.
+ #
+ # See #new(). The initial default value is a DRbIdConv instance.
+ def self.default_id_conv(idconv)
+ @@idconv = idconv
+ end
+
+ # Set the default safe level to +level+. The default safe level is 0
+ #
+ # See #new for more information.
+ def self.default_safe_level(level)
+ @@safe_level = level
+ end
+
+ # Set the default value of the :verbose option.
+ #
+ # See #new(). The initial default value is false.
+ def self.verbose=(on)
+ @@verbose = on
+ end
+
+ # Get the default value of the :verbose option.
+ def self.verbose
+ @@verbose
+ end
+
+ def self.make_config(hash={}) # :nodoc:
+ default_config = {
+ :idconv => @@idconv,
+ :verbose => @@verbose,
+ :tcp_acl => @@acl,
+ :load_limit => @@load_limit,
+ :argc_limit => @@argc_limit,
+ :safe_level => @@safe_level
+ }
+ default_config.update(hash)
+ end
+
+ # 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.
+ # :safe_level :: The safe level of the DRbServer. The attribute
+ # sets $SAFE for methods performed in the main_loop.
+ # Defaults to 0.
+ #
+ # 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.
+ 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]
+ @safe_level = @config[:safe_level]
+
+ @grp = ThreadGroup.new
+ @thread = run
+
+ DRb.regist_server(self)
+ end
+
+ # The URI of this DRbServer.
+ attr_reader :uri
+
+ # 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.
+ attr_reader :thread
+
+ # The front object of the DRbServer.
+ #
+ # This object receives remote method calls made on the server's
+ # URI alone, with an object id.
+ attr_reader :front
+
+ # The configuration of this DRbServer
+ attr_reader :config
+
+ # The safe level for this server. This is a number corresponding to
+ # $SAFE.
+ #
+ # The default safe_level is 0
+ attr_reader :safe_level
+
+ # Set whether to operate in verbose mode.
+ #
+ # In verbose mode, failed calls are logged to stdout.
+ def verbose=(v); @config[:verbose]=v; end
+
+ # Get whether the server is in verbose mode.
+ #
+ # In verbose mode, failed calls are logged to stdout.
+ def verbose; @config[:verbose]; end
+
+ # Is this server alive?
+ def alive?
+ @thread.alive?
+ end
+
+ # Is +uri+ the URI for this server?
+ def here?(uri)
+ @exported_uri.include?(uri)
+ end
+
+ # Stop this server.
+ def stop_service
+ DRb.remove_server(self)
+ if Thread.current['DRb'] && Thread.current['DRb']['server'] == self
+ Thread.current['DRb']['stop_service'] = true
+ else
+ if @protocol.respond_to? :shutdown
+ @protocol.shutdown
+ else
+ @thread.kill # xxx: Thread#kill
+ end
+ @thread.join
+ end
+ end
+
+ # Convert a dRuby reference to the local object it refers to.
+ def to_obj(ref)
+ return front if ref.nil?
+ return front[ref.to_s] if DRbURIOption === ref
+ @idconv.to_obj(ref)
+ end
+
+ # Convert a local object to a dRuby reference.
+ def to_id(obj)
+ return nil if obj.__id__ == front.__id__
+ @idconv.to_id(obj)
+ end
+
+ private
+
+ ##
+ # Starts the DRb main loop in a new thread.
+
+ def run
+ Thread.start do
+ begin
+ while main_loop
+ end
+ ensure
+ @protocol.close if @protocol
+ end
+ end
+ end
+
+ # List of insecure methods.
+ #
+ # These methods are not callable via dRuby.
+ INSECURE_METHOD = [
+ :__send__
+ ]
+
+ # Has a method been included in the list of insecure methods?
+ def insecure_method?(msg_id)
+ INSECURE_METHOD.include?(msg_id)
+ end
+
+ # Coerce an object to a string, providing our own representation if
+ # to_s is not defined for the object.
+ def any_to_s(obj)
+ obj.to_s + ":#{obj.class}"
+ rescue
+ sprintf("#<%s:0x%lx>", obj.class, obj.__id__)
+ end
+
+ # 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.
+ 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)
+
+ 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
+ end
+ public :check_insecure_method
+
+ class InvokeMethod # :nodoc:
+ def initialize(drb_server, client)
+ @drb_server = drb_server
+ @safe_level = drb_server.safe_level
+ @client = client
+ end
+
+ def perform
+ @result = nil
+ @succ = false
+ setup_message
+
+ if $SAFE < @safe_level
+ info = Thread.current['DRb']
+ if @block
+ @result = Thread.new {
+ Thread.current['DRb'] = info
+ $SAFE = @safe_level
+ perform_with_block
+ }.value
+ else
+ @result = Thread.new {
+ Thread.current['DRb'] = info
+ $SAFE = @safe_level
+ perform_without_block
+ }.value
+ end
+ else
+ if @block
+ @result = perform_with_block
+ else
+ @result = perform_without_block
+ end
+ end
+ @succ = true
+ if @msg_id == :to_ary && @result.class == Array
+ @result = DRbArray.new(@result)
+ end
+ return @succ, @result
+ rescue StandardError, ScriptError, Interrupt
+ @result = $!
+ return @succ, @result
+ end
+
+ private
+ def init_with_client
+ obj, msg, argv, block = @client.recv_request
+ @obj = obj
+ @msg_id = msg.intern
+ @argv = argv
+ @block = block
+ end
+
+ def check_insecure_method
+ @drb_server.check_insecure_method(@obj, @msg_id)
+ end
+
+ def setup_message
+ init_with_client
+ check_insecure_method
+ end
+
+ def perform_without_block
+ if Proc === @obj && @msg_id == :__drb_yield
+ if @argv.size == 1
+ ary = @argv
+ else
+ ary = [@argv]
+ end
+ ary.collect(&@obj)[0]
+ else
+ @obj.__send__(@msg_id, *@argv)
+ end
+ end
+
+ end
+
+ require 'drb/invokemethod'
+ class InvokeMethod
+ include InvokeMethod18Mixin
+ end
+
+ # 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.
+ 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
+ if !succ && verbose
+ p result
+ result.backtrace.each do |x|
+ puts x
+ end
+ end
+ client.send_reply(succ, result) rescue nil
+ ensure
+ client.close unless succ
+ if Thread.current['DRb']['stop_service']
+ Thread.new { stop_service }
+ end
+ break unless succ
+ end
+ end
+ end
+ end
+ end
+
+ @primary_server = nil
+
+ # Start a dRuby server locally.
+ #
+ # The new dRuby server will become the primary server, even
+ # if another server is currently the primary server.
+ #
+ # +uri+ is the URI for the server to bind to. If nil,
+ # the server will bind to random port on the default local host
+ # name and use the default dRuby protocol.
+ #
+ # +front+ is the server's front object. This may be nil.
+ #
+ # +config+ is the configuration for the new server. This may
+ # be nil.
+ #
+ # See DRbServer::new.
+ def start_service(uri=nil, front=nil, config=nil)
+ @primary_server = DRbServer.new(uri, front, config)
+ end
+ module_function :start_service
+
+ # The primary local dRuby server.
+ #
+ # This is the server created by the #start_service call.
+ attr_accessor :primary_server
+ module_function :primary_server=, :primary_server
+
+ # Get the 'current' server.
+ #
+ # In the context of execution taking place within the main
+ # thread of a dRuby server (typically, as a result of a remote
+ # call on the server or one of its objects), the current
+ # server is that server. Otherwise, the current server is
+ # the primary server.
+ #
+ # If the above rule fails to find a server, a DRbServerNotFound
+ # error is raised.
+ def current_server
+ drb = Thread.current['DRb']
+ server = (drb && drb['server']) ? drb['server'] : @primary_server
+ raise DRbServerNotFound unless server
+ return server
+ end
+ module_function :current_server
+
+ # Stop the local dRuby server.
+ #
+ # This operates on the primary server. If there is no primary
+ # server currently running, it is a noop.
+ def stop_service
+ @primary_server.stop_service if @primary_server
+ @primary_server = nil
+ end
+ module_function :stop_service
+
+ # Get the URI defining the local dRuby space.
+ #
+ # This is the URI of the current server. See #current_server.
+ def uri
+ drb = Thread.current['DRb']
+ client = (drb && drb['client'])
+ if client
+ uri = client.uri
+ return uri if uri
+ end
+ current_server.uri
+ end
+ module_function :uri
+
+ # Is +uri+ the URI for the current local server?
+ def here?(uri)
+ current_server.here?(uri) rescue false
+ # (current_server.uri rescue nil) == uri
+ end
+ module_function :here?
+
+ # Get the configuration of the current server.
+ #
+ # If there is no current server, this returns the default configuration.
+ # See #current_server and DRbServer::make_config.
+ def config
+ current_server.config
+ rescue
+ DRbServer.make_config
+ end
+ module_function :config
+
+ # Get the front object of the current server.
+ #
+ # This raises a DRbServerNotFound error if there is no current server.
+ # See #current_server.
+ def front
+ current_server.front
+ end
+ module_function :front
+
+ # Convert a reference into an object using the current server.
+ #
+ # This raises a DRbServerNotFound error if there is no current server.
+ # See #current_server.
+ def to_obj(ref)
+ current_server.to_obj(ref)
+ end
+
+ # Get a reference id for an object using the current server.
+ #
+ # This raises a DRbServerNotFound error if there is no current server.
+ # See #current_server.
+ def to_id(obj)
+ current_server.to_id(obj)
+ end
+ module_function :to_id
+ module_function :to_obj
+
+ # Get the thread of the primary server.
+ #
+ # This returns nil if there is no primary server. See #primary_server.
+ def thread
+ @primary_server ? @primary_server.thread : nil
+ end
+ module_function :thread
+
+ # Set the default id conversion object.
+ #
+ # This is expected to be an instance such as DRb::DRbIdConv that responds to
+ # #to_id and #to_obj that can convert objects to and from DRb references.
+ #
+ # See DRbServer#default_id_conv.
+ def install_id_conv(idconv)
+ DRbServer.default_id_conv(idconv)
+ end
+ module_function :install_id_conv
+
+ # Set the default ACL to +acl+.
+ #
+ # See DRb::DRbServer.default_acl.
+ def install_acl(acl)
+ DRbServer.default_acl(acl)
+ end
+ module_function :install_acl
+
+ @mutex = Mutex.new
+ def mutex # :nodoc:
+ @mutex
+ end
+ module_function :mutex
+
+ @server = {}
+ # Registers +server+ with DRb.
+ #
+ # This is called when a new DRb::DRbServer is created.
+ #
+ # If there is no primary server then +server+ becomes the primary server.
+ #
+ # Example:
+ #
+ # require 'drb'
+ #
+ # s = DRb::DRbServer.new # automatically calls regist_server
+ # DRb.fetch_server s.uri #=> #<DRb::DRbServer:0x...>
+ def regist_server(server)
+ @server[server.uri] = server
+ mutex.synchronize do
+ @primary_server = server unless @primary_server
+ end
+ end
+ module_function :regist_server
+
+ # Removes +server+ from the list of registered servers.
+ def remove_server(server)
+ @server.delete(server.uri)
+ end
+ module_function :remove_server
+
+ # Retrieves the server with the given +uri+.
+ #
+ # See also regist_server and remove_server.
+ def fetch_server(uri)
+ @server[uri]
+ end
+ module_function :fetch_server
+end
+
+# :stopdoc:
+DRbObject = DRb::DRbObject
+DRbUndumped = DRb::DRbUndumped
+DRbIdConv = DRb::DRbIdConv