class Rinda::RingServer
A RingServer allows a Rinda::TupleSpace to be located via UDP broadcasts. Default service location uses the following steps:
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A
RingServerbegins listening on the network broadcast UDP address. -
A
RingFingersends a UDP packet containing theDRbURIwhere it will listen for a reply. -
The
RingServerreceives the UDP packet and connects back to the providedDRbURIwith theDRbservice.
A RingServer requires a TupleSpace:
ts = Rinda::TupleSpace.new rs = Rinda::RingServer.new
RingServer can also listen on multicast addresses for announcements. This allows multiple RingServers to run on the same host. To use network broadcast and multicast:
ts = Rinda::TupleSpace.new rs = Rinda::RingServer.new ts, %w[Socket::INADDR_ANY, 239.0.0.1 ff02::1]
Public Class Methods
Advertises ts on the given addresses at port.
If addresses is omitted only the UDP broadcast address is used.
addresses can contain multiple addresses. If a multicast address is given in addresses then the RingServer will listen for multicast queries.
If you use IPv4 multicast you may need to set an address of the inbound interface which joins a multicast group.
ts = Rinda::TupleSpace.new rs = Rinda::RingServer.new(ts, [['239.0.0.1', '9.5.1.1']])
You can set addresses as an Array Object. The first element of the Array is a multicast address and the second is an inbound interface address. If the second is omitted then ‘0.0.0.0’ is used.
If you use IPv6 multicast you may need to set both the local interface address and the inbound interface index:
rs = Rinda::RingServer.new(ts, [['ff02::1', '::1', 1]])
The first element is a multicast address and the second is an inbound interface address. The third is an inbound interface index.
At this time there is no easy way to get an interface index by name.
If the second is omitted then ‘::1’ is used. If the third is omitted then 0 (default interface) is used.
# File lib/rinda/ring.rb, line 94 def initialize(ts, addresses=[Socket::INADDR_ANY], port=Ring_PORT) @port = port if Integer === addresses then addresses, @port = [Socket::INADDR_ANY], addresses end @renewer = Renewer.new @ts = ts @sockets = [] addresses.each do |address| if Array === address make_socket(*address) else make_socket(address) end end @w_services = write_services @r_service = reply_service end
Public Instance Methods
Pulls lookup tuples out of the TupleSpace and sends their DRb object the address of the local TupleSpace.
# File lib/rinda/ring.rb, line 218 def do_reply tuple = @ts.take([:lookup_ring, nil], @renewer) Thread.new { tuple[1].call(@ts) rescue nil} rescue end
Extracts the response URI from msg and adds it to TupleSpace where it will be picked up by reply_service for notification.
# File lib/rinda/ring.rb, line 193 def do_write(msg) Thread.new do begin tuple, sec = Marshal.load(msg) @ts.write(tuple, sec) rescue end end end
Creates a socket at address
If address is multicast address then interface_address and multicast_interface can be set as optional.
A created socket is bound to interface_address. If you use IPv4 multicast then the interface of interface_address is used as the inbound interface. If interface_address is omitted or nil then ‘0.0.0.0’ or ‘::1’ is used.
If you use IPv6 multicast then multicast_interface is used as the inbound interface. multicast_interface is a network interface index. If multicast_interface is omitted then 0 (default interface) is used.
# File lib/rinda/ring.rb, line 132 def make_socket(address, interface_address=nil, multicast_interface=0) addrinfo = Addrinfo.udp(address, @port) socket = Socket.new(addrinfo.pfamily, addrinfo.socktype, addrinfo.protocol) if addrinfo.ipv4_multicast? or addrinfo.ipv6_multicast? then if Socket.const_defined?(:SO_REUSEPORT) then socket.setsockopt(:SOCKET, :SO_REUSEPORT, true) else socket.setsockopt(:SOCKET, :SO_REUSEADDR, true) end if addrinfo.ipv4_multicast? then interface_address = '0.0.0.0' if interface_address.nil? socket.bind(Addrinfo.udp(interface_address, @port)) mreq = IPAddr.new(addrinfo.ip_address).hton + IPAddr.new(interface_address).hton socket.setsockopt(:IPPROTO_IP, :IP_ADD_MEMBERSHIP, mreq) else interface_address = '::1' if interface_address.nil? socket.bind(Addrinfo.udp(interface_address, @port)) mreq = IPAddr.new(addrinfo.ip_address).hton + [multicast_interface].pack('I') socket.setsockopt(:IPPROTO_IPV6, :IPV6_JOIN_GROUP, mreq) end else socket.bind(addrinfo) end socket rescue socket = socket.close if socket raise ensure @sockets << socket if socket end
Creates a thread that notifies waiting clients from the TupleSpace.
# File lib/rinda/ring.rb, line 206 def reply_service Thread.new do loop do do_reply end end end
Shuts down the RingServer
# File lib/rinda/ring.rb, line 227 def shutdown @renewer.renew = false @w_services.each do |thread| thread.kill thread.join end @sockets.each do |socket| socket.close end @r_service.kill @r_service.join end
Creates threads that pick up UDP packets and passes them to do_write for decoding.
# File lib/rinda/ring.rb, line 178 def write_services @sockets.map do |s| Thread.new(s) do |socket| loop do msg = socket.recv(1024) do_write(msg) end end end end