Class | DRb::DRbServer |
In: |
lib/drb/invokemethod.rb
lib/drb/drb.rb |
Parent: | Object |
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.
INSECURE_METHOD | = | [ :__send__ |
List of insecure methods.
These methods are not callable via dRuby. |
config | [R] | The configuration of this DRbServer |
front | [R] |
The front object of the DRbServer.
This object receives remote method calls made on the server‘s URI alone, with an object id. |
safe_level | [R] | |
thread | [R] |
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. |
uri | [R] | The URI of this DRbServer. |
# File lib/drb/drb.rb, line 1259 1259: def self.default_safe_level(level) 1260: @@safe_level = level 1261: 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. |
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.
# File lib/drb/drb.rb, line 1330 1330: def initialize(uri=nil, front=nil, config_or_acl=nil) 1331: if Hash === config_or_acl 1332: config = config_or_acl.dup 1333: else 1334: acl = config_or_acl || @@acl 1335: config = { 1336: :tcp_acl => acl 1337: } 1338: end 1339: 1340: @config = self.class.make_config(config) 1341: 1342: @protocol = DRbProtocol.open_server(uri, @config) 1343: @uri = @protocol.uri 1344: 1345: @front = front 1346: @idconv = @config[:idconv] 1347: @safe_level = @config[:safe_level] 1348: 1349: @grp = ThreadGroup.new 1350: @thread = run 1351: 1352: DRb.regist_server(self) 1353: 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.
# File lib/drb/drb.rb, line 1470 1470: def check_insecure_method(obj, msg_id) 1471: return true if Proc === obj && msg_id == :__drb_yield 1472: raise(ArgumentError, "#{any_to_s(msg_id)} is not a symbol") unless Symbol == msg_id.class 1473: raise(SecurityError, "insecure method `#{msg_id}'") if insecure_method?(msg_id) 1474: 1475: if obj.private_methods.include?(msg_id.to_s) 1476: desc = any_to_s(obj) 1477: raise NoMethodError, "private method `#{msg_id}' called for #{desc}" 1478: elsif obj.protected_methods.include?(msg_id.to_s) 1479: desc = any_to_s(obj) 1480: raise NoMethodError, "protected method `#{msg_id}' called for #{desc}" 1481: else 1482: true 1483: end 1484: end
Stop this server.
# File lib/drb/drb.rb, line 1392 1392: def stop_service 1393: DRb.remove_server(self) 1394: if Thread.current['DRb'] && Thread.current['DRb']['server'] == self 1395: Thread.current['DRb']['stop_service'] = true 1396: else 1397: @thread.kill 1398: end 1399: end
Convert a local object to a dRuby reference.
# File lib/drb/drb.rb, line 1409 1409: def to_id(obj) 1410: return nil if obj.__id__ == front.__id__ 1411: @idconv.to_id(obj) 1412: end
Convert a dRuby reference to the local object it refers to.
# File lib/drb/drb.rb, line 1402 1402: def to_obj(ref) 1403: return front if ref.nil? 1404: return front[ref.to_s] if DRbURIOption === ref 1405: @idconv.to_obj(ref) 1406: end
Coerce an object to a string, providing our own representation if to_s is not defined for the object.
# File lib/drb/drb.rb, line 1456 1456: def any_to_s(obj) 1457: obj.to_s + ":#{obj.class}" 1458: rescue 1459: sprintf("#<%s:0x%lx>", obj.class, obj.__id__) 1460: end
Has a method been included in the list of insecure methods?
# File lib/drb/drb.rb, line 1450 1450: def insecure_method?(msg_id) 1451: INSECURE_METHOD.include?(msg_id) 1452: end
# File lib/drb/drb.rb, line 1415 1415: def kill_sub_thread 1416: Thread.new do 1417: grp = ThreadGroup.new 1418: grp.add(Thread.current) 1419: list = @grp.list 1420: while list.size > 0 1421: list.each do |th| 1422: th.kill if th.alive? 1423: end 1424: list = @grp.list 1425: end 1426: end 1427: 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.
# File lib/drb/drb.rb, line 1583 1583: def main_loop 1584: Thread.start(@protocol.accept) do |client| 1585: @grp.add Thread.current 1586: Thread.current['DRb'] = { 'client' => client , 1587: 'server' => self } 1588: loop do 1589: begin 1590: succ = false 1591: invoke_method = InvokeMethod.new(self, client) 1592: succ, result = invoke_method.perform 1593: if !succ && verbose 1594: p result 1595: result.backtrace.each do |x| 1596: puts x 1597: end 1598: end 1599: client.send_reply(succ, result) rescue nil 1600: ensure 1601: client.close unless succ 1602: if Thread.current['DRb']['stop_service'] 1603: Thread.new { stop_service } 1604: end 1605: break unless succ 1606: end 1607: end 1608: end 1609: end