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.
List of insecure methods.
These methods are not callable via dRuby.
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.
The front object of the DRbServer.
This object receives remote method calls made on the server’s URI alone, with an object id.
The configuration of this DRbServer
The safe level for this server. This is a number corresponding to $SAFE.
The default safe_level is 0
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1305
def self.default_acl(acl)
@@acl = acl
end
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1291
def self.default_argc_limit(argc)
@@argc_limit = argc
end
Set the default value for the :argc_limit option.
See new(). The initial default value is 256.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1312
def self.default_id_conv(idconv)
@@idconv = idconv
end
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1298
def self.default_load_limit(sz)
@@load_limit = sz
end
Set the default value for the :load_limit option.
See new(). The initial default value is 25 MB.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1319
def self.default_safe_level(level)
@@safe_level = level
end
Set the default safe level to level. The default safe level is 0
See new for more information.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1393
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
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
ACLclass 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.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1331
def self.verbose
@@verbose
end
Get the default value of the :verbose option.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1326
def self.verbose=(on)
@@verbose = on
end
Set the default value of the :verbose option.
See new(). The initial default value is false.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1455
def alive?
@thread.alive?
end
Is this server alive?
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1522
def any_to_s(obj)
obj.to_s + ":#{obj.class}"
rescue
sprintf("#<%s:0x%lx>", obj.class, obj.__id__)
end
Coerce an object to a string, providing our own representation if to_s is not defined for the object.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1536
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
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 tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1635
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
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1460
def here?(uri)
@exported_uri.include?(uri)
end
Is uri the URI for this server?
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1516
def insecure_method?(msg_id)
INSECURE_METHOD.include?(msg_id)
end
Has a method been included in the list of insecure methods?
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1653
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
client.send_reply(succ, result)
rescue Exception => e
error_print(e) if verbose
ensure
client.close unless succ
if Thread.current['DRb']['stop_service']
Thread.new { stop_service }
end
break unless succ
end
end
end
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 tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1497
def run
Thread.start do
begin
while main_loop
end
ensure
@protocol.close if @protocol
end
end
end
Starts the DRb main loop in a new thread.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1465
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, *@grp.list].each {|thread| thread.kill} # xxx: Thread#kill
end
@thread.join
end
end
Stop this server.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1487
def to_id(obj)
return nil if obj.__id__ == front.__id__
@idconv.to_id(obj)
end
Convert a local object to a dRuby reference.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1480
def to_obj(ref)
return front if ref.nil?
return front[ref.to_s] if DRbURIOption === ref
@idconv.to_obj(ref)
end
Convert a dRuby reference to the local object it refers to.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1452
def verbose; @config[:verbose]; end
Get whether the server is in verbose mode.
In verbose mode, failed calls are logged to stdout.
# File tmp/rubies/ruby-2.4.10/lib/drb/drb.rb, line 1447
def verbose=(v); @config[:verbose]=v; end
Set whether to operate in verbose mode.
In verbose mode, failed calls are logged to stdout.