[ViewVC] Diff of: cvs/cvsroot/AnyEvent-MP/MP.pm

Comparing cvsroot/AnyEvent-MP/MP.pm (file contents):
Revision 1.50 by root, Fri Aug 14 14:01:05 2009 UTC vs.
Revision 1.63 by root, Thu Aug 27 21:29:37 2009 UTC

…		…
11	NODE $port # returns the noderef of the port	11	NODE $port # returns the noderef of the port
12		12
13	$SELF # receiving/own port id in rcv callbacks	13	$SELF # receiving/own port id in rcv callbacks
14		14
15	# initialise the node so it can send/receive messages	15	# initialise the node so it can send/receive messages
16	initialise_node; # -OR-	16	initialise_node;
17	initialise_node "localhost:4040"; # -OR-
18	initialise_node "slave/", "localhost:4040"
19		17
20	# ports are message endpoints	18	# ports are message endpoints
21		19
22	# sending messages	20	# sending messages
23	snd $port, type => data...;	21	snd $port, type => data...;
24	snd $port, @msg;	22	snd $port, @msg;
25	snd @msg_with_first_element_being_a_port;	23	snd @msg_with_first_element_being_a_port;
26		24
27	# creating/using ports, the simple way	25	# creating/using ports, the simple way
28	my $somple_port = port { my @msg = @_; 0 };	26	my $simple_port = port { my @msg = @_; 0 };
29		27
30	# creating/using ports, type matching	28	# creating/using ports, tagged message matching
31	my $port = port;	29	my $port = port;
32	rcv $port, ping => sub { snd $_[0], "pong"; 0 };	30	rcv $port, ping => sub { snd $_[0], "pong"; 0 };
33	rcv $port, pong => sub { warn "pong received\n"; 0 };	31	rcv $port, pong => sub { warn "pong received\n"; 0 };
34		32
35	# create a port on another node	33	# create a port on another node
…		…
69		67
70	=item port	68	=item port
71		69
72	A port is something you can send messages to (with the C<snd> function).	70	A port is something you can send messages to (with the C<snd> function).
73		71
74	Some ports allow you to register C<rcv> handlers that can match specific	72	Ports allow you to register C<rcv> handlers that can match all or just
75	messages. All C<rcv> handlers will receive messages they match, messages	73	some messages. Messages will not be queued.
76	will not be queued.
77		74
78	=item port id - C<noderef#portname>	75	=item port ID - C<noderef#portname>
79		76
80	A port id is normaly the concatenation of a noderef, a hash-mark (C<#>) as	77	A port ID is the concatenation of a noderef, a hash-mark (C<#>) as
81	separator, and a port name (a printable string of unspecified format). An	78	separator, and a port name (a printable string of unspecified format). An
82	exception is the the node port, whose ID is identical to its node	79	exception is the the node port, whose ID is identical to its node
83	reference.	80	reference.
84		81
85	=item node	82	=item node
86		83
87	A node is a single process containing at least one port - the node	84	A node is a single process containing at least one port - the node port,
88	port. You can send messages to node ports to find existing ports or to	85	which provides nodes to manage each other remotely, and to create new
89	create new ports, among other things.	86	ports.
90		87
91	Nodes are either private (single-process only), slaves (connected to a	88	Nodes are either private (single-process only), slaves (can only talk to
92	master node only) or public nodes (connectable from unrelated nodes).	89	public nodes, but do not need an open port) or public nodes (connectable
		90	from any other node).
93		91
94	=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>	92	=item node ID - C<[a-za-Z0-9_\-.:]+>
95		93
96	A node reference is a string that either simply identifies the node (for	94	A node ID is a string that either simply identifies the node (for
97	private and slave nodes), or contains a recipe on how to reach a given	95	private and slave nodes), or contains a recipe on how to reach a given
98	node (for public nodes).	96	node (for public nodes).
99		97
100	This recipe is simply a comma-separated list of C<address:port> pairs (for	98	This recipe is simply a comma-separated list of C<address:port> pairs (for
101	TCP/IP, other protocols might look different).	99	TCP/IP, other protocols might look different).
…		…
127	use base "Exporter";	125	use base "Exporter";
128		126
129	our $VERSION = $AnyEvent::MP::Kernel::VERSION;	127	our $VERSION = $AnyEvent::MP::Kernel::VERSION;
130		128
131	our @EXPORT = qw(	129	our @EXPORT = qw(
132	NODE $NODE *SELF node_of _any_	130	NODE $NODE *SELF node_of after
133	resolve_node initialise_node	131	resolve_node initialise_node
134	snd rcv mon kil reg psub spawn	132	snd rcv mon mon_guard kil reg psub spawn
135	port	133	port
136	);	134	);
137		135
138	our $SELF;	136	our $SELF;
139		137
…		…
143	kil $SELF, die => $msg;	141	kil $SELF, die => $msg;
144	}	142	}
145		143
146	=item $thisnode = NODE / $NODE	144	=item $thisnode = NODE / $NODE
147		145
148	The C<NODE> function returns, and the C<$NODE> variable contains	146	The C<NODE> function returns, and the C<$NODE> variable contains the
149	the noderef of the local node. The value is initialised by a call	147	node id of the local node. The value is initialised by a call to
150	to C<become_public> or C<become_slave>, after which all local port	148	C<initialise_node>.
151	identifiers become invalid.
152		149
153	=item $noderef = node_of $port	150	=item $nodeid = node_of $port
154		151
155	Extracts and returns the noderef from a portid or a noderef.	152	Extracts and returns the noderef from a port ID or a node ID.
156		153
157	=item initialise_node $noderef, $seednode, $seednode...	154	=item initialise_node $profile_name
158
159	=item initialise_node "slave/", $master, $master...
160		155
161	Before a node can talk to other nodes on the network it has to initialise	156	Before a node can talk to other nodes on the network it has to initialise
162	itself - the minimum a node needs to know is it's own name, and optionally	157	itself - the minimum a node needs to know is it's own name, and optionally
163	it should know the noderefs of some other nodes in the network.	158	it should know the noderefs of some other nodes in the network.
164		159
…		…
182		177
183	For public nodes, C<$noderef> (supplied either directly to	178	For public nodes, C<$noderef> (supplied either directly to
184	C<initialise_node> or indirectly via a profile or the nodename) must be a	179	C<initialise_node> or indirectly via a profile or the nodename) must be a
185	noderef (possibly unresolved, in which case it will be resolved).	180	noderef (possibly unresolved, in which case it will be resolved).
186		181
187	After resolving, the node will bind itself on all endpoints and try to	182	After resolving, the node will bind itself on all endpoints.
188	connect to all additional C<$seednodes> that are specified. Seednodes are	183
		184	=item slave nodes
		185
		186	When the C<$noderef> (either as given or overriden by the config file)
		187	is the special string C<slave/>, then the node will become a slave
		188	node. Slave nodes cannot be contacted from outside, and cannot talk to
		189	each other (at least in this version of AnyEvent::MP).
		190
		191	Slave nodes work by creating connections to all public nodes, using the
		192	L<AnyEvent::MP::Global> service.
		193
		194	=back
		195
		196	After initialising itself, the node will connect to all additional
		197	C<$seednodes> that are specified diretcly or via a profile. Seednodes are
189	optional and can be used to quickly bootstrap the node into an existing	198	optional and can be used to quickly bootstrap the node into an existing
190	network.	199	network.
191		200
192	=item slave nodes	201	All the seednodes will also be specially marked to automatically retry
193		202	connecting to them indefinitely, so make sure that seednodes are really
194	When the C<$noderef> (either as given or overriden by the config file)	203	reliable and up (this might also change in the future).
195	is the special string C<slave/>, then the node will become a slave
196	node. Slave nodes cannot be contacted from outside and will route most of
197	their traffic to the master node that they attach to.
198
199	At least one additional noderef is required (either by specifying it
200	directly or because it is part of the configuration profile): The node
201	will try to connect to all of them and will become a slave attached to the
202	first node it can successfully connect to.
203
204	=back
205
206	This function will block until all nodes have been resolved and, for slave
207	nodes, until it has successfully established a connection to a master
208	server.
209		204
210	Example: become a public node listening on the guessed noderef, or the one	205	Example: become a public node listening on the guessed noderef, or the one
211	specified via C<aemp> for the current node. This should be the most common	206	specified via C<aemp> for the current node. This should be the most common
212	form of invocation for "daemon"-type nodes.	207	form of invocation for "daemon"-type nodes.
213		208
…		…
216	Example: become a slave node to any of the the seednodes specified via	211	Example: become a slave node to any of the the seednodes specified via
217	C<aemp>. This form is often used for commandline clients.	212	C<aemp>. This form is often used for commandline clients.
218		213
219	initialise_node "slave/";	214	initialise_node "slave/";
220		215
221	Example: become a slave node to any of the specified master servers. This
222	form is also often used for commandline clients.
223
224	initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net";
225
226	Example: become a public node, and try to contact some well-known master	216	Example: become a public node, and try to contact some well-known master
227	servers to become part of the network.	217	servers to become part of the network.
228		218
229	initialise_node undef, "master1", "master2";	219	initialise_node undef, "master1", "master2";
230		220
…		…
279	=item snd $port, type => @data	269	=item snd $port, type => @data
280		270
281	=item snd $port, @msg	271	=item snd $port, @msg
282		272
283	Send the given message to the given port ID, which can identify either	273	Send the given message to the given port ID, which can identify either
284	a local or a remote port, and can be either a string or soemthignt hat	274	a local or a remote port, and must be a port ID.
285	stringifies a sa port ID (such as a port object :).
286		275
287	While the message can be about anything, it is highly recommended to use a	276	While the message can be about anything, it is highly recommended to use a
288	string as first element (a portid, or some word that indicates a request	277	string as first element (a port ID, or some word that indicates a request
289	type etc.).	278	type etc.).
290		279
291	The message data effectively becomes read-only after a call to this	280	The message data effectively becomes read-only after a call to this
292	function: modifying any argument is not allowed and can cause many	281	function: modifying any argument is not allowed and can cause many
293	problems.	282	problems.
…		…
351	The default callback received all messages not matched by a more specific	340	The default callback received all messages not matched by a more specific
352	C<tag> match.	341	C<tag> match.
353		342
354	=item rcv $local_port, tag => $callback->(@msg_without_tag), ...	343	=item rcv $local_port, tag => $callback->(@msg_without_tag), ...
355		344
356	Register callbacks to be called on messages starting with the given tag on	345	Register (or replace) callbacks to be called on messages starting with the
357	the given port (and return the port), or unregister it (when C<$callback>	346	given tag on the given port (and return the port), or unregister it (when
358	is C<$undef>).	347	C<$callback> is C<$undef> or missing). There can only be one callback
		348	registered for each tag.
359		349
360	The original message will be passed to the callback, after the first	350	The original message will be passed to the callback, after the first
361	element (the tag) has been removed. The callback will use the same	351	element (the tag) has been removed. The callback will use the same
362	environment as the default callback (see above).	352	environment as the default callback (see above).
363		353
…		…
375	rcv port,	365	rcv port,
376	msg1 => sub { ... },	366	msg1 => sub { ... },
377	...	367	...
378	;	368	;
379		369
		370	Example: temporarily register a rcv callback for a tag matching some port
		371	(e.g. for a rpc reply) and unregister it after a message was received.
		372
		373	rcv $port, $otherport => sub {
		374	my @reply = @_;
		375
		376	rcv $SELF, $otherport;
		377	};
		378
380	=cut	379	=cut
381		380
382	sub rcv($@) {	381	sub rcv($@) {
383	my $port = shift;	382	my $port = shift;
384	my ($noderef, $portid) = split /#/, $port, 2;	383	my ($noderef, $portid) = split /#/, $port, 2;
385		384
386	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}	385	$NODE{$noderef} == $NODE{""}
387	or Carp::croak "$port: rcv can only be called on local ports, caught";	386	or Carp::croak "$port: rcv can only be called on local ports, caught";
388		387
389	while (@_) {	388	while (@_) {
390	if (ref $_[0]) {	389	if (ref $_[0]) {
391	if (my $self = $PORT_DATA{$portid}) {	390	if (my $self = $PORT_DATA{$portid}) {
…		…
490	message loss has been detected. No messages will be lost "in between"	489	message loss has been detected. No messages will be lost "in between"
491	(after the first lost message no further messages will be received by the	490	(after the first lost message no further messages will be received by the
492	port). After the monitoring action was invoked, further messages might get	491	port). After the monitoring action was invoked, further messages might get
493	delivered again.	492	delivered again.
494		493
		494	Note that monitoring-actions are one-shot: once released, they are removed
		495	and will not trigger again.
		496
495	In the first form (callback), the callback is simply called with any	497	In the first form (callback), the callback is simply called with any
496	number of C<@reason> elements (no @reason means that the port was deleted	498	number of C<@reason> elements (no @reason means that the port was deleted
497	"normally"). Note also that I<< the callback B<must> never die >>, so use	499	"normally"). Note also that I<< the callback B<must> never die >>, so use
498	C<eval> if unsure.	500	C<eval> if unsure.
499		501
…		…
659	my $id = "$RUNIQ." . $ID++;	661	my $id = "$RUNIQ." . $ID++;
660		662
661	$_[0] =~ /::/	663	$_[0] =~ /::/
662	or Carp::croak "spawn init function must be a fully-qualified name, caught";	664	or Carp::croak "spawn init function must be a fully-qualified name, caught";
663		665
664	($NODE{$noderef} \|\| add_node $noderef)	666	snd_to_func $noderef, "AnyEvent::MP::_spawn" => $id, @_;
665	->send (["", "AnyEvent::MP::_spawn" => $id, @_]);
666		667
667	"$noderef#$id"	668	"$noderef#$id"
668	}	669	}
669		670
670	=back	671	=item after $timeout, @msg
671		672
672	=head1 NODE MESSAGES	673	=item after $timeout, $callback
673		674
674	Nodes understand the following messages sent to them. Many of them take	675	Either sends the given message, or call the given callback, after the
675	arguments called C<@reply>, which will simply be used to compose a reply	676	specified number of seconds.
676	message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and
677	the remaining arguments are simply the message data.
678		677
679	While other messages exist, they are not public and subject to change.	678	This is simply a utility function that come sin handy at times.
680		679
681	=over 4
682
683	=cut	680	=cut
684		681
685	=item lookup => $name, @reply	682	sub after($@) {
		683	my ($timeout, @action) = @_;
686		684
687	Replies with the port ID of the specified well-known port, or C<undef>.	685	my $t; $t = AE::timer $timeout, 0, sub {
688		686	undef $t;
689	=item devnull => ...	687	ref $action[0]
690		688	? $action[0]()
691	Generic data sink/CPU heat conversion.	689	: snd @action;
692		690	};
693	=item relay => $port, @msg	691	}
694
695	Simply forwards the message to the given port.
696
697	=item eval => $string[ @reply]
698
699	Evaluates the given string. If C<@reply> is given, then a message of the
700	form C<@reply, $@, @evalres> is sent.
701
702	Example: crash another node.
703
704	snd $othernode, eval => "exit";
705
706	=item time => @reply
707
708	Replies the the current node time to C<@reply>.
709
710	Example: tell the current node to send the current time to C<$myport> in a
711	C<timereply> message.
712
713	snd $NODE, time => $myport, timereply => 1, 2;
714	# => snd $myport, timereply => 1, 2, <time>
715		692
716	=back	693	=back
717		694
718	=head1 AnyEvent::MP vs. Distributed Erlang	695	=head1 AnyEvent::MP vs. Distributed Erlang
719		696
…		…
738	convenience functionality.	715	convenience functionality.
739		716
740	This means that AEMP requires a less tightly controlled environment at the	717	This means that AEMP requires a less tightly controlled environment at the
741	cost of longer node references and a slightly higher management overhead.	718	cost of longer node references and a slightly higher management overhead.
742		719
		720	=item * Erlang has a "remote ports are like local ports" philosophy, AEMP
		721	uses "local ports are like remote ports".
		722
		723	The failure modes for local ports are quite different (runtime errors
		724	only) then for remote ports - when a local port dies, you I<know> it dies,
		725	when a connection to another node dies, you know nothing about the other
		726	port.
		727
		728	Erlang pretends remote ports are as reliable as local ports, even when
		729	they are not.
		730
		731	AEMP encourages a "treat remote ports differently" philosophy, with local
		732	ports being the special case/exception, where transport errors cannot
		733	occur.
		734
743	=item * Erlang uses processes and a mailbox, AEMP does not queue.	735	=item * Erlang uses processes and a mailbox, AEMP does not queue.
744		736
745	Erlang uses processes that selctively receive messages, and therefore	737	Erlang uses processes that selectively receive messages, and therefore
746	needs a queue. AEMP is event based, queuing messages would serve no useful	738	needs a queue. AEMP is event based, queuing messages would serve no
747	purpose.	739	useful purpose. For the same reason the pattern-matching abilities of
		740	AnyEvent::MP are more limited, as there is little need to be able to
		741	filter messages without dequeing them.
748		742
749	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).	743	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).
750		744
751	=item * Erlang sends are synchronous, AEMP sends are asynchronous.	745	=item * Erlang sends are synchronous, AEMP sends are asynchronous.
752		746
753	Sending messages in Erlang is synchronous and blocks the process. AEMP	747	Sending messages in Erlang is synchronous and blocks the process (and
754	sends are immediate, connection establishment is handled in the	748	so does not need a queue that can overflow). AEMP sends are immediate,
755	background.	749	connection establishment is handled in the background.
756		750
757	=item * Erlang can silently lose messages, AEMP cannot.	751	=item * Erlang suffers from silent message loss, AEMP does not.
758		752
759	Erlang makes few guarantees on messages delivery - messages can get lost	753	Erlang makes few guarantees on messages delivery - messages can get lost
760	without any of the processes realising it (i.e. you send messages a, b,	754	without any of the processes realising it (i.e. you send messages a, b,
761	and c, and the other side only receives messages a and c).	755	and c, and the other side only receives messages a and c).
762		756
…		…
774	eventually be killed - it cannot happen that a node detects a port as dead	768	eventually be killed - it cannot happen that a node detects a port as dead
775	and then later sends messages to it, finding it is still alive.	769	and then later sends messages to it, finding it is still alive.
776		770
777	=item * Erlang can send messages to the wrong port, AEMP does not.	771	=item * Erlang can send messages to the wrong port, AEMP does not.
778		772
779	In Erlang it is quite possible that a node that restarts reuses a process	773	In Erlang it is quite likely that a node that restarts reuses a process ID
780	ID known to other nodes for a completely different process, causing	774	known to other nodes for a completely different process, causing messages
781	messages destined for that process to end up in an unrelated process.	775	destined for that process to end up in an unrelated process.
782		776
783	AEMP never reuses port IDs, so old messages or old port IDs floating	777	AEMP never reuses port IDs, so old messages or old port IDs floating
784	around in the network will not be sent to an unrelated port.	778	around in the network will not be sent to an unrelated port.
785		779
786	=item * Erlang uses unprotected connections, AEMP uses secure	780	=item * Erlang uses unprotected connections, AEMP uses secure

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Comparing cvsroot/AnyEvent-MP/MP.pm (file contents): Revision 1.50 by root, Fri Aug 14 14:01:05 2009 UTC vs. Revision 1.63 by root, Thu Aug 27 21:29:37 2009 UTC

Diff Legend

Comparing cvsroot/AnyEvent-MP/MP.pm (file contents):
Revision 1.50 by root, Fri Aug 14 14:01:05 2009 UTC vs.
Revision 1.63 by root, Thu Aug 27 21:29:37 2009 UTC