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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.51 by root, Fri Aug 14 14:07:44 2009 UTC vs.
Revision 1.64 by root, Fri Aug 28 00:58:44 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 send to ports will not be queued, regardless of
76	will not be queued.	74	anything was listening for them or not.
77		75
78	=item port id - C<noderef#portname>	76	=item port ID - C<noderef#portname>
79		77
80	A port id is normaly the concatenation of a noderef, a hash-mark (C<#>) as	78	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	79	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	80	exception is the the node port, whose ID is identical to its node
83	reference.	81	reference.
84		82
85	=item node	83	=item node
86		84
87	A node is a single process containing at least one port - the node	85	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	86	which provides nodes to manage each other remotely, and to create new
89	create new ports, among other things.	87	ports.
90		88
91	Nodes are either private (single-process only), slaves (connected to a	89	Nodes are either private (single-process only), slaves (can only talk to
92	master node only) or public nodes (connectable from unrelated nodes).	90	public nodes, but do not need an open port) or public nodes (connectable
		91	from any other node).
93		92
94	=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>	93	=item node ID - C<[a-za-Z0-9_\-.:]+>
95		94
96	A node reference is a string that either simply identifies the node (for	95	A node ID is a string that uniquely identifies the node within a
97	private and slave nodes), or contains a recipe on how to reach a given	96	network. Depending on the configuration used, node IDs can look like a
98	node (for public nodes).	97	hostname, a hostname and a port, or a random string. AnyEvent::MP itself
		98	doesn't interpret node IDs in any way.
99		99
100	This recipe is simply a comma-separated list of C<address:port> pairs (for	100	=item binds - C<ip:port>
101	TCP/IP, other protocols might look different).
102		101
103	Node references come in two flavours: resolved (containing only numerical	102	Nodes can only talk to each other by creating some kind of connection to
104	addresses) or unresolved (where hostnames are used instead of addresses).	103	each other. To do this, nodes should listen on one or more local transport
		104	endpoints - binds. Currently, only standard C<ip:port> specifications can
		105	be used, which specify TCP ports to listen on.
105		106
106	Before using an unresolved node reference in a message you first have to	107	=item seeds - C<host:port>
107	resolve it.	108
		109	When a node starts, it knows nothing about the network. To teach the node
		110	about the network it first has to contact some other node within the
		111	network. This node is called a seed.
		112
		113	Seeds are transport endpoint(s) of as many nodes as one wants. Those nodes
		114	are expected to be long-running, and at least one of those should always
		115	be available. When nodes run out of connections (e.g. due to a network
		116	error), they try to re-establish connections to some seednodes again to
		117	join the network.
108		118
109	=back	119	=back
110		120
111	=head1 VARIABLES/FUNCTIONS	121	=head1 VARIABLES/FUNCTIONS
112		122
…		…
127	use base "Exporter";	137	use base "Exporter";
128		138
129	our $VERSION = $AnyEvent::MP::Kernel::VERSION;	139	our $VERSION = $AnyEvent::MP::Kernel::VERSION;
130		140
131	our @EXPORT = qw(	141	our @EXPORT = qw(
132	NODE $NODE *SELF node_of _any_	142	NODE $NODE *SELF node_of after
133	resolve_node initialise_node	143	resolve_node initialise_node
134	snd rcv mon kil reg psub spawn	144	snd rcv mon mon_guard kil reg psub spawn
135	port	145	port
136	);	146	);
137		147
138	our $SELF;	148	our $SELF;
139		149
…		…
143	kil $SELF, die => $msg;	153	kil $SELF, die => $msg;
144	}	154	}
145		155
146	=item $thisnode = NODE / $NODE	156	=item $thisnode = NODE / $NODE
147		157
148	The C<NODE> function returns, and the C<$NODE> variable contains	158	The C<NODE> function returns, and the C<$NODE> variable contains the node
149	the noderef of the local node. The value is initialised by a call	159	ID of the node running in the current process. This value is initialised by
150	to C<become_public> or C<become_slave>, after which all local port	160	a call to C<initialise_node>.
151	identifiers become invalid.
152		161
153	=item $noderef = node_of $port	162	=item $nodeid = node_of $port
154		163
155	Extracts and returns the noderef from a portid or a noderef.	164	Extracts and returns the node ID part from a port ID or a node ID.
156		165
157	=item initialise_node $noderef, $seednode, $seednode...	166	=item initialise_node $profile_name
158		167
159	=item initialise_node "slave/", $master, $master...
160
161	Before a node can talk to other nodes on the network it has to initialise	168	Before a node can talk to other nodes on the network (i.e. enter
162	itself - the minimum a node needs to know is it's own name, and optionally	169	"distributed mode") it has to initialise itself - the minimum a node needs
163	it should know the noderefs of some other nodes in the network.	170	to know is its own name, and optionally it should know the addresses of
		171	some other nodes in the network to discover other nodes.
164		172
165	This function initialises a node - it must be called exactly once (or	173	This function initialises a node - it must be called exactly once (or
166	never) before calling other AnyEvent::MP functions.	174	never) before calling other AnyEvent::MP functions.
167		175
168	All arguments (optionally except for the first) are noderefs, which can be	176	The first argument is a profile name. If it is C<undef> or missing, then
169	either resolved or unresolved.	177	the current nodename will be used instead (i.e. F<uname -n>).
170		178
171	The first argument will be looked up in the configuration database first	179	The function then looks up the profile in the aemp configuration (see the
172	(if it is C<undef> then the current nodename will be used instead) to find	180	L<aemp> commandline utility).
173	the relevant configuration profile (see L<aemp>). If none is found then
174	the default configuration is used. The configuration supplies additional
175	seed/master nodes and can override the actual noderef.
176		181
177	There are two types of networked nodes, public nodes and slave nodes:	182	If the profile specifies a node ID, then this will become the node ID of
		183	this process. If not, then the profile name will be used as node ID. The
		184	special node ID of C<anon/> will be replaced by a random node ID.
178		185
179	=over 4	186	The next step is to look up the binds in the profile, followed by binding
		187	aemp protocol listeners on all binds specified (it is possible and valid
		188	to have no binds, meaning that the node cannot be contacted form the
		189	outside. This means the node cannot talk to other nodes that also have no
		190	binds, but it can still talk to all "normal" nodes).
180		191
181	=item public nodes	192	If the profile does not specify a binds list, then the node ID will be
		193	treated as if it were of the form C<host:port>, which will be resolved and
		194	used as binds list.
182		195
183	For public nodes, C<$noderef> (supplied either directly to	196	Lastly, the seeds list from the profile is passed to the
184	C<initialise_node> or indirectly via a profile or the nodename) must be a	197	L<AnyEvent::MP::Global> module, which will then use it to keep
185	noderef (possibly unresolved, in which case it will be resolved).	198	connectivity with at least on of those seed nodes at any point in time.
186		199
187	After resolving, the node will bind itself on all endpoints and try to
188	connect to all additional C<$seednodes> that are specified. Seednodes are
189	optional and can be used to quickly bootstrap the node into an existing
190	network.
191
192	=item slave nodes
193
194	When the C<$noderef> (either as given or overriden by the config file)
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
210	Example: become a public node listening on the guessed noderef, or the one	200	Example: become a distributed node listening on the guessed noderef, or
211	specified via C<aemp> for the current node. This should be the most common	201	the one specified via C<aemp> for the current node. This should be the
212	form of invocation for "daemon"-type nodes.	202	most common form of invocation for "daemon"-type nodes.
213		203
214	initialise_node;	204	initialise_node;
215		205
216	Example: become a slave node to any of the the seednodes specified via	206	Example: become an anonymous node. This form is often used for commandline
217	C<aemp>. This form is often used for commandline clients.	207	clients.
218		208
219	initialise_node "slave/";	209	initialise_node "anon/";
220		210
221	Example: become a slave node to any of the specified master servers. This	211	Example: become a distributed node. If there is no profile of the given
222	form is also often used for commandline clients.	212	name, or no binds list was specified, resolve C<localhost:4044> and bind
223		213	on the resulting addresses.
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
227	servers to become part of the network.
228
229	initialise_node undef, "master1", "master2";
230
231	Example: become a public node listening on port C<4041>.
232
233	initialise_node 4041;
234
235	Example: become a public node, only visible on localhost port 4044.
236		214
237	initialise_node "localhost:4044";	215	initialise_node "localhost:4044";
238
239	=item $cv = resolve_node $noderef
240
241	Takes an unresolved node reference that may contain hostnames and
242	abbreviated IDs, resolves all of them and returns a resolved node
243	reference.
244
245	In addition to C<address:port> pairs allowed in resolved noderefs, the
246	following forms are supported:
247
248	=over 4
249
250	=item the empty string
251
252	An empty-string component gets resolved as if the default port (4040) was
253	specified.
254
255	=item naked port numbers (e.g. C<1234>)
256
257	These are resolved by prepending the local nodename and a colon, to be
258	further resolved.
259
260	=item hostnames (e.g. C<localhost:1234>, C<localhost>)
261
262	These are resolved by using AnyEvent::DNS to resolve them, optionally
263	looking up SRV records for the C<aemp=4040> port, if no port was
264	specified.
265
266	=back
267		216
268	=item $SELF	217	=item $SELF
269		218
270	Contains the current port id while executing C<rcv> callbacks or C<psub>	219	Contains the current port id while executing C<rcv> callbacks or C<psub>
271	blocks.	220	blocks.
…		…
279	=item snd $port, type => @data	228	=item snd $port, type => @data
280		229
281	=item snd $port, @msg	230	=item snd $port, @msg
282		231
283	Send the given message to the given port ID, which can identify either	232	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	233	a local or a remote port, and must be a port ID.
285	stringifies a sa port ID (such as a port object :).
286		234
287	While the message can be about anything, it is highly recommended to use a	235	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	236	string as first element (a port ID, or some word that indicates a request
289	type etc.).	237	type etc.).
290		238
291	The message data effectively becomes read-only after a call to this	239	The message data effectively becomes read-only after a call to this
292	function: modifying any argument is not allowed and can cause many	240	function: modifying any argument is not allowed and can cause many
293	problems.	241	problems.
…		…
351	The default callback received all messages not matched by a more specific	299	The default callback received all messages not matched by a more specific
352	C<tag> match.	300	C<tag> match.
353		301
354	=item rcv $local_port, tag => $callback->(@msg_without_tag), ...	302	=item rcv $local_port, tag => $callback->(@msg_without_tag), ...
355		303
356	Register callbacks to be called on messages starting with the given tag on	304	Register (or replace) callbacks to be called on messages starting with the
357	the given port (and return the port), or unregister it (when C<$callback>	305	given tag on the given port (and return the port), or unregister it (when
358	is C<$undef>).	306	C<$callback> is C<$undef> or missing). There can only be one callback
		307	registered for each tag.
359		308
360	The original message will be passed to the callback, after the first	309	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	310	element (the tag) has been removed. The callback will use the same
362	environment as the default callback (see above).	311	environment as the default callback (see above).
363		312
…		…
375	rcv port,	324	rcv port,
376	msg1 => sub { ... },	325	msg1 => sub { ... },
377	...	326	...
378	;	327	;
379		328
		329	Example: temporarily register a rcv callback for a tag matching some port
		330	(e.g. for a rpc reply) and unregister it after a message was received.
		331
		332	rcv $port, $otherport => sub {
		333	my @reply = @_;
		334
		335	rcv $SELF, $otherport;
		336	};
		337
380	=cut	338	=cut
381		339
382	sub rcv($@) {	340	sub rcv($@) {
383	my $port = shift;	341	my $port = shift;
384	my ($noderef, $portid) = split /#/, $port, 2;	342	my ($noderef, $portid) = split /#/, $port, 2;
385		343
386	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}	344	$NODE{$noderef} == $NODE{""}
387	or Carp::croak "$port: rcv can only be called on local ports, caught";	345	or Carp::croak "$port: rcv can only be called on local ports, caught";
388		346
389	while (@_) {	347	while (@_) {
390	if (ref $_[0]) {	348	if (ref $_[0]) {
391	if (my $self = $PORT_DATA{$portid}) {	349	if (my $self = $PORT_DATA{$portid}) {
…		…
490	message loss has been detected. No messages will be lost "in between"	448	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	449	(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	450	port). After the monitoring action was invoked, further messages might get
493	delivered again.	451	delivered again.
494		452
		453	Note that monitoring-actions are one-shot: once released, they are removed
		454	and will not trigger again.
		455
495	In the first form (callback), the callback is simply called with any	456	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	457	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	458	"normally"). Note also that I<< the callback B<must> never die >>, so use
498	C<eval> if unsure.	459	C<eval> if unsure.
499		460
…		…
659	my $id = "$RUNIQ." . $ID++;	620	my $id = "$RUNIQ." . $ID++;
660		621
661	$_[0] =~ /::/	622	$_[0] =~ /::/
662	or Carp::croak "spawn init function must be a fully-qualified name, caught";	623	or Carp::croak "spawn init function must be a fully-qualified name, caught";
663		624
664	($NODE{$noderef} \|\| add_node $noderef)	625	snd_to_func $noderef, "AnyEvent::MP::_spawn" => $id, @_;
665	->send (["", "AnyEvent::MP::_spawn" => $id, @_]);
666		626
667	"$noderef#$id"	627	"$noderef#$id"
668	}	628	}
669		629
670	=back	630	=item after $timeout, @msg
671		631
672	=head1 NODE MESSAGES	632	=item after $timeout, $callback
673		633
674	Nodes understand the following messages sent to them. Many of them take	634	Either sends the given message, or call the given callback, after the
675	arguments called C<@reply>, which will simply be used to compose a reply	635	specified number of seconds.
676	message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and
677	the remaining arguments are simply the message data.
678		636
679	While other messages exist, they are not public and subject to change.	637	This is simply a utility function that come sin handy at times.
680		638
681	=over 4
682
683	=cut	639	=cut
684		640
685	=item lookup => $name, @reply	641	sub after($@) {
		642	my ($timeout, @action) = @_;
686		643
687	Replies with the port ID of the specified well-known port, or C<undef>.	644	my $t; $t = AE::timer $timeout, 0, sub {
688		645	undef $t;
689	=item devnull => ...	646	ref $action[0]
690		647	? $action[0]()
691	Generic data sink/CPU heat conversion.	648	: snd @action;
692		649	};
693	=item relay => $port, @msg	650	}
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		651
716	=back	652	=back
717		653
718	=head1 AnyEvent::MP vs. Distributed Erlang	654	=head1 AnyEvent::MP vs. Distributed Erlang
719		655
…		…
738	convenience functionality.	674	convenience functionality.
739		675
740	This means that AEMP requires a less tightly controlled environment at the	676	This means that AEMP requires a less tightly controlled environment at the
741	cost of longer node references and a slightly higher management overhead.	677	cost of longer node references and a slightly higher management overhead.
742		678
743	=item Erlang has a "remote ports are like local ports" philosophy, AEMP	679	=item * Erlang has a "remote ports are like local ports" philosophy, AEMP
744	uses "local ports are like remote ports".	680	uses "local ports are like remote ports".
745		681
746	The failure modes for local ports are quite different (runtime errors	682	The failure modes for local ports are quite different (runtime errors
747	only) then for remote ports - when a local port dies, you I<know> it dies,	683	only) then for remote ports - when a local port dies, you I<know> it dies,
748	when a connection to another node dies, you know nothing about the other	684	when a connection to another node dies, you know nothing about the other

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.51 by root, Fri Aug 14 14:07:44 2009 UTC vs. Revision 1.64 by root, Fri Aug 28 00:58:44 2009 UTC

Diff Legend

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.51 by root, Fri Aug 14 14:07:44 2009 UTC vs.
Revision 1.64 by root, Fri Aug 28 00:58:44 2009 UTC