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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.46 by root, Thu Aug 13 01:46:10 2009 UTC vs.
Revision 1.64 by root, Fri Aug 28 00:58:44 2009 UTC

…		…
9	$NODE # contains this node's noderef	9	$NODE # contains this node's noderef
10	NODE # returns this node's noderef	10	NODE # returns this node's noderef
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
		15	# initialise the node so it can send/receive messages
		16	initialise_node;
14		17
15	# ports are message endpoints	18	# ports are message endpoints
16		19
17	# sending messages	20	# sending messages
18	snd $port, type => data...;	21	snd $port, type => data...;
19	snd $port, @msg;	22	snd $port, @msg;
20	snd @msg_with_first_element_being_a_port;	23	snd @msg_with_first_element_being_a_port;
21		24
22	# miniports	25	# creating/using ports, the simple way
23	my $miniport = port { my @msg = @_; 0 };	26	my $simple_port = port { my @msg = @_; 0 };
24		27
25	# full ports	28	# creating/using ports, tagged message matching
26	my $port = port;	29	my $port = port;
27	rcv $port, smartmatch => $cb->(@msg);
28	rcv $port, ping => sub { snd $_[0], "pong"; 0 };	30	rcv $port, ping => sub { snd $_[0], "pong"; 0 };
29	rcv $port, pong => sub { warn "pong received\n"; 0 };	31	rcv $port, pong => sub { warn "pong received\n"; 0 };
30		32
31	# remote ports	33	# create a port on another node
32	my $port = spawn $node, $initfunc, @initdata;	34	my $port = spawn $node, $initfunc, @initdata;
33
34	# more, smarter, matches (_any_ is exported by this module)
35	rcv $port, [child_died => $pid] => sub { ...
36	rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3
37		35
38	# monitoring	36	# monitoring
39	mon $port, $cb->(@msg) # callback is invoked on death	37	mon $port, $cb->(@msg) # callback is invoked on death
40	mon $port, $otherport # kill otherport on abnormal death	38	mon $port, $otherport # kill otherport on abnormal death
41	mon $port, $otherport, @msg # send message on death	39	mon $port, $otherport, @msg # send message on death
…		…
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, $master...
160
161	Before a node can talk to other nodes on the network it has to initialise	168	Before a node can talk to other nodes on the network (i.e. enter
162	itself - the minimum a node needs to know is it's own name, and optionally	169	"distributed mode") it has to initialise itself - the minimum a node needs
163	it should know the noderefs of some other nodes in the network.	170	to know is its own name, and optionally it should know the addresses of
		171	some other nodes in the network to discover other nodes.
164		172
165	This function initialises a node - it must be called exactly once (or	173	This function initialises a node - it must be called exactly once (or
166	never) before calling other AnyEvent::MP functions.	174	never) before calling other AnyEvent::MP functions.
167		175
168	All arguments are noderefs, which can be either resolved or unresolved.	176	The first argument is a profile name. If it is C<undef> or missing, then
		177	the current nodename will be used instead (i.e. F<uname -n>).
169		178
170	There are two types of networked nodes, public nodes and slave nodes:	179	The function then looks up the profile in the aemp configuration (see the
		180	L<aemp> commandline utility).
171		181
172	=over 4	182	If the profile specifies a node ID, then this will become the node ID of
		183	this process. If not, then the profile name will be used as node ID. The
		184	special node ID of C<anon/> will be replaced by a random node ID.
173		185
174	=item public nodes	186	The next step is to look up the binds in the profile, followed by binding
		187	aemp protocol listeners on all binds specified (it is possible and valid
		188	to have no binds, meaning that the node cannot be contacted form the
		189	outside. This means the node cannot talk to other nodes that also have no
		190	binds, but it can still talk to all "normal" nodes).
175		191
176	For public nodes, C<$noderef> must either be a (possibly unresolved)	192	If the profile does not specify a binds list, then the node ID will be
177	noderef, in which case it will be resolved, or C<undef> (or missing), in	193	treated as if it were of the form C<host:port>, which will be resolved and
178	which case the noderef will be guessed.	194	used as binds list.
179		195
180	Afterwards, the node will bind itself on all endpoints and try to connect	196	Lastly, the seeds list from the profile is passed to the
181	to all additional C<$seednodes> that are specified. Seednodes are optional	197	L<AnyEvent::MP::Global> module, which will then use it to keep
182	and can be used to quickly bootstrap the node into an existing network.	198	connectivity with at least on of those seed nodes at any point in time.
183		199
184	=item slave nodes	200	Example: become a distributed node listening on the guessed noderef, or
185		201	the one specified via C<aemp> for the current node. This should be the
186	When the C<$noderef> is the special string C<slave/>, then the node will	202	most common form of invocation for "daemon"-type nodes.
187	become a slave node. Slave nodes cannot be contacted from outside and will
188	route most of their traffic to the master node that they attach to.
189
190	At least one additional noderef is required: The node will try to connect
191	to all of them and will become a slave attached to the first node it can
192	successfully connect to.
193
194	=back
195
196	This function will block until all nodes have been resolved and, for slave
197	nodes, until it has successfully established a connection to a master
198	server.
199
200	Example: become a public node listening on the default node.
201		203
202	initialise_node;	204	initialise_node;
203		205
204	Example: become a public node, and try to contact some well-known master	206	Example: become an anonymous node. This form is often used for commandline
205	servers to become part of the network.	207	clients.
206		208
207	initialise_node undef, "master1", "master2";
208
209	Example: become a public node listening on port C<4041>.
210
211	initialise_node 4041;	209	initialise_node "anon/";
212		210
213	Example: become a public node, only visible on localhost port 4044.	211	Example: become a distributed node. If there is no profile of the given
		212	name, or no binds list was specified, resolve C<localhost:4044> and bind
		213	on the resulting addresses.
214		214
215	initialise_node "locahost:4044";	215	initialise_node "localhost:4044";
216
217	Example: become a slave node to any of the specified master servers.
218
219	initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net";
220
221	=item $cv = resolve_node $noderef
222
223	Takes an unresolved node reference that may contain hostnames and
224	abbreviated IDs, resolves all of them and returns a resolved node
225	reference.
226
227	In addition to C<address:port> pairs allowed in resolved noderefs, the
228	following forms are supported:
229
230	=over 4
231
232	=item the empty string
233
234	An empty-string component gets resolved as if the default port (4040) was
235	specified.
236
237	=item naked port numbers (e.g. C<1234>)
238
239	These are resolved by prepending the local nodename and a colon, to be
240	further resolved.
241
242	=item hostnames (e.g. C<localhost:1234>, C<localhost>)
243
244	These are resolved by using AnyEvent::DNS to resolve them, optionally
245	looking up SRV records for the C<aemp=4040> port, if no port was
246	specified.
247
248	=back
249		216
250	=item $SELF	217	=item $SELF
251		218
252	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>
253	blocks.	220	blocks.
…		…
261	=item snd $port, type => @data	228	=item snd $port, type => @data
262		229
263	=item snd $port, @msg	230	=item snd $port, @msg
264		231
265	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
266	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.
267	stringifies a sa port ID (such as a port object :).
268		234
269	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
270	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
271	type etc.).	237	type etc.).
272		238
273	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
274	function: modifying any argument is not allowed and can cause many	240	function: modifying any argument is not allowed and can cause many
275	problems.	241	problems.
…		…
280	that Storable can serialise and deserialise is allowed, and for the local	246	that Storable can serialise and deserialise is allowed, and for the local
281	node, anything can be passed.	247	node, anything can be passed.
282		248
283	=item $local_port = port	249	=item $local_port = port
284		250
285	Create a new local port object that can be used either as a pattern	251	Create a new local port object and returns its port ID. Initially it has
286	matching port ("full port") or a single-callback port ("miniport"),	252	no callbacks set and will throw an error when it receives messages.
287	depending on how C<rcv> callbacks are bound to the object.
288		253
289	=item $port = port { my @msg = @_; $finished }	254	=item $local_port = port { my @msg = @_ }
290		255
291	Creates a "miniport", that is, a very lightweight port without any pattern	256	Creates a new local port, and returns its ID. Semantically the same as
292	matching behind it, and returns its ID. Semantically the same as creating
293	a port and calling C<rcv $port, $callback> on it.	257	creating a port and calling C<rcv $port, $callback> on it.
294		258
295	The block will be called for every message received on the port. When the	259	The block will be called for every message received on the port, with the
296	callback returns a true value its job is considered "done" and the port	260	global variable C<$SELF> set to the port ID. Runtime errors will cause the
297	will be destroyed. Otherwise it will stay alive.	261	port to be C<kil>ed. The message will be passed as-is, no extra argument
		262	(i.e. no port ID) will be passed to the callback.
298		263
299	The message will be passed as-is, no extra argument (i.e. no port id) will	264	If you want to stop/destroy the port, simply C<kil> it:
300	be passed to the callback.
301		265
302	If you need the local port id in the callback, this works nicely:	266	my $port = port {
303		267	my @msg = @_;
304	my $port; $port = port {	268	...
305	snd $otherport, reply => $port;	269	kil $SELF;
306	};	270	};
307		271
308	=cut	272	=cut
309		273
310	sub rcv($@);	274	sub rcv($@);
		275
		276	sub _kilme {
		277	die "received message on port without callback";
		278	}
311		279
312	sub port(;&) {	280	sub port(;&) {
313	my $id = "$UNIQ." . $ID++;	281	my $id = "$UNIQ." . $ID++;
314	my $port = "$NODE#$id";	282	my $port = "$NODE#$id";
315		283
316	if (@_) {	284	rcv $port, shift \|\| \&_kilme;
317	rcv $port, shift;
318	} else {
319	$PORT{$id} = sub { }; # nop
320	}
321		285
322	$port	286	$port
323	}	287	}
324		288
325	=item reg $port, $name
326
327	=item reg $name
328
329	Registers the given port (or C<$SELF><<< if missing) under the name
330	C<$name>. If the name already exists it is replaced.
331
332	A port can only be registered under one well known name.
333
334	A port automatically becomes unregistered when it is killed.
335
336	=cut
337
338	sub reg(@) {
339	my $port = @_ > 1 ? shift : $SELF \|\| Carp::croak 'reg: called with one argument only, but $SELF not set,';
340
341	$REG{$_[0]} = $port;
342	}
343
344	=item rcv $port, $callback->(@msg)	289	=item rcv $local_port, $callback->(@msg)
345		290
346	Replaces the callback on the specified miniport (after converting it to	291	Replaces the default callback on the specified port. There is no way to
347	one if required).	292	remove the default callback: use C<sub { }> to disable it, or better
348		293	C<kil> the port when it is no longer needed.
349	=item rcv $port, tagstring => $callback->(@msg), ...
350
351	=item rcv $port, $smartmatch => $callback->(@msg), ...
352
353	=item rcv $port, [$smartmatch...] => $callback->(@msg), ...
354
355	Register callbacks to be called on matching messages on the given full
356	port (after converting it to one if required) and return the port.
357
358	The callback has to return a true value when its work is done, after
359	which is will be removed, or a false value in which case it will stay
360	registered.
361		294
362	The global C<$SELF> (exported by this module) contains C<$port> while	295	The global C<$SELF> (exported by this module) contains C<$port> while
363	executing the callback.	296	executing the callback. Runtime errors during callback execution will
		297	result in the port being C<kil>ed.
364		298
365	Runtime errors during callback execution will result in the port being	299	The default callback received all messages not matched by a more specific
366	C<kil>ed.	300	C<tag> match.
367		301
368	If the match is an array reference, then it will be matched against the	302	=item rcv $local_port, tag => $callback->(@msg_without_tag), ...
369	first elements of the message, otherwise only the first element is being
370	matched.
371		303
372	Any element in the match that is specified as C<_any_> (a function	304	Register (or replace) callbacks to be called on messages starting with the
373	exported by this module) matches any single element of the message.	305	given tag on the given port (and return the port), or unregister it (when
		306	C<$callback> is C<$undef> or missing). There can only be one callback
		307	registered for each tag.
374		308
375	While not required, it is highly recommended that the first matching	309	The original message will be passed to the callback, after the first
376	element is a string identifying the message. The one-string-only match is	310	element (the tag) has been removed. The callback will use the same
377	also the most efficient match (by far).	311	environment as the default callback (see above).
378		312
379	Example: create a port and bind receivers on it in one go.	313	Example: create a port and bind receivers on it in one go.
380		314
381	my $port = rcv port,	315	my $port = rcv port,
382	msg1 => sub { ...; 0 },	316	msg1 => sub { ... },
383	msg2 => sub { ...; 0 },	317	msg2 => sub { ... },
384	;	318	;
385		319
386	Example: create a port, bind receivers and send it in a message elsewhere	320	Example: create a port, bind receivers and send it in a message elsewhere
387	in one go:	321	in one go:
388		322
389	snd $otherport, reply =>	323	snd $otherport, reply =>
390	rcv port,	324	rcv port,
391	msg1 => sub { ...; 0 },	325	msg1 => sub { ... },
392	...	326	...
393	;	327	;
		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, $otherport;
		336	};
394		337
395	=cut	338	=cut
396		339
397	sub rcv($@) {	340	sub rcv($@) {
398	my $port = shift;	341	my $port = shift;
399	my ($noderef, $portid) = split /#/, $port, 2;	342	my ($noderef, $portid) = split /#/, $port, 2;
400		343
401	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}	344	$NODE{$noderef} == $NODE{""}
402	or Carp::croak "$port: rcv can only be called on local ports, caught";	345	or Carp::croak "$port: rcv can only be called on local ports, caught";
403		346
404	if (@_ == 1) {	347	while (@_) {
		348	if (ref $_[0]) {
		349	if (my $self = $PORT_DATA{$portid}) {
		350	"AnyEvent::MP::Port" eq ref $self
		351	or Carp::croak "$port: rcv can only be called on message matching ports, caught";
		352
		353	$self->[2] = shift;
		354	} else {
405	my $cb = shift;	355	my $cb = shift;
406	delete $PORT_DATA{$portid};
407	$PORT{$portid} = sub {	356	$PORT{$portid} = sub {
408	local $SELF = $port;	357	local $SELF = $port;
409	eval {	358	eval { &$cb }; _self_die if $@;
410	&$cb	359	};
411	and kil $port;
412	};	360	}
413	_self_die if $@;	361	} elsif (defined $_[0]) {
414	};
415	} else {
416	my $self = $PORT_DATA{$portid} \|\|= do {	362	my $self = $PORT_DATA{$portid} \|\|= do {
417	my $self = bless {	363	my $self = bless [$PORT{$port} \|\| sub { }, { }, $port], "AnyEvent::MP::Port";
418	id => $port,
419	}, "AnyEvent::MP::Port";
420		364
421	$PORT{$portid} = sub {	365	$PORT{$portid} = sub {
422	local $SELF = $port;	366	local $SELF = $port;
423		367
424	eval {
425	for (@{ $self->{rc0}{$_[0]} }) {	368	if (my $cb = $self->[1]{$_[0]}) {
426	$_ && &{$_->[0]}	369	shift;
427	&& undef $_;	370	eval { &$cb }; _self_die if $@;
428	}	371	} else {
429
430	for (@{ $self->{rcv}{$_[0]} }) {
431	$_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1]
432	&& &{$_->[0]}	372	&{ $self->[0] };
433	&& undef $_;
434	}
435
436	for (@{ $self->{any} }) {
437	$_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1]
438	&& &{$_->[0]}
439	&& undef $_;
440	}	373	}
441	};	374	};
442	_self_die if $@;	375
		376	$self
443	};	377	};
444		378
445	$self
446	};
447
448	"AnyEvent::MP::Port" eq ref $self	379	"AnyEvent::MP::Port" eq ref $self
449	or Carp::croak "$port: rcv can only be called on message matching ports, caught";	380	or Carp::croak "$port: rcv can only be called on message matching ports, caught";
450		381
451	while (@_) {
452	my ($match, $cb) = splice @_, 0, 2;	382	my ($tag, $cb) = splice @_, 0, 2;
453		383
454	if (!ref $match) {	384	if (defined $cb) {
455	push @{ $self->{rc0}{$match} }, [$cb];	385	$self->[1]{$tag} = $cb;
456	} elsif (("ARRAY" eq ref $match && !ref $match->[0])) {
457	my ($type, @match) = @$match;
458	@match
459	? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match]
460	: push @{ $self->{rc0}{$match->[0]} }, [$cb];
461	} else {	386	} else {
462	push @{ $self->{any} }, [$cb, $match];	387	delete $self->[1]{$tag};
463	}	388	}
464	}	389	}
465	}	390	}
466		391
467	$port	392	$port
…		…
522	will arrive, or the monitoring action will be invoked after possible	447	will arrive, or the monitoring action will be invoked after possible
523	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"
524	(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
525	port). After the monitoring action was invoked, further messages might get	450	port). After the monitoring action was invoked, further messages might get
526	delivered again.	451	delivered again.
		452
		453	Note that monitoring-actions are one-shot: once released, they are removed
		454	and will not trigger again.
527		455
528	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
529	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
530	"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
531	C<eval> if unsure.	459	C<eval> if unsure.
…		…
692	my $id = "$RUNIQ." . $ID++;	620	my $id = "$RUNIQ." . $ID++;
693		621
694	$_[0] =~ /::/	622	$_[0] =~ /::/
695	or Carp::croak "spawn init function must be a fully-qualified name, caught";	623	or Carp::croak "spawn init function must be a fully-qualified name, caught";
696		624
697	($NODE{$noderef} \|\| add_node $noderef)	625	snd_to_func $noderef, "AnyEvent::MP::_spawn" => $id, @_;
698	->send (["", "AnyEvent::MP::_spawn" => $id, @_]);
699		626
700	"$noderef#$id"	627	"$noderef#$id"
701	}	628	}
702		629
703	=back	630	=item after $timeout, @msg
704		631
705	=head1 NODE MESSAGES	632	=item after $timeout, $callback
706		633
707	Nodes understand the following messages sent to them. Many of them take	634	Either sends the given message, or call the given callback, after the
708	arguments called C<@reply>, which will simply be used to compose a reply	635	specified number of seconds.
709	message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and
710	the remaining arguments are simply the message data.
711		636
712	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.
713		638
714	=over 4
715
716	=cut	639	=cut
717		640
718	=item lookup => $name, @reply	641	sub after($@) {
		642	my ($timeout, @action) = @_;
719		643
720	Replies with the port ID of the specified well-known port, or C<undef>.	644	my $t; $t = AE::timer $timeout, 0, sub {
721		645	undef $t;
722	=item devnull => ...	646	ref $action[0]
723		647	? $action[0]()
724	Generic data sink/CPU heat conversion.	648	: snd @action;
725		649	};
726	=item relay => $port, @msg	650	}
727
728	Simply forwards the message to the given port.
729
730	=item eval => $string[ @reply]
731
732	Evaluates the given string. If C<@reply> is given, then a message of the
733	form C<@reply, $@, @evalres> is sent.
734
735	Example: crash another node.
736
737	snd $othernode, eval => "exit";
738
739	=item time => @reply
740
741	Replies the the current node time to C<@reply>.
742
743	Example: tell the current node to send the current time to C<$myport> in a
744	C<timereply> message.
745
746	snd $NODE, time => $myport, timereply => 1, 2;
747	# => snd $myport, timereply => 1, 2, <time>
748		651
749	=back	652	=back
750		653
751	=head1 AnyEvent::MP vs. Distributed Erlang	654	=head1 AnyEvent::MP vs. Distributed Erlang
752		655
…		…
771	convenience functionality.	674	convenience functionality.
772		675
773	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
774	cost of longer node references and a slightly higher management overhead.	677	cost of longer node references and a slightly higher management overhead.
775		678
		679	=item * Erlang has a "remote ports are like local ports" philosophy, AEMP
		680	uses "local ports are like remote ports".
		681
		682	The failure modes for local ports are quite different (runtime errors
		683	only) then for remote ports - when a local port dies, you I<know> it dies,
		684	when a connection to another node dies, you know nothing about the other
		685	port.
		686
		687	Erlang pretends remote ports are as reliable as local ports, even when
		688	they are not.
		689
		690	AEMP encourages a "treat remote ports differently" philosophy, with local
		691	ports being the special case/exception, where transport errors cannot
		692	occur.
		693
776	=item * Erlang uses processes and a mailbox, AEMP does not queue.	694	=item * Erlang uses processes and a mailbox, AEMP does not queue.
777		695
778	Erlang uses processes that selctively receive messages, and therefore	696	Erlang uses processes that selectively receive messages, and therefore
779	needs a queue. AEMP is event based, queuing messages would serve no useful	697	needs a queue. AEMP is event based, queuing messages would serve no
780	purpose.	698	useful purpose. For the same reason the pattern-matching abilities of
		699	AnyEvent::MP are more limited, as there is little need to be able to
		700	filter messages without dequeing them.
781		701
782	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).	702	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).
783		703
784	=item * Erlang sends are synchronous, AEMP sends are asynchronous.	704	=item * Erlang sends are synchronous, AEMP sends are asynchronous.
785		705
786	Sending messages in Erlang is synchronous and blocks the process. AEMP	706	Sending messages in Erlang is synchronous and blocks the process (and
787	sends are immediate, connection establishment is handled in the	707	so does not need a queue that can overflow). AEMP sends are immediate,
788	background.	708	connection establishment is handled in the background.
789		709
790	=item * Erlang can silently lose messages, AEMP cannot.	710	=item * Erlang suffers from silent message loss, AEMP does not.
791		711
792	Erlang makes few guarantees on messages delivery - messages can get lost	712	Erlang makes few guarantees on messages delivery - messages can get lost
793	without any of the processes realising it (i.e. you send messages a, b,	713	without any of the processes realising it (i.e. you send messages a, b,
794	and c, and the other side only receives messages a and c).	714	and c, and the other side only receives messages a and c).
795		715
…		…
807	eventually be killed - it cannot happen that a node detects a port as dead	727	eventually be killed - it cannot happen that a node detects a port as dead
808	and then later sends messages to it, finding it is still alive.	728	and then later sends messages to it, finding it is still alive.
809		729
810	=item * Erlang can send messages to the wrong port, AEMP does not.	730	=item * Erlang can send messages to the wrong port, AEMP does not.
811		731
812	In Erlang it is quite possible that a node that restarts reuses a process	732	In Erlang it is quite likely that a node that restarts reuses a process ID
813	ID known to other nodes for a completely different process, causing	733	known to other nodes for a completely different process, causing messages
814	messages destined for that process to end up in an unrelated process.	734	destined for that process to end up in an unrelated process.
815		735
816	AEMP never reuses port IDs, so old messages or old port IDs floating	736	AEMP never reuses port IDs, so old messages or old port IDs floating
817	around in the network will not be sent to an unrelated port.	737	around in the network will not be sent to an unrelated port.
818		738
819	=item * Erlang uses unprotected connections, AEMP uses secure	739	=item * Erlang uses unprotected connections, AEMP uses secure
…		…
868	the network frequently, the serialising/deserialising would add lots of	788	the network frequently, the serialising/deserialising would add lots of
869	overhead, as well as having to keep a proxy object.	789	overhead, as well as having to keep a proxy object.
870		790
871	Strings can easily be printed, easily serialised etc. and need no special	791	Strings can easily be printed, easily serialised etc. and need no special
872	procedures to be "valid".	792	procedures to be "valid".
		793
		794	And a a miniport consists of a single closure stored in a global hash - it
		795	can't become much cheaper.
873		796
874	=item Why favour JSON, why not real serialising format such as Storable?	797	=item Why favour JSON, why not real serialising format such as Storable?
875		798
876	In fact, any AnyEvent::MP node will happily accept Storable as framing	799	In fact, any AnyEvent::MP node will happily accept Storable as framing
877	format, but currently there is no way to make a node use Storable by	800	format, but currently there is no way to make a node use Storable by

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.46 by root, Thu Aug 13 01:46:10 2009 UTC vs. Revision 1.64 by root, Fri Aug 28 00:58:44 2009 UTC

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Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.46 by root, Thu Aug 13 01:46:10 2009 UTC vs.
Revision 1.64 by root, Fri Aug 28 00:58:44 2009 UTC