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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.7 by root, Sat Aug 1 15:04:30 2009 UTC vs.
Revision 1.31 by root, Wed Aug 5 19:55:58 2009 UTC

…		…
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use AnyEvent::MP;	7	use AnyEvent::MP;
8		8
9	NODE # returns this node identifier
10	$NODE # contains this node identifier	9	$NODE # contains this node's noderef
		10	NODE # returns this node's noderef
		11	NODE $port # returns the noderef of the port
11		12
12	snd $port, type => data...;	13	snd $port, type => data...;
		14
		15	$SELF # receiving/own port id in rcv callbacks
13		16
14	rcv $port, smartmatch => $cb->($port, @msg);	17	rcv $port, smartmatch => $cb->($port, @msg);
15		18
16	# examples:	19	# examples:
17	rcv $port2, ping => sub { snd $_[0], "pong"; 0 };	20	rcv $port2, ping => sub { snd $_[0], "pong"; 0 };
…		…
27	This module (-family) implements a simple message passing framework.	30	This module (-family) implements a simple message passing framework.
28		31
29	Despite its simplicity, you can securely message other processes running	32	Despite its simplicity, you can securely message other processes running
30	on the same or other hosts.	33	on the same or other hosts.
31		34
		35	For an introduction to this module family, see the L<AnyEvent::MP::Intro>
		36	manual page.
		37
32	At the moment, this module family is severly brokena nd underdocumented,	38	At the moment, this module family is severly broken and underdocumented,
33	so do not use. This was uploaded mainly to resreve the CPAN namespace -	39	so do not use. This was uploaded mainly to reserve the CPAN namespace -
34	stay tuned!	40	stay tuned! The basic API should be finished, however.
35		41
36	=head1 CONCEPTS	42	=head1 CONCEPTS
37		43
38	=over 4	44	=over 4
39		45
40	=item port	46	=item port
41		47
42	A port is something you can send messages to with the C<snd> function, and	48	A port is something you can send messages to (with the C<snd> function).
43	you can register C<rcv> handlers with. All C<rcv> handlers will receive	49
44	messages they match, messages will not be queued.	50	Some ports allow you to register C<rcv> handlers that can match specific
		51	messages. All C<rcv> handlers will receive messages they match, messages
		52	will not be queued.
45		53
46	=item port id - C<noderef#portname>	54	=item port id - C<noderef#portname>
47		55
48	A port id is always the noderef, a hash-mark (C<#>) as separator, followed	56	A port id is normaly the concatenation of a noderef, a hash-mark (C<#>) as
49	by a port name (a printable string of unspecified format).	57	separator, and a port name (a printable string of unspecified format). An
		58	exception is the the node port, whose ID is identical to its node
		59	reference.
50		60
51	=item node	61	=item node
52		62
53	A node is a single process containing at least one port - the node	63	A node is a single process containing at least one port - the node
54	port. You can send messages to node ports to let them create new ports,	64	port. You can send messages to node ports to find existing ports or to
55	among other things.	65	create new ports, among other things.
56		66
57	Initially, nodes are either private (single-process only) or hidden	67	Nodes are either private (single-process only), slaves (connected to a
58	(connected to a master node only). Only when they epxlicitly "become	68	master node only) or public nodes (connectable from unrelated nodes).
59	public" can you send them messages from unrelated other nodes.
60		69
61	=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>	70	=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>
62		71
63	A noderef is a string that either uniquely identifies a given node (for	72	A node reference is a string that either simply identifies the node (for
64	private and hidden nodes), or contains a recipe on how to reach a given	73	private and slave nodes), or contains a recipe on how to reach a given
65	node (for public nodes).	74	node (for public nodes).
66		75
		76	This recipe is simply a comma-separated list of C<address:port> pairs (for
		77	TCP/IP, other protocols might look different).
		78
		79	Node references come in two flavours: resolved (containing only numerical
		80	addresses) or unresolved (where hostnames are used instead of addresses).
		81
		82	Before using an unresolved node reference in a message you first have to
		83	resolve it.
		84
67	=back	85	=back
68		86
69	=head1 VARIABLES/FUNCTIONS	87	=head1 VARIABLES/FUNCTIONS
70		88
71	=over 4	89	=over 4
72		90
73	=cut	91	=cut
74		92
75	package AnyEvent::MP;	93	package AnyEvent::MP;
76		94
77	use AnyEvent::MP::Util ();
78	use AnyEvent::MP::Node;	95	use AnyEvent::MP::Base;
79	use AnyEvent::MP::Transport;
80		96
81	use utf8;
82	use common::sense;	97	use common::sense;
83		98
84	use Carp ();	99	use Carp ();
85		100
86	use AE ();	101	use AE ();
87		102
88	use base "Exporter";	103	use base "Exporter";
89		104
90	our $VERSION = '0.01';	105	our $VERSION = '0.1';
91	our @EXPORT = qw(NODE $NODE $PORT snd rcv _any_);	106	our @EXPORT = qw(
		107	NODE $NODE *SELF node_of _any_
		108	resolve_node initialise_node
		109	snd rcv mon kil reg psub
		110	port
		111	);
92		112
93	our $DEFAULT_SECRET;	113	our $SELF;
94	our $DEFAULT_PORT = "4040";
95		114
96	our $CONNECT_INTERVAL = 5; # new connect every 5s, at least	115	sub _self_die() {
97	our $CONNECT_TIMEOUT = 30; # includes handshake	116	my $msg = $@;
98		117	$msg =~ s/\n+$// unless ref $msg;
99	sub default_secret {	118	kil $SELF, die => $msg;
100	unless (defined $DEFAULT_SECRET) {
101	if (open my $fh, "<$ENV{HOME}/.aemp-secret") {
102	sysread $fh, $DEFAULT_SECRET, -s $fh;
103	} else {
104	$DEFAULT_SECRET = AnyEvent::MP::Util::nonce 32;
105	}
106	}
107
108	$DEFAULT_SECRET
109	}	119	}
110		120
111	=item NODE / $NODE	121	=item $thisnode = NODE / $NODE
112		122
113	The C<NODE ()> function and the C<$NODE> variable contain the noderef of	123	The C<NODE> function returns, and the C<$NODE> variable contains
114	the local node. The value is initialised by a call to C<become_public> or	124	the noderef of the local node. The value is initialised by a call
115	C<become_slave>, after which all local port identifiers become invalid.	125	to C<become_public> or C<become_slave>, after which all local port
		126	identifiers become invalid.
116		127
117	=cut	128	=item $noderef = node_of $portid
118		129
119	our $UNIQ = sprintf "%x.%x", $$, time; # per-process/node unique cookie	130	Extracts and returns the noderef from a portid or a noderef.
120	our $ID = "a0";
121	our $PUBLIC = 0;
122	our $NODE;
123	our $PORT;
124		131
125	our %NODE; # node id to transport mapping, or "undef", for local node	132	=item $cv = resolve_node $noderef
126	our %PORT; # local ports
127	our %LISTENER; # local transports
128		133
129	sub NODE() { $NODE }	134	Takes an unresolved node reference that may contain hostnames and
		135	abbreviated IDs, resolves all of them and returns a resolved node
		136	reference.
130		137
131	{	138	In addition to C<address:port> pairs allowed in resolved noderefs, the
132	use POSIX ();	139	following forms are supported:
133	my $nodename = (POSIX::uname)[1];
134	$NODE = "$$\@$nodename";
135	}
136		140
137	sub _ANY_() { 1 }	141	=over 4
138	sub _any_() { \&_ANY_ }
139		142
140	sub add_node {	143	=item the empty string
141	my ($noderef) = @_;
142		144
143	return $NODE{$noderef}	145	An empty-string component gets resolved as if the default port (4040) was
144	if exists $NODE{$noderef};	146	specified.
145		147
146	for (split /,/, $noderef) {	148	=item naked port numbers (e.g. C<1234>)
147	return $NODE{$noderef} = $NODE{$_}
148	if exists $NODE{$_};
149	}
150		149
151	# for indirect sends, use a different class	150	These are resolved by prepending the local nodename and a colon, to be
152	my $node = new AnyEvent::MP::Node::Direct $noderef;	151	further resolved.
153		152
154	$NODE{$_} = $node	153	=item hostnames (e.g. C<localhost:1234>, C<localhost>)
155	for $noderef, split /,/, $noderef;
156		154
157	$node	155	These are resolved by using AnyEvent::DNS to resolve them, optionally
158	}	156	looking up SRV records for the C<aemp=4040> port, if no port was
		157	specified.
		158
		159	=back
		160
		161	=item $SELF
		162
		163	Contains the current port id while executing C<rcv> callbacks or C<psub>
		164	blocks.
		165
		166	=item SELF, %SELF, @SELF...
		167
		168	Due to some quirks in how perl exports variables, it is impossible to
		169	just export C<$SELF>, all the symbols called C<SELF> are exported by this
		170	module, but only C<$SELF> is currently used.
159		171
160	=item snd $portid, type => @data	172	=item snd $portid, type => @data
161		173
162	=item snd $portid, @msg	174	=item snd $portid, @msg
163		175
164	Send the given message to the given port ID, which can identify either a	176	Send the given message to the given port ID, which can identify either
165	local or a remote port.	177	a local or a remote port, and can be either a string or soemthignt hat
		178	stringifies a sa port ID (such as a port object :).
166		179
167	While the message can be about anything, it is highly recommended to use	180	While the message can be about anything, it is highly recommended to use a
168	a constant string as first element.	181	string as first element (a portid, or some word that indicates a request
		182	type etc.).
169		183
170	The message data effectively becomes read-only after a call to this	184	The message data effectively becomes read-only after a call to this
171	function: modifying any argument is not allowed and can cause many	185	function: modifying any argument is not allowed and can cause many
172	problems.	186	problems.
173		187
…		…
175	JSON is used, then only strings, numbers and arrays and hashes consisting	189	JSON is used, then only strings, numbers and arrays and hashes consisting
176	of those are allowed (no objects). When Storable is used, then anything	190	of those are allowed (no objects). When Storable is used, then anything
177	that Storable can serialise and deserialise is allowed, and for the local	191	that Storable can serialise and deserialise is allowed, and for the local
178	node, anything can be passed.	192	node, anything can be passed.
179		193
180	=cut	194	=item kil $portid[, @reason]
181		195
182	sub snd(@) {	196	Kill the specified port with the given C<@reason>.
		197
		198	If no C<@reason> is specified, then the port is killed "normally" (linked
		199	ports will not be kileld, or even notified).
		200
		201	Otherwise, linked ports get killed with the same reason (second form of
		202	C<mon>, see below).
		203
		204	Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks
		205	will be reported as reason C<< die => $@ >>.
		206
		207	Transport/communication errors are reported as C<< transport_error =>
		208	$message >>.
		209
		210	=item $guard = mon $portid, $cb->(@reason)
		211
		212	=item $guard = mon $portid, $otherport
		213
		214	=item $guard = mon $portid, $otherport, @msg
		215
		216	Monitor the given port and do something when the port is killed.
		217
		218	In the first form, the callback is simply called with any number
		219	of C<@reason> elements (no @reason means that the port was deleted
		220	"normally"). Note also that I<< the callback B<must> never die >>, so use
		221	C<eval> if unsure.
		222
		223	In the second form, the other port will be C<kil>'ed with C<@reason>, iff
		224	a @reason was specified, i.e. on "normal" kils nothing happens, while
		225	under all other conditions, the other port is killed with the same reason.
		226
		227	In the last form, a message of the form C<@msg, @reason> will be C<snd>.
		228
		229	Example: call a given callback when C<$port> is killed.
		230
		231	mon $port, sub { warn "port died because of <@_>\n" };
		232
		233	Example: kill ourselves when C<$port> is killed abnormally.
		234
		235	mon $port, $self;
		236
		237	Example: send us a restart message another C<$port> is killed.
		238
		239	mon $port, $self => "restart";
		240
		241	=cut
		242
		243	sub mon {
183	my ($noderef, $port) = split /#/, shift, 2;	244	my ($noderef, $port) = split /#/, shift, 2;
184		245
185	add_node $noderef	246	my $node = $NODE{$noderef} \|\| add_node $noderef;
186	unless exists $NODE{$noderef};
187		247
188	$NODE{$noderef}->send (["$port", [@_]]);	248	my $cb = shift;
		249
		250	unless (ref $cb) {
		251	if (@_) {
		252	# send a kill info message
		253	my (@msg) = ($cb, @_);
		254	$cb = sub { snd @msg, @_ };
		255	} else {
		256	# simply kill other port
		257	my $port = $cb;
		258	$cb = sub { kil $port, @_ if @_ };
		259	}
		260	}
		261
		262	$node->monitor ($port, $cb);
		263
		264	defined wantarray
		265	and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }
189	}	266	}
190		267
		268	=item $guard = mon_guard $port, $ref, $ref...
		269
		270	Monitors the given C<$port> and keeps the passed references. When the port
		271	is killed, the references will be freed.
		272
		273	Optionally returns a guard that will stop the monitoring.
		274
		275	This function is useful when you create e.g. timers or other watchers and
		276	want to free them when the port gets killed:
		277
		278	$port->rcv (start => sub {
		279	my $timer; $timer = mon_guard $port, AE::timer 1, 1, sub {
		280	undef $timer if 0.9 < rand;
		281	});
		282	});
		283
		284	=cut
		285
		286	sub mon_guard {
		287	my ($port, @refs) = @_;
		288
		289	mon $port, sub { 0 && @refs }
		290	}
		291
		292	=item lnk $port1, $port2
		293
		294	Link two ports. This is simply a shorthand for:
		295
		296	mon $port1, $port2;
		297	mon $port2, $port1;
		298
		299	It means that if either one is killed abnormally, the other one gets
		300	killed as well.
		301
		302	=item $local_port = port
		303
		304	Create a new local port object that can be used either as a pattern
		305	matching port ("full port") or a single-callback port ("miniport"),
		306	depending on how C<rcv> callbacks are bound to the object.
		307
		308	=item $portid = port { my @msg = @_; $finished }
		309
		310	Creates a "mini port", that is, a very lightweight port without any
		311	pattern matching behind it, and returns its ID.
		312
		313	The block will be called for every message received on the port. When the
		314	callback returns a true value its job is considered "done" and the port
		315	will be destroyed. Otherwise it will stay alive.
		316
		317	The message will be passed as-is, no extra argument (i.e. no port id) will
		318	be passed to the callback.
		319
		320	If you need the local port id in the callback, this works nicely:
		321
		322	my $port; $port = port {
		323	snd $otherport, reply => $port;
		324	};
		325
		326	=cut
		327
		328	sub port(;&) {
		329	my $id = "$UNIQ." . $ID++;
		330	my $port = "$NODE#$id";
		331
		332	if (@_) {
		333	my $cb = shift;
		334	$PORT{$id} = sub {
		335	local $SELF = $port;
		336	eval {
		337	&$cb
		338	and kil $id;
		339	};
		340	_self_die if $@;
		341	};
		342	} else {
		343	my $self = bless {
		344	id => "$NODE#$id",
		345	}, "AnyEvent::MP::Port";
		346
		347	$PORT_DATA{$id} = $self;
		348	$PORT{$id} = sub {
		349	local $SELF = $port;
		350
		351	eval {
		352	for (@{ $self->{rc0}{$_[0]} }) {
		353	$_ && &{$_->[0]}
		354	&& undef $_;
		355	}
		356
		357	for (@{ $self->{rcv}{$_[0]} }) {
		358	$_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1]
		359	&& &{$_->[0]}
		360	&& undef $_;
		361	}
		362
		363	for (@{ $self->{any} }) {
		364	$_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1]
		365	&& &{$_->[0]}
		366	&& undef $_;
		367	}
		368	};
		369	_self_die if $@;
		370	};
		371	}
		372
		373	$port
		374	}
		375
		376	=item reg $portid, $name
		377
		378	Registers the given port under the name C<$name>. If the name already
		379	exists it is replaced.
		380
		381	A port can only be registered under one well known name.
		382
		383	A port automatically becomes unregistered when it is killed.
		384
		385	=cut
		386
		387	sub reg(@) {
		388	my ($portid, $name) = @_;
		389
		390	$REG{$name} = $portid;
		391	}
		392
191	=item rcv $portid, type => $callback->(@msg)	393	=item rcv $portid, $callback->(@msg)
192		394
		395	Replaces the callback on the specified miniport (or newly created port
		396	object, see C<port>). Full ports are configured with the following calls:
		397
		398	=item rcv $portid, tagstring => $callback->(@msg), ...
		399
193	=item rcv $portid, $smartmatch => $callback->(@msg)	400	=item rcv $portid, $smartmatch => $callback->(@msg), ...
194		401
195	=item rcv $portid, [$smartmatch...] => $callback->(@msg)	402	=item rcv $portid, [$smartmatch...] => $callback->(@msg), ...
196		403
197	Register a callback on the port identified by C<$portid>, which I<must> be	404	Register callbacks to be called on matching messages on the given port.
198	a local port.
199		405
200	The callback has to return a true value when its work is done, after	406	The callback has to return a true value when its work is done, after
201	which is will be removed, or a false value in which case it will stay	407	which is will be removed, or a false value in which case it will stay
202	registered.	408	registered.
203		409
		410	The global C<$SELF> (exported by this module) contains C<$portid> while
		411	executing the callback.
		412
		413	Runtime errors wdurign callback execution will result in the port being
		414	C<kil>ed.
		415
204	If the match is an array reference, then it will be matched against the	416	If the match is an array reference, then it will be matched against the
205	first elements of the message, otherwise only the first element is being	417	first elements of the message, otherwise only the first element is being
206	matched.	418	matched.
207		419
208	Any element in the match that is specified as C<_any_> (a function	420	Any element in the match that is specified as C<_any_> (a function
…		…
213	also the most efficient match (by far).	425	also the most efficient match (by far).
214		426
215	=cut	427	=cut
216		428
217	sub rcv($@) {	429	sub rcv($@) {
218	my ($port, $match, $cb) = @_;	430	my $portid = shift;
219
220	my $port = $PORT{$port}
221	or do {
222	my ($noderef, $lport) = split /#/, $port;	431	my ($noderef, $port) = split /#/, $port, 2;
223	"AnyEvent::MP::Node::Self" eq ref $NODE{$noderef}	432
		433	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}
224	or Carp::croak "$port: can only rcv on local ports";	434	or Carp::croak "$noderef#$port: rcv can only be called on local ports, caught";
225		435
226	$PORT{$lport}	436	my $self = $PORT_DATA{$port}
227	or Carp::croak "$port: port does not exist";	437	or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught";
228		438
229	$PORT{$port} = $PORT{$lport} # also return	439	"AnyEvent::MP::Port" eq ref $self
		440	or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught";
		441
		442	while (@_) {
		443	my ($match, $cb) = splice @_, 0, 2;
		444
		445	if (!ref $match) {
		446	push @{ $self->{rc0}{$match} }, [$cb];
		447	} elsif (("ARRAY" eq ref $match && !ref $match->[0])) {
		448	my ($type, @match) = @$match;
		449	@match
		450	? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match]
		451	: push @{ $self->{rc0}{$match->[0]} }, [$cb];
		452	} else {
		453	push @{ $self->{any} }, [$cb, $match];
		454	}
		455	}
		456
		457	$portid
		458	}
		459
		460	=item $closure = psub { BLOCK }
		461
		462	Remembers C<$SELF> and creates a closure out of the BLOCK. When the
		463	closure is executed, sets up the environment in the same way as in C<rcv>
		464	callbacks, i.e. runtime errors will cause the port to get C<kil>ed.
		465
		466	This is useful when you register callbacks from C<rcv> callbacks:
		467
		468	rcv delayed_reply => sub {
		469	my ($delay, @reply) = @_;
		470	my $timer = AE::timer $delay, 0, psub {
		471	snd @reply, $SELF;
230	};	472	};
		473	};
231		474
232	if (!ref $match) {	475	=cut
233	push @{ $port->{rc0}{$match} }, [$cb];	476
234	} elsif (("ARRAY" eq ref $match && !ref $match->[0])) {	477	sub psub(&) {
235	my ($type, @match) = @$match;	478	my $cb = shift;
236	@match	479
237	? push @{ $port->{rcv}{$match->[0]} }, [$cb, \@match]	480	my $port = $SELF
238	: push @{ $port->{rc0}{$match->[0]} }, [$cb];	481	or Carp::croak "psub can only be called from within rcv or psub callbacks, not";
		482
		483	sub {
		484	local $SELF = $port;
		485
		486	if (wantarray) {
		487	my @res = eval { &$cb };
		488	_self_die if $@;
		489	@res
239	} else {	490	} else {
240	push @{ $port->{any} }, [$cb, $match];	491	my $res = eval { &$cb };
		492	_self_die if $@;
		493	$res
		494	}
241	}	495	}
242	}	496	}
243		497
244	sub _inject {	498	=back
245	my ($port, $msg) = @{+shift};
246		499
247	$port = $PORT{$port}	500	=head1 FUNCTIONS FOR NODES
248	or return;
249		501
250	@_ = @$msg;	502	=over 4
251		503
252	for (@{ $port->{rc0}{$msg->[0]} }) {	504	=item become_public $noderef
253	$_ && &{$_->[0]}
254	&& undef $_;
255	}
256		505
257	for (@{ $port->{rcv}{$msg->[0]} }) {	506	Tells the node to become a public node, i.e. reachable from other nodes.
258	$_ && [@_[1..$#{$_->[1]}]] ~~ $_->[1]
259	&& &{$_->[0]}
260	&& undef $_;
261	}
262		507
263	for (@{ $port->{any} }) {	508	The first argument is the (unresolved) node reference of the local node
264	$_ && [@_[0..$#{$_->[1]}]] ~~ $_->[1]	509	(if missing then the empty string is used).
265	&& &{$_->[0]}
266	&& undef $_;
267	}
268	}
269		510
270	sub normalise_noderef($) {	511	It is quite common to not specify anything, in which case the local node
271	my ($noderef) = @_;	512	tries to listen on the default port, or to only specify a port number, in
		513	which case AnyEvent::MP tries to guess the local addresses.
272		514
273	my $cv = AE::cv;	515	=cut
274	my @res;
275
276	$cv->begin (sub {
277	my %seen;
278	my @refs;
279	for (sort { $a->[0] <=> $b->[0] } @res) {
280	push @refs, $_->[1] unless $seen{$_->[1]}++
281	}
282	shift->send (join ",", @refs);
283	});
284
285	$noderef = $DEFAULT_PORT unless length $noderef;
286
287	my $idx;
288	for my $t (split /,/, $noderef) {
289	my $pri = ++$idx;
290
291	#TODO: this should be outside normalise_noderef and in become_public
292	if ($t =~ /^\d*$/) {
293	my $nodename = (POSIX::uname)[1];
294
295	$cv->begin;
296	AnyEvent::Socket::resolve_sockaddr $nodename, $t \|\| "aemp=$DEFAULT_PORT", "tcp", 0, undef, sub {
297	for (@_) {
298	my ($service, $host) = AnyEvent::Socket::unpack_sockaddr $_->[3];
299	push @res, [
300	$pri += 1e-5,
301	AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $host, $service
302	];
303	}
304	$cv->end;
305	};
306
307	# my (undef, undef, undef, undef, @ipv4) = gethostbyname $nodename;
308	#
309	# for (@ipv4) {
310	# push @res, [
311	# $pri,
312	# AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $_, $t \|\| $DEFAULT_PORT,
313	# ];
314	# }
315	} else {
316	my ($host, $port) = AnyEvent::Socket::parse_hostport $t, "aemp=$DEFAULT_PORT"
317	or Carp::croak "$t: unparsable transport descriptor";
318
319	$cv->begin;
320	AnyEvent::Socket::resolve_sockaddr $host, $port, "tcp", 0, undef, sub {
321	for (@_) {
322	my ($service, $host) = AnyEvent::Socket::unpack_sockaddr $_->[3];
323	push @res, [
324	$pri += 1e-5,
325	AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $host, $service
326	];
327	}
328	$cv->end;
329	}
330	}
331	}
332
333	$cv->end;
334
335	$cv
336	}
337
338	sub become_public {
339	return if $PUBLIC;
340
341	my $noderef = join ",", ref $_[0] ? @{+shift} : shift;
342	my @args = @_;
343
344	$NODE = (normalise_noderef $noderef)->recv;
345
346	for my $t (split /,/, $NODE) {
347	$NODE{$t} = $NODE{""};
348
349	my ($host, $port) = AnyEvent::Socket::parse_hostport $t;
350
351	$LISTENER{$t} = AnyEvent::MP::Transport::mp_server $host, $port,
352	@args,
353	on_error => sub {
354	die "on_error<@_>\n";#d#
355	},
356	on_connect => sub {
357	my ($tp) = @_;
358
359	$NODE{$tp->{remote_id}} = $_[0];
360	},
361	sub {
362	my ($tp) = @_;
363
364	$NODE{"$tp->{peerhost}:$tp->{peerport}"} = $tp;
365	},
366	;
367	}
368
369	$PUBLIC = 1;
370	}
371		516
372	=back	517	=back
373		518
374	=head1 NODE MESSAGES	519	=head1 NODE MESSAGES
375		520
376	Nodes understand the following messages sent to them. Many of them take	521	Nodes understand the following messages sent to them. Many of them take
377	arguments called C<@reply>, which will simply be used to compose a reply	522	arguments called C<@reply>, which will simply be used to compose a reply
378	message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and	523	message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and
379	the remaining arguments are simply the message data.	524	the remaining arguments are simply the message data.
380		525
		526	While other messages exist, they are not public and subject to change.
		527
381	=over 4	528	=over 4
382		529
383	=cut	530	=cut
384		531
385	#############################################################################	532	=item lookup => $name, @reply
386	# self node code
387		533
388	sub _new_port($) {	534	Replies with the port ID of the specified well-known port, or C<undef>.
389	my ($name) = @_;
390
391	my ($noderef, $portname) = split /#/, $name;
392
393	$PORT{$name} =
394	$PORT{$portname} = {
395	names => [$name, $portname],
396	};
397	}
398
399	$NODE{""} = new AnyEvent::MP::Node::Self noderef => $NODE;
400	_new_port "";
401		535
402	=item devnull => ...	536	=item devnull => ...
403		537
404	Generic data sink/CPU heat conversion.	538	Generic data sink/CPU heat conversion.
405		539
406	=cut
407
408	rcv "", devnull => sub { () };
409
410	=item relay => $port, @msg	540	=item relay => $port, @msg
411		541
412	Simply forwards the message to the given port.	542	Simply forwards the message to the given port.
413
414	=cut
415
416	rcv "", relay => sub { \&snd; () };
417		543
418	=item eval => $string[ @reply]	544	=item eval => $string[ @reply]
419		545
420	Evaluates the given string. If C<@reply> is given, then a message of the	546	Evaluates the given string. If C<@reply> is given, then a message of the
421	form C<@reply, $@, @evalres> is sent.	547	form C<@reply, $@, @evalres> is sent.
422		548
423	Example: crash another node.	549	Example: crash another node.
424		550
425	snd $othernode, eval => "exit";	551	snd $othernode, eval => "exit";
426		552
427	=cut
428
429	rcv "", eval => sub {
430	my (undef, $string, @reply) = @_;
431	my @res = eval $string;
432	snd @reply, "$@", @res if @reply;
433	()
434	};
435
436	=item time => @reply	553	=item time => @reply
437		554
438	Replies the the current node time to C<@reply>.	555	Replies the the current node time to C<@reply>.
439		556
440	Example: tell the current node to send the current time to C<$myport> in a	557	Example: tell the current node to send the current time to C<$myport> in a
441	C<timereply> message.	558	C<timereply> message.
442		559
443	snd $NODE, time => $myport, timereply => 1, 2;	560	snd $NODE, time => $myport, timereply => 1, 2;
444	# => snd $myport, timereply => 1, 2, <time>	561	# => snd $myport, timereply => 1, 2, <time>
445		562
446	=cut	563	=back
447		564
448	rcv "", time => sub { shift; snd @_, AE::time; () };	565	=head1 AnyEvent::MP vs. Distributed Erlang
		566
		567	AnyEvent::MP got lots of its ideas from distributed erlang (erlang node
		568	== aemp node, erlang process == aemp port), so many of the documents and
		569	programming techniques employed by erlang apply to AnyEvent::MP. Here is a
		570	sample:
		571
		572	http://www.erlang.se/doc/programming_rules.shtml
		573	http://erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4
		574	http://erlang.org/download/erlang-book-part1.pdf # chapters 5 and 6
		575	http://erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5
		576
		577	Despite the similarities, there are also some important differences:
		578
		579	=over 4
		580
		581	=item * Node references contain the recipe on how to contact them.
		582
		583	Erlang relies on special naming and DNS to work everywhere in the
		584	same way. AEMP relies on each node knowing it's own address(es), with
		585	convenience functionality.
		586
		587	This means that AEMP requires a less tightly controlled environment at the
		588	cost of longer node references and a slightly higher management overhead.
		589
		590	=item * Erlang uses processes and a mailbox, AEMP does not queue.
		591
		592	Erlang uses processes that selctively receive messages, and therefore
		593	needs a queue. AEMP is event based, queuing messages would serve no useful
		594	purpose.
		595
		596	(But see L<Coro::MP> for a more erlang-like process model on top of AEMP).
		597
		598	=item * Erlang sends are synchronous, AEMP sends are asynchronous.
		599
		600	Sending messages in erlang is synchronous and blocks the process. AEMP
		601	sends are immediate, connection establishment is handled in the
		602	background.
		603
		604	=item * Erlang can silently lose messages, AEMP cannot.
		605
		606	Erlang makes few guarantees on messages delivery - messages can get lost
		607	without any of the processes realising it (i.e. you send messages a, b,
		608	and c, and the other side only receives messages a and c).
		609
		610	AEMP guarantees correct ordering, and the guarantee that there are no
		611	holes in the message sequence.
		612
		613	=item * In erlang, processes can be declared dead and later be found to be
		614	alive.
		615
		616	In erlang it can happen that a monitored process is declared dead and
		617	linked processes get killed, but later it turns out that the process is
		618	still alive - and can receive messages.
		619
		620	In AEMP, when port monitoring detects a port as dead, then that port will
		621	eventually be killed - it cannot happen that a node detects a port as dead
		622	and then later sends messages to it, finding it is still alive.
		623
		624	=item * Erlang can send messages to the wrong port, AEMP does not.
		625
		626	In erlang it is quite possible that a node that restarts reuses a process
		627	ID known to other nodes for a completely different process, causing
		628	messages destined for that process to end up in an unrelated process.
		629
		630	AEMP never reuses port IDs, so old messages or old port IDs floating
		631	around in the network will not be sent to an unrelated port.
		632
		633	=item * Erlang uses unprotected connections, AEMP uses secure
		634	authentication and can use TLS.
		635
		636	AEMP can use a proven protocol - SSL/TLS - to protect connections and
		637	securely authenticate nodes.
		638
		639	=item * The AEMP protocol is optimised for both text-based and binary
		640	communications.
		641
		642	The AEMP protocol, unlike the erlang protocol, supports both
		643	language-independent text-only protocols (good for debugging) and binary,
		644	language-specific serialisers (e.g. Storable).
		645
		646	It has also been carefully designed to be implementable in other languages
		647	with a minimum of work while gracefully degrading fucntionality to make the
		648	protocol simple.
449		649
450	=back	650	=back
451		651
452	=head1 SEE ALSO	652	=head1 SEE ALSO
453		653

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Revision 1.7 by root, Sat Aug 1 15:04:30 2009 UTC vs.
Revision 1.31 by root, Wed Aug 5 19:55:58 2009 UTC