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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.5 by root, Sat Aug 1 07:44:02 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
		38	At the moment, this module family is severly broken and underdocumented,
		39	so do not use. This was uploaded mainly to reserve the CPAN namespace -
		40	stay tuned! The basic API should be finished, however.
		41
32	=head1 CONCEPTS	42	=head1 CONCEPTS
33		43
34	=over 4	44	=over 4
35		45
36	=item port	46	=item port
37		47
38	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).
39	you can register C<rcv> handlers with. All C<rcv> handlers will receive	49
40	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.
41		53
42	=item port id - C<noderef#portname>	54	=item port id - C<noderef#portname>
43		55
44	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
45	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.
46		60
47	=item node	61	=item node
48		62
49	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
50	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
51	among other things.	65	create new ports, among other things.
52		66
53	Initially, nodes are either private (single-process only) or hidden	67	Nodes are either private (single-process only), slaves (connected to a
54	(connected to a master node only). Only when they epxlicitly "become	68	master node only) or public nodes (connectable from unrelated nodes).
55	public" can you send them messages from unrelated other nodes.
56		69
57	=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>
58		71
59	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
60	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
61	node (for public nodes).	74	node (for public nodes).
62		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
63	=back	85	=back
64		86
65	=head1 VARIABLES/FUNCTIONS	87	=head1 VARIABLES/FUNCTIONS
66		88
67	=over 4	89	=over 4
68		90
69	=cut	91	=cut
70		92
71	package AnyEvent::MP;	93	package AnyEvent::MP;
72		94
73	use AnyEvent::MP::Util ();
74	use AnyEvent::MP::Node;	95	use AnyEvent::MP::Base;
75	use AnyEvent::MP::Transport;
76		96
77	use utf8;
78	use common::sense;	97	use common::sense;
79		98
80	use Carp ();	99	use Carp ();
81		100
82	use AE ();	101	use AE ();
83		102
84	use base "Exporter";	103	use base "Exporter";
85		104
86	our $VERSION = '0.0';	105	our $VERSION = '0.1';
87	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	);
88		112
89	our $DEFAULT_SECRET;	113	our $SELF;
90	our $DEFAULT_PORT = "4040";
91		114
92	our $CONNECT_INTERVAL = 5; # new connect every 5s, at least	115	sub _self_die() {
93	our $CONNECT_TIMEOUT = 30; # includes handshake	116	my $msg = $@;
94		117	$msg =~ s/\n+$// unless ref $msg;
95	sub default_secret {	118	kil $SELF, die => $msg;
96	unless (defined $DEFAULT_SECRET) {
97	if (open my $fh, "<$ENV{HOME}/.aemp-secret") {
98	sysread $fh, $DEFAULT_SECRET, -s $fh;
99	} else {
100	$DEFAULT_SECRET = AnyEvent::MP::Util::nonce 32;
101	}
102	}
103
104	$DEFAULT_SECRET
105	}	119	}
106		120
107	=item NODE / $NODE	121	=item $thisnode = NODE / $NODE
108		122
109	The C<NODE ()> function and the C<$NODE> variable contain the noderef of	123	The C<NODE> function returns, and the C<$NODE> variable contains
110	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
111	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.
112		127
113	=cut	128	=item $noderef = node_of $portid
114		129
115	our $UNIQ = sprintf "%x.%x", $$, time; # per-process/node unique cookie	130	Extracts and returns the noderef from a portid or a noderef.
116	our $PUBLIC = 0;
117	our $NODE;
118	our $PORT;
119		131
120	our %NODE; # node id to transport mapping, or "undef", for local node	132	=item $cv = resolve_node $noderef
121	our %PORT; # local ports
122	our %LISTENER; # local transports
123		133
124	sub NODE() { $NODE }	134	Takes an unresolved node reference that may contain hostnames and
		135	abbreviated IDs, resolves all of them and returns a resolved node
		136	reference.
125		137
126	{	138	In addition to C<address:port> pairs allowed in resolved noderefs, the
127	use POSIX ();	139	following forms are supported:
128	my $nodename = (POSIX::uname)[1];
129	$NODE = "$$\@$nodename";
130	}
131		140
132	sub _ANY_() { 1 }	141	=over 4
133	sub _any_() { \&_ANY_ }
134		142
135	sub add_node {	143	=item the empty string
136	my ($noderef) = @_;
137		144
138	return $NODE{$noderef}	145	An empty-string component gets resolved as if the default port (4040) was
139	if exists $NODE{$noderef};	146	specified.
140		147
141	for (split /,/, $noderef) {	148	=item naked port numbers (e.g. C<1234>)
142	return $NODE{$noderef} = $NODE{$_}
143	if exists $NODE{$_};
144	}
145		149
146	# for indirect sends, use a different class	150	These are resolved by prepending the local nodename and a colon, to be
147	my $node = new AnyEvent::MP::Node::Direct $noderef;	151	further resolved.
148		152
149	$NODE{$_} = $node	153	=item hostnames (e.g. C<localhost:1234>, C<localhost>)
150	for $noderef, split /,/, $noderef;
151		154
152	$node	155	These are resolved by using AnyEvent::DNS to resolve them, optionally
153	}	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.
154		171
155	=item snd $portid, type => @data	172	=item snd $portid, type => @data
156		173
157	=item snd $portid, @msg	174	=item snd $portid, @msg
158		175
159	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
160	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 :).
161		179
162	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
163	a constant string as first element.	181	string as first element (a portid, or some word that indicates a request
		182	type etc.).
164		183
165	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
166	function: modifying any argument is not allowed and can cause many	185	function: modifying any argument is not allowed and can cause many
167	problems.	186	problems.
168		187
…		…
170	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
171	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
172	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
173	node, anything can be passed.	192	node, anything can be passed.
174		193
175	=cut	194	=item kil $portid[, @reason]
176		195
177	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, $self => "restart";
		240
		241	=cut
		242
		243	sub mon {
178	my ($noderef, $port) = split /#/, shift, 2;	244	my ($noderef, $port) = split /#/, shift, 2;
179		245
180	add_node $noderef	246	my $node = $NODE{$noderef} \|\| add_node $noderef;
181	unless exists $NODE{$noderef};
182		247
183	$NODE{$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) }
184	}	266	}
185		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
186	=item rcv $portid, type => $callback->(@msg)	393	=item rcv $portid, $callback->(@msg)
187		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
188	=item rcv $portid, $smartmatch => $callback->(@msg)	400	=item rcv $portid, $smartmatch => $callback->(@msg), ...
189		401
190	=item rcv $portid, [$smartmatch...] => $callback->(@msg)	402	=item rcv $portid, [$smartmatch...] => $callback->(@msg), ...
191		403
192	Register a callback on the port identified by C<$portid>, which I<must> be	404	Register callbacks to be called on matching messages on the given port.
193	a local port.
194		405
195	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
196	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
197	registered.	408	registered.
198		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
199	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
200	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
201	matched.	418	matched.
202		419
203	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
…		…
208	also the most efficient match (by far).	425	also the most efficient match (by far).
209		426
210	=cut	427	=cut
211		428
212	sub rcv($@) {	429	sub rcv($@) {
213	my ($port, $match, $cb) = @_;	430	my $portid = shift;
214
215	my $port = $PORT{$port}
216	or do {
217	my ($noderef, $lport) = split /#/, $port;	431	my ($noderef, $port) = split /#/, $port, 2;
218	"AnyEvent::MP::Node::Self" eq ref $NODE{$noderef}	432
		433	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}
219	or Carp::croak "$port: can only rcv on local ports";	434	or Carp::croak "$noderef#$port: rcv can only be called on local ports, caught";
220		435
221	$PORT{$lport}	436	my $self = $PORT_DATA{$port}
222	or Carp::croak "$port: port does not exist";	437	or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught";
223		438
224	$PORT{$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;
225	};	472	};
		473	};
226		474
227	if (!ref $match) {	475	=cut
228	push @{ $port->{rc0}{$match} }, [$cb];	476
229	} elsif (("ARRAY" eq ref $match && !ref $match->[0])) {	477	sub psub(&) {
230	my ($type, @match) = @$match;	478	my $cb = shift;
231	@match	479
232	? push @{ $port->{rcv}{$match->[0]} }, [$cb, \@match]	480	my $port = $SELF
233	: 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
234	} else {	490	} else {
235	push @{ $port->{any} }, [$cb, $match];	491	my $res = eval { &$cb };
		492	_self_die if $@;
		493	$res
		494	}
236	}	495	}
237	}	496	}
238		497
239	sub _inject {	498	=back
240	my ($port, $msg) = @{+shift};
241		499
242	$port = $PORT{$port}	500	=head1 FUNCTIONS FOR NODES
243	or return;
244		501
245	@_ = @$msg;	502	=over 4
246		503
247	for (@{ $port->{rc0}{$msg->[0]} }) {	504	=item become_public $noderef
248	$_ && &{$_->[0]}
249	&& undef $_;
250	}
251		505
252	for (@{ $port->{rcv}{$msg->[0]} }) {	506	Tells the node to become a public node, i.e. reachable from other nodes.
253	$_ && [@_[1..$#{$_->[1]}]] ~~ $_->[1]
254	&& &{$_->[0]}
255	&& undef $_;
256	}
257		507
258	for (@{ $port->{any} }) {	508	The first argument is the (unresolved) node reference of the local node
259	$_ && [@_[0..$#{$_->[1]}]] ~~ $_->[1]	509	(if missing then the empty string is used).
260	&& &{$_->[0]}
261	&& undef $_;
262	}
263	}
264		510
265	sub normalise_noderef($) {	511	It is quite common to not specify anything, in which case the local node
266	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.
267		514
268	my $cv = AE::cv;	515	=cut
269	my @res;
270
271	$cv->begin (sub {
272	my %seen;
273	my @refs;
274	for (sort { $a->[0] <=> $b->[0] } @res) {
275	push @refs, $_->[1] unless $seen{$_->[1]}++
276	}
277	shift->send (join ",", @refs);
278	});
279
280	$noderef = $DEFAULT_PORT unless length $noderef;
281
282	my $idx;
283	for my $t (split /,/, $noderef) {
284	my $pri = ++$idx;
285
286	#TODO: this should be outside normalise_noderef and in become_public
287	if ($t =~ /^\d*$/) {
288	my $nodename = (POSIX::uname)[1];
289
290	$cv->begin;
291	AnyEvent::Socket::resolve_sockaddr $nodename, $t \|\| "aemp=$DEFAULT_PORT", "tcp", 0, undef, sub {
292	for (@_) {
293	my ($service, $host) = AnyEvent::Socket::unpack_sockaddr $_->[3];
294	push @res, [
295	$pri += 1e-5,
296	AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $host, $service
297	];
298	}
299	$cv->end;
300	};
301
302	# my (undef, undef, undef, undef, @ipv4) = gethostbyname $nodename;
303	#
304	# for (@ipv4) {
305	# push @res, [
306	# $pri,
307	# AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $_, $t \|\| $DEFAULT_PORT,
308	# ];
309	# }
310	} else {
311	my ($host, $port) = AnyEvent::Socket::parse_hostport $t, "aemp=$DEFAULT_PORT"
312	or Carp::croak "$t: unparsable transport descriptor";
313
314	$cv->begin;
315	AnyEvent::Socket::resolve_sockaddr $host, $port, "tcp", 0, undef, sub {
316	for (@_) {
317	my ($service, $host) = AnyEvent::Socket::unpack_sockaddr $_->[3];
318	push @res, [
319	$pri += 1e-5,
320	AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $host, $service
321	];
322	}
323	$cv->end;
324	}
325	}
326	}
327
328	$cv->end;
329
330	$cv
331	}
332
333	sub become_public {
334	return if $PUBLIC;
335
336	my $noderef = join ",", ref $_[0] ? @{+shift} : shift;
337	my @args = @_;
338
339	$NODE = (normalise_noderef $noderef)->recv;
340
341	for my $t (split /,/, $NODE) {
342	$NODE{$t} = $NODE{""};
343
344	my ($host, $port) = AnyEvent::Socket::parse_hostport $t;
345
346	$LISTENER{$t} = AnyEvent::MP::Transport::mp_server $host, $port,
347	@args,
348	on_error => sub {
349	die "on_error<@_>\n";#d#
350	},
351	on_connect => sub {
352	my ($tp) = @_;
353
354	$NODE{$tp->{remote_id}} = $_[0];
355	},
356	sub {
357	my ($tp) = @_;
358
359	$NODE{"$tp->{peerhost}:$tp->{peerport}"} = $tp;
360	},
361	;
362	}
363
364	$PUBLIC = 1;
365	}
366		516
367	=back	517	=back
368		518
369	=head1 NODE MESSAGES	519	=head1 NODE MESSAGES
370		520
371	Nodes understand the following messages sent to them. Many of them take	521	Nodes understand the following messages sent to them. Many of them take
372	arguments called C<@reply>, which will simply be used to compose a reply	522	arguments called C<@reply>, which will simply be used to compose a reply
373	message - C<$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
374	the remaining arguments are simply the message data.	524	the remaining arguments are simply the message data.
375		525
		526	While other messages exist, they are not public and subject to change.
		527
376	=over 4	528	=over 4
377		529
378	=cut	530	=cut
379		531
380	#############################################################################	532	=item lookup => $name, @reply
381	# self node code
382		533
383	sub _new_port($) {	534	Replies with the port ID of the specified well-known port, or C<undef>.
384	my ($name) = @_;
385		535
386	my ($noderef, $portname) = split /#/, $name;	536	=item devnull => ...
387		537
388	$PORT{$name} =	538	Generic data sink/CPU heat conversion.
389	$PORT{$portname} = {
390	names => [$name, $portname],
391	};
392	}
393
394	$NODE{""} = new AnyEvent::MP::Node::Self noderef => $NODE;
395	_new_port "";
396		539
397	=item relay => $port, @msg	540	=item relay => $port, @msg
398		541
399	Simply forwards the message to the given port.	542	Simply forwards the message to the given port.
400
401	=cut
402
403	rcv "", relay => \&snd;
404		543
405	=item eval => $string[ @reply]	544	=item eval => $string[ @reply]
406		545
407	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
408	form C<@reply, $@, @evalres> is sent.	547	form C<@reply, $@, @evalres> is sent.
409		548
410	Example: crash another node.	549	Example: crash another node.
411		550
412	snd $othernode, eval => "exit";	551	snd $othernode, eval => "exit";
413		552
414	=cut
415
416	rcv "", eval => sub {
417	my (undef, $string, @reply) = @_;
418	my @res = eval $string;
419	snd @reply, "$@", @res if @reply;
420	};
421
422	=item time => @reply	553	=item time => @reply
423		554
424	Replies the the current node time to C<@reply>.	555	Replies the the current node time to C<@reply>.
425		556
426	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
427	C<timereply> message.	558	C<timereply> message.
428		559
429	snd $NODE, time => $myport, timereply => 1, 2;	560	snd $NODE, time => $myport, timereply => 1, 2;
430	# => snd $myport, timereply => 1, 2, <time>	561	# => snd $myport, timereply => 1, 2, <time>
431		562
432	=cut	563	=back
433		564
434	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.
435		649
436	=back	650	=back
437		651
438	=head1 SEE ALSO	652	=head1 SEE ALSO
439		653

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Revision 1.5 by root, Sat Aug 1 07:44:02 2009 UTC vs.
Revision 1.31 by root, Wed Aug 5 19:55:58 2009 UTC