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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.27 by root, Tue Aug 4 22:13:45 2009 UTC vs.
Revision 1.48 by root, Thu Aug 13 02:59:42 2009 UTC

…		…
8		8
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
		14
		15	# initialise the node so it can send/receive messages
		16	initialise_node; # -OR-
		17	initialise_node "localhost:4040"; # -OR-
		18	initialise_node "slave/", "localhost:4040"
		19
		20	# ports are message endpoints
		21
		22	# sending messages
13	snd $port, type => data...;	23	snd $port, type => data...;
		24	snd $port, @msg;
		25	snd @msg_with_first_element_being_a_port;
14		26
15	$SELF # receiving/own port id in rcv callbacks	27	# creating/using miniports
		28	my $miniport = port { my @msg = @_; 0 };
16		29
		30	# creating/using full ports
		31	my $port = port;
17	rcv $port, smartmatch => $cb->($port, @msg);	32	rcv $port, smartmatch => $cb->(@msg);
18
19	# examples:
20	rcv $port2, ping => sub { snd $_[0], "pong"; 0 };	33	rcv $port, ping => sub { snd $_[0], "pong"; 0 };
21	rcv $port1, pong => sub { warn "pong received\n" };	34	rcv $port, pong => sub { warn "pong received\n"; 0 };
22	snd $port2, ping => $port1;
23		35
24	# more, smarter, matches (_any_ is exported by this module)	36	# more, smarter, matches (_any_ is exported by this module)
25	rcv $port, [child_died => $pid] => sub { ...	37	rcv $port, [child_died => $pid] => sub { ...
26	rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3	38	rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3
27		39
		40	# create a port on another node
		41	my $port = spawn $node, $initfunc, @initdata;
		42
		43	# monitoring
		44	mon $port, $cb->(@msg) # callback is invoked on death
		45	mon $port, $otherport # kill otherport on abnormal death
		46	mon $port, $otherport, @msg # send message on death
		47
		48	=head1 CURRENT STATUS
		49
		50	AnyEvent::MP - stable API, should work
		51	AnyEvent::MP::Intro - outdated
		52	AnyEvent::MP::Kernel - WIP
		53	AnyEvent::MP::Transport - mostly stable
		54
		55	stay tuned.
		56
28	=head1 DESCRIPTION	57	=head1 DESCRIPTION
29		58
30	This module (-family) implements a simple message passing framework.	59	This module (-family) implements a simple message passing framework.
31		60
32	Despite its simplicity, you can securely message other processes running	61	Despite its simplicity, you can securely message other processes running
…		…
35	For an introduction to this module family, see the L<AnyEvent::MP::Intro>	64	For an introduction to this module family, see the L<AnyEvent::MP::Intro>
36	manual page.	65	manual page.
37		66
38	At the moment, this module family is severly broken and underdocumented,	67	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 -	68	so do not use. This was uploaded mainly to reserve the CPAN namespace -
40	stay tuned! The basic API should be finished, however.	69	stay tuned!
41		70
42	=head1 CONCEPTS	71	=head1 CONCEPTS
43		72
44	=over 4	73	=over 4
45		74
46	=item port	75	=item port
47		76
48	A port is something you can send messages to with the C<snd> function, and	77	A port is something you can send messages to (with the C<snd> function).
49	you can register C<rcv> handlers with. All C<rcv> handlers will receive	78
50	messages they match, messages will not be queued.	79	Some ports allow you to register C<rcv> handlers that can match specific
		80	messages. All C<rcv> handlers will receive messages they match, messages
		81	will not be queued.
51		82
52	=item port id - C<noderef#portname>	83	=item port id - C<noderef#portname>
53		84
54	A port id is always the noderef, a hash-mark (C<#>) as separator, followed	85	A port id is normaly the concatenation of a noderef, a hash-mark (C<#>) as
55	by a port name (a printable string of unspecified format).	86	separator, and a port name (a printable string of unspecified format). An
		87	exception is the the node port, whose ID is identical to its node
		88	reference.
56		89
57	=item node	90	=item node
58		91
59	A node is a single process containing at least one port - the node	92	A node is a single process containing at least one port - the node
60	port. You can send messages to node ports to let them create new ports,	93	port. You can send messages to node ports to find existing ports or to
61	among other things.	94	create new ports, among other things.
62		95
63	Initially, nodes are either private (single-process only) or hidden	96	Nodes are either private (single-process only), slaves (connected to a
64	(connected to a master node only). Only when they epxlicitly "become	97	master node only) or public nodes (connectable from unrelated nodes).
65	public" can you send them messages from unrelated other nodes.
66		98
67	=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>	99	=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>
68		100
69	A noderef is a string that either uniquely identifies a given node (for	101	A node reference is a string that either simply identifies the node (for
70	private and hidden nodes), or contains a recipe on how to reach a given	102	private and slave nodes), or contains a recipe on how to reach a given
71	node (for public nodes).	103	node (for public nodes).
72		104
		105	This recipe is simply a comma-separated list of C<address:port> pairs (for
		106	TCP/IP, other protocols might look different).
		107
		108	Node references come in two flavours: resolved (containing only numerical
		109	addresses) or unresolved (where hostnames are used instead of addresses).
		110
		111	Before using an unresolved node reference in a message you first have to
		112	resolve it.
		113
73	=back	114	=back
74		115
75	=head1 VARIABLES/FUNCTIONS	116	=head1 VARIABLES/FUNCTIONS
76		117
77	=over 4	118	=over 4
78		119
79	=cut	120	=cut
80		121
81	package AnyEvent::MP;	122	package AnyEvent::MP;
82		123
83	use AnyEvent::MP::Base;	124	use AnyEvent::MP::Kernel;
84		125
85	use common::sense;	126	use common::sense;
86		127
87	use Carp ();	128	use Carp ();
88		129
89	use AE ();	130	use AE ();
90		131
91	use base "Exporter";	132	use base "Exporter";
92		133
93	our $VERSION = '0.1';	134	our $VERSION = $AnyEvent::MP::Kernel::VERSION;
		135
94	our @EXPORT = qw(	136	our @EXPORT = qw(
95	NODE $NODE *SELF node_of _any_	137	NODE $NODE *SELF node_of _any_
96	become_slave become_public	138	resolve_node initialise_node
97	snd rcv mon kil reg psub	139	snd rcv mon kil reg psub spawn
98	port	140	port
99	);	141	);
100		142
101	our $SELF;	143	our $SELF;
102		144
…		…
111	The C<NODE> function returns, and the C<$NODE> variable contains	153	The C<NODE> function returns, and the C<$NODE> variable contains
112	the noderef of the local node. The value is initialised by a call	154	the noderef of the local node. The value is initialised by a call
113	to C<become_public> or C<become_slave>, after which all local port	155	to C<become_public> or C<become_slave>, after which all local port
114	identifiers become invalid.	156	identifiers become invalid.
115		157
116	=item $noderef = node_of $portid	158	=item $noderef = node_of $port
117		159
118	Extracts and returns the noderef from a portid or a noderef.	160	Extracts and returns the noderef from a portid or a noderef.
		161
		162	=item initialise_node $noderef, $seednode, $seednode...
		163
		164	=item initialise_node "slave/", $master, $master...
		165
		166	Before a node can talk to other nodes on the network it has to initialise
		167	itself - the minimum a node needs to know is it's own name, and optionally
		168	it should know the noderefs of some other nodes in the network.
		169
		170	This function initialises a node - it must be called exactly once (or
		171	never) before calling other AnyEvent::MP functions.
		172
		173	All arguments are noderefs, which can be either resolved or unresolved.
		174
		175	There are two types of networked nodes, public nodes and slave nodes:
		176
		177	=over 4
		178
		179	=item public nodes
		180
		181	For public nodes, C<$noderef> must either be a (possibly unresolved)
		182	noderef, in which case it will be resolved, or C<undef> (or missing), in
		183	which case the noderef will be guessed.
		184
		185	Afterwards, the node will bind itself on all endpoints and try to connect
		186	to all additional C<$seednodes> that are specified. Seednodes are optional
		187	and can be used to quickly bootstrap the node into an existing network.
		188
		189	=item slave nodes
		190
		191	When the C<$noderef> is the special string C<slave/>, then the node will
		192	become a slave node. Slave nodes cannot be contacted from outside and will
		193	route most of their traffic to the master node that they attach to.
		194
		195	At least one additional noderef is required: The node will try to connect
		196	to all of them and will become a slave attached to the first node it can
		197	successfully connect to.
		198
		199	=back
		200
		201	This function will block until all nodes have been resolved and, for slave
		202	nodes, until it has successfully established a connection to a master
		203	server.
		204
		205	Example: become a public node listening on the default node.
		206
		207	initialise_node;
		208
		209	Example: become a public node, and try to contact some well-known master
		210	servers to become part of the network.
		211
		212	initialise_node undef, "master1", "master2";
		213
		214	Example: become a public node listening on port C<4041>.
		215
		216	initialise_node 4041;
		217
		218	Example: become a public node, only visible on localhost port 4044.
		219
		220	initialise_node "locahost:4044";
		221
		222	Example: become a slave node to any of the specified master servers.
		223
		224	initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net";
		225
		226	=item $cv = resolve_node $noderef
		227
		228	Takes an unresolved node reference that may contain hostnames and
		229	abbreviated IDs, resolves all of them and returns a resolved node
		230	reference.
		231
		232	In addition to C<address:port> pairs allowed in resolved noderefs, the
		233	following forms are supported:
		234
		235	=over 4
		236
		237	=item the empty string
		238
		239	An empty-string component gets resolved as if the default port (4040) was
		240	specified.
		241
		242	=item naked port numbers (e.g. C<1234>)
		243
		244	These are resolved by prepending the local nodename and a colon, to be
		245	further resolved.
		246
		247	=item hostnames (e.g. C<localhost:1234>, C<localhost>)
		248
		249	These are resolved by using AnyEvent::DNS to resolve them, optionally
		250	looking up SRV records for the C<aemp=4040> port, if no port was
		251	specified.
		252
		253	=back
119		254
120	=item $SELF	255	=item $SELF
121		256
122	Contains the current port id while executing C<rcv> callbacks or C<psub>	257	Contains the current port id while executing C<rcv> callbacks or C<psub>
123	blocks.	258	blocks.
…		…
126		261
127	Due to some quirks in how perl exports variables, it is impossible to	262	Due to some quirks in how perl exports variables, it is impossible to
128	just export C<$SELF>, all the symbols called C<SELF> are exported by this	263	just export C<$SELF>, all the symbols called C<SELF> are exported by this
129	module, but only C<$SELF> is currently used.	264	module, but only C<$SELF> is currently used.
130		265
131	=item snd $portid, type => @data	266	=item snd $port, type => @data
132		267
133	=item snd $portid, @msg	268	=item snd $port, @msg
134		269
135	Send the given message to the given port ID, which can identify either	270	Send the given message to the given port ID, which can identify either
136	a local or a remote port, and can be either a string or soemthignt hat	271	a local or a remote port, and can be either a string or soemthignt hat
137	stringifies a sa port ID (such as a port object :).	272	stringifies a sa port ID (such as a port object :).
138		273
…		…
148	JSON is used, then only strings, numbers and arrays and hashes consisting	283	JSON is used, then only strings, numbers and arrays and hashes consisting
149	of those are allowed (no objects). When Storable is used, then anything	284	of those are allowed (no objects). When Storable is used, then anything
150	that Storable can serialise and deserialise is allowed, and for the local	285	that Storable can serialise and deserialise is allowed, and for the local
151	node, anything can be passed.	286	node, anything can be passed.
152		287
153	=item kil $portid[, @reason]
154
155	Kill the specified port with the given C<@reason>.
156
157	If no C<@reason> is specified, then the port is killed "normally" (linked
158	ports will not be kileld, or even notified).
159
160	Otherwise, linked ports get killed with the same reason (second form of
161	C<mon>, see below).
162
163	Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks
164	will be reported as reason C<< die => $@ >>.
165
166	Transport/communication errors are reported as C<< transport_error =>
167	$message >>.
168
169	=item $guard = mon $portid, $cb->(@reason)
170
171	=item $guard = mon $portid, $otherport
172
173	=item $guard = mon $portid, $otherport, @msg
174
175	Monitor the given port and do something when the port is killed.
176
177	In the first form, the callback is simply called with any number
178	of C<@reason> elements (no @reason means that the port was deleted
179	"normally"). Note also that I<< the callback B<must> never die >>, so use
180	C<eval> if unsure.
181
182	In the second form, the other port will be C<kil>'ed with C<@reason>, iff
183	a @reason was specified, i.e. on "normal" kils nothing happens, while
184	under all other conditions, the other port is killed with the same reason.
185
186	In the last form, a message of the form C<@msg, @reason> will be C<snd>.
187
188	Example: call a given callback when C<$port> is killed.
189
190	mon $port, sub { warn "port died because of <@_>\n" };
191
192	Example: kill ourselves when C<$port> is killed abnormally.
193
194	mon $port, $self;
195
196	Example: send us a restart message another C<$port> is killed.
197
198	mon $port, $self => "restart";
199
200	=cut
201
202	sub mon {
203	my ($noderef, $port, $cb) = ((split /#/, shift, 2), shift);
204
205	my $node = $NODE{$noderef} \|\| add_node $noderef;
206
207	#TODO: ports must not be references
208	if (!ref $cb or "AnyEvent::MP::Port" eq ref $cb) {
209	if (@_) {
210	# send a kill info message
211	my (@msg) = ($cb, @_);
212	$cb = sub { snd @msg, @_ };
213	} else {
214	# simply kill other port
215	my $port = $cb;
216	$cb = sub { kil $port, @_ if @_ };
217	}
218	}
219
220	$node->monitor ($port, $cb);
221
222	defined wantarray
223	and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }
224	}
225
226	=item $guard = mon_guard $port, $ref, $ref...
227
228	Monitors the given C<$port> and keeps the passed references. When the port
229	is killed, the references will be freed.
230
231	Optionally returns a guard that will stop the monitoring.
232
233	This function is useful when you create e.g. timers or other watchers and
234	want to free them when the port gets killed:
235
236	$port->rcv (start => sub {
237	my $timer; $timer = mon_guard $port, AE::timer 1, 1, sub {
238	undef $timer if 0.9 < rand;
239	});
240	});
241
242	=cut
243
244	sub mon_guard {
245	my ($port, @refs) = @_;
246
247	mon $port, sub { 0 && @refs }
248	}
249
250	=item lnk $port1, $port2
251
252	Link two ports. This is simply a shorthand for:
253
254	mon $port1, $port2;
255	mon $port2, $port1;
256
257	It means that if either one is killed abnormally, the other one gets
258	killed as well.
259
260	=item $local_port = port	288	=item $local_port = port
261		289
262	Create a new local port object that supports message matching.	290	Create a new local port object that can be used either as a pattern
		291	matching port ("full port") or a single-callback port ("miniport"),
		292	depending on how C<rcv> callbacks are bound to the object.
263		293
264	=item $portid = port { my @msg = @_; $finished }	294	=item $port = port { my @msg = @_; $finished }
265		295
266	Creates a "mini port", that is, a very lightweight port without any	296	Creates a "miniport", that is, a very lightweight port without any pattern
267	pattern matching behind it, and returns its ID.	297	matching behind it, and returns its ID. Semantically the same as creating
		298	a port and calling C<rcv $port, $callback> on it.
268		299
269	The block will be called for every message received on the port. When the	300	The block will be called for every message received on the port. When the
270	callback returns a true value its job is considered "done" and the port	301	callback returns a true value its job is considered "done" and the port
271	will be destroyed. Otherwise it will stay alive.	302	will be destroyed. Otherwise it will stay alive.
272		303
273	The message will be passed as-is, no extra argument (i.e. no port id) will	304	The message will be passed as-is, no extra argument (i.e. no port id) will
274	be passed to the callback.	305	be passed to the callback.
275		306
276	If you need the local port id in the callback, this works nicely:	307	If you need the local port id in the callback, this works nicely:
277		308
278	my $port; $port = miniport {	309	my $port; $port = port {
279	snd $otherport, reply => $port;	310	snd $otherport, reply => $port;
280	};	311	};
281		312
282	=cut	313	=cut
		314
		315	sub rcv($@);
283		316
284	sub port(;&) {	317	sub port(;&) {
285	my $id = "$UNIQ." . $ID++;	318	my $id = "$UNIQ." . $ID++;
286	my $port = "$NODE#$id";	319	my $port = "$NODE#$id";
287		320
288	if (@_) {	321	if (@_) {
		322	rcv $port, shift;
		323	} else {
		324	$PORT{$id} = sub { }; # nop
		325	}
		326
		327	$port
		328	}
		329
		330	=item reg $port, $name
		331
		332	=item reg $name
		333
		334	Registers the given port (or C<$SELF><<< if missing) under the name
		335	C<$name>. If the name already exists it is replaced.
		336
		337	A port can only be registered under one well known name.
		338
		339	A port automatically becomes unregistered when it is killed.
		340
		341	=cut
		342
		343	sub reg(@) {
		344	my $port = @_ > 1 ? shift : $SELF \|\| Carp::croak 'reg: called with one argument only, but $SELF not set,';
		345
		346	$REG{$_[0]} = $port;
		347	}
		348
		349	=item rcv $port, $callback->(@msg)
		350
		351	Replaces the callback on the specified miniport (after converting it to
		352	one if required).
		353
		354	=item rcv $port, tagstring => $callback->(@msg), ...
		355
		356	=item rcv $port, $smartmatch => $callback->(@msg), ...
		357
		358	=item rcv $port, [$smartmatch...] => $callback->(@msg), ...
		359
		360	Register callbacks to be called on matching messages on the given full
		361	port (after converting it to one if required) and return the port.
		362
		363	The callback has to return a true value when its work is done, after
		364	which is will be removed, or a false value in which case it will stay
		365	registered.
		366
		367	The global C<$SELF> (exported by this module) contains C<$port> while
		368	executing the callback.
		369
		370	Runtime errors during callback execution will result in the port being
		371	C<kil>ed.
		372
		373	If the match is an array reference, then it will be matched against the
		374	first elements of the message, otherwise only the first element is being
		375	matched.
		376
		377	Any element in the match that is specified as C<_any_> (a function
		378	exported by this module) matches any single element of the message.
		379
		380	While not required, it is highly recommended that the first matching
		381	element is a string identifying the message. The one-string-only match is
		382	also the most efficient match (by far).
		383
		384	Example: create a port and bind receivers on it in one go.
		385
		386	my $port = rcv port,
		387	msg1 => sub { ...; 0 },
		388	msg2 => sub { ...; 0 },
		389	;
		390
		391	Example: create a port, bind receivers and send it in a message elsewhere
		392	in one go:
		393
		394	snd $otherport, reply =>
		395	rcv port,
		396	msg1 => sub { ...; 0 },
		397	...
		398	;
		399
		400	=cut
		401
		402	sub rcv($@) {
		403	my $port = shift;
		404	my ($noderef, $portid) = split /#/, $port, 2;
		405
		406	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}
		407	or Carp::croak "$port: rcv can only be called on local ports, caught";
		408
		409	if (@_ == 1) {
289	my $cb = shift;	410	my $cb = shift;
		411	delete $PORT_DATA{$portid};
290	$PORT{$id} = sub {	412	$PORT{$portid} = sub {
291	local $SELF = $port;	413	local $SELF = $port;
292	eval {	414	eval {
293	&$cb	415	&$cb
294	and kil $id;	416	and kil $port;
295	};	417	};
296	_self_die if $@;	418	_self_die if $@;
297	};	419	};
298	} else {	420	} else {
		421	my $self = $PORT_DATA{$portid} \|\|= do {
299	my $self = bless {	422	my $self = bless {
300	id => "$NODE#$id",	423	id => $port,
301	}, "AnyEvent::MP::Port";	424	}, "AnyEvent::MP::Port";
302		425
303	$PORT_DATA{$id} = $self;
304	$PORT{$id} = sub {	426	$PORT{$portid} = sub {
305	local $SELF = $port;	427	local $SELF = $port;
306		428
307	eval {	429	eval {
308	for (@{ $self->{rc0}{$_[0]} }) {	430	for (@{ $self->{rc0}{$_[0]} }) {
309	$_ && &{$_->[0]}	431	$_ && &{$_->[0]}
310	&& undef $_;	432	&& undef $_;
311	}	433	}
312		434
313	for (@{ $self->{rcv}{$_[0]} }) {	435	for (@{ $self->{rcv}{$_[0]} }) {
314	$_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1]	436	$_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1]
315	&& &{$_->[0]}	437	&& &{$_->[0]}
316	&& undef $_;	438	&& undef $_;
317	}	439	}
318		440
319	for (@{ $self->{any} }) {	441	for (@{ $self->{any} }) {
320	$_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1]	442	$_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1]
321	&& &{$_->[0]}	443	&& &{$_->[0]}
322	&& undef $_;	444	&& undef $_;
		445	}
323	}	446	};
		447	_self_die if $@;
324	};	448	};
325	_self_die if $@;	449
		450	$self
326	};	451	};
327	}
328		452
329	$port
330	}
331
332	=item reg $portid, $name
333
334	Registers the given port under the name C<$name>. If the name already
335	exists it is replaced.
336
337	A port can only be registered under one well known name.
338
339	A port automatically becomes unregistered when it is killed.
340
341	=cut
342
343	sub reg(@) {
344	my ($portid, $name) = @_;
345
346	$REG{$name} = $portid;
347	}
348
349	=item rcv $portid, tagstring => $callback->(@msg), ...
350
351	=item rcv $portid, $smartmatch => $callback->(@msg), ...
352
353	=item rcv $portid, [$smartmatch...] => $callback->(@msg), ...
354
355	Register callbacks to be called on matching messages on the given port.
356
357	The callback has to return a true value when its work is done, after
358	which is will be removed, or a false value in which case it will stay
359	registered.
360
361	The global C<$SELF> (exported by this module) contains C<$portid> while
362	executing the callback.
363
364	Runtime errors wdurign callback execution will result in the port being
365	C<kil>ed.
366
367	If the match is an array reference, then it will be matched against the
368	first elements of the message, otherwise only the first element is being
369	matched.
370
371	Any element in the match that is specified as C<_any_> (a function
372	exported by this module) matches any single element of the message.
373
374	While not required, it is highly recommended that the first matching
375	element is a string identifying the message. The one-string-only match is
376	also the most efficient match (by far).
377
378	=cut
379
380	sub rcv($@) {
381	my ($noderef, $port) = split /#/, shift, 2;
382
383	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}
384	or Carp::croak "$noderef#$port: rcv can only be called on local ports, caught";
385
386	my $self = $PORT_DATA{$port}
387	or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught";
388
389	"AnyEvent::MP::Port" eq ref $self	453	"AnyEvent::MP::Port" eq ref $self
390	or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught";	454	or Carp::croak "$port: rcv can only be called on message matching ports, caught";
391		455
392	while (@_) {	456	while (@_) {
393	my ($match, $cb) = splice @_, 0, 2;	457	my ($match, $cb) = splice @_, 0, 2;
394		458
395	if (!ref $match) {	459	if (!ref $match) {
396	push @{ $self->{rc0}{$match} }, [$cb];	460	push @{ $self->{rc0}{$match} }, [$cb];
397	} elsif (("ARRAY" eq ref $match && !ref $match->[0])) {	461	} elsif (("ARRAY" eq ref $match && !ref $match->[0])) {
398	my ($type, @match) = @$match;	462	my ($type, @match) = @$match;
399	@match	463	@match
400	? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match]	464	? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match]
401	: push @{ $self->{rc0}{$match->[0]} }, [$cb];	465	: push @{ $self->{rc0}{$match->[0]} }, [$cb];
402	} else {	466	} else {
403	push @{ $self->{any} }, [$cb, $match];	467	push @{ $self->{any} }, [$cb, $match];
		468	}
404	}	469	}
405	}	470	}
		471
		472	$port
406	}	473	}
407		474
408	=item $closure = psub { BLOCK }	475	=item $closure = psub { BLOCK }
409		476
410	Remembers C<$SELF> and creates a closure out of the BLOCK. When the	477	Remembers C<$SELF> and creates a closure out of the BLOCK. When the
…		…
441	$res	508	$res
442	}	509	}
443	}	510	}
444	}	511	}
445		512
446	=back	513	=item $guard = mon $port, $cb->(@reason)
447		514
448	=head1 FUNCTIONS FOR NODES	515	=item $guard = mon $port, $rcvport
449		516
450	=over 4	517	=item $guard = mon $port
451		518
452	=item become_public endpoint...	519	=item $guard = mon $port, $rcvport, @msg
453		520
454	Tells the node to become a public node, i.e. reachable from other nodes.	521	Monitor the given port and do something when the port is killed or
		522	messages to it were lost, and optionally return a guard that can be used
		523	to stop monitoring again.
455		524
456	If no arguments are given, or the first argument is C<undef>, then	525	C<mon> effectively guarantees that, in the absence of hardware failures,
457	AnyEvent::MP tries to bind on port C<4040> on all IP addresses that the	526	that after starting the monitor, either all messages sent to the port
458	local nodename resolves to.	527	will arrive, or the monitoring action will be invoked after possible
		528	message loss has been detected. No messages will be lost "in between"
		529	(after the first lost message no further messages will be received by the
		530	port). After the monitoring action was invoked, further messages might get
		531	delivered again.
459		532
460	Otherwise the first argument must be an array-reference with transport	533	In the first form (callback), the callback is simply called with any
461	endpoints ("ip:port", "hostname:port") or port numbers (in which case the	534	number of C<@reason> elements (no @reason means that the port was deleted
462	local nodename is used as hostname). The endpoints are all resolved and	535	"normally"). Note also that I<< the callback B<must> never die >>, so use
463	will become the node reference.	536	C<eval> if unsure.
464		537
		538	In the second form (another port given), the other port (C<$rcvport>)
		539	will be C<kil>'ed with C<@reason>, iff a @reason was specified, i.e. on
		540	"normal" kils nothing happens, while under all other conditions, the other
		541	port is killed with the same reason.
		542
		543	The third form (kill self) is the same as the second form, except that
		544	C<$rvport> defaults to C<$SELF>.
		545
		546	In the last form (message), a message of the form C<@msg, @reason> will be
		547	C<snd>.
		548
		549	As a rule of thumb, monitoring requests should always monitor a port from
		550	a local port (or callback). The reason is that kill messages might get
		551	lost, just like any other message. Another less obvious reason is that
		552	even monitoring requests can get lost (for exmaple, when the connection
		553	to the other node goes down permanently). When monitoring a port locally
		554	these problems do not exist.
		555
		556	Example: call a given callback when C<$port> is killed.
		557
		558	mon $port, sub { warn "port died because of <@_>\n" };
		559
		560	Example: kill ourselves when C<$port> is killed abnormally.
		561
		562	mon $port;
		563
		564	Example: send us a restart message when another C<$port> is killed.
		565
		566	mon $port, $self => "restart";
		567
465	=cut	568	=cut
		569
		570	sub mon {
		571	my ($noderef, $port) = split /#/, shift, 2;
		572
		573	my $node = $NODE{$noderef} \|\| add_node $noderef;
		574
		575	my $cb = @_ ? shift : $SELF \|\| Carp::croak 'mon: called with one argument only, but $SELF not set,';
		576
		577	unless (ref $cb) {
		578	if (@_) {
		579	# send a kill info message
		580	my (@msg) = ($cb, @_);
		581	$cb = sub { snd @msg, @_ };
		582	} else {
		583	# simply kill other port
		584	my $port = $cb;
		585	$cb = sub { kil $port, @_ if @_ };
		586	}
		587	}
		588
		589	$node->monitor ($port, $cb);
		590
		591	defined wantarray
		592	and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }
		593	}
		594
		595	=item $guard = mon_guard $port, $ref, $ref...
		596
		597	Monitors the given C<$port> and keeps the passed references. When the port
		598	is killed, the references will be freed.
		599
		600	Optionally returns a guard that will stop the monitoring.
		601
		602	This function is useful when you create e.g. timers or other watchers and
		603	want to free them when the port gets killed:
		604
		605	$port->rcv (start => sub {
		606	my $timer; $timer = mon_guard $port, AE::timer 1, 1, sub {
		607	undef $timer if 0.9 < rand;
		608	});
		609	});
		610
		611	=cut
		612
		613	sub mon_guard {
		614	my ($port, @refs) = @_;
		615
		616	#TODO: mon-less form?
		617
		618	mon $port, sub { 0 && @refs }
		619	}
		620
		621	=item kil $port[, @reason]
		622
		623	Kill the specified port with the given C<@reason>.
		624
		625	If no C<@reason> is specified, then the port is killed "normally" (linked
		626	ports will not be kileld, or even notified).
		627
		628	Otherwise, linked ports get killed with the same reason (second form of
		629	C<mon>, see below).
		630
		631	Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks
		632	will be reported as reason C<< die => $@ >>.
		633
		634	Transport/communication errors are reported as C<< transport_error =>
		635	$message >>.
		636
		637	=cut
		638
		639	=item $port = spawn $node, $initfunc[, @initdata]
		640
		641	Creates a port on the node C<$node> (which can also be a port ID, in which
		642	case it's the node where that port resides).
		643
		644	The port ID of the newly created port is return immediately, and it is
		645	permissible to immediately start sending messages or monitor the port.
		646
		647	After the port has been created, the init function is
		648	called. This function must be a fully-qualified function name
		649	(e.g. C<MyApp::Chat::Server::init>). To specify a function in the main
		650	program, use C<::name>.
		651
		652	If the function doesn't exist, then the node tries to C<require>
		653	the package, then the package above the package and so on (e.g.
		654	C<MyApp::Chat::Server>, C<MyApp::Chat>, C<MyApp>) until the function
		655	exists or it runs out of package names.
		656
		657	The init function is then called with the newly-created port as context
		658	object (C<$SELF>) and the C<@initdata> values as arguments.
		659
		660	A common idiom is to pass your own port, monitor the spawned port, and
		661	in the init function, monitor the original port. This two-way monitoring
		662	ensures that both ports get cleaned up when there is a problem.
		663
		664	Example: spawn a chat server port on C<$othernode>.
		665
		666	# this node, executed from within a port context:
		667	my $server = spawn $othernode, "MyApp::Chat::Server::connect", $SELF;
		668	mon $server;
		669
		670	# init function on C<$othernode>
		671	sub connect {
		672	my ($srcport) = @_;
		673
		674	mon $srcport;
		675
		676	rcv $SELF, sub {
		677	...
		678	};
		679	}
		680
		681	=cut
		682
		683	sub _spawn {
		684	my $port = shift;
		685	my $init = shift;
		686
		687	local $SELF = "$NODE#$port";
		688	eval {
		689	&{ load_func $init }
		690	};
		691	_self_die if $@;
		692	}
		693
		694	sub spawn(@) {
		695	my ($noderef, undef) = split /#/, shift, 2;
		696
		697	my $id = "$RUNIQ." . $ID++;
		698
		699	$_[0] =~ /::/
		700	or Carp::croak "spawn init function must be a fully-qualified name, caught";
		701
		702	($NODE{$noderef} \|\| add_node $noderef)
		703	->send (["", "AnyEvent::MP::_spawn" => $id, @_]);
		704
		705	"$noderef#$id"
		706	}
466		707
467	=back	708	=back
468		709
469	=head1 NODE MESSAGES	710	=head1 NODE MESSAGES
470		711
471	Nodes understand the following messages sent to them. Many of them take	712	Nodes understand the following messages sent to them. Many of them take
472	arguments called C<@reply>, which will simply be used to compose a reply	713	arguments called C<@reply>, which will simply be used to compose a reply
473	message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and	714	message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and
474	the remaining arguments are simply the message data.	715	the remaining arguments are simply the message data.
475		716
		717	While other messages exist, they are not public and subject to change.
		718
476	=over 4	719	=over 4
477		720
478	=cut	721	=cut
479		722
480	=item lookup => $name, @reply	723	=item lookup => $name, @reply
…		…
510		753
511	=back	754	=back
512		755
513	=head1 AnyEvent::MP vs. Distributed Erlang	756	=head1 AnyEvent::MP vs. Distributed Erlang
514		757
515	AnyEvent::MP got lots of its ideas from distributed erlang (erlang node	758	AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node
516	== aemp node, erlang process == aemp port), so many of the documents and	759	== aemp node, Erlang process == aemp port), so many of the documents and
517	programming techniques employed by erlang apply to AnyEvent::MP. Here is a	760	programming techniques employed by Erlang apply to AnyEvent::MP. Here is a
518	sample:	761	sample:
519		762
520	http://www.erlang.se/doc/programming_rules.shtml	763	http://www.Erlang.se/doc/programming_rules.shtml
521	http://erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4	764	http://Erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4
522	http://erlang.org/download/erlang-book-part1.pdf # chapters 5 and 6	765	http://Erlang.org/download/Erlang-book-part1.pdf # chapters 5 and 6
523	http://erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5	766	http://Erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5
524		767
525	Despite the similarities, there are also some important differences:	768	Despite the similarities, there are also some important differences:
526		769
527	=over 4	770	=over 4
528		771
…		…
539		782
540	Erlang uses processes that selctively receive messages, and therefore	783	Erlang uses processes that selctively receive messages, and therefore
541	needs a queue. AEMP is event based, queuing messages would serve no useful	784	needs a queue. AEMP is event based, queuing messages would serve no useful
542	purpose.	785	purpose.
543		786
544	(But see L<Coro::MP> for a more erlang-like process model on top of AEMP).	787	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).
545		788
546	=item * Erlang sends are synchronous, AEMP sends are asynchronous.	789	=item * Erlang sends are synchronous, AEMP sends are asynchronous.
547		790
548	Sending messages in erlang is synchronous and blocks the process. AEMP	791	Sending messages in Erlang is synchronous and blocks the process. AEMP
549	sends are immediate, connection establishment is handled in the	792	sends are immediate, connection establishment is handled in the
550	background.	793	background.
551		794
552	=item * Erlang can silently lose messages, AEMP cannot.	795	=item * Erlang can silently lose messages, AEMP cannot.
553		796
…		…
556	and c, and the other side only receives messages a and c).	799	and c, and the other side only receives messages a and c).
557		800
558	AEMP guarantees correct ordering, and the guarantee that there are no	801	AEMP guarantees correct ordering, and the guarantee that there are no
559	holes in the message sequence.	802	holes in the message sequence.
560		803
561	=item * In erlang, processes can be declared dead and later be found to be	804	=item * In Erlang, processes can be declared dead and later be found to be
562	alive.	805	alive.
563		806
564	In erlang it can happen that a monitored process is declared dead and	807	In Erlang it can happen that a monitored process is declared dead and
565	linked processes get killed, but later it turns out that the process is	808	linked processes get killed, but later it turns out that the process is
566	still alive - and can receive messages.	809	still alive - and can receive messages.
567		810
568	In AEMP, when port monitoring detects a port as dead, then that port will	811	In AEMP, when port monitoring detects a port as dead, then that port will
569	eventually be killed - it cannot happen that a node detects a port as dead	812	eventually be killed - it cannot happen that a node detects a port as dead
570	and then later sends messages to it, finding it is still alive.	813	and then later sends messages to it, finding it is still alive.
571		814
572	=item * Erlang can send messages to the wrong port, AEMP does not.	815	=item * Erlang can send messages to the wrong port, AEMP does not.
573		816
574	In erlang it is quite possible that a node that restarts reuses a process	817	In Erlang it is quite possible that a node that restarts reuses a process
575	ID known to other nodes for a completely different process, causing	818	ID known to other nodes for a completely different process, causing
576	messages destined for that process to end up in an unrelated process.	819	messages destined for that process to end up in an unrelated process.
577		820
578	AEMP never reuses port IDs, so old messages or old port IDs floating	821	AEMP never reuses port IDs, so old messages or old port IDs floating
579	around in the network will not be sent to an unrelated port.	822	around in the network will not be sent to an unrelated port.
…		…
582	authentication and can use TLS.	825	authentication and can use TLS.
583		826
584	AEMP can use a proven protocol - SSL/TLS - to protect connections and	827	AEMP can use a proven protocol - SSL/TLS - to protect connections and
585	securely authenticate nodes.	828	securely authenticate nodes.
586		829
		830	=item * The AEMP protocol is optimised for both text-based and binary
		831	communications.
		832
		833	The AEMP protocol, unlike the Erlang protocol, supports both
		834	language-independent text-only protocols (good for debugging) and binary,
		835	language-specific serialisers (e.g. Storable).
		836
		837	It has also been carefully designed to be implementable in other languages
		838	with a minimum of work while gracefully degrading fucntionality to make the
		839	protocol simple.
		840
		841	=item * AEMP has more flexible monitoring options than Erlang.
		842
		843	In Erlang, you can chose to receive I<all> exit signals as messages
		844	or I<none>, there is no in-between, so monitoring single processes is
		845	difficult to implement. Monitoring in AEMP is more flexible than in
		846	Erlang, as one can choose between automatic kill, exit message or callback
		847	on a per-process basis.
		848
		849	=item * Erlang tries to hide remote/local connections, AEMP does not.
		850
		851	Monitoring in Erlang is not an indicator of process death/crashes,
		852	as linking is (except linking is unreliable in Erlang).
		853
		854	In AEMP, you don't "look up" registered port names or send to named ports
		855	that might or might not be persistent. Instead, you normally spawn a port
		856	on the remote node. The init function monitors the you, and you monitor
		857	the remote port. Since both monitors are local to the node, they are much
		858	more reliable.
		859
		860	This also saves round-trips and avoids sending messages to the wrong port
		861	(hard to do in Erlang).
		862
		863	=back
		864
		865	=head1 RATIONALE
		866
		867	=over 4
		868
		869	=item Why strings for ports and noderefs, why not objects?
		870
		871	We considered "objects", but found that the actual number of methods
		872	thatc an be called are very low. Since port IDs and noderefs travel over
		873	the network frequently, the serialising/deserialising would add lots of
		874	overhead, as well as having to keep a proxy object.
		875
		876	Strings can easily be printed, easily serialised etc. and need no special
		877	procedures to be "valid".
		878
		879	And a a miniport consists of a single closure stored in a global hash - it
		880	can't become much cheaper.
		881
		882	=item Why favour JSON, why not real serialising format such as Storable?
		883
		884	In fact, any AnyEvent::MP node will happily accept Storable as framing
		885	format, but currently there is no way to make a node use Storable by
		886	default.
		887
		888	The default framing protocol is JSON because a) JSON::XS is many times
		889	faster for small messages and b) most importantly, after years of
		890	experience we found that object serialisation is causing more problems
		891	than it gains: Just like function calls, objects simply do not travel
		892	easily over the network, mostly because they will always be a copy, so you
		893	always have to re-think your design.
		894
		895	Keeping your messages simple, concentrating on data structures rather than
		896	objects, will keep your messages clean, tidy and efficient.
		897
587	=back	898	=back
588		899
589	=head1 SEE ALSO	900	=head1 SEE ALSO
590		901
591	L<AnyEvent>.	902	L<AnyEvent>.

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.27 by root, Tue Aug 4 22:13:45 2009 UTC vs. Revision 1.48 by root, Thu Aug 13 02:59:42 2009 UTC

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Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.27 by root, Tue Aug 4 22:13:45 2009 UTC vs.
Revision 1.48 by root, Thu Aug 13 02:59:42 2009 UTC