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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.73 by root, Mon Aug 31 11:08:25 2009 UTC vs.
Revision 1.102 by root, Tue Oct 6 13:37:52 2009 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent::MP - multi-processing/message-passing framework	3	AnyEvent::MP - erlang-style multi-processing/message-passing framework
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use AnyEvent::MP;	7	use AnyEvent::MP;
8		8
9	$NODE # contains this node's noderef	9	$NODE # contains this node's node ID
10	NODE # returns this node's noderef	10	NODE # returns this node's node ID
11	NODE $port # returns the noderef of the port
12		11
13	$SELF # receiving/own port id in rcv callbacks	12	$SELF # receiving/own port id in rcv callbacks
14		13
15	# initialise the node so it can send/receive messages	14	# initialise the node so it can send/receive messages
16	configure;	15	configure;
17		16
18	# ports are message endpoints	17	# ports are message destinations
19		18
20	# sending messages	19	# sending messages
21	snd $port, type => data...;	20	snd $port, type => data...;
22	snd $port, @msg;	21	snd $port, @msg;
23	snd @msg_with_first_element_being_a_port;	22	snd @msg_with_first_element_being_a_port;
31	rcv $port, pong => sub { warn "pong received\n" };	30	rcv $port, pong => sub { warn "pong received\n" };
32		31
33	# create a port on another node	32	# create a port on another node
34	my $port = spawn $node, $initfunc, @initdata;	33	my $port = spawn $node, $initfunc, @initdata;
35		34
		35	# destroy a prot again
		36	kil $port; # "normal" kill
		37	kil $port, my_error => "everything is broken"; # error kill
		38
36	# monitoring	39	# monitoring
37	mon $port, $cb->(@msg) # callback is invoked on death	40	mon $localport, $cb->(@msg) # callback is invoked on death
38	mon $port, $otherport # kill otherport on abnormal death	41	mon $localport, $otherport # kill otherport on abnormal death
39	mon $port, $otherport, @msg # send message on death	42	mon $localport, $otherport, @msg # send message on death
		43
		44	# temporarily execute code in port context
		45	peval $port, sub { die "kill the port!" };
		46
		47	# execute callbacks in $SELF port context
		48	my $timer = AE::timer 1, 0, psub {
		49	die "kill the port, delayed";
		50	};
40		51
41	=head1 CURRENT STATUS	52	=head1 CURRENT STATUS
42		53
43	bin/aemp - stable.	54	bin/aemp - stable.
44	AnyEvent::MP - stable API, should work.	55	AnyEvent::MP - stable API, should work.
45	AnyEvent::MP::Intro - uptodate, but incomplete.	56	AnyEvent::MP::Intro - explains most concepts.
46	AnyEvent::MP::Kernel - mostly stable.	57	AnyEvent::MP::Kernel - mostly stable API.
47	AnyEvent::MP::Global - stable API, protocol not yet final.	58	AnyEvent::MP::Global - stable API.
48
49	stay tuned.
50		59
51	=head1 DESCRIPTION	60	=head1 DESCRIPTION
52		61
53	This module (-family) implements a simple message passing framework.	62	This module (-family) implements a simple message passing framework.
54		63
…		…
56	on the same or other hosts, and you can supervise entities remotely.	65	on the same or other hosts, and you can supervise entities remotely.
57		66
58	For an introduction to this module family, see the L<AnyEvent::MP::Intro>	67	For an introduction to this module family, see the L<AnyEvent::MP::Intro>
59	manual page and the examples under F<eg/>.	68	manual page and the examples under F<eg/>.
60		69
61	At the moment, this module family is a bit underdocumented.
62
63	=head1 CONCEPTS	70	=head1 CONCEPTS
64		71
65	=over 4	72	=over 4
66		73
67	=item port	74	=item port
68		75
69	A port is something you can send messages to (with the C<snd> function).	76	Not to be confused with a TCP port, a "port" is something you can send
		77	messages to (with the C<snd> function).
70		78
71	Ports allow you to register C<rcv> handlers that can match all or just	79	Ports allow you to register C<rcv> handlers that can match all or just
72	some messages. Messages send to ports will not be queued, regardless of	80	some messages. Messages send to ports will not be queued, regardless of
73	anything was listening for them or not.	81	anything was listening for them or not.
74		82
…		…
85		93
86	Nodes are either public (have one or more listening ports) or private	94	Nodes are either public (have one or more listening ports) or private
87	(no listening ports). Private nodes cannot talk to other private nodes	95	(no listening ports). Private nodes cannot talk to other private nodes
88	currently.	96	currently.
89		97
90	=item node ID - C<[a-za-Z0-9_\-.:]+>	98	=item node ID - C<[A-Z_][a-zA-Z0-9_\-.:]*>
91		99
92	A node ID is a string that uniquely identifies the node within a	100	A node ID is a string that uniquely identifies the node within a
93	network. Depending on the configuration used, node IDs can look like a	101	network. Depending on the configuration used, node IDs can look like a
94	hostname, a hostname and a port, or a random string. AnyEvent::MP itself	102	hostname, a hostname and a port, or a random string. AnyEvent::MP itself
95	doesn't interpret node IDs in any way.	103	doesn't interpret node IDs in any way.
…		…
99	Nodes can only talk to each other by creating some kind of connection to	107	Nodes can only talk to each other by creating some kind of connection to
100	each other. To do this, nodes should listen on one or more local transport	108	each other. To do this, nodes should listen on one or more local transport
101	endpoints - binds. Currently, only standard C<ip:port> specifications can	109	endpoints - binds. Currently, only standard C<ip:port> specifications can
102	be used, which specify TCP ports to listen on.	110	be used, which specify TCP ports to listen on.
103		111
104	=item seeds - C<host:port>	112	=item seed nodes
105		113
106	When a node starts, it knows nothing about the network. To teach the node	114	When a node starts, it knows nothing about the network. To teach the node
107	about the network it first has to contact some other node within the	115	about the network it first has to contact some other node within the
108	network. This node is called a seed.	116	network. This node is called a seed.
109		117
110	Seeds are transport endpoint(s) of as many nodes as one wants. Those nodes	118	Apart from the fact that other nodes know them as seed nodes and they have
		119	to have fixed listening addresses, seed nodes are perfectly normal nodes -
		120	any node can function as a seed node for others.
		121
		122	In addition to discovering the network, seed nodes are also used to
		123	maintain the network and to connect nodes that otherwise would have
		124	trouble connecting. They form the backbone of an AnyEvent::MP network.
		125
111	are expected to be long-running, and at least one of those should always	126	Seed nodes are expected to be long-running, and at least one seed node
112	be available. When nodes run out of connections (e.g. due to a network	127	should always be available. They should also be relatively responsive - a
113	error), they try to re-establish connections to some seednodes again to	128	seed node that blocks for long periods will slow down everybody else.
114	join the network.
115		129
116	Apart from being sued for seeding, seednodes are not special in any way -	130	=item seeds - C<host:port>
117	every public node can be a seednode.	131
		132	Seeds are transport endpoint(s) (usually a hostname/IP address and a
		133	TCP port) of nodes that should be used as seed nodes.
		134
		135	The nodes listening on those endpoints are expected to be long-running,
		136	and at least one of those should always be available. When nodes run out
		137	of connections (e.g. due to a network error), they try to re-establish
		138	connections to some seednodes again to join the network.
118		139
119	=back	140	=back
120		141
121	=head1 VARIABLES/FUNCTIONS	142	=head1 VARIABLES/FUNCTIONS
122		143
…		…
134		155
135	use AE ();	156	use AE ();
136		157
137	use base "Exporter";	158	use base "Exporter";
138		159
139	our $VERSION = $AnyEvent::MP::Kernel::VERSION;	160	our $VERSION = 1.21;
140		161
141	our @EXPORT = qw(	162	our @EXPORT = qw(
142	NODE $NODE *SELF node_of after	163	NODE $NODE *SELF node_of after
143	configure	164	configure
144	snd rcv mon mon_guard kil reg psub spawn	165	snd rcv mon mon_guard kil psub peval spawn cal
145	port	166	port
146	);	167	);
147		168
148	our $SELF;	169	our $SELF;
149		170
…		…
161		182
162	=item $nodeid = node_of $port	183	=item $nodeid = node_of $port
163		184
164	Extracts and returns the node ID from a port ID or a node ID.	185	Extracts and returns the node ID from a port ID or a node ID.
165		186
		187	=item configure $profile, key => value...
		188
166	=item configure key => value...	189	=item configure key => value...
167		190
168	Before a node can talk to other nodes on the network (i.e. enter	191	Before a node can talk to other nodes on the network (i.e. enter
169	"distributed mode") it has to configure itself - the minimum a node needs	192	"distributed mode") it has to configure itself - the minimum a node needs
170	to know is its own name, and optionally it should know the addresses of	193	to know is its own name, and optionally it should know the addresses of
…		…
177		200
178	=item step 1, gathering configuration from profiles	201	=item step 1, gathering configuration from profiles
179		202
180	The function first looks up a profile in the aemp configuration (see the	203	The function first looks up a profile in the aemp configuration (see the
181	L<aemp> commandline utility). The profile name can be specified via the	204	L<aemp> commandline utility). The profile name can be specified via the
182	named C<profile> parameter. If it is missing, then the nodename (F<uname	205	named C<profile> parameter or can simply be the first parameter). If it is
183	-n>) will be used as profile name.	206	missing, then the nodename (F<uname -n>) will be used as profile name.
184		207
185	The profile data is then gathered as follows:	208	The profile data is then gathered as follows:
186		209
187	First, all remaining key => value pairs (all of which are conviniently	210	First, all remaining key => value pairs (all of which are conveniently
188	undocumented at the moment) will be interpreted as configuration	211	undocumented at the moment) will be interpreted as configuration
189	data. Then they will be overwritten by any values specified in the global	212	data. Then they will be overwritten by any values specified in the global
190	default configuration (see the F<aemp> utility), then the chain of	213	default configuration (see the F<aemp> utility), then the chain of
191	profiles chosen by the profile name (and any C<parent> attributes).	214	profiles chosen by the profile name (and any C<parent> attributes).
192		215
…		…
216	L<AnyEvent::MP::Global> module, which will then use it to keep	239	L<AnyEvent::MP::Global> module, which will then use it to keep
217	connectivity with at least one node at any point in time.	240	connectivity with at least one node at any point in time.
218		241
219	=back	242	=back
220		243
221	Example: become a distributed node using the locla node name as profile.	244	Example: become a distributed node using the local node name as profile.
222	This should be the most common form of invocation for "daemon"-type nodes.	245	This should be the most common form of invocation for "daemon"-type nodes.
223		246
224	configure	247	configure
225		248
226	Example: become an anonymous node. This form is often used for commandline	249	Example: become an anonymous node. This form is often used for commandline
…		…
231	Example: configure a node using a profile called seed, which si suitable	254	Example: configure a node using a profile called seed, which si suitable
232	for a seed node as it binds on all local addresses on a fixed port (4040,	255	for a seed node as it binds on all local addresses on a fixed port (4040,
233	customary for aemp).	256	customary for aemp).
234		257
235	# use the aemp commandline utility	258	# use the aemp commandline utility
236	# aemp profile seed setnodeid anon/ setbinds '*:4040'	259	# aemp profile seed nodeid anon/ binds '*:4040'
237		260
238	# then use it	261	# then use it
239	configure profile => "seed";	262	configure profile => "seed";
240		263
241	# or simply use aemp from the shell again:	264	# or simply use aemp from the shell again:
…		…
360	msg1 => sub { ... },	383	msg1 => sub { ... },
361	...	384	...
362	;	385	;
363		386
364	Example: temporarily register a rcv callback for a tag matching some port	387	Example: temporarily register a rcv callback for a tag matching some port
365	(e.g. for a rpc reply) and unregister it after a message was received.	388	(e.g. for an rpc reply) and unregister it after a message was received.
366		389
367	rcv $port, $otherport => sub {	390	rcv $port, $otherport => sub {
368	my @reply = @_;	391	my @reply = @_;
369		392
370	rcv $SELF, $otherport;	393	rcv $SELF, $otherport;
…		…
372		395
373	=cut	396	=cut
374		397
375	sub rcv($@) {	398	sub rcv($@) {
376	my $port = shift;	399	my $port = shift;
377	my ($noderef, $portid) = split /#/, $port, 2;	400	my ($nodeid, $portid) = split /#/, $port, 2;
378		401
379	$NODE{$noderef} == $NODE{""}	402	$NODE{$nodeid} == $NODE{""}
380	or Carp::croak "$port: rcv can only be called on local ports, caught";	403	or Carp::croak "$port: rcv can only be called on local ports, caught";
381		404
382	while (@_) {	405	while (@_) {
383	if (ref $_[0]) {	406	if (ref $_[0]) {
384	if (my $self = $PORT_DATA{$portid}) {	407	if (my $self = $PORT_DATA{$portid}) {
…		…
425	}	448	}
426		449
427	$port	450	$port
428	}	451	}
429		452
		453	=item peval $port, $coderef[, @args]
		454
		455	Evaluates the given C<$codref> within the contetx of C<$port>, that is,
		456	when the code throews an exception the C<$port> will be killed.
		457
		458	Any remaining args will be passed to the callback. Any return values will
		459	be returned to the caller.
		460
		461	This is useful when you temporarily want to execute code in the context of
		462	a port.
		463
		464	Example: create a port and run some initialisation code in it's context.
		465
		466	my $port = port { ... };
		467
		468	peval $port, sub {
		469	init
		470	or die "unable to init";
		471	};
		472
		473	=cut
		474
		475	sub peval($$) {
		476	local $SELF = shift;
		477	my $cb = shift;
		478
		479	if (wantarray) {
		480	my @res = eval { &$cb };
		481	_self_die if $@;
		482	@res
		483	} else {
		484	my $res = eval { &$cb };
		485	_self_die if $@;
		486	$res
		487	}
		488	}
		489
430	=item $closure = psub { BLOCK }	490	=item $closure = psub { BLOCK }
431		491
432	Remembers C<$SELF> and creates a closure out of the BLOCK. When the	492	Remembers C<$SELF> and creates a closure out of the BLOCK. When the
433	closure is executed, sets up the environment in the same way as in C<rcv>	493	closure is executed, sets up the environment in the same way as in C<rcv>
434	callbacks, i.e. runtime errors will cause the port to get C<kil>ed.	494	callbacks, i.e. runtime errors will cause the port to get C<kil>ed.
		495
		496	The effect is basically as if it returned C<< sub { peval $SELF, sub {
		497	BLOCK } } >>.
435		498
436	This is useful when you register callbacks from C<rcv> callbacks:	499	This is useful when you register callbacks from C<rcv> callbacks:
437		500
438	rcv delayed_reply => sub {	501	rcv delayed_reply => sub {
439	my ($delay, @reply) = @_;	502	my ($delay, @reply) = @_;
…		…
475		538
476	Monitor the given port and do something when the port is killed or	539	Monitor the given port and do something when the port is killed or
477	messages to it were lost, and optionally return a guard that can be used	540	messages to it were lost, and optionally return a guard that can be used
478	to stop monitoring again.	541	to stop monitoring again.
479		542
		543	In the first form (callback), the callback is simply called with any
		544	number of C<@reason> elements (no @reason means that the port was deleted
		545	"normally"). Note also that I<< the callback B<must> never die >>, so use
		546	C<eval> if unsure.
		547
		548	In the second form (another port given), the other port (C<$rcvport>)
		549	will be C<kil>'ed with C<@reason>, if a @reason was specified, i.e. on
		550	"normal" kils nothing happens, while under all other conditions, the other
		551	port is killed with the same reason.
		552
		553	The third form (kill self) is the same as the second form, except that
		554	C<$rvport> defaults to C<$SELF>.
		555
		556	In the last form (message), a message of the form C<@msg, @reason> will be
		557	C<snd>.
		558
		559	Monitoring-actions are one-shot: once messages are lost (and a monitoring
		560	alert was raised), they are removed and will not trigger again.
		561
		562	As a rule of thumb, monitoring requests should always monitor a port from
		563	a local port (or callback). The reason is that kill messages might get
		564	lost, just like any other message. Another less obvious reason is that
		565	even monitoring requests can get lost (for example, when the connection
		566	to the other node goes down permanently). When monitoring a port locally
		567	these problems do not exist.
		568
480	C<mon> effectively guarantees that, in the absence of hardware failures,	569	C<mon> effectively guarantees that, in the absence of hardware failures,
481	after starting the monitor, either all messages sent to the port will	570	after starting the monitor, either all messages sent to the port will
482	arrive, or the monitoring action will be invoked after possible message	571	arrive, or the monitoring action will be invoked after possible message
483	loss has been detected. No messages will be lost "in between" (after	572	loss has been detected. No messages will be lost "in between" (after
484	the first lost message no further messages will be received by the	573	the first lost message no further messages will be received by the
485	port). After the monitoring action was invoked, further messages might get	574	port). After the monitoring action was invoked, further messages might get
486	delivered again.	575	delivered again.
487		576
488	Note that monitoring-actions are one-shot: once messages are lost (and a	577	Inter-host-connection timeouts and monitoring depend on the transport
489	monitoring alert was raised), they are removed and will not trigger again.	578	used. The only transport currently implemented is TCP, and AnyEvent::MP
		579	relies on TCP to detect node-downs (this can take 10-15 minutes on a
		580	non-idle connection, and usually around two hours for idle connections).
490		581
491	In the first form (callback), the callback is simply called with any	582	This means that monitoring is good for program errors and cleaning up
492	number of C<@reason> elements (no @reason means that the port was deleted	583	stuff eventually, but they are no replacement for a timeout when you need
493	"normally"). Note also that I<< the callback B<must> never die >>, so use	584	to ensure some maximum latency.
494	C<eval> if unsure.
495
496	In the second form (another port given), the other port (C<$rcvport>)
497	will be C<kil>'ed with C<@reason>, iff a @reason was specified, i.e. on
498	"normal" kils nothing happens, while under all other conditions, the other
499	port is killed with the same reason.
500
501	The third form (kill self) is the same as the second form, except that
502	C<$rvport> defaults to C<$SELF>.
503
504	In the last form (message), a message of the form C<@msg, @reason> will be
505	C<snd>.
506
507	As a rule of thumb, monitoring requests should always monitor a port from
508	a local port (or callback). The reason is that kill messages might get
509	lost, just like any other message. Another less obvious reason is that
510	even monitoring requests can get lost (for exmaple, when the connection
511	to the other node goes down permanently). When monitoring a port locally
512	these problems do not exist.
513		585
514	Example: call a given callback when C<$port> is killed.	586	Example: call a given callback when C<$port> is killed.
515		587
516	mon $port, sub { warn "port died because of <@_>\n" };	588	mon $port, sub { warn "port died because of <@_>\n" };
517		589
…		…
524	mon $port, $self => "restart";	596	mon $port, $self => "restart";
525		597
526	=cut	598	=cut
527		599
528	sub mon {	600	sub mon {
529	my ($noderef, $port) = split /#/, shift, 2;	601	my ($nodeid, $port) = split /#/, shift, 2;
530		602
531	my $node = $NODE{$noderef} \|\| add_node $noderef;	603	my $node = $NODE{$nodeid} \|\| add_node $nodeid;
532		604
533	my $cb = @_ ? shift : $SELF \|\| Carp::croak 'mon: called with one argument only, but $SELF not set,';	605	my $cb = @_ ? shift : $SELF \|\| Carp::croak 'mon: called with one argument only, but $SELF not set,';
534		606
535	unless (ref $cb) {	607	unless (ref $cb) {
536	if (@_) {	608	if (@_) {
…		…
545	}	617	}
546		618
547	$node->monitor ($port, $cb);	619	$node->monitor ($port, $cb);
548		620
549	defined wantarray	621	defined wantarray
550	and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }	622	and ($cb += 0, AnyEvent::Util::guard { $node->unmonitor ($port, $cb) })
551	}	623	}
552		624
553	=item $guard = mon_guard $port, $ref, $ref...	625	=item $guard = mon_guard $port, $ref, $ref...
554		626
555	Monitors the given C<$port> and keeps the passed references. When the port	627	Monitors the given C<$port> and keeps the passed references. When the port
…		…
612	the package, then the package above the package and so on (e.g.	684	the package, then the package above the package and so on (e.g.
613	C<MyApp::Chat::Server>, C<MyApp::Chat>, C<MyApp>) until the function	685	C<MyApp::Chat::Server>, C<MyApp::Chat>, C<MyApp>) until the function
614	exists or it runs out of package names.	686	exists or it runs out of package names.
615		687
616	The init function is then called with the newly-created port as context	688	The init function is then called with the newly-created port as context
617	object (C<$SELF>) and the C<@initdata> values as arguments.	689	object (C<$SELF>) and the C<@initdata> values as arguments. It I<must>
		690	call one of the C<rcv> functions to set callbacks on C<$SELF>, otherwise
		691	the port might not get created.
618		692
619	A common idiom is to pass a local port, immediately monitor the spawned	693	A common idiom is to pass a local port, immediately monitor the spawned
620	port, and in the remote init function, immediately monitor the passed	694	port, and in the remote init function, immediately monitor the passed
621	local port. This two-way monitoring ensures that both ports get cleaned up	695	local port. This two-way monitoring ensures that both ports get cleaned up
622	when there is a problem.	696	when there is a problem.
623		697
		698	C<spawn> guarantees that the C<$initfunc> has no visible effects on the
		699	caller before C<spawn> returns (by delaying invocation when spawn is
		700	called for the local node).
		701
624	Example: spawn a chat server port on C<$othernode>.	702	Example: spawn a chat server port on C<$othernode>.
625		703
626	# this node, executed from within a port context:	704	# this node, executed from within a port context:
627	my $server = spawn $othernode, "MyApp::Chat::Server::connect", $SELF;	705	my $server = spawn $othernode, "MyApp::Chat::Server::connect", $SELF;
628	mon $server;	706	mon $server;
…		…
642		720
643	sub _spawn {	721	sub _spawn {
644	my $port = shift;	722	my $port = shift;
645	my $init = shift;	723	my $init = shift;
646		724
		725	# rcv will create the actual port
647	local $SELF = "$NODE#$port";	726	local $SELF = "$NODE#$port";
648	eval {	727	eval {
649	&{ load_func $init }	728	&{ load_func $init }
650	};	729	};
651	_self_die if $@;	730	_self_die if $@;
652	}	731	}
653		732
654	sub spawn(@) {	733	sub spawn(@) {
655	my ($noderef, undef) = split /#/, shift, 2;	734	my ($nodeid, undef) = split /#/, shift, 2;
656		735
657	my $id = "$RUNIQ." . $ID++;	736	my $id = "$RUNIQ." . $ID++;
658		737
659	$_[0] =~ /::/	738	$_[0] =~ /::/
660	or Carp::croak "spawn init function must be a fully-qualified name, caught";	739	or Carp::croak "spawn init function must be a fully-qualified name, caught";
661		740
662	snd_to_func $noderef, "AnyEvent::MP::_spawn" => $id, @_;	741	snd_to_func $nodeid, "AnyEvent::MP::_spawn" => $id, @_;
663		742
664	"$noderef#$id"	743	"$nodeid#$id"
665	}	744	}
666		745
667	=item after $timeout, @msg	746	=item after $timeout, @msg
668		747
669	=item after $timeout, $callback	748	=item after $timeout, $callback
…		…
686	? $action[0]()	765	? $action[0]()
687	: snd @action;	766	: snd @action;
688	};	767	};
689	}	768	}
690		769
		770	=item cal $port, @msg, $callback[, $timeout]
		771
		772	A simple form of RPC - sends a message to the given C<$port> with the
		773	given contents (C<@msg>), but adds a reply port to the message.
		774
		775	The reply port is created temporarily just for the purpose of receiving
		776	the reply, and will be C<kil>ed when no longer needed.
		777
		778	A reply message sent to the port is passed to the C<$callback> as-is.
		779
		780	If an optional time-out (in seconds) is given and it is not C<undef>,
		781	then the callback will be called without any arguments after the time-out
		782	elapsed and the port is C<kil>ed.
		783
		784	If no time-out is given (or it is C<undef>), then the local port will
		785	monitor the remote port instead, so it eventually gets cleaned-up.
		786
		787	Currently this function returns the temporary port, but this "feature"
		788	might go in future versions unless you can make a convincing case that
		789	this is indeed useful for something.
		790
		791	=cut
		792
		793	sub cal(@) {
		794	my $timeout = ref $_[-1] ? undef : pop;
		795	my $cb = pop;
		796
		797	my $port = port {
		798	undef $timeout;
		799	kil $SELF;
		800	&$cb;
		801	};
		802
		803	if (defined $timeout) {
		804	$timeout = AE::timer $timeout, 0, sub {
		805	undef $timeout;
		806	kil $port;
		807	$cb->();
		808	};
		809	} else {
		810	mon $_[0], sub {
		811	kil $port;
		812	$cb->();
		813	};
		814	}
		815
		816	push @_, $port;
		817	&snd;
		818
		819	$port
		820	}
		821
691	=back	822	=back
692		823
693	=head1 AnyEvent::MP vs. Distributed Erlang	824	=head1 AnyEvent::MP vs. Distributed Erlang
694		825
695	AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node	826	AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node
696	== aemp node, Erlang process == aemp port), so many of the documents and	827	== aemp node, Erlang process == aemp port), so many of the documents and
697	programming techniques employed by Erlang apply to AnyEvent::MP. Here is a	828	programming techniques employed by Erlang apply to AnyEvent::MP. Here is a
698	sample:	829	sample:
699		830
700	http://www.Erlang.se/doc/programming_rules.shtml	831	http://www.erlang.se/doc/programming_rules.shtml
701	http://Erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4	832	http://erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4
702	http://Erlang.org/download/Erlang-book-part1.pdf # chapters 5 and 6	833	http://erlang.org/download/erlang-book-part1.pdf # chapters 5 and 6
703	http://Erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5	834	http://erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5
704		835
705	Despite the similarities, there are also some important differences:	836	Despite the similarities, there are also some important differences:
706		837
707	=over 4	838	=over 4
708		839
709	=item * Node IDs are arbitrary strings in AEMP.	840	=item * Node IDs are arbitrary strings in AEMP.
710		841
711	Erlang relies on special naming and DNS to work everywhere in the same	842	Erlang relies on special naming and DNS to work everywhere in the same
712	way. AEMP relies on each node somehow knowing its own address(es) (e.g. by	843	way. AEMP relies on each node somehow knowing its own address(es) (e.g. by
713	configuraiton or DNS), but will otherwise discover other odes itself.	844	configuration or DNS), and possibly the addresses of some seed nodes, but
		845	will otherwise discover other nodes (and their IDs) itself.
714		846
715	=item * Erlang has a "remote ports are like local ports" philosophy, AEMP	847	=item * Erlang has a "remote ports are like local ports" philosophy, AEMP
716	uses "local ports are like remote ports".	848	uses "local ports are like remote ports".
717		849
718	The failure modes for local ports are quite different (runtime errors	850	The failure modes for local ports are quite different (runtime errors
…		…
731		863
732	Erlang uses processes that selectively receive messages, and therefore	864	Erlang uses processes that selectively receive messages, and therefore
733	needs a queue. AEMP is event based, queuing messages would serve no	865	needs a queue. AEMP is event based, queuing messages would serve no
734	useful purpose. For the same reason the pattern-matching abilities of	866	useful purpose. For the same reason the pattern-matching abilities of
735	AnyEvent::MP are more limited, as there is little need to be able to	867	AnyEvent::MP are more limited, as there is little need to be able to
736	filter messages without dequeing them.	868	filter messages without dequeuing them.
737		869
738	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).	870	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).
739		871
740	=item * Erlang sends are synchronous, AEMP sends are asynchronous.	872	=item * Erlang sends are synchronous, AEMP sends are asynchronous.
741		873
…		…
743	so does not need a queue that can overflow). AEMP sends are immediate,	875	so does not need a queue that can overflow). AEMP sends are immediate,
744	connection establishment is handled in the background.	876	connection establishment is handled in the background.
745		877
746	=item * Erlang suffers from silent message loss, AEMP does not.	878	=item * Erlang suffers from silent message loss, AEMP does not.
747		879
748	Erlang makes few guarantees on messages delivery - messages can get lost	880	Erlang implements few guarantees on messages delivery - messages can get
749	without any of the processes realising it (i.e. you send messages a, b,	881	lost without any of the processes realising it (i.e. you send messages a,
750	and c, and the other side only receives messages a and c).	882	b, and c, and the other side only receives messages a and c).
751		883
752	AEMP guarantees correct ordering, and the guarantee that after one message	884	AEMP guarantees correct ordering, and the guarantee that after one message
753	is lost, all following ones sent to the same port are lost as well, until	885	is lost, all following ones sent to the same port are lost as well, until
754	monitoring raises an error, so there are no silent "holes" in the message	886	monitoring raises an error, so there are no silent "holes" in the message
755	sequence.	887	sequence.
…		…
847	L<AnyEvent::MP::Kernel> - more, lower-level, stuff.	979	L<AnyEvent::MP::Kernel> - more, lower-level, stuff.
848		980
849	L<AnyEvent::MP::Global> - network maintainance and port groups, to find	981	L<AnyEvent::MP::Global> - network maintainance and port groups, to find
850	your applications.	982	your applications.
851		983
		984	L<AnyEvent::MP::LogCatcher> - simple service to display log messages from
		985	all nodes.
		986
852	L<AnyEvent>.	987	L<AnyEvent>.
853		988
854	=head1 AUTHOR	989	=head1 AUTHOR
855		990
856	Marc Lehmann <schmorp@schmorp.de>	991	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.73 by root, Mon Aug 31 11:08:25 2009 UTC vs. Revision 1.102 by root, Tue Oct 6 13:37:52 2009 UTC

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Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.73 by root, Mon Aug 31 11:08:25 2009 UTC vs.
Revision 1.102 by root, Tue Oct 6 13:37:52 2009 UTC