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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.103 by root, Sat Oct 17 01:42:39 2009 UTC vs.
Revision 1.127 by root, Sat Mar 3 20:35:10 2012 UTC

…		…
30	rcv $port, pong => sub { warn "pong received\n" };	30	rcv $port, pong => sub { warn "pong received\n" };
31		31
32	# create a port on another node	32	# create a port on another node
33	my $port = spawn $node, $initfunc, @initdata;	33	my $port = spawn $node, $initfunc, @initdata;
34		34
35	# destroy a prot again	35	# destroy a port again
36	kil $port; # "normal" kill	36	kil $port; # "normal" kill
37	kil $port, my_error => "everything is broken"; # error kill	37	kil $port, my_error => "everything is broken"; # error kill
38		38
39	# monitoring	39	# monitoring
40	mon $localport, $cb->(@msg) # callback is invoked on death	40	mon $localport, $cb->(@msg) # callback is invoked on death
…		…
78		78
79	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
80	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
81	anything was listening for them or not.	81	anything was listening for them or not.
82		82
		83	Ports are represented by (printable) strings called "port IDs".
		84
83	=item port ID - C<nodeid#portname>	85	=item port ID - C<nodeid#portname>
84		86
85	A port ID is the concatenation of a node ID, a hash-mark (C<#>) as	87	A port ID is the concatenation of a node ID, a hash-mark (C<#>)
86	separator, and a port name (a printable string of unspecified format).	88	as separator, and a port name (a printable string of unspecified
		89	format created by AnyEvent::MP).
87		90
88	=item node	91	=item node
89		92
90	A node is a single process containing at least one port - the node port,	93	A node is a single process containing at least one port - the node port,
91	which enables nodes to manage each other remotely, and to create new	94	which enables nodes to manage each other remotely, and to create new
92	ports.	95	ports.
93		96
94	Nodes are either public (have one or more listening ports) or private	97	Nodes are either public (have one or more listening ports) or private
95	(no listening ports). Private nodes cannot talk to other private nodes	98	(no listening ports). Private nodes cannot talk to other private nodes
96	currently.	99	currently, but all nodes can talk to public nodes.
97		100
		101	Nodes is represented by (printable) strings called "node IDs".
		102
98	=item node ID - C<[A-Z_][a-zA-Z0-9_\-.:]*>	103	=item node ID - C<[A-Za-z0-9_\-.:]*>
99		104
100	A node ID is a string that uniquely identifies the node within a	105	A node ID is a string that uniquely identifies the node within a
101	network. Depending on the configuration used, node IDs can look like a	106	network. Depending on the configuration used, node IDs can look like a
102	hostname, a hostname and a port, or a random string. AnyEvent::MP itself	107	hostname, a hostname and a port, or a random string. AnyEvent::MP itself
103	doesn't interpret node IDs in any way.	108	doesn't interpret node IDs in any way except to uniquely identify a node.
104		109
105	=item binds - C<ip:port>	110	=item binds - C<ip:port>
106		111
107	Nodes can only talk to each other by creating some kind of connection to	112	Nodes can only talk to each other by creating some kind of connection to
108	each other. To do this, nodes should listen on one or more local transport	113	each other. To do this, nodes should listen on one or more local transport
		114	endpoints - binds.
		115
109	endpoints - binds. Currently, only standard C<ip:port> specifications can	116	Currently, only standard C<ip:port> specifications can be used, which
110	be used, which specify TCP ports to listen on.	117	specify TCP ports to listen on. So a bind is basically just a tcp socket
		118	in listening mode thta accepts conenctions form other nodes.
111		119
112	=item seed nodes	120	=item seed nodes
113		121
114	When a node starts, it knows nothing about the network. To teach the node	122	When a node starts, it knows nothing about the network it is in - it
115	about the network it first has to contact some other node within the	123	needs to connect to at least one other node that is already in the
116	network. This node is called a seed.	124	network. These other nodes are called "seed nodes".
117		125
118	Apart from the fact that other nodes know them as seed nodes and they have	126	Seed nodes themselves are not special - they are seed nodes only because
119	to have fixed listening addresses, seed nodes are perfectly normal nodes -	127	some other node I<uses> them as such, but any node can be used as seed
120	any node can function as a seed node for others.	128	node for other nodes, and eahc node cna use a different set of seed nodes.
121		129
122	In addition to discovering the network, seed nodes are also used to	130	In addition to discovering the network, seed nodes are also used to
123	maintain the network and to connect nodes that otherwise would have	131	maintain the network - all nodes using the same seed node form are part of
124	trouble connecting. They form the backbone of an AnyEvent::MP network.	132	the same network. If a network is split into multiple subnets because e.g.
		133	the network link between the parts goes down, then using the same seed
		134	nodes for all nodes ensures that eventually the subnets get merged again.
125		135
126	Seed nodes are expected to be long-running, and at least one seed node	136	Seed nodes are expected to be long-running, and at least one seed node
127	should always be available. They should also be relatively responsive - a	137	should always be available. They should also be relatively responsive - a
128	seed node that blocks for long periods will slow down everybody else.	138	seed node that blocks for long periods will slow down everybody else.
129		139
		140	For small networks, it's best if every node uses the same set of seed
		141	nodes. For large networks, it can be useful to specify "regional" seed
		142	nodes for most nodes in an area, and use all seed nodes as seed nodes for
		143	each other. What's important is that all seed nodes connections form a
		144	complete graph, so that the network cannot split into separate subnets
		145	forever.
		146
		147	Seed nodes are represented by seed IDs.
		148
130	=item seeds - C<host:port>	149	=item seed IDs - C<host:port>
131		150
132	Seeds are transport endpoint(s) (usually a hostname/IP address and a	151	Seed IDs are transport endpoint(s) (usually a hostname/IP address and a
133	TCP port) of nodes that should be used as seed nodes.	152	TCP port) of nodes that should be used as seed nodes.
134		153
135	The nodes listening on those endpoints are expected to be long-running,	154	=item global nodes
136	and at least one of those should always be available. When nodes run out	155
137	of connections (e.g. due to a network error), they try to re-establish	156	An AEMP network needs a discovery service - nodes need to know how to
138	connections to some seednodes again to join the network.	157	connect to other nodes they only know by name. In addition, AEMP offers a
		158	distributed "group database", which maps group names to a list of strings
		159	- for example, to register worker ports.
		160
		161	A network needs at least one global node to work, and allows every node to
		162	be a global node.
		163
		164	Any node that loads the L<AnyEvent::MP::Global> module becomes a global
		165	node and tries to keep connections to all other nodes. So while it can
		166	make sense to make every node "global" in small networks, it usually makes
		167	sense to only make seed nodes into global nodes in large networks (nodes
		168	keep connections to seed nodes and global nodes, so makign them the same
		169	reduces overhead).
139		170
140	=back	171	=back
141		172
142	=head1 VARIABLES/FUNCTIONS	173	=head1 VARIABLES/FUNCTIONS
143		174
…		…
145		176
146	=cut	177	=cut
147		178
148	package AnyEvent::MP;	179	package AnyEvent::MP;
149		180
		181	use AnyEvent::MP::Config ();
150	use AnyEvent::MP::Kernel;	182	use AnyEvent::MP::Kernel;
		183	use AnyEvent::MP::Kernel qw(%NODE %PORT %PORT_DATA $UNIQ $RUNIQ $ID);
151		184
152	use common::sense;	185	use common::sense;
153		186
154	use Carp ();	187	use Carp ();
155		188
156	use AE ();	189	use AE ();
		190	use Guard ();
157		191
158	use base "Exporter";	192	use base "Exporter";
159		193
160	our $VERSION = 1.22;	194	our $VERSION = $AnyEvent::MP::Config::VERSION;
161		195
162	our @EXPORT = qw(	196	our @EXPORT = qw(
163	NODE $NODE *SELF node_of after	197	NODE $NODE *SELF node_of after
164	configure	198	configure
165	snd rcv mon mon_guard kil psub peval spawn cal	199	snd rcv mon mon_guard kil psub peval spawn cal
166	port	200	port
		201	db_set db_del db_reg
167	);	202	);
168		203
169	our $SELF;	204	our $SELF;
170		205
171	sub _self_die() {	206	sub _self_die() {
…		…
194	some other nodes in the network to discover other nodes.	229	some other nodes in the network to discover other nodes.
195		230
196	This function configures a node - it must be called exactly once (or	231	This function configures a node - it must be called exactly once (or
197	never) before calling other AnyEvent::MP functions.	232	never) before calling other AnyEvent::MP functions.
198		233
		234	The key/value pairs are basically the same ones as documented for the
		235	F<aemp> command line utility (sans the set/del prefix), with these additions:
		236
		237	=over 4
		238
		239	=item norc => $boolean (default false)
		240
		241	If true, then the rc file (e.g. F<~/.perl-anyevent-mp>) will I<not>
		242	be consulted - all configuraiton options must be specified in the
		243	C<configure> call.
		244
		245	=item force => $boolean (default false)
		246
		247	IF true, then the values specified in the C<configure> will take
		248	precedence over any values configured via the rc file. The default is for
		249	the rc file to override any options specified in the program.
		250
		251	=item secure => $pass->($nodeid)
		252
		253	In addition to specifying a boolean, you can specify a code reference that
		254	is called for every remote execution attempt - the execution request is
		255	granted iff the callback returns a true value.
		256
		257	See F<semp setsecure> for more info.
		258
		259	=back
		260
199	=over 4	261	=over 4
200		262
201	=item step 1, gathering configuration from profiles	263	=item step 1, gathering configuration from profiles
202		264
203	The function first looks up a profile in the aemp configuration (see the	265	The function first looks up a profile in the aemp configuration (see the
…		…
216	That means that the values specified in the profile have highest priority	278	That means that the values specified in the profile have highest priority
217	and the values specified directly via C<configure> have lowest priority,	279	and the values specified directly via C<configure> have lowest priority,
218	and can only be used to specify defaults.	280	and can only be used to specify defaults.
219		281
220	If the profile specifies a node ID, then this will become the node ID of	282	If the profile specifies a node ID, then this will become the node ID of
221	this process. If not, then the profile name will be used as node ID. The	283	this process. If not, then the profile name will be used as node ID, with
222	special node ID of C<anon/> will be replaced by a random node ID.	284	a unique randoms tring (C</%u>) appended.
		285
		286	The node ID can contain some C<%> sequences that are expanded: C<%n>
		287	is expanded to the local nodename, C<%u> is replaced by a random
		288	strign to make the node unique. For example, the F<aemp> commandline
		289	utility uses C<aemp/%n/%u> as nodename, which might expand to
		290	C<aemp/cerebro/ZQDGSIkRhEZQDGSIkRhE>.
223		291
224	=item step 2, bind listener sockets	292	=item step 2, bind listener sockets
225		293
226	The next step is to look up the binds in the profile, followed by binding	294	The next step is to look up the binds in the profile, followed by binding
227	aemp protocol listeners on all binds specified (it is possible and valid	295	aemp protocol listeners on all binds specified (it is possible and valid
…		…
233	used, meaning the node will bind on a dynamically-assigned port on every	301	used, meaning the node will bind on a dynamically-assigned port on every
234	local IP address it finds.	302	local IP address it finds.
235		303
236	=item step 3, connect to seed nodes	304	=item step 3, connect to seed nodes
237		305
238	As the last step, the seeds list from the profile is passed to the	306	As the last step, the seed ID list from the profile is passed to the
239	L<AnyEvent::MP::Global> module, which will then use it to keep	307	L<AnyEvent::MP::Global> module, which will then use it to keep
240	connectivity with at least one node at any point in time.	308	connectivity with at least one node at any point in time.
241		309
242	=back	310	=back
243		311
244	Example: become a distributed node using the local node name as profile.	312	Example: become a distributed node using the local node name as profile.
245	This should be the most common form of invocation for "daemon"-type nodes.	313	This should be the most common form of invocation for "daemon"-type nodes.
246		314
247	configure	315	configure
248		316
249	Example: become an anonymous node. This form is often used for commandline	317	Example: become a semi-anonymous node. This form is often used for
250	clients.	318	commandline clients.
251		319
252	configure nodeid => "anon/";	320	configure nodeid => "myscript/%n/%u";
253		321
254	Example: configure a node using a profile called seed, which si suitable	322	Example: configure a node using a profile called seed, which is suitable
255	for a seed node as it binds on all local addresses on a fixed port (4040,	323	for a seed node as it binds on all local addresses on a fixed port (4040,
256	customary for aemp).	324	customary for aemp).
257		325
258	# use the aemp commandline utility	326	# use the aemp commandline utility
259	# aemp profile seed nodeid anon/ binds '*:4040'	327	# aemp profile seed binds '*:4040'
260		328
261	# then use it	329	# then use it
262	configure profile => "seed";	330	configure profile => "seed";
263		331
264	# or simply use aemp from the shell again:	332	# or simply use aemp from the shell again:
…		…
334	sub _kilme {	402	sub _kilme {
335	die "received message on port without callback";	403	die "received message on port without callback";
336	}	404	}
337		405
338	sub port(;&) {	406	sub port(;&) {
339	my $id = "$UNIQ." . $ID++;	407	my $id = $UNIQ . ++$ID;
340	my $port = "$NODE#$id";	408	my $port = "$NODE#$id";
341		409
342	rcv $port, shift \|\| \&_kilme;	410	rcv $port, shift \|\| \&_kilme;
343		411
344	$port	412	$port
…		…
492	Remembers C<$SELF> and creates a closure out of the BLOCK. When the	560	Remembers C<$SELF> and creates a closure out of the BLOCK. When the
493	closure is executed, sets up the environment in the same way as in C<rcv>	561	closure is executed, sets up the environment in the same way as in C<rcv>
494	callbacks, i.e. runtime errors will cause the port to get C<kil>ed.	562	callbacks, i.e. runtime errors will cause the port to get C<kil>ed.
495		563
496	The effect is basically as if it returned C<< sub { peval $SELF, sub {	564	The effect is basically as if it returned C<< sub { peval $SELF, sub {
497	BLOCK } } >>.	565	BLOCK }, @_ } >>.
498		566
499	This is useful when you register callbacks from C<rcv> callbacks:	567	This is useful when you register callbacks from C<rcv> callbacks:
500		568
501	rcv delayed_reply => sub {	569	rcv delayed_reply => sub {
502	my ($delay, @reply) = @_;	570	my ($delay, @reply) = @_;
…		…
617	}	685	}
618		686
619	$node->monitor ($port, $cb);	687	$node->monitor ($port, $cb);
620		688
621	defined wantarray	689	defined wantarray
622	and ($cb += 0, AnyEvent::Util::guard { $node->unmonitor ($port, $cb) })	690	and ($cb += 0, Guard::guard { $node->unmonitor ($port, $cb) })
623	}	691	}
624		692
625	=item $guard = mon_guard $port, $ref, $ref...	693	=item $guard = mon_guard $port, $ref, $ref...
626		694
627	Monitors the given C<$port> and keeps the passed references. When the port	695	Monitors the given C<$port> and keeps the passed references. When the port
…		…
650		718
651	=item kil $port[, @reason]	719	=item kil $port[, @reason]
652		720
653	Kill the specified port with the given C<@reason>.	721	Kill the specified port with the given C<@reason>.
654		722
655	If no C<@reason> is specified, then the port is killed "normally" (ports	723	If no C<@reason> is specified, then the port is killed "normally" -
656	monitoring other ports will not necessarily die because a port dies	724	monitor callback will be invoked, but the kil will not cause linked ports
657	"normally").	725	(C<mon $mport, $lport> form) to get killed.
658		726
659	Otherwise, linked ports get killed with the same reason (second form of	727	If a C<@reason> is specified, then linked ports (C<mon $mport, $lport>
660	C<mon>, see above).	728	form) get killed with the same reason.
661		729
662	Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks	730	Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks
663	will be reported as reason C<< die => $@ >>.	731	will be reported as reason C<< die => $@ >>.
664		732
665	Transport/communication errors are reported as C<< transport_error =>	733	Transport/communication errors are reported as C<< transport_error =>
…		…
731	}	799	}
732		800
733	sub spawn(@) {	801	sub spawn(@) {
734	my ($nodeid, undef) = split /#/, shift, 2;	802	my ($nodeid, undef) = split /#/, shift, 2;
735		803
736	my $id = "$RUNIQ." . $ID++;	804	my $id = $RUNIQ . ++$ID;
737		805
738	$_[0] =~ /::/	806	$_[0] =~ /::/
739	or Carp::croak "spawn init function must be a fully-qualified name, caught";	807	or Carp::croak "spawn init function must be a fully-qualified name, caught";
740		808
741	snd_to_func $nodeid, "AnyEvent::MP::_spawn" => $id, @_;	809	snd_to_func $nodeid, "AnyEvent::MP::_spawn" => $id, @_;
742		810
743	"$nodeid#$id"	811	"$nodeid#$id"
744	}	812	}
		813
745		814
746	=item after $timeout, @msg	815	=item after $timeout, @msg
747		816
748	=item after $timeout, $callback	817	=item after $timeout, $callback
749		818
…		…
819	$port	888	$port
820	}	889	}
821		890
822	=back	891	=back
823		892
		893	=head1 DISTRIBUTED DATABASE
		894
		895	AnyEvent::MP comes with a simple distributed database. The database will
		896	be mirrored asynchronously at all global nodes. Other nodes bind to one of
		897	the global nodes for their needs.
		898
		899	The database consists of a two-level hash - a hash contains a hash which
		900	contains values.
		901
		902	The top level hash key is called "family", and the second-level hash key
		903	is called "subkey" or simply "key".
		904
		905	The family must be alphanumeric, i.e. start with a letter and consist
		906	of letters, digits, underscores and colons (C<[A-Za-z][A-Za-z0-9_:]*>,
		907	pretty much like Perl module names.
		908
		909	As the family namespace is global, it is recommended to prefix family names
		910	with the name of the application or module using it.
		911
		912	The subkeys must be non-empty strings, with no further restrictions.
		913
		914	The values should preferably be strings, but other perl scalars should
		915	work as well (such as undef, arrays and hashes).
		916
		917	Every database entry is owned by one node - adding the same family/subkey
		918	combination on multiple nodes will not cause discomfort for AnyEvent::MP,
		919	but the result might be nondeterministic, i.e. the key might have
		920	different values on different nodes.
		921
		922	Different subkeys in the same family can be owned by different nodes
		923	without problems, and in fact, this is the common method to create worker
		924	pools. For example, a worker port for image scaling might do this:
		925
		926	db_set my_image_scalers => $port;
		927
		928	And clients looking for an image scaler will want to get the
		929	C<my_image_scalers> keys:
		930
		931	db_keys "my_image_scalers" => 60 => sub {
		932	#d##TODO#
		933
		934	=over
		935
		936	=item db_set $family => $subkey [=> $value]
		937
		938	Sets (or replaces) a key to the database - if C<$value> is omitted,
		939	C<undef> is used instead.
		940
		941	=item db_del $family => $subkey
		942
		943	Deletes a key from the database.
		944
		945	=item $guard = db_reg $family => $subkey [=> $value]
		946
		947	Sets the key on the database and returns a guard. When the guard is
		948	destroyed, the key is deleted from the database. If C<$value> is missing,
		949	then C<undef> is used.
		950
		951	=cut
		952
		953	=back
		954
824	=head1 AnyEvent::MP vs. Distributed Erlang	955	=head1 AnyEvent::MP vs. Distributed Erlang
825		956
826	AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node	957	AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node
827	== aemp node, Erlang process == aemp port), so many of the documents and	958	== aemp node, Erlang process == aemp port), so many of the documents and
828	programming techniques employed by Erlang apply to AnyEvent::MP. Here is a	959	programming techniques employed by Erlang apply to AnyEvent::MP. Here is a
…		…
859	ports being the special case/exception, where transport errors cannot	990	ports being the special case/exception, where transport errors cannot
860	occur.	991	occur.
861		992
862	=item * Erlang uses processes and a mailbox, AEMP does not queue.	993	=item * Erlang uses processes and a mailbox, AEMP does not queue.
863		994
864	Erlang uses processes that selectively receive messages, and therefore	995	Erlang uses processes that selectively receive messages out of order, and
865	needs a queue. AEMP is event based, queuing messages would serve no	996	therefore needs a queue. AEMP is event based, queuing messages would serve
866	useful purpose. For the same reason the pattern-matching abilities of	997	no useful purpose. For the same reason the pattern-matching abilities
867	AnyEvent::MP are more limited, as there is little need to be able to	998	of AnyEvent::MP are more limited, as there is little need to be able to
868	filter messages without dequeuing them.	999	filter messages without dequeuing them.
869		1000
870	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).	1001	This is not a philosophical difference, but simply stems from AnyEvent::MP
		1002	being event-based, while Erlang is process-based.
		1003
		1004	You cna have a look at L<Coro::MP> for a more Erlang-like process model on
		1005	top of AEMP and Coro threads.
871		1006
872	=item * Erlang sends are synchronous, AEMP sends are asynchronous.	1007	=item * Erlang sends are synchronous, AEMP sends are asynchronous.
873		1008
874	Sending messages in Erlang is synchronous and blocks the process (and	1009	Sending messages in Erlang is synchronous and blocks the process until
		1010	a conenction has been established and the message sent (and so does not
875	so does not need a queue that can overflow). AEMP sends are immediate,	1011	need a queue that can overflow). AEMP sends return immediately, connection
876	connection establishment is handled in the background.	1012	establishment is handled in the background.
877		1013
878	=item * Erlang suffers from silent message loss, AEMP does not.	1014	=item * Erlang suffers from silent message loss, AEMP does not.
879		1015
880	Erlang implements few guarantees on messages delivery - messages can get	1016	Erlang implements few guarantees on messages delivery - messages can get
881	lost without any of the processes realising it (i.e. you send messages a,	1017	lost without any of the processes realising it (i.e. you send messages a,
882	b, and c, and the other side only receives messages a and c).	1018	b, and c, and the other side only receives messages a and c).
883		1019
884	AEMP guarantees correct ordering, and the guarantee that after one message	1020	AEMP guarantees (modulo hardware errors) correct ordering, and the
885	is lost, all following ones sent to the same port are lost as well, until	1021	guarantee that after one message is lost, all following ones sent to the
886	monitoring raises an error, so there are no silent "holes" in the message	1022	same port are lost as well, until monitoring raises an error, so there are
887	sequence.	1023	no silent "holes" in the message sequence.
		1024
		1025	If you want your software to be very reliable, you have to cope with
		1026	corrupted and even out-of-order messages in both Erlang and AEMP. AEMP
		1027	simply tries to work better in common error cases, such as when a network
		1028	link goes down.
888		1029
889	=item * Erlang can send messages to the wrong port, AEMP does not.	1030	=item * Erlang can send messages to the wrong port, AEMP does not.
890		1031
891	In Erlang it is quite likely that a node that restarts reuses a process ID	1032	In Erlang it is quite likely that a node that restarts reuses an Erlang
892	known to other nodes for a completely different process, causing messages	1033	process ID known to other nodes for a completely different process,
893	destined for that process to end up in an unrelated process.	1034	causing messages destined for that process to end up in an unrelated
		1035	process.
894		1036
895	AEMP never reuses port IDs, so old messages or old port IDs floating	1037	AEMP does not reuse port IDs, so old messages or old port IDs floating
896	around in the network will not be sent to an unrelated port.	1038	around in the network will not be sent to an unrelated port.
897		1039
898	=item * Erlang uses unprotected connections, AEMP uses secure	1040	=item * Erlang uses unprotected connections, AEMP uses secure
899	authentication and can use TLS.	1041	authentication and can use TLS.
900		1042
…		…
903		1045
904	=item * The AEMP protocol is optimised for both text-based and binary	1046	=item * The AEMP protocol is optimised for both text-based and binary
905	communications.	1047	communications.
906		1048
907	The AEMP protocol, unlike the Erlang protocol, supports both programming	1049	The AEMP protocol, unlike the Erlang protocol, supports both programming
908	language independent text-only protocols (good for debugging) and binary,	1050	language independent text-only protocols (good for debugging), and binary,
909	language-specific serialisers (e.g. Storable). By default, unless TLS is	1051	language-specific serialisers (e.g. Storable). By default, unless TLS is
910	used, the protocol is actually completely text-based.	1052	used, the protocol is actually completely text-based.
911		1053
912	It has also been carefully designed to be implementable in other languages	1054	It has also been carefully designed to be implementable in other languages
913	with a minimum of work while gracefully degrading functionality to make the	1055	with a minimum of work while gracefully degrading functionality to make the
914	protocol simple.	1056	protocol simple.
915		1057
916	=item * AEMP has more flexible monitoring options than Erlang.	1058	=item * AEMP has more flexible monitoring options than Erlang.
917		1059
918	In Erlang, you can chose to receive I<all> exit signals as messages	1060	In Erlang, you can chose to receive I<all> exit signals as messages or
919	or I<none>, there is no in-between, so monitoring single processes is	1061	I<none>, there is no in-between, so monitoring single Erlang processes is
920	difficult to implement. Monitoring in AEMP is more flexible than in	1062	difficult to implement.
921	Erlang, as one can choose between automatic kill, exit message or callback	1063
922	on a per-process basis.	1064	Monitoring in AEMP is more flexible than in Erlang, as one can choose
		1065	between automatic kill, exit message or callback on a per-port basis.
923		1066
924	=item * Erlang tries to hide remote/local connections, AEMP does not.	1067	=item * Erlang tries to hide remote/local connections, AEMP does not.
925		1068
926	Monitoring in Erlang is not an indicator of process death/crashes, in the	1069	Monitoring in Erlang is not an indicator of process death/crashes, in the
927	same way as linking is (except linking is unreliable in Erlang).	1070	same way as linking is (except linking is unreliable in Erlang).
…		…
949	overhead, as well as having to keep a proxy object everywhere.	1092	overhead, as well as having to keep a proxy object everywhere.
950		1093
951	Strings can easily be printed, easily serialised etc. and need no special	1094	Strings can easily be printed, easily serialised etc. and need no special
952	procedures to be "valid".	1095	procedures to be "valid".
953		1096
954	And as a result, a miniport consists of a single closure stored in a	1097	And as a result, a port with just a default receiver consists of a single
955	global hash - it can't become much cheaper.	1098	code reference stored in a global hash - it can't become much cheaper.
956		1099
957	=item Why favour JSON, why not a real serialising format such as Storable?	1100	=item Why favour JSON, why not a real serialising format such as Storable?
958		1101
959	In fact, any AnyEvent::MP node will happily accept Storable as framing	1102	In fact, any AnyEvent::MP node will happily accept Storable as framing
960	format, but currently there is no way to make a node use Storable by	1103	format, but currently there is no way to make a node use Storable by
…		…
976		1119
977	L<AnyEvent::MP::Intro> - a gentle introduction.	1120	L<AnyEvent::MP::Intro> - a gentle introduction.
978		1121
979	L<AnyEvent::MP::Kernel> - more, lower-level, stuff.	1122	L<AnyEvent::MP::Kernel> - more, lower-level, stuff.
980		1123
981	L<AnyEvent::MP::Global> - network maintainance and port groups, to find	1124	L<AnyEvent::MP::Global> - network maintenance and port groups, to find
982	your applications.	1125	your applications.
		1126
		1127	L<AnyEvent::MP::DataConn> - establish data connections between nodes.
983		1128
984	L<AnyEvent::MP::LogCatcher> - simple service to display log messages from	1129	L<AnyEvent::MP::LogCatcher> - simple service to display log messages from
985	all nodes.	1130	all nodes.
986		1131
987	L<AnyEvent>.	1132	L<AnyEvent>.

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.103 by root, Sat Oct 17 01:42:39 2009 UTC vs. Revision 1.127 by root, Sat Mar 3 20:35:10 2012 UTC

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Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.103 by root, Sat Oct 17 01:42:39 2009 UTC vs.
Revision 1.127 by root, Sat Mar 3 20:35:10 2012 UTC