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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.134 by root, Mon Mar 12 14:47:23 2012 UTC vs.
Revision 1.156 by root, Sat Oct 23 03:35:49 2021 UTC

…		…
47	# execute callbacks in $SELF port context	47	# execute callbacks in $SELF port context
48	my $timer = AE::timer 1, 0, psub {	48	my $timer = AE::timer 1, 0, psub {
49	die "kill the port, delayed";	49	die "kill the port, delayed";
50	};	50	};
51		51
52	=head1 CURRENT STATUS	52	# distributed database - modification
		53	db_set $family => $subkey [=> $value] # add a subkey
		54	db_del $family => $subkey... # delete one or more subkeys
		55	db_reg $family => $port [=> $value] # register a port
53		56
54	bin/aemp - stable.	57	# distributed database - queries
55	AnyEvent::MP - stable API, should work.	58	db_family $family => $cb->(\%familyhash)
56	AnyEvent::MP::Intro - explains most concepts.	59	db_keys $family => $cb->(\@keys)
57	AnyEvent::MP::Kernel - mostly stable API.	60	db_values $family => $cb->(\@values)
58	AnyEvent::MP::Global - stable API.	61
		62	# distributed database - monitoring a family
		63	db_mon $family => $cb->(\%familyhash, \@added, \@changed, \@deleted)
59		64
60	=head1 DESCRIPTION	65	=head1 DESCRIPTION
61		66
62	This module (-family) implements a simple message passing framework.	67	This module (-family) implements a simple message passing framework.
63		68
…		…
71		76
72	=over 4	77	=over 4
73		78
74	=item port	79	=item port
75		80
76	Not to be confused with a TCP port, a "port" is something you can send	81	Not to be confused with TCP ports, a "port" is something you can send
77	messages to (with the C<snd> function).	82	messages to (with the C<snd> function).
78		83
79	Ports allow you to register C<rcv> handlers that can match all or just	84	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	85	some messages. Messages send to ports will not be queued, regardless of
81	anything was listening for them or not.	86	whether anything was listening for them or not.
82		87
83	Ports are represented by (printable) strings called "port IDs".	88	Ports are represented by (printable) strings called "port IDs".
84		89
85	=item port ID - C<nodeid#portname>	90	=item port ID - C<nodeid#portname>
86		91
…		…
113	each other. To do this, nodes should listen on one or more local transport	118	each other. To do this, nodes should listen on one or more local transport
114	endpoints - binds.	119	endpoints - binds.
115		120
116	Currently, only standard C<ip:port> specifications can be used, which	121	Currently, only standard C<ip:port> specifications can be used, which
117	specify TCP ports to listen on. So a bind is basically just a tcp socket	122	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.	123	in listening mode that accepts connections from other nodes.
119		124
120	=item seed nodes	125	=item seed nodes
121		126
122	When a node starts, it knows nothing about the network it is in - it	127	When a node starts, it knows nothing about the network it is in - it
123	needs to connect to at least one other node that is already in the	128	needs to connect to at least one other node that is already in the
124	network. These other nodes are called "seed nodes".	129	network. These other nodes are called "seed nodes".
125		130
126	Seed nodes themselves are not special - they are seed nodes only because	131	Seed nodes themselves are not special - they are seed nodes only because
127	some other node I<uses> them as such, but any node can be used as seed	132	some other node I<uses> them as such, but any node can be used as seed
128	node for other nodes, and eahc node cna use a different set of seed nodes.	133	node for other nodes, and eahc node can use a different set of seed nodes.
129		134
130	In addition to discovering the network, seed nodes are also used to	135	In addition to discovering the network, seed nodes are also used to
131	maintain the network - all nodes using the same seed node form are part of	136	maintain the network - all nodes using the same seed node are part of the
132	the same network. If a network is split into multiple subnets because e.g.	137	same network. If a network is split into multiple subnets because e.g. the
133	the network link between the parts goes down, then using the same seed	138	network link between the parts goes down, then using the same seed nodes
134	nodes for all nodes ensures that eventually the subnets get merged again.	139	for all nodes ensures that eventually the subnets get merged again.
135		140
136	Seed nodes are expected to be long-running, and at least one seed node	141	Seed nodes are expected to be long-running, and at least one seed node
137	should always be available. They should also be relatively responsive - a	142	should always be available. They should also be relatively responsive - a
138	seed node that blocks for long periods will slow down everybody else.	143	seed node that blocks for long periods will slow down everybody else.
139		144
…		…
163		168
164	Any node that loads the L<AnyEvent::MP::Global> module becomes a global	169	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	170	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	171	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	172	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	173	keep connections to seed nodes and global nodes, so making them the same
169	reduces overhead).	174	reduces overhead).
170		175
171	=back	176	=back
172		177
173	=head1 VARIABLES/FUNCTIONS	178	=head1 VARIABLES/FUNCTIONS
…		…
178		183
179	package AnyEvent::MP;	184	package AnyEvent::MP;
180		185
181	use AnyEvent::MP::Config ();	186	use AnyEvent::MP::Config ();
182	use AnyEvent::MP::Kernel;	187	use AnyEvent::MP::Kernel;
183	use AnyEvent::MP::Kernel qw(%NODE %PORT %PORT_DATA $UNIQ $RUNIQ $ID);	188	use AnyEvent::MP::Kernel qw(
		189	%NODE %PORT %PORT_DATA $UNIQ $RUNIQ $ID
		190	add_node load_func
		191
		192	NODE $NODE
		193	configure
		194	node_of port_is_local
		195	snd kil
		196	db_set db_del
		197	db_mon db_family db_keys db_values
		198	);
184		199
185	use common::sense;	200	use common::sense;
186		201
187	use Carp ();	202	use Carp ();
188		203
189	use AE ();	204	use AnyEvent ();
190	use Guard ();	205	use Guard ();
191		206
192	use base "Exporter";	207	use base "Exporter";
193		208
194	our $VERSION = $AnyEvent::MP::Config::VERSION;	209	our $VERSION = '2.02'; # also in MP/Config.pm
195		210
196	our @EXPORT = qw(	211	our @EXPORT = qw(
197	NODE $NODE *SELF node_of after
198	configure	212	configure
		213
		214	NODE $NODE
		215	*SELF
		216
		217	node_of port_is_local
		218
		219	snd kil
199	snd rcv mon mon_guard kil psub peval spawn cal	220	port rcv mon mon_guard psub peval spawn cal
200	port
201	db_set db_del db_reg	221	db_set db_del db_reg
202	db_mon db_family db_keys db_values	222	db_mon db_family db_keys db_values
		223
		224	after
203	);	225	);
204		226
205	our $SELF;	227	our $SELF;
206		228
207	sub _self_die() {	229	sub _self_die() {
…		…
218		240
219	=item $nodeid = node_of $port	241	=item $nodeid = node_of $port
220		242
221	Extracts and returns the node ID from a port ID or a node ID.	243	Extracts and returns the node ID from a port ID or a node ID.
222		244
		245	=item $is_local = port_is_local $port
		246
		247	Returns true iff the port is a local port.
		248
223	=item configure $profile, key => value...	249	=item configure $profile, key => value...
224		250
225	=item configure key => value...	251	=item configure key => value...
226		252
227	Before a node can talk to other nodes on the network (i.e. enter	253	Before a node can talk to other nodes on the network (i.e. enter
…		…
238	=over 4	264	=over 4
239		265
240	=item norc => $boolean (default false)	266	=item norc => $boolean (default false)
241		267
242	If true, then the rc file (e.g. F<~/.perl-anyevent-mp>) will I<not>	268	If true, then the rc file (e.g. F<~/.perl-anyevent-mp>) will I<not>
243	be consulted - all configuraiton options must be specified in the	269	be consulted - all configuration options must be specified in the
244	C<configure> call.	270	C<configure> call.
245		271
246	=item force => $boolean (default false)	272	=item force => $boolean (default false)
247		273
248	IF true, then the values specified in the C<configure> will take	274	IF true, then the values specified in the C<configure> will take
249	precedence over any values configured via the rc file. The default is for	275	precedence over any values configured via the rc file. The default is for
250	the rc file to override any options specified in the program.	276	the rc file to override any options specified in the program.
251
252	=item secure => $pass->($nodeid)
253
254	In addition to specifying a boolean, you can specify a code reference that
255	is called for every remote execution attempt - the execution request is
256	granted iff the callback returns a true value.
257
258	See F<semp setsecure> for more info.
259		277
260	=back	278	=back
261		279
262	=over 4	280	=over 4
263		281
…		…
284	this process. If not, then the profile name will be used as node ID, with	302	this process. If not, then the profile name will be used as node ID, with
285	a unique randoms tring (C</%u>) appended.	303	a unique randoms tring (C</%u>) appended.
286		304
287	The node ID can contain some C<%> sequences that are expanded: C<%n>	305	The node ID can contain some C<%> sequences that are expanded: C<%n>
288	is expanded to the local nodename, C<%u> is replaced by a random	306	is expanded to the local nodename, C<%u> is replaced by a random
289	strign to make the node unique. For example, the F<aemp> commandline	307	string to make the node unique. For example, the F<aemp> commandline
290	utility uses C<aemp/%n/%u> as nodename, which might expand to	308	utility uses C<aemp/%n/%u> as nodename, which might expand to
291	C<aemp/cerebro/ZQDGSIkRhEZQDGSIkRhE>.	309	C<aemp/cerebro/ZQDGSIkRhEZQDGSIkRhE>.
292		310
293	=item step 2, bind listener sockets	311	=item step 2, bind listener sockets
294		312
295	The next step is to look up the binds in the profile, followed by binding	313	The next step is to look up the binds in the profile, followed by binding
296	aemp protocol listeners on all binds specified (it is possible and valid	314	aemp protocol listeners on all binds specified (it is possible and valid
297	to have no binds, meaning that the node cannot be contacted form the	315	to have no binds, meaning that the node cannot be contacted from the
298	outside. This means the node cannot talk to other nodes that also have no	316	outside. This means the node cannot talk to other nodes that also have no
299	binds, but it can still talk to all "normal" nodes).	317	binds, but it can still talk to all "normal" nodes).
300		318
301	If the profile does not specify a binds list, then a default of C<*> is	319	If the profile does not specify a binds list, then a default of C<*> is
302	used, meaning the node will bind on a dynamically-assigned port on every	320	used, meaning the node will bind on a dynamically-assigned port on every
…		…
399	=cut	417	=cut
400		418
401	sub rcv($@);	419	sub rcv($@);
402		420
403	my $KILME = sub {	421	my $KILME = sub {
404	(my $tag = substr $_[0], 0, 30) =~ s/([\x20-\x7e])/./g;	422	(my $tag = substr $_[0], 0, 30) =~ s/([^\x20-\x7e])/./g;
405	kil $SELF, unhandled_message => "missing (tag or fallback) callback for message '$tag'";	423	kil $SELF, unhandled_message => "no callback found for message '$tag'";
406	};	424	};
407		425
408	sub port(;&) {	426	sub port(;&) {
409	my $id = $UNIQ . ++$ID;	427	my $id = $UNIQ . ++$ID;
410	my $port = "$NODE#$id";	428	my $port = "$NODE#$id";
…		…
467		485
468	sub rcv($@) {	486	sub rcv($@) {
469	my $port = shift;	487	my $port = shift;
470	my ($nodeid, $portid) = split /#/, $port, 2;	488	my ($nodeid, $portid) = split /#/, $port, 2;
471		489
472	$NODE{$nodeid} == $NODE{""}	490	$nodeid eq $NODE
473	or Carp::croak "$port: rcv can only be called on local ports, caught";	491	or Carp::croak "$port: rcv can only be called on local ports, caught";
474		492
475	while (@_) {	493	while (@_) {
476	if (ref $_[0]) {	494	if (ref $_[0]) {
477	if (my $self = $PORT_DATA{$portid}) {	495	if (my $self = $PORT_DATA{$portid}) {
…		…
520	$port	538	$port
521	}	539	}
522		540
523	=item peval $port, $coderef[, @args]	541	=item peval $port, $coderef[, @args]
524		542
525	Evaluates the given C<$codref> within the contetx of C<$port>, that is,	543	Evaluates the given C<$codref> within the context of C<$port>, that is,
526	when the code throews an exception the C<$port> will be killed.	544	when the code throws an exception the C<$port> will be killed.
527		545
528	Any remaining args will be passed to the callback. Any return values will	546	Any remaining args will be passed to the callback. Any return values will
529	be returned to the caller.	547	be returned to the caller.
530		548
531	This is useful when you temporarily want to execute code in the context of	549	This is useful when you temporarily want to execute code in the context of
…		…
596	$res	614	$res
597	}	615	}
598	}	616	}
599	}	617	}
600		618
		619	=item $guard = mon $port, $rcvport # kill $rcvport when $port dies
		620
		621	=item $guard = mon $port # kill $SELF when $port dies
		622
601	=item $guard = mon $port, $cb->(@reason) # call $cb when $port dies	623	=item $guard = mon $port, $cb->(@reason) # call $cb when $port dies
602
603	=item $guard = mon $port, $rcvport # kill $rcvport when $port dies
604
605	=item $guard = mon $port # kill $SELF when $port dies
606		624
607	=item $guard = mon $port, $rcvport, @msg # send a message when $port dies	625	=item $guard = mon $port, $rcvport, @msg # send a message when $port dies
608		626
609	Monitor the given port and do something when the port is killed or	627	Monitor the given port and do something when the port is killed or
610	messages to it were lost, and optionally return a guard that can be used	628	messages to it were lost, and optionally return a guard that can be used
611	to stop monitoring again.	629	to stop monitoring again.
612		630
		631	The first two forms distinguish between "normal" and "abnormal" kil's:
		632
		633	In the first form (another port given), if the C<$port> is C<kil>'ed with
		634	a non-empty reason, the other port (C<$rcvport>) will be kil'ed with the
		635	same reason. That is, on "normal" kil's nothing happens, while under all
		636	other conditions, the other port is killed with the same reason.
		637
		638	The second form (kill self) is the same as the first form, except that
		639	C<$rvport> defaults to C<$SELF>.
		640
		641	The remaining forms don't distinguish between "normal" and "abnormal" kil's
		642	- it's up to the callback or receiver to check whether the C<@reason> is
		643	empty and act accordingly.
		644
613	In the first form (callback), the callback is simply called with any	645	In the third form (callback), the callback is simply called with any
614	number of C<@reason> elements (no @reason means that the port was deleted	646	number of C<@reason> elements (empty @reason means that the port was deleted
615	"normally"). Note also that I<< the callback B<must> never die >>, so use	647	"normally"). Note also that I<< the callback B<must> never die >>, so use
616	C<eval> if unsure.	648	C<eval> if unsure.
617		649
618	In the second form (another port given), the other port (C<$rcvport>)
619	will be C<kil>'ed with C<@reason>, if a @reason was specified, i.e. on
620	"normal" kils nothing happens, while under all other conditions, the other
621	port is killed with the same reason.
622
623	The third form (kill self) is the same as the second form, except that
624	C<$rvport> defaults to C<$SELF>.
625
626	In the last form (message), a message of the form C<@msg, @reason> will be	650	In the last form (message), a message of the form C<$rcvport, @msg,
627	C<snd>.	651	@reason> will be C<snd>.
628		652
629	Monitoring-actions are one-shot: once messages are lost (and a monitoring	653	Monitoring-actions are one-shot: once messages are lost (and a monitoring
630	alert was raised), they are removed and will not trigger again.	654	alert was raised), they are removed and will not trigger again, even if it
		655	turns out that the port is still alive (but monitoring actions added after
		656	that will again trigger).
631		657
632	As a rule of thumb, monitoring requests should always monitor a port from	658	As a rule of thumb, monitoring requests should always monitor a remote
633	a local port (or callback). The reason is that kill messages might get	659	port locally (using a local C<$rcvport> or a callback). The reason is that
634	lost, just like any other message. Another less obvious reason is that	660	kill messages might get lost, just like any other message. Another less
635	even monitoring requests can get lost (for example, when the connection	661	obvious reason is that even monitoring requests can get lost (for example,
636	to the other node goes down permanently). When monitoring a port locally	662	when the connection to the other node goes down permanently). When
637	these problems do not exist.	663	monitoring a port locally these problems do not exist.
638		664
639	C<mon> effectively guarantees that, in the absence of hardware failures,	665	C<mon> effectively guarantees that, in the absence of hardware failures,
640	after starting the monitor, either all messages sent to the port will	666	after starting the monitor, either all messages sent to the port will
641	arrive, or the monitoring action will be invoked after possible message	667	arrive, or the monitoring action will be invoked after possible message
642	loss has been detected. No messages will be lost "in between" (after	668	loss has been detected. No messages will be lost "in between" (after
…		…
851	#=item $cb2 = timeout $seconds, $cb[, @args]	877	#=item $cb2 = timeout $seconds, $cb[, @args]
852		878
853	=item cal $port, @msg, $callback[, $timeout]	879	=item cal $port, @msg, $callback[, $timeout]
854		880
855	A simple form of RPC - sends a message to the given C<$port> with the	881	A simple form of RPC - sends a message to the given C<$port> with the
856	given contents (C<@msg>), but adds a reply port to the message.	882	given contents (C<@msg>), but appends a reply port to the message.
857		883
858	The reply port is created temporarily just for the purpose of receiving	884	The reply port is created temporarily just for the purpose of receiving
859	the reply, and will be C<kil>ed when no longer needed.	885	the reply, and will be C<kil>ed when no longer needed.
860		886
861	A reply message sent to the port is passed to the C<$callback> as-is.	887	A reply message sent to the port is passed to the C<$callback> as-is.
…		…
940		966
941	Different subkeys in the same family can be owned by different nodes	967	Different subkeys in the same family can be owned by different nodes
942	without problems, and in fact, this is the common method to create worker	968	without problems, and in fact, this is the common method to create worker
943	pools. For example, a worker port for image scaling might do this:	969	pools. For example, a worker port for image scaling might do this:
944		970
945	db_set my_image_scalers => $port;	971	db_set my_image_scalers => $port; # value not used
946		972
947	And clients looking for an image scaler will want to get the	973	And clients looking for an image scaler will want to get the
948	C<my_image_scalers> keys from time to time:	974	C<my_image_scalers> keys from time to time:
949		975
950	db_keys my_image_scalers => sub {	976	db_keys my_image_scalers => sub {
…		…
964	If you feel the need to monitor or query a single subkey, try giving it	990	If you feel the need to monitor or query a single subkey, try giving it
965	it's own family.	991	it's own family.
966		992
967	=over	993	=over
968		994
969	=item db_set $family => $subkey [=> $value]	995	=item $guard = db_set $family => $subkey [=> $value]
970		996
971	Sets (or replaces) a key to the database - if C<$value> is omitted,	997	Sets (or replaces) a key to the database - if C<$value> is omitted,
972	C<undef> is used instead.	998	C<undef> is used instead.
973		999
		1000	When called in non-void context, C<db_set> returns a guard that
		1001	automatically calls C<db_del> when it is destroyed.
		1002
974	=item db_del $family => $subkey...	1003	=item db_del $family => $subkey...
975		1004
976	Deletes one or more subkeys from the database family.	1005	Deletes one or more subkeys from the database family.
977		1006
978	=item $guard = db_reg $family => $subkey [=> $value]	1007	=item $guard = db_reg $family => $port => $value
979		1008
980	Sets the key on the database and returns a guard. When the guard is	1009	=item $guard = db_reg $family => $port
981	destroyed, the key is deleted from the database. If C<$value> is missing,	1010
982	then C<undef> is used.	1011	=item $guard = db_reg $family
		1012
		1013	Registers a port in the given family and optionally returns a guard to
		1014	remove it.
		1015
		1016	This function basically does the same as:
		1017
		1018	db_set $family => $port => $value
		1019
		1020	Except that the port is monitored and automatically removed from the
		1021	database family when it is kil'ed.
		1022
		1023	If C<$value> is missing, C<undef> is used. If C<$port> is missing, then
		1024	C<$SELF> is used.
		1025
		1026	This function is most useful to register a port in some port group (which
		1027	is just another name for a database family), and have it removed when the
		1028	port is gone. This works best when the port is a local port.
		1029
		1030	=cut
		1031
		1032	sub db_reg($$;$) {
		1033	my $family = shift;
		1034	my $port = @_ ? shift : $SELF;
		1035
		1036	my $clr = sub { db_del $family => $port };
		1037	mon $port, $clr;
		1038
		1039	db_set $family => $port => $_[0];
		1040
		1041	defined wantarray
		1042	and &Guard::guard ($clr)
		1043	}
983		1044
984	=item db_family $family => $cb->(\%familyhash)	1045	=item db_family $family => $cb->(\%familyhash)
985		1046
986	Queries the named database C<$family> and call the callback with the	1047	Queries the named database C<$family> and call the callback with the
987	family represented as a hash. You can keep and freely modify the hash.	1048	family represented as a hash. You can keep and freely modify the hash.
…		…
994	=item db_values $family => $cb->(\@values)	1055	=item db_values $family => $cb->(\@values)
995		1056
996	Same as C<db_family>, except it only queries the family I<values> and passes them	1057	Same as C<db_family>, except it only queries the family I<values> and passes them
997	as array reference to the callback.	1058	as array reference to the callback.
998		1059
999	=item $guard = db_mon $family => $cb->($familyhash, \@added, \@changed, \@deleted)	1060	=item $guard = db_mon $family => $cb->(\%familyhash, \@added, \@changed, \@deleted)
1000		1061
1001	Creates a monitor on the given database family. Each time a key is set	1062	Creates a monitor on the given database family. Each time a key is
1002	or or is deleted the callback is called with a hash containing the	1063	set or is deleted the callback is called with a hash containing the
1003	database family and three lists of added, changed and deleted subkeys,	1064	database family and three lists of added, changed and deleted subkeys,
1004	respectively. If no keys have changed then the array reference might be	1065	respectively. If no keys have changed then the array reference might be
1005	C<undef> or even missing.	1066	C<undef> or even missing.
1006		1067
1007	If not called in void context, a guard object is returned that, when	1068	If not called in void context, a guard object is returned that, when
…		…
1035	return unless %$family;	1096	return unless %$family;
1036	undef $guard;	1097	undef $guard;
1037	print "My::Module::workers now nonempty\n";	1098	print "My::Module::workers now nonempty\n";
1038	};	1099	};
1039		1100
1040	Example: print all changes to the family "AnyRvent::Fantasy::Module".	1101	Example: print all changes to the family "AnyEvent::Fantasy::Module".
1041		1102
1042	my $guard = db_mon AnyRvent::Fantasy::Module => sub {	1103	my $guard = db_mon AnyEvent::Fantasy::Module => sub {
1043	my ($family, $a, $c, $d) = @_;	1104	my ($family, $a, $c, $d) = @_;
1044		1105
1045	print "+$_=$family->{$_}\n" for @$a;	1106	print "+$_=$family->{$_}\n" for @$a;
1046	print "*$_=$family->{$_}\n" for @$c;	1107	print "*$_=$family->{$_}\n" for @$c;
1047	print "-$_=$family->{$_}\n" for @$d;	1108	print "-$_=$family->{$_}\n" for @$d;
…		…
1098	filter messages without dequeuing them.	1159	filter messages without dequeuing them.
1099		1160
1100	This is not a philosophical difference, but simply stems from AnyEvent::MP	1161	This is not a philosophical difference, but simply stems from AnyEvent::MP
1101	being event-based, while Erlang is process-based.	1162	being event-based, while Erlang is process-based.
1102		1163
1103	You cna have a look at L<Coro::MP> for a more Erlang-like process model on	1164	You can have a look at L<Coro::MP> for a more Erlang-like process model on
1104	top of AEMP and Coro threads.	1165	top of AEMP and Coro threads.
1105		1166
1106	=item * Erlang sends are synchronous, AEMP sends are asynchronous.	1167	=item * Erlang sends are synchronous, AEMP sends are asynchronous.
1107		1168
1108	Sending messages in Erlang is synchronous and blocks the process until	1169	Sending messages in Erlang is synchronous and blocks the process until
1109	a conenction has been established and the message sent (and so does not	1170	a connection has been established and the message sent (and so does not
1110	need a queue that can overflow). AEMP sends return immediately, connection	1171	need a queue that can overflow). AEMP sends return immediately, connection
1111	establishment is handled in the background.	1172	establishment is handled in the background.
1112		1173
1113	=item * Erlang suffers from silent message loss, AEMP does not.	1174	=item * Erlang suffers from silent message loss, AEMP does not.
1114		1175
…		…
1212	Keeping your messages simple, concentrating on data structures rather than	1273	Keeping your messages simple, concentrating on data structures rather than
1213	objects, will keep your messages clean, tidy and efficient.	1274	objects, will keep your messages clean, tidy and efficient.
1214		1275
1215	=back	1276	=back
1216		1277
		1278	=head1 PORTING FROM AnyEvent::MP VERSION 1.X
		1279
		1280	AEMP version 2 has a few major incompatible changes compared to version 1:
		1281
		1282	=over 4
		1283
		1284	=item AnyEvent::MP::Global no longer has group management functions.
		1285
		1286	At least not officially - the grp_* functions are still exported and might
		1287	work, but they will be removed in some later release.
		1288
		1289	AnyEvent::MP now comes with a distributed database that is more
		1290	powerful. Its database families map closely to port groups, but the API
		1291	has changed (the functions are also now exported by AnyEvent::MP). Here is
		1292	a rough porting guide:
		1293
		1294	grp_reg $group, $port # old
		1295	db_reg $group, $port # new
		1296
		1297	$list = grp_get $group # old
		1298	db_keys $group, sub { my $list = shift } # new
		1299
		1300	grp_mon $group, $cb->(\@ports, $add, $del) # old
		1301	db_mon $group, $cb->(\%ports, $add, $change, $del) # new
		1302
		1303	C<grp_reg> is a no-brainer (just replace by C<db_reg>), but C<grp_get> is
		1304	no longer instant, because the local node might not have a copy of the
		1305	group. You can either modify your code to allow for a callback, or use
		1306	C<db_mon> to keep an updated copy of the group:
		1307
		1308	my $local_group_copy;
		1309	db_mon $group => sub { $local_group_copy = $_[0] };
		1310
		1311	# now "keys %$local_group_copy" always returns the most up-to-date
		1312	# list of ports in the group.
		1313
		1314	C<grp_mon> can be replaced by C<db_mon> with minor changes - C<db_mon>
		1315	passes a hash as first argument, and an extra C<$chg> argument that can be
		1316	ignored:
		1317
		1318	db_mon $group => sub {
		1319	my ($ports, $add, $chg, $del) = @_;
		1320	$ports = [keys %$ports];
		1321
		1322	# now $ports, $add and $del are the same as
		1323	# were originally passed by grp_mon.
		1324	...
		1325	};
		1326
		1327	=item Nodes not longer connect to all other nodes.
		1328
		1329	In AEMP 1.x, every node automatically loads the L<AnyEvent::MP::Global>
		1330	module, which in turn would create connections to all other nodes in the
		1331	network (helped by the seed nodes).
		1332
		1333	In version 2.x, global nodes still connect to all other global nodes, but
		1334	other nodes don't - now every node either is a global node itself, or
		1335	attaches itself to another global node.
		1336
		1337	If a node isn't a global node itself, then it attaches itself to one
		1338	of its seed nodes. If that seed node isn't a global node yet, it will
		1339	automatically be upgraded to a global node.
		1340
		1341	So in many cases, nothing needs to be changed - one just has to make sure
		1342	that all seed nodes are meshed together with the other seed nodes (as with
		1343	AEMP 1.x), and other nodes specify them as seed nodes. This is most easily
		1344	achieved by specifying the same set of seed nodes for all nodes in the
		1345	network.
		1346
		1347	Not opening a connection to every other node is usually an advantage,
		1348	except when you need the lower latency of an already established
		1349	connection. To ensure a node establishes a connection to another node,
		1350	you can monitor the node port (C<mon $node, ...>), which will attempt to
		1351	create the connection (and notify you when the connection fails).
		1352
		1353	=item Listener-less nodes (nodes without binds) are gone.
		1354
		1355	And are not coming back, at least not in their old form. If no C<binds>
		1356	are specified for a node, AnyEvent::MP assumes a default of C<:>.
		1357
		1358	There are vague plans to implement some form of routing domains, which
		1359	might or might not bring back listener-less nodes, but don't count on it.
		1360
		1361	The fact that most connections are now optional somewhat mitigates this,
		1362	as a node can be effectively unreachable from the outside without any
		1363	problems, as long as it isn't a global node and only reaches out to other
		1364	nodes (as opposed to being contacted from other nodes).
		1365
		1366	=item $AnyEvent::MP::Kernel::WARN has gone.
		1367
		1368	AnyEvent has acquired a logging framework (L<AnyEvent::Log>), and AEMP now
		1369	uses this, and so should your programs.
		1370
		1371	Every module now documents what kinds of messages it generates, with
		1372	AnyEvent::MP acting as a catch all.
		1373
		1374	On the positive side, this means that instead of setting
		1375	C<PERL_ANYEVENT_MP_WARNLEVEL>, you can get away by setting C<AE_VERBOSE> -
		1376	much less to type.
		1377
		1378	=back
		1379
		1380	=head1 LOGGING
		1381
		1382	AnyEvent::MP does not normally log anything by itself, but since it is the
		1383	root of the context hierarchy for AnyEvent::MP modules, it will receive
		1384	all log messages by submodules.
		1385
1217	=head1 SEE ALSO	1386	=head1 SEE ALSO
1218		1387
1219	L<AnyEvent::MP::Intro> - a gentle introduction.	1388	L<AnyEvent::MP::Intro> - a gentle introduction.
1220		1389
1221	L<AnyEvent::MP::Kernel> - more, lower-level, stuff.	1390	L<AnyEvent::MP::Kernel> - more, lower-level, stuff.

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.134 by root, Mon Mar 12 14:47:23 2012 UTC vs. Revision 1.156 by root, Sat Oct 23 03:35:49 2021 UTC

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Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.134 by root, Mon Mar 12 14:47:23 2012 UTC vs.
Revision 1.156 by root, Sat Oct 23 03:35:49 2021 UTC