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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.135 by root, Mon Mar 12 14:55:55 2012 UTC vs.
Revision 1.141 by root, Fri Mar 23 03:24:41 2012 UTC

…		…
46		46
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
52	=head1 CURRENT STATUS
53
54	bin/aemp - stable.
55	AnyEvent::MP - stable API, should work.
56	AnyEvent::MP::Intro - explains most concepts.
57	AnyEvent::MP::Kernel - mostly stable API.
58	AnyEvent::MP::Global - stable API.
59		51
60	=head1 DESCRIPTION	52	=head1 DESCRIPTION
61		53
62	This module (-family) implements a simple message passing framework.	54	This module (-family) implements a simple message passing framework.
63		55
…		…
184		176
185	use common::sense;	177	use common::sense;
186		178
187	use Carp ();	179	use Carp ();
188		180
189	use AE ();	181	use AnyEvent ();
190	use Guard ();	182	use Guard ();
191		183
192	use base "Exporter";	184	use base "Exporter";
193		185
194	our $VERSION = $AnyEvent::MP::Config::VERSION;	186	our $VERSION = $AnyEvent::MP::Config::VERSION;
…		…
247		239
248	IF true, then the values specified in the C<configure> will take	240	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	241	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.	242	the rc file to override any options specified in the program.
251		243
252	=item secure => $pass->($nodeid)	244	=item secure => $pass->(@msg)
253		245
254	In addition to specifying a boolean, you can specify a code reference that	246	In addition to specifying a boolean, you can specify a code reference that
255	is called for every remote execution attempt - the execution request is	247	is called for every code execution attempt - the execution request is
256	granted iff the callback returns a true value.	248	granted iff the callback returns a true value.
		249
		250	Most of the time the callback should look only at
		251	C<$AnyEvent::MP::Kernel::SRCNODE> to make a decision, and not at the
		252	actual message (which can be about anything, and is mostly provided for
		253	diagnostic purposes).
257		254
258	See F<semp setsecure> for more info.	255	See F<semp setsecure> for more info.
259		256
260	=back	257	=back
261		258
…		…
596	$res	593	$res
597	}	594	}
598	}	595	}
599	}	596	}
600		597
		598	=item $guard = mon $port, $rcvport # kill $rcvport when $port dies
		599
		600	=item $guard = mon $port # kill $SELF when $port dies
		601
601	=item $guard = mon $port, $cb->(@reason) # call $cb when $port dies	602	=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		603
607	=item $guard = mon $port, $rcvport, @msg # send a message when $port dies	604	=item $guard = mon $port, $rcvport, @msg # send a message when $port dies
608		605
609	Monitor the given port and do something when the port is killed or	606	Monitor the given port and do something when the port is killed or
610	messages to it were lost, and optionally return a guard that can be used	607	messages to it were lost, and optionally return a guard that can be used
611	to stop monitoring again.	608	to stop monitoring again.
612		609
		610	The first two forms distinguish between "normal" and "abnormal" kil's:
		611
		612	In the first form (another port given), if the C<$port> is C<kil>'ed with
		613	a non-empty reason, the other port (C<$rcvport>) will be kil'ed with the
		614	same reason. That is, on "normal" kil's nothing happens, while under all
		615	other conditions, the other port is killed with the same reason.
		616
		617	The second form (kill self) is the same as the first form, except that
		618	C<$rvport> defaults to C<$SELF>.
		619
		620	The remaining forms don't distinguish between "normal" and "abnormal" kil's
		621	- it's up to the callback or receiver to check whether the C<@reason> is
		622	empty and act accordingly.
		623
613	In the first form (callback), the callback is simply called with any	624	In the third form (callback), the callback is simply called with any
614	number of C<@reason> elements (no @reason means that the port was deleted	625	number of C<@reason> elements (empty @reason means that the port was deleted
615	"normally"). Note also that I<< the callback B<must> never die >>, so use	626	"normally"). Note also that I<< the callback B<must> never die >>, so use
616	C<eval> if unsure.	627	C<eval> if unsure.
617		628
618	In the second form (another port given), the other port (C<$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	629	In the last form (message), a message of the form C<$rcvport, @msg,
627	C<snd>.	630	@reason> will be C<snd>.
628		631
629	Monitoring-actions are one-shot: once messages are lost (and a monitoring	632	Monitoring-actions are one-shot: once messages are lost (and a monitoring
630	alert was raised), they are removed and will not trigger again.	633	alert was raised), they are removed and will not trigger again, even if it
		634	turns out that the port is still alive.
631		635
632	As a rule of thumb, monitoring requests should always monitor a port from	636	As a rule of thumb, monitoring requests should always monitor a remote
633	a local port (or callback). The reason is that kill messages might get	637	port locally (using a local C<$rcvport> or a callback). The reason is that
634	lost, just like any other message. Another less obvious reason is that	638	kill messages might get lost, just like any other message. Another less
635	even monitoring requests can get lost (for example, when the connection	639	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	640	when the connection to the other node goes down permanently). When
637	these problems do not exist.	641	monitoring a port locally these problems do not exist.
638		642
639	C<mon> effectively guarantees that, in the absence of hardware failures,	643	C<mon> effectively guarantees that, in the absence of hardware failures,
640	after starting the monitor, either all messages sent to the port will	644	after starting the monitor, either all messages sent to the port will
641	arrive, or the monitoring action will be invoked after possible message	645	arrive, or the monitoring action will be invoked after possible message
642	loss has been detected. No messages will be lost "in between" (after	646	loss has been detected. No messages will be lost "in between" (after
…		…
964	If you feel the need to monitor or query a single subkey, try giving it	968	If you feel the need to monitor or query a single subkey, try giving it
965	it's own family.	969	it's own family.
966		970
967	=over	971	=over
968		972
969	=item db_set $family => $subkey [=> $value]	973	=item $guard = db_set $family => $subkey [=> $value]
970		974
971	Sets (or replaces) a key to the database - if C<$value> is omitted,	975	Sets (or replaces) a key to the database - if C<$value> is omitted,
972	C<undef> is used instead.	976	C<undef> is used instead.
973		977
		978	When called in non-void context, C<db_set> returns a guard that
		979	automatically calls C<db_del> when it is destroyed.
		980
974	=item db_del $family => $subkey...	981	=item db_del $family => $subkey...
975		982
976	Deletes one or more subkeys from the database family.	983	Deletes one or more subkeys from the database family.
977		984
978	=item $guard = db_reg $family => $subkey [=> $value]	985	=item $guard = db_reg $family => $port => $value
979		986
980	Sets the key on the database and returns a guard. When the guard is	987	=item $guard = db_reg $family => $port
981	destroyed, the key is deleted from the database. If C<$value> is missing,	988
982	then C<undef> is used.	989	=item $guard = db_reg $family
		990
		991	Registers a port in the given family and optionally returns a guard to
		992	remove it.
		993
		994	This function basically does the same as:
		995
		996	db_set $family => $port => $value
		997
		998	Except that the port is monitored and automatically removed from the
		999	database family when it is kil'ed.
		1000
		1001	If C<$value> is missing, C<undef> is used. If C<$port> is missing, then
		1002	C<$SELF> is used.
		1003
		1004	This function is most useful to register a port in some port group (which
		1005	is just another name for a database family), and have it removed when the
		1006	port is gone. This works best when the port is a local port.
		1007
		1008	=cut
		1009
		1010	sub db_reg($$;$) {
		1011	my $family = shift;
		1012	my $port = @_ ? shift : $SELF;
		1013
		1014	my $clr = sub { db_del $family => $port };
		1015	mon $port, $clr;
		1016
		1017	db_set $family => $port => $_[0];
		1018
		1019	defined wantarray
		1020	and &Guard::guard ($clr)
		1021	}
983		1022
984	=item db_family $family => $cb->(\%familyhash)	1023	=item db_family $family => $cb->(\%familyhash)
985		1024
986	Queries the named database C<$family> and call the callback with the	1025	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.	1026	family represented as a hash. You can keep and freely modify the hash.
…		…
1212	Keeping your messages simple, concentrating on data structures rather than	1251	Keeping your messages simple, concentrating on data structures rather than
1213	objects, will keep your messages clean, tidy and efficient.	1252	objects, will keep your messages clean, tidy and efficient.
1214		1253
1215	=back	1254	=back
1216		1255
		1256	=head1 PORTING FROM AnyEvent::MP VERSION 1.X
		1257
		1258	AEMP version 2 has a few major incompatible changes compared to version 1:
		1259
		1260	=over 4
		1261
		1262	=item AnyEvent::MP::Global no longer has group management functions.
		1263
		1264	At least not officially - the grp_* functions are still exported and might
		1265	work, but they will be removed in some later release.
		1266
		1267	AnyEvent::MP now comes with a distributed database that is more
		1268	powerful. Its database families map closely to port groups, but the API
		1269	has changed (the functions are also now exported by AnyEvent::MP). Here is
		1270	a rough porting guide:
		1271
		1272	grp_reg $group, $port # old
		1273	db_reg $group, $port # new
		1274
		1275	$list = grp_get $group # old
		1276	db_keys $group, sub { my $list = shift } # new
		1277
		1278	grp_mon $group, $cb->(\@ports, $add, $del) # old
		1279	db_mon $group, $cb->(\%ports, $add, $change, $del) # new
		1280
		1281	C<grp_reg> is a no-brainer (just replace by C<db_reg>), but C<grp_get> is
		1282	no longer instant, because the local node might not have a copy of the
		1283	group. You can either modify your code to allow for a callback, or use
		1284	C<db_mon> to keep an updated copy of the group:
		1285
		1286	my $local_group_copy;
		1287	db_mon $group => sub { $local_group_copy = $_[0] };
		1288
		1289	# now "keys %$local_group_copy" always returns the most up-to-date
		1290	# list of ports in the group.
		1291
		1292	C<grp_mon> can be replaced by C<db_mon> with minor changes - C<db_mon>
		1293	passes a hash as first argument, and an extra C<$chg> argument that can be
		1294	ignored:
		1295
		1296	db_mon $group => sub {
		1297	my ($ports, $add, $chg, $lde) = @_;
		1298	$ports = [keys %$ports];
		1299
		1300	# now $ports, $add and $del are the same as
		1301	# were originally passed by grp_mon.
		1302	...
		1303	};
		1304
		1305	=item Nodes not longer connect to all other nodes.
		1306
		1307	In AEMP 1.x, every node automatically loads the L<AnyEvent::MP::Global>
		1308	module, which in turn would create connections to all other nodes in the
		1309	network (helped by the seed nodes).
		1310
		1311	In version 2.x, global nodes still connect to all other global nodes, but
		1312	other nodes don't - now every node either is a global node itself, or
		1313	attaches itself to another global node.
		1314
		1315	If a node isn't a global node itself, then it attaches itself to one
		1316	of its seed nodes. If that seed node isn't a global node yet, it will
		1317	automatically be upgraded to a global node.
		1318
		1319	So in many cases, nothing needs to be changed - one just has to make sure
		1320	that all seed nodes are meshed together with the other seed nodes (as with
		1321	AEMP 1.x), and other nodes specify them as seed nodes. This is most easily
		1322	achieved by specifying the same set of seed nodes for all nodes in the
		1323	network.
		1324
		1325	Not opening a connection to every other node is usually an advantage,
		1326	except when you need the lower latency of an already established
		1327	connection. To ensure a node establishes a connection to another node,
		1328	you can monitor the node port (C<mon $node, ...>), which will attempt to
		1329	create the connection (and notify you when the connection fails).
		1330
		1331	=item Listener-less nodes (nodes without binds) are gone.
		1332
		1333	And are not coming back, at least not in their old form. If no C<binds>
		1334	are specified for a node, AnyEvent::MP assumes a default of C<:>.
		1335
		1336	There are vague plans to implement some form of routing domains, which
		1337	might or might not bring back listener-less nodes, but don't count on it.
		1338
		1339	The fact that most connections are now optional somewhat mitigates this,
		1340	as a node can be effectively unreachable from the outside without any
		1341	problems, as long as it isn't a global node and only reaches out to other
		1342	nodes (as opposed to being contacted from other nodes).
		1343
		1344	=item $AnyEvent::MP::Kernel::WARN has gone.
		1345
		1346	AnyEvent has acquired a logging framework (L<AnyEvent::Log>), and AEMP now
		1347	uses this, and so should your programs.
		1348
		1349	Every module now documents what kinds of messages it generates, with
		1350	AnyEvent::MP acting as a catch all.
		1351
		1352	On the positive side, this means that instead of setting
		1353	C<PERL_ANYEVENT_MP_WARNLEVEL>, you can get away by setting C<AE_VERBOSE> -
		1354	much less to type.
		1355
		1356	=back
		1357
		1358	=head1 LOGGING
		1359
		1360	AnyEvent::MP does not normally log anything by itself, but sinc eit is the
		1361	root of the contetx hierarchy for AnyEvent::MP modules, it will receive
		1362	all log messages by submodules.
		1363
1217	=head1 SEE ALSO	1364	=head1 SEE ALSO
1218		1365
1219	L<AnyEvent::MP::Intro> - a gentle introduction.	1366	L<AnyEvent::MP::Intro> - a gentle introduction.
1220		1367
1221	L<AnyEvent::MP::Kernel> - more, lower-level, stuff.	1368	L<AnyEvent::MP::Kernel> - more, lower-level, stuff.

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.135 by root, Mon Mar 12 14:55:55 2012 UTC vs. Revision 1.141 by root, Fri Mar 23 03:24:41 2012 UTC

Diff Legend

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.135 by root, Mon Mar 12 14:55:55 2012 UTC vs.
Revision 1.141 by root, Fri Mar 23 03:24:41 2012 UTC