[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 1.142 by root, Fri Mar 23 13:44:01 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)
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
260	=back	244	=back
261		245
262	=over 4	246	=over 4
263		247
264	=item step 1, gathering configuration from profiles	248	=item step 1, gathering configuration from profiles
…		…
400		384
401	sub rcv($@);	385	sub rcv($@);
402		386
403	my $KILME = sub {	387	my $KILME = sub {
404	(my $tag = substr $_[0], 0, 30) =~ s/([\x20-\x7e])/./g;	388	(my $tag = substr $_[0], 0, 30) =~ s/([\x20-\x7e])/./g;
405	kil $SELF, unhandled_message => "missing (tag or fallback) callback for message '$tag'";	389	kil $SELF, unhandled_message => "no callback found for message '$tag'";
406	};	390	};
407		391
408	sub port(;&) {	392	sub port(;&) {
409	my $id = $UNIQ . ++$ID;	393	my $id = $UNIQ . ++$ID;
410	my $port = "$NODE#$id";	394	my $port = "$NODE#$id";
…		…
596	$res	580	$res
597	}	581	}
598	}	582	}
599	}	583	}
600		584
		585	=item $guard = mon $port, $rcvport # kill $rcvport when $port dies
		586
		587	=item $guard = mon $port # kill $SELF when $port dies
		588
601	=item $guard = mon $port, $cb->(@reason) # call $cb when $port dies	589	=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		590
607	=item $guard = mon $port, $rcvport, @msg # send a message when $port dies	591	=item $guard = mon $port, $rcvport, @msg # send a message when $port dies
608		592
609	Monitor the given port and do something when the port is killed or	593	Monitor the given port and do something when the port is killed or
610	messages to it were lost, and optionally return a guard that can be used	594	messages to it were lost, and optionally return a guard that can be used
611	to stop monitoring again.	595	to stop monitoring again.
612		596
		597	The first two forms distinguish between "normal" and "abnormal" kil's:
		598
		599	In the first form (another port given), if the C<$port> is C<kil>'ed with
		600	a non-empty reason, the other port (C<$rcvport>) will be kil'ed with the
		601	same reason. That is, on "normal" kil's nothing happens, while under all
		602	other conditions, the other port is killed with the same reason.
		603
		604	The second form (kill self) is the same as the first form, except that
		605	C<$rvport> defaults to C<$SELF>.
		606
		607	The remaining forms don't distinguish between "normal" and "abnormal" kil's
		608	- it's up to the callback or receiver to check whether the C<@reason> is
		609	empty and act accordingly.
		610
613	In the first form (callback), the callback is simply called with any	611	In the third form (callback), the callback is simply called with any
614	number of C<@reason> elements (no @reason means that the port was deleted	612	number of C<@reason> elements (empty @reason means that the port was deleted
615	"normally"). Note also that I<< the callback B<must> never die >>, so use	613	"normally"). Note also that I<< the callback B<must> never die >>, so use
616	C<eval> if unsure.	614	C<eval> if unsure.
617		615
618	In the second form (another port given), the other port (C<$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	616	In the last form (message), a message of the form C<$rcvport, @msg,
627	C<snd>.	617	@reason> will be C<snd>.
628		618
629	Monitoring-actions are one-shot: once messages are lost (and a monitoring	619	Monitoring-actions are one-shot: once messages are lost (and a monitoring
630	alert was raised), they are removed and will not trigger again.	620	alert was raised), they are removed and will not trigger again, even if it
		621	turns out that the port is still alive.
631		622
632	As a rule of thumb, monitoring requests should always monitor a port from	623	As a rule of thumb, monitoring requests should always monitor a remote
633	a local port (or callback). The reason is that kill messages might get	624	port locally (using a local C<$rcvport> or a callback). The reason is that
634	lost, just like any other message. Another less obvious reason is that	625	kill messages might get lost, just like any other message. Another less
635	even monitoring requests can get lost (for example, when the connection	626	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	627	when the connection to the other node goes down permanently). When
637	these problems do not exist.	628	monitoring a port locally these problems do not exist.
638		629
639	C<mon> effectively guarantees that, in the absence of hardware failures,	630	C<mon> effectively guarantees that, in the absence of hardware failures,
640	after starting the monitor, either all messages sent to the port will	631	after starting the monitor, either all messages sent to the port will
641	arrive, or the monitoring action will be invoked after possible message	632	arrive, or the monitoring action will be invoked after possible message
642	loss has been detected. No messages will be lost "in between" (after	633	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	955	If you feel the need to monitor or query a single subkey, try giving it
965	it's own family.	956	it's own family.
966		957
967	=over	958	=over
968		959
969	=item db_set $family => $subkey [=> $value]	960	=item $guard = db_set $family => $subkey [=> $value]
970		961
971	Sets (or replaces) a key to the database - if C<$value> is omitted,	962	Sets (or replaces) a key to the database - if C<$value> is omitted,
972	C<undef> is used instead.	963	C<undef> is used instead.
973		964
		965	When called in non-void context, C<db_set> returns a guard that
		966	automatically calls C<db_del> when it is destroyed.
		967
974	=item db_del $family => $subkey...	968	=item db_del $family => $subkey...
975		969
976	Deletes one or more subkeys from the database family.	970	Deletes one or more subkeys from the database family.
977		971
978	=item $guard = db_reg $family => $subkey [=> $value]	972	=item $guard = db_reg $family => $port => $value
979		973
980	Sets the key on the database and returns a guard. When the guard is	974	=item $guard = db_reg $family => $port
981	destroyed, the key is deleted from the database. If C<$value> is missing,	975
982	then C<undef> is used.	976	=item $guard = db_reg $family
		977
		978	Registers a port in the given family and optionally returns a guard to
		979	remove it.
		980
		981	This function basically does the same as:
		982
		983	db_set $family => $port => $value
		984
		985	Except that the port is monitored and automatically removed from the
		986	database family when it is kil'ed.
		987
		988	If C<$value> is missing, C<undef> is used. If C<$port> is missing, then
		989	C<$SELF> is used.
		990
		991	This function is most useful to register a port in some port group (which
		992	is just another name for a database family), and have it removed when the
		993	port is gone. This works best when the port is a local port.
		994
		995	=cut
		996
		997	sub db_reg($$;$) {
		998	my $family = shift;
		999	my $port = @_ ? shift : $SELF;
		1000
		1001	my $clr = sub { db_del $family => $port };
		1002	mon $port, $clr;
		1003
		1004	db_set $family => $port => $_[0];
		1005
		1006	defined wantarray
		1007	and &Guard::guard ($clr)
		1008	}
983		1009
984	=item db_family $family => $cb->(\%familyhash)	1010	=item db_family $family => $cb->(\%familyhash)
985		1011
986	Queries the named database C<$family> and call the callback with the	1012	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.	1013	family represented as a hash. You can keep and freely modify the hash.
…		…
1212	Keeping your messages simple, concentrating on data structures rather than	1238	Keeping your messages simple, concentrating on data structures rather than
1213	objects, will keep your messages clean, tidy and efficient.	1239	objects, will keep your messages clean, tidy and efficient.
1214		1240
1215	=back	1241	=back
1216		1242
		1243	=head1 PORTING FROM AnyEvent::MP VERSION 1.X
		1244
		1245	AEMP version 2 has a few major incompatible changes compared to version 1:
		1246
		1247	=over 4
		1248
		1249	=item AnyEvent::MP::Global no longer has group management functions.
		1250
		1251	At least not officially - the grp_* functions are still exported and might
		1252	work, but they will be removed in some later release.
		1253
		1254	AnyEvent::MP now comes with a distributed database that is more
		1255	powerful. Its database families map closely to port groups, but the API
		1256	has changed (the functions are also now exported by AnyEvent::MP). Here is
		1257	a rough porting guide:
		1258
		1259	grp_reg $group, $port # old
		1260	db_reg $group, $port # new
		1261
		1262	$list = grp_get $group # old
		1263	db_keys $group, sub { my $list = shift } # new
		1264
		1265	grp_mon $group, $cb->(\@ports, $add, $del) # old
		1266	db_mon $group, $cb->(\%ports, $add, $change, $del) # new
		1267
		1268	C<grp_reg> is a no-brainer (just replace by C<db_reg>), but C<grp_get> is
		1269	no longer instant, because the local node might not have a copy of the
		1270	group. You can either modify your code to allow for a callback, or use
		1271	C<db_mon> to keep an updated copy of the group:
		1272
		1273	my $local_group_copy;
		1274	db_mon $group => sub { $local_group_copy = $_[0] };
		1275
		1276	# now "keys %$local_group_copy" always returns the most up-to-date
		1277	# list of ports in the group.
		1278
		1279	C<grp_mon> can be replaced by C<db_mon> with minor changes - C<db_mon>
		1280	passes a hash as first argument, and an extra C<$chg> argument that can be
		1281	ignored:
		1282
		1283	db_mon $group => sub {
		1284	my ($ports, $add, $chg, $lde) = @_;
		1285	$ports = [keys %$ports];
		1286
		1287	# now $ports, $add and $del are the same as
		1288	# were originally passed by grp_mon.
		1289	...
		1290	};
		1291
		1292	=item Nodes not longer connect to all other nodes.
		1293
		1294	In AEMP 1.x, every node automatically loads the L<AnyEvent::MP::Global>
		1295	module, which in turn would create connections to all other nodes in the
		1296	network (helped by the seed nodes).
		1297
		1298	In version 2.x, global nodes still connect to all other global nodes, but
		1299	other nodes don't - now every node either is a global node itself, or
		1300	attaches itself to another global node.
		1301
		1302	If a node isn't a global node itself, then it attaches itself to one
		1303	of its seed nodes. If that seed node isn't a global node yet, it will
		1304	automatically be upgraded to a global node.
		1305
		1306	So in many cases, nothing needs to be changed - one just has to make sure
		1307	that all seed nodes are meshed together with the other seed nodes (as with
		1308	AEMP 1.x), and other nodes specify them as seed nodes. This is most easily
		1309	achieved by specifying the same set of seed nodes for all nodes in the
		1310	network.
		1311
		1312	Not opening a connection to every other node is usually an advantage,
		1313	except when you need the lower latency of an already established
		1314	connection. To ensure a node establishes a connection to another node,
		1315	you can monitor the node port (C<mon $node, ...>), which will attempt to
		1316	create the connection (and notify you when the connection fails).
		1317
		1318	=item Listener-less nodes (nodes without binds) are gone.
		1319
		1320	And are not coming back, at least not in their old form. If no C<binds>
		1321	are specified for a node, AnyEvent::MP assumes a default of C<:>.
		1322
		1323	There are vague plans to implement some form of routing domains, which
		1324	might or might not bring back listener-less nodes, but don't count on it.
		1325
		1326	The fact that most connections are now optional somewhat mitigates this,
		1327	as a node can be effectively unreachable from the outside without any
		1328	problems, as long as it isn't a global node and only reaches out to other
		1329	nodes (as opposed to being contacted from other nodes).
		1330
		1331	=item $AnyEvent::MP::Kernel::WARN has gone.
		1332
		1333	AnyEvent has acquired a logging framework (L<AnyEvent::Log>), and AEMP now
		1334	uses this, and so should your programs.
		1335
		1336	Every module now documents what kinds of messages it generates, with
		1337	AnyEvent::MP acting as a catch all.
		1338
		1339	On the positive side, this means that instead of setting
		1340	C<PERL_ANYEVENT_MP_WARNLEVEL>, you can get away by setting C<AE_VERBOSE> -
		1341	much less to type.
		1342
		1343	=back
		1344
		1345	=head1 LOGGING
		1346
		1347	AnyEvent::MP does not normally log anything by itself, but sinc eit is the
		1348	root of the contetx hierarchy for AnyEvent::MP modules, it will receive
		1349	all log messages by submodules.
		1350
1217	=head1 SEE ALSO	1351	=head1 SEE ALSO
1218		1352
1219	L<AnyEvent::MP::Intro> - a gentle introduction.	1353	L<AnyEvent::MP::Intro> - a gentle introduction.
1220		1354
1221	L<AnyEvent::MP::Kernel> - more, lower-level, stuff.	1355	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 1.142 by root, Fri Mar 23 13:44:01 2012 UTC

Diff Legend

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.134 by root, Mon Mar 12 14:47:23 2012 UTC vs.
Revision 1.142 by root, Fri Mar 23 13:44:01 2012 UTC