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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.47 by root, Thu Aug 13 01:57:10 2009 UTC vs.
Revision 1.51 by root, Fri Aug 14 14:07:44 2009 UTC

…		…
9	$NODE # contains this node's noderef	9	$NODE # contains this node's noderef
10	NODE # returns this node's noderef	10	NODE # returns this node's noderef
11	NODE $port # returns the noderef of the port	11	NODE $port # returns the noderef of the port
12		12
13	$SELF # receiving/own port id in rcv callbacks	13	$SELF # receiving/own port id in rcv callbacks
		14
		15	# initialise the node so it can send/receive messages
		16	initialise_node; # -OR-
		17	initialise_node "localhost:4040"; # -OR-
		18	initialise_node "slave/", "localhost:4040"
14		19
15	# ports are message endpoints	20	# ports are message endpoints
16		21
17	# sending messages	22	# sending messages
18	snd $port, type => data...;	23	snd $port, type => data...;
19	snd $port, @msg;	24	snd $port, @msg;
20	snd @msg_with_first_element_being_a_port;	25	snd @msg_with_first_element_being_a_port;
21		26
22	# miniports	27	# creating/using ports, the simple way
23	my $miniport = port { my @msg = @_; 0 };	28	my $somple_port = port { my @msg = @_; 0 };
24		29
25	# full ports	30	# creating/using ports, type matching
26	my $port = port;	31	my $port = port;
27	rcv $port, smartmatch => $cb->(@msg);
28	rcv $port, ping => sub { snd $_[0], "pong"; 0 };	32	rcv $port, ping => sub { snd $_[0], "pong"; 0 };
29	rcv $port, pong => sub { warn "pong received\n"; 0 };	33	rcv $port, pong => sub { warn "pong received\n"; 0 };
30		34
31	# remote ports	35	# create a port on another node
32	my $port = spawn $node, $initfunc, @initdata;	36	my $port = spawn $node, $initfunc, @initdata;
33
34	# more, smarter, matches (_any_ is exported by this module)
35	rcv $port, [child_died => $pid] => sub { ...
36	rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3
37		37
38	# monitoring	38	# monitoring
39	mon $port, $cb->(@msg) # callback is invoked on death	39	mon $port, $cb->(@msg) # callback is invoked on death
40	mon $port, $otherport # kill otherport on abnormal death	40	mon $port, $otherport # kill otherport on abnormal death
41	mon $port, $otherport, @msg # send message on death	41	mon $port, $otherport, @msg # send message on death
…		…
163	it should know the noderefs of some other nodes in the network.	163	it should know the noderefs of some other nodes in the network.
164		164
165	This function initialises a node - it must be called exactly once (or	165	This function initialises a node - it must be called exactly once (or
166	never) before calling other AnyEvent::MP functions.	166	never) before calling other AnyEvent::MP functions.
167		167
168	All arguments are noderefs, which can be either resolved or unresolved.	168	All arguments (optionally except for the first) are noderefs, which can be
		169	either resolved or unresolved.
		170
		171	The first argument will be looked up in the configuration database first
		172	(if it is C<undef> then the current nodename will be used instead) to find
		173	the relevant configuration profile (see L<aemp>). If none is found then
		174	the default configuration is used. The configuration supplies additional
		175	seed/master nodes and can override the actual noderef.
169		176
170	There are two types of networked nodes, public nodes and slave nodes:	177	There are two types of networked nodes, public nodes and slave nodes:
171		178
172	=over 4	179	=over 4
173		180
174	=item public nodes	181	=item public nodes
175		182
176	For public nodes, C<$noderef> must either be a (possibly unresolved)	183	For public nodes, C<$noderef> (supplied either directly to
177	noderef, in which case it will be resolved, or C<undef> (or missing), in	184	C<initialise_node> or indirectly via a profile or the nodename) must be a
178	which case the noderef will be guessed.	185	noderef (possibly unresolved, in which case it will be resolved).
179		186
180	Afterwards, the node will bind itself on all endpoints and try to connect	187	After resolving, the node will bind itself on all endpoints and try to
181	to all additional C<$seednodes> that are specified. Seednodes are optional	188	connect to all additional C<$seednodes> that are specified. Seednodes are
182	and can be used to quickly bootstrap the node into an existing network.	189	optional and can be used to quickly bootstrap the node into an existing
		190	network.
183		191
184	=item slave nodes	192	=item slave nodes
185		193
186	When the C<$noderef> is the special string C<slave/>, then the node will	194	When the C<$noderef> (either as given or overriden by the config file)
		195	is the special string C<slave/>, then the node will become a slave
187	become a slave node. Slave nodes cannot be contacted from outside and will	196	node. Slave nodes cannot be contacted from outside and will route most of
188	route most of their traffic to the master node that they attach to.	197	their traffic to the master node that they attach to.
189		198
190	At least one additional noderef is required: The node will try to connect	199	At least one additional noderef is required (either by specifying it
191	to all of them and will become a slave attached to the first node it can	200	directly or because it is part of the configuration profile): The node
192	successfully connect to.	201	will try to connect to all of them and will become a slave attached to the
		202	first node it can successfully connect to.
193		203
194	=back	204	=back
195		205
196	This function will block until all nodes have been resolved and, for slave	206	This function will block until all nodes have been resolved and, for slave
197	nodes, until it has successfully established a connection to a master	207	nodes, until it has successfully established a connection to a master
198	server.	208	server.
199		209
200	Example: become a public node listening on the default node.	210	Example: become a public node listening on the guessed noderef, or the one
		211	specified via C<aemp> for the current node. This should be the most common
		212	form of invocation for "daemon"-type nodes.
201		213
202	initialise_node;	214	initialise_node;
		215
		216	Example: become a slave node to any of the the seednodes specified via
		217	C<aemp>. This form is often used for commandline clients.
		218
		219	initialise_node "slave/";
		220
		221	Example: become a slave node to any of the specified master servers. This
		222	form is also often used for commandline clients.
		223
		224	initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net";
203		225
204	Example: become a public node, and try to contact some well-known master	226	Example: become a public node, and try to contact some well-known master
205	servers to become part of the network.	227	servers to become part of the network.
206		228
207	initialise_node undef, "master1", "master2";	229	initialise_node undef, "master1", "master2";
…		…
210		232
211	initialise_node 4041;	233	initialise_node 4041;
212		234
213	Example: become a public node, only visible on localhost port 4044.	235	Example: become a public node, only visible on localhost port 4044.
214		236
215	initialise_node "locahost:4044";	237	initialise_node "localhost:4044";
216
217	Example: become a slave node to any of the specified master servers.
218
219	initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net";
220		238
221	=item $cv = resolve_node $noderef	239	=item $cv = resolve_node $noderef
222		240
223	Takes an unresolved node reference that may contain hostnames and	241	Takes an unresolved node reference that may contain hostnames and
224	abbreviated IDs, resolves all of them and returns a resolved node	242	abbreviated IDs, resolves all of them and returns a resolved node
…		…
280	that Storable can serialise and deserialise is allowed, and for the local	298	that Storable can serialise and deserialise is allowed, and for the local
281	node, anything can be passed.	299	node, anything can be passed.
282		300
283	=item $local_port = port	301	=item $local_port = port
284		302
285	Create a new local port object that can be used either as a pattern	303	Create a new local port object and returns its port ID. Initially it has
286	matching port ("full port") or a single-callback port ("miniport"),	304	no callbacks set and will throw an error when it receives messages.
287	depending on how C<rcv> callbacks are bound to the object.
288		305
289	=item $port = port { my @msg = @_; $finished }	306	=item $local_port = port { my @msg = @_ }
290		307
291	Creates a "miniport", that is, a very lightweight port without any pattern	308	Creates a new local port, and returns its ID. Semantically the same as
292	matching behind it, and returns its ID. Semantically the same as creating
293	a port and calling C<rcv $port, $callback> on it.	309	creating a port and calling C<rcv $port, $callback> on it.
294		310
295	The block will be called for every message received on the port. When the	311	The block will be called for every message received on the port, with the
296	callback returns a true value its job is considered "done" and the port	312	global variable C<$SELF> set to the port ID. Runtime errors will cause the
297	will be destroyed. Otherwise it will stay alive.	313	port to be C<kil>ed. The message will be passed as-is, no extra argument
		314	(i.e. no port ID) will be passed to the callback.
298		315
299	The message will be passed as-is, no extra argument (i.e. no port id) will	316	If you want to stop/destroy the port, simply C<kil> it:
300	be passed to the callback.
301		317
302	If you need the local port id in the callback, this works nicely:	318	my $port = port {
303		319	my @msg = @_;
304	my $port; $port = port {	320	...
305	snd $otherport, reply => $port;	321	kil $SELF;
306	};	322	};
307		323
308	=cut	324	=cut
309		325
310	sub rcv($@);	326	sub rcv($@);
		327
		328	sub _kilme {
		329	die "received message on port without callback";
		330	}
311		331
312	sub port(;&) {	332	sub port(;&) {
313	my $id = "$UNIQ." . $ID++;	333	my $id = "$UNIQ." . $ID++;
314	my $port = "$NODE#$id";	334	my $port = "$NODE#$id";
315		335
316	if (@_) {	336	rcv $port, shift \|\| \&_kilme;
317	rcv $port, shift;
318	} else {
319	$PORT{$id} = sub { }; # nop
320	}
321		337
322	$port	338	$port
323	}	339	}
324		340
325	=item reg $port, $name
326
327	=item reg $name
328
329	Registers the given port (or C<$SELF><<< if missing) under the name
330	C<$name>. If the name already exists it is replaced.
331
332	A port can only be registered under one well known name.
333
334	A port automatically becomes unregistered when it is killed.
335
336	=cut
337
338	sub reg(@) {
339	my $port = @_ > 1 ? shift : $SELF \|\| Carp::croak 'reg: called with one argument only, but $SELF not set,';
340
341	$REG{$_[0]} = $port;
342	}
343
344	=item rcv $port, $callback->(@msg)	341	=item rcv $local_port, $callback->(@msg)
345		342
346	Replaces the callback on the specified miniport (after converting it to	343	Replaces the default callback on the specified port. There is no way to
347	one if required).	344	remove the default callback: use C<sub { }> to disable it, or better
348		345	C<kil> the port when it is no longer needed.
349	=item rcv $port, tagstring => $callback->(@msg), ...
350
351	=item rcv $port, $smartmatch => $callback->(@msg), ...
352
353	=item rcv $port, [$smartmatch...] => $callback->(@msg), ...
354
355	Register callbacks to be called on matching messages on the given full
356	port (after converting it to one if required) and return the port.
357
358	The callback has to return a true value when its work is done, after
359	which is will be removed, or a false value in which case it will stay
360	registered.
361		346
362	The global C<$SELF> (exported by this module) contains C<$port> while	347	The global C<$SELF> (exported by this module) contains C<$port> while
363	executing the callback.	348	executing the callback. Runtime errors during callback execution will
		349	result in the port being C<kil>ed.
364		350
365	Runtime errors during callback execution will result in the port being	351	The default callback received all messages not matched by a more specific
366	C<kil>ed.	352	C<tag> match.
367		353
368	If the match is an array reference, then it will be matched against the	354	=item rcv $local_port, tag => $callback->(@msg_without_tag), ...
369	first elements of the message, otherwise only the first element is being
370	matched.
371		355
372	Any element in the match that is specified as C<_any_> (a function	356	Register callbacks to be called on messages starting with the given tag on
373	exported by this module) matches any single element of the message.	357	the given port (and return the port), or unregister it (when C<$callback>
		358	is C<$undef>).
374		359
375	While not required, it is highly recommended that the first matching	360	The original message will be passed to the callback, after the first
376	element is a string identifying the message. The one-string-only match is	361	element (the tag) has been removed. The callback will use the same
377	also the most efficient match (by far).	362	environment as the default callback (see above).
378		363
379	Example: create a port and bind receivers on it in one go.	364	Example: create a port and bind receivers on it in one go.
380		365
381	my $port = rcv port,	366	my $port = rcv port,
382	msg1 => sub { ...; 0 },	367	msg1 => sub { ... },
383	msg2 => sub { ...; 0 },	368	msg2 => sub { ... },
384	;	369	;
385		370
386	Example: create a port, bind receivers and send it in a message elsewhere	371	Example: create a port, bind receivers and send it in a message elsewhere
387	in one go:	372	in one go:
388		373
389	snd $otherport, reply =>	374	snd $otherport, reply =>
390	rcv port,	375	rcv port,
391	msg1 => sub { ...; 0 },	376	msg1 => sub { ... },
392	...	377	...
393	;	378	;
394		379
395	=cut	380	=cut
396		381
…		…
399	my ($noderef, $portid) = split /#/, $port, 2;	384	my ($noderef, $portid) = split /#/, $port, 2;
400		385
401	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}	386	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}
402	or Carp::croak "$port: rcv can only be called on local ports, caught";	387	or Carp::croak "$port: rcv can only be called on local ports, caught";
403		388
404	if (@_ == 1) {	389	while (@_) {
		390	if (ref $_[0]) {
		391	if (my $self = $PORT_DATA{$portid}) {
		392	"AnyEvent::MP::Port" eq ref $self
		393	or Carp::croak "$port: rcv can only be called on message matching ports, caught";
		394
		395	$self->[2] = shift;
		396	} else {
405	my $cb = shift;	397	my $cb = shift;
406	delete $PORT_DATA{$portid};
407	$PORT{$portid} = sub {	398	$PORT{$portid} = sub {
408	local $SELF = $port;	399	local $SELF = $port;
409	eval {	400	eval { &$cb }; _self_die if $@;
410	&$cb	401	};
411	and kil $port;
412	};	402	}
413	_self_die if $@;	403	} elsif (defined $_[0]) {
414	};
415	} else {
416	my $self = $PORT_DATA{$portid} \|\|= do {	404	my $self = $PORT_DATA{$portid} \|\|= do {
417	my $self = bless {	405	my $self = bless [$PORT{$port} \|\| sub { }, { }, $port], "AnyEvent::MP::Port";
418	id => $port,
419	}, "AnyEvent::MP::Port";
420		406
421	$PORT{$portid} = sub {	407	$PORT{$portid} = sub {
422	local $SELF = $port;	408	local $SELF = $port;
423		409
424	eval {
425	for (@{ $self->{rc0}{$_[0]} }) {	410	if (my $cb = $self->[1]{$_[0]}) {
426	$_ && &{$_->[0]}	411	shift;
427	&& undef $_;	412	eval { &$cb }; _self_die if $@;
428	}	413	} else {
429
430	for (@{ $self->{rcv}{$_[0]} }) {
431	$_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1]
432	&& &{$_->[0]}	414	&{ $self->[0] };
433	&& undef $_;
434	}
435
436	for (@{ $self->{any} }) {
437	$_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1]
438	&& &{$_->[0]}
439	&& undef $_;
440	}	415	}
441	};	416	};
442	_self_die if $@;	417
		418	$self
443	};	419	};
444		420
445	$self
446	};
447
448	"AnyEvent::MP::Port" eq ref $self	421	"AnyEvent::MP::Port" eq ref $self
449	or Carp::croak "$port: rcv can only be called on message matching ports, caught";	422	or Carp::croak "$port: rcv can only be called on message matching ports, caught";
450		423
451	while (@_) {
452	my ($match, $cb) = splice @_, 0, 2;	424	my ($tag, $cb) = splice @_, 0, 2;
453		425
454	if (!ref $match) {	426	if (defined $cb) {
455	push @{ $self->{rc0}{$match} }, [$cb];	427	$self->[1]{$tag} = $cb;
456	} elsif (("ARRAY" eq ref $match && !ref $match->[0])) {
457	my ($type, @match) = @$match;
458	@match
459	? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match]
460	: push @{ $self->{rc0}{$match->[0]} }, [$cb];
461	} else {	428	} else {
462	push @{ $self->{any} }, [$cb, $match];	429	delete $self->[1]{$tag};
463	}	430	}
464	}	431	}
465	}	432	}
466		433
467	$port	434	$port
…		…
771	convenience functionality.	738	convenience functionality.
772		739
773	This means that AEMP requires a less tightly controlled environment at the	740	This means that AEMP requires a less tightly controlled environment at the
774	cost of longer node references and a slightly higher management overhead.	741	cost of longer node references and a slightly higher management overhead.
775		742
		743	=item Erlang has a "remote ports are like local ports" philosophy, AEMP
		744	uses "local ports are like remote ports".
		745
		746	The failure modes for local ports are quite different (runtime errors
		747	only) then for remote ports - when a local port dies, you I<know> it dies,
		748	when a connection to another node dies, you know nothing about the other
		749	port.
		750
		751	Erlang pretends remote ports are as reliable as local ports, even when
		752	they are not.
		753
		754	AEMP encourages a "treat remote ports differently" philosophy, with local
		755	ports being the special case/exception, where transport errors cannot
		756	occur.
		757
776	=item * Erlang uses processes and a mailbox, AEMP does not queue.	758	=item * Erlang uses processes and a mailbox, AEMP does not queue.
777		759
778	Erlang uses processes that selctively receive messages, and therefore	760	Erlang uses processes that selectively receive messages, and therefore
779	needs a queue. AEMP is event based, queuing messages would serve no useful	761	needs a queue. AEMP is event based, queuing messages would serve no
780	purpose.	762	useful purpose. For the same reason the pattern-matching abilities of
		763	AnyEvent::MP are more limited, as there is little need to be able to
		764	filter messages without dequeing them.
781		765
782	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).	766	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).
783		767
784	=item * Erlang sends are synchronous, AEMP sends are asynchronous.	768	=item * Erlang sends are synchronous, AEMP sends are asynchronous.
785		769
786	Sending messages in Erlang is synchronous and blocks the process. AEMP	770	Sending messages in Erlang is synchronous and blocks the process (and
787	sends are immediate, connection establishment is handled in the	771	so does not need a queue that can overflow). AEMP sends are immediate,
788	background.	772	connection establishment is handled in the background.
789		773
790	=item * Erlang can silently lose messages, AEMP cannot.	774	=item * Erlang suffers from silent message loss, AEMP does not.
791		775
792	Erlang makes few guarantees on messages delivery - messages can get lost	776	Erlang makes few guarantees on messages delivery - messages can get lost
793	without any of the processes realising it (i.e. you send messages a, b,	777	without any of the processes realising it (i.e. you send messages a, b,
794	and c, and the other side only receives messages a and c).	778	and c, and the other side only receives messages a and c).
795		779
…		…
807	eventually be killed - it cannot happen that a node detects a port as dead	791	eventually be killed - it cannot happen that a node detects a port as dead
808	and then later sends messages to it, finding it is still alive.	792	and then later sends messages to it, finding it is still alive.
809		793
810	=item * Erlang can send messages to the wrong port, AEMP does not.	794	=item * Erlang can send messages to the wrong port, AEMP does not.
811		795
812	In Erlang it is quite possible that a node that restarts reuses a process	796	In Erlang it is quite likely that a node that restarts reuses a process ID
813	ID known to other nodes for a completely different process, causing	797	known to other nodes for a completely different process, causing messages
814	messages destined for that process to end up in an unrelated process.	798	destined for that process to end up in an unrelated process.
815		799
816	AEMP never reuses port IDs, so old messages or old port IDs floating	800	AEMP never reuses port IDs, so old messages or old port IDs floating
817	around in the network will not be sent to an unrelated port.	801	around in the network will not be sent to an unrelated port.
818		802
819	=item * Erlang uses unprotected connections, AEMP uses secure	803	=item * Erlang uses unprotected connections, AEMP uses secure

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.47 by root, Thu Aug 13 01:57:10 2009 UTC vs. Revision 1.51 by root, Fri Aug 14 14:07:44 2009 UTC

Diff Legend

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.47 by root, Thu Aug 13 01:57:10 2009 UTC vs.
Revision 1.51 by root, Fri Aug 14 14:07:44 2009 UTC