[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 1.52 by root, Fri Aug 14 15:13:20 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, tagged message 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
…		…
143	kil $SELF, die => $msg;	143	kil $SELF, die => $msg;
144	}	144	}
145		145
146	=item $thisnode = NODE / $NODE	146	=item $thisnode = NODE / $NODE
147		147
148	The C<NODE> function returns, and the C<$NODE> variable contains	148	The C<NODE> function returns, and the C<$NODE> variable contains the
149	the noderef of the local node. The value is initialised by a call	149	noderef of the local node. The value is initialised by a call to
150	to C<become_public> or C<become_slave>, after which all local port	150	C<initialise_node>.
151	identifiers become invalid.
152		151
153	=item $noderef = node_of $port	152	=item $noderef = node_of $port
154		153
155	Extracts and returns the noderef from a portid or a noderef.	154	Extracts and returns the noderef from a port ID or a noderef.
156		155
157	=item initialise_node $noderef, $seednode, $seednode...	156	=item initialise_node $noderef, $seednode, $seednode...
158		157
159	=item initialise_node "slave/", $master, $master...	158	=item initialise_node "slave/", $master, $master...
160		159
…		…
163	it should know the noderefs of some other nodes in the network.	162	it should know the noderefs of some other nodes in the network.
164		163
165	This function initialises a node - it must be called exactly once (or	164	This function initialises a node - it must be called exactly once (or
166	never) before calling other AnyEvent::MP functions.	165	never) before calling other AnyEvent::MP functions.
167		166
168	All arguments are noderefs, which can be either resolved or unresolved.	167	All arguments (optionally except for the first) are noderefs, which can be
		168	either resolved or unresolved.
		169
		170	The first argument will be looked up in the configuration database first
		171	(if it is C<undef> then the current nodename will be used instead) to find
		172	the relevant configuration profile (see L<aemp>). If none is found then
		173	the default configuration is used. The configuration supplies additional
		174	seed/master nodes and can override the actual noderef.
169		175
170	There are two types of networked nodes, public nodes and slave nodes:	176	There are two types of networked nodes, public nodes and slave nodes:
171		177
172	=over 4	178	=over 4
173		179
174	=item public nodes	180	=item public nodes
175		181
176	For public nodes, C<$noderef> must either be a (possibly unresolved)	182	For public nodes, C<$noderef> (supplied either directly to
177	noderef, in which case it will be resolved, or C<undef> (or missing), in	183	C<initialise_node> or indirectly via a profile or the nodename) must be a
178	which case the noderef will be guessed.	184	noderef (possibly unresolved, in which case it will be resolved).
179		185
180	Afterwards, the node will bind itself on all endpoints and try to connect	186	After resolving, the node will bind itself on all endpoints and try to
181	to all additional C<$seednodes> that are specified. Seednodes are optional	187	connect to all additional C<$seednodes> that are specified. Seednodes are
182	and can be used to quickly bootstrap the node into an existing network.	188	optional and can be used to quickly bootstrap the node into an existing
		189	network.
183		190
184	=item slave nodes	191	=item slave nodes
185		192
186	When the C<$noderef> is the special string C<slave/>, then the node will	193	When the C<$noderef> (either as given or overriden by the config file)
		194	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	195	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.	196	their traffic to the master node that they attach to.
189		197
190	At least one additional noderef is required: The node will try to connect	198	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	199	directly or because it is part of the configuration profile): The node
192	successfully connect to.	200	will try to connect to all of them and will become a slave attached to the
		201	first node it can successfully connect to.
193		202
194	=back	203	=back
195		204
196	This function will block until all nodes have been resolved and, for slave	205	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	206	nodes, until it has successfully established a connection to a master
198	server.	207	server.
199		208
200	Example: become a public node listening on the default node.	209	Example: become a public node listening on the guessed noderef, or the one
		210	specified via C<aemp> for the current node. This should be the most common
		211	form of invocation for "daemon"-type nodes.
201		212
202	initialise_node;	213	initialise_node;
		214
		215	Example: become a slave node to any of the the seednodes specified via
		216	C<aemp>. This form is often used for commandline clients.
		217
		218	initialise_node "slave/";
		219
		220	Example: become a slave node to any of the specified master servers. This
		221	form is also often used for commandline clients.
		222
		223	initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net";
203		224
204	Example: become a public node, and try to contact some well-known master	225	Example: become a public node, and try to contact some well-known master
205	servers to become part of the network.	226	servers to become part of the network.
206		227
207	initialise_node undef, "master1", "master2";	228	initialise_node undef, "master1", "master2";
…		…
210		231
211	initialise_node 4041;	232	initialise_node 4041;
212		233
213	Example: become a public node, only visible on localhost port 4044.	234	Example: become a public node, only visible on localhost port 4044.
214		235
215	initialise_node "locahost:4044";	236	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		237
221	=item $cv = resolve_node $noderef	238	=item $cv = resolve_node $noderef
222		239
223	Takes an unresolved node reference that may contain hostnames and	240	Takes an unresolved node reference that may contain hostnames and
224	abbreviated IDs, resolves all of them and returns a resolved node	241	abbreviated IDs, resolves all of them and returns a resolved node
…		…
261	=item snd $port, type => @data	278	=item snd $port, type => @data
262		279
263	=item snd $port, @msg	280	=item snd $port, @msg
264		281
265	Send the given message to the given port ID, which can identify either	282	Send the given message to the given port ID, which can identify either
266	a local or a remote port, and can be either a string or soemthignt hat	283	a local or a remote port, and must be a port ID.
267	stringifies a sa port ID (such as a port object :).
268		284
269	While the message can be about anything, it is highly recommended to use a	285	While the message can be about anything, it is highly recommended to use a
270	string as first element (a portid, or some word that indicates a request	286	string as first element (a port ID, or some word that indicates a request
271	type etc.).	287	type etc.).
272		288
273	The message data effectively becomes read-only after a call to this	289	The message data effectively becomes read-only after a call to this
274	function: modifying any argument is not allowed and can cause many	290	function: modifying any argument is not allowed and can cause many
275	problems.	291	problems.
…		…
280	that Storable can serialise and deserialise is allowed, and for the local	296	that Storable can serialise and deserialise is allowed, and for the local
281	node, anything can be passed.	297	node, anything can be passed.
282		298
283	=item $local_port = port	299	=item $local_port = port
284		300
285	Create a new local port object that can be used either as a pattern	301	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"),	302	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		303
289	=item $port = port { my @msg = @_; $finished }	304	=item $local_port = port { my @msg = @_ }
290		305
291	Creates a "miniport", that is, a very lightweight port without any pattern	306	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.	307	creating a port and calling C<rcv $port, $callback> on it.
294		308
295	The block will be called for every message received on the port. When the	309	The block will be called for every message received on the port, with the
296	callback returns a true value its job is considered "done" and the port	310	global variable C<$SELF> set to the port ID. Runtime errors will cause the
297	will be destroyed. Otherwise it will stay alive.	311	port to be C<kil>ed. The message will be passed as-is, no extra argument
		312	(i.e. no port ID) will be passed to the callback.
298		313
299	The message will be passed as-is, no extra argument (i.e. no port id) will	314	If you want to stop/destroy the port, simply C<kil> it:
300	be passed to the callback.
301		315
302	If you need the local port id in the callback, this works nicely:	316	my $port = port {
303		317	my @msg = @_;
304	my $port; $port = port {	318	...
305	snd $otherport, reply => $port;	319	kil $SELF;
306	};	320	};
307		321
308	=cut	322	=cut
309		323
310	sub rcv($@);	324	sub rcv($@);
		325
		326	sub _kilme {
		327	die "received message on port without callback";
		328	}
311		329
312	sub port(;&) {	330	sub port(;&) {
313	my $id = "$UNIQ." . $ID++;	331	my $id = "$UNIQ." . $ID++;
314	my $port = "$NODE#$id";	332	my $port = "$NODE#$id";
315		333
316	if (@_) {	334	rcv $port, shift \|\| \&_kilme;
317	rcv $port, shift;
318	} else {
319	$PORT{$id} = sub { }; # nop
320	}
321		335
322	$port	336	$port
323	}	337	}
324		338
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)	339	=item rcv $local_port, $callback->(@msg)
345		340
346	Replaces the callback on the specified miniport (after converting it to	341	Replaces the default callback on the specified port. There is no way to
347	one if required).	342	remove the default callback: use C<sub { }> to disable it, or better
348		343	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...] => $callback->(@msg), ...
354
355	Register callbacks to be called on matching messages on the given full
356	port (after converting it to one if required) and return the port.
357
358	The callback has to return a true value when its work is done, after
359	which is will be removed, or a false value in which case it will stay
360	registered.
361		344
362	The global C<$SELF> (exported by this module) contains C<$port> while	345	The global C<$SELF> (exported by this module) contains C<$port> while
363	executing the callback.	346	executing the callback. Runtime errors during callback execution will
		347	result in the port being C<kil>ed.
364		348
365	Runtime errors during callback execution will result in the port being	349	The default callback received all messages not matched by a more specific
366	C<kil>ed.	350	C<tag> match.
367		351
368	If the match is an array reference, then it will be matched against the	352	=item rcv $local_port, tag => $callback->(@msg_without_tag), ...
369	first elements of the message, otherwise only the first element is being
370	matched.
371		353
372	Any element in the match that is specified as C<_any_> (a function	354	Register callbacks to be called on messages starting with the given tag on
373	exported by this module) matches any single element of the message.	355	the given port (and return the port), or unregister it (when C<$callback>
		356	is C<$undef>).
374		357
375	While not required, it is highly recommended that the first matching	358	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	359	element (the tag) has been removed. The callback will use the same
377	also the most efficient match (by far).	360	environment as the default callback (see above).
378		361
379	Example: create a port and bind receivers on it in one go.	362	Example: create a port and bind receivers on it in one go.
380		363
381	my $port = rcv port,	364	my $port = rcv port,
382	msg1 => sub { ...; 0 },	365	msg1 => sub { ... },
383	msg2 => sub { ...; 0 },	366	msg2 => sub { ... },
384	;	367	;
385		368
386	Example: create a port, bind receivers and send it in a message elsewhere	369	Example: create a port, bind receivers and send it in a message elsewhere
387	in one go:	370	in one go:
388		371
389	snd $otherport, reply =>	372	snd $otherport, reply =>
390	rcv port,	373	rcv port,
391	msg1 => sub { ...; 0 },	374	msg1 => sub { ... },
392	...	375	...
393	;	376	;
394		377
395	=cut	378	=cut
396		379
…		…
399	my ($noderef, $portid) = split /#/, $port, 2;	382	my ($noderef, $portid) = split /#/, $port, 2;
400		383
401	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}	384	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}
402	or Carp::croak "$port: rcv can only be called on local ports, caught";	385	or Carp::croak "$port: rcv can only be called on local ports, caught";
403		386
404	if (@_ == 1) {	387	while (@_) {
		388	if (ref $_[0]) {
		389	if (my $self = $PORT_DATA{$portid}) {
		390	"AnyEvent::MP::Port" eq ref $self
		391	or Carp::croak "$port: rcv can only be called on message matching ports, caught";
		392
		393	$self->[2] = shift;
		394	} else {
405	my $cb = shift;	395	my $cb = shift;
406	delete $PORT_DATA{$portid};
407	$PORT{$portid} = sub {	396	$PORT{$portid} = sub {
408	local $SELF = $port;	397	local $SELF = $port;
409	eval {	398	eval { &$cb }; _self_die if $@;
410	&$cb	399	};
411	and kil $port;
412	};	400	}
413	_self_die if $@;	401	} elsif (defined $_[0]) {
414	};
415	} else {
416	my $self = $PORT_DATA{$portid} \|\|= do {	402	my $self = $PORT_DATA{$portid} \|\|= do {
417	my $self = bless {	403	my $self = bless [$PORT{$port} \|\| sub { }, { }, $port], "AnyEvent::MP::Port";
418	id => $port,
419	}, "AnyEvent::MP::Port";
420		404
421	$PORT{$portid} = sub {	405	$PORT{$portid} = sub {
422	local $SELF = $port;	406	local $SELF = $port;
423		407
424	eval {
425	for (@{ $self->{rc0}{$_[0]} }) {	408	if (my $cb = $self->[1]{$_[0]}) {
426	$_ && &{$_->[0]}	409	shift;
427	&& undef $_;	410	eval { &$cb }; _self_die if $@;
428	}	411	} else {
429
430	for (@{ $self->{rcv}{$_[0]} }) {
431	$_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1]
432	&& &{$_->[0]}	412	&{ $self->[0] };
433	&& undef $_;
434	}
435
436	for (@{ $self->{any} }) {
437	$_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1]
438	&& &{$_->[0]}
439	&& undef $_;
440	}	413	}
441	};	414	};
442	_self_die if $@;	415
		416	$self
443	};	417	};
444		418
445	$self
446	};
447
448	"AnyEvent::MP::Port" eq ref $self	419	"AnyEvent::MP::Port" eq ref $self
449	or Carp::croak "$port: rcv can only be called on message matching ports, caught";	420	or Carp::croak "$port: rcv can only be called on message matching ports, caught";
450		421
451	while (@_) {
452	my ($match, $cb) = splice @_, 0, 2;	422	my ($tag, $cb) = splice @_, 0, 2;
453		423
454	if (!ref $match) {	424	if (defined $cb) {
455	push @{ $self->{rc0}{$match} }, [$cb];	425	$self->[1]{$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 {	426	} else {
462	push @{ $self->{any} }, [$cb, $match];	427	delete $self->[1]{$tag};
463	}	428	}
464	}	429	}
465	}	430	}
466		431
467	$port	432	$port
…		…
771	convenience functionality.	736	convenience functionality.
772		737
773	This means that AEMP requires a less tightly controlled environment at the	738	This means that AEMP requires a less tightly controlled environment at the
774	cost of longer node references and a slightly higher management overhead.	739	cost of longer node references and a slightly higher management overhead.
775		740
		741	=item Erlang has a "remote ports are like local ports" philosophy, AEMP
		742	uses "local ports are like remote ports".
		743
		744	The failure modes for local ports are quite different (runtime errors
		745	only) then for remote ports - when a local port dies, you I<know> it dies,
		746	when a connection to another node dies, you know nothing about the other
		747	port.
		748
		749	Erlang pretends remote ports are as reliable as local ports, even when
		750	they are not.
		751
		752	AEMP encourages a "treat remote ports differently" philosophy, with local
		753	ports being the special case/exception, where transport errors cannot
		754	occur.
		755
776	=item * Erlang uses processes and a mailbox, AEMP does not queue.	756	=item * Erlang uses processes and a mailbox, AEMP does not queue.
777		757
778	Erlang uses processes that selctively receive messages, and therefore	758	Erlang uses processes that selectively receive messages, and therefore
779	needs a queue. AEMP is event based, queuing messages would serve no useful	759	needs a queue. AEMP is event based, queuing messages would serve no
780	purpose.	760	useful purpose. For the same reason the pattern-matching abilities of
		761	AnyEvent::MP are more limited, as there is little need to be able to
		762	filter messages without dequeing them.
781		763
782	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).	764	(But see L<Coro::MP> for a more Erlang-like process model on top of AEMP).
783		765
784	=item * Erlang sends are synchronous, AEMP sends are asynchronous.	766	=item * Erlang sends are synchronous, AEMP sends are asynchronous.
785		767
786	Sending messages in Erlang is synchronous and blocks the process. AEMP	768	Sending messages in Erlang is synchronous and blocks the process (and
787	sends are immediate, connection establishment is handled in the	769	so does not need a queue that can overflow). AEMP sends are immediate,
788	background.	770	connection establishment is handled in the background.
789		771
790	=item * Erlang can silently lose messages, AEMP cannot.	772	=item * Erlang suffers from silent message loss, AEMP does not.
791		773
792	Erlang makes few guarantees on messages delivery - messages can get lost	774	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,	775	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).	776	and c, and the other side only receives messages a and c).
795		777
…		…
807	eventually be killed - it cannot happen that a node detects a port as dead	789	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.	790	and then later sends messages to it, finding it is still alive.
809		791
810	=item * Erlang can send messages to the wrong port, AEMP does not.	792	=item * Erlang can send messages to the wrong port, AEMP does not.
811		793
812	In Erlang it is quite possible that a node that restarts reuses a process	794	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	795	known to other nodes for a completely different process, causing messages
814	messages destined for that process to end up in an unrelated process.	796	destined for that process to end up in an unrelated process.
815		797
816	AEMP never reuses port IDs, so old messages or old port IDs floating	798	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.	799	around in the network will not be sent to an unrelated port.
818		800
819	=item * Erlang uses unprotected connections, AEMP uses secure	801	=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 1.52 by root, Fri Aug 14 15:13:20 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 1.52 by root, Fri Aug 14 15:13:20 2009 UTC