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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.35 by root, Thu Aug 6 10:21:48 2009 UTC vs.
Revision 1.39 by root, Fri Aug 7 23:21:48 2009 UTC

…		…
8		8
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
		14
		15	# ports are message endpoints
		16
		17	# sending messages
13	snd $port, type => data...;	18	snd $port, type => data...;
		19	snd $port, @msg;
		20	snd @msg_with_first_element_being_a_port;
14		21
15	$SELF # receiving/own port id in rcv callbacks	22	# miniports
		23	my $miniport = port { my @msg = @_; 0 };
16		24
		25	# full ports
		26	my $port = port;
17	rcv $port, smartmatch => $cb->($port, @msg);	27	rcv $port, smartmatch => $cb->(@msg);
18
19	# examples:
20	rcv $port2, ping => sub { snd $_[0], "pong"; 0 };	28	rcv $port, ping => sub { snd $_[0], "pong"; 0 };
21	rcv $port1, pong => sub { warn "pong received\n" };	29	rcv $port, pong => sub { warn "pong received\n"; 0 };
22	snd $port2, ping => $port1;	30
		31	# remote ports
		32	my $port = spawn $node, $initfunc, @initdata;
23		33
24	# more, smarter, matches (_any_ is exported by this module)	34	# more, smarter, matches (_any_ is exported by this module)
25	rcv $port, [child_died => $pid] => sub { ...	35	rcv $port, [child_died => $pid] => sub { ...
26	rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3	36	rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3
27
28	# linking two ports, so they both crash together
29	lnk $port1, $port2;
30		37
31	# monitoring	38	# monitoring
32	mon $port, $cb->(@msg) # callback is invoked on death	39	mon $port, $cb->(@msg) # callback is invoked on death
33	mon $port, $otherport # kill otherport on abnormal death	40	mon $port, $otherport # kill otherport on abnormal death
34	mon $port, $otherport, @msg # send message on death	41	mon $port, $otherport, @msg # send message on death
…		…
112		119
113	our $VERSION = '0.1';	120	our $VERSION = '0.1';
114	our @EXPORT = qw(	121	our @EXPORT = qw(
115	NODE $NODE *SELF node_of _any_	122	NODE $NODE *SELF node_of _any_
116	resolve_node initialise_node	123	resolve_node initialise_node
117	snd rcv mon kil reg psub	124	snd rcv mon kil reg psub spawn
118	port	125	port
119	);	126	);
120		127
121	our $SELF;	128	our $SELF;
122		129
…		…
305	$port	312	$port
306	}	313	}
307		314
308	=item reg $port, $name	315	=item reg $port, $name
309		316
310	Registers the given port under the name C<$name>. If the name already	317	=item reg $name
311	exists it is replaced.	318
		319	Registers the given port (or C<$SELF><<< if missing) under the name
		320	C<$name>. If the name already exists it is replaced.
312		321
313	A port can only be registered under one well known name.	322	A port can only be registered under one well known name.
314		323
315	A port automatically becomes unregistered when it is killed.	324	A port automatically becomes unregistered when it is killed.
316		325
317	=cut	326	=cut
318		327
319	sub reg(@) {	328	sub reg(@) {
320	my ($port, $name) = @_;	329	my $port = @_ > 1 ? shift : $SELF \|\| Carp::croak 'reg: called with one argument only, but $SELF not set,';
321		330
322	$REG{$name} = $port;	331	$REG{$_[0]} = $port;
323	}	332	}
324		333
325	=item rcv $port, $callback->(@msg)	334	=item rcv $port, $callback->(@msg)
326		335
327	Replaces the callback on the specified miniport (after converting it to	336	Replaces the callback on the specified miniport (after converting it to
…		…
332	=item rcv $port, $smartmatch => $callback->(@msg), ...	341	=item rcv $port, $smartmatch => $callback->(@msg), ...
333		342
334	=item rcv $port, [$smartmatch...] => $callback->(@msg), ...	343	=item rcv $port, [$smartmatch...] => $callback->(@msg), ...
335		344
336	Register callbacks to be called on matching messages on the given full	345	Register callbacks to be called on matching messages on the given full
337	port (after converting it to one if required).	346	port (after converting it to one if required) and return the port.
338		347
339	The callback has to return a true value when its work is done, after	348	The callback has to return a true value when its work is done, after
340	which is will be removed, or a false value in which case it will stay	349	which is will be removed, or a false value in which case it will stay
341	registered.	350	registered.
342		351
343	The global C<$SELF> (exported by this module) contains C<$port> while	352	The global C<$SELF> (exported by this module) contains C<$port> while
344	executing the callback.	353	executing the callback.
345		354
346	Runtime errors wdurign callback execution will result in the port being	355	Runtime errors during callback execution will result in the port being
347	C<kil>ed.	356	C<kil>ed.
348		357
349	If the match is an array reference, then it will be matched against the	358	If the match is an array reference, then it will be matched against the
350	first elements of the message, otherwise only the first element is being	359	first elements of the message, otherwise only the first element is being
351	matched.	360	matched.
…		…
354	exported by this module) matches any single element of the message.	363	exported by this module) matches any single element of the message.
355		364
356	While not required, it is highly recommended that the first matching	365	While not required, it is highly recommended that the first matching
357	element is a string identifying the message. The one-string-only match is	366	element is a string identifying the message. The one-string-only match is
358	also the most efficient match (by far).	367	also the most efficient match (by far).
		368
		369	Example: create a port and bind receivers on it in one go.
		370
		371	my $port = rcv port,
		372	msg1 => sub { ...; 0 },
		373	msg2 => sub { ...; 0 },
		374	;
		375
		376	Example: create a port, bind receivers and send it in a message elsewhere
		377	in one go:
		378
		379	snd $otherport, reply =>
		380	rcv port,
		381	msg1 => sub { ...; 0 },
		382	...
		383	;
359		384
360	=cut	385	=cut
361		386
362	sub rcv($@) {	387	sub rcv($@) {
363	my $port = shift;	388	my $port = shift;
…		…
470	}	495	}
471	}	496	}
472		497
473	=item $guard = mon $port, $cb->(@reason)	498	=item $guard = mon $port, $cb->(@reason)
474		499
475	=item $guard = mon $port, $otherport	500	=item $guard = mon $port, $rcvport
476		501
		502	=item $guard = mon $port
		503
477	=item $guard = mon $port, $otherport, @msg	504	=item $guard = mon $port, $rcvport, @msg
478		505
479	Monitor the given port and do something when the port is killed.	506	Monitor the given port and do something when the port is killed, and
		507	optionally return a guard that can be used to stop monitoring again.
480		508
481	In the first form, the callback is simply called with any number	509	In the first form (callback), the callback is simply called with any
482	of C<@reason> elements (no @reason means that the port was deleted	510	number of C<@reason> elements (no @reason means that the port was deleted
483	"normally"). Note also that I<< the callback B<must> never die >>, so use	511	"normally"). Note also that I<< the callback B<must> never die >>, so use
484	C<eval> if unsure.	512	C<eval> if unsure.
485		513
486	In the second form, the other port will be C<kil>'ed with C<@reason>, iff	514	In the second form (another port given), the other port (C<$rcvport)
487	a @reason was specified, i.e. on "normal" kils nothing happens, while	515	will be C<kil>'ed with C<@reason>, iff a @reason was specified, i.e. on
488	under all other conditions, the other port is killed with the same reason.	516	"normal" kils nothing happens, while under all other conditions, the other
		517	port is killed with the same reason.
489		518
		519	The third form (kill self) is the same as the second form, except that
		520	C<$rvport> defaults to C<$SELF>.
		521
490	In the last form, a message of the form C<@msg, @reason> will be C<snd>.	522	In the last form (message), a message of the form C<@msg, @reason> will be
		523	C<snd>.
		524
		525	As a rule of thumb, monitoring requests should always monitor a port from
		526	a local port (or callback). The reason is that kill messages might get
		527	lost, just like any other message. Another less obvious reason is that
		528	even monitoring requests can get lost (for exmaple, when the connection
		529	to the other node goes down permanently). When monitoring a port locally
		530	these problems do not exist.
491		531
492	Example: call a given callback when C<$port> is killed.	532	Example: call a given callback when C<$port> is killed.
493		533
494	mon $port, sub { warn "port died because of <@_>\n" };	534	mon $port, sub { warn "port died because of <@_>\n" };
495		535
496	Example: kill ourselves when C<$port> is killed abnormally.	536	Example: kill ourselves when C<$port> is killed abnormally.
497		537
498	mon $port, $self;	538	mon $port;
499		539
500	Example: send us a restart message another C<$port> is killed.	540	Example: send us a restart message when another C<$port> is killed.
501		541
502	mon $port, $self => "restart";	542	mon $port, $self => "restart";
503		543
504	=cut	544	=cut
505		545
506	sub mon {	546	sub mon {
507	my ($noderef, $port) = split /#/, shift, 2;	547	my ($noderef, $port) = split /#/, shift, 2;
508		548
509	my $node = $NODE{$noderef} \|\| add_node $noderef;	549	my $node = $NODE{$noderef} \|\| add_node $noderef;
510		550
511	my $cb = shift;	551	my $cb = @_ ? $_[0] : $SELF \|\| Carp::croak 'mon: called with one argument only, but $SELF not set,';
512		552
513	unless (ref $cb) {	553	unless (ref $cb) {
514	if (@_) {	554	if (@_) {
515	# send a kill info message	555	# send a kill info message
516	my (@msg) = ($cb, @_);	556	my (@msg) = @_;
517	$cb = sub { snd @msg, @_ };	557	$cb = sub { snd @msg, @_ };
518	} else {	558	} else {
519	# simply kill other port	559	# simply kill other port
520	my $port = $cb;	560	my $port = $cb;
521	$cb = sub { kil $port, @_ if @_ };	561	$cb = sub { kil $port, @_ if @_ };
…		…
547	=cut	587	=cut
548		588
549	sub mon_guard {	589	sub mon_guard {
550	my ($port, @refs) = @_;	590	my ($port, @refs) = @_;
551		591
		592	#TODO: mon-less form?
		593
552	mon $port, sub { 0 && @refs }	594	mon $port, sub { 0 && @refs }
553	}	595	}
554		596
555	=item lnk $port1, $port2
556
557	Link two ports. This is simply a shorthand for:
558
559	mon $port1, $port2;
560	mon $port2, $port1;
561
562	It means that if either one is killed abnormally, the other one gets
563	killed as well.
564
565	=item kil $port[, @reason]	597	=item kil $port[, @reason]
566		598
567	Kill the specified port with the given C<@reason>.	599	Kill the specified port with the given C<@reason>.
568		600
569	If no C<@reason> is specified, then the port is killed "normally" (linked	601	If no C<@reason> is specified, then the port is killed "normally" (linked
…		…
575	Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks	607	Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks
576	will be reported as reason C<< die => $@ >>.	608	will be reported as reason C<< die => $@ >>.
577		609
578	Transport/communication errors are reported as C<< transport_error =>	610	Transport/communication errors are reported as C<< transport_error =>
579	$message >>.	611	$message >>.
		612
		613	=cut
		614
		615	=item $port = spawn $node, $initfunc[, @initdata]
		616
		617	Creates a port on the node C<$node> (which can also be a port ID, in which
		618	case it's the node where that port resides).
		619
		620	The port ID of the newly created port is return immediately, and it is
		621	permissible to immediately start sending messages or monitor the port.
		622
		623	After the port has been created, the init function is
		624	called. This function must be a fully-qualified function name
		625	(e.g. C<MyApp::Chat::Server::init>).
		626
		627	If the function doesn't exist, then the node tries to C<require>
		628	the package, then the package above the package and so on (e.g.
		629	C<MyApp::Chat::Server>, C<MyApp::Chat>, C<MyApp>) until the function
		630	exists or it runs out of package names.
		631
		632	The init function is then called with the newly-created port as context
		633	object (C<$SELF>) and the C<@initdata> values as arguments.
		634
		635	A common idiom is to pass your own port, monitor the spawned port, and
		636	in the init function, monitor the original port. This two-way monitoring
		637	ensures that both ports get cleaned up when there is a problem.
		638
		639	Example: spawn a chat server port on C<$othernode>.
		640
		641	# this node, executed from within a port context:
		642	my $server = spawn $othernode, "MyApp::Chat::Server::connect", $SELF;
		643	mon $server;
		644
		645	# init function on C<$othernode>
		646	sub connect {
		647	my ($srcport) = @_;
		648
		649	mon $srcport;
		650
		651	rcv $SELF, sub {
		652	...
		653	};
		654	}
		655
		656	=cut
		657
		658	sub _spawn {
		659	my $port = shift;
		660	my $init = shift;
		661
		662	local $SELF = "$NODE#$port";
		663	eval {
		664	&{ load_func $init }
		665	};
		666	_self_die if $@;
		667	}
		668
		669	sub spawn(@) {
		670	my ($noderef, undef) = split /#/, shift, 2;
		671
		672	my $id = "$RUNIQ." . $ID++;
		673
		674	$_[0] =~ /::/
		675	or Carp::croak "spawn init function must be a fully-qualified name, caught";
		676
		677	($NODE{$noderef} \|\| add_node $noderef)
		678	->send (["", "AnyEvent::MP::_spawn" => $id, @_]);
		679
		680	"$noderef#$id"
		681	}
580		682
581	=back	683	=back
582		684
583	=head1 NODE MESSAGES	685	=head1 NODE MESSAGES
584		686
…		…
717	or I<none>, there is no in-between, so monitoring single processes is	819	or I<none>, there is no in-between, so monitoring single processes is
718	difficult to implement. Monitoring in AEMP is more flexible than in	820	difficult to implement. Monitoring in AEMP is more flexible than in
719	Erlang, as one can choose between automatic kill, exit message or callback	821	Erlang, as one can choose between automatic kill, exit message or callback
720	on a per-process basis.	822	on a per-process basis.
721		823
722	=item * Erlang has different semantics for monitoring and linking, AEMP has the same.	824	=item * Erlang tries to hide remote/local connections, AEMP does not.
723		825
724	Monitoring in Erlang is not an indicator of process death/crashes,	826	Monitoring in Erlang is not an indicator of process death/crashes,
725	as linking is (except linking is unreliable in Erlang). In AEMP, the	827	as linking is (except linking is unreliable in Erlang).
726	semantics of monitoring and linking are identical, linking is simply	828
727	two-way monitoring with automatic kill.	829	In AEMP, you don't "look up" registered port names or send to named ports
		830	that might or might not be persistent. Instead, you normally spawn a port
		831	on the remote node. The init function monitors the you, and you monitor
		832	the remote port. Since both monitors are local to the node, they are much
		833	more reliable.
		834
		835	This also saves round-trips and avoids sending messages to the wrong port
		836	(hard to do in Erlang).
728		837
729	=back	838	=back
730		839
731	=head1 SEE ALSO	840	=head1 SEE ALSO
732		841

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.35 by root, Thu Aug 6 10:21:48 2009 UTC vs. Revision 1.39 by root, Fri Aug 7 23:21:48 2009 UTC

Diff Legend

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.35 by root, Thu Aug 6 10:21:48 2009 UTC vs.
Revision 1.39 by root, Fri Aug 7 23:21:48 2009 UTC