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

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.1 by root, Thu Jul 30 08:38:50 2009 UTC vs.
Revision 1.22 by root, Tue Aug 4 18:33:30 2009 UTC

…		…
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use AnyEvent::MP;	7	use AnyEvent::MP;
8		8
		9	$NODE # contains this node's noderef
		10	NODE # returns this node's noderef
		11	NODE $port # returns the noderef of the port
		12
		13	snd $port, type => data...;
		14
		15	$SELF # receiving/own port id in rcv callbacks
		16
		17	rcv $port, smartmatch => $cb->($port, @msg);
		18
		19	# examples:
		20	rcv $port2, ping => sub { snd $_[0], "pong"; 0 };
		21	rcv $port1, pong => sub { warn "pong received\n" };
		22	snd $port2, ping => $port1;
		23
		24	# more, smarter, matches (_any_ is exported by this module)
		25	rcv $port, [child_died => $pid] => sub { ...
		26	rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3
		27
9	=head1 DESCRIPTION	28	=head1 DESCRIPTION
10		29
		30	This module (-family) implements a simple message passing framework.
		31
		32	Despite its simplicity, you can securely message other processes running
		33	on the same or other hosts.
		34
		35	At the moment, this module family is severly brokena nd underdocumented,
		36	so do not use. This was uploaded mainly to reserve the CPAN namespace -
		37	stay tuned!
		38
		39	=head1 CONCEPTS
		40
		41	=over 4
		42
		43	=item port
		44
		45	A port is something you can send messages to with the C<snd> function, and
		46	you can register C<rcv> handlers with. All C<rcv> handlers will receive
		47	messages they match, messages will not be queued.
		48
		49	=item port id - C<noderef#portname>
		50
		51	A port id is always the noderef, a hash-mark (C<#>) as separator, followed
		52	by a port name (a printable string of unspecified format).
		53
		54	=item node
		55
		56	A node is a single process containing at least one port - the node
		57	port. You can send messages to node ports to let them create new ports,
		58	among other things.
		59
		60	Initially, nodes are either private (single-process only) or hidden
		61	(connected to a master node only). Only when they epxlicitly "become
		62	public" can you send them messages from unrelated other nodes.
		63
		64	=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>
		65
		66	A noderef is a string that either uniquely identifies a given node (for
		67	private and hidden nodes), or contains a recipe on how to reach a given
		68	node (for public nodes).
		69
		70	=back
		71
		72	=head1 VARIABLES/FUNCTIONS
		73
		74	=over 4
		75
11	=cut	76	=cut
12		77
13	package AnyEvent::MP;	78	package AnyEvent::MP;
14		79
		80	use AnyEvent::MP::Base;
		81
15	use common::sense;	82	use common::sense;
16		83
		84	use Carp ();
		85
17	use AE ();	86	use AE ();
18		87
		88	use base "Exporter";
		89
19	our $VERSION = '0.0';	90	our $VERSION = '0.02';
		91	our @EXPORT = qw(
		92	NODE $NODE *SELF node_of _any_
		93	become_slave become_public
		94	snd rcv mon kil reg psub
		95	port
		96	);
20		97
21	sub nonce($) {	98	our $SELF;
22	my $nonce;
23		99
24	if (open my $fh, "</dev/urandom") {	100	sub _self_die() {
25	sysread $fh, $nonce, $_[0];	101	my $msg = $@;
26	} else {	102	$msg =~ s/\n+$// unless ref $msg;
27	# shit...	103	kil $SELF, die => $msg;
28	our $nonce_init;
29	unless ($nonce_init++) {
30	srand time ^ $$ ^ unpack "%L*", qx"ps -edalf" . qx"ipconfig /all";
31	}
32
33	$nonce = join "", map +(chr rand 256), 1 .. $_[0]
34	}
35
36	$nonce
37	}	104	}
38		105
39	our $DEFAULT_SECRET;	106	=item $thisnode = NODE / $NODE
40		107
41	sub default_secret {	108	The C<NODE> function returns, and the C<$NODE> variable contains
42	unless (defined $DEFAULT_SECRET) {	109	the noderef of the local node. The value is initialised by a call
43	if (open my $fh, "<$ENV{HOME}/.aemp-secret") {	110	to C<become_public> or C<become_slave>, after which all local port
44	sysread $fh, $DEFAULT_SECRET, -s $fh;	111	identifiers become invalid.
		112
		113	=item $noderef = node_of $portid
		114
		115	Extracts and returns the noderef from a portid or a noderef.
		116
		117	=item $SELF
		118
		119	Contains the current port id while executing C<rcv> callbacks or C<psub>
		120	blocks.
		121
		122	=item SELF, %SELF, @SELF...
		123
		124	Due to some quirks in how perl exports variables, it is impossible to
		125	just export C<$SELF>, all the symbols called C<SELF> are exported by this
		126	module, but only C<$SELF> is currently used.
		127
		128	=item snd $portid, type => @data
		129
		130	=item snd $portid, @msg
		131
		132	Send the given message to the given port ID, which can identify either
		133	a local or a remote port, and can be either a string or soemthignt hat
		134	stringifies a sa port ID (such as a port object :).
		135
		136	While the message can be about anything, it is highly recommended to use a
		137	string as first element (a portid, or some word that indicates a request
		138	type etc.).
		139
		140	The message data effectively becomes read-only after a call to this
		141	function: modifying any argument is not allowed and can cause many
		142	problems.
		143
		144	The type of data you can transfer depends on the transport protocol: when
		145	JSON is used, then only strings, numbers and arrays and hashes consisting
		146	of those are allowed (no objects). When Storable is used, then anything
		147	that Storable can serialise and deserialise is allowed, and for the local
		148	node, anything can be passed.
		149
		150	=item kil $portid[, @reason]
		151
		152	Kill the specified port with the given C<@reason>.
		153
		154	If no C<@reason> is specified, then the port is killed "normally" (linked
		155	ports will not be kileld, or even notified).
		156
		157	Otherwise, linked ports get killed with the same reason (second form of
		158	C<mon>, see below).
		159
		160	Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks
		161	will be reported as reason C<< die => $@ >>.
		162
		163	Transport/communication errors are reported as C<< transport_error =>
		164	$message >>.
		165
		166	=item $guard = mon $portid, $cb->(@reason)
		167
		168	=item $guard = mon $portid, $otherport
		169
		170	=item $guard = mon $portid, $otherport, @msg
		171
		172	Monitor the given port and do something when the port is killed.
		173
		174	In the first form, the callback is simply called with any number
		175	of C<@reason> elements (no @reason means that the port was deleted
		176	"normally"). Note also that I<< the callback B<must> never die >>, so use
		177	C<eval> if unsure.
		178
		179	In the second form, the other port will be C<kil>'ed with C<@reason>, iff
		180	a @reason was specified, i.e. on "normal" kils nothing happens, while
		181	under all other conditions, the other port is killed with the same reason.
		182
		183	In the last form, a message of the form C<@msg, @reason> will be C<snd>.
		184
		185	Example: call a given callback when C<$port> is killed.
		186
		187	mon $port, sub { warn "port died because of <@_>\n" };
		188
		189	Example: kill ourselves when C<$port> is killed abnormally.
		190
		191	mon $port, $self;
		192
		193	Example: send us a restart message another C<$port> is killed.
		194
		195	mon $port, $self => "restart";
		196
		197	=cut
		198
		199	sub mon {
		200	my ($noderef, $port, $cb) = ((split /#/, shift, 2), shift);
		201
		202	my $node = $NODE{$noderef} \|\| add_node $noderef;
		203
		204	#TODO: ports must not be references
		205	if (!ref $cb or "AnyEvent::MP::Port" eq ref $cb) {
		206	if (@_) {
		207	# send a kill info message
		208	my (@msg) = ($cb, @_);
		209	$cb = sub { snd @msg, @_ };
45	} else {	210	} else {
46	$DEFAULT_SECRET = nonce 32;	211	# simply kill other port
		212	my $port = $cb;
		213	$cb = sub { kil $port, @_ if @_ };
47	}	214	}
48	}	215	}
49		216
50	$DEFAULT_SECRET	217	$node->monitor ($port, $cb);
		218
		219	defined wantarray
		220	and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }
51	}	221	}
		222
		223	=item $guard = mon_guard $port, $ref, $ref...
		224
		225	Monitors the given C<$port> and keeps the passed references. When the port
		226	is killed, the references will be freed.
		227
		228	Optionally returns a guard that will stop the monitoring.
		229
		230	This function is useful when you create e.g. timers or other watchers and
		231	want to free them when the port gets killed:
		232
		233	$port->rcv (start => sub {
		234	my $timer; $timer = mon_guard $port, AE::timer 1, 1, sub {
		235	undef $timer if 0.9 < rand;
		236	});
		237	});
		238
		239	=cut
		240
		241	sub mon_guard {
		242	my ($port, @refs) = @_;
		243
		244	mon $port, sub { 0 && @refs }
		245	}
		246
		247	=item $local_port = port
		248
		249	Create a new local port object that supports message matching.
		250
		251	=item $portid = port { my @msg = @_; $finished }
		252
		253	Creates a "mini port", that is, a very lightweight port without any
		254	pattern matching behind it, and returns its ID.
		255
		256	The block will be called for every message received on the port. When the
		257	callback returns a true value its job is considered "done" and the port
		258	will be destroyed. Otherwise it will stay alive.
		259
		260	The message will be passed as-is, no extra argument (i.e. no port id) will
		261	be passed to the callback.
		262
		263	If you need the local port id in the callback, this works nicely:
		264
		265	my $port; $port = miniport {
		266	snd $otherport, reply => $port;
		267	};
		268
		269	=cut
		270
		271	sub port(;&) {
		272	my $id = "$UNIQ." . $ID++;
		273	my $port = "$NODE#$id";
		274
		275	if (@_) {
		276	my $cb = shift;
		277	$PORT{$id} = sub {
		278	local $SELF = $port;
		279	eval {
		280	&$cb
		281	and kil $id;
		282	};
		283	_self_die if $@;
		284	};
		285	} else {
		286	my $self = bless {
		287	id => "$NODE#$id",
		288	}, "AnyEvent::MP::Port";
		289
		290	$PORT_DATA{$id} = $self;
		291	$PORT{$id} = sub {
		292	local $SELF = $port;
		293
		294	eval {
		295	for (@{ $self->{rc0}{$_[0]} }) {
		296	$_ && &{$_->[0]}
		297	&& undef $_;
		298	}
		299
		300	for (@{ $self->{rcv}{$_[0]} }) {
		301	$_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1]
		302	&& &{$_->[0]}
		303	&& undef $_;
		304	}
		305
		306	for (@{ $self->{any} }) {
		307	$_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1]
		308	&& &{$_->[0]}
		309	&& undef $_;
		310	}
		311	};
		312	_self_die if $@;
		313	};
		314	}
		315
		316	$port
		317	}
		318
		319	=item reg $portid, $name
		320
		321	Registers the given port under the name C<$name>. If the name already
		322	exists it is replaced.
		323
		324	A port can only be registered under one well known name.
		325
		326	A port automatically becomes unregistered when it is killed.
		327
		328	=cut
		329
		330	sub reg(@) {
		331	my ($portid, $name) = @_;
		332
		333	$REG{$name} = $portid;
		334	}
		335
		336	=item rcv $portid, tagstring => $callback->(@msg), ...
		337
		338	=item rcv $portid, $smartmatch => $callback->(@msg), ...
		339
		340	=item rcv $portid, [$smartmatch...] => $callback->(@msg), ...
		341
		342	Register callbacks to be called on matching messages on the given port.
		343
		344	The callback has to return a true value when its work is done, after
		345	which is will be removed, or a false value in which case it will stay
		346	registered.
		347
		348	The global C<$SELF> (exported by this module) contains C<$portid> while
		349	executing the callback.
		350
		351	Runtime errors wdurign callback execution will result in the port being
		352	C<kil>ed.
		353
		354	If the match is an array reference, then it will be matched against the
		355	first elements of the message, otherwise only the first element is being
		356	matched.
		357
		358	Any element in the match that is specified as C<_any_> (a function
		359	exported by this module) matches any single element of the message.
		360
		361	While not required, it is highly recommended that the first matching
		362	element is a string identifying the message. The one-string-only match is
		363	also the most efficient match (by far).
		364
		365	=cut
		366
		367	sub rcv($@) {
		368	my ($noderef, $port) = split /#/, shift, 2;
		369
		370	($NODE{$noderef} \|\| add_node $noderef) == $NODE{""}
		371	or Carp::croak "$noderef#$port: rcv can only be called on local ports, caught";
		372
		373	my $self = $PORT_DATA{$port}
		374	or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught";
		375
		376	"AnyEvent::MP::Port" eq ref $self
		377	or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught";
		378
		379	while (@_) {
		380	my ($match, $cb) = splice @_, 0, 2;
		381
		382	if (!ref $match) {
		383	push @{ $self->{rc0}{$match} }, [$cb];
		384	} elsif (("ARRAY" eq ref $match && !ref $match->[0])) {
		385	my ($type, @match) = @$match;
		386	@match
		387	? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match]
		388	: push @{ $self->{rc0}{$match->[0]} }, [$cb];
		389	} else {
		390	push @{ $self->{any} }, [$cb, $match];
		391	}
		392	}
		393	}
		394
		395	=item $closure = psub { BLOCK }
		396
		397	Remembers C<$SELF> and creates a closure out of the BLOCK. When the
		398	closure is executed, sets up the environment in the same way as in C<rcv>
		399	callbacks, i.e. runtime errors will cause the port to get C<kil>ed.
		400
		401	This is useful when you register callbacks from C<rcv> callbacks:
		402
		403	rcv delayed_reply => sub {
		404	my ($delay, @reply) = @_;
		405	my $timer = AE::timer $delay, 0, psub {
		406	snd @reply, $SELF;
		407	};
		408	};
		409
		410	=cut
		411
		412	sub psub(&) {
		413	my $cb = shift;
		414
		415	my $port = $SELF
		416	or Carp::croak "psub can only be called from within rcv or psub callbacks, not";
		417
		418	sub {
		419	local $SELF = $port;
		420
		421	if (wantarray) {
		422	my @res = eval { &$cb };
		423	_self_die if $@;
		424	@res
		425	} else {
		426	my $res = eval { &$cb };
		427	_self_die if $@;
		428	$res
		429	}
		430	}
		431	}
		432
		433	=back
		434
		435	=head1 FUNCTIONS FOR NODES
		436
		437	=over 4
		438
		439	=item become_public endpoint...
		440
		441	Tells the node to become a public node, i.e. reachable from other nodes.
		442
		443	If no arguments are given, or the first argument is C<undef>, then
		444	AnyEvent::MP tries to bind on port C<4040> on all IP addresses that the
		445	local nodename resolves to.
		446
		447	Otherwise the first argument must be an array-reference with transport
		448	endpoints ("ip:port", "hostname:port") or port numbers (in which case the
		449	local nodename is used as hostname). The endpoints are all resolved and
		450	will become the node reference.
		451
		452	=cut
		453
		454	=back
		455
		456	=head1 NODE MESSAGES
		457
		458	Nodes understand the following messages sent to them. Many of them take
		459	arguments called C<@reply>, which will simply be used to compose a reply
		460	message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and
		461	the remaining arguments are simply the message data.
		462
		463	=over 4
		464
		465	=cut
		466
		467	=item lookup => $name, @reply
		468
		469	Replies with the port ID of the specified well-known port, or C<undef>.
		470
		471	=item devnull => ...
		472
		473	Generic data sink/CPU heat conversion.
		474
		475	=item relay => $port, @msg
		476
		477	Simply forwards the message to the given port.
		478
		479	=item eval => $string[ @reply]
		480
		481	Evaluates the given string. If C<@reply> is given, then a message of the
		482	form C<@reply, $@, @evalres> is sent.
		483
		484	Example: crash another node.
		485
		486	snd $othernode, eval => "exit";
		487
		488	=item time => @reply
		489
		490	Replies the the current node time to C<@reply>.
		491
		492	Example: tell the current node to send the current time to C<$myport> in a
		493	C<timereply> message.
		494
		495	snd $NODE, time => $myport, timereply => 1, 2;
		496	# => snd $myport, timereply => 1, 2, <time>
		497
		498	=back
52		499
53	=head1 SEE ALSO	500	=head1 SEE ALSO
54		501
55	L<AnyEvent>.	502	L<AnyEvent>.
56		503

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Comparing AnyEvent-MP/MP.pm (file contents): Revision 1.1 by root, Thu Jul 30 08:38:50 2009 UTC vs. Revision 1.22 by root, Tue Aug 4 18:33:30 2009 UTC

Diff Legend

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.1 by root, Thu Jul 30 08:38:50 2009 UTC vs.
Revision 1.22 by root, Tue Aug 4 18:33:30 2009 UTC