AnyEvent-MP/MP.pm

=head1 NAME

AnyEvent::MP - multi-processing/message-passing framework

=head1 SYNOPSIS

   use AnyEvent::MP;

   $NODE      # contains this node's noderef
   NODE       # returns this node's noderef
   NODE $port # returns the noderef of the port

   snd $port, type => data...;

   $SELF      # receiving/own port id in rcv callbacks

   rcv $port, smartmatch => $cb->($port, @msg);

   # examples:
   rcv $port2, ping => sub { snd $_[0], "pong"; 0 };
   rcv $port1, pong => sub { warn "pong received\n" };
   snd $port2, ping => $port1;

   # more, smarter, matches (_any_ is exported by this module)
   rcv $port, [child_died => $pid] => sub { ...
   rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3

=head1 DESCRIPTION

This module (-family) implements a simple message passing framework.

Despite its simplicity, you can securely message other processes running
on the same or other hosts.

At the moment, this module family is severly brokena nd underdocumented,
so do not use. This was uploaded mainly to reserve the CPAN namespace -
stay tuned!

=head1 CONCEPTS

=over 4

=item port

A port is something you can send messages to with the C<snd> function, and
you can register C<rcv> handlers with. All C<rcv> handlers will receive
messages they match, messages will not be queued.

=item port id - C<noderef#portname>

A port id is always the noderef, a hash-mark (C<#>) as separator, followed
by a port name (a printable string of unspecified format).

=item node

A node is a single process containing at least one port - the node
port. You can send messages to node ports to let them create new ports,
among other things.

Initially, nodes are either private (single-process only) or hidden
(connected to a master node only). Only when they epxlicitly "become
public" can you send them messages from unrelated other nodes.

=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>

A noderef is a string that either uniquely identifies a given node (for
private and hidden nodes), or contains a recipe on how to reach a given
node (for public nodes).

=back

=head1 VARIABLES/FUNCTIONS

=over 4

=cut

package AnyEvent::MP;

use AnyEvent::MP::Base;

use common::sense;

use Carp ();

use AE ();

use base "Exporter";

our $VERSION = '0.02';
our @EXPORT = qw(
   NODE $NODE *SELF node_of _any_
   become_slave become_public
   snd rcv mon kil reg psub
   port
);

our $SELF;

sub _self_die() {
   my $msg = $@;
   $msg =~ s/\n+$// unless ref $msg;
   kil $SELF, die => $msg;
}

=item $thisnode = NODE / $NODE

The C<NODE> function returns, and the C<$NODE> variable contains
the noderef of the local node. The value is initialised by a call
to C<become_public> or C<become_slave>, after which all local port
identifiers become invalid.

=item $noderef = node_of $portid

Extracts and returns the noderef from a portid or a noderef.

=item $SELF

Contains the current port id while executing C<rcv> callbacks or C<psub>
blocks.

=item SELF, %SELF, @SELF...

Due to some quirks in how perl exports variables, it is impossible to
just export C<$SELF>, all the symbols called C<SELF> are exported by this
module, but only C<$SELF> is currently used.

=item snd $portid, type => @data

=item snd $portid, @msg

Send the given message to the given port ID, which can identify either
a local or a remote port, and can be either a string or soemthignt hat
stringifies a sa port ID (such as a port object :).

While the message can be about anything, it is highly recommended to use a
string as first element (a portid, or some word that indicates a request
type etc.).

The message data effectively becomes read-only after a call to this
function: modifying any argument is not allowed and can cause many
problems.

The type of data you can transfer depends on the transport protocol: when
JSON is used, then only strings, numbers and arrays and hashes consisting
of those are allowed (no objects). When Storable is used, then anything
that Storable can serialise and deserialise is allowed, and for the local
node, anything can be passed.

=item kil $portid[, @reason]

Kill the specified port with the given C<@reason>.

If no C<@reason> is specified, then the port is killed "normally" (linked
ports will not be kileld, or even notified).

Otherwise, linked ports get killed with the same reason (second form of
C<mon>, see below).

Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks
will be reported as reason C<< die => $@ >>.

Transport/communication errors are reported as C<< transport_error =>
$message >>.

=item $guard = mon $portid, $cb->(@reason)

=item $guard = mon $portid, $otherport

=item $guard = mon $portid, $otherport, @msg

Monitor the given port and do something when the port is killed.

In the first form, the callback is simply called with any number
of C<@reason> elements (no @reason means that the port was deleted
"normally"). Note also that I<< the callback B<must> never die >>, so use
C<eval> if unsure.

In the second form, the other port will be C<kil>'ed with C<@reason>, iff
a @reason was specified, i.e. on "normal" kils nothing happens, while
under all other conditions, the other port is killed with the same reason.

In the last form, a message of the form C<@msg, @reason> will be C<snd>.

Example: call a given callback when C<$port> is killed.

   mon $port, sub { warn "port died because of <@_>\n" };

Example: kill ourselves when C<$port> is killed abnormally.

   mon $port, $self;

Example: send us a restart message another C<$port> is killed.

   mon $port, $self => "restart";

=cut

sub mon {
   my ($noderef, $port, $cb) = ((split /#/, shift, 2), shift);

   my $node = $NODE{$noderef} || add_node $noderef;

   #TODO: ports must not be references
   if (!ref $cb or "AnyEvent::MP::Port" eq ref $cb) {
      if (@_) {
         # send a kill info message
         my (@msg) = ($cb, @_);
         $cb = sub { snd @msg, @_ };
      } else {
         # simply kill other port
         my $port = $cb;
         $cb = sub { kil $port, @_ if @_ };
      }
   }

   $node->monitor ($port, $cb);

   defined wantarray
      and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }
}

=item $guard = mon_guard $port, $ref, $ref...

Monitors the given C<$port> and keeps the passed references. When the port
is killed, the references will be freed.

Optionally returns a guard that will stop the monitoring.

This function is useful when you create e.g. timers or other watchers and
want to free them when the port gets killed:

  $port->rcv (start => sub {
     my $timer; $timer = mon_guard $port, AE::timer 1, 1, sub {
        undef $timer if 0.9 < rand;
     });
  });

=cut

sub mon_guard {
   my ($port, @refs) = @_;

   mon $port, sub { 0 && @refs }
}

=item $local_port = port

Create a new local port object that supports message matching.

=item $portid = port { my @msg = @_; $finished }

Creates a "mini port", that is, a very lightweight port without any
pattern matching behind it, and returns its ID.

The block will be called for every message received on the port. When the
callback returns a true value its job is considered "done" and the port
will be destroyed. Otherwise it will stay alive.

The message will be passed as-is, no extra argument (i.e. no port id) will
be passed to the callback.

If you need the local port id in the callback, this works nicely:

   my $port; $port = miniport {
      snd $otherport, reply => $port;
   };

=cut

sub port(;&) {
   my $id = "$UNIQ." . $ID++;
   my $port = "$NODE#$id";

   if (@_) {
      my $cb = shift;
      $PORT{$id} = sub {
         local $SELF = $port;
         eval {
            &$cb
               and kil $id;
         };
         _self_die if $@;
      };
   } else {
      my $self = bless {
         id    => "$NODE#$id",
      }, "AnyEvent::MP::Port";

      $PORT_DATA{$id} = $self;
      $PORT{$id} = sub {
         local $SELF = $port;

         eval {
            for (@{ $self->{rc0}{$_[0]} }) {
               $_ && &{$_->[0]}
                  && undef $_;
            }

            for (@{ $self->{rcv}{$_[0]} }) {
               $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1]
                  && &{$_->[0]}
                  && undef $_;
            }

            for (@{ $self->{any} }) {
               $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1]
                  && &{$_->[0]}
                  && undef $_;
            }
         };
         _self_die if $@;
      };
   }

   $port
}

=item reg $portid, $name

Registers the given port under the name C<$name>. If the name already
exists it is replaced.

A port can only be registered under one well known name.

A port automatically becomes unregistered when it is killed.

=cut

sub reg(@) {
   my ($portid, $name) = @_;

   $REG{$name} = $portid;
}

=item rcv $portid, tagstring        => $callback->(@msg), ...

=item rcv $portid, $smartmatch      => $callback->(@msg), ...

=item rcv $portid, [$smartmatch...] => $callback->(@msg), ...

Register callbacks to be called on matching messages on the given port.

The callback has to return a true value when its work is done, after
which is will be removed, or a false value in which case it will stay
registered.

The global C<$SELF> (exported by this module) contains C<$portid> while
executing the callback.

Runtime errors wdurign callback execution will result in the port being
C<kil>ed.

If the match is an array reference, then it will be matched against the
first elements of the message, otherwise only the first element is being
matched.

Any element in the match that is specified as C<_any_> (a function
exported by this module) matches any single element of the message.

While not required, it is highly recommended that the first matching
element is a string identifying the message. The one-string-only match is
also the most efficient match (by far).

=cut

sub rcv($@) {
   my ($noderef, $port) = split /#/, shift, 2;

   ($NODE{$noderef} || add_node $noderef) == $NODE{""}
      or Carp::croak "$noderef#$port: rcv can only be called on local ports, caught";

   my $self = $PORT_DATA{$port}
      or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught";

   "AnyEvent::MP::Port" eq ref $self
      or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught";

   while (@_) {
      my ($match, $cb) = splice @_, 0, 2;

      if (!ref $match) {
         push @{ $self->{rc0}{$match}      }, [$cb];
      } elsif (("ARRAY" eq ref $match && !ref $match->[0])) {
         my ($type, @match) = @$match;
         @match
            ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match]
            : push @{ $self->{rc0}{$match->[0]} }, [$cb];
      } else {
         push @{ $self->{any}              }, [$cb, $match];
      }
   }
}

=item $closure = psub { BLOCK }

Remembers C<$SELF> and creates a closure out of the BLOCK. When the
closure is executed, sets up the environment in the same way as in C<rcv>
callbacks, i.e. runtime errors will cause the port to get C<kil>ed.

This is useful when you register callbacks from C<rcv> callbacks:

   rcv delayed_reply => sub {
      my ($delay, @reply) = @_;
      my $timer = AE::timer $delay, 0, psub {
         snd @reply, $SELF;
      };
   };

=cut

sub psub(&) {
   my $cb = shift;

   my $port = $SELF
      or Carp::croak "psub can only be called from within rcv or psub callbacks, not";

   sub {
      local $SELF = $port;

      if (wantarray) {
         my @res = eval { &$cb };
         _self_die if $@;
         @res
      } else {
         my $res = eval { &$cb };
         _self_die if $@;
         $res
      }
   }
}

=back

=head1 FUNCTIONS FOR NODES

=over 4

=item become_public endpoint...

Tells the node to become a public node, i.e. reachable from other nodes.

If no arguments are given, or the first argument is C<undef>, then
AnyEvent::MP tries to bind on port C<4040> on all IP addresses that the
local nodename resolves to.

Otherwise the first argument must be an array-reference with transport
endpoints ("ip:port", "hostname:port") or port numbers (in which case the
local nodename is used as hostname). The endpoints are all resolved and
will become the node reference.

=cut

=back

=head1 NODE MESSAGES

Nodes understand the following messages sent to them. Many of them take
arguments called C<@reply>, which will simply be used to compose a reply
message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and
the remaining arguments are simply the message data.

=over 4

=cut

=item lookup => $name, @reply

Replies with the port ID of the specified well-known port, or C<undef>.

=item devnull => ...

Generic data sink/CPU heat conversion.

=item relay => $port, @msg

Simply forwards the message to the given port.

=item eval => $string[ @reply]

Evaluates the given string. If C<@reply> is given, then a message of the
form C<@reply, $@, @evalres> is sent.

Example: crash another node.

   snd $othernode, eval => "exit";

=item time => @reply

Replies the the current node time to C<@reply>.

Example: tell the current node to send the current time to C<$myport> in a
C<timereply> message.

   snd $NODE, time => $myport, timereply => 1, 2;
   # => snd $myport, timereply => 1, 2, <time>

=back

=head1 SEE ALSO

L<AnyEvent>.

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

1

Revision:	1.22
Committed:	Tue Aug 4 18:33:30 2009 UTC (14 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.21:	+198 -116 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3			AnyEvent::MP - multi-processing/message-passing framework
4
5			=head1 SYNOPSIS
6
7			use AnyEvent::MP;
8
9	root	1.22	$NODE # contains this node's noderef
10			NODE # returns this node's noderef
11			NODE $port # returns the noderef of the port
12	root	1.2
13			snd $port, type => data...;
14
15	root	1.22	$SELF # receiving/own port id in rcv callbacks
16
17	root	1.2	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
28	root	1.1	=head1 DESCRIPTION
29
30	root	1.2	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	root	1.6	At the moment, this module family is severly brokena nd underdocumented,
36	root	1.21	so do not use. This was uploaded mainly to reserve the CPAN namespace -
37	root	1.6	stay tuned!
38
39	root	1.2	=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	root	1.3	=item port id - C<noderef#portname>
50	root	1.2
51	root	1.3	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	root	1.2
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	root	1.3	(connected to a master node only). Only when they epxlicitly "become
62			public" can you send them messages from unrelated other nodes.
63	root	1.2
64	root	1.5	=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>
65	root	1.2
66	root	1.3	A noderef is a string that either uniquely identifies a given node (for
67	root	1.2	private and hidden nodes), or contains a recipe on how to reach a given
68			node (for public nodes).
69
70			=back
71
72	root	1.3	=head1 VARIABLES/FUNCTIONS
73	root	1.2
74			=over 4
75
76	root	1.1	=cut
77
78			package AnyEvent::MP;
79
80	root	1.8	use AnyEvent::MP::Base;
81	root	1.2
82	root	1.1	use common::sense;
83
84	root	1.2	use Carp ();
85
86	root	1.1	use AE ();
87
88	root	1.2	use base "Exporter";
89
90	root	1.9	our $VERSION = '0.02';
91	root	1.8	our @EXPORT = qw(
92	root	1.22	NODE $NODE *SELF node_of _any_
93	root	1.8	become_slave become_public
94	root	1.22	snd rcv mon kil reg psub
95			port
96	root	1.8	);
97	root	1.2
98	root	1.22	our $SELF;
99
100			sub _self_die() {
101			my $msg = $@;
102			$msg =~ s/\n+$// unless ref $msg;
103			kil $SELF, die => $msg;
104			}
105
106			=item $thisnode = NODE / $NODE
107
108			The C<NODE> function returns, and the C<$NODE> variable contains
109			the noderef of the local node. The value is initialised by a call
110			to C<become_public> or C<become_slave>, after which all local port
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 $SELF
118
119			Contains the current port id while executing C<rcv> callbacks or C<psub>
120			blocks.
121	root	1.3
122	root	1.22	=item SELF, %SELF, @SELF...
123
124			Due to some quirks in how perl exports variables, it is impossible to
125			just export C<$SELF>, all the symbols called C<SELF> are exported by this
126			module, but only C<$SELF> is currently used.
127	root	1.3
128			=item snd $portid, type => @data
129
130			=item snd $portid, @msg
131
132	root	1.8	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	root	1.3
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	root	1.22	=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	root	1.18
168	root	1.21	=item $guard = mon $portid, $otherport
169
170			=item $guard = mon $portid, $otherport, @msg
171
172	root	1.22	Monitor the given port and do something when the port is killed.
173
174			In the first form, the callback is simply called with any number
175			of C<@reason> elements (no @reason means that the port was deleted
176			"normally"). Note also that I<< the callback B<must> never die >>, so use
177			C<eval> if unsure.
178
179			In the second form, the other port will be C<kil>'ed with C<@reason>, iff
180			a @reason was specified, i.e. on "normal" kils nothing happens, while
181			under all other conditions, the other port is killed with the same reason.
182	root	1.20
183	root	1.22	In the last form, a message of the form C<@msg, @reason> will be C<snd>.
184
185			Example: call a given callback when C<$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, $self => "restart";
196	root	1.18
197			=cut
198
199			sub mon {
200	root	1.21	my ($noderef, $port, $cb) = ((split /#/, shift, 2), shift);
201	root	1.18
202	root	1.22	my $node = $NODE{$noderef} \|\| add_node $noderef;
203	root	1.18
204	root	1.21	#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, @_ };
210			} else {
211			# simply kill other port
212			my $port = $cb;
213	root	1.22	$cb = sub { kil $port, @_ if @_ };
214	root	1.21	}
215			}
216	root	1.18
217			$node->monitor ($port, $cb);
218
219			defined wantarray
220			and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }
221			}
222
223	root	1.21	=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	root	1.22	=item $local_port = port
248	root	1.2
249	root	1.22	Create a new local port object that supports message matching.
250	root	1.3
251	root	1.22	=item $portid = port { my @msg = @_; $finished }
252	root	1.10
253	root	1.15	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	root	1.17	The message will be passed as-is, no extra argument (i.e. no port id) will
261	root	1.15	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	root	1.10
269			=cut
270
271	root	1.22	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	root	1.10
316	root	1.22	$port
317	root	1.10	}
318
319	root	1.22	=item reg $portid, $name
320	root	1.8
321	root	1.22	Registers the given port under the name C<$name>. If the name already
322			exists it is replaced.
323	root	1.8
324	root	1.22	A port can only be registered under one well known name.
325	root	1.8
326	root	1.22	A port automatically becomes unregistered when it is killed.
327	root	1.8
328			=cut
329
330	root	1.22	sub reg(@) {
331			my ($portid, $name) = @_;
332	root	1.8
333	root	1.22	$REG{$name} = $portid;
334			}
335	root	1.18
336	root	1.22	=item rcv $portid, tagstring => $callback->(@msg), ...
337	root	1.3
338	root	1.22	=item rcv $portid, $smartmatch => $callback->(@msg), ...
339	root	1.3
340	root	1.22	=item rcv $portid, [$smartmatch...] => $callback->(@msg), ...
341	root	1.3
342	root	1.22	Register callbacks to be called on matching messages on the given port.
343	root	1.3
344			The callback has to return a true value when its work is done, after
345			which is will be removed, or a false value in which case it will stay
346			registered.
347
348	root	1.22	The global C<$SELF> (exported by this module) contains C<$portid> while
349			executing the callback.
350
351			Runtime errors wdurign callback execution will result in the port being
352			C<kil>ed.
353
354	root	1.3	If the match is an array reference, then it will be matched against the
355			first elements of the message, otherwise only the first element is being
356			matched.
357
358			Any element in the match that is specified as C<_any_> (a function
359			exported by this module) matches any single element of the message.
360
361			While not required, it is highly recommended that the first matching
362			element is a string identifying the message. The one-string-only match is
363			also the most efficient match (by far).
364
365			=cut
366
367			sub rcv($@) {
368	root	1.22	my ($noderef, $port) = split /#/, shift, 2;
369	root	1.3
370	root	1.22	($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	root	1.3	}
393	root	1.2	}
394
395	root	1.22	=item $closure = psub { BLOCK }
396	root	1.2
397	root	1.22	Remembers C<$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	root	1.3
410	root	1.8	=cut
411	root	1.3
412	root	1.22	sub psub(&) {
413			my $cb = shift;
414	root	1.3
415	root	1.22	my $port = $SELF
416			or Carp::croak "psub can only be called from within rcv or psub callbacks, not";
417	root	1.1
418	root	1.22	sub {
419			local $SELF = $port;
420	root	1.2
421	root	1.22	if (wantarray) {
422			my @res = eval { &$cb };
423			_self_die if $@;
424			@res
425			} else {
426			my $res = eval { &$cb };
427			_self_die if $@;
428			$res
429			}
430			}
431	root	1.2	}
432
433	root	1.8	=back
434
435			=head1 FUNCTIONS FOR NODES
436
437			=over 4
438	root	1.2
439	root	1.8	=item become_public endpoint...
440
441			Tells the node to become a public node, i.e. reachable from other nodes.
442
443			If no arguments are given, or the first argument is C<undef>, then
444			AnyEvent::MP tries to bind on port C<4040> on all IP addresses that the
445			local nodename resolves to.
446
447			Otherwise the first argument must be an array-reference with transport
448			endpoints ("ip:port", "hostname:port") or port numbers (in which case the
449			local nodename is used as hostname). The endpoints are all resolved and
450			will become the node reference.
451	root	1.2
452	root	1.8	=cut
453	root	1.1
454	root	1.4	=back
455
456			=head1 NODE MESSAGES
457
458	root	1.5	Nodes understand the following messages sent to them. Many of them take
459			arguments called C<@reply>, which will simply be used to compose a reply
460			message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and
461			the remaining arguments are simply the message data.
462	root	1.4
463			=over 4
464
465			=cut
466
467	root	1.22	=item lookup => $name, @reply
468	root	1.3
469	root	1.8	Replies with the port ID of the specified well-known port, or C<undef>.
470	root	1.3
471	root	1.7	=item devnull => ...
472
473			Generic data sink/CPU heat conversion.
474
475	root	1.4	=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	root	1.5	form C<@reply, $@, @evalres> is sent.
483
484			Example: crash another node.
485
486			snd $othernode, eval => "exit";
487	root	1.4
488			=item time => @reply
489
490			Replies the the current node time to C<@reply>.
491
492	root	1.5	Example: tell the current node to send the current time to C<$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	root	1.2	=back
499
500	root	1.1	=head1 SEE ALSO
501
502			L<AnyEvent>.
503
504			=head1 AUTHOR
505
506			Marc Lehmann <schmorp@schmorp.de>
507			http://home.schmorp.de/
508
509			=cut
510
511			1
512