AnyEvent-MP/MP/Kernel.pm

=head1 NAME

AnyEvent::MP::Kernel - the actual message passing kernel

=head1 SYNOPSIS

   use AnyEvent::MP::Kernel;

=head1 DESCRIPTION

This module provides most of the basic functionality of AnyEvent::MP,
exposed through higher level interfaces such as L<AnyEvent::MP> and
L<Coro::MP>.

This module is mainly of interest when knowledge about connectivity,
connected nodes etc. are needed.

=head1 GLOBALS AND FUNCTIONS

=over 4

=cut

package AnyEvent::MP::Kernel;

use common::sense;
use POSIX ();
use Carp ();
use MIME::Base64 ();

use AE ();

use AnyEvent::MP::Node;
use AnyEvent::MP::Transport;

use base "Exporter";

our $VERSION = '0.8';
our @EXPORT = qw(
   %NODE %PORT %PORT_DATA $UNIQ $RUNIQ $ID
   add_node load_func snd_to_func snd_on eval_on

   NODE $NODE node_of snd kil
   port_is_local
   resolve_node initialise_node
   known_nodes up_nodes mon_nodes node_is_known node_is_up
);

our $DEFAULT_PORT = "4040";

our $CONNECT_INTERVAL =  2; # new connect every 2s, at least
our $NETWORK_LATENCY  =  3; # activity timeout
our $MONITOR_TIMEOUT  = 15; # fail monitoring after this time

=item $AnyEvent::MP::Kernel::WARN->($level, $msg)

This value is called with an error or warning message, when e.g. a connection
could not be created, authorisation failed and so on.

C<$level> sould be C<0> for messages ot be logged always, C<1> for
unexpected messages and errors, C<2> for warnings, C<7> for messages about
node connectivity and services, C<8> for debugging messages and C<9> for
tracing messages.

The default simply logs the message to STDERR.

=cut

our $WARN = sub {
   my ($level, $msg) = @_;

   $msg =~ s/\n$//;

   printf STDERR "%s <%d> %s\n",
          (POSIX::strftime "%Y-%m-%d %H:%M:%S", localtime time),
          $level,
          $msg;
};

sub load_func($) {
   my $func = $_[0];

   unless (defined &$func) {
      my $pkg = $func;
      do {
         $pkg =~ s/::[^:]+$//
            or return sub { die "unable to resolve '$func'" };
         eval "require $pkg";
      } until defined &$func;
   }

   \&$func
}

sub nonce($) {
   my $nonce;

   if (open my $fh, "</dev/urandom") {
      sysread $fh, $nonce, $_[0];
   } else {
      # shit...
      our $nonce_init;
      unless ($nonce_init++) {
         srand time ^ $$ ^ unpack "%L*", qx"ps -edalf" . qx"ipconfig /all";
      }

      $nonce = join "", map +(chr rand 256), 1 .. $_[0]
   }

   $nonce
}

sub alnumbits($) {
   my $data = $_[0];

   if (eval "use Math::GMP 2.05; 1") {
      $data = Math::GMP::get_str_gmp (
                  (Math::GMP::new_from_scalar_with_base (+(unpack "H*", $data), 16)),
                  62
              );
   } else {
      $data = MIME::Base64::encode_base64 $data, "";
      $data =~ s/=//;
      $data =~ s/\//s/g;
      $data =~ s/\+/p/g;
   }

   $data
}

sub gen_uniq {
   alnumbits pack "wNa*", $$, time, nonce 2
}

=item $AnyEvent::MP::Kernel::PUBLIC

A boolean indicating whether this is a public node, which can create and
accept direct connections from other nodes.

=cut

our $CONFIG; # this node's configuration

our $RUNIQ  = alnumbits nonce 16;; # remote uniq value
our $UNIQ   = gen_uniq; # per-process/node unique cookie
our $NODE   = "anon/$RUNIQ";
our $ID     = "a";

our %NODE; # node id to transport mapping, or "undef", for local node
our (%PORT, %PORT_DATA); # local ports

our %RMON; # local ports monitored by remote nodes ($RMON{nodeid}{portid} == cb)
our %LMON; # monitored _local_ ports

our %LISTENER;
our $LISTENER; # our listeners, as arrayref

our $SRCNODE; # holds the sending node during _inject

sub NODE() {
   $NODE
}

sub node_of($) {
   my ($node, undef) = split /#/, $_[0], 2;

   $node
}

BEGIN {
   *TRACE = $ENV{PERL_ANYEVENT_MP_TRACE}
      ? sub () { 1 }
      : sub () { 0 };
}

sub _inject {
   warn "RCV $SRCNODE->{id} -> @_\n" if TRACE && @_;#d#
   &{ $PORT{+shift} or return };
}

# this function adds a node-ref, so you can send stuff to it
# it is basically the central routing component.
sub add_node {
   my ($node) = @_;

   $NODE{$node} ||= new AnyEvent::MP::Node::Direct $node
}

sub snd(@) {
   my ($nodeid, $portid) = split /#/, shift, 2;

   warn "SND $nodeid <- $portid @_\n" if TRACE;#d#

   ($NODE{$nodeid} || add_node $nodeid)
      ->{send} (["$portid", @_]);
}

=item $is_local = port_is_local $port

Returns true iff the port is a local port.

=cut

sub port_is_local($) {
   my ($nodeid, undef) = split /#/, $_[0], 2;

   $NODE{$nodeid} == $NODE{""}
}

=item snd_to_func $node, $func, @args

Expects a node ID and a name of a function. Asynchronously tries to call
this function with the given arguments on that node.

This function can be used to implement C<spawn>-like interfaces.

=cut

sub snd_to_func($$;@) {
   my $nodeid = shift;

   ($NODE{$nodeid} || add_node $nodeid)
      ->send (["", @_]);
}

=item snd_on $node, @msg

Executes C<snd> with the given C<@msg> (which must include the destination
port) on the given node.

=cut

sub snd_on($@) {
   my $node = shift;
   snd $node, snd => @_;
}

=item eval_on $node, $string

Evaluates the given string as Perl expression on the given node.

=cut

sub eval_on($@) {
   my $node = shift;
   snd $node, eval => @_;
}

sub kil(@) {
   my ($nodeid, $portid) = split /#/, shift, 2;

   length $portid
      or Carp::croak "$nodeid#$portid: killing a node port is not allowed, caught";

   ($NODE{$nodeid} || add_node $nodeid)
      ->kill ("$portid", @_);
}

sub _nodename {
   require POSIX;
   (POSIX::uname ())[1]
}

sub _resolve($) {
   my ($nodeid) = @_;

   my $cv = AE::cv;
   my @res;

   $cv->begin (sub {
      my %seen;
      my @refs;
      for (sort { $a->[0] <=> $b->[0] } @res) {
         push @refs, $_->[1] unless $seen{$_->[1]}++
      }
      shift->send (@refs);
   });

   $nodeid = $DEFAULT_PORT unless length $nodeid;

   my $idx;
   for my $t (split /,/, $nodeid) {
      my $pri = ++$idx;

      $t = length $t ? _nodename . ":$t" : _nodename
         if $t =~ /^\d*$/;
      
      my ($host, $port) = AnyEvent::Socket::parse_hostport $t, "aemp=$DEFAULT_PORT"
         or Carp::croak "$t: unparsable transport descriptor";

      $cv->begin;
      AnyEvent::Socket::resolve_sockaddr $host, $port, "tcp", 0, undef, sub {
         for (@_) {
            my ($service, $host) = AnyEvent::Socket::unpack_sockaddr $_->[3];
            push @res, [
               $pri += 1e-5,
               AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $host, $service
            ];
         }
         $cv->end;
      };
   }

   $cv->end;

   $cv
}

sub initialise_node($;%) {
   my ($profile) = @_;

   $profile = _nodename
      unless defined $profile;

   $CONFIG = AnyEvent::MP::Config::find_profile $profile;
   $NODE = exists $CONFIG->{nodeid} ? $CONFIG->{nodeid}
         : $profile eq "anon/"      ? $NODE
                                    : $profile;

   $NODE{$NODE} = $NODE{""};
   $NODE{$NODE}{id} = $NODE;

   my $seeds = $CONFIG->{seeds};
   my $binds = $CONFIG->{binds};

   $binds ||= [$NODE];

   $WARN->(8, "node $NODE starting up.");

   for (map _resolve $_, @$binds) {
      for my $bind ($_->recv) {
         my ($host, $port) = AnyEvent::Socket::parse_hostport $bind
            or Carp::croak "$bind: unparsable local bind address";

         $LISTENER{$bind} = AnyEvent::MP::Transport::mp_server $host, $port;
         push @$LISTENER, $bind;
      }
   }

   # the global service is mandatory currently
   require AnyEvent::MP::Global;

   # connect to all seednodes
   AnyEvent::MP::Global::set_seeds (map $_->recv, map _resolve $_, @$seeds);

   for (@{ $CONFIG->{services} }) {
      if (s/::$//) {
         eval "require $_";
         die $@ if $@;
      } else {
         (load_func $_)->();
      }
   }
}

#############################################################################
# node monitoring and info

sub _uniq_nodes {
   my %node;

   @node{values %NODE} = values %NODE;

   values %node;
}

sub _public_nodes {
   &_uniq_nodes
}

=item node_is_known $nodeid

Returns true iff the given node is currently known to the system.

=cut

sub node_is_known($) {
   exists $NODE{$_[0]}
}

=item node_is_up $nodeid

Returns true if the given node is "up", that is, the kernel thinks it has
a working connection to it.

If the node is known but not currently connected, returns C<0>. If the
node is not known, returns C<undef>.

=cut

sub node_is_up($) {
   ($NODE{$_[0]} or return)->{transport}
      ? 1 : 0
}

=item known_nodes

Returns the node IDs of all public nodes connected to this node, including
itself.

=cut

sub known_nodes {
   map $_->{id}, _public_nodes
}

=item up_nodes

Return the node IDs of all public nodes that are currently connected
(excluding the node itself).

=cut

sub up_nodes {
   map $_->{id}, grep $_->{transport}, _public_nodes
}

=item $guard = mon_nodes $callback->($nodeid, $is_up, @reason)

Registers a callback that is called each time a node goes up (connection
is established) or down (connection is lost).

Node up messages can only be followed by node down messages for the same
node, and vice versa.

The function returns an optional guard which can be used to de-register
the monitoring callback again.

=cut

our %MON_NODES;

sub mon_nodes($) {
   my ($cb) = @_;

   $MON_NODES{$cb+0} = $cb;

   wantarray && AnyEvent::Util::guard { delete $MON_NODES{$cb+0} }
}

sub _inject_nodeevent($$;@) {
   my ($node, $up, @reason) = @_;

   for my $cb (values %MON_NODES) {
      eval { $cb->($node->{id}, $up, @reason); 1 }
         or $WARN->(1, $@);
   }

   $WARN->(7, "$node->{id} is " . ($up ? "up" : "down") . " (@reason)");
}

#############################################################################
# self node code

our %node_req = (
   # internal services

   # monitoring
   mon0 => sub { # disable monitoring
      my $portid = shift;
      my $node   = $SRCNODE;
      $NODE{""}->unmonitor ($portid, delete $node->{rmon}{$portid});
   },
   mon1 => sub { # enable monitoring
      my $portid = shift;
      my $node   = $SRCNODE;
      $NODE{""}->monitor ($portid, $node->{rmon}{$portid} = sub {
         $node->send (["", kil => $portid, @_]);
      });
   },
   kil => sub {
      my $cbs = delete $SRCNODE->{lmon}{+shift}
         or return;

      $_->(@_) for @$cbs;
   },

   # "public" services - not actually public

   # relay message to another node / generic echo
   snd => \&snd,
   snd_multi => sub {
      snd @$_ for @_
   },

   # informational
   info => sub {
      snd @_, $NODE;
   },
   known_nodes => sub {
      snd @_, known_nodes;
   },
   up_nodes => sub {
      snd @_, up_nodes;
   },

   # random garbage
   eval => sub {
      my @res = eval shift;
      snd @_, "$@", @res if @_;
   },
   time => sub {
      snd @_, AE::time;
   },
   devnull => sub {
      #
   },
   "" => sub {
      # empty messages are sent by monitoring
   },
);

$NODE{""} = $NODE{$NODE} = new AnyEvent::MP::Node::Self $NODE;
$PORT{""} = sub {
   my $tag = shift;
   eval { &{ $node_req{$tag} ||= load_func $tag } };
   $WARN->(2, "error processing node message: $@") if $@;
};

=back

=head1 SEE ALSO

L<AnyEvent::MP>.

=head1 AUTHOR

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

=cut

1

Revision:	1.21
Committed:	Thu Aug 27 21:29:37 2009 UTC (14 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.20:	+66 -130 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3	root	1.3	AnyEvent::MP::Kernel - the actual message passing kernel
4	root	1.1
5			=head1 SYNOPSIS
6
7	root	1.3	use AnyEvent::MP::Kernel;
8	root	1.1
9			=head1 DESCRIPTION
10
11			This module provides most of the basic functionality of AnyEvent::MP,
12			exposed through higher level interfaces such as L<AnyEvent::MP> and
13			L<Coro::MP>.
14
15	root	1.3	This module is mainly of interest when knowledge about connectivity,
16			connected nodes etc. are needed.
17
18			=head1 GLOBALS AND FUNCTIONS
19	root	1.1
20			=over 4
21
22			=cut
23
24			package AnyEvent::MP::Kernel;
25
26			use common::sense;
27	root	1.16	use POSIX ();
28	root	1.1	use Carp ();
29			use MIME::Base64 ();
30
31			use AE ();
32
33			use AnyEvent::MP::Node;
34			use AnyEvent::MP::Transport;
35
36			use base "Exporter";
37
38	root	1.19	our $VERSION = '0.8';
39	root	1.1	our @EXPORT = qw(
40	root	1.13	%NODE %PORT %PORT_DATA $UNIQ $RUNIQ $ID
41	root	1.21	add_node load_func snd_to_func snd_on eval_on
42	root	1.1
43	root	1.10	NODE $NODE node_of snd kil
44	root	1.17	port_is_local
45	root	1.1	resolve_node initialise_node
46	root	1.13	known_nodes up_nodes mon_nodes node_is_known node_is_up
47	root	1.1	);
48
49			our $DEFAULT_PORT = "4040";
50
51			our $CONNECT_INTERVAL = 2; # new connect every 2s, at least
52			our $NETWORK_LATENCY = 3; # activity timeout
53			our $MONITOR_TIMEOUT = 15; # fail monitoring after this time
54
55	root	1.16	=item $AnyEvent::MP::Kernel::WARN->($level, $msg)
56	root	1.1
57			This value is called with an error or warning message, when e.g. a connection
58			could not be created, authorisation failed and so on.
59
60	root	1.16	C<$level> sould be C<0> for messages ot be logged always, C<1> for
61			unexpected messages and errors, C<2> for warnings, C<7> for messages about
62			node connectivity and services, C<8> for debugging messages and C<9> for
63			tracing messages.
64
65	root	1.1	The default simply logs the message to STDERR.
66
67			=cut
68
69			our $WARN = sub {
70	root	1.16	my ($level, $msg) = @_;
71
72	root	1.1	$msg =~ s/\n$//;
73	root	1.16
74			printf STDERR "%s <%d> %s\n",
75			(POSIX::strftime "%Y-%m-%d %H:%M:%S", localtime time),
76			$level,
77			$msg;
78	root	1.1	};
79
80	root	1.6	sub load_func($) {
81			my $func = $_[0];
82
83			unless (defined &$func) {
84			my $pkg = $func;
85			do {
86			$pkg =~ s/::[^:]+$//
87			or return sub { die "unable to resolve '$func'" };
88			eval "require $pkg";
89			} until defined &$func;
90			}
91
92			\&$func
93			}
94
95	root	1.1	sub nonce($) {
96			my $nonce;
97
98			if (open my $fh, "</dev/urandom") {
99			sysread $fh, $nonce, $_[0];
100			} else {
101			# shit...
102			our $nonce_init;
103			unless ($nonce_init++) {
104			srand time ^ $$ ^ unpack "%L*", qx"ps -edalf" . qx"ipconfig /all";
105			}
106
107			$nonce = join "", map +(chr rand 256), 1 .. $_[0]
108			}
109
110			$nonce
111			}
112
113	root	1.21	sub alnumbits($) {
114	root	1.1	my $data = $_[0];
115
116			if (eval "use Math::GMP 2.05; 1") {
117			$data = Math::GMP::get_str_gmp (
118			(Math::GMP::new_from_scalar_with_base (+(unpack "H*", $data), 16)),
119			62
120			);
121			} else {
122			$data = MIME::Base64::encode_base64 $data, "";
123			$data =~ s/=//;
124			$data =~ s/\//s/g;
125			$data =~ s/\+/p/g;
126			}
127
128			$data
129			}
130
131			sub gen_uniq {
132	root	1.21	alnumbits pack "wNa*", $$, time, nonce 2
133	root	1.1	}
134
135	root	1.3	=item $AnyEvent::MP::Kernel::PUBLIC
136
137	root	1.21	A boolean indicating whether this is a public node, which can create and
138			accept direct connections from other nodes.
139	root	1.3
140			=cut
141
142	root	1.20	our $CONFIG; # this node's configuration
143	root	1.21
144			our $RUNIQ = alnumbits nonce 16;; # remote uniq value
145	root	1.1	our $UNIQ = gen_uniq; # per-process/node unique cookie
146	root	1.21	our $NODE = "anon/$RUNIQ";
147	root	1.1	our $ID = "a";
148
149			our %NODE; # node id to transport mapping, or "undef", for local node
150			our (%PORT, %PORT_DATA); # local ports
151
152	root	1.21	our %RMON; # local ports monitored by remote nodes ($RMON{nodeid}{portid} == cb)
153	root	1.1	our %LMON; # monitored _local_ ports
154
155			our %LISTENER;
156	root	1.21	our $LISTENER; # our listeners, as arrayref
157	root	1.1
158			our $SRCNODE; # holds the sending node during _inject
159
160			sub NODE() {
161			$NODE
162			}
163
164			sub node_of($) {
165	root	1.21	my ($node, undef) = split /#/, $_[0], 2;
166	root	1.1
167	root	1.21	$node
168	root	1.1	}
169
170	root	1.17	BEGIN {
171			*TRACE = $ENV{PERL_ANYEVENT_MP_TRACE}
172			? sub () { 1 }
173			: sub () { 0 };
174			}
175	root	1.1
176			sub _inject {
177	root	1.21	warn "RCV $SRCNODE->{id} -> @_\n" if TRACE && @_;#d#
178	root	1.1	&{ $PORT{+shift} or return };
179			}
180
181	root	1.20	# this function adds a node-ref, so you can send stuff to it
182			# it is basically the central routing component.
183	root	1.1	sub add_node {
184	root	1.21	my ($node) = @_;
185	root	1.1
186	root	1.21	$NODE{$node} \|\|= new AnyEvent::MP::Node::Direct $node
187	root	1.13	}
188
189	root	1.1	sub snd(@) {
190	root	1.21	my ($nodeid, $portid) = split /#/, shift, 2;
191	root	1.1
192	root	1.21	warn "SND $nodeid <- $portid @_\n" if TRACE;#d#
193	root	1.1
194	root	1.21	($NODE{$nodeid} \|\| add_node $nodeid)
195	root	1.2	->{send} (["$portid", @_]);
196	root	1.1	}
197
198	root	1.17	=item $is_local = port_is_local $port
199
200			Returns true iff the port is a local port.
201
202			=cut
203
204			sub port_is_local($) {
205	root	1.21	my ($nodeid, undef) = split /#/, $_[0], 2;
206	root	1.17
207	root	1.21	$NODE{$nodeid} == $NODE{""}
208	root	1.17	}
209
210	root	1.18	=item snd_to_func $node, $func, @args
211	root	1.11
212	root	1.21	Expects a node ID and a name of a function. Asynchronously tries to call
213	root	1.11	this function with the given arguments on that node.
214
215	root	1.20	This function can be used to implement C<spawn>-like interfaces.
216	root	1.11
217			=cut
218
219	root	1.18	sub snd_to_func($$;@) {
220	root	1.21	my $nodeid = shift;
221	root	1.11
222	root	1.21	($NODE{$nodeid} \|\| add_node $nodeid)
223	root	1.11	->send (["", @_]);
224			}
225
226	root	1.18	=item snd_on $node, @msg
227
228			Executes C<snd> with the given C<@msg> (which must include the destination
229			port) on the given node.
230
231			=cut
232
233			sub snd_on($@) {
234			my $node = shift;
235			snd $node, snd => @_;
236			}
237
238			=item eval_on $node, $string
239
240			Evaluates the given string as Perl expression on the given node.
241
242			=cut
243
244			sub eval_on($@) {
245			my $node = shift;
246			snd $node, eval => @_;
247			}
248
249	root	1.1	sub kil(@) {
250	root	1.21	my ($nodeid, $portid) = split /#/, shift, 2;
251	root	1.1
252			length $portid
253	root	1.21	or Carp::croak "$nodeid#$portid: killing a node port is not allowed, caught";
254	root	1.1
255	root	1.21	($NODE{$nodeid} \|\| add_node $nodeid)
256	root	1.1	->kill ("$portid", @_);
257			}
258
259	root	1.7	sub _nodename {
260			require POSIX;
261			(POSIX::uname ())[1]
262			}
263
264	root	1.21	sub _resolve($) {
265			my ($nodeid) = @_;
266	root	1.1
267			my $cv = AE::cv;
268			my @res;
269
270			$cv->begin (sub {
271			my %seen;
272			my @refs;
273			for (sort { $a->[0] <=> $b->[0] } @res) {
274			push @refs, $_->[1] unless $seen{$_->[1]}++
275			}
276	root	1.21	shift->send (@refs);
277	root	1.1	});
278
279	root	1.21	$nodeid = $DEFAULT_PORT unless length $nodeid;
280	root	1.1
281			my $idx;
282	root	1.21	for my $t (split /,/, $nodeid) {
283	root	1.1	my $pri = ++$idx;
284	root	1.7
285			$t = length $t ? _nodename . ":$t" : _nodename
286			if $t =~ /^\d*$/;
287	root	1.1
288	root	1.7	my ($host, $port) = AnyEvent::Socket::parse_hostport $t, "aemp=$DEFAULT_PORT"
289			or Carp::croak "$t: unparsable transport descriptor";
290
291			$cv->begin;
292			AnyEvent::Socket::resolve_sockaddr $host, $port, "tcp", 0, undef, sub {
293			for (@_) {
294			my ($service, $host) = AnyEvent::Socket::unpack_sockaddr $_->[3];
295			push @res, [
296			$pri += 1e-5,
297			AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $host, $service
298			];
299	root	1.1	}
300	root	1.7	$cv->end;
301			};
302	root	1.1	}
303
304			$cv->end;
305
306			$cv
307			}
308
309	root	1.21	sub initialise_node($;%) {
310			my ($profile) = @_;
311	root	1.1
312	root	1.21	$profile = _nodename
313			unless defined $profile;
314	root	1.6
315	root	1.21	$CONFIG = AnyEvent::MP::Config::find_profile $profile;
316			$NODE = exists $CONFIG->{nodeid} ? $CONFIG->{nodeid}
317			: $profile eq "anon/" ? $NODE
318			: $profile;
319	root	1.6
320	root	1.21	$NODE{$NODE} = $NODE{""};
321			$NODE{$NODE}{id} = $NODE;
322	root	1.20
323	root	1.21	my $seeds = $CONFIG->{seeds};
324			my $binds = $CONFIG->{binds};
325	root	1.3
326	root	1.21	$binds \|\|= [$NODE];
327	root	1.1
328	root	1.21	$WARN->(8, "node $NODE starting up.");
329	root	1.1
330	root	1.21	for (map _resolve $_, @$binds) {
331			for my $bind ($_->recv) {
332			my ($host, $port) = AnyEvent::Socket::parse_hostport $bind
333			or Carp::croak "$bind: unparsable local bind address";
334	root	1.20
335	root	1.21	$LISTENER{$bind} = AnyEvent::MP::Transport::mp_server $host, $port;
336			push @$LISTENER, $bind;
337			}
338	root	1.1	}
339
340	root	1.21	# the global service is mandatory currently
341			require AnyEvent::MP::Global;
342	root	1.1
343	root	1.21	# connect to all seednodes
344			AnyEvent::MP::Global::set_seeds (map $_->recv, map _resolve $_, @$seeds);
345	root	1.1
346	root	1.20	for (@{ $CONFIG->{services} }) {
347	root	1.13	if (s/::$//) {
348			eval "require $_";
349			die $@ if $@;
350			} else {
351			(load_func $_)->();
352			}
353			}
354	root	1.1	}
355
356			#############################################################################
357	root	1.6	# node monitoring and info
358	root	1.3
359			sub _uniq_nodes {
360			my %node;
361
362			@node{values %NODE} = values %NODE;
363
364			values %node;
365			}
366
367	root	1.20	sub _public_nodes {
368	root	1.21	&_uniq_nodes
369	root	1.20	}
370
371	root	1.21	=item node_is_known $nodeid
372	root	1.13
373			Returns true iff the given node is currently known to the system.
374
375			=cut
376
377			sub node_is_known($) {
378			exists $NODE{$_[0]}
379			}
380
381	root	1.21	=item node_is_up $nodeid
382	root	1.13
383			Returns true if the given node is "up", that is, the kernel thinks it has
384			a working connection to it.
385
386			If the node is known but not currently connected, returns C<0>. If the
387			node is not known, returns C<undef>.
388
389			=cut
390
391			sub node_is_up($) {
392			($NODE{$_[0]} or return)->{transport}
393			? 1 : 0
394			}
395
396	root	1.3	=item known_nodes
397
398	root	1.21	Returns the node IDs of all public nodes connected to this node, including
399	root	1.18	itself.
400	root	1.3
401			=cut
402
403			sub known_nodes {
404	root	1.21	map $_->{id}, _public_nodes
405	root	1.3	}
406
407			=item up_nodes
408
409	root	1.21	Return the node IDs of all public nodes that are currently connected
410	root	1.20	(excluding the node itself).
411	root	1.3
412			=cut
413
414			sub up_nodes {
415	root	1.21	map $_->{id}, grep $_->{transport}, _public_nodes
416	root	1.3	}
417
418	root	1.21	=item $guard = mon_nodes $callback->($nodeid, $is_up, @reason)
419	root	1.3
420			Registers a callback that is called each time a node goes up (connection
421			is established) or down (connection is lost).
422
423			Node up messages can only be followed by node down messages for the same
424			node, and vice versa.
425
426	root	1.13	The function returns an optional guard which can be used to de-register
427	root	1.3	the monitoring callback again.
428
429			=cut
430
431			our %MON_NODES;
432
433			sub mon_nodes($) {
434			my ($cb) = @_;
435
436			$MON_NODES{$cb+0} = $cb;
437
438			wantarray && AnyEvent::Util::guard { delete $MON_NODES{$cb+0} }
439			}
440
441			sub _inject_nodeevent($$;@) {
442	root	1.16	my ($node, $up, @reason) = @_;
443	root	1.3
444			for my $cb (values %MON_NODES) {
445	root	1.21	eval { $cb->($node->{id}, $up, @reason); 1 }
446	root	1.16	or $WARN->(1, $@);
447	root	1.3	}
448	root	1.16
449	root	1.21	$WARN->(7, "$node->{id} is " . ($up ? "up" : "down") . " (@reason)");
450	root	1.3	}
451
452			#############################################################################
453	root	1.1	# self node code
454
455			our %node_req = (
456			# internal services
457
458			# monitoring
459			mon0 => sub { # disable monitoring
460			my $portid = shift;
461			my $node = $SRCNODE;
462			$NODE{""}->unmonitor ($portid, delete $node->{rmon}{$portid});
463			},
464			mon1 => sub { # enable monitoring
465			my $portid = shift;
466			my $node = $SRCNODE;
467			$NODE{""}->monitor ($portid, $node->{rmon}{$portid} = sub {
468			$node->send (["", kil => $portid, @_]);
469			});
470			},
471			kil => sub {
472			my $cbs = delete $SRCNODE->{lmon}{+shift}
473			or return;
474
475			$_->(@_) for @$cbs;
476			},
477
478	root	1.18	# "public" services - not actually public
479	root	1.1
480			# relay message to another node / generic echo
481	root	1.15	snd => \&snd,
482			snd_multi => sub {
483	root	1.1	snd @$_ for @_
484			},
485
486	root	1.4	# informational
487			info => sub {
488			snd @_, $NODE;
489			},
490			known_nodes => sub {
491			snd @_, known_nodes;
492			},
493			up_nodes => sub {
494			snd @_, up_nodes;
495			},
496
497	root	1.1	# random garbage
498			eval => sub {
499			my @res = eval shift;
500			snd @_, "$@", @res if @_;
501			},
502			time => sub {
503			snd @_, AE::time;
504			},
505			devnull => sub {
506			#
507			},
508	root	1.15	"" => sub {
509			# empty messages are sent by monitoring
510			},
511	root	1.1	);
512
513	root	1.18	$NODE{""} = $NODE{$NODE} = new AnyEvent::MP::Node::Self $NODE;
514	root	1.1	$PORT{""} = sub {
515			my $tag = shift;
516			eval { &{ $node_req{$tag} \|\|= load_func $tag } };
517	root	1.16	$WARN->(2, "error processing node message: $@") if $@;
518	root	1.1	};
519
520			=back
521
522			=head1 SEE ALSO
523
524			L<AnyEvent::MP>.
525
526			=head1 AUTHOR
527
528			Marc Lehmann <schmorp@schmorp.de>
529			http://home.schmorp.de/
530
531			=cut
532
533			1
534